全文获取类型
收费全文 | 312篇 |
免费 | 13篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 29篇 |
化学工业 | 75篇 |
金属工艺 | 14篇 |
机械仪表 | 14篇 |
建筑科学 | 9篇 |
能源动力 | 7篇 |
轻工业 | 26篇 |
水利工程 | 9篇 |
无线电 | 12篇 |
一般工业技术 | 55篇 |
冶金工业 | 6篇 |
原子能技术 | 20篇 |
自动化技术 | 52篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 9篇 |
2015年 | 10篇 |
2014年 | 10篇 |
2013年 | 27篇 |
2012年 | 20篇 |
2011年 | 26篇 |
2010年 | 11篇 |
2009年 | 20篇 |
2008年 | 20篇 |
2007年 | 16篇 |
2006年 | 12篇 |
2005年 | 14篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 5篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 6篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 2篇 |
排序方式: 共有328条查询结果,搜索用时 281 毫秒
101.
Modeling of aerobic biodegradation of feces using sawdust as a matrix 总被引:15,自引:0,他引:15
Composting in the bio-toilet system is a continuous thermophilic-aerobic biodegradation process. Unlike to the traditional composting systems, biodegradation rates of organic matter are very important because feces are daily added into the composting reactor of the bio-toilet and an accelerated decomposition is aimed. The models developed for conventional composting processes include simple formulations of biodegradation kinetics and deal mainly with energy and water balances. Therefore, formulation of kinetics that can reasonably describe the biodegradation process in the bio-toilet system is required for better modeling predictions. In this work, a bio-kinetic model was introduced to describe the aerobic biodegradation of feces in the bio-toilet system. This model includes three processes for carbonaceous material degradation and is prepared by using the activated sludge modeling techniques and formulations. Stoichiometric parameters were adopted from literature on activated sludge processes. Kinetic parameters were estimated by conducting batch tests for several organic loadings and by using respirometry, curve-fitting techniques, and sensitivity analysis. Feasibility and applicability of these parameters were assessed by conducting feces intermittent-feeding tests and by simulating the experimental respiration rates. Model, stoichiometric and kinetic parameters proved to be affordable for describing the biodegradation of feces in the bio-toilet system. 相似文献
102.
Naoyuki Takahashi Naoki Yoshii Shinichi Nonobe Takato Nakamura Masayuki Yoshioka 《Journal of Electronic Materials》2003,32(10):1107-1110
The ZrO2 films were deposited onto a Si(100) substrate using an alternate reaction of ZrCl4 and O2 under atmospheric pressure. It is found that the growth rate of ZrO2 film depends on the growth conditions, such as growth temperature, partial pressure of the sources being supplied, and exposure
time of the substrate to the gaseous sources. Self-limiting growth of the ZrO2 was achieved in the range of the growth temperature of 673–923 K. The x-ray diffractogram of the ZrO2 films showed a typical diffraction pattern assigned to the tetragonal polycrystalline phase. The obtained ZrO2 films were of smooth and uniform surface. It was found that the [O]/[Zr] ratio of the ZrO2 films are similar to that of the ZrO2 bulk. 相似文献
103.
104.
Naoyuki Kobayashi Hirotaka Kaneda Yukinobu Kano Shouhei Koshino 《Journal of the Institute of Brewing》1993,99(2):143-146
Linoleic and linolenic acid hydroperoxides in malt, mash, or wort were determined with high sensitivity and high selectivity by the chemiluminescence-high performance liquid chromatography (CL-HPLC) method using isoluminol-microperoxidase solution as a luminescing reagent. The determination limit of this method for both hydroperoxides was 0.1 μM in mash or wort. During the mashing in a laboratory mash bath, the hydroperoxides started to increase just after mashing-in, reached a maximum at 65°C, and then decreased. Though the hydroperoxides were detected in mash just before the lautering in a pilot scale brewing, they disappeared during the lautering and could not be detected during the subsequent stages of wort production. Therefore, it was thought that the mashing process is the most important of the lipid oxidation reactions during wort production. It is also expected that the CL-HPLC method can give useful information on lipid oxidation mechanisms during wort production. 相似文献
105.
