Search

Cordyceps militaris is a large fungus whose fruiting body is prone to degeneration. In the study of C. militaris FREQUENCY (CmFRQ), the negative regulator of C. militaris circadian clock, it was found that after the high concentration of mannitol was applied to the regeneration culture of conidial protoplast of degenerated C. militaris strain F3411D, the rejuvenated strain CmFRQ-454 with the increased content of CmFRQ was obtained, and its growth vitality of fruiting body was recovered. After six successive asexual subcultures of the rejuvenated C. militaris strain CmFRQ-454, the accumulation of CmFRQ in mycelia gradually decreased, and the fruiting bodies of C. militaris also tended to degenerate from generation to generation. After treatment with proteasome inhibitor MG132 or high concentration of sorbitol, the degenerated asexual reproduction strain CmFRQ-454 to the 7th or 11th generation regained its growth vitality, and the accumulation of CmFRQ in mycelium was increased. Our results demonstrate that after hypertonic solution or MG132 treatment, the key circadian regulator CmFRQ was accumulate in mycelium, which brought the rejuvenation to the degenerated C. militaris. [ABSTRACT FROM AUTHOR]

Glycolysis takes place in all cells of the body and plays an important role in the metabolism of the organism. The detection of intermediate metabolites in the glycolysis pathway is critical in understanding metabolic alterations that occur in many metabolic disorders. The intermediate metabolites of glycolysis such as glycerate 3-phosphate (3PG), β-fructose 6-phosphate (F6P) and α-glucose 6-phosphate (G6P) in biological samples have poor stability and low abundance, which makes their separation and detection more challenging. In this work, an optimal protocol for detecting 10 glycolysis metabolites in serum samples was developed using gas chromatography triple quadrupole mass spectrometry. Single factor experiment and response surface methodology were used to optimize the pretreatment of serum samples. The optimal conditions were as follows: the volume of the derivatization reagent, 100 μL; extraction solvent, 80% methanol; derivatization temperature, 80 °C; and derivatization time, 60 min. The protocol showed an acceptable linearity (R2 ≥ 0.9872), the lowest detection limit (0.0002–0.2382 μg mL−1), the limits of quantitation (0.0007–0.7940 μg mL−1), and the satisfactory intra-day (RSD% ≤ 13.67%) and inter-day precision (RSD% ≤ 12.01%). The results of the stability test showed that it was a better choice to determine metabolites during 2 months when the serum was stored at −80 °C in order to avoid the change in 3PG and G6P. Furthermore, the metabolites in serum were relatively stable for detection (RSD% < 18.77%) after 4 freeze–thaw cycles. Finally, this protocol was applied to the quantitative analysis of glycolysis metabolites from gastric cancer patients, and was beneficial to find out the metabolic changes of the glycolysis pathway and explain the pathogenesis of the disease. [ABSTRACT FROM AUTHOR]

Background: The self-reported quality of life (QoL) should be carefully listened to in progressive supranuclear palsy (PSP) from the patient-centered perspective. However, there was still a lack of short QoL measurement tool in atypical parkinsonism. Objective: We aimed to test whether the short Parkinson's Disease Questionnaire-8 (PDQ-8) was effective in assessing QoL in PSP, comparing with Progressive Supranuclear Palsy Quality of Life Scale (PSP-QoL) and Parkinson's Disease Questionnaire-39 (PDQ-39). Methods: 132 patients with clinical diagnosed PSP, including PSP-Richardson syndrome (RS) subtype (n = 71) and PSP-non-RS subtype (n = 61) were recruited for clinical evaluation including QoL assessment. The detailed QoL profiles and possibility of using PDQ-8 were systemically analyzed. The determinants to the QoL were then calculated by multivariate linear regression analysis. Results: The PSP-QoL total score summary index (SI) was 22.8 (10.1, 41.1), while the PDQ-8 and PDQ-39 total SI score were 28.1 (12.5, 46.9) and 29.5 (15.4, 49.4). Mobility, activities of daily life, cognition and communication were the main affected QoL subdomains (median SI: 40.0, 31.3, 25.0 and 25.0 respectively). PSP-RS subtype showed more severe damage physically (p<0.001) and mentally (p = 0.002) compared to other subtypes. More importantly, the strong relevance of PDQ-8 and recommended PSP QoL tools were confirmed (p<0.001). In addition, disease severity, depression and daytime sleepiness were proved to be critical determinants for QoL in PSP. Conclusions: PDQ-8 could be an easy, reliable, and valid tool to evaluate QoL in patients with PSP. Besides motor symptoms, more attention should be paid to non-motor impairment such as depression in PSP. [ABSTRACT FROM AUTHOR]

ATP binding cassette subfamily C member 8 (ABCC8) encodes a protein regulating the ATP-sensitive potassium channel. Whether the level of ABCC8 mRNA in lower grade glioma (LGG) correlates with immune cell infiltration and patient outcomes has not been evaluated until now. Comparisons of ABCC8 expression between different tumors and normal tissues were evaluated by exploring publicly available datasets. The association between ABCC8 and tumor immune cell infiltration, diverse gene mutation characteristics, tumor mutation burden (TMB), and survival in LGG was also investigated in several independent datasets. Pathway enrichment analysis was conducted to search for ABCC8-associated signaling pathways. Through an online database, we found that ABCC8 expression in LGG was lower than in normal tissues. Then, the association of ABCC8 expression and immune cell infiltration in LGG was discussed. As we expected, the ABCC8 mRNA levels were negatively associated with non-T immune cell infiltration levels in all datasets. Consistently, TCGA_LGG RNA-seq data revealed that ABCC8 downregulated several non-T immune cell-associated signaling pathways in gene set enrichment analysis. Different ABCC8 expression groups showed diverse gene mutation characteristics and TMB. The high expression of ABCC8 was linked to improved survival of LGG patients. A pathway enrichment analysis of ABCC8-associated genes indicated that the GABAergic synapse signaling pathway might be involved in regulating immunity in LGG. Our findings show that ABCC8 reflects LGG tumor immunity and is an ideal prognostic biomarker for LGG. [ABSTRACT FROM AUTHOR]

Contrast agents are used to enhance the visibility of rodent organs during in vivo micro-computed tomography imaging. Specifically, this non-invasive technique can study liver tumor growth and progression in small animals. Fenestra VC and the novel Fenestra HDVC were compared for enhancement in the liver of healthy and tumor-bearing mice, and the images were compared for their ability to define the tumor border, volume and quantity of tumors. Fenestra VC and Fenestra HDVC were injected into healthy eight-week-old female mice (C57BL/6) via the tail vein then imaged at seven different time points. The experimental results showed that 0.005 mL/g of Fenestra HDVC resulted in the same enhancement for all eight organs as 0.01 mL/g of Fenestra VC across all time points. For the tumor study, B16F10 tumors were surgically introduced into ten eight-week-old female mice (C57BL/6) then imaged in vivo over a 3 day period. Ex vivo micro-CT images of the excised livers were also obtained. The tumor volume and quantity were measured in each image, and the tumour progression observed over 3 days. We showed Fenestra HDVC is effective for in vivo imaging in rodents because the optimal enhancement level in organs is maintained at a reduced injection volume. [ABSTRACT FROM AUTHOR]

Background: Chondrocyte migration in native cartilage is limited and has been implicated as one of the reasons for the poor integration of native implants. Through use of an in vitro integration model, it has previously been shown that cells from bioengineered cartilage can migrate into the native host cartilage during integration. Platelet-rich plasma (PRP) treatment further enhanced integration of bioengineered cartilage to native cartilage in vitro. However, it is not known how PRP treatment of the bioengineered construct promotes this. Hypothesis: PRP supports cell migration from bioengineered cartilage and these migratory cells have the ability to accumulate cartilage-like matrix. Study Design: Controlled laboratory study. Methods: Osteochondral-like constructs were generated by culturing primary bovine chondrocytes on the top surface of a porous bone substitute biomaterial composed of calcium polyphosphate. After 1 week in culture, the constructs were submerged in PRP and placed adjacent, but 2 mm distant, to a native bovine osteochondral plug in a co-culture model for 2 weeks. Cell migration was monitored using phase-contrast imaging. Cell phenotype was determined by evaluating the gene expression of matrix metalloprotease 13 (MMP-13), Ki67, and cartilage matrix molecules using quantitative polymerase chain reaction. When tissue formed, it was assessed by histology, immunohistochemistry, and quantification of matrix content. Results: PRP treatment resulted in the formation of a fiber network connecting the bioengineered cartilage and native osteochondral plug. Cells from both the bioengineered cartilage and the native osteochondral tissue migrated onto the PRP fibers and formed a tissue bridge after 2 weeks of culture. Migratory cells on the tissue bridge expressed higher levels of collagen types II and I (COL2, COL1), Ki67 and MMP-13 mRNA compared with nonmigratory cells in the bioengineered cartilage. Ki67 and MMP-13–positive cells were found on the edges of the tissue bridge. The tissue bridge accumulated COL1 and COL2 and aggrecan and contained comparable collagen and glycosaminoglycan content to the bioengineered cartilage matrix. The tissue bridge did not reliably develop in the absence of cells from the native osteochondral plug. Conclusion: Bioengineered cartilage formed by bovine chondrocytes contains cells that can migrate on PRP fibers and form cartilaginous tissue. Clinical Relevance: Migratory cells from bioengineered cartilage may promote cartilage integration. Further studies are required to determine the role of migratory cells in integration in vivo. [ABSTRACT FROM AUTHOR]

