全文获取类型
收费全文 | 1185篇 |
免费 | 84篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 338篇 |
金属工艺 | 45篇 |
机械仪表 | 60篇 |
建筑科学 | 37篇 |
矿业工程 | 2篇 |
能源动力 | 59篇 |
轻工业 | 202篇 |
水利工程 | 4篇 |
石油天然气 | 7篇 |
无线电 | 77篇 |
一般工业技术 | 218篇 |
冶金工业 | 37篇 |
原子能技术 | 11篇 |
自动化技术 | 165篇 |
出版年
2024年 | 9篇 |
2023年 | 24篇 |
2022年 | 24篇 |
2021年 | 56篇 |
2020年 | 45篇 |
2019年 | 33篇 |
2018年 | 61篇 |
2017年 | 60篇 |
2016年 | 76篇 |
2015年 | 60篇 |
2014年 | 87篇 |
2013年 | 219篇 |
2012年 | 56篇 |
2011年 | 67篇 |
2010年 | 72篇 |
2009年 | 74篇 |
2008年 | 51篇 |
2007年 | 30篇 |
2006年 | 33篇 |
2005年 | 15篇 |
2004年 | 16篇 |
2003年 | 7篇 |
2002年 | 17篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 10篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1996年 | 10篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 4篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1973年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1271条查询结果,搜索用时 31 毫秒
1.
2.
3.
4.
Physically based simulation of human hair is a well studied and well known problem. But the “pure” physically based representation of hair (and other animation elements) is not the only concern of the animators, who want to “control” the creation and animation phases of the content. This paper describes a sketch-based tool, with which a user can both create hair models with different styling parameters and produce animations of these created hair models using physically and key frame-based techniques. The model creation and animation production tasks are all performed with direct manipulation techniques in real-time. 相似文献
5.
A protein which masks galactose receptor mediated phage susceptibility in Lactococcus lactis subsp. lactis MPL56 总被引:1,自引:0,他引:1
Yasin Tuncer & Mustafa Akçelik 《International Journal of Food Science & Technology》2002,37(2):139-144
A 28.5-kb plasmid, isolated from Lactococcus lactis subsp. lactis MPL56, causes complete inhibition of four lactococcal phages. Cell wall characteristics of wild-type strain MPL56 were compared with its 28.5 kb plasmid-cured, phage-sensitive derivative MPL56-22. After proteolytic enzyme treatments, adsorption of phages occurred at high levels, an example is 94.6–98.5% in MPL56 cells. Analysis of cell wall extracts of MPL56-22 by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) indicated that the only difference between strains was the 55.4 kDa band in protein patterns of MPL56. Adsorption of the four phages was completely inhibited when MPL56-22 cells were subjected to SDS, Triton-X-100, HCl and NaOH treatments. Lectins that were specific for glucose/mannose and N-acetylglucosamine did not prevent adsorption of phages in cell wall extracts of MPL 56-22. However a lectin specific for galactose (MCA; Momordica charantia ) completely inhibited adsorption of these phages in cell wall extracts of MPL56-22. HPLC patterns of cell wall carbohydrates of MPL56-22 and its HCl treated preparations showed that the most prevalent difference was the galactose on untreated MPL56-22 cell wall chromatograms. 相似文献
6.
Relation between abrasion resistance and flexural strength of high volume fly ash concrete 总被引:2,自引:0,他引:2
In this paper, abrasion of high volume fly ash (HVFA) concretes made with 50% and 70% of cement replacement with fly ash was
assessed in terms of its relation to flexural tensile strength. Comparisons were made between normal Portland cement (NPC)
concrete and fly ash concrete. Comparisons were also made between fly ash concretes. Investigation results have shown that
the abrasion resistance increased as flexural tensile strength increased. Analysis of the results showed that, for concrete
with tensile strength of greater than 4–5 MPa, the abrasion resistance of HVFA concrete with 70% replacement with cement was
found to be higher than that of counterpart control NPC concrete and concrete made with 50% fly ash. The comparison between
the relation of abrasion to compressive strength and abrasion to flexural tensile strength made in terms of R2 of the linear regression showed that a stronger relation existed between abrasion and flexural tensile strength than that
of abrasion to compressive strength of the concrete studied.
