全文获取类型
收费全文 | 1559篇 |
免费 | 88篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 15篇 |
综合类 | 1篇 |
化学工业 | 386篇 |
金属工艺 | 32篇 |
机械仪表 | 41篇 |
建筑科学 | 63篇 |
矿业工程 | 3篇 |
能源动力 | 61篇 |
轻工业 | 196篇 |
水利工程 | 17篇 |
石油天然气 | 6篇 |
武器工业 | 1篇 |
无线电 | 156篇 |
一般工业技术 | 293篇 |
冶金工业 | 82篇 |
原子能技术 | 9篇 |
自动化技术 | 288篇 |
出版年
2024年 | 2篇 |
2023年 | 26篇 |
2022年 | 55篇 |
2021年 | 66篇 |
2020年 | 55篇 |
2019年 | 60篇 |
2018年 | 57篇 |
2017年 | 56篇 |
2016年 | 50篇 |
2015年 | 53篇 |
2014年 | 67篇 |
2013年 | 128篇 |
2012年 | 97篇 |
2011年 | 137篇 |
2010年 | 93篇 |
2009年 | 75篇 |
2008年 | 101篇 |
2007年 | 69篇 |
2006年 | 59篇 |
2005年 | 44篇 |
2004年 | 43篇 |
2003年 | 46篇 |
2002年 | 33篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 18篇 |
1997年 | 15篇 |
1996年 | 14篇 |
1995年 | 13篇 |
1994年 | 11篇 |
1993年 | 14篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1985年 | 11篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1979年 | 2篇 |
1976年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有1650条查询结果,搜索用时 15 毫秒
51.
Data-set of monthly global solar irradiance covering periods of at least 20 years over selected stations in Nigeria have been utilised to investigate the sky optical conditions over the five major vegetation zones of the country. The monthly variation of the clearness index for the selected stations has been investigated. Results show that the clearness index has its minimum in August which indicates reduced insolation during the monsoon month of August and maximum around November, December and February which shows high insolation. Statistical analysis of the monthly clearness index which gives the percentage depletion by the sky of the incoming insolation and the subsequent characterisation of the sky conditions based on this were also done. The results show that cloudy sky conditions prevail in the rainforest and mangrove swamp zones (e.g. Lagos, KT=0.40) while clear sky conditions prevail in the Sudan and Sahel vegetation (e.g. Nguru KT=0.66) and Kano (KT=0.65). 相似文献
52.
Emmanuel Creusé Patrick Dular Serge Nicaise 《Computers & Mathematics with Applications》2019,77(6):1563-1582
In this paper, we deal with some magnetostatic models considered in vector potential formulations and solved by a Finite Element solver. In order to ensure the uniqueness of the solution, a gauge condition has to be imposed, and several possibilities occur. Moreover, the source term has to be correctly defined to ensure a physically admissible solution. We show the equivalence between some of these choices for several kinds of boundary conditions. Moreover, we highlight their characteristic behaviors on some numerical benchmarks to illustrate our theoretical results. 相似文献
53.
Emmanuel Bernuau Andrey Polyakov Denis Efimov Wilfrid Perruquetti 《Systems & Control Letters》2013,62(12):1159-1167
Several conditions are proposed to check different robustness properties (ISS, iISS, IOSS and OSS) for generic nonlinear systems applying the weighted homogeneity concept (global or local). The advantages of this result are that, under some mild conditions, the system robustness can be established as a function of the degree of homogeneity. 相似文献
54.
Mohammadreza Kosari Uzma Anjum Shibo Xi Alvin M. H. Lim Abdul Majeed Seayad Emmanuel A. J. Raj Sergey M. Kozlov Armando Borgna Hua Chun Zeng 《Advanced functional materials》2021,31(47):2102896
Beyond the catalytic activity of nanocatalysts, the support with architectural design and explicit boundary could also promote the overall performance through improving the diffusion process, highlighting additional support for the morphology-dependent activity. To delineate this, herein, a novel mazelike-reactor framework, namely multi-voids mesoporous silica sphere (MVmSiO2), is carved through a top-down approach by endowing core-shell porosity premade Stöber SiO2 spheres. The precisely-engineered MVmSiO2 with peripheral one-dimensional pores in the shell and interconnecting compartmented voids in the core region is simulated to prove combined hierarchical and structural superiority over its analogous counterparts. Supported with CuZn-based alloys, mazelike MVmSiO2 nanoreactor experimentally demonstrated its expected workability in model gas-phase CO2 hydrogenation reaction where enhanced CO2 activity, good methanol yield, and more importantly, a prolonged stable performance are realized. While tuning the nanoreactor composition besides morphology optimization could further increase the catalytic performance, it is accentuated that the morphological architecture of support further boosts the reaction performance apart from comprehensive compositional optimization. In addition to the found morphological restraints and size-confinement effects imposed by MVmSiO2, active sites of catalysts are also investigated by exploring the size difference of the confined CuZn alloy nanoparticles in CO2 hydrogenation employing both in-situ experimental characterizations and density functional theory calculations. 相似文献
55.
