全文获取类型
收费全文 | 266篇 |
免费 | 9篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 68篇 |
金属工艺 | 1篇 |
机械仪表 | 2篇 |
建筑科学 | 25篇 |
矿业工程 | 6篇 |
能源动力 | 2篇 |
轻工业 | 20篇 |
水利工程 | 5篇 |
无线电 | 17篇 |
一般工业技术 | 40篇 |
冶金工业 | 41篇 |
原子能技术 | 1篇 |
自动化技术 | 42篇 |
出版年
2023年 | 2篇 |
2022年 | 18篇 |
2021年 | 21篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 22篇 |
2011年 | 22篇 |
2010年 | 10篇 |
2009年 | 10篇 |
2008年 | 25篇 |
2007年 | 15篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 5篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
1969年 | 2篇 |
1967年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 62 毫秒
71.
Pravin Kumar Sahu Suryakant Chakradhari Elise Sipeniece Inga Miina Ying Qian Ania Grygier Magdalena Rudziska Khageshwar Singh Patel Pawe Grna 《European Journal of Lipid Science and Technology》2020,122(7)
The oil yield and composition of fatty acids, tocopherols, tocotrienols, sterols, carotenoids, and squalene in the seeds of three species—Hyptis suaveolens, Leonotis nepetifolia, Ocimum sanctum—belonging to the Lamiaceae family, are studied. The oil yields are 12.1%, 16.1%, and 29.0% in O. sanctum, H. suaveolens, and L. nepetifolia, respectively. The unsaturated fatty acids are a predominant group (86.8–92.1%) in all three investigated plants; however, the profile for each species is unique. The main fatty acid differs as follows: H. suaveolens—linoleic acid (85.8%), L. nepetifolia—oleic acid (58.3%), and O. sanctum—α‐linolenic (48.6%). γ‐Tocopherol accounts for over 97%, 90%, and 93% of the total tocochromanol content (sum of tocopherols and tocotrienols) in H. suaveolens, L. nepetifolia, and O. sanctum, respectively. Two tocotrienol homologues, α and γ, are detected only in L. nepetifolia. β‐Sitosterol is the main detected sterol (38–59%) in all three species. High levels of campesterol (18–20%), Δ5‐stigmasterol (9–21%), and Δ5‐avenasterol (7–12%) are also detected. Squalene is detected only in O. sanctum (45.8 mg/100 g oil). The content of sterols, tocochromanols, and carotenoids in the investigated Lamiaceae plant seed oils ranges between 279.5–576.3, 54.5–66.7, and 0.3–3.1 mg/100 g oil, respectively. Practical Applications: Lamiaceae plants are of medicinal interest due to the presence of a broad spectrum of bioactive molecules. The present study demonstrates that seeds of the species H. suaveolens, L. nepetifolia, and O. sanctum are rich sources of bioactive compounds of lipophilic nature. There is limited knowledge associated with the composition of tocopherols, tocotrienols, sterols, carotenoids, and squalene. The results of the studied medicinal plants may enhance future targeted applications in various sectors. 相似文献
72.
Laurence Delbrassinne Mirjana Andjelkovic Andreja Rajkovic Pauline Dubois Elise Nguessan Jacques Mahillon Joris Van Loco 《Food Analytical Methods》2012,5(5):969-979
Cereulide is the heat-stable toxin produced by certain strains of Bacillus cereus. It is the main virulence factor of emetic B. cereus strains, which causes the emetic food poisoning syndrome, including rare fatal cases of food intoxications. Due to presumably low intoxication doses, a sensitive, specific, and robust technique is needed for its detection. In 2002, a LC–MS method was developed which allowed absolute quantification of cereulide using valinomycin as standard. This study describes the validation, according to the Commission Decision 2002/657/EC, of the LC–MS2 method, a tandem mass spectrometry technique, which guarantees lower detection limit and higher specificity. The LC–MS2 method, calibrated with valinomycin, was validated in rice and tested on various matrices (i.e., red beans, spices, and chili con carne) containing cereulide. The process combines a simple extraction step from the food matrix followed by LC–MS2 analysis and detection by ion trap mass spectrometer. The detection limit for cereulide in rice was 0.5 ng eq/g, which is 20 to 2,500 times lower than currently understood intoxicative doses between 10 and 1.280 ng/g previously reported for cereulide. The validated method was specific, sensitive, repeatable, and reproducible with recoveries ranging from 77% to 101%. 相似文献
73.
