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Journal of Hydrodynamics 2023年第1期35卷 36-45页

作者： Sai zhang Qi-Hang Chen Chang Liu A-man zhang Shuai Li College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China

The underwater launch of high-speed vehicles involves complex bubble-structure interactions,which are not currently well *** this study,two small-scale experiments are carried out involving transient bubble-cylinder *** adopt the underwater electric discharge method to generate a high-pressure bubble that drives a cylinder to a maximum velocity of∼25 m/s within 1 ms.A tail bubble forms as the cylinder is ejected from the launch ***,we observe a shoulder cavity around the head of the cylinder due to the pressure reduction in the *** better understand the complex interaction between bubbles and the high-speed cylinder,we use the boundary element method to establish a bubble—structure interaction *** numerical model reproduces the experimental observations quite well,including the cylinder motion and the transient evolution of the ***,a systematic study is carried out to reveal the dependence of the bubble-cylinder interactions on the initial pressure of the tail bubble *** obtain a scaling law for the maximum velocity of the cylinder v_(m) with respect to p_(0),namely,v_(m) ∝ p_(0)^(0.45).The findings from this study may provide a reference for subsequent research into underwater launches.

关键词： Bubble dynamics underwater launch cavitation boundary element method

Catalytic activity of noble metal nanoparticles toward hydrodechlorination： influence of catalyst electronic structure and nature of adsorption

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Frontiers of Environmental Science & Engineering 2015年第5期9卷 888-896页

作者： man zhang Feng HE Dongye ZHAO Department of Civil Engineering Auburn University Auburn AL 36849 USA College of Biological and Environmental Engineering Zhejiang University of Technology Hangzhou 310014 China

In this study, stabilized Pd, Pt and Au nanoparticles were successfully prepared in aqueous phase using sodium carboxymethyl cellulose （CMC） as a capping agent. These metal nanoparticles were then tested for catalytic hydrodechlorination toward two classes of organochlorinated compounds （vinyl polychlorides includ- ing trichloroethylene （TCE）, tetrachloroethylene （PCE）, and alkyl polychlorides including 1,1,1-trichloroethane （1,1,1-TCA）, and 1,1,1,2-tetrachloroethane （1,1,1,2- TeCA）） to determine the rate-limiting steps and to explore the reaction mechanisms. The surface area normalized reaction rate constant, ksA, showed a systematic depen- dence on the electronic structure （the density of states at the Fermi level） of the metals, suggesting that adsorption of organochlorinated reactants on the metal catalyst surfaces is the rate-limiting step for catalytic hydrodechlorination. Hydrodechlorination rates of 1,1,1-TCA and 1,1,1,2-TeCA agreed with the bond strength of the first （weakest） dissociated C-C1 bond, suggesting that C-C1 bond cleavage, which is the first step for dissociative adsorption of the alkyl polychlorides, controlled the catalytic hydro- dechlorination rate. However, hydrodechlorination rates of TCE and PCE correlated with the adsorption energies of their molecular （non-dissociative） adsorption on the noble metals rather than with the first C-C1 bond strength, suggesting that molecular adsorption governs the reaction rate for hydrodechlorination of the vinyl polychlorides.

关键词： catalytic hydrodechlorination electronicstructure metal nanoparticles reaction mechanisms

Inverse design of quasi-bound states in the continuum metasurface for the polarization independent enhancement of Goos-H?nchen shift

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Science China(Physics,Mechanics & Astronomy) 2024年第12期67卷 79-86页

作者： Zuhai Ma Youzhi Shi Yu Chen Yu Xue Gan Wan Chi zhang Hui Jing Le-man Kuang Xinxing zhou Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education School of Physics and ElectronicsHunan Normal UniversityChangsha 410081China International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology Engineering Technology Research Center for 2D Material Information Function Devices and Systems of Guangdong ProvinceInstitute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China Key Laboratory of Physics and Devices in Post-Moore Era College of Hunan ProvinceChangsha 410081China Academy for Quantum Science and Technology Zhengzhou University of Light IndustryZhengzhou 450002China Institute of Interdisciplinary Studies Hunan Normal UniversityChangsha 410081China

Bound states in the continuum(BIC)have been widely researched and applied in optics due to their unique electromagnetic ***,there are still difficulties in predicting and customizing BIC *** address this issue,we design an efficient combined neural network for highly accurate prediction of quasi-bound states in the continuum(q-BIC)spectrum,as well as for the inverse design of the polarization independent enhancement of the Goos-H?nchen(GH)***,we propose a C_(4)symmetric metasurface for achieving q-BIC spectrum and providing the condition of enhanced GH *** employing a combined neural network,the intensity,position,shape,and phase of q-BIC spectrum with ultra-narrow resonance can be accurately predicted and on-demand customized,even under a small ***,we develop a screening algorithm for the q-BIC spectrum to quickly realize the polarization independent enhancement of GH *** an application,an ultra-high sensitivity refractive index sensor has been proposed,whose sensitivity can reach 2.31×10~7μm/RIU for TM polarization and 1.03×10~6μm/RIU for TE ***,this work brings new solutions for quick prediction of q-BIC spectrum and the development of flexible polarization photonic devices.

