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Because oil and gas pipelines reside in high-temperature, high-pressure and highly acidic environments for a long time, it is very common for such pipes to experience corrosion thinning. To solve the long-term online monitoring problem of piezoelectric ultrasonic dry coupling of monitored objects with different surface roughnesses, the effects of different thicknesses of silver plates, different surface roughnesses and different coaxial loads on piezoelectric ultrasonic dry coupling were studied here. To improve the low SNR of the acquired signal, a Batworth high-pass filter and zero-phase digital filter are proposed for online ultrasonic monitoring. The effects of three kinds of roughness and axial load on the piezoelectric ultrasonic dry coupling signal are studied, and the relationship between the roughness, thickness of the silver plate and axial load is obtained. The results show that under different roughness conditions, the SNR of the ultrasonic signal increases with increasing axial load. When the axial load reaches a certain magnitude, the SNR of the ultrasonic signal tends to be stable. When the surface roughness is Ra = 1.6 µm and the thickness of the silver plate is 0.05 mm, the SNR of the ultrasonic signal reaches the best value, and the required axial load is minimal. [ABSTRACT FROM AUTHOR]

Top seal failure of ram blowout preventer (BOP) is one of the main factors leading to well control risk. The constitutive model and parameters of nitrile butadiene rubber (NBR) were optimized by compression and tensile tests, and the failure analysis model of the contact seal of the ram BOP top seal was built. The nonlinear contact mechanical behavior of the connection part of the BOP top seal was analyzed by the finite element method. Then, the influence of corrosion and wear defects at the top seal position of the 2FZ35-70 BOP under rated working pressure on the contact seal were studied, and the results showed that the overall contact pressure distribution of the top seal corrosion defects was uniform, the local contact pressure of the corrosion pit edge increased, and the top contact pressure decreased. The overall contact pressure of the wear defect of the top seal decreased linearly, the contact pressure at the maximum depth of the wear defect was the smallest, and the contact pressure gradually decreased to both sides. Ultimately, to guarantee the safety and reliability of the ram BOP, it is suggested that the acceptable depths of the seal corrosion pit and the wear at the top of the ram BOP are 4.0 mm and 0.2 mm, respectively, thus the reliability evaluation problem of the quantitative seal of the ram BOP top seal is solved. [ABSTRACT FROM AUTHOR]

A series of Cu−Mn−(La)−Zr catalysts with molecular ratios of 6 : 3 : (0.35) : 1 was synthesized by sol‐gel (CMLZ−S), co‐precipitation (CML−CP, CMLZ−CP) and hydrothermal (CMLZ−H) methods, respectively. The effects of the Mn and La on the activity of catalysts were investigated. It was found that the addition of La promoted the formation of the medium basic sites. Mn acted as an electronic promotor that transfer electrons through redox reactions, causing other metals to exhibit different valence states, thus promoting the adsorption and activation of H2 and CO2. At a certain temperature, methanol selectivity decreased in the order of CMLZ−H>CMLZ−S>CMLZ−CP>CMZ−CP. The selectivity of methanol is correlated with the distribution of basic sites. For the CMLZ−H catalyst, the highest percentage of moderate basic sites facilitated the activation of CO2, resulting in the highest selectivity of methanol. The CO2 conversion was correlated with the Cu specific surface area. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) is highly sensitive to cold stress, which leads to large reductions in rice yield at the booting stage. In this study, Kongyu131 and Kenjiandao6 rice cultivars with different levels of cold stress sensitivity were sprayed with diethylaminoethyl hexanoate (DA-6) concentrations of 500, 200, 20, 2, 0.2, and 0 mg/L one day before undergoing cold water stress (CWS). We analyzed changes in yield and its factors, dry matter production, stem characteristics, and physiological and biochemical characteristics of the rice plants. The results showed that DA-6 increased peroxidase activity, delayed nitrogen and chlorophyll degradation, maintained soluble protein and potassium contents, and suppressed the accumulation of malondialdehyde in the leaves of both cultivars under CWS. DA-6 also increased the phosphorous content and superoxide dismutase activity in Kenjiandao6 under CWS; however, in Kongyu131, DA-6 increased the soluble sugar content. In addition, DA-6 treatment increased the weight of the panicle at maturity, and of the leaf, panicle, and stem-sheath at heading in both cultivars. The lengths of the panicle, the top first internode, the export rate of stem-sheath, translocation rate of stem-sheath, and export of stem-sheath from heading to maturity were increased in Kenjiandao6; however, in Kongyu131, DA-6 increased the dry weight ratio of panicle to total plant and reduced the dry weight ratio of stem-sheath to total plant at maturity. Furthermore, DA-6 improved yield in both cultivars, mainly by increasing the grain weight in the inferior grains (IG) and middle grains (MG) under CWS. DA-6 increased the grain weight in the IG and MG in Kenjiandao6 mainly by enhancing the seed setting rate and number of filled grains (NFG) in the IG and MG, and in Kongyu131 by improving the NFG in MG and IG. The optimal concentration of DA-6 to alleviate CWS was 2 mg/L. In conclusion, exogenous DA-6 was effective for maintaining dry matter production and physiology in two early japonica rice cultivars under CWS at booting, thereby improving cold tolerance and enhancing yield. The less cold-tolerant cultivar Kenjiandao6 was more sensitive to the effects of DA-6 and displayed better results than the more cold-tolerant cultivar Kongyu131. [ABSTRACT FROM AUTHOR]

This study aims to investigate an accurate detection method to detect defects in the gasket ring groove of the blowout preventer (BOP) using the ultrasonic phased array technology. Traditionally, it is difficult to accurately determine the type and size of defects in the gasket ring groove due to the complexity of the BOP configuration and the interference between the defect echo and the structural echo when using the ultrasonic phased array detection technology. In this study, firstly, the appropriate detection process parameters are determined by using simulation software for simulating and analyzing the defects of different sizes and types in the gasket ring groove of a BOP. Thereafter, according to the detection process parameters determined by the simulation analysis, we carry out a corresponding actual detection test. Simulation analysis and detection test results show that the relative amplitude of the test results and the simulation results differ within 1 dB, and the simulation results have a guiding role for the actual detection. The defect echo and structure echo can be clearly distinguished by selecting appropriate detection process parameters, such as probe frequency 5 MHz, array elements 36, and probe aperture 16 mm. The research results can provide theoretical reference for the detection of blowout preventer. [ABSTRACT FROM AUTHOR]

[Display omitted] • A metal-dielectric-metal system composed by thiol modified Au nanospheres-graphene oxide-Ag nanowires hierarchical nanostructures was fabricated. • The dielectric layer composed of mercaptan and GO was sandwiched by the top Au nanospheres and the bottom Ag nanowires. • PAHs were exactly absorbed by hydrophobic interaction of mercaptan and π-π stacking interaction of GO in the enhanced EM field area. • The hierarchical system was able to identify various types of PAHs in single and multi-component mixture as well as in real water environment. Due to the wide variety, inaccessible self-degradation, high mutagenicity and carcinogenicity of polycyclic aromatic hydrocarbons (PAHs), it still remains challenging to efficiently identify them, especially in real environment. Herein, we develop a bottom-up self-assembly strategy to construct a sandwich-like hierarchical metal-dielectric-metal system composed of mercaptan-modified Au nanospheres-graphene oxide (GO)-Ag nanowires as surface-enhanced Raman spectroscopy (SERS) sensors for sensitive detection of PAHs. The synergistic integration of metallic layers and the organic mercaptan and GO layer not only provides localized enhanced electromagnetic field region which is induced by the nanogap between the top Au nanospheres and the bottom Ag nanowires, but also effectively traps PAHs in the middle layer through hydrophobic interaction of mercaptan and π-π stacking interaction of GO. By rationally optimizing the SERS substrates, the lowest detection concentrations of pyrene, anthracene, phenanthrene and benzo[a]pyrene could be reached, respectively, at 10−8 M, 10−8 M, 10−8 M and 10−7 M. The hierarchical system shows excellent uniformity, reproducibility and is able to identify various types of PAHs in multi-component mixtures as well as in real water environment. This strategy can provide a general platform to identify hazardous pollutants that are hydrophobic or contain benzene rings, such as pesticides, dyes and polychlorinated biphenyls. [ABSTRACT FROM AUTHOR]

