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Background: Esophageal cancer (ESCA) is a highly invasive malignant tumor with poor prognosis. This study aimed to discover a generalized and high‐sensitivity immune prognostic signature that could stratify ESCA patients and predict their overall survival, and to discover potential therapeutic drugs by the connectivity map. Methods: The key gene modules significantly related to clinical traits (survival time and state) of ESCA patients were selected by weighted gene coexpression network analysis (WCGNA), then the univariate and least absolute shrinkage and selection operator (LASSO) Cox regression analyses were used to construct a 15‐immune‐related gene prognostic signature. Results: The immune‐related risk model was related to clinical and pathologic factors and remained an effective independent prognostic factor. Enrichment analyses revealed that the differentially expressed genes (DEGs) of the high‐ and low‐risk groups were associated with tumor cell proliferation and immune mechanisms. Based on the gathered data, a small molecule drug named perphenazine (PPZ) was elected. The pharmacological analysis indicates that PPZ could help in adjuvant therapy of ESCA through regulation of metabolic process and cellular proliferation, enhancement of immunologic functions, and inhibition of inflammatory reactions. Furthermore, molecular docking was performed to explore and verify the PPZ‐core target interactions. Conclusion: We succeed in structuring the immune‐related prognostic model, which could be used to distinguish and predict patients' survival outcome, and screening a small molecule drug named PPZ. Prospective studies also are needed to further validate its analytical accuracy for estimating prognoses and confirm the potential use of PPZ for treating ESCA. [ABSTRACT FROM AUTHOR]

Developing chiral electrode catalysts for enantioselective electrosynthesis is a great challenge, as it requires catalysts that possess both high activity and enantioselectivity. Precise synthesis of nanoclusters and single atoms coexisting chiral catalysts provide a promising pathway for enhancing asymmetric catalytic performance. Herein, chiral electrode catalysts are fabricated comprising gold clusters (R‐AuC) and single atoms (R‐AuS) on graphene oxide (R‐AuC/S@GO) through an assembly‐irradiation strategy. Thereinto, the R‐Aus is in situ generated from R‐AuC under light irradiation. The monoatomization process can be precisely regulated by changing the wavelength of the light, resulting in four Au‐based chiral electrode (R‐Au@GO) catalysts with different ratios of nanoclusters and single atoms. These chiral electrodes are applied in the electrocatalytic enantioselective hydrogenation of methyl benzoylformate (MB) to chiral methyl mandelate (S‐MM), and the R‐AuC/S‐2@GO with ≈26% R‐AuC and 74% R‐AuS achieve the highest catalytic activity (35 µmol cm−2 h−1 productivity) and enantioselectivity [97% enantiomeric excess (ee)]. Detailed experimental analysis and density functional theory calculations reveal that the R‐AuS on GO promotes the in situ generation of H* species, and R‐AuC mainly drives the enantioselective conversion of MB by transferring the H* species to the carbonyl group of MB, ultimately yielding chiral S‐MM. [ABSTRACT FROM AUTHOR]

Choroidal osteoma is a benign ossifying tumor within the choroid. Complications associated with choroidal osteoma, including disruption of retinal pigment epithelium, atrophy of photoreceptors, subretinal fluid, and choroidal neovascularization, present challenges for clinicians, and management remain controversial. We performed a comprehensive search in the PubMed, EMBASE, and Ovid databases for published studies and case reports relating to the management of choroidal osteoma. Since it was first described in 1978, various case reports of ocular complications associated with choroidal osteoma have been documented, and various therapies have yielded different outcomes. We systematically evaluate the literature published on this rare entity. [ABSTRACT FROM AUTHOR]

Recent study has found excellent bulk and surface insulation property of Si 3 N 4 ceramic which make it potential to serve as key insulation component in various energy transmission apparatus. Charge accumulation at gas-solid interface is a critical insulation property but few relevant study on Si 3 N 4 can be found. This contribution has investigated the surface charge property of Si 3 N 4 ceramic compared to traditional insulation polymer under different electrical-thermal stress. Through its comparison with the electric field distribution, the main source of the surface charge accumulation is analyzed, indicating that the superior surface charge suppression performance of Si 3 N 4 lies on its low carrier density and conduction barrier, which considerably prevent charge injection and suppress the normal electric field which drives the charge to the gas-solid interface. The proposed mechanism is also validated by the characterization on conducting and space charge property for Si 3 N 4 as well as dynamic simulation on surface charge accumulation. [ABSTRACT FROM AUTHOR]

As trapping sites for surface charges, the surface trap is an important factor affecting the insulation performance of the epoxy–SF6 interface, which is closely related to the microstructure and its evolution. However, existing studies often ignore the effect of the degradation of the epoxy surface on the surface traps and charge accumulation during the long-term service of the insulation system. In this study, the surface physicochemical evolution and its influence on surface traps of a typical epoxy–SF6 insulation structure were researched under a DC-temperature gradient condition, and an evolution mechanism of surface traps was proposed. The results show that the free radicals introduced during the material degradation process increase the density and depth of both positive and negative charge traps on the epoxy surface. The effect of free radicals formed by the cleavage of epoxy molecules on the electronic orbital and molecular electrostatic potential of epoxy molecules is the intrinsic reason for the evolution of surface trap evolution. This work may help to understand the long-term evolution mechanisms of the physicochemical characteristics of the epoxy–SF6 interface in DC field and may provide a theoretical basis for the long-term failure mechanism revealing and the insulation performance enhancement. [ABSTRACT FROM AUTHOR]

Lung adenocarcinoma (LUAD) is a highly invasive malignant tumor with poor prognosis, and there is growing evidence that obstructive sleep apnea (OSA) could significantly promotes the risk of LUAD. In order to improve the treatment outcomes of patients with LUAD and OSA, we aim to screen OSA-related genes that may potentially affect LUAD and to discover a high sensitivity prognostic signature that can stratify LUAD/OSA patients and to further accurately identify LUAD patients who might respond to immunotherapy. Molecular subtypes classified by the prognostic signature did not belong to any previously reported subtypes of LUAD. The tumor microenvironment (TME), mutation, and so on, were significantly distinct between patients within different risk groups or clusters. Combined with gene set variation analysis (GSVA) and drug susceptibility analysis, patients in the low-risk group (The vast majority of patients belonging to cluster2 by molecular subtyping) were not suitable for immunotherapy due to T-cell exhaustion caused by long-term inflammatory response; the question of how to reverse T-cell exhaustion may be a primary consideration. Cluster3 patients had the highest benefit from immunotherapy, and although cluster1 patients had the worst prognosis, they were more sensitive to traditional chemotherapeutic drugs. Animal experiments showed that chronic intermittent hypoxia (CIH) could not only significantly promote the tumor growth of LUAD, but also increase the expression levels of risk genes. This risk model may contribute greatly to the evaluation of prognosis, molecular characteristics, and treatment modalities of LUAD/OSA, and could be further translated into clinical applications to ameliorate the treatment dilemmas. • We first established a reliable fourteen-LAOSGs prognostic signature for LUAD. • Two populations featured different TME and so on, which could guide decision making. • Three clusters were determined, which should be helpful for precision medicine. • This study highlights the values of risk score for patients receiving immunotherapy. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenides (TMDCs) films are potential two‐dimensional materials for next‐generation optoelectronic and electronic devices. Chemical Vapor Deposition, Atomic Layer Deposition, and Metal‐Organic Chemical Vapor Deposition are usually used for the synthesis of the MoS2 films by taking Mo(CO)6 as precursors. However, the mechanism of adsorption and reaction of Mo(CO)6 on the substrate at the molecular level are hardly to know only by the experiments. In this study, the detailed reactions of Mo(CO)6 on α‐Al2O3(0001) are investigated by density functional theory to demonstrate the growth mechanism of MoS2. It is found that, Mo(CO)6 could form a stable chemical bond with the Al‐1 site on the surface, which has large adsorption energy and charge transfer. The decomposition of Mo(CO)6 into Mo(CO)3 exists in a clear order, with the top carbonyl composing firstly, follow by the two parallel carbonyls. In order to determine the stable model of Mo(CO)3, adsorption energy and DOS are analyzed. The Ead is −5.65 eV and the 4d5 s orbitals of Mo atom overlap with the 2 s2p orbitals of O atom, indicating the new chemical bond is forming in 3O‐Al‐2 model. Finally, the LST/QST (Linear Synchronous Transit/Quadratic Synchronous Transit) method is used to search for transition states of Mo(CO)3 sulfuration reactions with CH3S2CH3, H2S, and S2 respectively. This paper provides a theoretical basis for the experimental preparation of MoS2 and provides research ideas for the general synthesis of TMDCs. [ABSTRACT FROM AUTHOR]

