全文获取类型
收费全文 | 355篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
化学工业 | 37篇 |
金属工艺 | 1篇 |
建筑科学 | 9篇 |
能源动力 | 13篇 |
轻工业 | 3篇 |
石油天然气 | 1篇 |
无线电 | 2篇 |
一般工业技术 | 4篇 |
冶金工业 | 290篇 |
自动化技术 | 2篇 |
出版年
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2014年 | 3篇 |
2013年 | 6篇 |
2011年 | 6篇 |
2010年 | 6篇 |
2009年 | 7篇 |
2008年 | 4篇 |
2007年 | 2篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 4篇 |
1998年 | 71篇 |
1997年 | 52篇 |
1996年 | 29篇 |
1995年 | 16篇 |
1994年 | 17篇 |
1993年 | 10篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1985年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 5篇 |
1978年 | 2篇 |
1977年 | 26篇 |
1976年 | 46篇 |
1975年 | 1篇 |
排序方式: 共有362条查询结果,搜索用时 31 毫秒
91.
92.
VN Balin VF Chernysh AM Kovalevski? AK Iordanishvili 《Canadian Metallurgical Quarterly》1996,75(5):45-47
Bioceramics-based materials manufactured in Russia were experimentally and clinically tried with the aim of optimizing repair osteogenesis of the jaws. Powder, granules, and porous blocks of hydroxyapatite alone and mixed with tricalcium phosphate may be effectively used for plastic repair of osseous pouches and post-operative defects of the jaws in surgical treatment of periodontitis, periradicular cysts of the jaws, and for filling the wells after removal of teeth. 相似文献
93.
IM Kakhnovski? VF Marinin SV Arkhipova LA Sorokina GK Makhnach 《Canadian Metallurgical Quarterly》1998,70(9):73-76
AIM: To investigate efficiency of inhacort in long-term (6 months to 2 years) treatment of bronchial asthma (BA). MATERIALS AND METHODS: 67 inpatients and 65 outpatients with moderate BA were divided into two groups. 96 patients of group 1 had received standard combined treatment without glucocorticosteroids (GCS), 36 patients of group 2 had received GCS. Inpatients were given inhacort in a dose 1000 micrograms/day, outpatients took inhacort in a daily dose 500 micrograms/day. The examination scheme included assessment of external respiration function (ERF), blood hydrocortisone, sputum rheology and diagnosis of candidosis. RESULTS: Inhacort treatment has reduced frequency of asphyxia attacks 2.5-fold 30 and 25% of the patients stopped taking sympathomimetics and GCS, respectively. None of the patients had asphyxia as a status. ERF, sputum viscosity improved, hydrocortisone secretion was unchanged. Only 3.8% of the patients developed oral candidosis. CONCLUSION: Inhacort in a dose 1 mg controls BA. 73% of the patients treated outpatiently had no need in hospitalization. 相似文献
94.
Recent investigations suggested that clinical exercise testing can be optimized by individualizing the protocol, depending on the purpose of the test and the subject tested. This requires some knowledge of a patient's exercise capacity before beginning the test. The accuracy of a simple physical activity questionnaire and readily available clinical data in predicting subsequent treadmill performance was examined. A brief, self-administered questionnaire (VSAQ) was developed for veterans who were referred to exercise testing for clinical reasons. The VSAQ was designed to determine which specific daily activities were associated with symptoms of cardiovascular disease (fatigue, chest pain and shortness of breath). Two hundred twelve consecutive patients (mean age 62 +/- 8 years) referred for maximal exercise testing were studied. Clinical and demographic variables were added to VSAQ responses in a stepwise regression model to determine their ability to predict treadmill performance. Only metabolic equivalents by VSAQ, and age were significant predictors of treadmill performance; these 2 variables yielded R = 0.82 (SEE 1.43; p < 0.001), and explained 67% of the variance in exercise capacity. The regression equation reflecting the relation between age, VSAQ and exercise capacity was: achieved metabolic equivalents = 4.7 + 0.97 (VSAQ) - 0.06 (age). Using this equation, a nomogram was developed. Incorporating the VSAQ with the nomogram requires only a few minutes, and yields a reasonably accurate estimate of a patient's exercise capacity. Although the present equation is population-specific, a similar approach in different populations may be useful for individualizing protocols for clinical exercise testing. 相似文献
95.
AIM: To test a New Zealand originated, designed and funded remote infant heart rate monitor in the home and hospital settings (temporarily named the King Monitor) for accuracy and reliability. METHODS: The units were pretested using ECG simulators and on infants already being monitored in the neonatal unit. Longer term trials on hospital infants and infants being simultaneously monitored at home were then conducted. RESULTS: Interference and electrode problems were corrected during the pretesting phase. The unit worked accurately when compared with the standard neonatal heart and respiratory rate monitor in hospital and appeared in some infants to give earlier warning of problems than the standard home apnoea monitor. CONCLUSION: This simple to use monitor worked reliably and accurately under a wide variety of settings and with varying sized infants. In addition, the lack of direct connection between the infant and the control unit allowed freedom of movement of normal infants around the cot or bassinet. The monitor will require to be adapted for portable use at home and during travel. 相似文献
96.
97.