关键词： Goos-Hanchen shift bound states in the continuum deep learning

Identifying the limiting distribution by a general approach of Stein's method

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Science China Mathematics 2016年第12期59卷 2379-2392页

作者： SHAO Qi-man zhang Zhuo-Song Department of Statistics The Chinese University of Hong Kong

A general exchange pair approach is developed to identify the limiting distribution for any sequence of random variables, by calculating the conditional mean and the conditional second moments. The error of approximation is also studied. In particular, a Berry-Esseen type bound of O(n^(-3/4)) is obtained for the Curie-Weiss model at the critical temperature.

关键词： Stein's method exchangeable pair limiting distribution Berry-Esseen bounds Curie-Weiss model

5-羟甲基糠醛在CuPd(111)上的加氢反应机理研究

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原子与分子物理学报 2025年第4期42卷 53-57页

作者：张兴云周广丽石云山东临沂大学化学化工学院临沂276000

采用密度泛函理论,利用包含零点能校正的PBE-D3方法研究了5-羟甲基糠醛在双金属催化剂CuPd(111)上表面的加氢还原反应,考虑了两种反应路径,第一种反应路径是侧链上的醛基氧首先发生加氢反应生成F-CHOH中间体,然后F-CHOH中间体继续加氢生... 详细信息

采用密度泛函理论,利用包含零点能校正的PBE-D3方法研究了5-羟甲基糠醛在双金属催化剂CuPd(111)上表面的加氢还原反应,考虑了两种反应路径,第一种反应路径是侧链上的醛基氧首先发生加氢反应生成F-CHOH中间体,然后F-CHOH中间体继续加氢生成2,5-二羟甲基呋喃;第二种反应路径是侧链上的醛基碳先加氢原还原生成F-CH_(2)O中间体,生成的F-CH_(2)O进一步加氢还原生成2,5-二羟甲基呋喃.计算了两种竞争反应路径的活化能垒和反应热,结果表明,5-羟甲基糠醛在CuPd(111)面加氢还原生成2,5-二羟甲基呋喃的最佳反应路径为:F-CHO→F-CHOH→F-CH_(2)OH.

关键词： 5-羟甲基糠醛活化能垒反应热

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Impact of biosolids,ZnO,ZnO/biosolids on bacterial community and enantioselective transformation of racemic–quizalofop–ethyl in agricultural soil

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Journal of Environmental Sciences 2020年第1期32卷 163-172页

作者： Qing zhou Xu zhang School of Resources and Environmental Science Wuhan University

The effects of biosolids,ZnO,and ZnO/biosolids on soil microorganism and the environmental fate of coexisting racemic–quizalofop–ethyl(rac-QE)were *** biomass carbon in native soil,soil/biosolids decreased by 62%and 52%in the presence of ZnO(2‰,weight ratio).The soil bacterial community structure differed significantly among native soil,soil/biosolids,soil/ZnO,and soil/biosolids/ZnO based on a principal co-ordinate analysis(PCo A)of OTUs and one-way ANOVA test of bacterial *** transformation caused by ZnO only contributed 4%and 3% of the overall transformation of R-quizalofop-ethyl(R-QE)and S-quizalofop-ethyl(S-QE)in soil/*** inhibition effect of ZnO on the initial transformation rate of R-QE(rR-QE)and S-QE(rR-QE)in soil only observed when enantiomer concentration was larger than 10 mg/*** embedded with ZnO(biosolids/ZnO)caused a 17%–42% and 22%–38%decrease of rR-QE and rS-QE,although rR-QE and rS-QE increased by 0%–17% and 22%–58%by the addition of *** results also demonstrated that the effects of biosolids on agricultural soil microorganism and enantioselective transformation of chiral pesticide was altered by the embedded nanoparticles.

