检索结果-内蒙古大学图书馆

Application of high temperature superconducting wire to magnetostrictive transducers for underwater sonar

NAVAL ENGINEERS JOURNAL 1997年第1期109卷 31-39页

作者： Joshi, CH Lindberg, JF Clark, AE Dr. Chad H. Joshi:is president of Energen Incorporated an engineering and development firm specializing in cryogenic and electromechanical systems. The research presented here was conducted while he was employed at American Superconductor Coporation where he held both technical and program management positions. While there Dr. Joshi managed the development of several demonstration products including the sonar transducer presented here. He holds M.S. and Sc.D. degreesfrom the Massachusetts Institute of Technology and a B.S. degree from the Worcester Polytechnic Institute. He has worked in several diverse fields including solar energy fluidized bed technology and superconductivity. His work on stochastic analysis of solar insolation was recognized by the ASME and his doctoral research was accorded international recognition for its unique contribution to understanding quenching in superconducting magnets. Dr. Joshi has numerous patents and more than thirty-five technical publications to his credit. He is a registered Professional Engineer in Massachusetts and an active member of ASME and IEEE. He is a co-founder and treasurer of the New England Chapter of the Cryogenics Society of America. He will be listed in Whos Who in the East in 1997. Jan Lindberg:is a physicist in the Transducers and Arrays Division of the Naval Undersea Warfare Center in New London Connecticut. He leads NUWC'S exploratory development efforts for transduction science and currently is spearheading an effort to introduce high-energy density active materials into tactical sonar systems. With the discovery of high temperature superconductivity he saw the potential benefit of integrating several emerging technologies and enticed American Superconductor Corp. to develop a high temperature superconducting transducer which resulted in the March 1993 demonstration of the world's first integrated high temperature superconducting device. Mr. Lindberg's current interests involve design of high power ultrasonic copolymer arrays characterization of

A low-frequency underwater acoustic transducer integrating high-temperature superconducting (HTS) coils and terbium-dysprosium (Tbdy) magnetostrictive material was designed, fabricated and tested. This represents a novel application for high-temperature superconductivity and is a first example of an integrated system involving HTS coils cooled by a mechanical cryocooler. It also brings HTS technology together with a novel magnetic materials technology. The I-ITS coils were fabricated using react-and-wind BiSrCaCuO-2223 HTS wires. They produce a peak field of 0.1 Tesla at 50 K. A single-stage, Stirling-cycle cryocooler was used to cool the coils and the Tbdy driver to cryogenic temperatures (50-65K). The coils provide an AC magnetic field superimposed on a dC bias field, which produces oscillatory strain within the magnetostrictive rod;this motion is transmitted through a cryostat to two head masses which project sound into the surrounding environment. High power acoustic output can be obtained by operating the transducer at its resonance frequencies of 520 Hz in air and 430 Hz underwater. This development demonstrates that, unlike low temperature superconductors, HTS wires can be considered for AC applications due to the low losses in these superconductors and the higher heat capacities of materials at temperatures above liquid helium.

关键词： Underwater equipment

来源：评论

学校读者我要写书评

暂无评论

Proof Method for correctness of refinements of algebraic specification in abstract sequential machine style

引用

systems ANd COMPUTERS IN JAPAN 1996年第5期27卷 25-38页

作者： Okano, K Higashino, T Taniguchi, K Member Faculty of Engineering Science Osaka University Toyonaka Japan 560 Teruo Hipshino received his B.E. M.E.and Ph.D. degrees in Information and Computer Sciences from Osaka University Osaka Japan in 1R9 1981 and 1984 respectively. He joined the Faculty of Osaka University in 1984. Since 1991 he has been an Associate Professor in the Department of Information and Computer Sciences at Osaka University. In 1990 he was a Visiting Researcher of Dept. I.R.O. at University of Montreal Canada. His current research interests include design and analysis of distributed systems specification and verification of communication protocols and formal approach of program design. He is a member of IEEE-CS ACM IEICE of Japan and IPS of Japan.

In this paper, new methods for providing the correctness of refinement among abstract sequential machine style programs are described. The programs are described in algebraic language ASL using some useful notions, i.e., the extended projection and the valid reachability condition for each transition function. These notions allow a designer to refine a given text (program or specification) to a concrete text more freely than the text that does not use such notions. These notions can also enhance the expressive power of the text. On the other hand, these advantages would have lost half their values, if useful methods to prove the correctness of refinement among the texts using them are not found. Thus new methods for proving the correctness of the texts are proposed, and they do not require much proof loads. First, the correctness of refinement among the ASL texts with the extended projection is defined. Second, a method is proposed for proving the correctness of refinement among such texts. Also proposed is a definition of the correctness of refinement among the texts with the valid reachability conditions and a method to prove their correctness. These methods do not require more proof loads than the usual methods for the texts that do not use such notions in the abstract sequential machine style. Therefore, these methods are useful.

