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The multiple roles of crop structural change in productivity,nutrition and environment in China:A decomposition analysis

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Journal of Integrative Agriculture 2024年第5期23卷 1763-1773页

作者： xiangyang zhang Yumei zhang Shenggen Fan College of Economics and Management China Agricultural UniversityBejing 100083China Academy of Global Food Economics and Policy China Agricultural UniversityBejing 100083China

China's crop structure has undergone significant changes in the last two decades since 2000,with an increase in the share of cereals,vegetables,and fruit,squeezing out other crops.As a result,land productivity,nutrient supply,and carbon emissions have changed.How to reallocate limited farmland among crops to achieve the multiple goals of agrifood systems becomes an important issue.This study explores the sources of land productivity and nutrition supply growth and carbon emissions reduction,and identifies the multiple roles of crop structural change from 2003 to 2020 based on a decomposition analysis.The results reveal that the growth within crops is still the primary driver in land productivity and nutrition supply and the reduction in carbon emissions.However,structural change also plays various roles at different periods.From 2003 to 2010,crop structural change increased the total calorie supply but lowered land productivity and contributed at least 70%of the total growth of carbon emissions.The crop structure was relatively stable,and their effects were modest from 2010 to 2015.From 2015 to 2020,the crop structural change began to play a greater role and generate synergistic effects in improving land productivity,micronutrient supply,and reducing carbon emissions,contributing to approximately a quarter of the growth of land productivity and 30%of total carbon emissions reduction.These results suggest that strategies for crop structural change should comprehensively consider its multiple impacts,aiming to achieve co-benefits while minimizing trade-offs.

关键词： crop structural change land productivity nutrition carbon emissions

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Mediating effect of resilience on the relationship between rumination and suicide attempts in Chinese adolescents with mood disorders

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General Psychiatry 2024年第2期37卷 306-310页

作者： Dianying Liu Gang Lei Hongdong Deng xiangyang zhang Yonghui Dang College of Medicine&Forensics Xi'an Jiaotong University Health Science CenterXi'anShaanxiChina Ganzhou City Key Laboratory of Mental Health The Third People's Hospital of Ganzhou CityGanzhouJiangxiChina Institute of Psychology Chinese Academy of SciencesBeijingChina

To the editor:Mood disorders(MD)are serious mental illnesses that commonly affect adolescents,leading to a high incidence of suicidal behaviour.1 In China,the suicide attempt(SA)rate for adolescents with MD is 51.96%,2 and over 500000 adolescent SA are reported annually in the USA due to depression.3 Risk factors for SA include gender,hormone levels,family conflict and,particularly,negative cognitive styles such as rumination.

关键词： adolescent disorders annually

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Experimental Study on Seepage Characteristics of a Soil-Rock Mixture in a Fault Zone

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Fluid Dynamics & Materials Processing 2022年第2期18卷 271-283页

作者： Pengfei Wang xiangyang zhang Key Laboratory of Safety and High-Efficiency Coal Mining Ministry of EducationAnhui University of Science and TechnologyHuainan232001China School of Architecture and Civil Engineering Huangshan UniversityHuangshan245041China

A mixture of fault gouge and rubble taken out from a fault zone is used to prepare a S-RM(Soil-Rock Mixture)sample with rock block proportions of 20%,30%,40%,50%,60%and 70%,respectively.A GDS triaxial test system is used accordingly to measure the seepage characteristics of such samples under different loading and unloading confining pressures in order to determine the variation law of the permeability coefficient.The test results show that:(1)The permeability coefficient of the S-RM samples decreases as the pressure increases,and the decrease rate of this coefficient in the initial stage of confining pressure loading is obviously higher than in the semi-late period;(2)The permeability coefficient at different confining pressure levels presents a common trend as the rock block proportion is increased,i.e.,it decreases first then it increases(the permeability coefficient of the sample with rock block proportion 40%being the smallest,70%the largest);(3)In the stage of confining pressure unloading,the recovery degree of the permeability coefficient grows with the increase of rock block proportion(the recovery rate of S-RM sample with rock block proportion 70%reaches 50.2%);(4)In the stage of confining pressure loading and unloading,the sensitivity of the permeability coefficient to the rock block proportion displays the inverse“Z”variation rule(when rock block proportion reaches 60%,the sensitivity is highest);(5)In the stage of confining pressure loading,the relationship between the permeability coefficient and confining pressure can be described by an exponential relationship.

