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破碎泥岩注浆结石体动力特性的SHPB试验及其数值模拟研究

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岩土力学 2017年第7期38卷 2096-2102页

作者：詹金武李涛北京交通大学土木建筑学院北京100044

通过简化控制注浆模仿过程制备注浆结石体试样,借助分离式Hopkinson压杆(SHPB)装置,开展了不同注浆含量比及含水状态条件下破碎泥岩注浆结石体的动力特性研究,同时利用有限元软件Ansys/LS-Dyna对SHPB试验过程进行了数值模拟,对比分析数... 详细信息

通过简化控制注浆模仿过程制备注浆结石体试样,借助分离式Hopkinson压杆(SHPB)装置,开展了不同注浆含量比及含水状态条件下破碎泥岩注浆结石体的动力特性研究,同时利用有限元软件Ansys/LS-Dyna对SHPB试验过程进行了数值模拟,对比分析数值模拟与试验实测结果的相似性。试验结果显示,注浆含量比变化对试样的动态力学性能有较大的影响,只有在泥岩破碎程度适中、浆液具备较好压注条件时注浆效果才能达到最佳;在相同含量比条件下,含水率变化对试样动态力学性也有较大影响,试样含水率越高,其峰值强度及弹性模量普遍越小。数值模拟得到的应力-应变曲线与实测的应力-应变曲线具有较好的吻合效果;对HJC模型参数选取的合理性分析表明,模型参数A和B与动态峰值应力之间有较强的关联性,其值随着强度的增长有不断增加的趋势。

关键词： SHPB试验动力特性泥岩注浆结石体数值模拟 HJC模型

Kinetic model of vibration screening for granular materials based on biological neural network

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Particuology 2024年第5期88卷 98-106页

作者： zhan Zhao Yan zhang Fang Qin Mingzhi jin School of Agricultural Engineering Jiangsu UniversityZhenjiang212013China Shandong Academy of Agricultural Machinery Sciences Ji'nan250100China

The kinetic model is the theoretical basis for optimizing the structure and operation performance of vibration screening *** this paper,a biological neurodynamic equation and neural connections were established according to the motion and interaction properties of the material under vibration *** material feeding to the screen and the material passing through apertures were considered as excitatory and inhibitory inputs,respectively,and the generated stable neural activity landscape was used to describe the material distribution on the 2D screen *** dynamic process of material vibration screening was simulated using discrete element method(DEM).By comparing the similarity between the material distribution established using biological neural network(BNN)and that obtained using DEM simulation,the optimum coefficients of BNN model under a certain screening parameter were determined,that is,one relationship between the BNN model coefficients and the screening operation parameters was *** screening parameters were randomly selected,and the corresponding relationships were established as a ***,with straw/grain ratio,aperture diameter,inclination angle,vibration strength in normal and tangential directions as inputs,five independent adaptive neuro-fuzzy inference systems(ANFIS)were established to predict the optimum BNN model coefficients,*** training results indicated that ANFIS models had good stability and *** flexibility and adaptability of the proposed BNN method was demonstrated by modeling material distribution under complex feeding conditions such as multiple regions and non-uniform rate.

关键词： Kinetic model Material distribution Vibration screening Biological neural network DEM simulation Adaptive neuro-fuzzy inference systems

Electro-optic 3D snapshot of a laser wakefield accelerated kilo-ampere electron bunch

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Light(Science & Applications) 2024年第5期13卷 823-834页

作者： Kai Huang zhan jin Nobuhiko Nakanii Tomonao Hosokai Masaki Kando Kansai Institute for Photon Science(KPSI) National Institutes for Quantum Science and Technology(QST)KyotoJapan. Laser Accelerator R&D Innovative Light Sources DivisionRIKEN SPring-8 CenterHyogoJapan. SANKEN Osaka UniversityOsakaJapan

Laser wakefield acceleration,as an advanced accelerator concept,has attracted great attentions for its ultrahigh acceleration gradient and the capability to produce high brightness electron *** three-dimensional(3D)density serves as an evaluation metric for the particle bunch quality and is intrinsically related to the applications of an *** its significance,this parameter has not been experimentally measured in the investigation of laser wakefield *** report on an electro-optic 3D snapshot of a laser wakefield electron bunch at a position outside the *** 3D shape of the electron bunch was detected by simultaneously performing optical transition radiation imaging and electro-optic *** 3D structures to a few micrometer levels were reconstructed using a genetic *** electron bunch possessed a transverse size of less than 30 *** current profile shows a multi-peak *** main peak had a duration of1 *** maximum electron 3D number density was~9×10^(21)m^(-3).This research demonstrates a feasible way of 3D density monitoring on femtosecond kilo-ampere electron bunches,at any position of a beam transport line for relevant applications.

