全文获取类型
收费全文 | 26244篇 |
免费 | 2351篇 |
国内免费 | 1206篇 |
专业分类
电工技术 | 1980篇 |
技术理论 | 18篇 |
综合类 | 3139篇 |
化学工业 | 1074篇 |
金属工艺 | 265篇 |
机械仪表 | 1272篇 |
建筑科学 | 10033篇 |
矿业工程 | 589篇 |
能源动力 | 647篇 |
轻工业 | 357篇 |
水利工程 | 1080篇 |
石油天然气 | 448篇 |
武器工业 | 137篇 |
无线电 | 1944篇 |
一般工业技术 | 1574篇 |
冶金工业 | 602篇 |
原子能技术 | 63篇 |
自动化技术 | 4579篇 |
出版年
2024年 | 74篇 |
2023年 | 366篇 |
2022年 | 654篇 |
2021年 | 864篇 |
2020年 | 830篇 |
2019年 | 711篇 |
2018年 | 524篇 |
2017年 | 773篇 |
2016年 | 808篇 |
2015年 | 928篇 |
2014年 | 1952篇 |
2013年 | 1789篇 |
2012年 | 1841篇 |
2011年 | 2200篇 |
2010年 | 1886篇 |
2009年 | 1649篇 |
2008年 | 1706篇 |
2007年 | 1723篇 |
2006年 | 1652篇 |
2005年 | 1372篇 |
2004年 | 1142篇 |
2003年 | 906篇 |
2002年 | 713篇 |
2001年 | 710篇 |
2000年 | 521篇 |
1999年 | 355篇 |
1998年 | 244篇 |
1997年 | 206篇 |
1996年 | 136篇 |
1995年 | 120篇 |
1994年 | 85篇 |
1993年 | 76篇 |
1992年 | 71篇 |
1991年 | 40篇 |
1990年 | 34篇 |
1989年 | 29篇 |
1988年 | 29篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1985年 | 9篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1975年 | 2篇 |
1964年 | 4篇 |
1956年 | 2篇 |
1955年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Yangjun Chen 《Information Processing Letters》2006,99(1):19-26
A precise analysis of the retrieval of signature trees is presented. A signature tree is a data structure constructed over a signature file to speed up searching all those signatures, which match a given query signature. The methods used include a detailed study of probabilistic analysis in conjunction with suitable contour integration of complex variabled functions. 相似文献
102.
大规模定制为生产带来了变革和影响。针对新的生产方式的要求,根据推动大规模定制的过程方法和技术来分析他们对于质量控制产生的影响和要求,给出了大规模定制条件下的质量控制系统的建议,并给出了一个简要的系统模型。 相似文献
103.
Barrier options are financial derivative contracts that are activated or deactivated according to the crossing of specified
barriers by an underlying asset price. Exact models for pricing barrier options assume continuous monitoring of the underlying
dynamics, usually a stock price. Barrier options in traded markets, however, nearly always assume less frequent observation,
e.g. daily or weekly. These situations require approximate solutions to the pricing problem. We present a new approach to
pricing such discretely monitored barrier options that may be applied in many realistic situations. In particular, we study
daily monitored up-and-out call options of the European type with a single underlying stock. The approach is based on numerical
approximation of the transition probability density associated with the stochastic differential equation describing the stock
price dynamics, and provides accurate results in less than one second whenever a contract expires in a year or less. The flexibility
of the method permits more complex underlying dynamics than the Black and Scholes paradigm, and its relative simplicity renders
it quite easy to implement. 相似文献
104.
105.
中国城市土地利用结构优化研究述评 总被引:9,自引:0,他引:9
城市土地利用结构的确定和优化是城市总体规划的核心内容,从土地使用制度变迁,学科交叉,数理模型方法三方面回顾了中国城市土地利用结构优化研究的发展历程,分析了中国城市土地利用结构优化研究的新气象。在此基础上,指出当前研究工作的不足和问题,并提出未来研究的方向。 相似文献
106.
107.
徐向红 《沙洲职业工学院学报》2003,6(1):20-23
通过分析各种冲突解决方法的特点,提出了一种冲突的集成解决方案。采用面向对象的Object Pascal语言编制了一个实例,给出了该方法在零件结构工艺性设计中的具体应用。 相似文献
108.
Intelligent multisensor surveillance systems consist of several types of sensors, which are installed on fixed and mobile devices. These components provide a huge quantity of information that has to be contrasted, correlated and integrated in order to recognize and react on special situations. These systems work in highly dynamic environments, with severe security and robustness requirements. All these characteristics imply the need for distributed solutions. In these solutions, scattered components can decide and act with some degree of autonomy (for instance, if they become isolated), or cooperate and coordinate for a complete tracking of special situations. In order to cope with these requirements and to better structure the solution, we have decided to design surveillance system control as a multiagent system. This is done by applying an agent-orientated methodology, which is assessed with concrete scenarios. 相似文献
109.
Chin-Wan Chung 《Journal of Systems Integration》1995,5(3):253-274
Currently relational databases are widely used, while object-oriented databases are emerging as a new generation of database technology. This paper presents a methodology to provide effective sharing of information in object-oriented databases and relational databases. The object-oriented data model is selected as a common data model to build an integrated view of the diverse databases. An object-oriented query language is used as a standard query language. A method is developed to transform a relational data definition to an equivalent object-oriented data definition and to integrate local data definitions. Two distributed query processing methods are derived. One is for general queries and the other for a special class of restricted queries. Using the methods developed, it is possible to access distributed object-oriented databases and relational databases such that the locations and the structural differences of the databases are transparent to users. 相似文献
110.
Martin Sulzmann Kenny Zhuo Ming Lu 《Electronic Notes in Theoretical Computer Science》2006,148(2):239
We consider the problem of integrating XDuce into ML. This is difficult because of incompatible type and value representations. Our solution is a type-driven translation scheme from XDuce to ML based on a structured representation of XDuce values. XDuce type inference guides the insertion of appropriate coercion functions to translate regular expression pattern matching and uses of semantic subtyping. We can extend our translation scheme to include ML function calls and patterns into XDuce. Thus, we can embed XDuce into ML. Our results allow to enrich the ML language with support for dealing with semi-structured data. 相似文献