排序方式: 共有49条查询结果,搜索用时 0 毫秒
41.
引入非线性空间变换,用伪谱方法求解了一维原子在强激光场中的薛定谔方程,计算了一维原子在强激光场中的高次谐波和电离几率,其结果与分裂算符法得到的结果符合得很好. 相似文献
42.
自由振动圆柱绕流近尾迹湍流普朗特数 总被引:1,自引:1,他引:0
对自由振动圆柱后尾迹中的湍流普朗特数进行了实验研究 ,并与刚性柱体尾迹的结果作了比较 .加热圆柱后的流场温度比环境温度高 1℃左右 ,对流场影响很小 .用自制的X热线和一根冷线相结合的三线探头测量速度和温度的脉动 ,并用激光测振仪测量了该柱体的振动情况 .结果表明 ,在自由振动后的尾迹中 ,湍流脉动引起的能量输运能力比动量输运能力强 ,湍流的梯度输运假设与实验结果符合较好 相似文献
43.
报道寄生于细尾异齿鱼日女 Oreoglanisdelacouri(Pellegrin)鳃丝上的一种异齿 鱼日女 新施分虫新种 相似文献
44.
Yang X Ongusaha PP Miles PD Havstad JC Zhang F So WV Kudlow JE Michell RH Olefsky JM Field SJ Evans RM 《Nature》2008,451(7181):964-969
45.
近年来,有一种趋势起源于日本公司通过在夏天提高室内温度设定值以达到节能目的.香港特别行政区政府建议商业办公室的理想室内温度设定值为25.5℃,这一建议引起了公众的广泛关注.本文主要针对两个问题:哪种措施能用来在夏天节能:提升室内温度设定值是否理想.通过在东莞一个典型居民住宅进行实验,获得了上述两个问题的相关结果.结果标明:通过提升室内温度设定值并维持室内环境PMV在理想值,那么可以在夏天达到节能效果. 相似文献
46.
A new multivariate stochastic volatility model is developed in this paper. The main feature of this model is to allow threshold asymmetry in a factor covariance structure. The new model provides a parsimonious characterization of volatility and correlation asymmetry in response to market news. Statistical inferences are drawn from Markov chain Monte Carlo methods. We introduce news impact analysis to analyze volatility asymmetry with a factor structure. This analysis helps us to study different responses of volatility to historical market information in a multivariate volatility framework. Our model is successful when applied to an extensive empirical study of twenty stocks. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
47.
指出了光突发交换(OBS)网络的一个关键问题是如何解决资源冲突,偏射路由是光网络中的冲突解决机制之一.提出了OBS网络非循环偏射路由算法(ADR),此算法基于各网络节点的路径度来确定路由中的偏射路径,支持突发数据的有序传输,将偏射路径的流量分布到具有低路径度的中间节点.利用此算法实现了区别服务以支持QoS,并通过仿真分析了其在优化OBS网络中的性能. 相似文献
48.
T. So H.-O. Ito M. Hirata T. Ueda T. Imoto 《Cellular and molecular life sciences : CMLS》1999,55(8-9):1187-1194
The blood half-life of a protein is prolonged by conjugating a protein with a linear amphiphilic polymer, monomethoxypolyethylene
glycol (mPEG). The conjugation gives a protein immunotolerogenicity; hence, it is likely that the long half-life is crucial
for the tolerogenicity. We prepared a tolerogenic mPEG conjugate of hen egg lysozyme (mPEG1.5-HEL), which is conjugated 1.5-fold the molecular weight of mPEG against that of HEL, and evaluated the relationship between
in vivo stability and the tolerogenicity. mPEG1.5-HEL retained immunogenicity to prime HEL-specific T cell and antibody responses and had a long blood half-life, more than
27 times that of native HEL. The tolerant state was maintained as long as mPEG1.5-HEL was detected in sera. With a decrease in the blood mPEG1.5-HEL level, the tolerant state returned gradually to the responsive state; however, reinjection of mPEG1.5-HEL again restored the tolerance. Thus, the extended blood half-life of HEL by mPEG conjugation is probably vital for establishing
and maintaining the tolerant states.
Received 17 May 1999; accepted 1 June 1999 相似文献
49.
Andresen GB Ashkezari MD Baquero-Ruiz M Bertsche W Bowe PD Butler E Cesar CL Chapman S Charlton M Deller A Eriksson S Fajans J Friesen T Fujiwara MC Gill DR Gutierrez A Hangst JS Hardy WN Hayden ME Humphries AJ Hydomako R Jenkins MJ Jonsell S Jørgensen LV Kurchaninov L Madsen N Menary S Nolan P Olchanski K Olin A Povilus A Pusa P Robicheaux F Sarid E el Nasr SS Silveira DM So C Storey JW Thompson RI van der Werf DP Wurtele JS Yamazaki Y 《Nature》2010,468(7324):673-676
Antimatter was first predicted in 1931, by Dirac. Work with high-energy antiparticles is now commonplace, and anti-electrons are used regularly in the medical technique of positron emission tomography scanning. Antihydrogen, the bound state of an antiproton and a positron, has been produced at low energies at CERN (the European Organization for Nuclear Research) since 2002. Antihydrogen is of interest for use in a precision test of nature's fundamental symmetries. The charge conjugation/parity/time reversal (CPT) theorem, a crucial part of the foundation of the standard model of elementary particles and interactions, demands that hydrogen and antihydrogen have the same spectrum. Given the current experimental precision of measurements on the hydrogen atom (about two parts in 10(14) for the frequency of the 1s-to-2s transition), subjecting antihydrogen to rigorous spectroscopic examination would constitute a compelling, model-independent test of CPT. Antihydrogen could also be used to study the gravitational behaviour of antimatter. However, so far experiments have produced antihydrogen that is not confined, precluding detailed study of its structure. Here we demonstrate trapping of antihydrogen atoms. From the interaction of about 10(7) antiprotons and 7?×?10(8) positrons, we observed 38 annihilation events consistent with the controlled release of trapped antihydrogen from our magnetic trap; the measured background is 1.4?±?1.4 events. This result opens the door to precision measurements on anti-atoms, which can soon be subjected to the same techniques as developed for hydrogen. 相似文献