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Mechanical and damage evolution properties of sandstone under triaxial compression

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International Journal of Mining Science and Technology 2016年第4期26卷 601-607页

作者： Zong Yijiang Han Lijun wei jianjun Wen Shengyong State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and Technology Xuzhou 221116 China Jiangsu Collaborative Innovation Center for Building Energy Saving and Construction Technology Jiangsu Jianzhu Institute Xuzhou 221116 China

To study the mechanical and damage evolution properties of sandstone under triaxial compression, we analyzed the stress strain curve characteristics, deformation and strength properties, and failure process and characteristics of sandstone samples under different stress states. The experimental results reveal that peak strength, residual strength, elasticity modulus and deformation modulus increase linearly with confining pressure, and failure models transform from fragile failure under low confining pressure to ductility failure under high confining pressure. Macroscopic failure forms of samples under uniaxial compression were split failure parallel to the axis of samples, while macroscopic failure forms under uniaxial compression were shear failure, the shear failure angle of which decreased linearly with confin- ing pressure. There were significant volume dilatation properties in the loading process of sandstone under different confining pressures, and we analyzed the damage evolution properties of samples based on acoustic emission damage and volumetric dilatation damage, and established damage constitutive model, realizing the real-time Quantitative evaluation of samnles damage state in loading process.

关键词： Rock mechanics Mechanical properties Dilatation Damage evolution Failure characteristics

Effects of particle composition and environmental parameters on catalytic hydrodechlorination of trichloroethylene by nanoscale bimetallic Ni-Fe

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Journal of Environmental Sciences 2014年第5期26卷 1162-1170页

作者： jianjun wei Yajing Qian Wenjuan Liu Lutao Wang Yijie Ge Jianghao Zhang Jiang Yu Xingmao Ma Department of Environmental Science and Engineering Beijing University of Chemical Technology Department of Civil and Environmental Engineering Southern Illinois University Carbondale

Catalytic nickel was successfully incorporated into nanoscale iron to enhance its dechlorination efficiency for trichloroethylene （TCE）, one of the most commonly detected chlorinated organic compounds in groundwater. Ethane was the predominant product. The greatest dechlorination efficiency was achieved at 22 molar percent of nickel. This nanoscale Ni-Fe is poorly ordered and inhomogeneous; iron dissolution occurred whereas nickel was relatively stable during the 24-hr reaction. The morphological characterization provided significant new insights on the mechanism of catalytic hydrodcchlorination by bimetallic nanoparticles. TCE degradation and ethane production rates were greatly affected by environmental parameters such as solution pH, temperature and common groundwater ions. Both rate constants decreased and then increased over the pH range of 6.5 to 8.0, with the minimum value occurring at pH 7.5. TCE degradation rate constant showed an increasing trend over the temperature range of 10 to 25℃. However, ethane production rate constant increased and then decreased over the range, with the maximum value occurring at 20℃, Most salts in the solution appeared to enhance the reaction in the first half hour but overall they displayed an inhibitory effect. Combined ions showed a similar effect as individual salts.

关键词： nanoscale Ni-Fe trichloroethylene hydrodechlorination catalytic dechlorination composition environmental parameters

A low-power DC offset calibration method independent of IF gain for zero-IF receiver

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Science China(Information Sciences) 2014年第10期57卷 213-222页

作者： DONG JingJing JIANG HanJun ZHANG Lingwei wei jianjun LI FuLe ZHANG Chun WANG ZhiHua Tsinghua National Laboratory for Information Science and Technology Institute of Microelectronics Tsinghua University Research Institute of Tsinghua University in Shenzhen

A novel low-power DC offset calibration(DCOC) method independent of intermediate frequency(IF) gain for zero-IF receiver applications has been reported. The conventional analog DCOC method consumes greater power and affects the performance of the receiver. The conventional mixed-signal method requires enhanced memory to store the calibration results at different receiver gains as the DC offset is relative to the radio frequency(RF) and IF gain. A novel algorithm is presented to make the DCOC process independent of IF gain, which significantly reduces the memory area. With the proposed circuit, the receiver calibrates only once so settle-time and power consumption of the IF circuit is lowered. A DCOC circuit with the proposed method is manufactured in 0.18 μm CMOS technology that drains nearly 0 mA equivalent current from a 1.8 V power supply.

