全文获取类型
收费全文 | 5488篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 38篇 |
建筑科学 | 4篇 |
能源动力 | 1篇 |
轻工业 | 2篇 |
无线电 | 10篇 |
一般工业技术 | 14篇 |
冶金工业 | 5401篇 |
原子能技术 | 2篇 |
自动化技术 | 17篇 |
出版年
2022年 | 1篇 |
2020年 | 3篇 |
2019年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 3篇 |
2009年 | 1篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 4篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 158篇 |
1998年 | 1657篇 |
1997年 | 894篇 |
1996年 | 637篇 |
1995年 | 324篇 |
1994年 | 315篇 |
1993年 | 332篇 |
1992年 | 37篇 |
1991年 | 57篇 |
1990年 | 77篇 |
1989年 | 67篇 |
1988年 | 63篇 |
1987年 | 82篇 |
1986年 | 59篇 |
1985年 | 58篇 |
1984年 | 2篇 |
1983年 | 11篇 |
1982年 | 31篇 |
1981年 | 34篇 |
1980年 | 39篇 |
1979年 | 1篇 |
1978年 | 8篇 |
1977年 | 144篇 |
1976年 | 336篇 |
1975年 | 10篇 |
1973年 | 1篇 |
1970年 | 1篇 |
1965年 | 1篇 |
1955年 | 5篇 |
排序方式: 共有5489条查询结果,搜索用时 15 毫秒
11.
SL Kamholz RJ Brewer G Grijalva J Burack MJ Del Rio M Vaynblatt N Lawson S Squinto WL Fodor AJ Norin 《Canadian Metallurgical Quarterly》1997,21(9):951-955
The lack of sufficient suitable human donor lungs for the many patients requiring pulmonary transplantation as life-saving therapy for end-stage lung diseases has generated extensive interest in cross-species lung transplantation. Ethical concerns and those of animal rights advocates have prompted studies of nonprimate species as potential solid organ donors for humans. This paper provides an overview of some of the laboratory studies of cross-species pulmonary transplantation performed over the past 20 years and focuses, in particular, on more recent work (from our laboratory and others) in the area of porcine-to-primate pulmonary xenotransplantation. 相似文献
12.
JN Vauthey RJ Tomczak T Helmberger P Gertsch C Forsmark J Caridi A Reed MR Langham GY Lauwers P Goffette J Lerut 《Canadian Metallurgical Quarterly》1997,113(4):1390-1401
BACKGROUND & AIMS: Arterioportal fistulas (APFs) are rare vascular disorders of the mesenteric circulation. The aim of this study was to determine the etiology, anatomical location, and main symptom at presentation of APFs, and analyze the various modes of treatment. METHODS: The etiology, clinical presentation, radiographs, and treatment of 12 patients with APFs are reported in detail, and another 76 cases published since 1980 are reviewed. RESULTS: APFs result from trauma (n = 25, 28%), iatrogenic procedures (n = 14, 16%), congenital vascular malformations (n = 13, 15%), tumor (n = 13, 15%), aneurysm (n = 12, 14%), and other causes (n = 11, 12%). The origin of APFs is the hepatic artery in the majority of patients (n = 56, 65%). The main symptoms at presentation are lower or upper gastrointestinal bleeding (n = 29, 33%), ascites (n = 23, 26%), heart failure (n = 4.5%), or diarrhea (n = 4.5%). Radiological intervention provides definitive treatment in 42% (n = 33) of patients, whereas the remainder are treated by surgery alone (n = 27, 31%) or a combination of radiological intervention and surgery (n = 8, 9%). CONCLUSIONS: APFs result in a protean syndrome variously combining portal hypertension and other hemodynamic imbalances (heart failure, intestinal ischemia). Single or multiple interventional radiological procedures using arterial and/or venous approaches allow definitive treatment of most APFs. With increasing technological advances, it is anticipated that surgery will only be indicated in rare instances after failure of radiological intervention(s). 相似文献
13.
14.
15.
16.
Wilhelm Conrad Roentgen's discovery of the X-ray one century ago has been ranked in importance with the discovery and development of anesthesia and the discovery of microorganisms and their role in disease. Roentgen's scientific devotion and the persistence of C. Edmund Kells, who took Roentgen's discovery and applied it to dentistry, had a great impact on how dentists practice today. 相似文献
17.
Five percent of children in the United States have asthma. Status asthmaticus is one of the most common conditions for which children seek care in a pediatric emergency department. beta 2-Agonists such as albuterol are the mainstay of emergency therapy for such children. We present a case of a 4-year-old boy who experienced supraventricular tachycardia (SVT) following albuterol therapy. This is believed to be the first report of adenosine being successfully used to treat a child with albuterol-induced SVT. We also briefly review the recognition and management of SVT in children and the pharmacokinetics of and indications for adenosine. 相似文献
18.
RJ Mathewson 《Canadian Metallurgical Quarterly》1993,14(5):656, 658-656, 662
19.
20.