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Effects of Maize Residue Quality and Soil Water Content on Soil Labile Organic Carbon Fractions and Microbial Properties

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Pedosphere 2016年第6期26卷 829-838页

作者： li zengqiang ZHAO Bingzi ZHANG Jiabao State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) University of Chinese Academy of Sciences Beijing 100049(China)

Investigating the effects of residue chemical composition on soil labile organic carbon （LOC） will improve our understanding of soil carbon sequestration. The effects of maize residue chemical composition and soil water content on soil LOC fractions and microbial properties were investigated in a laboratory incubation experiment. Maize shoot and root residues were incorporated into soil at 40% and 70% field capacity. The soils were incubated at 20 ℃ for 150 d and destructive sampling was conducted after 15, 75, and 150 d. Respiration, dissolved organic carbon （DOC）, hot-water extractable organic carbon （HEOC）, and microbial biomass carbon （MBC） were recorded, along with cellulase and β-glucosidase activities and community-level physiological profiles. The results showed that the cumulative respiration was lower in root-amended soils than in shoot-amended soils, indicating that root amendment may be beneficial to C retention in soil. No significant differences in the contents of DOG, HEOC and MBC, enzyme activities, and microbial functional diversity were observed between shoot- and root-amended soils. The high soil water content treatment significantly increased the cumulative respiration, DOC and HEOC contents, and enzyme activities compared to the low soil water content treatment. However, the soil water content treatments had little influence on the MBC content and microbial functional diversity. There were significantly positive correlations between LOC fractions and soil microbial properties. These results indicated that the chemical composition of maize residues had little influence on the DOC, HEOC, and MBC contents, enzyme activities, and microbial functional diversity, while soil water content could significantly influence DOC and HEOC contents and enzyme activities.

关键词： community-level physiological profile dissolved organic carbon enzyme activities hot-water extractable organic carbon maize roots maize shoots

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冲击地压矿井充填工作面超前采动应力对充填体充实率的反馈机制

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煤炭学报 2024年第4期49卷 1804-1818页

作者：王兆会陈明振李强王伟李增强徐德生郑晓晨孙少龙吴传平郭心洋安君琦中国矿业大学(北京)能源与矿业学院北京100083 济宁市能源局山东济宁272000 兖矿能源集团股份有限公司山东煤炭科技研究院分公司山东济南250117 山东东山古城煤矿有限公司山东济宁272000 冀中能源峰峰集团有限公司梧桐庄矿河北邯郸056011

高应力是深部矿井冲击地压灾变频率走高的主要原因,充填开采则是控制岩层运动,缓解采动应力集中程度,降低围岩破坏和冲击风险的有效手段。为研究采空区充填体对超前采动应力的控制能力,以山东古城煤矿1123充填工作面为工程背景,采用理... 详细信息

高应力是深部矿井冲击地压灾变频率走高的主要原因,充填开采则是控制岩层运动,缓解采动应力集中程度,降低围岩破坏和冲击风险的有效手段。为研究采空区充填体对超前采动应力的控制能力,以山东古城煤矿1123充填工作面为工程背景,采用理论分析、室内试验、现场实测手段探究充填开采工作面采动应力分布规律,揭示超前采动应力对充填体充实率的反馈机制,指导冲击地压矿井充实率确定。结果表明:工作面开采初期充填体充实率低于80%,坚硬顶板下沉量大,超前采动影响范围大于30 m,应力集中系数达到1.5,断层影响区采动应力影响范围和集中系数分别增至60 m和1.65,片帮冒顶等围岩失稳现象增多;实测了采空区充填体承载应力全程动态演化特征,承载应力分布曲线划分为“快速降低—短暂稳定—快速升高—缓慢降低—二次稳定”5个阶段,低充实率条件下采空区上、中、下3个区域承载应力稳定值分别为1.9、5.2、2.8 MPa;将采空区充填体划分为非充分压实区和充分压实区,构建了充填体支撑作用下坚硬顶板连续沉降模型,得到了坚硬顶板“ʅ”型沉降曲线,非充分压实区范围随充实率近似呈线性减小;试验得到充填体弹性模量和单轴抗压强度随凝固时间的演化曲线,结合顶板沉降曲线和推进速度得到工作面前后采动应力全区域分布曲线;建立了超前采动应力集中程度与充填体承载能力的负指数函数关系,揭示了超前采动应力对充填体充实率的负向反馈机制,实现充填开采降载防冲效果的定量评价;提出了充填体充实率“三位一体”协同提升措施,将1123工作面充实率升高至90%,增强了充填体承载能力,超前采动应力集中系数降至1.3,厚顶煤膨胀变形量减少至50 mm,坚硬顶板破断致冲风险显著降低。