In this paper, a high-pressure rheometer (MARS 60) was used to conduct rheological experiments on crude oil under varying parameters, including temperature, static pressure, and methane (CH4) dissolution. Combining the Williams–Landel–Ferry equation (WLF equation), Barus equation, and Kishimoto – Fujita model (F-K model), a new model of combined shift factor was used to quantify the effects of different oil parameters on crude-oil viscosity. The results show that higher temperature, lower static pressure, and lower CH4 dissolution reduce crude-oil viscosity. Static pressure and CH4 dissolution have a more significant effect on viscosity in lower-temperature conditions when compared to higher-temperature conditions. Due to the combined effect of the saturation pressure, there is an optimal condition of CH4 dissolution for reducing the viscosity. The shift factor of CH4 concentration is defined as the ratio of the viscosity of crude oil under saturation pressure of CH4 and static pressure, and the results agree with the F-K model. A new model of the combined shift factor was developed with average deviations of the predicted shift factors for Shengli crude oil and Nanyang crude oil being 3.35% and 2.16%, respectively. Finally, the predicted and tested values are basically in agreement. [ABSTRACT FROM AUTHOR]

Epoxy post-insulator is one of the key parts in SF6 gas-insulated DC wall bushing, which is irreplaceable in high voltage direct current transmission projects. Flashovers occur on post-insulators frequently, where a great number of tiny metal particles exist. The micron metal particles attached to the epoxy will change the insulation state of the surface. However, this relation between microstructure of material and macroscopic electrical properties on flashover would still arouse controversy. In order to study the effect of particles on the flashover characteristics, the particles generated from wear of spring in DC wall bushing were selected, the surface potential decay along surface and the DC flashover voltage of epoxy attached with particles were measured. The results show that the discrete particles could increase surface trap level by 0.025 eV under the effect of Van der Waals force. Furthermore, the deeper traps could capture the charge during the streamer development and inhibit the flashover, when the particle amount less than 500 per mm2. If the particles are more enough to form the continuous paths, these conductive paths could promote the streamer to propagate, which shortens the insulation distance, increases the electric field, and decreases the flashover voltage by 50% finally. [ABSTRACT FROM AUTHOR]

The charge accumulation phenomenon at the gas–solid interface under the co-action of DC electric field and temperature gradient is of great significance, but its long-time evolution characteristics are still unclear. In this work, the accumulation and dissipation characteristics of the surface charge on the epoxy-SF6 interface within 216 h were obtained, indicating that, (a) the normal surface electric field is increased by the temperature gradient along the gas–solid interface, which results in a prominent increase in the surface charge density; (b) there are different evolution processes of surface charge in high and low temperature regions under the co-action of DC-temperature gradient, and the increase of the charge trap density caused by the degradation of solid material is considered to be an important reason for the charge evolution; (c) the total charge dissipation ratio within 600 s decreases with the increase of charging time in DC electric field, and the surface charge dissipates mainly to the gas side of the interface; (d) the large amount of charge accumulated at the interface distorts the surface electric field at the triple junction points. The total electric field strength at the low-temperature tri-junction point increases by 35.5%, while the direction of the tangential field at the high-temperature tri-junction point reverses during the long-time co-action of the DC-temperature gradient. The results of this work may be helpful to understand the long-time charge evolution characteristics of the gas–solid interface under the DC-temperature gradient and to reveal the failure mechanism of the gas–solid interface. [ABSTRACT FROM AUTHOR]

The charge accumulation phenomenon at the gas–solid interface under the co-action of DC electric field and temperature gradient is of great significance, but its long-time evolution characteristics are still unclear. In this work, the accumulation and dissipation characteristics of the surface charge on the epoxy-SF6 interface within 216 h were obtained, indicating that, (a) the normal surface electric field is increased by the temperature gradient along the gas–solid interface, which results in a prominent increase in the surface charge density; (b) there are different evolution processes of surface charge in high and low temperature regions under the co-action of DC-temperature gradient, and the increase of the charge trap density caused by the degradation of solid material is considered to be an important reason for the charge evolution; (c) the total charge dissipation ratio within 600 s decreases with the increase of charging time in DC electric field, and the surface charge dissipates mainly to the gas side of the interface; (d) the large amount of charge accumulated at the interface distorts the surface electric field at the triple junction points. The total electric field strength at the low-temperature tri-junction point increases by 35.5%, while the direction of the tangential field at the high-temperature tri-junction point reverses during the long-time co-action of the DC-temperature gradient. The results of this work may be helpful to understand the long-time charge evolution characteristics of the gas–solid interface under the DC-temperature gradient and to reveal the failure mechanism of the gas–solid interface. [ABSTRACT FROM AUTHOR]

Epoxy post-insulator is one of the key parts in SF6 gas-insulated DC wall bushing, which is irreplaceable in high voltage direct current transmission projects. Flashovers occur on post-insulators frequently, where a great number of tiny metal particles exist. The micron metal particles attached to the epoxy will change the insulation state of the surface. However, this relation between microstructure of material and macroscopic electrical properties on flashover would still arouse controversy. In order to study the effect of particles on the flashover characteristics, the particles generated from wear of spring in DC wall bushing were selected, the surface potential decay along surface and the DC flashover voltage of epoxy attached with particles were measured. The results show that the discrete particles could increase surface trap level by 0.025 eV under the effect of Van der Waals force. Furthermore, the deeper traps could capture the charge during the streamer development and inhibit the flashover, when the particle amount less than 500 per mm2. If the particles are more enough to form the continuous paths, these conductive paths could promote the streamer to propagate, which shortens the insulation distance, increases the electric field, and decreases the flashover voltage by 50% finally. [ABSTRACT FROM AUTHOR]

Deciphering the genetic basis underlying agronomic traits is of importance for soybean improvement. However, covariation, modulated by genetic correlations between complicated traits via hub QTLs, commonly affects the efficiency and accuracy of soybean improvement. The goals of soybean improvement have nearly all focused on agronomic traits, including yield, plant type traits, and seed-related traits especially. To decipher the hub QTLs of yield, plant type, and seed, nine pertinent traits of an F2 population (181 plants) derived from a cross between KeXin No.03 and JiDou 17, which were different in multiple traits such as plant height, seed protein, and 100-seed weight, were investigated with a high-density genetic map covering 2708.63 cM. A highly significant negative phenotypic correlation (−0.95) was found between seed protein (Pro) and seed oil (Oil). A total of 35 final QTLs after combining the ones closely linked physically were identified for eight traits explaining from 0.10% to 24.63% of the phenotypic variance explained (PVE) using composite interval mapping (CIM) and inclusive composite interval mapping (ICIM) procedures, and 13 QTLs were novel genes. A genomic region on chromosome 14 (qPro14, qOil14.2, and qSw14) was associated with three seed-related traits based on the relationship within and among the three trait modules. In addition, four genomic regions were detected as hub QTLs which linked to the seed-related module and plant-type model, including the E loci (E1 and E2). From the QTL results, 31 candidate genes were annotated, including the verified genes E1, E2, and QNE1, and they were grouped into three categories of biological processes. These results illustrate the genetic architecture as correlations among various soybean traits, and the hub QTLs should provide insights into the genetic improvement of complex traits in soybean. [ABSTRACT FROM AUTHOR]

