全文获取类型
收费全文 | 88篇 |
免费 | 4篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 14篇 |
建筑科学 | 8篇 |
能源动力 | 10篇 |
轻工业 | 18篇 |
水利工程 | 3篇 |
无线电 | 5篇 |
一般工业技术 | 11篇 |
冶金工业 | 8篇 |
自动化技术 | 11篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 2篇 |
2014年 | 4篇 |
2013年 | 14篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有93条查询结果,搜索用时 31 毫秒
1.
Mesay Yami Alemayehu Wubie Abebe Cheffo Yared Mesfin 《Lakes & Reservoirs: Research and Management》2020,25(2):230-243
The present study was conducted to share the experience of promoting fish production and marketing from the Tendaho Reservoir of the Afar region, Ethiopia. The study results indicate the reservoir is serving its purpose, namely to generate gainful employment for the pastoralist youth and to create sustainable livelihoods and sources of income for the pastoralist‐fishermen of the Afar region. Further, the reservoir fish production has improved the nutrition and food security status of children. It also created a new business entry for hotels and restaurants in the area. Fishermen in the study areas, however, face problems getting the required support for such efforts, in the form of training in fish post‐harvest practices. The present study also indicates dried catfish marketing should be targeted in the short run to address the substantial fish spoilage observed in the high‐production hot season. Dried catfish marketing is highly recommended for the Afar region since it is well adapted to the climate of the study area, noting the product is less perishable and can be sold throughout the country. Dried catfish marketing is also expected to address the problem of gender inclusiveness, an issue clearly missing in the fish production system in the study areas. 相似文献
2.
Alemayehu Molla 《Information Systems Frontiers》2013,15(5):705-723
IT firms vary in their performance to improve the environmental sustainability of their own operations and in their ability to provide products and solutions that enable and transform the environmental sustainability of other industries. In the parlance of the balanced scorecard, performance has two dimensions, that is, “drivers” and “outcomes”. The drivers, also known as leading performance indicators, refer to learning and innovation, processes, and customer value propositions. The outcomes, also known as lagging performance indicators, refer to financial results. This study has developed and validated an instrument to measure the environmentally sustainable IT performance (eSITP) drivers. We established the nomological network of the eSITP by drawing from several theoretical domains in the areas of innovation antecedents and values, balanced performance measurement and IT and eco-sustainability. Based on a survey of 133 IT firms, we developed and validated a four-dimension, 17 items eSITP instrument covering eco-learning, eco-process, eco-brand and eco-value governance. The instrument is validated by following a seven step rigorous process. The paper breaks new ground from both research and practice perspectives. The instrument makes it easier for other researchers who wish to explain the leading (drivers) and lagging (outcomes) of IT firms’ environmental sustainability and for IT business managers who want to improve their environmental sustainability performance. 相似文献
3.
Alemayehu Gebremedhin Jarle De Oliveira Granheim 《Renewable & Sustainable Energy Reviews》2012,16(3):1611-1615
This paper presents the results of a Norwegian power system analysis. An energy system analysis model based on linear programming is used for modelling and optimisation. The analyses cover a number of scenarios where the studied system is subjected to changes by introducing other renewable energy sources, energy conservation measures and measures to promote renewable energy. The study shows that due to a combination of cheap hydropower and high investment costs, it is quite difficult for new generation units to be profitable. This is also true during periods of low precipitation where the system tends to survive on imported power instead of investing in new generation units. However, this does not apply to energy conservation measures that easily enter the system. On the other hand, biomass based CHP, wind power and wave power could be viable if measures are introduced to promote their use. Most of the scenarios show a high potential for reducing global emissions. 相似文献
4.
5.