关键词：冲击地压充填开采坚硬顶板采动应力反馈机制

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冲击地压矿井充填开采工作面采动应力激增与跌落机制

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煤炭学报 2024年第S1期49卷 22-35页

作者：唐岳松孙文超李增强曹鹏王伟郑晓晨张付强陈明振王兆会中国矿业大学(北京)能源与矿业学院山东东山古城煤矿有限公司兖矿能源集团股份有限公司山东煤炭科技研究院分公司济宁市能源局

高应力、多断层是深部矿井冲击地压灾害频率走高的主要原因，充填开采作为降载减冲的最直接手段，依然无法根除冲击地压灾害的发生。为降低冲击地压对冲击倾向性煤层安全开采的影响，采用现场实测、理论分析和室内试验手段研究深部充填... 详细信息

高应力、多断层是深部矿井冲击地压灾害频率走高的主要原因，充填开采作为降载减冲的最直接手段，依然无法根除冲击地压灾害的发生。为降低冲击地压对冲击倾向性煤层安全开采的影响，采用现场实测、理论分析和室内试验手段研究深部充填开采条件下采动应力激增与跌落机制，探究坚硬顶板预裂爆破与大直径钻孔协同卸压效果。在高应力、多断层、不等宽煤柱和开采扰动多因素叠加影响下，充填开采工作面采动应力存在集中、激增与跌落现象，集中程度小于2.0，非断层影响区超前采动影响范围达到30 m，断层影响下增加至50 m，断层与煤柱叠加影响下增加至70 m；断层活化和围岩破坏引起应变能瞬间释放，转变为破坏煤岩动能，转换率达到17%；揭示了动载应力波产生原理，动载应力波与静态应力场叠加引起采动应力状态骤变；叠加前后若煤岩始终处于破碎状态，则它呈现压实硬化力学行为，发生应力激增现象；若煤岩由完整过渡至破碎状态，则它呈现脆性松脱力学行为，发生应力跌落现象；若煤岩始终处于完整状态，则它呈现弹性回弹力学行为，发生动载冲击现象。微震监测未发现105 J以上的大能量事件，表明充填体支撑下坚硬顶板未发生大范围破断；断层导致微震事件非对称分布，进风巷侧呈现高频低能分布模式，回风巷侧呈现低频高能分布模式，因此，回风巷发生2次冲击地压监测预警，进风巷发生1次冲击地压监测预警；提出了坚硬顶板爆破预裂与大直径钻孔协同卸压技术，顶板岩层形成了大尺度爆破裂隙，有效控制了应力集中程度和应力增长速度，降低了深部开采冲击地压灾害风险。

关键词：冲击地压充填开采采动应力断层构造微震监测

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Finite Element Investigation of the Influence of SiC Particle Distribution on Diamond Cutting of SiCp/AI Composites

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Nanomanufacturing and Metrology 2020年第4期3卷 251-259页

作者： Shijin Lu zengqiang li Junjie Zhang Jianguo Zhang Xiaohui Wang Yongda Yan Tao Sun Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China Technology and Innovation Research Center of Jiangyan Economic Development Zone Taizhou 225300China State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Mechanical Engineering University of JinanJinan 250022China

