全文获取类型
收费全文 | 822篇 |
免费 | 3篇 |
专业分类
化学工业 | 2篇 |
轻工业 | 4篇 |
无线电 | 4篇 |
一般工业技术 | 4篇 |
冶金工业 | 801篇 |
自动化技术 | 10篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2018年 | 2篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 1篇 |
2011年 | 2篇 |
2009年 | 2篇 |
2008年 | 1篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 4篇 |
2001年 | 1篇 |
1999年 | 30篇 |
1998年 | 243篇 |
1997年 | 138篇 |
1996年 | 94篇 |
1995年 | 56篇 |
1994年 | 36篇 |
1993年 | 42篇 |
1992年 | 6篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 10篇 |
1988年 | 12篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 2篇 |
1981年 | 7篇 |
1980年 | 11篇 |
1977年 | 20篇 |
1976年 | 52篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有825条查询结果,搜索用时 46 毫秒
41.
A test battery related to ergonomics of protective clothing 总被引:2,自引:0,他引:2
Specialised protective clothing, such as that worn by firefighters, is usually tested only to standards which give requirements for the materials used (e.g. EN469). However, this testing often neglects the effect the manufacturing process of the garment has on the material properties, the effects of clothing design, sizing and fit, as well as the interaction of the clothing with other components of the standard gear for the profession. Such effects can only be tested by looking at the protective gear as a whole. This paper deals with methods to do additional testing on protective garments with firefighter clothing as example. In other words, methods which go beyond EN469. Human subject tests for physiological load, heat protection, ergonomic design, loss of performance, rain/moisture protection and conspicuity/visibility of the clothing are described and proposed for evaluation of protective clothing in general and for further development of standards on firefighters' clothing. 相似文献
42.
The effects of environmental and individual factors on thermal sensation in air-conditioned office environments were analysed for two large, fully compatible thermal comfort field studies in contrasting Australian climates. In the hot - humid location of Townsville, 836 office workers were surveyed; 935 workers participated in hot - arid Kalgoorlie-Boulder. Overall perceived work area temperature and measured indoor operative temperature correlated moderately with thermal sensation for Townsville (T) subjects but only perceived temperature correlated with Kalgoorlie-Boulder (KB) sensation. Multiple regression analyses confirmed that indoor climatic variables (including Predicted Mean Vote) contributed to actual thermal sensation vote (24% T; 15% KB), with operative temperature having more of an effect in T than in KB. Subsequent analyses of individual characteristics showed no linear contributions to thermal sensation. The remaining variances were significantly related to perceived work area temperature (7% additional explained variance in T; 12% in KB). Mann - Whitney analyses (after correction for climatic variables) showed that T subjects with higher job satisfaction had thermal sensations closer to 'neutral'. Males, healthier subjects, non-smokers, respondents with earlier survey times and underweight occupants had lower median thermal sensations in KB. Townsville occupants appeared more adapted to their outdoor climatic conditions than Kalgoorlie-Boulder respondents, perhaps due to limited home air-conditioning. Further research into non-thermal impacts on gender-related thermal acceptability is suggested. 相似文献
43.
44.
45.
46.
TJ Whelan EA Mohide AR Willan A Arnold M Tew S Sellick A Gafni MN Levine 《Canadian Metallurgical Quarterly》1997,80(8):1518-1524
BACKGROUND: The objective of this study was to examine the physical and emotional health status, self-perceived problems, and needs of newly diagnosed cancer patients to determine and plan supportive care strategies. METHODS: A cross-sectional survey of newly diagnosed cancer patients attending a regional cancer center during a 6-month period was performed. Patients with breast, colorectal, head and neck, lung, and prostate carcinoma as well as nonmelanoma of the skin were selected randomly. Patients were interviewed prior to their first appointment at the clinic. Physical health status was assessed using the Symptom Distress Scale, psychologic health status was assessed with the General Health Questionnaire (GHQ), day-to-day functioning with the Rapid Disability Scale, and social support with the modified Sarason's Social Support Scale. Perceived needs were assessed in a number of ways, including identification of patients' specific social concerns and informational needs, and by asking them to list their current problems or concerns. RESULTS: Of 156 eligible patients, 134 completed the interview. One hundred and twenty-nine patients (96%) reported current symptoms that included fatigue (66%), worried outlook (61%), difficulty sleeping (48%), and pain (42%). Forty-four patients (33%) were identified as psychologically distressed with a GHQ score of > or = 6. One hundred and fourteen patients (85%) had informational needs, 89 (66%) indicated > or = 1 social concerns, and 55 (41%) reported a need for assistance with day-to-day living. CONCLUSIONS: Patients with newly diagnosed cancer commonly report symptoms related to fatigue, pain, and psychologic distress. Other frequently reported issues relate to the need for information and social concerns regarding the patients' ability to take care of their home and maintain family and other relationships. Awareness of these issues is important for planning supportive care interventions for newly diagnosed cancer patients. 相似文献
47.
48.
Three leading and competitive commercial products of paracetamol tablets coded as brands A, B and C (A, being the innovator product) in the country were evaluated for their in vitro properties and in vivo comparative bioavailability. The studies included chemical equivalence, hardness, disintegration time, dissolution rate and systemic availability among eight healthy volunteers. The disintegration times were 2.1 min for brand A, 5.7 min for brand B and 36.2 min for brand C. The dissolution rate (T70) were 33.0 min, 74.5 min and 56.5 min for brands A, B and C, respectively. While brand A passed all the in vitro tests as specified in the official monograph, brand B failed only the dissolution rate test and brand C failed both the disintegration and dissolution tests. These significant differences observed among the products after in vitro tests were not reflected in the in vivo availability. While the absorption rate (indicated by tmax) of brand C was significantly faster (i.e. shorter) than those of Brands A and B, the extent of absorption (indicated by AUC) was comparable among the three brands. The relative bioavailabilities (with respect to brand A) were 92 and 91% for brands B and C, respectively indicating that the products were bioequivalent. Comparison of the in vitro and in vivo data suggest that the systemic absorption of paracetamol may not be dissolution--rate limited and that using in vitro dissolution rate studies alone to establish bioequivalency of paracetamol tablets should be done with caution. 相似文献
49.
JL Mu?oz-Bellido M Alonzo Manzanares JA Martínez Andrés MN Guttiérrez Zufiaurre G Ortiz M Segovia Hernández JA García-Rodríguez 《Canadian Metallurgical Quarterly》1999,43(2):354-356
Fluoroquinolone efflux was studied in 47 Staphylococcus aureus clinical strains with MICs of ciprofloxacin (CFX) of < or = 2 micrograms/ml. Forty-three strains were wild type for gyrA, gyrB, and grlA quinolone resistance-determining regions and for norA and its promoter region. Forty of these strains (MICs of CFX, 0.1 to 0.2 microgram/ml) did not show efflux of fluoroquinolones. Three strains (MICs of CFX, 1 to 2 micrograms/ml) showed efflux. These results suggest that efflux can appear in S. aureus clinical strains in the absence of mutations in norA and its promoter. 相似文献
50.