• The novel SOC was proposed and integrated into the PBR-MFC to achieve the improvement of the system's CO 2 fixation/power generation performance. • The maximum biomass productivity, CO 2 fixation efficiency and power density were obtained in PBR-MFC-SOC-1, which reached 0.19 g·L−1·d−1, 26.7 % and 474 mW·m−2, respectively. • SOC allowed for the optimization of protons transport and the regulation of oxygen distribution, which are the two key aspects of its favorable benefits. Owing to the virtues of high efficiency, green and sustainability, the microalgae photobioreactor (PBR) is coupled with microbial fuel cell (MFC) to achieve CO 2 fixation and electricity/bioenergy collection. In this paper, a novel self-breathing oxygen-consuming carbon felt (SOC) is firstly proposed. It is subsequently integrated into the PBR-MFC to optimize O 2 concentration distribution and separate microalgae/bacteria. The results show that the solution environment (pH, dissolved oxygen and internal resistance) of the PBR-MFC coupling system are significantly regulated by SOC. After the introduction of SOC, the solution environment tends to be neutral (the value of pH on the day 7 increases from 6.88 to 7.0), and the dissolved oxygen concentration of electrolyte in cathode is increased by 6.1 %. The dissolved oxygen concentration in anode, system's ohmic resistance and charge transfer resistance are dramatically decreased by 64.6 %, 59.2 % and 19.0 %, respectively. After embedding a 1 cm-thick SOC in PBR-MFC, the maximum CO 2 fixation efficiency and power density of this system reaches 26.7 % and 474 mW·m−2, improving by 21.9 % and 36.1 % compared to PBR-MFC, respectively. The integration of SOC into the PBR-MFC is credited with the improvement of system performance. The optimization of protons transport and the regulation of oxygen distribution are the two key aspects of its favorable benefits. This strategy of integrating SOC into PBR-MFC system will provide a new sight on high-efficiency energy conversion technologies for CO 2 fixation and electricity/bioenergy collection. [ABSTRACT FROM AUTHOR]

The flexibility transformation of coal-fired power plants (CFPP) is of significant importance for the new power system primarily based on new energy sources. Coupling thermal energy storage (TES) technology is one effective approach to enhance the load-following capability of CFPPs. In this study, the S–CO 2 CFPP coupled with TES technology is taken as the research object. An integrated dynamic energy analysis model, from components to the entire system, is established for variable working conditions. A comprehensive comparison is made among different TES methods, including flue gas TES, CO 2 TES and electrical heating TES, in terms of system's minimum output power, thermal efficiency, energy round-trip efficiency and other off-design performance indicators. Furthermore, through hierarchical integrated configuration of the three thermal energy storage methods, efficient load regulation from 0% to 100% is achieved for the S–CO 2 CFPP. The results indicate that, to achieve efficient load regulation from 0% to 100% for a 1000 MWe S–CO 2 CFPP, the priority configuration for thermal energy storage is CO 2 TES, followed by flue gas TES and electrical heating TES, with powers of 285.17 MWth, 342.80 MWth, and 329.95 MWth, respectively. The overall heat storage/release ratio is 3.43:1 and the energy storage round-trip efficiency is 73.58%. Compared to using only electrical heating TES, the addition of 142.34 MWth of TES improves the energy round-trip efficiency by 11 percentage points. [Display omitted] • The dynamic performance comparison of three TES methods is performed. • TES capacity configuration and energy distribution scheme for S–CO 2 CFPP is proposed. • High-efficiency full-load adjustability from 0% to 100% for S–CO 2 CFPP is achieved. • The energy round-trip efficiency of the system is improved by 11 percentage points. [ABSTRACT FROM AUTHOR]

Carbohydrates are crucial in determining the metabolic alterations that occur in various diseases. The separation and detection of carbohydrates in biological samples are particularly difficult because of their structural similarities. A comparative analysis of silylation and acylation derivatization protocols for carbohydrates in serum was performed using gas chromatography-triple quadrupole mass spectrometry and the stable isotope-labeled internal standard method. A comprehensive investigation was performed with regard to the pretreatment of serum, conditions of the derivatization reaction, robustness toward matrix effects, validation of the method, and quantitation using a set of reference compounds that comprised nine monosaccharides, lactose, galacturonic acid, and glucuronic acid. Both approaches offered strong linearity and sensitivity, as well as acceptable accuracy and precision. The limits of quantitation (LOQ) of the silylation protocol varied from 0.0010 to 1.2500 μg mL−1, while the correlation coefficients of regression curves ranged from 0.9871 to 0.9996. The satisfactory correlation coefficients in acylation protocol (0.9869–0.9991) were obtained, while the LOQ ranged from 0.0003 to 2.8432 μg mL−1. The separation conditions revealed that 12 carbohydrates were detected in silylation, but lactose and galacturonic acid peaks were not obtained in the acylation protocol. However, the acylation approaches were superior to the silylation approaches due to the high stability of derivatives, minor relative standard deviations (0.05–8.67), and low sensitivity toward matrix effects. Finally, we applied two protocols to the serum samples from the patients with gastric carcinoma. This protocol was, in particular, of great importance in the quantitative analysis of complex carbohydrate profiles in human serum, providing novel insights into the change in the carbohydrate metabolism for the disease. [ABSTRACT FROM AUTHOR]

To improve the receiver's solar-thermal conversion efficiency at high temperature for the next-generation concentrating solar power (CSP), a receiver with the light-trapping nanostructured coating is proposed herein. However, for the CSP plant with the light-trapping nanostructure coated receiver, the scale of the heliostat field is on the order of meters (∼10m), the solar receiver tube on the order of millimeters (∼10 mm), and the light-trapping coating on the order of nanometers (∼100 nm). The whole system spans nine orders of magnitude, which makes it extremely complicated and difficult to evaluate the receiver's optical and thermal performance. To solve this problem, a multi-scale model is proposed by combining Monte Carol Ray tracing method (MCRT), finite difference time domain (FDTD) method, and finite volume method (FVM). Then, the influences of three typical light-trapping nanostructured coatings, including pyramid nanostructure, moth-eye nanostructure, and cone nanostructure, on the receiver's optical-thermal performance are studied. Among these three typical nanostructures, the cone nanostructure can maximize the receiver's optical-thermal performance, with a receiver efficiency more than 88%, which is higher than that of the commercial Pyromark2500 coating by 6–10% points. The study demonstrates that the receiver with light-trapping nanostructured coatings can achieve high receiver efficiency for the next-generation CSP. [ABSTRACT FROM AUTHOR]

In order to realize the efficient and stable operation of the solid oxide fuel cell (SOFC)-combined heat and power (CHP) system in the typical applied scenario, three different energy management schemes are proposed in this study. First, a coupled calculation model of the solid oxide fuel cell-gas turbine-combined heat and power (SOFC-GT-CHP) system with a rated power of 30 kW for the SOFC stack is constructed. The inlet temperature and inlet pressure of the SOFC stack are optimized. The recommended design for the proposed system is thence obtained. Second, three operation schemes of SOFC-GT-CHP are proposed. They consist of the operation scheme of single-stack, multi-stack and optimal operation scheme coupled with vanadium redox flow battery (VRB). Finally, four types of typical applied scenarios in North China are selected. The real-time performance of the SOFC-GT-CHP system when applying three different operation schemes is obtained and comparatively analyzed. The results are presented as follows. First, the SOFC-GT-CHP system achieves a rated power of 44.50 kW and a rated system efficiency of 47.20 % when the inlet temperature and pressure of the stack are preferably 505 °C and 709.1 kPa. Second, the application of the multi-stack SOFC-GT-CHP system has the advantage of high efficiency in the low-load operation domain. With a net output power at 20 kW, the time average efficiency of SOFC-GT-CHP is increased from 38.37 % to 46.96 %. Finally, the SOFC-GT-CHP system achieves the highest time average generation efficiency of 46.13 % in the hotel applied scenario when applying the optimal operation scheme coupled with VRB. This meets the practical operation requirement of the SOFC stack. The reduction of the net output power range of SOFC-GT-CHP is 67.87 %. It shows that the optimal operation scheme is efficient and stable. The study can provide a reference for the energy management of the SOFC-GT-CHP system in typical applied scenarios. • The recommended design solution for SOFC-GT-CHP is obtained by constructing the coupled calculation model. • Operation schemes of SOFC-GT-CHP including the single-stack, multi-stack and optimal scheme coupled with VRB are proposed. • The characteristics of the proposed three operation schemes are studied and compared based on simple user loads. • A comparative study of the performance of SOFC-GT-CHP when applying three schemes is conducted with 4 applied scenarios. [ABSTRACT FROM AUTHOR]

Under the background of renewable energy infiltration, the generation-grid-load-storage type integrated system presents the double-side randomization characteristics. The multi-time scale interactive response mechanism of multiple subsystems is complicated. The effective dynamic control method is important for the efficient and stable operation of the integrated energy system. In this paper, dynamic characteristic analysis and simulation experiment study of the integrated system under double-side randomization conditions are carried out. First, a multi-time scale dynamic response model of the integrated system coupled with millisecond level on the electrical side and kilo-second level on the thermal side is developed. Second, based on the frequency hierarchical idea, an algorithm of subsystems cooperation is proposed. It is suitable for different distributed energy systems and can be applied to both day-ahead control and intra-day control. Third, the dynamic characteristics of the integrated system under double-side randomization conditions are analyzed. Working conditions include sunny day, cloudy day and rainy conditions on the generation side and industrial load, commercial load and appliance load conditions on the load side. Finally, based on the dynamic experimental platform of the generation-grid-load-storage type integrated system designed and built by our research group, experiment studies are carried out. The results present that the frequency hierarchical control method can reduce the power purchase and abandonment rate. The average of them is reduced by 1.76%, 10.47% and 11.93% under different loads. The maximum error between experimental data and simulation data is 12.32%. The switching process of the vanadium redox flow battery charge and discharge is the main reason of errors. [Display omitted] • A multi-time scale dynamic response model of integrated energy system is developed. • The frequency hierarchical control method of integrated energy system is proposed. • The system performance under double-side randomization conditions are analyzed. • The control method is verified on an experimental platform with dynamic real-time load. [ABSTRACT FROM AUTHOR]

