一种实现显微荧光寿命图的测量方法

将脉宽120fs、重复率76MHz激光引入激光扫描显微镜的激发光路,利用其扫描系统对荧光标记样品激发扫描,将激发出的荧光从荧光探测光路引入备用的外部探测口;在探测口接一快速光电倍增管,将光电倍增管的信号送给时间相关单光子计数器,获得时间相关的荧光强度图;最后通过计算机处理获得荧光寿命图。应用此系统对青色荧光蛋白(CFP)、黄色荧光蛋白(YFP)荧光寿命进行了测量,并应用CFP、YFP实现荧光共振能量转移的测量。通过实验看出利用已有的激光扫描显微镜,配合较先进的寿命测量方法,可以很好地实现显微荧光寿命图的测量。     

Extended Group Foliation Method and Functional Separation of Variables to Nonlinear Wave Equations

Generalized functional separation of variables to nonlinear evolution equations is studied in terms of the extended group foliation method, which is based on the Lie point symmetry method. The approach is applied to nonlinear wave equations with variable speed and external force. A complete classification for the wave equation which admits functional separable solutions is presented. Some known results can be recovered by this approach.     

GaAs基GaAsSb/GaInAs双层量子阱的发光

嵌入GaAs中的GaAsSb／GaInAs量子阱因其在1．3～1．5μm光通信波段发光的潜力而受到关注,我们研究了一系列MBE生长的GaAsSb／GaInAs量子阱样品的光致发光,发现所有样品在室温下都出现了一个较强的、波长在1．3μm附近的低能峰和一个较弱的高能峰。变温及变激发功率的荧光谱测量研究发现,高能峰只有在150K以上的测试条件下才能观测到,并且其相对强度随着温度的升高而增加,其调制光谱显示出第一类跃迁的特征。他们建立了理论模型,计算的结果支持将这一发光峰指派为GaInAs层内电子的基态与重空穴激发态间的跃迁,并与实验数据吻合得很好。同时初步讨论了改善1．3μm的低能峰发光的方法。     

Effect of Temperature on Polaron Stability in a One-Dimensional Organic Lattice

Effect of temperature on the polaron stability in a one-dimensional organic lattice is investigated within the Su-Schrieffer-Heeger model. The temperature effect is simulated by introducing random forces to the equation of the lattice motion. It is found that the localized polaron state becomes delocalized even at low temperatures. The time of polaron keeping localized depends on the magnitude of temperatures. By taking into account the thermal effect, we find that the dissociation field is weaker as compared with earlier works.     

Polarization and Angular Distribution of Ll X-Ray Following Inner-Shell 2p3/2 Photoionization of Magnesium-Like Ions

The inner-shell 2pa/2 photoionization and the subsequent decay of Mg-like Fe^14＋, Cd^36＋, W^62＋ and U^80＋ ions are studied theoretically within the multiconfiguration Dirac-Fock method and the density matrix theory. Special attention is paid to exploring the influence of the non-dipole terms which arise from the multipole expansion of the electron-photon interaction in the photoionization process. The results show that the non-dipole contribution to the total cross section, the magnetic sublevels cross section of the photoionization process, the degree of linear polarization and angular distribution of the subsequent characteristic x-ray radiation become more important with the increase of photons energy and atomic nuclear Z. Especially for the cross section and the degree of linear polarization, the non-dipole contribution arrives at 50% for U^80＋ at four time energy threshold units. However, for the angular distribution, the maximum contribution does not exceed 4%, even for U^80＋ ions.     

用近红外无损肌氧及运动心率检测技术评定100 m极量强度运动对心脏冲击影响

利用连续双波长近红外光技术测量肌肉中血红蛋白含氧量的变化情况,同时应用运动心率无线实时采集设备,设计了检测实时肌肉组织血氧含量和瞬时心率实验方案,对6名健康男性进行了100 m跑同步实测实验。实验表明,肌肉组织氧合血红蛋白浓度在100 m跑结束后继续降低,达到最低值的时刻滞后于运动结束时刻的时间为(6.65±1.10)s;心率则在运动结束后继续上升,达到最高值的时刻滞后于运动结束时刻的时间为(8.00±1.57)s。这些结果显示了双波长近红外光组织氧测试技术和运动心率无线实时采集系统能够正确检测极量强度运动时的血氧参数和心率,揭示了极量强度运动过程中肌肉中氧运输与消耗的过程及其与心率之间的动力学特征。     

电磁激励器屏幕发声系统的数理模型

目前,全面屏手机已经成为一种趋势。为提升全面屏的用户体验效果,业界开发了屏下指纹识别、伸缩式摄像头等技术,对于音频(主要是语音通话),则开发了基于压电陶瓷和电磁激励器的两种屏幕发声方案,其代表产品分别为小米MIX与VIVO NEX。该文针对电磁激励器屏幕发声技术,分别从平板弯曲振动、平板声辐射、电磁激励器阵列驱动等模型出发,推导电磁激励器驱动屏幕振动发声的原理以及简化的力电类比等效线路图;给出仿真与实测频响曲线以及某型号手机语音通话测试数据;最后简要归纳电磁激励器屏幕发声的设计指南以及进一步的研究方向。     

微波辅助萃取加拿大一枝黄花的花中总黄酮的工艺研究

对加拿大一枝黄花的花进行微波处理,考察微波辅助萃取对加拿大一枝黄花的花中总黄酮提取率的影响.以卢丁为标准品,用硝酸铝做显色剂,采用分光光度法在530nm波长处测定了加拿大一枝黄花的花中总黄酮的含量,探讨了料液比、乙醇浓度、微波功率、微波处理时间等因素对加拿大一枝黄花的花中总黄酮提取率的影响.结果表明,在料液比1:10、乙醇浓度70%、微波功率700W、微波处理时间15min最优条件下,加拿大一枝黄花的花中总黄酮的提取率为17.86%.     

小磁岛转动引起的沿磁力线电流对撕裂模的影响

利用离子香蕉轨道中心坐标和香蕉轨道平均算符,讨论了磁岛转动引起的沿磁力线电流分布及其对新经典撕裂模演进的影响。结果显示,考虑此电流的影响,当磁岛旋转频率ω=ω_*i 时,被离子香蕉轨道宽度效应削弱的自举电流驱动项基本恢复;当ω=ω_*e时,离子香蕉轨道宽度效应对自举电流驱动项的削弱则加剧。这意味着磁岛转动方向不同时,此沿力线电流能显著增大或减弱离子香蕉轨道宽度效应对自举电流驱动项的削弱作用。     

Attacks and Improvement of Quantum Sealed-Bid Auction with EPR Pairs

Recently, an experimentally feasible three-party quantum sealed-bid auction protocol based on EPR pairs [Z.Y. Wang, Commun. Theor. Phys. 54 （2010） 997] was proposed. However, this study points out Wang＇s protocol cannot resist some internal bidders＇ attacks, such as the Twiee-CNOT attack, the collusion attack. A malicious bidder can launch the Twice-CNOT attack to obtain the other＇s bid, or the dishonest auctioneer may collude with one bidder and help him/her win the action by changing his/her bid. For preventing against these attacks, a simple solution by using the QKD-based message encryption and a post-confirmation mechanism by adopting the hash function are proposed.