A COMPUTER MODEL FOR PREDICTING NOISE LEVELS FROM A COMPLEX VEHICLE STREAM ON A MULTI-LANE ROAD WITH SOME VEHICLE BUNCHES

In this article,a simple computer simulation method for synthetically predicting noise levels froma random complex traffic stream on a multi-lane road is presented.The probability distributionfunction,probability density function and the expectation of successive headways of a computer model(M_2 model)Which can simulate complex traffic stream with some vehicle bunches are derived in details.The transformation formula producing the random numbers that obey this distribution is also derived.Then,the simulation flow chart is given.A comparison among some simulation results based onM_2 model and M_1 model(exponential distribution model)is made.Corresponding computer programis worked out according to standard method of measurement regulation of road traffic noise in China.Provided that some parameters,such as traffic volume,traffic component and the distances betweenobserver and equivalent lane and every lane are fed into computer,the noise levels L_(10),L_(50),and L_A,eqwill be printed out.Calculations show     

2p4n) 126Ba at the beam energy of 73 MeV. Lifetimes of the states around the

通过束流能量为７３ＭｅＶ的１１６（１６Ｏ，２ｐ４ｎ）１２６Ｂａ反应布居１２６Ｂａ的高自旋态，利用多普勒移动衰减法测量了转晕带回弯区的能级寿命，相应的归一化崳拢ǎ牛玻┲翟冢保埃停保玻飨越档停笛榻峁肓Ｗ右蛔幽Ｐ偷睦砺墼ぱ宰髁吮冉稀Ｊ笛椋拢ǎ牛玻┲档陀诶砺壑怠关键词     

完全气体一元变截面不定常带激波流动的一套显式解析解

本文绘出了可压缩完全气体一元变截面不定常带撤波流动的一套代数显式解析解。据作者所知此解是不定常带激波流的第一个显式解析解。此解除在理论上有其重要意义外，还可以用来作为检验各种数值解及研究各种数值解法之用，也有重大实用价值。     

A COMPUTER MODEL FOR PREDICTING THE EFFECTS OF MOTOR VEHICLE NOISE ON BUILDINGS ADJACENT TO URBAN STREETS

Based on the principles of geometrical acoustics and the superposition of important early reflectedsound energy on direct sound energy,a computer model which considers the containment effects asso-ciated with basically unbroken facades parallel and adjacent to a street is given in this paper.Theformulae deciding the orders of important early reflected sound rays which are dependent on the heightsof buildings and the distances between facades and lanes are derived.The early reflected sound ray'slengths are also decided.This paper also gives another computer simulation method,having the aidof scale map of street and nearby buildings,which can be used for predicting the noise levels of penetra-tion through a gap between rows of houses perpendicular to the street.     

压缩态J—C模中的崩坍—复原现象

本文详细讨论了单模压缩相干态光场同单个二能级原子多光子相互作用过程中原子能级布居数反转的动力学行为.     

128Ce16+转晕态的寿命测量

通过入射能量为141MeV的¹⁰⁰Ru(³²S,2p2n)¹²⁸Ce反应布居¹²⁸Ce的高自旋态,利用多普勒移动衰减法测量了16⁺态的寿命.相应的B(E2)值与理论计算的转动值相当.     

理论,批判和哲学(续)

 抛弃旧概念 科学进展到这个阶段最困难之处在于抛弃一些重要的旧概念,任何好的物理学家都愿意接受新概念,但即使是最优秀的物理学家有时却非常不情愿放弃某些显然可靠的旧概念,在量子力学的发展中人们不能从旧概念摆脱产出来的情绪也是十分强烈的,大家都知道在相对论的发展中这种情绪一直非常强烈,即使在今天还时而出现一些论文,其作者依然拒不承认狭义相对论.     

鼓泡浆液反应器的应用开发研究Ⅰ.气含率和固相浓度分布特性

研究了以粉体氧化铝水合物为固相的鼓泡浆液反应器的平均气含率和固体浓度分布特性。考察了表观气速、体系温度、静液高度、固相浓度及气体分布板的开孔率等对气含率的影响和不同性质氧化铝水合物在塔中的悬浮和轴向浓度分布情况。结果表明气速增大或开孔率较大时气含率增大，但固相浓度大小对气含率没有影响。水合氧化铝固体粉末在鼓泡塔中的浓度分布特性与固体的堆积密度和吸水性能有关，吸水率大堆积密度小的拟薄水铝石在低气速条件下就可完全均匀悬浮。以上结果为用气液固三相鼓泡反应器制备晶粒大小均匀的拟薄水铝石提供了可能性。     

NONLINEAR MECHANISM OF ABRUPT CHANGE OF ATMOSPHERIC CIRCULATION DURING JUNE AND OCTOBER

By the low-order spectral model, the abrupt change of the circulation in the barotropic atmosphere is studied. In certain parametric combinations, along with the gradual change of the external thermal forcing, the quasi-cusp pattern abrupt changes of both the spectral coefficients and the locations of west jet stream are stimulated, which are similar to the rapid northward jumping and suddenly establishing of the "South-Branch" jet stream during June and October respectively. Depending on the changes of the parametric combinations, the motional form of the abrupt change can be substituted by that of the gradual change of one stable equilibrium, or by that of the branching phenomena of the multiple equilibria. The abrupt change mechanism of the atmospheric circulation is a nonlinear mechanism which contains the thermal forcing, dissipation, and thermal and dynamic effects.     

一种新型的OFDM系统频率同步方案

本文提出了一种正交频分复用（OFDM）系统的频率同步方案。该方案包含一个细同步算法和一个粗同步算法。细同步算法是对MOOSE算法的改进，使其频率捕获范围扩大一倍；粗同步算法通过对特殊的长训练序列进行频域相关运算，来估计大范围的频率偏移，它与改进的细同步算法合，能够纠正达到半个系统带宽的频偏。仿真表明这是一种准确而可靠的频率同步方案。