全文获取类型
收费全文 | 4884篇 |
免费 | 196篇 |
国内免费 | 19篇 |
专业分类
电工技术 | 51篇 |
技术理论 | 1篇 |
综合类 | 264篇 |
化学工业 | 2727篇 |
金属工艺 | 26篇 |
机械仪表 | 14篇 |
建筑科学 | 82篇 |
矿业工程 | 5篇 |
能源动力 | 7篇 |
轻工业 | 1532篇 |
水利工程 | 1篇 |
石油天然气 | 66篇 |
武器工业 | 4篇 |
无线电 | 16篇 |
一般工业技术 | 274篇 |
冶金工业 | 16篇 |
原子能技术 | 3篇 |
自动化技术 | 10篇 |
出版年
2024年 | 10篇 |
2023年 | 22篇 |
2022年 | 82篇 |
2021年 | 86篇 |
2020年 | 100篇 |
2019年 | 113篇 |
2018年 | 76篇 |
2017年 | 108篇 |
2016年 | 75篇 |
2015年 | 107篇 |
2014年 | 210篇 |
2013年 | 316篇 |
2012年 | 283篇 |
2011年 | 316篇 |
2010年 | 214篇 |
2009年 | 213篇 |
2008年 | 203篇 |
2007年 | 319篇 |
2006年 | 348篇 |
2005年 | 283篇 |
2004年 | 257篇 |
2003年 | 233篇 |
2002年 | 228篇 |
2001年 | 178篇 |
2000年 | 137篇 |
1999年 | 143篇 |
1998年 | 105篇 |
1997年 | 80篇 |
1996年 | 56篇 |
1995年 | 46篇 |
1994年 | 28篇 |
1993年 | 28篇 |
1992年 | 27篇 |
1991年 | 9篇 |
1990年 | 20篇 |
1989年 | 15篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
排序方式: 共有5099条查询结果,搜索用时 15 毫秒
21.
22.
23.
24.
25.
应用粘弹谱仪考察了不同摩尔质量的聚酯(PET、PBT、PBT/PET)的动态力学性能,结果表明摩尔质量增大将提高其模量,但亦导致结晶速度变慢,使测得的模量反而比摩尔质量较低的试样小. 相似文献
26.
27.
28.
Conductive Papers Containing Metallized Polyester Fibers for Electromagnetic Interference Shielding 总被引:7,自引:0,他引:7
Conductive papers were developed for preventing or reducing electromagnetic interference (EMI), and their shielding efficiency was evaluated. This type of conductive paper consists of wood pulp, synthetic pulp and metallized polyester fibers (0.5–2.0 mm long and 14 m in diameter) whose surfaces are coated with nickel alone (Ni-PET) or copper and nickel double layers (Ni-Cu-PET) by electroless plating. In this report, the effect of the characteristics of these metallized fibers, such as their conductivity, geometry and the concentration of fibers in paper, which lead to high efficiency for shielding effectiveness is discussed. For instance, one of the conductive papers (80 g/m2) which was prepared by mixing 40% Ni-Cu-PET and 60% synthetic polyethylene pulp showed over 40 dB shielding effectiveness between 10 MHz and 1 GHz. 相似文献
29.
聚酯酰胺热熔胶的合成及其性能研究 总被引:2,自引:1,他引:2
研究了以聚酯胶和聚酰胺胶为原料在催化剂作用下加热共熔,通过大分子链交换反应制备织物用聚酯酰胺热熔胶的方法。用聚酯胶的溶剂对所得产品进行溶取试验并且通过红外光谱分析都证明了链交换反应的存在。用该法所得产品粘接强度大,既耐水洗又耐干洗,适用于粘合衬生产。 相似文献
30.
How garments contribute to performance of the clothing system during wear is of interest, as is understanding the value of using fabric properties to inform end-use characteristics. To investigate the influences of layering upper-body garments, four fabrics were used to construct two first-layer garments (wool and polyester) and two outer-layer garments (wool and membrane laminate). Over six sessions, 10 moderately trained males wore each first-layer garment as a single layer and in combination with each outer-layer garment while resting, running and walking in cold environmental conditions (8 ± 1°C, 81 ± 4% RH). Here, the type of garment arrangement worn (fabric type or number of layers) had little influence on heart rate, core body temperature and change in body mass. Weighted mean covered skin temperature was warmer and weighted mean next-to-skin vapour pressure was typically higher (following the onset of exercise) with two layers versus one. Differences among fabrics for individual properties were typically overstated compared to differences among corresponding garments for physiological and psychophysical variables under the conditions of this study. These findings inform the interpretation of particular fabric properties and highlight issues to be acknowledged during development/refinement of fabric test methods.
Practitioner Summary: We examined the way in which selected fibre, fabric and garment (layering) characteristics contribute to performance of the clothing system during wear under cold conditions. Selected properties of the constituent fabrics were found to provide limited insight into how garments perform during wear under the conditions of this study. 相似文献