全文获取类型
收费全文 | 1163篇 |
免费 | 24篇 |
专业分类
电工技术 | 39篇 |
化学工业 | 250篇 |
金属工艺 | 28篇 |
机械仪表 | 33篇 |
建筑科学 | 21篇 |
矿业工程 | 2篇 |
能源动力 | 25篇 |
轻工业 | 108篇 |
水利工程 | 5篇 |
无线电 | 118篇 |
一般工业技术 | 204篇 |
冶金工业 | 219篇 |
原子能技术 | 31篇 |
自动化技术 | 104篇 |
出版年
2023年 | 4篇 |
2022年 | 15篇 |
2021年 | 20篇 |
2020年 | 7篇 |
2019年 | 16篇 |
2018年 | 24篇 |
2017年 | 21篇 |
2016年 | 34篇 |
2015年 | 9篇 |
2014年 | 30篇 |
2013年 | 68篇 |
2012年 | 49篇 |
2011年 | 61篇 |
2010年 | 50篇 |
2009年 | 46篇 |
2008年 | 70篇 |
2007年 | 51篇 |
2006年 | 43篇 |
2005年 | 31篇 |
2004年 | 23篇 |
2003年 | 25篇 |
2002年 | 16篇 |
2001年 | 18篇 |
2000年 | 21篇 |
1999年 | 21篇 |
1998年 | 85篇 |
1997年 | 58篇 |
1996年 | 46篇 |
1995年 | 29篇 |
1994年 | 15篇 |
1993年 | 24篇 |
1992年 | 10篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 10篇 |
1986年 | 11篇 |
1985年 | 9篇 |
1984年 | 12篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1974年 | 6篇 |
1972年 | 3篇 |
排序方式: 共有1187条查询结果,搜索用时 15 毫秒
121.
122.
123.
Chang Seok Ki Jong Wook Kim Jin Ho Hyun Ki Hoon Lee Masahiro Hattori Dong Kyun Rah Young Hwan Park 《应用聚合物科学杂志》2007,106(6):3922-3928
Practical application to three‐dimensional (3‐D) tissue culture has been limited by the structural restriction of two‐dimensional (2‐D) nature of electrospun nanofiber mat. In this study, for constructing 3‐D nanofibrous structure as real 3‐D tissue engineering scaffold, we developed new fabrication process with silk fibroin (SF) by electrospinning and evaluated the features of this SF nanofiber scaffold (SFNS) through morphological and cell‐culture analyses. Foam type of the SFNS exhibited high porosity as well as large pores and its cell proliferation well occurred inside (inner spaces of pores), which makes this suitable for 3‐D cell‐culture scaffold. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
124.
Md. Nazrul Islam Keisuke Ando Hidefumi Yamauchi Nobuaki Hattori 《Holz als Roh- und Werkstoff》2009,67(2):129-133
Penetration of liquid by passive impregnation method for Douglas-fir (Pseudotsuga menziesii Franco), sugi (Cryptomeria japonica D. Don) and Japanese larch (Larix leptolepis Gordon) was studied. Effects of initial moisture content of sugi (16, 43 and 70% moisture content) on liquid penetration were also studied. Dried Douglas-fir (mc=14%) and sugi (mc=16%), and green Japanese larch (mc=45%) and sugi (mc=70%) were treated by passive impregnation method for penetration analysis. It was observed that dried sugi had the highest level of liquid penetration both in length (170 mm) and width (8 mm) for all measured sections followed by green sugi, green Japanese larch and dried Douglas-fir. In case of different initial moisture content, the highest absorption (624 kg/m3) and penetration (maximum 87 and 96% at cross and longitudinal surfaces, respectively) was observed for sugi having the lowest initial moisture content under the same passive impregnation conditions. Absorption and penetration decreased with the increase of initial moisture content for sugi. These results could help in designing incising pattern and density, as well as solving the problems related to high initial moisture content of wood for passive impregnation. 相似文献
125.
Michihiro Asakawa Sadayuki Kaneko Reiji Hattori 《Journal of the Society for Information Display》2011,19(10):693-699
Abstract— A shrunk multiline addressing method (SMLA) in a passive‐matrix‐driven liquid powder display will be discussed. An algorithm to generate SMLA data that effectively reduces the number of scanning lines has been devised. The update time is reduced by 44.5% on average, and this reduction is maintained despite increased sizes of the images. The SMLA data generated by this algorithm is applied to e‐paper panels, thereby confirming the reduction in update time and that the image quality of the panels driven by SMLA is equal to that of conventionally driven ones. 相似文献
126.
