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Effects of the vegetation restoration years on soil microbial community composition and biomass in degraded lands in Changting County,China

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Journal of Forestry Research 2020年第4期31卷 1295-1308页

作者： Yonghui Bai Xuan zha Shifa chen Key Laboratory for Subtropical Mountain Ecology(Ministry of Science and Technology and Fujian Province Funded) School of Geographical SciencesFujian Normal UniversityFuzhou 350007China College of Tourism and geography Shaoguan UniversityShaoguan 512005China

We evaluated the effects of the number of years of restoration of vegetation on soil microbial community structure and biomass in degraded *** investigated the microbial community structure by analyzing their phospholipid fatty acids then examined microbial biomass carbon and nitrogen by chloroform fumigation extraction of restoration soils over several *** data were compared with those of highly degraded lands and native vegetation *** results show that the duration of vegetation on the sites substantially increased microbial biomass and shifted the microbial community structure even after only 4 ***,microbial communities and biomass did not recover to the status of native vegetation even after 35 years of vegetation cover.A redundancy analysis and Pearson correlation analysis indicated that soil organic carbon,total nitrogen,available potassium,soil water content,silt content and soil hardness explained 98.4%of total variability in the microbial community *** organic carbon,total nitrogen,available potassium and soil water content were positively correlated with microbial community structure and biomass,whereas,soil hardness and silt content were negatively related to microbial community structure and *** study provides new insights into microbial community structure and biomass that influence organic carbon,nitrogen,phosphorus and potassium accumulation,and clay content in soils at different stages of restoration.

关键词： Vegetation restoration Soil microorganisms Environmental factors PLFA Degraded red soil lands

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聚丁二酸丁二醇酯熔融缩聚增黏特性

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化工进展 2024年第10期43卷 5663-5670页

作者：徐涛王勇军林启松戴钧明查全亮吕汪洋陈文兴浙江理工大学纺织纤维材料与加工技术国家地方联合工程实验室浙江杭州310018 浙江省现代纺织技术创新中心浙江绍兴312000 绍兴九洲化纤有限公司浙江绍兴312000

为解决生物可降解聚丁二酸丁二醇酯(PBS)长期正常储存过程中易发生降解而导致分子量下降的难题,通过熔融缩聚增黏方法实现了PBS分子量的提升。研究了反应温度、反应时间、初始特性黏度以及熔体膜厚等对PBS特性黏度、分子量、热性能和流... 详细信息

为解决生物可降解聚丁二酸丁二醇酯(PBS)长期正常储存过程中易发生降解而导致分子量下降的难题,通过熔融缩聚增黏方法实现了PBS分子量的提升。研究了反应温度、反应时间、初始特性黏度以及熔体膜厚等对PBS特性黏度、分子量、热性能和流变性能的影响。结果表明:PBS分子量随熔融缩聚增黏温度升高而升高;220℃反应60min,PBS特性黏度即可从1.049dL/g升至2.072dL/g;PBS初始黏度越低其增黏速率越高;而PBS的熔体膜厚与其增黏反应速率呈反比;PBS特性黏度的升高导致结晶困难,进而使其熔点下降。流变测试结果表明随着特性黏度升高,PBS熔体强度与热稳定性均提升,能满足重新加工和使用的需求,通过熔融再聚合方法可有效解决PBS因降解而无法满足其后续加工和使用需求的难题。

关键词：聚合物聚合聚合物加工聚丁二酸丁二醇酯熔融缩聚热性能流变性能

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全球典型流域地表覆盖变化与净生态系统碳交换量时空相关性分析

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测绘通报 2024年第2期 8-13,31页

作者：陈磊马颖查逢丽蔺妍臻时广彬天津师范大学地理与环境科学学院天津300387 二十一世纪(安徽)空间技术应用有限公司安徽淮南232008 天津师范大学体育科学学院天津300387

随着社会经济的发展,流域管理目标已从早期的防洪、供水、航运等转变为注重资源利用和生态保护的综合管理,并在全球生态系统碳平衡中扮演着重要角色。作为量化生态系统固碳能力的重要指标,净生态系统碳交换量(NEE)在不同地表覆盖类型中... 详细信息