Solution-based bottom-gate zinc oxide thin film transistors (TFTs) were fabricated, remaining functional and demonstrating stability under extreme gamma irradiation conditions. Unpassivated TFTs were fabricated on samples with different number of ZnO layers grown via sol-gel spin coating technique. The devices were characterized before and after exposure to a cumulative dose of 220 MRad (air) of gamma irradiation. Atomic force microscopy (AFM), x-ray diffraction (XRD), and photoluminescence (PL) were employed to characterize the TFT active layers. Thickness measurements and optical images suggest the removal of the channel surface, conceivably due to cumulative effect of displacement damage near the ZnO surface. Device electrical characteristics were extracted from current–voltage measurements. The impact of displacement damage on the degradation/enhancement of device characteristics as a consequence of surface/bulk effects is discussed. [ABSTRACT FROM AUTHOR]

The efficacy of surgical intervention in ameliorating long-term prognosis for moderate volume of cerebral hemorrhage in the thalamus-internal capsule region remains unsubstantiated by clinical investigations. Consequently, the acquisition of credible evidence is imperative to authenticate the effectiveness of these methodologies. One hundred and three eligible patients with moderate-volume thalamus-internal capsule region cerebral hemorrhage. Twenty-seven pairs of successful matches after using the 1:1 propensity score matching method, totaling 54 patients, were analyzed. The short- and long-term treatment outcomes of patients in the stereotactic surgery and conservative treatment groups were compared. The prognosis of the 2 groups of patients was analyzed by logistic regression analysis and model comparison. The primary outcome of this study was to assess the assessment of daily living scores after 6 months of treatment. Based on the analysis of this study, the assessment of daily living of the surgical group were significantly higher than those of the conservative treatment group after 6 months of treatment (P < 0.001), and the difference was statistically significant. The amount of residual hematoma was significantly lower in the stereotactic surgery group than in the conservative treatment group at 3 days, 7 days, and 2 weeks after the onset of the disease (P < 0.001), and the complication rate was lower than the conservative treatment group (P < 0.05). Univariate logistic regression showed that the risk of severe neurological dysfunction for patients in the surgery group was (odds ratio -0.27, 95% confidence interval: 0.08–0.86, P < 0.05). In multivariate logistic regression analysis, the odds ratio was 0.29 (95% confidence interval: 0.09–0.96, P < 0.05) after adjusting for all covariates. For moderate-volume thalamus-internal capsule region cerebral hemorrhage, stereotactic paracentesis has the advantage of a shorter hospital stay and a lower complication rate than conservative treatment. Moreover, it yields superior outcomes in terms of daily living assessment scores after six months of treatment and enhanced neurological recovery. [ABSTRACT FROM AUTHOR]

Odontogenic infections can spread to the respiratory tract. Despite the known role of Tannerella forsythia as the primary pathogen in periodontitis, the association between T. forsythia infection and risk of pneumonia or lung abscess remains unknown. In this report, we present a case of lung abscess caused by T. forsythia infection. The pathogen was detected by metagenomic next‐generation sequencing (mNGS) in the bronchoalveolar lavage fluid of the patient. The clinical characteristics and possible mechanisms of the infection are discussed. T. forsythia is a conditional pathogen that can cause lung abscess in the presence of helper bacteria and reduced host immune status. The course of treatment should be personalized and might be longer than 3 months. [ABSTRACT FROM AUTHOR]

The area of forest established through afforestation/reforestation has been increasing on a global scale, which is particularly important as these planted forests attenuate climate change by sequestering carbon. However, the determinants of soil organic carbon (SOC) sequestration and their contribution to the ecosystem carbon sink of planted forests remain uncertain. By using globally distributed data extracted from 154 peer‐reviewed publications and a total of 355 sampling points, we investigated above‐ground biomass carbon (ABC) sequestration and SOC sequestration across three different climatic zones (tropical, warm temperate, and cold temperate) through correlation analysis, regression models, and structural equation modeling (SEM). We found that the proportion of SOC sequestration in the ecosystem C sequestration averaged 14.1% globally, being the highest (27.0%) in the warm temperate and the lowest (10.7%) in the tropical climatic zones. The proportion was mainly affected by latitude. The sink rate of ABC (RABC) in tropical climates (2.48 Mg C ha−1 year−1) and the sink rate of SOC (RSOC) in warm temperate climates (0.96 Mg C ha−1 year−1) were higher than other climatic zones. The main determinants of RSOC were the number of frost‐free days, latitude, mean annual precipitation (MAP), and SOC density (SOCD) at the initial observation; however, these variables depended on the climatic zone. According to the SEM, frost‐free period, mean annual temperature (MAT) and MAP are the dominant driving factors affecting RSOC in Chinese plantations. MAT has a positive effect on RSOC, and global warming may increase RSOC of temperate plantations in China. Our findings highlight the determinants of SOC sequestration and quantitatively reveal the substantial global contribution of SOC sequestration to ecosystem carbon sink provided by planted forests. Our results help managers identify and control key factors to increase carbon sequestration in forest ecosystems. [ABSTRACT FROM AUTHOR]

Solid–liquid phase equilibria for the two aqueous systems (LiBO2 + NaBO2 + H2O) and (LiBO2 + KBO2 + H2O) at T = 288.15 K and p = 0.1 MPa were determined using the isothermal dissolution equilibrium method. The experimental results show that the phase diagrams consist of one two-salt co-saturated invariant point, two univariant solubility isotherms, and three crystallization fields. The two systems belong to simple co-saturated type, and neither double salt nor solid solution were found. The densities change regularly as the sodium metaborate (potassium metaborate) concentration increases in solution, and reach their maximum values at the invariant point. Based on the Pitzer and its extended Harvie–Møller–Weare (HMW) model, the solubilities for the ternary systems at 288.15 K were represented, and the calculated results agree well with the experimental values. [ABSTRACT FROM AUTHOR]

The central nervous system (CNS) is regarded as an immune privileged environment; however, changes in the neuroimmunology paradigm have led to an increased interest in systematic immunotherapy in lung cancer therapy. The presence of the lymphatic system in the CNS as well as the physiological and biochemical changes in the blood–brain barrier in the tumor microenvironment suggests that immunocytes are fully capable of entering and exiting the CNS. Emerging clinical data suggest that inhibitors of programmed death receptor-1/programmed death ligand 1 (PD-1/PD-L1) can stimulate surrounding T cells and thus have antitumor effects in the CNS. For example, PD-1 antibody (pembrolizumab) monotherapy has displayed a 20– 30% encephalic response rate in patients with brain metastases from malignant melanoma or non-small cell lung cancer. Combined application of nivolumab and ipilimumab anti-PD-1 and anti-cytotoxic T-lymphocyte-associated protein 4 showed an encephalic response rate of 55% in patients with brain metastases of melanoma. Further evidence is required to verify these response rates and identify the mechanisms of curative effects and drug tolerance. While regional treatments such as whole-brain radiosurgery, stereotactic radiosurgery, and brain surgery remain the mainstream, PD-1/PD-L1 inhibitors display potential decreased neurotoxic effects. To date, five drugs have been approved for use in patients with encephalic metastases of lung carcinoma: the anti-PD-1 drugs, pembrolizumab and nivolumab, and the anti-PD-L1 agents, atezolizumab, durvalumab, and avelumab. In recent years, clinical trials of inhibitors in combination with other drugs to treat brain metastasis have also emerged. This review summarizes the biological principles of PD-1/PD-L1 immunotherapy for brain metastasis of lung cancer, as well as ongoing clinical trials to explore unmet needs. [ABSTRACT FROM AUTHOR]

