Analysis of planar waveguides with index discontinuity or index slope discontinuity

In this paper, we propose a novel analytic transfer matrix method (ATMM) to the analysis of planar waveguides with index discontinuity or index slope discontinuity, for the cases when the conventional WKB method is no longer valid. We also analyze the physical insight of the approximations in WKB theory, and according to our research, the phase shift at the turning point is not /2, but exactly . Test calculations are done for an index profile with a known solution and the comparison shows that our method gives extremely accurate propagation constant.     

The Near-Infrared Transition of CuCl Observed by Intracavity Laser Spectroscopy

The near-infrared electronic transition of CuCl, occurring in the region of 745 nm, was recorded using intracavity laser absorption spectroscopy. The (0, 0), (1, 1), and (2, 2) vibronic bands were analyzed, and from this the molecular constants for the two electronic states were derived. Originally assigned as A' (3)Sigma(+)-X(1)Sigma(+), we have confirmed that this transition does not connect to the ground state, but occurs between two unknown excited states. The excited CuCl molecules were produced in a copper hollow cathode, operated using argon and a small amount of CCl(4). Line positions were referenced to iodine spectra observed from a heated extracavity cell using the broadband spectral output of the intracavity laser as the light source. Copyright 2000 Academic Press.     

Evidence for changing of cosmic ray composition between 10(17) and 10(18) eV from multicomponent measurements

The average mass composition of cosmic rays with primary energies between 10(17) and 10(18) eV has been studied using a hybrid detector consisting of the High Resolution Fly's Eye (HiRes) prototype and the MIA muon array. Measurements have been made of the change in the depth of shower maximum and the muon density as a function of energy. The results show that the composition is changing from a heavy to lighter mix as the energy increases.     

物理教学中让学生学会提出问题

分析了当前学生缺乏提出问题能力的原因，从教师的教学实际出发，借鉴成功教育的理念，通过培养学生在探究学习中敢问、能问，直到学生会问，逐步提高学生的学习、探究和创新的能力．     

2×n阶网络侧端等效电阻的另一种公式

再次研究了2×n阶梯形网络的侧端等效电阻,通过网络分析构建差分方程模型,给出了2×n阶梯形网络侧端等效电阻的另外一个普适规律,并通过具体的特例进行了比较与验证.     

纳米材料用于吸收电磁波的物理机制

本文从物理学的角度分析吸波材料与电磁波作用的影响因素和纳米材料在吸波应用上的微观机制，随着纳米材料和纳米科技的深入发展，纳米吸波材料将以更优异的性能广泛应用于军事装备和民用电磁波防护上．     

Adaptive synchronization and lag synchronization of uncertain dynamical system with time delay based on parameter identification

In this paper, the adaptive synchronization and lag synchronization are considered for uncertain dynamical system with time delay based on parameter identification and a novel control method is then further given using the Lyapunov functional method. With this new and effective method, parameter identification and lag synchronization can be achieved simultaneously. Simulation results are given to justify the theoretical analysis in this paper.     

Use of elemental size distributions in identifying particle formation modes

The chemical composition of particles generated during pulverized coal combustion is the consequence of their formation processes. This work aims to use the size resolved elemental composition of coal-derived particles to identify their formation modes. A size-classified bituminous coal is burnt in a laboratory drop tube furnace at 1150, 1250, and 1350 °C, respectively. The elemental composition of the size-segregated particles from coal combustion is analyzed and the total mass fraction size distributions of Si and Al are obtained. Three particle formation modes are observed in these distribution profiles. The coarse mode has the highest value of the total mass fraction of Si and Al while the ultrafine mode has the lowest one. The total mass fraction of Si and Al in these two modes is nearly independent of particle size. It is believed that the coarse mode is formed by the mineral coalescence mechanism and the ultrafine mode by the vaporization–condensation mechanism. The difference in the total mass fraction of Si and Al between the central mode and the other two indicates that the central mode is formed by different mechanisms. Based on the observation that the total mass fraction of Si and Al in this mode increases with increasing particle size, heterogeneous condensation of vaporized species on existing fine residual ash particles is proposed to account for the formation of these particles. The study of the elemental composition of the three modes represented in five categories verifies the proposed formation mechanisms for them to some extent.     

Efficient polymer white-light-emitting diodes with a single-emission layer of fluorescent polymer blend

Efficient polymer white-light-emitting diodes (WPLEDs) have been fabricated with a single layer of fluorescent polymer blend. The device structure consists of ITO/PEDOT/PVK/emissive layer/Ba/Al. The emissive layer is a blend of poly(9,9-dioctylfluorene) (PFO), phenyl-substituted PPV derivative (P-PPV) and a copolymer of 9,9-dioctylfluorene and 4,7-di(4-hexylthien-2-yl)-2,1,3-benzothiadiazole (PFO-DHTBT), which, respectively, emits blue, green and red light. The emission of pure and efficient white light was implemented by tuning the blend weight ratio of PFO: P-PPV: PFO-DHTBT to 96:4:0.4. The maximum current efficiency and luminance are, respectively, 7.6 cd/A at 6.7 V and 11930 cd/m² at 11.2 V. The CIE coordinates of white-light emission were stable with the drive voltages.