检索结果-南通市图书馆

Trial application of the envelope method to the potential ambiguity problem

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第1期35卷 73-80页

作者： Li-Yuan Hu Yu-Shou song Fundamental Science on Nuclear Safety and Simulation Technology Laboratory Harbin Engineering UniversityHarbin 150001China College of Nuclear Science and Technology Harbin Engineering UniversityHarbin 150001China Key Laboratory of Nuclear Safety and Advanced Nuclear Energy Technology Ministry of Industry and Information TechnologyHarbin 150001China

The optical potential ambiguity is a long-standing problem in the analysis of elastic scattering *** a specific collid-ing system,ambiguous potential families can lead to different behaviors in the nearside and farside scattering *** contrast,the envelope method can decompose the experimental data into two components with negative and positive deflection angles,***,a question arises as to whether the comparison between the calculated nearside(or farside)component and the derived positive-deflection-angle(or negative-deflection-angle)component can help analyze the potential ambiguity *** this study,we conducted a trial application of the envelope method to the potential ambiguity *** envelope method was improved by including uncertainties in the experimental *** colliding systems of 16O+28Si at 215.2 MeV and 12C+12C at 1016 MeV were considered in the *** each colliding system,the angular distribution experimental data were described nearly equally well by two potential sets,one of which is“surface transpar-ent”and the other is *** calculated angular distributions were decomposed into nearside and farside scattering *** the improved envelope method,the experimental data were decomposed into the positive-deflection-angle and negative-deflection-angle components,which were then compared with the calculated nearside and farside *** capability of the envelope method to analyze the potential ambiguities was also discussed.

关键词： Elastic scattering Optical potential ambiguities Envelope method Nearside/farside decomposition

Pr-Tb synergistic strengthening on coercivity of Nd-Ce-Fe-B magnets grain boundary diffused with Pr-Tb-Al-Ga alloys

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第9期42卷 1704-1709,I0003页

作者： Ruifang song Hang Zhao Haibo Feng Institute of Functional Materials Central Iron&Steel Research InstituteBeijing100081China

Sintered Nd-Ce-Fe-B magnets were grain boundary diffused(GBDed) with Pr_(x)Tb_(80-x)Al_(10)Ga_(10)(at%)(x=0,20,40,60,80) *** effect of Pr/Tb content in diffusion source on magnetic properties,microstructure and elements distribution of GBDed magnets was *** Pr is used to substitute for 75% Tb in diffusion source,Tb consumption per unit coercivity improvement of GBDed magnet reduces by 77%,compared with the Tb_(80)Al_(10)Ga_(10) diffused *** element diffuses into magnets and then forms Tb-rich shell with high magneto-crystalline anisotropy field surrounding main phase grains,resulting in substantial coercivity *** with low melting point diffuses deeply along liquid grain boundary phase during GBD *** can eliminate some sharp defects of main phase grains and make grain boundaries smooth,which provides diffusion channels for further diffusion of Tb ***,there are more diffusion channels for Tb and less Tb enriched at surface region,making Tb diffuse more deeply and improving Tb utilization *** method significantly improves the coercivity,and realizes the green,efficient and high-quality utilization of heavy rare earth(HRE)elements.

关键词： Grain boundary diffusion Rare earths Microstructure Synergistic strengthening

Effect of succinic acid on morphology transformation of the anhydrous magnesium carbonate particles prepared by magnesium chloride hexahydrate and urea

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第7期90卷 209-217页

作者： song Liu Guojun Cheng Zhongfeng Tang School of Materials Science and Engineering Anhui University of Science and TechnologyHuainan232001China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China Anhui Province Key Laboratory of Environment-friendly Polymer Materials Anhui UniversityHefei230601China

The homogeneous and controllable morphology of anhydrous magnesium carbonate(MgCO_(3))particles with excellent properties is difficult to obtain because of a variety of synthetic *** effect of succinic acid as a crystal modifier on the particle morphology transformation of anhydrous MgCO_(3)was investigated by the hydrothermal *** effect of the addition of succinic acid on the particles was similar to that of temperature *** morphology of particles with a folded diamond-like shape was gradually uniform,and the particle size was between 3.3 and 7.5μ*** MgCO_(3)particles prepared at pH 9 could easily agglomerate,and the average particle size increased from diamond-like to cube-like as the reaction time *** interaction between succinic acid and magnesium ions at different concentrations was the main factor responsible for the morphological *** pH,temperature,and time affected the molecular motion rate and crystal growth.

