全文获取类型
收费全文 | 388篇 |
免费 | 26篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 15篇 |
综合类 | 2篇 |
化学工业 | 96篇 |
金属工艺 | 21篇 |
机械仪表 | 9篇 |
建筑科学 | 10篇 |
能源动力 | 10篇 |
轻工业 | 29篇 |
水利工程 | 4篇 |
无线电 | 34篇 |
一般工业技术 | 73篇 |
冶金工业 | 49篇 |
原子能技术 | 11篇 |
自动化技术 | 52篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 16篇 |
2021年 | 16篇 |
2020年 | 7篇 |
2019年 | 16篇 |
2018年 | 22篇 |
2017年 | 22篇 |
2016年 | 31篇 |
2015年 | 14篇 |
2014年 | 19篇 |
2013年 | 24篇 |
2012年 | 24篇 |
2011年 | 28篇 |
2010年 | 16篇 |
2009年 | 22篇 |
2008年 | 21篇 |
2007年 | 15篇 |
2006年 | 5篇 |
2005年 | 15篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 3篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1980年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有415条查询结果,搜索用时 0 毫秒
71.
Masahiko Tachibana Kazushige Ishida Yoichi Wada Ryosuke Shimizu Nobuyuki Ota Nobuyoshi Hara 《Journal of Nuclear Science and Technology》2013,50(2):253-262
In order to examine the anodic polarization characteristics of typical structural materials of boiling water reactors (BWRs), the anodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in deaerated high purity water at 553 K using the previously reported measurement method which was confirmed suitable for high temperature – high purity water. In order to specify which constituent element determines the dissolution characteristics of these materials, the anodic polarization curves of pure iron, pure nickel, and pure chromium were also surveyed. The anodic polarization curve of 316L SS was determined to have active, passive, and transpassive states which were the same as type 304 SS (304 SS) showed. But, Alloy 182 had different polarization characteristics especially near the corrosion potential as it had no active state. From comparison results of the polarization characteristics of these materials and their constituent elements, the corrosion characteristics of these materials were concluded to be mainly determined by the corrosion characteristics of chromium. 相似文献
72.
目的:通过试食实验,评价沙拉酱对人体部分血脂指标影响的效果。方法:采用自身对照设计的方法。47例18~22岁青年健康男性参与为期70d的试食实验。在不影响试食者饮食习惯的前提下,每日提供15g沙拉酱。分别在实验前及试食过程中的30、60、70d后分别进行检测。并于实验结束后37d再进行一次检测,以观察试食者在食用沙拉酱后血脂指标的变化。结果:试食至30d,试食者低密度脂蛋白胆固醇(LDL-C)含量显著下降(P<0.01)。试食至60d,血清总胆固醇(TC)、甘油三酯(TG)的含量显著上升(P<0.01),LDL-C值显著下降(P<0.01)。试食至70d,TC、TG含量显著上升(P<0.01)、高密度脂蛋白胆固醇(HDL-C)含量显著上升(P<0.01)。结论:在实验所指定的剂量下,沙拉酱未对人体血脂造成不良影响。值得注意的是,试食至50d时,由于节日原因,试食者饮食结构发生突变,饮酒和动物性脂肪摄入较多,导致第60天及第70天检测所得数据中TC和TG等有异常变化,证明饮食结构的变化直接影响血脂指标的变化。本次试食实验的数据表明,沙拉酱对提高HDL-C含量、降低LDL-C含量具有一定的促进作用。 相似文献
73.
Takuya Niikawa Chika Hagino Eri Nishi Ryosuke Kawachi Kotaro Minato Yoshinobu Takada 《IEEJ Transactions on Electrical and Electronic Engineering》2012,7(2):190-196
To clarify the motor function of the infant tongue during sucking, we developed an artificial nipple that contained multiple small built‐in force sensors integrated with a PC‐based system which is capable of measuring tongue–artificial nipple contact pressures in real time. The force sensor is a cantilever structure with a small, thin stainless steel beam where an all‐purpose foil strain gauge is attached to the surface of the beam. An artificial nipple made of an elastomer containing these sensors is connected through an amplifier and an A/D converter to a PC via a USB port. Using this system, measurements were taken in three infants whose oral feeding was well established and in one infant of low birth weight. The results from each force sensor showed a pressure waveform of a nearly simple harmonic motion that indicated a peristalsis‐like movement of the tongue; the sucking frequency was found to be about two times per second. In addition, in the low‐birth‐weight infant, the pressure changed as the infant grew. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
74.
