全文获取类型
收费全文 | 2240篇 |
免费 | 0篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 8篇 |
金属工艺 | 1篇 |
轻工业 | 7篇 |
水利工程 | 1篇 |
无线电 | 3篇 |
一般工业技术 | 7篇 |
冶金工业 | 2207篇 |
原子能技术 | 1篇 |
自动化技术 | 3篇 |
出版年
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2013年 | 3篇 |
2012年 | 4篇 |
2010年 | 2篇 |
2007年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 3篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 74篇 |
1998年 | 708篇 |
1997年 | 432篇 |
1996年 | 249篇 |
1995年 | 130篇 |
1994年 | 98篇 |
1993年 | 125篇 |
1992年 | 18篇 |
1991年 | 17篇 |
1990年 | 16篇 |
1989年 | 23篇 |
1988年 | 33篇 |
1987年 | 17篇 |
1986年 | 15篇 |
1985年 | 10篇 |
1983年 | 2篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 16篇 |
1978年 | 3篇 |
1977年 | 61篇 |
1976年 | 144篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1968年 | 1篇 |
1964年 | 1篇 |
1955年 | 3篇 |
排序方式: 共有2240条查询结果,搜索用时 15 毫秒
141.
142.
143.
The records of 628 patients admitted to the Joint Study of Extracranial Arterial Occlusion with transient symptoms of carotid system ischemic disease were examined to determine the accuracy of predicting disease of the extracranial internal carotid artery on the basis of clinical information alone. A patient with a history of episodes of amaurosis fugax is more likely to have a lesion of the internal carotid artery on the same side than if he were having only transient cerebral ischemic attacks. In patients with transient symptoms and a carotid bruit on the appropriate side, the incidence of an angiographically normal carotid artery was 15%. In those patients with transient symptoms and no palpable pulsation in the cervical region on the appropirate side, the incidence of an angiographically normal carotid artery was zero. 相似文献
144.
145.
Tuberculous lesions were observed at necropsy of 2 East African oryxes (Oryx gazella beisa) at a municipal zoological park in Jackson, Ms. Microscopic examination revealed granulomas containing acid-fast bacilli in the lungs and liver of both animals, as well as in the uterus and mediastinal lymph nodes of 1 animal. Mycobacterium tuberculosis was isolated from the tissues of both oryxes and from fluid aspirated from the mammary gland of 1 oryx; the organism was pathogenic for guinea pigs but not for rabbits. 相似文献
146.
The relatives of 25 index patients with primary parathyroid hyperplasia were tested for hypercalcemia. At least 13 of these patients had one or more first degree relatives with hypercalcemia. Two familial syndromes each with autosomal dominant transmission were recognized. Two index patients were part of large kindreds categorized as having familial hypocalciuric hypercalcemia (FHH). Manifestations of multiple endocrine neoplasia type I were present in the kindreds of at least four other index patients (FMEN I). In seven other kindreds there were too few affected members to allow definitive classification. Differences between manifestations of FHH and FMEN I were described. Among offspring of affected persons in kindreds with FHH, as distinct from FMEN I, the prevalence of hypercalcemia approached the theoretic maximum of 50 per cent during the first two decades. In FHH, nephrolithiasis and peptic disease were unusual; moderate hypercalcemia occurred without hypercalciuria; and subtotal parathyroidectomy did not abolish hypercalcemia. Concentrations of peptide hormones other than parathyroid hormone (PTH) were normal in those with FHH; in FMEN I high concentrations of glucagon in plasma were found in five of six patients tested, and high concentrations of gastrin were found in three of 12 patients. Hypergastrinemia generally accompanied obvious peptic disease. Distinction of the two conditions is important since patients with FHH may not benefit from subtotal parathyroidectomy, but they generally have a better clinical prognosis than do patients with FMEN I. 相似文献
147.
JT Willerson RW Parkey EM Stokely FJ Bonte S Lewis RA Harris G Blomqvist LR Poliner LM Buja 《Canadian Metallurgical Quarterly》1977,11(4):291-298
The dynamics of changes in serum lipids (free fatty acids, free glycerol, triglycerides, total cholesterol, and phospholipids) were studied in male Wistar rats irradiated in an open experimental field with a daily dose of 15.48 mC.kg.--1 (60 R) up to a total exposure of 774.0 mC. kg.--1 (3,000 R). The resulting changes occurred in several periods. Initial period of 0--7 days included a drop in triglyceride level and a rise in free glycerol, total cholesterol, and phospholipids in both control and irradiated rats. The period of 14--25 days marked the appearance of serum hyperlipaemia. Between 25--50 days, the levels of the different fractions oscillated and existing changes became more pronounced. The general level of serum lipids during continuous gamma-irradiation exceeded that found in controls. Changes in control animals from experimental field reflected the influence of a changed environment. The modifying factor affecting both irradiated and control rats was night fasting prior to sacrificing the animals and, probably, also the presence of an infradian rhythm in some serum lipid fractions. 相似文献
148.
149.
The work describes results of the application of a new highly effective hemostatic drug--Caprofer. The investigations were performed in 61 rabbits who were given graded injuries of the liver, kidney and spleen. In all the cases hemostasis made its appearance quickly within 1-20 sec. after the application of Caprofer. Reliability of hemostasis was checked by the method of hydropressure of the organs under study which was shown to be very high. Caprofer was used under clinical conditions in 61 patients in operations for traumas and diseases of the liver, kidney, spleen, gallbladder and in resection of the prostate. The results obtained speak of high efficiency of Caprofer for parenchymatous bleedings. Pronounced adhesive properties of the drug were noted as well as the absence of undesirable side effects. 相似文献
150.
EM Wall 《Canadian Metallurgical Quarterly》1993,48(6):1026, 1031-1026, 1032