全文获取类型
收费全文 | 180篇 |
免费 | 22篇 |
专业分类
电工技术 | 1篇 |
综合类 | 1篇 |
化学工业 | 56篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 2篇 |
能源动力 | 7篇 |
轻工业 | 62篇 |
石油天然气 | 1篇 |
无线电 | 4篇 |
一般工业技术 | 31篇 |
冶金工业 | 7篇 |
原子能技术 | 1篇 |
自动化技术 | 25篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 12篇 |
2019年 | 10篇 |
2018年 | 10篇 |
2017年 | 12篇 |
2016年 | 5篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 9篇 |
2012年 | 12篇 |
2011年 | 16篇 |
2010年 | 18篇 |
2009年 | 13篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 10篇 |
2005年 | 5篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有202条查询结果,搜索用时 2 毫秒
1.
A. T. Sousa P. S. Fialho C. A. Nieto de Castro R. Tufeu B. Le Neindre 《International Journal of Thermophysics》1996,17(3):551-560
The density of HCFC 141b has been measured at several temperatures between 260 and 320 K, Mid pressures up to 20 MPa, with a mechanical oscillator densimeter. The densimeter was calibrated with 2,2,4-trimethylpentane, whose density was obtained from a correlating cyuation with 0.3% uncertainty. The density data obtained for HCFC 14H) hits a reproducibility of 0.05% and an uncertainty of 0.3%. The data obtained were fitted to a Tait-type equation. which reproduced the experimental densities within 0.11 % and were compared with the data obtained in other works.Paper presented at the Twelfth Symposium on Thermophysical Properties, June 19–24, 1994, Boulder, Colorado, U.S.A. 相似文献
2.
In this paper we consider the l1-state feedback problem with an internal stability constraint. In particular, we establish the connection between controlled-invariant contractive sets and static control laws that achieve a level of l1 performance as well as a desired unforced rate of convergence. We outline two algorithms for computing controlled-invariant contractive sets. The first is a modification of standard recursive techniques used in the literature, whereas the second is based on dynamic games and involves solving an appropriate discrete Isaacs recursion. The latter approach results in a min-max characterization of l1-state feedback controllers. We point out that the Isaacs recursion provides a one-shot (as opposed to iterative) computation of the optimal l1 performance 相似文献
3.
Effect of silicon content in steel and oxidation temperature on scale growth and morphology 总被引:1,自引:0,他引:1
Amine Alaoui Mouayd Alexey Koltsov Eliane Sutter Bernard Tribollet 《Materials Chemistry and Physics》2014
The effect of high silicon content in steel, 1.6 wt.%Si and 3.2 wt.%Si, and high oxidation temperatures (850–1200 °C) on scale growth rate and morphology were investigated. The steels were oxidized in a 15% humid air with short isothermal oxidation times (15 min). The scale growth rate of the non-alloyed steel follows a parabolic law with time; it is an iron diffusion controlled oxidation. The presence of silicon delays scale growth by forming a silica SiO2 barrier layer at the scale/metal interface, this effect is more important for the steel containing 3.2 wt.%Si and induces a discontinuous scale. Silicon oxides are concentrated at the scale/metal interface; their morphology depends on the oxidation temperature. For temperatures lower than 950 °C, silica is formed. Between 950 °C and 1150 °C, fayalite (Fe2SiO4) grains appear in the wüstite matrix close to the scale/metal interface. For temperatures higher than 1177 °C, a fayalite–wüstite eutectic is formed; this molten phase favours iron diffusion leading to high scale growth. After cooling, a continuous fayalite layer with small wüstite grains is obtained at the scale/steel interface. 相似文献
4.
Initial moisture and pre-wetting method influence on the water absorption of recycled concrete aggregates (RCA) have been studied experimentally. For this purpose, RCA were pre-wetted by three methods: soaking under partial vacuum (simulating long term wetting), soaking under atmospheric pressure, and spraying (simulating short term wetting). The results show that the same initial amount of water in two samples of RCA do not lead to the same total amount of water absorbed by RCA during 5–120 min. The latter depends on the way they have been pre-wetted (either long term or short term). It is suggested that this phenomenon is related to the accessibility filled pores in the different pre-wetting methods. So, the pre-wetting history of RCA could change the amount of total water absorbed by the RCA up to 1%. When mixing and casting concrete are produced with RCA, the corresponding error in the determination of the effective water should have adverse effects on the fresh and hardened concrete characteristics. In this study real applications on mixtures of recycled concrete have been carried out, where the influence of initial moisture content and pre-wetting history of RCA on fresh recycled concrete properties (slump) have been investigated. 相似文献
5.
6.
