全文获取类型
收费全文 | 3306篇 |
免费 | 90篇 |
国内免费 | 14篇 |
专业分类
系统科学 | 120篇 |
丛书文集 | 3篇 |
教育与普及 | 2篇 |
理论与方法论 | 26篇 |
现状及发展 | 1005篇 |
研究方法 | 44篇 |
综合类 | 2193篇 |
自然研究 | 17篇 |
出版年
2024年 | 17篇 |
2023年 | 27篇 |
2022年 | 9篇 |
2020年 | 12篇 |
2017年 | 9篇 |
2016年 | 31篇 |
2015年 | 56篇 |
2014年 | 26篇 |
2013年 | 22篇 |
2012年 | 148篇 |
2011年 | 169篇 |
2008年 | 12篇 |
2007年 | 12篇 |
2006年 | 26篇 |
2005年 | 236篇 |
2004年 | 534篇 |
2003年 | 499篇 |
2002年 | 164篇 |
2001年 | 76篇 |
2000年 | 138篇 |
1999年 | 76篇 |
1992年 | 37篇 |
1991年 | 25篇 |
1990年 | 35篇 |
1989年 | 34篇 |
1988年 | 32篇 |
1987年 | 16篇 |
1986年 | 26篇 |
1985年 | 35篇 |
1984年 | 26篇 |
1983年 | 24篇 |
1982年 | 15篇 |
1981年 | 11篇 |
1980年 | 16篇 |
1979年 | 61篇 |
1978年 | 39篇 |
1977年 | 30篇 |
1976年 | 29篇 |
1975年 | 38篇 |
1974年 | 56篇 |
1973年 | 49篇 |
1972年 | 50篇 |
1971年 | 66篇 |
1970年 | 54篇 |
1969年 | 68篇 |
1968年 | 59篇 |
1967年 | 41篇 |
1966年 | 55篇 |
1965年 | 41篇 |
1964年 | 11篇 |
排序方式: 共有3410条查询结果,搜索用时 218 毫秒
261.
MIAOHuai-kou LIUHui LIUJing LIXiao-bo 《武汉大学学报:自然科学英文版》2004,9(5):722-730
Component-based development needs a well-designed components library and a set of support tools. This paper presents the design and implementation of a components library system model and its support tool UMLCASE. A set of practical CASE tools is constructed. UMLCASE can use UML to design Use Case Diagram. Class Diagram etc. And it integrates with components library system. 相似文献
262.
LIUAn-feng CHENZhi-gang LONGGuo-ping 《武汉大学学报:自然科学英文版》2004,9(5):749-754
A new admission control algorithm considering the network self-similar access characteristics is proposed. Taking advantage of the mathematical model of the network traffic admission control which can effectively overcome the self-similar characteristics of tile network requests, through the scheduling of the differential service queue based on priority while at the same time taking into account various factors including access characteristics of requests, load information, etc. smoothness of the admission control is ensured by the algorlthm proposed in this paper. We design a non-linear self-adapting control algorithm by introducing an exponential admission function, thus overcomes the negative aspects introduced by static threshold parameters. Simulation results show that the scheme proposed in this paper can effectively improve the resource utilization of the clusters, while at the same time protecting the service with high priority. Our simulation resuhs also show that this algorithm can improve system stability and reliability too. 相似文献
263.
An improved double-threshold method based on gradient histogram 总被引:2,自引:0,他引:2
YANGShen CHENShu-zhen ZHANGBing 《武汉大学学报:自然科学英文版》2004,9(4):473-476
This paper analyzes the characteristics of the output gradient histogram and shortages of several traditional automatic threshold methods in order to segment the gradient image better. Then an improved double-threshold method is proposed, which is combined with the method of maximum classes variance, estimatingarea method and double-threshold method. This method can automatically select two different thresholds to segment gradient images. The computer simulation is performed on the traditional methods and this algorithm and proves that this method can get satisfying result. 相似文献
264.
QIANQuan GENGHuan-tong WANGXu-fa 《武汉大学学报:自然科学英文版》2004,9(5):765-769
This paper introduces the cost sensitive feature weighting strategy and its application in intrusion detection. Cost factors and cost matrix are proposed to demonstrate the misclassification cost for IDS. How to get the whole minimal risk. is mainly discussed in this paper in detail. From experiments, it shows that although decision cost based weight learning exists somewhat attack miselassifieation, it can achieve relatively low misclassification costs on the basis of keeping relatively high rate of recognition precision. 相似文献
265.
266.
267.
268.
Comparison of the localization of several muscle proteins in relaxed and contracted myofibrils. 总被引:1,自引:0,他引:1
The localization of several muscle proteins in relaxed and contracted myofibrils is compared. The morphology of the myofibrils and the behavior of these proteins was also investigated under extraction conditions. 相似文献
269.
270.