全文获取类型
收费全文 | 5795篇 |
免费 | 432篇 |
国内免费 | 15篇 |
专业分类
电工技术 | 62篇 |
综合类 | 2篇 |
化学工业 | 1473篇 |
金属工艺 | 169篇 |
机械仪表 | 232篇 |
建筑科学 | 162篇 |
矿业工程 | 14篇 |
能源动力 | 184篇 |
轻工业 | 1092篇 |
水利工程 | 75篇 |
石油天然气 | 31篇 |
无线电 | 338篇 |
一般工业技术 | 933篇 |
冶金工业 | 439篇 |
原子能技术 | 37篇 |
自动化技术 | 999篇 |
出版年
2024年 | 26篇 |
2023年 | 68篇 |
2022年 | 210篇 |
2021年 | 319篇 |
2020年 | 212篇 |
2019年 | 270篇 |
2018年 | 288篇 |
2017年 | 276篇 |
2016年 | 265篇 |
2015年 | 202篇 |
2014年 | 266篇 |
2013年 | 447篇 |
2012年 | 391篇 |
2011年 | 452篇 |
2010年 | 294篇 |
2009年 | 323篇 |
2008年 | 262篇 |
2007年 | 227篇 |
2006年 | 180篇 |
2005年 | 143篇 |
2004年 | 110篇 |
2003年 | 115篇 |
2002年 | 85篇 |
2001年 | 71篇 |
2000年 | 68篇 |
1999年 | 59篇 |
1998年 | 143篇 |
1997年 | 84篇 |
1996年 | 73篇 |
1995年 | 50篇 |
1994年 | 51篇 |
1993年 | 29篇 |
1992年 | 23篇 |
1991年 | 16篇 |
1990年 | 10篇 |
1989年 | 28篇 |
1988年 | 11篇 |
1987年 | 10篇 |
1986年 | 14篇 |
1985年 | 9篇 |
1984年 | 11篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1977年 | 4篇 |
1976年 | 13篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 2篇 |
排序方式: 共有6242条查询结果,搜索用时 15 毫秒
11.
12.
13.
Chinh Ngo Radhika Mehta Kanchan Aggarwal Audrey G. Fikes Dr. Ines C. Santos Dr. Sylvester M. Greer Prof. Dr. Emily L. Que 《Chembiochem : a European journal of chemical biology》2019,20(8):1003-1007
One-third of all proteins are estimated to require metals for structural stability and/or catalytic activity. Desthiobiotin probes containing metal binding groups can be used to capture metalloproteins with exposed active-site metals under mild conditions so as to prevent changes in metallation state. The proof-of-concept was demonstrated with carbonic anhydrase (CA), an open active site, Zn2+-containing protein. CA was targeted by using sulfonamide derivatives. Linkers of various lengths and structures were screened to determine the optimal structure for capture of the native protein. The optimized probes could selectively pull down CA from red blood cell lysate and other protein mixtures. Pull-down of differently metallated CAs was also investigated. 相似文献
14.
D.R. Santos‐Peñate C.M. Campos‐Rodríguez J.A. Moreno‐Pérez 《International Transactions in Operational Research》2019,26(1):340-363
The ‐centroid problem or leader–follower problem is generalized considering different customer choice rules where a customer may use facilities belonging to different firms, if the difference in travel distance (or time) is small enough. Assuming essential goods, some particular customer choice rules are analyzed. Linear programming formulations for the generalized ‐medianoid and ‐centroid problems are presented and an exact solution approach is applied. Some computational examples are included. 相似文献
15.
Mauro D. Santos Ivonne Delgadillo Jorge A. Saraiva 《International Journal of Food Science & Technology》2020,55(3):1171-1179
Hyperbaric storage (HS) was evaluated as a new food preservation methodology at room temperature (RT) for beef and pork meat, both minced and in pieces, and compared to refrigeration (RF) storage. The meat samples were stored at 50, 75 and 100 MPa and variable RT up to 60 days. HS at 75 and 100 MPa could not only inhibit microbial growth but also inactivate microorganisms. Regarding physicochemical analyses, an overall equal to better pH maintenance in HS samples was achieved, and similar colour differences between HS and RF were observed. Generally, similarities in moisture content and drip loss between HS (mostly 75 and 100 MPa) and RF were detected (tendency for lower values in the former and higher values in the latter for the higher pressure level). Protein solubility revealed a decrease of sarcoplasmic protein values during storage with a pressure level dependency in some samples. 相似文献
16.
17.
Ricardo Cambraia Parreira Diana Paola Gmez‐Mendoza Itamar Couto Guedes de Jesus Rafael Pereira Lemos Anderson Kennedy Santos Cristiana Perdigo Rezende Henrique Csar Pereira Figueiredo Mauro Cunha Xavier Pinto Frank Kjeldsen Silvia Guatimosim Rodrigo Ribeiro Resende Thiago Verano‐Braga 《Proteomics. Clinical applications》2020,14(4)
18.
Caio Felippe Curitiba Marcellos Camila M. Senna Figueiredo Frederico W. Tavares Maurício Bezerra de Souza Jr. Paulo Laranjeira da Cunha Lage João Francisco Cajaiba da Silva Argimiro R. Secchi Amaro G. Barreto Jr. 《加拿大化工杂志》2020,98(11):2435-2450
An experimental methodology for inferring brine dissolution rate in monoethylene glycol (MEG) solutions at different temperatures using a webcam combined with a mathematical model is presented. The measurement system is designed to track the RGB (red, green, and blue) colour variations during the dissolution process. A dynamic model augmented with the population balance equation is applied to describe the dissolution process. Moreover, the dissolution rate is consistently related to the temperature and MEG concentration through the driving force based on the Gibbs energy and chemical affinity. The applied low-cost measurement apparatus proved to be a useful resource for tracking the dissolution dynamics in a wide range of undersaturation. 相似文献
19.
Erika Aparecida Silveira Golnaz Vaseghi Annelisa Silva de Carvalho Santos Nathalie Kliemann Farzad Masoudkabir Matias Noll Noushin Mohammadifard Nizal Sarrafzadegan Cesar de Oliveira 《International journal of molecular sciences》2020,21(23)
The association between obesity, cancer and cardiovascular disease (CVD) has been demonstrated in animal and epidemiological studies. However, the specific role of visceral obesity on cancer and CVD remains unclear. Visceral adipose tissue (VAT) is a complex and metabolically active tissue, that can produce different adipokines and hormones, responsible for endocrine-metabolic comorbidities. This review explores the potential mechanisms related to VAT that may also be involved in cancer and CVD. In addition, we discuss the shared pharmacological treatments which may reduce the risk of both diseases. This review highlights that chronic inflammation, molecular aspects, metabolic syndrome, secretion of hormones and adiponectin associated to VAT may have synergistic effects and should be further studied in relation to cancer and CVD. Reductions in abdominal and visceral adiposity improve insulin sensitivity, lipid profile and cytokines, which consequently reduce the risk of CVD and some cancers. Several medications have shown to reduce visceral and/or subcutaneous fat. Further research is needed to investigate the pathophysiological mechanisms by which visceral obesity may cause both cancer and CVD. The role of visceral fat in cancer and CVD is an important area to advance. Public health policies to increase public awareness about VAT’s role and ways to manage or prevent it are needed. 相似文献
20.