随着社会经济的发展,流域管理目标已从早期的防洪、供水、航运等转变为注重资源利用和生态保护的综合管理,并在全球生态系统碳平衡中扮演着重要角色。作为量化生态系统固碳能力的重要指标,净生态系统碳交换量(NEE)在不同地表覆盖类型中的碳源/汇能力存在显著差异。探究全球典型流域地表覆盖类型与NEE的时空相关性对流域生态管理等具有重要意义。本文以全球30 m地表覆盖数据(globeLand30)和全球陆地净生态系统碳交换量数据为基础,分析2000—2020年全球8个典型流域的地表覆盖及NEE时空变化特征,研究地表覆盖类型变化与NEE的时空相关性。结果表明:①2000—2020年,流域内耕地、裸地、人造地表、湿地、水体及苔原面积增加,草地面积先增加后减少,整体为增加状态;②2000—2020年,流域整体NEE先减小后增加,整体为减小趋势,碳汇能力增强;③2000—2020年,草地与NEE呈显著负相关,耕地、裸地、人造地表、湿地及水体面积与NEE在2010—2020年呈正相关,地表覆盖类型变化对NEE有显著影响。本文可为流域碳中和管制和土地利用空间优化调控提供理论参考,推动流域协同减排和高质量发展。

关键词：净生态系统碳交换量地表覆盖类型时空变化典型流域

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Research progress on low dielectric constant modification of cellulose insulating paper for power transformers

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Frontiers of Chemical Science and Engineering 2023年第8期17卷 991-1009页

作者： Wenchang Wei Haiqiang chen Junwei zha Yiyi zha.g guangxi Power Transmission and Distribution Network Lightning Protection Engineering Techndogy Research Center Guangxi UniversityNanning 530004China School of Chemistry and Biological Engineering University of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials genome Engineering University of Science and Technology BeijingBeijing 100083China

Because of the increase in the transmission voltage levels,the demand for insulation reliability of power transformers has increasingly become *** insulating paper is the main insulating component of power *** improve the insulation level of ultrahigh voltage transformers and reduce their weight and size,reducing the dielectric constant of oil-immersed cellulose insulating paper is highly *** is used to produce power-transformer insulating papers owing to its excellent electrical properties,renewability,biodegradability and *** dielectric constant of a cellulose insulating paper can be effectively reduced by chemical or physical *** study presents an overview of the foreign and domestic research status of the use of modification technology to reduce the dielectric constant of cellulose insulating *** the mentioned methods are analyzed in this ***,some recommendations for future modified cellulose insulating paper research and applications are *** paper can provide a reference for further research on low dielectric constant cellulose insulating paper in the future.

关键词： low dielectric constant chemical and physical modification cellulose insulating paper transformer nanomaterials

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考虑电池总数的锂离子电池组双层均衡方法

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电源技术 2024年第7期48卷 1289-1302页

作者：吴铁洲查欢陈泽中李昱青湖北工业大学太阳能高效利用及储能运行控制湖北省重点实验室湖北武汉430068

为了适应电池总数变化并有效提高锂离子电池组均衡速度等,设计了一种双层均衡方法。首先对电池进行分组分层,底层组内分为奇数次和偶数次均衡电路,以适应电池总数存在奇偶性不同的情况;顶层组间采用可重构电路,将满足均衡条件的电池组... 详细信息

为了适应电池总数变化并有效提高锂离子电池组均衡速度等,设计了一种双层均衡方法。首先对电池进行分组分层,底层组内分为奇数次和偶数次均衡电路,以适应电池总数存在奇偶性不同的情况;顶层组间采用可重构电路,将满足均衡条件的电池组接进或隔离出电路;同时从电池奇偶性、均衡速度和能量转移效率等方面推论出该均衡电路的优越性。其次以电池SOC为均衡变量,采用组内和组间同时均衡的控制策略,进一步提高均衡速度。最后考虑电池总数奇偶性不同,分别选用六节、七节锂离子电池在MATLAB/Simulink平台进行实验,与传统分布式可重构双层电路相比,充电均衡时间缩短了125.44和128.92 s,放电均衡时间缩短了114.99和115.69 s;与传统集中式可重构双层电路相比,充电均衡时间缩短了57.49和59.14 s,放电均衡时间缩短了51.24和50.63 s。同时通过比较均衡完成时电池组平均SOC及SOC离散度,可以得出该均衡电路在能量转移效率和减小电池组不一致性方面的优势,验证了所设计的均衡方法的有效性。

关键词：电池总数均衡速度双层均衡方法

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Triple-phase interfaces of graphene-like carbon clusters on antimony trisulfide nanowires enable high-loading and long-lasting liquid Li_(2)S_(6)-based lithium-sulfur batteries

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Journal of Energy Chemistry 2021年第8期30卷 599-607,I0013页

作者： chenyang zha Donghai Wu Xiuquan gu Houyang chen Key Laboratory of Flexible Electronics(KLOFE) Institute of Advanced Materials(IAM)Nanjing Tech UniversityNanjing 211816China Henan Key Laboratory of Nanocomposites and Applications Institute of Nanostructured Functional MaterialsHuanghe Science and Technology CollegeZhengzhou 450006China School of Materials and Physics China University of Mining and TechnologyXuzhou 221116JiangsuChina Department of Chemical and Biological Engineering State University of New York at Buffalo14260-4200 BuffaloUSA

