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菱锌矿硫化浮选机理及影响因素研究进展

化工进展 2024年第7期43卷 4015-4031页

作者：林翔焦芬魏茜张政权中南大学资源加工与生物工程学院湖南长沙410083

随着锌资源开发利用的深入,低品位难选氧化锌矿成为锌的重要来源,菱锌矿作为分布最多的典型氧化锌矿,是锌的重要矿产来源。本文详细介绍了菱锌矿重要的浮选手段——表面硫化浮选,阐述了硫化浮选的作用机理,解释了菱锌矿硫化过程中化学... 详细信息

随着锌资源开发利用的深入,低品位难选氧化锌矿成为锌的重要来源,菱锌矿作为分布最多的典型氧化锌矿,是锌的重要矿产来源。本文详细介绍了菱锌矿重要的浮选手段——表面硫化浮选,阐述了硫化浮选的作用机理,解释了菱锌矿硫化过程中化学吸附、化学反应以及详细阐述菱锌矿硫化过程中沉淀-溶解反应机理,指出硫化过程是硫化层的沉淀与氧化层脱落的动态平衡过程,成核过程为受到以溶度积为主要驱动力所发生的非均质成核,该过程不同阶段硫化速度随时间而变化。本文列举了浮选过程中矿浆pH、硫化时间、硫化温度等因素对沉淀-溶解硫化的影响方式。同时指出高效强化硫化与绿色硫化是菱锌矿硫化浮选未来研究的重中之重,通过添加药剂进行硫化的高效强化能有效减少硫化钠的用量,通过开发绿色有机硫化剂来减少硫化钠等无机硫化剂的使用,降低选矿废水的污染以及处理难度,最后点明硫化浮选在当前乃至将来都是菱锌矿有效分选的重要方法。

关键词：菱锌矿浮选硫化机理硫化因素

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基于GaN器件的包络跟踪电源设计

电子技术（上海） 2024年第4期53卷 4-9页

作者：崔文奇张政权西南交通大学物理科学与技术学院四川611756

阐述针对半桥D类音频功放因固定电压高于实际需要的电压而导致能效降低的问题,提出一种基于GaN器件的全桥LLC谐振变换器的双极性对称输出音频包络跟踪电源。该电源采用调频与移相混合控制策略实现宽电压输出范围,并利用扩展函数描述法... 详细信息

阐述针对半桥D类音频功放因固定电压高于实际需要的电压而导致能效降低的问题,提出一种基于GaN器件的全桥LLC谐振变换器的双极性对称输出音频包络跟踪电源。该电源采用调频与移相混合控制策略实现宽电压输出范围,并利用扩展函数描述法对系统进行建模分析,进行系统优化设计和闭环补偿设计,实现高带宽的稳定系统。仿真结果表明,该包络跟踪电源能够精确跟踪参考电压的变化,在不同频率和幅值范围内保持输出波形的稳定性和精度。

关键词： LLC谐振变换器扩展函数描述法包络跟踪电源混合控制

Key techniques for 5G wireless communications:network architecture, physical layer,and MAC layer perspectives

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Science China(Information Sciences) 2015年第4期58卷 5-24页

作者： MA Zheng zhang zhengquan DING ZhiGuo FAN PingZhi LI HengChao Provincial Key Lab of Information Coding and Transmission Southwest Jiaotong University Department of Communication Systems Lancaster University

The fourth generation(4G) mobile communication systems are offering service worldwide *** 4G systems could be loaded with much more services and data than previous systems, there is still a dramatic gap between the people’s practical requirements and what can be offered by the 4G ***, the research and development for the fifth generation(5G) systems have already been started. This article presents an overview of potential network architecture and highlights several promising techniques which could be employed in the future 5G systems. These techniques include non-orthogonal multiple access(NOMA),massive multiple input and multiple output(MIMO), cooperative communications and network coding, full duplex(FD), device-to-device(D2D) communications, millimeter wave communications, automated network organization, cognitive radio(CR), and green communications. The state-of-art and implementation issue of these techniques are also addressed.

关键词： 5G software defined network non-orthogonal multiple access massive MIMO full duplex deviceto-device communications millimeter wa

Experimental Study on the Properties of Line-Shaped Laser-Plasma

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Chinese Physics Letters 1994年第5期11卷 277-280页

作者： HAN Shensheng zhang Lingqing XU Zhizhan zhang zhengquan SUN Lan Shanghai Institute of Optics and Fine Mechanics Academia SinicaShanghai 201800

Line-focused high power laser was used to irradiate a magnesium slab target in order to generate line-shaped *** parameter profile distribution(electron temperature and electron density)on the direction perpendicular to the target surface was obtained by spectroscopic diagnostic method,which is quite different from that of the spot-shaped *** experimental phenomena that can be interpreted as“plasma satellites”were also observed.

