全文获取类型
收费全文 | 1896篇 |
免费 | 3篇 |
专业分类
电工技术 | 1篇 |
综合类 | 2篇 |
化学工业 | 7篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 2篇 |
能源动力 | 3篇 |
轻工业 | 4篇 |
无线电 | 7篇 |
一般工业技术 | 30篇 |
冶金工业 | 1833篇 |
自动化技术 | 6篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2010年 | 1篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2007年 | 4篇 |
2005年 | 3篇 |
2003年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 56篇 |
1998年 | 538篇 |
1997年 | 294篇 |
1996年 | 224篇 |
1995年 | 112篇 |
1994年 | 90篇 |
1993年 | 123篇 |
1992年 | 20篇 |
1991年 | 24篇 |
1990年 | 18篇 |
1989年 | 35篇 |
1988年 | 22篇 |
1987年 | 27篇 |
1986年 | 17篇 |
1985年 | 19篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 15篇 |
1981年 | 14篇 |
1980年 | 17篇 |
1978年 | 4篇 |
1977年 | 60篇 |
1976年 | 124篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1967年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1899条查询结果,搜索用时 31 毫秒
1.
Computer modeling of the neuron network offered in [1] is discussed. Organization and feature of modeling are described, as well as the changes, which are introduced in the network during researches. Results of modeling are present. 相似文献
2.
JB Hale JA Hoeppner MB DeWitt DL Coury DG Ritacco B Trommer 《Canadian Metallurgical Quarterly》1998,31(6):595-607
We introduce a novel application for linkage analysis: using bone marrow donor-recipient sib pairs to search for genes influential in graft-versus-host disease (GVHD), a major cause of morbidity and mortality following allogeneic bone marrow transplantation. In particular, we show that transplant sib pairs in which the recipient developed severe GVHD can be used to map genes in the same way as traditional discordant (affected/unaffected) sib pairs (DSPs). For a plausible GVHD model, we demonstrate that the transplant/discordant sib pair analog of the "possible triangle test" [Holmans (1993) Am J Hum Genet 52:362-374] has similar power to that of the simpler "restricted test" proposed by Risch [(1990b) Am J Hum Genet 46:229-241; (1992) Am J Hum Genet 51:673-675]. Moreover, we show that the restricted test has superior power in much of the DSP possible triangle and significantly inferior power in only a small region. Thus, we conclude that the restricted test is preferable for localizing genes with transplant/discordant sib pairs. Finally, we examine the effects of heterogeneity on the power to detect GVHD loci and demonstrate the gain in efficiency by dividing the sample into genetically more homogeneous subgroups. 相似文献
3.
Possibilities of involution of changes in lesser circulation after closure of experimental aortopulmonary anastomosis were studied. 37 observations at various intervals after closure of anastomosis (several minutes to 13.5 months) in 25 dogs were analyzed. Before closure the anastomosis had functioned for 1-7 months. The results of histological examinations of lungs, pressure measurements in lesser circulation, heart weight, electrocardiographic and spirographic examinations were analyzed. It was found that complete involution of changes in lesser circulation was possible only in first month of existence of anastomosis, in this case with changes of both "early" and "late" types. "Late"-type changes after four months function of anastomosis had both reversible and irreversible character, whereas "early"-type changes became irreversible already after three-month duration of anastomosis. With the "late"-type changes, the operation itself (closure of anastomosis) was accompanied by symptoms of pulmonary vasomotor paresis and heart failure, whereas in the presence of "early"-type changes the operation elicited no morphological or functional changes. 相似文献
4.
Bypass surgery for vascular disease of the carotid system 总被引:2,自引:0,他引:2
TM Sundt RG Siekert DG Piepgras FW Sharbrough OW Houser 《Canadian Metallurgical Quarterly》1976,51(11):677-692
A series of 58 operations on 56 patients, in whom a branch of the superficial temporal artery was anastomosed to a branch of the middle cerebral artery (STA-MCA bypass or Yasargil procedure), is reviewed. These operations were performed chiefly for occlussions or for inaccessible stenotic lesions of the internal carotid or middle cerebral arteries. Patency in eight patients operated on from April 1971 through November 1973 was low (25%). Patency in patients operated on since July 1974 has been high (95%). There have been no deaths and no major ischemic strokes attributable to the surgery. The rationale for this procedure is considered in relationship to the anatomy and physiology of the cerebral circulation and the pathogenesis of syndromes of cerebral ischemia. The operation appears to have a low morbidity in good-risk patients. The role of this operation in managing common manifestations of cerebral vascular disease such as focal transient cerebral ischemic attacks (TIAs) and amaurosis fugax, although not fully established, appears encouraging. The procedure seems useful for orthostatic cerebral ischemia caused by multiple occlusions of major extracranial (and intracranial) vessels and, occasionally, for progressing strokes related to internal carotid artery occlusion, both of which are relatively uncommon manifestations of cerebral vascular occlusive disease. It may have application in the rare "slow stroke." The procedure is probably of limited value, if any, in the management of large completed infarcts but may be indicated in selected patients with small infarctions who have preserved most of their cerebral function and who have had evidence of subsequent focal ischemic events. The procedure is useful for bypassing giant aneurysms or basofrontal tumors invading major vessels. It may have a role in the management of fibromuscular disease of the internal carotid artery. 相似文献
5.
