全文获取类型
收费全文 | 1141篇 |
免费 | 107篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 17篇 |
综合类 | 14篇 |
化学工业 | 433篇 |
金属工艺 | 36篇 |
机械仪表 | 15篇 |
建筑科学 | 43篇 |
矿业工程 | 10篇 |
能源动力 | 19篇 |
轻工业 | 143篇 |
水利工程 | 10篇 |
石油天然气 | 17篇 |
武器工业 | 2篇 |
无线电 | 67篇 |
一般工业技术 | 186篇 |
冶金工业 | 115篇 |
原子能技术 | 4篇 |
自动化技术 | 125篇 |
出版年
2024年 | 4篇 |
2023年 | 17篇 |
2022年 | 78篇 |
2021年 | 70篇 |
2020年 | 53篇 |
2019年 | 38篇 |
2018年 | 42篇 |
2017年 | 45篇 |
2016年 | 65篇 |
2015年 | 47篇 |
2014年 | 49篇 |
2013年 | 72篇 |
2012年 | 87篇 |
2011年 | 83篇 |
2010年 | 58篇 |
2009年 | 65篇 |
2008年 | 44篇 |
2007年 | 41篇 |
2006年 | 36篇 |
2005年 | 38篇 |
2004年 | 24篇 |
2003年 | 21篇 |
2002年 | 15篇 |
2001年 | 16篇 |
2000年 | 5篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 17篇 |
1996年 | 12篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 9篇 |
1992年 | 5篇 |
1990年 | 5篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 3篇 |
1983年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1974年 | 6篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有1256条查询结果,搜索用时 15 毫秒
71.
72.
F. S. Henna Lu Nina S. Nielsen Charlotte Jacobsen 《European Journal of Lipid Science and Technology》2013,115(2):246-251
The dynamic headspace (DHS) thermal desorption principle using Tenax GR tube, as well as the solid phase micro‐extraction (SPME) tool with carboxen/polydimethylsiloxane 50/30 µm CAR/PDMS SPME fiber, both coupled to GC/MS were implemented for the isolation and identification of both lipid and Strecker derived volatiles in marine phospholipids (PL) emulsions. Comparison of volatile extraction efficiency was made between the methods. For marine PL emulsions with a highly complex composition of volatiles headspace, a fiber saturation problem was encountered when using CAR/PDMS‐SPME for volatiles analysis. However, the CAR/PDMS‐SPME technique was efficient for lipid oxidation analysis in emulsions of less complex headspace. The SPME method extracted volatiles of lower molecular weights more efficient than the DHS method. On the other hand, DHS Tenax GR appeared to be more efficient in extracting volatiles of higher molecular weights and it provided a broader volatile spectrum for marine PL emulsion than the CAR/PDMS‐SPME method. 相似文献
73.
Nina Hammer Karina Mathisen Tina Zscherpe De Chen Magnus R?nning 《Topics in Catalysis》2011,54(13-15):922-930
The impact of thermal treatment at various preparation stages of carbon supported Au/TiO2 catalysts prior to oxidation of CO in the presence and absence of hydrogen was studied. An increase in catalytic activity for thermally treated samples due to a more ordered structure of TiO2 was observed. A reversible deactivation of the catalysts occurred in the absence of hydrogen. However, the activity was restored at preferential CO oxidation conditions in presence of hydrogen. 相似文献
74.
Robert Hrastar Ling‐Zhi Cheong Xuebing Xu Charlotte Jacobsen Nina Skall Nielsen Rasmus Leth Miller Iztok Jože Košir 《European Journal of Lipid Science and Technology》2011,113(4):513-521
Camelina sativa oil (CO) is characterized by a high content (up to 40 wt %) of essential α‐linolenic acid and characteristic odour and flavour. Deodorization of highly unsaturated oils requires great attention as the refining process involves thermal treatment which affects oil integrity. In the present study RSM and principal component analysis (PCA) were used to optimize bench‐scale deodorization of CO. Mathematical models were generated through multiple regressions with backward elimination, describing the effects of process parameters (temperature, steam flow, time) on oil quality indicators [peroxide value (PV), p‐anisidine value (p‐AV), γ‐tocopherol (γ‐T) and oxidative stability (OS)]. Additionally, sensory evaluation was performed. RSM analysis showed a significant effect of deodorization temperature and to a lesser extent, deodorization steam flow and time on removal of oxidative compounds, flavour and odour. PCA of chemical and sensory results showed that deodorization temperature affected the sensory properties in the samples. The best conditions for removing undesirable flavour and odour were achieved by using a deodorization temperature of 195–210°C. 相似文献
75.
