检索结果-南通市图书馆

Research on new beneficiation process of low-grade magnesite using vertical roller mill

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2020年第4期27卷 432-442页

作者： chuang Li chuan-yao Sun Yu-lian wang Ya-feng fu Peng-yun Xu Wan-zhong Yin School of Resources and Civil Engineering Northeastern UniversityShenyang 110819China State Key Laboratory of Mineral Processing Beijing 102628China National Engineering Research Center of WEEE Recycling Engineering Jingmen 448124China School of Materials Science and Engineering Shenyang Ligong UniversityShenyang 110159China College of Zijin Mining Fuzhou UniversityFuzhou 350108China

We investigated whether the vertical roller mill can be efficiently used in the beneficiation of low-grade magnesite and whether it can improve upon the separation indices achieved by the ball *** conducted experiments involving the reverse flotation and positive flotation of low-grade magnesite to determine the optimum process parameters,and then performed closed-circuit beneficiation experiments using the vertical roller mill and ball *** results show that the optimum process parameters for the vertical roller mill are as follows:a grinding fineness of 81.6wt%of particles less than 0.074 mm,a dodecyl amine(DDA)dosage in magnesite reverse flotation of 100 g·t?1,and dosages of Na2CO3,(NaPO3)6,and NaOL in the positive flotation section of 1000,100,and 1000 g·t?1,*** with the ball mill,the use of the vertical roller mill in the beneficiation of low-grade magnesite resulted in a 1.28%increase in the concentrate grade of MgO and a 5.88%increase in the recovery of *** results of our causation mechanism analysis show that a higher specific surface area and greater surface roughness are the main reasons for the better flotation performance of particles ground by the vertical roller mill in the beneficiation of lowgrade magnesite.

关键词： low-grade magnesite vertical roller mill reverse flotation positive flotation new beneficiation process

在线全文

学校读者我要写书评

暂无评论

大别山地区摇蚊科昆虫多样性调查研究

环境昆虫学报 2024年第3期46卷 606-615,I0002-I0017页

作者：徐紫刚李传仁王嘉鑫余鹏肖云丽傅悦黄冈师范学院生物与农业资源学院湖北黄冈438000 长江大学农学院湖北荆州434000 湖北大学生命科学学院武汉430000

大别山地区动植物资源丰富,但摇蚊科昆虫还尚未见系统报道。通过对大别山地区不同生境及海拔下的摇蚊进行采集,经研究得出4亚科37属131种,摇蚊亚科Chironominae 17属83种,直突摇蚊亚科Orthocladiinae 14属38种,长足摇蚊亚科Tanypodinae ... 详细信息

大别山地区动植物资源丰富,但摇蚊科昆虫还尚未见系统报道。通过对大别山地区不同生境及海拔下的摇蚊进行采集,经研究得出4亚科37属131种,摇蚊亚科Chironominae 17属83种,直突摇蚊亚科Orthocladiinae 14属38种,长足摇蚊亚科Tanypodinae 5属9种,寡角摇蚊亚科Diamesinae 1属1种。其中,中国新纪录种18种。采用Menhinick丰富度指数进行丰富度分析,摇蚊亚科中多足摇蚊属Polypedilum丰富度指数最高(m=2.25),直突摇蚊亚科中趋流摇蚊属Rheocricotopus丰富度指数最高(m=2.33)。在不同生境下摇蚊种类有着明显的差异,摇蚊亚科、直突摇蚊亚科在山间溪流生境下种类分布最多。采用Mcnaughton优势度指数对摇蚊优势度进行分析,城市湖泊生境中,中国长足摇蚊Tanypus chinensis wang和暗绿二叉摇蚊Dicrotendipes pelochloris(Kieffer)为绝对优势种,台湾短须摇蚊Nilodorum tainanus(Kieffer)、德永雕翅摇蚊Glyptotendipes tokunagai Sasa和平铗枝角摇蚊Cladopelma edwardsi(Kruseman)为优势种。在村庄农田中,花翅摇蚊Chironomus kiiensis Tokunaga为绝对优势种,平铗枝角摇蚊、Polypedilum kyotoense(Tokunaga)和台湾短须摇蚊为优势种。在坑塘生境下,林间环足摇蚊Cricotopus sylvestris(Fabricius)为绝对优势种,蚊型前突摇蚊Procladius culiciformis(Linnaeus)、中国长足摇蚊和花翅摇蚊为优势种。在山间溪流生境下,双斑环足摇蚊Cricotopus bimaculatus Tokunaga和Lipiniella fujiprimus(Sasa)为优势种。随着海拔的升高摇蚊的种类会随之下降,特别是摇蚊亚科和长足摇蚊亚科表现明显。根据世界陆地动物地理分区,大别山地区摇蚊以古北+东洋种类为主;根据世界淡水动物地理区域划分,大别山摇蚊种类主要分布在中印区,占75.7%,其次是中印区+全北区;中印区中,以东亚亚区较多,共计39种,占52.7%,说明大别山地区摇蚊种类分布存在明显的集中性。本研究丰富了该地区摇蚊科昆虫的多样性,为大别山地区水质监测和生态环境研究提供了重要依据。

