全文获取类型
收费全文 | 2043篇 |
免费 | 112篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 23篇 |
综合类 | 4篇 |
化学工业 | 493篇 |
金属工艺 | 45篇 |
机械仪表 | 50篇 |
建筑科学 | 41篇 |
矿业工程 | 7篇 |
能源动力 | 58篇 |
轻工业 | 120篇 |
水利工程 | 9篇 |
石油天然气 | 24篇 |
武器工业 | 1篇 |
无线电 | 188篇 |
一般工业技术 | 641篇 |
冶金工业 | 59篇 |
原子能技术 | 37篇 |
自动化技术 | 360篇 |
出版年
2024年 | 7篇 |
2023年 | 16篇 |
2022年 | 49篇 |
2021年 | 102篇 |
2020年 | 72篇 |
2019年 | 64篇 |
2018年 | 78篇 |
2017年 | 70篇 |
2016年 | 76篇 |
2015年 | 49篇 |
2014年 | 109篇 |
2013年 | 149篇 |
2012年 | 151篇 |
2011年 | 201篇 |
2010年 | 90篇 |
2009年 | 102篇 |
2008年 | 96篇 |
2007年 | 115篇 |
2006年 | 87篇 |
2005年 | 71篇 |
2004年 | 75篇 |
2003年 | 51篇 |
2002年 | 69篇 |
2001年 | 24篇 |
2000年 | 21篇 |
1999年 | 23篇 |
1998年 | 28篇 |
1997年 | 23篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 9篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1965年 | 1篇 |
1958年 | 2篇 |
排序方式: 共有2160条查询结果,搜索用时 15 毫秒
51.
Igor Cverdelj-Fogaraši Goran Sladić Stevan Gostojić Milan Segedinac Branko Milosavljević 《Information Systems and E-Business Management》2017,15(2):257-304
This paper proposes a non-domain-specific metadata ontology as a core component in a semantic model-based document management system (DMS), a potential contender towards the enterprise information systems of the next generation. What we developed is the core semantic component of an ontology-driven DMS, providing a robust semantic base for describing documents’ metadata. We also enabled semantic services such as automated semantic translation of metadata from one domain to another. The core semantic base consists of three semantic layers, each one serving a different view of documents’ metadata. The core semantic component’s base layer represents a non-domain-specific metadata ontology founded on ebRIM specification. The main purpose of this ontology is to serve as a meta-metadata ontology for other domain-specific metadata ontologies. The base semantic layer provides a generic metadata view. For the sake of enabling domain-specific views of documents’ metadata, we implemented two domain-specific metadata ontologies, semantically layered on top of ebRIM, serving domain-specific views of the metadata. In order to enable semantic translation of metadata from one domain to another, we established model-to-model mappings between these semantic layers by introducing SWRL rules. Having the semantic translation of metadata automated not only allows for effortless switching between different metadata views, but also opens the door for automating the process of documents long-term archiving. For the case study, we chose judicial domain as a promising ground for improving the efficiency of the judiciary by introducing the semantics in this field. 相似文献
52.
53.
Intrigila B Melatti I Tofani A Macchiarelli G 《Computer methods and programs in biomedicine》2007,86(3):232-244
Collagen extracellular matrix is one of the factors related to high passive stiffness of cardiac muscle. However, the architecture and the mechanical aspects of the cardiac collagen matrix are not completely known. In particular, endomysial collagen contribution to the passive mechanics of cardiac muscle as well as its micro anatomical arrangement is still a matter of debate. In order to investigate mechanical and structural properties of endomysial collagen, we consider two alternative computational models of some specific aspects of the cardiac muscle. These two models represent two different views of endomysial collagen distribution: (1) the traditional view and (2) a new view suggested by the data obtained from scanning electron microscopy (SEM) in NaOH macerated samples (a method for isolating collagen from the other tissue). We model the myocardial tissue as a net of spring elements representing the cardiomyocytes together with the endomysial collagen distribution. Each element is a viscous elastic spring, characterized by an elastic and a viscous constant. We connect these springs to imitate the interconnections between collagen fibers. Then we apply to the net of springs some external forces of suitable magnitude and direction, obtaining an extension of the net itself. In our setting, the ratio forces magnitude /net extension is intended to model the stress /strain ratio of a microscopical portion of the myocardial tissue. To solve the problem of the correct identification of the values of the different parameters involved, we use an artificial neural network approach. In particular, we use this technique to learn, given a distribution of external forces, the elastic constants of the springs needed to obtain a desired extension as an equilibrium position. Our experimental findings show that, in the model of collagen distribution structured according to the new view, a given stress /strain ratio (of the net of springs, in the sense specified above) is obtained with much smaller (w.r.t. the other model, corresponding to the traditional view) elasticity constants of the springs. This seems to indicate that by an appropriate structure, a given stiffness of the myocardial tissue can be obtained with endomysial collagen fibers of much smaller size. 相似文献
54.
