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study on mixing and segregation behaviors in particulate fluidized bed system for mineral process.n.

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International Journal of Mining science and Technology 2015年第3期25卷 459-464页

作者： sahu s.n. sahu A.K. Biswal s.K. Mineral Process.n. Department CSIR-Institute of Minerals and Materials Technology

In order to identify the mixing and segregation behaviors in a mineral process.n. operation, pres.n. study aimed on the hydrodynamics of solid–liquid fluidization. The study was carried out in a fluidization column with tapings at different height of the bed to collect the sample. The binary particles considered in this study are hematite(4800 kg/m3) and quartz(2600 kg/m3) at different size fractions in the range of average size 87×10^(-6)m to 400×10^(-6)m. It is observed that for various binary mixtures, both quartz and hematite particles share the equal composition by mass(50%) at a particular height of fluidized bed, referred as ‘‘locus point'' of mixing. study indicates that the mixing zone volume will increase for a continuous fluidized bed plant operation. It is observed that the number of locus points varies from 1 to 3 signifying their dependency on the size ratios of binary mixture. Whenever, the difference in terminal velocity between quartz and hematite particles approaches to zero, mixing is ***, the pres.n. study is extended to find the segregation index for the different size ratios of quartz and hematite particles. It is evident that depending on the size ratios, various regions such as complete segregation, partial mixing and complete mixing can be observed.

关键词： Liquid-solid fluidization Mixing segregation Locus point Mineral process.n.

Effect of Gas Velocity on the Dust sediment Layer in the Coupled Field of Corona Plasma and Cyclone

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Plasma science and Technology 2006年第5期8卷 588-590页

作者：魏名山马朝臣李明华 DAnIsH s.n. school of Mechanical and Vehicular Engineering Beijing Institute of Technology Beijing 100081 China China north Vehicle Research Institute Beijing 100072 China

A dust sediment layer was found on the outer tube wall when the EsCP （electrostatic centrifugal precipitator） trapped diesel particulates or ganister s.n.. The Compton back scatter method was used to measure the sediment thickness during the experiment. The effect of the inlet gas velocity on the dust sediment layer was investigated. PIV （Particle Image Velocimetry） was used to measure the velocity field between the inner barb tube wall and the outer tube wail. Experiments showed that the thickness of the sediment increased with time, and the sediment layer at the lower end was much thicker than that at the upper end. The agglomeration on the outer tube wall could be removed when the inlet gas velocity was increased to a certain value.

关键词： corona plasma cyclone sediment Compton back scatter method

Thermodynamic Aspects of nanostructured CoAl Intermetallic Compound during Mechanical Alloying

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Journal of Materials science & Technology 2011年第7期27卷 601-606页

作者： s.n. Hosseini T. Mousavi F. Karimzadeh M.H. Enayati Department of Materials Engineering Nanotechnology and Advanced Materials Institute Isfahan University of Technology84156-83111 Iran

The nanostructured CoAl intermetallic compound was produced by mechanical alloying （MA） of the Co50Al50 elemental powder mixture in a planetary high energy ball mill. The ordered B2-CoAl structure with the grain size of about 6 nm was formed via a gradual reaction after 10 h of MA. A thermodynamic analysis of the process was also done. The results showed that the intermetallic compound of CoAl had the minimum Gibbs free energy compared to solid solution and amorphous states indicating the initial MA product was the most stable phase in the Co-Al system which was changed to a partially disordered structure with a steady long-range order of 0.82 at further milling. This amount of disordering caused the enthalpy of final product to show an increase of about 5.1 kJ·mol-1. Calculation of enthalpy related to the triple defect formation revealed that the enthalpy required for Al anti-sites formation was about 3 times greater than that for Co anti-sites formation.

关键词： Intermetallics CoAl nanostructured materials Mechanical alloying Thermodynamics

Implication of s.n.itive Reactions to Ignition of Methyl Pentanoate:H-Abstraction Reactions by H and CH_(3) Radicals

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Chemical Research in Chinese Universities 2021年第3期37卷 711-717页

作者： sHAnG Yanlei nInG Hongbo sHI Jinchun LUO s.n. Key Laboratory of Advanced Technologies of Materials Ministry of EducationSouthwest Jiaotong UniversityChengdu610031P.R.China The Peac Institute of Multiscale sciences Chengdu610027P.R.China

