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The development of China's foreign exchange market and the reform of Chinese yuan (hereinafter “CNY”) exchange rate are closely linked with each other. Their respective journey through the past 70 years can both be divided into three historical periods; as follows: China's foreign exchange market underwent a difficult exploration period, a formation and development period and an innovative development period; in the meanwhile, the formation mechanism of CNY exchange rate also witnessed three periods marked successively by a single exchange rate system with administrative pricing, an explorative formation mechanism of CNY exchange rate and a reformed, marketized CNY exchange rate mechanism.

In the present world, the development of almost every country is closely linked to the international community, which is the result of the heterogeneity in system, market, humanity and history, in addition to the differences in natural resource endowments and the diversity in technology, administration, information, experience and diplomacy. International economic exchanges require foreign exchange, which gives rise to the existence and development of the foreign exchange market.

The 70-year history of China's foreign exchange market has proven the need to continue safeguarding national sovereignty and interests of the people, stick to the general direction of serving economic development, adhere to the strategy of steadily and orderly promoting the construction of the foreign exchange market, keep on making innovation in monetary policy operation and unbendingly stay away from any systemic financial risks.

During the 70-year history of the new China, as an indispensable economic resource in China's economic development, the foreign exchange mechanism bolstered each stage of economic development and was always an important manifestation of China's economic sovereignty. It is argued that during the 30-year planned economy that preceded reform and opening-up, China pursued a closed-door policy with few international economic exchanges. The subtext of such argument is that China did not have (or hardly had much of) a foreign exchange mechanism during this period, which is clearly in conflict with historical evidence. In fact, although China did not have an open foreign exchange market before the reform and opening-up, it had a clear foreign exchange management system and exchange rate system.

Marx’s monetary theory is an important part of Marxist economics and an irreplaceable milestone in the intellectual history of the monetary theory. The purpose of this paper is to summarize the main content of Marx’s monetary theory from three aspects: the source and nature of money, the function of money and the historical significance of money.

Moreover, this paper also gives an extended understanding of Marx’s monetary theory from four perspectives: the endogenous credit mechanism of money, the functions of money and demands for money, the financial function of money and the economic and social functions of money.

Lastly, the present paper discusses the practical significance of Marx’s monetary theory from three perspectives, namely, the inspection of “Bitcoin” from the nature and function of money, the definition of demands and the division of supplies at the monetary level, and the prevention of systemic financial risks and the focus of financial supervision.

Marx’s monetary theory is an important part of Marxist economics and an irreplaceable milestone in the intellectual history of the monetary theory. However, for a long time, the contribution of Marx has rarely been mentioned in the intellectual history of monetary theory. Even the book, Political Economy (On Capitalism), has been only summarily concerned with the source and function of money in Marx’s monetary theory, rather than revealing Marx’s outstanding contribution in the monetary theory and the financial connotation of Marx’s monetary theory, and expounding its practical significance.

The purpose of this study is to improve the thermal management of lithium-ion batteries. The phase change material (PCM) cooling does not require additional equipment to consume energy. To improve the heat dissipation capacity of batteries, fins are added in the PCM to enhance the heat transfer process.

Computational fluid dynamics method is used to study the influence of number of vertical fins and ring fins (i.e. 2, 4, 6 and 8 vertical fins, and 2, 3, 4 and 5 ring fins) and the combination of them on the cooling performance.

The battery maximum temperature can be decreased by the PCM with vertical or ring fins, and it can be further decreased by the combination of them. The PCM with eight vertical fins and five ring fins reduces the battery maximum temperature by 5.21 K. In addition, the temperature and liquid-phase distributions of the battery and PCM are affected by the design of the cooling system.

This work can provide guidelines for the development of new and efficient PCM cooling systems for lithium-ion batteries.

The combination of PCM and fins can be used to reduce the battery maximum temperature and temperature difference.

The purpose of this study is to design a new type of cold plate to improve the thermal performance of liquid-cooled thermal management system of lithium-ion batteries.

A cold plate with leaf type channels is proposed to enhance the cooling performance. Effects of the leaf type channel parameters (i.e. channel angle 20°, 40°, 60°, 80°; coolant mass flow rate 0.25 × 10^–3, 0.50 × 10^–3, 0.75 × 10^–3, 1.00 × 10^–3, 1.25 × 10^–3 kg·s⁻¹; channel number 1, 3, 5, 7) on the performance are numerically investigated by using a 3D mathematical model.

Compared to the traditional I type channels, the leaf type channels have better cooling performance. It is found that the battery temperature variation and channel pressure drop are decreased with decreasing channel angle and increasing channel number. In addition, the cooling performance can be improved by increasing the coolant mass flow rate.