关键词： Bacterial structure Biosolids Chirality Enantiomer fraction ZnO

Electrochemical transformation of biomass-derived oxygenates

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Science China Chemistry 2023年第4期66卷 1011-1031页

作者： Peng zhou Jie zhang School of Chemistry Monash UniversityClaytonVictoria 3800Australia

Replacing conventional fossil resources with renewable raw materials for chemical production and energy generation is crucial for achieving the carbon-neutral goal and alleviating the emerging energy *** has been considered as one of the most promising candidates for this purpose owing to its great natural abundance and inherent ability to fix CO_(2) in the form of multicarbon ***,biomass conversion through an electrochemical route is intriguing because of its operability near ambient conditions,flexible scalability(suitable for distributed manufacturing and even domestic use)and green generation of oxidative or reductive equivalents instead of wasteful and possibly explosive or flammable ***,recent progress in electrochemical transformation of biomass,including hydrogenation and amination,is reviewed with the emphasis on catalysts and strategies for enhancing catalytic *** advances in mechanistic understanding using in-situ spectroscopy are also briefly ***,recommendations for the directions for future development are also provided.

关键词： biomass utilization electrochemical hydrogenation reductive amination catalyst in-situ spectroscopy mechanism

maneuvering target state estimation based on separate model-ing of target trajectory shape and dynamic characteristics

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Journal of Systems Engineering and Electronics 2022年第5期33卷 1195-1209页

作者： zhang Zhuanhua zhou Gongjian School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China

The state estimation of a maneuvering target,of which the trajectory shape is independent on dynamic characteristics,is *** conventional motion models in Cartesian coordinates imply that the trajectory of a target is completely determined by its dynamic ***,this is not true in the applications of road-target,sea-route-target or flight route-target tracking,where target trajectory shape is uncoupled with target velocity *** this paper,a new estimation algorithm based on separate modeling of target trajectory shape and dynamic characteristics is *** trajectory of a target over a sliding window is described by a linear function of the arc *** determine the unknown target trajectory,an augmented system is derived by denoting the unknown coefficients of the function as states in mileage *** every estimation cycle except the first one,the interaction(mixing)stage of the proposed algorithm starts from the latest estimated base state and a recalculated parameter vector,which is determined by the least squares(LS).Numerical experiments are conducted to assess the performance of the proposed *** results show that the proposed algorithm can achieve better performance than the conventional coupled model-based algorithms in the presence of target maneuvers.

关键词： maneuvering target tracking separate modeling natural parametric function interacting multiple model(IMM)filter data fitting state augmentation

Optimal predictive sliding-mode guidance law for intercepting near-space hypersonic maneuvering target

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Chinese Journal of Aeronautics 2022年第4期35卷 320-331页

作者： Bolun zhang Di zhou School of Astronautics Harbin Institute of TechnologyHarbin 150001China

The design of optimal guidance law for intercepting a near-space hypersonic maneuvering target with bounded inputs is considered. Firstly, a maneuvering model for near-space hypersonic aircraft is given. Then, the aircraft acceleration prediction can be obtained using this model with two neural networks. By using the target acceleration prediction, which is taken into account when calculating the Zero Effort Miss(ZEM), an optimal sliding-mode guidance law is proposed to fulfill the guidance task. An adaptive sliding-mode switch term is designed to deal with actuator saturation and prediction errors. Finally, numerical simulations show that the proposed guidance law can reduce the energy consumption and the terminal acceleration command of the interceptor effectively.

关键词： Adaptive sliding-mode control Near-space hypersonic aircraft Neural networks Optimal control Predictive guidance law

Regulating the recrystallized grain to induce strong cube texture in oriented silicon steel

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Journal of Materials Science & Technology 2022年第1期96卷 126-139页

作者： Mengcheng zhou Xinfang zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

Cube texture contains two easy magnetization directionsparallel to rolling and transverse direction,respectively,which is the most ideal magnetic texture suitable not only for transformers but also for rotating *** this study,a strong cube texture with ODF density of 50.73 mrd was successfully obtained by regulating the recrystallized grain orientation using cross-rolling and pulsed electric current,compared to conventional thermal annealing(the average cube texture intensity is~10 mrd in lots of latest studies).Cross cold rolling process intentionally"created"metastable deformed cube orientation in oriented silicon steel and the specific recrystallization texture rotation path was identified under pulsed electric current in 5 min:{114}→{114}→{114}→{001}→{001}.The cube-oriented grains were induced by pulsed electric current(800℃)and rapid heating(51.9℃/s,750℃),while the cube grains were observed in the annealed samples at the high temperature(1060℃).Recrystallized grain size of pulsed samples is about twice that of the annealed *** phenomenon is considered that the concurrent effects of electron wind force and Joule heating affected the nucleation,growth and rotation of cube grains by reducing the nuclear barrier,producing higher grain boundary mobility and structural evolution towards a state with lower electrical *** idea of current-controlled texture is worthy of popularization in more materials and the realization of an electromagnetic field to crystal orientation selection is an interesting topic.

关键词： Cube texture Cross-rolling Recrystallization Pulsed electric current EBSD