共查询到20条相似文献,搜索用时 185 毫秒
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"冰毒"拉曼散射振动模式的研究 总被引:2,自引:0,他引:2
利用显微拉曼技术对致幻药物-“冰毒”做了测试分析研究。在激发光514.5nm和室温环境下,得到了“冰毒”分子的拉曼散射谱。根据两种分子同属单取代苯类,具有Cy2v对称性,对安非他明和甲基安非他明分子的拉曼振动模式进行了识别。只出现在甲基安非他明拉曼谱中的2459cm^-1谱线,是其他毒品分子拉曼谱中都湍有的,我们认为极可能是C-N^+-C之间的伸缩振动。 相似文献
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清华大学单原子分子测控科学与技术研究中心简介马万云(清华大学物理系,北京100084)1基本情况单原子、分子测控科学与技术是指在单个原子、分子层次上对物质(存在的种类、数量与结构……)进行精确的探测、识别与控制,即对以原子和分子为单位的“极细微领域的... 相似文献
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合成了一种新型两亲分子4-甲基-5-羟乙基-噻唑-十八酸酯(以下简写为HISE),利用FTIR,^1H NMR,MS等手段对其进行了表征,并研究了在不同pH值的亚相溶液中HISE单分子膜的形成,通过表面压-分子面积等温线(π-A)的测定,发现随着亚相pH值的增加,单分子膜的崩溃压升高,HISE的成膜性能逐渐增强,单分子膜从膨胀型向压缩型转变。通过对微分曲线dπ/dA-A的分析,研究了不同pH值的亚相中HISE单分子膜的不可压缩性和相变过程。结果表明,碱性介质中HISE单分子膜具有良好的稳定性和不可压缩性。 相似文献
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从《BIO-X》计划看物理学在21世纪生命科学发展中的作用 总被引:1,自引:0,他引:1
在简述20世纪物理学和生物学交互融合、推动了生命科学现代化方面的成就之后,着重介绍了国外为了更进一步有计划地推进生命科学发展而提出的所谓《BIO-X》计划,并以蛋白质组学、单分子与纳米技术在生物学中的应用、神经生物学、技术的研究和计算生物学为例,说明物理学在21世纪将继续在生命科学中发挥更大的作用,由此说明学科间的融合已成为自然科学发展的必然趋势。 相似文献
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ω-巯基己酸自组装修饰金电极及其对叶绿素的催化氧化还原作用 总被引:2,自引:0,他引:2
用自组装技术以ω-巯基己酸(6-MHA)对金电极进行修饰。通过表面增强拉曼散射(SERS)光谱和电化学方法研究了6-MHA自组装单分子膜(SAM)在金电极表面的形成及由此引起的电极双电层电容的变化,并研究了该自组装单分子膜的结构模型及修饰电极对叶绿素的催化性能。结果表明,6-MHA在金电极表面能够形成一层自组装膜,并对叶绿素的氧化还原过程具有明显的催化作用。 相似文献
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Langmuir单分子膜的动态稳定性: 总被引:1,自引:0,他引:1
应用KSV LB-5000型Langmuir膜天平的VISCOS模式,对硬脂酸和19,21-二炔二十二碳酸(DDA)单分子膜在有无亚相离子、不同目标膜坟、不同膜障振动频率和不同温度下的动态稳定性作了研究。实验表明,单分子膜的目标膜压越低,膜障交变振动的频率越低,单分子膜越稳定,亚相中加有金属正离子对单分子膜的动态稳定性也有利。 相似文献
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德州大学奥斯分校(University of Texas at Austin)的实验小组最近以受激拉曼跃迁的方法的将玻色-爱因斯坦凝聚体(Bose-Einstein condensate)中的铷原子转换为单一内部能态,温度约为100nK的铷分子(Rb2)^[1P。美国国家标准局(NIST)的资深物理学家Paul Julienne说,这可能是宇宙中最冷的分子。由于用传统的激光冷却的方式产生超冷分子有一定的难度,奥斯汀小组的实验为此另辟一条新种,并为分子凝聚体(molecular condensate)的诞生跨出了第一步。 相似文献
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We consider the Dirichlet Laplacian for astrip in
with one straight boundary and a width
, where $f$ is a smooth function of acompact support with a length 2b. We show that in the criticalcase,
, the operator has nobound statesfor small
.On the otherhand, a weakly bound state existsprovided
. In thatcase, there are positive c
1,c
2 suchthat the corresponding eigenvalue satisfies
for all
sufficiently small. 相似文献
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We consider the large time asymptotic behavior of solutions to the Cauchy problem for the modified Korteweg–de Vries equation
, with initial data
. We assume that the coefficient
is real, bounded and slowly varying function, such that
, where
. We suppose that the initial data are real-valued and small enough, belonging to the weighted Sobolev space
. In comparison with the previous paper (Internat. Res. Notices
8 (1999), 395–418), here we exclude the condition that the integral of the initial data u
0 is zero. We prove the time decay estimates
and
for all
, where