关键词： laser acceleration field

Tailoring the surface and interface structures of photocatalysts to enhance hydrogen production

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Science China Chemistry 2024年第4期67卷 1161-1174页

作者： tao zhang Pengfei Wang Shuai Yue Fei Li Zhiyong Zhao Sihui zhan MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Remediation and Pollution Control College of Environmental Science and EngineeringNankai UniversityTianjin 300350China

Photocatalytic water splitting using semiconductor photocatalysts is a promising approach for the production of carbon-neutral,sustainable and clean hydrogen ***,the separation and transport of photoinduced carriers are generally considered to be rate-limiting steps,and their low efficiency remains a major ***,much effort has been devoted to developing new strategies in surface/interface engineering of photocatalysts to improve the dynamics of charge separation/*** feature article briefly summarizes recent advances in photocatalyst surface/interface engineering by our research group,which have been achieved through the design of various novel photocatalysts,including interfacial modulation,heterostructure construction,heteroatom doping,single atom and diatom *** article is divided into three parts:first,we briefly introduce the three key processes involved in solar water splitting and reveal relationships between the properties of nanostructural photocatalysts and the fundamentals of water splitting;second,we detail methods and strategies for surface and interfacial structures to improve the efficiency of the fundamental processes,especially charge separation;finally,we explore prospects for photocatalytic water splitting *** article provides a valuable resource and strategies for researchers currently working in the field of photocatalytic water splitting.

关键词： photocatalytic water splitting surface/interface structures dual-functional photocatalysis

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环境规制、农业绿色生产率与粮食安全

中国人口·资源与环境 2019年第3期29卷 167-176页

作者：展进涛徐钰娇南京农业大学经济管理学院江苏南京210095 南京农业大学中国粮食安全研究中心江苏南京210095

绿色发展将成为中国未来粮食安全保障的重点内容,衡量农业绿色生产率有利于判断当前的发展位点,且合理的农业环境规制是促进绿色生产效率提升和解决粮食供需矛盾的有效途径。本文引入碳排放交易和排污费征收标准,在将考虑了环境成本的... 详细信息

绿色发展将成为中国未来粮食安全保障的重点内容,衡量农业绿色生产率有利于判断当前的发展位点,且合理的农业环境规制是促进绿色生产效率提升和解决粮食供需矛盾的有效途径。本文引入碳排放交易和排污费征收标准,在将考虑了环境成本的农业绿色GDP作为产出运用随机前沿函数模型(SFA)核算中国2000—2015年省级农业绿色全要素生产率的基础上,采用GMM方法检验了农业绿色全要素生产率与粮食安全保障程度之间是否具有因果关系,并构建联立方程模型具体分析了两者之间的影响机制,以及不同环境规制因素对两者的驱动机制。结果表明:①2000—2015年间全国平均农业绿色全要素生产率年均增长4. 10%,呈现明显的时序波动性以及地区之间的梯度性特征;②农业绿色全要素生产率和粮食安全之间存在双向因果关系;③农业绿色生产率的提高会降低粮食安全的保障程度,而过度重视粮食安全保障反过来会抑制农业绿色生产率的增长;④命令控制型环境政策规制对农业绿色全要素生产率和粮食安全均产生正向影响,激励性碳排放交易规制对农业绿色全要素生产率和粮食安全分别产生了正向作用和负向作用,自愿性环保投资规制仅对农业绿色全要素生产率产生了显著正向影响。因此,精心设计环境监管工具,改善环境规制政策的适度性和适用性,建立强化能够充分调动农民实施清洁生产的激励机制和市场化排污交易机制,大力整合不同类型环境法规从而构建均衡的"环境规制组合"体系,是提高农业绿色生产率增长和保障粮食安全可持续发展的关键。

关键词：农业绿色生产率粮食安全环境规制因果关系联立方程模型

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生态标志型水稻要素资源需求与经济效应分析

经济问题 2008年第5期 88-90页

作者：展进涛陈超南京农业大学经济管理学院南京210095

基于对调查数据的处理,主要研究生态标志型水稻与常规水稻在投入品需求、成本收益及生产效率等方面的差异及其影响因素,以期把握我国生态标志型水稻生产规律。

关键词：生态标志型农户行为经济效应

The chemical environment and structural ordering in liquid Mg-Y-Zn system:An ab-initio molecular dynamics investigation of melt for the formation mechanism of LPSO structure

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Journal of Magnesium and Alloys 2024年第2期12卷 815-824页