In this paper, the dynamic performance of Proton Exchange Membrane Fuel Cell-based Combined Cooling Heating and Power (PEMFC-based CCHP) system combined with a data center real-time load is studied. A novel synergistic control method is proposed to achieve optimization of energy flow between system units under fluctuating load. First, the off-design working condition models of PEMFC-based CCHP system are constructed. The delay in the changes of data center temperature is considered because of the thermal inertia under dynamic conditions. Second, the dynamic performance of PEMFC-based CCHP system to step changes of data center load is analyzed. Third, to further reveal the energy flow between units, the units output under varying load conditions are compared under the constraints of power and refrigeration supply. Finally, the dynamic performance of PEMFC-based CCHP system under the traditional control method of following electric load are revealed. A novel synergistic control method for the PEMFC-based CCHP system is proposed by refining the traditional method to optimize the energy flow between units. The result presents that the average energy efficiency reaches 78.29 %. Compared with the following electric load method, the energy efficiency is increased by 6.02 %. The response time of synergistic control method is 27.0 ms. Improved energy efficiency and fast response have been achieved. • The off-design working condition model of PEMFC-based CCHP system is constructed. • The step response characteristic of PEMFC-based CCHP system is analyzed. • Full working condition performances of PEMFC-based CCHP system are studied. • A novel synergistic control method for the PEMFC-based CCHP system is proposed. [ABSTRACT FROM AUTHOR]

The operating voltage of an aluminum electrolytic capacitor is determined by the breakdown voltage (Ub) of the Al2O3 anode. Ub is related to the molecular adsorption at the Al2O3/electrolyte interface. Therefore, we have employed sum-frequency vibrational spectroscopy (SFVS) to study the adsorption states of a simple electrolyte, ethylene glycol (EG) solution with ammonium adipate, on an α-Al2O3 surface. In an acidic electrolyte (pH < 6), the Al2O3 surface is positively charged. The observed SFVS spectra show that long chain molecules poly ethylene glycol and ethylene glycol adipate adopt a "lying" orientation at the interface. In an alkaline electrolyte (pH > 8), the Al2O3 surface is negatively charged and the short chain EG molecules adopt a "tilting" orientation. The Ub results exhibit a much higher value at pH < 6 compared with that at pH > 8. Since the "lying" long chain molecules cover and protect the Al2O3 surface, Ub increases with a decrease of pH. These findings provide new insights to study the breakdown mechanisms and to develop new electrolytes for high operating voltage capacitors. [ABSTRACT FROM AUTHOR]

Solar power tower (SPT) system is a promising candidate to improve the flexibility of renewable energy power systems. Accurately predicting the dynamic performance of the SPT system is an important prerequisite for stabilizing or dispatching the system. To this end, an integrated transient model of an SPT system has been established, taking into account the dynamic behavior of all its subsystems, including concentration, thermal energy storage, and power cycle. System dynamic response characteristics are then explored under varying environmental and operational parameters. Then, a dual-time-scale hybrid method combining steady and transient models is proposed to predict system performances. Finally, based on predicted annual performances, the capacities of subsystems are optimized. The results indicate that the direct normal irradiance (DNI) and mass flow rate of molten salts and working fluids have substantial impact on the system. When the DNI and mass flow rate of molten salt vary by more than 30 %, the required adjustment time exceeds 280 s, potentially resulting in a significant reduction in output power. The proposed hybrid method allows for rapid and accurate forecasting of overall performance, reducing calculation time by 32 % while maintaining a low relative error compared with the complete transient model. Additionally, based on the annual performances predicted by the proposed calculation method, the solar multiple and thermal storage time are optimized to be 3.0 and 12.5 h, respectively, which have considered the system efficiency, stability, and cost of energy storage. • An integrated transient model of the entire SPT system is established. • Dynamic response characteristics of the system are analyzed. • A dual-time-scale hybrid method for performance prediction is proposed. • The capacity configuration of subsystems is optimized. [ABSTRACT FROM AUTHOR]

The paper aims to study the impact of Thermal Energy Storage (TES) technology on the dynamic characteristics of Concentrated Solar Power (CSP). An integrated dynamic model of a CSP plant is firstly established, which combines the concentrating system, the TES system, and S–CO 2 Brayton power cycle system. Three TES alternatives are considered: two-tank molten salt TES (TT-TES), packed-bed TES with solid fillers (PBS-TES), packed-bed TES with phase change materials (PBP-TES). Using this integrated dynamic model, the thermal performance and economic feasibility of different TES technologies applied to CSP are compared and analyzed. The results indicate that utilization of packed-bed TES primarily impacts the optical efficiency of the heliostat field and the thermal efficiency of the power cycle, while having minimal effect on the receiver's thermal efficiency. Furthermore, during the vernal equinox, the daily average system efficiencies of CSP configurations integrating TT-TES, PBS-TES, PBP-TES technologies are 26.0 %, 25.5 %, and 24.5 %, respectively. Meanwhile, the use of packed-bed TES systems significantly reduces the material cost of the TES. In comparison to the TT-TES, the PBP-TES and the PBS-TES can reduce cost by 21.2 % and 42.3 %, respectively, and decrease TES volume by 83.0 % and 63.8 %, respectively. • An integrated dynamic model of a concentrated solar power is established. • The influence of three TES technologies on the dynamic characteristics of CSP is studied. • The TES technologies include two-tank molten salt TES, packed-bed TES with solid fillers, and packed-bed TES with PCMs. • Packed-bed TES affects charging and discharging processes, causing energy loss. • Packed-bed TES reduces cost and volume compared to two-tank molten salt TES. [ABSTRACT FROM AUTHOR]

In the concentrating solar power generation (CSP), the latent heat thermal energy storage system (LHTES) is under the constraint of the outlet threshold temperatures, which caused lower effective utilization rate (U ma) of the phase change material (PCM). The objective of the present work is to improve the performance of the shell-and-tube LHTES which is under the constraint of the outlet threshold temperatures in charging and discharging processes. In this study, a transient, two-dimensional, and axisymmetric model of a shell-and-tube LHTES is established. Based on the model prediction, first, the sensitivity analysis of the geometry parameters to the performance of the LHTES shows that with the increase of the specific surface area and the porosity, the U ma monotonically increases, but the investment cost for LHTES per unit of stored heat (c TES) has a minimum value. Then based on the influence of the number and filling thickness of cascaded PCMs, a design criterion of the cascaded PCMs distribution is proposed for the shell-and-tube LHTES constrained by the outlet threshold temperatures, and the effectiveness of this design criteria is verified. Based on the proposed design criterion, the U ma of the optimal shell-and-tube LHTES with 5-cascaded PCMs can reach 77.6%, which is 3.1 times larger than that of a non-cascaded LHTES. Its c TES is only about 2/5 of a non-cascaded LHTES. The results of optimizing the geometry parameters of the TES device and the distribution of cascaded PCMs can be beneficial to the shell-and-tube LHTES which is under the constraint of outlet threshold temperatures in the real utilization of CSP. • A mathematical model of the LHTES constrained by outlet threshold temperatures is established. • The LHTES is utilized in CSP which is coupled with supercritical CO2 Brayton cycle. • Sensitivity analysis of geometry parameters to performances of LHTES is studied. • The influence of the number and filling thickness of cascaded PCMs is studied. • A design criterion for maximizing effective utilization rate of PCM is proposed. [ABSTRACT FROM AUTHOR]

• An integrated numerical model for free-falling particle receiver is developed. • Thermal performance of the particle receiver within one day is obtained. • A nonuniform flow rate control approach is proposed to improve receiver efficiency. • An increase of 2.7 percent points in efficiency is achieved by proposed approach. Free-falling particle receiver is a promising candidate for the receivers in the 3rd-generation concentrated solar power plants. In this paper, an integrated numerical model is established by combining the complete Monte Carlo ray-tracing method and finite volume method to investigate the complex energy conversion processes of the receiver. Based on the model, influential effects of key parameters on the receiver efficiency (η) are analyzed including the particle release location and the solar absorptivity of cavity walls. Then, the variation of η in a day is obtained. In the end, to further improve η , a novelty methodology called 'non-uniform particle mass flow rate control' is proposed based on the 'optical-thermal matching' principle to accommodate curtain opacity to non-uniform solar irradiation. The results present that the center of the top cavity wall is the optimum location to release particles. The reduction of the solar absorptivity of cavity walls can significantly improve η. Compared with molten salt receivers, the operating time per day of the particle receiver is shorter under the condition of high temperature. The proposed non-uniform mass flow control approach can improve η by a maximum value of 2.7 percentage points. The results indicate that the integrated numerical model established in this paper can accurately predict the optical-thermal performance of the free-falling particle receiver, and can be applied to the design and optimization of free-falling particle receivers. [ABSTRACT FROM AUTHOR]