Justine Dumay Marion Allery Claire Donnay‐Moreno Gilles Barnathan Pascal Jaouen Marie Elise Carbonneau Jean Pascal Bergé 《Journal of the science of food and agriculture》2009,89(9):1599-1606
BACKGROUND: Fish by‐products are not considered as valuable raw materials even if they usually contain valuable components such as lipids. Fish lipids are well known for their nutritional potential and health effects but their extraction remains problematic due to the use of organic solvents. Enzymatic hydrolysis such as the proteolysis of tissues can lead to lipid extraction. RESULTS: Hydrolysis of sardine heads by Protamex was studied (temperature, hydrolysis time and enzyme–substrate ratio) using response surface methodology in order to obtain the highest release of lipids and particularly phospholipids. No relation between the degree of hydrolysis and lipid recovery were depicted; however, optimum conditions for both the release of lipids and phospholipids were found to be similar (29 min, 31 °C with 2.6 g kg?1 enzyme). Under these hydrolysis conditions, rich lipid and phospholipid fractions (oily and aqueous fractions) can be recovered when time, temperature and enzyme consumption are minimized. Analytical data have revealed that they contain high‐quality lipids, especially ω3 fatty acid. CONCLUSION: This study demonstrated that proteolysis can be used for high lipid recovery from little‐exploited biomass like fish heads without requiring solvent or thermal treatment. Resulting phospholipids, fatty acids and peptides could be utilized for nutritional or feed purposes. Copyright © 2009 Society of Chemical Industry 相似文献
74.
Fate of alkylphenolic compounds during activated sludge treatment: impact of loading and organic composition 总被引:2,自引:0,他引:2
McAdam EJ Bagnall JP Soares A Koh YK Chiu TY Scrimshaw MD Lester JN Cartmell E 《Environmental science & technology》2011,45(1):248-254
The impact of loading and organic composition on the fate of alkylphenolic compounds in the activated sludge plant (ASP) has been studied. Three ASP designs comprising carbonaceous, carbonaceous/nitrification, and carbonaceous/nitrification/denitrification treatment were examined to demonstrate the impact of increasing levels of process complexity and to incorporate a spectrum of loading conditions. Based on mass balance, overall biodegradation efficiencies for nonylphenol ethoxylates (NPEOs), short chain carboxylates (NP(1-3)EC) and nonylphenol (NP) were 37%, 59%, and 27% for the carbonaceous, carbonaceous/nitrification, and carbonaceous/nitrification/denitrification ASP, respectively. The presence of a rich community of ammonia oxidizing bacteria does not necessarily facilitate effective alkylphenolic compound degradation. However, a clear correlation between alkylphenolic compound loading and long chain ethoxylate compound biodegradation was determined at the three ASPs, indicating that at higher initial alkylphenolic compound concentrations (or load), greater ethoxylate biotransformation can occur. In addition, the impact of settled sewage organic composition on alkylphenolic compound removal was evaluated. A correlation between the ratio of chemical oxygen demand (COD) to alkylphenolic compound concentration and biomass activity was determined, demonstrating the inhibiting effect of bulk organic matter on alkylphenol polyethoxylate transformation activity. At all three ASPs the biodegradation pathway proposed involves the preferential biodegradation of the amphiphilic ethoxylated compounds, after which the preferential attack of the lipophilic akylphenol moiety occurs. The extent of ethoxylate biodegradation is driven by the initial alkylphenolic compound concentration and the proportion of COD constituted by the alkylphenol polyethoxylates (APEOs) and their metabolites relative to the bulk organic concentration of the sewage composed of proteins, acids, fats, and polysaccharides. Secondary effluents from this study are characterized by low bulk organic concentrations and comparatively high micropollutant concentrations. Based on the biodegradation mechanism proposed in this study, application of high rate tertiary biological treatment processes to secondary effluents characterized by low bulk organic concentrations and comparatively high APEO concentrations is predicted to provide a sustainable solution to micropollutant removal. 相似文献
75.
