全文获取类型
收费全文 | 86379篇 |
免费 | 9589篇 |
国内免费 | 5656篇 |
专业分类
电工技术 | 6390篇 |
技术理论 | 6篇 |
综合类 | 8089篇 |
化学工业 | 12627篇 |
金属工艺 | 5433篇 |
机械仪表 | 5776篇 |
建筑科学 | 6875篇 |
矿业工程 | 3073篇 |
能源动力 | 2683篇 |
轻工业 | 8075篇 |
水利工程 | 2315篇 |
石油天然气 | 3795篇 |
武器工业 | 1117篇 |
无线电 | 9707篇 |
一般工业技术 | 8642篇 |
冶金工业 | 3552篇 |
原子能技术 | 1332篇 |
自动化技术 | 12137篇 |
出版年
2024年 | 238篇 |
2023年 | 1510篇 |
2022年 | 3182篇 |
2021年 | 4304篇 |
2020年 | 3166篇 |
2019年 | 2397篇 |
2018年 | 2654篇 |
2017年 | 2838篇 |
2016年 | 2546篇 |
2015年 | 3878篇 |
2014年 | 4704篇 |
2013年 | 5672篇 |
2012年 | 6683篇 |
2011年 | 6870篇 |
2010年 | 6497篇 |
2009年 | 6214篇 |
2008年 | 6256篇 |
2007年 | 5648篇 |
2006年 | 5106篇 |
2005年 | 4076篇 |
2004年 | 2973篇 |
2003年 | 2226篇 |
2002年 | 2223篇 |
2001年 | 1945篇 |
2000年 | 1645篇 |
1999年 | 1332篇 |
1998年 | 878篇 |
1997年 | 746篇 |
1996年 | 692篇 |
1995年 | 529篇 |
1994年 | 480篇 |
1993年 | 326篇 |
1992年 | 294篇 |
1991年 | 201篇 |
1990年 | 155篇 |
1989年 | 148篇 |
1988年 | 84篇 |
1987年 | 61篇 |
1986年 | 47篇 |
1985年 | 29篇 |
1984年 | 22篇 |
1983年 | 22篇 |
1982年 | 18篇 |
1981年 | 17篇 |
1980年 | 28篇 |
1979年 | 14篇 |
1974年 | 2篇 |
1970年 | 2篇 |
1959年 | 27篇 |
1951年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Niu Hao Yang Dan-Lei Pu Yuan Wang Dan Wang Jie-Xin 《Journal of Materials Science》2022,57(10):5788-5804
Journal of Materials Science - Nanocomposites have been used in various industries due to their excellent properties. For some of them, high filler content (over 50 wt%) is beneficial to improving... 相似文献
2.
为缓解我国水、能源和粮食资源紧张问题,促进资源可持续利用,构建水-能源-粮食系统,利用耦合协调度模型对我国的30个省(自治区、直辖市)进行测算,并利用空间杜宾模型分析主要影响因素。结果表明:2003—2017年,我国能源、粮食评价[JP]指数高于水资源评价指数,系统综合评价指数逐年递增;大部分省份耦合协调度处于初级协调水平且呈现逐年上升的态势,个别省份耦合协调度濒临失调;耦合协调度空间自相关性较强,虽有明显波动,但是呈现逐年加强的态势;影响耦合协调度的主要因素有从业人口数、固定资产投资额、人均生产总值、人口总数、[JP]文盲人口占比、工业污染排放、城镇化。 相似文献
3.
4.
Zhang Qi Wang Yujing Zhang Xueling Song Jun Li Yinlei Wu Xuehong Yuan Kunjie 《Journal of Materials Science》2022,57(14):7208-7224
Journal of Materials Science - Form-stable composite phase change materials (C-PCMs) prepared by microencapsulation method and porous matrix adsorption method need for compression molding after... 相似文献
5.
6.
Mariah J. Nondorf Yuan H. Brad Kim 《International Journal of Food Science & Technology》2022,57(5):3021-3030
The aim of this study was to determine the effects of tumbling at different post-mortem times on the proteolytic features and quality attributes of beef loins (M. longissimus lumborum). Loins (n = 12) were cut into 4 sections and assigned to tumbling at 1, 6 or 11 days post-mortem or non-tumbled control. Upon tumbling, additional ageing was applied to a common post-mortem time of 16 days. In general, tumbling had no considerable impacts on water-holding ability of samples. Tumbling resulted in an immediate decrease in shear force values (WBSF) of beef samples. Tumbling at 1 day post-mortem with no ageing had similar WBSF compared to the non-tumbled controls at 16 days (P > 0.05). With ageing, tumbling increased amounts of protein degradation, myofibrillar fragmentation and calpain-1 autolysis of samples. These results suggest that early post-mortem tumbling coupled with ageing can synergistically impact the tenderness development of beef loins and shorten the necessary ageing period. 相似文献
8.
Xiao Chen Minlan Yuan Yuting Wang Yan Zhou Xiaohong Sun 《International Journal of Food Science & Technology》2022,57(5):2670-2679
The present study aimed to evaluate the effect of fermentation and gastrointestinal digestion of three kinds of fermented kiwifruit pulps with different Lactobacillus (Lactobacillus plantarum, Lactobacillus acidophilus and Lactobacillus casei). The changes in bioactive substances (total phenolic acid, total flavonoid, vitamin C and the viable count), antioxidant capacity (DPPH, ABTS, hydroxyl radical and superoxide anion radical scavenging activity) and phenolic profiles (protocatechuic acid, protocatechualdehyde, chlorogenic acid, caffeic acid and p-coumaric acid) were detected. The result showed, compared to non-fermented kiwifruit pulp, fermentation with LP and LA had higher content of TPA, TF and VC, as well as antioxidant capacity. Fermentation with LP and the content of protocatechualdehyde, p-coumaric acid and chlorogenic acid were increased. However, after digestion, LP showed more effect in maintaining the content of antioxidants, antioxidant capacity and the viable count rather than LA. During digestion, the content of protocatechualdehyde and p-coumaric acid was increased in fermented samples compared with non-fermented samples. Overall, compared with LA and LC, LP is more suitable for the fermentation of kiwifruit pulp. 相似文献
10.
Baohua Yuan Lili Wei Lixia Yang Liangjiu Bai Huawei Yang Donglei Wei Feng Wang Wenxiang Wang Hou Chen 《Journal of the American Ceramic Society》2022,105(2):801-805
Solar steam generation has attracted considerable interest due to its easy accessibility and sustainability. However, dye molecules were gradually concentrated on bulk water or the surface of solar absorbers during the disposal of dye wastewater. Herein, LaB6/g-C3N4 composites were immobilized on porous cotton cloth, served as a solar absorber resistant to dye clogging. The optimal solar absorber possessed solar harvesting of 92.3% and showed great application potential in the field of the treatment of dye wastewater. This study presented a new approach for the treatment of dye wastewater. 相似文献