全文获取类型
收费全文 | 687篇 |
免费 | 14篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 15篇 |
综合类 | 2篇 |
化学工业 | 156篇 |
金属工艺 | 30篇 |
机械仪表 | 22篇 |
建筑科学 | 6篇 |
矿业工程 | 28篇 |
能源动力 | 21篇 |
轻工业 | 16篇 |
水利工程 | 1篇 |
石油天然气 | 27篇 |
无线电 | 40篇 |
一般工业技术 | 127篇 |
冶金工业 | 115篇 |
原子能技术 | 51篇 |
自动化技术 | 46篇 |
出版年
2023年 | 8篇 |
2022年 | 30篇 |
2021年 | 22篇 |
2020年 | 7篇 |
2019年 | 12篇 |
2018年 | 24篇 |
2017年 | 25篇 |
2016年 | 33篇 |
2015年 | 12篇 |
2014年 | 34篇 |
2013年 | 33篇 |
2012年 | 37篇 |
2011年 | 44篇 |
2010年 | 24篇 |
2009年 | 26篇 |
2008年 | 29篇 |
2007年 | 25篇 |
2006年 | 25篇 |
2005年 | 36篇 |
2004年 | 13篇 |
2003年 | 8篇 |
2002年 | 11篇 |
2001年 | 10篇 |
2000年 | 5篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1989年 | 9篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 4篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1969年 | 9篇 |
1967年 | 3篇 |
1964年 | 3篇 |
1961年 | 4篇 |
排序方式: 共有703条查询结果,搜索用时 15 毫秒
11.
On the Convergence of Temporal-Difference Learning with Linear Function Approximation 总被引:1,自引:0,他引:1
Vladislav Tadić 《Machine Learning》2001,42(3):241-267
The asymptotic properties of temporal-difference learning algorithms with linear function approximation are analyzed in this paper. The analysis is carried out in the context of the approximation of a discounted cost-to-go function associated with an uncontrolled Markov chain with an uncountable finite-dimensional state-space. Under mild conditions, the almost sure convergence of temporal-difference learning algorithms with linear function approximation is established and an upper bound for their asymptotic approximation error is determined. The obtained results are a generalization and extension of the existing results related to the asymptotic behavior of temporal-difference learning. Moreover, they cover cases to which the existing results cannot be applied, while the adopted assumptions seem to be the weakest possible under which the almost sure convergence of temporal-difference learning algorithms is still possible to be demonstrated. 相似文献
12.
Lee B Parr CS Plaisant C Bederson BB Veksler VD Gray WD Kotfila C 《IEEE transactions on visualization and computer graphics》2006,12(6):1414-1426
Despite extensive research, it is still difficult to produce effective interactive layouts for large graphs. Dense layout and occlusion make food Webs, ontologies and social networks difficult to understand and interact with. We propose a new interactive visual analytics component called TreePlus that is based on a tree-style layout. TreePlus reveals the missing graph structure with visualization and interaction while maintaining good readability. To support exploration of the local structure of the graph and gathering of information from the extensive reading of labels, we use a guiding metaphor of "plant a seed and watch it grow." It allows users to start with a node and expand the graph as needed, which complements the classic overview techniques that can be effective at (but often limited to) revealing clusters. We describe our design goals, describe the interface and report on a controlled user study with 28 participants comparing TreePlus with a traditional graph interface for six tasks. In general, the advantage of TreePlus over the traditional interface increased as the density of the displayed data increased. Participants also reported higher levels of confidence in their answers with TreePlus and most of them preferred TreePlus 相似文献
13.
Alexander Blagov Elena B. Zhigmitova Margarita A. Sazonova Liudmila M. Mikhaleva Vladislav Kalmykov Nikolay K. Shakhpazyan Varvara A. Orekhova Alexander N. Orekhov 《International journal of molecular sciences》2022,23(9)
Crohn’s disease remains one of the challenging problems of modern medicine, and the development of new and effective and safer treatments against it is a dynamic field of research. To make such developments possible, it is important to understand the pathologic processes underlying the onset and progression of Crohn’s disease at the molecular and cellular levels. During the recent years, the involvement of mitochondrial dysfunction and associated chronic inflammation in these processes became evident. In this review, we discuss the published works on pathogenetic models of Crohn’s disease. These models make studying the role of mitochondrial dysfunction in the disease pathogenesis possible and advances the development of novel therapies. 相似文献
14.
Michal Firstenberg Kammasandra Nanjunda Shivananda Irit Cohen Olga Solomeshch Vladislav Medvedev Nir Tessler Yoav Eichen 《Advanced functional materials》2011,21(4):634-643
Sequence‐independent or “click”‐type chemistry is applied for the preparation of novel π‐conjugated oligomers. A variety of bi‐functional monomers for Wittig–Horner olefination are developed and applied in a sequential protection–deprotection process for the preparation of structurally similar π‐conjugated oligomers. Selected oligomers are incorporated as the organic semiconductors in light‐emitting diodes and a field‐effect transistor, demonstrating the potential of the approach. 相似文献
15.
