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Vacancy engineering induced reaction kinetics enhancement of cobalt metaphosphate for pH-universal hydrogen evolution

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Nano Research 2024年第5期17卷 3879-3887页

作者： Yuting Chen Tian Meng Zhicai Xing Yueying Yan Yang Yang Bohan Yao dewen wang Xiurong Yang State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China

Developing efficient pH-universal hydrogen evolution reaction(HER)catalysts is critical in the field of water electrolysis,however,which is severely hampered by the sluggish kinetics in alkaline ***,a ruthenium(Ru)incorporation induced vacancy engineering strategy is firstly proposed to precisely construct oxygen vacancy(V_(O))-riched cobalt-ruthenium metaphosphate(CRPO)for high-efficiency pH-universal *** V_(O) modifies the electronic structure,improves the superficial hydrophilic and gas spillover capacity,it also reduces the coordination number of Ru atoms and regulates the coordination *** calculations indicate that Ru tends to adsorb H_(2)O and H^(*),whereas V_(O) tends to adsorb OH^(-),which greatly promotes the H_(2)O adsorption and the dissociation of HO-H ***,CRPO-2 exhibits remarkable HER performance,the mass activity is about 18.34,21.73,and 38.07 times higher than that of Pt/C in acidic,neutral,and alkaline media,respectively,at the same time maintain excellent *** findings may pave a new avenue for the rational design of electrocatalysts toward pH-universal water electrolysis.

关键词： cobalt metaphosphate pH-universal hydrogen evolution reaction(HER) vacancy engineering low-coordination atoms oxygen vacancy

Kinetically and thermodynamically expediting elementary steps via high-valence Cr-incorporated of nickel selenide for water electrolysis

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Nano Research 2024年第3期17卷 1199-1208页

作者： Huafeng Fan Dongxu Jiao Jinchang Fan dewen wang Bilal Zaman Wei Zhang Lei Zhang Weitao Zheng Xiaoqiang Cui State Key Laboratory of Automotive Simulation and Control School of Materials Science and EngineeringKey Laboratory of Automobile Materials of MOEJilin Provincial International Cooperation Key Laboratory of High-Efficiency Clean Energy MaterialsElectron Microscopy CenterJilin UniversityChangchun 130012China College of Chemistry Jilin UniversityChangchun 130012China

Designing high-performance electrocatalysts toward hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is essential to reduce the activation barrier and optimize free adsorption energy of reactive ***,we report that incorporating high-valence Cr into NiSe_(2)(Cr_(x)Ni_(1-x)Se_(2))kinetically and thermodynamically expedites elementary steps of both HER and *** as-prepared Cr_(0.05)Ni_(0.95)Se_(2) catalyst displays excellent HER and OER activities,with low overpotentials of 89 and 272 mV at the current density of 10 mA·cm^(-2)(j10),respectively,and remains stable during operation for 30 h.A low cell voltage of only 1.59 V is required to drive j10 in alkaline *** situ Raman spectroscopy reveals that Cr incorporation facilitates the formation of NiOOH active species during the OER ***,theoretical explorations demonstrate that high-valence Cr incorporation efficiently accelerates water dissociation kinetics and improves H*adsorption during HER process,lowering the activation barrier of OER and optimizing the adsorption energy of oxygen-based intermediate,thus kinetically and thermodynamically enhancing the intrinsic performance of NiSe_(2) for over water *** strategy provides a new horizon to design transition metal based electrocatalysts in the clean energy field.

