SBS新介质C4Cl6参数确定及性能研究

 从介质对光的吸收机理出发，研究了吸收系数较小的受激布里渊散射（SBS）新介质六氯-1,3-丁二烯（C4Cl6）。通过基本的物理参数，确定了入射光波长为1 064 nm时C₄Cl₆的SBS参数，其吸收系数约为0.003 cm^-1，声子寿命约为0.25 ns，增益系数约为4.9 cm·GW^-1。分析了入射光波长与介质SBS参数的关系，布里渊频移与入射光波长成反比，声子寿命与入射光波长的平方成正比，增益系数一般与入射光波长无关。在单池SBS系统中，利用Nd:YAG调Q激光器研究了C₄Cl₆的SBS性能。实验结果表明：由于其吸收系数小，与具有相同增益系数的H₂O比较，C₄Cl₆具有较高的能量反射率（饱和能量反射率大于55%）和较宽的SBS脉宽；由于其声子寿命短，与具有相同吸收系数的CS₂比较，C₄Cl₆的SBS波形上升时间较短。吸收系数小和声子寿命短的特点，使C₄Cl₆适合作为放大池介质，这对优化SBS介质选取，提高SBS系统性能具有一定意义。     

利用表面增强拉曼光谱(SERS)技术快速检测水与尿液中舒芬太尼的研究

该文建立了基于表面增强拉曼光谱(SERS)技术检测水和尿液中舒芬太尼的方法。首先制备了银溶胶SERS基底并进行表征。随后通过理论计算和实验对比,对舒芬太尼的拉曼特征峰进行了归属。通过探索最佳实验条件,确定了促凝剂及其浓度。对水和人工尿液中的舒芬太尼进行了SERS检测,检出限分别为0.09μg/mL和1.55μg/mL。水和尿液中舒芬太尼的特征峰(1 004 cm~(-1))强度与舒芬太尼质量浓度在一定范围内呈线性关系,相关系数(r~2)分别为0.979和0.968。水和尿液中舒芬太尼的回收率分别为96.3%～107%和95.8%～106%,相对标准偏差分别为4.2%～4.7%和3.3%～5.2%。该方法具有快速、准确、无损、操作简便等优点,为水和尿液中舒芬太尼的快速检测打下了良好的基础。     

Pulse Compression Based on Laser-Induced Optical Breakdown in Suspension

Pulse compression based on laser-induced optical breakdown in suspension is investigated. The physical mechanism behind it is analyzed theoretically and validated in the Q-switched Nd：YAG laser system. A 12-ns pump pulse is suppressed to 5ns With good fidelity in the front edge and sharp steepness in the trailing edge. The HT-270, which has a small gain coefficient and absorption coefficient, is used as a solvent, and therefore the disturbance induced by stimulated Brillouin scattering and absorption are minimized and the transmittivity is enhanced.     

The dependence of scattering length on van der Waals interaction and reduced mass of the system in two-atomic collision at cold energies

The static exchange model (SEM) and the modified static exchange model (MSEM) recently introduced by Ray in Pramana – J. Phys.83, 907 (2014) are used to study the elastic collision between two hydrogen-like atoms when both are in ground states by considering the system as a four-body Coulomb system in the centre of mass frame, in which all the Coulomb interaction terms in direct and exchange channels are treated exactly. The SEM includes the non-adiabatic short-range effect due to electron exchange. The MSEM added in it, the long-range effect due to induced dynamic dipole polarizabilities between the atoms e.g., the van der Waals interaction. Applying the SEM code in different H-like two-atomic systems, a reduced mass (μ) dependence on the scattering length is observed. Again, applying the MSEM code on H(1s)–H(1s) elastic scattering and varying the minimum values of interatomic distance R₀, the dependence of scattering length on the effective interatomic potential consistent with the existing physics is observed. Both these basic findings in low and cold energy atomic collision physics are quite useful and are being reported for the first time.     

Collision between two ortho-positronium (Ps) atoms: A four-body Coulomb problem

The elastic collision between two ortho-positronium (e.g. S = 1) atoms is studied using an ab-initio static exchange model (SEM) in the centre of mass (CM) frame by considering the system as a four-body Coulomb problem where all the Coulomb interaction terms in the direct and exchange channels are treated exactly. A coupled channel methodology in momentum space is used to solve Lippman–Schwinger equation following the integral approach. A new SEM code is developed in which the Born–Oppenheimer (BO) scattering amplitude acts as input to derive the SEM amplitude adapting the partial wave analysis. The s-, p- and d-wave elastic phase shifts and the corresponding partial cross-sections for the spin alignment S = 0, i.e., singlet (+) and S = 2, i.e., triplet (?) states are studied. An augmented Born approximation is used to include the contribution of higher partial waves more accurately to determine the total/integrated elastic cross-section (σ), the quenching cross-section (σ_q) and ortho-to-para conversion ratio (σ/σ_q). The effective range theory is used to determine the scattering lengths and effective ranges in the s-wave elastic scattering. The theory includes the non-adiabatic short-range effects due to exchange.     

