全文获取类型
收费全文 | 474篇 |
免费 | 10篇 |
专业分类
电工技术 | 18篇 |
综合类 | 2篇 |
化学工业 | 192篇 |
金属工艺 | 18篇 |
机械仪表 | 9篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 12篇 |
轻工业 | 83篇 |
石油天然气 | 1篇 |
无线电 | 19篇 |
一般工业技术 | 70篇 |
冶金工业 | 22篇 |
原子能技术 | 7篇 |
自动化技术 | 26篇 |
出版年
2023年 | 3篇 |
2022年 | 14篇 |
2021年 | 12篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 6篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 11篇 |
2014年 | 16篇 |
2013年 | 31篇 |
2012年 | 24篇 |
2011年 | 35篇 |
2010年 | 17篇 |
2009年 | 24篇 |
2008年 | 28篇 |
2007年 | 25篇 |
2006年 | 28篇 |
2005年 | 12篇 |
2004年 | 12篇 |
2003年 | 18篇 |
2002年 | 14篇 |
2001年 | 9篇 |
2000年 | 11篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 12篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有484条查询结果,搜索用时 15 毫秒
21.
Hiromi Yoshida Takaaki Tanigawa Naoko Yoshida Isoko Kuriyama Yuka Tomiyama Yoshiyuki Mizushina 《Food chemistry》2011
Endogenous tocochromanols in extracted lipids from rice brans of the five cultivars were determined by high-performance liquid chromatography, and were investigated in relation to the fatty acid (FA) distribution of triacylglycerols (TAG) and phospholipids (PL). The dominant tocols were α-tocopherol and γ-tocotrienol, followed by α-tocotrienol and with much smaller amounts of γ-tocopherol and δ-tocotrienol. The lipids of these rice brans comprised mainly TAG (80.6–86.0 wt.%), free FA (4.2–9.0 wt.%), and phospholipids (5.5–6.7 wt.%), whilst other components were also detected in minor proportions (0.2–2.1 wt.%). The PL components included phosphatidyl choline (31.8–46.8 wt.%), phosphatidyl ethanolamine (25.0–38.9 wt.%) and phosphatidyl inositol (20.2–23.2 wt.%). Comparison of these different cultivars showed, with a few exceptions, no significant differences (P > 0.05) in FA distribution. FA distribution of TAG among the five cultivars was evident in the rice brans: unsaturated FA were predominantly concentrated at the sn-2 position and saturated FA primarily occupying the sn-1 or sn-3 position. These results suggest that the tocopherol content, lipid component, and FA distribution in rice brans are not dependent on the cultivation areas during the growing season. 相似文献
22.
In a sample of 263 male GO players at 48 levels of expertise and ranging from 18 to 78 years of age, it was found that factors of expertise deductive reasoning (EDR) and expertise working memory (EWM) were independent of factors of fluid reasoning (Gf) and short-term working memory (STWM) that, along with cognitive speed (Gs), have been found to characterize decline of intelligence in adulthood. The main effects of analyses of cross-sectional age differences indicated age-related decline in EDR and EWM as well as in Gf, STWM, and Gs. However, interaction and partialing analyses indicated that decline in EDR and EWM decreased to no decline with increase in level of expertise. The results thus suggest that with increase in factors known to raise the level of expertise—particularly, intensive, well-designed practice there may be no age-related decline in the intelligence that is measured in the abilities of expertise. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
23.
The rare earth manganite BaLn2Mn2O7 (Ln=rare earth element) has a Sr3Ti2O7-type layered perovskite structure with double-block oxygen octahedra belonging to the Ruddlesden-Popper-type homologous series AO(ABO3)2. In Pr-manganite, a novel phase transition was first observed in situ at 1040 K by a thermal transmission electron microscope. At 1040 K, reflections began to split along the c-direction in the selected area diffraction pattern. This indicates that a new phase appears in the original phase matrix; the c length of the new phase is 1.5% longer than that of the original phase. After about 5 min, the original phase disappears. No change in the crystal symmetry (space group I4/mmm) is observed above 1040 K. 相似文献
24.
Inhibition by gluconic acid-1 : 5-lactone (gluconolactone) and phenyl alpha-glucoside of the hydrolysis of maltodextrin catalyzed by glucoamylase [EC 3.2.1.3] from Rhizopus niveus was investigated in relation to the subsite structure of the enzyme. Inhibition by gluconolactone was of the mixed type, whereas that by phenyl alpha-glucoside was purely competitive. These inhibition types were consistent with a theoretical prediction based on the assumption that gluconolactone and phenyl alpha-glucoside bind mainly to Subsites 1 and 2, respectively. The inhibitor constant of gluconolatone was determined to be 1.5 mM, which is in good agreement with the dissociation constant estimated by difference spectrophotometry (1.5 mM) (Ohnishi, M, et al. (1975) J. Biochem, 77, 695-703). 相似文献
25.