关键词： Fault zone rock block proportion soil-rock mixture confining pressure loading and unloading seepage characteristic

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Design of high-performance molybdenum alloys via doping metal oxide and carbide strengthening:A review

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Journal of Materials Science & Technology 2023年第29期160卷 161-180页

作者： Hairui Xing Ping Hu Chaojun He xiangyang zhang Jiayu Han Fan Yang Run Bai Wen zhang Kuaishe Wang Alex AVolinsky School of Metallurgy Engineering Xi’an University of Architecture and TechnologyXi’an 710055China National and Local Joint Engineering Research Center for Functional Materials Processing Xi’an University of Architecture and TechnologyXi’an 710055China Northwest Institute for Non-ferrous Metal Research Xi’an 710016China Department of Mechanical Engineering University of South Florid14202 E.Fowler Ave.ENG 030Tamp1FL 33620USA

Metal oxide and carbide strengthening molybdenum(Mo)alloys have been designed as promising ad-vanced materials in refractory metals to solve some of the core engineering problems in superalloy ap-plications.Hence,there is a need to summarize the results obtained and evaluate the opportunities for preparing high-performance Mo alloys by strengthening metal oxides and carbides to improve the per-formance characteristics of Mo metal materials.This paper reviews the results of the reported work con-cerning the structure and properties of Mo alloys with different metal oxide and carbide strengthening methods added to Mo matrix.The influence of the doping of La 2 O 3 and Y 2 O 3 particles,ceramic Al 2 O 3 and ZrO 2 particles,and refractory TiC and ZrC carbides particles of Mo alloys are discussed.The impacts of particle morphology,size,distribution and volume fractions of oxide and carbide are analyzed,as well as the specific features of different doping techniques for obtaining high-performance Mo alloys mate-rials.This work will guide future research on the design of high-performance refractory Mo alloys by adding oxides and carbide particles,helping to solve the core issues in the field of superalloy application research.

关键词： Molybdenum alloy Metal oxide and carbide addition Oxide dispersion-strengthened Carbide precipitation-strengthened Microstructure Mechanical properties

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Extradural injections and manual repositioning of spine in treatment of megalgia caused by cervical spondylotic radiculopathy

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Journal of Traditional Chinese Medicine 2013年第1期33卷 74-77页

作者： Yishan Liu Xia Liu xiangyang zhang Hong zhang Bone-setting Center by Means of Combination of Traditional Chinese Medicine with Western Medicine Air Force General Hospital of the People's Liberation Army Department of Rehabilitation Air Force General Hospital of the People's Liberation Army

OBJECTIVE: To ascertain if it is effective to use extradural injections and manual repositioning of the spine to treat megalgia caused by cervical spondylotic radiculopathy (CSR). METHODS: Patients with megalgia caused by CSR were divided into a treatment group (n=46) treated by extradural injection and manual repositioning of the spine and a control group (n=46) treated by a conventional method. RESULTS: The prevalence of cure was 58.69% and the total prevalence of effective cure in the treatment group was 97.83% and was 23.91% and 78.26%, respectively, in the control group: this difference between the two groups was significant (P< 0.05). CONCLUSION: Treatment of megalgia caused by CSR by extradural injections and manual repositioning of the spine has a good curative effect with rapid analgesia and short therapeutic course.

关键词：颈椎病治疗定位手动硬膜注射脊椎根型

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厚煤硬顶条件下综放末采回采效率提高对策研究

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采矿与安全工程学报 2024年第2期41卷 295-304页

作者：张向阳李修冠童治鹏高银贵赵向阳安徽理工大学矿业工程学院安徽淮南232001 华兴能源有限责任公司内蒙古鄂尔多斯017000

针对厚煤硬顶工作面末采期间存在大面积悬顶引起的采动应力集中及回采效率低的问题,以唐家会煤矿61304工作面为工程背景,运用相似模拟试验、理论分析、数值模拟和现场实测等综合研究方法,在分析16.8 m特厚煤层以及15.8 m厚硬基本顶工作... 详细信息

针对厚煤硬顶工作面末采期间存在大面积悬顶引起的采动应力集中及回采效率低的问题,以唐家会煤矿61304工作面为工程背景,运用相似模拟试验、理论分析、数值模拟和现场实测等综合研究方法,在分析16.8 m特厚煤层以及15.8 m厚硬基本顶工作面末采期间覆岩垮落规律、悬臂结构力学传递机制、应力演化特征等影响因素的基础上,采用爆破切顶协同控制顶板技术,以达到提高回采率的目的。结果表明:覆岩悬臂结构在回采时期产生超前应力集中,导致末采期间顶煤回收量降低,停采煤柱被迫增加;爆破切顶破坏末采时期悬臂结构,切断超前采动应力传播途径,厚硬基本顶对工作面传递压力减弱,工作面放顶距离延长;悬臂角度与超前应力峰值呈负相关,悬臂长度与超前应力峰值呈正相关,通过破坏悬臂结构缩短悬臂长度可降低超前应力峰值;末采期间爆破切顶后超前应力峰值平均降低约5.76 MPa,停采煤柱缩短20 m,煤炭回收效率提高。工程实践表明,爆破切顶工艺能改善末采时期顶板悬空引起的采动应力集中,有效控制平巷围岩变形,极大提高煤炭回收效率,保障末采期间安全高效回采。

关键词：特厚煤层爆破切顶采动应力悬臂结构回采率

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Application of improved equivalent edge currents in synthetic aperture radar imaging

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Journal of Systems Engineering and Electronics 2010年第4期21卷 566-571页

作者： Yanwei Zhao Ping Zhou xiangyang zhang Min zhang School of Science Xidian University Xi'an 710071 R R. China National Electromagnetic Scattering Laboratory Beijing 100854 E R. China

Target modeling and scattering function calculating are important prerequisites and groundwork for the synthetic aperture radar（SAR） imaging simulation.According to the difficult problems that normal methods cannot calculate the scattering function of electrically large object under the condition to wideband,an effective method of improved equivalent edge currents is presented and applied to SAR imaging simulation for the first time.This method improves calculating velocity and has relatively high precision.The concrete steps of applying the method are given.By way of the simulation experiment,the effectiveness of the method is verified.