56.
Poulia Anthoula Georgatis Emmanuel Karantzalis Alexander 《Metals and Materials International》2019,25(6):1529-1540
Metals and Materials International - MoTaNbVTi refractory high entropy alloy was synthesized by the vacuum arc melting technique in its equi-atomic composition. The modification of its... 相似文献
57.
Paul Beaucaire Nicolas Gayton Emmanuel Duc Maurice Lemaire Jean-Yves Dantan 《Computers & Industrial Engineering》2012
The quality level of a mechanism can be evaluated a posteriori after several months by following the number of warranty returns. However, it is more interesting to evaluate a predicted quality level in the design stage: this is one of the aims of statistical tolerance analysis. A possible method consists of computing the defect probability (PD) expressed in ppm. It represents the probability that a functional requirement will not be satisfied in mass production. For assembly reasons, many hyperstatic mechanisms require gaps, which their functional requirements depend on. The defect probability assessment of such mechanisms is not straightforward, and requires advanced numerical methods. This problem particularly interests the VALEO W.S. company, which experiences problems with an assembly containing gaps. This paper proposes an innovative methodology to formulate and compute the defect probability of hyperstatic mechanisms with gaps in two steps. First, a complex feasibility problem is converted into a simpler problem. Then the defect probability is efficiently computed thanks to system reliability methods and the m-dimensional multivariate normal distribution Φm. Finally, a sensitivity analysis is provided to improve the original design. The whole approach is illustrated with an industrial case study, but can be adapted to other similar problems. 相似文献
58.
Riad Kahoul Fran?ois Gueyffier Emmanuel Amsallem Margaret Haugh Ivanny Marchant Fran?ois-Henri Boissel Jean-Pierre Boissel 《Journal of the Royal Society Interface》2014,11(100)
Healthcare authorities make difficult decisions about how to spend limited budgets for interventions that guarantee the best cost-efficacy ratio. We propose a novel approach for treatment decision-making, OMES—in French: Objectif thérapeutique Modèle Effet Seuil (in English: Therapeutic Objective–Threshold–Effect Model; TOTEM). This approach takes into consideration results from clinical trials, adjusted for the patients'' characteristics in treatment decision-making. We compared OMES with the French clinical practice guidelines (CPGs) for the management of dyslipidemia with statin in a computer-generated realistic virtual population, representing the adult French population, in terms of the number of all-cause deaths avoided (number of avoided events: NAEs) under treatment and the individual absolute benefit. The total budget was fixed at the annual amount reimbursed by the French social security for statins. With the CPGs, the NAEs was 292 for an annual cost of 122.54 M€ compared with 443 with OMES. For a fixed NAEs, OMES reduced costs by 50% (60.53 M€ yr−1). The results demonstrate that OMES is at least as good as, and even better than, the standard CPGs when applied to the same population. Hence the OMES approach is a practical, useful alternative which will help to overcome the limitations of treatment decision-making based uniquely on CPGs. 相似文献
59.
Aoues Younès Pagnacco Emmanuel Lemosse Didier Khalij Leila 《Structural and Multidisciplinary Optimization》2017,55(4):1471-1482
Structural and Multidisciplinary Optimization - The reliability-based design optimization (RBDO) aims to find the most balanced design through a compromise between cost and safety when... 相似文献
60.
Impact of oxygen transport properties on the kinetic modeling of polypropylene thermal oxidation. II. Effect of oxygen diffusivity
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alexandre François‐Heude Emmanuel Richaud Alain Guinault Eric Desnoux Xavier Colin 《应用聚合物科学杂志》2015,132(6)
The kinetic model, established in a previous article (François‐Heude et al., J. Appl. Polym. Sci., in press) to predict the homogeneous oxidation in iPP films typically thinner than 100 µm, is now extended to simulate the oxidation profiles in thicker plates by coupling the oxygen diffusion and its consumption by the chemical reactions. In this perspective, oxygen transport properties (namely oxygen solubility, diffusivity, and permeability) are measured by permeametry on a reference iPP. These values are compared with an exhaustive compilation of literature data to evaluate their variability among the whole iPP family, which one has been reasonably ascribed to initial differences in polymer morphology, but also to evaluate their consistency, especially their temperature dependence between 20 and 140°C. Failing to simulate oxidation profiles, the kinetic model is then used as an inverse resolution method for estimating more satisfactory values of oxygen transport properties. It is thus evidenced that the crystallinity changes induced by thermal oxidation largely explains the dramatic decrease in oxygen penetration toward the sample core just after the induction period. A strategy aimed for introducing the relationship between the polymer crystalline morphology and oxygen transport properties into the kinetic model is given in the graphical abstract, although the effect of polymer polarity remains to be established prior to this implementation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41562. 相似文献