全文获取类型
收费全文 | 246篇 |
免费 | 10篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 80篇 |
金属工艺 | 2篇 |
机械仪表 | 5篇 |
建筑科学 | 11篇 |
矿业工程 | 1篇 |
能源动力 | 9篇 |
轻工业 | 37篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 23篇 |
一般工业技术 | 17篇 |
冶金工业 | 32篇 |
原子能技术 | 1篇 |
自动化技术 | 30篇 |
出版年
2023年 | 3篇 |
2022年 | 18篇 |
2021年 | 19篇 |
2020年 | 14篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 2篇 |
2016年 | 7篇 |
2015年 | 9篇 |
2014年 | 5篇 |
2013年 | 11篇 |
2012年 | 9篇 |
2011年 | 8篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 10篇 |
2007年 | 9篇 |
2006年 | 4篇 |
2005年 | 3篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 11篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1969年 | 1篇 |
1931年 | 2篇 |
1913年 | 6篇 |
1912年 | 4篇 |
排序方式: 共有256条查询结果,搜索用时 15 毫秒
1.
2.
SL Kamholz RJ Brewer G Grijalva J Burack MJ Del Rio M Vaynblatt N Lawson S Squinto WL Fodor AJ Norin 《Canadian Metallurgical Quarterly》1997,21(9):951-955
The lack of sufficient suitable human donor lungs for the many patients requiring pulmonary transplantation as life-saving therapy for end-stage lung diseases has generated extensive interest in cross-species lung transplantation. Ethical concerns and those of animal rights advocates have prompted studies of nonprimate species as potential solid organ donors for humans. This paper provides an overview of some of the laboratory studies of cross-species pulmonary transplantation performed over the past 20 years and focuses, in particular, on more recent work (from our laboratory and others) in the area of porcine-to-primate pulmonary xenotransplantation. 相似文献
3.
4.
Daun Marian Brings Jennifer Krajinski Lisa Stenkova Viktoria Bandyszak Torsten 《Requirements Engineering》2021,26(3):325-370
Requirements Engineering - Collaborative cyber-physical systems are capable of forming networks at runtime to achieve goals that are unachievable for individual systems. They do so by connecting to... 相似文献
5.
Summary The hydrolytic degradation of Kevlar 49 fibers when dissolved in H2SO4 is characterized from (i) Fourier transform infrared (FTIR), CNH analyses and optical microscopy studies of insoluble crystals formed in the PPTA-H2SO4 dope and (ii) the rates of H2SO4-catalyzed hydrolysis of model compound aromatic amides. After hydrolysis of a PPTA amide linkage, the amide linkage adjacent to the freshly formed-COOH macromolecular end group rapidly hydrolyses resulting in the formation of terephthalic acid which then forms insoluble crystals in the PPTA-H2SO4 dope.Dedicated to Professor Dragutin Fle on the occasion of his 70th birthdaySupported in part by U.S. Department of Energy, LL National Laboratory under Contract W-7405-Eng-48 相似文献
6.
In this paper, we characterize all weakly smooth uninorms (i.e., uninorms with smooth underlying operators) defined on a finite chain. It is proved that any such uninorm is determined by three unary functions and vice versa. As a by‐product, we obtain the characterizations of smooth t‐norms, smooth t‐conorms through additive generators and show that on a finite chain, there exists no counterpart of the class of uninorms continuous in ]0, 1[2. 相似文献
7.
An experimental and computational protocol was established for the simultaneous determination of several key gasoline properties from a single Fourier transform infrared (FT-IR) spectrum. The study has shown that midband FT-IR spectroscopy combined with multivariate calibration analysis is a versatile, efficient, and accurate technique for the simultaneous estimation of key gasoline properties within about 1 min with less than 2 mL of sample. The FT-IR-derived values of gasoline properties include research and motor octane numbers, aromatic, olefinic, and saturated hydrocarbon content, benzene content, and concentrations of ethanol, methyl tert-butyl ether, and total oxygen. Concentrations of other oxygenated compounds are expected to be equally predictable. However, since these oxygen-containing species have not been adequately represented among the currently commercially available gasoline samples, their calibration may only be achieved using laboratory fuel blends. Midrange boiling point data may also be estimated. Fuel properties determined by minor concentrations of fuel components, e.g., flash point, sulfur content, etc., may not be modeled because the corresponding FT-IR signals are below detection limits of presented experimental protocol. The precision of this procedure was shown to be comparable to reproducibility of the standard laboratory analyses used for direct measurement of specific fuel properties, with squared correlation coefficient (R(2)) ranging from 0.94 to 0.99 between the two sets of measurements. This new methodology could increase the corresponding output of the petroleum laboratories by a factor of over 200 to 1 while maintaining data integrity and minimizing sample requirements, environmental hazards, and cost. 相似文献
8.
