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The establishment of free trade zones (FTZs) is an important experiment as part of the reform and opening up policy. This paper aims to focus on the issue of production efficiency of environmental protection enterprises in FTZs. Changes in the external and internal environments of enterprises can easily lead to changes in the production efficiencies of enterprises. The establishment of FTZs can change the external environment of enterprises. Knowledge accumulation changes the internal environment of enterprises. However, traditional efficiency analysis has usually ignored the internal and external heterogeneity of decision-making units, resulting in the distortion of the evaluation results.

This paper examines the relationship between knowledge accumulation and development potential based on financial data of environmental protection enterprises that were listed in Shanghai and Shenzhen A stocks, from 2009 to 2016. Then, through data envelopment analysis cross-efficiency analysis of the listed environmental protection enterprises from external heterogeneity, BP neural network model is set up.

The results show that the model set up in this paper is stable and reliable. The paper makes policy suggestions such as stimulating trade inside industry, quickening technological progress and enhancing environmental protection.

This paper analyzes the economy, environmental protection, science and technology and education to simulate the external environment of enterprises. Based on the experience data from the completion of Shanghai FTZ, this paper predicts the future development potential of Hainan FTZ enterprises.

The purpose of this paper is to implement the macro-modeling and passivity enforcement for the equivalent high frequency circuit model of a single-phase winding for an alternating current (AC) three-phase motor. It provides a stable and strictly passive Foster-type circuit macro-model for the winding. Consequently, a stable circuit network is guaranteed when it is connected with an external passive circuit. The equivalent circuit is validated on a three-phase permanent magnet synchronous motor. Furthermore, the corresponding three-phase windings macro-model could be obtained accordingly.

The following techniques are used: the least square method, vector fitting method, the fast residue perturbation method, circuit synthesis, sequence quadratic programming method and simulated annealing method.

This work presents an effective approach to model an equivalent high frequency circuit macro-model for a single-phase winding. Simultaneously, both the characteristics of port passivity and component passivity are guaranteed.

This paper carries out both the port passivity and the component passivity enforcement for a single-phase winding of a motor during the macro-modeling procedure. This equivalent motor winding model can be applied to obtain the conducted electromagnetic interference and the overvoltage performance analysis for an adjustable speed motor drive system.

This paper aims to propose a novel multiple transient modeling scheme for the 12-pulse phase-shifting reactor (PSR) rectifier to enhance the efficiency of full-cycle design evaluation.

The detailed time-domain method is adopted to model the rectifier at the behavioral layer. The diode bridges/transformer model at the architecture layer is established by using the switch function and Park transformation. The frequency domain model at the functional layer is derived with the time-varying Fourier decomposition and frequency-shifting. At the component layer, the magneto-thermal characteristics of the rectifier are analyzed with field-circuit and magnetic-thermal coupling methods. A computer-aided design program integrating multiple modeling is also developed for industrial product design.

The function layer modeling is preferred in the initial design stage, making up for the lack of modeling accuracy at the architectural layer and the lack of modeling rapidity at the behavioral layer. The component modeling is irreplaceable for the detailed evaluation in the latter design stage. The multiple modeling scheme based on the four-layer modeling helps the designers achieve high-quality products with a short development cycle.

The singular transient modeling cannot cover the needs of different stages in the full-cycle design evaluation. This paper fills this gap with a novel multiple modeling scheme. Meanwhile, the proposed multiple modeling scheme and developed computer-aided design program provide a great convenience for full cycle design evaluation of the 12-pulse PSR rectifier.

The purpose of this paper is to analyze the influence that the financial restrictions of Chinese enterprises exert on their green innovation abilities with their increased integration into the global supply chain (GSC).

This study uses customs, import, and export data for 222,773 Chinese enterprises and examined them by ownership type, capital density, and degree of pollution.

The results show that the deeper the integration into the GSC, the looser the financing environment would be, and the stronger the green innovation abilities of the enterprises.

The findings suggest that China should step up privatization of state-owned enterprises, increase government subsidies to private enterprises, and loosen their financing restrictions to address the recent economic decline in the country and ensure smooth and fast economic growth.

This paper is one of the first of its kind to develop and empirically analyze the relationship between the GSC and the financing restrictions and their determinant factors in China. It uniquely contributes to help the authors find approaches to constructing China’s green innovation and has far-reaching implications for other developing countries.

Technical progress is an important technique within improving China’s comparative advantages, as new and renewable technologies will be beneficial for energy security. Productive technical progress and green technical innovation are necessary to improve working conditions and productivity of industries. Therefore, the purpose of this paper is to study technical progress in China under such harsh competitive circumstances, as well as types of technical progress that can be promoted, productive technical progress or green technology progress, and how technical progress will affect China’s competitive advantages.

The authors perform a multi-index multi-factor constitutive model based on a sample of 468 Chinese industries, and divide the industries into four categories.

The results indicate that there is a “U”-shape relationship between green technology progress and comparative advantages and an inverted “U”-shape relationship between the intensity of market competition and comparative advantages.

China has crossed the inflection point of the “U”-shaped curve. This, coupled with the slowing of economic growth, demonstrates the need for advocating green technology in China to decrease the pollutant discharge. Establishing Chinese national brands within overseas markets and earning a profit through the downstream of production chain enhance China’s international competitiveness.

One of the most original findings of this paper points out that China is faced with a situation in which exports are severely decreased and domestic environment pollution is increased. Vigorous promotion of green technology progress, improvement of the quality and the technical content of exported products, the establishment of national brand within the overseas market, as well as enhancement of China’s international competitiveness, is needed.

The purpose of this paper is to study the saturation and nonlinear performance of magnetic field in the air gap of switched reluctance motor (SRM).