Goto T Horita M Nagai H Nagatomo A Nishida N Matsuura Y Nagaoka S 《Molecular nutrition & food research》2012,56(3):435-445
Scope Recent studies have reported that tiliroside, a glycosidic flavonoid, possesses anti‐diabetic activities. In the present study, we investigated the effects of tiliroside on carbohydrate digestion and absorption in the gastrointestinal tract. Methods and results This study showed that tiliroside inhibits pancreatic α‐amylase (IC50 = 0.28 mM) in vitro. Tiliroside was found as a noncompetitive inhibitor of α‐amylase with Ki values of 84.2 μM. In male ICR mice, the increase in postprandial plasma glucose levels was significantly suppressed in the tiliroside‐administered group. Tiliroside treatment also suppressed hyperinsulinemia after starch administration. Tiliroside administration inhibited the increase of plasma glucose levels in an oral glucose tolerance test, but not in an intraperitoneal glucose tolerance test. In human intestinal Caco‐2 cells, the addition of tiliroside caused a significant dose‐dependent inhibition of glucose uptake. The inhibitory effects of both sodium‐dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2) inhibitors (phlorizin and phloretin, respectively) on glucose uptake were significantly inhibited in the presence of tiliroside, suggesting that tiliroside inhibited glucose uptake mediated by both SGLT1 and GLUT2. Conclusion These findings indicate that the anti‐diabetic effects of tiliroside are at least partially mediated through inhibitory effects on carbohydrate digestion and glucose uptake in the gastrointestinal tract. 相似文献
75.
Shigeki Hirasawa Ryosuke Wakiya Yuichi Hashikawa Tsuyoshi Kawanami Katsuaki Shirai 《机械工程与自动化:英文版》2014,(10):763-769
Precise temperature control to decrease movements in positions due to thermal expansion of work pieces is required in the manufacturing processes to achieve nanometer-order accuracy. We analytically examined the effect of a method of minimizing movements in positions on a plate with varying generation of noise-heat. Control by monitoring temperature changes caused larger movements in positions than that without control because maximum change in temperature occurred at non-monitoring positions. The best method of minimizing movements in positions due to thermal expansion of a plate with varying generation of noise-heat was model predictive control by the monitoring movements and distributed temperature changes in the control heater according to the effects of the generation of noise-heat. The maximum movement in positions was 6 nm, which was 1/4 times of that without control. 相似文献
76.
T. Nagatomo Y. KobayashiM.K. Kubo Y. YamadaM. Mihara W. SatoJ. Miyazaki S. SatoA. Kitagawa 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(4):455-459
In-beam Mössbauer spectroscopy utilizing unstable 57Mn beams is a powerful method to extract physical and chemical properties at the atomic scale. A parallel plate avalanche counter (PPAC), optimized to detect conversion electrons generated by the Mössbauer effect, can be employed to suppress higher-energy background γ rays. However, β rays are emitted by the 57Mn parent nuclei of 57Fe, which can significantly degrade the spectrum quality. In the present work, we have developed a new anti-coincidence-detection system with a thin plastic scintillation counter (0.5 mmt), which can be used to detect β rays and reject them from the recorded PPAC events. To demonstrate the anti-coincidence system, we carried out Mössbauer spectroscopy utilizing 57Mn nuclei that were implanted into a non-magnetic aluminum metal plate at room temperature. Using the anti-coincidence method, we obtained a typical Mössbauer spectrum of high quality, despite a very low number of implanted 57Mn atoms, of ∼5 × 109. The signal to noise ratio of the obtained spectrum was increased remarkably, and the relative peak height above the baseline increased from 10% to 220% using the anti-coincidence method. The developed detection system is applicable to investigation of in situ properties, and avoids the potentially problematic agglomeration of probes in a sample. 相似文献
77.
