全文获取类型
收费全文 | 607篇 |
免费 | 46篇 |
国内免费 | 31篇 |
专业分类
电工技术 | 63篇 |
综合类 | 29篇 |
化学工业 | 118篇 |
金属工艺 | 30篇 |
机械仪表 | 51篇 |
建筑科学 | 24篇 |
矿业工程 | 13篇 |
能源动力 | 12篇 |
轻工业 | 81篇 |
水利工程 | 24篇 |
石油天然气 | 32篇 |
武器工业 | 2篇 |
无线电 | 77篇 |
一般工业技术 | 55篇 |
冶金工业 | 17篇 |
原子能技术 | 8篇 |
自动化技术 | 48篇 |
出版年
2024年 | 2篇 |
2023年 | 15篇 |
2022年 | 37篇 |
2021年 | 28篇 |
2020年 | 18篇 |
2019年 | 10篇 |
2018年 | 22篇 |
2017年 | 26篇 |
2016年 | 17篇 |
2015年 | 33篇 |
2014年 | 36篇 |
2013年 | 35篇 |
2012年 | 45篇 |
2011年 | 49篇 |
2010年 | 56篇 |
2009年 | 35篇 |
2008年 | 28篇 |
2007年 | 31篇 |
2006年 | 33篇 |
2005年 | 29篇 |
2004年 | 11篇 |
2003年 | 20篇 |
2002年 | 15篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 13篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有684条查询结果,搜索用时 0 毫秒
11.
12.
沙城产区酿酒葡萄病虫害综合防治技术 总被引:1,自引:1,他引:1
沙城产区是中国十大葡萄产区之一,自然条件得天独厚,非常适合葡萄的生长.但是由于各方面的因素,近年来葡萄病虫害发生有增加的趋势,给葡萄生产造成影响,对葡萄产业的发展不利,应该引起高度重视. 相似文献
13.
14.
15.
16.
17.
Bingxian Ou Lixin Lu Qinsheng Wang Qing He YiLin Xie Junxia Yan 《International journal of molecular sciences》2022,23(11)
Titanium matrix composites (TMCs) with excellent mechanical properties, reinforced by graphene, is deemed the lightweight and high strength structural materials. In this study, TC11 titanium alloy powder and graphene nanosheets (GNPs) were used as raw materials, and the composite powder with good uniformity and fluidity was obtained through non-interventional homogeneous mixing by a planetary mixer. The microstructure and mechanical properties of the GNPs-TC11 composites and TC11 alloy were compared. The results showed that the microstructure of TC11 and the composites was acicular martensite α’ phase under the process parameters of 280 W laser power, 1200 mm/s scanning speed, and 0.1 mm hatch spacing. The GNPs in addition, in the composites, reduced the acicular martensite particle size and expanded the proportion of low-angle grain boundaries. The tensile strength and percentage elongation after the fracture of the TC11 titanium alloy were 1265 MPa and 4.3%, respectively. Because of addition of the GNPs, the strength and percentage elongation after the fracture of the composite increased to 1384 MPa and 8.1%, respectively, at a GNPs mass content of 0.2%. The enhancement of mechanical properties can be attributed to grain refinement, dislocation strengthening, Orowan strengthening, and load transfer strengthening. 相似文献
18.
Yan Liu Tiexin Cheng Dongmei Li Pengbo Jiang Junxia Wang Wenxing Li Yingli Bi Kaiji Zhen 《Catalysis Letters》2003,85(1-2):101-107
CO2 reforming of CH4 was studied over a magnetoplumbite-type hexaaluminate La0.8Pr0.2NiAl11O19 catalyst, which showed very high activity for over 300 h without deactivation at 1023 K. This catalyst showed good resistance to carbon deposition, which in this reaction and in CH4 decomposition was investigated by means of XPS and TEM. It is suggested that nano-tube-like carbon is an intermediate in this reaction and a spillover of carbon from crystalline Ni onto the hexaaluminate oxide occurred during the reaction. 相似文献
19.
Junxia Wang Genshui Wang Hengchang Nie Xuefeng Chen Fei Cao Xianlin Dong Yan Gu Hongliang He 《Journal of the American Ceramic Society》2013,96(8):2370-2373
The low‐temperature sintering and electric properties of Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 (PZTN 95/5) ferroelectric ceramics with CuO addition was investigated. The CuO addition significantly promoted the densification and reduced the sintering temperature of PZTN 95/5 ceramics by more than 200°C. The 0.2 wt% CuO‐added sample sintered at 1150°C exhibited the optimum relative density of 96.7% and excellent electric properties with values of Pr = 37.80 μC/cm2, TC = 223°C, εr = 329, and tan δ = 0.016, which were superior to that of PZTN 95/5 ceramics sintered at 1350°C. 相似文献
20.
辉光放电电解是一种新型的产生等离子体的电化学方法。在惰性电解质水溶液中进行辉光放电电解,可以产生大量的.OH、.H、e-aq、HO2.等活性粒子,且产物的总生成量超过了根据法拉第定律计算的产量,每通过1 mol电子可生成12 mol.OH。.OH氧化能力非常强,可以无选择地降解各种有机物。文章探讨了电压、初始浓度、pH、催化剂Fe2+等因素对辉光放电降解直接黑EX效果的影响。用紫外可见吸收光谱检测了染料的降解过程。实验表明:利用该方法可以使水中染料大部分降解。直接黑EX优化降解条件为:工作电压610 V,pH 3.12,Fe2+催化作用下降解效率明显提高。 相似文献