• To realize precise location and self-correction of a fault sensor in HVAC, an exponential function method is proposed. • A novel decentralized flat sensor diagnosis network for HVAC system is established. • A decentralized swarm intelligence optimization algorithm for sensors fault detection and self-correction is developed. • The convergence of the algorithm is proved theoretically and the feasibility is demonstrated by hardware test. Under a self-organizing and flat sensors network structure, a novel decentralized sensors fault detection and self-correction method is proposed. In the self-organizing sensors network, each sensor is updated as smart agent and is connected based on basic physical relations and can communicate with adjacent nodes. This network possess the advantages of plug-and-play and can reduce the high labor and maintenance cost, without having to build central monitor. For the proposed decentralized method, each smart sensor is treated as an individual which has its own utility with local coupling between adjacent nodes. And a decentralized swarm intelligence optimization algorithm is designed and executed in all the smart nodes in parallel to achieve the sensors fault detection and self-correction. Moreover, convergence property of the presented method is analyzed theoretically. Simulation results and hardware platform test on an actual HVAC system illustrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

We synthesized ultrafine Mn 2 O 3 quantum dots embedded into N-doped carbon to generate two-dimensional (2D) composites (MNC) with robust interfacial heterostructural interactions (C O Mn bonds) via a facile solvent-free tactics, which could enhance the Na+-storage properties with the fast kinetics, superior reversibility and long-life stability. [Display omitted] • 2D Mn 2 O 3 quantum dots embedded into N-doped carbon composites (MNC) was prepared. • Interfacial heterostructural C-O-Mn bonds boost Na storage stability and reversibility. • N doped carbon raises electronic conductivity and kinetic reaction rate. • MNC shows superior storage property for SIBs/SIHCs and practical applications. The ingenious architectural structural engineering is extensively identified as a cogent means for facilitating the electrochemical properties of conversion-type anode materials for sodium-ion storage. Herein, a delicate, scalable and controllable solvent-free strategy is proposed to synthesize ultrafine Mn 2 O 3 quantum dots embedded into N-doped carbon to generate two-dimensional (2D) composites (MNC) with robust interfacial heterostructural interactions for high sodium ion storage and fast reaction kinetics, which averts the use of solvents and environmental pollution, greatly reduces time and production costs. The introduction of metallic Mn species simultaneously achieves the construction of ultrafine Mn 2 O 3 quantum dots and strong interfacial heterostructural C O Mn bonds between metal species and 2D N-doped carbon matrix. The synergistic effect of the formation of oxide quantum dots, the combination of 2D N-doped carbon and the construction of robust interfacial interactions provides the stable electrode structure, fast reaction kinetics and high electrochemical storage capability of anode materials. Hence, MNC composites in SIBs convey remarkable reversible rate capability. Its superior capacity reaches 215 mAh g−1 for 50 cycles at 0.2 A g−1 and 155 mAh g−1 for 1000 cycles at a high current density of 5 A g−1, which shows good long-term stability. The assembled sodium-ion hybrid capacitors (SIHCs) device delivers outstanding energy density of 138 Wh kg−1 at a power density of 126 W kg−1 and 98% capacity retention after 2000 cycles at 2 A g−1, and tremendous capability for practical applications (69 LEDs can be easily lighted). This work not merely offers guidance for the rational interfacial engineering design of high-capacity Mn-based electrode materials in a feasible and scalable solvent-free tactics for Na+ storage, but also broadens the routes for projecting a better electrode material for other battery systems. [ABSTRACT FROM AUTHOR]

In this paper, Chitosan(CS)/graphene oxide(GO)/SnO 2 composite is proposed as the sensing material of an impedance-type humidity sensor. The composite was synthesized via a facile solution mixing method. And it was formed by adding CS and SnO 2 to GO aqueous solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectrometer (FT-IR) were executed to characterize the structure and morphology of the composite. At room temperature, the CS/GO/SnO 2 composite shows more favorable humidity-sensing properties compared with the CS, CS/GO, and CS/SnO 2 material. The resulted sensor exhibits high response (72683%), high sensitivity (402.5 kΩ/%RH), rapid response and recovery time (8 s/8 s). Moreover, small humidity hysteresis value (<7%) under maximum impedance difference, good repeatability and long-term stability are demonstrated. Therefore, the CS/GO/SnO 2 composite is a promising candidate for humidity sensing. • Impedance humidity sensor based on chitosan/graphene oxide/SnO 2 composite is prepared. • Graphene oxide and SnO 2 can obviously improve the response of chitosan. • Chitosan/graphene oxide/SnO 2 composite exhibits a high response, rapid response and recovery time and good repeatability. • Chitosan/graphene oxide/SnO 2 composite is easily recycled. [ABSTRACT FROM AUTHOR]

Abstract The feasibility of using rhenium diselenide (ReSe 2) as the saturable absorber for the broadband passively Q-switched (PQS) thulium solid-state lasers was demonstrated in this paper. In the short wavelength of 2 μm region, the combination of Tm:YLF and ReSe 2 was used to achieve the PQS operation with multi-wavelength around 1900 nm. A maximum average output power of 862 mw, a shortest pulse width of 527.9 ns and a repetition rate of 54 kHz were obtained. In the long wavelength of 2 μm region, a ReSe 2 -based PQS multi-wavelength Tm:Y 2 O 3 laser around 2050 nm was realized, generating a maximum average output power of 1.04 W, a shortest pulse width of 727 ns and a repetition rate of 106 kHz. The output performance of the ReSe 2 -based pulsed laser is competitive among these PQS thulium solid-state lasers using the emerging two-dimensional materials as SAs, indicating that ReSe 2 is a promising broadband SA for the 2 μm solid-state lasers. Highlights • The results demonstrate the possibility of generating 2 μm nanosecond pulses by using ReSe 2 as broadband saturable absorbers. • The ReSe 2 -based output mirror combines the function of passive Q-switching and output coupling. • The output performance of the ReSe2 passively Q-switched Tm solid-state lasers is competitive. [ABSTRACT FROM AUTHOR]

Highlights • A novel decentralized constrained optimization model for islanded power system is presented. • A decentralized flat DGs control network structure is established. • Developing a decentralized algorithm based on penalty function achieves the global optimal optimum solution. • The convergence of presented algorithm is proved and the feasibility is demonstrated as well. Abstract A novel decentralized method for optimal load distribution in an isolated power system is proposed. In contrast to the traditional centralized method, the load economic dispatch is distributed to every smart distributed generator (DG) without the need for a monitoring host. Similar to the structure, mechanism and characteristics of biological communities, a smart DG node can communicate with adjacent nodes and operate collaboratively to complete the optimal operation of an isolated power system. The task is formulated as a decentralized optimization with a number of local constraints and is solved by a penalty function method. With the economic dispatch algorithm computed in all of the DG nodes in parallel, a new, fully distributed flat control network is established. The convergence property of the novel method is analysed theoretically. Simulation results on an illustrative system provide support for the validity of the proposed method. [ABSTRACT FROM AUTHOR]

Highlights • An simultaneous dual-wavelength mid-IR OPO at 3295 and 3469 nm was demonstrated. • An extremely low-loss singly resonant OPO cavity for the signal wave was designed. • High pulse peak powers generation at the two Mid-IR wavelengths were achieved. Abstract An optical parametric oscillator (OPO) simultaneously generating dual-wavelength mid-IR radiation at 3295 and 3469 nm was demonstrated in this paper. In an extremely low-loss singly resonant OPO for the signal wave, two OPO crystals, KTA and KTP, were placed coaxially in the resonator with their Y axes perpendicular to each other. So the different polarization component of the 1064 nm fundamental wave from one Nd:YAG laser could separately pump the two OPO crystals, constructing a parallel stacked OPO scheme. Simultaneous dual-wavelength operation at the idler wavelengths of 3295 and 3469 nm were obtained, with the maximum average powers being 1.01 and 0.81 W, respectively. The achieved minimum pulse width was 6.2 ns for the two wavelengths, producing pulse peak powers of 23.3 and 18.7 kW for 3295 and 3469 nm, respectively. The wavelength designability and power scalability makes the parallel stacked OPO a promising multi-wavelength mid-infrared laser source for high speed differential absorption lidars. [ABSTRACT FROM AUTHOR]

