全文获取类型
收费全文 | 171085篇 |
免费 | 6782篇 |
国内免费 | 3951篇 |
专业分类
电工技术 | 5341篇 |
技术理论 | 10篇 |
综合类 | 4209篇 |
化学工业 | 22523篇 |
金属工艺 | 9066篇 |
机械仪表 | 7436篇 |
建筑科学 | 7943篇 |
矿业工程 | 2162篇 |
能源动力 | 4973篇 |
轻工业 | 10225篇 |
水利工程 | 1800篇 |
石油天然气 | 5014篇 |
武器工业 | 549篇 |
无线电 | 23947篇 |
一般工业技术 | 30187篇 |
冶金工业 | 28655篇 |
原子能技术 | 2151篇 |
自动化技术 | 15627篇 |
出版年
2024年 | 305篇 |
2023年 | 1349篇 |
2022年 | 2290篇 |
2021年 | 3189篇 |
2020年 | 2506篇 |
2019年 | 2412篇 |
2018年 | 3030篇 |
2017年 | 3276篇 |
2016年 | 3135篇 |
2015年 | 3532篇 |
2014年 | 4702篇 |
2013年 | 8463篇 |
2012年 | 6788篇 |
2011年 | 8260篇 |
2010年 | 6952篇 |
2009年 | 7369篇 |
2008年 | 7463篇 |
2007年 | 7620篇 |
2006年 | 7436篇 |
2005年 | 6582篇 |
2004年 | 5402篇 |
2003年 | 4969篇 |
2002年 | 4561篇 |
2001年 | 4687篇 |
2000年 | 4432篇 |
1999年 | 5061篇 |
1998年 | 11175篇 |
1997年 | 7596篇 |
1996年 | 6128篇 |
1995年 | 4209篇 |
1994年 | 3795篇 |
1993年 | 3422篇 |
1992年 | 2164篇 |
1991年 | 2022篇 |
1990年 | 1836篇 |
1989年 | 1575篇 |
1988年 | 1403篇 |
1987年 | 1005篇 |
1986年 | 989篇 |
1985年 | 992篇 |
1984年 | 839篇 |
1983年 | 731篇 |
1982年 | 738篇 |
1981年 | 703篇 |
1980年 | 581篇 |
1979年 | 481篇 |
1978年 | 415篇 |
1977年 | 533篇 |
1976年 | 959篇 |
1975年 | 299篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
Ava Kwong Cecilia Y. S. Ho Vivian Y. Shin Chun Hang Au Tsun Leung Chan Edmond S. K. Ma 《International journal of molecular sciences》2021,22(2)
The germline carrier of the BRCA1 pathogenic mutation has been well proven to confer an increased risk of breast and ovarian cancer. Despite BRCA1 biallelic pathogenic mutations being extremely rare, they have been reported to be embryonically lethal or to cause Fanconi anemia (FA). Here we describe a patient who was a 48-year-old female identified with biallelic pathogenic mutations of the BRCA1 gene, with no or very subtle FA-features. She was diagnosed with ovarian cancer and breast cancer at the ages of 43 and 44 and had a strong family history of breast and gynecological cancers. 相似文献
23.
Yan Jing Zhu Rongying Wu Fan Zhao Ziyin Ye Huan Hou Mengying Liu Yong Yin Lichen 《Nano Research》2020,13(10):2706-2715
Nano Research - Insufficient intratumoral penetration greatly hurdles the anticancer performance of nanomedicine. To realize highly efficient tumor penetration in a precisely and spatiotemporally... 相似文献
24.
25.
26.
27.
28.
Wireless Personal Communications - The existing long term evolution networks originally designed for human-to-human communications are hard to tackle numerous and bursty random access requests from... 相似文献
29.
J. Cochard P. Léonide J. Borgomano Y. Guglielmi G. Massonnat J-P. Rolando L. Marié A. Pasquier 《Journal of Petroleum Geology》2020,43(1):75-94
Upper Barremian – Lower Aptian inner platform “Urgonian” limestones in the Mont de Vaucluse region, SE France, consist of alternating metre-scale microporous and tight intervals. This paper focuses on the influence of structural deformation on the reservoir properties of the Urgonian limestone succession in a study area near the town of Rustrel. Petrographic, petrophysical and structural data were recovered from five fully-cored boreholes, from the walls of a 100 m long underground tunnel, and from a 50 m long transect at a nearby outcrop. The data allowed reservoir property variations in the Urgonian limestones to be studied from core to reservoir scale. Eleven Reservoir Rock Types (RRTs) were identified based on petrographic features (texture, grain size), reservoir properties (porosity, permeability), and the frequency of structural discontinuities such as fractures, faults and stylolites. Tight and microporous reservoir rock types were distinguished. Tight reservoir rock types were characterised by early cementation of intergranular pore spaces and by the presence of frequent structural discontinuities. By contrast microporous reservoir rock types contained preserved intragranular microporosity and matrix permeability, but had very few structural discontinuities. Observed vertical alternations of microporous and tight rock types are interpreted to have been controlled by the early diagenesis of the Urgonian carbonates. Deformation associated with regional-scale tectonic phases, including Albian – Cenomanian “Durancian” uplift (∼105 to 96 Ma) and Pyrenean compression (∼55 to 25 Ma), resulted in the modification of the initial petrophysical properties of the Urgonian limestones. An early diagenetic imprint conditioned both the intensity of structural deformations and the associated circulations of diagenetic and meteoric fluids. Evolution of the Reservoir Rock Types is therefore linked both to the depositional conditions and to subsequent phases of structural deformation. 相似文献
30.