全文获取类型
收费全文 | 1814篇 |
免费 | 107篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 1922篇 |
出版年
2024年 | 6篇 |
2023年 | 17篇 |
2022年 | 29篇 |
2021年 | 59篇 |
2020年 | 47篇 |
2019年 | 40篇 |
2018年 | 70篇 |
2017年 | 59篇 |
2016年 | 64篇 |
2015年 | 52篇 |
2014年 | 75篇 |
2013年 | 124篇 |
2012年 | 101篇 |
2011年 | 120篇 |
2010年 | 80篇 |
2009年 | 79篇 |
2008年 | 82篇 |
2007年 | 73篇 |
2006年 | 62篇 |
2005年 | 43篇 |
2004年 | 37篇 |
2003年 | 35篇 |
2002年 | 37篇 |
2001年 | 23篇 |
2000年 | 27篇 |
1999年 | 24篇 |
1998年 | 64篇 |
1997年 | 50篇 |
1996年 | 29篇 |
1995年 | 40篇 |
1994年 | 27篇 |
1993年 | 29篇 |
1992年 | 16篇 |
1991年 | 10篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 15篇 |
1983年 | 8篇 |
1982年 | 12篇 |
1981年 | 17篇 |
1980年 | 14篇 |
1979年 | 16篇 |
1978年 | 12篇 |
1977年 | 9篇 |
1976年 | 10篇 |
1975年 | 6篇 |
排序方式: 共有1922条查询结果,搜索用时 93 毫秒
21.
Lopes Elio Jordan Kataria Shaolin Keshav Shashank Ikram Sumaiya Thaseen Ghalib Muhammad Rukunuddin Shankar Achyut Krichen Moez 《Wireless Networks》2022,28(7):3111-3125
Wireless Networks - In centralized video streaming platforms, the platform owner, rather than the content producer, controls most of the content uploaded on the centralized video... 相似文献
22.
Melo Karla R. B. Grace John R. Lopes Gabriela C. 《Clean Technologies and Environmental Policy》2022,24(2):623-632
Clean Technologies and Environmental Policy - Fluidized bed bioreactors are widely used in wastewater treatment applications. Such reactors employ gel beads or hard particles covered with a biofilm... 相似文献
23.
Poly(vinylidene fluoride), PVDF, and its copolymers are the family of polymers with the highest dielectric constant and electroactive response, including piezoelectric, pyroelectric and ferroelectric effects. The electroactive properties are increasingly important in a wide range of applications such as in biomedicine, energy generation and storage, monitoring and control, and include the development of sensors and actuators, separator and filtration membranes and smart scaffolds, among others. For many of these applications the polymer should be in one of its electroactive phases. This review presents the developments and summarizes the main characteristics of the electroactive phases of PVDF and copolymers, indicates the different processing strategies as well as the way in which the phase content is identified and quantified. Additionally, recent advances in the development of electroactive composites allowing novel effects, such as magnetoelectric responses, and opening new applications areas are presented. Finally, some of the more interesting potential applications and processing challenges are discussed. 相似文献
24.
Juliane Resges Orives Diego Galvan Jaqueline Laís Pereira Rodolfo Lopes Coppo Dionísio Borsato 《Journal of the American Oil Chemists' Society》2014,91(10):1805-1811
Oxidation stability is a parameter of great importance for biodiesel quality control to both producers and subsequent consumers. To maintain the quality of biodiesel, currently the most effective and economical method is the addition of antioxidants that prevent or retard the biofuel oxidation reaction. In this study, efficiency and cost of synthetic antioxidants added to B100 biodiesel from soybean oil and pork fat were evaluated, using butylhydroxyanisole (BHA), butylhydroxytoluene (BHT) and tert-butylhydroquinone (TBHQ), in pure form or in mixtures, according to a simplex-centroid mixture experimental design. Results demonstrate an increased induction period (IP) in all trials when compared to the control sample, and TBHQ was the only antioxidant alone that met all the specification standards, while BHT and BHA alone met only the American standard specifications. The antioxidant mixture that presented the highest synergistic effect was that of TBHQ and BHA. Multi-response optimization indicated an optimum formulation containing 75 % TBHQ and 25 % BHA with an IP of 7.27 h at 110 °C and the antioxidant mixture cost of 31.31 USD, to be added for a ton of biodiesel. This simplex-centroid mixture experimental design shows an ability to be applied in the biodiesel, oils and fats industry to evaluate the oxidation stability and the occurrence of synergism between different mixtures of synthetic or natural antioxidants and their costs. 相似文献
25.
Hallinan Noel C 《精细化工原料及中间体》2014,(12)
正生产醋酸的过程包括:在醋酸生产系统中得到碘化氢;连续将络合剂引入系统,在该系统中络合剂和碘化氢反应形成络合物。 相似文献
26.
27.
The Annals of Regional Science - 相似文献
28.
Incorporation of Alpha‐Linolenic Acid and Enhancement of n‐3 Fatty Acids in Nile Tilapia: a Factorial Design 下载免费PDF全文
Vanessa Vivian Almeida Schneider Fabiana Carbonera Paula Fernandes Montanher Ana Paula Lopes Makoto Matsushita Jesuí Vergílio Visentainer 《Journal of the American Oil Chemists' Society》2015,92(5):693-700
A 22 factorial design (two factors at two levels, in triplicate) was performed to investigate the influence of factors A (time of treatment, 15 and 30 days) and B (chia oil content in a supplemented diet, at 2.1 and 4.2 %) in three responses of interest referring to: (a) the incorporation of alpha‐linolenic acid (LNA) in lipids of Nile tilapia fillet; (b) the enhancement of n‐3 fatty acids; and (c) the decrease in the omega‐6/omega3 (n‐6/n‐3) ratio in fish. Factors A and B were significant in the three regression models obtained and the interaction AB was a significant contributor to the LNA and n‐6/n‐3 ratio. Analysis of variance suggested three significant and predictive mathematical models. Response surfaces analyses from designs indicated higher LNA and n‐3 contents and a lower n‐6/n‐3 ratio using both factors A and B in the higher levels (30 days of treatment and 4.2 % of chia oil in the diet for fish) chosen for this study. 相似文献
29.
Professor Jorge Manuel Martins Margarida Lopes Almeida Professor Cristina Maria Coelho Dr João Ferra 《The Journal of Adhesion》2015,91(10-11):792-800
This paper presents a study on the curing conditions of several resin-impregnated papers and its impact on the performance of HPL (high-pressure decorative laminate). A new methodology for evaluating the bond strength development between the different layers of a HPL(overlay, decorative, and kraft papers) was developed using ABES (Automated Bonding Evaluation System) equipment. The proposed method can be applied to the study of the curing step of the different impregnated paper and the development of bonds between them (overlay paper on decorative paper, decorative paper on kraft paper, and kraft paper on kraft paper) trying to simulate the hot-pressing of an industrial HPL. This will permit to establish a more adapted temperature gradient in hot-press in order to achieve the same curing rate for all layers and provide a good final overall product quality. 相似文献
30.
We propose an integer‐valued stochastic process with conditional marginal distribution belonging to the class of infinitely divisible discrete probability laws. With this proposal, we introduce a wide class of models for count time series that includes the Poisson integer‐valued generalized autoregressive conditional heteroscedastic (INGARCH) model (Ferland et al., 2006) and the negative binomial and generalized Poisson INGARCH models (Zhu, 2011, 2012a). The main probabilistic analysis of this process is developed stating, in particular, first‐order and second‐order stationarity conditions. The existence of a strictly stationary and ergodic solution is established in a subclass including the Poisson and generalized Poisson INGARCH models. 相似文献