全文获取类型
收费全文 | 290篇 |
免费 | 17篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 1篇 |
综合类 | 4篇 |
化学工业 | 80篇 |
金属工艺 | 6篇 |
机械仪表 | 6篇 |
建筑科学 | 13篇 |
矿业工程 | 3篇 |
能源动力 | 8篇 |
轻工业 | 27篇 |
水利工程 | 1篇 |
无线电 | 29篇 |
一般工业技术 | 64篇 |
冶金工业 | 16篇 |
自动化技术 | 51篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 10篇 |
2013年 | 30篇 |
2012年 | 9篇 |
2011年 | 26篇 |
2010年 | 18篇 |
2009年 | 17篇 |
2008年 | 16篇 |
2007年 | 15篇 |
2006年 | 2篇 |
2005年 | 9篇 |
2004年 | 11篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 9篇 |
1999年 | 9篇 |
1998年 | 9篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1994年 | 3篇 |
1993年 | 5篇 |
1992年 | 8篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 6篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1979年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有309条查询结果,搜索用时 0 毫秒
61.
Eshuis Elise H. ter Vrugte Judith Anjewierden Anjo Bollen Lars Sikken Jakob de Jong Ton 《International Journal of Computer-Supported Collaborative Learning》2019,14(1):53-76
International Journal of Computer-Supported Collaborative Learning - New societal demands call for schools to train students’ collaboration skills. However, research thus far has focused... 相似文献
62.
Ton V. W. Janssens Bjerne S. Clausen Britt Hvolbæk Hanne Falsig Claus H. Christensen Thomas Bligaard Jens K. Nørskov 《Topics in Catalysis》2007,44(1-2):15-26
The origin of the extraordinary catalytic activity of gold nanoparticles is discussed on the basis of density-functional calculations,
adsorption studies on single crystal surfaces, and activity measurements on well characterized supported gold particles. A
number of factors are identified contributing to the activity, and it is suggested that it is useful to consider low-coordinated
Au atoms as the active sites, for example, CO oxidation and that the effect of the support can be viewed as structural and
electronic promotion. We identify the adsorption energy of oxygen and the Au-support interface energy as important parameters
determining the catalytic activity. 相似文献
63.
The morphology developing during the spinodal decomposition process of polystyrene (PS)/poly(vinyl methyl ether) (PVME) blends was successfully controlled by photo-crosslink reactions between PS chains. The crosslink reaction was carried out by taking advantage of the photodimerization of anthracene moieties that are labeled on PS chains. Effects of photo-crosslinks on the morphology induced by temperature jumps (T-jump) from the one-phase region into the spinodal region were examined under several experimental conditions such as T-jump depths and irradiation times. It was found that the concentration fluctuations developing during the spinodal decomposition process were efficiently frozen upon irradiation using a XeF excimer laser as well as a mercury (Hg) lamp. Furthermore, these ordered structures are quite stable upon annealing. These results demonstrate that the morphology developing during the spinodal decomposition process can be well controlled by easily accessible light sources such as high pressure mercury lamps. Thus the photo-crosslink reaction described in this work can provide the basis for a potential technique to design multiphase polymer materials with controllable ordered structures. 相似文献
64.
Abbas Ghanbari Marie‐Claude Heuzey Pierre J Carreau Minh‐Tan Ton‐That 《Polymer International》2013,62(3):439-448
Poly(ethylene terephthalate) (PET) nanocomposite films containing two different organoclays, Cloisite 30B® (C30B) and Nanomer I.28E® (N28E), were prepared by melt blending. In order to increase the gallery spacing of the clay particles, a sulfopolyester (PET ionomer or PETi) was added to the nanocomposites via a master‐batch approach. The morphological, thermal and gas barrier characteristics of the nanocomposite films were studied using several characterization techniques such as scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, differential scanning calorimetry, dynamic mechanical analysis, rheometry and oxygen permeability. PET and PETi were found to form immiscible polymer blends and the nanoparticles were preferentially located in the PETi dispersed phase. A better dispersion of clay was obtained for nanocomposites containing N28E with PETi. On the contrary, for nanocomposites containing C30B and PETi, the number of tactoids increased and the clay distribution and dispersion became worse than for C30B alone. Overall, the best properties were obtained for the PET/C30B nanocomposite without PETi. Higher crystallinity was found for all nanocomposite films in comparison to that of neat PET. © 2012 Society of Chemical Industry 相似文献
65.
66.
67.
68.
69.
NOW IS THE TIME TO PLAN FOR THE integration of signifi cant quantities of solar energy into the electricity grid. Although solar energy constitutes a very small portion of our energy system today, the size of the resource is enormous: The earth receives more energy from the sun in one hour than the global population uses in an entire year. In addition, the solar photovoltaic (PV) industry is growing very rapidly, sustaining an annual growth rate of more than 40% for the last decade. The combination of this rapid growth, falling costs, and a vast technical potential could make solar energy a serious contender for meeting our future energy needs. 相似文献
70.
Maryam Dini Tahereh Mousavand Pierre J. Carreau Musa R. Kamal Minh‐Tan Ton‐That 《Polymer Engineering and Science》2014,54(8):1879-1892
Poly(ethylene terephthalate) (PET)/Cloisite 30B (C30B) nanocomposites containing different concentrations of the organoclay were prepared using two different twin‐screw extrusion processes: conventional melt mixing and water‐assisted melt mixing. The reduction of the molecular weight of the PET matrix, caused by hydrolysis during the water‐assisted extrusion, was compensated by subsequent solid‐state polymerization (SSP). X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy analyses showed intercalated/exfoliated morphology in all PET/C30B nanocomposites, with a higher degree of intercalation and delamination for the water‐assisted process. Rheological, thermal, mechanical, and gas barrier properties of the PET nanocomposites were also studied. Enhanced mechanical and barrier properties were obtained in PET‐C30B nanocomposites compared to the neat PET. The nanocomposites exhibited higher tensile modulus and lower oxygen permeability after SSP. The elongation at break was significantly higher for SSP nanocomposites than for nanocomposites processed by conventional melt mixing. POLYM. ENG. SCI., 54:1879–1892, 2014. © 2013 Society of Plastics Engineers 相似文献