全文获取类型
收费全文 | 2096篇 |
免费 | 258篇 |
国内免费 | 92篇 |
专业分类
电工技术 | 134篇 |
综合类 | 175篇 |
化学工业 | 296篇 |
金属工艺 | 109篇 |
机械仪表 | 159篇 |
建筑科学 | 156篇 |
矿业工程 | 107篇 |
能源动力 | 54篇 |
轻工业 | 92篇 |
水利工程 | 64篇 |
石油天然气 | 75篇 |
武器工业 | 8篇 |
无线电 | 238篇 |
一般工业技术 | 243篇 |
冶金工业 | 124篇 |
原子能技术 | 11篇 |
自动化技术 | 401篇 |
出版年
2024年 | 4篇 |
2023年 | 40篇 |
2022年 | 76篇 |
2021年 | 104篇 |
2020年 | 87篇 |
2019年 | 77篇 |
2018年 | 65篇 |
2017年 | 64篇 |
2016年 | 73篇 |
2015年 | 102篇 |
2014年 | 100篇 |
2013年 | 123篇 |
2012年 | 145篇 |
2011年 | 122篇 |
2010年 | 112篇 |
2009年 | 118篇 |
2008年 | 90篇 |
2007年 | 106篇 |
2006年 | 108篇 |
2005年 | 66篇 |
2004年 | 64篇 |
2003年 | 84篇 |
2002年 | 131篇 |
2001年 | 90篇 |
2000年 | 84篇 |
1999年 | 62篇 |
1998年 | 30篇 |
1997年 | 19篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 7篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
排序方式: 共有2446条查询结果,搜索用时 812 毫秒
1.
Ligang Yu Yong Li Yukun Yang Caixia Guo Meiping Li 《International Journal of Food Science & Technology》2022,57(7):4646-4655
This study investigated the inhibitory effects of curcumin and piperine on fluorescent advanced glycation end products (fAGEs) formation in a bovine serum albumin (BSA)–fructose model. Model systems of BSA and fructose were prepared, and curcumin or piperine was added. fAGEs and BSA oxidation product (dityrosine, kynurenine and N'-formylkynurenine) contents were determined. The results showed that fAGEs content decreased with increasing concentration of curcumin and piperine (P < 0.05). Addition of curcumin and piperine at 160 µg mL−1 could inhibit fluorescent AGEs by 100% and 93% respectively. Dityrosine and N'-formylkynurenine contents decreased as curcumin and piperine concentration increased (P < 0.05). Furthermore, the result of principal component analysis indicated that curcumin and piperine markedly impeded BSA oxidation, resulting in a lower level of fAGEs in model systems. Therefore, adding curcumin and piperine may facilitate reduced fAGEs levels in BSA–fructose model. 相似文献
2.
Youngseok Lee Cheolmin Park Nagarajan Balaji Youn-Jung Lee Vinh Ai Dao 《Israel journal of chemistry》2015,55(10):1050-1063
Over the past few decades, crystalline silicon solar cells have been extensively studied due to their high efficiency, high reliability, and low cost. In addition, these types of cells lead the industry and account for more than half of the market. For the foreseeable future, Si will still be a critical material for photovoltaic devices in the solar cell industry. In this paper, we discuss key issues, cell concepts, and the status of recent high-efficiency crystalline silicon solar cells. 相似文献
3.
4.
5.
P Rajasekariah RS Warlow ME Campbell N Ozsarac PL Dao MK Swanton RS Walls 《Canadian Metallurgical Quarterly》1998,30(3):353-367
Bradykinin (BK) is a potent mediator with a broad spectrum of pharmacological and inflammatory actions which are exerted through cell surface receptors. We report here the affinity chromatographic purification of a novel 14 kDa BK binding protein from human blood neutrophils and also peripheral blood mononuclear cells (PBMC), 80% of which are lymphocytes. Radioreceptor crosslinking experiments using bifunctional crosslinkers and radiolabelled BK identified a 14 kDa protein in these cell types both on the cell surface, in glycerol purified plasma membranes and in detergent solubilized cell extracts. Purification by BK affinity chromatography from a variety of BK responsive human cell types i.e. CCD-16Lu lung fibroblasts, HL60 promyelocytes, U937 myelomonocytes and Jurkat T lymphocytes also demonstrated a 14 kDa protein. Purified material obtained from three different BK affinity columns all demonstrated three major proteins at 190, 50 and 14 kDa when eluted with either excess BK or mild acid. Neutrophil fractions from detergent solubilized cell extracts contained an additional 150 kDa protein when eluted with mild acid. Neutrophil and PBMC crude plasma membrane BK affinity column purifications yielded only a single 14 kDa protein. Radioreceptor dot assays of the purified neutrophil eluates containing the 14 kDa protein revealed specific binding to [125I]-BK with a 160 fold excess signal ratio over the original membrane extract. Our data indicates that we have successfully isolated a 14 kDa novel human BK specific binding protein expressed on the surface of inflammatory cells. 相似文献
6.
7.
8.
9.
10.