关键词： abstract sequential machine ASL language proof algebraic specification

来源：评论

学校读者我要写书评

暂无评论

COMPARATIVE-ANALYSIS OF TRIMETHYLMETHOXYSILANE ANd TRIMETHYLCHLOROSILANE BONdING ON POLISHEd COPPER SURFACES

引用

JOURNAL OF VACUUM science & TECHNOLOGY A-VACUUM SURFACES ANd FILMS 1995年第3期13卷 1281-1285页

作者： MISHRA, S WEIMER, JJ Joint Materials Science Ph.D Program University of Alabama&#x2013 Huntsville Huntsville Alabama 35899|c|

Bonding of two monofunctional silanes, trimethylmethoxysilane and trimethylchlorosilane, was studied on copper surfaces. Polished and silinated surfaces were analyzed using x‐ray photoelectron spectroscopy,... 详细信息

关键词： Silanes

来源：评论

学校读者我要写书评

暂无评论

Affordability, logistics R&d and fleet systems

引用

NAVAL ENGINEERS JOURNAL 1996年第3期108卷 199-213页

作者： Schulte, dP Skolnick, A He has supported the development and operation of several naval systems including advanced component selection for Trident II fire control and navigation systems. He served as branch manager of the Surface Ship ASW Combat System Branch which acted as the acquisition engineering agent for the AN/SQQ-89 Surface Ship Anti-Submarine Warfare Weapon System. He was then selected to manage the Module Engineering Department which provided engineering support to numerous naval systems including the AN/BSY-1 Submarine Combat System and the Trident II fire control and navigation system. He then served as the deputy program manager for NAVSEA Progressive Maintenance (2M/ATE). He holds a B.S. degree in Electrical Engineering from Purdue University and currently is pursuing a Maste's degree in Public Environmental Affairs at Indiana University—Purdue University Indianapolis. He served at Applied Physics Laboratory/The Johns Hopkins University in missile development then aboard USS Boston (CAG-1) and played leading roles in several weapon system developments (Regulus Terrier Tartar Talos) inertial navigation (Polaris) deep submergence (DSRV) and advanced ship designs (SES). He later was director Combat System Integration Naval Sea Systems Command and head Combat Projects Naval Ship Engineering Center. He led the Navy's High Energy Lasers and Directed Energy Weapons development efforts. He was vice president advanced technology at Operations Research Inc. and vice president maritime engineering at Defense Group Inc. before starting SSC in 1991. Dr. Skolnick holds a B.S. degree in Mathematics and Economics Queens College an M.A. degree in Mathematics and Philosophy Columbia University an M.S. degree in Electrical/Aeronautical Engineering U.S. Naval Postgraduate School and a Ph.D. in Electrical Engineering and Applied Mathematics from Polytechnic University in New York. He is the author of many published papers on engineering design issues source selection procedures and large-scale complex technology problems

The Fleet continues to require high performance systems that can operate with dependability in the seas' unforgiving environments and under hostile action. Those demands are not new. What has changed is the urgent priority formerly assigned to national defense issues. The arguments for continued superpower military strength are now roiled in politics along with unsettled budgets and uncertain force level projections. Current expectations revolve about indefinite fiscal and operational issues (difficult funding constraints and broadband threats). In the actual event of ''doing more with less,'' a practical response is to apply the creative power available from sound engineering judgement and the crucible of experience to the immediate needs of the Fleet. The attempt to shorten the path between advanced development effort and Fleet use has been tried occasionally in the past, often, without exemplary results. The Sustainable Hardware and Affordable Readiness Practices (SHARP) program, is a generic R&d effort under OpNav sponsorship that has been working steadily on sensible solutions to product engineering problems. Armed today with fast-time, large-scale computation abilities and modern tools for technical problem solving coupled with specialized engineering knowledge, it has been refreshed and is underway satisfying existing Fleet needs. The relationship between fully responsive engineering services and current operational needs is always demanding. The connection between advanced engineering development (6.3 category funds) and immediate Fleet usage brings added complexity and challenge, both technical and organizational. Illustrative examples of affordable engineering solutions to ''retain, revise, replace or retire'' questions are presented within the context of both Fleet realities and budgetary limitations. The discussion covers legacy system support, civil/military considerations and Fleet maintenance issues. It describes the substantial and critical payoffs i

