首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1704篇
  免费   90篇
  国内免费   2篇
电工技术   7篇
综合类   2篇
化学工业   321篇
金属工艺   58篇
机械仪表   68篇
建筑科学   17篇
能源动力   68篇
轻工业   149篇
水利工程   3篇
石油天然气   4篇
无线电   196篇
一般工业技术   331篇
冶金工业   395篇
原子能技术   5篇
自动化技术   172篇
  2024年   2篇
  2023年   15篇
  2022年   25篇
  2021年   46篇
  2020年   34篇
  2019年   29篇
  2018年   37篇
  2017年   46篇
  2016年   42篇
  2015年   39篇
  2014年   68篇
  2013年   80篇
  2012年   79篇
  2011年   124篇
  2010年   93篇
  2009年   87篇
  2008年   82篇
  2007年   69篇
  2006年   52篇
  2005年   53篇
  2004年   48篇
  2003年   56篇
  2002年   37篇
  2001年   38篇
  2000年   20篇
  1999年   35篇
  1998年   122篇
  1997年   76篇
  1996年   43篇
  1995年   42篇
  1994年   34篇
  1993年   34篇
  1992年   15篇
  1991年   15篇
  1990年   15篇
  1989年   10篇
  1988年   6篇
  1987年   13篇
  1986年   11篇
  1985年   8篇
  1984年   1篇
  1982年   3篇
  1981年   1篇
  1980年   3篇
  1976年   6篇
  1975年   1篇
  1972年   1篇
排序方式: 共有1796条查询结果,搜索用时 62 毫秒
1.
To modify the glycan part of glycosides, the gene encoding β‐glycosidase was cloned from Bacteroides thetaiotaomicron VPI‐5482. The cloned gene, bt_1780, was expressed in Escherichia coli MC1061 and the expressed enzyme was purified using Ni‐NTA affinity chromatography. The purified enzyme, BTBG, showed optimal activity at 50 °C and pH 5.5. Interestingly, this enzyme did not have any hydrolysing activity on ordinary β‐linkage–containing substrates such as xylobiose, lactose and cello‐oligosaccharide, but specifically hydrolysed isoflavone glycosides such as daidzin, genistin and glycitin. Compared to a commercial beta glucosidase, BTBG selectively hydrolysed isoflavone glycosides in soybean extract mixture solution. These results suggest that BTBG may be a specialized enzyme for the hydrolysis of glycosides and that the substrate specificity of BTBG is applicable for the bioconversion of isoflavone glycosides in the food industry.  相似文献   
2.
Food Science and Biotechnology - To determine the physiochemical properties of the 4-α-glucanotransferase from Bifidobacterium sp., the bllj_0114 gene encoding 4-α-glucanotransferase was...  相似文献   
3.
Vegetable soup (VS), a plant-based functional food, has been used as a traditional folk medicine and is attracting attention for its ability to enhance the immune response. β-Glucan, a well-established and effective immunomodulator, has synergistic effects when used in combination with some bioactive compounds. In the present study, we aimed to evaluate the synergistic immunomodulatory effects of the combination of VS and β-glucan on macrophage-mediated immune responses. β-Glucan was demonstrated to synergistically enhance the VS-stimulated immune response, including the production of interleukin-6, tumor necrosis factor-α, and nitric oxide, mainly through the mitogen-activated protein kinase pathway in macrophages. In addition, this combination has the potential for further development in functional foods with immune-enhancing activity.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10068-021-00888-x.  相似文献   
4.
OBJECTIVE: To examine the relationship between pregnancy incidence and the level of serum E2 during danazol therapy. DESIGN: Danazol was given by 200 mg four times daily for 3 months. Serum E2 level was checked after completing the therapy, but before stopping medication. Patients then were advised to conceive at the appropriate time over a 6-month period. SETTING: Reproductive and Endocrine Laboratory of the Department of Obstetrics and Gynecology, Keelung Chang Gung Memorial Hospital, Keelung, Taiwan. PATIENTS: Infertile women with invasive endometriosis receiving conservative surgery and danazol treatment. INTERVENTIONS: Serum E2 is checked before medication and at the end of danazol therapy, but before stopping medication. MAIN OUTCOME MEASURES: Whether pregnancy is related to the change of serum E2 caused by danazol therapy. RESULTS: There were 24 pregnancies in 38 patients with invasive endometriosis after treatment. Pregnant patients had significantly lower serum E2 levels as compared with the nonpregnant patients. CONCLUSIONS: After conservative surgery for invasive endometriosis associated with infertility, the therapeutic period of danazol treatment could be shortened to 3 months. Because there is significant correlation of fecundability and serum E2 after danazol medication, serum E2 could be a guideline for predicting pregnancy or for prolonging or changing of treatment after danazol therapy.  相似文献   
5.
6.
7.
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   
8.
The intraneural ganglion of the peroneal nerve is a rare lesion. The differential diagnosis includes lesions of the knee especially the tendinopathia of the knee flexors. Clinical examination, electrophysiological investigations, ultrasound imaging and magnetic resonance tomography will establish the diagnosis. We report a case in which an artificial puncture of the ganglion caused a temporary peroneal palsy. Surgical procedure led to complete restoration of the nerve function.  相似文献   
9.
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号