Characteristics of internal microstructures have a strong impact on the properties of particulate reinforced metal *** the present work,we perform finite element simulations to elucidate fundamental mechanisms involved in the ultraprecision orthogonal cutting of aluminum-based silicon carbide composites(SiCp/AI),with an emphasis on the influence of particle distribution *** SiCp/AI composite with a particle volume fraction of 25 vol%and a mean particle size of 10|im consists of randomly distributed polygon-shaped SiC particles,the elastic deformation and brittle failure of which are described by the brittle cracking *** results reveal that in addition to metal matrix tearing,cuttinginduced particle deformation in terms of dislodging,debonding,and cracking plays an important role in the microscopic deformation and correlated machining force variation and machined surface *** is found that the standard deviation of particle size to the mean value has a strong influence on the machinability of microscopic particle-tool edge interactions and macroscopically observed machining *** present work provides a guideline for the rational synthesis of particulate-reinforced metal composites with high machinability.

关键词： SiCp/AI composites Orthogonal cutting Particle-tool interaction Particle distribution FE simulation

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Cutting path-dependent machinability of SiCp/Al composite under multi-step ultra-precision diamond cutting

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Chinese Journal of Aeronautics 2021年第4期34卷 241-252页

作者： Shijin LU Junjie ZHANG zengqiang li Jianguo ZHANG Xiaohui WANG Alexander HARTMAIER Jianfeng XU Yongda YAN Tao SUN Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Mechanical Engineering University of JinanJinan 250022China Interdisciplinary Centre for Advanced Materials Simulation Ruhr-University BochumBochum 44780Germany

Particle-tool interactions,which govern the synergetic deformation of SiC particle reinforced Al matrix composites under mechanical machining,strongly depend on the geometry of particle position residing on cutting *** the present work,we investigate the influence of cutting path on the machinability of a SiCp/Al composite in multi-step ultra-precision diamond cutting by combining finite element simulations with experimental observations and *** consistent with experimentally characterized microstructures,the simulated SiCp/Al composite is considered to be composed of randomly distributed polygonally-shaped SiC particles with a volume fraction of 25 vol%.A multi-step cutting strategy with depths of cut ranging from 2 to 10 lm is adopted to achieve an ultimate depth of cut of 10 *** material parameters and extrinsic cutting conditions utilized in finite element simulations of SiCp/Al cutting are consistent with those used in corresponding *** results reveal different particle-tool interactions and failure modes of SiC particles,as well as their correlations with machining force evolution,residual stress distribution and machined surface topography.A detailed comparison between numerical simulation results and experimental data of multi-step diamond cutting of SiCp/Al composite reveals a substantial impact of the number of cutting steps on particle-tool interactions and machined surface *** findings provide guidelines for achieving high surface finish of SiCp/Al composites by ultra-precision diamond cutting.

关键词： Cutting path Diamond cutting Finite element simulation Particle-tool interaction SiCp/Al composites

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Research on the shear model and optimal algorithm of long products

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Baosteel Technical Research 2022年第3期16卷 41-46页

作者： li zengqiang WANG Xuemin li He LUO Xiangyu Research Institute Baoshan Iron&Steel Co.Ltd.Shanghai 201999China Northeastern University Shenyang 110000China

Incoming materials sometimes must be slit according to the customers’ order requirements.A reasonable shear model can reduce residual materials and improve the rate of finished *** this paper, a shear model is established, and several commonly used optimization algorithms are compared, with the minimum residual materials, running time, and CPU ratio as the evaluation *** show that the genetic algorithm is the best algorithm that can be used in online automatic shear control to achieve the highest yield and highest computational efficiency.

关键词： automatic shearing genetic algorithm hill-climbing algorithm simulated annealing algorithm

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Molecular Epidemiological Study of a Human Brucellosis Outbreak—Weihai City,Shandong Province,China,2022

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China CDC weekly 2024年第12期6卷 230-234页

作者： Yan li Yifan Yu Jian Zhao Shujun Ding Guoying Zhang Xiaolin Yu zengqiang Kou Shandong Provincial Center for Disease Control and Prevention Jinan CityShandong ProvinceChina Shandong First Medical University Shandong Academy of Medical SciencesJinan CityShandong ProvinceChina Weihai Municipal Center for Disease Control and Prevention Weihai CityShandong ProvinceChina

