康奈尔势模型中的强子矩阵元

本文用康奈尔势模型计算了赝标介子的衰变常数和D⁰-D⁰系统、B⁰-B⁰系统中的B参数.     

Performance analysis of LDPC codes on OOK terahertz wireless channels

Atmospheric absorption, scattering, and scintillation are the major causes to deteriorate the transmission quality of terahertz(THz) wireless communications. An error control coding scheme based on low density parity check(LDPC) codes with soft decision decoding algorithm is proposed to improve the bit-error-rate(BER) performance of an on-off keying(OOK) modulated THz signal through atmospheric channel. The THz wave propagation characteristics and channel model in atmosphere is set up. Numerical simulations validate the great performance of LDPC codes against the atmospheric fading and demonstrate the huge potential in future ultra-high speed beyond Gbps THz communications.     

界面反射超声散斑一阶统计特性

对界面反射超声斑场的一阶统计特性进行了理论和实验分析,在假设条件下,推导了超声散斑场的振幅分布和相位分布,实测数据显示理论与实验结果有很好的吻合,这表明理论假设是合理的并在实践中可行,这还表明,在B超影像分析中,超声扫描截面上散斑场统计特性的结果与该文的结果一致。     

利用介质极性调节制备纯二氧化钛可见光催化剂

利用介质极性调节与表面活性剂(十二烷基磺酸钠,SDS)辅助TiCl4水解,成功地制备了纯二氧化钛光催化剂(TPC).所制备的样品均具有可见光催化降解甲基橙的活性,而且随着TiCl4与SDS摩尔比及TiCl4与正辛烷摩尔比增大、甲基橙的初始浓度降低,催化降解效率提高.介质极性调节与表面活性剂(十二烷基磺酸钠,SDS)协同作用,可调控粒子间的相互作用强度以及高能氧桥键的分布,从而调控可见光催化活性;TPC光催化降解甲基橙的反应具有假一级反应的动力学特征.使用TiCl4与SDS摩尔比为51.2、TiCl4与正辛烷摩尔比为3.5的TPC_4,在可见光(35 W普通民用光源)下照射3h,甲基橙降解率高达69.6;.     

θ_(13) and the Higgs Mass from High Scale Supersymmetry

In the framework in which supersymmetry is used for understanding fermion masses rather than stabilizing the electroweak scale, we elaborate on the phenomenological analysis for the neutrino physics. A relatively large sinθ13 0.13 is naturally obtained. The model further predicts vanishingly small CP violation in neutrino oscillations. While the high scale supersymmetry generically results in a Higgs mass of about 141 GeV, our model reduces this mass to 126 GeV via introducing SU(2)L triplet fields which make the electroweak vacuum metastable (with a safe lifetime) and also contribute to neutrino masses.     

界面反射超声散斑统计特性

对粗糙界面反射超声散斑场的一阶和二阶统计特性进行了理论和实验分析。在假设条件下,理论分析的结果表明反射空间中超声散斑的振幅和相位分别服从瑞利分布和均匀分布,而且用聚焦探头所接收的超声散斑的平均横向尺寸仅取决于测量系统的特性,与散斑的空间位置无关。为验证理论分析结果,作者建立了专门的实验系统,用圆形孔径聚焦探头接收从粗糙液－固界面上反射在不同空间位置上的超声散斑信号。实测数据显示假设条件是合理的,理论分析是正确的。     

受支架支撑的血管管壁变形及应力分析

摘要：为了计算动脉粥样硬化和局部斑块形成的堵塞对血管壁工作状态的影响,本文根据血液流动的连续性方程、运动方程及管壁运动方程,在给定了血压波形函数的基础上,求得了狭窄血管管壁的径向位移及环向应力。分析了不同狭窄程度对血管壁变形及应力的影响;给出了不同狭窄情况下及局部斑块硬化程度不同时,血管植入支架所需的作用力。从而计算出了植入支架后血管壁的径向位移及应力状态。本文的研究结果可供临床上对狭窄血管植入支架后的变形与受力分析,和支架的正确安放参考,可避免发生堵塞严重或血管过渡硬化时,由于安放支架不当而使发生血管破裂的医疗事故。     

Neutrino Phenomenology of a High Scale Supersymmetry Model

CP violation in the lepton sector, and other aspects of neutrino physics, are studied within a high scale supersymmetry model. In addition to the sneutrino vacuum expectation values(VEVs), the heavy vector-like triplet also contributes to neutrino masses. Phases of the VEVs of relevant fields, complex couplings, and Zino mass are considered.The approximate degeneracy of neutrino masses m_(ν1) and m_(ν2) can be naturally understood. The neutrino masses are then normal ordered, ～ 0.020 eV, 0.022 eV, and 0.054 eV. Large CP violation in neutrino oscillations is favored. The effective Majorana mass of the electron neutrino is about 0.02 eV.     

酸处理及二次焙烧温度对钛酸钾晶须结构及形貌的影响

本文利用不同的处理方法制备了六钛酸钾晶须,并通过XRD及SEM对样品进行表征,研究了酸处理条件以及二次焙烧温度对晶须结构及形貌的影响.实验表明:随着pH值的降低,六钛酸钾含量逐渐升高;随着二次焙烧温度的升高,晶须的长径比以及形貌逐渐变差.利用pH =4的盐酸处理(80℃、10 h)、600℃焙烧(2 h),可得到形貌良好的高纯度六钛酸钾晶须.     

Supersymmetric extension of the minimal dark matter model

The minimal dark matter model is given a supersymmetric extension. A super SU(2)_L quintuplet is introduced with its fermionic neutral component still being the dark matter, and the dark matter mass is about 19.7 TeV. Mass splitting among the quintplet due to supersymmetry particles is found to be negligibly small compared to the electroweak corrections. Other properties of this supersymmetry model are studied, it has the solutions to the PAMELA and Fermi-LAT anomaly, and the predictions in higher energies need further experimental data to verify them.