Hiromi?YoshidaEmail author Kyoko?Matsuda Yuki?Hirakawa Yoshiyuki?Mizushina 《Journal of the American Oil Chemists' Society》2003,80(7):665-674
To clarify the effects of microwave roasting on the distribution of tocopherols and FA of phospholipids within soybeans, whole
soybeans (Glycine max) were treated by microwave and further evaluted as compared to a raw sample. Tocopherol homologs, measured using HPLC, and
phospholipid profiles, quantified with GC, were determined in the seed coat, the embryonic axis, and selections of cotyledons
separated from three cultivars. The tocopherols were predominantly detected in the axis, followed by the cotyledons, and then
very little in the coat. As much as 25% of the individual tocopherols originally present in the coat were lost at 12 min of
roasting, whereas <25% was lost in the cotyledons and the axis after 20 min of roasting. The greatest rate of phospholipid
loss (P<0.05) was observed in PE, followed by PC and PI, and their changing patterns were more pronounced in the coat than in the
cotyledons or the axis. Thus, tocopherol content and phospholipid profiles change with microwave roasting according to tissue. 相似文献
26.
Hongzhi Xie Yi‐Fen Li Hiromi K. Kagawa Jonathan D. Trent Kumara Mudalige Mircea Cotlet Basil I. Swanson 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(9):1036-1042
Genetic engineering of a novel protein–nanoparticle hybrid system with great potential for biosensing applications and for patterning of various types of nanoparticles is described. The hybrid system is based on a genetically modified chaperonin protein from the hyperthermophilic archaeon Sulfolobus shibatae. This chaperonin is an 18‐subunit double ring, which self‐assembles in the presence of Mg ions and ATP. Described here is a mutant chaperonin (His‐β‐loopless, HBLL) with increased access to the central cavity and His‐tags on each subunit extending into the central cavity. This mutant binds water‐soluble semiconductor quantum dots, creating a protein‐encapsulated fluorescent nanoparticle. The new bioconjugate has high affinity, in the order of strong antibody–antigen interactions, a one‐to‐one protein–nanoparticle stoichiometry, and high stability. By adding selective binding sites to the solvent‐exposed regions of the chaperonin, this protein–nanoparticle bioconjugate becomes a sensor for specific targets. 相似文献
27.
Hiromi Odaka Masataka Yamada Ryohei Sakuma Cuie Ding Eiji Kaneko Satoru Yanabu 《Electrical Engineering in Japan》2007,161(1):17-25
A high‐speed vacuum circuit breaker (HSVCB) has been investigated. HSVCB makes high‐frequency current superimposed on a fault current so that the current is forced to be zero and is interrupted. Its interruption performance is considered to be dependent on the rate of change of the current (di/dt). As a fundamental research, we investigated the di/dt– dv/dt characteristics and the insulation recovery characteristic after interrupting the counter‐pulse current for various contact materials of AgWC, CuW, and CuCr. The results revealed that the case where the gap length is larger is better in a current interruption performance. Moreover, it was found that di/dt is not dependent on the insulation recovery characteristics, but the magnitude of interruption current is of great influence. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 161(1): 17– 25, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20362 相似文献
28.
以DC铸造法制备的Al-Zn-Mg-Cu高强铝合金扁锭为研究对象,基于阿基米德原理测量孔洞体积分数,考察了铸锭横截面上的孔洞分布,并给出了厚度方向及宽度方向上孔洞体积分数的变化规律。结果表明,铸锭横截面上,由表层至心部孔洞体积分数呈逐渐上升的趋势;厚度方向上,由表层至心部,1/2宽度处和1/4宽度处孔洞体积分数均呈总体上升趋势;宽度方向上,1/2厚度处,由表层至心部,孔洞体积分数先迅速上升,而后在某一区间内波动;1/4厚度处,由表层至心部,孔洞体积分数先缓慢上升,而后缓慢下降。铸锭内部孔洞体积分数大小与局部冷却速率密切相关,铸锭表层附近的冷却速率快,对应孔洞体积分数较低,而靠近铸锭心部冷却速率慢,因而孔洞体积分数较高。 相似文献
29.
Sayoko Shironita Tomoya Takasaki Takashi Kamegawa Kohsuke Mori Hiromi Yamashita 《Topics in Catalysis》2010,53(3-4):218-223
Using microwave-assisted deposition method the uniform and nano-sized platinum metal particles were prepared on the tetrahedrally coordinated Ti-oxide moieties isolated within the framework of mesoporous silica supports. The present nano-sized metal catalyst exhibited a higher activity for hydrogenation of nitrobenzene than the catalyst prepared by a conventional impregnation method. 相似文献
30.
Masashi Ohno Fumiakira Mori Yasuhiro Minamikawa R. M. Thushara Damayanthi Hiroyuki Takahashi Hiromi Sato Hidenori Toyokawa 《Journal of Low Temperature Physics》2008,151(1-2):229-233
To realize new TES imaging for high energy X-ray or gamma-ray spectrometer with a large pixel array and high count rate, we
will try to develop a new radiation absorber self-adjusting the operating temperature and adopting an original reading out
method of large pixel array using parallel biasing scheme. Our first prototype TES pixel using Au/Ti/Au tri-layer which consists
of the small heat sensors and the radiation absorption area, and these are biased in serial. In this device, the current pulse
with the decay time constant of less than 20 microseconds of incident X-rays from 55Fe source were observed.
相似文献