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   545篇
  免费   0篇
化学工业   2篇
金属工艺   1篇
建筑科学   2篇
矿业工程   1篇
轻工业   1篇
石油天然气   1篇
一般工业技术   13篇
冶金工业   522篇
自动化技术   2篇
  2022年   1篇
  2020年   1篇
  2019年   1篇
  2017年   1篇
  2016年   3篇
  2013年   1篇
  2011年   7篇
  2010年   1篇
  2009年   2篇
  2008年   1篇
  2007年   1篇
  2006年   2篇
  2003年   4篇
  2002年   1篇
  1999年   7篇
  1998年   131篇
  1997年   80篇
  1996年   62篇
  1995年   28篇
  1994年   36篇
  1993年   27篇
  1992年   1篇
  1991年   9篇
  1990年   8篇
  1989年   10篇
  1988年   6篇
  1987年   5篇
  1986年   3篇
  1985年   5篇
  1982年   5篇
  1981年   5篇
  1980年   5篇
  1978年   2篇
  1977年   29篇
  1976年   54篇
排序方式: 共有545条查询结果,搜索用时 15 毫秒
31.
32.
33.
Therapeutical efficacy of laferon (J2-interferon) was in children of preschool and school ages with acute respiratory viral infections. Endonasal employment of the drug during 3 days of acute period of the illness significantly decreases the duration of the period of catarrh and intoxication, being accompanied by positive immunological reactions on the part of T-cellular immunity and immunoglobulin synthesis.  相似文献   
34.
35.
Pharmacokinetics was studied of kefsole administered by intravenous and endolymphatic routes to patients (n = 23) with acute pancreatitis. The studies made showed that intravenous route for the drug administration makes for a quicker entering of the antibiotic into the peritoneal exudate. Apart from these reasons, endolymphatic antibacterial therapy does not appear to avert the development of complications involving pus-formation/discharging in acute pancreatitis and does not seem to be essential in the complex of therapeutic measures to be applied for treating the above patients.  相似文献   
36.
37.
Nanoscale zerovalent iron (NZVI) represents one of the most interesting reagents for the remediation of contaminated aquifers, but its application is hindered by a lack of colloidal stability. Prior studies have shown that nanoscale iron slurries can be successfully stabilized against aggregation and sedimentation through dispersion in xanthan solutions; thus, further research was carried out by focusing on the flow behavior of xanthan-modified NVZI suspensions. This work aims at understanding the rheological properties of NZVI-xanthan suspensions, which have been extensively tested under two different flow conditions: simple shear flow and flow through a porous medium. According to both experimental approaches, the suspensions show a shear thinning behavior that is dependent on iron concentration. These rheological properties are explained by referring to the microstructure of the colloidal system. Flow equations have been formulated and solved in radial coordinates in order to demonstrate the feasibility of such suspensions in field scale applications.  相似文献   
38.
BACKGROUND: The prognosis of patients with brain metastasis as the only manifestation of an undetected primary tumor generally is considered to be poor. Therefore, most treatment is palliative. The authors reviewed the clinical outcomes and treatment results of patients presenting with brain metastasis from an undetected primary tumor at The University of Texas M. D. Anderson Cancer Center. METHODS: Between 1977-1996, 220 patients were referred to the study department for the treatment of brain metastasis from an undetected primary tumor. The patients' records were reviewed to identify those for whom brain metastasis was the only manifestation of the primary tumor. The majority of patients were excluded from the current analysis because extracranial metastasis also were present. Thirty-nine patients qualified for this retrospective review. The level of neurosurgical excision varied, but all patients received radiotherapy. Tumor control in the brain and survival were analyzed by various tumor-related and treatment-related factors. RESULTS: In 31 patients, the brain metastasis were adenocarcinomas, whereas the remaining patients had tumors of various other histologies. In 12 patients, the primary tumor eventually was found, most commonly in the lung. The median survival time for all patients was 13.4 months. Overall survival rates (OS) at 1, 3, and 5 years were 56%, 19%, and 15%, respectively. Intracranial disease control was 72% at 5 years. Patients who received gross total resection (GTR) and radiotherapy had significantly better OS than patients who received radiotherapy alone. The OS of patients whose primary tumor was identified was similar to that of patients in whom the primary tumor remained occult. CONCLUSIONS: Brain metastasis as the only manifestation of an unknown primary tumor is a distinct clinical entity. The prognosis for patients with this presentation is better than that of patients with brain metastasis in general. Although the majority of patients die of extracranial disease, a few will achieve long term survival. Treatment to the brain is effective in controlling local disease; aggressive treatment with GTR and radiotherapy is recommended.  相似文献   
39.
Pentachlorophenol (PCP) and molybdate have been shown to inhibit the sulfoconjugation of various chemicals in rats and therefore are useful to examine the role of sulfoconjugation on the toxicity of a chemical. PCP inhibits sulfation by competing with substrates for phenol-sulfotransferases, but not hydroxysteroid-sulfotransferases. In contrast, molybdate decreases sulfation by limiting sulfate availability and thereby decreasing the synthesis of 3'-phosphoadenosine 5'-phosphosulfate (PAPS), which is the obligate cosubstrate for sulfation. Therefore, it was of interest to determine whether PCP or molybdate is effective in decreasing the in vivo sulfation of dehydroepiandrosterone (DHEA), which is a substrate for hydroxysteroid-sulfotransferases. PCP (40 micromol/kg ip) or molybdate (7.5 mmol/kg po) was given 45 min and 4 h, respectively, prior to the start of DHEA infusion. The effects of these two sulfation inhibitors on DHEA sulfation were dependent on the rate of DHEA infusion in rats. PCP had different effects on the sulfation of various infusion rates of DHEA in rats. PCP had little effect on the sulfation after the two lowest infusion rates of DHEA (12.5 and 25 mg/kg) and actually increased (233%) DHEA-sulfate serum concentrations with the highest DHEA infusion rate (50 mg/kg). Although molybdate had little affect on the sulfation of the lowest DHEA infusion rate, it significantly decreased (50-85%) DHEA-sulfate serum concentrations with the two higher DHEA infusion rates. These data indicate that molybdate, unlike PCP, decreases the sulfation of DHEA and may be a useful tool to decrease the sulfation of other substrates of hydroxysteroid-sulfotransferases.  相似文献   
40.
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