全文获取类型
收费全文 | 6276篇 |
免费 | 213篇 |
国内免费 | 98篇 |
专业分类
电工技术 | 77篇 |
综合类 | 238篇 |
化学工业 | 4142篇 |
金属工艺 | 171篇 |
机械仪表 | 178篇 |
建筑科学 | 401篇 |
矿业工程 | 48篇 |
能源动力 | 14篇 |
轻工业 | 325篇 |
水利工程 | 25篇 |
石油天然气 | 71篇 |
武器工业 | 40篇 |
无线电 | 197篇 |
一般工业技术 | 576篇 |
冶金工业 | 45篇 |
原子能技术 | 3篇 |
自动化技术 | 36篇 |
出版年
2024年 | 19篇 |
2023年 | 38篇 |
2022年 | 61篇 |
2021年 | 89篇 |
2020年 | 94篇 |
2019年 | 119篇 |
2018年 | 93篇 |
2017年 | 125篇 |
2016年 | 135篇 |
2015年 | 136篇 |
2014年 | 243篇 |
2013年 | 617篇 |
2012年 | 341篇 |
2011年 | 345篇 |
2010年 | 286篇 |
2009年 | 304篇 |
2008年 | 265篇 |
2007年 | 334篇 |
2006年 | 336篇 |
2005年 | 308篇 |
2004年 | 289篇 |
2003年 | 282篇 |
2002年 | 234篇 |
2001年 | 228篇 |
2000年 | 161篇 |
1999年 | 167篇 |
1998年 | 157篇 |
1997年 | 118篇 |
1996年 | 121篇 |
1995年 | 130篇 |
1994年 | 94篇 |
1993年 | 93篇 |
1992年 | 82篇 |
1991年 | 28篇 |
1990年 | 18篇 |
1989年 | 32篇 |
1988年 | 15篇 |
1987年 | 21篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1964年 | 1篇 |
排序方式: 共有6587条查询结果,搜索用时 15 毫秒
71.
72.
73.
Although carbon fiber epoxy composite materials have excellent properties for structures, the joint in composite materials often reduces the efficiency of the composite structure because the joint is often the weakest area in the composite structure.
In this paper, the effects of the adhesive thickness and the adherend surface roughness on the static and fatigue strengths of adhesively-bonded tubular polygonal lap joints have been investigated by experimental methods. The dependencies of the static and fatigue strengths on the stacking sequences of the composite adherends were observed.
From the experimental investigations, it was found that the fatigue strength of the circular adhesively-bounded joints was quite dependent on the surface roughness of the adherends and that polygonal adhesively-bonded joints had better fatigue strength characteristics than circular adhesively-bonded joints. 相似文献
In this paper, the effects of the adhesive thickness and the adherend surface roughness on the static and fatigue strengths of adhesively-bonded tubular polygonal lap joints have been investigated by experimental methods. The dependencies of the static and fatigue strengths on the stacking sequences of the composite adherends were observed.
From the experimental investigations, it was found that the fatigue strength of the circular adhesively-bounded joints was quite dependent on the surface roughness of the adherends and that polygonal adhesively-bonded joints had better fatigue strength characteristics than circular adhesively-bonded joints. 相似文献
74.
简单介绍了双组分环氧胶粘剂的特点、组成及固化反应机理 ,并且详细叙述了我厂双组分环氧胶粘剂的组分、配制工艺和灌胶工艺以及讨论了双组分环氧胶粘剂在我厂的应用情况 ,为我厂的军品及民用电器产品的灌封胶接提供了广泛的前景 相似文献
75.
An investigation was undertaken on the application of dilute chitosan solutions gelled by tyrosinase‐catalyzed reaction with 3,4‐dihydroxyphenethylamine (dopamine). The tyrosinase‐catalyzed reaction with dopamine conferred water‐resistant adhesive properties to the semidilute chitosan solutions. The viscosity of the chitosan solutions increased highly by the tyrosinase‐catalyzed reaction and the subsequent reactions between o‐quinone compounds and chitosan. These highly viscous, gel‐like modified chitosan materials were allowed to spread onto the surfaces of the glass slides, which were tightly lapped together and held them in water. Tensile shear adhesive strength of over 400 kPa was observed for the modified chitosan samples. The increase in the amino group concentration of the chitosan solutions and the molecular mass of the chitosan used effectively led to the increase in adhesive strength of the glass slides. In addition, in the case where the chitosan solution was gelled by the enzymatic reaction with dopamine in the presence of poly(ethylene glycol), adhesive strength sharply increased at shorter reaction times concomitantly with the increase in the viscosity of the chitosan solutions because the tyrosinase activity effectively was retained by poly(ethylene glycol). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1818–1827, 2007 相似文献
76.
Binder effect on cycling performance of silicon/carbon composite anodes for lithium ion batteries 总被引:1,自引:0,他引:1
Libao Chen Xiaohua Xie Jingying Xie Ke Wang Jun Yang 《Journal of Applied Electrochemistry》2006,36(10):1099-1104
The cycling performance of a silicon/carbon composite anode has been significantly enhanced by using acrylic adhesive and modified acrylic adhesive as binder to fabricate the electrodes for lithium ion batteries. The capacity retentions of Si/C composite electrodes bound by acrylic adhesive and modified acrylic adhesive are 79% and 90% after 50 cycles, respectively. These two binders are electrochemically stable in the organic electrolyte in the working window. They also show larger adhesion strength between the coating and the Cu current collector as well as smaller solvent absorption in the electrolyte solvent than polyvinylidene fluoride (PVDF). Furthermore, sodium carboxyl methyl cellulose (CMC) plays an important role on improving the properties of acrylic adhesive, which increases the adhesive strength of acrylic adhesive and improves the activation of the electrodes. 相似文献
77.
本文研究广丙烯酸酯单体的共聚合反应以及交联型压敏胶带的制备过程,从而确定了最佳工艺条件,并测定了压敏胶带的老化,贮存期,可剥离等性能。 相似文献
78.
79.
80.
用多元乳液共聚法制备了用于粘贴导静电PVC地板胶粘剂,加入乙炔碳黑赋予乳液胶粘剂导静电性能。研究了影响胶接强度和初粘力的主要因素,确定m(VAc)/m(BA+VAc)较合适比为1∶3;研究了乳化剂和交联单体对乳液性能的影响,研究得出,适量加入AA和HMAM可以减少乳化剂的用量,提高乳液的性能;考查了影响导静电性能的因素,研究表明,导静电性能由乙炔碳黑决定,其加入量越大,导静电性能越好。得到的导静电乳液胶粘剂胶接强度达到0.51MPa以上,导静电可达到7.2×103Ω,两项指标均超过国家标准。 相似文献