Wavefront correction of Ti:sapphire terawatt laser with varying precision of phase conjugation between deformable mirror and wavefront sensor

The phase conjugation between the deformable mirror and the wavefront sensor in the aberration correction of a terawatt Ti:sapphire laser is studied experimentally and theoretically in this paper. At varying values of phase-conjugation precision, we focus the corresponding beams into spots of the same size of 5.1 μm×5.3 μm with a f/4 parabola in the 32 TW/36 fs Ti:sapphire laser system. The results show that the precision of conjugation can induce an intensity modulation but does not significantly affect the wavefront correction.     

用高效液相色谱法制备雌三醇标准品

市售雌三醇试剂,考虑到一般性用途及成本,在常规生产中不可能精制得相当纯,而免疫分析用的雌三醇标准品,关系到测定样品中抗原含量的正确定量问题,要求标准品具有高纯度,无交叉物存在。用分析型液相色谱仪可制备毫克级样品。此制备量足以满足科学研究和鉴定的需要,因此,对于纯度要求高、需求量又不大的放射免疫分析用标准品试剂,用高压液相色谱法制备是有其特色的。本工作特制备样品是上海第十二制药厂中间产品雌三醇。     

开式热沉内冷刀具的设计及其导热性能分析

车削加工温度对工件的表面加工质量和刀具的使用寿命具有重要影响. 设计了一种开式热沉内冷刀具，计算了在实际加工工艺参数下刀具受到的切削力和前刀面上的热流密度，分析了刀具的结构强度；建立了刀具热-流-固耦合温度场模型，探讨了热稳态条件下刀具的温度场分布，以及刀片冷却液流道内热沉数量对刀具导热性能的影响规律，比较了在相同热源条件下开式热沉内冷刀具与其他内冷刀具的导热性能. 结果表明:对于刀片材料为硬质合金YT5的刀具，在热流密度为10 W/mm2的条件下，内置6个热沉的设计方案可获得最佳冷却效果，刀具的最高切削温度控制为187.1 ℃；与其他内冷刀具相比，开式热沉内冷刀具的最高切削温度降低了12.1 ℃.      

Sterilization of mycete attached on the unearthed silk fabrics by an atmospheric pressure plasma jet

The sterilization of the simulated unearthed silk fabrics using an atmospheric pressure plasma jet(APPJ) system employing Ar/O_2 or He/O_2 plasma to inactivate the mycete attached on the silk fabrics is reported. The effects of the APPJ characteristics(particularly the gas type and discharge power) on the fabric strength, physical-chemical structures,and sterilizing efficiency were investigated. Experimental results showed that the Ar/O_2 APPJ plasma can inactivate the mycete completely within 4.0 min under a discharge power of 50.0 W. Such an APPJ treatment had negligible impact on the mechanical strength of the fabric and the surface chemical characteristics. Moreover, the Ar ions, O and OH radicals were shown to play important roles on the sterilization of the mycete attached on the unearthed silk fabrics.     

Enhancement of electron–ion recombination rates at low energy range in the heavy ion storage ring CSRm

Recombination of Ar¹⁴⁺, Ar¹⁵⁺, Ca¹⁶⁺, and Ni¹⁹⁺ ions with electrons has been investigated at low energy range based on the merged-beam method at the main cooler storage ring CSRm in the Institute of Modern Physics, Lanzhou,China. For each ion, the absolute recombination rate coefficients have been measured with electron–ion collision energies from 0 meV to 1000 meV which include the radiative recombination(RR) and also dielectronic recombination(DR)processes. In order to interpret the measured results, RR cross sections were obtained from a modified version of the semiclassical Bethe and Salpeter formula for hydrogenic ions. DR cross sections were calculated by a relativistic configuration interaction method using the flexible atomic code(FAC) and AUTOSTRUCTURE code in this energy range. The calculated RR + DR rate coefficients show a good agreement with the measured value at the collision energy above 100 meV.However, large discrepancies have been found at low energy range especially below 10 meV, and the experimental results show a strong enhancement relative to the theoretical RR rate coefficients. For the electron–ion collision energy below 1 meV, it was found that the experimentally observed recombination rates are higher than the theoretically predicted and fitted rates by a factor of 1.5 to 3.9. The strong dependence of RR rate coefficient enhancement on the charge state of the ions has been found with the scaling rule of q^3.0, reproducing the low-energy recombination enhancement effects found in other previous experiments.     

