全文获取类型
收费全文 | 15004篇 |
免费 | 873篇 |
国内免费 | 33篇 |
专业分类
电工技术 | 193篇 |
综合类 | 7篇 |
化学工业 | 3774篇 |
金属工艺 | 285篇 |
机械仪表 | 503篇 |
建筑科学 | 547篇 |
矿业工程 | 26篇 |
能源动力 | 608篇 |
轻工业 | 2459篇 |
水利工程 | 166篇 |
石油天然气 | 66篇 |
武器工业 | 2篇 |
无线电 | 1022篇 |
一般工业技术 | 2400篇 |
冶金工业 | 1132篇 |
原子能技术 | 103篇 |
自动化技术 | 2617篇 |
出版年
2024年 | 49篇 |
2023年 | 171篇 |
2022年 | 504篇 |
2021年 | 650篇 |
2020年 | 418篇 |
2019年 | 502篇 |
2018年 | 569篇 |
2017年 | 568篇 |
2016年 | 627篇 |
2015年 | 473篇 |
2014年 | 657篇 |
2013年 | 1154篇 |
2012年 | 1000篇 |
2011年 | 1229篇 |
2010年 | 841篇 |
2009年 | 895篇 |
2008年 | 807篇 |
2007年 | 671篇 |
2006年 | 526篇 |
2005年 | 394篇 |
2004年 | 348篇 |
2003年 | 302篇 |
2002年 | 288篇 |
2001年 | 192篇 |
2000年 | 177篇 |
1999年 | 174篇 |
1998年 | 365篇 |
1997年 | 286篇 |
1996年 | 195篇 |
1995年 | 139篇 |
1994年 | 99篇 |
1993年 | 89篇 |
1992年 | 50篇 |
1991年 | 47篇 |
1990年 | 45篇 |
1989年 | 38篇 |
1988年 | 33篇 |
1987年 | 26篇 |
1986年 | 20篇 |
1985年 | 34篇 |
1984年 | 33篇 |
1983年 | 36篇 |
1982年 | 19篇 |
1981年 | 24篇 |
1980年 | 21篇 |
1979年 | 13篇 |
1978年 | 9篇 |
1977年 | 26篇 |
1976年 | 29篇 |
1973年 | 12篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
111.
Ortega-Cabezas Pedro Miguel Colmenar-Santos Antonio Borge-Diez David Blanes-Peiró Jorge Juan Higuera-Pérez Jorge Alcaide Eric 《Software Quality Journal》2022,30(3):687-728
Software Quality Journal - The number of electronic control units (ECU) installed in vehicles is increasingly high. Manufacturers must improve the software quality and reduce cost by proposing... 相似文献
112.
Roldão Luis de Charette Raoul Verroust-Blondet Anne 《International Journal of Computer Vision》2022,130(8):1978-2005
International Journal of Computer Vision - Semantic scene completion (SSC) aims to jointly estimate the complete geometry and semantics of a scene, assuming partial sparse input. In the last years... 相似文献
113.
Mu Lei Wang Yuan Zang Yong Araujo Stemler Pedro Malaquias 《Journal of Failure Analysis and Prevention》2017,17(2):321-329
This paper is a contribution to the prediction of edge fracture behavior using uncoupled ductile fracture models. A fully integrated simulation framework for the edge fracture prediction is proposed with the shear-induced pre-damage considered. User-defined material subroutines are coded with uncoupled ductile fracture models (Lou-Huh, Oh, Brozzo) incorporated, which are calibrated using the fracture strains of various loading paths. A series of 3D numerical simulations are performed and compared with the results of hole-expansion tests. The effects of pre-damage field and fracture models are analyzed and discussed.
相似文献114.
Guilherme Ferreira Gomes Camila Aparecida Diniz Sebastião Simões da CunhaJr. Antonio Carlos AncelottiJr. 《Journal of Failure Analysis and Prevention》2017,17(4):740-749
The investigation of possible failures in composite materials is a matter of very great importance, and the Tsai-Wu criterion is an effective criterion for analyzing those flaws in anisotropic materials and defining whether the material at a given load will or will not suffer structural failure. In this study, an optimization procedure is proposed to minimize the maximum value of Tsai-Wu of laminated composite tubes subject to axial loading. Artificial neural networks and genetic algorithms are chosen as optimization tools. The results of this study show that the developed algorithm converges faster. Then, the maximum Tsai-Wu value is used as the objective function and the fiber orientations are the constraints in the optimization process. The results yielded by them are compared and discussed. Optimal results are compared with respect to the usual initial design. The design approach is recommended for structures where composites are the key load-carrying members such as orthopedic prosthesis. 相似文献
115.
