The influence of reflections from the train body and the ground on the sound radiation from a railway rail

Purpose – The vibration of the rails is a significant source of railway rolling noise, often forming the dominantcomponent of noise in the important frequency region between 400 and 2000 Hz. The purpose of the paper is toinvestigate the influence of the ground profile and the presence of the train body on the sound radiation fromthe rail.Design/methodology/approach – Two-dimensional boundary element calculations are used, in which therail vibration is the source. The ground profile and various different shapes of train body are introduced in themodel, and results are observed in terms of sound power and sound pressure. Comparisons are also made withvibro-acoustic measurements performed with and without a train present.Findings – The sound radiated by the rail in the absence of the train body is strongly attenuated by shieldingdue to the ballast shoulder. When the train body is present, the sound from the vertical rail motion is reflectedback down toward the track where it is partly absorbed by the ballast. Nevertheless, the sound pressure at thetrackside is increased by typically 0–5 dB. For the lateral vibration of the rail, the effects are much smaller. Oncethe sound power is known, the sound pressure with the train present can be approximated reasonably well withsimple line source directivities.Originality/value – Numerical models used to predict the sound radiation from railway rails have generallyneglected the influence of the ground profile and reflections from the underside of the train body on the soundpower and directivity of the rail. These effects are studied in a systematic way including comparisons with measurements.

对《Mathematical Reflections》问题S662的深入探究

本文给出《Mathematical Reflections》问题S662的一个加强、下界估计和三个类似。

Conversion hip arthroplasty for failed nailing of intertrochanteric fracture: Reflections on some important aspects

In this editorial,I present my comments on the article by Solarino et al.Conversion hip arthroplasty,which is an optional salvage procedure performed following unsuccessful fixation of intertrochanteric femur fractures in elderly pati-ents,entails more complex processes and higher rates of operative complications than primary arthroplasty.Hence,it is important to consider the appropriateness of the primary treatment choice,as well as the adequacy of nailing fixation for intertrochanteric fractures.This article briefly analyzes the possible factors contributing to the nailing failure of intertrochanteric fractures and attempts to find corresponding countermeasures to prevent fixation failures.It also analyzes the choice of treatment between nailing fixation and primary arthroplasty for intertrochanteric fractures.

Reflections on,and Improvements of,the Mediation Functions of People's Assessors

Legislatively,the people’s assessors are defined as individuals who share judicial power.However,in the context of dispute resolutions,their role is restricted by the courts,which affects the extent of their assessorial activities.It is imperative to reconsider the implications of the people’s assessors’deep involvement in mediation from the standpoint of societal division of labor.To enhance this division of labor,it is advisable that the people’s assessors relinquish their mediation roles.It is necessary to redefine the distinctions between people’s assessors,judges,and people’s mediators,including specially invited mediators.This would not only make up the deficiencies in the role of professional judges but also relieve the tension between judicial professionalism and popular accountability.

Reflections on Humanity from the Modern Vampirism

Vampirism is a very popular theme in modern novels, movies or other forms of literature genres. This paper tries to explore the development of vampirism literatures and by doing so makes some deep reflections on humanity from the modern vampirism.

Reflections on Tools and Methods for Differentiated Assessments of Individual Scientists, Groups of Scientists and Scientific Journals

Requirements for research assessments There are huge differences in mission, emphasis, inherent capability, and targeted utilization of research among scientific institutions. Hence, when it comes to assessments, a one-size-fits-all approach cannot meet the goal(s) of these assessments. Probably even larger differences exist between individuals, research teams and departments.

Reflections on Non-English Major Postgraduate English Teaching Reform

This paper presents some reflections on non-English major postgraduate English teaching reform. The author points out some understandings on the English proficiency of non-English major postgraduate students and curriculum changes in the reform. The author thinks that postgraduate English teaching reform is a systematic project, with a goal to meet the practical needs of postgraduate students and improve their ability to use English in their study and work. Hence, every effort of the reform should be made to satisfy the practical needs of the students and to make their English study contribute to their achievements in their own subject area.

Review and Reflections on Russian Telecommunications Reform

Russian telecommunications market develops rapidly in recent years.Currently,the number of Russian telephone users has achieved 195 million,which is 5.5 times of that of 2000;telephone penetration rate has reached 137%.The achievements of Russian telecommunications industry rely on the recovery of Russian economy,and link closely with the reforms in telecommunications sector.

English Language Education in China： Progress, Problems and Reflections

The thesis is aimed at putting forward to some problems existing in contemporary China＇s English teaching by showing progress made in recent years. Reflections have formed by contemplating the gaps of English teaching with that of Asian ＆ European countries. This thesis, through a general perspective, outlines what English teachers will do to push Chinese English learning to a new level.