扭转对碳纳米管束热物性的影响

采用非平衡分子动力学方法(NEMD)研究了扭转对碳纳米管(CNT)管束热导率的影响。CNT管束由7根(10,10) CNT组成。通过对CNT管束施加不同程度扭转,结果表明CNT管束热导率随着扭转程度增大迅速下降。采用T形法测量了扭转前后CNT管束热导率随温度的变化,实验结果与模拟预测趋势吻合。声子谱和拉曼光谱的结果表明扭转对原结构的破坏,结构有序性降低造成声子软化,最终导致了热导率的下降。     

共混型聚合物太阳电池原理及研究进展

共混聚合物太阳电池是一种将电子给体材料与电子受体材料混合的新型异质结光伏电池,这种新型太阳电池由于增大了异质结的表面积,减少了光生激子的复合,互穿网络结构有利于电荷的传输,再加上其成本低、工艺简单、能大面积制备等优点,近年来已成为国内外研究的热点.本文综述了聚合物太阳电池的研究进展,讨论了聚合物太阳电池的基本原理,解释了表征太阳电池的物理量开路电压(Voc)、短路电流(Isc)、填充因子(FF)和能量转换效率(η),分析了制作工艺、材料、电极等因素对器件性能的影响,阐述了国内外聚合物太阳电池研究的现状及存在问题.     

高分子基质对光学-氧压敏感涂料压力灵敏度的影响

光学-氧压敏感涂料(pressure sensitive paint,PSP)由氧敏感的发光探针和聚合物载体组成,涂料的氧压灵敏度既与发光探针有关,也与聚合物载体有关.以四(五氟苯基)卟啉铂(PtTFPP)为发光探针,将它分别与四种聚合物即聚二甲基硅氧烷(PDMS)、聚甲基苯基硅氧烷(PMPS)、聚甲基氟丙基硅氧烷(PFS)和三氟氯乙烯-醋酸乙烯酯共聚物(PFC)混合成膜.研究不同聚合物对PSP的氧压灵敏度的影响,在室温和氧浓度[O2]分别为0%、20%、40%、60%、80%和100%环境下,以λ=365 nm的光激发,测定其对荧光强度I的猝灭作用,从I0/I(I0为纯N2气氛下的荧光强度)对[O2]的关系可知:它们的氧猝灭灵敏度随聚合物的氧透过性而增加,即PDMSPMPSPFSPFC,该结果表明上述体系的氧猝灭可从扩散控制机理得到解释.     

紫外光解强化生物滤塔去除疏水性α-蒎烯的传质及降解动力学分析

利用紫外光解（UV）作为预处理工艺来强化生物过滤塔（BF）和生物滴滤塔（BTF）对疏水性化合物α-蒎烯的去除,基于试验数据对滤塔内α-蒎烯的传质行为和微生物活性进行了模型和理论分析.Michaelis-Menten动力学分析表明,α-蒎烯在UV-BTF内的气相饱和常数为1.0gm-3,是其在BTF内的20倍,而α-蒎烯在BF内的气相饱和常数略大于UV-BF内相应数值.UV-BTF的理论临界进气浓度为555.22mgm-3,高于其他处理系统.微生物代谢活性和比耗氧速率分析表明,UV-BTF内的微生物世代时间明显缩短,α-蒎烯及其光解产物的最大比耗氧速率分别达到了1.16、0.34、0.41和0.25mgO2mg-1DWh-1,略高于其他处理系统中相应数值的150%-200%.以上模型拟合数据从理论上说明UV光解工艺能减轻α-蒎烯在BTF内的传质抑制效应,进而提高整体宏观去除能力;但是由于BF工艺的自身特性和累积臭氧的毒害效应,UV光解不适合作为BF的预处理工艺.     

Tunable Bistability in the Goos–H?nchen Effect with Nonlinear Graphene

We present a planar model system of a silica covered with a monolayer of nonlinear graphene to achieve a tunable Goos–H?nchen(GH) shift in the terahertz range. It is theoretically found that the transition between a negative shift and a large positive one can be realized by altering the intensity of incident light. Moreover, by controlling the chemical potential of graphene and the incident angle of light, we can further control the tunable GH shift dynamically. Numerical simulations for GH shifts based on Gaussian waves are in good agreement with our theoretical calculations.