全文获取类型
收费全文 | 744篇 |
免费 | 75篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 25篇 |
综合类 | 51篇 |
化学工业 | 96篇 |
金属工艺 | 116篇 |
机械仪表 | 24篇 |
建筑科学 | 147篇 |
矿业工程 | 8篇 |
能源动力 | 29篇 |
轻工业 | 31篇 |
水利工程 | 5篇 |
石油天然气 | 2篇 |
武器工业 | 2篇 |
无线电 | 33篇 |
一般工业技术 | 156篇 |
冶金工业 | 76篇 |
原子能技术 | 1篇 |
自动化技术 | 28篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 15篇 |
2021年 | 12篇 |
2020年 | 23篇 |
2019年 | 16篇 |
2018年 | 32篇 |
2017年 | 24篇 |
2016年 | 33篇 |
2015年 | 27篇 |
2014年 | 37篇 |
2013年 | 40篇 |
2012年 | 49篇 |
2011年 | 57篇 |
2010年 | 57篇 |
2009年 | 40篇 |
2008年 | 45篇 |
2007年 | 57篇 |
2006年 | 50篇 |
2005年 | 37篇 |
2004年 | 41篇 |
2003年 | 28篇 |
2002年 | 20篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1984年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有830条查询结果,搜索用时 15 毫秒
11.
C. M. Sonsino H. Kaufmann R. Masendorf A. Hatscher H. Zenner C.‐P. Bork J. Hinterdorfer H. M. Sonne B. Engl G. Steinbeck 《Materialwissenschaft und Werkstofftechnik》2004,35(8):522-533
Materials Data for Fatigue Life Calculation of Steel Sheet Structures for Automotive Engineering Within a joint project of the steel and automotive industry 17 steel sheet materials for automotive engineering in various delivery and forming conditions at temperatures of –40 °C, 22 °C and 100 °C were investigated. In the course of 37 test series strain controlled fatigue curves to crack initiation and stress‐strain‐curves under monotonic and cyclic loading were determined. All experimental data, hysteresis loops and determined cyclic properties are available in a database. A correlation between the mechanical properties from tensile tests and the properties from strain controlled cyclic experiments seems to be possible. 相似文献
12.
13.
Ying Xie Bo Zhang Shuxian Wang Dong Wang Aizhu Wang Zeyan Wang Haohai Yu Huaijin Zhang Yanxue Chen Mingwen Zhao Baibiao Huang Liangmo Mei Jiyang Wang 《Advanced materials (Deerfield Beach, Fla.)》2017,29(17)
Photodetectors with excellent detecting properties over a broad spectral range have advantages for the application in many optoelectronic devices. Introducing imperfections to the atomic lattices in semiconductors is a significant way for tuning the bandgap and achieving broadband response, but the imperfection may renovate their intrinsic properties far from the desire. Here, by controlling the deviation from the perfection of the atomic lattice, ultrabroadband multilayer MoS2 photodetectors are originally designed and realized with the detection range over 2000 nm from 445 nm (blue) to 2717 nm (mid‐infrared). Associated with the narrow but nonzero bandgap and large photoresponsivity, the optimized deviation from the perfection of MoS2 samples is theoretically found and experimentally achieved aiming at the ultrabroadband photoresponse. By the photodetection characterization, the responsivity and detectivity of the present photodetectors are investigated in the wavelength range from 445 to 2717 nm with the maximum values of 50.7 mA W?1 and 1.55 × 109 Jones, respectively, which represent the most broadband MoS2 photodetectors. Based on the easy manipulation, low cost, large scale, and broadband photoresponse, this present detector has significant potential for the applications in optoelectronics and electronics in the future. 相似文献
14.
