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Mo_(2)P Monolayer as a Superior Electrocatalyst for Urea Synthesis from Nitrogen and Carbon Dioxide Fixation:A Computational Study

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Energy & Environmental Materials 2024年第1期7卷 207-214页

作者： Dongxu Jiao Zhongxu Wang Yuejie Liu Qinghai Cai Jingxiang Zhao Carlos R.Cabrera Zhongfang Chen College of Chemistry and Chemical Engineering and Key Laboratory of Photonic and Electronic Bandgap Materials Ministry of EducationHarbin Normal UniversityHarbin 150025China Modern Experiment Center Harbin Normal UniversityHarbin 150025China heilongjiang province Collaborative Innovation Center of Cold Region Ecological Safety Harbin 150025China Department of Chemistry and Biochemistry The University of Texas at El PasoEl Paso TX 79968USA Department of Chemistry University of Puerto RicoRio Piedras CampusSan JuanPuerto Rico 00931USA

Urea synthesis through the simultaneous electrocatalytic reduction of N_(2)and CO_(2)molecules under ambient conditions holds great promises as a sustainable alternative to its industrial production,in which the development of stable,highly efficient,and highly selective catalysts to boost the chemisorption,activation,and coupling of inert N_(2)and CO_(2)molecules remains rather ***,by means of density functional theory computations,we proposed a new class of two-dimensional nanomaterials,namely,transition-metal phosphide monolayers(TM_(2)P,TM=Ti,Fe,Zr,Mo,and W),as the potential electrocatalysts for urea *** results showed that these TM_(2)P materials exhibit outstanding stability and excellent metallic ***,the Mo_(2)P monolayer was screened out as the best catalyst for urea synthesis due to its small kinetic energy barrier(0.35 eV)for C-N coupling,low limiting potential(-0.39 V),and significant suppressing effects on the competing side *** outstanding catalytic activity of the Mo_(2)P monolayer can be ascribed to its optimal adsorption strength with the key^(*)NCON species due to its moderate positive charges on the Mo active *** findings not only propose a novel catalyst with high-efficiency and high-selectivity for urea production but also further widen the potential applications of metal phosphides in electrocatalysis.

关键词： C-N coupling density functional theory Mo_(2)P monolayer urea synthesis

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Ag-doped Ti3C2Tx sensor: A promising candidate for low-concentration H2S gas sensing

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HIGH VOLTAGE 2024年第3期9卷 537-545页

作者： Zeng, Fuping Feng, Xiaoxuan Chen, Xiaoyue Qiu, Hao Yan, Yiming Yao, Qiang Tang, Ju Wuhan Univ Sch Elect Engn & Automat Wuhan Peoples R China Hubei Key Lab Power Equipment & Syst Secur Integra Wuhan Peoples R China State Grid Chengdu Elect Power Supply Co Chengdu Peoples R China Chongqing Univ State Key Lab Power Transmiss Equipment Syst Secur Chongqing Peoples R China State Grid Chongqing Elect Power Res Inst Chongqing Peoples R China

Trace hydrogen sulphide (H2S) could reflect the severity of insulation faults in gas-insulated switchgear (GIS), therefore, accurate and fast detection of low-concentration H2S is important for on-line monitoring, fault diagnosis, and state evaluation in GIS. Ag-Ti3C2Tx chemiresistive-type sensors were fabricated via drop-coating with self-reduction synthesised Ag-doped Ti3C2Tx. The as-prepared sensors exhibited an excellent sensitivity and selectivity to H2S with an extremely low detection of limit of 18.57 parts per billion (ppb) at 25 degrees C (room temperature). The response of Ag-Ti3C2Tx sensor to 10 parts per million (ppm) H2S was enhanced similar to 12 times than that of the pristine Ti3C2Tx sensor. The compositing of Ti3C2Tx with Ag nanoparticles (NPs) enabled the fast response/recovery time for H2S detection. Further analysis found that the enhanced H2S sensing performances could be attributed to chemical sensitisation, adsorbed oxygen species regulation and high Brunauer-Emmett-Teller (BET) surface area. This study paves the way for Ag-Ti3C2Tx as room-temperature sensing materials to detect low-concentration H2S in GIS.