关键词： MgCO_(3) MgCl_(2)·6H_(2)O Urea Succinic acid Morphology

Practical Prescribed Time Tracking Control With Bounded Time-Varying Gain Under Non-Vanishing Uncertainties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 219-230页

作者： Dahui Luo Yujuan Wang Yongduan song the Key Laboratory of Dependable Service Computing in Cyber Physical Society Ministry of EducationChongqing UniversityChongqing 400044 the School of Automation Chongqing UniversityChongqing 400044 the Star Institute for Intelligent Systems Chongqing 400044 IEEE

This paper investigates the prescribed-time control(PTC) problem for a class of strict-feedback systems subject to non-vanishing uncertainties. The coexistence of mismatched uncertainties and non-vanishing disturbances makes PTC synthesis nontrivial. In this work, a control method that does not involve infinite time-varying gain is proposed, leading to a practical and global prescribed time tracking control solution for the strict-feedback systems, in spite of both the mismatched and nonvanishing uncertainties. Different from methods based on control switching to avoid the issue of infinite control gain that involves control discontinuity at the switching point, in our method a softening unit is exclusively included to ensure the continuity of the control action. Furthermore, in contrast to most existing prescribed-time control works where the control scheme is only valid on a finite time interval, in this work, the proposed control scheme is valid on the entire time interval. In addition, the prior information on the upper or lower bound of gi is not in need,enlarging the applicability of the proposed method. Both the theoretical analysis and numerical simulation confirm the effectiveness of the proposed control algorithm.

关键词： Adaptive control prescribed time control(PTC) strict-feedback systems tracking control

An optimization-oriented modeling approach using input convex neural networks and its application on optimal chiller loading

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2024年第4期17卷 639-655页

作者： Shanshuo Xing Jili Zhang song Mu Dalian University of Technology Dalian116024China guangdong Airport Baiyun Information Technology Co. Ltd.Guangzhou510000China

Optimization for the multi-chiller system is an indispensable approach for the operation of highly efficient chiller *** optima obtained by model-based optimization algorithms are dependent on precise and solvable objective *** classical neural networks cannot provide convex input-output mappings despite capturing impressive nonlinear fitting capabilities,resulting in a reduction in the robustness of model-based *** this paper,we leverage the input convex neural networks(ICNN)to identify the chiller model to construct a convex mapping between control variables and the objective function,which enables the NN-based OCL as a convex optimization problem and apply it to multi-chiller optimization for optimal chiller loading(OCL).Approximation performances are evaluated through a four-model comparison based on an experimental data set,and the statistical results show that,on the premise of retaining prior convexities,the proposed model depicts excellent approximation power for the data set,especially the unseen ***,the ICNN model is applied to a typical OCL problem for a multi-chiller system and combined with three types of optimization *** with conventional and meta-heuristic methods,the numerical results suggest that the gradient-based BFGS algorithm provides better energy-saving ratios facing consecutive cooling load inputs and an impressive convergence speed.

关键词： chiller plant input convex neural network optimal load distribution convex optimization

Stereoselective synthesis of substituted 1,3-dienes from propargylic esters: electrophilic-metal or redox catalysis?

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第5期67卷 1384-1396页

作者： Mengfu Dai Liangliang song Liang-An Chen Jiangsu Collaborative Innovation Center of Biomedical Functional Materials Jiangsu Key Laboratory of New Power BatteriesSchool of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023China Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources International Innovation Center for Forest Chemicals and MaterialsCollege of Chemical EngineeringNanjing Forestry UniversityNanjing 210037China

1,3-Diene architectures are not only widely present in natural products, pharmaceuticals, and functional organic materials but also serve as versatile building blocks to furnish important functionalized molecules in synthetic chemistry due to conjugated repeating C=C units. Accordingly, various strategies to access substituted 1,3-dienes in a stereoselective manner have been developed. However, chemo-, regio-and stereoselective synthesis of highly substituted 1,3-dienes still remains elusive and challenging. Readily available propargylic esters have emerged as an appealing class of synthetic intermediates for accessing functionalized 1,3-dienes, especially challenging tri-or tetrasubstituted variants, via transition-metal catalysis, including electrophilic metal and redox neutral catalysis. This review, for the first time, systematically highlights recent advances in transitionmetal catalyzed synthesis of substituted 1,3-dienes from propargylic esters, discusses the mechanisms and synthetic utilities, and gives the remaining challenges and potential opportunities in this field.