The micron metal particles are inevitably produced in long-term operation condition of high voltage direct current SF6 insulated apparatus, which could frequently cause the surface discharge. Degradation of long-term surface discharge will be a severe threat to the insulation strength. Aiming at this problem, the surface charge accumulation and flashover voltage of epoxy itself before and after discharge degradation by particles were compared in this paper. The composition after degradation was measured by EDS and FTIR. The microstructure was observed by SEM. The roughness was measured as well. The trap distribution was measured by SPD. The mechanism of degradation and its effect on insulation characteristics were analyzed. The results show that the surface charge accumulation increase three times after degradation. Additionally, flashover voltage decreases 19% after degradation. The smoothly surface after degradation decrease the trap energy level for 14%, which might be the change reason of surface charge accumulation and flashover voltage. This paper can offer as a reference for the effect of micron metal particles on insulation degradation in SF6 gas insulated equipment. [ABSTRACT FROM AUTHOR]

DC wall bushing is one of the key equipment in high-voltage direct current (HVDC) transmission project. At present, post insulators based on epoxy composites are widely used for supporting insulation in SF6-insulated apparatus. However, the flashover faults caused by surface charge accumulation can be a severe threat to the long-term operation of the post insulators under dc field. Therefore, the issue of charge accumulation on epoxy post insulators in HVDC wall bushing and its effect on flashover has been widely concerned. Aiming at this problem, the flashover characteristics of epoxy samples in SF6 gas under polarity reversal conditions with dc voltage prestressed for 10–600 min were measured in this article. The flashover process is analyzed through surface charge distribution measurement and electric field computation. The results show that with the increase of prestressed time, the accumulated negative charge density could reach $-14.8\,\,\mu \text{C}/\text{m}^{{2}}$ , which led to a 12% increase in maximum field strength. As a result, the polarity reversal flashover voltage could decrease by 12% and the flashover time delay could decrease by 84.6%. This article can offer as a reference for the effect of surface charge accumulation on flashover in SF6 gas-insulated equipment. [ABSTRACT FROM AUTHOR]

The treatment of oil and water pollutants generated in industrial production and daily life is an urgent issue that needs to be addressed globally. Inspired by superhydrophobic self-cleaning lotus leaves, durable and sturdy superhydrophobic water-filled barriers, and lightweight bird bones with hollow structures, researchers can obtain superhydrophobic surfaces by creating rough surfaces of layered micro- and nanostructures. In this study, hydrophobic polycaprolactone (PCL) membranes with layered structures were prepared by electrospinning. The surface roughness of the PCL membrane was improved by compounding graphene oxide (GO) functional components on the PCL membrane surface, thereby enhancing its hydrophobicity. The infrared spectrum of the PCL/GO membrane shows that PCL and GO are physically mixed, and no chemical changes occur during the electrospinning process. Scanning electron microscopy (SEM) images of the composite fibre membranes reveal the interconnections between fibres. Fourier transform infrared spectroscopy (FTIR) provides information on the chemical components of the membranes. Thermogravimetric analysis (TGA) was employed to assess the thermal stability of the membranes. The oil-water separation test demonstrated that the PCL/GO membrane exhibited a separation efficiency of 99.94% for hexane-water mixtures. In the oil adsorption test, the maximum adsorption capacity of the membrane for n-hexane was 35.8 g/g. In the contact angle measurement experiment, the water contact angle of the nanofiber membrane increased from 120.12° to 140.15° with increasing GO content, indicating that the composite membrane exhibited enhanced hydrophobicity. [Display omitted] • Hydrophobic polycaprolactone (PCL) membranes with layered structures prepared by electrospinning technology. • Surface roughness of PCL membrane improved by graphene oxide (GO) functional components. • The separation efficiency of PCL/GO membrane for hexane-water mixture is as high as 99.94%. • The increase of GO content improved hydrophobicity of composite membrane. [ABSTRACT FROM AUTHOR]

This paper provides a stabilizing method for preparation of quantum Gaussian states by utilizing continuous measurement. We first present a necessary and sufficient condition for the Riccati equation of the covariance matrix of the Gaussian states to have a unique stabilizing steady solution. Then general parametric conditions of how to prepare a Gaussian state with desired covariance matrix are provided. These conditions are much weaker than those required when preparing Gaussian states via dissipation-induced approach. Thus, our method provides more degrees of freedom to choose the system Hamiltonian and the system–environment coupling operators. These results may benefit practical experimental implementations in preparing quantum Gaussian states. [ABSTRACT FROM AUTHOR]

In the context of the vigorous development of the sports industry and rapid technological innovation, the wrong actions of sports athletes can also be intelligently recognized. Human action recognition based on computer pattern recognition is becoming more and more popular and ubiquitous in life. This article aims to study how to recognize the human body based on the computer model and how to apply intelligent recognition to the wrong actions of sports athletes. The study of the application of intelligent recognition to the wrong actions of sports athletes is of great significance to sports athletes. This article proposes how to intelligently recognize the wrong actions of sports athletes based on computer pattern recognition. In the experiment in this article, wrong sports actions can cause a series of undesirable consequences, such as joint sprains and muscle damage. Among them, the proportion of joint damage caused by wrong actions has reached 24% and has been rising with the increase of the number of experiments and finally reached 35%, which shows that the probability is still very high. After the pull-up adopts intelligent recognition, the error of the pull-up action can be quickly identified and corrected in time, with the correct rate reaching 78%. Therefore, in order to reduce the physical damage caused by sports athletes' wrong movements, it is necessary to study the intelligent recognition of sports athletes' wrong movements. The recognition of wrong actions of sports athletes can be carried out through intelligent recognition based on 3D convolutional neural networks, which is of great significance to intelligent recognition. [ABSTRACT FROM AUTHOR]

Accurately characterizing the conformational variation of novel molecular assemblies is important but often ignored due to limited characterization methods. Herein, we reported the use of ion-mobility mass spectrometry (IMS/MS) to investigate the conformational changes of four azobenzene covalently functionalized Keggin hybrids (azo-Keggins, compounds 1–4). The as-prepared azo-Keggins showed the general molecular formula of [C16H36N]4[SiW11O40(Si(CH2)3NH–CO(CH2)nO–C6H4N=NC6H4–R)2] (R = H, n = 0 (1); R = NO2, n = 0 (2); R = H, n = 5 (3); R = H, n = 10 (4)). The resultant azo-Keggins maintained stable monomeric states in the gas phase with intact molecular structures. Furthermore, the subtle photo-responsive trans-cis conformational variations of azo-Keggins were clearly revealed by the molecular shape-related collision cross-section value difference ranging from 2.44 Å2 to 6.91 Å2. The longer the alkyl chains linkers were, the larger the conformational variation was. Moreover, for compounds 1 and 2, higher stability in trans-conformation can be observed, while for compounds 3 and 4, bistability can be achieved for both of them. [ABSTRACT FROM AUTHOR]

This article focuses on optimizing electric vehicle charging in distribution networks, emphasizing technical and economic considerations. Unlike traditional methods, the proposed intelligent approach tailors each EV's charging based on specific daily trip energy requirements. Vehicle owners provide trip data to the charge management system, enabling precise charging calculations considering factors such as energy tariffs, distribution network limits, and charging levels. The paper introduces the horse herd optimization algorithm, inspired by horse herd behavior, offering advantages like reduced computational time and improved convergence in maximizing power generation, especially under shading conditions. The comparative analysis of smart EV charging under normal and fast conditions, considering various constraints and load response programs, demonstrates the proposed method's effectiveness. Numerical results reveal a 46.02 % average load reduction and a 20.53 % peak load decrease with a Load Response Program. Charging costs are optimized, with Case 2 exhibiting a 2.61 % cost reduction compared to Case 3. The study delves into charging frequencies, discharge frequencies, total unsupplied energy, and unloaded energy for each case, providing crucial insights into algorithmic performance. The horse herd optimization algorithm-based approach proves superior, offering a promising solution for efficient and cost-effective electric vehicle charging in distribution networks. Furthermore, graphical representations illustrate the algorithm's impact on charging power, energy allocation, power passing through distribution posts, and megavolt-ampere flow through network lines. These numerical and graphical analyses provide a comprehensive understanding of the horse herd optimization algorithm capabilities, emphasizing its potential to optimize power distribution, reduce costs, and enhance the resilience of residential distribution networks. • Prioritizes EV charging based on daily travel and battery levels using discrete charge rates. • Compares normal and fast charging rates, considering transformer overloads. • Adapts network and load model from real data, balancing subscriber and operator interests. • Assesses method's impact with and without a load response program for adaptability. • Introduces the Horse Herd Optimization Algorithm (HOA) inspired by horse herd behavior. [ABSTRACT FROM AUTHOR]