Patricia Bondia Rocío Jurado Santiago Casado José M. Domínguez‐Vera Natividad Gálvez Cristina Flors 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(17)
The combination of complementary techniques to characterize materials at the nanoscale is crucial to gain a more complete picture of their structure, a key step to design and fabricate new materials with improved properties and diverse functions. Here it is shown that correlative atomic force microscopy (AFM) and localization‐based super‐resolution microscopy is a useful tool that provides insight into the structure and emissive properties of fluorescent β‐lactoglobulin (βLG) amyloid‐like fibrils. These hybrid materials are made by functionalization of βLG with organic fluorophores and quantum dots, the latter being relevant for the production of 1D inorganic nanostructures templated by self‐assembling peptides. Simultaneous functionalization of βLG fibers by QD655 and QD525 allows for correlative AFM and two‐color super‐resolution fluorescence imaging of these hybrid materials. These experiments allow the combination of information about the topography and number of filaments that compose a fibril, as well as the emissive properties and nanoscale spatial distribution of the attached fluorophores. This study represents an important step forward in the characterization of multifunctionalized hybrid materials, a key challenge in nanoscience. 相似文献
116.
Healing Effect of Controlled Anti‐Electromigration on Conventional and High‐Tc Superconducting Nanowires 下载免费PDF全文
Xavier D. A. Baumans Joseph Lombardo Jérémy Brisbois Gorky Shaw Vyacheslav S. Zharinov Ge He Heshan Yu Jie Yuan Beiyi Zhu Kui Jin Roman B. G. Kramer Joris Van de Vondel Alejandro V. Silhanek 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(26)
The electromigration process has the potential capability to move atoms one by one when properly controlled. It is therefore an appealing tool to tune the cross section of monoatomic compounds with ultimate resolution or, in the case of polyatomic compounds, to change the stoichiometry with the same atomic precision. As demonstrated here, a combination of electromigration and anti‐electromigration can be used to reversibly displace atoms with a high degree of control. This enables a fine adjustment of the superconducting properties of Al weak links, whereas in Nb the diffusion of atoms leads to a more irreversible process. In a superconductor with a complex unit cell (La2?x Cex CuO4), the electromigration process acts selectively on the oxygen atoms with no apparent modification of the structure. This allows to adjust the doping of this compound and switch from a superconducting to an insulating state in a nearly reversible fashion. In addition, the conditions needed to replace feedback controlled electromigration by a simpler technique of electropulsing are discussed. These findings have a direct practical application as a method to explore the dependence of the characteristic parameters on the exact oxygen content and pave the way for a reversible control of local properties of nanowires. 相似文献
117.
Organ‐On‐A‐Chip: Biomechanical Strain Exacerbates Inflammation on a Progeria‐on‐a‐Chip Model (Small 15/2017) 下载免费PDF全文
118.
119.
In the steel industry, the iron making system deals with large quantities of materials and energy and so it can play a critical role in reducing emissions and production costs. More specifically, excess by-product gases should be used for electricity generation; otherwise, they lead to pollution. A life cycle analysis is performed to compare the environmental impact of an iron making system with a combined cycle power plant (CCPP), to a system producing the same amount of electricity in a coal power plant. The results for a Chinese steel plant show a 33% reduction in the energy conservation and emission reduction potential for the CCPP system, which is thus more environmentally friendly. A mathematical programming formulation is then proposed for optimal scheduling. It incorporates key technological constraints and is sensitive to hourly changing electricity prices. The outcome is a 19% increase in revenue from electricity sales compared to a schedule that does not dynamically adjust to the price profile. The results also show that emissions from by-product gases can be avoided completely. The paper ends with a sensitivity analysis to evaluate the impact of changes in product demand, gas storage and CCPP capacity, and emission cost. 相似文献
120.
DNA Imaging: DNA Binding Peptide Directed Synthesis of Continuous DNA Nanowires for Analysis of Large DNA Molecules by Scanning Electron Microscope (Small 2/2017) 下载免费PDF全文