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   124篇
  免费   11篇
  国内免费   1篇
化学工业   58篇
金属工艺   2篇
能源动力   1篇
轻工业   4篇
石油天然气   1篇
无线电   27篇
一般工业技术   18篇
冶金工业   21篇
原子能技术   1篇
自动化技术   3篇
  2023年   2篇
  2022年   1篇
  2021年   2篇
  2020年   1篇
  2019年   3篇
  2018年   2篇
  2017年   4篇
  2016年   3篇
  2015年   5篇
  2014年   5篇
  2013年   11篇
  2012年   7篇
  2011年   6篇
  2010年   6篇
  2009年   7篇
  2008年   2篇
  2006年   3篇
  2005年   6篇
  2004年   2篇
  2003年   6篇
  2002年   5篇
  2001年   3篇
  2000年   2篇
  1999年   4篇
  1998年   9篇
  1997年   3篇
  1996年   3篇
  1995年   1篇
  1994年   3篇
  1993年   5篇
  1992年   1篇
  1989年   2篇
  1987年   2篇
  1985年   1篇
  1983年   2篇
  1982年   1篇
  1976年   2篇
  1973年   2篇
  1972年   1篇
排序方式: 共有136条查询结果,搜索用时 15 毫秒
11.
Fungal growth and fat formation on date extract “dibis” medium were poor and slow. Addition of corn-steep liquor (c.s.l.) as a source of nitrogen and other nutritive substances led to a remarkable increase in growth and in fat yield. The fat content in fungal mycelium increased about 4 times. Shaken cultures were superior to still cultures with regard to growth and fat yield only when a high concentration of c.s.l. was added to dibis medium. Under other experimental conditions, still cultures led to heavier mycelium and higher fat contents than shaken cultures.  相似文献   
12.
Current therapy does not cure the majority of patients with B cell non-Hodgkin's lymphoma (NHL) and further intensification does not benefit the patient. Therefore, new approaches are necessary. Immunotherapy has become again a major interest as a new treatment modality for B cell lymphoma since the discovery that the lymphoma specific Id can be presented to antigen-specific T cells. Vaccination of the tumour-bearing host is one of the major strategies to induce a T cell mediated anti-tumour immunity in vivo. For B cell lymphomas the lymphoma specific Id can be used as a tumour-specific antigen to stimulate T cells. Alternatively, the malignant B cells can be modified to become efficient antigen presenting cells (APCs) and present peptides from their own tumour-specific antigens to the autologous T cells. Currently explored and future vaccination strategies for B cell lymphoma will be discussed here.  相似文献   
13.
We report our experience (1987-1993) with Meniere's disease patients treated with a retrolabyrinthine vestibular neurectomy. The current literature was reviewed and our results have been compared with those of previous reports. The overall success rate for vertigo relief was 96.7%, with no serious or permanent complications resulting from the procedure. The technical elements of the operation, as they apply to our approach and those of others, have been analyzed, with special attention given to the anatomical features of the region and their influence on success or failure. We conclude that the retrolabyrinthine approach for vestibular nerve section remains a safe and highly successful technique which merits continued use.  相似文献   
14.
Radiolabeling permits the detection of trace amounts of zwitterionic detergent remaining in extracted hydrophobic or membrane proteins. To develop a sensitive and specific assay for its presence, the commonly used zwitterionic membrane protein detergent 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (Chaps) was synthesized in a tritiated form. Synthesis via 7-ketodeoxycholic acid gave [7-3H]Chaps in 53% yield with a specific activity of 0.85 mCi/mmol. A novel solvent extraction system for cholic acid obviated the need for chromatographic isolation of this intermediate. The protocol can be readily modified to yield [7-3H]Chaps of higher specific activity. [7-3H]Chaps was used to monitor the efficiency of various strategies for detergent removal from concentrated bacterial culture supernatants containing 0.2% (w/v) Chaps. Dialysis removed 95% of Chaps and the addition of detergent-affinity beads to the dialysis buffer resulted in 97% removal of Chaps. Gel-filtration chromatography removed 99.9% of Chaps, while a detergent-affinity bead chromatography column removed 99.99%. Overall, gel-filtration chromatography was the most convenient and economical method for the one-step removal of the zwittergent from complex biological mixtures.  相似文献   
15.
