全文获取类型
收费全文 | 4198篇 |
免费 | 257篇 |
国内免费 | 177篇 |
专业分类
电工技术 | 142篇 |
综合类 | 283篇 |
化学工业 | 747篇 |
金属工艺 | 244篇 |
机械仪表 | 221篇 |
建筑科学 | 271篇 |
矿业工程 | 136篇 |
能源动力 | 256篇 |
轻工业 | 381篇 |
水利工程 | 65篇 |
石油天然气 | 90篇 |
武器工业 | 11篇 |
无线电 | 300篇 |
一般工业技术 | 533篇 |
冶金工业 | 400篇 |
原子能技术 | 47篇 |
自动化技术 | 505篇 |
出版年
2024年 | 18篇 |
2023年 | 25篇 |
2022年 | 50篇 |
2021年 | 56篇 |
2020年 | 96篇 |
2019年 | 94篇 |
2018年 | 112篇 |
2017年 | 88篇 |
2016年 | 122篇 |
2015年 | 66篇 |
2014年 | 106篇 |
2013年 | 245篇 |
2012年 | 155篇 |
2011年 | 155篇 |
2010年 | 120篇 |
2009年 | 171篇 |
2008年 | 163篇 |
2007年 | 148篇 |
2006年 | 138篇 |
2005年 | 90篇 |
2004年 | 190篇 |
2003年 | 370篇 |
2002年 | 603篇 |
2001年 | 479篇 |
2000年 | 185篇 |
1999年 | 129篇 |
1998年 | 126篇 |
1997年 | 73篇 |
1996年 | 54篇 |
1995年 | 33篇 |
1994年 | 34篇 |
1993年 | 17篇 |
1992年 | 10篇 |
1991年 | 16篇 |
1990年 | 10篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 8篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 10篇 |
1982年 | 4篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1976年 | 4篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1965年 | 3篇 |
排序方式: 共有4632条查询结果,搜索用时 15 毫秒
51.
材料表面可控修饰新技术 总被引:1,自引:0,他引:1
聚合物"刷"是端接枝超薄聚合物层的形象描述,在材料表面形成聚合物"刷"是控制材料表面性质的一种有效手段.因其在材料表面结构分子设计中具有突出的优越性,近年引起了材料表面改性专家的广泛关注.介绍了表面引发可控/"活性"聚合制备可控聚合物"刷"技术,并展示了其在材料表面可控修饰中的应用. 相似文献
52.
53.
54.
Effect of sodium monofluorophosphate treatment on microstructure and frost salt scaling durability of slag cement paste 总被引:1,自引:0,他引:1
Sodium-monofluorophosphate (Na-MFP) is currently in use as a surface applied corrosion inhibitor in the concrete industry. Its basic mechanism is to protect the passive layer of the reinforcement steel against disruption due to carbonation. Carbonation is known as the most detrimental environmental effect on blast furnace slag cement (BFSC) concrete with respect to frost salt scaling. In this paper the effect of Na-MFP on the microstructure and frost salt scaling resistance of carbonated BFSC paste is presented. The results of electron microscopy, mercury intrusion porosimetry (MIP) and X-ray diffraction (XRD) are discussed. It is found that the treatment modifies the microstructure and improves the resistance of carbonated BFSC paste against frost salt attack. 相似文献
55.
Because of the variety of climate conditions very different oil plants except of some tropical kinds grow in Turkey. In this work four groups of raw material of Turkish vegetable oils were investigated. The first group consists of olive, sunflower and cotton, which are important raw materials in Turkey. About 97% of the oil produced in Turkey base on these three raw materials. The second group consists of sesame, poppy, linseed, hemp-seed, rape, soyabean, safflower, castor bean and groundnut, which are temporary of lower importance for Turkey. The third group consists of the non-traditional oil raw materials like tobacco seed, grape seed, scabious, fig seed, tomato seed, laurel seed, pistacia terebinthus, rice bran, maize germs, anise seed, peach-stones and pumpkin seed. The fourth group consists of fruits rich in oil like hazel-nuts, walnuts, almonds and pistachio-nuts, whose production is of great importance in Turkey. 相似文献
56.
57.
This paper is the first one of the two papers entitled “modeling and solving mixed-model assembly line balancing problem with setups”, which has the aim of developing the mathematical programming formulation of the problem and solving it with a hybrid meta-heuristic approach. In this current part, a mixed-integer linear mathematical programming (MILP) model for mixed-model assembly line balancing problem with setups is developed. The proposed MILP model considers some particular features of the real world problems such as parallel workstations, zoning constraints, and sequence dependent setup times between tasks, which is an actual framework in assembly line balancing problems. The main endeavor of Part-I is to formulate the sequence dependent setup times between tasks in type-I mixed-model assembly line balancing problem. The proposed model considers the setups between the tasks of the same model and the setups because of the model switches in any workstation. The capability of our MILP is tested through a set of computational experiments. Part-II tackles the problem with a multiple colony hybrid bees algorithm. A set of computational experiments is also carried out for the proposed approach in Part-II. 相似文献
58.
自蔓延高温合成法制备金属—陶瓷复合材料 总被引:5,自引:0,他引:5
本文就自蔓延高温合成技术(SHS)在制备金属-陶瓷复合材料方面的进展进行了回顾,对SHS技术用于制备金属-陶瓷块体复合材料,梯度功能材料(FaM),金属-陶瓷复合管,金属-陶瓷的焊接工艺原理以及金属材料的陶瓷涂层进行了探讨。 相似文献
59.
60.