全文获取类型
收费全文 | 134篇 |
免费 | 6篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 40篇 |
金属工艺 | 5篇 |
机械仪表 | 9篇 |
建筑科学 | 4篇 |
能源动力 | 1篇 |
轻工业 | 8篇 |
石油天然气 | 1篇 |
无线电 | 3篇 |
一般工业技术 | 55篇 |
冶金工业 | 6篇 |
原子能技术 | 1篇 |
自动化技术 | 6篇 |
出版年
2023年 | 1篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 8篇 |
2012年 | 1篇 |
2011年 | 10篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 15篇 |
2006年 | 9篇 |
2005年 | 6篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1973年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有140条查询结果,搜索用时 15 毫秒
61.
Combined decontamination processes for wastes containing PCBs 总被引:1,自引:0,他引:1
This project has focused on the development of a complex assembly of mutually corresponding technological units: a low temperature thermal process for the desorption of PCBs and other organics from soils and other contaminated solid wastes; the extraction of PCBs from soils by an ecological friendly aqueous solution of selected surfactants; the chemical decontamination of PCBs in oils and in-oil-in-water emulsions by metallic sodium and potassium in polyethylene glycols in the presence of aluminum powder; the modified alkaline catalyzed chemical decontamination of PCBs in oil-in-water dispersions in a solid-state reactor (in a film of reacting emulsion on solid carriers); and the breakdown of PCBs in aqueous emulsions with activated hydroxyl radicals enhanced by UV radiation. The processes operate in a closed loop configuration with effluents circulating among the process unit. These technologies have been verified at laboratory and pilot-plant scales. 相似文献
62.
63.
JS Krop NR Powe WE Weller TJ Shaffer CD Saudek GF Anderson 《Canadian Metallurgical Quarterly》1998,21(5):747-752
BACKGROUND: Rapid quantifiable diagnostic techniques for the diagnosis of cytomegalovirus (CMV) infection may predict patients at risk of CMV pneumonitis and allow preemptive antiviral treatment. METHODS: Using CMV antigenemia as a prospective surveillance technique for CMV infection, we compared the outcome of preemptive treatment (PT) with ganciclovir, 10 mg/kg/day for 21 days directed by "high levels" of CMV antigenemia (PT group, n= 19), with the outcome in a group of historical controls (n=18) treated with ganciclovir when CMV illness occurred. Greater than 50 antigen-positive cells per 2 x 10(5) polymorphonuclear leukocytes was considered to be high-level antigenemia. RESULTS: Nine of the 18 controls developed high-level CMV antigenemia at a median of 33 days (range: 13-65 days) and 5 of the 9 developed CMV disease. Ten of the 19 PT group had high levels of CMV antigenemia detected at a median of 47 days (range: 20-63 days) and were given ganciclovir; none developed CMV disease. There was a significantly lower incidence of CMV disease in the PT group in comparison to controls (0 of 19 vs. 5 of 18: P=0.019). CONCLUSION: We have reduced the incidence of CMV disease using preemptive treatment, and because of a 100% negative predictive value, we omitted unnecessary antiviral prophylaxis for many at-risk patients. 相似文献
64.
65.
Zemek F Herman M Kierdorf H Kierdorf U Sedlácek F 《The Science of the total environment》2006,370(2-3):491-505
We assessed the spatial variation of fluoride load on the local ecosystem in the Czech part of the Ore Mountains region and its southern foothills - a heavily polluted part of Europe's "Black Triangle" region. Dental fluorosis in roe deer (Capreolus capreolus) served as a biomarker of fluoride exposure and thus as an indicator of environmental pollution by fluoride. The mean dental lesion index of fluorosis (DLI) calculated from the analyzed mandibles of wild roe deer (>or=2 years of age) was assigned to the hunting ground from which the specimens originated and classified into one of the eight fluorosis categories. Environmental factors potentially related to dental fluorosis (atmospheric deposition of sulfur, concentration of fluoride in and pH of surface waters, geomorphologic features, bedrock and soil type, and vegetation cover), which were represented in the study by GIS layers, were examined to explain the distribution pattern and severity of fluorosis in the roe deer. The study revealed that 75.5% of 616 analyzed mandibles showed dental fluorosis to different extent, with individual DLIs ranging from 0 to 21. The spatial pattern of marked fluorosis on the Czech side continues that found in a previous study on the German side of the Ore Mountains. Together they create a landscape island around several thermal power plants in the region. General Linear Model (GLM) analyses revealed significant relationships between degree of forest damage, soil type, and atmospheric sulfur deposition from air pollution and dental fluorosis, expressed as mean DLI in the roe deer. 相似文献
66.
67.
68.
Vacuum contact drying kinetics of a model system consisting of nonporous glass beads and water has been experimentally measured on a laboratory scale. A methodology for determination of drying curves from experimental data in a statistically robust way has been developed. The effects of jacket temperature, head-space pressure, particle bed depth, vessel diameter, and particle size on drying rate during constant and falling rate periods have been studied. It was found that in the range of parameters investigated, drying rate does not depend on the means of realization of the driving force (by temperature or pressure); drying rate in the constant-rate period decreases with increasing bed depth while the overall heat-transfer rate increases due to increased surface area. A very strong dependence of drying rate and regime on particle size was observed; the constant-rate period disappeared for small particles. 相似文献
69.
Frantisek Stulajter 《时间序列分析杂志》2001,22(3):365-373
Predictions in time series using multivariate regression models are studied with respect to their mean squared errors. Two new methods of prediction are proposed: the simple one and the method based on the kriging theory. The mean squared errors of these predictions are computed and it is shown that the first one can be regarded as a special case of the kriging approach. 相似文献
70.
Marco Dozza Lorenzo Chiari Frantisek Hlavacka Angelo Cappello Fay B Horak 《IEEE transactions on neural systems and rehabilitation engineering》2006,14(4):505-512
Although both visual and audio biofeedback (BF) systems for postural control can reduce sway during stance, a direct comparison between the two systems has never been done. Further, comparing different coding designs of audio and visual BF may help in elucidating how BF information is integrated in the control of posture, and may improve knowledge for the design of innovative BF systems for postural control. The purpose of this paper is to compare the effects of linear versus sigmoid coding of trunk acceleration for audio and visual BF on postural sway in a group of eight, healthy subjects while standing on a foam surface. Results showed that sigmoid-coded audio BF reduced sway acceleration more than did a linear-coded audio BF, whereas a linear-coded visual BF reduced sway acceleration more than a sigmoid-coded visual BF. In addition, audio BF had larger effects on reducing center of pressure (COP) displacement whereas visual BF had larger effects on reducing trunk sway. These results suggest that audio and visual BF for postural control benefit from different types of sensory coding and each type of BF may encourage a different type of postural sway strategy. 相似文献