质子与乙烯分子碰撞的密度泛函理论研究(英文)

采用含时局域密度近似与分子动力学相结合的方法研究了不同入射速度的质子与乙烯分子碰撞的动力学。计算了质子的能量损失及碰撞后乙烯分子的电子和离子的运动状态, 研究了质子的入射方向及入射动能对整个系统的碰撞动力学的影响。计算结果表明, 当入射质子的动能较小（E_k0<250 eV）时, 在相同的入射速度下, 当质子垂直于分子平面入射时, 系统的电离最大, 质子俘获的电子多; 当质子的入射动能E_k0>250 eV时, 质子的能量损失与入射方向有密切的关系。In the framework of the time dependent local density approximation (TDLDA),which applied to valence electrons, coupled non adiabatically to molecular dynamics of ions, the microscopic mechanisms of collisions between energetic protons and ethylene are studied. Not only the amount of energy lost of the projectile, but also the electron and vibration excitations of the target are identified. In addition, the influences of the collision orientation on the energy loss of the proton and excitation dynamics of ethylene are discussed. It is found that the ionization is enhanced and more electrons are captured by the proton when the proton with the impact energy less than 250 eV moves perpendicularly to the molecular plane. A strong relation between the proton energy lost and the impact orientation is obtained when the impact energy is larger than 250 eV.     

测量平板玻璃折射率实验中激光散斑削减方法的探究

本文描述了以激光为光源测量平板玻璃折射率实验中成像场产生散斑的现象,并获得了一种简单有效的散斑削减方法.理论上激光经过漫散体后产生微光束干涉场,利用统计学的规律,总结出了散斑元之间对比度的影响因素.实验中,选取动-静毛玻璃对作为削减器件,利用静止漫散体增加入射光的粗糙程度,通过缓慢旋转的运动漫散体,可将散斑对比度降为4%左右,使干涉条纹清晰可见.     

Enrichment of microplastic pollution by micro-nanobubbles

Microplastic pollution has become a global environmental concern. It has been reported that microplastics are easily accessible to a wide range of aquatic organisms and ultimately enter the human body along the food chain. They pose a severe threat to ecosystems, organisms and even human health due to their durability and persistence. However, how to reduce microplastic pollution still remains a challenge in terms of scientific techniques and policy-making. There is currently still a lack of effective methods for microplastic recycling and removal. Luckily, a new technique, micro-nanobubbles (MNBs), may provide a possible and highly effective method to enrich microplastic pollution: their great advantages^[1] include a high specific surface area, long lifetime and ability to adsorb microplastics of the same size and hydrophobicity. Then they further adsorb on larger bubbles such as microbubbles or millimeter bubbles and float to the water surface together. In this study, we present a new method using MNBs to enrich microplastic pollution with high efficiency. Two types of microplastics, millimeter-scale plastic fragments and microplastic particles, were chosen as the model microplastic pollution systems to study the enrichment efficiency of MNBs on microplastics. Results showed that MNBs can efficiently enrich these microplastics. The enrichment efficiency increases with flotation time until a maximum value is reached. It is proved that MNBs not only collect the microplastic pollution but also reduce detergent use in domestic laundry sewage. This is because detergent, as a surfactant, is easily absorbed on the surface of MNBs and can be collected together with the microplastic pollution. Our research has demonstrated that the MNB technique could be promising for use in microplastic recycling and reducing detergent pollution in daily life.     

Taqman-MGB实时荧光PCR定量检测转基因玉米MON863

运用实时荧光聚合酶链式反应技术(polymerase chain reaction,PCR)对转基因玉米MON863进行品种特异性检测和定量分析。通过设计玉米内源基因和外源基因边界序列特异性引物和Taqman-MGB探针,验证了内源基因的物种特异性和外源基因边界序列的品种特异性。利用已知转基因百分含量的MON863玉米作为标准品,进行荧光定量反应,建立定量标准曲线,通过标准曲线对玉米样品MON863玉米成份进行含量分析。结果表明,该方法重复性好,检测特异性强,最低检测限浓度达到0.001 ng/μL,即14个拷贝。由于使用实时荧光PCR技术,检测周期短,操作简便,可广泛运用于转基因玉米MON863的进出口检测和转基因产品的含量分析。     

使用分光计观测太阳光谱

采用分光计和光栅对太阳光谱进行观测,通过分光计的准直管使极窄的一束太阳光通过空间频率为1 200mm-1的闪耀光栅,在望远镜处观察到了若干条夫琅禾费线,测出了典型谱线的波长.通过分析光谱照片及分光计成像光路,利用几何关系及光学公式得到了亚纳米量级谱宽观测方法,并对典型夫琅禾费线宽进行了估算大致确定了夫琅禾费线的谱宽的范围.     