DG Pappas 《Canadian Metallurgical Quarterly》1976,82(1):ORL100-ORL101
6.
A commercially available recording of Northwestern University Auditory Test No. 6 (N.U. No. 6) produced by Auditec of St. Louis was evaluated in a series of four studies. Interlist equivalence of this version was initially investigated, and then normative intelligibility functions were developed using listerners with normal hearing. Intelligibility functions for the original version of N.U. No. 6. prepared by Northwestern University, were then derived, concurrently with functions of the Auditec version, using (1) a group of listeners with normal hearing; and (2) a group with sensorineural hearing loss. The results demonstrated good interlist equivalence for the Auditec version of N.U. No. 6. The comparative intelligibility functions for the Auditec and Northwestern versions of N.U. No 6 furthermore indicated a difference between the two recordings, but it was concluded that for clinical purposes the two versions may be considered equivalent. 相似文献
7.
DG Lambie JW Paxon RN Nanda RH Johnson JG Ratcliffee ID Melville GD Morrice 《Canadian Metallurgical Quarterly》1976,21(2):93-94
Using Wistar stain male rats, it has been shown that 2 atmospheric pressures associated with oxygen saturation, together or singly for 90 minutes daily for successive 46 days, resulted in no significant change on the ratio of testes to body weight. No significant change was observed in the incorporation of 3H-thymidine into testes and pituitary glands between the pressure-treated groups and the control group. 相似文献
8.
Medullary carcinoma is an unusual malignant neoplasm. The cell of origin is considered to be the C-cell which is derived from the ultimobranchial body and neural crest. The tumor is solid and has characteristic amyloid in the stroma. The lesion usually presents as a neck mass, and multicentricity is not unusual. In some patients diarrhea may be an important presenting symptom. Serum calcitonin is typically elevated and is important in the diagnostic confirmation. About 10 percent of the cases are part of a familial endocrine syndrome which includes pheochromocytomas, mucosal neuromas, and other endocrine gland adenomas. Frequent multicentricity and early cervical lymphatic and systemic metastases necessitate total thyroidectomy and radical neck dissection. Prognosis varies from a rapid demise to long term survival. 相似文献
9.
Twenty-four patients hospitalized for overdose of a tricyclic antidepressant were monitored clinically, and serial plasma-drug measurements were taken for up to 144 hours. Six of 24 patients had maximum antidepressant plasma levels greater than or equal to 1,000 ng/ml, and their plasma levels at 96 hours ranged from 170 to 1,280 ng/ml. Patients ingesting substantial tricyclic overdoses may remain medically unstable for days. When high tricyclic levels persist, accurate psychiatric assessment is often impossible. 相似文献
10.
DG Skinner JB Dekernion PA Brower KP Ramming YH Pilch 《Canadian Metallurgical Quarterly》1976,115(3):246-250
Herein we describe the first clinical treatment of renal cell carcinoma in humans with xenogeneic immune ribonucleic acid. Twelve patients with advanced renal cell carcinoma have been treated by appropriate operations to remove tumor bulk followed by specific passive immunotherapy. Xenogeneic specific immune ribonucleic acid was prepared from the spleen of normal sheep that had received 4 weekly injections of a homogenate of renal cell carcinoma. Results indicate that 1) xenogeneic specific immune ribonucleic acid can safely be given to humans without local or systemic toxicity, 2) there is a suggestion of clinical benefit, since only 2 patients have had progression of known metastases during treatment with immune ribonucleic acid and 3) xenogeneic immune ribonucleic acid can enhance the immune response to renal cell carcinoma, as demonstrated by in vitro lymphocytoxicity tests. 相似文献