全文获取类型
收费全文 | 1632篇 |
免费 | 238篇 |
国内免费 | 134篇 |
专业分类
电工技术 | 46篇 |
综合类 | 108篇 |
化学工业 | 32篇 |
金属工艺 | 8篇 |
机械仪表 | 49篇 |
建筑科学 | 47篇 |
矿业工程 | 6篇 |
能源动力 | 19篇 |
轻工业 | 17篇 |
水利工程 | 18篇 |
石油天然气 | 3篇 |
武器工业 | 8篇 |
无线电 | 110篇 |
一般工业技术 | 80篇 |
冶金工业 | 74篇 |
原子能技术 | 13篇 |
自动化技术 | 1366篇 |
出版年
2025年 | 16篇 |
2024年 | 50篇 |
2023年 | 41篇 |
2022年 | 66篇 |
2021年 | 60篇 |
2020年 | 51篇 |
2019年 | 54篇 |
2018年 | 53篇 |
2017年 | 53篇 |
2016年 | 41篇 |
2015年 | 83篇 |
2014年 | 78篇 |
2013年 | 112篇 |
2012年 | 103篇 |
2011年 | 101篇 |
2010年 | 68篇 |
2009年 | 104篇 |
2008年 | 109篇 |
2007年 | 124篇 |
2006年 | 102篇 |
2005年 | 74篇 |
2004年 | 75篇 |
2003年 | 51篇 |
2002年 | 42篇 |
2001年 | 46篇 |
2000年 | 21篇 |
1999年 | 17篇 |
1998年 | 21篇 |
1997年 | 19篇 |
1996年 | 11篇 |
1995年 | 20篇 |
1994年 | 27篇 |
1993年 | 16篇 |
1992年 | 11篇 |
1991年 | 3篇 |
1990年 | 12篇 |
1989年 | 10篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1957年 | 1篇 |
排序方式: 共有2004条查询结果,搜索用时 0 毫秒
1.
Lucja Iwanska 《Computational Intelligence》1997,13(3):348-390
Intensional negative adjectives alleged , artificial , fake , false , former , and toy are unusual adjectives that depending on context may or may not be restricting functions. A formal theory of their semantics, pragmatics, and context that uniformly accounts for their complex mathematical and computational characteristics and captures some peculiarities of individual adjectives is presented.
Such adjectives are formalized as new concept builders, negation‐like functions that operate on the values of intensional properties of the concepts denoted by their arguments and yield new concepts whose intensional properties have values consistent with the negation of the old values. Understanding these new concepts involves semantics, pragmatics and context‐dependency of natural language. It is argued that intensional negative adjectives can be viewed as a special‐purpose, weaker, conntext‐dependent negationin natural language. The theory explains and predicts many inferences licensed by expressions involving such adjectives. Implementation of sample examples demonstrates its computational feasibility. Computation of context‐dependent interpretation is discussed.
The theory allows one to enhance a knowledge representation system with similar concept building, negation‐like, context‐dependent functions, the availability of which appears to be a distinct characteristic of natural languages. 相似文献
Such adjectives are formalized as new concept builders, negation‐like functions that operate on the values of intensional properties of the concepts denoted by their arguments and yield new concepts whose intensional properties have values consistent with the negation of the old values. Understanding these new concepts involves semantics, pragmatics and context‐dependency of natural language. It is argued that intensional negative adjectives can be viewed as a special‐purpose, weaker, conntext‐dependent negationin natural language. The theory explains and predicts many inferences licensed by expressions involving such adjectives. Implementation of sample examples demonstrates its computational feasibility. Computation of context‐dependent interpretation is discussed.
The theory allows one to enhance a knowledge representation system with similar concept building, negation‐like, context‐dependent functions, the availability of which appears to be a distinct characteristic of natural languages. 相似文献
2.
WEI WANG 《International journal of human-computer studies》2001,55(6):919
One salient impact of information technology on students' lives is the ever-increasing use of the Internet. Although there exist many reports in the media regarding the unhealthy Internet use among students, research is still limited and has mainly relied upon on-line self-selected reports on Internet dependency or “Internet addiction”. This paper attempts to look into the alleged Internet dependency within the Eriksonian psychosocial development framework. The results of a survey of the Internet use among 217 students in an Australian regional university are reported. The measures of patterns of the Internet use were correlated with that of psychosocial maturity and self-efficacy. The results showed that the Internet dependency seemed to be independent of the psychosocial maturity and the general perceived self-efficacy. A factor analysis extracted six factors from a set of 28 Internet experience-related questions and indicated that the Internet dependency could be of a multifaceted nature. The findings and their implications were discussed and a contextual perspective was proposed. 相似文献
3.