Teruhiro Kasagi Takanori Tsutaoka Kenichi Hatakeyama 《Journal of the European Ceramic Society》2010,30(2):401-406
Dielectric and electrical properties of Permalloy granular composite materials have been studied considering the application to left-handed meta-materials. Surface oxidized Permalloy particles have high surface electrical resistance; the eddy current effect in the composite structure is suppressed. The electrical conductivity of compacted Permalloy particles increases with increasing temperature and indicates the semiconductive layer formation on the particle. The low frequency ac electrical conductivity of Permalloy composite materials shows a drastic increase in the particle content between 50 and 60 vol.%. Electrical permittivity spectra of Permalloy composites show a non-metallic characteristic and the enhancement of permittivity is observed with increase of Permalloy particle content. 相似文献
127.
Harumi Yokokawa Natsuko Sakai Teruhisa Horita Katsuhiko Yamaji Yueping Xiong Takanori Otake Hiroo Yugami Tatsuya Kawada Junichiro Mizusaki 《Journal of Phase Equilibria》2001,22(3):331-338
Phase diagram calculations that were made previously for the ZrO2-MO m/2 (m = 2, 3, 4) systems and for the ZrO2-YO1.5-MO m/2 (M = transition metals) systems have been extended to the ZrO2-YO1.5-CeO2(-CeO1.5) system to make an attempt to explain (1) thermogravimetric (TG) results as a function of oxygen potential, (2) electronic conductivity as a function of oxygen potential, and (3) a miscibility gap observed in air. The interaction parameters for the CeO2-CeO1.5-YO1.5 system were obtained from the reported oxygen nonstoichiometry in CeO2−x and rate earth doped ceria, (Ce,RE)O2−δ . The interaction parameters for the ZrO2-CeO2 subsystem were obtained so as to reproduce the observed miscibility gap at 1273 K. Those thermodynamic properties can reproduce consistently the experimental behaviors of the electronic conductivity and the TG results in the (Zr1−x Ce x )0.8Y0.2O1.9 solid solutions; these indicate the enhancement of reduction of CeO2. 相似文献
128.
The authors have developed an experimental
in HDTV digital videocassette recorder (VCR). The VCR can record HDTV digital base-band signals for more than 64 min on a
in metal particle (MP) tape. An eight-to-eight modulation (
) scheme has been developed for this VCR to realize high-density recording. In order to suppress sufficiently the low-frequency components and reduce the occurrence probability of long-run-lengths for the recording data sequence, a new conversion table and bit-rearrangement method have been introduced in this modulation scheme. This conversion table has been particularly structured to reduce run-length using the bit-rearrangement process. Three kinds of typical HDTV images were used to evaluate the performance compared with the scrambled-NRZ method. The run-length distribution and the frequency spectrum were calculated for each image. The results showed that the occurrence probability of long-run-lengths were well reduced and the low-frequency components along with the DC component were sufficiently suppressed. Cross-talk interferences and overwriting noises were also found to be much less than those for the scrambled-NRZ method. 相似文献
129.
K. Takahama M. Yokoyama S. Hirao S. Yamanaka M. Hattori 《Journal of Materials Science》1992,27(5):1297-1301
The interlayers of montmorillonite clay were pillared with silica-titania sol particles by ion exchange in aqueous solutions. The water in the pillared clay was substituted with ethanol which was in turn extracted with CO2 under supercritical conditions. This drying procedure avoids the formation of liquid-vapour interfaces which give rise to shrinkage of the swelled pillared structure. Highly porous structures with well developed card-house structures resulted. The pore structure was investigated and compared with that of samples prepared by conventional air-drying procedures. 相似文献
130.
Takanori Sone Hirokazu Akagi Hisao Watarai 《Journal of the American Ceramic Society》1991,74(12):3151-3153
Pore behavior as influenced by migration of an abnormal grain boundary was studied. The pore behavior during the discontinuous growth of hot-pressed spinel (MgAl2 O4 ) — whether the pore can move attached to the grain boundary — is particularly governed by the pore size and the matrix grain size. These phenomena can be understood from the interaction between the pore and the abnormal grain boundary. 相似文献