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排序方式: 共有873条查询结果,搜索用时 31 毫秒
31.
Mitsumasa TAGUCHI Takuji KOJIMA 《核技术(英文版)》2007,18(1):35-38
Dependence of yields of OH (hydroxyl) radicals on the mass and specific energy of heavy ions and elapsed time after irradiation was investigated, to understand chemical reactions of aqueous solutions. The yields of irradiation products of phenol, super-linearly increased with the incident energy of He, C, and Ne ions ranging from 2 to 18 MeV/u. The yields of the OH radicals were estimated by analyzing the yields of the irradiation products of phenol. The yields of the OH radicals increased with the specific energy for each ion, but decreased both with the mass of each ion at the same specific energy and elapsed time after irradiation. 相似文献
32.
统一强度理论的发展及其在土木水利等工程中的应用和经济意义 总被引:10,自引:5,他引:10
统一强度理论是在中国本土原创产生和发展起来的关于材料强度和结构强度的系统新理论。它从连续统力学最基本的单元体力学模型开始,到数学建模方法,理论公式的表述,以及一系列新的理论公式都不同于以往的各种理论。它将以往各种适合于某一类材料的单一强度理论推进为可以适合于多种材料的统一强度理论。经过40多年的发展,它不仅自己形成了系统的理论,而且将很多著名的理论包容其中,形成了范围更宽广、功能更强大的理论体系。由于它具有一个统一的力学模型,清晰的物理意义,简单的线性数学表述式,能反映材料的基本特性,即sD效应(不同的抗拉强度和抗压强度)、静水应力效应、正应力效应、中间主应力效应和中间主剪应力效应,以及结构强度分析的破坏准则效应,并且与现有的实验数据相吻合,能容易地适合许多新情况;此外,统一强度理论既容易用来取得解析解,也容易用于计算机程序取得数值解。统一强度理论已被推广应用于很多领域。在连续介质和工程应用的框架下对统一强度理论的发展及其在土木工程中的应用和经济意义进行较为系统的小结。 相似文献
33.
R.W. Callis J.L. Doane H.J. Grunloh K. Kajiwara A. Kasugai C.P. Moeller Y. Oda R.A. Olstad K. Sakamoto K. Takahashi 《Fusion Engineering and Design》2009,84(2-6):526-529
Initial testing on the Japan Atomic Energy Agency Gyrotron Test Stand of ITER-relevant TL components, has shown reasonable efficiencies, but identified that trapped modes between closely located miter bends, as well as mode conversion at miter bends can lead to excessive heating of the connecting waveguides. General Atomics has designed, built, and will test components to address this issue as well as ITER relevant components that have not been tested at the levels of 1 MW, 170 GHz, for extended pulse lengths. Some of the components that will be tested are ultra low loss miter bends, dc breaks, polarizers, power monitors, bellows, waveguide switches, waveguide cooling clamps, etc. Details of the components and test results will be presented. 相似文献
34.
Application of electron beam for the reduction of PCDD/F emission from municipal solid waste incinerators 总被引:1,自引:0,他引:1
Hirota K Hakoda T Taguchi M Takigami M Kim H Kojima T 《Environmental science & technology》2003,37(14):3164-3170
The electron-beam technology was applied to reduce the emission of polychlorinated dibenzo-p-dioxins (PCDD) and polychlorinated dibenzofurans (PCDF) in a flue gas of 1000 m(3)N/h from the municipal solid waste incinerator (MSWI) at a temperature of 200 degrees C. More than 90% decomposition of PCDD/Fs was obtained using an electron accelerator at a dose of 14 kGy. The decomposition was initiated through reactions with OH radicals produced by the irradiation of flue gases, followed by oxidation such as the ring cleavage of the aromatic ring, the dissociation of ether bond, and dechlorination. The cost analysis estimated that the electron-beam system can cut the annualized cost by approximately 50% for the treatment of PCDD/Fs in a pre-dusted MSWI flue gas as compared with a bag-filter system when operating on electricity generated from an incineration. Electron-beam technology is an economically and technologically useful method for reducing PCDD/Fs in an incineration flue gas. 相似文献
35.
The n-6/n-3 fatty acid (FA) ratio has increased in the Western-style diet to ~10–15:1 during the last century, which may have
contributed to the rise in cardiovascular disease (CVD). Prior studies have evaluated the effects on CVD risk factors of manipulating
the levels of n-6 and n-3 FA using food and supplements or investigated the metabolic fate of linoleic acid (LNA) and α-linolenic
acid (ALA) by varying the n-6/n-3 ratios. However, no previous studies have investigated the potential interaction between
diet ratios and supplementation with eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). We used
a factorial design approach with adults (n = 24) in a controlled feeding trial to compare the accretion of EPA and DHA into red blood cell membranes (RBC) by adding
a direct source (algal oil supplement) of EPA and DHA in a diet with a 10:1 versus 2:1 ratio of n-6/n-3 FA. Subjects were
randomized into 8-week crossover diet sequences and each subject consumed three of four diets [10:1, 10:1 plus supplement
(10:1 + S), 2:1 and 2:1 + S]. LNA and ALA intakes were 9.4 and 7.7%, and 1.0 and 3.0% during the low and high ALA diets, respectively.
