全文获取类型
收费全文 | 1200篇 |
免费 | 2篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 3篇 |
矿业工程 | 2篇 |
轻工业 | 2篇 |
一般工业技术 | 2篇 |
冶金工业 | 1194篇 |
出版年
2016年 | 1篇 |
2015年 | 1篇 |
2010年 | 1篇 |
2005年 | 1篇 |
2003年 | 2篇 |
1999年 | 28篇 |
1998年 | 320篇 |
1997年 | 219篇 |
1996年 | 154篇 |
1995年 | 104篇 |
1994年 | 60篇 |
1993年 | 73篇 |
1992年 | 6篇 |
1991年 | 22篇 |
1990年 | 7篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 11篇 |
1980年 | 14篇 |
1979年 | 1篇 |
1978年 | 6篇 |
1977年 | 47篇 |
1976年 | 93篇 |
排序方式: 共有1203条查询结果,搜索用时 0 毫秒
991.
The phosphorescence exitation and emission spectra and the phosphorescence lifetimes of polymerized malonic aldehyde, Shiff bases, linoleic acid, phosphatidylcholine, phosphatidylethanolamine, cardiolipine, total lipid fraction from human erythrocyte membranes were measured at 77 K. The nature of chromophores of lipid peroxidation products capable of phosphorescence was discussed. 相似文献
992.
993.
VM Ezrokhin 《Canadian Metallurgical Quarterly》1996,75(6):33-36
Different classes of antibodies to polycyclic aromatic hydrocarbons (PAH) and immunogenicity of carcinoembryonic antigen (CEA) were investigated in breast cancer patients versus course. Prior to treatment, the levels of IgM, IgG and IgA antibodies to PAHs were 5.9, 7.7 and 32.5%, respectively. In cases of tumor regression, they were 13.8, 25.0 and 19.2%, while in those of progression-2.4, 2.8 and 12.8%, respectively. The immunogenicity of CEA, i.e. the power of forming circulating immune complexes, appeared to be higher in cases of tumor regression than in those of progression. CEA concentration in immune complexes exceeding 5ng/ml was observed in 24.0 and 15.1% of cases, respectively, while in whole serum, the concentration in excess of 10 ng/ml was in 8.0 and 42.4%, respectively. 相似文献
994.
995.
VM Savchenko SS Soldatchenko AV Pidaiev OIe Korotkov 《Canadian Metallurgical Quarterly》1998,98(4):154-157
During 1994-1996 at the Clinic of Cardiovascular and Transplantation Surgery of IKEM 17 patients were operated with acute dissection of the thoracic aorta type A. Based on the applied surgical tactics the patients were retrospectively divided into two groups. The first included 8 patients where surgical reconstruction of the ascending aorta was implemented in the standard way, the second group comprised 9 patients where the method of deep hypothermia and circulatory arrest were used. Three operated patients died, all from the group with deep hypothermia. The cause of death was twice multiorgan failure and once haemorrhage in a female patient with cardiac tamponade before surgery. The authors discuss the advantages and some pitfalls of surgery in deep hypothermia and circulatory arrest and maintain that neurological disorders are most serious. In the conclusion they draw attention to some possible ways how to improve hitherto achieved results. They include e.g. reduction of the time interval between the development of symptoms of dissection and surgery, careful checking of the cooling and heating when using deep hypothermia, as well as better prevention of cerebral embolic attacks. 相似文献
996.
YC Zang M Kozovska I Aebischer S Li S Boehme P Crowe VM Rivera JZ Zhang 《Canadian Metallurgical Quarterly》1998,10(7):991-998
T cell responses to myelin basic protein (MBP) are thought to play an important role in the pathogenesis of multiple sclerosis (MS). The response to the 83-99 region of MBP represents a dominant response to MBP in patients with MS and is associated with HLA-DR2 that is linked with susceptibility to MS. Although T cell clones reactive to various regions of MBP have been found to exhibit heterogeneous TCR Vbeta gene usage in patients with MS, it is unclear whether T cell clones uniformly recognizing the 83-99 peptide of MBP in the context of the same DR molecule would have restricted TCR V gene rearrangements and recognition motifs. In this study, a panel of DR2- or DR4-restricted T cell clones specific for the MBP83-99 peptide were derived from 11 patients with MS and examined for TCR V gene usage by PCR and the recognition motifs using analog peptides. Our study revealed that despite a few T cell clone pairs having similar recognition motifs and shared sequence homology in the CDR3, the overall recognition motifs of MBP83-99-specific T cells were considerably diverse. Interestingly, the DR2-restricted T cell clones displayed a biased V gene usage for Valpha3 and Valpha8, while Vbeta gene rearrangements were highly heterogeneous. This study provided experimental evidence suggesting a limited heterogeneity in TCR Valpha gene rearrangements of MBP-reactive T cells in DR2 patients with MS. 相似文献
997.