关键词： shaped magnesium spectroscopic

Application of EDTMPS as a novel calcite depressant in scheelite flotation

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International Journal of Mining Science and Technology 2023年第5期33卷 639-647页

作者： Fen Jiao Wei Li Xu Wang Congren Yang zhengquan zhang Liwen Fu Wenqing Qin School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China

In this study, the innovative use of ethylenediamine tetramethylene phosphonic sodium(EDTMPS) as a calcite depressant in scheelite flotation was investigated by flotation experiments, and its selective depression mechanism was revealed by contact angle measurement, FTIR analysis, Zeta potential test and XPS analysis. The flotation experiment results showed that scheelite and calcite could be efficiently separated under the following conditions: pulp p H=9.5, Na OL concentration of 1.5×10^(-4)mol/L, EDTMPS concentration of 3.0×10^(-5)mol/L, a scheelite concentrate with WO3grade of 65.49%, recovery of 83.29%and separation efficiency of 65.29% could be obtained from the artificially mixed minerals. The analysis results of mineral surface properties demonstrated that EDTMPS was strongly adsorbed onto the calcite surface through the reaction between the phosphonate group and the calcium ions, which hindered Na OL adsorption and increased the hydrophilicity of calcite. However, EDTMPS had weak adsorption strength on the scheelite surface, which didn’t affect further adsorption of Na OL, hence, the scheelite remained hydrophobic. Consequently, the selective adsorption of EDTMPS on the two minerals’ surfaces increased a difference in wettability and thus enabling them to be separated by flotation. Finally, the mechanism model of this flotation separation process was established.

关键词： Ethylenediamine tetramethylene phosphonic sodium Scheelite Calcite Flotation Selective depression

Time-Evolution of X-Ray Emission Nonuniformity in Line-Shaped Laser Plasmas

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Chinese Physics Letters 1995年第10期12卷 601-604页

作者： zhang Lingqing HAN Shensheng XU Zhizhan zhang zhengquan WANG Xiaofang FAN Pinzhong SONG Xiangyang QIAN Aidi Shanghai Institute of Optics and Fine Mechanics Academia SinicaShanghai 201800

The spatially and time resolved 2D images of x-ray emission of line-shaped Ti laser plasmas have been obtained with a pinhole transmission grating spectrometer coupled with a x-ray streak *** x-ray emission nonuniformity of the plasma is quantitatively analyzed using a perturbation spectrum analysis *** results show that the nonuniformity has a minimum value at a time corresponding to the peak time of the pumping laser pulse,and increases after that.A brief discussion on the nonuniformity mechanism has also been presented.

关键词： pumping Nonuniform spatially

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苍山大型真菌多样性

大理大学学报 2024年第6期9卷 59-66页

作者：苏锡钧何俊牛开阳韩林张正权罗宗龙杨力权大理大学农学与生物科学学院云南大理671003 苍山洱海一体化保护与流域绿色发展云南省高校协同创新中心云南大理671003 苍山森林生态系统云南省野外科学观测研究站云南大理671003 大理大学生物科学馆云南大理671003 滇西科技师范学院生物技术与工程学院云南临沧677000

目的:调查苍山大型真菌物种资源,初步讨论苍山不同海拔、不同植被类型与大型真菌多样性之间的关系,提出合理保护与利用的建议。方法:采用随机踏查、样线调查的方法,以经典分类学为基础,结合分子生物学的方法对采集到的标本进行鉴定,分... 详细信息