. We also find the asymptotics for large time of the solution in the neighborhood of the self-similar solution. 相似文献
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通过超短脉冲激光与合适的介质相互作用,在普通光学实验室中可以产生聚变中子,经过特殊设计的固体靶结构和特殊安排的级联过程,亚TW激光即可引发光核反应产生中子,通过台面超强激光与固体靶相互作用利用对离子的自导通道径向加速机制,可获得较多的高能离子和较多的中子产率,由于超强激光辐照下大的团簇爆炸时可获得大量高能离子,团簇靶实验中实现的中子产率比相似激光能量的固体靶实验高两个量级,文章讨论了上述三种产生中 相似文献
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In this article, we investigate the long time behaviour of a correlation function $c_{\mu _{0}}$ which is associated with a nematic liquid crystal system that is undergoing an isotropic-nematic phase transition. Within the setting of Landau–de Gennes theory, we confirm a hypothesis in the condensed matter physics literature on the average self-similar behaviour of this correlation function in the asymptotic regime at time infinity, namely $$\begin{aligned} \left\| c_{\mu _{0}}(r, t)-e^{-\frac{|r|^{2}}{8t}}\right\| _{L^{\infty }(\mathbb {R}^{3}, \,dr)}=\mathcal {O}(t^{-\frac{1}{2}}) \quad \mathrm as \quad t\longrightarrow \infty . \end{aligned}$$ In the final sections, we also pass comment on other scaling regimes of the correlation function. 相似文献
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Barry Simon 《Communications in Mathematical Physics》1990,134(1):209-212
For large classes of Schrödinger operators and Jacobi matrices we prove that ifh has only one point spectrum then for φ0 of compact support $$\mathop {\lim }\limits_{t \to \infty } t^{ - 2} \left\| {xe^{ - ith} \phi _0 } \right\|^2 = 0.$$ 相似文献
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Density functional Theory (DFT) (B3p86) of Gaussian03 has been used to optimize the structure of Os2 molecule. The result shows that the ground state for Os2 molecule is 9-multiple state and its electronic configuration is ^9∑^+g, which shows spin polarization effect of Os2 molecule of transition metal elements for the first time. Meanwhile, we have not found any spin pollution because the wavefunction of the ground state does not mingle with wavefunctions with higher energy states. So, the fact that the ground state for Os2 molecule is a 9-multiple state is indicative of spin polarization effect of Os2 molecule of transition metal elements. That is, there exist 8 parallel spin electrons. The non-conjugated electron is greatest in number. These electrons occupy different spacious tracks, so that the energy of Os2 molecule is minimized. It can be concluded that the effect of parallel spin of Os2 molecule is larger than the effect of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters for the ground state ^9∑^+g and other states of Os2 molecule are derived. Dissociation energy De for the ground state of Os2 molecule is 3.3971eV, equilibrium bond length Re is 0.2403nm, vibration frequency ωe is 235.32cm^-1. Its force constants f2, f3, and f4 are 3.1032×10^2aJ·nm^-2, -14.3425×10^3aJ·nm^-3 and 50.5792×10^4aJ·nm^-4 respectively. The other spectroscopic data for the ground state of Os2 molecule ωexe, Be and ae are 0.4277cm^- 1, 0.0307cm^- 1 and 0.6491 × 10^-4cm^-1 respectively. 相似文献