Comparison of vacuum impregnation and soaking techniques for addition of the probiotic Lactobacillus acidophilus to minimally processed melon
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Patrícia Martins de Oliveira Afonso Mota Ramos Eliane Maurício Furtado Martins Érica Nascif Rufino Vieira Ariana de Souza Soares Marcel Cardoso de Noronha 《International Journal of Food Science & Technology》2017,52(12):2547-2554
This study aimed to evaluate the vacuum impregnation (VI) and soaking methods in the addition of Lactobacillus acidophilusLA‐3 to minimally processed melon (MPM). The melons were washed, sanitised in chlorine solution (200 mg L?1), peeled and cutted into cubes. Lactobacillus acidophilusLA‐3 (1.4 × 1010 CFU g?1) were added to the MPM through both techniques. The L. acidophilusLA‐3 count in MPM was similar to those commonly found in dairy products having probiotic claim, but VI was more efficient than soaking in maintaining the viability (8.61 and 7.98 Log CFU g?1, respectively). The pH, acidity and soluble solids were not affected by probiotic culture and the incorporation technique; however, the VI affected the firmness of fruit. The MPM was within Brazilian standards for their microbiological characteristics. MPM may be used as a carrier of probiotic bacteria, being one more alternative for individuals who consume probiotic products. 相似文献
7.
Iron incorporated into food systems induces oxidation and precipitation. The consequences are reduced bioavailability and a functional modification of other food components such as proteins. The iron-chelates such as ferrous bisglycinate represent a possibility to avoid side effects, since the iron is protected. The aim of this study is to investigate the effects of iron-chelates compounds on the properties of an oil/water interface stabilized by caseinate or β-lacotoglobulin, under environmental conditions at 20 °C. Analyses were performed using dynamic drop tensiometry during 5000 s. The aqueous bulk phase is an imidazole/acetate buffer (0.1 M), containing 0.4 × 10−6 M protein, and 0.2 × 10-6 9 M iron-chelates compounds. The results indicate that, under neutral conditions, the addition of some irons salts (NaFe-EDTA or Fe-bisglycinate) do not change the structure of the interface stabilized by a protein containing no phosphate groups (β-lactoglobulin). In the case of caseinate, NaFe-EDTA addition increases the lowering rate of surface tension at pH 6.5. On the contrary, the lowering rate of surface tension with caseinate is inhibited by Fe-bisglycinate at pH 6.5. Such an effect is not observed with β-lactoglobulin. The low transfer of irons ions from the bulk to the interface stabilized by β-lactoglobulin is confirmed by zetameter and FTIR measurements. These results indicate an effective strategy to follow for controlling the physical and chemical stability of an emulsion stabilized with proteins. 相似文献
8.
Sara Alouf Giovanni Neglia Iacopo Carreras Daniele Miorandi Álvaro Fialho 《Computer Networks》2010,54(18):3402-3420
In this work, we introduce a framework for enabling the on-line evolution of network protocols. The proposed approach is based on the use of techniques and tools drawn from evolutionary computing research, and it enables embedding evolutionary features in the operation of network protocols. In this way, it becomes possible to build a system in which the operation of the network changes at run-time to adapt to the current conditions. As a case study, we apply the proposed framework to the evolution of forwarding schemes in intermittently connected wireless networks. Simulation results are reported to validate the ability of the proposed scheme to converge to the optimal operating point and to explore the various trade-offs deriving from its design and implementation. 相似文献
9.
Monique Hoogwijk Stephane de la Rue du Can Aleksandra Novikova Diana Urge-Vorsatz Eliane Blomen Kornelis Blok 《Energy Policy》2010
The greenhouse gas mitigation potential of different economic sectors in three world regions are estimated using a bottom-up approach. These estimates provide updates of the numbers reported in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR4). This study is part of a larger project aimed at comparing greenhouse gas mitigation potentials from bottom-up and top-down approaches. The sectors included in the analysis are energy supply, transport, industry and the residential and service sector. The mitigation potentials range from 11 to 15 GtCO2eq. This is 26–38% of the baseline in 2030 and 47–68% relative to the year 2000. Potential savings are estimated for different cost levels. The total potential at negative costs is estimated at 5–8% relative to the baseline, with the largest share in the residential and service sector and the highest reduction percentage for the transport and industry sectors. These (negative) costs include investment, operation and maintenance and fuel costs and revenues at moderate discount rates of 3–10%. At costs below 100 US$/tCO2, the largest potential reductions in absolute terms are estimated in the energy supply sector, while the transport sector has the lowest reduction potential. 相似文献
10.
Parameters effect on proton conductivity to obtain chitosan membranes for use as electrolytes in PEMFC
下载免费PDF全文
![点击此处可从《国际能源研究杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jéssica V. Schaffer Karine N. Lupatini Bruna Machado Eliane S. Silva Ricardo J. Ferracin Helton J. Alves 《国际能源研究杂志》2018,42(3):1381-1385
The chitosan biopolymer can be used as a proton‐conducting membrane in proton‐exchange membrane fuel cell. In the forms that they have normally obtained and tested, chitosan membranes typically show poor performance in conduction of protons, requiring modifications in the structure of the biopolymer or blending with other polymers to increase its proton conductivity. The present work investigates the individual properties of chitosan and relates them to the proton conductivity performance of membranes composed of this polymer. Evaluation was made of the effects of variables such as the degree of deacetylation (DD) and the molar mass (Mv) of chitosan membranes without addition of any other polymer. The DD and Mv values of the chitosan used to produce membranes determined the proton conduction, with lower DD and higher Mv resulting in higher conductivity. The thicker membranes presented greater crystallinity, with conductivity between 2.0 × 10?4 and 1.8 × 10?3 S cm?1. The characteristic stages of degradation of the chitosan membranes were in the ranges 200 to 300°C and 500 to 600°C, indicating good thermal stability of the material. 相似文献