Inactivation of bovine immunodeficiency virus by photodynamic therapy with HMME

To investigate the effect of photodynamic therapy (PDT) with hematoporphrin monomethyl ether (HMME) on bovine immunodeficiency virus (BIV) can provide the basis theory for photoinactivation of human immunodeficiency virus (HIV). To assess the protection of HMME-PDT on the cell line Cf2Th infected with BIVR29 by 3-(4,5)-dimethylthiahiazol-2-yl-3,5-di-phenytetrazolium bromide (MTT) with power density of 5 and 25 mW/cm2 and energy density from 0.6 to 3 J/cm<'2>. To observe the inhibition of membrane fusion using a new reporter cell line BIVE by fluorescence microscope. HMME-PDT has significant protectant effects on Cf2Th-BIVR29 with both power densities, especially in the group of high power density. Fluorescent microscope shows that there is no significant difference between the group of PDT and control, which means PDT could not inhibit the BIV-mediated membrane fusion.     

Thermal conductivity of nanofluids and size distribution of nanoparticles by Monte Carlo simulations

Nanofluids, a class of solid–liquid suspensions, have received an increasing attention and studied intensively because of their anomalously high thermal conductivites at low nanoparticle concentration. Based on the fractal character of nanoparticles in nanofluids, the probability model for nanoparticle’s sizes and the effective thermal conductivity model are derived, in which the effect of the microconvection due to the Brownian motion of nanoparticles in the fluids is taken into account. The proposed model is expressed as a function of the thermal conductivities of the base fluid and the nanoparticles, the volume fraction, fractal dimension for particles, the size of nanoparticles, and the temperature, as well as random number. This model has the characters of both analytical and numerical solutions. The Monte Carlo simulations combined with the fractal geometry theory are performed. The predictions by the present Monte Carlo simulations are shown in good accord with the existing experimental data.     

Rheological Behaviors of Poly(Vinylidene Fluoride)/“Bud-Branched” Nanotubes Nanocomposites

Bud-branched nanotubes, fabricated by growing metal particles on the surfaces of multiwall carbon nanotubes (MWCNTs), were used to prepare poly(vinylidene fluoride) (PVDF)-based nanocomposites. The melt viscoelastic behaviors of PVDF and its nanocomposites were characterized. The results showed that the introduction of both the MWCNTs and bud-branched nanotubes (MWCNTs-B) increased the storage modulus, loss modulus, and complex viscosity of the nanocomposites. However, the bud-branched nanotubes were more efficient to increase the elasticity than the MWCNTs that have relatively smooth surfaces. In particular, it was observed that the bud-branched nanotubes caused an increase of normal force and crossover modulus, while for MWCNTs, no variation in the normal force and a decrease of the crossover modulus were observed.     

The transition form factors for semi-leptonic weak decays of J/ψ in QCD sum rules

Within the standard model, we investigate the semi-leptonic weak decays of J/ψ. The various form factors of J/ψ making the transition to a single charmed meson (D^(*) _(d,s)) are studied in the framework of QCD sum rules. These form factors fully determine the rates of the weak semi-leptonic decays of J/ψ and provide valuable information on non-perturbative QCD effects. Our results indicate that the decay rate of the semi-leptonic weak decay mode J/ψ→D^(*)- _s+e⁺+ν_e is at the order of 10^-10. PACS 13.20.Gd; 13.25.Gv; 11.55.Hx     

Temporal and spectral properties of ultrashort pulsed Laguerre-Gaussian beams in dispersive media

The temporal and spectral properties of ultrashort pulsed Laguerre-Gaussian (LG) beams propagating in dispersive media are studied both theoretically and numerically. It is shown that the on-axis pulse broadens with increasing propagation distance and the on-axis spectrum is blueshifted. For the off-axis spectrum the blueshifts decrease and then the spectrum becomes redshifted as the radial distance increases. The propagation of ultrashort pulsed LG beams in free space and of ultrashort pulsed Gaussian beams can be regarded as special cases of our results, and some interesting properties are discussed.     