关键词： nickel selenide electrocatalytic water splitting high-valence Cr density functional theory(DFT)calculation

Atomic Dispersed Hetero‑Pairs for Enhanced Electrocatalytic CO_(2)Reduction

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Nano-Micro Letters 2024年第1期16卷 55-67页

作者： Zhaoyong Jin Meiqi Yang Yilong Dong Xingcheng Ma Ying wang Jiandong Wu Jinchang Fan dewen wang Rongshen Xi Xiao Zhao Tianyi Xu Jingxiang Zhao Lei Zhang David J.Singh Weitao Zheng Xiaoqiang Cui State Key Laboratory of Automotive Simulation and Control School of Materials Science and EngineeringKey Laboratory of Automobile Materials of MOEElectron Microscopy CenterJilin UniversityChangchun 130012People’s Republic of China Key Laboratory of Photonic and Electronic Bandgap Materials Ministry of Educationand College of Chemistry and Chemical EngineeringHarbin Normal UniversityHarbin 150025People’s Republic of China College of Chemistry Jilin UniversityChangchun 130012People’s Republic of China Department of Physics and Astronomy and Department of Chemistry University of MissouriColumbiaMO 65211USA

Electrochemical carbon dioxide reduction reaction(CO_(2)RR)involves a variety of intermediates with highly correlated reaction and ad-desorption energies,hindering optimization of the catalytic *** example,increasing the binding of the*COOH to the active site will generally increase the*CO desorption *** this relationship may be expected to dramatically improve the intrinsic activity of CO_(2)RR,but remains an unsolved ***,we addressed this conundrum by constructing a unique atomic dispersed hetero-pair consisting of Mo-Fe di-atoms anchored on N-doped carbon *** system shows an unprecedented CO_(2)RR intrinsic activity with TOF of 3336 h−1,high selectivity toward CO production,Faradaic efficiency of 95.96%at−0.60 V and excellent *** calculations show that the Mo-Fe diatomic sites increased the*COOH intermediate adsorption energy by bridging adsorption of*COOH *** the same time,d-d orbital coupling in the Mo-Fe di-atom results in electron delocalization and facilitates desorption of*CO ***,the undesirable correlation between these steps is *** work provides a promising approach,specifically the use of di-atoms,for breaking unfavorable relationships based on understanding of the catalytic mechanisms at the atomic scale.

关键词： CO_(2)reduction reaction Atomic dispersed catalyst Hetero-diatomic pair Ad-desorption energy Linear scaling relation

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基于二次分解的不同太阳辐射下光伏功率预测

太阳能学报 2024年第9期45卷 360-368页

作者：王德文焦天媛华北电力大学控制与计算机工程学院保定071003 复杂能源系统智能计算教育部工程研究中心保定071003 河北省能源电力知识计算重点实验室保定071003

考虑不同太阳辐射对光伏功率的影响,提出一种基于二次分解和改进粒子群算法的光伏功率预测模型。通过Spearman和Kendall对影响光伏功率的各气象因素进行相关性分析,发现总倾斜辐射、总水平辐射、漫射倾斜辐射、漫射水平辐射与光伏功率... 详细信息

考虑不同太阳辐射对光伏功率的影响,提出一种基于二次分解和改进粒子群算法的光伏功率预测模型。通过Spearman和Kendall对影响光伏功率的各气象因素进行相关性分析,发现总倾斜辐射、总水平辐射、漫射倾斜辐射、漫射水平辐射与光伏功率的相关系数较大。然后利用CLARANS将样本数据按太阳辐射强度分为强辐射、中辐射和弱辐射,针对3类数据采用自适应噪声完备集合经验模态分解(CEEMDAN)对关键气象因素和功率进行二次分解,充分挖掘时序信息并降低数据的不稳定性。提出一种改进粒子群算法(GWCPSO)用于优化卷积神经网络和双向长短期记忆网络的超参数,提高调参效率,最后构建预测模型进行光伏功率预测。分析3种太阳辐射类型下不同分解方法与网络模型的预测误差,结果表明,所的预测模型可有效提高不同太阳辐射下光伏功率的预测精度。