In this paper we prove that, under suitable conditions, Atanassov’s Kα operators, which act on intervals, provide the same numerical results as OWA operators of dimension two. On one hand, this allows us to recover OWA operators from Kα operators. On the other hand, by analyzing the properties of Atanassov’s operators, we can generalize them. In this way, we introduce a class of aggregation functions - the generalized Atanassov operators - that, in particular, include two-dimensional OWA operators. We investigate under which conditions these generalized Atanassov operators satisfy some properties usually required for aggregation functions, such as bisymmetry, strictness, monotonicity, etc. We also show that if we apply these aggregation functions to interval-valued fuzzy sets, we obtain an ordered family of fuzzy sets. 相似文献
9.
Automatic image annotation using visual content and folksonomies 总被引:2,自引:4,他引:2
Stefanie Lindstaedt Roland Mörzinger Robert Sorschag Viktoria Pammer Georg Thallinger 《Multimedia Tools and Applications》2009,42(1):97-113
Automatic image annotation is an important and challenging task, and becomes increasingly necessary when managing large image collections. This paper describes techniques for automatic image annotation that take advantage of collaboratively annotated image databases, so called visual folksonomies. Our approach applies two techniques based on image analysis: First, classification annotates images with a controlled vocabulary and second tag propagation along visually similar images. The latter propagates user generated, folksonomic annotations and is therefore capable of dealing with an unlimited vocabulary. Experiments with a pool of Flickr images demonstrate the high accuracy and efficiency of the proposed methods in the task of automatic image annotation. Both techniques were applied in the prototypical tag recommender “tagr”. 相似文献
10.
Jeremy Rott Eva Teresa Toepfer Maria Bartosova Ana Kolevica Alexander Heuser Michael Rabe Geert Behets Patrick C. DHaese Viktoria Eichwald Manfred Jugold Ivan Damgov Sotirios G. Zarogiannis Rukshana Shroff Anton Eisenhauer Claus Peter Schmitt 《International journal of molecular sciences》2022,23(14)
Serum calcium isotopes (δ44/42Ca) have been suggested as a non-invasive and sensitive Ca balance marker. Quantitative δ44/42Ca changes associated with Ca flux across body compartment barriers relative to the dietary Ca and the correlation of δ44/42CaSerum with bone histology are unknown. We analyzed Ca and δ44/42Ca by mass-spectrometry in rats after two weeks of standard-Ca-diet (0.5%) and after four subsequent weeks of standard- and of low-Ca-diet (0.25%). In animals on a low-Ca-diet net Ca gain was 61 ± 3% and femur Ca content 68 ± 41% of standard-Ca-diet, bone mineralized area per section area was 68 ± 15% compared to standard-Ca-diet. δ44/42Ca was similar in the diets, and decreased in feces and urine and increased in serum in animals on low-Ca-diet. δ44/42CaBone was higher in animals on low-Ca-diet, lower in the diaphysis than the metaphysis and epiphysis, and unaffected by gender. Independent of diet, δ44/42CaBone was similar in the femora and ribs. At the time of sacrifice, δ44/42CaSerum inversely correlated with intestinal Ca uptake and histological bone mineralization markers, but not with Ca content and bone mineral density by µCT. In conclusion, δ44/42CaBone was bone site specific, but mechanical stress and gender independent. Low-Ca-diet induced marked changes in feces, serum and urine δ44/42Ca in growing rats. δ44/42CaSerum inversely correlated with markers of bone mineralization. 相似文献