Excitation and Ionization of Ethylene by Charged Projectiles

Using the time dependent local density approximation, applied to valence electrons, coupled non-adiabatically to molecular dynamics of ions, the collision process between ethylene and fast charged projectiles is studied in the microscopic way. The impact of ionic motion on the ionization is explored to show the importance of treating electronic and ionic degrees of freedom simultaneously. The number of escaped electrons, ionization probabilities are obtained. Furthermore, it is found that the ionic extensions in different directions show the different patterns.     

光学驻波腔实验系统的设计与实现

以实现腔单模运转为目的,设计了腔长连续可调的光学驻波腔实验系统.为帮助学生更好地理解纵模共振机制和横模模式匹配方法,掌握驻波腔调节的过程,系统采用开放式设计.通过测量驻波由共焦腔变为近共心腔条件下的腔透射谱,探究分析了驻波腔自由光谱区、腔模线宽和精细度等参量随腔长的变化规律,并分析了腔镜的透射损耗对实验结果的影响.     

高效液相色谱-二极管阵列/荧光检测器串联法同时测定精油中的七种性激素

建立了高效液相色谱法(HPLC)-二极管阵列检测器(DAD)/荧光检测器(FLD)串联技术同时测定精油中7种性激素(雌二醇、雌三醇、雌酮、睾酮、甲基睾酮、孕酮、己烯雌酚)的方法。样品先用正己烷溶解后,用90%的甲醇水溶液提取,弃去正己烷层,下层清液再用正己烷脱脂、净化2次,目标化合物以水-甲醇-乙腈(体积比为50:30:20)为流动相,经XTerraRP18色谱柱(250 mm×4.6 mm, 5 μm )分离,用DAD-FLD串联法进行检测。雌二醇、雌三醇、雌酮、己烯雌酚的DAD检测波长为197 nm,睾酮、甲基睾酮、孕酮的DAD检测波长为240 nm。雌二醇、雌三醇、雌酮同时用FLD定性定量,激发波长为280 nm,发射波长为310 nm。7种性激素分离效果良好并消除了样品中杂质峰的干扰。7种性激素除孕酮的回收率为79.5%以外,其余组分的平均回收率均在93%以上;相对标准偏差为0.90%～1.89%;检出限为0.010 ～1.0 mg/L。该方法简便、准确,可用于同时测定精油中的7种性激素。     

Collision of Low Energy Proton with Ethylene

In the framework of the time-dependent local density approximation, applied to valence electrons, coupled non- adiabatically to molecular dynamics of ions, we investigate the microscopic mechanism of collisions between low energetic protons and ethylene. Not only the amount of energy lost by the projectile, but also the electronic and vibronic excitations of the target are identified. We dynamics of the target depends sensitively on the impact find that the energy loss of the proton and excitation energy.     

采用光纤光栅级联结构实现光纤延迟线

在使用光纤光栅实现皮秒级别时延的基础上,提出一种光纤光栅与单模光纤相结合的微秒级别级联结构,该结构可以实现中心波长1 550～1 553 nm范围内,间距为1 nm的窄波长反射型时延线,共1, 1.5, 2和2.5μs四种不同的时延。将单波长反射的啁啾布拉格光纤光栅与103 m单模光纤连接构成延迟单元,再利用光环形器将4个延迟单元级联并使用内半径为3 cm的光纤绕线盘,将四种延时单元的传输光纤进行整合。借助光纤光栅的反射镜作用,控制不同波长光信号通过不同的传输距离,从而达到时延目的。本文通过对啁啾布拉格光纤光栅的反射谱进行仿真分析,发现相邻反射谱的旁瓣会出现交叠现象,因此使用六个切趾函数对旁瓣滤除。结果显示：不同切趾函数的滤除效果也不同,能够完全滤除旁瓣并且对反射谱包络影响最小的是柯西切趾函数,经柯西切趾后能使不同波长光信号在对应中心波长1 nm范围内反射率达到1,而其他位置均为0。由于使用光纤绕线盘整合延迟单元传输光纤会产生一定损耗,因此对弯曲损耗进行仿真分析,结果表明：弯曲半径相同时,损耗与工作波长成正比;工作波长相同时,弯曲损耗与弯曲半径成反比。当弯曲半径大于2.9 cm时,弯曲...