This paper proposes a duplex antenna, with four square patches to form a sequential rotating array, which can generate dual circular polarization radiation. A feeding network consisting of power dividers, phase shifters and couplers feeds the antenna with ± 90 ° phase difference and achieves dual circular polarization. A band stop filter with low reflection is employed in the receive port to increase the isolation in the transmitting band (14–14.5 GHz) to over 30 dB. The receive port achieves a gain of over 4.8 dBi and an axial ratio under 3 dB in the receiving band (10.7–12.7 GHz). The transmit port has a gain of more than 5.1 dBi and a 3 dB axial ratio in the whole frequency band (10.5–15 GHz). [ABSTRACT FROM AUTHOR]

The phenolic adhesive and casein adhesive are two kinds of adhesives used in pressboard block production. The partial discharge characteristics of pressboard block containing the two types of adhesives under AC, DC and AC/DC composite voltage are researched in this paper. Using the block samples with phenolic adhesive or casein adhesive, the partial discharge characteristics, flashover characteristics and the influence of the adhesive layer orientations were obtained. The results show that the use of adhesive may introduce a weak zone of insulation performance and reduce the insulation strength of the pressboard block. There exist polar effects on partial discharge and flashover characteristics under DC voltage, and there is no significant difference in the partial discharge characteristics and flashover voltages between the pressboard blocks with casein and phenolic adhesive. The phenomena are analyzed in terms of molecular characteristics of adhesives and cellulose pressboard. The research results of this paper provide significant theoretical and practical reference for the optimization of transformer insulation materials. [ABSTRACT FROM AUTHOR]

A reverse circulation Down-The-Hole (DTH) hammer drill bit in Casing-while-Drilling (CwD) processes is designed and applied to drilling under complicated formation. The drill bit is a special retractable drill bit with an exclusive reverse circulation gas channel. Using numerical simulations and experiments, the influence of the gas channel structure parameters of the drill bit, including the inner jet nozzles, flushing nozzles, suction channel, and other parameters, on its reverse circulation performance is analyzed, and the optimal gas channel structure parameters of the drill bit are determined to improve the reverse circulation effect. The results show that the flushing nozzles and inner jet nozzles have an important influence on entrainment performance. The entrainment rate η decreases as the flushing nozzle diameter increases and decreases as the inner jet nozzle diameter increases. An increase in the suction channel diameter can improve the reverse circulation effect of the drill bit. The spiral slot drill bit is more conducive to air being sucked into the central channel in the form of spiral flow, so it can improve the entrainment performance. The entrainment rate η can reach 23.4% with the optimum structured drill bit. [ABSTRACT FROM AUTHOR]

We mixed high-pressure supercritical carbon dioxide (scCO 2) and graphite together without any auxiliary means for exfoliation. Combined with small-angle X-ray scattering (SAXS) and other characterizations, the influence of process parameters on the quantity and quality of graphene was studied. We calculated the Hansen solubility parameters and the critical conditions for exfoliation and used the response surface method to probe the effect of process parameters on the graphene exfoliation. The mechanism for exfoliation was critically discussed. The results showed that the highest (1.625 mg/mL) concentration was obtained after mixing at 45 MPa for 48 h and centrifuging at 1000 rpm for 30min. The number of layers and lateral dimensions of graphene sheets could be controlled by adjusting process parameters. Up to 75% of the produced graphene after mixing at 45 MPa for 48 h was about 3-6layers, and 90% of the lateral dimensions were less than 1.4 μm. The kinetic energy generated by the flowing CO 2 was the main reason for exfoliation. The critical speed of exfoliation at 50 °C and 45 MPa was about 2.851–2.981 m/s. This method had no complicated operation steps, the obtained graphene surface was not oxidized, no solvent remained, and few-layer graphene did not need further purification. [Display omitted] [ABSTRACT FROM AUTHOR]

Keggin clusters are the most widely used polyoxometalate building blocks for the construction advanced materials, but effective methods for precisely recognizing the isostructural analogues of Keggins are still limited. In this study we employed the zwitterionic molecule 4,4′‐dipyridyl N,N′‐dioxide as a recognition receptor to specifically bind to the three Keggin analogues PW12O403−, PMo12O403−, and SiW12O404−, which separately co‐assembled into three different types of spherical charged colloids of different sizes. The recognition phenomena were confirmed by electrochemical methods and their crystallization behavior. Compared with solely anion–cation interaction‐driven systems, the synergism with the anion–π interactions between the superchaotropic Keggins and the electron‐deficient pyridine rings is believed to enhance the recognition. This observation is intriguing as the long‐range solution assembly of Keggins is mainly driven by short‐range anion–π interactions. Our results show that the little‐noticed hydration shell of Keggins is significantly influenced by the superchaotropic effect, leading to differentiated binding affinity to the receptors and more obvious recognition phenomena between tungsten/molybdenum Keggin analogues. [ABSTRACT FROM AUTHOR]

Polyoxometalate-intercalated layered double hydroxide (POM–LDH) nanocomposites have received considerable attention in recent years because such nanocomposites not only inherit the intrinsic properties of POMs and LDHs but also exert significant synergistic effects during the catalytic process. In this frontier article, we present the latest advances on the POM–LDH nanocomposites ranging from new synthetic methods to catalytic applications. By making use of the host layer modification method and exfoliation assembly method, the as-prepared POM–LDH nanocomposites show a wide range of catalytic applications. The challenges and future opportunities are also discussed by highlighting some creative work on related POM- or LDH-based materials. [ABSTRACT FROM AUTHOR]

Objective: To explore the mechanisms of crocin against glycocalyx damage and inflammatory injury in lipopolysaccharide (LPS)-induced acute respiratory distress syndrome (ARDS) mice and LPS-stimulated human umbilical vein endothelial cells (HUVECs). Methods: Mice were randomly divided into control, LPS, and crocin + LPS (15, 30, and 60 mg/kg) groups. HUVECs were separated into eight groups: control, crocin, matrix metalloproteinase 9 inhibitor (MMP-9 inhib), cathepsin L inhibitor (CTL inhib), LPS, MMP-9 inhib + LPS, CTL inhib + LPS, and crocin + LPS. The potential cytotoxic effect of crocin on HUVECs was mainly evaluated through methylthiazolyldiphenyl-tetrazolium bromide assay. Histological changes were assessed via hemotoxylin and eosin staining. Lung capillary permeability was detected on the basis of wet–dry ratio and through fluorescein isothiocyanate-albumin assay. Then, protein levels were detected through Western blot analysis, immunohistochemical staining, and immunofluorescence. Results: This study showed that crocin can improve the pulmonary vascular permeability in mice with LPS-induced ARDS and inhibit the inflammatory signaling pathways of high mobility group box, nuclear factor κB, and mitogen-activated protein kinase in vivo and in vitro. Crocin also protected against the degradation of endothelial glycocalyx heparan sulfate and syndecan-4 by inhibiting the expressions of CTL, heparanase, and MMP-9 in vivo and in vitro. Overall, this study revealed the protective effects of crocin on LPS-induced ARDS and elaborated their underlying mechanism. Conclusion: Crocin alleviated LPS-induced ARDS by protecting against glycocalyx damage and suppressing inflammatory signaling pathways. [ABSTRACT FROM AUTHOR]