关键词： 2ND DISSOCIATION-CONSTANT PARTIAL DISCHARGE NEURAL-NETWORK DECOMPOSITION MOLECULES REMOVAL

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肖特基结多数载流子积累新型绝缘栅双极晶体管

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物理学报 2024年第7期73卷 325-332页

作者：段宝兴刘雨林唐春萍杨银堂西安电子科技大学微电子学院宽禁带半导体材料与器件教育部重点实验室西安 710071

绝缘栅双极晶体管(insulated gate bipolar transistor,IGBT)是现代功率半导体器件的核心,因其良好的电学特性得到了广泛的应用.本文提出了一种具有肖特基结接触的栅半导体层新型多数载流子积累模式IGBT,并对其进行特性研究和仿真分析.... 详细信息

绝缘栅双极晶体管(insulated gate bipolar transistor,IGBT)是现代功率半导体器件的核心,因其良好的电学特性得到了广泛的应用.本文提出了一种具有肖特基结接触的栅半导体层新型多数载流子积累模式IGBT,并对其进行特性研究和仿真分析.当新型IGBT处于导通状态,栅极施加正向偏压,由于肖特基势垒二极管极低的正向导通压降,使得栅半导体层的电压几乎等于栅极电压,从而能够在漂移区中积累大量的多数载流子电子.除了现有的电子外,这些积累的电子增大了漂移区的电导率,从而显著降低了正向导通压降.因此,打破了传统IGBT正向导通压降受漂移区掺杂浓度的限制.轻掺杂的漂移区可以使新型IGBT具有较高的击穿电压,同时减小了关断过程中器件内部耗尽层电容,因此整体米勒电容减小,提升了关断速度,减小了关断时间和关断损耗.分析结果表明,600 V级别的击穿电压时,新型IGBT的正向导通压降,关断损耗和关断时间相比常规IGBT分别降低了 46.2％,52.5％,30％,打破了 IGBT中正向导通压降和关断损耗之间的矛盾.此外,新型IGBT具有更高的抗闩锁能力和更大的正偏安全工作区.新型结构的提出满足了未来IGBT器件性能的发展要求,对于功率半导体器件领域具有重大指导意义.

关键词：绝缘栅双极晶体管积累模式正向导通压降关断损耗

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A low-frequency and broadband wave-insulating vibration isolator based on plate-shaped metastructures

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1171-1188页

作者： Wei WEI Feng GUAN Xin FANG College of Intelligent science National University of Defense TechnologyChangsha410073China Naval Research Academy Beijing100161China

A metamaterial vibration isolator,termed as wave-insulating isolator,is proposed,which preserves enough load-bearing capability and offers ultra-low and broad bandgaps for greatly enhanced wave *** consists of plate-shaped metacells,whose symmetric and antisymmetric local resonant modes offer several low and broad mode bandgaps although the complete bandgap remains high and *** bandgap mechanisms,vibration isolation properties,effects of key parameters,and robustness to complex conditions are *** experimentally demonstrated,the wave-insulating isolator can improve the vibration insulation in the ranges of[50 Hz,180 Hz]and[260 Hz,400 Hz]by 15 dB and 25 dB,respectively,in contrast to the conventional isolator with the same first resonant frequency.

关键词： metamaterial and metastructure vibration isolation bandgap wave insulation plate

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Dynamic manipulation of multimodal emission in Er^(3+)-activated non-core-shell structure for optical thermometry and information security

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Rare Metals 2024年第4期43卷 1702-1712页

作者： Xuan Liu Zi-Xia Lin Yin-Biao Shi Xiao-Yan Wang Ming-Ye Ding Xiao-Fei Yang College of science Nanjing Forestry UniversityNanjing210037China Testing Center Yangzhou UniversityYangzhou225009China

