全文获取类型
收费全文 | 1802篇 |
免费 | 1篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 15篇 |
金属工艺 | 1篇 |
机械仪表 | 3篇 |
建筑科学 | 2篇 |
能源动力 | 3篇 |
轻工业 | 6篇 |
石油天然气 | 1篇 |
无线电 | 6篇 |
一般工业技术 | 17篇 |
冶金工业 | 1742篇 |
自动化技术 | 4篇 |
出版年
2020年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 2篇 |
2008年 | 3篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 1篇 |
1999年 | 48篇 |
1998年 | 501篇 |
1997年 | 283篇 |
1996年 | 195篇 |
1995年 | 94篇 |
1994年 | 91篇 |
1993年 | 111篇 |
1992年 | 21篇 |
1991年 | 28篇 |
1990年 | 27篇 |
1989年 | 26篇 |
1988年 | 39篇 |
1987年 | 36篇 |
1986年 | 26篇 |
1985年 | 25篇 |
1984年 | 2篇 |
1983年 | 6篇 |
1982年 | 14篇 |
1981年 | 11篇 |
1980年 | 12篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 51篇 |
1976年 | 107篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 4篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1966年 | 1篇 |
1959年 | 1篇 |
1956年 | 3篇 |
1955年 | 1篇 |
排序方式: 共有1803条查询结果,搜索用时 15 毫秒
41.
GS Panayi 《Canadian Metallurgical Quarterly》1997,9(3):236-240
In rats carbaryl undergoes extensive biotransformation involving both albumin-mediated hydrolysis and cytochrome P-450-mediated metabolism; studies have suggested that approximately one-half of a carbaryl dose is hydrolysed and one-half is metabolized. Fluosol is known to be an inducer of cytochrome P-450, and Fluosol haemodilution reduces plasma albumin concentrations. The disposition of carbaryl was, therefore, determined in rats for 72 h after 40 mL kg-1 haemodilution with Fluosol or normal saline (0.9% NaCl). Volumes of distribution were significantly reduced after saline haemodilution for 72 h but only at 48 h after Fluosol haemodilution. Fluosol and saline haemodilution had little influence on carbaryl total body clearance (CL). These results indicate that both hepatic and non-hepatic clearance pathways were not influenced by the haemodiluents or the haemodilution procedure. 相似文献
42.
43.
Dr GS Yakubu 《Renewable Energy》1996,8(1-4)
This paper presents a study of a user-experience survey about living in passive solar homes. It was carried out at the Energy Park located in the western part of Milton Keynes. The survey focuses on the reality of living in passive solar homes as perceived or experienced by the occupant. It is hoped that the findings would come to bear on strategic passive solar design decisions that would address the improvement of the well-being of the occupant.. The survey is aimed at assessing user satisfaction with the overall performance of their homes as well as a study of some of the problems that are believed to be common in passive solar housing.Results from the survey seem to indicate that the majority of those who buy passive solar homes are motivated to do so by a desire for thermal comfort at low cost. The building aesthetics is the second most important factor, showing that passive solar home lovers are also conscious of the quality of the architectural design. The overall performance of passive solar homes in this study, with regard to thermal and visual comfort, seems to be generally satisfactory. Statistical analysis showed some significant association between some important environmental design parameters. 相似文献
44.
JD Belcher RC Ellison WE Shepard C Bigelow LS Webber JH Wilmore GS Parcel DM Zucker RV Luepker 《Canadian Metallurgical Quarterly》1993,22(2):143-153
Male and female isometric strength curves for elbow fixation, shoulder flexion, and wrist supination-pronation are obtained during systematic variation in arm configuration. The shape of a given moment-angle curve is found to be a function of the orientations of joints kinematically coupled to the primary joint. It is also found that female elbow strength curves are shifted toward flexion with respect to male elbow-strength curves, suggesting that the in situ rest length of upper-limb muscles relative to joint angle may be longer for males than for females. Experimental results were contrasted with simulation results obtained using a three-dimensional musculoskeletal model which estimates the relationships between initial joint orientations, muscle tension-length behavior, and joint moments. In most of the cases, simulation results complimented experimental data and provided insights into likely in situ muscle rest lengths and moments arms, especially for the multiarticular biceps brachii muscle. Where inconsistencies exist between simulated and experimental data, subtle biomechanical complexities within the forearm and the shoulder girdle complex are identified that require future investigation. 相似文献
45.