Previous studies have shown that personality types may lead to different health status. The current study aims to refine a previous typological profile of strength using a heterogeneous sample (N = 5776) and clarify further the associations between strength profiles and mental wellbeing (e.g., flourishing), mental illbeing (e.g., depression, anxiety, and stress), strength knowledge, and strength use. Latent profile analysis was implemented to distinguish subgroups on the basis of the three-dimensional inventory of character strengths (e.g., self-control, inquisitiveness, and caring). Results refined previous findings and indicated three specific profiles, namely, Strength, Common, and Risk Groups. The Strength Group scored relatively high on self-control and inquisitiveness but low on caring; the Common Group scored relatively high on caring; and the Risk Group had relatively high scores on self-control. As expected, the Strength Group had the highest strength knowledge and strength use, whereas the Risk Group had the least strength knowledge and strength use. The three proposed profiles have significant differences of anxiety, stress, and flourishing; however, the difference of depression between the Strength and Risk Groups was insignificant compared with the Common Group. This study can be helpful in refining strength typologies for future effective strength-based interventions. [ABSTRACT FROM AUTHOR]

The emergence of resource conflicts and overload control problems during the playback of smart TV terminals has brought many obstacles to the operation of smart TV terminals, which has seriously affected the user experience of smart TV terminal users. In this regard, the adaptive media playback algorithm is optimized for smart TV terminals. This method performs dynamic priority preemptive scheduling on exclusive resources according to resource characteristics and application priorities to optimize resource allocation and improve media playback. The feedback control algorithm is used to perform QoS scheduling on shared resources until QoS proportional fairness is achieved, and QoS proportional compression is used to eliminate resource overload. Finally, a DASH server on Apache and implements an analog DASH client using Python are built. In order to verify the performance of the algorithm, the research results show that the adaptive media playback algorithm has the overload control capability, which only solves the resource conflict and improves the response performance under heavy load of the system, and the algorithm consumes only 4.5% of the overall system QoS. Compared with the existing methods, it is about 30% lower, which is more suitable for resource scheduling of smart TV terminals. The research in this paper shows that the adoption of QoS scheduling mechanism contributes to the optimization of media playback resources and allocation ratio, thus making the playback process of smart TV terminals, which provides a reference for the optimization of smart TV terminal playback. [ABSTRACT FROM AUTHOR]

A high-density electrical pressboard plays a significant role in maintaining the safe and stable operation of power equipment. In response to concerns about finding an evaluation method based on the dielectric performance of the pressboard, this study set up a measurement platform to capture data for three key dielectric properties, namely, relative permittivity, volume resistivity, and surface resistivity. Five kinds of pressboards obtained from representative insulating materials manufacturers were chosen as test samples, and the effects of temperature and moisture content of the pressboards on their dielectric properties were quantitatively investigated. The results indicated that (1) with increasing temperature and moisture content of the pressboards, there was an increase in the relative permittivity, with a maximum increase of 55.85%; (2) the higher the temperature and moisture content of the pressboards, the lower the volume and surface resistivity, and the maximum reduction was as much as 98.25%; (3) significant differences exist in the dielectric properties of different batches of pressboards from the same manufacturer; and (4) the results of tests of conventional physical and chemical properties of pressboards could help explain the differences in dielectric properties between different types of pressboards. Finally, based on the variation in dielectric properties for different test conditions, a method for evaluating the performance of pressboards is proposed. Using this method, the dielectric properties of different insulating pressboard products can be compared horizontally, which will provide data support and technical reference for the design of insulation structures and the selection of insulating materials for different applications. [ABSTRACT FROM AUTHOR]

The design of the oil–pressboard/paper insulation structure is the key to maintain the safe and reliable operation of power transformers, which mainly relies on simulation and verification test undertaken with simple or equivalent models, falling short of the physical entity verification undertaken in the large-scale structure. Based on the Kerr electro-optic effect and the optical fiber technology, a novel electric field measuring sensor was developed in this paper for the application test in the large-scale oil–pressboard structure. The sensor is contained of collimator, total reflection prism, coupler, and customized optical elements, whose appearance is a miniature capsule-shaped configuration. The key technical performance parameters of sensor were obtained, for instance, and the effect of imported sensor on the electric field under measurement is an average 1.17% reduction in intensity; the sensitivity of designed system is 162.84 V/mm under ac voltage and 40.43 V/mm under dc voltage. Under dc voltage, the measuring accuracy of the designed system is greater than 97.42%, while in the context of ac voltage, it could reach 97.14%. The application test was conducted to capture the dynamic process of the electric field in oil in the large-scale outlet device model, which has three uniformly spaced oil spacings divided by pressboards, under ac voltage, dc voltage, and polarity reversal voltage. The experimental results verify that the developed electric field sensor could be effectively and reliably applied in the large-scale oil–pressboard insulation, and it could be confidently inferred that the larger the scale of insulation structure, the better is the performance of sensor. [ABSTRACT FROM AUTHOR]

This paper proposes a duplex dual circularly polarized antenna, using four half-Vivaldi antennas to form a sequential rotation array, which can generate circular polarization by sequential feeding. A mental cavity and half of a Vivaldi antenna form a new Vivaldi antenna. The Vivaldi antenna has broadband characteristics to cover the uplink and downlink bands and is compact with an area of 0. 69 λ c × 0. 69 λ c . To achieve duplex dual circular polarization, a feeding network that can sequentially output + 90 ° and − 90 ° is designed. The feeding network, which contains two broadband power dividers, two directional couplers and two phase-shifters, generates the sequential feeding signals for sequential rotation group array with equal amplitude and ± 90 ° phase difference. Both the impedance bandwidth and the 3 dB axial ratio bandwidth of the transmitter and receiver can cover the band of 10–15 GHz. The gain of the antenna is higher than 5.75 dBi. The isolation between the receive and the transmit ports can reach 25.49 dB or higher in the uplink band. [ABSTRACT FROM AUTHOR]

Highlights • All the measurement were conducted on an actual well-built GIS/GIL platform. • Quantitative influence of surface charge on the flashover voltage are put forward. • Impacting mechanism of surface charges on flashover voltage is proposed. • The conclusion could provide guidance for the insulation design and fault diagnosis. Abstract Under AC, DC and switching impulse voltages, the surface charges accumulated on the basin insulators of Gas Insulated Substation (GIS) or Gas Insulated Metal Enclosed Transmission Line (GIL) could distort local electric field and even reduce the surface flashover voltage. In order to quantitatively measure the influence of surface charge accumulation on flashover voltage of insulator in actual GIS/GIL apparatus, a high-precision 3D surface charge measurement platform and a reasonable model were established for flashover tests in reference to the insulation design and flashover properties of actual 220 kV GIS basin insulator. The surface charge accumulation dynamics and corresponding flashover voltages of the built models under different conditions were captured and analyzed. The results indicate that, as the density of accumulated surface charges increases under either AC, DC or switching impulse voltage application, the surface flashover voltage would decrease from 62.1 kV to 55.7 kV, namely a margin of 10.3% under AC voltage application. In the context of DC voltage, there appears a 22.8% flashover voltage drop, from 61.0 kV to 47.1 kV. While for the case of switching impulse voltage, the charge accumulation reduced the flashover voltage to 52.9 kV with a 13.6% decline from 61.2 kV. Based on the simulation and theoretical calculations, the 'enhanced electric field zone' was identified to justify the influencing mechanism of surface charges on flashover voltage. The research results could contribute to optimal insulation design and fault diagnosis of basin insulator in GIS/GIL. [ABSTRACT FROM AUTHOR]