Regulating luminescent dynamics of lanthanide-based luminescent materials via external stimuli is of great significance in the fields of optical thermometry and high-level ***,it is still a huge challenge to realize multimodal emissions with tunable color outputs from a single activator in simple structures via smart dynamic control of photon transition ***,we present a mechanistic strategy to achieve multimodal luminescence of Er^(3+)activators with color-switchable outputs in a non-core-shell *** the control of excitation dynamics(λ_(ex)=980,808,1532,377 nm),the population among the intermediate en ergy levels of Er^(3+)and the interaction between Er^(3+)and Yb^(3+)could be precisely modulated through energy transfer and migration processes,leading to the generation of colortunable multimodal luminescence upon diverse excitation modes(non-steady-state,single-/dual-wavelength steady,thermal activation).Inspired by its special luminescent performance,the as-obtained material exhibits great potential in noncontact thermometry,multimodal anticounterfeiting,and high-capacity information encryption by performing a series of proof-of-concept *** findings might provide a conceptual model to modulate the luminescent dynamics in a simple-structured system for the generation of color-adjustable multimodal emissions,which is convenient for the development of advanced luminescent materials toward versatile cuttingedge applications.

关键词： Lanthanide ions Multimodal emission Upconversion Downshifting Anti-counterfeiting Luminescent thermometry

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Hollow Ni Mo-based nitride heterojunction with super-hydrophilic/aerophobic surface for efficient urea-assisted hydrogen production

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Journal of Energy Chemistry 2024年第8期95卷 428-439,I0009页

作者： Yuying Fan Ying Gu Dongxu Wang Yanqing Jiao Aiping Wu Chungui Tian Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education of the People’s Republic of ChinaHeilongjiang UniversityHarbin 150080HeilongjiangChina College of Chemistry Chemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbin 150040HeilongjiangChina

Hydrogen evolution reaction(HER)and urea oxidation reaction(UOR)are key reactions of the watercycling associated catalytic process/*** design of catalysts with a super-hydrophilic/aerophobic structure and optimized electron distribution holds great ***,we have designed a threedimensional(3D)hollow Ni/NiMoN hierarchical structure with arrayed-sheet surface based on a onepot hydrothermal route for efficient urea-assisted HER based on a simple hydrothermal *** Ni/NiMoN catalyst exhibits super-hydrophilic/aerophobic properties with a small droplet contact angle of 6.07°and an underwater bubble contact angle of 155.7°,thus facilitating an escape of bubbles from the *** functional theory calculations and X-ray photoelectron spectroscopy results indicate the optimized electronic structure at the interface of Ni and NiMoN,which can promote the adsorption/desorption of reactants and *** virtues combining with a large specific surface area endow Ni/NiMoN with efficient catalytic activity of low potentials of 25 mV for HER and 1.33 V for UOR at10 mA cm^(-2).The coupled HER and UOR system demonstrates a low cell voltage of 1.42 V at 10 mA cm^(-2),which is approximately 209 mV lower than water electrolysis.

关键词： Hydrogen evolution Transition metal nitrides Hollow heterojunctions Urea electrooxidation Super hydrophilic/aerophobic

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A benchmark-based method for evaluating hyperparameter optimization techniques of neural networks for surface water quality prediction

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Frontiers of Environmental science & Engineering 2024年第5期18卷 13-27页

作者： Xuan Wang Yan Dong Jing Yang Zhipeng Liu Jinsuo Lu School of Environmental and Municipal Engineering Xi’an University of Architecture and TechnologyXi’an710055China Shaanxi Key Laboratory of Environmental Engineering Xi’an University of Architecture and TechnologyXi’an710055China State Key Laboratory of Green Building in West China Xi’an University of Architecture and TechnologyXi’an710055China

