基于虚坡模型的交叉口交通流的解耦方法

交叉口交通流的模型是进行红绿灯优化管理仿真模拟的基础。传统的方法仍有其不足之处，主要表现在对统计手段有较大的依赖性。为此，提出了一种基于虚坡模型的解耦方法，它将路口的红灯黄灯效应用假想路障代替，将一个方向上的车流对另一个方向上车流的影响用另一个假想的宽度变化的路障代替，而假想路障则在虚坡模型中表示为速度为零的车辆。由此，交叉口两个方向上的交通流被表示为两条独立道路上的交通流，用虚坡模型算出每一方向上各车的行驶规律，并求出折合行驶延误时间。调整信号灯切换时问令总体延误时问为最小，就能得到最佳的信号灯管理方案。通过对一个大规模问题的试算，得到了有用的结果，表明可用虚坡模型通过仿真手段对交通管理问题进行直接研究。     

柴油加氢反应器缺陷原因及安全性分析

通过对反应器主焊缝外壁产生的裂纹成因分析，为板式反应器的制造、使用提供借鉴。     

Large-area profile measurement of sinusoidal freeform surfaces using a new prototype scanning tunneling microscopy

This paper presents large-area profile measurement of ultra-precision diamond turned sinusoidal surfaces by using a specially developed scanning tunneling microscopy (STM). The new prototype of STM system employs a long stroke PZT servo actuator as the Z-directional scanner, an integrated capacitance displacement sensor to accurately measure the Z-directional profile height, a motorized stage with long traveling stroke for carrying out large-area scanning. A simple method for self-calibration of the inevitable sample tilt is proposed in order to achieve large-area measurement without tip-crashing or losing of tip-sample interaction. Several types of ultra-precision machined sinusoidal freeform surfaces with different geometrical parameters are measured by the new STM system over large scanning areas at the scale of millimeters. Specially, a sinusoidal surface with peak-valley amplitude of 22 μm and periodical wavelength of 550 μm is successfully measured and imaged by the STM system. The measurement repeatability error, repeatability standard deviation and measured profile deviation are also evaluated. It is confirmed that the new STM system is capable of carrying out large-area as well as large-amplitude measurement of the ultra-precision machined sinusoidal surfaces.     

非对称成对载波多址信号的相位误差分析及幅度改进算法

针对由主站和小站信号同频混合而成的非对称成对载波多址（PCMA）信号解调问题，构建了一种实现此类信号解调的框架。参数估计是非对称PCMA通信系统在实现两路信号分离解调时不可或缺的环节，对于幅度参数估计精度问题，提出一种基于四次方法的搜索式幅度估计算法。首先建立非对称PCMA系统解调模型并作出基本假设，然后对不同假设下的相位误差进行对比并分析相位误差对幅度估计算法的影响，最后提出一种新的幅度估计算法。实验结果表明在相同信噪比（SNR）下，正态相位误差下的小站信号解调性能要劣于其均值条件下的解调性能。当误比特率（BER）在数量级为10^-4时，改进算法下小站信号的解调性能提升了1 dB，说明改进算法优于四次方法。     

Efficient autonomous signature exchange on ubiquitous networks

Fair signature exchange in emerging ubiquitous commerce (u-commerce) poses new security challenges. In particular, its operations are highly distributed and autonomous, and typically run on much open, dynamic and resource-diversified ubiquitous networks. These characteristics make the exchange very vulnerable to security attacks. Some effort has been made to address the challenges. As a result, an approach to autonomous fair exchange has been proposed specifically for u-commerce. Despite a number of novel features offered by the approach, its weaknesses are low efficiency and high complexity.This paper is aimed at proposing a more efficient and simpler solution for allowing the task of signature exchange to be delegated securely to selected devices in order to facilitate autonomous fair signature exchange on ubiquitous networks. To accomplish this aim, we have produced a novel approach to symmetric-key based verifiable proxy encryption to simplify the signature exchange delegation. Based on this approach, we have developed a new protocol for autonomous fair signature exchange in u-commerce. An analysis of the new protocol has been carried out to confirm its security, fairness and performance. A comparison with related work has demonstrated its better efficiency and simplicity.     

某现浇混凝土梁板结构性能检验分析

结合典型案例,对某一已经出现裂缝的楼面梁板进行了短期静力原位加载试验,通过观察裂缝的发展情况,判断了裂缝成因并采取了相应的处理措施,以确保梁板的安全性能。     

Amino-functionalized Fe3O4/SiO2 magnetic submicron composites and In3+ ion adsorption properties

Five kinds of amino-functionalized (polyaniline, poly(1,2-diaminobenzene), poly(1,3-diaminobenzene), poly(diphenylamine), and poly(o-toluidine)) Fe₃O₄/SiO₂ submicron composites (SCs) were prepared. The SEM and TEM results showed that these SCs possessed a sphere-like core/shell structure with an average diameter of ~500 nm. The XRD results indicated good crystallinity of Fe₃O₄ core, the amorphous SiO₂, and amino-functionalized shells. The XPS results confirmed that amino groups were plentiful rich outside the surface of these SCs which acted as the effective groups for adsorbing the metal ions. These SCs showed a good thermal stability at 20–250 °C. The high saturation magnetization of 60–70 emu/g is better than other similar reports. In³⁺ adsorption coefficients from aqueous solution by these SCs were higher than 10⁶ mL/g, indicating the higher selectivity and affinity to In³⁺ compared with Cd²⁺ and Hg²⁺ ions. In addition, these SCs could be magnetically reclaimed within 30 s and regenerated with acid after adsorption. The adsorption capabilities only decreased by 6 % after five cycles. The present work indicates that the amino-functionalized Fe₃O₄/SiO₂ SCs are promising for removal of In³⁺ ions in field application.     

基础隔震结构扭转减震评价

对不同隔震层偏心率的基础隔震结构进行了分析,提出了扭转减震系数的概念。通过对比水平减震系数与扭转减震系数,得到如下结论:隔震层偏心率在5%以下时,上部结构水平减震系数要大于扭转减震率;当隔震层偏心率大于5%时,上部结构水平减震系数要小于扭转减震系数,此时结构减震效果不能用水平减震系数来表示。     

浅论我国低碳房地产的发展

近年来,房地产业在我国得到了快速的发展。在发展低碳经济的背景下,探讨我国低碳房地产的发展,显然具有重要的意义。分析总结了我国发展低碳房地产的重要意义,指出了发展低碳房地产中存在的问题。在此基础上对我国低碳房地产的未来发展进行思考,提出相应的建议和措施。     

小波矩量法分析环形微带缝隙天线*

将矩量法和小波变换理论结合起来,应用于求解电磁场积分方程,分析计算了环形微带缝隙天线磁流分布、驻波、阻抗特性和辐射方向图,通过用小波基代替一般的分域基矩量法中的权函数和基函数,使矩量法中与算子相对应的阻抗矩阵变成为大量元素为零的稀疏矩阵,减小了数值方法对存储量的要求,在达到允许精度的前提下,使计算量显著降低。文中给出计算实例,验证该方法,计算结果与用一般矩量法计算结果和实际测试结果相比,吻合较好。