首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   762篇
  免费   2篇
化学工业   3篇
轻工业   1篇
无线电   5篇
一般工业技术   13篇
冶金工业   741篇
自动化技术   1篇
  2019年   3篇
  2016年   2篇
  2013年   2篇
  2012年   1篇
  2011年   2篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2004年   1篇
  2003年   3篇
  2002年   1篇
  2001年   1篇
  1999年   14篇
  1998年   193篇
  1997年   109篇
  1996年   77篇
  1995年   43篇
  1994年   41篇
  1993年   35篇
  1992年   7篇
  1991年   1篇
  1990年   5篇
  1989年   8篇
  1988年   2篇
  1987年   4篇
  1986年   2篇
  1985年   2篇
  1983年   3篇
  1982年   6篇
  1981年   13篇
  1980年   13篇
  1978年   4篇
  1977年   66篇
  1976年   92篇
  1975年   3篇
  1973年   1篇
  1955年   1篇
排序方式: 共有764条查询结果,搜索用时 0 毫秒
41.
D Parry  A Hextall  VP Robinson  NR Banner  MH Yacoub 《Canadian Metallurgical Quarterly》1996,51(11):1162-4; discussion 1164-5
Successful pregnancy in a single lung transplant recipient has not been reported previously. The long term effect of pregnancy on graft function and management of deteriorating pulmonary function is not defined. This case describes the management, outcome, and problems encountered when a single lung transplant recipient developed a progressive deterioration in pulmonary function during pregnancy, attributed to accelerated obliterative bronchiolitis.  相似文献   
42.
During the past 20 years, biologists have become used to finding that proteins first identified in simple, genetically manipulable eukaryotic organisms are conserved in higher eukaryotes. This article draws attention to the similarity between NUDF protein, which is required for nuclear migration in the filamentous fungus Aspergillus nidulans, and a mammalian homologue, LIS1, whose malfunction causes lissencephaly, a neuronal migration disease. The authors suggest that there might be an underlying similarity of mechanism between nuclear migration in the fungus and neuronal migration in the brain.  相似文献   
43.
Perineural spread of head and neck tumors is a form of metastatic disease in which tumor disseminates to noncontiguous regions along the endoneurium or perineurium. Both computed tomography (CT) and magnetic resonance (MR) imaging can help detect perineural spread, although MR imaging is the modality of choice because of its multiplanar capability, its superior soft-tissue contrast, and the decreased amount of artifact from dental hardware. Perineural spread most commonly occurs in adenoid cystic carcinoma and squamous cell carcinoma. Nerve enlargement may lead to foraminal enlargement and, ultimately, to foraminal destruction, findings that are best seen at CT. Extension through the foramen ovale and involvement of the Meckel cave is best seen on coronal T1-weighted MR images, and nerve enhancement is best seen on fat-suppressed T1-weighted MR images. Other radiologic findings include obliteration of fat planes at foraminal openings, neuropathic atrophy, cavernous sinus enlargement, and replacement of the trigeminal subarachnoid cistern with soft tissue. The pathway of perineural tumor spread is predictable with knowledge of the pertinent cranial nerve anatomy; however, patients with radiologically or pathologically proved perineural spread may have normal nerve function at clinical examination. Therefore, it is imperative that the radiologist be familiar with both normal cranial nerve anatomy and the radiologic appearance and assessment of perineural tumor extension.  相似文献   
44.
The authors studied the permeability of the blood-brain barrier (CEB) to two nootropics: calcium ketogomopantothenate (KRA-Ca), a GABA derivative, and and calcium salt of oxybutyrate (OB-Ca), a derivative of GOBA. It was established that both preparations penetrate the CEB easily and are found in the brain at different intervals after their administration. However, essential differences in the distribution constant of these drugs were disclosed: KPA-Ca permeated the CEB more intensively and was accumulated in larger amounts in the late-term intervals.  相似文献   
45.
46.
While examination of 83 patients it was established that in the presence of complicated gastric and duodenal ulcer disease the secondary immune deficiency is developing, which deepens after the surgical intervention conduction. Tiotriazolin, promoting the immune system state and the blood biochemistry indexes normalization, the immune system state and the blood biochemistry indexes stimulation, hemopoiesis stimulation, the treatment results improvement, was applied for immunomodulation.  相似文献   
47.
As the data collected in a survey we conducted show, a major part of the modern general practitioner's work continues to be in the field of family medicine. This fact is also confirmed by the results of other surveys of general practice today. Patients still appreciate their GPs as a source of good medical care and counseling for the whole family. Our own study has shown that most patients would even like to see an expansion of the GP's counseling activities. The duration of the doctor-family relationship extends over many years, and is frequently longer than a decade.  相似文献   
48.
49.
In neonates and infants, hearing impairment leads to impaired language and cognitive development. For that reason, early detection of this sensory deficit is of outstanding importance, particularly in pre-term neonates, who constitute a high risk population in regard to very early acquired hearing loss. Evoked (EOAE) and spontaneous otoacoustic emission (SOAE) recording in 93 pre-term and full-term neonates revealed that this technique is potentially useful for auditory screening in neonatology units. EOAEs and SOAEs can be recorded successfully from 30 weeks of conceptional age. SOAEs were found to be prevalent in females and presented higher peak numbers in right than in left ears. Furthermore, SOAE incidence in pre-term and full-term neonates was found to be high in EOAE positive ears, associated with strong and robust EOAEs.  相似文献   
50.
The study covered influence of combined toxic chemicals on fire extinguishers. Acute exposure of respiratory and peripheral nervous systems was demonstrated. Consequences of the exposure were proved to include polyneuropathies, neuroses and other health disorders.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号