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901.
针对我国煤炭资源开采中的低效率和浪费现象,在综合考虑了煤炭资源利用率和回采率等方面问题后,通过建立煤炭资源最优开采的动态优化模型,分析了影响煤炭资源利用率和回采率的因素,提出了提高煤炭资源利用率的合理方案.分析表明,对煤炭资源的基础储量征税可以实现煤炭企业在兼顾利润最大化的同时提高煤炭资源的利用率和回采率,同时通过级差税的调节可以有效降低因放弃低品位资源带来的浪费.  相似文献   
902.
Problems of interacting common-property resources are set up as stochastic differential games. A class of models is solved where equilibrium closed-loop strategies keep harvest rates proportional to stocks. Corrective taxes, etc., are considered.Dedicated to G. LeitmannEarlier versions of this paper (Ref. 1) were presented at the International Conference on Economics and Control, Cambridge University, England, June 18–21, 1979, and at the Winter Econometric Society Meetings, Atlanta, Georgia, December 1978. Space limitations shortened this paper; a complete working paper is available from the authors. The authors would like to extend their appreciation to George Leitmann, who first introduced them to differential games.  相似文献   
903.
We propose and develop a new framework for studying the problem of preventing biological invasions caused by ships transporting internationally traded goods between countries and continents. Specifically, we apply the methods of queuing theory to analyze the problem of preventing a biological invasion from a long run perspective. First, we characterize two simple regulatory regimes as two different kinds of queues. Second, we show how to pose a publically owned port manager’s decision problem as an optimization problem using queuing theoretic techniques. Third, we compare and contrast the optimality conditions emanating from our analysis of the M/M/I/U and the M/M/I/I inspection regimes. We conclude by discussing possible extensions to our basic models.  相似文献   
904.
One of the most ubiquitous of the fishery management problems to have arisen as a result of E.F.J. is that of managing transboundary resources. Economic analysis of this problem rests upon models blending the standard dynamic economic analysis of fisheries with game theory. The analysis reveals that noncooperation is likely to have severe economic consequences and that cooperative arrangements must deal with possible conflicting goals of management, as well as the division of economic returns from the fishery. While the existing economic analysis of transboundary fishery management is far from complete, it can be shown that the analysis is capable of providing important insights into existing real world cases of transboundary resource management.  相似文献   
905.
The paper considers a game of timing which is closely related to the so-called duels. This is a game connected with the distribution of resources by two players. Each of the players is in possession of some amount of resource to be distributed by him in the time interval [0, 1]. In his behavior, Player 1 is restricted by the necessity of taking all of his resources at a single point, while Player 2 has no restrictions. For the payoff function, defined as for duels, the game is solved; explicit formulas on the value of the game and the optimal strategies for the players are found.  相似文献   
906.
A series of two‐dimensional donor–acceptor–donor (D1–A(D2)) type of conducting polymers (CPs) all with electroactive bulky side chain structure has been designed, synthesized, and investigated by introducing the donor–acceptor (D1–A) thiophene–quinoxaline moiety in the main chain alongside and additional donor and hole transporting units in the side chain. All the UV‐vis spectra of the 2D polymers, PTPQT, PFPQT, and PCPQT, each with triphenylamine, fluorene, and carbazole units as the D2 side chain, possess strong intramolecular charge transfer absorption, thus resulting in better light harvesting. Their optical and electronic properties were thoroughly explored experimentally and computationally. The effect of molecular weight of the narrow polydispersity polymers on their optoelectronic property was studied in detail. In summary, the 2‐D CPs show potential for use as an active material in optoelectronic devices. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1217–1227  相似文献   
907.
Novel trifunctional monomers based on renewable resources were prepared and subsequently polymerized via the Diels‐Alder (DA) polycondensation between furan and maleimide complementary moieties. Three basic approaches were considered for these nonlinear DA polycondensations, namely the use of (i) a bisfuran monomer in combination with a trismaleimide (A2 + B3 system) and (ii) a trisfuran monomer in conjunction with a bismaleimide (A3 + B2 system) leading to branched or crosslinked materials, and (iii) the use of monomers incorporating both furan and maleimide end groups (A2B or AB2 systems), which lead to hyperbranched structures. The application of the retro‐DA reaction to the ensuing polymers confirmed their thermoreversible character. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013  相似文献   
908.
This paper computes open loop and subgame perfect Nash equilibria for an infinite horizon, common property resource model with congestion and stock externalities. The model permits the comparison of the game-theoretic approach and the traditional commons literature, which preceded the widespread recognition of the games, because the underlying assumptions are equivalent. With access to the commons restricted, the subgame perfect equilibrium captures the inefficiency associated with the strategic scramble to capture the resource reserves the open loop does not. Under sole ownership, the two equilibrium concepts coincide with the surplus maximizing extraction policy. In free access, the extraction strategies under both equilibrium concepts coincide with complete rent dissipation.  相似文献   
909.
Fully understand the chemical science and reasonable use of existing resources is an important premise to chemical science popularization. This paper summarizes the current resource types of popular science of chemistry in China. The chemical science resources in China are sorted out and analyzed, including China Association for Science and Technology of chemical science, popular science base of scientific research institutes and universities, scientific public class and the chemical science online open courses, and WeChat public platform chemical resources. This paper will provide a meaningful introduction of chemical science resources for the public, and provide valuable reference for the practice of chemical science in China.  相似文献   
910.
Hongwei Sun  Lan Chen 《大学化学》1986,36(1):2008056-0
In this paper, several methods based on electronic educational resources have been presented for teaching structural chemistry. The constructions of multimedia materials, VRML models, teaching videos and website can not only improve the classroom effect, but also provide the students with a useful post-class learning platform. Meanwhile, further teaching reforms can be made on the foundations of these techniques.  相似文献   
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