BESⅢ端盖TOF本征时间分辨的MC模拟

BESⅢ飞行时间探测器(端盖部分)由2×48个塑料闪烁探测器模块构成. 采用Monte Carlo模拟软件包Geant4，对该探测器测量高能带电粒子的性能进行了模拟研究. 文章讨论了最小电离粒子击中闪烁体不同位置，以及闪烁体形状，闪烁体表面覆盖材料对本征时间分辨的影响，给出了详细的模拟结果，并与宇宙线测试结果进行了比较. 为该探测器研制和工程设计提供必要的参考数据.     

手性叔胺脲催化靛红亚胺与苯胺的不对称aza-Mannich反应

报道了Takemoto型手性(硫)脲催化靛红亚胺与苯胺的不对称aza-Mannich反应。在0.1 mmol反应量下,筛选出最佳催化剂体系为：10 mol%催化剂N-[3,5-二(三氟甲基)苯基]-N′-[(1S,2S)-2-(二甲氨基)环己基]脲1d,1 mL乙醚,0℃反应。以71～82%的收率和最高达97%ee获得系列手性3-N,N′-靛红缩酮。     

橙皮中橙皮苷的分光光度法测定

建立了分光光度测定橙皮中橙皮苷含量的简便方法。橙皮苷和Al(NO3)3水溶液反应后生成的络合物在420nm处有最大吸收,在0—100μg/mL的浓度范围内吸光度具有良好的线性关系。可用于分光光度测定橙皮中橙皮苷。方法简单、快速,具有处理量大的优点。     

稀疏孔径光学系统成像的图像恢复算法研究

提出两种稀疏孔径光学系统成像的图像恢复模型.分析维纳滤波、最小二乘方滤波和极大似然法盲去卷积三种图像恢复算法的适用条件.针对存在噪声干扰的稀疏孔径光学系统,通过实验对比,指出维纳滤波和最小二乘方滤波把相机光学传函当作系统传函,其理论推导能够达到最优.盲去卷积把大气传输函数和相机光学传函作为系统传函进行恢复,其恢复结果优于维纳滤波带入常数K和最小二乘方滤波调整参量结果.     

Non-parametric reconstruction of dark energy and cosmic expansion from the Pantheon compilation of type Ia supernovae

The equation of state(EoS) of dark energy plays an important role in the evolution of the universe and has attracted considerable interest in the recent years. With the progress in observational technique, a precise constraint on the EoS of dark energy can be obtained. In this study, we reconstruct the EoS of dark energy and cosmic expansion using Gaussian processes(GP) from the most up-to-date Pantheon compilation of type Ia supernovae(SNe Ia),which consists of 1048 finely calibrated SNe Ia. The reconstructed EoS of dark energy has a large uncertainty owing to its dependence on the second-order derivative of the construction. Adding the direct measurements of Hubble parameters H(z) as an additional constraint on the first-order derivative can partially reduce the uncertainty; however, it is still not sufficiently precise to distinguish between the evolving and the constant dark energy. Moreover, the results heavily rely on the prior of the Hubble constant H0. The H0 value inferred from SNe+ H(z) without prior is H0= 70.5 ± 0.5 km s~(-1) Mpc~(-1). Moreover, the matter density ?M has a non-negligible effect on the reconstruction of dark energy. Therefore, more accurate determinations on H_0 and ?_M are required to tightly constrain the EoS of dark energy.     

用稀土多元渗法制备钾稀土钨青铜KxLayWO3的XPS研究

Potassium tungsten bronze K_xLa_yWO₃ (x>0.5 and y<0.01) was synthesized by rare earth co-permeation method using α-K₇[SiMg₃(OH₂)₃W₉O₃₇] as the precursor. Binding energies of La, W, O and C were determined by XPS. From the XPS data, a peak at 34.21 eV indicates that some W⁶⁺ turned into W⁵⁺ by rare earth co-permeation. The binding energies La3d were the same in the surface and inner of the composite, showing that rare earth element La could diffuse into the body of the composite and the compound of K_xLa_yWO₃ was formed at the same time. The binding energies of O1s in K_xLa_yWO₃ surface were 531.4 eV and 532.0 eV, respectively, while peak at 531.4 eV disappeared through etching process. The result implies that the binding energy of 531.4 eV was due to the adsorbent O. In addition, the binding energies of C1s in the surface were 283.5 eV, 285.0 eV and 286.7 eV respectively, while the inner had only one peak at 285.0 eV due to standard C1s. This proves that there was no C in the core.     

原位聚合制备PEDOT-PSS/PVA电磁波吸收功能复合导电织物

在自行织造的聚(3,4-乙烯二氧噻吩)-聚对苯乙烯磺酸钠/聚乙烯醇(PEDOT-PSS/PVA)导电织物表面,通过原位聚合法生成了致密的PEDOT-PSS导电聚合物覆盖层,所得织物称之为in situ PEDOT-PSS/PVA复合导电织物.研究发现,在优化的合成条件下,in situ PEDOT-PSS/PVA复合导电织物具有优异的导电性能,其表面电阻最低可达2?/cm~2.电磁屏蔽性能测试结果表明,单层in situ PEDOT-PSS/PVA导电复合织物的电磁屏蔽效能可达12 dB左右,屏蔽率约为75%;在4~18 GHz的范围内,其电磁波反射率大部分都在-5~-10dB之间,可吸收75%~90%的电磁波,基本达到了军事吸波材料的要求.     

型钢-钢板混凝土组合墙抗震性能试验研究1)

提出一种型钢-钢板混凝土组合墙,为了研究其抗震性能,设计制作该形式的型钢-钢板混凝土组合墙进行拟静力试验。通过改变试件的轴压比、剪跨比,研究其在低周往复载荷作用下的受力机理、滞回性能、刚度退化及耗能能力等。试验结果表明：试件的破坏形态为压弯破坏,组合墙两端方钢管正面及侧面发生撕裂,两侧底部钢板屈曲严重,混凝土压溃;随着轴压比减小,试件具有更好的塑性变形能力和耗能能力,剪跨比对组合墙的抗震性能影响较小。     

基于耗能模型的超空泡射弹水下侵彻鱼雷等效关系研究

超空泡射弹是水下防御技术的研究热点之一。水下毁伤试验费用大,成本高,陆上等效试验是一种可能的替代方案。为此需要获得水下超空泡射弹侵彻条件下目标与相关材料的等效关系。以MK48-5鱼雷为对象,构建由壳体和14个关键部件组成的典型鱼雷结构模型。考虑水介质对侵彻的影响,将水下超空泡射弹侵彻鱼雷的过程分为两个阶段（a. 射弹侵彻水介质和鱼雷壳体,b. 射弹侵彻鱼雷内部关键部件）;建立水介质耗能模型和靶板耗能模型;依据极限穿透速度等效原则和能量等效原则,分别得出两个阶段目标和等效靶之间的靶板厚度关系;为了获得射弹垂直命中鱼雷不同方向及不同工况毁伤效果,需要对纵向侵彻全雷和横向侵彻鱼雷战雷段、控制段、燃料舱和后舱雷尾4个典型舱段分别进行研究;并基于此建立了水下侵彻和不同工况条件下射弹侵彻鱼雷的多层等效靶模型。     

二水醋酸镉与邻氨基苯甲酸的分步固相反应的热化学研究

用溶解量热法,以一定比例的盐酸(0.2mol·L