The polarity reversal test is one of the routine tests for the evaluation of electric insulation in converter transformers. The polarity reversal time (PRT) has significant effect on the accumulation of interface charges in oil-impregnated pressboard insulation. IEC standard recommends that polarity reversal should be performed within 2 min so as to match with the dispersion rate of interface charges in uniform filed, but not necessarily in the non-uniform field. In order to investigate the influence of PRT on the dissipation rate of interface charges in non-uniform electric field, the density of interface charges was measured by an electrostatic capacitance probe in the needle-plate non-uniform field at the PRT of 2 ms, 4 ms and 2 min respectively. The results showed that the polarity of interface charges did not change with the applied voltage jump at the PRT of 2 ms and 4 ms, while the polarity of interface charges almost synchronously changed with the polarity reversal of applied voltage at the PRT of 2 min. For the PRT of 2 ms and 4 ms, the electric field nearby the needle electrode would be enhanced with applied electric field of the same direction, whilst the total electric field of insulation system would be weakened at the PRT of 2 min. It was inferred that polarity of interface charge might have not enough time to change in polarity reversal test within the PRT of 4 ms under non-uniform electric field, which was more close to the severe condition of covert transformer. The paper suggest that the value of PRT be reconsidered when the polarity reversal test is performed in non-uniform electric field. [ABSTRACT FROM AUTHOR]

In the development and production process of domestic and foreign oil fields, large amounts of oil-bearing wastewater with complex compositions containing toxic and harmful pollutants are generated. These oil-bearing wastewaters will cause serious environmental pollution if they are not effectively treated before discharge. Among these wastewaters, the oily sewage produced in the process of oilfield exploitation has the largest content of oil-water emulsion. In order to solve the problem of oil-water separation of oily sewage, the paper summarizes the research of many scholars in many aspects, such as the use of physical and chemical methods such as air flotation and flocculation, or the use of mechanical methods such as centrifuges and oil booms for sewage treatment. Comprehensive analysis shows that among these oil-water separation methods, membrane separation technology has higher separation efficiency in the separation of general oil-water emulsions than other methods and also exhibits a better separation effect for stable emulsions, which has a broader application prospect for future developments. To present the characteristics of different types of membranes more intuitively, this paper describes the applicable conditions and characteristics of various types of membranes in detail, summarizes the shortcomings of existing membrane separation technologies, and offers prospects for future research directions. [Display omitted] • Summarize the research of use of physical and chemical methods, or mechanical methods for sewage treatment. • Describes the applicable conditions and characteristics of various types of membranes. • Provide new insight on material design for membrane separation technologies. [ABSTRACT FROM AUTHOR]

The Anderson localization phase transition in the Aubry-André-Harper (AAH) model with p-wave superconducting (SC) pairing is numerically investigated by suddenly changing the on-site potential from zero to various finite values which fall into the extended, critical and localized phase regimes shown in this model. The time evolution of entanglement entropy (EE), mean width of wave packets and Loschmidt echo of the system exhibit distinct but consistent dynamical signatures in those three phases. Specifically, the EE grows as a power function of time with the exponent of which varies in the extended phase but keeps almost unchanged in the critical phase for different quench parameters. However, if the system is in the localized phase after a quench, the EE grows much slower and will soon get saturated. The time-dependent width of wave packets in the system shows similar behaviors as the EE. In addition, from the perspective of the dynamical phase transition, we find that the Loschmidt echo oscillates and always keeps finite when the system is quenched in the extended phase. In contrast, in the critical or localized phase, the echo will reach to zero at some time intervals or will decay almost to zero after a long-time evolution. The universal features of these quantities in the critical phase of the system with various SC pairing amplitudes are also observed. [ABSTRACT FROM AUTHOR]

The objective of the current study was to investigate the effect of dietary β-alanine supplementation on growth performance, meat quality, antioxidant ability, carnosine content, and gene expression of carnosine-related enzymes in broiler chicks. We randomly assigned 540 1-day-old Arbor Acres broilers to 5 dietary treatments supplemented with 0 (control group), 250, 500, 1,000, or 2,000 mg/kg of β-alanine (mg β-alanine per kg feed). Each treatment included 6 replicates of 18 birds. The feeding trial lasted for 42 d. Dietary β-alanine supplementation linearly and quadratically increased the average daily gain (ADG) during the starting period (d 1 to 21, P = 0.02 and P = 0.002). The feed conversion ratio (FCR) decreased quadratically in response to dietary β-alanine supplementation during the starting and entire periods (P < 0.001 and P = 0.003, respectively). For the entire period, the predicted best FCR would be achieved when β-alanine was fed at a level of 1,100 mg/kg from quadratic regression. The concentrations of carnosine and β-alanine in breast muscle increased quadratically with dietary β-alanine supplementation (d 42, P < 0.001 and P = 0.001, respectively). The predicted dietary β-alanine level for highest breast carnosine content was 1,196 mg/kg. Dietary supplementation with β-alanine reduced the taurine concentrations in plasma (d 42, linear and quadratic, P < 0.001). Breast muscle yield increased linearly and quadratically in response to dietary β-alanine addition (d 21, P = 0.017 and P = 0.007). Dietary supplementation with β-alanine quadratically reduced the shear force (P = 0.003), whereas a*45 min and a*24 h values increased quadratically in response to dietary β-alanine supplementation (d 42, P = 0.020 and P = 0.021, respectively). Dietary β-alanine addition quadratically enhanced the expression of carnosine synthase and taurine transporter mRNAs (P < 0.05). Overall, dietary β-alanine supplementation improved growth performance and carnosine content, ameliorated antioxidant capacity and meat quality, and upregulated the gene expression of carnosine synthesis-related enzymes in broiler chicks. [ABSTRACT FROM AUTHOR]

The Gas Insulated Switchgear (GIS) equipment observes surface charge accumulation under DC or AC voltage in real operation, which could distort the electric field and incur flashover eventually. With a 3D high-resolution surface charge measurement system established on actual 220 kV GIS basin insulator, the present research captured the surface charge distribution characteristics of the insulator under DC and AC voltage through high-precision probe scanning on the insulator surface. The test results show that: 1) Surface charge demonstrates obvious polarity effect under DC voltage. Under positive DC voltage, there accumulated mainly positive surface charges. Under negative DC voltage, the polarity of accumulated surface charges is all negative. Regardless of charge polarities, the surface charge density increases as the voltage amplitudes mounts and the voltage application duration prolongs. 2) Surface charge accumulation also takes place under AC voltage application. All charges are negative and distribute in a uniformed manner but in smaller density comparing to the DC scenario. As the voltage amplitudes increase, the surface charge density first increases, then decreases and finally reaches a near saturation state. As voltage application goes on, the surface charge accumulation becomes more obvious. Above all, the insulation issues in relation to surface charge accumulation require due attention in the application and maintenance of GIS equipment, and the present research attempts to provide useful reference for the optimal design of GIS/GIL insulators. [ABSTRACT FROM PUBLISHER]

Carbonate weathering and the CO 2 consumption in karstic area are extensive affected by anthropogenic activities, especially sulfuric and nitric acids usage in the upper-middle reaches of Wujiang River, China. The carbonic acid would be substituted by protons from sulfuric and nitric acids which can be reduce CO 2 absorption. Therefore, The goal of this study was to highlight the impacts of sulfuric and nitric acids on carbonate dissolution and the associated deficit of CO 2 uptaking during carbonate weathering. The hydrochemistries and carbon isotopic signatures of dissolved inorganic carbon from groundwater were measured during the rainy season (July; 41 samples) and post-rainy season (October; 26 samples). Our results show that Ca 2 + and Mg 2 + were the dominant cations (55.87–98.52%), and HCO 3 – was the dominant anion (63.63–92.87%). The combined concentrations of Ca 2 + and Mg 2 + commonly exceeded the equivalent concentration of HCO 3 − , with calculated [Ca 2 + + Mg 2 + ]/[HCO 3 − ] equivalent ratios of 1.09–2.12. The mean measured groundwater δ 13 C DIC value (− 11.38‰) was higher than that expected for carbonate dissolution mediated solely by carbonic acid (− 11.5‰), and the strong positive correlation of these values with [SO 4 2 − + NO 3 − ]/HCO 3 – showed that additional SO 4 2 − and NO 3 − were required to compensate for this cation excess. Nitric and sulfuric acids are, therefore, suggested to have acted as the additional proton-promoted weathering agents of carbonate in the region, alongside carbonic acid. The mean contribution of atmospheric/pedospheric CO 2 to the total aquatic HCO 3 – decreased by 15.67% (rainy season) and 14.17% (post-rainy season) due to the contributions made by these acids. The annual mean deficit of soil CO 2 uptake by carbonate weathering across the study area was 14.92%, which suggests that previous workers may have overestimated the absorption of CO 2 by carbonate weathering in other karstic areas worldwide. [ABSTRACT FROM AUTHOR]

