全文获取类型
收费全文 | 2627篇 |
免费 | 85篇 |
国内免费 | 7篇 |
学科分类
工业技术 | 2719篇 |
出版年
2021年 | 26篇 |
2020年 | 11篇 |
2019年 | 24篇 |
2018年 | 26篇 |
2017年 | 19篇 |
2016年 | 56篇 |
2015年 | 44篇 |
2014年 | 70篇 |
2013年 | 123篇 |
2012年 | 83篇 |
2011年 | 124篇 |
2010年 | 95篇 |
2009年 | 101篇 |
2008年 | 123篇 |
2007年 | 106篇 |
2006年 | 104篇 |
2005年 | 102篇 |
2004年 | 87篇 |
2003年 | 59篇 |
2002年 | 77篇 |
2001年 | 52篇 |
2000年 | 47篇 |
1999年 | 67篇 |
1998年 | 135篇 |
1997年 | 86篇 |
1996年 | 76篇 |
1995年 | 70篇 |
1994年 | 52篇 |
1993年 | 44篇 |
1992年 | 30篇 |
1991年 | 33篇 |
1990年 | 42篇 |
1989年 | 50篇 |
1988年 | 44篇 |
1987年 | 36篇 |
1986年 | 43篇 |
1985年 | 38篇 |
1984年 | 27篇 |
1983年 | 23篇 |
1982年 | 34篇 |
1981年 | 27篇 |
1980年 | 29篇 |
1979年 | 21篇 |
1978年 | 15篇 |
1977年 | 25篇 |
1976年 | 18篇 |
1975年 | 12篇 |
1967年 | 14篇 |
1966年 | 12篇 |
1965年 | 13篇 |
排序方式: 共有2719条查询结果,搜索用时 93 毫秒
61.
Shinichi Kitade Kazuo Asuka Isamu Akiba Yusuke Sanada Kazuo Sakurai Hiroyasu Masunaga 《Polymer》2013,54(1):246-257
Shear-induced crystallization of a long chain hyper-branched polypropylene (LCB-PP, denoted PP-3) was carried out at a relatively high temperature of 170 °C, close to its melting temperature of 158 °C. Small-angle X-ray scattering (SAXS) showed that the intensity ratio of the normal to the perpendicular to the shear (V/H) was always larger than 1 for PP-3, indicating that shish-like structures were predominately formed and further growth to kebab was suppressed in PP-3. The crystallization behavior of PP-3 can be explained by the nature of PP-3 that there were a large amount of crystallization nuclei due to their branching points, and the point-like precursors formed from these nuclei were arrayed linearly along the shear direction and transformed into thread-like precursors or premature shishs; however, owing to the large amount of branching, further progress in crystallization was suppressed. 相似文献
62.
63.
Shinsuke Takase Kazuo Kashiyama Seizo Tanaka Tayfun E. Tezduyar 《Computational Mechanics》2011,48(3):293-306
We show that combination of the Deforming-Spatial-Domain/Stabilized Space–Time and the Streamline-Upwind/Petrov–Galerkin formulations
can be used quite effectively for computation of shallow-water flows with moving shorelines. The combined formulation is supplemented
with a stabilization parameter that was originally introduced for compressible flows, a compressible-flow shock-capturing
parameter adapted for shallow-water flows, and remeshing based on using a background mesh. We present a number of test computations
and provide comparisons to theoretical results, experimental data and results computed with nonmoving meshes. 相似文献
64.
Hiroshi Saeki Hiroyasu EgoTakahiro Watanabe Katsuya IshibashiTakafumi Satoh Kazuo Miyamoto 《Vacuum》2011,85(10):975-977
A new vacuum seal for a rectangular flange used in r.f. equipments, was developed. The vacuum seal consists of a recess with a flat surface, machined into a rectangular flange, a rectangular metal gasket with a raised projection on one face, and a mating flange with a recess and raised projection. No leak greater than 1 × 10−10 Pa m3/s was found in leak tests, before and after baking cycles (100 °C, 12 h). 相似文献
65.
