自动变速器辛普森行星齿轮典型结构速比分析

辛普森（Sim pson）结构是汽车自动变速器行星齿轮的基本结构之一。TOYOTA A40DE自动变速器行星齿轮机构由共太阳轮式辛普森齿系和超速行星排组成,可实现4个前进速比。TOYOTA U340自动变速器行星齿轮机构为独立太阳轮式,可实现4个前进速比。

采棉机液压机械无级变速器设计与分析

根据液压机械无级变速器能够以小功率的液压元件传递大功率转矩的特性,设计了一种新型的采棉机等差式液压机械无级变速器,该液压机械无级变速器起步采用纯液压段,前进作业段为等差两区段。基于变速器的等差连续性,确定了变速器总体传动方案;采用离合器与制动器相配合的方式实现变速器的控制逻辑,对变速器传动系统参数进行了设计,并分析了液压机各区段传动特性。分析表明:该液压机械无级变速方案能够实现采棉机的作业速度连续均匀变化且在采收作业工况有较高的效率。

Quality of Service Improvement for High-Speed Railway Communications

With the fast development of highspeed railways,a call for fulfilling the notion of communication at "anytime,anywhere" for high-speed train passengers in the Train Operating Control System is on the way.In order to make a realization of that,new railway wireless communication networks are needed.The most promising one is the Long Term Evolution for Railway which will provide broadband access,fast handover,and reliable communication for high mobility users.However,with the increase of speed,the system is subjected to high bit error rate,Doppler frequency shift and handover failure just like other system does.This paper is trying to solve these problems by employing MIMO technique.Specifically,the goal is to provide higher data rate,higher reliability,less delay,and other relative quality of services for passengers.MIMO performance analysis,resource allocation,and access control for handover and various services in a two-hop model are proposed in this paper.Analytical results and simulation results show that the proposed model and schemes perform well in improving the system performances.

Crustal Thickness and Velocity Ratio beneath National Seismic Stations in the Sichuan-Yunnan Area Based on Receiver Function Analysis

By using the teleseismic receiver function method, this paper analyzes the crustal thickness and Vp/Vs ratios beneath the 4 National seismic stations （KMI, TNC, CD2 and PZH） in the Sichuan-Yunnan area. This study gives the variance of Moho depths and velocity ratios of the 4 stations in different directions. The results show that the Moho depth beneath the Kunming station is around 50km, and the vdocity ratio varies between 1.62 and 1.69. The thickness of crust and the velocity ratio do not change much with the direction. The crust beneath Tengchong station shows clear directivity, being 40.7km thick in the northeast and 49.7km thick in the southeast. The difference of the Vp/Vs values is remarkable between the two directions, reaching 0.2. The Chengdu station also has shallow Moho, about 40km, but is 8km deeper in the northeast and southwest and the vdocity ratio has a change of 0.13 between the two directions. The crust beneath the Panzhihua station is stable. In all directions, the Moho depth is around 60km and the Vp/Vs ratio doesn＇t change significantly.

INFLUENCE OF UNCERTAINTY OF ROCK PROPERTIES ON SEISMIC RESPONSES OF REACTOR BUILDINGS

The influence of the dispersion and uncertainty of the dynamic shear wave velocity and Poisson＇s ratio of soil in a hard rock site was investigated on the seismic response of reactor building structure. The analysis is performed by considering the soil-structure interaction effects and based on the model of the reactor building in a typical pressurized water reactor nuclear power plant （NPP）. The numerical results show that for the typical floor selected, while the relative increment ratio of the dynamic shear wave velocity varies from -30% to 30% compared to the basis of 1 930 m/s, the relative variation of the horizontal response spectra peak value lies in the scope of ±10% for the internal structure, and the relative variation of the frequency corresponding to the spectra peak is 0.0% in most cases. The relative variation of the vertical response spectra peak value lies in the scope of - 10% to 22%, and the relative variation of the frequency corresponding to the Spectra peak lies in the scope of - 22% to 4%. The analysis indicates that the dynamic shear wave velocity and the Poisson＇s ratio of the rock would affect the seismic response of structure and the soil-structure interaction effects should be considered in seismic analysis and design of NPP even for a hard rock site.

Faster Focus Group Interviews--CurroCus Groups--An Improved Faster Approach to Collect Consumer Data

There is a need for cost-efficient methods in consumer research. Existing qualitative methods are expensive to conduct. This paper aims to improve the focus group method. The objective was to improve focus groups with different aims： shorter time conducting interviews, interview greater number of respondents, deliver results faster than traditionally analysis of data, and lower total cost. CurroCus groups of 15-45 minutes duration were tested in five different experiments, including 70 to 160 respondents in groups of 7-11 respondents. The name of the new method is formed from the word ＂Curro＂ in Latin that means speed in English, and ＂Cus＂ that is the last syllable of the word ＂focus＂, thereby forming a new word： CurroCus~ on the method. The results from testing of the CurroCus~ group method at different cases showed that trained moderators and observers could collect relevant responses in a given time for each group. It was possible to process a number of 6 to 10 respondents for each group. By conducting several successive groups, saturation of information was reached after an adequate number of CurroCus~ groups. Therefore, the total number of respondents can be optimized and results can be more precise, with reduced risk of inaccuracy. At the same time, the cost for each case can be lowered substantially, in our cases to approximately 1/10 of a traditional focus group cost. The role （skills） of the moderator is important. A disadvantage is the risk that some of the respondents are not able to express their thoughts in due time when time is limited. There is a need for more research on all parts of the CurroCus group process.