Rahela Kulčar Mojca Friškovec Marta Klanjšek Gunde Nina Knešaurek 《Coloration Technology》2011,127(6):411-417
Leuco dye‐based thermochromic inks reversibly change from the coloured to the discoloured state in a defined, comparatively wide temperature region. Inside this region, the colour of a sample depends on the temperature and thermal history, which is known as the hysteresis effect. The colour of such a sample as a function of temperature has the shape of a hysteresis loop. Commercially available thermochromic inks have different loops, narrow or broad, and their shapes range from approximately symmetric to highly asymmetric. These properties are also important in mixtures of inks. The hysteresis loop of a mixture reveals its binary nature if the individual pure inks have well‐separated hysteresis. When inks with close‐separated loops, i.e. with similar activation temperatures, are mixed together, the loop of the mixture fuses together into an apparently single loop. Our research shows that some of their dynamic colour properties could be predicted in advance. However, optic and colorimetric properties of mixtures are not additive. 相似文献
76.
<正>本刊讯6月10日上午,景德镇陶瓷学院材料科学与工程学院第四届宏宇奖助学金颁奖仪式在景德镇陶瓷学院(湘湖校区)图书馆报告厅举行,广东宏宇集团副总经理欧家瑞、市场总监王勇,景德镇陶瓷学院院长江伟辉教授、校党委学工部部长王海波、教务处副处长吴晟、团委副书记常成玉、材料学 相似文献
77.
Koren-Karie Nina; Oppenheim david; Dolev Smadar; Sher Efrat; Etzion-Carasso Ayelet 《Canadian Metallurgical Quarterly》2002,38(4):534
This study examined the associations among mothers' insightfulness into their infants' internal experience, mothers' sensitivity to their infants' signals, and infants' security of attachment to their mothers. The insightfulness of 129 mothers of 12-month-old infants was assessed by showing mothers 3 videotaped segments of observations of their infants and themselves and interviewing them regarding their infants' and their own thoughts and feelings. Interviews were classified into 1 insightful and 3 noninsightful categories. Mothers' sensitivity was assessed during play sessions at home and at the laboratory, and infant-mother attachment was assessed with the Strange Situation. Mothers classified as positively insightful were rated as more sensitive and were more likely to have securely attached children than were mothers not classified as positively insightful. Insightfulness also accounted for variance in attachment beyond the variance explained by maternal sensitivity. These findings add an important dimension to research on caregiving, suggesting that mothers' seeking of explanations for the motives underlying their infants' behavior is related to both maternal sensitivity and infant attachment. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
78.
Physiological and pathological vascular responses depend on the action of numerous intercellular mediators, ranging from hormones to gases like nitric oxide, proteins, and lipids. The last group consists not only of the different types of lipoproteins, but also includes a broad array of other lipophilic signaling molecules such as fatty acids, eicosanoids, phospholipids and their derivatives, sphingolipids and isoprenoids. Due to space limitations, it is impossible to discuss all the vascular effects of lipophilic mediators or compounds. Therefore, we will focus on one of the most important lipid-mediated diseases, atherosclerosis. Lipoproteins and especially their native or oxidized lipid compounds affect vascular function in many different ways, and these effects do not only modulate atherogenesis but are of paramount physiological and pathophysiological importance in other diseases, such as inflammation, tumor metastasis, or normal wound healing. 相似文献
79.
N. M. Demina 《Glass and Ceramics》1999,56(7-8):216-219
Current trends in the consumption of silane fibers by fiberglass manufacturing companies are discussed. New brands of organosilicon coupling agents offered by the leading world producers are described. The possibility of using silanes with different functional groups in the production of fiberglass materials with improved consumer properties is investigated. Translated from Steklo i Keramika, No. 7, pp. 18 – 21, July, 1999. 相似文献
80.
Nadezhda S. Tian Tamara K. Meleshko Galina A. Polotskaya Iosif V. Gofman Anna V. Kashina Nina V. Kukarkina Elena N. Vlasova Zoolsho F. Zoolshoev Alexander V. Yakimansky 《Polymer Engineering and Science》2020,60(3):481-490
Composite films based on polyamide (poly(m-phenylene-iso-phthalamide)) (PA) and a brush-like polymer with polyimide (PI) backbone and side poly(methyl methacrylate) chains (PI-PMMA) were prepared by mixing individual solutions of PA and PI-PMMA and subsequent film casting. Macromolecular brushes with the same backbone length and density of side chains but with various lengths of side PMMA chains were synthesized via activator generated by electron transfer atom transfer radical polymerization. Interactions between PA and PI-PMMA, as well as distribution of PI-PMMA filler inside the PA matrix, were studied by viscometry, dynamic light scattering, differential scanning calorimetry, scanning electron microscopy, and IR spectroscopy. The mechanical properties of polymer samples were also investigated. Microphase separation was revealed in PA/PI-PMMA films. The length of side chains influences interactions between PA and PI-PMMA. At the same time, the degree of reduction in the rigidity parameters and in the elasticity parameter depends on the side chain length. Diffusion membranes were prepared on the basis of compositions with the best mechanical properties; these membranes proved to be highly efficient in pervaporation of methanol–hexane mixture. It was established that the fluxes and separation factors of the studied membranes are several times higher as compared to the corresponding characteristics of known commercial membranes. POLYM. ENG. SCI., 60:481–490, 2020. © 2019 Society of Plastics Engineers 相似文献