Adam Alemayehu Dominika Zákutná Soňa Kohúteková Václav Tyrpekl 《Journal of the American Ceramic Society》2022,105(7):4621-4631
Ceria, pure or doped, is an important electrolyte material in solid oxide fuel cells, catalysts, and plutonium surrogates. Even though ceria is a widely studied material, its coprecipitation with the most common doping element, gadolinium, remains mostly overlooked. Here, we present a comprehensive study of gadolinium–cerium oxalates prepared by coprecipitation of gadolinium (III) and cerium (III) salts by oxalic acid under different reaction conditions and element ratios. For this purpose, we assessed the effects of basic precipitation conditions on the final oxalate size, shape, and conversion into the corresponding oxides. The results showed that coprecipitation with oxalic acid yields and ideal solid solution, which translates into the oxides. This low-cost and straightforward synthetic route provides then high-quality solid solutions of Ge–Gd in the oxide lattice. Thus, this approach has a high industrialization potential, with significant advantages over hydrolysis or hydrothermal techniques. 相似文献
6.
Jürgen Liebscher Alemayehu Areda Berhanu Abegaz 《Advanced Synthesis \u0026amp; Catalysis》1983,325(5):689-694
7.
8.
This paper analyses the thermal and roughness effects on different characteristics of finite rough tilted pad slider bearings. The roughness is assumed to be stochastic, Gaussian randomly distributed. Density and viscosity are assumed to be temperature dependent. In this study, two models of one-dimensional roughness, longitudinal and transverse, are considered. The irregular domain due to roughness is mapped to a regular domain so that the numerical method can be easily applied. The modified Reynolds equation, momentum equation, continuity equation and energy equation are coupled and solved using the finite difference method to yield various bearing characteristics. It is observed that for nonparallel slider bearing the load carrying capacity due to the combined effect is less than the load capacity due to the roughness effect for both longitudinal and transverse roughness models. However, in case of a parallel pad slider bearing, the reverse is true, though the load capacity is not significant. It is also observed that the load carrying capacity due to the combined effect is larger than the load carrying capacity due to the thermal effect for both roughness models. 相似文献
9.
E Barry A Krumholz GK Bergey H Chatha S Alemayehu L Grattan 《Canadian Metallurgical Quarterly》1998,39(4):427-431
BACKGROUND: The aim of this experimental study was to evaluate the risk of tumor recurrence after laparoscopic cecal resection (LCR) of colonic carcinoma in the rat. METHODS: The experimental cancer consisted of one million cells (DHK/K12), incorporated in an extracellular matrix, placed and secured to the cecal serosa in 110 BD9 rats. Four weeks later, all animals were reoperated through a laparotomy to control tumor growth, and animals with diffuse carcinomatosis were excluded. Eligible animals were randomized either to laparoscopic cecal resection (group LCR, n = 10), to open resection (group OCR, n = 13), or to a control group without resection (group C, n = 13). Resection was always considered as macrocopically complete. All animals were killed 4 weeks after the resection to determine the tumor recurrence and quantify carcinomatosis. RESULTS: We noted diffuse carcinomatosis in 70% of rats in groups C and LCR versus 23% in group OCR (p = 0.038). For tumors noted as S- (not extending outside the serosa), diffuse carcinomatosis was observed in all animals of group C (3 of 3), in 6 of 8 in group LCR, and 0 of 6 in group OCR (p = 0.004). The rate of port site or incisional metastases was not significantly different between groups. CONCLUSIONS: These preliminary results demonstrated the deleterious impact of the laparoscopy for resection of large bowel malignancy. LCR increased significantly the incidence of a diffuse carcinomatosis even when performed for locally noninvasive tumors (S-). 相似文献
10.
Regions with densely concentration of industries and district heating systems (DHS) could be interesting study object from the light of an integrated heat market on local basis. System analysis with a widened system boundary could be used as an approach to evaluate the benefit of an integrated heat supply system. In this study, an energy system model consisting of totally seven different participants is designed and the optimization results of the system analysis are presented. With applied data and assumptions, the study shows that a significant amount of the heat demand within two sub‐systems can be covered by heat supply from the heat market (the entire heat comes from two industries). Shadow prices, which can be used for heat pricing, indicate the advantage of an integrated system. The system cost reduction through integration and the availability of several actors with diverse energy supply system, makes the region under study an interesting area to prove a locally deregulated heat market. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献