关键词： Warships

来源：评论

学校读者我要写书评

暂无评论

LOW-FLOW PURGING ANd SAMPLING OF GROUNd-WATER MONITORING WELLS WITH dEdICATEd systems

引用

GROUNd WATER MONITORING ANd REMEdIATION 1995年第1期15卷 116-123页

作者： PULS, RW PAUL, CJ Robert W. Puls is currently employed at the R.S. Kerr Environmental Research Laboratory (RSKERL) U.S. EPA Subsurface Systems Branch in the Research Division (Acta OK 74820). He received his Ph.D. in soil and water science from the University of Arizona. Following completion of his doctorate he worked on the High Level Nuclear Waste Repository Research Program (DOE) investigating the fate and transport of radionuclides in ground water. He has been employed at RSKERL since 1987. Recent topics of particular interest include the following: surface chemical factors which influence colloidal stability and transport in subsurface systems surface redox-mediated transformations of inorganic contaminants in soils and ground water in situ remediation of contaminated metals sites and the development of ground water sampling techniques that provide representative and reproducible contaminant concentrations for the purposes of risk assessment remedial performance at hazardous waste sites. Cynthia J. Paul is currently employed by the U.S. EPA at RSKERL. She received her bachelor's degree from East Central University in 1990 and will complete her master's degree in environmental science at the University of Oklahoma in 1995. Her research interests include adsorption-desorption and oxidation-reduction reactions of inorganics as related to subsurface contaminant fate and transport. Other interests include ground water sampling methodologies and turbidity effects on volatile organic contaminants.

A field study was conducted to assess purging requirements for dedicated sampling systems in conventional monitoring wells and for pumps encased in short screens and buried within a shallow sandy aquifer. Low-flow purging methods were used, and wells were purged until water quality indicator parameters (dissolved oxygen, specific conductance, turbidity) and contaminant concentrations (chromate, trichloroethylene, dichloroethylene) reached equilibrium. Eight wells, varying in depth from 4.6 to 15.2 m below ground surface, were studied. The data show that purge volumes were independent of well depth or casing volumes. Contaminant concentrations equilibrated with less than 7.5 L of purge volume in all wells. Initial contaminant concentration values were generally within 20 percent of final values. Water quality parameters equilibrated in less than 10 L in all wells and were conservative measures for indicating the presence of adjacent formation water. Water quality parameters equilibrated faster in dedicated sampling systems than in portable systems and initial turbidity levels were lower.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A Sophisticated Ground Water Analytical Tool

引用

Groundwater Monitoring & Remediation 1995年第2期15卷 134-139页

作者： Tonjes, david J. Heil, James H. Black, John A. David J. Tonjes is a doctoral candidate in coastal oceanography at the Marine Sciences Research Center University at Stony Brook through its Waste Management Institute (Waste Management Institute Marine Sciences Research Center University at Stony Brook 11794–5000). Under a grant from the Town Board he is a technical adviser to the commissioner of waste management of the town of Brookhaven New York in solid waste planning regulatory compliance and environmental site monitoring. Tonjes has a B.A. in liberal arts from St. John's College an M.S. in computer science from New York Institute of Technology and an M.S. in technological systems management from the University at Stony Brook. James H. Heil is commissioner of waste management for the town of Brookhaven (Department of Waste Management Town of Brookhaven 3233 Rte. 112 Medford NY 11763). Heil received a B.S. from Manhattan College and an M.S. from New York University in civil engineering and is a licensed professional engineer in New York. He is a former president of the New York State Solid Waste Management Association. John A. Black is the coordinator of the environmental science program at Suffolk County Community College (Environmental Science Program Suffolk County Community College Selden NY 11784). He is currently the chair of the Ecology Committee of the Pine Barrens Advisory Committee for Suffolk County and is a member of the Suffolk County Pine Barrens Review Commission. Black received a B.S. in chemistry from Adephi University an M.S. in public administration from the University at Stony Book an M. S. from Hofstra University and a Ph. D. from Adlephi in marine sciences.

