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   476篇
  免费   18篇
  国内免费   13篇
电工技术   5篇
综合类   12篇
化学工业   12篇
金属工艺   7篇
机械仪表   10篇
建筑科学   2篇
矿业工程   2篇
能源动力   3篇
轻工业   30篇
水利工程   6篇
石油天然气   6篇
无线电   38篇
一般工业技术   30篇
冶金工业   302篇
原子能技术   18篇
自动化技术   24篇
  2022年   2篇
  2021年   5篇
  2020年   3篇
  2019年   5篇
  2018年   3篇
  2017年   9篇
  2016年   5篇
  2015年   4篇
  2014年   9篇
  2013年   5篇
  2012年   9篇
  2011年   9篇
  2010年   9篇
  2009年   7篇
  2008年   10篇
  2007年   9篇
  2006年   6篇
  2005年   10篇
  2004年   7篇
  2003年   4篇
  2002年   14篇
  2001年   6篇
  2000年   2篇
  1999年   7篇
  1998年   70篇
  1997年   56篇
  1996年   40篇
  1995年   20篇
  1994年   15篇
  1993年   21篇
  1992年   5篇
  1991年   2篇
  1990年   1篇
  1989年   1篇
  1988年   5篇
  1987年   1篇
  1983年   4篇
  1982年   4篇
  1981年   2篇
  1980年   8篇
  1978年   6篇
  1977年   16篇
  1976年   53篇
  1975年   7篇
  1973年   2篇
  1972年   2篇
  1971年   2篇
  1970年   2篇
  1966年   2篇
  1965年   1篇
排序方式: 共有507条查询结果,搜索用时 817 毫秒
451.
452.
The maturity of full-term newborns was studied by immunological, biochemical, and ecogenetic methods. The study yielded basic immunochemical and ecogenetic evidence. It shows that chronic intrauterine hypoxia and unfavourable ecogenetic factors apparently influence concurrently and result in severe fetal immaturity.  相似文献   
453.
454.
The aim of our study was to access the 24-hr ambulatory blood pressure (BP) in diabetic patients with autonomic neuropathy (AN). Twenty-two NIDDM patients without hypertension, being treated with sulfonylureas, were studied. The 24-hr ambulatory blood pressure recordings were performed using portable non-invasive automatic system. Autonomic neuropathy was assessed by standard cardiovascular reflex tests. There were ten patients with and 12 without AN, matched for age, body mass index, duration of diabetes and glycemic control. Mean BP increased at night in four of the subjects with AN and decreased in the remaining 18 patients. The group of subjects with nocturnal increases in BP had more severe autonomic nerve dysfunction compared with those with decreases in nocturnal BP. No significant difference between clinical and ambulatory day-time measurements was found. In three patients with AN after 5 weeks intensified therapy. 24-hr BP did not show any significant difference.  相似文献   
455.
Application of Freund's complete adjuvant containing killed and dried Mycobacterium butyricum led to a two-phase hyperthermic response in white rats, much more obvious in female than in male rats. The difference seems to be due to a more obvious increase of the tumour necrosis alpha-factor, progesterone, and thyrotropic hormone in the blood of female rats, as well as to prevalence of pyretic activity over the pyretic one in them.  相似文献   
456.
Two-directional cava-pulmonary anastomosis was done in 35 patients with a inborn heart failure, ageing from 10 months to 11 years. In 29 patients the significant improvement of their state was noted. The level of arterial blood saturation with an oxygen have rised up to (90.1 +/- 2)% at average. Of 7 patients with the syndrome of right ventriculus hypoplasia one have died, of 27 patients with the single venticular heart-3.  相似文献   
457.
458.
Radiofrequency ablation is successful in most supraventricular tachyarrhythmias and the first results in percutaneous applications in atrial fibrillation have been published. At present, all the surgical techniques for the treatment of atrial fibrillation use extensive atrial incisions. A case report is presented of a 67 year old woman with chronic atrial fibrillation and rheumatic mitral and tricuspid valve disease. At surgery, pulmonary vein isolation was performed using a continuous linear ablation around the pulmonary veins, instead of using extensive atrial incisions. Concommitantly, a mitral valve replacement and tricuspid valve annuloplasty were performed. Five months after surgery, the patient remains with a stable sinus rhythm surgery and in functional class I (NYHA).  相似文献   
459.
460.
Hyperlipoproteinemia occurs commonly in diabetics and may contribute to early atherosclerosis in these patients. The effect of dietary carbohydrate restriction on lipid abnormalities has been examined in 42 newly diagnosed maturity-onset diabetics, in whom plasma lipoproteins were measured before treatment was started and at regular intervals during ten months of dietary therapy. Twenty-four patients (57%) had abnormal lipids when diabetes was first diagnosed. Nine were classed as Type II and 15 as Type IV hyperlipoproteinemia. Plasma lipids reverted to normal in half these patients after dietary treatment for one month. Only 8 diabetics (19%) showed persistent lipid abnormality after ten months' treatment: all had been unable to diet satisfactorily as judged by persisting obesity and hyperglycemia. The common lipoprotein abnormalities of maturity-onset diabetes can usually be returned to normal by the simplest possible carbohydrate-restricted diet, if patients adhere to this. Specialized and complex diets or lipid-lowering drugs are unncessary in the majority of patients.  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