Mobile micro-clouds are promising for enabling performance-critical cloud applications. However, one challenge therein is the dynamics at the network edge. In this paper, we study how to place service instances to cope with these dynamics, where multiple users and service instances coexist in the system. Our goal is to find the optimal placement (configuration) of instances to minimize the average cost over time, leveraging the ability of predicting future cost parameters with known accuracy. We first propose an offline algorithm that solves for the optimal configuration in a specific look-ahead time-window. Then, we propose an online approximation algorithm with polynomial time-complexity to find the placement in real-time whenever an instance arrives. We analytically show that the online algorithm is $O(1)$ -competitive for a broad family of cost functions. Afterwards, the impact of prediction errors is considered and a method for finding the optimal look-ahead window size is proposed, which minimizes an upper bound of the average actual cost. The effectiveness of the proposed approach is evaluated by simulations with both synthetic and real-world (San Francisco taxi) user-mobility traces. The theoretical methodology used in this paper can potentially be applied to a larger class of dynamic resource allocation problems. [ABSTRACT FROM PUBLISHER]

Polysaccharide is one of the main active components of Polygonatum sibiricum. For this study, P. sibiricum polysaccharides (PSP) were obtained through purification using DEAE-Cellulose52 and Sephacryl G-150 column chromatography. The obtained samples were named PSP1, PSP2 and PSP3. The PSP1 sample was found to have the highest content and the best solubility, and a subsequent. So, its structure and characterization were analyzed. The main sugar residue linkages were found to be → 1)-β-D-Fruf-(2 → 1)-β-D-Fruf-(2 → 1), 1 → -β-D-Fruf-(2 → 6)α-D-Glcp (1→, →4)-β-D-Manp-(1 → 4)-β-D-Manp-(1→ and →6)-β-D-Glcp-(1 → 4)-β-D-Manp-(1→ link existed. Branch chain analysis indicated →1,6)-β-D-Fruf-(2→, β-D-Fruf-(2→, →1,6)-β-D-Fruf-(2→, →6)-β-D- Fruf-(2→ link existed, and the link site was at position C-6. In vitro antioxidant activity tests showed that PSP1 had a certain scavenging effect on DPPH, hydroxyl radical, superoxide anion radical and a particular effect on the chelating ability of ferrous. This suggested that P. sibiricum polysaccharides may be a potential antioxidant. [ABSTRACT FROM AUTHOR]

A decentralized control structure is introduced into the heating, ventilation, and air conditioning (HVAC) system to solve the high maintenance and labor cost problem in actual engineering. Based on this new control system, a decentralized optimization method is presented for sensor fault repair and optimal group control of HVAC equipment. Convergence property of the novel method is theoretically analyzed considering both convex and nonconvex systems with constraints. In this decentralized control system, traditional device is fitted with a control chip such that it becomes a smart device. The smart device can communicate and operate collaboratively with the other devices to accomplish some designated tasks. The effectiveness of the presented method is verified by simulations and hardware tests. [ABSTRACT FROM AUTHOR]

Bauxite mining on karst results in several ecological and environmental issues including heavy metal pollution, soil erosion and the destruction of vegetation. In turn, these may affect the distribution of plant communities and endanger human health. In general, bryophytes (mosses, liverworts and hornworts) are pioneer plants, lacking roots, vascular systems and well-developed cuticles. Due to their high sensitivity to the environment, they are often used to monitor air and soil pollution. A total of 25 bryophyte taxa from 19 genera and 9 families were recorded on Goujiang karst bauxite near the city of Zunyi in the Guizhou Province of southwestern China. Eleven principal bryophyte communities were identified, most of which consisted of only one species (monospecific assemblage), although the proportion of these single-species communities differed at the six locations. The levels of heavy metals also differed in soil from the six locations: iron, 8748.9–10,023 μg/g; zinc, 146.7–240.9 μg/g; copper, 24.6–60.4 μg/g; and nickel, 35.6–95.1 μg/g. A canonical correspondence analysis (CCA) of the bryophyte communities and environmental variables revealed the effect of gradient (slope), altitude and heavy metals in the soil on the distribution of the principal bryophyte communities. More than 36% of bryophyte taxa identified reproduced asexually by gemmae, as gemmiferous bryophyte communities tolerate substrates with high levels of heavy metals more readily than non-gemmiferous communities do. The distribution of heavy metals in the soil is reflected in the distribution of the bryophyte communities. The distribution characteristics of the principal bryophyte communities and of the gemmiferous bryophyte communities are useful in monitoring heavy metal pollution in karst bauxite. [ABSTRACT FROM AUTHOR]

The solubilities and physicochemical properties, including density and pH, in the ternary system (LiBO + CaBO + HO) at (288.15 and 298.15) K were investigated using the isothermal dissolution equilibrium method. According to the experimental results of the ternary system at (288.15 and 298.15) K, the stable phase diagrams and the diagrams of physicochemical properties were plotted versus composition. In the phase diagrams of the ternary system at (288.15 and 298.15) K, there is one invariant point (LiBO·8HO + CaBO·6HO), two univariant isotherm dissolution curves, and two crystallization regions corresponding to lithium metaborate octahydrate (LiBO·8HO) and calcium metaborate hexahydrate (CaBO·6HO), respectively. This system at both temperatures belongs to hydrate type I classification and neither double salt nor solid solution were found. A comparison of the phase diagrams for the ternary system at (288.15 and 298.15) K shows that the numbers of solid phase and the minerals present are the same; the crystallized area of CaBO·6HO increased at the higher temperature, while that of LiBO·8HO decreased. The physicochemical properties (density and pH values) of the ternary system at the two temperatures change regularly with increasing lithium metaborate concentration. The calculated values of density using empirical equations of the ternary system are in good agreement with the experimental values. [ABSTRACT FROM AUTHOR]

The solubility and density in the thermodynamic phase equilibria ternary system (Li 2 SO 4 + K 2 SO 4 + H 2 O) at 288.15 K and 0.1 MPa were investigated experimentally with the method of isothermal dissolution equilibrium. This system at 288.15 K consists of two invariant points, three univariant isothermal dissolution curves; and three crystallization regions. The salt Li 2 SO 4 ·K 2 SO 4 belongs to the incongruent double salt, and no solid solution was found. Based on the Pitzer model and its extended Harvie–Weare (HW) model, the mixing ion-interaction parameters of θ Li,K , ψ Li,K,SO4 at 288.15 K and the solubility equilibrium constants K sp of solid phases Li 2 SO 4 ·H 2 O and Li 2 SO 4 ·K 2 SO 4 , which are not reported in the literature were acquired. A comparison between the calculated and experimental results at 288.15 K for the ternary system shows that the calculated solubilities obtained with the extended HW model agree well with experimental data. [ABSTRACT FROM AUTHOR]

Abstract: To evaluate the effects of Pseudomonas aeruginosa mannose-sensitive hemagglutinin (PA-MSHA) injection on the survival rate of rats post cecal ligation and puncture (CLP), Sprague–Dawley (SD) rats were subcutaneously injected with 0.125ml, 0.25ml or 0.5ml PA-MSHA for 8days or 16days before CLP. The survival rate and physiological appearance of rats in each group were monitored daily post CLP. The expression of Toll-like receptor 4 (TLR4) and cytokines related to inflammation was evaluated. We found that the 0.5ml-8d (0.5ml PA-MSHA injected for 8days) group had the highest 7-day survival rate (91.7%), which was significantly improved compared with the CLP-only group (33.3%). Furthermore, our results showed that PA-MSHA effectively increased serum pro-inflammatory mediators (TNF-α, IL-1β and IL-6) at the early stage (8days) but increased anti-inflammatory mediators (IL-4 and IL-10) at the late stage (16days). PA-MSHA significantly up-regulated the mRNA expression of TLR4 at 8 and 16days. After PA-MSHA pretreatment, CLP had no marked effect on the levels of most inflammatory factors. To explore potential protective mechanisms of PA-MSHA against CLP, we examined the effect of PA-MSHA on murine macrophage-like RAW264.7 cells and found that PA-MSHA induced endotoxin tolerance. In conclusion, this study suggested that precisely controlling the dosage and time of PA-MSHA administration can effectively increase the rat survival rate post CLP, which may be mediated through regulating inflammatory mediators and inducing endotoxin tolerance. [Copyright &y& Elsevier]