DV Pyshny? IA Pyshnaia SG Lokhov EM Ivanova VF Zarytova 《Canadian Metallurgical Quarterly》1997,23(11):895-902
It was demonstrated that any mismatches in a complex formed by an ssDNA target and a tetranucleotide at 25 or 37 degrees C can be discriminated by alkylating the DNA with a tetranucleotide carrying a 4-[N-methyl-N-(2-chloroethyl)]aminobenzylethylamine residue at the 5'-terminal phosphate in the presence of a pair of flanking effectors, octanucleotide di-N-(2-hydroxyethyl)-phenazinium derivatives. The discrimination factor (ratio of the extent of the target modification in the perfect and mismatch-containing complexes) for a single mismatch in the tetranucleotide binding site at 25 degrees C varied between 4 and 500 depending on the type of mismatch and its location in the complex and exceeded 400 at 37 degrees C for all the investigated mismatches. The DNA target modification by the alkylating derivative of the 3'-estrone ester of tetranucleotide pCAGX (mean = C, T, A or G) was selective in the presence of a pair of hydrophobic effectors, octanucleotide 5'-cholesteryl-3'-phenazinium derivatives. The discrimination factors for 3'-terminal mismatches T.G, A.G, and G.G were 1,8,400, and 400, respectively. 相似文献
98.
AM Nikiforov KM Svetikova NI Chalisova SG Shcherbak IA Ivanov AV Pershin VF Magira 《Canadian Metallurgical Quarterly》1996,110(6):100-105
Biopsies of stomach and duodenum different regions mucosa obtained from patients with gastroduodenitis (liquidators of consequences of accident in Chernobyl nuclear station--LCA CNS-- and control patients) were studied cultured in vitro. The following are the differences found. Mononuclear cells, differentiating into macrophages were exposed from control biopsies. Mononuclear cells exposed from LCA CNS biopsies formed rosette-like accumulations after mitotic dividing on a distance from the explant. Part of cells within the rosettes acquired processes and formed syncytial structure. 相似文献
99.
PURPOSE: To quantify S-antigen-specific (S-Ag) T cells in the retina after adoptive transfer, and to evaluate their role in the initiation and progress of destructive ocular inflammation in experimental autoimmune uveoretinitis (EAU). METHODS: Lewis rats were administered 10 x 10(6) S-Ag-specific T cells from the SP35 cell line or 10 x 10(6) concanavalin A-stimulated syngeneic spleen cell lymphoblasts labeled with lipophilic PKH26 fluorescent dye immediately before intravenous inoculation. Labeled cells in each retina were counted at various times from 4 to 120 hours after cell transfer by fluorescence microscopic analysis of each dissociated retina. Recipient eyes were examined within the same period by light and confocal microscope. RESULTS: SP35 T cells showed a biphasic distribution in the retina. The first peak of 160 cells/retina was noted at 24 hours. A steady decline of labeled cells at 48 and 72 hours was followed by a rapid increase at 96 and 120 hours. Concanavalin A-stimulated, control-labeled cell populations showed an identical peak at 24 hours but a persistent decline thereafter; only two or three T cells were present in each retina at 120 hours. Concurrent inoculation of SP35 cells and nonspecific T cell blasts did not produce more SP35 cells than control cells in the retina at any time. Microscopic analysis showed mononuclear cell infiltration of the iris, ciliary body, and aqueous humor at 48 hours, which intensified rapidly and persisted through 120 hours. Retinal inflammation did not begin until 80 hours. Mononuclear cell adherence to vascular endothelium and perivascular macrophage infiltration of the innermost layers progressed to edema, and profound destructive inflammation and loss of retinal stratification were observed at 120 hours. CONCLUSIONS: There is no evidence of a blood-ocular or blood-retinal barrier to activated T cell blasts. Autologous S-Ag does not provoke a more rapid entry of specific T cells at that site. The data confirm that anterior segment inflammation precedes retinal inflammation, even though S-Ag-specific T cells were present in the retina within a few hours after cell transfer. Because S-Ag is clearly present in the retina, delay in antigen presentation at that site may account for the temporal difference between retinal and anterior segment inflammation. 相似文献
100.
M De W Yan RR de Jonge L Garrigue-Antar VF Vellucci M Reiss 《Canadian Metallurgical Quarterly》1998,58(9):1986-1992
We recently identified missense mutations at amino acid residues 526 and 537 located within the highly conserved subdomain XI of the transforming growth factor beta type II receptor (TbetaR-II) serine-threonine kinase in two human squamous carcinoma cell lines. These cell lines are resistant to transforming growth factor beta-mediated inhibition of growth. Moreover, treatment with transforming growth factor beta fails to increase the levels of type 1 plasminogen activator inhibitor and fibronectin synthesis. To test the effects of the mutations on receptor function, mutant TbetaR-II cDNAs were expressed in TbetaR-II-deficient T47D cells. Cyclin A promoter activity was reduced by 50% in cells expressing wild-type TbetaR-II but increased 2-fold in cells transfected with either of the two mutant receptors. Conversely, plasminogen activator inhibitor type 1 promoter activity was increased 6-fold in cells transfected with wild-type receptor but not with either of the two mutant receptors. Moreover, the activity of both mutant serine-threonine kinases was strongly reduced compared to that of the wild-type receptor. Thus, the amino acid residues at positions 526 and 537 seem to be essential for kinase function and signaling activity of the TbetaR-II. 相似文献