This study can provide guidance for the development of novel effective cold plates.

The design of cold plates with leaf type channels can be used in liquid-cooled thermal management system to reduce the battery temperature difference.

The purpose of this paper is to design the novel oil–air distributor (N-OAD). Its structure design, oil feeding reliability, service life and viscosity properties of air bubble (AB) oil were analyzed. Meanwhile, the formation mechanism of AB oil was established based on Kelvin–Helmholtz instability.

First, oil–air distributor (OAD) and N-OAD were randomly selected for testing when the air pressure was 0.25 MPa and oil feeding was 100 times per hour. Then, the bubbles were found in the lubricant during the experiment, and the void fraction and viscosity properties of AB oil were tested by image processing method and the MARS 40 rheometer, respectively.

N-OAD has longer service life and higher working reliability than OAD. The key factors of AB oil formation were air pressure and oil feeding. And the void fraction of AB oil has different results on the viscosity at high and low shear rates.

The outcome of this research paper gives an insight to improve the reliability of oil–air lubrication systems and the safety factor of machine tool spindle operation.

The purpose of this paper is to investigate the heat and mass transport characteristics in microchannel reactors with non-uniform catalyst distributions.

A two-dimensional model is developed to study the heat and mass transport characteristics in microchannel reactors. The heat and mass transport processes in the microchannel reactors with non-uniform catalyst distribution in the catalytic combustion channel are also studied.

The simulated results are compared in terms of the distributions of species mole fraction, temperature and reaction rate for the conventional and new designed reactors. It is found that the chemical reaction, heat and mass transport processes are significantly affected and the maximum temperature in the reactor is also greatly reduced when a non-uniform catalyst distribution is applied in the combustion catalyst layer.

This study can improve the understanding of the transportation characteristics in microchannel reactors with non-uniform catalyst distributions and provide guidance for the design of microchannel reactors.

The design of microchannel reactors with non-uniform catalyst distributions can be used in methane steam reforming to reduce the maximum temperature inside the reactor.

The purpose of this paper is to analyze raw materials, labor, capital, demand, related industries, strategies and policies influencing international competitiveness of Chinese textile and clothing industry.

The analysis is conducted using “Diamond Model”, in which raw materials, labor, capital, demand, related industries, strategies and policies are included as explanatory variables, and the impacts of international competitiveness on market share (MS), trade competitiveness(TC) and revealed comparative advantage(RCA) are examined based on the estimated coefficients of these variables.

These factors have different effects on TC, MS and RCA. While their effects on TC and MS are similar in sign even though their degree of significance differs, their effects on RCA are opposite to TC and MS except for capital. Raw materials and capital have negative effects on TC and MS, while the other factors have positive ones. Raw materials have positive effects on RCA, but all other factors have negative ones.

The results from this study imply that it is necessary to increase investment in fixed assets of Chinese textile and clothing industry, speed up the pace of upgrading equipment, improve the level of industrialization, while strengthening the supply of textile raw materials, and lowering raw material prices, thereby reducing the cost of textile and clothing enterprises.

To the best of the authors’ knowledge, this is the first empirical research made using econometric model about the impact of the main factors of trade competitiveness in Chinese textile and clothing industry based on the “Diamond Model”.

The purpose of this paper is to present a methodology based on an optimizer linked with electric finite element method (FEM) for automating the optimized design of power transformer insulation system structures.

The proposed methodology combines two stages to obtain the optimized design of transformer insulation system structures. First, an analytical calculation is carried out with the optimizer to search a candidate solution. Then, the candidate solution is numerically checked in detail to validate its consistency. Otherwise, these two steps are iteratively repeated until the optimizer finds a candidate solution according to the objective function.

The solutions found applying the proposed methodology reduce the inter-electrode distances compared to those insulation designs referenced in the literature for the same value of safety margin.

The proposed methodology explores a wide range of insulation system structures in an automated way which is not possible to do with the classical trial-and-error approach based on personal expertise.

The purpose of this paper is to study the insulation structure optimization method of multiwinding high-frequency transformer (HFT).

This paper takes 100 kW, 10 kHz multiwinding HFT as the research object. First, the distribution of electric field strength within the core window of multiwinding HFT with different winding configurations is simulated by the electrostatic field finite element method. The symmetrical hybrid winding structure with minimum electric field strength is selected as the insulation design. To reduce the electric field strength at the end region of the winding, the electrostatic ring and angle ring are designed based on the response surface method.

The optimal results show that the maximum electric field strength can be reduced by 15.4%, and the low voltage stress can be achieved.

The above research provides guidance and basis for the optimal design of insulation structure of multiwinding HFT.