A molecular-cage strategy is employed to encapsulate H 3 PMo 12 O 40 into cavities of ZIF-67. The fabricated Pt-Mo 6 Co 6 C heterojunctions uniformly embedded on dodecahedron carbon matrix and exhibit superior HER activity and stability than commercial Pt/C in universal PH solutions. [Display omitted] • A cage-confinement strategy was employed to encapsulate H 3 PMo 12 O 40 cluster into cavities of ZIF-67 without destroy its structure. • The Mo 6 Co 6 C nanoparticles was homogeneously embedded on dodecahedron carbon matrix without aggregation during pyrolysis process. • The Pt-Mo 6 Co 6 C heterojunction was fabricated through galvanic replacement which presents superior HER activity than commercial Pt/C in PH-universal solutions. • DFT calculation suggested that hydrogen adsorption free energy (ΔG H*) of Pt-Mo 6 Co 6 C heterojunction delivered a closer value to 0 eV than metallic Pt. Electrochemical water splitting has been highly considered as a promising technology to produce hydrogen with high purity and large quantity. Herein, a cage-confinement strategy is proposed to encapsulate H 3 PMo 12 O 40 clusters into cavities of ZIF-67. The ZIF-67 with cavity diameter of 1.16 nm and cavity window of 0.34 nm can appropriately confine H 3 PMo 12 O 40 with diameter of 1.0 nm. The H 3 PMo 12 O 40 served as guest species were also homogeneously encapsulated in well-defined cavities of ZIF-67 host without destroying the structure of ZIF-67. This cage-confinement strategy endow Mo 6 Co 6 C nanoparticles uniformly embedded in carbon matrix without aggregation and exposed abundant active sites during pyrolysis process. Furthermore, the heterojunction of Pt-Mo 6 Co 6 C was fabricated through galvanic replacement with H 2 PtCl 6. The prepared Pt-PMo/ZIF-67-800 electrocatalyst with a low Pt amount of 3.0 % exhibits excellent HER activity and stability and even superior to commercial Pt/C in PH-universal solutions. Density functional theory (DFT) calculation reveals that Pt-Mo 6 Co 6 C heterostructure results in a lower hydrogen adsorption free energy than commercial Pt/C and thus enhances its intrinsic catalytic activity. The outstanding HER performance of Pt-Mo 6 Co 6 C heterostructure confined on dodecahedron carbon matrix opens new perspectives for rational design polyoxometalate (POM) based catalyst for hydrogen evolution. [ABSTRACT FROM AUTHOR]

We consider federated learning in tiered communication networks. Our network model consists of a set of silos, each holding a vertical partition of the data. Each silo contains a hub and a set of clients, with the silo's vertical data shard partitioned horizontally across its clients. We propose Tiered Decentralized Coordinate Descent (TDCD), a communication-efficient decentralized training algorithm for such two-tiered networks. The clients in each silo perform multiple local gradient steps before sharing updates with their hub to reduce communication overhead. Each hub adjusts its coordinates by averaging its workers' updates, and then hubs exchange intermediate updates with one another. We present a theoretical analysis of our algorithm and show the dependence of the convergence rate on the number of vertical partitions and the number of local updates. We further validate our approach empirically via simulation-based experiments using a variety of datasets and objectives. [ABSTRACT FROM AUTHOR]

Experimental studies on the metastable solubilities and the physicochemical properties including density, refractive index, conductivity, and pH values in the reciprocal quaternary system containing lithium, sodium, chloride, and sulfate at 273.15 K were determined with the method of isothermal evaporation. According to the experimental results, the dry-salt phase diagram, the water phase diagram, and the physicochemical properties versus composition were plotted. In the dry-salt phase diagram, there are three invariant points, seven solubility isotherm curves, and five crystallization fields corresponding to sodium chloride, mirabilite, lithium chloride dehydrate (LiCl·2H2O), lithium sulfate monohydrate, and a double salt (Li2SO4·3Na2SO4·12H2O). There were no solid solutions formed in the reciprocal quaternary system. The crystallizing region of mirabilite is the largest, while the region of LiCl·2H2O is the smallest with the highest concentration and a strong salting-out effect to NaCl and Li2SO4·H2O. When compared with the stable phase diagram at 273.15 K, the area of the phase region of mirabilite is enlarged significantly, while the areas of the phase regions of NaCl, Li2SO4·H2O, and Li2SO4·3Na2SO4·12H2O are decreased. The calculated values of densities and refractive index in the quaternary system with empirical equations are in good agreement with the experimental values. [ABSTRACT FROM AUTHOR]

Schizophrenia, a psychiatric disorder, requires long-term treatment; however, large fluctuations in blood drug concentration increase the risk of adverse reactions. We prepared a long-term risperidone (RIS) implantation system that can stabilize RIS release and established in-vitro and in-vivo evaluation systems. Cumulative release, drug loading, and entrapment efficiency were used as evaluation indicators to evaluate the effects of different pore formers, polymer ratios, porogen concentrations, and oil–water ratios on a RIS implant (RIS-IM). We also built a mathematical model to identify the optimized formulation by stepwise regression. We also assessed the crystalline changes, residual solvents, solubility and stability after sterilization, in-vivo polymer degradation, pharmacokinetics, and tissue inflammation in the case of the optimized formulation. The surface of the optimized RIS microspheres was small and hollow with 134.4 ± 3.5 µm particle size, 1.60 SPAN, 46.7% ± 2.3% implant drug loading, and 93.4% entrapment efficiency. The in-vitro dissolution behavior of RIS-IM had zero-order kinetics and stable blood concentration; no lag time was released for over three months. Furthermore, the RIS-IM was not only non-irritating to tissues but also had good biocompatibility and product stability. Long-acting RIS-IMs with microspheres and film coatings can provide a new avenue for treating schizophrenia. [ABSTRACT FROM AUTHOR]

Abstract: The solubility and the density in the aqueous ternary system (Li2SO4 +MgSO4 +H2O) at T =308.15K were determined by the isothermal evaporation. Our experimental results permitted the construction of the phase diagram and the plot of density against composition. It was found that there is one eutectic point for (Li2SO4 ·H2O+MgSO4 ·7H2O), two univariant curves, and two crystallization regions corresponding to lithium sulphate monohydrate (Li2SO4 ·H2O) and epsomite (MgSO4 ·7H2O). The system belongs to a simple co-saturated type, and neither double salts nor solid solution was found. Based on the Pitzer ion-interaction model and its extended HW models of aqueous electrolyte solution, the solubility of the ternary system at T =308.15K has been calculated. The predicted solubility agrees well with the experimental values. [Copyright &y& Elsevier]

Due to the heterogeneity of program language and natural language query, it is difficult to identify the semantic relationship between them, which leads to the low efficiency of code recommendation. In order to solve the problems of the above code recommendation technology, a code recommendation method based on joint embedded attention network (JEAN) is proposed in this paper. The method uses GRU Network to embed code snippets and describe queries into vector representation, which solves the problem of heterogeneous code snippets and natural language queries. The Attention mechanism is then used to distribute totally different weights to different components of every mode of the code snippet. The reason for the Attention mechanism is that different components of every mode of the code snippet contribute differently to the semantic vector of the final code snippet, making it interpretable. Finally, two commonly used evaluation indexes of information retrieval, SuccessRate@k and MRR, are used for experimental comparison with other baseline models. The experimental results show that the code recommendation method based on joint embedded attention network proposed in this paper can effectively recommend appropriate code snippets according to the needs of developers, and its performance is better than other baseline methods. [ABSTRACT FROM AUTHOR]

