60 resultados para 740

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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格子Boltzmann数值模拟方法是研究复杂的多孔介质结构特别是Klinkenberg效应的有效方法之一,对处理复杂边值问题尤其有效。用格子Boltzmann方法研究了气流穿越多孔介质问题,并将数值计算结果与实验结果进行了比较,结果表明格子Boltzmann方法是数值模拟气流穿越多孔介质问题的有效方法之一。

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将实时相移Mach-Zehnder干涉技术与成像技术相结合,应用计算机技术、图象处理技术完成对NaClO_3晶体的实时诊断,实时观测了NaClO_3晶体溶解和结晶过程,得到了该过程的溶解条纹和生长条纹,反演计算出该过程的浓度场分布,同时分析了晶体生长过程中由重力引起的浮力对流现象,实验证明了这种对流现象直接影响着晶体各个晶面的生长速率.

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Linear Thomson scattering of a short pulse laser by relativistic electron lids been investigated using computer simulations. It is shown that scattering of an intense laser pulse of similar to 33 fs full width at half maximum, with an electron of gamma(o) = 10 initial energy, generates an ultrashort, pulsed radiation of 76 attoseconds, with a photon wavelength of 2.5 nm in the backward direction. The scattered radiation generated by a highly relativistic electron has superior quality in terms of its pulse width and angular distribution in comparison to the one generated by lower relativistic energy electron.

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The absorption spectra and upconversion fluorescence spectra of Er3+/-Yb3+-codoped natrium-gallium-germanium-bismuth glasses are measured and investigated. The intense green (533 and 549 nm) and red (672 nm) emission bands were simultaneously observed at room temperature. The quadratic dependence of the green and red emission on excitation power indicates that the two-photon absorption processes occur. The influence of Ga2C3 on upconversion intensity is investigated. The intensity of green emissions increases slowly with increasing Ga2O3 content, while the intensity of red emission increases significantly. The possible upconversion mechanisms for these glasses have also been discussed. The maximum phonon energy of the glasses determined based on the infrared (IR) spectral analysis is as low as 740 cm(-1). The studies indicate that Bi2O3-GeO2-Ga2O3-Na2O glasses may be potential materials for developing upconversion optical devices (c) 2006 Published by Elsevier B.V.

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阐述了用光学薄膜进行色散补偿的基本原理,介绍了设计的基本过程.根据Ti:Sapphire飞秒激光器中腔内色散补偿的要求,设定了色散补偿目标,通过计算机优化,得到了一种40层的Ta2O5/SiO2介质膜系.该膜系能在720~870am范围获得大于99.5%的反射率,在510~550nm获得大于90%的透射率,在740~850nm提供较平滑的-40fs^2的群延迟色散.这样的结果经过7次反射后,可以补偿5-mm Ti:sapphire晶体产生的绝大部分群延迟色散。

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本发明涉及饲料工业领域,具体地说是一种含有机硒多糖的非激素类饲料添加剂及其制备方法。具体:将硒粉加入到浓硝酸中,用水稀释得到的亚硒酸溶液,制得溶液I;再将配好的溶液I加入到溶有海藻多糖的氯化钠溶液中;在30℃-80℃下反应12-20小时,反应的剩余物即有机硒多糖和海藻多糖与填料混合,混合重量百分比例为0.05%-0.5%有机硒多糖, 0.06%-1.6%海藻多糖,其余为填料,干燥,粉碎,即得有机硒多糖饲料添加剂。本发明为无残留、无污染、可替代抗生素的绿色饲料添加剂,其生产效率高,周期短,硒的利用率高、且在使用中对食用动物体无副作用,安全可靠。

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Hundreds of tropical plant species house ant colonies in specialized chambers called domatia. When, in 1873, Richard Spruce likened plant-ants to fleas and asserted that domatia are ant-created galls, he incited a debate that lasted almost a century. Alth

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Rationale: Discriminating right from left is an everyday cognitive ability. Repeated exposure to certain drugs, such as heroin, can produce poor performance on many cognitive tasks. However, it is yet unclear whether drug abuse impairs the ability of right-left discrimination. Objectives: The aim of the present study is to examine whether the spatial ability measured by the right-left discrimination task can be affected by heroin abuse and whether such drug effect, if it exists, is gender related. Methods: A paper-and-pen test was used. The test consists of line drawings of a person with no arm, one arm, or both arms crossing the vertical body axis of the figure. The line drawings are viewed from the back, from the front, or randomly alternating between the back and front drawings. The subjects task is to mark which is the right or left hand in the figure as fast as possible. Results: A main finding in this study was that the ability to discriminate between left and right in visual space was impaired in heroin-dependent patients. Especially, heroin-dependent females performed poorer than control females in all conditions but heroin-dependent males only performed poorly in part of conditions. Conclusions: Recent heroin abuse impairs the ability of right-left discrimination and such impairment is gender related: heroin-dependent females demonstrated greater performance deficits than males.

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本实验评价了饲料中豆粕替代鱼粉蛋白后对异育银鲫的生长、饲料利用、氮代谢和鱼体免疫力等的影响。实验设计4种等氮等能的饲料,每种3个重复,分别以豆粕替代饲料中鱼粉蛋白的0(对照,D1)、20%(D2)、80%(D3)和100%(D4)。实验在半循环水养殖系统持续16周,鱼的初重约2.32g,实验期间水温23—30℃。结果表明,随着饲料中豆粕含量的升高,摄食率显著升高(p<0.05),特定生长率、饲料转化效率、蛋白沉积率和能量沉积率显著降低(p<0.05);蛋白表观消化率显著升高,干物质和能量表观消化率则显著降

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本文报道了采自新疆维吾尔自治区的桥弯藻科(硅藻门)中国新记录植物11种3变种,分别为Amphora mexi-canavar.major(Cleve)A.Cleve,Amphora twenteanaKrammer,Encyonema cespitosumK櫣tzing,Encyonema silesiacumvar.ventriformisKrammer,Cymbopleura albanicaKrammer et Miho,Cymbopleura apiculataKrammer,Cymbopleur

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国务院总理温家宝:太湖水污染治理工作开展多年,但未能从根本解决问题。太湖水污染事件给我们敲响了警钟,必须引起高度重视。要认真调查分析水污染的原因,在已有工作的基础上,加大综合治理的力度,研究提出具体的治理方案和措施。