关键词： DC offset calibration zero-IF receiver PGA digital to analog converter comparator

平菇菌糠发酵饲料对育肥猪生长性能、肠道微生物和免疫功能的影响

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中国饲料 2025年第2期 73-76页

作者：唐璐曹岩岩蔚建军重庆商务职业学院重庆400000 大庆师范学院黑龙江大庆163000 重庆市农业科学院重庆400050

文章旨在研究平菇菌糠发酵饲料对育肥猪生长性能、肠道微生物和免疫功能的影响。试验将300头均重(44.79±1.84)kg的三元(杜×长×大)杂交育肥猪随机分为4组,每6组1个重复,每个重复10头。试验日粮分别在基础日粮中添加0、1%、2%和4%的发... 详细信息

文章旨在研究平菇菌糠发酵饲料对育肥猪生长性能、肠道微生物和免疫功能的影响。试验将300头均重(44.79±1.84)kg的三元(杜×长×大)杂交育肥猪随机分为4组,每6组1个重复,每个重复10头。试验日粮分别在基础日粮中添加0、1%、2%和4%的发酵菌糠,试验为期32 d。试验结果表明,2%的平菇菌糠发酵料组平均日增重(ADG)较其他组分别显著提高3.82%、2.65%和1.94%(P <0.05);2%的平菇菌糠发酵料组料重比(F/G)较对照组显著降低4.1%(P <0.05)。2%和4%的平菇菌糠发酵料组育肥猪腹股沟淋巴指数显著提高(P <0.05)。2%的平菇菌糠发酵料组育肥猪血清免疫球蛋白A(IgA)、免疫球蛋白(IgM)和免疫球蛋白G(IgG)含量显著提高(P <0.05),白细胞介素-6(IL-6)含量显著降低(P <0.05),白细胞介素-10(IL-10)含量显著提高(P <0.05)。2%的平菇菌糠料组育肥猪回肠、结肠和盲肠乳酸杆菌含量均显著提高(P <0.05);2%和4%的平菇菌糠料组育肥猪回肠和结肠大肠杆菌含量显著降低(P <0.05);1%~4%的平菇菌糠料组育肥猪结肠沙门氏菌含量显著降低(P <0.05)。总之,在本试验条件下,平菇菌糠发酵料最适添加量为2%。

关键词：平菇菌糠育肥猪生长性能免疫肠道微生物

Optimal Electrochemical Performances of CO_2 Activated Carbon Aerogels for Supercapacitors

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Journal of Wuhan University of Technology(Materials Science) 2014年第2期29卷 213-218页

作者：常丽娟 FU Zhibing LIU Miao YUAN Lei wei jianjun HE Yong wei LIU Xichuan 王朝阳 Science and Technology on Plasma Physics Laboratory Institute of Atomic and Molecular Physics Sichuan University College of Material Science and Engineering Xihua University

Activated carbon aerogels（ACAs） derived from sol-gel polycondensation of resorcinol （R） and formaldehyde （F） were pyrolyzed under Ar flow and activated in CO2 atmosphere. The morphology of ACAs was characterized by scanning electron microscopy （SEM） and the structural properties were determined by N2 adsorption at 77 K. The results show that ACAs have a typical three-dimensional nanonetwork structure composing of cross-linking of carbon nanoparticles. The specific surface area and the total pore volume remarkably increase with increasing activation time while the previous porous structure still remains. The specific capacitance of the 950-10-ACA electrode can reach up to 212.3 F/g in 6 mol/L KOH electrolyte. The results of constant-current charge-discharge testing indicate that the ACAs electrodes present fast charge- discharge rate and long cycle life （about 98% capacitance retained after 3000 charge-discharge cycles at 1.25 mA/cm2）. Lower internal resistances can be achieved for 950-10-ACA electrode in KOH electrolyte. Our investigations are very important to improve the wettability and electrochemical performance of electrode for supercapacitors.

关键词： activated carbon aerogels specific surface area specific capacitance wettability cycling performance

Erosion research of CX-2002U carbon composites under low-temperature high-flux hydrogen plasma

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Plasma Science and Technology 2021年第2期23卷 93-100页

作者： Hengxin GUO Zongbiao YE Bizhou SHEN jianjun wei Bo WANG Yuchuan LUO Kun ZHANG Fujun GOU jianjun CHEN Bo CHEN Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610064People's Republic of China Institute of Nuclear Science and Technology Sichuan UniversityChengdu 610064People's Republic of China

The net erosion yield of CX-2002U carbon fiber composites under high-flux low-temperature hydrogen plasma is investigated using a linear plasma *** is found that the net erosion yield decreases rapidly first,and then tends to saturate with the increase of hydrogen–plasma *** the temperature of the sample eroded by hydrogen plasma is above 300°C,the hybridization of electrons outside the carbon atom would *** the carbon atoms combine with hydrogen atoms to form massive spherical nanoparticles of hydrocarbon compounds and deposit on the surface at the flux condition of 1.77×10^(22) m^(−2)·s^(−1).Under the irradiation of hydrogen plasma loaded with negative bias,the surface morphology of the matrix carbon is changed ***,the energy dependence of mass loss does not increase in proportion to the increase of hydrogen–plasma energy,but reaches a peak around 20 V negative bias *** on the analysis of different samples,it can be concluded that the enhancement of energy could make a contribution to chemical erosion and enlarge the size of pores existing on the surface.

