可用于高功率脉冲激光的面阵CCD模式测量装置

本文介绍了一种用面阵ＣＣＤ摄像机作探测器的激光光束测量装置。整个装置包括光束衰减器、单脉冲选取及脉冲同步、光束直径匹配、ＣＣＤ摄像机、图像卡、计算机及监示器以及系统软件。软件根据激光混合模的二阶矩阵理论［１］编制，可测量高功率、高重复频率脉冲激光的空间能量分布，并可对所测结果进行模拟。由软件给出所测的光束参数，可对光束质量作出正确评价。     

抑制光纤陀螺径向磁敏感性研究

研究了与光纤线圈平面平行的径向磁场作用下光纤陀螺的磁敏感性,分析了径向磁敏感性的主要机理是光纤扭转。基于此提出了利用补偿光纤环来抑制陀螺的径向磁敏感性的方法,通过控制补偿光纤的扭转分布特性,产生一个可控的补偿相位来抵消原有光纤环的径向磁敏感性误差。建立了补偿相位、径向磁敏感度与光纤扭转分布特性关系的数学模型,并对该模型进行了数据模拟和实验验证。通过定义补偿效能评估了径向磁敏感性的抑制效果,实验结果可以看出,径向磁敏感性补偿效能达到了63.76%,综合磁敏感性补偿效能达到了42.83%,表明该方法可以在一定程度上可以抑制光纤陀螺的径向磁敏感性。     

The Antioxidant and Hypolipidemic Effects of Mesona Chinensis Benth Extracts

In this study, the antioxidant and hypolipidemic effects of Mesona Chinensis Benth (MCB) extracts were evaluated. Seven fractions (F0, F10, F20, F30, F40, F50 and MTF) were obtained from the MCB ethanol extracts. Compared to the commercial antioxidants (vitamin C), MTF and F30 exhibited higher antioxidant activities in the antiradical activity test and the FRAP assay. The half-inhibition concentration (IC50) for MTF and F30 were 5.323 µg/mL and 5.278 µg/mL, respectively. MTF at 200 µg/mL significantly decreased the accumulation of TG in oleic acid (OA)-induced HepG2 cells and reversed the inhibitory effect of Compound C on AMPK (MTF and F30 significantly increased the glucose utilization of insulin-induced HepG2 cells). In addition, the components of MTF were identified by HPLC-MS, which were caffeic acid, quercetin 3-O-galactoside, isoquercetin, astragalin, rosmarinic acid, aromadendrin-3-O-rutinoside, rosmarinic acid-3-O-glucoside and kaempferol-7-O-glucoside. Through statistical correlations by Simca P software, it was found that the main antioxidant and hypolipidemic components of MCB might be caffeic acid, kaempferol-7-O-glucoside, rosmarinic acid-3-O-glucoside and aromadendrin-3-O-rutinoside, which may play important roles in the AMPK pathway. MTF and F30 in MCB could be potential health products for the treatment of hyperlipidemia.     

H2SO4-H2O中硝酸铜对脱硫石膏晶须生长的影响

以处理后的脱硫石膏为原料,在H₂SO₄-H₂O体系中以Cu(NO₃)₂为晶形控制剂采用水热法制备脱硫石膏晶须,探讨了Cu(NO₃)₂对脱硫石膏晶须生长的影响机理。结果表明:Cu(NO₃)₂对脱硫石膏有明显促溶作用,其中Cu²⁺可减小溶液中各离子的活度系数,使溶液中的Ca²⁺浓度增大。NO^-₃通过静电作用在Ca²⁺周围聚集并对SO^2-₄产生屏蔽作用,导致脱硫石膏继续溶解并使Ca²⁺和SO^2-₄的浓度处于相对稳定状态,有利于半水脱硫石膏晶体的形核与生长。此外,Cu²⁺还可在晶须的生长过程中选择性吸附在晶须表面,生成CuSO₄,促进了脱硫石膏的结晶生长,最终在Cu(NO₃)₂用量为2.0%(质量分数)时制备的脱硫石膏晶须长径比约为73。     

