全文获取类型
收费全文 | 246篇 |
免费 | 0篇 |
专业分类
电工技术 | 16篇 |
化学工业 | 38篇 |
金属工艺 | 2篇 |
机械仪表 | 7篇 |
建筑科学 | 1篇 |
能源动力 | 4篇 |
轻工业 | 10篇 |
水利工程 | 1篇 |
无线电 | 15篇 |
一般工业技术 | 43篇 |
冶金工业 | 72篇 |
原子能技术 | 1篇 |
自动化技术 | 36篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 3篇 |
2011年 | 8篇 |
2010年 | 11篇 |
2009年 | 5篇 |
2008年 | 12篇 |
2007年 | 10篇 |
2006年 | 5篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 9篇 |
2002年 | 1篇 |
2001年 | 10篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 27篇 |
1997年 | 14篇 |
1996年 | 17篇 |
1995年 | 9篇 |
1994年 | 11篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 9篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有246条查询结果,搜索用时 515 毫秒
41.
Suppressive effects of bifidobacteria on lipid peroxidation in the colonic mucosa of iron-overloaded mice 总被引:2,自引:0,他引:2
Ito M Sawada H Ohishi K Yoshida Y Yokoi W Watanabe T Yokokura T 《Journal of dairy science》2001,84(7):1583-1589
The antioxidative effects of live bifidobacteria on lipid peroxidation in the colonic mucosa were investigated. Bifidobacterium bifidum strain Yakult, which has been used for production of fermented milk, most effectively inhibited lipid peroxidation catalyzed by ferrous iron in liposomes among 10 species of bifidobacteria from human intestinal flora. Oral administration of B. bifidum strain Yakult for 2 wk significantly decreased the level of lipid peroxide (thiobarbituric acid reactive substance) in the colonic mucosa of iron-overload mice (Fe 0.07% in diet). The iron concentrations in plasma and cecum contents were not affected by administration of B. bifidum strain Yakult. Bifidobacterium bifidum strain Yakult had no chelating or incorporating activity for ferrous iron in vitro. Therefore, the antioxidative effect of B. bifidum strain Yakult in the colonic mucosa was not thought to be based on the removal of ferrous iron from the reaction system of lipid peroxidation. These results suggested that B. bifidum strain Yakult protected the colonic mucosa from oxidative injury without inhibiting iron absorption. 相似文献
42.
Takeshi Kobayashi Yuki Imade Daisuke Shishihara Kenji Homma Miki Nagao Ryota Watanabe Toshiyuki Yokoi Atsuo Yamada Ryoji Kanno Takashi Tatsumi 《Journal of power sources》2008
A high-capacity type of all solid-state battery was developed using sulfur electrode and the thio-LISICON electrolyte. New nano-composite of sulfur and acetylene black (AB) with an average particle size of 1–10 nm was fabricated by gas-phase mixing and showed a reversible capacity of 900 mAh g−1 at a current density of 0.013 mA cm−2. 相似文献
43.
Steels in which Cu content was altered from 0 to 1.5 mass% were subjected to various heat treatments to change the state of Cu. Concerning these respective steels, fatigue ratio by a stress controlled fatigue test and fatigue resistance by a strain controlled fatigue test thereof were compared. Furthermore dislocation substructure and surface defect during and after cyclic straining were investigated to clarify the effect of Cu on fatigue properties. The fatigue ratios at 2.0 × 106 loading cycles of the Cu added steels after aged at 450 and 750 degrees C are 0.7, remarkably high as compared with those of the Cu added steels after aged at 550 and 650 degrees C, the Cu free steels and any other conventional steels whose fatigue ratio are approximately between 0.5 and 0.6. The fatigue resistance of the as-rolled Cu added steel maintains steady cyclic hardening until fracture. To the contrary the Cu added steel after heat treatment at 550 degrees C shows cyclic hardening to the peak stress and then shows a cyclic softening until fracture. The surface roughness of the Cu added steels after cyclic straining are relatively shallow compared with those of the Cu free steel. The internal substructure of the Cu free steel shows typical cell structure but those of the Cu added steels exhibit vein structure. 相似文献
44.
Sakdinun Nuntang Sirilux Poompradub Suchada Butnark Toshiyuki Yokoi Takashi Tatsumi Chawalit Ngamcharussrivichai 《Materials Chemistry and Physics》2014
This study is the first report on synthesis, characterization and catalytic application of propylsulfonic acid-functionalized mesoporous composites based on natural rubber (NR) and hexagonal mesoporous silica (HMS). In comparison with propylsulfonic acid-functionalized HMS (HMS-SO3H), a series of NR/HMS-SO3H composites were prepared via an in situ sol–gel process using tetrahydrofuran as the synthesis media. Tetraethylorthosilicate as the silica source, was simultaneously condensed with 3-mercaptopropyltrimethoxysilane in a solution of NR followed by oxidation with hydrogen peroxide to achieve the mesoporous composites containing propylsulfonic acid groups. Fourier-transform infrared spectroscopy and 29Si MAS nuclear magnetic resonance spectroscopy results verified that the silica surfaces of the NR/HMS-SO3H composites were functionalized with propylsulfonic acid groups and covered with NR molecules. After the incorporation of NR and organo-functional group into HMS, the hexagonal mesostructure remained intact concomitantly with an increased framework wall thickness and unit cell size, as evidenced by the X-ray powder diffraction analysis. Scanning electron microscopy analysis indicated a high interparticle porosity of NR/HMS-SO3H composites. The textural properties of NR/HMS-SO3H were affected by the amount of MPTMS loading to a smaller extent than that of HMS-SO3H. NR/HMS-SO3H exhibited higher hydrophobicity than HMS-SO3H, as revealed by H2O adsorption–desorption measurements. Moreover, the NR/HMS-SO3H catalysts possessed a superior specific activity to HMS-SO3H in the esterification of lauric acid with ethanol, resulting in a higher conversion level. 相似文献
45.