Rationale: Low‐molecular‐weight organic acids that generally contain one to three carboxyl groups are involved in many important biological processes; therefore, it is important to develop a quantitative method for analyzing organic acids in serum in order to allow an evaluation of metabolic changes. In this study, we evaluated a protocol for detecting 26 organic acids in serum based on ultrasound‐assisted derivatization by gas chromatography/mass spectrometry (GC/MS). Methods: Serum samples were prepared using ultrasound‐assisted silane derivatization before GC/MS analysis to quantify concentrations of organic acids. Additionally, we investigated the variables affecting derivatization yields, including the extraction solvent, derivatization reagents, and derivatization conditions (reaction temperature, duration, and sonication parameters). The protocol was ultimately applied to detect organic acid profiles related to obesity. Results: We used acetone as the extraction solvent and determined suitable derivatization conditions, as follows: BSTFA + 1% TMCS, 50°C, 10 min, and 100% ultrasound power. The protocol showed satisfactory linearity (r = 0.9958–0.9996), a low limit of detection (0.04–0.42 μmol/L), good reproducibility (coefficient of variation (CV) %: 0.32–13.76%), acceptable accuracy (recovery: 82.97–114.96%), and good stability within 5 days (CV%: 1.35–12.01% at room temperature, 1.24–14.09% at 4°C, and 1.01–11.67% at −20°C). Moreover, the protocol was successfully applied to obtain the organic acid profiles from obese and healthy control subjects. Conclusions: We identified and validated a protocol for ultrasound‐assisted derivatization prior to GC/MS analysis for detecting 26 kinds of organic acids in serum. The results suggest the efficacy of this protocol for clinical applications to determine metabolic changes related to fluctuations in organic acid profiles. [ABSTRACT FROM AUTHOR]

Predictions of coupled conduction-radiation heat transfer processes in periodic composite materials are important for applications of the materials in high-temperature environments. The homogenization method is widely used for the heat conduction equation, but the coupled radiative transfer equation is seldom studied. In this work, the homogenization method is extended to the coupled conduction-radiation heat transfer in composite materials with periodic microscopic structures, in which both the heat conduction equation and the radiative transfer equation are analyzed. Homogenized equations are obtained for the macroscopic heat transfer. Unit cell problems are also derived, which provide the effective coefficients for the homogenized equations and the local temperature and radiation corrections. A second-order asymptotic expansion of the temperature field and a first-order asymptotic expansion of the radiative intensity field are established. A multiscale numerical algorithm is proposed to simulate the coupled conduction-radiation heat transfer in composite materials. According to the numerical examples in this work, compared with the fully resolved simulations, the relative errors of the multiscale model are less than 13% for the temperature and less than 8% for the radiation. The computational time can be reduced from more than 300 h to less than 30 min. Therefore, the proposed multiscale method maintains the accuracy of the simulation and significantly improves the computational efficiency. It can provide both the average temperature and radiation fields for engineering applications and the local information in microstructures of composite materials. [ABSTRACT FROM AUTHOR]

• A numerical model of GaAs-TE system with a nanostructured front surface. • Multi-physics coupling effects of nanostructure on GaAs-TE system performance. • The reflectance reduction in 0.28 ~ 0.875 μm improves system power by 374.3 W·m−2. • The reflectance reduction in 0.875 ~ 2.5 μm improves system power by 79.1 W·m−2. • Nanostructure with low reflectance in full spectrum is advised for system. Tandem PV-TE hybrid system is an effective full solar-spectrum utilization method. Nanostructured front surface can make the system absorb more solar light, thereby generating more carriers and more heat. The heat will decrease photovoltaic efficiency but increase thermoelectric efficiency. Therefore, it's necessary to clarify the combined effect of nanostructure's full-spectrum characteristics on PV-TE hybrid system. In this study, a multi-physics coupling model of a GaAs solar cell based PV-TE hybrid system with a nanostructured front surface was built and validated. The numerical results show that the system output power of nanostructure with a 1.8% average reflectance in 0.28 ~ 0.875 μm is 374.3 W·m−2 greater than that with a 8.7% average reflectance and the system output power of nanostructure with a 2.6% average reflectance in 0.875 ~ 2.5 μm is 79.1 W·m−2 greater than that with a 8.1% average reflectance under 100 concentration ratio. It means that both the reductions of reflectance in 0.28 ~ 0.875 μm and in 0.875 ~ 2.5 μm can effectively improve the system output power. Therefore, nanostructure with low reflectance in full spectrum (not only in short wavelengths) is advised for a GaAs solar cell based PV-TE hybrid system. [ABSTRACT FROM AUTHOR]

Phytophthora infestans (Mont.) de Bary, the oomycotic pathogen responsible for potato late blight, is the most devastating disease of potato production. The primary pesticides used to control oomycosis are phenyl amide fungicides, which cause environmental pollution and toxic residues harmful to both human and animal health. To address this, an antimicrobial peptide, NoPv1, has been screened to target Plasmopara viticola cellulose synthase 2 (PvCesA2) to inhibit the growth of Phytophthora infestans (P. infestans). In this study, we employed AlphaFold2 to predict the three-dimensional structure of PvCesA2 along with NoPv peptides. Subsequently, utilizing computational methods, we dissected the interaction mechanism between PvCesA2 and these peptides. Based on this analysis, we performed a saturation mutation of NoPv1 and successfully obtained the double mutants DP1 and DP2 with a higher affinity for PvCesA2. Meanwhile, dynamics simulations revealed that both DP1 and DP2 utilize a mechanism akin to the barrel-stave model for penetrating the cell membrane. Furthermore, the predicted results showed that the antimicrobial activity of DP1 was superior to that of NoPv1 without being toxic to human cells. These findings may offer insights for advancing the development of eco-friendly pesticides targeting various oomycete diseases, including late blight. [ABSTRACT FROM AUTHOR]

The widely used droplet–droplet collision outcome model distinguishing stretching separation (SS) and fast coalescence (FC) (named SS/FC model) proposed by Jiang et al. [J. Fluid Mech. 234, 171 (1992)] is corrected and improved in this study. By re-deriving the momentum conservation, the correct mathematical expression of the tangential velocity along the sliding direction is obtained. Moreover, to reduce the uncertainties of model applications, the model is improved by expressing the constants as a function of the Ohnesorge number and droplet size ratio. The validation results demonstrate the effectiveness of the improved SS/FC model. [ABSTRACT FROM AUTHOR]

The dynamic of plant-parasitic nematode populations in soil is closely related to soil microorganisms. Fungi from Heterodera zeae cysts were isolated to explore the phenomenon of decline in the H. zeae population in the soil. Phylogenetic study of partial ITS, BenA, CaM, and RPB2 gene sequences, in addition to morphological investigations, was utilized to identify a nematode-destroying fungus. The nematicidal activity of a novel strain GX1 against H. zeae was assessed in vitro and in the greenhouse. Our findings revealed that strain GX1 is a new species of Talaromyces, named Talaromyces cystophila. It has a strong parasitic and lethal effect on H. zeae cysts, with 91.11% parasitism on cysts at 3 days after treatment. The contents of second-stage juveniles (J2s) and eggs inside the cysts were degraded and formed dense vacuoles, and the damaged eggs could not hatch normally. The spore suspension exhibited high nematophagous activity against nematodes, and fermentation filtrate exhibited marked inhibition of egg hatching and nematicidal activities on J2s. The hatching inhibition rates of eggs exposed to 1 × 108 CFU/ml spore suspensions or 20% 1-week fermentation filtrate (1-WF) for 15 days were 98.56 and 100%, respectively. The mortality of J2s exposed to 1 × 108 CFU/ml spore suspension reached 100% at 24 h; exposure to 50% 2-WF was 98.65 and 100% at 24 and 48 h, respectively. Greenhouse experiments revealed that the spore suspension and fermentation broth considerably decreased H. zeae reproduction by 56.17 to 78.76%. T. cystophila is a potential biocontrol strain with nematophagous and nematicidal activity that deserves attention and application. [ABSTRACT FROM AUTHOR]

• Enhancement of charged SWCNT on specific heat capacity of molten salt is studied. • The influence of the SWCNT charge on the compressed ion layer is revealed. • Local enrichment of charges exists, and pairwise energy is increased as a result. • Charged SWCNT offers great enhancement to specific heat capacity of molten salts. This work focuses on the effects of charged single-walled carbon nanotubes (SWCNT) on the heat capacity of composite carbonate salt (Li 2 CO 3 -K 2 CO 3) using the Electric Double-Layer modeling (EDL) and the Molecular Dynamics (MD) simulation. The nanoparticle-enhanced molten salt ensemble is modeled considering the compressed ion layer surrounding the SWCNT, and the specific heat capacity (c p) enhancement of the nanoparticle-enhanced molten salt is analyzed. The results present the following issues. First, compressed ion layer is formed around the SWCNT surface. The density distributions of Li+, K+ and CO 3 2– are strongly related to the SWCNT charge. The density distributions of the ions present characteristics of oscillatory, and the densities of the ions can be increased by rise of SWCNT charge. Second, the charge density distribution is analyzed. The local enrichment of positive and negative charges is found to occur inside the compressed ion layer. It is found that increasing the SWCNT charge can promote the local enrichment of positive and negative charges, which contributes to the increase of the internal energy of the nanoparticle-enhanced molten salt ensemble and results in c p enhancement. Finally, c p is found to be increased with increasing SWCNT charge. The c p enhancement of 19.2% is achieved when the SWCNT carries surface charge of −280 e. The obtained results can provide guidance on the application of charged nanoparticles to enhance the specific capacity of molten salt. [ABSTRACT FROM AUTHOR]

• Novel heat exchangers for waste heat utilization of dusty flue gas are proposed. • The aligned elliptic tube and honeycomb circular tube bundles are presented. • Ash fouling and thermal-hydraulic characteristics in fouling state are examined. • The effects of transverse and longitudinal pitches are studied. • The correlations of Nu , f and fouling thermal resistance are obtained. In this paper, aiming at resolving the contradictions of heat transfer enhancement, resistance reduction and soot-blowing effect of common heat transfer surfaces, aligned elliptical tube bundle (AETB) and honeycomb tube bundle (HCTB) were proposed for the high dust content conditions, and the fouling characteristics and thermal-hydraulic performance before and after fouling were investigated. Firstly, the thermal-hydraulic performance of aligned circular tube bundle (ACTB), AETB, conventional staggered circular tube bundle (SCTB) and HCTB in the clean state were compared, and advantages of AETB and HCTB were verified. Secondly, based on the ash fouling model and prediction method established by the author's group, fouling distribution and morphology of AETB and HCTB were obtained, and ash fouling and thermal-hydraulic characteristics were examined by parameterization. Finally, in the range of geometry parameters studied in this paper, the correlations of the asymptotic value of fouling thermal resistance R f ∗ in fouling state, Nusselt number Nu and friction factor f in clean state were developed. Results show that the relative deviations between the predicted results and the numerical values is within 4%, which indicates that the proposed correlation is of sufficient accuracy for engineering purposes, and can accurately predict the thermal-hydraulic characteristics of flue gas heat exchanger. The results of this paper can provide a reference for development and engineering application of the heat-transfer surface for the efficient recovery of industrial flue gas waste heat. [ABSTRACT FROM AUTHOR]