Te溶剂Bridgman法CdMnTe晶体核辐射探测器的制备和表征

碲锰镉(CdMnTe)作为性能优异的室温核辐射探测器材料,可用于环境监测和工业无损检测领域。本文中采用Te溶剂Bridgman法生长In掺杂Cd_0.9Mn_0.1Te晶体,制备成10 mm×10 mm×2 mm大小的室温单平面探测器,研究了该探测器对²⁴¹Am@59.5 keV γ射线源的能谱响应。通过表征红外透过率、电阻率以及探测器能谱响应等参数,综合评定了探测器用CdMnTe晶体的质量、电学和探测器性能。结果表明,晶片的红外透过率均在55%以上,最好可达到60%。采用湿法钝化,100 V偏压下的漏电流由钝化前的9.48 nA降为钝化后的7.90 nA,钝化后的电阻率为2.832×10¹⁰ Ω·cm。在-400 V反向偏压下,CdMnTe探测器对²⁴¹Am@59.5 keV γ射线源的能量分辨率在钝化前后分别为13.53%和12.51%,钝化后的电子迁移率寿命积为1.049×10^-3 cm²/V。研究了探测器的能量分辨率随电压的变化特性,当偏压≤400 V时,探测器的能量分辨率主要由载流子的收集效率决定,而当偏压>400 V时,能量分辨率由漏电流决定。本文研究结果表明,Te溶剂Bridgman法生长的CdMnTe晶体质量较好,电阻率和电子迁移率寿命积满足探测器制备需求。     

Transition-metal-free synthesis of 1,4-benzoxazepines via [4+3]-cycloaddition of para-quinone methides with azaoxyallyl cations

A formal[4+3]-cycloaddition reaction of ortho-hydroxyphenyl-substituted para-quinone methides(p-QMs)with in-situ generated azaoxyallyl cations is reported.The reaction occurs under very mild reaction conditions(transition-metal free,room temperature,cheap inorganic base)and provides a very efficient route to a series of biologically important 1,4-benzoxazepine derivatives in good to excellent yields.     

First Organic–Inorganic Hybrid Compounds Formed by Ge-V-O Clusters and Transition Metal Complexes of Aromatic Organic Ligands

Three compounds based on Ge-V-O clusters were hydrothermally synthesized and characterized by IR, UV-Vis, XRD, ESR, elemental analysis and X-ray crystal structural analysis. Both [Cd(phen)(en)]₂[Cd₂(phen)₂V₁₂O₄₀Ge₈(OH)₈(H₂O)]∙12.5H₂O (1) and [Cd(DETA)]₂[Cd(DETA)₂]_0.5[Cd₂(phen)₂V₁₂O₄₁Ge₈(OH)₇(0.5H₂O)]∙7.5H₂O (2) (1,10-phen = 1,10-phenanthroline, en = ethylenediamine, DETA = diethylenetriamine) are the first Ge-V-O cluster compounds containing aromatic organic ligands. Compound 1 is the first dimer of Ge-V-O clusters, which is linked by a double bridge of two [Cd(phen)(en)]²⁺. Compound 2 exhibits an unprecedented 1-D chain structure formed by Ge-V-O clusters and [Cd₂(DETA)₂]⁴⁺ transition metal complexes (TMCs). [Cd(en)₃]{[Cd(η₂-en)₂]₃[Cd(η₂-en)(η₂-μ₂-en)(η₂-en)Cd][Ge₆V₁₅O₄₈(H₂O)]}∙5.5H₂O (3) is a novel 3-D structure which is constructed from [Ge₆V₁₅O₄₈(H₂O)]¹²⁻ and four different types of TMCs. We also synthesized [Zn₂(enMe)₃][Zn(enMe)]₂[Zn(enMe)₂(H₂O)]₂[Ge₆V₁₅O₄₈(H₂O)]∙3H₂O (4) and [Cd(en)₂]₂{H₈[Cd(en)]₂Ge₈V₁₂O₄₈(H₂O)}∙6H₂O (5) (enMe = 1,2-propanediamine), which have been reported previously. In addition, the catalytic properties of these five compounds for styrene epoxidation have been assessed.     

Numerical Study on an RBF-FD Tangent Plane Based Method for Convection–Diffusion Equations on Anisotropic Evolving Surfaces

In this paper, we present a fully Lagrangian method based on the radial basis function (RBF) finite difference (FD) method for solving convection–diffusion partial differential equations (PDEs) on evolving surfaces. Surface differential operators are discretized by the tangent plane approach using Gaussian RBFs augmented with two-dimensional (2D) polynomials. The main advantage of our method is the simplicity of calculating differentiation weights. Additionally, we couple the method with anisotropic RBFs (ARBFs) to obtain more accurate numerical solutions for the anisotropic growth of surfaces. In the ARBF interpolation, the Euclidean distance is replaced with a suitable metric that matches the anisotropic surface geometry. Therefore, it will lead to a good result on the aspects of stability and accuracy of the RBF-FD method for this type of problem. The performance of this method is shown for various convection–diffusion equations on evolving surfaces, which include the anisotropic growth of surfaces and growth coupled with the solutions of PDEs.     

长波红外n—HgCdTe材料的电阻比值与载流子寿命关系

少数载流子寿命是长波红外ＨｇＣｄＴｅ材料的重要性能参数。从大量实际数据统计中发现长波红外ｎ型ＨｇＣｄＴｅ材料的液氮温度电阻和室温电阻的比值与材料载流子寿命有定关系,电阻比值在２￣６之间有较大的载流子寿命值,而电阻比值大于１０的寿命值较小。