Neural networks(NNs)have been used extensively in surface water prediction tasks due to computing algorithm improvements and data *** essential step in developing an NN is the hyperparameter *** practice,it is common to manually determine hyperparameters in the studies of NNs in water resources *** may result in considerable randomness and require significant computation time;therefore,hyperparameter optimization(HPO)is *** study adopted five representatives of the HPO techniques in the surface water quality prediction tasks,including the grid sampling(GS),random search(RS),genetic algorithm(GA),Bayesian optimization(BO)based on the Gaussian process(GP),and the tree Parzen estimator(TPE).For the evaluation of these techniques,this study proposed a method:first,the optimal hyperparameter value sets achieved by GS were regarded as the benchmark;then,the other HPO techniques were evaluated and compared with the benchmark in convergence,optimization orientation,and consistency of the optimized *** results indicated that the TPE-based BO algorithm was recommended because it yielded stable convergence,reasonable optimization orientation,and the highest consistency rates with the benchmark *** optimization consistency rates via TPE for the hyperparameters hidden layers,hidden dimension,learning rate,and batch size were 86.7%,73.3%,73.3%,and 80.0%,*** the evaluation of HPO techniques directly based on the prediction performance of the optimized NN in a single HPO test,the proposed benchmark-based HPO evaluation approach is feasible and robust.

关键词： Neural networks Hyperparameter optimization Surface water quality prediction Bayes optimization Genetic algorithm

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Oleanolic acid improved intestinal immune function by activating and potentiating bile acids receptor signaling in E. coli-challenged piglets

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Journal of Animal science and Biotechnology 2024年第5期15卷 2137-2155页

作者： Chenyu Xue Hongpeng Jia Rujing Cao Wenjie Cai Weichen Hong Jianing Tu Songtao Wang Qianzhi Jiang Chongpeng Bi Anshan Shan Na Dong The Laboratory of Molecular Nutrition and Immunity College of Animal Science and TechnologyNortheast Agricultural UniversityHarbinP.R.China

Background Infection with pathogenic bacteria during nonantibiotic breeding is one of the main causes of animal intestinal *** acid(OA)is a pentacyclic triterpene that is ubiquitous in *** previous work demonstrated the protective effect of OA on intestinal health,but the underlying molecular mechanisms remain *** study investigated whether dietary supplementation with OA can prevent diarrhea and intestinal immune dysregulation caused by enterotoxigenic Escherichia coli(ETEC)in *** key molecular role of bile acid receptor signaling in this process has also been *** Our results demonstrated that OA supplementation alleviated the disturbance of bile acid metabolism in ETEC-infected piglets(P<0.05).OA supplementation stabilized the composition of the bile acid pool in piglets by regulating the enterohepatic circulation of bile acids and significantly increased the contents of UDCA and CDCA in the ileum and cecum(P<0.05).This may also explain why OA can maintain the stability of the intestinal microbiota structure in ETEC-challenged *** addition,as a natural ligand of bile acid receptors,OA can reduce the severity of intestinal inflammation and enhance the strength of intestinal epithelial cell antimicrobial programs through the bile acid receptors TGR5 and FXR(P<0.05).Specifically,OA inhibited NF-κB-mediated intestinal inflammation by directly activating TGR5 and its downstream c AMP-PKA-CREB signaling pathway(P<0.05).Furthermore,OA enhanced CDCA-mediated MEK-ERK signaling in intestinal epithelial cells by upregulating the expression of FXR(P<0.05),thereby upregulating the expression of endogenous defense molecules in intestinal epithelial *** In conclusion,our findings suggest that OA-mediated regulation of bile acid metabolism plays an important role in the innate immune response,which provides a new diet-based intervention for intestinal diseases caused by pathogenic bacterial infections in pig

关键词： Bile acid receptors Enterotoxigenic Escherichia coli Intestinal innate immunity Oleanolic acid

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Work-function-induced interfacial electron redistribution of MoO_(2)/WO_(2) heterostructures for high-efficiency electrocatalytic hydrogen evolution reaction

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Rare Metals 2024年第2期43卷 489-499页

作者： Tong-Fei Li Jing Li Lu-Ping Zhang Jia-Wei Ke Meng-Xing Fan Li-Fang Zhang Cheng-Wei Deng Yi Sun Tao Qian Cheng-Lin Yan School of Chemistry and Chemical Engineering Nantong UniversityNantong226019China Jiangsu Key Laboratory of New Power Batteries Jiangsu Collaborative Innovation Centre of Biomedical Functional MaterialsSchool of Chemistry and Materials ScienceNanjing Normal UniversityNanjing210023China Aerospace Hydrogen Energy Technology(Shanghai)Co.Ltd. Shanghai201800China Key Laboratory of Core Technology of High Specific Energy Battery and Key Materials for Petroleum and Chemical Industry College of EnergySoochow UniversitySuzhou215006China Light Industry Institute of Electrochemical Power Sources Suzhou215006China

