检索结果-内蒙古大学图书馆

1991 ULTRASONICS SYMP

作者： WANG, CL TSAI, CS Department of Electrical and Computer Engineering Institute for Surface and Interface Science University of California Irvine 92717 CA United States

Compact magnetostatic forward volume wavebased guided-wave magnetooptic (MO) Bragg cell modules have been realized by utilizing a pair of samarium-cobalt (Sm-Co) permanent magnets together with a pair of current-carrying coils. Detailed design procedures of this compact magnetic housing are presented. Tunable DC magnetic field as large as 2446 Oe corresponding to a tunable carrier frequency band of 6.85 GHz has been achieved. The resulting MO Bragg cell modules with carrier frequencies ranging from 2.0 to 12.0 GHz have provided performance characteristics comparable to those obtained by using a bulky electromagnet at the optical wavelength of 1.303 urn. Compact MO Bragg cell modules of even higher carrier frequency, larger range of tunable carrier frequency and smaller sizes can be constructed to facilitate their potential applications such as modulation, scanning and switching of light beam as well as real-time processing of wideband microwave signals without frequency downconversion. © 1991 IEEE.

关键词： Modulation

来源：评论

学校读者我要写书评

暂无评论

developments in projection lenses for HDTV

Developments in projection lenses for HDTV

引用

Large-Screen-Projection, Avionic, and Helmet-Mounted Displays

作者： Rudolph, John D. U.S. Precision Lens Inc. Cincinnati OH USA

ISBN: (纸本)0819405558

Recent focus on the development of HDTV systems worldwide has raised a critical concern - the economic viability of HDTV for the home marketplace. While projection systems performing at or above HDTV-quality levels exist today, they are designed for the institutional market and are priced far above the threshold for the individual consumer. Manufacturers will be under considerable pressure to significantly reduce the cost of HDTV projectors, as will the suppliers of key components such as lenses. Fortunately, recent developments have been made in the design, development and manufacturing technologies used to produce hybrid lenses for high-performance projection systems. This is particularly true for CRT-based front- and rear-projection systems for data and graphics applications. Extending these advances to HDTV would suggest that by the time HDTV is ready for high volume mass production, cost-effective projection lenses will be enhancing, not retarding, the market acceptance of HDTV.

关键词： Lenses

来源：评论

学校读者我要写书评

暂无评论

New developments in CCD imaging devices for low-level confocal light imaging

New developments in CCD imaging devices for low-level confoc...

引用

Proceedings of Three-Dimensional Bioimaging Systems and Lasers in the Neurosciences

作者： Masters, Barry R. Uniformed Services Univ of the Health Sciences Bethesda United States

The authors have coupled a new CCD imager to a Nipkow disk, confocal light microscope and evaluated its performance using both reflected light and low light level fluorescence imaging. The CCD imager is a TK515, silicon CCD which is sensitive=ev from the UV to the near-IR. The sensor is a full frame area imager, with CCD's fabricated using a buried channel, three-level polysilicon gate process with very high charge-transfer efficiency (>0.9999) and low dark current. Low noise on-chip amplifiers provide and interface to external preamplifiers with readout noise typically 80% at 400 nm and >90% at 600 nm. To determine its performance the Tektronix CCD was mounted in a Photometrics liquid cooled camera, attached to a Technical Instruments K2Bio confocal microscope.

关键词： Imaging Techniques

来源：评论

学校读者我要写书评

暂无评论

EVALUATION of ELECTRIC FIELDS INDUCED in BIOLOGICAL SYSTEMS 9

EVALUATION of ELECTRIC FIELDS INDUCED in BIOLOGICAL SYSTEMS

引用

9th International Zurich Symposium and Technical Exhibition on Electromagnetic Compatibility, EMC 1991

作者： Stuchly, Stanislaw S. Stuchly, Maria A. Departement of Electrical Engineering University of Ottawa 770 King Edward AVenueOttawa OntarioONKlN 6N5 Canada Burreau of Radiation and Medical Devices Room 66 HPB OttawaONKIA 0L2 Canada

ISBN: (纸本)9781509031948

We describe several recent developments in our laboratory, that deal with external fields measurement and theoretical and experimental dosimetry evaluation of the induced electric fields, and place them in a broader picture of the current state of knowledge. Recently, we have developed antennas and sensors for transient and pulsed electric and magnetic fields. This resulted in the development of several active and electro-optical devices capable of measurements of single (transient) and multiple electric and magnetic field pulses. In the area of dosimetry, extensive measurements of induced electric fields were made in a homogeneous and heterogeneous model of man exposed in the far-field and in the nearfield of various sources ranging in frequency from 150 to 915 MHz. A numerical analysis using the finite- difference time-domain method was also performed and its results were found to be in general agreement with the experimental data. © 1991 9th International Zurich Symposium and Technical Exhibition on Electromagnetic Compatibility, EMC 1991. All rights reserved.

