Determination of Stray Inductance of Low-Inductive Laminated Planar Multiport Busbars Using Vector Synthesis Method

Laminated busbars connect capacitors with switching power modules, and they are designed to have low stray inductance to minimize electromagnetic interference. Attempts to accurately measure the stray inductance of these busbars have not been successful. The challenge lies with the capacitors, as they excite the busbar producing their individual stray inductances. These individual stray inductances cannot be arithmetically averaged to establish the total stray inductance that applies when all the capacitors excite the busbar at the same time. It is also not possible to measure the stray inductance by simultaneous excitation of each capacitor port using impedance analyzers. This paper presents a solution to the above dilemma. A vector synthesis method is proposed, whereby the individual stray inductance from each capacitor port is measured using an impedance analyzer. Each stray inductance is then mapped into an xyz frame with a distinct direction. This mapping exercise allows the data to be vectored. The total stray inductance is then the sum of all the vectors. The effectiveness of the proposed method is demonstrated on a busbar designed for H-bridge inverters by comparing the simulation and practical results. The absolute error of the total stray inductance between the simulation and the proposed method is 0.48 nH. The proposed method improves the accuracy by 14.9% compared to the conventional technique in measuring stray inductances

UK-China collaborative study on low carbon technology transfer: final report

No description supplie

China and Brazil Productive Structure and Economic Growth Compared: 1980’s to 2000’s

China and Brazil are two countries with continental dimensions, with differences in availability of natural resources, population sizes, and which have adopted different strategies of economic growth in the past. China has been following consistently a strategy of Export Led Growth (ELG), while Brazil, until the mid 1990s had a strategy based on Import Substitution Industrialization (ISI) with a relatively closed economy to the external market; however, recently Brazil has been switching to a more open economy, based on primary goods exports. In the mid 1980s the Gross National Income measured in US$ using purchasing power parity rates (GNI-PPP) of China and Brazil were at approximately the same level, but by the mid 2000s the GNI-PPP of China was around 4 times greater than Brazil’s. By looking at a series of input-output tables and their indicators, like multipliers and linkages, for China (1987, 1992, 1997, 2002, 2007) and Brazil (1985, 1992, 1997, 2002, 2007), we analyze, and compare the productive structures, and their changes over time, for these two countries. From the results, we are able to show the differences between these two countries and the results of the development strategies used by them.China, Brazil, Input-Output, Productive Structure, Economic Growth

Exports, Technical Progress and Productivity Growth in Chinese Manufacturing Industries

Theories suggesting either static or dynamic productivity gains derived from exports often assume the prior existence of a perfect market. In the presence of market failure, however, the competition effect and the resource reallocation effect of exports on productive efficiency may be greatly reduced; and there may actually be disincentives for innovation. This paper analyses the impact of exports on total factor productivity (TFP) growth in a transition economy using a panel of Chinese manufacturing industries over the period 1990-1997. TFP growth is estimated by employing a non-parametric approach and is decomposed into technical progress and efficiency change. We have not found evidence suggesting significant productivity gains at the industry level resulting from exports. Findings of the current study suggest that, for exports to generate significant positive effect on TFP growth, a well?developed domestic market and a neutral, outward-oriented policy are necessary.exports, industrial efficiency, technical progress, productivity

How Much of Chinese Exports is Really Made In China? Assessing Domestic Value-Added When Processing Trade is Pervasive

The rise of China in world trade has brought both benefits and anxiety to other economies. For many policy questions, it is crucial to know the extent of domestic value added (DVA) in exports, but the computation is more complicated when processing trade is pervasive. We propose a method for computing domestic and foreign contents that allows for processing trade. By our estimation, the share of domestic content in exports by the PRC was about 50% before China’s WTO membership, and has risen to over 60% since then. There are also interesting variations across sectors. Those sectors that are likely labeled as relatively sophisticated such as electronic devices have particularly low domestic content (about 30% or less).