目的:调查苍山大型真菌物种资源,初步讨论苍山不同海拔、不同植被类型与大型真菌多样性之间的关系,提出合理保护与利用的建议。方法:采用随机踏查、样线调查的方法,以经典分类学为基础,结合分子生物学的方法对采集到的标本进行鉴定,分析区域内物种组成和分布特征。结果:本次科学考察共采集苍山大型真菌标本2490份,鉴定出大型真菌400种,隶属于6纲18目59科147属,包括1个新物种——苏氏地星Geastrum suae;物种数≥10的优势科有9个,占已知科的15.25%,牛肝菌科Boletaceae 54种、红菇科Russulaceae 51种、鹅膏菌科Amanitaceae 33种、伞菌科Agaricaceae 29种、丝盖伞科Inocybaceae 15种、丝膜菌科Cortinariaceae 14种、马勃科Lycoperdaceae 13种、膨瑚菌科Physalacriaceae 13种及蜡伞科Hygrophoraceae 11种,共计233种,占总物种数的58.25%;物种数≥10的优势属有6个,占已知属数的4.08%,红菇属Russula 30种、鹅膏菌属Amanita 30种、乳菇属Lactarius 19种、牛肝菌属Boletus 16种、蘑菇属Agaricus 12种及丝盖伞属Inocybe 11种,共计118种,占总物种数的29.50%;苍山共有食用菌187种、药用菌56种,毒菌83种,食毒不明的124种,可栽培大型真菌28种;苍山大型真菌物种分布在海拔上符合典型的单峰分布格局,随着海拔的上升,物种数量呈现出先增加后减少的分布格局;苍山大型真菌物种在阔叶林中更为丰富,针阔叶混交林次之,针叶林中大型真菌种类最少。结论:苍山大型真菌资源较为丰富,具有较好的开发利用价值和科研价值,需有效保护,科学合理地利用苍山大型真菌资源。

关键词：大型真菌物种多样性种质资源苍山

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A Survey on Low Complexity Detectors for OTFS Systems

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ZTE Communications 2021年第4期19卷 3-15页

作者： zhang zhengquan LIU Heng WANG Qianli FAN Pingzhi Key Lab of Information Coding and Transmission Southwest Jiaotong UniversityChengdu 611756China State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an 710071China

The newly emerging orthogonal time frequency space(OTFS)modulation can ob⁃tain delay-Doppler diversity gain to significantly improve the system performance in high mobility wireless communication scenarios such as vehicle-to-everything(V2X),high-speed railway and unmanned aerial vehicles(UAV),by employing inverse symplectic finite Fouri⁃er transform(ISFFT)and symplectic finite Fourier transform(SFFT).However,OTFS modu⁃lation will dramatically increase system complexity,especially at the receiver ***,de⁃signing low complexity OTFS receiver is a key issue for OTFS modulation to be adopted by new-generation wireless communication *** this paper,we review low complexity OTFS detectors and provide some insights on future *** firstly present the OTFS system model and basic principles,followed by an overview of OTFS detector structures,classifications and comparative *** also survey the principles of OTFS detection ***,we discuss the design of hybrid OTFS and orthogonal frequency di⁃vision multiplexing(OFDM)detectors in single user and multi-user multi-waveform commu⁃nication ***,we address the main challenges in designing low complexity OT⁃FS detectors and identify some future research directions.

关键词： high mobility wireless communications OTFS ISFFT SFFT delay-Doppler di⁃versity iterative maximum ratio combining(MRC)detection message passing detection

Research progresses of nanomaterials as lubricant additives

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Friction 2024年第7期12卷 1347-1391页

作者： zhengquan JIANG Yankun SUN Bokang LIU Laigui YU Yuping TONG Mingming YAN Zhongzheng YANG Yongxing HAO Linjian SHANGGUAN Shengmao zhang Weihua LI School of Materials Science and Engineering North China University of Water Resources and Electric PowerZhengzhou 450045China Institute of Special Friction and Lubricating Materials North China University of Water Resources and Electric PowerZhengzhou 450045China Nanomaterials Engineering Research Center Henan UniversityKaifeng 475001China School of Mechanical Engineering North China University of Water Resources and Electric PowerZhengzhou 450045China

Friction and wear are unavoidable in mechanical *** use of lubricants with nano-additives can effectively reduce friction and wear,which is of great significance to saving energy and protecting the *** present,great progress has been made in the scientific research and industrial application of nano-additives for *** paper mainly introduces the types of nano-additives for lubricants(such as carbon nanomaterials,nano-metals,nano-oxides,sulfides,complexes,polymers,etc.),the tribological properties of lubricants with different components of nano-additives,and the lubrication mechanisms of the nano-additives(including tribofilm formation,rolling ball bearing effect,repairing effect,polishing effect,and synergistic effect).It also deals with the dispersion of nano-additives in lubricants and the influences of their particle size and microstructure on the tribological properties of *** review outlines the performance requirements of nano-additives in different lubrication states,discusses the use of nano-additives in challenging working conditions,and identifies various industrial oil nano-additives with reference to the appropriate options in diverse working ***,the existing problems of nano-additives and their application prospects are *** review,hopefully,would help to shed light on the design and synthesis of novel high-performance nano-additives and promote their application in engineering.

关键词： nanomaterials lubricant additive lubrication mechanism research progress