Vladimir Ivanovich Lysenko Sergey Bardakhanov Alexey Korchagin Nikolay Kuksanov Alexander Lavrukhin Rustam Salimov Sergey Fadeev Vladislav Cherepkov Mikhail Veis Andrey Nomoev 《Bulletin of Materials Science》2011,34(4):677-681
Electron-beam evaporation of various natural and industrial materials in the atmosphere of different gases at atmospheric pressure can be used for the synthesis of nanosize powders. These powders are characterized by high purity and may exhibit unusual properties. In particular, nanopowders of silicon dioxide and oxide (SiO2, SiO), magnesia (MgO), alumina (Al2O3), titania (TiO2), gadolinium oxide (Gd2O3), various metals (tantalum, molybdenum, nickel, aluminium, copper, silver), semiconductor (Si), nitrides (AlN, TiN), and some other substances had been produced. The process of nanopowder synthesis is highly effective; in particular, the yield of oxides can exceed ten kilograms per hour. 相似文献
16.
H. F. Chen G. D. Wei X. Han S. Li P. P. Wang M. Chubik A. Gromov Z. P. Wang W. Han 《Journal of Materials Science: Materials in Electronics》2011,22(3):252-259
In this paper, we report a facile, an environmental friendly ultrasonic-assisted hydrothermal route for preparation of goethite flower structures using Fe nanopowders at low temperature (85°C). The flower structure consisted of tens of hundreds of nanowires and such structures can further self-assemble with the flake with micro size area. Structural, morphological, and elemental analysis revealed that the products consisted of flower-like structures with high structural uniformity, good crystal quality, and high yields. Influencing factors such as the reaction temperature, pH value, and the deposition time were systematically investigated. A possible formation mechanism was proposed on the basis of the experimental results. Magnetic measurements showed that the as-obtained goethite flowers exhibited weakly ferromagnetic characteristics at room temperature, which were quite different from those of the corresponding bulk materials. 相似文献
17.
The paper presents several sorting methods of γ-ray events which were implemented in the data acquisition, processing and visualization system, developed at the Institute of Physics of the Slovak Academy of Sciences. The sorting methods using various shapes of gates (conditions) are presented, including rectangular windows, polygons, gates defined by arithmetic functions, spherical, ellipsoidal and composed gates. The examples illustrating the use of these methods are presented as well. 相似文献
18.
19.
Anastasia V. Poznyak Vasily N. Sukhorukov Alexander Zhuravlev Nikolay A. Orekhov Vladislav Kalmykov Alexander N. Orekhov 《International journal of molecular sciences》2022,23(3)
For more than a decade, atherosclerosis has been one of the leading causes of death in developed countries. The issue of treatment and prevention of the disease is especially acute. Despite the huge amount of basic and clinical research, a significant number of gaps remain in our understanding of the pathogenesis of atherosclerosis, and only their closure will bring us closer to understanding the causes of the disease at the cellular and molecular levels and, accordingly, to the development of an effective treatment. One of the seemingly well-studied elements of atherogenesis is the mTOR signaling pathway. However, more and more new details are still being clarified. Therapeutic strategies associated with rapamycin have worked well in a number of different diseases, and there is every reason to believe that targeting components of the mTOR pathway may pay off in atherosclerosis as well. 相似文献
20.
Marie Ebeyer-Masotta Tanja Eichhorn Ren Weiss Vladislav Semak Lucia Laukov Michael B. Fischer Viktoria Weber 《International journal of molecular sciences》2022,23(3)
Inflammation and thrombosis are closely intertwined in numerous disorders, including ischemic events and sepsis, as well as coronavirus disease 2019 (COVID-19). Thrombotic complications are markers of disease severity in both sepsis and COVID-19 and are associated with multiorgan failure and increased mortality. Immunothrombosis is driven by the complement/tissue factor/neutrophil axis, as well as by activated platelets, which can trigger the release of neutrophil extracellular traps (NETs) and release further effectors of immunothrombosis, including platelet factor 4 (PF4/CXCL4) and high-mobility box 1 protein (HMGB1). Many of the central effectors of deregulated immunothrombosis, including activated platelets and platelet-derived extracellular vesicles (pEVs) expressing PF4, soluble PF4, HMGB1, histones, as well as histone-decorated NETs, are positively charged and thus bind to heparin. Here, we provide evidence that adsorbents functionalized with endpoint-attached heparin efficiently deplete activated platelets, pEVs, PF4, HMGB1 and histones/nucleosomes. We propose that this elimination of central effectors of immunothrombosis, rather than direct binding of pathogens, could be of clinical relevance for mitigating thrombotic complications in sepsis or COVID-19 using heparin-functionalized adsorbents. 相似文献