共查询到19条相似文献,搜索用时 93 毫秒
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对H-D光谱实验进行计算机仿真,由计算机控制的摄谱仪进行氢氘光谱摄谱,对谱线寻峰,计算出里德伯常量、氢氘质量比和同位素位移,并画出了氢原子的能谱图. 相似文献
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本文在国内首次将Fabry-perot干涉仪用于托卡马克等离子体诊断。实验采用一台压电驱动式Fabry-perot干涉仪通过对Hα和Dα谱线轮廓的测量来推算等离子体的氢氘含量比,从而避免了在传统的氢氘比测量中因重复放电所引起的不准确性。 相似文献
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刘海风张弓木张其黎宋红州李琼赵艳红孙博宋海峰 《高压物理学报》2018,(5):1-24
针对近二十多年的氢氘物态方程理论研究工作进行了综述分析,结合本课题组改进的自由能模型、直接量子蒙特卡洛和量子分子动力学方法的模拟结果,对多个研究小组采用不同方法获得的氢氘宽区物态方程数据进行了定量评估分析。结果表明:在当前理论框架下,仅基于第一原理数值模拟得到的氢氘物态方程能够描述的热力学相空间有限;多模型集成的H-REOS.3数据库在105K以下温度与数值模拟结果的相对差别较大,且数据稀少,二者均不能满足工程应用需求。建议采用基于半经验模型的宽区域物态方程研究方法,即结合高精度的实验研究、数值模拟和解析模型,构建满足工程应用需求的氢氘宽区实用物态方程。 相似文献
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用密度泛函理论在B3LYP/6.311++g(d,P)基组水平上对A12O3X2(X=H,D,T)分子的可能较低能量构型进行了几何优化.结果表明该分子的基态电子态和对称性为A12O3X2(X=H,D,T)(1A’)G,计算了氢同位素分子及A12O3X2(X=H,D,T)的电子能量E、定容热容Cv和熵S.用电子振动近似方法计算了固体A12O3的氢化热力学函数△H0,△S0,△G0,以及平衡压力与温度的关系.当A1203吸附氢(氘,氚)形成固体时,反应的氢氘氚排代效应的顺序为氚排代氘,氘排代氢,与钛等金属与氢及其同位素反应的氢氘氚排代效应的顺序相反.总体来说,这种排代效应都非常弱.随着温度的增加,这系列反应的氢氘氚排代效应趋于消失. 相似文献
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针对近二十多年的氢氘物态方程理论研究工作进行了综述分析,结合本课题组改进的自由能模型、直接量子蒙特卡洛和量子分子动力学方法的模拟结果,对多个研究小组采用不同方法获得的氢氘宽区物态方程数据进行了定量评估分析。结果表明:在当前理论框架下,仅基于第一原理数值模拟得到的氢氘物态方程能够描述的热力学相空间有限;多模型集成的H-REOS.3数据库在105K以下温度与数值模拟结果的相对差别较大,且数据稀少,二者均不能满足工程应用需求。建议采用基于半经验模型的宽区域物态方程研究方法,即结合高精度的实验研究、数值模拟和解析模型,构建满足工程应用需求的氢氘宽区实用物态方程。 相似文献
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金属钛作为高真空环境下的贮氢材料,具有易氢脆和固氦能力差等固有缺陷。金属铪和钛同为VIB族元素,贮氢体积密度相近,但铪的吸氢体胀率(15%)远小于钛的(24%),因而可望在抗氢脆方面较钛有所改善。文中研究铪吸氘反应动力学,获得铪氘反应的速率常数和表观活化能,从而评价铪吸氘的动力学性能。 相似文献
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在宇宙最初几分钟时的元素合成(大爆炸核合成)问题是核天体物理中的重要问题。这一合成过程产生的氘与氢的比值(D/H)是固定的,与我们在今天的宇宙中所看到的一样,大爆炸过程也产生了原初的轻的原子,这些原子又形成星体,根据加州理工学院的研究人员的研究结果,通过测量宇宙微波背景辐射被“宇宙黑暗年代”中存在的中性气体吸收的情况,可以计算出D/H比值。(“宇宙黑暗年代”大约处在大爆炸后十万年到十亿年之间.)氢和氘吸收不同波长的宇宙微波背景光子,这种测量需要观测由空间不同位置上氢与氘气体密度的变化所引起的吸收的微小涨落。例如,宇宙中具有高密度的氢原子区域比低密度区域要吸收更多的宇宙微波背景光子。 相似文献
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We present the first complete data set for the permeability, diffusivity, and solubility of both deuterium and hydrogen in 316L stainless steel (316L SS) obtained over a wide temperature range of 350–850 °C that accommodates both nuclear fusion and nuclear hydrogen technology applications. The deuterium results were also compared with the hydrogen results to estimate the isotope effect. The isotope effect ratio for diffusivity was different from the classical prediction. Furthermore, some of our results were compared with the results previously reported for 316 SS. Results and discussion are presented with an emphasis on the deuterium permeation and isotope effects. 相似文献
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A. L. Buchachenko 《Russian Journal of Physical Chemistry B, Focus on Physics》2017,11(6):974-977
The replacement of hydrogen atoms by deuterium in hydrogen bonds of base pairs AT and GC decreases the rate of unwinding DNA by more than 30% per each unzipped base pair. In active helicases this isotope effect refers to the ratio of the rate constants for unzipping closed base pairs in protiated and deuterated DNA. In passive helicases the effect is controlled by ratio of equilibrium constants for opening and closing base pairs in protiated and deuterated DNA. Hydrogen/deuterium isotope effects on the unwindening of double strand DNA seems to explain, at least partly, biological and pharmacological effects of heavy water on living organisms and may be used as a means to explore new facets of the helicase functioning. 相似文献
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A. Yu. Didyk E. Haewska A. Hofman V. S. Kulikauskas S. V. Serushkin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2014,8(4):814-820
Using the method of the elastic recoil detection (ERD) of hydrogen nuclei and a Plasma Focus setup (PF-4), we study the processes of the storage and redistribution of hydrogen and deuterium atoms in a stack of two tantalum foils and a deuterated polyethylene film sandwiched between them under pulsed irradiation with hot nitrogen plasma. It is established that the redistribution of implanted deuterium and hydrogen occurs at greater depths in both tantalum foils after 30 pulses of nitrogen plasma. The maximum concentrations of hydrogen and deuterium, namely 7 and 45 at % are observed on the surface of the second tantalum foil which is more distant from the PF-4 setup. The redistribution of deuterium from deuterated polyethylene onto the surface and volume of both Ta foils is observed. The observed phenomenon can be explained by the breaking of chemical bonds in the deuterated polyethylene and the transfer of freed deuterium into the Ta foils under the action of strong shock waves formed in the structure, as well as the accelerated diffusion of hydrogen and deuterium in the stress field caused by the shock wave. 相似文献
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Adamov M.R.G. Obradovic B.M. Kuraica M.M. Konjevic N. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》2003,31(3):444-454