Résumé L'étude a pour but d'estimer la relation entre la résistance à l'usure avec la résistance à la traction en flexion des bétons contenant de 50% et 70% de cendres volantes. On a comparé le béton pur au béton contenant des cendres volantes. Des comparaisons ont été faites également entre les différents bétons contenant des cendres volantes. Les resultats de la recherche ont montré que la résistance à l'usure augmente à mesure que la résistance à la traction en flexion de 4∼5 MPa ont une résistance à l'usure plus grande s'ils contienneint 70% de cendres volantes que s'ils étaient purs ou contenaient 50% de cendres volantes. La comparaison entre les relation de la résistance à l'usure en compression et de la résistance à l'usure en traction a été établie en termes de R2 de la régression linéaire. On a prouvé qu'une relation plus forte a été obtenue entre la résistance à l'usure et la résistance à la traction en flexion par rapport à la résistance à l'usure en compression du béton étudié.相似文献
7.
The aim of this research was to develop a method of local production of collagen graft materials which are presently imported. The following methods were used to produce collagen membrane and sponge from human placentas and rat tail tendons. Collagen type I was isolated from human placenta and rat tail tendon by acetic acid extraction and characterised by SDS-PAGE. The collagen sponge was prepared by dissolving the collagen in HCl. The resulting dispersion was poured into a glass container, freeze-dried and then cross-linked by immersion in glutaraldehyde solution. It was then washed with distilled water and freeze-dried again. The collagen membrane was also similarly prepared by dispersing lyophilized collagen in HCl but then mixed with glutaraldehyde, exposed to U.V. light and later air dried. 相似文献
8.
This study proposes Chebyshev wavelet collocation method for partial differential equation and applies to solve magnetohydrodynamic (MHD) flow equations in a rectangular duct in the presence of transverse external oblique magnetic field. Approximate solutions of velocity and induced magnetic field are obtained for steady‐state, fully developed, incompressible flow for a conducting fluid inside the duct. Numerical results of the MHD flow problem show that the accuracy of proposed method is quite good even in the case of a small number of grid points. The results for velocity and induced magnetic field are visualized in terms of graphics for values of Hartmann number Ha ≤ 1000.
相似文献9.
Conventional constant false alarm rate (CFAR) methods use a fixed number of cells to estimate the background variance. For homogeneous environments, it is desirable to increase the number of cells, at the cost of increased computation and memory requirements, in order to improve the estimation performance. For nonhomogeneous environments, it is desirable to use less number of cells in order to reduce the number of false alarms around the clutter edges. In this work, we present a solution with two exponential smoothers (first order IIR filters) having different time-constants to leverage the conflicting requirements of homogeneous and nonhomogeneous environments. The system is designed to use the filter having the large time-constant in homogeneous environments and to promptly switch to the filter having the small time constant once a clutter edge is encountered. The main advantages of proposed Switching IIR CFAR method are computational simplicity, small memory requirement (in comparison to windowing based methods) and its good performance in homogeneous environments (due to the large time-constant smoother) and rapid adaptation to clutter edges (due to the small time-constant smoother). 相似文献
10.
Jianu R Demiralp Ç Laidlaw DH 《IEEE transactions on visualization and computer graphics》2012,18(6):978-987
We introduce two-dimensional neural maps for exploring connectivity in the brain. For this, we create standard streamtube models from diffusion-weighted brain imaging data sets along with neural paths hierarchically projected into the plane. These planar neural maps combine desirable properties of low-dimensional representations, such as visual clarity and ease of tract-of-interest selection, with the anatomical familiarity of 3D brain models and planar sectional views. We distribute this type of visualization both in a traditional stand-alone interactive application and as a novel, lightweight web-accessible system. The web interface integrates precomputed neural-path representations into a geographical digital-maps framework with associated labels, metrics, statistics, and linkouts. Anecdotal and quantitative comparisons of the present method with a recently proposed 2D point representation suggest that our representation is more intuitive and easier to use and learn. Similarly, users are faster and more accurate in selecting bundles using the 2D path representation than the 2D point representation. Finally, expert feedback on the web interface suggests that it can be useful for collaboration as well as quick exploration of data. 相似文献