46.
In-vitro heat-generating and apatite-forming abilities of PMMA bone cement containing TiO2 and Fe3O4
Moe Kubota Taishi Yokoi Tomoyuki Ogawa Shin Saito Maiko Furuya Kotone Yokota Hiroyasu Kanetaka Balachandran Jeyadevan Masakazu Kawashita 《Ceramics International》2021,47(9):12292-12299
Poly (methyl methacrylate) (PMMA) bone cement is widely used as a filler for repairing bone defects. To improve the effectiveness of the treatment for bone defects caused by metastatic bone tumours, we propose the formulation of PMMA cement containing titania (TiO2) and magnetite (Fe3O4) that offers high bone affinity, making the cement suitable for use in magnetic hyperthermia. The TiO2 and Fe3O4 contents of the PMMA cement varied from 20 to 45 mass%. The various cement samples were evaluated for their apatite-forming ability and heat-generation characteristics. The samples containing TiO2 in concentrations of 15 mass% or higher formed apatite on their surfaces within 14 days in a simulated body fluid. The heat-generation characteristics of the samples were evaluated by applying an alternating current (AC) magnetic field under the following conditions: |H| = 40 Oe and f = 600 kHz, or |H| = 100 Oe and f = 100 kHz. The surface temperatures of the samples containing 25 and 30 mass% Fe3O4 reached 42.3 and 44.8 °C, respectively, at |H| = 40 Oe and f = 600 kHz. During hyperthermia treatment, cancer cells die at temperatures higher than 42 °C, and the cement samples fabricated in this study could reach this temperature. However, since some degree of heat loss will occur in vivo, it is necessary to ensure that the temperature is higher than 42 °C by varying the AC magnetic field. Nevertheless, the fact that the samples containing Fe3O4 concentrations of 25 mass% or higher generated enough heat under the AC magnetic field makes them suitable for clinical use in hyperthermia. Thus, PMMA cement containing 15 mass% or more of TiO2 and 25 mass% or more of Fe3O4 should be investigated as a bioactive bone cement with a strong hyperthermia effect. 相似文献
47.
H Ohtake H Urayama K Kimura K Yokoi Y Tsunezuka T Kawakami M Kawasuji Y Watanabe 《Canadian Metallurgical Quarterly》1997,45(11):527-530
The jet injector route for ketamine was used on 30 children 1-6 years of age undergoing various surgical procedures. A randomly selected dose of 2.5, 3.5, or 6.0 mg/kg of ketamine was given to induce anesthesia. Peak plasma ketamine levels did not follow a simple arithmetic increment related to dose. Dosage based on mg/m2 body surface area or mg/kg body weight provided similar blood levels of ketamine. The beta-phase t1/2 of ketamine in these children was shorter than that found in adults. Considerable individual variability was observed in both the plasma levels to a given dose of jet-injected ketamine and in the beta-phase t1/2. The ketamine beta-t1/2s were not dose related. 相似文献
48.
49.
In this paper we describe an algorithm to render the asterism or chatoyancy effect in gems. This effect is due to light dispersion caused by inclusions consisting of vast numbers of thin fibrous needles. We develop models for distribution of the microfacet directions of the inclusions and of the light dispersion by them. Based on these models we derive an algorithm to render gems with the asterism effect. By introducting a ray distribution map, a new algorithm for tracing dispersed light rays is developed. 相似文献
50.
K Nunoya Y Yokoi K Kimura T Kodama M Funayama K Inoue K Nagashima Y Funae N Shimada C Green T Kamataki 《Canadian Metallurgical Quarterly》1996,277(2):768-774
(+)-cis-3,5-dimethyl-2-(3-pyridyl)thiazolidin-4-one hydrochloride (SM-12502) was oxidized by human liver microsomes to produce the S-oxide as a sole metabolite. Indirect evidence suggested that the S-oxidation was catalyzed by cytochrome P450 (CYP). Eadie-Hofstee plots showed biphasic pattern, suggesting that at least two enzymes were involved in the S-oxidation in human liver microsomes. Kinetic parameters of the S-oxidase with high-affinity showed Km and Vmax values of 20.9 +/- 4.4 microM and 0.111 +/- 0.051 nmol/min/mg microsomal protein, respectively. The S-oxidase activity was inhibited by coumarin and anti-CYP2A antibody. Among the contents of forms of CYP 20 samples of human liver microsomes, the content of CYP2A6 correlated with S-oxidase activity measured with 50 microM SM-12502 (r = .808, P < .0005). A close correlation (r = .908, P < .0001) was observed between activities of SM-12502 S-oxidase and coumarin 7-hydroxylase. Microsomes from genetically engineered human B-lymphoblastoid cells expressing CYP2A6 metabolized SM-12502 to the S-oxide efficiently. The results indicate that CYP2A6 isozyme is a major form of CYP responsible for the S-oxidation of SM-12502 in human liver microsomes. Thus, SM-12502 will be a useful tool in further research to analyze a human genetic polymorphism of CYP2A6. 相似文献