检索结果-南通市图书馆

基于活性炭颗粒的圆振动筛主要技术参数优化分析

在线全文

学校读者我要写书评

暂无评论

煤炭加工与综合利用 2024年第1期 79-83页

作者：冯霏韩松洁柴二威沈阳化工大学辽宁沈阳110142

为验证圆运动振动筛在对活性炭颗粒筛分时,振动筛各运动参数对筛分效率的影响,采用平均筛分效率来代表活性炭筛分效果。采用Box-Behnken响应面分析来研究圆运动振动筛的振动幅度、运动倾角以及振动频率对筛分效果的影响并进行仿真模拟,... 详细信息

为验证圆运动振动筛在对活性炭颗粒筛分时,振动筛各运动参数对筛分效率的影响,采用平均筛分效率来代表活性炭筛分效果。采用Box-Behnken响应面分析来研究圆运动振动筛的振动幅度、运动倾角以及振动频率对筛分效果的影响并进行仿真模拟,探讨3个因素之间对活性炭筛分的影响作用。验证结果表明:对筛分效果影响最大的是振动频率,影响最弱的是运动倾角,振动幅度和运动倾角之间具有显著影响作用,在振动幅度为4.21 mm、运动倾角16.07°以及振动频率13.83 Hz时筛分效果达到最大值40.86%。通过该方法优化的圆振动筛,可提高活性炭的筛分效率。

关键词：活性炭物料圆运动振动筛响应面分析离散单元法平均筛分效率

Few-layer Tellurium:one-dimensional-like layered elementary semiconductor with striking physical properties

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2018年第3期63卷 159-168页

作者： Jingsi Qiao Yuhao Pan feng Yang Cong Wang Yang chai Wei Ji Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices Department of Physics Renmin University of China Department of Applied Physics The Hong Kong Polytechnic University

Few-layer Tellurium, an elementary semiconductor, succeeds most of striking physical properties that black phosphorus(BP) offers and could be feasibly synthesized by simple solution-based methods. It is comprised of non-covalently bound parallel Te chains, among which covalent-like feature *** feature is, we believe, another demonstration of the previously found covalent-like quasi-bonding(CLQB) where wavefunction hybridization does occur. The strength of this inter-chain CLQB is comparable with that of intra-chain covalent bonding, leading to closed stability of several Te allotropes. It also introduces a tunable bandgap varying from nearly direct 0.31 eV(bulk) to indirect 1.17 eV(2L) and four(two) complex, highly anisotropic and layer-dependent hole(electron) pockets in the first Brillouin *** also exhibits an extraordinarily high hole mobility(~10~5 cm^2/Vs) and strong optical absorption along the non-covalently bound direction, nearly isotropic and layer-dependent optical properties, large ideal strength over 20%, better environmental stability than BP and unusual crossover of force constants for interlayer shear and breathing modes. All these results manifest that the few-layer Te is an extraordinary-high-mobility, high optical absorption, intrinsic-anisotropy, low-cost-fabrication, tunable bandgap, better environmental stability and nearly direct bandgap semiconductor. This ‘‘one-dimen sion-like" few-layer Te, together with other geometrically similar layered materials, may promote the emergence of a new family of layered materials.

关键词： Two-dimensional systems First-principles calculations Tellurium High carrier mobility Covalent-like quasi-bonding One-dimension-like layered materials

Newly Discovered Native Gold and Bismuth in the Cihai Iron-Cobalt Deposit, Eastern Tianshan, Northwest China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2016年第3期90卷 928-938页

作者： ZHENG Jiahao MAO Jingwen YANG Fuquan chai fengmei LIU feng Key Laboratory of Orogenic Belts and Crustal Evolution Ministry of Education School of Earth and Space Sciences Peking University MLR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral Resources Chinese Academy of Geological Sciences Xinjiang Key Laboratory for Geodynamic Processes and Metallogenic Prognosis of the Central Asian Orogenic Belt Xinjiang University

The Cihai iron-cobalt deposit is located in the southern part of the eastern Tianshan iron- polymetallic metallogenic belt. Anomalous native gold and bismuth have been newly identified in Cinan mining section of the Cihai deposit. Ore formation in the deposit can be divided into three stages based on geological and petrographical observations：（I） skarn, with the main mineral assemblage being garnet-pyroxene-magnetite; （II） retrograde alteration, forming the main iron ores and including massive magnetite, native gold, native bismuth, and cobalt-bearing minerals, with the main mineral assemblage being ilvaite-magnetite-native gold-native bismuth; and （III） quartz-calcite- sulfide assemblage that contains quartz, calcite, pyrrhotite, cobaltite, and safflorite. Native gold mainly coexists with native bismuth, and they are paragenetically related. The temperature of initial skarn formation was higher than 340~C, and then subsequently decreased to -312~C and ~266~C. The temperature of the hydrothermal fluid during the iron ore depositional event was higher than the melting point of native bismuth （271~C）, and native bismuth melt scavenged gold in the hydrothermal fluid, forming a Bi-Au melt. As the temperature decreased, the Bi-Au melt was decomposed into native gold and native bismuth. The native gold and native bismuth identified during this study can provide a scientific basis for prospecting and exploration for both gold- and bismuth-bearing deposits in the Cihai mining area. The gold mineralization in Cihai is a part of the Early Permian Cu-Ni-Au-Fe polymetallic ore-forming event, and its discovery has implications for the resource potential of other iron skarn deposits in the eastern Tianshan.