• A novel nonlinear thermal conductivity distribution in the nanolayer is proposed. • Effects on nanolayer thickness of diathermic oil-based nanofluid are analyzed. • A semi-empirical model of the nanofluid thermal conductivity is developed. • The semi-empirical model is validated by lots of experimental data from literatures. In this paper, a novel semi-empirical model is developed for predicting the thermal conductivity of Diathermic Oil (DO)-based nanofluid for solar thermal application. First, a corrected thermal conductivity model of nanofluid is developed based on the widely used Yu-Choi model. In this corrected model, the thermal conductivity distribution of nanolayer is treated as a quadratic form instead of a constant value along with the distance from nanoparticle. The corrected model shows the predicted thermal conductivity of nanofluid is significantly influenced by nanolayer thickness. Then, the semi-analytical nanolayer thicknesses for different DO-based nanofluid are calculated utilizing the corrected model and the experimental data in literatures. It is found that the nanolayer thickness of DO-based nanofluid is not a constant value but varies with the volume fraction of nanoparticles, nanoparticle radius, and nanofluid temperature. According to the semi-analytical results, the empirical equations between the above variables and nanolayer thickness are summarized. Finally, by adopting the empirical equation of the nanolayer thickness in the corrected model, a novel semi-empirical thermal conductivity model is developed for predicting the thermal conductivity of DO-based nanofluid. The semi-empirical thermal conductivity model is validated by a large number of experimental data from literatures. [ABSTRACT FROM AUTHOR]

Depression is one of the most common mood disturbances worldwide. The Si-ni-san formula (SNS) is a famous classic Traditional Chinese Medicine (TCM) widely used to treat depression for thousands of years in clinics. However, the mechanism underlying the therapeutic effect of SNS in improving depression-like behaviors following chronic unpredictable mild stress (CUMS) remains unknown. This study aimed to investigate whether SNS alleviates depression-like behaviors in CUMS mice by regulating dendritic spines via NCOA4-mediated ferritinophagy in vitro and in vivo. In vivo, mice were exposed to CUMS for 42 days, and SNS (4.9, 9.8, 19.6 g/kg/d), fluoxetine (10 mg/kg/d), 3-methyladenine (3-MA) (30 mg/kg/d), rapamycin(1 mg/kg/d), and deferoxamine (DFO) (200 mg/kg/d) were conducted once daily during the last 3 weeks of the CUMS procedure. In vitro, a depressive model was established by culture of SH-SY5Y cells with corticosterone, followed by treatment with different concentrations of freeze-dried SNS (0.001, 0.01, 0.1 mg/mL) and rapamycin (10 nM), NCOA4-overexpression, Si-NCOA4. After the behavioral test (open-field test (OFT), sucrose preference test (SPT), forced swimming test (FST) and tail suspension test (TST), dendritic spines, GluR2 protein expression, iron concentration, and ferritinophagy-related protein levels (P62, FTH, NCOA4, LC3-II/LC3-I) were tested in vitro and in vivo using immunohistochemistry, golgi staining, immunofluorescence, and Western blot assays. Finally, HEK-293T cells were transfected by si-NCOA4 or GluR2-and NCOA4-overexpression plasmid and treated with corticosterone(100 μM), freeze-dried SNS(0.01 mg/mL), rapamycin(25 nM), and 3-MA(5 mM). The binding amount of GluR2, NCOA4, and LC3 was assessed by the co-immunoprecipitation (CO-IP) assay. 3-MA, SNS, and DFO promoted depressive-like behaviors in CUMS mice during OFT, SPT, FST and TST, improved the amount of the total, thin, mushroom spine density and enhanced GluR2 protein expression in the hippocampus. Meanwhile, treatment with SNS decreased iron concentrations and inhibited NCOA4-mediated ferritinophagy activation in vitro and in vivo. Importantly, 3-MA and SNS could prevent the binding of GluR2, NCOA4 and LC3 in corticosterone-treated HEK-293T, and rapamycin reversed this phenomenon after treatment with SNS. SNS alleviates depression-like behaviors in CUMS mice by regulating dendritic spines via NCOA4-mediated ferritinophagy. [Display omitted] [ABSTRACT FROM AUTHOR]

Exacerbation of pain by chronic stress and comorbidity of pain with stress-related psychiatric disorders, including anxiety and depression, represent significant clinical challenges. However, the underlying mechanisms still remain unclear. Here, we investigated whether chronic forced swim stress (CFSS)-induced exacerbation of neuropathic pain is mediated by the integration of stress-affect-related information with nociceptive information in the central nucleus of the amygdala (CeA). We first demonstrated that CFSS indeed produces both depressive-like behaviors and exacerbation of spared nerve injury (SNI)-induced mechanical allodynia in rats. Moreover, we revealed that CFSS induces both sensitization of basolateral amygdala (BLA) neurons and augmentation of long-term potentiation (LTP) at the BLA-CeA synapse and meanwhile, exaggerates both SNI-induced sensitization of CeA neurons and LTP at the parabrachial (PB)-CeA synapse. In addition, we discovered that CFSS elevates SNI-induced functional up-regulation of GluN2B-containing NMDA (GluN2B-NMDA) receptors in the CeA, which is proved to be necessary for CFSS-induced augmentation of LTP at the PB-CeA synapse and exacerbation of pain hypersensitivity in SNI rats. Suppression of CFSS-elicited depressive-like behaviors by antidepressants imipramine or ifenprodil inhibits the CFSS-induced exacerbation of neuropathic pain. Collectively, our findings suggest that CFSS potentiates synaptic efficiency of the BLA-CeA pathway, leading to the activation of GluN2B-NMDA receptors and sensitization of CeA neurons, which subsequently facilitate pain-related synaptic plasticity of the PB-CeA pathway, thereby exacerbating SNI-induced neuropathic pain. We conclude that chronic stress exacerbates neuropathic pain via the integration of stress-affect-related information with nociceptive information in the CeA. [ABSTRACT FROM AUTHOR]

A new electrochemical tubular photobioreactor is designed for the efficient cultivation of chlorella, alongside eliminating the inhibition of the growth of microalgae caused by the high dissolved oxygen content. With the aid of anion-exchange membrane alkaline fuel cell, the dissolved oxygen in the photobioreactor which is produced by the photosynthesis of microalgae can be consumed and the energy consumption of photobioreactor can be reduced. Besides, the effects of different components and operating parameters on the efficiency of dissolved oxygen removal and the cell performance have been detailed investigated. The experiment results are shown as follows. First, by applying the double-cylinder alkaline direct glucose fuel cell to consume the dissolved oxygen of the microalgae suspension in the tubular photobioreactor on-line, the dissolved oxygen content rapidly decreases from over 20.0 mg L−1 to 10.72 mg L−1 below within 45 min. Second, the efficiency of dissolved oxygen consumption and cell performance increase significantly by using the bimetallic catalyst Pt-Ru as the cathode catalyst in the double-cylinder alkaline direct glucose fuel cell compared with the mono-metallic cathode catalyst by adopting Pd and Pt. Third, it exists an optimal cathode catalyst loading (1.5 mg PtRu ·cm−2) to consume the dissolved oxygen with the fuel cell yielding the best performance. • The proposed electrochemical method can consume the dissolved oxygen efficiently. • The dissolved oxygen content decreases rapidly with the aid of the AEM-DGFC. • Pt 40 Ru 20 as the cathode catalyst performs best on dissolved oxygen consumption. • There exists an optimal cathode catalyst loading for the cell performance. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Heat transfer and friction of salts in pipe flow under different fluxes are studied. • Non-uniform flux has no obvious effect on heat transfer performance and friction. • Filonenko's equation can describe the friction of four molten salts accurately. • Deviations between heat transfer data and classical correlations are observed. • A correlation that predicts heat transfer of salts more accurately is developed. Abstract This article investigated the heat transfer performance and flow friction of molten salts in turbulent tube flow, where four salts including Hitec, Solar Salt, NaF-NaBF 4 , and FLiNaK were studied. A computational model was developed to analyze the flow and heat transfer features of the salts in the tube, and experiments were conducted to test the heat transfer performance of a representative salt Hitec in the tubes of a salt-oil heat exchanger. Comparison of simulation results with the experimental data shows that the average errors are smaller than ±4%, which validates the simulation model. Based on the model, firstly the influences of heat flux uniformity at the tube outer wall were examined. The results show that the non-uniform wall flux can lead to local high-temperature region but influences little on the flow friction coefficient and the heat transfer performance. Then, the model was utilized to investigate the friction and heat transfer features of the salts under broad ranges of the temperature and the velocity. Comparisons of the simulated heat transfer results with Hansen's, Sider-Tate's and Gnielinski's correlations show that the largest errors can reach +25%, +13% and −15%, respectively. Furthermore, the errors between the simulated friction coefficients and the Filonenko's correlation are smaller than ±2%, which indicates that this correlation is suitable for predicting the friction of the salts. Finally, to predict the heat transfer performance more accurately for these representative salts, a new correlation was developed. It was found that the errors between all simulation results and the proposed correlation are smaller than ±5%, while the corresponding values for 80% experiment data of three salts are also lower than ±5%. The current study can offer beneficial results and correlation for the applications of molten salts in energy systems. [ABSTRACT FROM AUTHOR]