镁合金板材轧制技术与工艺的研究进展 总被引:4,自引:0,他引:4
综述轧制工艺参数以及轧制技术对镁合金板材组织、力学性能及轧制成形性能的影响,详细阐述常规轧制技术和双辊铸轧、异步轧制、等径角轧制、累积复合轧制、交叉轧制等最新轧制技术的基本原理、特点和应用,分析不同的轧制技术对应的晶粒细化机制和织构特点。最后总结评价上述轧制技术与工艺,并指出目前存在的问题及今后的发展方向。 相似文献
15.
The performance of a lubricant largely depends on the additives it involves. However, currently used additives cause severe pollution if they are burned and exhausted. Therefore, it is necessary to develop a new generation of green additives. Graphene oxide (GO) consists of only C, H and O and thus is considered to be environmentally friendly. So the tribological properties of the few-layer GO sheet as an additive in hydrocarbon base oil are investigated systematically. It is found that, with the addition of GO sheets, both the coefficient of friction (COF) and wear are decreased and the working temperature range of the lubricant is expanded in the positive direction. Moreover, GO sheets has better performance under higher sliding speed and the optimized concentration of GO sheets is determined to be 0.5wt%. After rubbing, GO is detected on the wear scars through Raman spectroscopy. And it is believed that, during the rubbing, GO sheets adhere to the sliding surfaces, behaving like protective films and preventing the sliding surfaces from contacting with each other directly. This paper proves that the GO sheet is an effective lubricant additive, illuminates the lubrication mechanism, and provides some critical parameters for the practical application of GO sheets in lubrication. 相似文献
16.
17.
18.
流化床反应器的静电与结片的消除方法 总被引:1,自引:0,他引:1
文中论述了UNIPOL流化床反应器在生产过程中产生静电的机理及危害.分析了静电及结片产生的因素,并对此提出了行之有效的预防及消除方法. 相似文献
19.
Gabriela Huminic Alexandru Vrdaru Angel Huminic Claudiu Fleac Florian Dumitrache Ion Morjan 《International journal of molecular sciences》2022,23(6)
In the current paper, a new hybrid nanofluid based on graphene oxide sheets and silicon nanoparticles is proposed for thermal applications. GO sheets and Si nanoparticles with different mixture ratios are dispersed in distilled water. Dynamic viscosity is measured at temperatures within the range 20–50 °C and the values are compared to the results available in the literature. The results indicated that the viscosity increases with increasing the mixture ratio of graphene oxide. A new correlation for the dynamic viscosity based on the experimental findings is proposed. Finally, the criteria for the performance of new hybrid nanofluid for thermal applications are analyzed. 相似文献
20.
One‐Step Construction of N,P‐Codoped Porous Carbon Sheets/CoP Hybrids with Enhanced Lithium and Potassium Storage 下载免费PDF全文
Jing Bai Baojuan Xi Hongzhi Mao Yue Lin Xiaojian Ma Jinkui Feng Shenglin Xiong 《Advanced materials (Deerfield Beach, Fla.)》2018,30(35)
Despite the desirable advancement in synthesizing transition‐metal phosphides (TMPs)‐based hybrid structures, most methods depend on foreign‐template‐based multistep procedures for tailoring the specific structure. Herein, a self‐template and recrystallization–self‐assembly strategy for the one‐step synthesis of core–shell‐like cobalt phosphide (CoP) nanoparticles embedded into nitrogen and phosphorus codoped porous carbon sheets (CoP?NPPCS), is first proposed. Relying on the unusual coordination ability of melamine with metal ions and the cooperative hydrogen bonding of melamine and phytic acid to form a 2D network, a self‐synthesized single precursor can be attained. Importantly, this approach can be easily expanded to synthesize other TMPs?NPPCS. Due to the unique compositional and structural characteristics, these CoP?NPPCSs manifest outstanding electrochemical performances as anode materials for both lithium‐ and potassium‐ion batteries. The unusual hybrid architecture, the high specific surface area, and porous features make the CoP?NPPCS attractive for other potential applications, such as supercapacitors and electrocatalysis. 相似文献