全文获取类型
收费全文 | 603篇 |
免费 | 16篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 89篇 |
金属工艺 | 16篇 |
机械仪表 | 14篇 |
建筑科学 | 32篇 |
能源动力 | 9篇 |
轻工业 | 20篇 |
石油天然气 | 1篇 |
无线电 | 88篇 |
一般工业技术 | 151篇 |
冶金工业 | 71篇 |
原子能技术 | 7篇 |
自动化技术 | 113篇 |
出版年
2023年 | 4篇 |
2022年 | 8篇 |
2021年 | 20篇 |
2020年 | 12篇 |
2019年 | 8篇 |
2018年 | 17篇 |
2017年 | 15篇 |
2016年 | 13篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 32篇 |
2012年 | 19篇 |
2011年 | 28篇 |
2010年 | 26篇 |
2009年 | 25篇 |
2008年 | 28篇 |
2007年 | 28篇 |
2006年 | 19篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 14篇 |
2002年 | 15篇 |
2001年 | 13篇 |
2000年 | 10篇 |
1999年 | 12篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 20篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 8篇 |
1973年 | 6篇 |
1972年 | 4篇 |
排序方式: 共有619条查询结果,搜索用时 406 毫秒
1.
2.
3.
Summary The thermal post buckling behavior of simply-supported, antisymmetric cross-ply plates with immovable edges is investigated in this paper. For this purpose, a one term approximation for the inplane and transverse displacements is assumed and Rayleigh-Ritz method is used to obtain the equations of equilibrium. The question, whether the true thermal buckling (bifurcation buckling under thermal loads) exists for such plates is also addressed to. The conditions under which the thermal buckling in the classical sense occurs are derived. It is shown that nonlinear bending stiffness for such plates is direction dependent, because of an extra quadratic nonlinear term in addition to the usual cubic nonlinear term in the governing equilibrium equation. Results are presented for various plate configurations. 相似文献
4.
Compositional data occur as natural realizations of multivariate observations comprising element proportions of some whole
quantity. Such observations predominate in disciplines like geology, biology, ecology, economics and chemistry. Due to unit
sum constraint on compositional data, specialized statistical methods are required for analyzing these data. Dirichlet distributions
were originally used to study compositional data even though this family of distribution is not appropriate (see Aitchison,
1986) because of their extreme independence properties. Aitchison (1982) endeavored to provide a viable alternative to existing
methods by employing Logistic Normal distribution to analyze such constrained data. However this family does not include the
Dirichlet class and is therefore unable to address the issue of extreme independence. In this paper generalized Liouville
family is investigated to model compositional data which includes covariates. This class permits distributions that admit
negative or mixed correlation and also contains non-Dirichlet distributions with non-positive correlation and overcomes deficits
in the Dirichlet class. Semiparametric Bayesian methods are proposed to estimate the probability density. Predictive distributions
are used to assess performance of the model. The methods are illustrated on a real data set. 相似文献
5.
A framework is presented for examining the effectiveness of limiting and modelling arguments used in the analysis of fluid
flows. It consists of examining the consequences of the arguments on the flow problem as a whole and breaking down the limiting/modelling
process into a sequence of steps and associated sequence of flow problems, termed here as ‘lidels’. The notion of validity
of lidels is given. Several examples are given to explain the present approach.
Invited general lecture at 3rd ACFM, Tokyo, September 1986 相似文献
6.
7.
Six Gs-stimulated adenylyl cyclases have been cloned. Two additional forms have been identified as partial cDNAs. These adenylyl cyclases have distinct functional properties and are differentially regulated by protein kinases. The adenylyl cyclases have distinct patterns of distribution in peripheral tissues and various brain regions. The unique functional characteristics of the members of this effector family may allow each cell type and/or brain region to customize the signal-recognition and integrative properties of its cAMP-generation system by varying the ratios of the various adenylyl cyclases. 相似文献
8.
The dislocation structures of bulk textured and epitaxial thin film YBa2Cu3O7 superconductors are examined. Correlations between increases in flux pinning and dislocation densities are noted. A model
for flux pinning by individual dislocations is presented. This gives a treatment of strain induced effects and effects of
normal state region interactions. It is shown that the values of pinning predicted are in line with experimental observations. 相似文献
9.
Undoped and Te-doped gallium antimonide (GaSb) layers have been grown on GaSb bulk substrates by the liquid phase epitaxial
technique from Ga-rich and Sb-rich melts. The nucleation morphology of the grown layers has been studied as a function of
growth temperature and substrate orientation. MOS structures have been fabricated on the epilayers to evaluate the native
defect content in the grown layers from theC-V characteristics. Layers grown from antimony rich melts always exhibitp-type conductivity. In contrast, a type conversion fromp- ton- was observed in layers grown from gallium rich melts below 400 C. The electron mobility of undopedn-type layers grown from Ga-rich melts and tellurium doped layers grown from Sb- and Ga-rich solutions has been evaluated.
Paper presented at the poster session of MRSI AGM VI. Kharagpur. 1995 相似文献
10.
This article discusses about the developing paradigms of data for sensor-actuator networks that perform engineering tasks. We provide a new foundation for data fusion based on two concepts: a conceptual framework and the goal-seeking paradigm. The conceptual framework emphasizes the dominant structures in the system. The goal-seeking paradigm is a mechanism for representing system evolution that explicitly manages uncertainty. The goal-seeking formulation for data fusion helps to distinguish between subjective decisions that can be executed by computers. These notions are useful for critical tasks, such as security management in large-scale distributed systems. Investigations in this area, and further refinement of the goal-seeking formulation for instrumentation and measurement applications, are likely to future systems that facilitate holistic user decision making. 相似文献