全文获取类型
收费全文 | 2281篇 |
免费 | 103篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 23篇 |
综合类 | 3篇 |
化学工业 | 579篇 |
金属工艺 | 34篇 |
机械仪表 | 47篇 |
建筑科学 | 80篇 |
矿业工程 | 5篇 |
能源动力 | 95篇 |
轻工业 | 249篇 |
水利工程 | 37篇 |
石油天然气 | 10篇 |
无线电 | 171篇 |
一般工业技术 | 327篇 |
冶金工业 | 234篇 |
原子能技术 | 14篇 |
自动化技术 | 484篇 |
出版年
2024年 | 5篇 |
2023年 | 33篇 |
2022年 | 92篇 |
2021年 | 116篇 |
2020年 | 78篇 |
2019年 | 65篇 |
2018年 | 69篇 |
2017年 | 75篇 |
2016年 | 79篇 |
2015年 | 79篇 |
2014年 | 66篇 |
2013年 | 152篇 |
2012年 | 155篇 |
2011年 | 157篇 |
2010年 | 105篇 |
2009年 | 113篇 |
2008年 | 99篇 |
2007年 | 101篇 |
2006年 | 92篇 |
2005年 | 77篇 |
2004年 | 63篇 |
2003年 | 42篇 |
2002年 | 52篇 |
2001年 | 28篇 |
2000年 | 16篇 |
1999年 | 27篇 |
1998年 | 56篇 |
1997年 | 39篇 |
1996年 | 23篇 |
1995年 | 19篇 |
1994年 | 16篇 |
1993年 | 18篇 |
1992年 | 9篇 |
1991年 | 14篇 |
1990年 | 8篇 |
1989年 | 18篇 |
1988年 | 8篇 |
1987年 | 14篇 |
1986年 | 12篇 |
1985年 | 7篇 |
1984年 | 11篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 15篇 |
1979年 | 4篇 |
1976年 | 9篇 |
1975年 | 4篇 |
1974年 | 7篇 |
1972年 | 4篇 |
排序方式: 共有2392条查询结果,搜索用时 15 毫秒
21.
Kwiatkowska Marta Norman Gethin Parker David Santos Gabriel 《Formal Methods in System Design》2021,58(1-2):188-250
Formal Methods in System Design - Automated verification techniques for stochastic games allow formal reasoning about systems that feature competitive or collaborative behaviour among rational... 相似文献
22.
Sebastian Reiter Dmitry Logashenko Alfio Grillo Gabriel Wittum 《Computing and Visualization in Science》2012,15(4):209-225
This work presents an extension of grid generation techniques for finite-volume discretizations of density-driven flow in fractured porous media, in which fractures are considered as low-dimensional manifolds and are resolved by sides of grid elements. The proposed technique introduces additional degrees of freedom for the unknowns assigned to the fractures and thus allows to reconstruct jumps of the solution over a fracture. Through the concept of degenerated elements, the proposed technique can be used for arbitrary junctions of fractures but is sufficiently simple regarding the implementation and allows for the application of conventional numerical solvers. Numerical experiments presented at the end of the paper demonstrate the applicability of this technique in two and three dimensions for complicated fracture networks. 相似文献
23.
Olga Azevedo Filipa Cordeiro Miguel Fernandes Gago Gabriel Miltenberger-Miltenyi Catarina Ferreira Nuno Sousa Damio Cunha 《International journal of molecular sciences》2021,22(9)
Fabry disease (FD) is an X-linked lysosomal storage disorder caused by mutations of the GLA gene that result in a deficiency of the enzymatic activity of α-galactosidase A and consequent accumulation of glycosphingolipids in body fluids and lysosomes of the cells throughout the body. GB3 accumulation occurs in virtually all cardiac cells (cardiomyocytes, conduction system cells, fibroblasts, and endothelial and smooth muscle vascular cells), ultimately leading to ventricular hypertrophy and fibrosis, heart failure, valve disease, angina, dysrhythmias, cardiac conduction abnormalities, and sudden death. Despite available therapies and supportive treatment, cardiac involvement carries a major prognostic impact, representing the main cause of death in FD. In the last years, knowledge has substantially evolved on the pathophysiological mechanisms leading to cardiac damage, the natural history of cardiac manifestations, the late-onset phenotypes with predominant cardiac involvement, the early markers of cardiac damage, the role of multimodality cardiac imaging on the diagnosis, management and follow-up of Fabry patients, and the cardiac efficacy of available therapies. Herein, we provide a comprehensive and integrated review on the cardiac involvement of FD, at the pathophysiological, anatomopathological, laboratory, imaging, and clinical levels, as well as on the diagnosis and management of cardiac manifestations, their supportive treatment, and the cardiac efficacy of specific therapies, such as enzyme replacement therapy and migalastat. 相似文献
24.