关键词： Cihai iron-cobalt deposit native gold native bismuth eastern Tianshan

Transmission Line Distance Protection Under Current Transformer Saturation

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2021年第1期9卷 68-76页

作者： Yuping Zheng Tonghua Wu feng Hong Gang Yao Jimin chai Zhinong Wei the College of Energy and Electrical Engineering Hohai UniversityNanjing 210098China State Key Laboratory of Smart Grid Protection and Control NARI Group CorporationNanjing 211106China Changzhou Institute of Technology Changzhou 213032China

Conventional transmission line distance protection approaches are subject to malfunction under reverse fault-induced current transformer(CT) saturation for the typically employed breaker-and-a-half configuration. This paper addresses this issue by proposing a new distance protection approach that combines the blocking and unblocking criteria of distance protection based on the values of incomplete differential current,operation voltage, and current harmonic content. The proposed approach is verified by theoretical analysis, dynamic simulation testing, and field operation to ensure that the obtained distance protection is reliable and refrains from operating unnecessarily under reverse fault-induced CT saturation in the breaker-and-ahalf configuration. Meanwhile, the proposed approach is demonstrated can operate reliably when forward faults occur or various reverse faults are converted to forward faults.

关键词： Breaker-and-a-half configuration current transformer(CT)saturation distance protection power frequency variation operation voltage

Spectroscopic analysis of acetamide-AlCl_(3)-based ionic liquid analog and their catalytic performance in isobutene oligomerization

在线全文

学校读者我要写书评

暂无评论

Green Chemical Engineering 2021年第2期2卷 233-238页

作者： Pengcheng Hu Ruimin chai Aonan Lai Shu-feng Zhou College of Chemical Engineering Huaqiao UniversityXiamen361021FujianChina

The spectral structures of acetamide-AlCl_(3)-based ionic liquid(IL)analogs were determined in detail through IR,NMR,and Raman *** spectroscopy showed that 0.65AA-1.0AlCl_(3) was the coordination structure of Al and O atoms because of the resonance structure of *** mutual verification of the results of ^(27)Al NMR and ^(1)H NMR indicated that acetamide coexisted mainly in the form of cationic Al species and molecular Al species in xAA-1.0AlCl_(3),and AA/AlCl_(3) molar ratio affected the transformation of cationic Al species to molecular Al ***-1.0AlCl_(3) was used as a green acidic catalyst for isobutene oligomerization,and the effects of AA/AlCl_(3) molar ratio,reaction temperature,reaction time,and volumetric ratio between IL analog and isobutene on product distribution were *** reaction conditions were AA/AlCl_(3) molar ratio of 0.75,reaction temperature of 60 C,reaction time of 30 min,and catalyst/i-C4¼volumetric ratio of 1.4 v/*** optimal conditions,isobutene conversion,(C8^(-)+C12^(-))selectivity,(C16^(-)+C20^(-))selectivity,and by-product selectivity were 85.26,80.20,6.80,and 13.00 wt%,respectively。

关键词： Oligomerization Isobutene Ionic liquid analog Catalytic performance

Effect of Sm-doping on the morphology and magnetic properties of radio frequency magnetron sputtered Ni-Mn-Ga films

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2012年第6期19卷 555-560页

作者： feng-hua Chen Min-gang Zhang Yue-sheng chai Chang-wei Gong College of Materials Science and Engineering Taiyuan University of Science and Technology Talyuan 030024 China

Ni55.5Mn21Ga23.5 and Ni54Mn22Ga23Sml films were prepared by radio frequency （RF） magnetron sputtering. The effect of Sm do- pant on the morphologic and magnetic properties of Ni55.5Mn21Ga23.5 films was investigated. Sm doping can refine the particle size of the films from 100 to 60 nm, and further grain growth is not occurs even after annealing at 1073 K for 3.6 ks. Compared to Ni55.5Mn21Ga23.5 films, Sm-doped Ni54Mn22Ga23Sml films are easier to be magnetized and have a lower martensitic transformation temperature. In addition, the Curie temperature can also be adjusted, decreasing from 350 to 325 K after Sm doping. Martensitic transformation is not observed in the Sm-free films, which is close to the Curie temperature in the Sm-doped films, giving rise to the overlap of the structural and magnetic transi- tion temperatures.