关键词：光伏功率预测二次分解粒子群算法卷积神经网络双向长短期记忆网络

基于二次分解双向门控单元新型电力系统超短期负荷预测

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电力科学与工程 2024年第3期40卷 1-9页

作者：王德文安涵华北电力大学控制与计算机工程学院河北保定071003

在新型电力系统中,电力负荷随机性和波动性较强,现有预测方法难以对其实现高精度预测。为此,提出一种基于二次分解和双向门控循环单元的超短期负荷预测模型。首先,针对电力负荷的强随机性和强波动性,利用自适应噪声完备经验模态分解对... 详细信息

在新型电力系统中,电力负荷随机性和波动性较强,现有预测方法难以对其实现高精度预测。为此,提出一种基于二次分解和双向门控循环单元的超短期负荷预测模型。首先,针对电力负荷的强随机性和强波动性,利用自适应噪声完备经验模态分解对电力负荷历史序列进行初步分解,使负荷序列更加平稳。随后,对初步分解得到的强非平稳分量运用连续变分模态分解进行二次分解,降低其预测难度。最后,为充分学习电力负荷的时序特征,在预测过程构建基于双向门控循环单元的超短期电力负荷预测模型。实验结果表明,该模型相较于现有优秀预测模型有更高的预测精度。

关键词：新型电力系统超短期负荷负荷预测二次分解双向门控循环单元

Cloud-based parallel power flow calculation using resilient distributed datasets and directed acyclic graph

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Journal of Modern Power Systems and Clean Energy 2019年第1期7卷 65-77页

作者： dewen wang Fangfang ZHOU Jiangman LI School of Control and Computer Engineering North China Electric Power University

With the integration of distributed generation and the construction of cross-regional long-distance power grids, power systems become larger and more *** require faster computing speed and better scalability for power flow calculations to support unit *** on the analysis of a variety of parallelization methods, this paper deploys the large-scale power flow calculation task on a cloud computing platform using resilient distributed datasets(RDDs).It optimizes a directed acyclic graph that is stored in the RDDs to solve the low performance problem of the MapReduce *** paper constructs and simulates a power flow calculation on a large-scale power system based on standard IEEE test *** are conducted on Spark cluster which is deployed as a cloud computing *** show that the advantages of this method are not obvious at small scale, but the performance is superior to the stand-alone model and the MapReduce model for large-scale *** addition, running time will be reduced when adding cluster *** not tested under practical conditions, this paper provides a new way of thinking about parallel power flow calculations in large-scale power systems.

关键词： Power flow calculation Parallel programming model Distributed memory-shared model Resilient distributed datasets(RDDs) Directed acyclic graph(DAG)

Analytical Solution for Three-dimensional Forging Taking into Account Bulging of Sides by Mean Yield Criterion

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Chinese Journal of Mechanical Engineering 2010年第4期23卷 477-483页

作者： DU Haijun ZHAO dewen wang Genji wang Guodong State Key Laboratory of Rolling and Automation Northeastern University Shenyang 110004 China

Currently, for some complex plastic deformations, the analytical solution can not be obtained by using Mises yield criterion, because Mises yield criterion is nine dimensions, the velocity field is complex, and the solving methods are not innovative. Corresponding solutions of these problems are that yield criterion is linearized to reduce the variable numbers, and the velocity field and the solving methods are reasonably simplified, respectively. In this paper, a new linear yield criterion--mean yield（MY） criterion and inner-product of strain rate vector are used to analytically solve 3D forging taking into account bugling of sides. The velocity field is expressed as a vector in three dimensions, and rotation and divergence are applied to confirm that the velocity field is kinematically admissible. Then, the corresponding strain rate tensor of the velocity field is transformed into principal one by making the determinant of coefficients of the tensor cubic equation be zero. By using MY criterion, the plastic power is term by term integrated and summed according to inner-product of strain rate vector. An upper bound analytical solution is obtained for the forging, and verified by a pure lead press test. The test result turns out that the total pressure calculated by MY criterion is higher by 2.5%-15% than measuring value. In addition, a measuring formula of bulging parameter （a） is proposed, but the values of a measured by the formula are lower than those optimized by the golden section search. The total pressure calculated by MY criterion is compared with the ones by twin shear, Trasca yield, and Mises yield criterion. The comparing result shows that the total pressure calculated by MY criterion is slightly higher than the mean value of that by twin shear and Trasca yield criterion, and lower than that by Mises yield criterion, but more close to that by Mises yield criterion compared with that by other two. The proposed analytical solving methods can be effectively