76.
Elise Legghe Emmanuel Aragon Lénaïk Bélec André Margaillan Denis Melot 《Progress in Organic Coatings》2009
Epoxy adhesion to steel is known to be weakened by the presence of water. 相似文献
77.
Weerts Elise M.; Fantegrossi William E.; Goodwin Amy K. 《Canadian Metallurgical Quarterly》2007,15(4):309
The use of nonhuman primates (NHP) is invaluable for drug abuse research. The laboratory animals most closely related to humans are NHP. The phylogeny, anatomy, physiology, neurochemistry, and behavior of NHP are more similar to humans than other laboratory species. There is now an extensive body of literature documenting the neuroanatomical, neurochemical, and neuropharmacological similarities between NHP and humans and the differences between NHP and other laboratory species in dopamine, norepinephrine, serotonin, opioid, and gamma aminobutyric acid systems. Comprehensive studies comparing pharmacokinetics in humans, monkeys, dogs, and rats have shown that data in monkeys are the most predictive of human pharmacokinetic parameters. The long life span and extended adolescent period for NHP permits intensive, long-term investigations and the use of within-subject experimental designs similar to those used in human laboratory studies. Within-subject designs require fewer subjects than standard between-group designs and permit the careful evaluation of individual differences. NHP have been used extensively in drug abuse research for over 40 years and have provided useful information on the behavioral processes associated with drug abuse and addiction as well as drug abuse liability in humans. This review focuses on important species differences between rodents and NHP and on the value of NHP in bridging the gap between rodents and humans to enhance the ability to generalize preclinical findings to human drug abuse. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
78.
Ganzel Barbara; Casey B. J.; Glover Gary; Voss Henning U.; Temple Elise 《Canadian Metallurgical Quarterly》2007,7(2):227
Does trauma exposure have a long-term impact on the brain and behavior of healthy individuals? The authors used functional magnetic resonance imaging to assess the impact of proximity to the disaster of September 11, 2001, on amygdala function in 22 healthy adults. More than three years after the terrorist attacks, bilateral amygdala activity in response to viewing fearful faces compared to calm ones was higher in people who were within 1.5 miles of the World Trade Center on 9/11, relative to those who were living more than 200 miles away (all were living in the New York metropolitan area at time of scan). This activity mediated the relationship between group status and current symptoms of posttraumatic stress disorder. In turn, the effect of group status on both amygdala activation (fearful vs. calm faces) and current symptoms was statistically explained by time since worst trauma in lifetime and intensity of worst trauma, as indicated by reported symptoms at time of the trauma. These data are consistent with a model of heightened amygdala reactivity following high-intensity trauma exposure, with relatively slow recovery. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
79.
The competitive environment is giving rise to a paradigmatic transformation in how corporations organize and manage people. These transformations typically start with new outlying organizational units and progress slowly as innovations in management diffuse to older, more resistant organizations. Changes in these older units require the involvement of all stakeholders in designing an organization that will demand new behavior of them. Attitudes and new skills are developed through experience with new approaches to management, not education. Effective and rapid corporate transformation requires top management to develop a corporate context that will support diffusion. Champions who will lead change must be carefully placed to move change along, and they can benefit from the support of consultants skilled in both process and structural interventions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
80.
A numerical quadrature algorithm is developed, for integrands which may exhibit some kind of singular behaviour within the finite of infinite integration range. Using the automatical FORTRAN IV integration program, one should provide the abscissae the function is not “smooth” at. The quadrature formula has been obtained by applying the trapezoidal rule after transformation of the integrand. Standing severe tests which were based on the test functions of Casaletto et al. and on Kahaner's sample set, the integration scheme turned out to be of a remarkable reliability, efficiency and accuracy. 相似文献