关键词： Dosimetry

来源：评论

学校读者我要写书评

暂无评论

PERFORMANCE IMPROVEMENTS WITH ADVANCED design FOILS IN HIGH-current ELECTRON-BEAM DIODES

引用

IEEE TRANSACTIONS ON PLASMA SCIENCE 1991年第5期19卷 846-849页

作者： SHURTER, R COOGAN, J JONES, M OONA, H ROSE, E SADLER, C THOMAS, V Los Alamos National Laboratory Los Alamos NM USA

A novel design for the vacuum/pressure barrier of an electron-beam diode is ready to be fielded on a large krypton-fluoride excimer laser. The new barrier is a composite foil, fabricated from carbon fibers, Kapton-membrane, epoxy, and copper foil. This composite foil has advantages over more traditional metal foils, exhibiting particularly high tensile strength and a high modulus of elasticity. Other important properties of these composites for use in KrF excimer laser applications include: high electron transmission with low loss to scattering, chemical compatibility with fluorine, low porosity, and low reflectivity in the ultraviolet. The mechanical properties of the composite foil allow the design of support structures (hibachis) which incorporate larger openings than are possible with metal foils with similar electron transmission characteristics. This ability to span larger openings in the foil support structure will allow a reduction in the blocked fraction of the electron beam and promote enhanced energy delivery to the laser gas. Experiments to qualify the composite foils are underway on a diode with a 200 cm2 cathode. The composite foils will be fielded on the Aurora Intermediate Amplifier with a 280 x 40-cm cathode, producing a 20-A/cm2, 525-kV, 600-ns electron beam. The composite foil, mounted on a hibachi with 21.8 x 41.3-cm openings, will replace a 2-mil titanium foil mounted on a hibachi with 5.8 x 11.25-cm openings. Experimental results will be presented, as will the predictions from the ISIS 3-D electron-beam transport code.

关键词： Fiber lasers Chemical lasers Electrons optical design Diodes Copper Elasticity Laser applications Propagation losses Scattering

来源：评论

学校读者我要写书评

暂无评论

EVALUATION OF ELECTROLYTIC CAPACITORS FOR HIGH PEAK current PULSE DUTY

EVALUATION OF ELECTROLYTIC CAPACITORS FOR HIGH PEAK CURRENT ...

引用

3RD CONF ON PULSE POWER FOR LASERS

作者： HARRIS, K MCDUFF, G BURKES, TR Texas Tech Univ. (United States)

ISBN: (纸本)0819405019

Classically, electrolytic capacitors have been used for dc filter applications. However, the inherent advantages of 'electrolytics' such as self-healing and high energy density make them an attractive candidate for pulse circuitry. To this end, a new type of electrolytic capacitor has been developed specifically for high peak current applications. Preliminary results of an ongoing research effort to determine the operational characteristics of this new type of electrolytic are reported. Electrical characteristics such as equivalent series inductance (ESL) and equivalent series resistance (ESR) has been determined for the first generation test units. Along with the ESR determination, the adiabatic temperature rise per pulse was measured to assist in cooling system design as well as operation in environments where heat rejection is limited. The new electrolytic capacitors may facilitate the development of a new class of pulse generators based on high energy density components. Pulse generators for mass launchers, very low impedance loads, and space-based applications where volume and weight density are at a premium are ideal target applications for pulse electrolytics. High power flashlamp drivers for rod and slab lasers are of particular interest. With recent advances in fast solid state switching such as the dynistor, together the ultrahigh energy density capacitors can result in very compact pulsers. Compared to other energy storage alternatives, the electrolytic capacitor still offers the best source of Joules per dollar for traditional applications.

关键词： Capacitors Oxides Inductance Electrodes Resistance Capacitance Dielectrics Metals Aluminum Pulsed laser operation

来源：评论

学校读者我要写书评

暂无评论

Monolithic integration of AlGaAs/GaAs surface-emitting LEDs with silicon- or GaAs-based bipolar transistor driver circuits

Monolithic integration of AlGaAs/GaAs surface-emitting LEDs ...