高分辨质谱用于分析和检测α-硫羰基硫代甲酰胺类化合物

苯乙酮及其衍生物与氯化亚砜反应所得中间产物再与仲胺反应得α－羰基硫代甲酰胺（1a-1f),经硫代得目标物α－硫羰基硫代甲酰胺（2a-2f)。化合物2a-2f含有二个硫羰基,为深红或深绿色晶体,可用作远红外吸收染料、激光Q开关及有机导体等。本文利用英国Micromass公司的OA－TOF高分辨质谱仪对α－硫羰基硫代甲酰胺类化合物的裂解行为进行了详细的研究。结果表明该类化合物容易失去S2分子形成特征的碎片离子M－S2（基峰）,为分析和检测这类化合物提供了一种有效的分析方法。OA－TOF高分辨质谱仪体积小、操作简单、快速,适合于分析纯的α－硫羰基硫代甲酰胺类化合物、检测混合物中及作为反应中间体的这类化合物。     

Simultaneous measurement of SO_2 and NO_2 concentration using an optical fiber-based LP-DOAS system

SO2 and NO2 are the most important pollution in atmosphere.An optimized long path(LP)differential optical absorption spectroscopy(DOAS)system of high light intensity at an ultraviolet(UV)wavelength is proposed and used to measure the concentration of SO2 and NO2 simultaneously.In contrast to the traditional DOAS,the system adopted a Y-type optical fiber structure instead of a combination of mirrors in the telescope.The UV light intensity test shows that the light intensity of UV can arrive to above 80% of the max measuring range when the light path reaches 135 m,and the integral time of the spectrograph is only 15 ms.The system is proved to be efficacious through laboratory calibration.The maximum error of SO2 calibration is 4.19%,and is 5.22% for NO2.The error of the SO2 and NO2 mixture calibration is within 10%.Field measurement is implemented in a wastewater treatment plant in winter.The measurement light path is 738 m.The concentration of SO2 varies from 6μg/m^3(2.26 ppb)to 20μg/m^3(7.52 ppb),and the concentration of NO2varies from 100μg/m^3(53.2 ppb)to 200μg/m^3(106.4 ppb)approximately.The results are in accordance with the data from a monitoring station nearby in magnitude order and variation tendency mostly.     

真空条件下LiCl溶液蒸发量随浓度变化规律研究

除湿溶液再生是除湿空调系统的核心过程,为了提高除湿溶液再生效率,以蒸发量作为评价标准,在不同的真空度下对不同浓度LiCl溶液进行再生。对不同再生条件下,溶液的再生情况进行数学模拟及实验研究,并将模拟结果与实验结果进行对比分析,结果表明,实验结果同模拟结果具有相同的变化趋势。在6 kPa和8 kPa的压强下,LiCl溶液的蒸发量随浓度的增大先上升后下降,而在1 kPa的压强下,LiCl溶液的蒸发量随浓度的增大呈现出先下降再升高接着又下降的趋势。     

激光惯性约束聚变中光学汤姆逊散射研究进展

当前,激光惯性约束聚变在越来越接近点火的极端能量密度条件下,实验与模拟的偏离逐渐增大,一个关键原因是缺乏对黑腔等离子体状态及其影响黑腔能量学和内爆对称性的细致研究和判断。光学汤姆逊散射主动式、诊断精确、参数完备的优点,使之成为激光惯性约束聚变黑腔等离子体状态参数精密诊断的标准方法。中国面向激光惯性约束聚变研究的光学汤姆逊散射实验技术的发展与神光系列激光装置的建设和在其上开展的物理实验紧密相关。近年来,四倍频汤姆逊散射实验技术在神光III原型和100 kJ激光装置上相继建立,部分实验结果不仅加深了对激光惯性约束聚变靶物理的认识,还反映了实验条件对汤姆逊散射诊断的影响,促进了实验技术的精密化发展。在未来,还需要进一步发展多支路汤姆逊散射、五倍频汤姆逊散射和超热相干汤姆逊散射等新技术,面向点火黑腔条件,大幅提升激光等离子体状态参数的诊断精度,开展新物理机制的探索和研究,在激光惯性约束聚变和其他高能量密度物理科学领域发挥更重要的作用。     

Effects of doping on the surface energies of nanocrystals and evidence from studies at high pressure

Zn_1−XMn_XS (X=0.85% and 1.26%) nanoparticles have been synthesized using a specially designed equipment and we have studied the influence of doping Mn²⁺ on the surface energy of ZnS. The high pressure behaviors of ZnS nanocrystals with different dopant contents have been investigated using angle-dispersive synchrotron X-ray powder diffraction up to 45.1 GPa. Theoretical calculations show that doping with Mn²⁺ increases the surface energy of the nanocrystals. The theoretical result has been further corroborated by our experimental observation of an increase in the phase transition pressure of Mn²⁺ doped ZnS nanocrystals in diamond-anvil-cell studies.