Lightning is a major cause of tripping faults in overhead transmission lines. Multi-chamber lightning arresters are widely used to protect high-voltage lines from lightning because of their reliable arc-quenching performance. This paper analyzes the development and quenching process of an arc after a lightning breakdown arrester and studies the quenching mechanism of a multi-chamber arc structure based on its structural characteristics. We built an impulse-current test platform and carried out an impulse-current test for the multi-chamber arrester. The arc motion was captured by a high-speed camera, and the height, speed, and temperature of the arc ejection were obtained by signal processing. The multi-chamber arrester structure is optimized by using the maximum arc ejection height and the maximum ejection speed as metrics to find the optimal combination of the quenching-hole diameter and depth and the gap distance of the multi-chamber structure. [ABSTRACT FROM AUTHOR]

Electrochemical water splitting is one of the most economical and sustainable methods for large-scale hydrogen production. However, the development of earth-abundant non-noble-metal catalysts toward hydrogen evolution reaction, with excellent activity and stability, remains a great challenge. In this work, the coupled hybrids of β-Mo 2 C nanoparticles and porous N -doped carbon nanoplates is successfully constructed by the one-pot solution-free strategy. The hybrids exhibits high electrocatalytic activity for hydrogen evolution reaction with a small overpotential of 116 mV and 187 mV to deliver a current density of 10 mA/cm2 in 1.0 M KOH and 0.5 M H 2 SO 4 solution. Furthermore, the hybrids have excellent stability in not only acidic solutions but also basic solutions. The superior activity and remarkable stability originated from the N -doped carbon nanoplates supplying enough surface area, the ultrafine β-Mo 2 C nanoparticles providing sufficient electrocatalytic active sites, the mesoporous structure facilitating the charge/mass transportation, and the coupling effect dropping the adsorption free energy of hydrogen. This work presents a simple and effective approach to prepare molybdenum-based materials with excellent electrocatalytic performance for hydrogen production. Image 1 [ABSTRACT FROM AUTHOR]

Long non-coding RNAs (lncRNAs) have been reported to be involved in regulating epilepsy. The purpose of this study is to investigate the possibly regulatory mechanism of small nucleolar RNA host gene 1 (SNHG1) on epilepsy. Quantitative real-time PCR was utilized to detect the expression of SNHG1, microRNA (miR)-181a, and B-cell lymphoma-2 (BCL-2). Through an enzyme-linked immunosorbent assay, the levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6, and cyclooxygenase-2 (COX-2) were determined. The viability and apoptosis of CTX-TNA2 cells were measured using MTT assay and flow cytometry analysis, respectively. Western blot assay was performed to analyze the protein levels of Bcl-2, BCL2-associated X, and Caspase-3. The relationships between miR-181a and SNHG1/BCL-2 were confirmed by the dual-luciferase reporter assay. SNHG1 expression was down-regulated in EP tissues and kainic acid (KA)-induced CTX-TNA2 cells. The apoptosis and release of inflammatory factors (TNF-α, IL-1β, IL-6, and COX-2) in KA-induced CTX-TNA2 cells were suppressed by SNHG1 overexpression and promoted by miR-181a up-regulation. In addition, we confirmed that SNHG1 targeted miR-181a, whereas BCL-2 was a target gene of miR-181a. Negative correlations between SNHG1 and miR-181a, as well as miR-181a and BCL-2 were exhibited. Both the up-regulation of miR-181a and down-regulation of BCL-2 reversed the inhibiting effects of SNHG1 on apoptosis and inflammatory response of KA-induced CTX-TNA2 cells, and the promoting effect upon cell viability. SNHG1 alleviated the progression of EP by modulating the miR-181a/BCL-2 axis in vitro, thus SNHG1 could act as a possible therapeutic target for treating EP. [ABSTRACT FROM AUTHOR]

Tests Effinger and Hayes' theorem about the Goldbach 3-primes property for polynomial rings over certain infinite fields. Application of the model-theoretic method in the investigation; Existence of infinitely many fields that satisfy Goldbach 3-primes property.

• The adsorption capacity of ZnFC-PA/PSF composite spheres for Cs+ was 305.38 mg/g. • Its practicability is superior than of most previously reported adsorbents. • A fixed bed reactor loaded with ZnFC-PA/PSF spheres was used for cesium removal. • The effects of operating parameters on the breakthrough curves were investigated. Radioisotope leaking from nuclear waste has become an intractable problem due to its gamma radiation and strong water solubility. In this work, a novel porous ZnFC-PA/PSF composite sphere was fabricated by immobilization of ferrocyanides modified zinc phytate into polysulfone (PSF) substrate for the treatment of Cs-contaminated water. The maximum adsorption capacity of ZnFC-PA/PSF was 305.38 mg/g, and the removal efficiency of Cs+ was reached 94.27% within 2 hr. The ZnFC-PA/PSF presented favorable stability with negligible dissolution loss of Zn2+ and Fe2+ (< 2%). The ZnFC-PA/PSF achieved high-selectivity towards Cs+ (K d = 2.24×104 mL/g) even in actual geothermal water. The adsorption mechanism was inferred to be the ion-exchange between Cs+ and K+. What's more, ZnFC-PA/PSF worked well in the fixed-bed adsorption (E = 91.92%), indicating the application potential for the hazardous Cs+ removal from wastewater. [Display omitted] [ABSTRACT FROM AUTHOR]

• Fe-doped α-MoO 3 nanoarrays was first synthesized by a simplistic solid-state chemical reaction strategy. • Fe-doped MoO 3 nanoarrays exhibited a high response. • The high response originated from more internal oxygen vacancies and surface ionized oxygen species. • The nanoarrays have also excellent selectivity, rapid response-recovery and good long-term stability. Fe-doped α-MoO 3 nanoarrays have been synthesized via a facile two-step solid-state chemical reaction process. The Fe element was effectively doped into the α-MoO 3 nanoarrays self-assembled by nanoplates via an initial room-temperature solid-state reaction and a subsequent mesothermal calcination. The gas-sensing properties of Fe-doped α-MoO 3 nanoarrays were investigated and the possibility of its application to gas sensors was explored. The result indicated that 0.3 mol% Fe-doped α-MoO 3 nanoarrays exhibited a high response value (28.5) towards 100 ppm xylene within 2 s, which is attributed to its more oxygen vacancies and surface ionized oxygen species. Furthermore, the 0.3 mol% Fe-doped α-MoO 3 nanoarrays also manifested a good selectivity and long-term stability. Therefore, the Fe-doped MoO 3 nanoarrays are a potential candidate for xylene sensor in future sensing applications. [ABSTRACT FROM AUTHOR]

In this work, based on colloidal lithography, a strategy is developed to produce a new type of hybrid plasmonic–photonic system comprising a periodic array of nanoholes in a photoreconfigurable polymer layer deposited on a gold surface. By controlling the experimental conditions, the geometric parameters of the nanoholes can be easily adjusted; hence, the optical properties of the systems are widely tunable. Importantly, the shape and topology of the round nanohole arrays can be easily reconfigured with proper photoirradiation, providing a means to modulate the optical properties and produce new functionalities, as exemplified by the formation of arrays with anisotropic or gradient structural features. Moreover, rubbing dielectric spheres into the formed nanoholes can further tune the topological structures of the dielectric components in the hybrid system, leading to a dramatic modification of the spatial energy distributions and inducing the formation of uniform electromagnetic fields confined near the embedded sphere surfaces, which are more beneficial for practical applications. All the results indicate that the combined use of the unique properties of both a photoreconfigurable polymer and colloidal lithography opens a new avenue with great potential for efficient and large‐area fabrication of hybrid plasmonic–photonic systems with a high degree of optical tunability. [ABSTRACT FROM AUTHOR]