Stiff diagrams arc a multivariate method of analysis used to describe the chemical state of ground water. The use of Stiff diagrams to describe multiconstituent contamination sites, such as landfills, has distinct advantages over single constituent analyses. Problems associated with traditional Stiff diagram analyses, such as diagram attentuation, can be addressed by allowing the scale of the diagram to vary with the ionic strength of the analyzed sample. The use of these sliding scale Stiff diagrams reveals the chemical slate of the ground water over wide ranges of constituent concentrations and thus allows for sensitive and sophisticated depictions of complicated contamination sites in a fashion that is extremely difficult to replicate with single constituent analyses. This approach has possible applications for understanding and tracing the mixing and chemical changes in uncontaminated settings. Copyright © 1995, Wiley Blackwell. All rights reserved

关键词：

来源：评论

学校读者我要写书评

暂无评论

Multiagent fault‐diagnosis expert system in power systems

引用

European Transactions on Electrical Power 1995年第5期5卷 341-347页

作者： Wang, J.P. Trécat, J. Dr. Jianping Wang is a doctor fellow in the Faculte Polytechnique de Mons in Belgium. His current research field is parallel processing applications in power systems. Dr. Wang obtained his BS degree from Southwest Jiaotong University in P.R. Chinain 1982. From 1982 to 1990 he was appointed as an assistant lecturer. lecturer and associate professor respectively in the electrical engineering department of Southwest Jiaotong University. He obtained his Ph.D in the FacultC Polytechnique de Mons in July of 1993. (BD Dolez 3 1 FPMS B-7000 Mons Belgium T +32-65/37 41 87 Fax +32-65/37 43 00) Professor J. Trécat is a director in the power system laboratory in the Faculty Polytechnique de Mons. He obtained his Ph.D in the University of Manchester Institute of Science and Technology(UM1ST) in U.K. in 1970. He has been working in the fields of power system automation artificial intelligence application and computer vision in the Facult6 Polytechnique de Mons since 1970. He is a senior member of IEEE and he has made much contribution both in electrical engineering education and research. (BD Dolez 3 I FPMS B-7000 Mons T +32-651374185. Fax +32-6513743 00)

In order to solve the speed problem and shallow reasoning problem met in current research in fault diagnosis expert system, this paper presents a model based parallel fault diagnosis expert system for energy management systems (EMS). The Petri net model, which corresponds to the relationship between power system components and their protection systems, has been used for the inference in fault diagnosis. A multiagent parallel processing expert system, which is based on five transputers in Sun workstation, has been built for fault diagnosis purposes. The test results show that this expert system is not only fast but also has better performances. Copyright © 1995 John Wiley & Sons, Ltd.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A dISTRIBUTEd MEdIA ACCESS PROTOCOL FOR PACKET RAdIO NETWORKS ANd PERFORMANCE ANALYSIS .2. NETWORK SET-UP TIME ANd dATA RATE

引用

INTERNATIONAL JOURNAL OF COMMUNICATION systems 1995年第1期8卷 49-63页

作者： PONd, LC LI, VOK Communication Sciences Electrical Engineering Systems University of Southern California Los Angeles CA 90089-2565 U.S.A. Lawrence C. Pond received the M.Sc. and Ph.D. degrees in electrical engineering from the University of Southern California in 1983 and 1990 respectively. Dr. Pond is currently a scientist at Hughes Space and Communications Company having joined in 1980. He has worked in the fields of communication system design mobile communication network and spacecraft payload design. He is currently working on the development of satellite-based ATM transport and switching architectures for BISDN and Defense Information System Network amlications. Dr. Pond is a member of IEEE. Victor O. K. Li was born in Hong Kong in 1954. He received his SB SM and Sc.D. degrees in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology Cambridge Massachusetts in 1977 1979 and 1981 respectively. Since February 1981 he has been with the University of Southern California (USC) LOS Angeles California where he is Professor of Electrical Engineering and Director of the USC Communication Sciences Institute. He has published 150 technical papers and has lectured and consulted extensively around the world. His research interests include high-speed communication networks personal communication networks intelligent networks distributed databases queueing theory graph theory and applied probability. Dr. Li is very active in the Institute of Electrical and Electronic Engineers (IEEE) having been a member of the Computer Communications Technical Committee since 1983 and having served as Chairman from 1987–1989. He served as Chairman of the Los Angeles Chapter of the IEEE Information Theory Group from 1983–1985. He is the Steering Committee Chair of the International Conference on Computer Communications and Networks (IC3 N) General Chair of the 1st Annual IC3N held in San Diego California in June 1992 General Chair and Technical Program Chair of the 4th IEEE Workshop on Comp

In this, the second part of a two-part paper, the required time for establishing a mobile packet radio network using the virtual circuit and time division multiple access protocol developed in Part 1 is analysed. Tools are developed to determine the virtual circuit and network set-up times in terms of the channel bandwidth allocated to establish and maintain the network. The tools are then extended to include the effects of user mobility. Then these results are combined with the network capacity results of Part 1 to analyse the trade-off between the data rate and set-up time of the network. Next a hierarchical architecture is proposed and the network data rate versus set-up time trade-off of this architecture is analysed using these tools. This architecture is shown to both provide a higher data rate and establish faster than flat networks of the same number of nodes.

