全文获取类型
收费全文 | 167篇 |
免费 | 4篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 26篇 |
金属工艺 | 7篇 |
机械仪表 | 7篇 |
建筑科学 | 12篇 |
能源动力 | 17篇 |
轻工业 | 42篇 |
水利工程 | 2篇 |
无线电 | 17篇 |
一般工业技术 | 14篇 |
冶金工业 | 4篇 |
自动化技术 | 21篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 9篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 7篇 |
2013年 | 18篇 |
2012年 | 14篇 |
2011年 | 19篇 |
2010年 | 14篇 |
2009年 | 12篇 |
2008年 | 14篇 |
2007年 | 3篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 3篇 |
2002年 | 3篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 3篇 |
排序方式: 共有171条查询结果,搜索用时 343 毫秒
41.
Calculation of heat transfer from building foundations is a computationally intensive three-dimensional problem that can require several weeks to solve using current computing hardware. The Kiva numerical framework was developed to compare foundation heat transfer calculation methods and determine approaches that reduce computation time without sacrificing a balance of capability, ease-of-use, and accuracy. This paper demonstrates the application of the Kiva framework to determine an accurate method of approximating three-dimensional heat transfer effects using two-dimensional coordinate systems. In two-dimensions, problems that would otherwise take days or weeks to solve can be solved in less than a minute. Three existing two-dimensional approximation methods along with a new boundary layer adjustment method are tested across a range of foundation types, shapes, and insulation configurations. The boundary layer adjustment method is shown to provide results within 3% mean absolute deviation from the three-dimensional solution. 相似文献
42.
Hayet Ben Khaled Zohra Ghlissi Yassine Chtourou Ahmed Hakim Naourez Ktari Makni Ayadi Fatma Ahmed Barkia Zouheir Sahnoun Moncef Nasri 《Food research international (Ottawa, Ont.)》2012,45(1):60-68
This study was designed to test the hypolipidemic properties and antioxidative activities of sardinelle (Sardinella aurita) protein hydrolysates (SPHs) obtained by treatment with crude enzyme preparations from Bacillus pumilus A1(SPHA1), Bacillus mojavensis A21(SPHA21) and crude enzyme extract from sardinelle viscera (SPHEE).Wistar rats were fed during 7 weeks a standard laboratory diet, a cholesterol-enriched diet (1%) or a cholesterol SPH-enriched diet. The hypercholesterolemic diet induced the elevation of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C). Supplementing cholesterol-enriched diet with SPHs or whole sardinelle protein (WSP) at a concentration of 5% (w/w) increased the serum level of high-density lipoprotein cholesterol (HDL-C) and HDL-C/TC ratio and decreased the serum levels of TC, TG, LDL-C and LDL-C/HDL-C ratio significantly.The thiobarbituric acid-reactive substances (TBARS) level, as an indicator of lipid peroxidation, and the activity of superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were examined. The hepatic antioxidant enzymes activities were significantly decreased and the malondialdehyde (MDA) level was increased in rats fed a cholesterol-enriched diet compared to those fed a standard diet. The treatment of hypercholesterolemic (HCD) diet rats with SPHs reduced the MDA concentration and increased the antioxidant enzyme activities.These results suggested that the hypolipidemic effect of SPHs might be due to their abilities to lower serum TC, TG, and LDL-C levels as well as to their antioxidant activities preventing the lipid peroxidation process. 相似文献
43.
This paper summarizes the results of a series of parametric analyses performed to evaluate the impact of key design and operating conditions on the effectiveness of pre-cooling control strategies for reducing peak demand and overall energy costs for office buildings. The analyses were carried out using EnergyPlus, a whole building energy simulation program. The effects of various parameters were considered in the analysis including building location, mass level, pre-cooling control strategy, and time-of-use utility rate. 相似文献
44.