998.
To evaluate the effect of tympanostomy tube placement upon the hearing function of infants and young children, brainstem auditory evoked potentials (BAEP) were recorded in a group of young children (mean age 22 mos) receiving this treatment for otitis media with effusion (OME). For comparison, a group of healthy infants with normal behavioral audiometry were also tested with BAEP. Hearing loss was estimated for each ear using peak V latency-intensity curves. To evaluate the immediate effect of tube placement, 98 ears in 52 children were tested immediately before and after tube insertion. The 63 ears with effusion had prolonged peak latencies that decreased significantly (P < 0.001) immediately after tube placement and a mean hearing loss estimate of 22 dB that improved significantly (P < 0.0001) to 11 dB immediately after tube insertion. The 35 ears without effusion at myringotomy had a mean hearing loss estimate of 8 dB that did not change significantly after tube insertion. To evaluate the short-term effect of tube presence, 39 ears in 25 children were tested 3 weeks to 18 months after tube insertion. The 28 ears with dry tubes had a mean hearing loss estimate of 3 dB, and the 11 ears with otorrhea had a mean hearing loss estimate of 31 dB. The magnitude of mean hearing loss estimates in these young children with OME and the improvement in hearing function with tube placement is similar to that reported in older children studied with BAEP and audiometry. The study groups with a history of otitis media that had resolved by the time of testing had isolated prolongation of mean III-V interpeak latencies compared to normals (P < 0.01). These studies show that BAEP techniques are useful in estimating hearing loss in children with OME who are difficult to test by behavioral audiometry and show changes in rostral brainstem transmission in very young children with a history of OME. 相似文献
999.
T Lloyd VM Chinchilli N Rollings K Kieselhorst DF Tregea NA Henderson LI Sinoway 《Canadian Metallurgical Quarterly》1998,67(4):624-630
OBJECTIVE: The objective of this study was to determine the outcome of early and late suture removal after the triple procedure (i.e., penetrating keratoplasty, cataract extraction, lens implant). DESIGN AND PARTICIPANTS: The refractive and keratometric results of 106 eyes undergoing the triple procedure were reviewed. The target postoperative refractive error was -1 diopter (D). RESULTS: Average length of follow-up was 40.3 months. Twenty eyes had sutures removed early (<18 months after surgery), 39 had sutures removed late (> or = 18 months after surgery), and 47 had sutures still intact at last follow-up. A best spectacle-corrected visual acuity of 20/40 or better was achieved in 90% of eyes with sutures removed early, 82.1% with sutures removed late, and 70.2% with sutures in place. For all eyes, the mean spherical equivalent at last follow-up was -2.50 D, with 75% of eyes falling between -4 and +2 D. The mean final refractive error was -3.40 +/- 3.53 D for eyes with sutures removed early and -1.79 +/- 3.99 D for eyes with sutures removed late. Eyes with sutures remaining had a mean final refractive error of -0.33 +/- 2.25 D. There was an overall decrease in refractive and keratometric astigmatism after both early and late suture removal with no significant difference between groups. However, there was a wide range of change with some eyes experiencing a decrease and others an increase in astigmatism. Mean postoperative K readings increased significantly for both groups after suture removal (final mean K, 47.00 D) but remained stable for eyes with sutures in. CONCLUSION: The authors data suggest that the final refractive error and net change in refractive and keratometric astigmatism after the triple procedure are not dependent on the timing of suture removal. 相似文献
1000.