全文获取类型
收费全文 | 836篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 3篇 |
轻工业 | 2篇 |
石油天然气 | 2篇 |
一般工业技术 | 4篇 |
冶金工业 | 826篇 |
自动化技术 | 1篇 |
出版年
2017年 | 1篇 |
2013年 | 1篇 |
2011年 | 1篇 |
2005年 | 1篇 |
2004年 | 1篇 |
2003年 | 1篇 |
1999年 | 20篇 |
1998年 | 234篇 |
1997年 | 143篇 |
1996年 | 98篇 |
1995年 | 47篇 |
1994年 | 33篇 |
1993年 | 44篇 |
1992年 | 4篇 |
1991年 | 10篇 |
1990年 | 3篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 5篇 |
1986年 | 11篇 |
1985年 | 14篇 |
1983年 | 1篇 |
1982年 | 10篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 26篇 |
1976年 | 89篇 |
1955年 | 1篇 |
排序方式: 共有838条查询结果,搜索用时 187 毫秒
831.
832.
LP Krustev TA Tashev AA Popov JZ Apostolov BJ Borov MS Stefanova 《Canadian Metallurgical Quarterly》1976,20(6):597-603
The subjection of rats with body weight 150 +/- 10 g to complete starvation for a period of four days leads to a diminution of total protein, total lipids, blood sugar, body weight and liver weight. Lipid dystrophy develops in the liver, as well as deposition of lipofuscin-like pigment and atrophy. Lipid dystrophy and desposition of pigment increase during the first three days and abruptly decrease during the fourth. Atrophy is a progressive process. The delineation of three phases in the atrophic - dystrophic process is possible with the application of histological, enzyme-histochemical, morphometric, biochemical and electron microscopic methods: Phase I (first 24 hours) - a common adaptive phase. It engages both the liver, which must utilize the increased nutrients from the organism depots and the homeostatic mechanisms of the organism as a whole. Phase II - (second and third 24 hours) - alterative-restorative, manifested markedly at the liver parenchimal level and especially by autophagic lysosome function. Phase III - (fourth 24 hours) - alterative. Exhaustion of adaptive-restorative liver process (and the hepatocyte in particular), and the organism as a whole as well. 相似文献
833.
834.
Tardyferon was administered to 51 patients with iron deficiency anaemia. The drug was very well tolerated and even after administration to fasting patients it was tolerated well by 92% of patients. The iron absorption curve was on the average twice as high after 1 hour and increased up to 3 hours. A significant therapeutic effect with raised haemoglobin level by 10--27% was obtained after 4--6 weeks of treatment in 44 patients (86%). In the remaining cases the improvement was less pronounced. 相似文献
835.
836.
J Riedlberger C Amsler M Doser U Straumann P Tru?l D Bailey S Barlag U Gastaldi R Landua C Sabev KD Duch M Heel H Kalinowsky F Kayser E Klempt B May O Schreiber P Weidenauer M Ziegler W Dahme F Feld-Dahme U Schaefer WR Wodrich S Ahmad JC Bizot B Delcourt J Jeanjean H Nguyen N Prevot EG Auld DA Axen KL Erdman B Howard R Howard BL White M Comyn G Beer GM Marshall LP Robertson M Botlo C Laa H Vonach 《Canadian Metallurgical Quarterly》1989,40(6):2717-2731
837.
The intergeniculate leaflet (IGL), a major constituent of the circadian visual system, is one of 12 retinorecipient nuclei forming a "subcortical visual shell" overlying the diencephalic-mesencephalic border. The present investigation evaluated IGL connections with nuclei of the subcortical visual shell and determined the extent of interconnectivity between these nuclei. Male hamsters received stereotaxic, iontophoretic injections of the retrograde tracer, cholera toxin beta fragment, or the anterograde tracer, Phaseolus vulgaris-leucoagglutin, into nuclei of the pretectum (medial, commissural, posterior, olivary, anterior, nucleus of the optic tract, posterior limitans), into the superior colliculus, or into the visual thalamic nuclei (lateral posterior, dorsal lateral geniculate, intergeniculate leaflet, ventral lateral geniculate). Retrogradely labeled cell bodies identified nuclei with afferents projecting to the site of injection, whereas the presence of anterogradely labeled fibers with terminals revealed brain nuclei targeted by neurons at the site of injection. The IGL projects bilaterally to all nuclei of the visual shell except the lateral posterior and dorsal lateral geniculate nuclei. The IGL also has afferents from the same set of nuclei, except the nucleus of the optic tract. The extensive bilateral efferent projections distinguish IGL from the ventral lateral geniculate nucleus. The superior colliculus, commissural pretectal, olivary pretectal, and posterior pretectal nuclei also project bilaterally to the majority of subcortical visual nuclei. The IGL has a well-established role in circadian rhythm regulation, but there is as yet no known function for it in the larger context of the subcortical visual system, much of which is involved in oculomotor control. 相似文献
838.
This investigation was stimulated by the historical confusion concerning the identity of certain pretectal nuclei and by large differences reported between species with respect to which nuclei receive retinal innervation. Subcortical visual nuclei were studied using immunohistochemistry to identify retinal projections labeled following intraocular injection of cholera toxin, b fragment. In addition, neuropeptide Y (NPY) or enkephalin (ENK) immunoreactive cells and fibers were also evaluated in the retinorecipient pretectal and thalamic areas. The results confirm the established view that the retina directly innervates the nucleus of the optic tract (NOT), posterior (PPT), and olivary pretectal (OPT) nuclei. However, the retina also innervates the hamster medial (MPT) and anterior (APT; dorsal division) pretectal nuclei, results not previously reported in rodents. A commissural pretectal area (CPT) sparsely innervated by retina is also described. The data show for the first time that the posterior limitans nucleus (PLi) receives a moderately dense, direct retinal input. The PLi does not project to the cortex and appears to be a pretectal, rather than thalamic, nucleus. All retinal projections are bilateral, although predominantly contralateral. The PLi contains a moderately dense plexus of NPY- and ENK-IR fibers and terminals. However, peptidergic fibers also traverse the ATP and connect with the dorsomedial pretectium. The OPT contains ENK- and NPY-IR neurons and fibers, but is specifically identifiable by a moderately dense plexus of ENK-IR terminals. Numerous ENK-IR neurons are found in the NOT and PPT. The latter also has moderate numbers of ENK-IR fibers and terminals, but few NPY-IR neurons or fibers. The MPT contains modest numbers of ENK-IR fibers. The APT has no NPY-IR neurons or terminals, but an occasional ENK-IR neuron is seen and there is sparse ENK-IR innervation. Peptidergic innervation of the visual nuclei does not appear to be derived from the retina. The results show a set of retinally innervated, contiguous nuclei extending from the thalamic ventrolateral geniculate nucleus dorsomedially to the midbrain CPT. These nuclei plus the superior colliculus comprise a dorsal "visual shell" embracing a central core of caudal thalamus and rostral midbrain. 相似文献