The development of an automated algorithm for the categorization of normal and cancerous colon mucosa is reported. Six features based on texture analysis were studied. They were derived using the co-occurrence matrix and were angular second moment, entropy, contrast, inverse difference moment, dissimilarity, and correlation. Optical density was also studied. Forty-four normal images and 58 cancerous images from sections of the colon were analyzed. These two groups were split equally into two subgroups: one set was used for supervised training and the other to test the classification algorithm. A stepwise selection procedure showed that correlation and entropy were the features that discriminated most strongly between normal and cancerous tissue (P<0.0001). A parametric linear-discriminate function was used to determine the classification rule. For the training set, a sensitivity and specificity of 93.1% and 81.8%, respectively, were achieved, with an overall accuracy of 88.2%. These results mere confirmed with the test set, with a sensitivity and specificity of 93.1% and 86.4%, respectively, and an overall accuracy of 90.2%  相似文献   
16.
17.
BACKGROUND: The comparative clinical pharmacology of cisatracurium and rocuronium and their combinations has not been reported. In this study, the authors compared the relative potency and the clinical profile and characterized the interaction of both drugs. METHODS: Two hundred twenty adults classified as American Society of Anesthesiologists physical status I and anesthetized with propofol-fentanyl-nitrous oxide were studied. In part 1, the neuromuscular-blocking effects of cisatracurium and rocuronium were assessed after administration of bolus doses of 20-50 microg/kg and 100-300 microg/kg, respectively. In part 2, we compared the time course of 1xED50, 1, 1.5, and 2xED95 doses of both drugs (where ED50 and ED95 are, respectively, the doses producing 50% and 95% depression of the first twitch height [T1]). In part 3, equieffective combinations of both drugs were studied to characterize their interaction. RESULTS: The calculated ED50 values and their 95% confidence intervals were 111 (107-115) and 26.2 (25.8-26.5) microg/kg [corrected] for rocuronium and cisatracurium, respectively. Compared with equipotent doses of cisatracurium, rocuronium had a faster onset, and a faster spontaneous T1 and train-of-four recovery times that were significant except at maximum recovery with the 2xED95 dose. The interaction between rocuronium and cisatracurium was synergistic, and the time profile of the combination group was different from that of the single-dose groups. CONCLUSIONS: Cisatracurium is four to five times more potent than rocuronium. Rocuronium had a faster onset of action, a shorter clinical duration, and a faster spontaneous recovery rate compared with equipotent doses of cisatracurium.  相似文献   
18.
This paper presents a study on the potential application of artificial muscles based on shape memory alloys as linear robotic actuators. An extended discussion on various control techniques and ways of biologically inspired muscle arrangements is presented. A two DOF experimental robotic arm was built and used to test the performance of the proposed artificial muscle configurations, and a biologically inspired control strategy using a rule-base concept was developed and tested using the two DOF experimental robotic arm.  相似文献   
19.
A date extract known locally in Iraq as “dibis” was used as substrate for mycological fat formation by Penicillium lilacinum, P. soppii and Aspergillus nidulans. The three fungi were grown on dibis medium at three concentrations. Carbohydrates readily disappeared but this was accompanied by poor fungal growth and low yields of fat. Fungal growth on dibis media enriched with asparagine led to heavy mycelial yields together with higher fat contents. Both economic and fat coefficients rose considerably. It is concluded that nitrogen deficiency in dibis media is at least one of the major factors against good fungal growth and high fat formation.  相似文献   
20.
The free radical terpolymerization of indene (In), methyl methacrylate (MMA) and acrylonitrile (AN) has been investigated. The rate of polymerization of all the binary systems involved has been measured dilatometrically for the homogeneous polymerization. The reactivity ratios of the three binary systems were calculated and were found to be equal to 0.031 and 0.397 for In/AN copolymers and 0.02 and 3.82 for In/MMA copolymers and finally 0.152 and 1.20 for AN/MMA copolymers. The rate of terpolymerization in bulk has been measured as well as the relationship between the monomer mixture composition and the obtained terpolymer in order to construct the compositional triangle. Also the effect of initiator concentration on the rate of terpolymerization was investigated. The activation energy of terpolymerization was determined. The terpolymers were characterized by spectral and thermo-gravimetric analyses. The data indicates that polyindene improves the thermal stability of the prepared terpolymers.  相似文献   
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