关键词： magnetic films samarium doping magnetron sputtering martensitic transformation magnetic transition temperature magneticproperties rare earths

人工繁育条件下的褐菖鲉(Sebastiscus marmoratus)繁殖特性研究

在线全文

学校读者我要写书评

暂无评论

海洋与湖沼 2024年第4期55卷 1027-1036页

作者：邹雄阮泽超张燕王跃斌汪倩凤柴学军浙江海洋大学水产学院浙江舟山316022 浙江省海洋水产研究所浙江省海水增养殖重点实验室浙江舟山316021

为进一步了解和掌握人工繁育条件下褐菖鲉(Sebastiscus marmoratus)繁殖特性,从2021年5月至2023年6月采集不同月份的褐菖鲉性腺样本,对不同阶段的性腺表型和组织变化、发育周期、生殖腺指数及绝对繁殖力进行分析。结果表明,褐菖鲉为典... 详细信息

为进一步了解和掌握人工繁育条件下褐菖鲉(Sebastiscus marmoratus)繁殖特性,从2021年5月至2023年6月采集不同月份的褐菖鲉性腺样本,对不同阶段的性腺表型和组织变化、发育周期、生殖腺指数及绝对繁殖力进行分析。结果表明,褐菖鲉为典型的卵胎生鱼类,精巢为全囊成熟型,可分为6期;卵巢为部分同步型,交尾受精后存在妊娠期,共分为7期。各月份性腺分期及生殖腺指数统计结果显示,褐菖鲉繁殖高峰期为每年12月至翌年4月,其中雄性1龄性成熟,雌性2龄性成熟,生殖腺指数在发育阶段显著上升(P<0.05),在交尾排精和产仔后显著下降。此外,1~4龄褐菖鲉的平均绝对繁殖力分别为7087、(19726±4470)、(35924±4190)、(43203±6204)粒,各年龄组存在显著性差异,方程拟合得出绝对繁殖力与体长、体质量呈二项式相关。首次对人工繁育条件下的褐菖鲉性腺发育过程和繁殖特性进行两周年的持续追踪和研究,结果将有助于加深对其繁殖特性的了解,提升规模化繁育技术水平。

关键词：褐菖鲉(Sebastiscus marmoratus) 精巢卵巢组织学观察生殖腺指数绝对繁殖力

Strengthening and toughening mechanism of a Cu-bearing high-strength low-alloy steel with refined tempered martensite/bainite(M/B)matrix and minor inter-critical ferrite

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2021年第4期28卷 464-478页

作者： Fei Zhu feng chai Xiao-bing Luo Zheng-yan Zhang Cai-fu Yang Department of Structural Steels Central Iron and Steel Research InstituteBeijing 100081China

The microstructure–mechanical property relationship of a Cu-bearing low-carbon high-strength low-alloy steel,subjected to a novel multistage heat treatment including quenching(Q),lamellarization(L)and tempering(T),is *** strength of 989.5 MPa and average toughness at-80℃of 41 J were obtained in this steel after quenching and tempering(QT)heat *** QLT gained a little lower yield strength(982.5 MPa),but greatly enhanced average toughness at-80℃(137 J).To further clarify the strengthening and toughening mechanisms in specimen QLT,parameters of microstructural characteristic and crack propagation process were compared and analyzed for specimens Q,QL,QT and *** microstructure of tempered martensite/bainite(M/B)in specimen QT changed to refined tempered M/B matrix mixed with minor IF(inter-critical ferrite)in specimen ***-rich precipitates existed in tempered M/B for both specimens QT and QLT,as well as in *** with QT,adding a lamellarization step before tempering made the effective grains of specimen QLT refined and also led to coarser Cu-rich precipitates in tempered M/B *** weaker strengthening effect of coarser Cu-rich precipitates should be a key reason for the slightly lower yield strength in specimen QLT than in specimen *** austenite was found in all specimens Q,QL,QT and *** QLT showed purely ductile fracture mode at-80℃due to the refined effective *** greatly improved toughness is mainly attributed to the enhanced energy of crack *** combination of refined microstructure,softened matrix and deformation of minor'soft'IF during crack propagation led to the most superior toughness of specimen QLT among all specimens.

关键词： High-strength low-alloy steel Multistage heat treatment Low-temperature toughness Strengthening mechanism Grain refinement Crack propagation

Fault estimation based on high order iterative learning scheme for systems subject to nonlinear uncertainties

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

Science China(Information Sciences) 2022年第7期65卷 261-262页

作者： Li feng Shuiqing XU Ke ZHANG Yi chai Darong HUANG College of Traffic and Transportation Chongqing Jiaotong University College of Electrical Engineering and Automation Hefei University of Technology College of Automation Chongqing University

Dear editor, Due to the high load and continuous work, some equipment such as sensors and actuators in the system will inevitably degrade as the aging time increases. Also, they may evolve into faults causing the decline of system control performance. However, the stability of the system cannot be guaranteed due to the large loss of property and casualties caused by faults. Therefore, fault diagnosis and faulttolerant control [1, 2] are widely applied in the industrial system to solve these problems.

关键词： Fault estimation High order iterative learning scheme Nonlinear system Nonlinear uncertainties Iterative learning control