State reconstruction of molecular spatial rotation

We establish a reconstruction approach for the rotational quantum state of linear molecules possessing a magnetic manifold. Our approximate method contains an iteration with generalized matrix inverses, processing the tomographic integral of the time-dependent molecular-axis distribution in a polar angle. As shown in a simulated example for an alignment state, the density matrix is determined in a high fidelity. An analytic tomographic formula is also derived for the symmetric top rotation. The state coherent in the quantum space of both the angular momentum and its magnetic projection can be approximately retrieved from the observable time-resolved solid-angle distribution of the molecular axis.

Optimal approach to rotational state reconstruction of linear molecules

We present a simulation for the reconstruction of the rotational quantum state of linear molecules to retrieve the density matrix. An optimal approach in the sense of minimal error limit is proposed, in which a variable set of angular frequency is properly chosen and the least square inversion is then applied. This approach of reconstruction from time-dependent molecular-axis angular distribution is proved adaptable for various object states, which has a good numerical stability independent of the selected rotational space.

Dynamic NMR and Twisted Intramolecular Charge Transfer Excited States

In this paper the results of dynamic NMR studies on ethylmethylamino-tertiary-butyl-phenylborane (EMABPB) with or without light are reported. The NMR data were recorded on a Bruker 400 MHz NMR equipped with our custom-made optical probe and with our custom-made 450 watts (W) monochromatic light sources. The molecular photochemistry including twisted intramolecular charge-transfer-excited-state (TICT) of the EMABPB in several solvents has been investigated. These results indicate that the aminoborane demonstrates multiple configurations in CD3Cl and CD2Cl2 resulting in the shifts of the signals of the alkyl groups on the nitrogen and boron. This indicates that there are some time-dependent changes at constant temperature over the irradiation interval. At ﹣60°C and the presence of light (λ = 265 nm), we observed a large change in the populations of the two sites, and this by itself indicates a modification in the rotation around the boron nitrogen bond in the excited state. By considering the existence of the TICT state, many important energy technologies may be developed with higher efficiency by controlling the back-electron transfer processes.

环碳酸酯型聚氨酯的玻璃化温度分子模拟

非异氰酸酯环碳酸酯型路线合成聚氨酯不同于传统异氰酸酯合成聚氨酯,为研究非异氰酸酯合成聚氨酯的分子结构的反应合成机理,提出一种分子模拟法预测线型非异氰酸酯聚氨酯的玻璃化温度.首先通过软件建立非异氰酸酯聚氨酯的分子结构模型,基于Monte Carlo方法建立典型的构象结构,再通过分子动力学模拟得到不同温度条件下体积,最后通过体积-温度曲线的转折点确定玻璃化温度.结果表明:两种线型结构的非异氰酸酯聚氨酯的模拟值与实验值吻合较好,两种刚性结构的非异氰酸酯聚氨酯的模拟值与实验值有较大偏差;分子模拟方法可以应用于聚合物结构与性质的研究中.

聚亚甲基链在弹性形变时的链段取向研究

In this paper, molecular orientation behavior of polymethylene chains was investigated on the basis of considering long\|distance interactions by using the enumeration calculation method and the rotational isomeric state(RIS) model. The chain lengths are from \%N\%=12 to \%N=\%24, and the Lennord\|Jennes potential was adopted in the non\|local interaction calculations. The molecular orientation function(Legendre polynomial) may be well expressed as\$\$<P\-2(ζ)>/(λ\+2-λ\+\{-1\})=a(λ\+2-λ\+\{-1\})+b\$\$here\% a\% and\% b\% only depend on the chain length, and decrease with the increase of chain length, especially for \%b\%. In the meantime, we also calculate the Helmholtz free energy change in the process of tensile deformation. Comparisons with Gaussian chains are made, and our results are close to those obtained from the Roe and Krigbaum theory.

