第三讲 化学稳定分子的激光减速、冷却及其MOT技术

文章首先介绍了分子激光减速和冷却的基本原理、技术方案及其最新进展,主要包括分子的选择、分子激光减速、分子激光冷却、电光冷却多原子分子等。接着简单介绍了分子磁光囚禁的基本原理、技术方案及其最新研究进展。最后,就分子"激光减速、冷却与磁光囚禁"的研究进行了简单的总结与展望。     

嘧啶衍生物对牛蒡子苷元片段修饰的研究

用一系列具有生物活性的嘧啶衍生物修饰牛蒡子苷元,旨在寻找增强牛蒡苷元子抗肿瘤活性的同时又能降低嘧啶抗肿瘤副作用的先导化合物.本研究通过把卤代后的嘧啶衍生物与牛蒡子苷元酚羟基相接,合成得到11个新的化合物,通过1H NMR与LC-MS表征确定其结构.最终,增加了牛蒡子苷元抗肿瘤化合物库中化合物的数量,为接下来的体外活性筛选做准备.     

Production of CH （A2△） by multi-photon dissociation of （CH3）2CO,CH3NO2, CH2Br2, and CHBr3 at 213 nm

In order to realize electrostatic Stark deceleration of CH radicals and study cold chemistry, the fifth harmonic of a YAG laser is used to prepare CH(A2△) molecules through using the multi-photon dissociation of(CH3)2CO, CH3NO2, CH2Br2,and CHBr3 at ～ 213 nm. The CH product intensity is measured by using the emission spectrum of CH(A2△→ X2Π). The dependence of fluorescence intensity on laser power is studied, and the probable dissociation channels are analyzed. The relationship between the fluorescence intensity and some parameters, such as the temperature of the beam source, stagnation pressure, and the time delay between the opening of pulse valve and the photolysis laser, are also studied. The influence of three different carrier gases on CH signal intensity is investigated. The vibrational and rotational temperatures of the CH(A2△) product are obtained by comparing experimental data with the simulated ones from the LIFBASE program.     

Adiabatic cooling for cold polar molecules on a chip using a controllable high-efficiency electrostatic surface trap

We propose a controllable high-efficiency electrostatic surface trap for cold polar molecules on a chip by using two insulator-embedded charged rings and a grounded conductor plate. We calculate Stark energy structure pattern of ND3 molecules in an external electric field using the method of matrix diagonalization. We analyze how the voltages that are applied to the ring electrodes affect the depth of the efficient well and the controllability of the distance between the trap center and the surface of the chip. To obtain a better understanding, we simulate the dynamical loading and trapping processes of ND3 molecules in a ｜J, KM = ｜1,-1 state by using classical Monte–Carlo method. Our study shows that the loading efficiency of our trap can reach ～ 88%. Finally, we study the adiabatic cooling of cold molecules in our surface trap by linearly lowering the potential-well depth（i.e., lowering the trapping voltage）, and find that the temperature of the trapped ND3 molecules can be adiabatically cooled from 34.5 m K to ～ 5.8 m K when the trapping voltage is reduced from-35 k V to-3 k V.     

表面增强拉曼散射光谱法在环境污染物检测中的应用

对2002～2009年间表面增强拉曼散射光谱法在环境污染物检测中的应用进展作了评述,涉及的主题有在微生物、农药残留、多环芳香烃、三聚氰胺检测中的应用(引用文献21篇)。     

高功率平板波导螺旋阵列天线设计

提出了一种工作在C波段的高功率平板波导螺旋阵列天线。以平板波导馈电,降低了馈电复杂性和馈电结构高度;对基本的电探针结构进行改进,通过控制扇形缝隙的圆心角大小来调整耦合量,并采用上下脊结构消除反射;设计了短螺旋天线结构,通过分离的参数分别优化轴比和反射,得到天线的轴比在?7°～7°的范围内小于0.5 dB;构建了一个20单元的直线馈电阵列,通过电探针结构从平板波导中耦合能量,实现了20单元的等幅馈电。最后仿真了一个工作在4.3 GHz,包含20×20个单元的螺旋阵列天线,结果表明:该天线的增益为31.6 dB,口径效率为74%,在4.11～4.43 GHz的频带范围内反射小于?16 dB,功率容量3.6 GW。     

铕与醛糖及铕与D─核糖、L─氨基酸络合作用的伏安法研究

Ｅｕ（３＋）在ＨＡｃ－ＮａＡｃ（ｐＨ４．６）溶液中与五碳醛糖有弱的络合作用，用循环伏安法和微分脉冲极谱可以观察到Ｄ－核糖，Ｄ－阿拉伯糖，Ｄ－木糖对Ｅｕ（３＋）还原波形的络合影响，使还原和氧化过程变得较为可逆，其中Ｄ－核糖最为明显，而来苏糖无影响．Ｅｕ（３＋）与氨基酸在相同实验条件下有络合作用，且在汞电极上有吸附现象，因此分别加入Ｌ－苯丙氨酸、Ｌ－组氨酸和Ｌ－蛋氨酸等，进一步改善了Ｅｕ（３＋）的波形而接近于可逆氧化－还原过程，其中以Ｅｕ（３＋）－Ｄ－核糖－Ｌ－苯丙氨酸最明确。绘出了在电极表面形成三元络合物的示意图。     

基于单片机的温度控制系统的设计

针对单片机温度控制系统采用传统控制方法容易出现响应速度慢、振荡剧烈、控制精度低等问题,对单片机温度控制系统的硬件电路、控制精度、控制算法等方面进行了设计研究。基于以AT89C51单片机为核心运用DS18B20温度传感器的温度控制系统,提出了变论域模糊PID控制算法,将变论域模糊控制和PID控制相结合,结合生猪猪舍温度控制系统对传统PID控制算法以及变论域模糊PID控制进行对比分析。实验结果表明,设计的温度控制系统采用了变论域模糊PID控制算法,提高了控制精度,加快了系统的响应速度,从而增强了温度控制系统的实用性,产生了重要的实际工程意义。