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The purpose of this paper is to propose a simulation model for studying the lubricating gap between the ring gear and the case in internal gear pumps.

The pressure distribution of the wedge-shaped oil film between the ring gear and the case is obtained based on the theory of film lubrication using the Reynolds equation implemented with MATLAB. After that, the balance of the ring gear is achieved by the radial micro motion of the ring gear. The power loss due to the leakage and the shear stress is then calculated for optimized design of the radial clearance.

The hydrodynamic effect and the squeezing effect of the wedge-shaped oil film play a role in the hydrodynamic balance of the ring gear, and they become more intense when the operating speed gets lower and the pressure gets higher. The optimal radial clearance should stay between 20 and 25 µm for the minimum power loss.

The present research provides the first simulation model that treats the oil film between the ring gear and the case as wedge-shaped oil film and explains why the ring gear stays balanced. Furthermore, the simulation model can be regarded as a tool for optimized design of the radial clearance.

Though sustainable development is widely accepted, its realisation is hampered by numerous factors, many of which are located within the political system. The paper discusses some of these hindrances and the council on sustainable development which is designated to counterbalance and attenuate them. Special attention is given to the council’s functions and tasks, competencies and composition. Also, contradictions of different requirements and the contingencies of day‐to‐day politics are explored. Two existing national councils (USA and Switzerland) are discussed as exemplars. This paper argues that these councils do not have enough competencies and legitimisation to bring about a turn in politics towards sustainable development. Yet, they are a first step to having the idea of sustainable development represented institutionally within the political system.

This paper is written as an attempt to employ the Chinese Social Science Citation Index (CSSCI) in the evaluation of Chinese humanities and social science research.

This paper uses statistics in the CSSCI (2000‐2004) to analyze the academic impact of researchers, papers and works, institutions and regions on Chinese humanities and social science research.

The authors identify 100 highly cited people, 50 highly cited papers, 50 highly cited works, 20 highly productive institutions and 20 highly cited institutions. Also provided is some regional information about Chinese humanities and social science research.

It is hoped that the CSSCI, as well as the analysis and evaluation based on it, will give researchers a better understanding of Chinese humanities and social science research.