Naourez Ktari Hayet Ben Khaled Rim Nasri Kemel Jellouli Sofiane Ghorbel Moncef Nasri 《Food chemistry》2012,130(3):467-474
An alkaline trypsin was purified from the viscera of zebra blenny (Salaria basilisca) by ammonium sulphate (40?80% saturation) precipitation, Sephadex G-100, Mono Q-Sepharose and ultrafiltration. A yield of 12% with a purification-fold of 4.2 was obtained. The trypsin had an apparent molecular weight of 27 kDa. Soybean trypsin inhibitor and phenylmethylsulfonyl fluoride showed a strong inhibitory effect on the purified trypsin. Trypsin had maximal activity at pH 9.5 and 60 °C for the hydrolysis of Nα-benzoyl-dl-arginine-p-nitroanilide (BAPNA). It was stable at low temperatures and in the pH range of 7.0?12.0. The N-terminal amino acid sequence of the first 12 amino acids of the purified protease was IVGGRECTEPSQ. S. basilisca trypsin, which showed high homology with other fish trypsins, had a charged Arg residue at position 5, where Tyr is common in marine vertebrates and mammalian trypsins. The trypsin kinetic constants, Km and kcat for BAPNA, were 0.6 mM and 1.38 s?1, respectively. 相似文献
45.
Ali Bougatef Rozenn Ravallec Naima Nedjar-Arroume Ahmed Barkia Didier Guillochon Moncef Nasri 《Journal of Functional Foods》2010,2(1):10-16
Protein hydrolysates are of a significant interest, due to their potential application as a source of bioactive peptides in nutraceutical and pharmaceutical domains. The present study was focused on the effect of protein hydrolysate from smooth hound (Mustelus mustelus) (SHPH) in the regulation of components of the food intake control such as satiety. SHPH was produced by intestinal digestive proteases from the same species. The amino acid analysis by GC/MS showed that the hydrolysate was rich in leucine, alanine, glycine, threonine, serine, lysine and glutamate. The molecular weights of peptides in SHPH were estimated by ESI-MS to be between 200 and 2500 Da. Biological in vivo capacities of SHPH in rats were evaluated by determination of the CCK-like peptides and insulin content using a clinical human radioimmunoassay. The food intake and the body weight of rats were measured during the period of treatment. Rats treated with SHPH showed a significant decrease in body weight at the end of treatment, as well as a decrease of food intake. Our findings revealed a possible mechanism of the beneficial effects of SHPH in appetite regulation, and this might be important to prevent the risk of a number of medical conditions including type II diabetes. 相似文献
46.
B. SirotaJ. Reyes-Cuellar P. KohliL. Wang M.E. McCarrollS.M. Aouadi 《Thin solid films》2012,520(19):6118-6123
Nanowires of bismuth oxide were grown on Si substrates by unbalanced magnetron sputtering. Deposition time for the seed layer and oxygen partial pressure were varied to optimize the morphology of the resulting array of wires. A two step process involving variable oxygen flow rates was found to create the highest density of Bi2O3 nanowires in the array. Top-view and cross-sectional SEM micrographs suggested that the resulting Bi2O3 nanowires were approximately 300 nm in length with diameters of 100 nm at the base and 30 nm at the top. Investigation into the growth method suggests a self-catalytic process similar to vapor-liquid-solid growth. Band gap was determined by two different methods, using transmission spectroscopy and cyclic voltammetry which gave values of 2.53 eV and 2.61 eV respectively. Degradation experiments using rhodamine 6G display a direct relationship between nanowire density and photocatalytic results. 相似文献
47.
Amor B. Garali Mohamed Ouakad Moncef Gueddari 《Lakes & Reservoirs: Research and Management》2010,15(3):273-282
The decrease of the contents of TOC in sediment cores in the Bizerte Lagoon is synchronous with that of carbonates. This is attributed to a dilution phenomenon of the organic fraction by the carbonate component of the sediment in the lagoon. This phenomenon also can be explained by the effect of early diagenesis, resulting in the existence of more condensed products, or by removal of more labile organic fraction and/or by reorganization mechanisms leading to the solubilization of organic matter towards deep levels. It appears that the mechanisms controlling the geochemical sedimentation in the lagoon are similar to those observed today, with some occasional characteristics reflecting the impact of episodic phenomenon related to other factors and processes, especially a continental influence on the sediments, rather than marine influences. 相似文献
48.