It is known that the toxicity of effluent is more intensive than that of influent in the activated sludge process. In this study, we applied bioassay using cultured human cell lines to the decay process of activated sludge to evaluate the toxicity of organic matter generated and/or released from activated sludge bacteria. We also applied this bioassay to hydrophilic fraction of samples. The bioassay results showed that: (1) the variation in the dose-response relation obtained from assay with original samples was observed during decay; (2) on the other hand, the response curves of only hydrophilic fraction at each time show the same relationship between TOC and viability of MCF7 cells; (3) this trend was confirmed by plotting the time course of EC50. These results imply that: (1) the hydrophilic organic matter controlled for developing toxicity during decay process of activated sludge; and (2) the character of hydrophilic organic matter is not changed during the experimental period. 相似文献
106.
The effect of doping β-tricalcium phosphate with monovalent metal ions (lithium, sodium, and potassium ions) on its thermal stability was evaluated using the formation ratio of α-tricalcium phosphate and the rate constant for β-α transformation. The thermal stability of β-tricalcium phosphate doped with monovalent metal ions was higher than that of pure β-tricalcium phosphate, and increased with the amount of metal ions. The increase in stability was attributed to the occupation of all calcium sites including vacancy in β-tricalcium phosphate structure by the calcium ions and monovalent metal ions and the resultant crystal stabilization. However, the thermal stability of β-tricalcium phosphate doped with monovalent metal ions was lower than that of β-tricalcium phosphate doped with magnesium ions. These results indicate that the thermal stability of β-tricalcium phosphate is influenced by the difference in the structural stabilization caused by doping metal ions into different calcium sites in the crystal structure. 相似文献
107.
Complex and adaptive population behavior emerges in social insects. In ants, in particular, pheromone communication is the
key to understanding their swarm intelligence. This article proposes a swarm robot system based on pheromone communication,
and reports on the current status of the development of our robot system. We believe that the system could be used in swarm
robotics and complex systems education. 相似文献
108.
A pre-coagulation and bio-filtration process for advanced treatment of sewage was developed and experimentally discussed with a pilot plant. The bio-filtration unit consists of a denitrification filter, a nitrification filter with side stream to the denitrification filter, and a polishing filter with anoxic and aerobic parts. Concentrations of SS, T-COD(Cr), T-carbonaceous BOD, T-N and T-P in the effluent were stably kept at less than 3, 20, 5mg/L, 2mg N/L and 0.2mg P/L, respectively, and transparency at higher than 100 cm, under total hydraulic retention time of 3.2h in the bio-filtration parts (filter-bed). ORP in an anoxic tank before a nitrification tank should be at a low level of less than -120 mV to keep remaining NO(-)(x) - N less than 1mg N/L, but must be maintained at a level higher than -150 mV. The maximum nitrogen-loading rate under a water temperature of 18 degrees C should be less than 0.25 kg N/(m(3)-filter-bed.d). Concentrations of microorganisms kept in the reactors were as high as 4000-5000 mg COD/L-filter-bed. Denitrification activity of 0.4 or 0.7 kg N/(m(3)-filter-bed.d), and nitrification activity of 0.3 kg N/(m(3)-filter-bed.d) were obtained, respectively, under a water temperature of about 18 degrees C. Backwashing in each tank as well as methanol addition and aeration in the polishing filter were operated successfully by the automatic control systems. These results proved that this process is applicable to advanced treatment of sewage with easy maintenance. 相似文献
109.
T Kakimolo Y Imai N Funamizu T Takakuwa M Kunimoto 《Water science and technology》2006,54(11-12):421-428
Bio-Toilet is the name of a dry closet or composting toilet using sawdust as an artificial soil matrix for bioconversion of human excrement into compost. Since feces and urine contain several chemicals such as pharmaceutical residues and endocrine disruptors and they may still remain in compost after biological reaction in the Bio-Toilet, it is required to examine the possibility of soil and/or groundwater pollution by applying compost to a soil system in farmland. In this study, toxicity of Bio-Toilet compost was evaluated by measuring the viability of human neuroblast (NB-1). The bio-assay was applied to the water extract of compost from the Bio-Toilets which are in practical use in Japan. The assay results showed that (1) the extract of feces showed no toxicity, and the extracts of unused sawdust had no or low level toxicity and (2) the extracts of composts had heavier toxicity than unused sawdust. These results implied that some chemicals that have toxicity were generated by biological reactions or accumulated in toilet system. The bioassay results with fractionated organic matter by its molecular weight showed that the small molecular weight fraction had stronger toxicity than other fractions. The effect of inorganic matter on toxicity was examined by comparing the dose-response relationship of the extracts of compost with positive control with 1M of sodium chloride solution. The comparison showed that sodium concentration in the extract was too low to develop the toxicity and the effect of inorganic matter could be neglected in this study. 相似文献
110.