DC corona discharge has been widely used for the application of volatile organic compounds (VOCs) degradation. In this article, the microdischarge was found in an improved wire-plate corona discharge reactor, which could extremely promote the toluene degradation efficiency. Due to the porous insulating materials attached to the grounded electrode, microdischarge could be easily induced by the accumulated charge on the insulating layer during corona discharge. An influence of parameters of microdischarge was systematically investigated, such as volume resistivity of insulating materials, layer thickness ($d$), the number of pores ($n$), and pore size ($s$). It is found that a better toluene degradation could be obtained when a porous insulating layer with low volume resistivity and small pore was coated on the grounded electrode of the corona discharge reactor. With the polytetrafluoroethylene (PTFE) insulating layer of $d =5 0\,\,\mu \text{m}$ , n $= 50\,\,\mu \text{m}$ , and s $= 10\,\,\mu \text{m}$ , the degradation efficiency of toluene reached 54.2% when the discharge power was 24 W, while the efficiency is only 40.8% compared to the negative dc corona discharge alone. Besides, the concentration of CO2 and CO produced during the degradation of toluene was also increased by 189 and 293 ppm due to the induction of microdischarge. The investigations on the microdischarge-enhanced corona plasma reactor could not only offer an effective way for toluene degradation but also provide new insight on the improvement of plasma reactors for VOCs’ decomposition. [ABSTRACT FROM AUTHOR]

This study analyzed the regional climate variations in heavy rainfall across South China by using the IMERG precipitation data during 2001--2020. The research focused on the spatiotemporal distribution characteristics of heavy rainfall and the diurnal variations of extreme heavy rainfall before, during, and after the onset of the South China Sea summer monsoon. The results showed that: (1) The rainfall center in South China was influenced by diverse weather systems at different times of the year. The ratios of rainfall during the two rainy seasons to the annual precipitation were inversely distributed, and the proportion of heavy rainfall along the coast of Guangdong and Guangxi was significantly higher than those of other regions. Heavy rainfall contributed the most to the overall precipitation in the rainfall center of South China. (2) The coastal areas of Guangdong experienced two peaks of heavy rainfall in June and August, while Hainan Island observed a single peak in October. Other regions of Guangdong and Guangxi exhibited a single peak in June, which was closely related to the onset of the South China Sea summer monsoon. During the onset of the summer monsoon, the strong summer monsoon intensified the heavy rainfall in Zone I (Beibu Gulf), Zone II (area near Yangjiang), and Zone III (Pearl River Delta) along the coastal land areas of Guangdong and Guangxi. In the second rainy season, the summer monsoon continued to contribute to increased heavy rainfall across the entire coastal area and Hainan Island. In early June, Zone III and Zone IV (Shanwei and its eastern region) experienced a high frequency of heavy rainfall, primarily due to warm-sector heavy rainfall induced by the southwest summer monsoon. (3) Hainan Island exhibited the highest occurrence of extreme heavy rainfall in South China, predominantly in the afternoon. Guangdong followed with a lower occurrence, while Guangxi experienced the lowest occurrence. The diurnal variation of extreme heavy rainfall was most pronounced in the morning along the coastal area of Guangdong and Guangxi, especially from early morning to forenoon (5--11 am), which corresponded to the peak period in Zone II and Zone III. Inland areas of Guangdong only exhibited a peak period in the evening during the onset of summer monsoon. [ABSTRACT FROM AUTHOR]

NaNb x Ta 1-x O 3 , sodium tantalate and niobate with B atoms substitution is synthesized by a facile one-step hydrothermal method. They are effective photocatalysts for hydrogen evolution from water splitting without co-catalyst. NaNb 0.33 Ta 0.67 O 3 exhibits the best performance with produced H 2 of 1038 μmol g−1 in 5 h, which is more than 5 times than NaTaO 3 and NaNbO 3. It is also close to 5 times and 2 times than NaTaO 3 /Pt and NaNbO 3 /Pt, respectively. NaNb 0.33 Ta 0.67 O 3 has a transition state crystal structure between NaTaO 3 and NaNbO 3 crystalline phase. Moreover, XPS, ESR and TEM characterizations demonstrates that there are abundant oxygen vacancies in NaNb 0.33 Ta 0.67 O 3. These features give the catalyst excellent properties, such as good light harvesting and efficient charge separation confirmed by optical and electrochemical characterizations. This work may offer a strategy to develop perovskite sodium tantalate and niobate with controllable crystal structure and oxygen vacancies for highly efficient photocatalytic hydrogen evolution in the absence of co-catalyst. [Display omitted] • NaNb x Ta 1-x O 3 photocatalysts were prepared by a facile hydrothermal method. • NaNb x Ta 1-x O 3 had superior photocatalytic H 2 evolution ability without co-catalyst. • The maximum yield of H 2 was 1038 μmol. g−1 over NaNb 0.33 Ta 0.67 O 3 in 5 h. • Produced H 2 over NaNb 0.33 Ta 0.67 O 3 was more than 5 times than NaTaO 3 and NaNbO 3. • Excellent performance depended on transition state structure and oxygen vacancy. [ABSTRACT FROM AUTHOR]

Under dynamic conditions, motion blur is introduced to star images obtained by a star sensor. Motion blur affects the accuracy of the star centroid extraction and the identification of stars, further reducing the performance of the star sensor. In this paper, a star image restoration algorithm is investigated to reduce the effect of motion blur on the star image. The algorithm includes a blur kernel calculation aided by a MEMS gyroscope, blur kernel correction based on the structure of the star strip, and a star image reconstruction method based on scaled gradient projection (SGP). Firstly, the motion trajectory of the star spot is deduced, aided by a MEMS gyroscope. Moreover, the initial blur kernel is calculated by using the motion trajectory. Then, the structure information star strip is extracted by Delaunay triangulation. Based on the structure information, a blur kernel correction method is presented by utilizing the preconditioned conjugate gradient interior point algorithm to reduce the influence of bias and installation deviation of the gyroscope on the blur kernel. Furthermore, a speed-up image reconstruction method based on SGP is presented for time-saving. Simulated experiment results demonstrate that both the blur kernel determination and star image reconstruction methods are effective. A real star image experiment shows that the accuracy of the star centroid extraction and the number of identified stars increase after restoration by the proposed algorithm. [ABSTRACT FROM AUTHOR]

Light hydrocarbon (C2~C3) adsorption treatment in order to achieve exhaust emission standards of volatile organic compounds (VOCs) is very important and urgent in oil refining and oil storage enterprises. As an important adsorbent, metal‐organic frameworks (MOFs) with large specific surface area and good designability show excellent adsorption properties for light hydrocarbon. In this paper, by replacing the nitrate commonly used in the synthesis of MOFs with alkali metal, and adding a certain proportion of competing carboxylic acid into the reaction system, Cu‐BTC with improved pore structure and adsorption performance of light hydrocarbon was prepared at room temperature. More impressively, 10 L and 100 L scale‐up synthesis of Cu‐BTC were carried out by this method, which remained high light hydrocarbon adsorption capacities, showing great application prospect in the field of VOCs treatment. [ABSTRACT FROM AUTHOR]

To address the problems of traditional two‐level nested arrays (TTNA) with low degrees of freedom and high mutual coupling, a generalised two‐level nested MIMO radar array with high degrees of freedom and low mutual coupling for the direction of arrival (DOA) estimation is proposed. First, two coprime expansion factors are introduced in the TTNA to mitigate mutual coupling among array elements and enhance its degrees of freedom. Secondly, the range of consecutive lags and the total number of virtual array elements are derived in closed form under the structures of 'sum–difference co‐array'. Finally, utilising the atomic norm minimisation theory, the authors address the issue of discrete holes caused by different coprime expansion factors through filling in virtual arrays at discontinuities. Furthermore, a convex optimisation model to recover equivalent received signals from these filled virtual arrays is established, which is combined with a multiple signal classification algorithm for DOA estimation. Simulation results validate the rationality of the array structure and demonstrate the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