关键词：水生底栖动物新纪录分布区系分析

Super-exchange effect induced by early 3d metal doping on NiFe_(2)O_(4)(001)surface for oxygen evolution reaction

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2023年第3期78卷 21-29,I0002页

作者： Shuhao wang Xinyan Liu Xiang Chen Kamran Dastafkan Zhong-Heng fu Xin Tan Qiang Zhang chuan Zhao School of Chemistry The University of New South WalesSydneyNSW 2052Australia Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing 100084China Institute of fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 611731SichuanChina Integrated Materials Design Laboratory Department of Applied MathematicsResearch School of PhysicsThe Australian National UniversityCanberraACT 2601Australia

Understanding the intrinsic activity of oxygen evolution reaction(OER) is crucial for catalyst *** date,different metal-doping strategies have been developed to achieve this,but the involving mechanisms remain ***,the electronic structure of the transition metal-doped NiFe_(2)O_(4)(001) surface is scrutinized for OER intrinsic activity using density functional theory *** 3d-orbital filling metals(Ti,V,Cr,Mn,and Co) are introduced as dopants onto A-and B-layers of the NiFe_(2)O_(4)(001) surface,and variation of oxidation states over Fe sites is observed on *** the magnetic moment and charge transfer of surface cation sites reveals that the variation of Fe oxidation states originates from the super-exchange effect and is influenced by the t2g-electron configuration of 3d metal *** trend governs the generation of highly-active Fe3+sites on the B-layer,the adsorption strength of OER intermediates,i.e.,*O and*OH,and therefore the intrinsic *** finding of super-exchange mechanism induced by 3d early metal doping offers insights into electronic structure tailoring strategies for improving the intrinsic activity of OER electrocatalysts.

关键词： Oxygen evolution reaction NiFe spinel Oxidation states Super-exchange mechanism Density functional theory

Structure splitting framework for data-layout optimization

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2009年第5期16卷 107-113页

作者： fu Xiong , wang Ru-chuan College of Computer, Nanjing University of Posts and Telecommunications, Nanjing 210003, China College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China

To improve data cache performance, optimizing program data layout by data reorganization has become an important method of decreasing the impact of increasing gap of speed between processor and memory. In this article, a structure splitting framework with an analysis model named structure field relation graph （SFRG） is presented to optimize program data layout. The SFRG can be used to quantify relationship between fields. It helps to find an optimal layout for structure as well as the optimal program data layout. And the data cache performance is improved through SFRG-based structure splitting. Experiments show that this framework is effective in optimizing program data layout and improving the performance of data cache and whole program.