4.
This study explores how the public’s belief in false rumors about Middle East Respiratory Syndrome that spread across South Korea related to their accuracy-oriented information seeking as well as the moderating effects of people’s reasons for using social networking services (SNS). The survey results show that perceived credibility of false rumors did not affect accuracy-oriented information seeking. However, a significant result was shown in the moderating effect, such that SNS informational dependency interacted with false rumor credibility on accuracy-oriented information seeking. Overall, this study specifically identifies and discusses differences in SNS dependency and accuracy-oriented information seeking in the context of rumor communication to examine the construction of an informed public. Theoretical contributions of this study are discussed. 相似文献
5.
为了提高传统程序依赖性分析的应用范围和灵活性,提出一种新的程序分析方法。该方法分为不完整性分析和完整性分析两部分。在gcc3.2和Linux内核2.4.20-8的编译环境下,利用不同的词法和语法分析模块对程序结构、数据依赖和控制信息进行提取,加快了程序分析的速度,并有效降低了程序数据流依赖分析和控制流依赖分析中算法的复杂度。最后用具体的程序实现证明了该算法的可行性。 相似文献
6.
范士喜 《北京印刷学院学报》2015,(4):34-38
为了能够充分描述业务及信息资产依赖的关系,以便在评估威胁的业务影响时,能综合考虑资产依赖程度和业务安全目标或需求,建立了一个内部依赖的递阶层次结构的资产依赖模型,结合网络分析法(ANP)计算组织业务在保密性、可用性和完整性上对资产的依赖程度,以反映业务对资产的安全需求,威胁对业务的影响由威胁强度和安全需求共同确定。实例分析表明,ANP方法得到的资产依赖性结果与现实更相符,从而为风险评估结果的合理性提供了保证。 相似文献
7.
Semolina extrudates were reshaped, immediately after extrusion to form 0.5 mm thick × 2 mm wide × 130 mm long strips. Moisture content (W) was adjusted to 5 to 39% (dry basis) equilibrating in desiccators containing saturated salt solutions. The following tensile rheological properties of the prepared samples were determined at room temperature (21-24°C) using a Rheometrics solid analyzer: Young modulus (E), yield stress (σy), fracture stress (σc) and fracture stain (?c). Each of E, σy and σc was fitted by a semilogorithmically linear function of W with a negative slope. The property ?c fitted two semilogarithmically linear functions: for W < 24.2% a line with a positive slope and for W > 24.2% a line with near zero slope. Such data for moisture ranges used in conventional pasta drying can help to optimize conditions for pasta production without stress cracking. 相似文献
8.
《International Journal of Pavement Engineering》2012,13(2):187-199
This paper examines the importance of strain level, in addition to stresses, in evaluating the resilient modulus of unbound granular base/subbase materials used for pavement construction. A series of cyclic triaxial resilient modulus testing on selected granular materials were carried out following different loading schemes with both the applied stresses and resilient strain levels being adjusted. The experimental results clearly showed that the resilient modulus may not be uniquely determined from the bulk stress and the total deviator stress, particularly when the actual stress states were different from those in standard resilient modulus testing. Variation of resilient modulus with strain level can be described by a hyperbolic function, whereas the stress level dependence of resilient modulus can still be reasonably estimated by either Uzan's universal model or that recommended in NCHRP 1-37A. 相似文献
9.
The Fourier transform infrared (FTIR) spectroscopic studies of the poly-(styrene-co-acrylonitrile) (SAN) and poly(vinyl chloride-co-vinyl acetate) (VYHH) blends produced by different blending techniques, viz., solution blending, melt-blending, and also the co-precipitation methods of blending, were performed. In the case of miscible blend systems, substantial band shiftings took place, whereas immiscible blend systems showed slight or no band shifting. The miscible blends showed a substantial residual spectrum which was absent in the case of the immiscible system when a similar subtraction process was carried out. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 991–1000, 1997 相似文献
10.