Gabriel LaPlante Andrew E. Marble Bryce MacMillan Pearl Lee-Sullivan Bruce G. Colpitts Bruce J. Balcom 《NDT & E International》2005,38(6):501-507
Water ingress inside honeycomb sandwich panels during service has been linked to in-flight failure in some aircraft. There is an ongoing effort to develop nondestructive testing methods to detect the presence of water within the panels. Magnetic resonance (MR) represents an attractive approach in that it is sensitive to moisture. Using a unilateral MR sensor, testing can be applied directly to the surface of the panel. The viability of MR is demonstrated through laboratory imaging of both water within sandwich panels, as well as the adhesive itself. The detection of water using a one-sided handheld MR sensor is presented. It is shown that simple detection, as well as spatial localization of water within sandwich panels is possible. 相似文献
25.
Comparison of a contactor catalytic membrane reactor with a conventional reactor: example of wet air oxidation 总被引:1,自引:0,他引:1
Sylvain Miachon Victor Perez Gabriel Crehan Eddy Torp Henrik R der Rune Bredesen J. -A. Dalmon 《Catalysis Today》2003,82(1-4):75-81
A wet air oxidation reaction was carried out in a gas/liquid catalytic membrane reactor of the contactor type. The oxidation of formic acid was used as a model reaction. The mesoporous top-layer of a ceramic tubular membrane was used as catalyst (Pt) support, and was placed at the interface of the gas (air) and liquid (HCOOH solution) phases.
A similar reaction was carried out in a conventional batch reactor, using a steering rate high enough to avoid gas-diffusion limitations, and exactly identical conditions than for the CMR (amount of catalyst, pressure, etc.). At room temperature, the CMR showed an initial activity three to six times higher than the conventional reactor. This activity increase was attributed to an easier oxygen access to the catalytic sites. Nevertheless, the catalytic membrane gradually deactivated after a few hours of operation. Different deactivation mechanisms are presented. 相似文献
26.
27.
de Almeida Jhony Luiz Comunello Eros Sobieranski Antonio da Rocha Fernandes Anita Maria Cardoso Gabriel Schade 《Pattern Analysis & Applications》2021,24(3):907-914
Pattern Analysis and Applications - Digital holography is an imaging process able to recreate three-dimensional representations of objects from recording pattern interference among distinct waves.... 相似文献
28.
Daniel S. Camarda Matthew J. Lampe Alan J. Lesser Philippe Desbois Klaus Stoll Claus Gabriel Rupert Konradi 《应用聚合物科学杂志》2021,138(41):51203
The creation of graft copolymers by selectively grafting a second polymer to the amorphous fraction of a semi-crystalline polymer in supercritical CO2 is demonstrated herein. The graft copolymer is synthesized by free radical polymerization of a vinyl monomer within the semi-crystalline polymer below its melt temperature. Such conditions afford selective grafting on the amorphous regions (block “B”) while leaving the crystalline domains (block “A”) unmodified. Accordingly, unique A-B, A-B-A, A-B-A-B-A, and so forth. block structures are formed. In this work, styrene is polymerized within polyamide 6, polyethylene terephthalate, and isotactic polypropylene. Purification of these material is performed to remove the un-grafted homopolymer, allowing for determination of the graft yield, the portion of polymer which covalently bonds to the semi-crystalline matrix. Grafting yields achieved in polyamide 6, polyethylene terephthalate, and isotactic polypropylene were 98%, 59%, and 15%, respectively. Property enhancements were observed upon further characterization of polystyrene-polyamide 6 copolymers, including high glass transition temperatures, the ability to be remelted, and tunable grafting molecular weight. Additionally, hydrophobicity is controlled by varying polystyrene composition. The remarkable range of accessed properties demonstrates this as a potential route to upcycling plastics. 相似文献
29.
Dilute copper-aluminium alloys were oxidized in air from 700 to 1000 °C. Two distinctive behaviours were observed: alloys with at least 3 wt% aluminium showed excellent oxidation resistance in the whole temperature range. Alloys with 2 wt% or less aluminium exhibited good oxidation resistance up to 800 °C; but as the temperature was further increased, the oxidation rate of these alloys increased and became comparable to that of pure copper. A kinetic model was developed to explain the oxidation behaviour and indirectly determine the amount of dissolved oxygen in the alloys tested. It was found that the oxygen dissolved in alloys with up to 2 wt% Al exceeded its solubility limit in copper, whereas the dissolved oxygen in alloys with higher aluminium contents was below the solubility limit. This difference may account for the significantly different oxidation resistance. 相似文献
30.
This work presents new stabilised finite element methods for a bending moments formulation of the Reissner-Mindlin plate model. The introduction of the bending moment as an extra unknown leads to a new weak formulation, where the symmetry of this variable is imposed strongly in the space. This weak problem is proved to be well-posed, and stabilised Galerkin schemes for its discretisation are presented and analysed. The finite element methods are such that the bending moment tensor is sought in a finite element space constituted of piecewise linear continuos and symmetric tensors. Optimal error estimates are proved, and these findings are illustrated by representative numerical experiments. 相似文献