Abstract The studies of supercritical carbon dioxide (S-CO 2) power generation cycles have attracted wide attention from different energy industries in recent years. At present, there is a lack of studies on the dynamic characteristics of S-CO 2 power systems, especially in S-CO 2 coal-fired power plants. In order to further provide the theoretical and technical support for the integration of energy internet and the deep peak-load regulation, it is important to establish the dynamic model of the S-CO 2 power system. Heat exchanger is a key component of the system. Therefore, the dynamic response characteristics of the heat exchanger need to be studied because the related research will lay the foundation of building the dynamic model of the entire S-CO 2 power system. In this paper, the effects of dynamic responses characteristics of thermodynamic parameters (fluid outlet temperature, total surface heat flux and surface heat transfer coefficient of fluid channels) on the printed circuit heat exchanger (PCHE) of 1000 MW S-CO 2 coal-fired power plants are studied in detail. Afterward, a neural network is trained to predict the performance of the PCHE. First, the computational fluid dynamics (CFD) method is adopted to establish the dynamic model of the S-CO 2 /S-CO 2 PCHE. Second, when the fluid inlet temperature or the fluid mass flow rate is changed, the dynamic response trends of thermodynamic parameters on the PCHE of 1000 MW S-CO 2 coal-fired power plants are analyzed. Third, the comparisons of the equilibration time of the PCHE with different boundary conditions (the fluid mass flow rate and the fluid inlet temperature) are investigated. Finally, a neural network is trained to predict the performance of the PCHE. Highlights • The CFD method is adopted to establish the dynamic model of the S-CO 2 PCHE. • The dynamic response trends of key parameters on the PCHE are analyzed. • The equilibration time of the PCHE with different conditions are compared. • A neural network is trained to predict the performance of the PCHE. [ABSTRACT FROM AUTHOR]

Abstract By using R123 as the working fluid, experimental studies for basic organic Rankine cycle (BORC) and organic Rankine cycle with a regenerator (RORC) are carried out, two scroll expanders with different suction volumes are installed and examined (1# expander with the suction value of 66 mL/r; 2# expander with the suction value of 86 mL/r). Comparison between the different system configurations and expanders with different suction volumes are carried out under identical heat source conditions, how the expanders with the different suction volumes influence the system performance is investigated and analyzed. The torque of the expander is increased step by step during the experiment. The results show that: 2# expander shows a higher shaft power output as well as rotating speed, but lower isentropic efficiency in most situations; the highest shaft power output appears when the filling factor reaches to 0.8–0.9. For different system configurations, the maximum actual thermal efficiency of 2.96% is obtained in BORC using 2# expander. The heat transfer rate of the evaporator is decreased due to the regenerator, however, RORC still has a lower thermal efficiency due to its low shaft power output. The different mass flow rate caused by the different suction volume of the expander is the most important factor that influences the system performance. Highlights • Experimental studies of two ORC systems were operated using R123 as working fluid. • Two scroll expanders with different suction volumes were installed and examined. • Performances of systems and expanders were compared and analyzed, respectively. • How the size of the expander influence the system performance was investigated. [ABSTRACT FROM AUTHOR]

Abstract The potential to improve the performance of molten salt solar power tower system (SPT) is explored through the proposal of CO 2 -based binary mixture cycle in the present study. The feasibility of using xenon and butane as the additives to the S-CO 2 cycle are discussed from the perspective of thermodynamic analysis. The detail parametric study is performed to reveal the effects of crucial parameters on the performance of 4 system configurations. Furthermore, the systematic comparison is conducted for 4 cycle layouts adopting CO 2 /xenon, CO 2 and CO 2 /butane separately to illustrate the mechanism of performance improvement of SPT system coupled to CO 2 -based binary mixture cycle. The optimal performance of the SPT system is also demonstrated. Finally, the best performance system layout and suitable additives are recommended. The results indicate the following issues. Adding xenon into S-CO 2 cycle can obviously improve the overall thermal efficiency and exergy efficiency. While the effects of butane as an additive are converse. The inter-cooling CO 2 /xenon cycle is recommended as the most suitable layout coupled to the SPT system, and the exergy efficiency is 1.18%∼1.32% higher than that of the SPT system with S-CO 2 inter-cooling cycle. Detail exergy loss fraction distribution illustrates that the receiver is the highest exergy loss part and followed by the heliostat field, and butane as an additive is beneficial to reduce the receiver exergy loss for its smaller temperature difference. The study can provide a novel way to improve the SPT system performance and give a clue to the addition of CO 2 -based binary mixture in power cycles particularly for the application of SPT system. Highlights • Improvement on SPT performance is explored via using CO 2 -based mixture cycle. • Effects of key parameters on SPT with various CO 2 -based mixture cycle are analyzed. • Systematic comparison of different system layouts is performed. • Optimal additive and cycle configuration are recommended for SPT. [ABSTRACT FROM AUTHOR]

Abstract A comprehensive study of thermo-economic analysis and practical conceptual design of miniaturized lead-cooled fast reactor (LFR) composing supercritical CO 2 power cycle is proposed in order to promote the real application in the market. The thermodynamic model and economic model are established based on the following five supercritical CO 2 (S-CO 2) Brayton cycles integrating with the miniaturized LFR, separately. Moreover, the optimization algorithm is adopted to optimize the key parameters of five power cycles with the objectives of maximizing the system thermoelectric conversion efficiency and electricity production costs (EPC) simultaneously. The optimal cycle and optimum parameters are obtained for the integrated system. Furthermore, the structural parameters of key components are confirmed based on the above results. The main subsidiary systems are designed. Finally, the practical design of LFR composing S-CO 2 power cycle is carried out. The results shown that various parameters have different effects on the thermodynamic-economic performance of the system. The higher inlet temperature of turbine is beneficial to improve both thermodynamic and economic performance of the system. With the ƞ t,sys -EPC analyzed simultaneously, the recompression cycle is the optimal to operate with more working conditions. Its ƞ t,sys is from 36.68% to 44.46%, and EPC is from 0.050 $·kW−1·h−1 to 0.055 $·kW−1·h−1). [ABSTRACT FROM AUTHOR]

Abstract Molecular dynamics method is used to investigate the mass transfer rules of reactants H 3 O+ and O 2 in the cathode catalyst layer in the presence of five kinds of cations (Na+, K+, NH 4 +, Mg2+, Ca2+) in the microbial fuel cell solution environment. Structural characteristics of the catalyst layer Pt/C substrate/Nafion/solution three-phase interface are also analyzed. The results show that the transport mechanism and pathway of H 3 O+ in the catalyst layer are similar to those of monovalent cations (Na+, K+, NH 4 +). The minimum diffusion coefficient of H 3 O+ appears in the presence of K+. On the other hand, H 3 O+ mainly transport inside the water clusters in the presence of divalent cations (Mg2+, Ca2+). The diffusion law of metal cations (K+> Na+> Mg2+> Ca2+) is still applicable in the catalyst layer containing Nafion ionomer and unaffected by cation concentration. In general, the higher concentration of O 2 molecules in the main part of the Nafion phase and the farther distribution from the carbon substrate cause a larger O 2 diffusion coefficient. Moreover, the O 2 transport pathways in the main part of the Nafion phase are along the Nafion hydrophilic/hydrophobic phase interface and inside the hydrophobic phase. In the presence of Ca2+, the concentration of O 2 near the Pt particles is the highest. These O 2 molecules tend to adsorb on the surface of Pt particles with small size. Thus, the catalyst utilization rate is high. In addition, Ca2+ has a strong cross-linking effect on the sulfonic acid groups from different Nafion molecules, which helps to enhance the stability of the catalyst layer. Highlights • A mirror symmetry MD model of the MFC catalyst layer is proposed. • Monovalent cation and H 3 O+ have similar transport mechanism and pathway. • O 2 mainly diffuse along the Nafion hydrophilic/hydrophobic phase interface. • Ca2+ can ensure catalyst utilization rate and stability of catalyst layer. [ABSTRACT FROM AUTHOR]

Background: Although psychological distress is common among patients with chronic diseases, the degree of risk for developing psychological distress is not well-established. Our aim with this study is to determine the odds ratio for psychological distress in patients with cancer as compared to either 1) patients with chronic disease patients without cancer, or 2) healthy controls in a large representative sample of Chinese population.Methods: Using a multistage, stratified cluster sampling method, 21,101 subjects 18-79 years old were interviewed face-to-face in Jilin province, China. Their psychological status was assessed with the 12-item General Health Questionnaire (GHQ-12). A total score of ≥4 was used as the threshold for determining psychological distress.Results: The prevalence of psychological distress was 14.08% across the entire sample: 10.63% in healthy controls; 14.81% in patients with chronic diseases; and 20% in patients with cancer. Multiple logistic regression analysis indicated that, as compared to the health controls, both cancer (OR = 1.609, 95%CI = 1.245-2.081) and chronic disease patients (OR = 1.330, 95%CI = 1.189-1.478) were more likely to suffer from psychological distress. Moreover, cancer patients had a higher risk of psychological distress than patients with chronic diseases (OR = 1.295, 95%CI = 1.049-1.600; p = 0.016). In addition, the cancer group (2.68 ± 0.114) demonstrated a higher GHQ score than the patients with chronic diseases (2.30 ± 0.017) and healthy controls (1.98 ± 0.029) (both p < 0.001).Conclusion: Our results showed both a higher rate and greater degree of psychological distress in patients with cancer. This suggests a need for better psychological management in cancer patients to help alleviate their distress. [ABSTRACT FROM AUTHOR]