High performance of lithium-sulfur batteries have been dragged down by their shuttling behavior which is complicated multiphase transition-based 16-electron redox reactions of the S8/Li2 *** this article,the triple-phase interfaces of graphene-like carbon clusters on antimony trisulfide(C-Sb_(2)S_(3))nanowires are tailored to design a multifunctional polysulfide host which can inhibit migration of polysulfides and accelerate conversion kinetics of redox electrochemical *** from the triple-interface design of polysulfides/Sb_(2)S_(3)/carbon clusters,the C-Sb_(2)S_(3) electrode not only anchors polysulfide migration by the synergistic effect of Sb,S,and C atoms as interfacial active sites,but also the graphene-like carbon clusters shorten the diffusion paths to further favor redox electron/ion transport through the liquid(electrolyte/polysulfide)and solid(Li2 S/S8,carbon clusters,and Sb_(2)S_(3))-based ***,these Li_(2)S_(6)-based C-Sb_(2)S_(3) cells possess high sulfur loading,excellent cycling stability,impressive specific capacity,and great rate *** work of interfacial engineering reveals insight for powering reaction kinetics in the complicated multistep catalysis reaction with multiphase evolution-based chargetransfer/non-transfer processes.

关键词： Triple-phase interfaces graphene-like carbon Antimony trisulfide High preformance Lithium-sulfur batteries

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污泥水热液相大分子物质组成对聚集介质特性的影响

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环境科学学报 2024年第8期44卷 288-301页

作者：郁永蕊查晓黄勇孙昕陈硕君李雯丽苏州科技大学环境科学与工程学院苏州215009 苏州科技大学环境生物与技术研究所苏州215009

采取适宜的方式将城市污水中的有机物回收并转化为有价值的产品,可推进污水厂的资源回收与可持续发展.前期研究证实以污泥水热液相大分子物质(HL-MMP)为原料并通过接枝共聚法改性,制备出具备捕获生活污水中有机物能力的絮凝材料,即聚集... 详细信息

采取适宜的方式将城市污水中的有机物回收并转化为有价值的产品,可推进污水厂的资源回收与可持续发展.前期研究证实以污泥水热液相大分子物质(HL-MMP)为原料并通过接枝共聚法改性,制备出具备捕获生活污水中有机物能力的絮凝材料,即聚集介质,可经济有效地去除污水中的有机物,并将其以污泥的形式富集以便于回收利用.本文通过改变水热条件调控HL-MMP的组成特性,包括官能团、分子量及蛋白质、多糖含量等,在相同改性条件下,探讨HL-MMP不同组成特性对聚集介质特性,如电荷特性、分子量特性等的影响,进而分析其作用机制.结果表明,HL-MMP主要由蛋白质类、类腐殖质两大类物质组成.HL-MMP中酚羟基与多糖含量呈正相关;羧基、分子量与蛋白质类和类腐殖质物质含量呈正相关;不饱和基团与还原糖、蛋白质类和类腐殖质含量呈正相关.120~160℃,10~30 min水热条件下,HL-MMP主要来源于污泥中生物体的溶解、水解反应;180℃水热条件下,其主要来自于溶解、水解产物的再聚合.聚集介质电荷特性主要与HL-MMP的酸性基团(酚羟基、羧基)呈正相关,引发剂引发酸性基团产生自由基,结合DMC,使其携带正电荷;聚集介质分子量特性主要与HL-MMP分子量、不饱和基团呈正相关性,引发剂引发不饱和基团产生自由基,发生均聚反应,使其分子量增大.

关键词：污泥水热液相大分子物质聚集介质特性有机物捕获

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深冷轧制变形对新型Ni-W-Co-Ta高密度合金显微组织与性能的影响

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Transactions of Nonferrous Metals Society of China 2024年第4期34卷 1214-1225页

作者：舒康豪熊毅厉勇岳赟陈正阁查小琴韩顺王春旭河南科技大学材料科学与工程学院洛阳471023 有色金属新材料与先进加工技术省部共建协同创新中心洛阳471023 钢铁研究总院特殊钢研究所北京100081 西北核技术研究所激光与物质相互作用国家重点实验室西安710024 中国船舶重工集团第725研究所洛阳471000

采用熔炼-浇铸-锻造流程制备新型Ni-W-Co-Ta高强度合金,并对Ni-W-Co-Ta合金经深冷轧制变形后的显微组织及力学性能演变规律进行表征。结果表明:随着变形量的增加,新型Ni-W-Co-Ta高密度合金中等轴晶粒沿轧制方向不断被拉长,同时产生大量... 详细信息