The transport of suspended sediment in rivers with spur dikes is an important issue for bank protection and environmental management. Laboratory experiments were performed to study the characteristics of the flow and the transport of suspended sediment in an open channel with permeable dikes. Firstly, the essentials of these characteristics were studied by comparing results of flume experiments on permeable and impermeable dikes. The influence of the aspect ratio (d/l) of the interval between dikes (d) to the length of dikes (l) on these characteristics was then investigated. In these experiments, the properties of horizontal eddies, turbulence structures, and suspended sediment concentrations were studied. The results show that the development of large-scale horizontal eddies requires some distance in a shear layer for permeable dikes, although they are periodically generated from the first dike in the case of impermeable dikes. The basic structures of horizontal eddies are independent of the aspect ratio in the equilibrium region for permeable dikes. The suspended sediment concentrations for cases of permeable dikes gradually decrease between the several upstream dikes and they approach a uniform distribution in the downstream region, although those in the case of the impermeable dikes are relatively uniform in the downstream direction. 相似文献
78.
Ryosuke Kusumi 《Polymer》2011,52(25):5912-5921
Investigations were made into the molecular dynamics and intercomponent mixing state in solid films of two series of cellulosic graft copolymers, cellulose acetate-g-poly(ε-caprolactone) (CA-g-PCL) and cellulose butyrate-g-PCL (CB-g-PCL), both series being prepared over a wide range of compositions with CAs or CBs of acyl DS ≈ 2.1, 2.5, and 2.95. It was shown by T1ρH measurements in solid-state 13C NMR spectroscopy that all the copolymer samples, except ones using CA of DS = 2.98, formed an amorphous monophase in which the trunk and graft components were mixed homogeneously at least in a scale of a few nanometers. However, those copolymer samples gave, more or less, a response of dynamic heterogeneity, when examined under mechanical oscillation. Through dielectric relaxation measurements, a clear comparison was made between the CA-g-PCL and CB-g-PCL series, regarding the cooperativeness in segmental motions of the trunk and graft chains, directly associated with the extent of the dynamic heterogeneity. The cooperativeness was generally higher in the CB-based copolymer series, probably due to working of the butyryl substituent as an internal compatibilizer. 相似文献
79.
Shirouchi B Kawamura S Matsuoka R Baba S Nagata K Shiratake S Tomoyori H Imaizumi K Sato M 《Lipids》2011,46(8):789-793
Guar gum has a well-recognized hypolipidemic effect. This effect is thought to be due to the physicochemical properties of
guar gum, which may cause changes in adsorption of lipids or the viscosity of the intestinal contents. Guar gum is a non-specific
absorption inhibitor of any type of lipid-soluble compound. Permanent lymph duct cannulation was performed on rats to investigate
the effects of dietary guar gum on lymph flow and lipid transport. Rats fed a 5% guar gum diet were compared with those fed
a 5% cellulose diet, and lymph was collected after feeding. The water-holding capacity (WHC), settling volume in water (SV),
and viscosity of guar gum were compared with those of cellulose. Rats fed with the guar gum diet had significantly lower lymph
flow and lymphatic lipid transport than did rats fed with the cellulose diet. The WHC, SV, and viscosity of guar gum were
significantly higher than those of cellulose. We propose that dietary guar gum reduces lymph flow and thereby diminishes lipid
transport by means of its physicochemical properties related to water behavior in the intestine. 相似文献
80.
Poly(styrene‐co‐butyl methacrylate) and poly(styrene‐co‐butyl acrylate) latices were prepared by emulsion polymerization with alkali‐hydrolyzable and nonhydrolyzable cationic emulsifiers and were used as a dispersant and binder for waterborne carbon black (CB) paint. CB was dispersed in the latex solutions and then coated on filter paper pretreated with dilute aqueous Na2CO3 under mild conditions. The styrene (St)‐rich rigid copolymer latices easily dispersed the CB but fixed a little amount of the pigment on the paper surface. In contrast, the methacrylate‐ and acrylate‐rich soft latices tended to increase the adhesibility on it. We also demonstrated that the hydrolyzable‐emulsifier‐containing latices always had a higher adhesibility than the nonhydrolyzable‐emulsifier‐containing ones. Thus, the hydrolyzable‐emulsifier‐containing latices with an appropriate St content had the highest paintability, rapid adhesion, quick drying, reduced fading, superior fastness, and so on. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3869–3873, 2013 相似文献