Induction machine fault detection using stray flux EMF measurement and neural network-based decision
Khmais Bacha Humberto Henao Moncef Gossa Gérard-André Capolino 《Electric Power Systems Research》2008
The aim of this paper is to present the performances of voltage unbalance and rotor fault detections using an external stray flux sensor in a working three-phase induction machine. The automatic classification and fault severity degree evaluation are realized by using a neural network approach based on a multi-layer perceptron (MLP) structure. In this paper, it is proved that a simple external stray flux sensor is more efficient than the classical stator current sensor to detect rotor broken bar and voltage unbalance, using data processing at low-frequency resolution. 相似文献
49.
Rafik Balti Mourad Jridi Assaad Sila Nabil Souissi Naima Nedjar-Arroume Didier Guillochon Moncef Nasri 《Food Hydrocolloids》2011
The characteristics and functional properties of gelatin from skin cuttlefish (Sepia officinalis) were investigated and compared to those of halal bovine gelatin (HBG). The gelatin extraction efficiency was improved by an acid-swelling process in the presence of smooth hound crude acid protease extract (SHCAP). The yields of gelatins from cuttlefish skin after 48 h with acid and with crude acid protease (15 units/g alkaline-treated skin) were 2.21% and 7.84%, respectively. The gelatin from skin cuttlefish had high protein (91.35%) but low fat (0.28%) contents. Compared to HBG, the cuttlefish-skin gelatin (CSG) has different amino acids composition than halal bovine gelatin. CSG contained slightly low hydroxyproline and proline (180‰) than HBG (219‰), whereas the content of serine was higher (49‰ versus 29‰). The gel strength of the gelatin gel from CSG (181 g) was lower than that of HBG (259 g) (p < 0.05) possibly due to lower hydroxyproline content. Cuttlefish-skin gelatin exhibited a similar emulsifying activity but greater emulsifying and foam stability than the halal bovine gelatin (p < 0.05). Foam formation ability, foam stability and water-holding capacity of CSG were slightly lower than those of the HBG, but fat-binding capacity was higher in the cuttlefish gelatin. 相似文献
50.
Seasonal Survey of Contaminants (Cd and Hg) and Micronutrients (Cu and Zn) in Edible Tissues of Cephalopods from Tunisia: Assessment of Risk and Nutritional Benefits
下载免费PDF全文
![点击此处可从《Journal of food science》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Moncef Rjeibi Marc Metian Tarek Hajji Thierry Guyot Rafika Ben Chaouacha‐Chekir Paco Bustamante 《Journal of food science》2015,80(1):T199-T206
Concentrations of cadmium (Cd), copper (Cu), mercury (Hg), and zinc (Zn) were determined by atomic absorption spectrophotometry in the muscle tissues (arms and mantle) of 3 commercial cephalopods (Loligo vulgaris, Octopus vulgaris, and Sepia officinalis) caught in 3 different Tunisian coastal regions. The highest concentrations found correspond to the essential elements Cu and Zn. Octopuses and cuttlefish showed the highest levels of those elements whereas squid presented with significantly higher values of Hg in both muscular tissues. This may be related to different feeding behavior and detoxification processes among benthic and pelagic cephalopods. Variation of element concentrations between seasons was different between species and seemed to be mostly dependent on the sampling site. From a public health standpoint, average concentrations of Cd, Cu, Hg, and Zn measured in edible tissues of cephalopods from this study did not reveal, in general, any risk for consumers. The estimated target hazard quotients for Cd and Hg for consumers of the selected species were below 1 and within the safety range for human health. Moreover, their consumption could provide in an important contribution to the daily dietary intake of Cu for the Tunisian population, especially regarding the consumption of octopus and cuttlefish muscles. 相似文献