关键词： program optimization structure splitting data layout cache performance

Morphologies and Influential Factors of Forsterite Film in Grain-Oriented Silicon Steel

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2013年第11期20卷 105-110页

作者： fu Yong-jun JIANG Qi-wu wang Bao-chuan YANG Ping JIN Wen-xu School of Materials Science and Engineering University of Science and Technology Beijing Anshan Steel Co. Ltd.Cold Rolling Silicon Plant

The product quality of graiworiented silicon steel may be affected by each process because of its complicat- ed production technology. Morphologies, compositions and structures of forsterite film formed in different conditions on the samples subjected to high temperature annealing were measured by using a scanning electron microscope, an energy disperse spectroscope, an X ray diffractometer and Fourier transform infrared technique respectively. The morphologies and influential factors of forsterite film were investigated. The results showed that the major compo- nent of forsterite film composed of light-gray spherical particles was Mg2 SiO4, and the minor was MgAl2O4. If the amount of MgO coated on the surface of the steel was less, bare holes or even large-scale bare grains for forsterite film appeared. The higher temperature of water bath during decarburization annealing led to gaps of strips in forster ite film. Moreover, MgO coating method had great influence on forsterite film. Roller coating method was beneficial to increase compactness and smoothness of forsterite film, but was disadvantageous to its thickness.

关键词： grain-oriented silicon steel forsterite film bare grain

基于宏基因组测序揭示不同施肥方式对茶园土壤微生物群落的季节性影响

在线全文

学校读者我要写书评

暂无评论

中国土壤与肥料 2024年第3期 23-31页

作者：周雪刘声传周玉锋林开勤周富裕贵州省农业科学院茶叶研究所贵州贵阳550006 贵阳学院生物与环境工程学院贵州贵阳550005

为揭示不同施肥方式对茶园土壤微生物群落的季节性影响,采用宏基因组测序,比较分析了同一茶园习惯施肥(CF)、微生物有机肥配施控释复合肥(MC),在冬季至夏季3个时间点[11月14日(CF1、MC1)、3月1日(CF2、MC2)、5月15日(CF3、MC3)]的土壤... 详细信息

为揭示不同施肥方式对茶园土壤微生物群落的季节性影响,采用宏基因组测序,比较分析了同一茶园习惯施肥(CF)、微生物有机肥配施控释复合肥(MC),在冬季至夏季3个时间点[11月14日(CF1、MC1)、3月1日(CF2、MC2)、5月15日(CF3、MC3)]的土壤微生物群落组成和结构。结果表明,共获得311211956条高质量测序数据和1763759个Unigenes。主成分和相关性分析表明,MC1和CF1的土壤微生物基因丰度聚为一类,其他独聚一类。不同季节,CF和MC的细菌、古菌、真菌分别占微生物总数的88%~89%、0.8%~2.0%、0.02%~0.10%;古菌数量逐渐增加,真菌数量先增加后降低。CF2、CF3的古菌数量分别高于MC2、MC3,而真菌数量相反;CF2、CF3的细菌、真菌丰度分别显著低于MC2、MC3,古菌丰度相反。MC1、MC2、MC3之间的细菌、古菌、真菌丰度存在显著差异,而CF1与CF3的真菌丰度接近。相较于CF,MC提高了土壤细菌中的变形菌门、放线菌门、芽单胞菌门、绿弯菌门、拟杆菌门、硝化螺旋菌门、装甲菌门相对丰度,降低了酸杆菌门、疣微菌门、浮霉菌门相对丰度;提高了古菌中的奇古菌门相对丰度,降低了广古菌门、泉古菌门、深古菌门相对丰度;提高了真菌中的毛霉门、捕虫霉门、隐真菌门相对丰度,降低了担子菌门相对丰度。总体上,CF和MC优势细菌门、优势古菌门、优势真菌门相对丰度的季节性变化趋势存在一定差异。茶园土壤微生物群落组成和结构呈现一定的季节性、施肥方式性变化规律;微生物有机肥配施控释复合肥可以提高土壤细菌丰度、真菌数量和丰度,降低古菌数量和丰度,改变土壤优势菌群的组成,为充分利用微生物资源、提高茶树养分利用率等提供了理论依据。

关键词：茶园施肥方式宏基因组微生物丰度微生物群落结构季节

Light Scattering of Rough Orthogonal Anisotropic Surfaces with Secondary Most Probable Slope Distributions

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2011年第8期28卷 133-136页

作者： LI Hai-Xia CHENG chuan-fu College of Physics and Electronics Shandong Normal UniversityJinan 250014 Department of Information Science and Technology Shandong University of Politics Science and LawJinan 250014

We study the light scattering of an orthogonal anisotropic rough surface with secondary most probable slope *** is found that the scattered intensity profiles have obvious secondary maxima,and in the direction perpendicular to the plane of incidence,the secondary maxima are oriented in a curve on the observation plane,which is called the orientation *** numerical calculation of the scattering wave fields with the height data of the sample,it is validated that the secondary maxima are induced by the side face element,which constitutes the prismoid structure of the anisotropic *** derive the equation of the quadratic orientation ***,we construct the system for light scattering measurement using a *** scattered intensity profiles are extracted from the images at different angles of incidence along the orientation *** experimental results conform to the theory.

