全文获取类型
收费全文 | 634篇 |
免费 | 0篇 |
专业分类
化学工业 | 1篇 |
矿业工程 | 1篇 |
轻工业 | 1篇 |
无线电 | 1篇 |
一般工业技术 | 3篇 |
冶金工业 | 626篇 |
自动化技术 | 1篇 |
出版年
2020年 | 1篇 |
2013年 | 2篇 |
2010年 | 1篇 |
2009年 | 2篇 |
2007年 | 2篇 |
2003年 | 2篇 |
1999年 | 18篇 |
1998年 | 169篇 |
1997年 | 107篇 |
1996年 | 68篇 |
1995年 | 50篇 |
1994年 | 27篇 |
1993年 | 36篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1982年 | 6篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1978年 | 1篇 |
1977年 | 21篇 |
1976年 | 62篇 |
1975年 | 3篇 |
排序方式: 共有634条查询结果,搜索用时 0 毫秒
81.
82.
83.
84.
VS Alekseeva TA Karaseva VL Na?din NA Shtamberg 《Canadian Metallurgical Quarterly》1977,77(9):1329-1333
The report contains data concerning occupational and social rehabilitation of 46 patients operated on for aneurysma of the anterior communicative artery. It was established that the occupational prognosis depends upon the severity of the hemmorhage, character of surgical operation. Of significance are the conditions of work, time after the surgical operation. The authors mark that in 2/3 of the operated on patients the working capacity is being restored. A spontaneous restoration of diaturbed functions is slow and is not always sufficient. With this purpose it is expedient to repeat courses of a general tonic and special rehabilitative therapy. A favourable factor in the readaptation of patients is their early engagement in working activities. The authors give their recommendations for medical labour expert testimony for this category of patients. 相似文献
85.
86.
The influence of hepatocyte enlargement on intrahepatic hemodynamics was assessed in the isolated perfused rat liver preparation (IPRL) using two experimental models: hypotonic liver cell swelling and phenobarbitone-induced hepatocyte hypertrophy. The analysis of pressure-flow data obtained from the portal vascular bed over a flow range of 0 to 70 mL/min in the presence of a maximally-effective concentration of the vasodilator agent papaverine hydrochloride (6 x 10(-4) mol/L) enabled the calculation of P0, an estimate of the pressure required to passively distend the intrahepatic vasculature, and Gmax, the maximal portal vascular conductance. By comparison with an isotonic perfusion medium (Krebs-Henseleit buffer [KH] containing 2.5% bovine serum albumin [BSA]), perfusion with a hypotonic medium induced a significant increase in mean hepatocyte cross-sectional area (H(A)) (590 +/- 21 vs. 324 +/- 23 microm(-2), p < .05), a fall in Gmax (0.39 +/- 0.08 vs. 2.02 +/- 0.18 mL/min/g/mm hg, P < .001), and an increase in P0 (2.96 +/- 0.38 vs. 1.58 +/- 0.07 mm hg, P < .001). Phenobarbitone administered in drinking water (0.5 g/L) over a period of 60 days also induced a significant degree of hepatocyte enlargement (HA, 510 +/- 29 microm2, P < .05). On day 7, portal pressure measured in vivo in this group was significantly elevated compared with untreated controls (10.5 +/- 0.3 vs. 8.4 +/- 0.2 mm hg, P < .001), while in the IPRL Gmax was reduced (0.48 +/- 0.01 mL/min/g/mm hg, P < .001), and P0 was increased (2.23 +/- 0.17 mm hg, P < .05). However, with continued phenobarbitone treatment portal pressure, Gmax and P0 returned toward control values. The results confirm that hepatocyte enlargement is associated with a significant disturbance of intrahepatic hemodynamics but also that some adaptation occurs if hepatocyte enlargement is sustained over a prolonged period of time. 相似文献
87.
88.
EA Galati VL Nunes ME Dorval ET Oshiro G Cristaldo MA Espíndola HC da Rocha WB Garcia 《Canadian Metallurgical Quarterly》1996,30(2):115-128
Interleukin-1 beta (IL-1 beta) significantly inhibits insulin secretion from glucose stimulated islet cells. The mechanism for this inhibition has been hypothesized to be due to stimulation of the inducible form of nitric oxide synthase and a resulting increase in nitric oxide (NO) concentration. Ways to block the effect of IL-1 beta have focused on blocking the binding of IL-1 beta to the IL-1 receptor and the use of antioxidants to neutralize increases in NO. This report focuses on a 33 residue peptide synthesized based on the C-terminal region of the IL-1 beta molecule, a reported binding site of the IL-1 beta molecule, and the redoxcycling antioxidant pyrroloquinoline quinone (PQQ). The 33 residue peptide did not function as an antagonist, but as a weak agonist. High concentrations of PQQ itself inhibited glucose-dependent insulin release while low concentrations did not. PQQ had no effect on the actions of IL-1 beta. Three isosteric and isomeric analogues of PQQ were also investigated. One of the PQQ isomers had an inhibitory effect on insulin secretion at low concentrations where PQQ had no effect. These results reflect the sensitivity of islets to oxidative stress. 相似文献
89.
90.
Auditory evoked potentials were recorded from subjects who listened selectively to tone pips arriving over one of three input channels. Their task was to detect occasional target tones of a slightly longer duration. In different runs the three channels were distinguished from one another by (a) pitch cues alone (800, 1,800, and 2,800 Hz), (b) localization cues alone (right ear, midline, ane left ear), and (c) both of these cues conjointly. In all three conditions the direction of attention was reflected in the amplitude of the N1 wave of the evoked potential, which was selectively enhanced to tones in the attended channel; tones in the central channels in the single-cue conditions, however, produced the least N1 lability and were the least discriminable. The N1 wave was interpreted as a sign of an initial stimulus set or filtering mode of selective attention, whereas a subsequent P3 wave was specifically associated with detections of the target stimuli. 相似文献