作者： Tangpeng Ma jin Wang Kaiming Cheng Chengwei zhan Jixue Zhou jingyu Qin Guochen Zhao Xinfang zhang Shandong Provincial Key Laboratory of High Strength Lightweight Metallic Materials Advanced Materials InstituteQilu University of Technology(Shandong Academy of Sciences)Jinan 250014China Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong UniversityJinan 250061China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China

In an effort to clarify the formation mechanism of LPSO structure in Mg-Y-Zn alloy,the chemical environment and structural ordering in liquid Mg-rich Mg-Y-Zn system are investigated with the aid of ab-initio molecular dynamics *** liquid Mg-rich Mg-Y alloys,the strong Mg-Y interaction is determined,which promotes the formation of fivefold symmetric local *** Mg-Zn alloys,the weak Mg-Zn interaction results in the fivefold symmetry weakening in the liquid *** to the coexistence of Y and Zn,the strong attractive interaction is introduced in liquid Mg-Y-Zn ternary alloy,and contributes to the clustering of Mg,Y,Zn launched from *** is more,the distribution of local structures becomes closer to that in pure Mg compared with that in binary Mg-Y and Mg-Zn *** results should relate to the origins of the Y/Zn segregation zone and close-packed stacking mode in LPSO structure,which provides a new insight into the formation mechanism of LPSO structure at atomic level.

关键词： Mg-Y-Zn Chemical environment Structural ordering ab-initio molecular dynamics

信息可信度对消费者转基因技术应用态度的影响

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华南农业大学学报（社会科学版） 2016年第1期15卷 99-107页

作者：张明杨展进涛南京信息工程大学中国制造业发展研究院江苏南京210044 南京信息工程大学经济管理学院江苏南京210044 南京农业大学经济管理学院江苏南京210095

有效的风险与收益沟通有助于提升消费者的判断能力。通过梳理转基因风险沟通与收益沟通的机制,构建消费者转基因技术应用态度影响因素的理论模型,探讨信息发布主体和信息内容如何通过感知风险与收益进而影响消费者态度。基于城市消费者... 详细信息

有效的风险与收益沟通有助于提升消费者的判断能力。通过梳理转基因风险沟通与收益沟通的机制,构建消费者转基因技术应用态度影响因素的理论模型,探讨信息发布主体和信息内容如何通过感知风险与收益进而影响消费者态度。基于城市消费者调查数据的实证结果表明:消费者对专业可靠的信息发布主体越信任,抑或对具有积极属性的信息内容越信任,他们的感知风险越小,感知收益越大,进而消费者转基因技术应用态度越积极;而非专业可靠的信息发布主体和具有消极属性的信息内容产生的作用恰恰相反。此外,感知风险与收益还受到消费者一般态度、消费者认知的共同影响。

关键词：转基因技术信息可信度转基因食品信息发布消费者态度感知风险食品安全

Application of CFD and FEA Coupling to Predict Structural Dynamic Responses of A Trimaran in Uni-and Bi-Directional Waves

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China Ocean Engineering 2024年第1期38卷 81-92页

作者： LIAO Xi-yu XIA jin-song CHEN zhan-yang TANG Qin ZHAO Nan ZHAO Wei-dong GUI Hong-bin Marine Design&Research Institute of China Shanghai 200011China Ship Structure Division China Ship Scientific Research CenterWuxi 214082China College of Ocean Engineering Harbin Institute of TechnologyWeihaiWeihai 264209China State Key Laboratory of Structural Analysis Optimization and CAE Software for Industrial EquipmentDalian University of TechnologyDalian 116024China School of Foreign Studies Jiangnan UniversityWuxi 214122China

To predict the wave loads of a flexible trimaran in different wave fields,a one-way interaction numerical simulation method is proposed by integrating the fluid solver(Star-CCM+)and structural solver(Abaqus).Differing from the existing coupled CFD-FEA method for monohull ships in head waves,the presented method equates the mass and stiffness of the whole ship to the hull shell so that any transverse and longitudinal section stress of the hull in oblique waves can be ***,verification study and sensitivity analysis are carried out by comparing the trimaran motions using different mesh sizes and time step *** on the wave elevation of uni-and bi-directional waves is also carried *** a comprehensive analysis on the structural responses of the trimaran in different uni-directional regular wave and bi-directional cross sea conditions is carried out,***,the differences in structural response characteristics of trimaran in different wave fields are *** results show that the present method can reduce the computational burden of the two-way fluid-structure interaction simulations.

关键词： CFD-FEA fluid-structure coupling structural responses trimaran bi-directional cross sea