Magnetic Barkhausen Noise (MBN) detection technology shows great potential in the pipeline detection of stress, microstructure, and fatigue damage. However, in actual application, some pipes such as those near power plant are exposed to external magnetic fields or contain remanence. The presence of these magnetic fields will affect MBN features and then influence the testing results. To investigate the effect of DC magnetic field on MBN signal characteristics, theoretical analysis and experimental verification were carried out in this paper. It is found that the intensity and direction of the DC magnetic field have great effects on MBN signal characteristics, including the changes in the energy of MBN signal, the peak position and the shape of MBN signal profile. [ABSTRACT FROM AUTHOR]

The Ag 2 O/Ag 2 CO 3 heterostructure photocatalysts synthesized and regulated using simple one-step solid-state chemical process at room temperature exhibited outstanding visible light-driven photocatalytic acivity. • The heterojunction were in situ constructed by one-step room temperature solid-state method. • The composition of heterojunction can be in situ regulated by solid-state method. • The regulation mechanism of heterojunction has also been revealed. • The obtained Ag 2 O/Ag 2 CO 3 displays outstanding photocatalytic activity and reusability. Ag-based photocatalysts have excellent photocatalytic properties, but their photocatalytic degradation performance is limited by the serious photocatalytic corrosion. In order to enhance the stability of photocatalytic degradation of Ag-based photocatalysts, here, the Ag 2 O/Ag 2 CO 3 heterojunction was in-situ constructed and conveniently regulated by controlling the alkalinity of room temperature solid-state chemical reaction system. The photocatalytic degradation activity of the obtained heterojunction was influenced by the in-situ regulated component and band position of the Ag 2 O/Ag 2 CO 3 heterojunction. The obtained optimal products AAC-6 displayed remarkable photocatalytic activity and high reusability. The apparent rate constant of AAC-6 is 20 times than that of Ag 2 CO 3 , it is also far higher than that of P25. The significantly enhanced photocatalytic performance can be ascribed to the matching energy position between Ag 2 CO 3 and Ag 2 O, which can facilitate the visible light absorption ability and the efficient separation of photoinduced charges carriers. This study explored an in-situ one-step solid-state strategy to construct Ag 2 CO 3 -based heterojunction catalyst with outstanding photocatalytic performance, which may open a new perspective for the preparation of excellent photocatalytic degradation materials by solid-state chemical method. [ABSTRACT FROM AUTHOR]

CO 2 hydrogenation to methanol is an important technology for carbon utilization which not only provides a solution to the greenhouse gas mitigation but also produces value-added products. Copper-based catalyst has always been the research focus of the process. Cu 1.5 Mn 1.5 O 4 spinel has become an interesting alternative because it contains more oxygen defects and highly dispersed copper species that promote the CO 2 adsorption and conversion. In this paper, the effects of Cu and Zn on the performance of Cu-Mn-Zn/ZrO 2 catalysts for hydrogenation of CO 2 to methanol were studied. It was found that after Zn modification, the catalytic performance of the catalyst was greatly improved. Among all catalysts, Cu 3 MnZn 0.5 Zr 0.5 has the best CO 2 conversion (7.14%) and methanol selectivity (69.74%) at 260 °C and 5 MPa. XPS analysis showed that doped Zn replaced the position of Cu in Cu 1.5 Mn 1.5 O 4 spinel, forming the ZnO x and then increasing the content of oxygen defects, which resulted in the higher methanol selectivity. The increased Cu content promoted the activation of H 2 and the rate of *CO 3 hydrogenation to *HCOO, which in turn increases the conversion of CO 2. • Mn3+ induces partial reduction of ZnO for Cu-Mn-Zn/ZrO 2 catalysts. • Partial reduction of ZnO leads to the formation of oxygen defects. • Cu 3 MnZn 0.5 Zr 0.5 catalysts are efficient for CO 2 conversion to methanol • The intermediate *HCOO species are formed from the reaction of *CO 3 species either with *H or *H OH species • The production of methanol is controlled by the reaction of *HCOO with activated *H species. [ABSTRACT FROM AUTHOR]

Photovoltaic technology with low weight, high specific power in cold environments, and compatibility with flexible fabrication is highly desired for near‐space vehicles and polar region applications. Herein, we demonstrate efficient low‐temperature flexible perovskite solar cells by improving the interfacial contact between electron‐transport layer (ETL) and perovskite layer. We find that the adsorbed oxygen active sites and oxygen vacancies of flexible tin oxide (SnO2) ETL layer can be effectively decreased by incorporating a trace amount of titanium tetrachloride (TiCl4). The effective defects elimination at the interfacial increases the electron mobility of flexible SnO2 layer, regulates band alignment at the perovskite/SnO2 interface, induces larger perovskite crystal growth, and improves charge collection efficiency in a complete solar cell. Correspondingly, the improved interfacial contact transforms into high‐performance solar cells under one‐sun illumination (AM 1.5G) with efficiencies up to 23.7 % at 218 K, which might open up a new era of application of this emerging flexible photovoltaic technology to low‐temperature environments such as near‐space and polar regions. [ABSTRACT FROM AUTHOR]

Photovoltaic technology with low weight, high specific power in cold environments, and compatibility with flexible fabrication is highly desired for near‐space vehicles and polar region applications. Herein, we demonstrate efficient low‐temperature flexible perovskite solar cells by improving the interfacial contact between electron‐transport layer (ETL) and perovskite layer. We find that the adsorbed oxygen active sites and oxygen vacancies of flexible tin oxide (SnO2) ETL layer can be effectively decreased by incorporating a trace amount of titanium tetrachloride (TiCl4). The effective defects elimination at the interfacial increases the electron mobility of flexible SnO2 layer, regulates band alignment at the perovskite/SnO2 interface, induces larger perovskite crystal growth, and improves charge collection efficiency in a complete solar cell. Correspondingly, the improved interfacial contact transforms into high‐performance solar cells under one‐sun illumination (AM 1.5G) with efficiencies up to 23.7 % at 218 K, which might open up a new era of application of this emerging flexible photovoltaic technology to low‐temperature environments such as near‐space and polar regions. [ABSTRACT FROM AUTHOR]

Simple Summary: Here, we investigated the response of the coccolithophore Pleurochrysis carterae (P. carterae) isolated from the Bohai Sea to ocean acidification under different irradiance levels. A full factorial matrix of two pCO2 conditions (400 ppm and 800 ppm) and irradiance levels of 50, 200, 500 and 800 μmol photons m−2 s−1 were examined. The results suggest that ocean acidification suppressed the photosynthesis and increased the saturation irradiance for growth of the coccolithophore Pleurochrysis carterae. Further comparison with previously published results reveals that the physiological processes of the coastal coccolithophore specie Pleurochrysis carterae are less sensitive to ocean acidification than the smaller-sized species Emiliania huxleyi and Gephyrocapsa oceanica, and the saturation irradiance for the growth, particulate organic carbon (POC) and particulate inorganic carbon (PIC) production of Pleurochrysis carterae are much lower than those of the other two species. The ecologically important marine phytoplankton group coccolithophores have a global distribution. The impacts of ocean acidification on the cosmopolitan species Emiliania huxleyi have received much attention and have been intensively studied. However, the species-specific responses of coccolithophores and how these responses will be regulated by other environmental drivers are still largely unknown. To examine the interactive effects of irradiance and ocean acidification on the physiology of the coastal coccolithophore species Pleurochrysis carterae, we carried out a semi-continuous incubation experiment under a range of irradiances (50, 200, 500, 800 μmol photons m−2 s−1) at two CO2 concentration conditions of 400 and 800 ppm. The results suggest that the saturation irradiance for the growth rate was higher at an elevated CO2 concentration. Ocean acidification weakened the particulate organic carbon (POC) production of Pleurochrysis carterae and the inhibition rate was decreased with increasing irradiance, indicating that ocean acidification may affect the tolerating capacity of photosynthesis to higher irradiance. Our results further provide new insight into the species-specific responses of coccolithophores to the projected ocean acidification under different irradiance scenarios in the changing marine environment. [ABSTRACT FROM AUTHOR]