The analytical method of sub-domain combined with the saturation compensation method is used to determine the nonlinear distribution of air gap magnetic field in SRM. Also, the resolutions of the two-dimensional (2D) Laplace’s equation and Poisson’s equation in polar coordinates are used to obtain the simplified expression of magnetic flux density.

For verifying the effectiveness of analytical model, the results are compared with those obtained from the 2D finite element method (FEM). The influence of magnetic saturation is taken into account by associating the sub-domain analysis result with the nonlinear B-H properties of stator and rotor iron. The magnetic flux density in radial and tangential direction considering the saturation effect may be calculated accurately. It can be seen that one can easily determine the linear analytical results accurately, whereas it is difficult to determine the magnetic flux density with saturation influence; especially at some local positions, there is a larger difference between analytical and FE model due to the complex boundary conditions.

This paper presents the development and optimization design of high-performance SRM.

The magnetic saturation may be taken into account for the SRM and analytical models support to simulated system performance.

Recently, China has been paying increasing attention to how to improve the efficiency of the marine environment and realize a green and sustainable development of the marine economy. Consequently, the industrial structure is crucial to improving efficiency. The purpose of this paper is to introduce environmental factors into the efficiency analysis framework and explore the relationship between marine industrial structure and marine environmental efficiency.

This paper uses marine economic data under the DEA-BBC model to measure the marine environmental efficiency of provinces and cities and classifies them by cluster analysis. Then, the marine industrial structure and marine environmental efficiency are studied by an econometric model with human capital, ownership structure, land economic development level, scientific research input and government intervention degree as control variables.

The overall level of marine environmental efficiency is relatively low in China, increasing and then decreasing over the research period. The rationalization of industrial structure and scientific research input have significant promoting effects on marine environmental efficiency, while the degree of government intervention has a significant inhibiting effect. The positive effect of human capital on efficiency depends on whether it can be successfully converted into productivity. The effects of industrial structure advancement, ownership structure and land economic development level of on the marine environmental efficiency are mixed.

The results provide a theoretical and decision-making basis for China to transform and upgrade its marine industrial structure and sustainably develop the marine economy.

As the functions of environmental regulations cannot be quantified while assessing their environmental efficiency, there has been no comprehensive evaluation of environmental efficiency. The purpose of this paper is to evaluate environmental regulations based on triangular and trapezoidal fuzzy numbers.

This paper uses L-R fuzzy numbers to transform the evaluation language into triangular fuzzy numbers, and adopts an α-level flexible slacks-based measurement model to evaluate the performance of these regulations. Trapezoidal fuzzy numbers are combined with a data envelopment analysis model, and an α-slack-based measurement (SBM) model is used to evaluate the environmental efficiency. The α-SBM model is confirmed to be stable and sustainable.

Relevant index data from 16,375 enterprises were collected to test the proposed model, and models corresponding to triangular fuzzy numbers and trapezoidal fuzzy numbers were used to evaluate their environmental efficiency. Comparative results showed that the proposed model is feasible and stable.

The main contributions of this study are twofold. First, this paper provides a valuable evaluation method for environmental regulation. Second, our research improves the practical performance of trapezoidal fuzzy data envelopment analysis and enhances its feasibility and stability.

With the function of reconstructing and promoting traditional industries in China, logistic service industry (LSI) still consumes a great deal of energy. The purpose of this paper is to empirically analyse the relationship between energy consumption of logistics and its influential factors in China, and through this, identify the most important factor and give a significant research of this factor afterwards.

Using a quantitative analysis of the industry composition of energy consumption and the structure of energy consumption in LSI, the serious condition of China's energy conservation of LSI was found. Correlated analysis and co‐integration analysis were adopted to identify how these factors affected the energy conservation of LSI and how to construct environmental logistics in China.

The paper found mileage traveled by train is the most important factor of energy consumption in LSI, while traveling miles of highway is the second. The former was negative correlation with the total of energy consumption while the latter was positive correlation.

Because of the deficiency of data in China, this research is based on the data of 30 years, which is not testified as long enough for this research. This would indicate that the conclusions of this paper are approximate values. A closer look should be taken at the effectiveness of some of the other factors suggested in the previous research on this topic.

The paper outlines ways to effectively construct environmental logistics in China which would promote the energy conservation and sustainable development of this country. Since the total consumption of energy in China accounts for a certain proportion of the world, this will benefit other countries as well.

This paper is one of the first of its kind to develop and empirically analyze the relationship between energy consumption of LSI and its influential factors in China. It uniquely contributes towards helping us find approaches to constructing China's environmental logistics and will have far‐reaching implications for other developing countries.

Saturated core type superconducting fault current limiter (SFCL) can effectively limit the short-circuit current in power system. However, the high induced voltage will occur between the terminals of DC superconducting bias winding caused by the variation of magnetic flux linked by DC winding due to the increasing short-circuit current. The DC source may be damaged. Thus, the induced voltage should be considered in DC winding design. The paper aims to discuss these issues.

Three-dimensional finite element method coupled with electric circuit.

The short-circuit current flowing through AC windings and induced voltage of DC winding are analyzed by using three-dimensional finite element method coupled with electric circuit for a 220-kV three-phase SFCL. Several circuit elements, such as a capacitor connected with DC winding in parallel, an additional short-circuit winding wound around DC core column and an energy-released piezoresistor, are, respectively, used for induced voltage reduction. These methods aim to save magnetic coupled energy in DC winding, or oppose the variation of magnetic flux, or limit the voltage of DC winding by using a resistor with low resistance.

The different methods for reduction of induced voltage of superconducting DC winding are studied and discussed. The decreased induced voltage may benefit the safety of superconducting DC winding and the source.