关键词： carbon fiber composites hydrogen plasma chemical erosion redeposition nanoparticle

Cleaning of nitrogen-containing carbon contamination by atmospheric pressure plasma jet

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Plasma Science and Technology 2022年第10期24卷 127-138页

作者： Li YANG Sishu WANG Andong WU Bo CHEN jianjun CHEN Hongbin WANG Shuwei CHEN jianjun wei Kun ZHANG Zongbiao YE Fujun GOU Key Laboratory of Radiation Physics and Technology Ministry of EducationInstitute of Nuclear Science and TechnologySichuan UniversityChengdu 610064People's Republic of China Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610064People's Republic of China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000People's Republic of China College of Physics Sichuan UniversityChengdu 610064People's Republic of China

Atmospheric pressure plasma jet(APPJ)was used to clean nitrogen-containing carbon films(C–N)fabricated by plasma-assisted chemical vapor deposition method employing the plasma surface interaction linear device at Sichuan University(SCU-PSI).The properties of the contaminated films on the surface of pristine and He-plasma pre-irradiated tungsten matrix,such as morphology,crystalline structure,element composition and chemical structure were characterized by scanning electron microscopy,grazing incidence x-ray diffraction and x-ray photoelectron *** experimental results revealed that the removal of C–N film with a thickness of tens of microns can be realized through APPJ cleaning regardless of the morphology of the *** removal rates of 16.82 and 13.78μm min^(-1)were obtained for C–N films deposited on a smooth pristine W surface and rough fuzz-covered W surface,*** is a remarkable improvement in comparison to the traditional cleaning ***,slight surface oxidation was found after APPJ cleaning,but the degree of oxidation was acceptable with an oxidation depth increase of only 3.15 *** emission spectroscopy analysis and mass spectrometry analysis showed that C–N contamination was mainly removed through chemical reaction with reactive oxygen species during APPJ treatment using air as the working *** results make APPJ cleaning a potentially effective method for the rapid removal of C–N films from the wall surfaces of fusion devices.

关键词： N-containing C(C–N)film plasma-assisted chemical vapor deposition He-plasma irradiation atmospheric pressure plasma jet plasma cleaning

Adjustment of Emitted Power for Microwave Emitter in ECR Source

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IMP & HIRFL Annual Report 1995年 87-88页

作者： wei jianjun

Ａｄｊｕｓｔｍｅｎｔ　ｏｆ　Ｅｍｉｔｔｅｄ　Ｐｏｗｅｒ　ｆｏｒ　Ｍｉｃｒｏｗａｖｅ　Ｅｍｉｔｔｅｒ　ｉｎ　ＥＣＲ　ＳｏｕｒｃｅＡｄｊｕｓｔｍｅｎｔｏｆＥｍｉｔｔｅｄＰｏｗｅｒｆｏｒＭｉｃｒｏｗａｖｅＥｍｉｔｔｅｒｉｎ...

Ａｄｊｕｓｔｍｅｎｔ　ｏｆ　Ｅｍｉｔｔｅｄ　Ｐｏｗｅｒ　ｆｏｒ　Ｍｉｃｒｏｗａｖｅ　Ｅｍｉｔｔｅｒ　ｉｎ　ＥＣＲ　ＳｏｕｒｃｅＡｄｊｕｓｔｍｅｎｔｏｆＥｍｉｔｔｅｄＰｏｗｅｒｆｏｒＭｉｃｒｏｗａｖｅＥｍｉｔｔｅｒｉｎＥＣＲＳｏｕｒｃｅ￥ＷｅｉＪｉａｎ...

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2017—2022年汉中市手足口病实验室检测结果分析

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预防医学情报杂志 2025年第2期41卷 181-184,192页

作者：张久丁韩亦非邓彤陈真王苗苗魏建军汉中市疾病预防控制中心陕西汉中723000

目的分析2017—2022年汉中市手足口病实验室检测结果,为制定更有效手足口病防控方案提供科学依据。方法收集2017—2022年汉中市各区县临床诊断手足口病病例标本,采用实时荧光PCR法对标本进行核酸检测,采用描述流行病学方法进行统计分析... 详细信息

目的分析2017—2022年汉中市手足口病实验室检测结果,为制定更有效手足口病防控方案提供科学依据。方法收集2017—2022年汉中市各区县临床诊断手足口病病例标本,采用实时荧光PCR法对标本进行核酸检测,采用描述流行病学方法进行统计分析,率的比较采用χ2检验,检验水准α=0.05。结果2017—2022年汉中市共收集手足口病标本1872份,其中阳性1183份,总阳性率为63.19%。阳性标本中其他肠道病毒占比最高为61.45%(727/1183),其次为Cox A16型33.47%(396/1183),EV 71型占比最低为5.07%(60/1183)。手足口病流行存在2个高峰(5至7月和9至11月)。手足口病阳性病例主要集中于汉中市汉台区、南郑区、西乡县、城固县、勉县和洋县。手足口病阳性病例主要以1~4岁儿童为主。结论2017—2022年汉中市手足口病疫情总体平稳,应重视非EV 71型和Cox A16型的肠道病毒检测工作,实时监测手足口病病原谱变化。

关键词：手足口病肠道病毒病原学流行特征