全文获取类型
收费全文 | 7848篇 |
免费 | 218篇 |
国内免费 | 557篇 |
专业分类
系统科学 | 1425篇 |
丛书文集 | 115篇 |
教育与普及 | 1842篇 |
理论与方法论 | 130篇 |
现状及发展 | 209篇 |
研究方法 | 310篇 |
综合类 | 4550篇 |
自然研究 | 42篇 |
出版年
2021年 | 36篇 |
2018年 | 43篇 |
2017年 | 63篇 |
2016年 | 62篇 |
2015年 | 72篇 |
2014年 | 141篇 |
2013年 | 81篇 |
2012年 | 193篇 |
2011年 | 266篇 |
2010年 | 139篇 |
2009年 | 75篇 |
2008年 | 218篇 |
2007年 | 371篇 |
2006年 | 496篇 |
2005年 | 640篇 |
2004年 | 386篇 |
2003年 | 481篇 |
2002年 | 299篇 |
2001年 | 311篇 |
2000年 | 337篇 |
1999年 | 240篇 |
1998年 | 130篇 |
1997年 | 76篇 |
1996年 | 78篇 |
1995年 | 59篇 |
1994年 | 74篇 |
1993年 | 129篇 |
1992年 | 119篇 |
1991年 | 115篇 |
1990年 | 95篇 |
1989年 | 114篇 |
1988年 | 175篇 |
1987年 | 188篇 |
1986年 | 224篇 |
1985年 | 216篇 |
1984年 | 234篇 |
1983年 | 217篇 |
1982年 | 212篇 |
1981年 | 177篇 |
1980年 | 149篇 |
1979年 | 71篇 |
1964年 | 34篇 |
1960年 | 26篇 |
1959年 | 74篇 |
1958年 | 118篇 |
1957年 | 73篇 |
1956年 | 75篇 |
1955年 | 77篇 |
1954年 | 41篇 |
1946年 | 34篇 |
排序方式: 共有8623条查询结果,搜索用时 15 毫秒
121.
Tang Gongyou Zhao Yandong & Zhang Baolin Coll. of Information Science Engineering Ocean Univ. of China Qingdao P. R. China 《系统工程与电子技术(英文版)》2006,17(2):350-354
1 .INTRODUCTIONIn nature ,there are various external disturbancesaffecting the performances of systems . Many con-trol problemsinvolve designing a controller capableof stabilizing a given linear system while mini mi-zing the worst-case response to some additive dis-turbances . This problemis relevant to disturbancerejection and cancellation. One application area ofinterest is flight control through wind shear ,where disturbances arise from a modal for windshear based on harmonic oscillati… 相似文献
122.
Target tracking based on frequency spectrum amplitude 总被引:1,自引:0,他引:1
Guo Huidong Zhang Xinhua & Xia Zhijun Research Center on Signal Information Dalian Navy Academy Dalian P. R. China 《系统工程与电子技术(英文版)》2006,17(3):473-476
1 .INTRODUCTIONIn target tracking, attribute parameters can beused to i mprove the performance of data associa-tion. The probabilistic data association ( PDA)which employ the attribute enhance the capabilityof data association and i mprove the performancefor target tracking. The method of PDA is per-formedin the environment of high signal to noise(SNR) generally and the SNRis in excess of 10dB.But the SNRinthe actual environment is lowerthan 10 dB commonly . When SNRis below0 dB,… 相似文献
123.
Efficient structures for wideband digital receiver 总被引:1,自引:0,他引:1
Wang Hong Lu Youxin Wang Xuegang & Wan Yonglun Univ. of Electronic Science Technology of China Chengdu P. R. China 《系统工程与电子技术(英文版)》2006,17(3):483-486
1 .INTRODUCTIONWith the development of high perfor mance ana-logue-to-digital converters ( ADC) , applicationspecific integrated circuit ( ASIC) devices anddigital signal processing ( DSP) technology , dig-ital receiver has increasingly become popular inrecent years[1 ~7]. The digital receiver is a typi-cal application of software radio in radar . Itsmain purpose is to move the digital conversionprocess closer to the antenna and execute mainfunctions on general hardware . But the sign… 相似文献
124.
