High-order harmonics generation by few-cycle and multi-cycle femtosecond laser pulses

This paper investigates experimentally high-order harmonic generation(HHG) of neon gas with 5-fs and 25-fs driving laser pulses.It has been demonstrated that the cutoff energy of the harmonic extreme ultraviolet photons is extended to 131 eV and the HHG spectrum near the cutoff region becomes continuum as the driving laser pulse duration is 5 fs;whereas much lower cutoff photon energy and discrete harmonic spectrum near the cutoff region are presented as the laser pulse duration is 25 fs.The results can be explained by the fact that neutral atoms can be exposed to more intense laser field before they are depleted by ionization because of the extremely short rising time of the few-cycle pulse.The 5-fs driving laser pulse paves the way of generation of coherent x-ray in the water window and single attosecond pulse.     

分光光度法测定蜂王浆中10-HDA含量

蜂王浆是介于食品和药品之间的一种重要纯天然保健品,其有效成分之一是10-羟基2-癸烯酸(10-HDA),10-HDA含量直接影响蜂王浆的新鲜度和质量,它是蜂王浆的重要质量参数。文献表明在室温下新鲜蜂王浆保质期为三天;-15℃—-20℃冷冻保存保质期为1年。对于不同温度下保存的蜂王浆其癸烯酸含量的变化未见报道。本实验采用分光光度法来测定在不同温度下不同保存时间的蜂王浆中10-HDA含量。     

Ca5N4高压新相的第一性原理研究

通过在氮中引入杂质离子,利用高压手段获得具有新奇结构的多氮化合物是目前被广泛应用的研究方法.钙氮材料在催化、光电方面有着广泛的应用.具有较低电离能的钙(Ca)元素很容易和氮原子形成离子键钙氮化物.高压为寻找新型钙氮化合物提供了全新的技术途径.因此,利用高压方法,通过改变配比的方式,寻找具有新奇特性的钙氮高压结构,是一项非常有意义的工作.本文利用基于密度泛函理论的结构搜索方法,在100 GPa条件下,通过预测得到了一个稳定的Ca5N4相.该结构内部氮原子之间以N-N共价单键键合,氮原子和钙原子之间是离子键相互作用,且钙氮之间的电荷转移量为1.26 e/N atom.能带结构计算表明P 21/c-Ca5N4是一个直接带隙为1.447 eV的半导体结构.最后,系统地给出了该结构的拉曼振动光谱,并指认了拉曼振动模式,为实验合成该结构提供了理论指导.     

Electron–Neutron Detector Array (ENDA)

Physics of Atomic Nuclei - By accurate measurement of components and energy spectrum in the knee region, problem of origin of cosmic ray can be solved. In one extensive air shower (EAS), high...     

Preparations and characterizations of two MOFs constructed with hydroxylphenyl imidazole dicarboxylate

Using the hydrothermal reactions of Mn(Ⅱ) and Ba(Ⅱ) salts with 2-(3-hydroxylphenyl)-1H-imidazole-4,5-dicarboxylic acid(m-OHPhH_3IDC),two novel metal-organic frameworks,namely,{[Mn(mOHPhHIDC)(H_2O)]2H_2O}_n(1) and {[Ba(m-OHPhH_2IDC)_2(H_2O)_3]-2H_2O)_n,(2) have been synthesized and structurally characterized by single-crystal X-ray crystallography,elemental analyses,and IR spectroscopy.Complex 1 features a novel non-interpenetrated three-dimensional(3,4)-connected network with one-dimensional open channels.Complex 2 exhibits a two-dimensional layered structure with rhombic grids.The role of the central metals in the formation of final architectures has been discussed.Furthermore,luminescent and thermal properties of the two complexes have been studied.     