关键词： 1 3-diene propargylic ester lewis acid redox catalysis transition metal

Elasto-inertial microfluidic separation of microspheres with submicron resolution at high-throughput

在线全文

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2024年第1期10卷 203-216页

作者： Hyunwoo Jeon song Ha lee Jongho Shin Kicheol song Nari Ahn Jinsoo Park Department of Mechanical Engineering Chonnam National University77 Yongbong-ro Buk-guGwangju 61186Republic of Korea Analytical Engineering Team Samsung Display Co.Ltd.181 Samsung-roTangjeong-myeonAsan-siChungcheongnam-do 31454Republic of Korea

Elasto-inertial microfluidic separation offers many advantages including high throughput and separation *** though the separation efficiency highly depends on precise control of the flow conditions,no concrete guidelines have been reported yet in elasto-inertial ***,we propose a dimensionless analysis for precise estimation of the microsphere behaviors across the interface of Newtonian and viscoelastic *** number,modified Weissenberg number,and modified elastic number are used to investigate the balance between inertial and elastic lift *** on the findings,we introduce a new dimensionless number defined as the width of the Newtonian fluid stream divided by microsphere *** proposed dimensionless analysis allows us to predict whether the microspheres migrate across the co-flow *** theoretical estimation is found to be in good agreement with the experimental results using 2.1-and 3.2-μm-diameter polystyrene microspheres in a co-flow of water and polyethylene oxide *** on the theoretical estimation,we also realize submicron separation of the microspheres with 2.1 and 2.5μm in diameter at high throughput,high purity(>95%),and high recovery rate(>97%).The applicability of the proposed method was validated by separation of platelets from similar-sized Escherichia coli(***).

关键词： solution. separation estimation

Multi-scale modeling for prediction of mechanical performance in brazed GH99 thin-walled structure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 550-563页

作者： Yazhou LIU Shengpeng HU Yanyu song Wei FU Xiaoguo song Ning GUO Weimin LONG State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong Institute of Shipbuilding Technology Weihai 264209China China Machinery Intelligent Equipment Innovation Research Institute(Ningbo)Co. Ltd.Ningbo 315700China

Superalloy thin-walled structures are achieved mainly by brazing,but the deformation process of brazed joints is non-uniform,making it a challenging research *** paper records a thorough investigation of the effect of brazing parameters on the microstructure of joints and its mechanical properties,which mainly inquires into the deformation and fracture mechanisms in the shearing process of GH99/BNi-5a/GH99 *** macroscopic-microscopic deformation mechanism of the brazing interface during shearing was studied by Crystal Plasticity(CP)and Molecular Dynamics(MD)on the basis of the optimal brazing *** experimental results show that the brazing interface is mainly formed by(Ni,Cr,Co)(s,s)and possesses a shear strength of approximately 546 *** shearing fracture of the brazed joint occurs along the brazing seam,displaying the characteristics of intergranular *** simulations show that dislocations disassociate and transform into fine twinning with increased *** simulated the shear deformation process of the brazed *** multiscale simulation results are consistent with the experimental *** mechanical properties of thin-walled materials for brazing are predicted using MD and CP methods.

关键词： Multi-scale modeling Brazing Shear mechanisms Crystal plasticity GH99 superalloy

A Data Intrusion Tolerance Model Based on an Improved Evolutionary Game Theory for the Energy Internet

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第6期79卷 3679-3697页

作者： song Deng Yiming Yuan Institute of Advanced Technology Nanjing University of Posts and TelecommunicationsNanjing210003China College of Automation Nanjing University of Posts and TelecommunicationsNanjing210003China

Malicious attacks against data are unavoidable in the interconnected,open and shared Energy Internet(EI),Intrusion tolerant techniques are critical to the data security of *** intrusion tolerant techniques suffered from problems such as low adaptability,policy lag,and difficulty in determining the degree of *** address these issues,we propose a novel adaptive intrusion tolerance model based on game theory that enjoys two-fold ideas:(1)it constructs an improved replica of the intrusion tolerance model of the dynamic equation evolution game to induce incentive weights;and (2)it combines a tournament competition model with incentive weights to obtain optimal strategies for each stage of the game *** experiments are conducted in the IEEE 39-bus system,whose results demonstrate the feasibility of the incentive weights,confirm the proposed strategy strengthens the system’s ability to tolerate aggression,and improves the dynamic adaptability and response efficiency of the aggression-tolerant system in the case of limited resources.

关键词： Energy Internet Intrusion tolerance game theory racial competition adaptive intrusion response