全文获取类型
收费全文 | 1105篇 |
免费 | 7篇 |
专业分类
化学工业 | 39篇 |
机械仪表 | 10篇 |
建筑科学 | 8篇 |
能源动力 | 7篇 |
轻工业 | 11篇 |
石油天然气 | 3篇 |
武器工业 | 1篇 |
无线电 | 14篇 |
一般工业技术 | 14篇 |
冶金工业 | 974篇 |
原子能技术 | 1篇 |
自动化技术 | 30篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2019年 | 1篇 |
2017年 | 1篇 |
2016年 | 4篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 10篇 |
2012年 | 5篇 |
2011年 | 6篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 6篇 |
2006年 | 3篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 4篇 |
2002年 | 2篇 |
2001年 | 6篇 |
2000年 | 3篇 |
1999年 | 26篇 |
1998年 | 265篇 |
1997年 | 166篇 |
1996年 | 101篇 |
1995年 | 60篇 |
1994年 | 54篇 |
1993年 | 60篇 |
1992年 | 7篇 |
1991年 | 24篇 |
1990年 | 13篇 |
1989年 | 19篇 |
1988年 | 13篇 |
1987年 | 11篇 |
1986年 | 12篇 |
1985年 | 16篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 12篇 |
1980年 | 15篇 |
1979年 | 4篇 |
1978年 | 8篇 |
1977年 | 29篇 |
1976年 | 87篇 |
1975年 | 5篇 |
1973年 | 2篇 |
1970年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有1112条查询结果,搜索用时 156 毫秒
61.
JC Rutherford WL Taylor M Stowasser RD Gordon 《Canadian Metallurgical Quarterly》1998,22(12):1243-1245
Since February 1996 we have prospectively assessed residual adrenal autonomy by the fludrocortisone suppression test (FST) in 23 patients 3 months after unilateral adrenalectomy for Conn syndrome and in 45 patients after a longer interval. In regard to blood pressure, 36 (53%) patients were cured of hypertension and the remaining 32 (47%) patients had improved hypertension control at the time of their latest postoperative clinical assessment. In regard to the outcome of surgery, patients who achieved normal suppressibility of aldosterone were regarded as cured, and those who had greater suppressibility after surgery were considered improved. Time since surgery for the whole group averaged 26 months. By these biochemical criteria, 42 patients (62%) were cured by surgery, and the rest improved; 16 (76%) of 21 women were cured, and 26 (55%) of 47 men. The women (mean +/- SD age 47 +/- 11 years) were significantly (p < 0.05) younger than the men (52 +/- 9 years). Preoperative aldosterone levels before and after FST were similar in the cured and improved groups and fell significantly (p < 0.01) in both groups following surgery. After surgical reduction of autonomous aldosterone production, mean plasma renin activity levels increased sixfold in the cured group and threefold in the improved group. Surgical mortality in this group of 68 patients with Conn syndrome was zero. 相似文献
62.
Delayed aorto-pulmonary artery fistula represents an uncommon delayed sequelae of penetrating cardiac trauma. A case is presented that demonstrates the need for a high index of suspicion, follow-up, and a complete evaluation of the patient who survives a penetrating heart injury. The mechanisms of delayed presentation, diagnosis, and management of the fistula are discussed. 相似文献
63.
64.
65.
66.
67.
68.
69.
Rholes William S.; Blackwell Janette; Jordan Carol; Walters Connie 《Canadian Metallurgical Quarterly》1980,16(6):616
Examined susceptibility to learned helplessness among 20 children from each of kindergarten, Grade 1, Grade 3, and Grade 5 classes by exposing groups of Ss to either repeated failure or repeated success on hidden figures problems. Helplessness was measured by Ss' persistence in looking for hidden figures and their capacity to find them following repeated success or failure. It was hypothesized that younger Ss would be less susceptible to helplessness than older ones, due to age-related differences in causal attributions for success and failure. Results confirm the hypothesis in that failure, relative to success, had significantly less influence on the level of helplessness in younger Ss' behavior. It is suggested that the development of attributional capabilities during the preschool and early elementary school years has important ramifications for cognitive theories of motivation. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.