Design,synthesis and biological evaluation of novel arylpiperazine derivatives on human prostate cancer cell lines

A series of novel arylpiperazine derivatives was synthesized. The in vitro cytotoxic activities of all synthesized compounds against three human prostate cancer cell lines(PC-3, LNCa P, and DU145) were evaluated by a CCK-8 assay. Compounds 8, 10, 13, 17 and 20 exhibited strong cytotoxic activities against the tested cancer cell lines(IC_(50)3 μmol/L). In addition, these compounds exhibited weak cytotoxic effects on human epithelial prostate normal cells WPMY-1. The structure–activity relationship(SAR) of these arylpiperazine derivatives was also discussed based on the obtained experimental data.     

LED光化学反应器在环境化学实验教学中的应用

介绍了一种新型LED光化学反应器的设计思路及装置,并将其分别应用于Cr(Ⅵ)光还原和有机砷光氧化两个环境化学实验教学中。结果表明:在波长394 nm的LED光反应器中,Cr(Ⅵ)光还原效率高达95%;在波长664 nm的LED光反应器中,有机砷氧化效率大于80%;应用实验说明该反应器具有良好的稳定性,且安全可靠,完全能够满足环境光化学实验教学的要求。     

Dense Coding in a Two-Spin Squeezing Model with Intrinsic Decoherence

Quantum dense coding in a two-spin squeezing model under intrinsic decoherence with different initial states (Werner state and Bell state) is investigated. It shows that dense coding capacity χ oscillates with time and finally reaches different stable values. χ can be enhanced by decreasing the magnetic field Ω and the intrinsic decoherence γ or increasing the squeezing interaction μ, moreover, one can obtain a valid dense coding capacity (χ satisfies χ > 1) by modulating these parameters. The stable value of χ reveals that the decoherence cannot entirely destroy the dense coding capacity. In addition, decreasing Ω or increasing μ can not only enhance the stable value of χ but also impair the effects of decoherence. As the initial state is the Werner state, the purity r of initial state plays a key role in adjusting the value of dense coding capacity, χ can be significantly increased by improving the purity of initial state. For the initial state is Bell state, the large spin squeezing interaction compared with the magnetic field guarantees the optimal dense coding. One cannot always achieve a valid dense coding capacity for the Werner state, while for the Bell state, the dense coding capacity χ remains stuck at the range of greater than 1.     

Photoinduced energy transfer in bichromophoric co-assemblies based on amphiphilic poly(amidoamine) dendrons

Spherical co-assemblies were generated from an equivalent-molar-ratio mixture of amphiphilic poly(amidoamine) dendrons that were modified with focal carbazole and/or pyrene chromophores from the first to the third generation (DnCz I and DnPy, where n=1, 2, 3 denotes the generation of dendrons) in water at a concentration of 3.0 x 10(-6) M, lower than the individual critical aggregation concentrations (CAC) of either DnCz I or DnPy. UV-vis absorption and fluorescence emission spectra indicated that fluorescence resonance energy transfer (FRET) from carbazole to pyrene units occurred efficiently within the co-assemblies. Further study implied that part of the carbazole and/or pyrene units stacked homogeneously in the co-assemblies via pi-pi stacking and the dendritic branches served as connectors due to the hydrogen-bonding interaction.     

基于现场可编程门阵列的手机短信息混沌加密系统设计方案及硬件实现

手机的普及使得个人信息安全问题受到广泛关注, 其中手机短信息的安全性尤为重要. 本文致力于设计实现手机短信息加密与安全传输的硬件系统, 采用混沌A5/1混合算法, 提出一种基于现场可编程门阵列(FPGA)的手机短信息加密系统设计方案. 使用由Logistic混沌序列做初始密钥而改进的A5/1混合算法作为加密算法, 分析其伪随机性并证明圆周相关与线性相关的关系; 采用SIM300模块设计实现手机功能, 仿真普通手机短信息和加密短信息的传输; 开发一套软件测试平台, 可以在计算机上呈现硬件系统的测试结果. 经测试表明, 本文提出并实现的硬件系统可以加密手机短信息并保证其正常传输, 从而提高了手机短信息的安全性.