关键词： mean yield criterion three-dimensional forging bulging strain rate vector inner-product

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中国老年人群抑郁特征与政策启示

中国农村卫生事业管理 2024年第3期44卷 209-213,161页

作者：吴政宇王德文厦门大学公共事务学院福建厦门361000

目的了解我国60岁及以上老年人群抑郁特征与变化趋势,为改善老年人心理健康水平提供依据。方法采用中国家庭追踪调查(CFPS)2016、2018与2020年三波次调查数据,应用8题简版流调中心抑郁量表(CES-D 8)对老年人抑郁特征与变化趋势进行分析... 详细信息

目的了解我国60岁及以上老年人群抑郁特征与变化趋势,为改善老年人心理健康水平提供依据。方法采用中国家庭追踪调查(CFPS)2016、2018与2020年三波次调查数据,应用8题简版流调中心抑郁量表(CES-D 8)对老年人抑郁特征与变化趋势进行分析。结果共得到3020例有效样本,其中男性1568(51.92%)人,女性1452(48.08%)人。分析结果显示在2016—2020年间老年人群抑郁评分呈逐年增长趋势(F=4.98,P<0.01)。女性老人抑郁评分均高于男性(t_(2016)=9.31,P<0.001;t_(2018)=9.36,P<0.001;t_(2020)=8.82,P<0.001),农村老人抑郁评分高于城市老人(t_(2016)=7.25,P<0.001;t_(2018)=7.93,P<0.001;t_(2020)=7.84,P<0.001),文盲老人抑郁评分高于非文盲老人(t_(2016)=-9.68,P<0.001;t_(2018)=-10.97,P<0.001;t_(2020)=-7.71,P<0.001),患慢性病老人抑郁评分高于未患慢性病老人(t_(2016)=-10.95,P<0.001;t_(2018)=-6.75,P<0.001;t_(2020)=-5.84,P<0.001),独居老人抑郁评分高于非独居老人(t_(2016)=-6.10,P<0.001;t_(2018)=-6.59,P<0.001;t_(2020)=-6.73,P<0.001)。结论我国老年人群抑郁问题逐年加重,女性、农村、文盲、患慢性病与独居老年人抑郁问题更为明显。降低老年人群抑郁风险,改善老年人心理健康水平,需重点关注女性、文盲、患慢性疾病等老年弱势人群。

关键词：老年人抑郁 CES-D 8 心理健康城乡差异政策启示

China’s Urban and Rural Old Age Security System: Challenges and Options

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China & World Economy 2006年第1期14卷 102-116页

作者： dewen wang Associate Professor Institute of Population and Labor Economics Chinese Academy of Social Sciences Beijing China

This paper reviews the development of the urban and rural old age security system in China, and discusses the challenges in the process of constructing a sustained old age security system. Althoughfunding gaps and empty individual accounts have imposed a heavy burden on the sustainability of China ＇s urban pension system, there is a relatively high coverage rate of 35.3 percent for urban workers. However, China＇s pension system provides low coverage ratefor rural farmers. The more rapidly aging population and lower incomes in rural areas pose challenges to the vulnerable rural househoM support system. The separation of the oM age security system between rural and urban areas also puts great pressure as a result of urbanization on farmers who lose their farmland. Therefore, it is urgent for China to speed up the reform o fits old age security system to provide an institutional support for its economic and social transition.

关键词： accounts system fully individual contribution pay-as-you-go (PAYG) pension system reform sustainability