利用拉曼光谱技术检测中蒙药中朱砂的研究

朱砂有凉性、解热、收敛作用,一般以粉末状入药于中药或蒙药中。然而朱砂具有一定的毒性,因此有必要对药品中朱砂的含量进行检测分析。利用便携式拉曼光谱仪对朱砂进行了鉴别分析,获得了朱砂较为全面的分子结构振动信息。实验结果显示朱砂的拉曼光谱在253,290和343 cm-1等处出现了较强的拉曼特征峰,文中确定以此三处特征峰作为研究对象。同时,检测了蒙药八味止血红花散、朝伦-雄胡-5、外用溃疡散以及中药口腔溃疡散的拉曼光谱。结果在含有朱砂的几种蒙药八味止血红花散、朝伦-雄胡-5和外用溃疡散均检测到了朱砂的特征峰,而在不含有朱砂的中药口腔溃疡散中未检测到拉曼特征峰。此外,对口腔溃疡散中的朱砂进行半定量分析,检测极限可达到质量分数的10%左右。拟合得到了中药口腔溃疡散的拉曼光谱特征峰强度与其中朱砂的掺杂量之间的关系,获得曲线的相关系数r=0.995 9,验证了拟合结果的准确性。该拉曼光谱检测方法具有快速、简便、准确等优点,值得在中蒙药成分鉴定方面得到广泛的应用。     

具有三维开放骨架结构的亚硝酸锌{[Zn(NO_2)_3]~-·H_3O~+·H_2O}_n的溶剂热合成与晶体结构

本文通过溶剂热法合成出一种具有三维开放骨架结构的亚硝酸锌化合物{[Zn(NO_2)_3]~-·H_3O~+·H_2O}_n(Zn1). 通过XRD、IR、拉曼光谱、TG和X射线单晶衍射对其结构进行了表征.X射线单晶衍射分析表明:该化合物属三方晶系,空间群为R-3c,晶胞参数a=b=c=0.8814(6) nm,α=β=γ=55.51(2)°,V=2.0394(2) nm~3.Z=12,R_ 1=0.0325,wR_ 2=0.0829,GOF=1.077.Zn1的三维开放骨架结构由NO-2~-的O原子连接邻近的Zn原子构成,沿[100]和[110]方向上呈现八元环孔道.     

介质参数对受激布里渊散射特性的影响

 采用一维瞬态模型对受激布里渊散射（SBS）过程进行了数值模拟，研究了介质参数对SBS特性的影响规律；选取FC-72、FC-75、CCl₄、CS₂、丙酮、苯以及CCl₂/乙醇的混合溶液等作为散射介质，在Nd∶YAG调Q激光系统下进行了实验研究，比较了各种介质所产生的SBS脉宽、能量反射率和波形之间的差异，由此讨论了介质参数对SBS特性的影响。结果表明，介质增益系数越大，吸收系数越小，SBS能量反射率就越大；吸收系数越大，产生的SBS脉宽就越窄；声子寿命越短，SBS波形前沿就越陡，并且越容易出现调制现象。     

水溶性铜卟啉配合物的合成、与DNA的相互作用及抗肿瘤活性

合成了3种水溶性铜卟啉配合物,分别为水溶性含溴铜卟啉(CuP-1)及其溴取代衍生物(CuP-2、CuP-3),并采用核磁氢谱、元素分析、质谱等手段进行了结构表征。利用紫外光谱法、EB-DNA荧光淬灭法、粘度法以及圆二色谱法等光谱法研究了CuP-1、CuP-2和CuP-3与小牛胸腺DNA(CT-DNA)的相互作用。采用噻唑兰(MTT)法,以体外培养的宫颈癌细胞(Hela)和乳腺癌细胞(MDA)为测试细胞株对CuP-1~CuP-3的抗肿瘤活性进行检测。人成纤维细胞(L929)作为正常细胞系。光谱法实验结果表明,CuP-1以插入的方式与CT-DNA相互作用,而CuP-2和CuP-3与CT-DNA以沟面结合的方式相互作用,且CuP-1与CT-DNA的结合能力优于CuP-2和CuP-3。体外抗癌活性实验结果表明,CuP-1~CuP-3对Hela和MDA均有体外抑制细胞增殖作用,呈时间、剂量依赖关系,并且CuP-1的体外抗肿瘤活性明显优于CuP-2、CuP-3。     

拉曼光谱技术结合主成分分析-支持向量机对砷类矿物药的分类识别研究

为了快速检测砷类矿物药,建立了拉曼光谱技术结合主成分分析(PCA)-支持向量机(SVM)分类识别砷类矿物药的新方法.首先对雄黄、雌黄、信石和砒霜的拉曼光谱进行了归属,并进行了 PCA-SVM分类识别.然后分别测定了五个批次雄黄的拉曼光谱,并进行了 PCA-SVM分类识别,最后对其拉曼光谱的差异进行了分析.该方法快速、方...