One-tank molten salt thermocline heat storage system can reduce capital cost due to the use of cheap heat storage materials as compared with two-tank molten salt heat storage system. In order to develop a convenient method for the evaluation and design of the one-tank thermocline heat storage system, the idea of effectiveness-number of transfer unit method ( ε-NTU ) for heat exchanger design was employed in which three dimensionless design parameters are defined including the ratio between overall thermal conductance and the total thermal capacity of heat transfer fluid flowing through the system during discharging process (i.e., NTU ), the ratio between thermal capacity of solid particles and total thermal capacity of heat transfer fluid through the system during the discharging process (i.e., C s ∗ ), the ratio between overall thermal conductance in the charging process and that in the discharging process (i.e., ( hA ) ∗ ). A transient one-dimensional dispersion-concentric model is then applied to study the effects of three dimensionless parameters on the effectiveness of one-tank system. It is shown that the effectiveness of the one-tank thermocline heat storage system is closely related to NTU , C s ∗ and ( hA ) ∗ . Based on the simulated results, general performance evaluation charts and the related effectiveness correlations are also proposed for evaluation and design of the one-tank system. Moreover, the proposed effectiveness correlations are finally applied in the design of a one-tank molten salt thermocline heat storage system in a 50 MW e CSP plant. [ABSTRACT FROM AUTHOR]

A prototype rod baffle shell-and-tube heat exchanger (RB-STHX) was proposed for concentrating solar power (CSP). For investigating the heat transfer of molten salt in the shell side, the RB-STHX was experimentally studied. A ternary salt Hitec and an oil were adopted as the heat transfer fluids in the shell and tube sides, respectively. Experimental data was firstly obtained when the salt temperature is 212.7–279.6 °C with the Prandtl number of 14.2–23.3. The flow of the salt is turbulent with the Reynolds number ( Re ) of 2697–12,517. The average heat transfer rate ranges from 117 kW to 364 kW. Then, the experimental data was compared with two exiting correlations. The results indicate that an average error of −9.1∼-12.3% between the Nusselt numbers predicted by the two correlations and the experiment data was found. Finally, for predicting the heat transfer of the molten salt in the shell side more accurately, two modified heat transfer correlations which show satisfactory agreements with the experimental data were developed. The average deviations under different Re between the experiment data and the modified correlations are around ±4.4∼±4.6%. Results from current study offer reliable experimental data, useful correlations and helpful guidance for the design of realistic molten-salt RB-STHXs in the CSP systems. [ABSTRACT FROM AUTHOR]

In this paper, a new high-temperature packed-bed thermal energy storage system (PBTES) with macro-encapsulation of molten salt phase change material has been established. A new phase change material (PCM) capsule is designed and constructed with the macro-encapsulated molten salt as its PCM. The ternary carbonate Li 2 CO 3 -K 2 CO 3 -Na 2 CO 3 (32–35–33 wt%) has been selected as the optimal option of PCMs. The melting point is 395.1 °C and the energy storage density is 174.7 kJ·kg −1 . Moreover, the thermal performances such as the temperature evolution of heat transfer fluid and that of PCM capsule, average charging/discharging rate and overall heat storage efficiency are investigated in detail. Finally, a mathematical model is presented complementarily to simulate the thermal performance of PBTES. The results are concluded as follows. (1) The temperature variation of the heat transfer fluid and that of the capsule in the PBTES are obtained. There is a certain temperature difference between the capsule and the heat transfer fluid. Moreover, the convection heat transfer resistances of the capsule and the heat transfer fluid are the main influential factors in the heat exchange process. It can be improved by the inlet temperature and mass flow rate of the fluid. (2) The improvement of inlet temperature and mass flow rate in PBTES can increase its charging and discharging efficiencies. The overall efficiency of the system can be increased to 86.1% from 77.4% through increasing inlet temperature from 425 °C to 465 °C. The efficiency will up to 83.6% from the level of 80.6% by the rise of mass flow rate. (3) To compare the shell and tube thermal storage system, the charging and discharging rates of PBTES are 1.8–3.2 times that of the former one. The overall efficiency of PBTES is 1.9–2.4 times that of shell and tube thermal storage system. (4) According to the numerical simulation results, the good agreements of temperature evolution are achieved between the numerical results and experimental data, and the shorter diameter is optimal to the PBTES because a larger diameter will increase the charging time. In summary, the PBTES is an efficient method of heat storage. The study proposes a design of such the PBTES for a first step implementation of the technology and the improvement of thermal performance optimization. [ABSTRACT FROM AUTHOR]

Black silicon (nanostructured front surface) can significantly improve the efficiency of the silicon solar cell by absorbing more solar irradiance. However, due to the band gap of the semiconductor material, most part of the absorbed solar irradiance is converted into heat to increase the temperature of solar cell. Especially under the concentrating condition, the waste heat is more. Besides, multi-physics coupling problem makes it difficult to study the effects of nanostructures on the performances of the low concentrated black silicon photovoltaic system. In this study, a multi-physics model of a low concentration photovoltaics (LCPV) that employs an all-back-contact black silicon solar cell is built. As for the multi-physics problem in LCPV, a multi-physics coupling mathematical model is developed. Its advantage is to couple near-flied optics, photoelectric conversion, and heat transfer. Furthermore, through parameter sensitivity analysis, it is proved that the coupling mathematical model is more accurate, because it takes full account of the nonlinear correlation between the output power and the temperature, and the effects of series resistance under concentrating condition. Hence, the mathematical model is used to investigate the coupling effects of nanostructures, and it is found that the nanostructure with lower reflectance may not be beneficial for the low concentrated black silicon photovoltaic due to the increased temperature. According to different circumstances, the maximum output power with the lower cost could be achieved by choosing the nanostructure with appropriate reflectance. At last, the dynamic analysis proves that the coupling effects of nanostructure lead to the result that the nanostructure with lower reflectance reduces the annual power generation per square meter of the low concentrated black silicon photovoltaic system by about 116 kW h/m 2 when the concentration ratio is 10. [ABSTRACT FROM AUTHOR]

Nanostructured surface is an important way to improve the efficiency of solar energy by absorbing more solar irradiance. However, due the bandgap of semiconductor material, more absorbed irradiance results in more waste heat. As for photovoltaic-thermoelectric (PV-TE) hybrid system, more waste heat reduces the efficiency of PV module due to the increased temperature, but is beneficial for TE module. There are complex and coupling physical processes (near-field optics, photovoltaic conversion, thermoelectric effects, and heat transfer) in the PV-TE hybrid system. Therefore, a multi-physics coupling mathematic model is developed for investigating the effect of full-spectrum characteristics of nanostructure on the PV-TE hybrid system performances. At first, the full-spectrum characteristics of nanostructure is found and summed up. As an example, the II set of the cone nanostructures have two cone nanostructure (Ⅱ-1 cone nanostructure and Ⅱ-2 cone nanostructure) with different dimensions. They have the same average reflectance of the wavelength range from 0.35 μm to 1.1 μm (0.05), however the average reflectance of the wavelength range from 1.1 μm to 2.5 μm ( R a,1.1-2.5 ) of the Ⅱ-1 cone nanostructure is 74.8% lower than that of the Ⅱ-2 cone nanostructure, which results in that the output power density of the PV-TE hybrid system with the II-2 cone nanostructure being 8.4 W/m 2 more than that with the II-1 cone nanostructure when the concentration ratio is 10. Thus, the cone nanostructures with as high R a,1.1-2.5 as possible are more beneficial for the hybrid system. Then, by optimizing the heat transfer structure of the PV-TE hybrid system, the output power density is increased by 9.1%. At last, through dynamic analysis, it is found that the annual power generation per square meter of the PV-TE hybrid system with II-2 cone nanostructure is about 17 kW·h/m 2 greater than that with the II-1 cone nanostructure. As a result, combined with the structural analysis of the cone nanostructure, the bottom diameter should be as short as possible for the cone nanostructure. [ABSTRACT FROM AUTHOR]

In this paper, a series of experiments on the high-temperature cascaded molten salt latent heat thermal energy storage (LHTES) system are carried out to investigate its charging and discharging behavior. First, three kinds of carbonates are chosen as the phase change materials (PCM), and their thermal properties are measured. They are PCM1 (34.83 wt% Li 2 CO 3 -65.17 wt% K 2 CO 3 ), PCM2 (46.59 wt% Li 2 CO 3 -53.41 wt% K 2 CO 3 ) and PCM3 (22.0 wt% Li 2 CO 3 -62.0 wt% K 2 CO 3 -16.0 wt% Na 2 CO 3 ). The melting temperatures are 499.7 °C, 483.9 °C and 422.0 °C respectively, indicating that the materials can be combined as cascaded PCM. Second, the above-mentioned materials have been adopted to the charging and discharging experiments. The temperature evolution during the charging process reveals that the issue of non-thoroughly melting in the non-cascaded LHTES is solved by using the cascaded LHTES. Moreover, compared to the non-cascaded LHTES, the melting time is shortened, and the final temperature of the PCM is increased by at most 21 °C in the cascaded LHTES. Furthermore, the thermal performance of the cascaded LHTES and the non-cascaded LHTES under various working conditions is investigated. The parameters of HTF inlet temperature and the flow rate during the charging process under different working conditions are as follows. 570 °C-260 kg·h −1 for the condition α, 600 °C-260 kg·h −1 for the condition β, and 600 °C-220 kg·h −1 for the condition γ. Under the three working conditions, the overall heat storage and release quantities of the cascaded LHTES are higher than those of the non-cascaded LHTES by 39.51% and 35.74% at most, respectively. The average charging powers and the average discharging powers of the cascaded LHTES are at most 38.40% and 27.02% higher than those of the non-cascaded LHTES, respectively. Finally, the influence of HTF inlet temperature and flow rate on the charging and discharging performance of the cascaded LHTES and the non-cascaded LHTES has been analyzed. The conclusions drawn in this research can provide a theoretical basis for the application of the high-temperature molten salt cascaded LHTES system in concentrating solar power plants. [ABSTRACT FROM AUTHOR]

