GaN MESFET的微波性能

用ＭＯＣＶＤ法制备了在高电阻率ＧａＮ层上生长沟道厚度为０．２５μｍ的ＧａＮＭＥＳＦＥＴ，这些器件的跨导为２０ｍＳ／ｍｍ，其中一个栅长为０．７μｍ的器件，测得其ｆＴ和ｆｍａｘ分别为８和１７ＧＨｚ。     

CeBIT’96走马观花

CｅＢＩＴ’９６于３月１４日至２０日在德国汉诺威国际展览中心隆重举行。７，０００多家厂商在九个专题展区中参展。ＣｅＢＩＴ’９６第一大的观众就超过了４０，０００人，笔者只有一天时间，只能看一些皮毛，供大家参考。施振荣是本届展会最引人注目的华人佳宾。他率领宏著弟兄占据了大片展台，是几个最大的展台之一。而巨无霸ＩＢＭ公司则在多个专题展区中摆开阵势，在信息技术展区中，强力地推行ＯＳ／２系统，与边上的微软视窗９５针锋相对。几乎所有世界级大公司都上阵拼杀，苹果电脑的展台被安排在中间，更显其勇，与近日传闻其困…     

浅谈会计准则与会计制度

介绍了会计准则与会计制度的联系 ,分析了二者的差别 ,认为会计准则取代会计制度是可能的 ,也是必然的。     

多模式声音效果处理器

<正> AN7338K是松下公司新近推出的多模式声音效果处理IC。它能针对不同的节目源的特点进行相应的处理,使各种节目源的长处得到淋漓尽致的发挥。AN7338K一共预设了五种工作模式,即古典乐、摇滚乐、爵士乐,流行乐和平直模式,操作简单明了,有发光二极管指示相应的工作状态,音效处理效果明显。 AN7338K采用双列直插式22脚封装。图1给出了AN7338K的内部结构方框图,其工作原理是对不同的音乐节目,在音域的低端和高端分别作有选择的提升,来创造不同的声音效果。AN7338K的引脚功能如下:①、(22)脚一右、左声道输入,②、(21)脚—右、左声道负反馈1,③、(20)脚—右、左声道低音部分处理,④、(19)脚—右、左声道高音部分处理,⑤、(18)脚—右、左声道负反馈2,⑥、(17)脚—右、左声道输出,⑦脚—古典音乐效果选择,⑧脚—摇滚音乐效果选择,⑨脚—爵士音乐效果选择,⑩脚—流行音乐效果选择,(11)脚—平直效果选择,(12)脚—地端,(13)脚—电源,(14)脚—纹波抑制,(15)脚—静音时间常数,(16)脚—参考电压。 表1列出了AN7338K工作在平直模式时的性能指标,     

Development and validation of a Monte Carlo simulation of photon transport in an Anger camera

The geometric component of the point spread function (PSF) of a gamma camera collimator can be determined analytically, and the penetration component can be calculated readily by numerical ray-tracing. A Monte Carlo simulation of photon transport which includes collimator scatter is developed. The simulation was implemented with an array processor which propagates up to 1024 photons in parallel, allowing accurate estimates of the total radial PSF in less than a day. The simulation was tested by imaging monoenergetic point sources of Tc-99m, Cr-51, and Sr-85 (140, 320, and 514 keV, respectively) on a General Electric Star Cam with low-energy, general-purpose, and medium-energy collimators. Comparisons of measured and simulated PSFs demonstrate the validity of the model and the significance of collimator scatter in the degradation of image quality.     

OSHA's bloodborne pathogens rule an opportunity/threat

If you supply healthcare linen, OSHA's new ruling comes with a price tag, but it may be a marketing boon as well. The costs of compliance are high--about $1.19 million annually. One of the most costly and important parts of the ruling is the required employer-paid hepatitis B vaccination of employees. But behind the costs, there's good news for the textile rental industry. The opportunity to serve small medical facilities and nursing homes as well as hospitals with reusable healthcare garments could create a revenue source estimated to be at least $177 million a year.     

Knowing healthcare customer needs key to profitable niche marketing

A potential $177 million-a-year market has been opened to textile rental operators, thanks to OSHA's recent ruling on bloodborne pathogens. Healthcare providers nationwide are now searching for solutions to their protective apparel needs. Such customer needs are what drive niche markets. Whether you've been serving the healthcare market for years or are just now targeting it, here are the marketing strategies you need.     

Bloodborne pathogens compliance update. Local OSHA regulations cover textile rental companies in 23 states and two U.S. territories

The last phase of the federal OSHA standard on occupational exposure to bloodborne pathogens became effective July 6. However, compliance deadlines may vary in the 23 states and two U.S. territories that have their own OSHA offices. The states and territories have the option of adopting the federal standard or drafting their own plans. Here's a status report on the OSHA-approved state programs for bloodborne pathogens.