全文获取类型
收费全文 | 10315篇 |
免费 | 282篇 |
国内免费 | 14篇 |
专业分类
电工技术 | 142篇 |
综合类 | 8篇 |
化学工业 | 2351篇 |
金属工艺 | 243篇 |
机械仪表 | 190篇 |
建筑科学 | 449篇 |
矿业工程 | 54篇 |
能源动力 | 302篇 |
轻工业 | 679篇 |
水利工程 | 105篇 |
石油天然气 | 106篇 |
无线电 | 652篇 |
一般工业技术 | 1776篇 |
冶金工业 | 1844篇 |
原子能技术 | 102篇 |
自动化技术 | 1608篇 |
出版年
2022年 | 109篇 |
2021年 | 150篇 |
2020年 | 121篇 |
2019年 | 115篇 |
2018年 | 160篇 |
2017年 | 159篇 |
2016年 | 201篇 |
2015年 | 173篇 |
2014年 | 255篇 |
2013年 | 715篇 |
2012年 | 391篇 |
2011年 | 495篇 |
2010年 | 367篇 |
2009年 | 402篇 |
2008年 | 448篇 |
2007年 | 394篇 |
2006年 | 387篇 |
2005年 | 329篇 |
2004年 | 301篇 |
2003年 | 255篇 |
2002年 | 257篇 |
2001年 | 178篇 |
2000年 | 171篇 |
1999年 | 168篇 |
1998年 | 230篇 |
1997年 | 191篇 |
1996年 | 175篇 |
1995年 | 145篇 |
1994年 | 154篇 |
1993年 | 143篇 |
1992年 | 130篇 |
1991年 | 111篇 |
1990年 | 111篇 |
1989年 | 144篇 |
1988年 | 101篇 |
1987年 | 119篇 |
1986年 | 122篇 |
1985年 | 135篇 |
1984年 | 158篇 |
1983年 | 116篇 |
1982年 | 117篇 |
1981年 | 95篇 |
1980年 | 90篇 |
1979年 | 99篇 |
1978年 | 82篇 |
1977年 | 102篇 |
1976年 | 98篇 |
1975年 | 87篇 |
1974年 | 92篇 |
1973年 | 75篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Image morphing: a survey 总被引:29,自引:0,他引:29
George Wolberg 《The Visual computer》1998,14(8-9):360-372
62.
George E. Weldon SFPE 《Fire Technology》1973,9(4):263-270
A discussion of the use of pressure-relieving and pressure-resistant building construction to minimize the damage caused by
combustion explosions. 相似文献
63.
64.
Jorge Lopez-Tello Maria Angeles Jimenez-Martinez Esteban Salazar-Petres Ritik Patel Amy L. George Richard G. Kay Amanda N. Sferruzzi-Perri 《International journal of molecular sciences》2022,23(11)
Pregnancy is characterized by adaptations in the function of several maternal body systems that ensure the development of the fetus whilst maintaining health of the mother. The renal system is responsible for water and electrolyte balance, as well as waste removal. Thus, it is imperative that structural and functional changes occur in the kidney during pregnancy. However, our knowledge of the precise morphological and molecular mechanisms occurring in the kidney during pregnancy is still very limited. Here, we investigated the changes occurring in the mouse kidney during pregnancy by performing an integrated analysis involving histology, gene and protein expression assays, mass spectrometry profiling and bioinformatics. Data from non-pregnant and pregnant mice were used to identify critical signalling pathways mediating changes in the maternal kidneys. We observed an expansion of renal medulla due to proliferation and infiltration of interstitial cellular constituents, as well as alterations in the activity of key cellular signalling pathways (e.g., AKT, AMPK and MAPKs) and genes involved in cell growth/metabolism (e.g., Cdc6, Foxm1 and Rb1) in the kidneys during pregnancy. We also generated plasma and urine proteomic profiles, identifying unique proteins in pregnancy. These proteins could be used to monitor and study potential mechanisms of renal adaptations during pregnancy and disease. 相似文献
65.
