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1.
从1961年至今全世界已经研制和发射的业余卫星超过一百颗,参与策划、设计和制造业余卫星的国家包括美国、澳大利亚、德国、英国、法国、俄国、日本、意大利、芬兰、挪威、新西兰、韩国、墨西哥、哥伦比亚、以色列、泰国、智利、巴西、阿根廷、葡萄牙、南非、沙特阿拉伯、马来西亚、印度等发达国家和发展中国家,参加业余卫星通信活动的业余无线电爱好者以及体检过业余卫星通信的青少年学生更是遍及全世界的每个角落。我国的业余无线电爱好者也已完成业余卫星的研制,正在积极筹备准备发射。  相似文献   

2.
2007年1月26日下午4点30分,位于北京西城区西黄城根北街二号的全国人大会议中心门口,突然出现了大量的车辆和人群,他们是来出席《IT时代周刊》在京举行的首次新春答谢晚宴的。他们来自微软、亚马逊、INTEL、HP、IBH、索尼爱立信、诺基亚、爱立信、SONY、摩托罗拉、AMD、思科、联想、华硕、三星、SAP、埃森哲、戴尔、华为、丰田汽车、标志汽车、光大银行、CA、明基、TGC等;科技部和信息产业部的相关领导也出席了晚宴。  相似文献   

3.
通过对样品进行微波消解的处理,应用ICP-AES和ICP-MS法对云南普洱茶及其种植土壤中所含的Al、Ca、Fe、K、Mg、Na、P、S、Sb、Ti、V、Zn、As、Ba、Cd、Co、Cr、Cu、Li、Mn、Mo、Ni、Pb、Rb、Sr、La、Cs 27种元素进行了含量的考查,采用国家一级标准物质茶叶(GBW10016)、茶叶(GBW07605)和土壤(GBW07403)、土壤(GBW07404)验证了方法的准确性,结果表明,标准物质的测定结果与参考值基本一致,该方法有良好的准确性和精密度。  相似文献   

4.
工业气体主要是指机械、电子、冶金、化工、建材、航空航天、造船、食品等工业部门使用的氧气、氮气、氢气、乙炔气、压缩空气、稀有气体和保护气体等。各种类型的工业气体广泛应用于各行各业的金属冶炼、金属热处理和加工、焊接切割、燃烧气体、  相似文献   

5.
“更高、更快、更强”,不是奥运的专利,这也是人类对影像的追求。科技的飞速发展,让电视的功能倍增到令人发指的地步:大屏幕、高清、4K、8K、CRT、背投、液晶、等离子、超薄、LED、OLED、全息、卡拉OK、点播、存储、无线、游戏、上网、语音/视频通讯、缴费等等。所以无论是有文化的,还是没文化的,在面对电视时都要学习怎么看电视、怎么用电视,而“用”电视,意味着思想上的革命。  相似文献   

6.
动态信息     
中国电子学会/中国声学学会声频工程分会第四届委员会委员产生中国电子学会/中国声学学会声频工程分会第四届委员会委员到2001年3月已届满。经过大家的两轮选举后,现第四届委员会的委员已经产生,共有55名全国声频界的专家、学者、声频工程技术人员和热心学会工作的各方面的人士当选。他们是:沙冰、翁泰来、徐柏龄、骆学聪、谢菠荪、田静、钟厚琼、韩捷、范宝元、赵其昌、潘立超、倪诚策、王铮然、王以真、华子兴、杨锦刚、崔广中、徐文学、管善群、刘书兰、祁家堃、吴凯申、俞锦元、杨定军、曹孝振、李冉、马军、叶世伟、沈勇、…  相似文献   

7.
达物大比拼     
《数码》2007,(5):198-201
达物,即你喜欢的身边物品,一切达物.都可以成为拍摄的主题。 头饰、耳环、项链、襟章、腰带、手表、手机挂饰、特色的扣子、鞋子、毛公仔、玩具模型、珍藏的邮票、杯子、书桌上的摆设、装饰画,或是旅游时搜集回来的精品玩意,还有精致的餐具、古董、纪念版的相机等,你想到的都可以拍摄哦!  相似文献   

8.
总论     
该年鉴属介绍世界电子工业生产和市场的系列丛书。本卷预测了西欧到2001年的电子产品市场,包括16个国家(奥地利、比利时、丹麦、芬兰、法国、希腊、爱尔兰、意大利、荷兰、挪威、葡萄牙、西班牙、瑞典、瑞士)的电子设备和元器件的生产和市场数据。电子设备主要指控制设备、仪器、通信和雷达设备、医疗和工业生产设备、消费类(视频设备、音频设备、彩电、录象机、摄象机、元器件)等。  相似文献   

9.
在总结和完善第一批3.5GHz地面固定无线接入系统频率使用权评选(招标)试点工作的基础上,近日,信息产业部决定继续推进3.5GHz频段地面固定无线接入系统频率使用权的评选(招标)试点工作,试点范围由第一批的5个城市扩大到了北京、天津、石家庄、太原、呼和浩特、沈阳、长春、哈尔滨、上海、杭州、合肥、福州、南昌、济南、郑州、长沙、广州、南宁、海口、成都、贵阳、昆明、拉萨、西安、兰州、西宁、银川、乌鲁木齐、大连、青岛、宁波、深圳等32个城市。长期以来,我国一直采用单一的行政审批的方式对无线电频率资源进行分配。随着我…  相似文献   

10.
《中国有线电视》2006,(19):1889-1889
由中瑞国际展览公司等单位联合主办的“2006移动电视(手机电视)国际高峰论坛暨展示交流会”(简称“Mobile TV2006”)于9月2日在深圳会展中心梅花厅落幕。广电和电信系统20多位专家、清华研究院、韩国电子通信研究院(DMB)、信息产业部电信研究院、Intel、Samsung、ADI、Infineon、Frontier Silicon、Thomason、Megachips、Zoran、意法半导体、德州仪器、哈里斯、爱迪德、矽玛特、展讯、中星微、珠海矩力、法国迪康、MOTO、SONY、Samsung、飞利浦、NEC.松下、LG、阿尔卡特、华为、中兴、普天、大唐、UT斯达康、富士康、联想、海尔、海信、TCL、创维、康佳、天时达、国虹、步步高、德赛、宇阳、友利通、万利达、创维、天时达、松讯达、、华禹、金立、运营商DoCoMo、法国电信、台湾威宝电信、央视国际、GGTV、凤凰卫视、华娱卫视、文广传媒、南方传媒、深圳力合、风网科技、互联天下、神州掌讯及北京、上海、江苏、江西、福建、广东、山东、浙江、安徽、湖北、香港等40多个城市移动运营机构等产业链高层代表667人参加“Mobile TV2006”,会议就各标准在中国的运营状态、商业模式、国际合作、研发设计、终端产品转型、内容服务及产业链的打造展开尖峰对话。与业内共同分享全球移动电视产业的发展现状和新的技术成果,同时为各大公司参与亚洲及中国的移动电视产业合作提供了一个面对面的交流平台。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

15.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

16.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

17.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

18.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

19.
In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal (200) (2d = 0.4027 nm) is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line(w), the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line(x), the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines(y), the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line(z) in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line(q) in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution(λ/△ 2) is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.  相似文献   

20.
High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET > PDMAT > TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.  相似文献   

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