Methyl pentanoate(MP)was identified as a potential *** facilitate the application of MP with high efficiency in engines,a comprehensive understanding of combustion chemical kinetics of MP is *** this work,the H-abstraction reactions from MP by H and CH_(3) radicals,critical in controlling the initial fuel consumption,are theoretically investigated at the DLPnO-CCsD(T)/CBs(T-Q)//M06-2X/cc-pVTZ level of *** multistructural torsional(Ms-T)anharmonicity is characterized us.n. the dual-level Ms-T method;the HF/3-21G and M06-2X/cc-pVTZ methods are chos.n.as the low-and high-level methods,*** conventional transition state theory(TsT)is employed to calculate the high-pressure limit rate constants at 298-2000 K with the Eckart tunneling *** calculations indicate that the hydrogen atoms of the methylene functional group are easier to be abstracted by H and CH_(3) *** multistructural torsional anharmonicities of H-abstraction reactions MP+H/CH_(3) are significant within the temperature range *** tunneling effects are more pronounced at low temperatures,and contribute considerably to the rate constants below 500 *** model from the work of Diévart et *** updated with our calculations,and the simulations of the updated model are in excellent agreement with the reported ignition delay time of MP/O2/Ar and MP/Air *** s.n.itivity analysis indicates that the H-abstraction reactions,MP+H-CH_(3)CH_(2)CHCH_(2)C(-O)OCH_(3)/CH_(3)CHCH_(2)CH_(2)C(-O)OCH_(3)+H2,are critical in controlling the initial fuel consumption and ignition delay time of MP.

关键词： Methyl pentanoate H-Abstraction Dual-level Ms-T Ignition delay time Kinetic modeling

InFLUEnCEs　OF　sULPHUREOUs　IMPURITY　AnD　MICROsHRInKAGE　On　HAC　BEHAVIOR　OF　sUPER－sTREnGTH　sTEEL

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Acta Metallurgica s.n.ca(English Letters) 1996年第6期9卷 619-625页

作者： s.K.He G.s. Wang and s.n. Wang(Beijing institute of Aeronautical Materials,Beijing 100095,) Beijing Inst of Aeronautical Materials Beijing China

Influences of sulphureous impurity and micro-shrinkage on hydrogen assisted cracking (HAC) and fracture behavior of the super-strength low-alloy steel 40CrMnszMo VA have been studied in this *** way of scanning electron microfractography (sEM)and electron probe microanalyser to investigate the fractography of material constantly strained to failure, it was found that the microscopic segregation of sulphureous impurity and micro-shrinkage not only increased strongly the susceptibility to hydrongen embrittlement (HE), but also made the HAC to initiate preferably in such regions with the assistant of stress induced diffusion of hydrogen. The microscopic observation revealed that the steel has commonly intergranular (IG) and quasi-cleavage (QC)features around the segregation of sulphureous impurity and micro-shrinkage for their strong effects of irreversible traps for hydrogen.

关键词： micro-shrinkage sulphureous impurity HAC HE susceptibility

Managing Congestion in Mobile Devices by Combating TCP Based Attacks

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Managing Congestion in Mobile Devices by Combating TCP Based...

作者： nJUKI s.n.（桑胜）中南大学

学位级别：硕士

基于传输控制协议（Transmission Control Protocol, TCP）的攻击是拒绝服务攻击的一种,且所有TCP/IP实施在一定程度上都是脆弱的。每个半开放的TCP连接使得服务器向数据结构中添加一条记录以存储所有挂起连接的描述信息。这个数据结构... 详细信息

基于传输控制协议（Transmission Control Protocol, TCP）的攻击是拒绝服务攻击的一种,且所有TCP/IP实施在一定程度上都是脆弱的。每个半开放的TCP连接使得服务器向数据结构中添加一条记录以存储所有挂起连接的描述信息。这个数据结构的大小是受限的,攻击行为能够通过故意制造大量的部分开放性连接而造成信息溢出。受侵服务器系统上半开放连接数据结构将最终被填充,如果不将数据结构表清空,系统将会无法接收到新到达的连接。一般来说,一个挂起连接都会设置一个超时时限,所以半开放连接最终将终止,受侵系统将恢复。然而,攻击系统可以简单地持续发送欺骗性的IP数据包,并且使用超过受侵系统可终止挂起连接的速度去建立新的连接。在某些情况下,系统内存将会被耗尽,系统将崩溃或不起作用。本论文提出的机制主要是为了节约移动设备的有限资源,并且核查攻击来源以检测出无效的或欺骗性的确认（ACK）和复位（RsT）。目前,已存在一些解决低带宽移动设备拥塞控制和丢包策略的方案,其中一种方案使用防火墙进行验证。本论文提出了一种改进方法,在解决基于TCP攻击的同时减小了TCP建立连接的延时。该方法的基本思想是,在允许客户端连接到网络之前通过防火墙检测其有效性。具体过程是：首先,客户端通过防火墙发送一个同步请求（s.n.request）给TCP服务器;其次,防火墙发送一个带有错误序列号的同步／确认（s.n.ACK）给客户端;再次,客户端发送一个复位（RsT）给防火墙,防火墙在发送s.n.服务器之前检测该复位的序列号是否匹配;然后,服务器通过防火墙返回一个同步／确认（s.n.ACK）给客户端;最后,防火墙在收到客户端发来的ACK后复查s.n.RsT和ACK的序列号。如果这些序列号匹配,将允许客户端与网络连接,否则,防火墙使用建议的丢弃无效分组机制（Drop Invalid packets Mechanism, DIM）通过发送RsT来要求服务器释放所有与客户端相关的资源。除此之外,防火墙使用一个计时器等待RsT和ACK。如果超过了设定的时间没有收到这些信息,则该客户端被证明是无效的,因此丢弃该连接。相关实验的研究结果表明,此验证引起的延时仅仅在微秒级,提高了先前解决方案的性能,且对于欺骗分组的及时丢弃减小了移动设备网络中的拥塞程度。