关键词： modeling and simulation,improved equivalent edge currents,synthetic aperture radar image,scattering function.

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区域研学实践教材的编写与出版探讨——以《南浔研学实践》为例

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地理教学 2024年第13期 61-64页

作者：张向阳中国地图出版社集团有限公司北京100054

为贯彻立德树人总要求,国家出台了系列综合素质教育规定。各地积极行动,结合区域特点,编写了跨学科综合实践课程教材,引导学生开展课外实践活动。本文以2023年出版的研学实践教材《南浔研学实践》为例,从研学旅行政策、实践教材的特征... 详细信息

为贯彻立德树人总要求,国家出台了系列综合素质教育规定。各地积极行动,结合区域特点,编写了跨学科综合实践课程教材,引导学生开展课外实践活动。本文以2023年出版的研学实践教材《南浔研学实践》为例,从研学旅行政策、实践教材的特征、编写内容和体例以及出版需要注意的问题,探讨基于区域研学实践教材的编写与出版。

关键词：研学旅行实践教材教材出版

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Parallel Construction Heuristic Combined with Constraint Propagation for the Car Sequencing Problem

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 373-384页

作者： xiangyang zhang Liang GAO Long WEN Zhaodong HUANG Faulty of Maritime and Transportation Ningbo UniversityNingbo 315211China State Key Lab.of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China National Traffic Management Engineering and Technology Research Centre Ningbo University Sub-center Ningbo UniversityNingbo 315211China

For the car sequencing（CS） problem, the draw-backs of the ＂sliding windows＂ technique used in the objective function have not been rectified, and no high quality initial solution has been acquired to accelerate the improvement of the solution quality. Firstly, the objective function is improved to solve the double and bias counting of violations broadly discussed. Then, a new method combining heuristic with constraint propagation is proposed which constructs initial solutions under a parallel framework. Based on constraint propagation, three filtering rules are designed to intersecting with three greedy functions, so the variable domain is narrowed in the process of the construction. The parallel framework is served to show its robustness in terms of the quality of the solution since it greatly increases the performance of obtaining the best solution. In the computational experiments, 109 instances of 3 sets from the CSPLib＇ s benchmarks are used to test the performance of the proposed method. Experiment results show that the proposed method outperforms others in acquiring the best-known results for 85 best-known results of 109 are obtained with only one construction. The proposed research provides an avenue to remedy the deficiencies of ＂sliding windows＂ technique and construct high quality initial solutions.

关键词： Car sequencing problem · Constraint propagation · Parallel construction heuristic · Filtering rule

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Experimental and numerical study of failure behavior and mechanism of coal under dynamic compressive loads

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International Journal of Mining Science and Technology 2020年第5期30卷 613-621页

作者： Junjun Feng Enyuan Wang Qisong Huang Houcheng Ding xiangyang zhang Civil Engineering and Architecture Anhui University of TechnologyMaanshanAnhui 243002China Key Laboratory of Safety and High-efficiency Coal Mining Ministry of EducationAnhui University of Science and TechnologyHuainanAnhui 232001China State Key Laboratory Cultivation Base for Gas Geology and Gas Control Henan Polytechnic UniversityJiaozuoHenan 454003China Key Laboratory of Gas and Fire Control for Coal Mines China University of Mining and TechnologyXuzhouJiangsu 221116China

A comprehensive understanding of the failure behavior and mechanism of coal is a prerequisite for dealing with dynamic problems in mining space.In this study,the failure behavior and mechanism of coal under uniaxial dynamic compressive loads were experimentally and numerically investigated.The experiments were conducted using a split Hopkinson pressure bar(SHPB)system.The results indicated that the typical failure of coal is lateral and axial at lower loading rates and totally smashed at higher loading rates.The further fractography analysis of lateral and axial fracture fragments indicated that the coal failure under dynamic compressive load is caused by tensile brittle fracture.In addition,the typical failure modes of coal under dynamic load were numerically reproduced.The numerical results indicated that the axial fracture is caused directly by the incident compressive stress wave and the lateral fracture is caused by the tensile stress wave reflected from the interface between coal specimen and transmitted bar.Potential application was further conducted to interpret dynamic problems in underground coal mine and it manifested that the lateral and axial fractures of coal constitute the parallel cracks in the coal mass under roof fall and blasting in mining space.

关键词： Split Hopkinson pressure bar Stress wave Failure mode Fracture mechanism Fractography

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