BACKGROUND: Oxidation has been reported as the one of the deterioration reactions of proteins in aquatic products. Searching for new bioactive substances from marine algae has been one of the main areas in food science and additives. RESULTS: In this study, a novel protein from the red alga Porphyra haitanensis was determined after ammonium sulfate precipitation and gel filtration chromatography. It closely corresponded to the antioxidant activity and was identified as an uncharacterized protein with a molecular mass of 43 kDa, designated Ph43. Bioinformatic analysis revealed that Ph43 is a novel protein of non‐phycobiliprotein family with putative chordin domains and rich in α‐helical conformation. Recombinant protein (rPh43) was expressed in Escherichia coli as a Hig‐tagged protein using a pET‐22b vector system and purified by affinity high‐performance liquid chromatography. Spectroscopy analysis revealed that there were no structural differences between rPh43 and natural recovered Ph43. Moreover, rPh43 showed equal/higher antioxidant activity compared with Ph43. rPh43 has the potential for application as a natural antioxidant for food stabilization. CONCLUSION: Our results identified a novel antioxidant protein with molecular mass of 43 kDa derived from Porphyra haitanensis that belongs to the non‐phycobiliprotein family. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The electric field distribution of the oil-pressboard structure under impulse voltage provides vital reference for the design of transformer insulation. The electric field distribution under impulse voltage is usually held equivalent to that of the capacitive field and calculated by simulation software. An appropriate margin to the calculation results is then selected according to the allowable strength. The design value identified in such a manner, however, falls short of support and verification of actual measurement. The present paper proposes a non-contact real-time measuring method to explore the electric field distribution of the oil-pressboard structure under impulse voltage, using a created measuring apparatus that is composed of optical system, photoelectric converter device, sealed cavity, and impulse voltage generator. Calibrated and verified by a pair of plate electrodes which generated uniform electric field along the propagating direction of the laser beam, the measured values proved to tally well with the actual values of the electric field in terms of both variation trend and numerical value. The minimum sensitivity of the established measuring apparatus was recorded as 3.5 kV/mm and the maximum deviation was 3.6%. [ABSTRACT FROM PUBLISHER]

A Central Business District (CBD) is a relatively independent urban system integrating office, entertainment, public facilities, and residential buildings into one. It should be planned and constructed under the guidance of green ecological idea. Taking the green planning practice of a CBD in Xi’an, a western city of China for example, this study conducts a general layout analysis on the green planning of the CBD, carries out researches by dint of building and environment simulation software such as CFD, and gives the future construction and development blueprint of CBD and formulates the contents of efficient planning based on six aspects. Besides, the outdoor wind environment of CBD is simulated with the CFD analytical method to analyze how comfort the outdoor activity is and how good the building ventilation is. The outdoor environment is also designed in an optimized way, providing scientific basis for the more in-depth and detailed planning. [ABSTRACT FROM PUBLISHER]

• H 2 improves survival, visual and spatial learning, and memory in septic mice. • H 2 improves dendritic spine density and hippocampal normal neuron number. • H 2 protects cognition may be related to the inhibition of tau phosphorylation by inhibiting TTBK1. Sepsis-associated encephalopathy (SAE) is a cognitive dysfunction caused by sepsis. Hyperphosphorylated tau is considered to play a significant role in the progression of neurodegenerative disease and also contributes to cognitive dysfunction in septic mice. Molecular hydrogen (H 2) plays an antioxidant and anti-inflammatory role, and plays a protective role in septic mice. This study explored the possible effects of H 2 on cognition and tau phosphorylation in a mouse model of SAE. The model of sepsis was established in C57BL/6J male mice by cecal ligation and puncture surgery. Mice treated with 2 % H 2 inhalation for 60 min at 1 h and 6 h after surgery, respectively. HY-15769, the inhibitor of Tau Tubulin Kinase 1 (TTBK1), was injected 1 h before the surgery. The 7-day survival rates of the mice were recorded. Cognitive behavior was tested with both novel object recognition and the Y-maze novelty arm recognition on day 7 after surgery. Hematoxylin-eosin staining was used to observe the histological damage in CA1 region of hippocampus. The expression of inflammatory factors in hippocampus was assessed by Elisa. Western blotting was adopted to determine the tau phosphorylation levels at AT8 epitopes (pSer202 and pThr205) and T22 epitopes (neurofibrillary tangle protein oligomer), and the GSK3β phosphorylation levels (Tyr216), as well as p-Ser422 and TTBK1 levels in the hippocampus. The number of dendritic spine and mushroom type of dendritic spines in the hippocampus were assessed by Golgi staining. The survival rate, visual and spatial learning ability, and memory ability were improved in septic mice treated with H 2. After H 2 treatment, the density of dendritic spine, mushroom type of dendritic spine, and the number of normal hippocampal neurons were progressively elevated. H 2 decreased the levels of phosphorylated tau protein, tau oligomer and TTBK1, as well as the phosphorylation of tau key kinase. Furthermore, the injection of HY-15769 (a TTBK1 inhibitor) protected SAE through the similar way. The protective effect of H 2 on cognitive dysfunction induced by SAE may be achieved by inhibiting tau phosphorylation, which is perhaps related with the inhibition of TTBK1. [ABSTRACT FROM AUTHOR]

The Resistive-Capacitive (RC) model has been widely adopted for analysis of the electric field in oil-pressboard insulation under DC voltage. However, studies in this regard have indicated that the charge polarity effect in oil-pressboard insulation, namely the stronger adsorption of negative charges by pressboard, could not be adequately captured by the RC model. In order to analyze the electric field with due consideration of charge polarity effect, the present paper adopted the Kerr electro-optic techniques to have measured the electric field in the oil spacing under DC voltage for two experiments models with Model I having two oil spacing divided by a pressboard at the spacing ratio of 1:1, and the Model II at the spacing ratio of 1:2. As Model I is concerned, the strength of electric field in the upper oil spacing reached 1.61 times of the initial one under positive voltage and 1.60 times under negative voltage, while the field in the lower oil spacing registered as one eighth of the initial one under both positive and negative voltages. For Model II, the electric field strength in the upper oil spacing reached 2.3 times of the initial field under positive voltage and one fourth of that under negative voltage, showing much stronger charge polarity effect compared to that in Model I. In order to analyze the effect of interface charge on electric field, an electric field analysis model based on interface charge, named Interface Charge Polarity Effect (ICPE) Model, is proposed in this paper. Referring to the different adhesive abilities of positive and negative charges on pressboard, the influence of interface charge on electric field can be analyzed by the proposed model, which could make the contribution to the insulating design and proofread for the converter transformer. [ABSTRACT FROM PUBLISHER]

Converter transformers use oil-pressboard as their main dielectric medium and are operated mainly in AC-DC combined electric field. For oil-pressboard insulation, the electric field under DC voltage shows distinctive characteristics from that in AC electric field. Compared to conventional AC power transformers, the electric filed distribution in the converter transformers is much more complicated and remains a big challenge for optimization of insulation design. Existing simulation research in this field falls short of experimental verification and shows limitations in the insulation design of the converter transformers. This paper attempts to fill the gap by measuring the dynamic process and distribution of electric filed in oil-pressboard insulation under the combined field so as to provide reference for insulation design. With the established Kerr-effect electric field measurement platform, the present paper recorded the dynamic process and distribution of AC and DC electric fields at different AC/DC ratios for the double-layer overlapping oil-pressboard insulation model. The research results indicate that 1) the AC electric field distribution in oil is homogeneous and symmetric. The field strengths form linear relation with the amplitudes of applied voltages; 2) the DC electric field distribution in oil is heterogeneous and asymmetric. Under the application of positive DC voltage, the field strength around the upper electrode is much smaller than that of the lower one. The DC electric field strength shows no linear growth with the increase of the applied voltages; 3) the accumulation of interface charges forms the major cause resulting in the asymmetric distribution of the DC electric field at different positions of the insulation. The research results imply that although RC model is recognized as effective simulation method for insulation design of conventional transformers, it shows its limitations and should be enriched and adjusted according to the electric field distribution under AC-DC combined voltage and taking into full consideration of the accumulation of interface charges. [ABSTRACT FROM PUBLISHER]