Chinmay Vijay Tikhe Victor Cardoso-Jaime Shengzhang Dong Natalie Rutkowski George Dimopoulos 《International journal of molecular sciences》2022,23(14)
Cysteine-rich trypsin inhibitor-like domain (TIL)-harboring proteins are broadly distributed in nature but remain understudied in vector mosquitoes. Here we have explored the biology of a TIL domain-containing protein of the arbovirus vector Aedes aegypti, cysteine-rich venom protein 379 (CRVP379). CRVP379 was previously shown to be essential for dengue virus infection in Ae. aegypti mosquitoes. Gene expression analysis showed CRVP379 to be highly expressed in pupal stages, male testes, and female ovaries. CRVP379 expression is also increased in the ovaries at 48 h post-blood feeding. We used CRISPR-Cas9 genome editing to generate two mutant lines of CRVP379 with mutations inside or outside the TIL domain. Female mosquitoes from both mutant lines showed severe defects in their reproductive capability; mutant females also showed differences in their follicular cell morphology. However, the CRVP379 line with a mutation outside the TIL domain did not affect male reproductive performance, suggesting that some CRVP379 residues may have sexually dimorphic functions. In contrast to previous reports, we did not observe a noticeable difference in dengue virus infection between the wild-type and any of the mutant lines. The importance of CRVP379 in Ae. aegypti reproductive biology makes it an interesting candidate for the development of Ae. aegypti population control methods. 相似文献
66.
Daniel Octavian Costache Oana Feroiu Adelina Ghilencea Mihaela Georgescu Ana Cruntu Constantin Cruntu Sorin George
iplica Mariana Jinga Raluca Simona Costache 《International journal of molecular sciences》2022,23(9)
The systemic inflammatory syndrome concept is one of the foundations that stand at the basis of revolutionary modern and future therapies, based on the in-depth understanding of the delicate mechanisms that govern the collaboration between the systems and organs of the human body and, at the same time, the fine balance that ensures a reproach-free operation. An interesting concept that we propose is that of the environment-inadequacy status, a concept that non-specifically incorporates all the situations of the organism’s response disorders in the face of imprecisely defined situations of the environment. The correlation between these two concepts will define the future of modern medicine, along with the gene-adjustment mechanisms. Psoriasis is a clear example of an inadequate body response as a result of exposure to as of yet undefined triggers with an excessive systemic inflammatory reaction and hitherto insufficiently controllable. Modern biological therapies, such as TNF-α, IL-12 family, and IL-17 inhibitors, are intended to profoundly reshape the cytokine configuration of patients with inflammatory diseases such as psoriasis, with tremendous success in disease control. Yet, because of the important roles of cytokines in cancer promotion and control, concern was raised about the fact that the use of biologicals may alter immune surveillance and promote cancer progression. Both theoretical and practical data nevertheless showed that the treatment-induced control of cytokines may be beneficial for reducing the inflammatory milieu that promotes cancer and such have a beneficial role in maintaining health. We briefly present the intricate roles of those cytokine families on cancer control, with some debates on if their inhibition might or might not promote additional tumoral development. 相似文献
67.
68.
69.
Industrial parks, characterized as a cluster of enterprises situated in one location to share common resources, have played an indispensible role in boosting regional economic and industrial development. However, further development has been impeded by the shortage of land space, especially for the construction of warehouses. This paper proposes the concept of Supply Hub in Industrial Park (SHIP) as a promising approach addressing this challenge. SHIP is defined as a public provider of warehousing and logistics services for manufacturing enterprises located within an industrial park. The research reported in this paper focuses on evaluating the value of freight consolidation, one of the typical benefits of applying the SHIP approach. Two mathematical models of the supply chain in a typical industrial park are formulated: with and without SHIP. Genetic Algorithm (GA) is applied for solving the two models, and sensitivity experiments are conducted for comparative analysis between the two scenarios. The computational results show that through consolidating shipments, SHIP brings benefits to the whole industrial park. Total cost savings resulted from the application of SHIP would increase with the size of the supply chain, the vehicle capacity, and the rates of fixed transportation costs and holding costs of finished products at manufacturers. 相似文献
70.
George A. Taylor 《EDPACS》2013,47(9):14-16
Abstract Data Base Directions, The Next Steps. John L. Berg, Editor. U. S. Department of Commerce, National Bureau of Standards. (Order from Superintendent of Documents, U. S. Government Printing Office, Washington, DC, 20402. Ask f o r SD Cat.No. C13.10:451.) 158 pages; $2.45. 相似文献