55.
We consider the symmetric formulation of the interior penalty discontinuous Galerkin finite element method for the numerical
solution of the biharmonic equation with Dirichlet boundary conditions in a bounded polyhedral domain in
. For a shape-regular family of meshes consisting of parallelepipeds, we derive hp-version a priori bounds on the global error measured in the L2 norm and in broken Sobolev norms. Using these, we obtain hp-version bounds on the error in linear functionals of the solution. The bounds are optimal with respect to the mesh size h and suboptimal with respect to the degree of the piecewise polynomial approximation p. The theoretical results are confirmed by numerical experiments, and some practical applications in Poisson–Kirchhoff thin
plate theory are presented. 相似文献
56.
Robust regression for high throughput drug screening 总被引:1,自引:0,他引:1
Effective analysis of high throughput screening (HTS) data requires automation of dose-response curve fitting for large numbers of datasets. Datasets with outliers are not handled well by standard non-linear least squares methods, and manual outlier removal after visual inspection is tedious and potentially biased. We propose robust non-linear regression via M-estimation as a statistical technique for automated implementation. The approach of finding M-estimates by Iteratively Reweighted Least Squares (IRLS) and the resulting optimization problem are described. Initial parameter estimates for iterative methods are important, so self-starting methods for our model are presented. We outline the software implementation, done in Matlab and deployed as an Excel application via the Matlab Excel Builder Toolkit. Results of M-estimation are compared with least squares estimates before and after manual editing. 相似文献
57.
Recent research has shown that multilayer feedforward networks with sigmoidal activation functions are universal approximators, and that this holds for more general activations as well. The mathematical underpinning for these results has been various: Kolmogorov's resolution of Hilbert's thirteenth problem; the Stone-Weierstrass theorem; approximation of Fourier and Radon integral representations; and convergence of probability measures. This paper
The second result extends and simplifies some of the recent results of Stinchcombe and White, at least for the special cases ofL
1 andL
2 functions. 相似文献
Rigorously establishes the robustness of feedforward network realizations. | |
Uses a theorem of Wiener and ideas of translation invariant subspaces to provide conditions for universal approximations toL 1 andL 2 functions by networks, for quite general activation functions. |
58.
59.
Balance-sheet data offer a potentially large number of candidate predictors of corporate financial failure. In this paper we provide a novel predictor selection procedure based on non-parametric regression and classification tree method (CART) and test its performance within a standard logit model. We show that a simple logit model with dummy variables created in accordance with the nodes of estimated classification tree outperforms both standard logit model with step-wise-selected financial ratios, and CART itself. On a population of Slovenian companies our method achieves remarkable rates of precision in out-of-sample bankruptcy prediction. Our selection method thus represents an efficient way of introducing non-linear effects of predictor variables on the default probability in standard single-index models like logit. These findings are robust to choice-based sampling of estimation samples. 相似文献
60.
Igor Goldfarb Vladimir Gol’dshtein J. Barry. Greenberg Ann Zinoviev 《Journal of Engineering Mathematics》2006,56(2):129-142
Recent experimental evidence has uncovered the peculiar behavior of certain gel droplets which, under appropriate ambient
thermal conditions, evaporate and burn in an oscillatory fashion. In this work a preliminary foray is made into the theoretical
analysis of the nature of the evolution of a hot gas mixture containing organic gel fuel droplets with oscillatory evaporation
within the context of thermal-explosion theory. The problem is modeled as a system of highly nonlinear singularly perturbed
ordinary differential equations. Non-dimensionalization of the equations enables identification of the parameters that play
a major role in determining the dynamical regimes of the system of equations. The method of integral manifolds is exploited
for the analysis and it is found, that for certain parametric regions, the system exhibits new dynamical behavior that is
quite different from that found for conventional liquid droplets. 相似文献