全文获取类型
收费全文 | 522504篇 |
免费 | 8037篇 |
国内免费 | 1448篇 |
学科分类
工业技术 | 531989篇 |
出版年
2021年 | 4856篇 |
2020年 | 3474篇 |
2019年 | 4551篇 |
2018年 | 7808篇 |
2017年 | 7613篇 |
2016年 | 7933篇 |
2015年 | 5561篇 |
2014年 | 9243篇 |
2013年 | 24075篇 |
2012年 | 14628篇 |
2011年 | 20145篇 |
2010年 | 15799篇 |
2009年 | 17695篇 |
2008年 | 18092篇 |
2007年 | 17776篇 |
2006年 | 15504篇 |
2005年 | 14208篇 |
2004年 | 13604篇 |
2003年 | 13400篇 |
2002年 | 12636篇 |
2001年 | 12831篇 |
2000年 | 11869篇 |
1999年 | 12593篇 |
1998年 | 32816篇 |
1997年 | 22898篇 |
1996年 | 17448篇 |
1995年 | 13037篇 |
1994年 | 11285篇 |
1993年 | 10974篇 |
1992年 | 7913篇 |
1991年 | 7417篇 |
1990年 | 7261篇 |
1989年 | 7014篇 |
1988年 | 6468篇 |
1987年 | 5765篇 |
1986年 | 5655篇 |
1985年 | 6185篇 |
1984年 | 5827篇 |
1983年 | 5097篇 |
1982年 | 4818篇 |
1981年 | 4906篇 |
1980年 | 4653篇 |
1979年 | 4555篇 |
1978年 | 4356篇 |
1977年 | 5280篇 |
1976年 | 6911篇 |
1975年 | 3748篇 |
1974年 | 3502篇 |
1973年 | 3629篇 |
1972年 | 2956篇 |
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
1.
2.
3.
4.
Journal of Computer and Systems Sciences International - It is shown that the Lyapunov theorem on the distribution properties of the sum of random variables with different distribution densities... 相似文献
5.
Multimedia Tools and Applications - Mammograms are the images used by radiologists to diagnose breast cancer. Breast cancer is one of the most common cancers in women. The early detection of breast... 相似文献
6.
Kuznetsov Yu. A. Markov M. A. Kravchenko I. N. Krasikov A. V. Bykova A. D. 《Refractories and Industrial Ceramics》2021,62(4):421-425
Refractories and Industrial Ceramics - The paper introduces a promising technology for utilizing a traditional scheme for implementing a flow-through micro-arc oxidation method to restore localized... 相似文献
7.
Multimedia Tools and Applications - Recently, many concepts in technology has been changed. According to the digital transformation trends, Internet of Things (IoT) represents an interested... 相似文献
8.
Deepika M. Malini Raajan N. R. Srinivasan A. 《Multimedia Tools and Applications》2022,81(9):12701-12724
Multimedia Tools and Applications - The three-dimensional models of brain tumors serve as diagnostic assistance for physicians, surgeons, and radiologists. The proposed system establishes an... 相似文献
9.
10.
David Diaz Elisa Lopez-Dolado Sergio Haro Jorge Monserrat Carlos Martinez-Alonso Dimitrios Balomeros Agustín Albillos Melchor Alvarez-Mon 《International journal of molecular sciences》2021,22(2)
Our aim was to investigate the subset distribution and function of circulating monocytes, proinflammatory cytokine levels, gut barrier damage, and bacterial translocation in chronic spinal cord injury (SCI) patients. Thus, 56 SCI patients and 28 healthy donors were studied. The levels of circulating CD14+highCD16−, CD14+highCD16+, and CD14+lowCD16+ monocytes, membrane TLR2, TLR4, and TLR9, phagocytic activity, ROS generation, and intracytoplasmic TNF-α, IL-1, IL-6, and IL-10 after lipopolysaccharide (LPS) stimulation were analyzed by polychromatic flow cytometry. Serum TNF-α, IL-1, IL-6 and IL-10 levels were measured by Luminex and LPS-binding protein (LBP), intestinal fatty acid-binding protein (I-FABP) and zonulin by ELISA. SCI patients had normal monocyte counts and subset distribution. CD14+highCD16− and CD14+highCD16+ monocytes exhibited decreased TLR4, normal TLR2 and increased TLR9 expression. CD14+highCD16− monocytes had increased LPS-induced TNF-α but normal IL-1, IL-6, and IL-10 production. Monocytes exhibited defective phagocytosis but normal ROS production. Patients had enhanced serum TNF-α and IL-6 levels, normal IL-1 and IL-10 levels, and increased circulating LBP, I-FABP, and zonulin levels. Chronic SCI patients displayed impaired circulating monocyte function. These patients exhibited a systemic proinflammatory state characterized by enhanced serum TNF-α and IL-6 levels. These patients also had increased bacterial translocation and gut barrier damage. 相似文献