全文获取类型
收费全文 | 406篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 91篇 |
金属工艺 | 1篇 |
机械仪表 | 9篇 |
建筑科学 | 14篇 |
能源动力 | 27篇 |
轻工业 | 37篇 |
石油天然气 | 1篇 |
无线电 | 45篇 |
一般工业技术 | 52篇 |
冶金工业 | 91篇 |
原子能技术 | 4篇 |
自动化技术 | 40篇 |
出版年
2022年 | 2篇 |
2021年 | 8篇 |
2020年 | 2篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 5篇 |
2014年 | 10篇 |
2013年 | 26篇 |
2012年 | 11篇 |
2011年 | 22篇 |
2010年 | 7篇 |
2009年 | 11篇 |
2008年 | 17篇 |
2007年 | 15篇 |
2006年 | 19篇 |
2005年 | 15篇 |
2004年 | 10篇 |
2003年 | 23篇 |
2002年 | 14篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 11篇 |
1998年 | 33篇 |
1997年 | 17篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 10篇 |
1993年 | 16篇 |
1992年 | 5篇 |
1989年 | 4篇 |
1987年 | 3篇 |
1985年 | 6篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1966年 | 2篇 |
1965年 | 1篇 |
排序方式: 共有416条查询结果,搜索用时 15 毫秒
51.
Y Vandenplas D Belli S Cadranel S Cucchiara C Dupont H Heymans I Polanco 《Canadian Metallurgical Quarterly》1998,87(4):462-468
Previous studies established that retrovirally infected young mice produced large amounts of autoantibodies to certain T-cell receptor (TCR) peptides whose administration diminished retrovirus-induced immune abnormalities. C57BL/6 young (4 weeks) and old (16 months) female mice were injected with these same synthetic human TCR V beta 8.1 or 5.2 peptides. Administration of these autoantigenic peptides to old mice prevent immunosenescence, such as age-related reduction in splenocyte proliferation and interleukin-2 (IL-2) secretion. TCR V beta peptide injection into young mice had no effect on T- or B-cell mitogenesis and IL-4 production while modifying tumour necrosis factor-alpha (TNF-alpha), IL-6, and interferon-gamma (IFN-gamma) secreted by mitogen-stimulated spleen cells. TCR V beta injection also retarded the excessive production of IL-4, IL-6 and TNF-alpha induced by ageing. These data suggest that immune dysfunction and abnormal cytokine production, induced by the ageing process, were largely prevented by injection of selected TCR V beta CDR1 peptides. 相似文献
52.
This paper presents a dynamic study of moist air dehumidification in view of its use in an air conditioning process by evaporative cooling in tropical climates. A special device has been built to study dehumidification of tropical-like inlet air, through a fixed compact bed of silicagel and activated alumina. The compact desiccant storage is composed of two parallel beds to reduce the pressure drop. A good agreement is obtained for our experiment, and the computed amount of cycled water from the numerical model in the adiabatic process. This analytical model is used to simulate a complete air conditioning open cycle operating with hot and humid air. 相似文献
53.
BACKGROUND: Unilateral dystonic posturing of limbs occurs frequently in medial temporal lobe epilepsy (MTLE) but its underlying anatomic basis is still unknown. OBJECTIVE: To investigate the pathophysiology of dystonic posturing, we examined the relation between the occurrence of dystonia and interictal cerebral metabolic abnormalities using fluorodeoxyglucose (FDG)-PET in MTLE patients. METHODS: Video recordings of 30 patients with documented MTLE were reviewed to assess the presence of ictal dystonic posturing. Interictal FDG-PET was performed in all patients. RESULTS: Eighteen patients exhibited dystonic posturing--contralateral to the seizure focus in 16 cases, bilateral in one, and ipsilateral in one. Dystonia was statistically associated with more severe hypometabolism in the striatal and in the orbitofrontal regions ipsilateral to the seizure focus. CONCLUSION: Hypometabolism observed in the striatal region of patients with ictal dystonic posturing suggests that the basal ganglia are involved in the generation of ictal dystonic posturing in MTLE. 相似文献
54.
Clinical and radiographic healing observations were categorized into four patterns: rapid, typical, delayed, and adverse. While considerable overlap of characteristics was noted between the categories, singular factors or combinations of factors enabled pattern identification. The factor primarily associated with the rapid healing pattern was the appearance of bone in the former defect adjacent to the membrane at removal. In contrast, the adverse healing pattern depicted surface necrosis or loss of tissue height at membrane removal. One hundred random sites were evaluated, revealing 13% rapid healing patterns, 76% typical healing patterns, 8% delayed healing patterns, and 3% adverse healing patterns. With favorable patient compliance with oral hygiene and follow-up care, the rapid and typical healing patterns became clinically successful cases. The level of clinical success varied with the delayed healing pattern; the adverse pattern failed to achieve the therapeutic objective. 相似文献
55.
56.
Daniel Dupont 《Color research and application》2002,27(2):88-99
This article presents and compares different methods applied to the reconstruction of reflectance curves. These are optimization methods such as the simplex method, simulated annealing, genetic algorithms, neural networks, and Hawkyard's method, which is specific to colorimetry. Improvements have been made to these methods to maximize their application, notably to ensure a convergence toward the global optimum by avoiding being trapped in local optima and to obtain physically viable reflectance curves. Objective and subjective criteria were used to compare these methods; the study used textile samples (cotton fibers), with a panel of 15 samples covering the CIELAB L*a*b* space. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 88–99, 2002; DOI 10.1002/col.10031 相似文献
57.
Recent numerical methods for calculating the flow of fluids of the integral type have been extended to the case of swirling flows in geometries of revolution. Such flows are important in rheometry, as it was suggested in early experimental results by Savins and Metzner [1]. After having developed the necessary background for the numerical calculation, we apply the method to the flow in disk-and-plate and cone-and-plate rheogoniometers. 相似文献
58.
59.
Male and female weanling rats were fed diets containing 2 or 42% of calories as corn oil or 40% as beef tallow plus 2% as
corn oil until they were 12 or 18 weeks of age. Incorporation of C14-acetate into lipids of serum and liver and concentration of lipids in serum, liver, and carcass at the end of these periods
were determined.
Net synthesis of noncholesterol lipid was repressed by changing the diet from 2% to 42% of calories from either dietary fat
in both sexes and at both ages. Cholesterol net synthesis was enhanced 29-fold in males and 22-fold in females fed 42% corn
oil compared to 2% corn oil to the age of 12 weeks. It was enhanced only 2.6-fold for males and 3.4-fold for females by 40%
beef tallow plus 2% corn oil. At 18 weeks of age cholesterol synthesis in males fed 42% corn oil was 7.3 and in females 9.1
times the value for those fed 2% corn oil. At this age the values for rats fed 40% beef tallow plus 2% corn oil were 1.2 and
3.7 times those for 2% corn oil fed rats of the respective sexes. 相似文献
60.