The engineering of the electronic configurations of active sites,together with the production of more accessible active sites through heterostructure design,has been established as a forceful methodology for boosting water electrolysis ***,a facile approach is developed to fabricate well-dispersed MoO_(2) and WO_(2) nanoparticles with abundant heterointerfaces entrapped in N,P-doped carbon nanofibers(referred to as MoO_(2)/WO_(2)@N,P-CNFs hereafter)as hydrogen evolution reaction(HER)electrocatalysts in alkaline and acidic *** spectroscopic analyses and theoretical findings manifest that the heterointerface formed by the work function modulation of MoO_(2)/WO_(2) triggers the spontaneous electron redistribution from MoO_(2)to WO_(2) and a built-in electric field,which is essential to promote water adsorption,optimize the H-intermediate adsorption energy,result in the enhanced charge transfer efficiency,and ultimately increase the intrinsic HER ***,the intimate confinement of MoO_(2)/WO_(2) heterostructures in the porous carbon substrate can restrain the active sites from unfavorable coarsening and detachment,thus ensuring facilitated HER kinetics and outstanding structural *** a result,MoO_(2)/WO_(2)@N,P-CNFs exhibit superior catalytic HER performance in acidic and basic solutions,requiring 118 and 95 mV overpotentials to achieve 10 mA·cm^(−2),respectively,surpassing a number of reported non-noble metal-based *** work provides guidelines for the rational design and construction of special metallic heterocomponents with optimized interfacial electronic structure for various electrochemical technologies.

关键词： Electrospinning MoO_(2)/WO_(2) heterostructure Work function Hydrogen evolution reaction

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Methylthio side-chain modified quinoidal benzo-[1,2-b:4,5-b']dithiophene derivatives for high-performance ambipolar organic field-effect transistors

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science China Chemistry 2024年第10期67卷 3357-3365页

作者： Li Chen Xiaoqi Luo Nuoya Li Shaoqian Peng Qing Jiang Di Wu Jianlong Xia State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Center of Smart Materials and DevicesWuhan University of TechnologyWuhan 430070China School of Chemistry Chemical Engineering and Life ScienceWuhan University of TechnologyWuhan 430070China Department of Chemistry National University of SingaporeSingapore 117543Singapore

Quinoidal small molecule semiconductors hold huge potential in ambipolar organic field-effect transistors(OFETs)and organic spintronic ***,two quinoidal molecules with methylthio side chains were synthesized to develop molecular semiconductors with high ambipolar mobility,designated QBDTS and *** theoretical calculation results reveal that QBDTS has a closed-shell structure while QTBDTS showed an open-shell structure with a biradical character(y0)of 0.46 and its magnetic properties were further investigated using electron paramagnetic resonance(EPR)and superconducting quantum interference device(SQUID)*** methyl side chains showed a large impact on the molecular orbital *** HOMO/LUMO levels of QBDTS and QTBDTS were measured to be-5.66/-4.56 and-5.27/-4.48 eV,respectively,which are favorable for ambipolar charge transport in ***,the spin-coated QBDTS displayed hole and electron mobilities of 0.01 and 0.5 cm^(2)V^(-1)s^(-1)while QTBDTS showed a record high hole mobility of 1.8 cm^(2)V^(-1)s^(-1)and electron mobility of 0.3 cm^(2)V^(-1)s^(-1).Moreover,comparative studies of the thin film morphologies also manifested the beneficial influence of methyl side chains on film crystallinity and molecule *** results strongly proved that methyl side chain engineering can be a simple but efficient strategy for modulating electronic properties and molecular stacking *** work also represents a big advancement for quinoidal molecular semiconductors in ambipolar OFET applications.

关键词： side-chain modification quinoidal molecules ambipolar diradicals organic field-effect transistors

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