INNOVATIVE CITY IN WEST CHINA CHONGQING

This working paper offers insights on science and technology in China with supporting official and interview data. The paper, as evidenced from the title, is indicating the future role of Chongqing and its evolution primarily focusing on the period of rapid development of the Municipality after Chongqing became a political entity on the same level as provinces of China. This has coincided with the planning, construction and completion of the Three Gorges Dam Project involving the resettlement of 1,000,000 people – most them coming to the rural areas Chongqing Municipality. Three major sub-themes are highlighted. First, the city played important role during more than 2000 years of its history (in 1981, for example it became first inland port in China open for foreign commerce). In the XX century Chongqing was national capital during the Second World War and the Japanese invasion (Nationalists government). Since then it enjoyed higher political status and economic independence than any other city of the same size in whole western China. Second, the municipality’s geographical position and demographic condition makes it quite unique in West China. It has a population of 31 million, an area of 82 square km, a population density of 379 persons per km2 and a location at the upper reaches of Chang (Yangtze) River. This makes it the gate of Southwest China. Third, Chongqing has a strong basic multi-faced economy in the region. Central investment since the 1950s has assisted the development of a relatively strong modern industrial base in the city. Despite the post-Mao reform era’s impact on social and economic disparities as between the coastal areas and the west, Chongqing remains one of the China’s strongest city economies. Its industrial output value ranked 11th among the 35 biggest city economies in China in 2000, though it ranked behind the top ten most industrialized coastal cities, all of which had attracted much greater foreign investment during the reform era. The campaign to Open up the West provides Chongqing with the opportunity to act as the growth pole for a number of less industrialized provincial-level units in north-west and south-west China. Fourth, the initiatives by central authorities and the extraordinary task of Three Gorges Dam project required among other great tasks also relocation of over 1,2 million people, the rebuilding of two cities, eleven county towns and one hundred sixteen townships from the site of Three Gorges Dam water reservoir. Until 2005 there were already almost one million residents resettled. Less than 20 per cent moved outside Chongqing municipality and the majority was to be accommodated within the region of Chongqing Municipality.Regional development; clusters; Regional innovation System (RIS); Development block; competence block; technology system; High Technology Parks; Overview of Science and Technology; FDI

Calculation and Analysis of Two Level Traps Model in Polymeric Materials

Space charge formation in polymeric materials can cause some serious concern for design engineers as the electric field may severely be distorted, leading to part of the material being overstressed, resulting in material degradation and possibly premature failure at the worst. It is therefore important to understand charge generation, trapping, and detrapping processes in the material. Trap depths and concentration of materials are important as they are potentially related to microstructure of the material. Changes in these parameters may reflect aging taken place in the material. In the present paper, characteristics of charge trapping and detrapping in low density polyethylene (LDPE) under dc electric field have been investigated using the pulsed electroacoustic (PEA) technique. A simple trapping and detrapping model based on two trapping levels has been used to qualitatively explain the observation. Numerical simulation based on the above model has been carried out to extract parameters related to the material. It has been found that trap depths and concentration of both shallow and deep traps show significant differences for the sample with different periods of electric field application. Besides, the trap energy levels of these shallow and deep traps are compared with the values in literature to evaluate the model. The results indicate that trap depths and concentration of both shallow and deep traps may be used as aging markers as changes in the material will certainly affect trapping characteristics (trap depth and concentration)

Good Bulbs, Bad Jobs: Workers and Conditions Behind Your New Compact Fluorescent

The study highlights labor violations at a Xiamen Topstar Lighting Co. Ltd. factory, a joint venture in which GE has a stake. The report recommends that GE follow its own policies and ensure that its bulbs are made in a way that does not compromise the health and rights of workers who make them

Domestic Value Added and Employment Generated by Chinese Exports: A Quantitative Estimation

We develop an input-output methodology to estimate how Chinese exports affect the country’s total domestic value added (DVA) and employment for 1995 and 2002. Total DVA generated by exports is obtained by subtracting all direct and indirect imported intermediate goods from the gross value of exports, and total employment is obtained by adding all direct and indirect employment generated by exports. To implement these estimations, we use hitherto unpublished Chinese government data to construct several completely new datasets, including an input-output table with separate input-output and employment-output coefficients for processing and non-processing exports. In 2002 (1995), for every US$1,000 dollar of Chinese exports, DVA and employment are estimated to be US$466 (US$545) and 0.242 (0.375) person-year, respectively.Input-output tables, Chinese exports, employment, domestic value added