关键词： PACKET RAdIO NETWORK EPLRS dISTRIBUTEd NETWORK TdMA VIRTUAL CIRCUITS MULTIHOP NETWORK BOUNdEd dELAY MOBILITY NETWORK SET-UP TIME HIERARCHICAL NETWORK NETWORK dATA RATE

来源：评论

学校读者我要写书评

暂无评论

CHEMICAL MASS-BALANCE APPROACH TO FIELd-EVALUATION OF BIOREMEdIATION

引用

ENVIRONMENTAL PROGRESS 1995年第1期14卷 F2-F3页

作者： SIMS, RC SIMS, JL Utah State University Department of Civil and Environmental Engineering and Utah Water Research Laboratory Logan UT 84322 Professor and Head of the Division of Environmental Engineering at Utah State University. He holds degrees in biology (B.S.) environmental chemistry and biology (M.S.) environmental engineering (M.S.) and biological and agricultural engineering (Ph.D). He has worked as Director of the International Program in Industrial Development Chapel Hill NC as Supervisor of the Environmental Control Laboratory for Mobay Chemical Corporation Charleston SC and as environmental engineer with Research Triangle Institute NC. Dr. Sims currently is involved in teaching research and technology transfer in the area of contaminated soil characterization and remediation. Research Assistant Professor in the Division of Environmental Engineering at Utah State University. She holds degrees in biology (B.S.) environmental chemistry and biology (M.S.) and soil science (M.S.). She has held positions as an Associate in a private consulting firm in Raleigh NC and as Chairperson of the on-site wastewater disposal committee of the State of Utah. Judith Sims is currently involved in teaching research and technology transfer in the area of contaminated soil characterization and remediation.

来源：评论

学校读者我要写书评

暂无评论

PARALLEL ANd dISTRIBUTEd TLM COMPUTATION WITH SIGNAL-PROCESSING FOR ELECTROMAGNETIC-FIELd MOdELING

引用

INTERNATIONAL JOURNAL OF NUMERICAL MOdELLING-ELECTRONIC NETWORKS dEVICES ANd FIELdS 1995年第3-4期8卷 169-185页

作者： SO, PPM ESWARAPPA, C HOEFER, WJR NSERC/MPR Teltech Research Chair in RF Engineering Department of Electrical and Computer Engineering University of Victoria Victoria British Columbia V8W 3P6 Canada Poman So received his B.Sc. degree in computer science and physics from the University of Toronto Toronto Onatario Canada in 1985. He obtained his B.A. Sc. and M.A.Sc. degrees in electrical engineering (summa cum laude) from the University of Ottawa Ottawa Ontario Canada in 1987 and 1989 respectively. Mr So was a research engineer in the University of Ottawa from January 1989 to October 1991 his research interests included CAD techniques of microwave circuits and numerical methods for electromagnetic wave modelling. He specialized in the development of electromagnetic engineering CAD software and successfully implemented a number of electromagnetic wave simulators based on the two-dimensional and three-dimensional transmission-line matrix methods. From August 1990 to February 1991 he accompanied Professor W. J. R. Hoefer to Rome Italy and Sophia Antiopolas France. During that time he implemented a parallel version of the 3D-TLM simulator for the CM-2 Connection Machine using C-Star and X Windows Library. He is a research engineer and a Ph.D. student at the University of Victoria Victoria British Columbia Canada. He ported the 2D- and 3D-TLM simulators to DECmpp 1200 massively parallel computer using MPL C and C++. He also combined OSA90/hope a commercially available microwave CAD program with a 2D-TLM simulation module for geometry optimization using the Datapipe technique of OSA90/hope. Recently he has developed a distributed client-server computing technique for the TLM method this technique could accelerate the TLM simulation by more than an order of magnitude. Channabasappa Eswarappa received the M.Tech. degree in electrical engineering from the Indian Institute of Technology Kanpur India in 1983 and Ph. D. degree from the University of Ottawa Canada in 1990. He worked as an Assistant Executive Engineer and later as

This paper describes the implementation of transmission-line matrix (TLM) method algorithms on a massively parallel computer (dECmpp 12000), the technique of distributed computing in the UNIX environment, and the combination of TLM analysis with Prony's method as well as with autoregressive moving average (ARMA) digital signal processing for electromagnetic field modelling. By combining these advanced computation techniques, typical electromagnetic field modelling of microwave structures by TLM analysis can be accelerated by a few orders of magnitude.

关键词： Mathematical models

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：