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   5436篇
  免费   195篇
  国内免费   6篇
电工技术   63篇
综合类   25篇
化学工业   1018篇
金属工艺   166篇
机械仪表   95篇
建筑科学   292篇
矿业工程   80篇
能源动力   63篇
轻工业   616篇
水利工程   95篇
石油天然气   2篇
无线电   324篇
一般工业技术   855篇
冶金工业   1222篇
原子能技术   26篇
自动化技术   695篇
  2023年   37篇
  2021年   63篇
  2020年   45篇
  2019年   42篇
  2018年   85篇
  2017年   84篇
  2016年   145篇
  2015年   120篇
  2014年   142篇
  2013年   201篇
  2012年   264篇
  2011年   267篇
  2010年   167篇
  2009年   166篇
  2008年   213篇
  2007年   179篇
  2006年   219篇
  2005年   115篇
  2004年   103篇
  2003年   104篇
  2002年   114篇
  2001年   77篇
  2000年   69篇
  1999年   97篇
  1998年   383篇
  1997年   213篇
  1996年   178篇
  1995年   107篇
  1994年   124篇
  1993年   110篇
  1992年   44篇
  1991年   65篇
  1990年   51篇
  1989年   68篇
  1988年   37篇
  1987年   52篇
  1986年   44篇
  1985年   58篇
  1984年   55篇
  1983年   50篇
  1982年   64篇
  1981年   54篇
  1980年   43篇
  1979年   50篇
  1978年   40篇
  1977年   52篇
  1976年   101篇
  1975年   45篇
  1974年   37篇
  1973年   31篇
排序方式: 共有5637条查询结果,搜索用时 234 毫秒
31.
32.
BACKGROUND: Cisplatin-based combination chemotherapy will cure 70% to 80% of patients with metastatic non-seminomatous germ cell tumors but is associated with the possibility of severe neuro-, oto- and nephro-toxicities. Carboplatin, a cisplatin analogue, is an active drug in testicular cancer with a more favourable spectrum of side effects. In a randomized trial, the German Testicular Cancer Study Group compared a combination regimen of carboplatin, etoposide and bleomycin (CEB) to standard cisplatin, etoposide and bleomycin (PEB) chemotherapy for patients with 'minimal-' and moderate-disease' non-seminomatous germ cell tumors, according to the Indiana University classification. PATIENTS AND METHODS: PEB was given for three cycles at standard doses (given days 1-5), and the CEB regimen consisted of carboplatin (target AUC of 5 mg/ml x min) on day 1, etoposide 120 mg/m2 on days 1 to 3 and bleomycin 30 mg on days 1, 8 and 15. Four cycles of CEB were given, with the omission of bleomycin in the fourth cycle. Thus, the cumulative doses of etoposide and bleomycin applied in the two treatment arms were comparable. Fifty-four patients were entered on the trial, 29 were treated with PEB and 25 with CEB chemotherapy. Patients were stratified according to disease extent (minimal versus moderate) and the degree of tumor marker elevation. Thirty-two patients (59%) belonged to the group with minimal disease and low markers. RESULTS: No significant difference in response to chemotherapy was seen between the two arms, with CR rates of 81% for the PEB arm and 76% for CEB treatment. However, more patients treated with CEB (32% versus 13%) have relapsed after therapy, and 4 patients (16%) have died of disease progression after CEP in contrast to 1 (3%) after PEB therapy. The first interim analysis of negative events (relapse, vital tumor at secondary resection, death from disease and therapy-associated death) showed a significantly higher rate after CEB than after PEB therapy, and the trial was terminated early. After a median follow-up of 33 months for all patients, the calculation of negative events is still significantly in favour of PEB-treated patient, particularly since three late relapses > 2 years have been observed in the CEB arm (P = 0.03). CONCLUSION: This randomized trial demonstrates that even with the use of adequate doses of etoposide and full-dose bleomycin, carboplatin cannot altogether replace cisplatin in patients with testicular cancer. Treatment with the PEB regimen remains the standard approach in patients with 'good-risk' non-seminomatous germ cell tumors.  相似文献   
33.
34.
35.
36.
37.
A new on-line texture-analyzing system and its application to nondestructive r value determination is discussed. In addition to providing a brief theoretical background and describing the instrumental set-up, the article presents off-line measurements with this equipment and demonstrates the high accuracy of the determined r-values. A special feature of the unit is the possibility to simultaneously measure the most important r values—r0, r45, r90, and rm.  相似文献   
38.
39.
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