基于非线性观测器的传感器融合与旋转运动重构

虽然测量和记录人身体在空间中运动的加速度和角速度非常容易,但是从这些旋转位移测量中重建并不是一个简单的任务。为了定义位移量这些量需要集成,信号中存在的噪音对测量结果有明显的影响,限制了该技术在工业应用技术领域的发展,常用的噪声滤波技术(如卡尔曼滤波)对约束非线性运动学问题是一个很大的挑战。通过对刚体假设下的问题给出一个简洁的表述,探讨了非线性状态观测器在测量数据的处理、人体运动的数据融合和重建等方面的应用。在扩展卡尔曼滤波器技术和所提出的方法之间进行比较,需要特别注意影响这两种方法性能的条件。为了更好地说明方法之间的差异,本文对数值实验的结果进行了比较。

Rotational dephasing of the molecular alignment by centrifugal distortion [Invited]

The dephasing of molecular alignment can lead to the deformation of the alignment signal during its periodic revivals.Most studies are concentrated on the first few rotational revival periods of the molecular alignment and neglect the dephasing effect.However,study of the alignment dephasing is still of great significance for both the long-term dynamics of the molecular alignment and the dephasing itself.In this work,we theoretically demonstrate that the dephasing effect is correlated with both the rotational temperature and the rotational revival period of the molecules.The results present that the dephasing is especially significant for those molecules with long rotational revival period at high rotational temperatures.The physics behind it is explored by taking advantage of the coherence of the rotational quantum state population.This work deepens our understanding of rotational dynamics and rotational spectroscopy in molecular alignment.

皮下注射轮转图在低分子肝素治疗恶性血液病血栓前状态中的应用

目的探讨皮下注射轮转图在低分子肝素治疗恶性血液病血栓前状态中的应用效果。方法 102例恶性血液病血栓前状态的患者随机均分为两组,均接受皮下注射低分子肝素治疗,其中对照组采用常规注射方法,实验组依据皮下注射轮转图进行注射,比较两组患者注射并发症的发生情况和血凝状态的变化。结果与对照组相比较,实验组患者皮下青紫、硬结的发生率显著下降。与治疗前相比较,两组患者的血凝状态均显著改善,其中实验组的改善更加明显。结论采用皮下注射轮转图有利于提高低分子肝素对恶性血液病血栓前状态的治疗效果,降低并发症的发生率。

Cluster decay of the high-lying excited states in 14C＊

A cluster-transfer experiment of 9Be（gBe,14 C --＋ a＋lOBe）e： at an incident energy of 45 MeV was carried out in order to investigate the molecular structure in high-lying resonant states in 14C. This reaction is of extremely large Q-value, making it an excellent case to select the reaction mechanism and the final states in outgoing nuclei. The high-lying resonances in 14C are reconstructed for three sets of well discriminated final states in 10Be. The results confirm the previous decay measurements with clearly improved decay-channel selections and also show a new state at 23.5（1） MeV. The resonant states at 22.4（3） and 24.0（3） MeV decay primarily into the typical molecular states at about 6 MeV in 10Be, indicating a well developed cluster structure in these high-lying states in l4C. Further measurements of more states of this kind are suggested.

超快飞秒激光场中原子分子量子态调控

超快激光及其调控技术的发展使得原子分子量子态超快测控受到广泛关注,这些研究加深了对强激光与原子分子量子态相互作用的认识。本文回顾了相关领域的研究进展,特别集中在超快激光场对分子转动、解离的调控以及原子分子电离的量子态调控的研究,并对未来发展进行了展望。

从随机到取向——分子转动动力学的超快调控

分子取向物理是研究如何操控分子空间排列方向以及如何制备具有特定方向的分子。近十多年来,分子取向物理学取得巨大进展,人们通过各种技术对分子取向物理进行研究,使人们对分子取向的认识达到一个全新的高度。文章首先介绍了分子的量子态及其分布,转动量子态选择方法和分子的转动动力学,然后概述通过制备和调控转动态的相干布居来控制分子取向的方法。实验和理论表明,分子的不同转动态在相同激光条件作用下产生的转动波包不一样,从而导致分子的准直和取向程度随时间演化完全不一样。通过选择合适的转动量子态能够很好地提高分子取向程度。取向分子作为相互作用靶,为原子分子动力学、精密测量物理、立体化学反应和表面碰撞过程等提供了更加丰富多彩的研究内容。