Simulating Ultrasound Reflections Using Rayleigh Integral Method in Complex Biological Media

This paper exploits the Rayleigh integral method to simulate the propagation of transmitted ultrasonic waves and received echoes through various media. Performed simulations study the effect of apodization using different types of windows and the effect of medium properties on the reflections obtained. All estimations are done using the Rayleigh integral method simplified by the Fresnel approximation. Five different interfaces are considered： tissue-bone-tissue, tissue-fat-bone, fat-muscle-bone, air-fat-bone and water-fat-bone. The apodization simulations show that the hamming window is more efficient than the rectangular and triangular windows for obtaining a more consistent beam. In the second set of simulations, reflections are mapped with respect to the depth from which these reflections are generated. It demonstrates that the solid and water media allow for the attainment of echoes from deeper regions as compared to the air medium. Matlab is used as the simulation framework.

Reflections on the Transformation of World Pattern and Resoonsibility Adjustment

The year of 2000 is at the turn of the century as well as of the millennium. Themankind waves farewell to the 20th century as well as the second millenniumand welcomes the 21st century and the third millennium. At this special juncture,looking closely at the future based on understanding which was obtained from re-viewing and summarizing the past and present world politics from historical andphilosophical standpoints, we can find that it has become an unavoidable subject onhow to regard the trend of the world pattern toward multi-polarization and respon-sibility adjustment arising from it.

Some Reflections on the Titles of English Majors＇ B.A. Theses

English majors＇ B.A. （Bachelor of Arts） thesis writing is an important part and test of the students＇ four-year undergraduate education. It lays solid foundation for their future study and work. Yet serious problems exist during the process. The author of the paper collects and analyzes the 289 titles of English majors＇ B.A. writing in the recent two years in Changchun University, China. The results of the analysis reveal that almost 40% of the titles are on literature every year and among them there are some similar titles. In view of this situation, the author first explores the reasons that caused those problems. One of the important reasons is that the increasing of the supervisors and reference materials cannot keep the pace of the expanding of students＇ numbers. The author, after that, makes some reflections on those problems, then proposes five practical supervising strategies, and makes some relevant suggestions for English major＇s thesis writing. Meanwhile some other related problems in thesis writing in China are also discussed.

Reflections on Hong Kong

AMONG the topics I think I know well, I do not count Hong Kong. Although I visit Hong Kong, have friends there, and have researched the place for my writings — for example, its repatriation to China and the Asian Financial Crisis, both in 1997, and the recent Greater Bay Area coordinated development plan — I do not know Hong Kong like I know Beijing. That is why, when the protest movement began there, and then the violence, I was reluctant, at least initially, to accept interview requests from the international media.

Reflections on 2001 Int'l Situation

The first year of the new century witnessed volatility, reflections, readjustment and opportunities in the world. The international situation became even tenser, thereby exerting a great impact on the security and strategic conception of world major powers, and pushing them to readjust

Reflections on China's Neighboring Security Environment

There is a Chinese saying that goes like this, when stormy weather comes, a giant dragon will rise. It is the feature of the present era. When China begins to rise, it will advance at an enormous inertial force. It has become the important factor that influences world future trend. In the meanwhile, changes in international situation also exerted increasing influence on China. Therefore it is of special significance to discuss and assess the international environment that China faces.

Wahaha vs. Danone Dispute Leads to Reflections on China's FDI Policies——A Special Interview with ZONG Qinghou and Emmanuel Faber

Background: In 1996, Wahaha, Danone and BNP (Hong Kong) jointly invested in and incorporated 5 companies to manufacture Wahaha brand products, including purified water and eight-treasure porridge. Wahaha holds 49% equity interests in these companies, while Danone later became the dominant shareholder with a 51% stake after acquiring shares held by BNP in the aftermath of the Asian financial crisis. Danone then proposed to transfer the Wahaha brand to a joint venture but did not succeed. Subsequently, a trademark usage contract was signed by both parties instead. In the ensuing years, the Wahaha Group established non-JV companies in west China, central China and the Three Gorges reservoir area. These companies had RMB 5.6 billion of total assets as of December 31st, 2006 and made a net income of RMB 1.04 billion in that year. On April 3rd, 2007, Danone intended to force a deal by which it could acquire 51% equity interests in those non-JV companies for a sum of RMB 4 billion. Wahaha Chairman Zong Qinghou later complained that he and Wahaha fell into a trap set up by Danone. Both parties have since engaged in a lengthy "war of words", thereby arousing a grand debate on China's FDI policies.

Reflections on Sino-Russian Strategic Partnership

China and Russia announced“their resolve to develope a strategic partnership ofequality.mutual confidence and mutual coordination toward the 21stcentury" during President Yeltsin’s China visit in April 1996。 The partnership represents a new type of slate-to-state relations based on e-quality and mutual confidence.It aims at safeguarding each other’s national inter-ests and building a fair,just international political and economic order.It is charac-

REFLECTIONS ON THE TRANS-CENTURY WORLD SITUATION

The most salient and significant phenomenon in 1997 is the large scale adjust-ment of various bilateral and multilateral state relations,propelled specificallyby the big powers and major local powers.This will set the tune for the still-on-the-way transition of the world pattern from the old to the new in the dawning ofthe new century.