全文获取类型
收费全文 | 1461篇 |
免费 | 65篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 17篇 |
综合类 | 3篇 |
化学工业 | 360篇 |
金属工艺 | 37篇 |
机械仪表 | 25篇 |
建筑科学 | 55篇 |
矿业工程 | 1篇 |
能源动力 | 52篇 |
轻工业 | 178篇 |
水利工程 | 13篇 |
石油天然气 | 12篇 |
无线电 | 202篇 |
一般工业技术 | 232篇 |
冶金工业 | 109篇 |
原子能技术 | 9篇 |
自动化技术 | 228篇 |
出版年
2024年 | 5篇 |
2023年 | 46篇 |
2022年 | 67篇 |
2021年 | 145篇 |
2020年 | 88篇 |
2019年 | 61篇 |
2018年 | 91篇 |
2017年 | 53篇 |
2016年 | 120篇 |
2015年 | 37篇 |
2014年 | 63篇 |
2013年 | 81篇 |
2012年 | 67篇 |
2011年 | 78篇 |
2010年 | 60篇 |
2009年 | 48篇 |
2008年 | 50篇 |
2007年 | 43篇 |
2006年 | 27篇 |
2005年 | 20篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 14篇 |
2001年 | 16篇 |
2000年 | 10篇 |
1999年 | 8篇 |
1998年 | 28篇 |
1997年 | 19篇 |
1996年 | 20篇 |
1995年 | 17篇 |
1994年 | 8篇 |
1993年 | 13篇 |
1992年 | 8篇 |
1991年 | 3篇 |
1990年 | 8篇 |
1989年 | 10篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 4篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 4篇 |
排序方式: 共有1533条查询结果,搜索用时 15 毫秒
101.
102.
Huong Quynh Dinh Turk G. Slabaugh G. 《IEEE transactions on pattern analysis and machine intelligence》2002,24(10):1358-1371
We present a new method of surface reconstruction that generates smooth and seamless models from sparse, noisy, nonuniform, and low resolution range data. Data acquisition techniques from computer vision, such as stereo range images and space carving, produce 3D point sets that are imprecise and nonuniform when compared to laser or optical range scanners. Traditional reconstruction algorithms designed for dense and precise data do not produce smooth reconstructions when applied to vision-based data sets. Our method constructs a 3D implicit surface, formulated as a sum of weighted radial basis functions. We achieve three primary advantages over existing algorithms: (1) the implicit functions we construct estimate the surface well in regions where there is little data, (2) the reconstructed surface is insensitive to noise in data acquisition because we can allow the surface to approximate, rather than exactly interpolate, the data, and (3) the reconstructed surface is locally detailed, yet globally smooth, because we use radial basis functions that achieve multiple orders of smoothness. 相似文献
103.
A Bhandari DG Jones JR Schullek K Vo CA Schunk LL Tamanaha D Chen Z Yuan MC Needels MA Gallop 《Canadian Metallurgical Quarterly》1998,8(17):2303-2308
Phosphomannose Isomerase (PMI) has been shown by genetic methods to be an essential enzyme in fungal cell wall biosynthesis. The PMI inhibitor AF14049 was discovered as an unanticipated side product from high-throughput library screening against the enzyme from C, albicans. Solid-phase synthetic methods were developed and a series of libraries and discrete analogs synthesized to explore SAR around AF14049. 相似文献
104.
N. V. Vo C. C. Neo A. J. Bourdillon S. X. Dou H. K. Liu 《Journal of Superconductivity and Novel Magnetism》1996,9(6):605-614
It has been found that the degree of thermal stability of Bi(Pb)-2223/Ag pancake-shaped coils at 77 K can be determined by controlling the amount of matrix and superconducting materials during processing. The intermediate deformation step between sintering stages has been found to be crucial in optimizing the performance of the processed composite tapes as well as governing the thermal stability of the subsequently made pancake-shaped coils. Results obtained from numerical analysis of the finite element method has shown that monolayer coils produced from Bi(Pb)-2223/Ag composite tapes are thermally very stable with high values of the fill factor. However, increasing the number of co-wound tapes would require either a reduction in the fill factor or an increase in cooling rate for thermal stability to be sustained as would otherwise be achieved with the metallurgically same single tape. 相似文献
105.
