全文获取类型
收费全文 | 2477篇 |
免费 | 2篇 |
专业分类
化学工业 | 8篇 |
金属工艺 | 1篇 |
轻工业 | 4篇 |
石油天然气 | 1篇 |
一般工业技术 | 2篇 |
冶金工业 | 2457篇 |
自动化技术 | 6篇 |
出版年
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 1篇 |
2012年 | 1篇 |
2006年 | 2篇 |
2004年 | 3篇 |
2003年 | 6篇 |
1999年 | 76篇 |
1998年 | 809篇 |
1997年 | 408篇 |
1996年 | 288篇 |
1995年 | 159篇 |
1994年 | 121篇 |
1993年 | 175篇 |
1992年 | 30篇 |
1991年 | 24篇 |
1990年 | 29篇 |
1989年 | 20篇 |
1988年 | 30篇 |
1987年 | 29篇 |
1986年 | 22篇 |
1985年 | 25篇 |
1983年 | 1篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 26篇 |
1978年 | 4篇 |
1977年 | 52篇 |
1976年 | 108篇 |
1974年 | 1篇 |
1955年 | 3篇 |
排序方式: 共有2479条查询结果,搜索用时 15 毫秒
991.
H Prast C Lamberti H Fischer MH Tran A Philippu 《Canadian Metallurgical Quarterly》1996,354(6):731-735
This study applied a social-genetic perspective to examine hypotheses concerning displays of cooperation. The sample included children from 14 monozygotic and 16 dizygotic twin pairs, organized into 30 unfamiliar partnerships. Two puzzle completion sessions were videotaped and evaluated on five dimensions of cooperation. Repeated measures of analysis of variance indicated significantly higher ratings among female than male pairs on Overall Cooperation, Mutuality of Goal and Accommodation. Contrary to expectation, social-interactional differences between unfamiliar MZ and DZ dyads were not detected. Findings are discussed with reference to new research perspectives on cooperative behavior. 相似文献
992.
993.
994.
We report a 15-year-old girl with a 10-year-old history of typical skin features of dermatomyositis (DM) without evidence of muscle involvement. Amyopathic dermatomyositis (ADM) is defined by the presence of biopsy confirmed classic cutaneous findings of dermatomyositis in the absence of any clinical or laboratory signs of muscle disease for at least 2 years after onset of skin pathology. To exclude muscle involvement muscle enzymes should be normal; moreover additional use of magnetic resonance imaging and muscle ultrasound is currently being proposed. It is as yet undetermined, whether early aggressive immunosuppressive treatment of ADM might prevent the development of myositis at a later date or influence the course of the skin disease. In a paediatric patient with ADM we advocate a more expectant attitude with careful and regular monitoring for possible development of muscle disease. 相似文献
995.
996.
STUDY DESIGN: A case of severe postoperative angioedema after excision of cervical osteophyte is presented. Emergent tracheostomy was required. OBJECTIVES: To discuss the etiologies, diagnosis, and management of this unusual cause of acute respiratory distress after an anterior cervical spinous procedure. SUMMARY OF BACKGROUND DATA: To our knowledge, angioedema as a complication of cervical spine surgery has not been reported previously. The patient had no history of angioedema, was not receiving an acetyl choline esterase inhibitor, and had a normal C1-esterase-inhibitor level. METHODS: The patient was a 61-year-old man with ankylosing spondylitis who, because of progressive dysphagia and choking episodes, underwent excision of a large C3-C4 osteophyte and anterior cervical discectomy and fusion. While in the postanesthesia care unit, the patient experienced massive edema of the tongue and neck, with associated difficulty breathing. Reexploration of the wound revealed a small (30 cc) hematoma, which was removed with no obvious benefit to the patient, who ultimately required a tracheotomy. RESULTS: The patient was managed with intravenous corticosteroids. The tracheotomy tube was removed without incident after 7 days. The patient noted decreased neck pain and dramatic improvement in his ability to swallow postoperatively. He has had no further incidents of angioedema, to date. CONCLUSION: Angioedema should be considered in the differential diagnosis in patients with upper extremity respiratory obstruction after anterior surgery of the cervical spine. 相似文献
997.
JW Ramos TK Kojima PE Hughes CA Fenczik MH Ginsberg 《Canadian Metallurgical Quarterly》1998,273(51):33897-33900
Increased integrin ligand binding affinity (activation) is triggered by intracellular signaling events. A Ras-initiated mitogen-activated protein kinase pathway suppresses integrin activation in fibroblasts. We used expression cloning to isolate cDNAs that prevent Ras suppression of integrin activation. Here, we report that PEA-15, a small death effector domain (DED)-containing protein, blocks Ras suppression. PEA-15 does not block the capacity of Ras to activate the ERK mitogen-activated protein kinase pathway. Instead, it inhibits suppression via a pathway blocked by a dominant-negative form of the distinct small GTPase, R-Ras. Heretofore, all known DEDs functioned in the regulation of apoptosis. In contrast, the DED of PEA-15 is essential for its capacity to reverse suppression of integrin activation. Thus, certain DED-containing proteins can regulate integrin activation as opposed to apoptotic protease cascades. 相似文献
998.
The aim of the current study is to detect glycation of betaL-, betaS- and gamma-crystallins in the young bovine lens. To determine which of the crystallins are glycated, we have made isoelectric focusing of the water-soluble crystallins of four bovine lenses of 1. 183+/-0.070 years. Samples are stained: (1) with Coomassie Brilliant Blue for proteins; (2) with the lectin Concanavalin-A, followed by horse-radish peroxidase (HRP) and diaminobenzidine (DAB). Experiments are performed with crystallins in native form, in absence of denaturants. The crystallins are separated by isoelectric focusing into: alpha-crystallins of high-molecular weight (HM)-, alphaL-, betaH-, betaL-, betaS- and gamma-crystallins. In the lectin staining experiments only HM-, beta L-, betaS- and gamma-crystallins are positive, whereas the alphaL- and betaH-crystallins do not stain. Though glycation in the bovine lens is very low, lectin staining is sufficiently sensitive to detect the various glycated crystallins. 相似文献
999.
1000.
The feasibility and efficacy of treating peritoneal cancer implants by applying heat to the peritoneal surfaces were studied in inbred Buffalo A rats given i.p. injections of Morris hepatoma 5123TC tumor cells. Heat was delivered to the peritoneum by contact with a heated physiological salt solution (Normosol-R) in the peritoneal cavity. A treatment temperature of 43.3 +/- 0.3 degrees was maintained for 30 min by an immersed stainless steel coil through which hot liquid circulated. Rats implanted with 0.5 to 1.0 x 10(8) tumor cells were treated at 1 to 4 hr (Group I), 4 to 5 days (Group II), and 22 to 24 days (Group III) after tumor implantation to simulate treatment for the clinical conditions of surgically spilled cancer cells, established microscopic cancer implants, and macroscopic cancer implants, respectively. A statistically significant improvement in survival was observed in Groups I and II compared with sham-treated control animals; 58% of the heat-treated animals were cured. Only a slight but statistically insignificant improvement was noted in Group III. These observations indicate that i.p. surface heat treatment of peritoneal implanted cancer is feasible and effective. 相似文献