关键词：拥塞控制 TCP三次握手移动设备防火墙泛洪攻击丢包策略

Rock composition and origin of the Duwi Formation calcareous rocks, Upper Egypt

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Chinese Journal Of Geochemistry 2005年第4期24卷 316-326页

作者： Baioumy H.M. Attia A.M. Boulis s.n. Hass.n.M.s. Helmy M.E. Central Metallurgical Research and Development Institute 87 Helwan Cairo EgyptCentral Metallurgical Research and Development Institute 87 Helwan Cairo EgyptCentral Metallurgical Research and Development Institute 87 Helwan Cairo EgyptCentral Metallurgical Research and Development Institute 87 Helwan Cairo EgyptGeology Dept. Faculty of Science Ain Shams University Abbasia Cairo Egypt

Upper Cretaceous phosphorite beds of the Duwi Formation, Upper Egypt, are intercalated with limestone, s.n.y limestone, marl, calcareous shales, and calcareous s.n.stone. Calcareous intercalations were subjected to field and detailed petrographic, mineralogical and geochemical investigations in order to constrain their rock composition and origin.; Mineralogically, dolomite, calcite, quartz, francolite and feldspars are the non-clay minerals. smectite, kaolinite and illite repres.n. the clay minerals. Major and trace elements can be classified as the detrital and carbonate fractions based on their sources. The detrital fraction includes the elements that are derived from detrital sources, mainly clay minerals and quartz, such as si, Al, Fe, Ti, K, Ba, V, ni, Co, Cr, Zn, Cu, Zr, and Mo. The carbonate fraction includes the elements that are derived from carbonates, maily calcite and dolomite, such as Ca, Mg and sr. ; Dolomite occurs as being dense, uniform, mosaic, very fine-to-fine, non-ferroan, and non-stoichiometrical, suggesting its early diagenetic formation in a near-shore oxidizing shallow marine environment. The close association and positive correlation between dolomite and smectite indicates the role of clay minerals in the formation of dolomite as a source of Mgs.n.-rich solutions.; Calcareous rocks were deposited in marine, oxidizing and weakly alkaline conditions, marking a semi-arid climatic period. The calcareous/argillaceous alternations are due to oscillations in clay/carbonate ratio.

关键词：岩石埃及石灰质白云石成岩作用

Evolution of X-pinch loads for pulsed power generators with current from 50 to 5000 kA

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Matter and Radiation at Extremes 2018年第6期3卷 267-277页

作者： T.A.shelkovenko s.A.Pikuz I.n.Tilikin M.D.Mitchell s.n.Bland D.A.Hammer Cornell University IthacaNY14850USA P.n.Lebedev Institute Moscow119991Russia Blackett Laboratory Imperial College LondonLondonSW72AZUK University of Evansville EvansvilleINUSA

A review of X-pinches of various configurations and of different materials as an X-ray source for various applications is pres.n.ed. Theadvantages and disadvantages of different designs of X-pinches as a load for generators with a wide range of output parameters and as a sourceof X-ray radiation for X-ray point-projection imaging were analyzed.

关键词： X-pinch X-ray source X-ray point-projection imaging

Fuzzy Logic Based Power Flow Control Analysis of Advanced Unified Power Flow Controller

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Journal of Energy and Power Engineering 2011年第3期5卷 252-259页

作者： s.K. srivastava s.n. s.n.h Department of Electrical Engineering MMM Engineering College Gorakhpur-273010 India Department of Electrical Engineering Indian Institute of Technology Kanpur-208016 India

Due to rapidly development of high power semiconductor devices with fast control features have made possible to control the power flow more efficiently and effectively. The Flexible AC Transmission systems （FACTs） in this category introduces several innovative operating control devices. One of the recent devices is Advanced Unified Power Flow Controller （AUPFC） or multi-converter UPFC, which can control bus voltage and real and reactive power flows of more than one line or even a sub-network. This paper pres.n.s performance analysis of AUPFC based on d-q axis model theory. Based on the analysis, a new fuzzy logic rules based control algorithm has been developed in this paper which improves the system performance. The control rules are structured depending upon the relationship between series inserted voltages in multi-line and the desired changes of real and reactive power flows in the control network. The impacts of different controllers along with parameters of series connected transformers and transmission lines have been investigated through developed control block models in sIMULInK. The effectiveness of the proposed scheme is demonstrated by a case study.

关键词： FACTs AUPFC multi-converter UPFC fuzzy-PI controller sIMULInK FLC.