What is already known about this topic?Brucellosis,mainly caused by Brucella melitensis(***),is regarded as a significant zoonotic disease in *** Weihai,located at the eastern end of the Shandong Peninsula,brucellosis has been in a low epidemic phase for the past five *** is added by this report?This was the initial report of a brucellosis outbreak in the last five *** of *** bv.3 from Weihai and other cities showed a close genetic relationship,suggesting a potential common *** are the implications for public health practice?Epidemiological investigations depend on standardized and effective molecular typing methods and analysis tools for public health laboratories to identify and trace *** the circulation patterns of livestock in free-range households in heavily affected areas is essential for controlling the spread of brucellosis.

关键词： Shandong China. break

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Neutronics Calculation of ITER HC-SB TBM

Southwestern Institute of Physics Annual Report

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Southwestern Institute of Physics Annual Report 2005年第1期 104-105页

作者： li zengqiang FENG Kaiming ZHANG Guoshu

ITER＇s test blanket modules （ TBM ） is a test-bed to demonstrate tritium self-sufficiency and extraction of high-grade heat for a future fusion reactor. It is also a test plateform to test electro- magnetic, thermo-hydraulic and tritium breeder for DEMO blanket relevant technologies. A great deal of the largest and the most important nuclear issues are related to neutronics. In consideration of strict requirements of absolute safe operation for ITER and TBM, all of probable or potential problems of TBM must be investigated such as power generation, tritium generation, thermo-hydraulics and energy production and so on.

关键词： Tritium breeding ratio Power density TBM

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Calculations of the 3-D Neutronics for ITER HC-SB TBM

Southwestern Institute of Physics Annual Report

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Southwestern Institute of Physics Annual Report 2005年第1期 90-91页

作者： ZHANG Guoshu FENG Kaiming YUAN Tao li zengqiang

China HC-SB TBM is designed as 3×3 sub-modules which making its structure to become robust but much complex. HC-SB TBM box is mounted inside a 20 cm of frame for a 1/4 of 1TER test port with 66.4 cm in width, and 44.5 cm in height, and 67 cm in depth. There have two 2 cm of gaps on side faces. A frame thickness around TBM module is 20 cm. In module of HC-SB TBM, liaSiO4 pebble bed is used as tritium breeder zone. The packing factor of liaSiO4 pebble bed is 0.59. The concentration of li6 is 80%. Be pebble bed is used as neutron multiplication zone. The packing factor for Be pebble bed is selected as 0.8. All structural materials are Eurofer in which are helium cooling channel with diameter 0.6 cm of circular cross section. All sub-modules have a common FW that is independently cooled. There are only 4 li4SiO4 regions which is lower volume ratio compared to Be. It is an advantage because Be has a better heat conductivity than li4SiO4.

关键词： Blanket Neutronics TBR

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Cooperative Adaptive Cruise Control Platoon Fleet Formation Model Considering Efficiency and Stability

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Journal of Electronic Research and Application 2024年第5期8卷 148-153页

作者： Shunli li zengqiang Wang Chengdu Eastern Urban and Rural Construction Development Co. LTD.Chengdu 610000Sichuan ProvinceChina School of Management Xihua UniversityChengdu 610000Sichuan ProvinceChina

In the existing formation model,vehicles in the same lane or adjacent lane are regarded as the structure,and the driving behavior of vehicles is studied from the perspectives of safety,speed consistency,and stability,and the speed control model is proposed from the perspective of vehicles themselves,to obtain a stable fleet with the same distance and ***,in this process,the initial condition of the vehicle,the traffic flow environment,and the efficiency of the fleet formation are less ***,based on summarizing the existing fleet building model,this paper puts forward the rapid construction model and algorithm of a cooperative adaptive cruise control platoon *** of the important goals of forming a team is to enter the team with the smoothest trajectory in the shortest ***,this chapter studies the trajectory optimization of the vehicle formation process from the perspective of vehicle dynamics.

关键词： Cooperative adaptive cruise control platoon Fleet stability Communication rules Travel time

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