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   2236篇
  免费   2篇
化学工业   26篇
金属工艺   3篇
机械仪表   2篇
建筑科学   3篇
能源动力   1篇
轻工业   17篇
水利工程   1篇
无线电   8篇
一般工业技术   8篇
冶金工业   2158篇
原子能技术   4篇
自动化技术   7篇
  2023年   1篇
  2018年   2篇
  2016年   1篇
  2015年   1篇
  2013年   9篇
  2012年   2篇
  2011年   1篇
  2010年   2篇
  2009年   2篇
  2008年   2篇
  2007年   5篇
  2006年   1篇
  2005年   3篇
  2004年   1篇
  2003年   8篇
  2002年   1篇
  2001年   3篇
  2000年   1篇
  1999年   65篇
  1998年   693篇
  1997年   381篇
  1996年   253篇
  1995年   149篇
  1994年   119篇
  1993年   136篇
  1992年   17篇
  1991年   22篇
  1990年   23篇
  1989年   28篇
  1988年   35篇
  1987年   30篇
  1986年   13篇
  1985年   19篇
  1984年   4篇
  1983年   7篇
  1982年   11篇
  1981年   11篇
  1980年   17篇
  1979年   2篇
  1978年   6篇
  1977年   39篇
  1976年   98篇
  1975年   5篇
  1974年   2篇
  1973年   1篇
  1971年   1篇
  1970年   2篇
  1967年   1篇
  1955年   2篇
排序方式: 共有2238条查询结果,搜索用时 0 毫秒
51.
OBJECTIVE: The authors present their experience with patients having undergone orthotopic heart transplantation (OHT) in whom surgical conditions subsequently developed that required operative intervention. The incidence, morbidity, and mortality of these procedures are reported. SUMMARY BACKGROUND DATA: Several studies have evaluated the management options of biliary tract disease after OHT. Multiple reports of patients having undergone OHT who subsequently underwent peripheral vascular reconstructions, plastic reconstructive, and thoracic procedures also have been published. METHODS: A chart review of 349 patients who underwent OHT between 1985 and 1996 was conducted to identify surgical procedures that were required in the post-transplant period. Their outcomes are reported. RESULTS: Of 349 patients who underwent OHT, conditions requiring 94 surgical procedures developed in 54 patients (15%). Biliary tract disease developed in 17 patients (5%) who required cholecystectomy, 2 of the 5 patients with acute cholecystitis died. Eight patients (2%) underwent orthopedic procedures with no operative mortality. Flap advancements for sternal wound infections were performed in five patients and four deaths occurred. Seventeen thoracic procedures were performed in 11 patients with an overall mortality of 45%. Twenty-one vascular procedures were performed on 17 patients with 1 delayed death due to a malignancy. Seven patients underwent procedures of the colon and rectum with no mortality. Seven patients underwent repair of inguinal or incisional hernias with no mortality. Various infections occurred with one resultant death after operative intervention. Six procedures were performed for diseases of the small intestine with no resultant mortalities. CONCLUSIONS: Patients having undergone OHT and chronic immunosuppression are at increased risk of having complications develop from infection. Acute cholecystitis and sternal wound infection caused an inordinate risk of complications and death. Malignancies developed in four patients who required surgical intervention. A heightened awareness of coexisting peripheral vascular disease in patients transplanted for ischemic cardiomyopathy should exist. Close screening before surgery and surveillance after surgery to identify risk factors for infection and vascular disease and to screen for malignancies are essential.  相似文献   
52.
The analysis of health state of drivers sent for an extra health examination for the estimation of driving capability for the driving of motor vehicle in alcoholic state was presented. The study included 380 drivers who were found driving drunk by traffic police (studied group) and 180 drivers of control group sent for an extra health examination for some other reason. The disorders in psychomotor sphere were noticed in the drivers of studied group and it was determined that they had caused significantly larger number of traffic accidents in last five-year period compared to the drivers of control group. The alcohol consumption in driving population represents significant medical, social, economic and traffic problem. The control of driver's alcoholism, the sending of alcoholic drivers to an extra health examination for the repeated estimation of driving capability and including in therapeutic and health-educational program can present significant measure of the primary prevention of road traffic traumatism which is on the constant increase.  相似文献   
53.
54.
55.
56.
57.
58.
59.
60.
Fuller's Earth, a dioctahedral calcium montmorillonite clay mineral of the smectite group, undergoes thermal transformation via a series of complex intermediate states that are highly structurally disordered. Fuller's Earth is a commercially significant material with considerable levels of paramagnetic iron (Fe3+) substitution into octahedrally coordinated metal sites. Despite the high iron-content (approximately 10% of the occupied octahedral metal sites) in these samples 29Si and 27Al magic angle spinning (MAS) NMR spectra of sufficient quality are obtained to reveal structural changes in samples that have been heated from room temperature to 1400 degrees C. Two major structural changes are clearly observed, initial dehydroxylation and then collapse of the layer structure into more highly connected silica-rich domains and an alumina-rich phase.  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