Compared to the Western-style 10:1 diet, the 2:1 diet increased EPA by 60% (P < 0.0001) in RBC membranes without the direct EPA source and a 34% increase (P = 0.027) was observed with the 10:1 + S diet; however, DHA levels increased in both diet ratios only with a direct DHA source.
Shifting towards a 2:1 diet is a valid alternative to taking EPA-containing supplements. 相似文献
36.
K. Kainosho M. Ohta M. Uchida M. Nakamura O. Oda 《Journal of Electronic Materials》1996,25(3):353-356
Recently, it was found that undoped semi-insulating InP can be obtained by highpressure annealing of high purity materials.
The reproducibility and the uniformity was, however, not satisfactory. In the present work, we found that not only Fe concentrations
but also Cr and Ni concentrations in annealed wafers were slightly increased during annealing. Since it seems that the origin
of the contamination was due to the vapor source of red phosphorus, conductive InP with a trace amount of Fe was annealed
under low phosphorus vapor pressure in order to reduce the contamination. By preventing the contamination of Cr and Ni, preparation
of semi-insulating InP became highly reproducible. The minimum Fe concentration for realizing semi-insulating InP was found
to be 1 x 1015cm−3. It was also found that the better resistivity uniformity can be obtained at higher annealing temperatures. 相似文献
37.
Takuji Kobayashi Katsuhiko Sasaki 《Journal of Materials Science: Materials in Electronics》2009,20(4):343-353
This paper discusses uniaxial ratchetting deformation of lead-free solder alloy Sn–3Ag–0.5Cu and lead-containing solder alloy
Sn–37Pb, which were subjected to tension–compression loading with several stress amplitudes and stress ratios, minimum stress
over maximum stress. First the uniaxial ratchetting tests were conducted with three maximum stresses and four stress ratios.
All tests were conducted using cylindrical bulk specimens of the solder alloys at 313 K. The test results show that there
are differences in the ratchetting deformation behavior of the two solder alloys; the larger ratchetting strain occurs in
the lead-containing solder alloy than in the lead-free solder alloy. The ratchetting deformation was simulated by the dislocation
based constitutive model proposed by Estrin et al. (J Eng Mater Technol 118:441, 1996). The evolution equation of the back
stress employed in the constitutive model was modified considering a dynamic recovery term. The effect of the modification
of the back stress evolution is discussed by comparing the simulations with the corresponding experimental results. The simulations
suggest that the recovery term in the kinematic hardening rule plays an important role in fitting the simulation to the experimental
results of the ratchetting deformation of the solder alloys. 相似文献
38.
Kiyoharu Nakagawa Hirokazu Oda Akira Yamashita Masahiro Okamoto Yoichi Sato Hidenori Gamo Mikka Nishitani-Gamo Kazuyuki Ogawa Toshihiro Ando 《Journal of Materials Science》2009,44(1):221-226
We developed a novel spherical carbon material. The spherical carbon is composed of a high density of carbon nanotubes or
nanofilaments, and includes an oxidized diamond particle as a core. Syntheses of this carbon in high volume with high selectivity
may be possible. It is expected that this carbon will be useful as a catalyst material for fuel cells, electric double-layer
capacitors, etc. 相似文献
39.
Takuji Yamamoto Tomofumi Nishimura Tetsuo Suzuki Hajime Tamon 《Drying Technology》2001,19(7):1319-1333
Resorcinol-formaldehyde hydrogels were synthesized by sol-gel polycondensation of resorcinol with formaldehyde in a slightly basic aqueous solution. RF cryogels, RF xerogels, and RF xerogels (MW gels) were respectively prepared from RF hydrogels by freeze drying, hot air drying, and microwave drying. Carbon cryogels, carbon xerogels and carbon MW gels were subsequently obtained by pyrolyzing RF drygels in an inert atmosphere. Freeze drying and microwave drying were effective to prepare mesoporous RF drygels and carbon gels. RF cryogels and carbon cryogels showed high mesoporosity over wide ranges of the molar ratio of resorcinol to catalyst (R/C) and the ratio of resorcinol to water (R/W) used in sol-gel polycondensation. Although RF xerogels had a few mesopores, carbon xerogels had no mesopores. RF MW gels and carbon MW gels showed mesoporosity if appropriate values of R/C and R/W were selected. 相似文献
40.
东丽以"Innovation by Chemistry"为核心,通过融合有机化学、高分子科学、生物化学、纳米技术等进行技术革新,挑战具有创新意义的新素材及新技术,为全球用户创造新的价值,致力于改善地球环境,技术创新开发。东丽纤维研究所(中国)有限公司成立于2002年5月,与日本东丽株式会社共同致力于中国的纤维及高分子材料的研究。设有南通总公司和上海分公司,本次就公司的研究开发概要作报告。着重报告东丽(株)正在推进的环境友好型新材料研究开发状况。包括生物基聚合物聚乳酸、PTT、生物尼龙等相关的技术概要及特征。另外介绍一下具有环境保护技术的绿色工艺的纤维素纤维。 相似文献