S Bielamowicz J Kreiman BR Gerratt MS Dauer GS Berke 《Canadian Metallurgical Quarterly》1996,39(1):126-134
Dysphonic voices are often analyzed using automated voice analysis software. However, the reliability of acoustic measures obtained from these programs remains unknown, particularly when they are applied to pathological voices. This study compared perturbation measures from CSpeech, Computerized Speech Laboratory, SoundScope, and a hand marking voice analysis system. Sustained vowels from 29 male and 21 female speakers with mild to severe dysphonia were digitized, and fundamental frequency (F0), jitter, shimmer, and harmonics- or signal-to-noise ratios were computed. Commercially available acoustical analysis programs agreed well, but not perfectly, in their measures of F0. Measures of perturbation in the various analysis packages use different algorithms, provide results in different units, and often yield values for voices that violate the assumption of quasi-periodicity. As a result, poor rank order correlations between programs using similar measures of perturbation were noted. Because measures of aperiodicity apparently cannot be reliably applied to voices that are even mildly aperiodic, we question their utility in quantifying vocal quality, especially in pathological voices. 相似文献
46.
47.
GS Bhudhikanok J Lim R Marcus A Harkins RB Moss LK Bachrach 《Canadian Metallurgical Quarterly》1996,97(1):103-111
The responses to heat shock in Tritrichomonas mobilensis, a squirrel monkey parasite and Tritrichomonas augusta, an amphibian trichomonad, were evaluated by means of metabolic labeling with [35S]methionine. Electrophoretically separated trichomonad proteins synthesized at different temperatures were visualized by autoradiography and the label incorporation quantitated by a trichloroacetic acid precipitation procedure. A considerable difference in thermotolerance between the two species was found as the protein synthesis reached a maximum at 41 C in T. mobilensis and 37 C in T. augusta. The latter tolerated temperature increases 13 C above normal cultivation temperatures as compared to only 4 C thermotolerance range above normal in T. mobilensis. Major heat shock proteins (Hsps) were expressed in both T. mobilensis (with apparent Mr 94, 72, and 58 kDa) and T. augusta (Mr 94, 70, and 56 kDa) as revealed by autoradiography. Western blot analysis with polyclonal antibody against DnaK of Escherichia coli showed the presence of antigenic Hsp70 homologs in both trichomonads. Similarly, a polyclonal antibody against Hsp60 with broad interspecies cross-reactivity detected Hsp60 homologs in both T. mobilensis and T. augusta. The anti-DnaK antibody cross-reacted with a T. mobilensis protein localized in Golgi apparatus as demonstrated by immunoelectron microscopy. Immunocytochemistry on trichomonad frozen sections revealed the presence of the Hsp60 homolog in light-microscopic granules corresponding to hydrogenosomes. 相似文献
48.
49.
50.
RJ O''Hara J Greenman PJ Drew AW McDonald GS Duthie PW Lee JR Monson 《Canadian Metallurgical Quarterly》1998,41(4):460-463
OBJECTIVE: Spontaneous spinal epidural hematoma (SSEH) is an idiopathic accumulation of blood in the vertebral epidural space without identifiable predisposing factors. First reported in 1869, the clinical outcome in children younger than 18 years old has not been clearly delineated. DESIGN: A comprehensive review of the English language literature revealed 26 patients younger than 18 years old with reported clinical outcomes. The 27th case is presented. RESULTS: Complete neurologic recovery occurred in 14 of 27 (52%) patients, partial recovery in 12 of 27 (44%) patients, and death in 1 of 27 (4%) patients. CONCLUSION: There is an overall good prognosis for neurologic recovery in children who experience SSEH. 相似文献