关键词： surface curve theory

Fe–Al Phase Formation Studied by Internal Friction during Heating Process

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics Letters 2020年第3期37卷 41-44页

作者： Gang-Ling Hao Yu-chuan Li Xing-fu wang Wei-Guo wang Xin-fu wang Dan wang Xian-Yu Li College of Physics and Electronic Information Yan 5an UniversityYan'an 716000 Key Laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of SciencesHefei 230031

We systematically investigate the internal friction properties of a Fe-(43 at.%)Al powder mixture compact during the heating process with the expectation to understand the phase formation and transition *** internal friction peaks are successively observed during the heating process from room temperature to 750℃,but almost completely disappear in the subsequent cooling *** internal friction peaks exhibit obvious measuring frequency dependence,which increases with decreasing the *** first internal friction peak originates from the micro-sliding of weak bonding interface between Al particles corresponding to a *** process of deformed Al *** second internal friction peak is attributed to a phase formation process associated with the formation of the intermediate phase *** third internal friction peak is considered to result from the formation of the FeAl intermetallic compound owing to the reaction of Fe2Al5 and residual Fe initiated by a dramatic thermal explosion reaction.

关键词： friction intermetallic Internal

在线全文

学校读者我要写书评

暂无评论

爬高型堰塞坝漫顶溃决机理研究

防灾减灾工程学报 2024年第4期44卷 910-920页

作者：赵天龙岳亮李方芳付长静张川李泓鑫重庆交通大学河海学院重庆400074 重庆交通大学水利水运工程教育部重点实验室重庆400074 中国水利水电第三工程局有限公司陕西西安710024 重庆市水利电力建筑勘测设计研究院有限公司重庆401120 中建三局绿色产业投资有限公司湖北武汉430058

我国西南地区频发的地质构造活动和极端自然灾害诱发了大量的堰塞坝,属于堰塞坝的高发地,其形成的堰塞坝具有突然性强、危险性大的特点,严重威胁所在流域人民的生命财产安全,深入研究爬高型堰塞坝溃坝过程可为除险减灾提供科学理论支撑... 详细信息

我国西南地区频发的地质构造活动和极端自然灾害诱发了大量的堰塞坝,属于堰塞坝的高发地,其形成的堰塞坝具有突然性强、危险性大的特点,严重威胁所在流域人民的生命财产安全,深入研究爬高型堰塞坝溃坝过程可为除险减灾提供科学理论支撑。为此,以土颗粒级配、背水面坡度、爬高型堰塞坝坝顶形状为影响堰塞坝漫顶溃决的主要因素,从漫顶溃决过程、溃口流量过程、溃口演变过程、溃后残留坝体及下游淤积情况等方面,分析了爬高型堰塞坝漫顶溃决演化过程。试验结果表明:随着土石料级配变宽,坝体整体稳定性增强溃决历时延长,洪峰流量减小,峰现时间较晚,残留溃口上宽小坝体体积大,距坝趾泥沙输移长度短且距坝趾1 m处泥沙厚度薄;背水坡面越陡,水流获得的动能越大,加速了整个坝体溃决过程,溃口扩展得到充足发育,洪峰流量增大,峰现时间提前,残留溃口上宽较大坝体体积小,距坝趾泥沙输移长度长且距坝趾1 m处泥沙厚度较厚;宽深比越大,则溃口相对位置越高,冲蚀阶段所具有的水头差大,加速了坝体冲刷进程,溃口扩展得到充分发育,残留溃口上宽尺度大坝体总量小,距坝趾泥沙输移距离远且距坝趾1 m处泥沙厚度较厚。

关键词：爬高型堰塞坝溃决过程漫顶溃决机理物理模型试验