Sensor management based on fisher information gain 总被引:2,自引:0,他引:2
Tian Kangsheng~ & Zhu Guangxi~ . Dept. of Telecommunication Engineering Huazhong Univ. of Science & Technology Wuhan P. R. China . Dept. of Command Automation Engineering Airforce Radar Academy Wuhan P. R. China 《系统工程与电子技术(英文版)》2006,17(3):531-534
1 .INTRODUCTIONSensor management can be described as a systemor process that provides automatic or semi-auto-matic control of a group of sensors[1]. The basicobjective of sensor management is to select rightsensors to do the right service on the right targetat right ti me based on external measurements orcriteria[2]. A variety of techniques have been pro-posed or appliedtothe area of sensor management .One of the first articles to apply opti mization tech-nique to sensor management is by … 相似文献
125.
Chen Niansheng~ Li Layuan~ & Dong Wushi~ .School of Computer Science Wuhan Univ. of Technlogy Wuhan R. R. China .Dept.of Computer Science Hubei Normal Univ. Wuhan P. R. China 《系统工程与电子技术(英文版)》2006,17(3):642-647
1 .INTRODUCTIONA mobile Ad hoc network refers to a temporal multi-hop autonomy system,whichis constituted by a groupof mobile nodes containing wireless send-receive equip-ments[1].It possesses manycharacteristics-fast-deploy-able,self-organized,acentric , movable and of multi-hop.It can be wildly applied to many fields ,such asnational defense,emergency and disaster ,scientificin-vestigation and exploration etc .,and uponthat ,it hasgreat prospects[1 ,3 6]. With the wide spread of mo-bile… 相似文献
126.
Gan Rongbing & Wang Jianguo .National Electronic Warfare Lab Chengdu P.R.China .School of Electronic Engineering Univ. of Electronic Science Techndogy Chengdu P. R. China 《系统工程与电子技术(英文版)》2006,17(4):717-721
1. INTRODUCTION Many researches have been made on automatic target recognition (ATR) from SAR images in the past few years. Lincoln Laboratory has developed a complete, end-to-end ATR system[1-4]. The whole system inclu- des three stages: detection (or prescreening), discri- mination and classification. In the detection stage, a two-parameter CFAR (constant false alarm rate) detector is used as a prescreener to select candidate targets in an SAR image on the basis of local brightne… 相似文献
127.
Zhang Yougang & Xu Bugong Coll. of Automatic Science & Engineering South China Univ. of Technology Guangzhou P. R. China 《系统工程与电子技术(英文版)》2006,17(4):836-845
1. INTRODUCTION Large-scale dynamic system theory has been intensi- vely studied during the past decade[1~3], but for fuzzy large-scale systems, namely large-scale systems comp- osed of a series of fuzzy subsystems, has been seldom done in literature. In Ref.[4], decentralized stabiliz- ation problem of fuzzy large-scale systems composed of a series of fuzzy subsystems was considered. Sufficient conditions for asymptotic stability of the fuzzy large-scale system and design methods of dec… 相似文献
128.
Liu ChenFirst Inst. Equipment Research Inst. of Second Artillery Beijing P. R. China 《系统工程与电子技术(英文版)》2006,17(4):901-909
1. INTRODUCTION Weapon equipments acquisition and demonstration has become more and more prominent in the informationalized war conditions while operational effectiveness evaluation is its core part. The compl- exity and uncertainty of weapon systems operational effectiveness evaluation make traditional analysis methods or expert evaluation methods less effective to solve problems. Simulation based operational effe- ctiveness evaluation is an efficient solution. The increased complexity o… 相似文献
129.
130.
随着时间的推移,我们的世界似乎在不断地变小,不仅如此,新的发明创造也在向着更小更精细的方向发展。然而,这些“小玩意儿”在发展的道路上总会遭遇瓶颈,至少在以摩尔定律(Moore's Law)为准规则的计算世界会这样。如果根据英特尔公司(INTEL)创办人之一Gordon Moore的建议,即一个电脑芯片上所能容纳的晶体管数目每隔18~24个月增加一倍,那么一块硅片上 相似文献