引用

Integrated Optoelectronics for Communication and Processing 1991

作者： Cotter, Jeffrey E. Mauk, Michael G. Garrett, Lam D. Berryhill, John B. Hobart, Karl D. Barnett, Allen M. AstroPower Inc. Solar Park NewarkDE19716-2000 United States Electrical Engineering Dept. University of Delaware NewarkDE19711 United States

The design, fabrication, and testing of a new monolithic transmitter for fiber optic interconnects is described. The transmitter is comprised of a surface-emitting AlGaAs/GaAs light-emitting diode (LED) integrated with a bipolar transistor driver circuit configured as a differential-pair current switch. Two approaches are being are being pursued: 1. the LED is integrated with a silicon-based bipolar transistor driver circuit using a novel heteroepitaxy process based on a combined chemical-vapor deposition Iliquid-phase epitaxy technique, and 2. the LED is integrated with a GaAs-based bipolar transistor driver circuit using selective liquid-phase epitaxy and diffusion processes. Transmitter components have demonstrated sub-nanosecond rise-times. © 1991 SPIE. All rights reserved.

关键词： Timing circuits

来源：评论

学校读者我要写书评

暂无评论

Military optical memory storage

Military optical memory storage

引用

IEEE National Conference on Aerospace and Electronics (NAECON)

作者： A. Lovett R. Lyells Defense Avionics Systems Division Honeywell Inc. Albuquerque NM USA

It is pointed out that, in the 1980s, many companies erroneously believed that it was possible to modify a commercial optical drive and media design for use in the military environment. Honeywell has successfully developed a militarized 300-Mbyte write-once read-many (WORM) optical drive, took it into full production, and is applying this flight-proven knowledge to rewritable magnetooptic (MO) technology. The authors describe the lessons learned and how those lessons apply to current and future military optical drive developments.< >

关键词： optical refraction Glass optical design Aerospace electronics Military aircraft Moisture optical recording optical distortion Production Magnetooptic devices

来源：评论

学校读者我要写书评

暂无评论

LOW-THRESHOLD INGAAS/GAAS STRAINED-LAYER RIDGE WAVE-GUIDE SURFACE EMITTING LASERS WITH 2 45-DEGREES ANGLE ETCHED INTERNAL TOTAL REFLECTION MIRRORS

引用

APPLIED PHYSICS LETTERS 1991年第13期59卷 1532-1534页

作者： CHAO, CP LAW, KK MERZ, JL Department of Electrical and Computer Engineering University of California Santa Barbara Santa Barbara California 93106

A new type of in-plane surface emitting laser structure with two 45-degrees mirrors has been demonstrated. The device is a ridge waveguide laser with total reflection mirrors etched at 45-degrees to the plane of the active layer, having an epitaxially grown distributed Bragg reflector. Continous-wave threshold current as low as 10 mA with 12% external differential quantum efficiency is achieved on a 5-mu-m-wide, 400-mu-m-long device.

关键词： SEMICONDUCTOR LASERS LASER CAVITIES design LASER MIRRORS INDIUM ARSENIDES GALLIUM ARSENIDES WAVEGUIDES INTERNAL REFLECTION QUANTUM EFFICIENCY INTEGRATED OPTICS optical SYSTEMS

来源：评论

学校读者我要写书评

暂无评论

SCHEDULERS ASSISTANT - A TOOL FOR INTELLIGENT SCHEDULING

SCHEDULERS ASSISTANT - A TOOL FOR INTELLIGENT SCHEDULING

引用

CONF ON APPLICATIONS OF ARTIFICIAL INTELLIGENCE 9

作者： GRIFFIN, N Perceptics Corp. (United States)

ISBN: (纸本)0819405779

The objective of this project was to use expert system technology to aid in the scheduling activities performed at the White Sands Missile Range (WSMR). The WSMR range scheduling problem presents a complex interactive environment. A human factors approach was undertaken, in that, the goal was to implement a system which mimics current WSMR scheduling procedures. The results of this project have produced a prototypic scheduling tool, called Scheduler's Assistant (SA), to aid WSMR range schedulers to generate a daily schedule. The system provides resource conflict detection and resolution advice through a series of cooperating expert systems. Immediate advantages of the system are increased safety, insurance of proper schedule execution and improved speed for turnaround time of sudden schedule changes. Additional benefits of SA include: expandability as future operations grow, allows for rapid redeployment for changing resources, promotes efficient management of WSMR resources, provides a formal representation of knowledge such that years of range personnel experience is preserved and enables the flexibility of a scheduling aid as opposed to a rigid methodology. Prior development efforts by Perceptics have produced a sophisticated expert system development tool, called Knowledge Shaper, which was used to implement all of the expert systems. The development of SA included a library of routines (the SA toolbox) to permit the manipulation of internal data tables and define a data transfer protocol to and from the SA environment. The combination of Knowledge Shaper and the SA toolbox provide a powerful set of design tools for the development of future scheduling applications.

关键词： Radar Artificial intelligence Safety Missiles Aerospace engineering Human-machine interfaces Data modeling Roads Space operations Computer architecture

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：