Study of Vehicle Exhaust Variation with Test Modes

Nowadays harmful gas in vehicle exhaust has pollute d air heavily. To prevent the environment from polluting, the request of emissions control legislation becomes more stringent. New legislation prescribes not only the emissions limitation of vehicles, but also testing instruments and methods. Test car must be operated on the chassis dynamometer and data must be collect ed and analyzed with prescriptive exhaust analysis system as well. The mass of harmful exhaust gas, containing the concentration and volume of emis sion, which is independent from the model of automobile and engine, can be used as a criterion to evaluate the pollution of an automobile. Constant Volume Sampl e System (CVS) is used to measure vehicle emissions, but it is too expensive to apply extensively. The Vehicle Mass Analysis System(Vmas), a new vehicle exhaust mass analysis system produced in USA late 1990s,is used to test and analyze veh icle exhaust. As a test instrument, it has the virtue of cheapness and easy mana geability. In this paper, Vmas is used to measure the emissions of a light truck CA1020F. A ccording to 15 running modes of Vehicle Exhaust Legislation, the test car is ope rated on the chassis dynamometer and data are collected and analyzed with Vmas. The test results show that it is viable to measure and evaluate automobile emiss ion with Vmas. Most of HC exhaust is produced when the car is decelerating. The major factor that influences the mass of HC emission is the sudden decrease of e ngine load causing incomplete combustion in decelerating mode. Test results indi cate CO and NOx are mainly produced in the process of increasing load. The forme r reason is incomplete combustion and the latter is high burning temperature cau sed by the increasing load. The methods of reducing automobile emission are also discussed in this paper.

Studying gene duplication and genetic variation of budding yeast:a systems and interdisciplinary approach

Budding yeast (Saccharomyces cerevisiae) is a single cell model organism that is amenable to genome wide experimental interrogation using high-throughput genomics, proteomics

Research on English Translation of Chinese Literary Terms from the Perspective of International Communication: Interpretation and Standardization

Literary terms are the crystallization of Chinese ideology and wisdom. Translation and communication function as an important link in the construction of the discourse system with Chinese characteristics. Standardized translation of literary terms is an important way to help the world understand China and promote international communication of Chinese culture, which is conducive to the inheritance and interpretation of fine traditional Chinese culture. From the perspective of the "going global" strategy of Chinese culture in the new era, and the existing asymmetry of English translation of Chinese literary terms in international cultural communication, we analyzed the divergence, variation and imposed interpretation of the translations of Chinese literary terms and put forward some suggestions for their standardization. We believe that the translation of Chinese literary terms should adhere to the principle of "localization" in cultural communication and focus on the transmission of Chinese cultural connotation to correct the imposed interpretations of Chinese literature in the West. Standardizing the translations of literary terms will facilitate the communication of "Chinese knowledge" to the world. The paper is expected to provide reference for research on construction and enhancement of discourse system for global communication with Chinese characteristics.

Variational transition state theory study of the reactions Li+HF and Li+HCl on the BO potential energy surfaces

Variational transition state theory is used to study the kinetics of the reactions Li+HF and Li+HCl on the BO potential energy surfaces, fitted to ab initio values by Lagana et al. The saddle point, the location of generalized transition state and other kinetic features on the bottleneck of the po- tential energy surface are obtained. We point out that the location of generalized transition state tends to the direction in which the two atoms with larger reduced mass separate off. It can be determined whether a potential energy surface is accurate or not by a fine analysis of its bottleneck region and a comparison of kinetic calculation with experimental result. This is helpful for building a more accurate potential energy surface.

Various Theories——and Variation Theory

Since its beginning in Europe around two hundred years ago,comparative literature has branched out in different approaches,some with a national or regional anchoring,others with a more theoretical foundation.This has been going on until today,also when comparative literature later expanded to other continents,blending with their local traditions and literatures or redefining itself.With the more recent re-emerging interest in world literature,this development has been reinforced,but has also left the question open how to deal with comparative literature,its history as a discipline and the different cultural underpinnings it has received,not least through research institutions and higher education in different cultures.Before one can evaluate particular and often competing theoretical contributions to this development,it will be important to look at the overall requirements a comparative theory and practice should satisfy to be relevant today,taking into account the role of literature in the multicultural and multidimensional contact zones of globalization.On this background the article will try to evaluate various theories and variation theory and their position,necessity and potential in comparative literature today.

An Efficient Class of Estimators for the Mean of a Finite Population in Two-Phase Sampling Using Multi-Auxiliary Variates

This paper presents an efficient class of estimators for estimating the population mean of the variate under study in two-phase sampling using information on several auxiliary variates.The expressions for bias and mean square error(MSE)of the proposed class have been obtained using Taylor series method.In addition,the minimum attainableMSE of the proposed class is obtained to the first order of approximation.The proposed class encompasses a wide range of estimators of the sampling literature.Efficiency comparison has been made for demonstrating the performance of the proposed class.An attempt has been made to find optimum sample sizes under a known fixed cost function.Numerical illustrations are given in support of theoretical findings.

Estimation of Mean in Double Sampling Using Exponential Technique on Multi-auxiliary Variates

This paper presents exponential-type ratio and product estimators for a finite population mean in double sampling using information on several auxiliary variates.The proposed estimators can be viewed as a generalization over the estimators suggested by Singh and Vishwakarma(Austrian J Stat 36(3):217–225,2007).The expressions for biases and mean square errors(MSEs)of the proposed estimators have been derived to the first degree of approximation.In addition,the expressions for minimum attainable MSEs are also investigated using the criterion for optimality of the weights.An empirical study is carried out in the support of the present study.Both theoretical andempirical findings are encouraging and support thesoundness that the proposed procedures for mean estimation perform better than the usual unbiased estimators and other well-known estimators under some realistic conditions.