The lead is considered as a more attractive material of coolant than lead/bismuth because of higher availability, lower price and fast neutron spectrum in recent years. In this paper, the thermodynamic analysis and cost-benefit-analysis of miniaturized lead-cooled fast reactor (LFR) composing different power cycles have been investigated to examine the optimization result of the miniaturized system in the commercial market. The study proposes a design of such the miniaturized LFR system for a first step implementation of the technology. First, the typical cycles include the reheating recompression supercritical CO 2 Brayton cycle (hereinafter referred to as S-CO 2 cycle), the traditional steam Rankine cycle and the helium (He) Brayton cycle. Second, main parameters of thermodynamic analysis and economic analysis are based on the National Standards of Chinese Industry and the realistic financial and cost estimating assumptions in China. Third, the reheating recompression S-CO 2 Brayton cycle is the optimal option to the LFR. The main results demonstrate that the thermal efficiency of the reheating recompression S-CO 2 Brayton cycle is 43.72%. The efficiency of the LFR generation system comprising reheating recompression S-CO 2 Brayton cycle is 41.53%. Both of them are greater than the efficiencies of steam Rankine cycle (38.62%, 36.69%) and He cycle (37%, 35.41%). Finally, the electricity production costs (EPC) of LFR generation system is obtained as $0.0536/(kW·h), which is lower than the average electricity price in China ($0.0632/kW·h). The payback period of the investment is 31.4 years while the lifespan is 40 years. The profit of company undertaking the LFR generation system is $6.3 million. Therefore, it can be found that the reheating recompression S-CO 2 Brayton cycle is the primary choice of the LFR system, and its profit for commercialization of the system is beneficial. [ABSTRACT FROM AUTHOR]

Supercritical CO 2 (S-CO 2 ) Brayton cycles are recently proposed to be integrated into the solar power tower (SPT) due to their high efficiency and compactness. Comparison of different S-CO 2 Brayton cycle layouts is of great significance for selecting a suitable one in the SPT plant. Both of the efficiency and specific work are important performance criteria for the SPT plant. However, previous studies compared only one individual criterion, or both of them just separately. This paper puts forward a systematic comparison of different S-CO 2 Brayton cycle layouts based on multi-objective optimizations. The two performance criteria are compared simultaneously between different S-CO 2 cycle layouts by comparing the Pareto optimal fronts obtained from multi-objective optimizations. The results suggest that the inter-cooling cycle layout and the partial-cooling cycle layout can generally yield the most excellent performances, and followed by the recompression cycle layout and the pre-compression cycle layout, while the simple recuperation cycle layout has the worst performances. The advantages of the partial-cooling cycle layout and the inter-cooling cycle layout are more prominent compared with the other cycle layouts in the case of high compressor inlet temperature. The provided systematic comparison can be helpful in selecting the most suitable cycle layout for the application in SPT when there are specified requirements for the efficiency and the specific work. In addition, novel salts with high upper limit temperature (higher than 650 °C) are recommended to be developed as the heat transfer fluid for improving system performances. [ABSTRACT FROM AUTHOR]

In the paper, melting performance of a latent heat thermal energy storage (LHTES) unit with phase change materials (PCMs) locally enhanced by porous media was numerically investigated. The filling ratio of the porous inserts was fixed to a low degree to reduce the material cost. The optimal configuration of the porous inserts was obtained after the discussion about the effects of porous geometry and porosity on the velocity and temperature distribution of melting process. To reveal the superiority of the optimized result, different cases were compared with the help of a new comprehensive criterion about the input-output performance. Then a generalization expression was fitted out with some dimensionless parameters for the rapid calculation of melting fraction of the optimized result in practical application. The results indicated that in the horizontal LHTES unit, the limited porous inserts should be concentrated in the bottom part without interval between the neighboring porous inserts, providing an effective enhancement in the lower part and a low degree of thermal stratification. If the mass of porous inserts is fixed, high porosity is preferred to make the thermal-conduction-dominated area sufficiently covered by the porous inserts. Compared with the non-enhancement case, the selected result in this study can remarkably save more than 80% of the melting time and enhance the melting rate by 5.1 times. More significantly, the selected result has the highest melting rate per cost of the material when the price ratio of the addition to the PCM is larger than 5 based on the results of economic assessment. Therefore, it offers an economical solution to the thermal enhancement problem of the LHTES unit in the practical application. The normalized equation of melting fraction is obtained for the parameter range of 0.187 <  Ste  < 0.374, 1.325 × 10 6  <  Ra  < 2.649 × 10 6 : f = 0.596 X + 0.0438 X 2 - 0.0825 X 3 + 0.0130 X 4 , where X  =  SteFoRa 1/8  < 2.796. [ABSTRACT FROM AUTHOR]

The direct coupling scheme between the molecular dynamics (MD) and lattice Boltzmann method (LBM) is established in this paper. Different from the existing coupling schemes which are based on the exchange of the density and velocities, the proposed coupling scheme is based on the velocity distribution functions. Firstly, the relations between the discrete velocity distribution functions of LBM and the continuous velocity distribution functions of MD are derived based on the Hermite expansions. Then, the coupling schemes between MD and LBM are proposed. The inconsistency between the equation of states of MD and LBM is specially treated and the deviatoric stresses are exchanged. The coupling simulations of the Poiseuille flow and Couette flow demonstrate that both the velocity and stress can be well exchanged by the coupling scheme. The coupling simulation of the flow past a nanotube shows that the proposed method can be further used in the study of microscopic fluid flow problems. [ABSTRACT FROM AUTHOR]

A fully coupled heat transfer model at pore-scale of volumetric solar receiver is established in this paper. The X-ray computed tomography technique is applied to reconstruct the porous structure. By generating the voxel mesh and coupling with the Monte Carlo Ray Tracing method, the energy source due to the solar radiation could be determined and then added to the unstructured CFD mesh. The governing equations are solved by the commercial CFD software FLUENT. The results show that the details of the fluid flow and heat transfer in volumetric solar receiver are successfully captured. The pressure drop correlation corresponds satisfactorily to the previous study. The local convective heat transfer coefficient varies in a small range along the inlet fluid flow direction inside volumetric solar receiver and the average Nusselt number could be correlated to a power function of the Reynolds number. The radiation transfer inside the porous media is visualized and thermal radiation loss is evident at the entrance of the solar receiver. The proportion taken by radiation in the total heat transfer is determined as a function of the average temperature of porous skeleton. [ABSTRACT FROM AUTHOR]

• The dynamic response model of VRB involving a coupled computational model, a simplified equivalent circuit model and an energy storage converter model is developed. • A basic operation scheme and an optimized operation scheme based on the moving average filtering method are selected as the load distribution algorithms. • The energy filtering optimization management process for microgrid is proposed with the objective of the economy, stability and efficiency. • The proposed energy management process has been validated in the "source-grid-load-storage" integrated energy system at the Western China Science & Technology Innovation Harbour in Xi'an. For the efficient application of vanadium redox flow battery (VRB) in microgrid containing the clean renewable energy and advanced coal-fired power system such as the supercritical carbon dioxide (S-CO 2) Brayton cycle power plant, a feasible energy filtering optimization process is proposed in this paper. A coupled dynamic response model of VRB and an optimized load distribution algorithm are covered in the process. First, the U stack - I battery -SOC curves are fitted based on the coupled calculation model of VRB. The equivalent resistance of the simplified equivalent circuit model is further calculated. The dynamic response model is refined for the fast calculation of real-time efficiencies. Second, a basic operation scheme and an optimized operation scheme based on the moving average filtering method are selected as the load distribution algorithms. An energy filtering optimization management process that includes a configuration optimization design part and a load distribution part is further constructed. Finally, a case application is carried out to verify the feasibility of the proposed energy management process. The relevant results are presented as follows. First, the combination of the experimental data and the fitted curves can be used to calculate the equivalent resistance of the dynamic response model. The maximum U stack of 86.14 V is obtained at the SOC of 0.99 and I battery of 10A when charging. Second, when applying the optimized operation scheme, the time average efficiency of VRB is operating at an efficient level of 82.75%. The change frequency of load command for each equipment and its dynamic response characteristic can be well matched. Finally, compared to the case where the basic operation scheme is selected in the experimental system, the time average efficiency of VRB is increased from 69.50% to 82.13%., the time average efficiency of S-CO 2 power plant is increased from 39.79% to 40.02%. The application of energy filtering optimization management process for the actual microgrid is feasible. The study can provide the operation scheme and case application for VRB energy storage system in the actual microgrid. [ABSTRACT FROM AUTHOR]

Lactate racemase (LarA), a new nickel enzyme discovered recently, catalyzes the racemization between d- and l-lactates with a novel nickel pincer cofactor (Ni-PTTMN) derived from nicotinic acid. In this study, by using DFT and a 200-atom active-site model, LarA is revealed to employ a modified proton-coupled hydride-transfer mechanism in which a hydride is transferred to a cofactor pyridine carbon from the substrate α-carbon along with proton transfer from the substrate hydroxy group to a histidine, and then moved back from the opposite side. Tyr294 and Lys298 provide significant acceleration effects by orientating substrates and stabilizing the negative charge developing at the substrate hydroxy oxygen. The barrier was determined to be 12.0 kcal mol−1, which reveals enhanced racemase activity relative to the LarA reaction using NAD+-like cofactors. Compared with NAD+, Ni-PTTMN has a stronger hydride-addition reactivity in moderate and high environmental polarity and may fit perfectly the moderately polar active site of LarA. [ABSTRACT FROM AUTHOR]