采用熔炼-浇铸-锻造流程制备新型Ni-W-Co-Ta高强度合金,并对Ni-W-Co-Ta合金经深冷轧制变形后的显微组织及力学性能演变规律进行表征。结果表明:随着变形量的增加,新型Ni-W-Co-Ta高密度合金中等轴晶粒沿轧制方向不断被拉长,同时产生大量的滑移带以协调剧烈的塑性变形,并最终形成纤维组织。变形量的增大导致位错密度急剧增大,位错交互作用显著加强,进而使晶粒尺寸细化至纳米量级;合金强度、硬度随着变形量的增加而显著提高,伸长率则急剧下降。断口形貌则由韧性断裂(未变形)向准解理-韧性混合型断裂转变(90%变形量)。

关键词： Ni-W-Co-Ta高密度合金深冷轧制纤维组织力学性能准解理-韧性混合型断裂

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Effect of Working Position on Vertical Motion Straightness of Open Hydrostatic guideways in grinding Machine

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Chinese Journal of Mechanical Engineering 2017年第1期30卷 46-52页

作者： zha JUn WANg Zhiwei XUE Fei chen Yaolong State Key Laboratory for Manufacturing Systems Engineering Xi 'an Jiaotong University Xi 'an 710049 China College of Mechanical and Electronic Engineering Shandong University of Science and Technology Qingdao 266590 China

Hydrostatic guideways have various applications in precision machine tools due to their high motion accuracy. The analysis of motion straightness in hydrostatic guideways is generally ignoring the external load on the slider. A variation force also exists, caused by the different working positions, together with the dead load of the slider and that of other auxiliary devices. The effect of working position on vertical motion straightness is investigated based on the equivalent static model, considering the error averaging effort of pressured oil film in open hydrostatic guideways. Open hydrostatic guideways in LgF1000 are analyzed with this approach. The theoretical results show that the slider has maximum vertical motion straightness when the working position is closer the guiderail of Y axis. The vertical motion straightness reaches a minimum value as the working position is located at the center of the two guiderails on the Y axis. The difference between the maximum and minimum vertical motion straightness is 34.7%. The smaller vertical motion straightness is attributed to the smaller spacing of the two pads centers, along the Y direction. The experimental results show that the vertical motion straightness is 4.15 μm/1200 mm, when the working position is located in the middle of the Xbeam, and 5.08 pro/1200 mm, when the working position is approaching the Y guiderails, denoting an increase of 18.3%. The changing trends of the measured results validate the correctness of the theoretical model. The research work can be used to reveal the variation law of accuracy of the open hydrostatic guideways, under different working positions, to predict the machining precision, and provides the basis for an error compensation strategy for gantry type grinding machines.

关键词： open hydrostatic guideways error averaging vertical motion straightness working position

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Fabrication and electrochemical properties of 3D nano-network LiFePO4@multiwalled carbon nanotube composite using risedronic acid as the phosphorus source

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Progress in Natural Science:Materials International 2019年第2期29卷 156-162页

作者： Liping He Wenke zha Dachuan chen State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body and College of Mechanical & Vehicle Engineering Hunan University College of Civil Engineering Hunan University

LiFePO4@multiwalled carbon nanotubes(LFP@MWCNTs) nanocomposite has been fabricated using risedronic acid(RDA) as a new eco-friendly phosphorus source. Microscopic, spectroscopic, and electrochemical characterization demonstrate that the MWCNTs are in the form of coiled and cross-linking nanoribbon, which wrapped and encrusted around LiFePO4particles to form a three-dimensional(3D) nano-network *** microstructure of 3D nano-network is obtained due to the reactions between RDA’s special functional groups with Fe2+and C-OH,-C=O or-COOH on the surface of the functionalized MWCNTs. The results also show that the particle size of the fabricated LiFePO4@MWCNTs composite is below 300 nm with the pure crystal of olivine. This nanocomposite indicates an enhanced reversible capacity of 162.2 mAh g-1at 0.2C, and high capacity retention of 76.5% even at 10C after the 800 th cycles. The electric conductivity and Li+diffusion coefficient(DLi+) of the LiFePO4@MWCNTs are 3.79 × 10-2S cm-1and 4.46 × 10-11cm2s-1, *** improved electrochemical parameters can be attributed to the nano-sized effect of particles, MWCNTs’ wrapping effect and 3D nano-network microstructure of the LFP@MWCNTs resulted from using RDA as a new phosphorus source.

关键词： Risedronic acid 3D nano-network Electrochemical properties LiFePO4@multiwalled nanotube Lithium-ion battery

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