In free space optical (FSO) communication, atmospheric turbulence will introduce aberration to the laser wavefront, which will reduce the coupling efficiency of space light to optical fiber. The system based on blind optimization principle can realize wavefront aberration compensation by using actuators such as fast steering mirror (FSM) and deformable mirror (DM), combined with blind optimization control algorithms. Stochastic parallel gradient descent (SPGD) algorithm is widely used in this kind of system. The disadvantages of SPGD algorithm are possibly local convergence and slow convergence. In order to improve the convergence performance of the SPGD algorithm, we proposed improved SPGD algorithms called Adagrad & Staged SPGD algorithm (AS-SPGD). Specifically, to accelerate SPGD algorithm, the Adagrad SPGD algorithm (A-SPGD) integrated Adagrad's adaptive gain strategy is proposed firstly in wavefront tip–tilt aberration compensation using FSM. Then, we consider compensating the wavefront high-order aberration using DM. By adopting the strategy of using SPGD algorithm with different settings in different stages, the Staged SPGD algorithm (S-SPGD) is proposed to improve the local convergence of the traditional SPGD algorithm. The simulation results show that the Adagrad SPGD algorithm converges faster than the traditional SPGD algorithm in the compensation of tip–tilt aberrations of different amplitude; the Staged SPGD algorithm has better global convergence ability than the traditional SPGD algorithm in high-order aberration compensation. • The blind optimization control is used to realize wavefront aberration compensation. • The Adagrad SPGD algorithm is proposed to improve the convergence speed. • The Staged SPGD algorithm is proposed to improve the local convergence. • Simulation results verify the modified SPGD methods have better performance. [ABSTRACT FROM AUTHOR]

The degradation of insulation would be accelerated by the partial discharge (PD) incurred by an internal air-gap defect in oil-pressboard insulation. At different bridge rectifier locations in the converter transformer, the oil-pressboard insulation typically endures various ratios of combined ac and positive dc voltages. Therefore, the dielectric status of the converter transformer is closely correlated to the ratios of ac to dc voltages. It is practically significant to conduct the study of the correlation between discharge characteristics and ac-dc ratios. At the same time, it enhances the diagnosis of faults in converter transformers. According to the actual internal operation conditions of converter transformers, the study established a test platform. Furthermore, the conventional pulse current method was adopted to compare the discharge characteristics at the initiation and close-to-breakdown stages. Under these ratios, test results display distinctive PD dynamics. The PD of the air gap generates surface charges. These charges, in turn, establish an inverse electric field. As a result, the proportion of dc in the ac-dc combined voltage increases, and total initial voltage and total breakdown voltage increase continuously, but the recurrence rate of discharge pulse and discharge magnitude decrease at the initiation and close-to-breakdown stages. As the positive dc proportion increases, the discharge recurrence rate in the negative half cycle gradually exceeds that in the positive one. These research findings provide useful criteria for the fault diagnosis of converter transformers. [ABSTRACT FROM PUBLISHER]

Kerr-effect based methods show great potential for the measurement of electric field in liquid dielectric. However, the accuracy of the Kerr-effect based measurement over the DC electric field in oil-pressboard insulation remains to be a challenge. With the establishment of a Kerr-effect based non-contact and real-time electric field measurement system, the present paper analyzes the factors causing the measurement errors and thus proposes the countermeasures accordingly. It is indicated that the measurement errors resulted from the edge effect generated by electrode and pressboard could be reduced to 1.3% by lengthening the electrode, shortening the spacing distance between the electrode and the test chamber, and providing the electrode covering. The errors caused by non-ideal characteristics of the optical devices could be adjusted through the calibration of its parameters. The errors caused by the noise from laser source could be reduced to 0.86% for DC electric field and 1.6% for AC electric field through suitable selection of AC modulation frequency as 1310 Hz, which could also improve the signal-to-noise ratio. The test results conclude that the measurement system established under the present research could accurately measure DC electric field of 20 V/mm with the error being smaller than 5.4%. [ABSTRACT FROM PUBLISHER]

We study the conductance and interference effects through an AB interferometer with an embedded quantum dot (QD) side-coupled to a single Majorana bound state (MBS) by using non-equilibrium Green's function method. The energy levels appearing in the QD are calculated by diagonalizing the Hamiltonian of the embedded QD–MBS system. When the single QD energy level ϵ 0 is set to 0, there are three discrete energy levels in the QD appearing at around ω = 0 , ± ϵ M 2 + 2 λ 2 due to the coupling with MBS where ϵ M is the coupling strength between the two MBSs at the two ends of the nanowire and λ is the coupling strength between the MBS and the QD. Asymmetric Fano lineshapes are found around these levels in the conductance due to the interference between electrons traversing through different paths. The phase shift of electrons through the QD changes from π / 2 to − π / 2 at each of these three energy values. However, the phase does not vary smoothly between these three energy levels but shows severe changes from − π / 2 to π / 2 at ω = ± ϵ M 2 + λ 2 . As a comparison, we also study the similar AB interferometer in which the QD–MBS system is replaced by a normal QD–QD system or a simple single QD system, which shows only two or one Fano peak and the phase shifts from π / 2 to − π / 2 only at the Fano peaks. These differences reflect the distinct influences of Majorana bound state on the transport properties of AB interferometer. [ABSTRACT FROM AUTHOR]

Converter transformers use oil-pressboard as its main dielectric medium and are operated mainly in AC-DC composite electric field. Creepage discharge is one of the common defects for oil-pressboard insulation, especially in converter transformers. Oil-pressboard insulation shows distinctive flashover behaviors and surface electric strengths in AC-DC composite electric field from that in pure AC or DC electric field. Compared to conventional power transformers, there remain bigger challenges to realize insulation assessment and fault diagnosis for the converter transformers. Adequate knowledge of the phenomenon and characteristics of oil-pressboard insulation creepage discharge is critical for fault diagnosis of converter transformers. This paper attempts to fill the existing research gap by studying the dynamic process and phenomenon of creepage discharge in the composite field so as to provide criteria for insulation diagnosis and assessment. With the established experimental platform, the present paper observed the phenomenon of oil-pressboard insulation creepage discharge from its initiation till final flashover under composite AC-DC voltages, identified the trends of partial discharge and dissolved gas throughout the entire process, and summarized accordingly the criteria for insulation diagnosis and assessment. Results indicate that 1) for creepage discharge of oil-pressboard insulation under AC-DC superimposed voltages, abrupt changes were observed in terms of discharge repetition rate and magnitude. Discharge phases kept enlarging during the whole discharge evolution process; 2) based on the observed discharge characteristics, the evolution process of creepage discharge could be classified into three stages which imply three severity levels of the discharge; 3) compared to that in AC electric field, the creepage discharge in AC-DC composite field witnessed much less amount of and different composition of dissolved gas in oil. More C₂H₆ and C₂H₂ were observed in the AC-DC composite electric field whereas CH4 and C₂H₂ dominated the AC electric field. The research results indicate that as much as both PD-identification and DGA methods are recognized as effective means of fault diagnosis for converter transformers, the referential assessment criteria should be enriched and adjusted for diagnosis of creep discharge under AC-DC composite voltages, taking into full consideration of the distinctive characteristics of both discharge and gases dissolved in oil. [ABSTRACT FROM PUBLISHER]