Tetsuya Tanigami Nobuyuki Maruyama Koji Yamazaki Yoko Ichikawa Hiroyuki Nagai Kaori Shimizu 《应用聚合物科学杂志》2002,86(7):1807-1815
An almost fully saponified atactic poly(vinyl alcohol) and an atactic poly(vinyl alcohol‐block‐vinyl acetate) of which degree of saponification is 89 mol % were blended by a solution casting method. The phase structure of the blend film was analyzed by optical microscopy, 13C‐NMR, and differential scanning calorimetry. The most remarkable structure of the blend was composed of cylindrical domains penetrating the film. The swelling behavior of the blend films was also investigated in the dimethylsulfoxide and water mixed solvents to find differences in solubility and diffusion behavior between the matrix and the domain. The cylindrical domains could be selectively dissolved away in water and the film became porous. We tried to change the size of the cylindrical domain with various film preparation conditions. This aimed to turn the film into the useful filter membrane. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1807–1815, 2002 相似文献
66.
Kazuo Kamagata 《应用聚合物科学杂志》1987,34(1):261-269
The intermolecular compound of 2,4-diamino-6-vinyl-s-triazine and isocyanuric acid was synthesized, and the glass transition temperature and the adhesive properties of the cured epoxide resin containing the above compound were studied. Epoxide reacted with amino groups of 2,4-diamino-6-vinyl-s-triazine and isocyanuric acid at the curing conditions of 150 to 180°C for 60 min and formed the cured compounds. The infrared spectra showed that epoxide reacted with isocyanuric acid in the presence of imidazole compounds and converted to 2-oxazolidinone compound on the curing process. The glass transition temperatures of the cured compounds having isocyanurate and 2-oxazolidinone rings in their structures were higher than that of the epoxide resin cured with imidazole and rise as the curing temperature rises, but fall as 2-oxazolidinone ring content increases in their cured compounds. The tensile shear and peel strengths of the steel and steel bonded with the cured compounds and the cured epoxide resin were measured at 25 and 150°C. The adhesive strengths were improved due to isocyanurate and 2-oxazolidinone rings formed in their cured compounds. 相似文献
67.
68.
Kodama K Fukuzawa S Nakayama H Sakamoto K Kigawa T Yabuki T Matsuda N Shirouzu M Takio K Yokoyama S Tachibana K 《Chembiochem : a European journal of chemical biology》2007,8(2):232-238
A new carbon-carbon bond has been regioselectively introduced into a target position (position 32 or 174) of the Ras protein by two types of organopalladium reactions (Mizoroki-Heck and Sonogashira reactions). Reaction conditions were screened by using a model peptide, and the stability of the Ras protein under the reaction conditions was examined by using the wild-type Ras protein. Finally, the iF-Ras proteins containing a 4-iodo-L-phenylalanine residue were subjected to organopalladium reactions with vinylated or propargylated biotin. Site-specific biotinylations of the Ras protein were confirmed by Western blot and LC-MS/MS. 相似文献
69.
Takeshi Yagi Kazuo Shinozaki Nobuo Ishizawa Nobuyasu Mizutani Masanori Kato Akihiko Tsuge 《Journal of the American Ceramic Society》1988,71(7):334-C
The thermal diffusivity of AlN ceramics was significantly decreased by the addition of SiO2 . The AlN ceramics with 4 wt% SiO2 could not be densified by pressureless sintering in the temperature range 1400° to 1800°C. The thermal diffusivity of these samples was very low because of their porous structure. The AlN ceramics containing 2, 4, and 8 wt% SiO2 were densified by hot-pressing and also had low thermal diffusivity. In these samples, the grains of the 27R polytype that resulted from the reaction between AlN and SiO2 were dispersed, obstructing the conduction of heat. The relation between the amount of 27R polytype and the thermal diffusivity of the AlN ceramics was determined. 相似文献
70.
The crystal structure of urea-polyethylene complex in the hexagonal form, obtained by one of our preparation methods, is analysed by X-ray power diffractometry. In this analysis, the fixed molecular parameters of urea are used, and three models with respect to rotational disorder of the guest polyethylene molecule are assumed. It is shown that the host lattice structure constructed by urea molecules is essentially the same as that of urea-n-paraffin complex. Effects of the disorder structure of the guest on X-ray scattering of the complex are presented. However, there is a difficulty in identifying the disorder structure by X-ray analysis. With the aid of a potential energy calculation between the hexagonal urea tunnel and the guest molecule, a rotational disorder model is preferred. 相似文献