Contract Mechanism of Water Environment Regulation for Small and Medium Sized Enterprises Based on Optimal Control Theory

The small and scattered enterprise pattern in the county economy has formed numerous sporadic pollution sources, hindering the centralized treatment of the water environment, increasing the cost and difficulty of treatment. How enterprises can make reasonable decisions on their water environment behavior based on the external environment and their own factors is of great significance for scientifically and effectively designing water environment regulation mechanisms. Based on optimal control theory, this study investigates the design of contractual mechanisms for water environmental regulation for small and medium-sized enterprises. The enterprise is regarded as an independent economic entity that can adopt optimal control strategies to maximize its own interests. Based on the participation of multiple subjects including the government, enterprises, and the public, an optimal control strategy model for enterprises under contractual water environmental regulation is constructed using optimal control theory, and a method for calculating the amount of unit pollutant penalties is derived. The water pollutant treatment cost data of a paper company is selected to conduct empirical numerical analysis on the model. The results show that the increase in the probability of government regulation and public participation, as well as the decrease in local government protection for enterprises, can achieve the same regulatory effect while reducing the number of administrative penalties per unit. Finally, the implementation process of contractual water environmental regulation for small and medium-sized enterprises is designed.

EXPERIMENT STUDY ON THE EFFECT OF SHENG-MAI INJECTION ON THE CONTRACTIVITY OF DIAPHRAGM AND ITS MECHANISM

In this study the effect of Sheng-ai Injection i.e. Red Ginseng-Ophiopogon Root Injection (one kind of traditional Chinese medicines) on the contractivity of diaphragm was observed. The results confirmed that Sheng-ai Injection increased Pdi of the fatigued diaphragm in rabbits and reduced the time needed for the recovery of Pdi of fatigued diaphragm to the normal value. These results suggest that Sheng-Mai Injection can increase the contractive force and promote the recovery of the fatigued diaphragm. The effect of Sheng-ai Injection on the contractivity of the isolated diaphragmatic bundle of rats was also observed and the results confirmed that Sheng-ai Injection increased the diaphragmatic contractive force directly. This effect of increasing the contractive force of diaphragm was attenuated by adding calcium channel blocker isoptin and disappeared when there was no calcium in the extracellular fluid. It is deduced, therefore, that the mechanism of the effect of Sheng-mai Injection is related to the increased influx of calcium from extracellular fluid into the cells.

Negative thermal expansion: Mechanisms and materials

Negative thermal expansion(NTE)of materials is an intriguing phenomenon challenging the concept of traditional lattice dynamics and of importance for a variety of applications.Progresses in this field develop markedly and update continuously our knowledge on the NTE behavior of materials.In this article,we review the most recent understandings on the underlying mechanisms(anharmonic phonon vibration,magnetovolume effect,ferroelectrorestriction and charge transfer)of thermal shrinkage and the development of NTE materials under each mechanism from both the theoretical and experimental aspects.Besides the low frequency optical phonons which are usually accepted as the origins of NTE in framework structures,NTE driven by acoustic phonons and the interplay between anisotropic elasticity and phonons are stressed.Based on the data documented,some problems affecting applications of NTE materials are discussed and strategies for discovering and design novel framework structured NET materials are also presented.