The results of hydrogen and deuterium Balmer alpha line shapes and line intensities study in an abnormal glow discharge are reported and analyzed. The Doppler shifts along line wings are used to determine energies of excited hydrogen and deuterium atoms. For 12 different cathodes, intensity and shape of line wings are examined and dependence upon cathode material is determined. Tentative explanation of line wings intensity dependence is related to the sputtering of cathode material and back-scattering coefficients of incident hydrogen or deuterium ions and atoms from cathode surface. The influence of the light reflected on a cathode surface to the line shape measurements along discharge axis is considered. In hydrogen, deuterium, and Ar+3%H/sub 2/ discharges, basic mechanisms of fast hydrogen generation and excitation are studied. The shape and intensities of the H/sub /spl alpha// line profiles in pure hydrogen and in argon-hydrogen mixture may be correlated with hydrogen atom-carrier gas collision excitation cross sections. In order to assess the importance of reflected fast hydrogen atoms back scattered from the cathode surface, for the Balmer line shape formation, a simulation program is used. The results are in a qualitative agreement with Balmer line shapes observations. 相似文献
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The isotopic effect on the generation of the molecular high-order harmonics is studied by numerically solving the one-dimensional time-dependent Schrödinger equation when the model hydrogen molecule ions/hydrogen deuterium molecule ions are exposed to an intense laser pulse. To explain the effect more clearly, not only the ionization probabilities but also the electron–nuclear probability density distributions and time-frequency profiles are calculated. The results show that more intense harmonics are generated in the asymmetric diatomic molecule ions/hydrogen deuterium molecule ions than those of hydrogen molecule ions. Moreover, the interference minimum in the harmonic spectra is investigated by adjusting the laser intensity and the initial vibrational state. It is shown that the interference minimum is sensitive to the laser intensity and the initial vibrational level for hydrogen molecule ions; in contrast, it is only dependent on the initial vibrational level for hydrogen deuterium molecule ions. 相似文献
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K.S. Dubey 《Journal of Physics and Chemistry of Solids》1978,39(7):699-704
The lattice thermal conductivity of solid HD has been calculated in the temperature range 0.2–4°K. The important scatterers of phonons are found to be boundary walls of the crystal, isotopic impurities, phonons and molecules of ortho hydrogen and para deuterium. The presence of molecules of ortho hydrogen and para deuterium in solid HD which act as rotational impurities, are responsible for one and two phonon scattering processes in the system. The entire study is based on the Callaway model of the lattice thermal conductivity of an insulator. Excellent agreement is found between calculated and experimental values of phonon conductivity. The extra lattice thermal resistivity due to the presence of the ortho hydrogen and para deuterium is also calculated. 相似文献
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We discuss how measurements of fluctuations in the absorption of cosmic microwave background photons by neutral gas at redshifts z approximately 7-200 could reveal the primordial deuterium abundance of the Universe. The strength of the cross-correlation of brightness-temperature fluctuations in the redshifted 21-cm line of hydrogen with those in the redshifted 92-cm line of deuterium is proportional to the value of the deuterium-to-hydrogen ratio [D/H] fixed during big bang nucleosynthesis. Although challenging, this measurement would provide the cleanest possible determination of [D/H], free from contamination by structure formation processes at lower redshifts. We additionally report our result for the thermal spin-change cross section in deuterium-hydrogen scattering. 相似文献
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G. G. Bondarenko A. Yu. Didyk I. V. Borovitskaya V. S. Kulikauskas A. A. Eriskin V. Ya. Nikulin P. V. Silin I. V. Volobuev E. N. Peregudova W. Belous Y. Wasjak E. Hajewska 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2017,11(3):557-561
Assemblies made of Ta|CD2|Ta, Ta|Ta|CD2|Ta|Ta and Nb|CD2|Nb foils are irradiated with pulses of high-temperature argon plasma created by means of a “Plasma Focus” setup. The irradiated foil samples are investigated by recording the recoil nuclei of hydrogen and deuterium. It is found that hydrogen and deuterium are redistributed in foil stacks. The ultradeep penetration of light gas impurities (hydrogen and deuterium) can be explained by the influence of shock waves on the foils and accelerated diffusion under an external force. 相似文献