106.
Dong Thi Thanh Thu A Lipińska L K?yszejko-Stefanowicz 《Canadian Metallurgical Quarterly》1981,28(2):175-181
1. SDS-polyacrylamide gel electrophoresis showed some slight quantitative species-dependent differences in total non-histone chromatin proteins and nuclear phosphoproteins (phenol-soluble fraction of non-histone chromatin proteins) but no differences in the DNA-binding non-histone proteins. 2. Comparative studies on DNA and RNA content, and amino acid composition of nuclear phosphoproteins and DNA-binding non-histone proteins of pancreas demonstrated a striking similarity between the two species studied. 相似文献
107.
The transfer function of the model of imperfectly mixed tanks in series, involving the three parameters p, m and n, is presented. It is thus possible to evaluate easily the residence time distribution curve E(θ) and the output response for a given input. This model is compared to the axial dispersion model, through the variance of the curve for E(θ) and the average absolute error between theoretical values and experimental data. A graphical representation relates the Péclet number of the axial dispersion model to the parameters of the p, m, n model and also to the variance of the curve for E(θ). The p, m, n model gives a good approximation of experimental data; it is shown to be more versatile than the axial dispersion model. 相似文献
108.
The sterol substrate analog 25-thialanosterol and its corresponding sulfonium salt were evaluated for their ability to serve
as antifungal agents and to inhibit sterol methyltransferase (SMT) activity in Candida albicans. Both compounds inhibited cell proliferation, were fungistatic, interrupted the yeastlike-form to germ-tube-form transition,
and resulted in the accumulation of zymosterol and related Δ24-sterols concurrent with a decrease in ergosterol, as was expected for the specific inhibition of SMT activity. Feedback on
sterol synthesis was evidenced by elevated levels of cellular sterols in treated vs. control cultures. However, neither farnesol
nor squalene accumulated in significant amounts in treated cultures, suggesting that carbon flux is channeled from the isoprenoid
pathway to the sterol pathway with minor interruption or redirection until blockage at the C-methylation step. Activity assays using solubilized C. albicans SMT confirmed the inhibitors impair SMT action. Kinetic analysis indicated that 25-thialanosterol inhibited SMT with the
properties of a time-dependent mechanismbased inactivator K
i of 5 =gmM and apparent k
inact of 0.013 min−1, whereas the corresponding sulfonium salt was a reversible-type transition state analog exhibiting a K
i of 20 nM. The results are interpreted to imply changes in ergosterol homeostasis as influenced by SMT activity can control
growth and the morphological transition in C. albicans, possibly affecting disease development. 相似文献
109.
The Internet is a set of interconnected domains in which different QoS technologies can be deployed. The dynamic provision of end-to-end QoS over heterogeneousip networks assumes the negotiation of mutually acceptablesla. This paper presents the concept of intra-, inter- and multiple-domain service level negotiation using thecops-sls protocol. The negotiation process gives different parties in the negotiation the ability to agree upon the service level that a data stream can obtain, along with the permissible pricing of the service. 相似文献
110.
Container terminal operation and operations research - a classification and literature review 总被引:23,自引:11,他引:12
In the last four decades the container as an essential part of a unit-load-concept has achieved undoubted importance in international sea freight transportation. With ever increasing containerization the number of seaport container terminals and competition among them have become quite remarkable. Operations are nowadays unthinkable without effective and efficient use of information technology as well as appropriate optimization (operations research) methods. In this paper we describe and classify the main logistics processes and operations in container terminals and present a survey of methods for their optimization.
Correspondence to: Stefan Voß 相似文献