全文获取类型
收费全文 | 2636篇 |
免费 | 20篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 18篇 |
综合类 | 1篇 |
化学工业 | 149篇 |
金属工艺 | 14篇 |
机械仪表 | 38篇 |
建筑科学 | 61篇 |
矿业工程 | 13篇 |
能源动力 | 45篇 |
轻工业 | 106篇 |
水利工程 | 7篇 |
石油天然气 | 2篇 |
无线电 | 79篇 |
一般工业技术 | 133篇 |
冶金工业 | 1863篇 |
原子能技术 | 6篇 |
自动化技术 | 122篇 |
出版年
2022年 | 8篇 |
2021年 | 8篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 13篇 |
2016年 | 13篇 |
2014年 | 16篇 |
2013年 | 41篇 |
2012年 | 24篇 |
2011年 | 33篇 |
2010年 | 16篇 |
2009年 | 23篇 |
2008年 | 23篇 |
2007年 | 39篇 |
2006年 | 28篇 |
2005年 | 32篇 |
2004年 | 26篇 |
2003年 | 22篇 |
2002年 | 17篇 |
2001年 | 19篇 |
2000年 | 15篇 |
1999年 | 82篇 |
1998年 | 565篇 |
1997年 | 315篇 |
1996年 | 224篇 |
1995年 | 111篇 |
1994年 | 109篇 |
1993年 | 115篇 |
1992年 | 29篇 |
1991年 | 34篇 |
1990年 | 44篇 |
1989年 | 38篇 |
1988年 | 32篇 |
1987年 | 31篇 |
1986年 | 39篇 |
1985年 | 34篇 |
1984年 | 19篇 |
1983年 | 23篇 |
1982年 | 19篇 |
1981年 | 22篇 |
1980年 | 36篇 |
1979年 | 11篇 |
1978年 | 13篇 |
1977年 | 51篇 |
1976年 | 99篇 |
1975年 | 15篇 |
1974年 | 12篇 |
1973年 | 12篇 |
1972年 | 7篇 |
1968年 | 6篇 |
排序方式: 共有2657条查询结果,搜索用时 7 毫秒
1.
SG Bryant 《Canadian Metallurgical Quarterly》1996,53(19):2339-40, 2343
2.
SG Rijpkema RG Herbes N Verbeek-De Kruif JF Schellekens 《Canadian Metallurgical Quarterly》1996,117(3):563-566
Epiglottic disruption is an uncommon injury usually associated with significant supraglottic trauma. This injury may be overlooked because of the difficulty in examining the larynx or other associated severe injuries. We present two cases of clinically unsuspected epiglottic disruption that were first seen on MR images of the neck. 相似文献
3.
4.
SA Khotimchenko VM Kodentsova IA Alekseeva SG Vlaskina OA Vrzhesinskaia AA Sokol''nikov LA Kharitonchik IP Aleshko-Ozhevskií LV Sheviakova 《Canadian Metallurgical Quarterly》1997,43(3):158-164
Gamma delta T-Cells represent a minor subpopulation of T-lymphocytes in man and their role in normal and diseased human skin is unknown. This article is a comprehensive review of T-lymphocytes bearing the gamma delta T-cell receptor in normal and pathological human skin. Firstly, we have documented the occurrence of gamma delta T-cells in normal skin and in a range of reactive and malignant skin conditions. We have then discussed the experimental findings regarding the repertoire used by gamma delta T-cells in normal human skin and in cutaneous disorders with an increased percentage of gamma delta T-cells. 相似文献
5.
6.
HJ Lee HK Ha MH Kim YK Jeong PN Kim MG Lee JS Kim DJ Suh SG Lee YI Min YH Auh 《Canadian Metallurgical Quarterly》1997,169(2):517-520
OBJECTIVE: The purpose of this study was to evaluate ERCP and CT findings of ectopic drainage of the common bile duct into the duodenal bulb. CONCLUSION: Although rare, the diagnosis of ectopic drainage of the common bile duct into the duodenal bulb is important to prevent inadvertent damage during biliary tract or gastric surgery and to clarify the cause of chronic peptic ulcers. 相似文献
7.
EB Poluéktova NK Khitrov VI Andreev SG Pak BK Danilkin 《Canadian Metallurgical Quarterly》1997,69(11):14-16
Changes in the activity of acid phosphatase (AP) and its isoenzymes (tartrate-insensitive AP and formalin-insensitive AP) were investigated in patients with food poisoning in the course of the disease. The activity of AP and its isoenzymes in the serum started to grow in early convalescence and reached maximum in late convalescence. Total activity of AP in food toxic infections consists primarily of the activity of its platelet fraction. AP activity may serve as an additional criterion to predict vascular platelet involvement of hemostasis. 相似文献
8.
Advances in genetic engineering and expression systems have led to a rapid progress in the development of immunoglobulins fused to other proteins. These 'antibody fusion proteins' have novel properties and include antibodies fused to the cytokine interleukin-2. In the present review we describe strategies for construction of these antibody-interleukin-2 fusion proteins and discuss their in vitro and in vivo properties. Antibody-interleukin-2 fusion proteins retain both antibody associated functions such as antigen binding, complement activation and Fc gamma receptor binding as well as interleukin-2 associated functions such as the stimulation of proliferation of CTLL2 cells. In vivo, they produce strong potentiation of the host immune response against any associated antigen. In addition, these novel molecules are able to target tumor cells and produce a specific and effective T cell response capable of eliminating the tumor. These properties suggest that antibody-interleukin-2 fusion proteins will be useful in the diagnosis and/or treatment of human cancer as well as in the potentiation of human response against any associated antigen. 相似文献
9.
The influence of school- and age-related variables was examined separately on 2 tasks involving elementary quantitative skills: conservation of number and mental addition. Performance on these tasks was compared by using a cutoff design with 3 groups of kindergarten and Grade 1 children who differed in age but not amount of schooling (grade), in schooling but not age, or in both age and schooling. The effects of age and schooling were distinct. On conservation of number, performance improved as a function of age but not schooling. On mental arithmetic, accuracy improved with schooling rather than age but children's use of various solution procedures (e.g., retrieval, counting) was not influenced by schooling. Thus, in the domain of elementary mathematical skills, the influence of schooling can be very specific, and age-related variables other than schooling play an important role in the development of elementary mathematical skills. Results illustrate the utility of the cutoff design for investigating instructional and developmental influences on cognitive development. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.