全文获取类型
收费全文 | 222篇 |
免费 | 11篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 78篇 |
金属工艺 | 7篇 |
机械仪表 | 3篇 |
建筑科学 | 8篇 |
能源动力 | 10篇 |
轻工业 | 26篇 |
石油天然气 | 2篇 |
无线电 | 18篇 |
一般工业技术 | 26篇 |
冶金工业 | 26篇 |
原子能技术 | 4篇 |
自动化技术 | 18篇 |
出版年
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 2篇 |
2014年 | 10篇 |
2013年 | 7篇 |
2012年 | 7篇 |
2011年 | 13篇 |
2010年 | 7篇 |
2009年 | 15篇 |
2008年 | 10篇 |
2007年 | 11篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 10篇 |
1998年 | 14篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有233条查询结果,搜索用时 765 毫秒
191.
Shohei Ishikawa Kazutoshi Iijima Daisuke Matsukuma Michihiro Iijima Shigehito Osawa Hidenori Otsuka 《应用聚合物科学杂志》2020,137(19):48893
Chitosan-based hydrogels as scaffolds for culturing chondrocytes were prepared using linkers with and without hydrolysable poly(dl -lactide) (PLA) segments. The evaluation of the cultured chondrocytes in them indicated that the accelerated degradation of the hydrogel via hydrolysis of the PLA slightly promoted production of the sulfated glycosaminoglycan and drastically improved that of collagen from the encapsulated chondrocytes, which are the chondrospecific extracellular matrix components. Furthermore, the accelerated degradability significantly upregulated the gene expression for Collagen II production and downregulated that for Collagen I production of the encapsulated chondrocytes. Because major component of the articular cartilage tissue is Collagen II-rich hyaline cartilage, these results suggest the degradation of the scaffolds is an important parameter in cartilage tissue regeneration and the accelerated degradability may have benefits on promotion of cartilage tissue regeneration especially from the viewpoint of hyaline cartilage-like collagen production. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48893. 相似文献
192.
Michihiro Miyake Masaki Iwaya Takashi Suzuki Hiroyuki Kakehi Takeshi Mitsuda 《Journal of the American Ceramic Society》1990,73(11):3524-3527
A successful Al-substituted gyrolite has been hydrothermally synthesized at 220°C under saturated steam pressure, and its cation exchange characteristics for K+ and Cs+ ions have been investigated. Al-substituted gyrolite took up K+ and Cs+ ions of 14 and 20 mequiv/100 g, respectively, and these removal amounts are smaller than those by Al-substituted tobermorites (ca. 80 mequiv/100 g). It was found that Al-substituted gyrolite exhibited selectivity for univalent cations in the following order: Na+ < K+ < Cs+ in the low-concentration regions of K+ and Cs+ ions. Al-substituted gyrolite did not lose its crystallinity and morphology, and its basal spacing did not change in the cation exchange. These results, therefore, suggest that Al-substituted gyrolite may be useful for separation and waste disposal. 相似文献
193.
Conjugated linoleic acid modulates tissue levels of chemical mediators and immunoglobulins in rats 总被引:40,自引:0,他引:40
The effects of conjugated linoleic acid (CLA) on the levels of chemical mediators in peritoneal exudate cells, spleen and
lung, and the concentration of immunoglobulins in mesenteric lymph node and splenic lymphocytes and in serum were examined
in rats. After feeding diets containing either 0 (control), 0.5 or 1.0% CLA for 3 wk, there was a trend toward a reduction
in the release of leukotriene B4 (LTB4) from the exudate cells in response to the dietary CLA levels. However, CLA did not appear to affect the release of histamine.
A similar dose-response pattern also was observed in splenic LTB4, lung LTC4 and serum prostaglandin E2 levels, and the differences in these indices between the control and 1.0% CLA groups were all statistically significant.
The reduction by CLA of the proportions of n−6 polyunsaturated fatty acids in peritoneal exudate cells and splenic lymphocyte
total lipids seems to be responsible at least in part for the reduced eicosanoid levels. Splenic levels of immunoglobulin
A (IgA), IgG, and IgM increased while those of IgE decreased significantly in animals fed the 1.0% CLA diet. This was reflected
in the serum levels of immunoglobulins. The levels of IgA, IgG, and IgM in mesenteric lymph node lymphocytes increased in
a dose-dependent manner, while IgE was reduced in those fed the higher CLA intake. However, no differences were seen in the
proportion of T-lymphocyte subsets of mesenteric lymph node. These results support the view that CLA mitigates the food-induced
allergic reaction. 相似文献
194.
NISHI Michihiro 《机械工程学报(英文版)》2007,20(1):5-9
To develop vortex generator jet (VGJ) method for flow control, the turbulence flow in a 144°conical diffuser with and without vortex generator jets are simulated by solving Navier-Stokes equations with κ -ε turbulence model. The diffuser performance, based on different velocity ratio (ratio of the jet speed to the mainstream velocity), is investigated and compared with the experimental study. On the basis of the flow characteristics using computation fluid dynamics (CFD) method observed in the conical diffuser and the downstream development of the longitudinal vortices, attempt is made to correlate the pressure recovery coefficient with the behavior of vortices produced by vortex generator jets. 相似文献
195.
Tamaki Hada Manabu Kanazawa Nanako Miyamoto Hengyi Liu Maiko Iwaki Yuriko Komagamine Shunsuke Minakuchi 《International journal of molecular sciences》2022,23(4)
Photopolymer resins are widely used in the production of dental prostheses, but their mechanical properties require improvement. We evaluated the effects of different zirconia filler contents and printing directions on the mechanical properties of photopolymer resin. Three-dimensional (3D) printing was used to fabricate specimens using composite photopolymers with 0 (control), 3, 5, and 10 wt.% zirconia filler. Two printing directions for fabricating rectangular specimens (25 mm × 2 mm × 2 mm) and disk-shaped specimens (φ10 mm × 2 mm) were used, 0° and 90°. Three-point bending tests were performed to determine the flexural strengths and moduli of the specimens. The Vickers hardness test was performed to determine the hardness of the specimens. Tukey’s multiple comparison tests were performed on the average values of the flexural strengths, elastic moduli, and Vickers hardness after one-way ANOVA (α = 0.05). The flexural strengths and elastic moduli at 0° from high to low were in the order of 0, 3, 10, and 5 wt.%, and those at 90° were in the order of 3, 0, 10, and 5 wt.% (p < 0.05). For 5 and 10 wt.%, no significant differences were observed in mechanical properties at 0° and 90° (p < 0.05). The Vickers hardness values at 0° and 90° from low to high were in the order of 0, 3, 5, and 10 wt.% (p < 0.05). Within the limits of this study, the optimal zirconia filler content in the photopolymer resin for 3D printing was 0 wt.% at 0° and 3 wt.% at 90°. 相似文献
196.
197.
The purpose of this study is to investigate various characteristics of thin aluminium alloy structural plate joints welded by the friction stir welding (FSW) process. A number of reports have been published concerning these characteristics. Most of these reports concern joints made by the relevant company's unique procedures using selected parent materials; consequently, the joints were made under restricted specified conditions. Accordingly, for this study, welded joints were produced by combinations of identical alloy base metals manufactured by several companies using the friction stir welding process with procedures which are unique to each individual company; an investigation was carried out into a variety of characteristics whilst attention was paid to the differences due to variations in the base metal and welding procedures. 相似文献
198.
Hiroyuki Iwaki Shufeng Ye Haruo Katagiri Kuniyuki Kitagawa 《Applied Catalysis A: General》2004,270(1-2):237-243
In this paper, wastepaper gasification with carbon dioxide or steam has been investigated in the presence of molten carbonate catalysts. The reactions of wastepaper with steam or carbon dioxide have been compared. Hydrogen was the main product on the condition of steam used as reactant gas, but in the case where carbon dioxide was used, the amount of carbon monoxide generated from wastepaper gasification greatly increased via the Boudouard reaction. Different ratios of mixtures of lithium, sodium and potassium carbonates as the catalysts have been tested; the lithium carbonate was found to play a critical role. The reaction rate of carbon conversion was approximately first order for low carbon conversions. Both the rate constants and the activation energies have been calculated at different temperatures (923–1023 K). In additions, the flexibility of this technique was examined with three different types of wastepaper. The results suggest that this process can promote effective use of wastepaper and recovery of carbon dioxide. At 1023 K, a high value of cold gas efficiency of about 95% was acquired. 相似文献
199.
200.
Michihiro Shintani Takumi Uezono Kazumi Hatayama Kazuya Masu Takashi Sato 《Journal of Electronic Testing》2016,32(5):601-609
In this study, a novel path clustering technique for adaptive path delay testing, where the test paths are altered according to the extracted device parameters, is proposed. The proposed algorithm is based on the k-means++ algorithm. By considering the probability function of the die-to-die systematic process variation, the proposed algorithm clusters path sets to minimize the total number of test paths. A figure of merit for clustering, which represents the expected number of test paths, is also proposed for quantitatively evaluating path clustering under different conditions. The proposed clustering method is evaluated numerically by applying it to the OpenCores benchmark circuit. Using our clustering technique, the average number of test paths in the adaptive test is reduced to less than 92 % compared with those in the conventional test. In addition, adaptive testing using the proposed technique can reduce the test patterns by 94.26 % while retaining the test quality. 相似文献