A rock burst disaster not only destroys the pit facilities and results in economic loss but it also threatens the life of the miners. Pillar rock burst has a higher frequency of occurrence in the pit compared to other...A rock burst disaster not only destroys the pit facilities and results in economic loss but it also threatens the life of the miners. Pillar rock burst has a higher frequency of occurrence in the pit compared to other kinds of rock burst. Understanding the cause, magnitude and prevention of pillar rock burst is a significant undertaking. Equations describing the bending moment and displacement of the rock beam in asymmetric mining have been deduced for simplified asymmetric beam-pillar systems. Using the symbolic operation software MAPLE 9.5 a catastrophe model of the dynamic failure of an asymmetric rock-beam pillar system has been established. The differential form of the total potential function deduced from the law of conservation of energy was used for this deduction. The critical conditions and the initial and final positions of the pillar during failure have been given in analytical form. The amount of elastic energy released by the rock beam at the instant of failure is determined as well as. A diagrammatic form showing the pillar failure was plotted using MATLAB software. This plot contains a wealth of information and is important for understanding the behavior during each deformation phase of the rock-beam pillar system. The graphic also aids in distinguishing the equivalent stiffness of the rock beam in different directions.展开更多
This paper discusses the ben efits of developing cross border in tercon nection. It was writte n to promote the ben efits of interc on nectio n to facilitate ren ewable en ergy developme nt and trading. It illustrates...This paper discusses the ben efits of developing cross border in tercon nection. It was writte n to promote the ben efits of interc on nectio n to facilitate ren ewable en ergy developme nt and trading. It illustrates the assessme nt of the ben efit with coupling between two power systems with an example importing renewable energy. The strategy for the development of European wide in tercon necti on to level prices is described together with the trading arrangeme nts. The process to evaluate the pote ntial for new intercon nectio n investment is outli ned together with a discussi on of the tech no logy options. The paper concludes with an illustration of the arrangements for cross border trading.展开更多
A thermal power plant of Sinopec has 9 boilers, which generally have problems of high exhaust gas temperature and high flying ash carbon content. In order to improve the adaptability of coals, the stability of coal po...A thermal power plant of Sinopec has 9 boilers, which generally have problems of high exhaust gas temperature and high flying ash carbon content. In order to improve the adaptability of coals, the stability of coal powder ignition, the burn-off rate of pulverized coals and the boiler efficiency, a series of renovation projects about importing hot air into mill exhauster are proposed. For the sake of verifying the renovation effects, an efficiency performance test is conducted on the renovated #5 boiler. The test result shows that the boiler heat efficiency has improved by 0.4% and it operates more safely and reliably after the renovation. At last, this paper recommends an optimized operation mode.展开更多
Successful cases have not been rare, that is to import funds accelerate hospital building by means of raising funds, borrowing, renting, jointing, and so on. The same characteristics is raising money at first and then...Successful cases have not been rare, that is to import funds accelerate hospital building by means of raising funds, borrowing, renting, jointing, and so on. The same characteristics is raising money at first and then working, and the investor will earn high proportional benefits. 'Importing funds' has solved some practical problems, but it also causes some negative effects, such as difficulty in management, being difficult to work, inequitable benefit allocation, little benefits earned by the hospital, a big venture, and so on.By means of installment, the hospital has imported much equipment, such as very expensive Magnetic Resonating Instrument (MRI), spiral CT, straight accelerator, ECT and so on. Connecting with practice, the authors has analyzed objectively the profits and the harm of importing equipment by installment. There are four reasons for applying installment: firstly, it solves the problem of shortage of funds of the hospital; secondly, it efficiently avoids the inconvenience resulted from the management by both jointing sides together; thirdly, it raises the investing earnings of the hospital; finally, it is advantages which are as follows. Importing large-scale foreign equipment from abroad by installment has not been popular in the native hospital, and there are not relatively regular and ripe rules to be followed. Moreover, because effective institution is required to act as an economic guarantor, an extra content of work will, be added to practice.The authors prefer that attentions should be paid to the five aspects in importing equipment by means of installment; selecting the suitable importing project, selecting a favorable cooperating partner and deciding suitable cooperating items; selecting an excellent company or institution to guarantee for the hospital, and grasping the practice of the contract.展开更多
基金Projects Y2005-A03 supported by the Natural Science Foundation of Shandong Province of ChinaG04D15 by the Educational Committee ofShandong Province of China
文摘A rock burst disaster not only destroys the pit facilities and results in economic loss but it also threatens the life of the miners. Pillar rock burst has a higher frequency of occurrence in the pit compared to other kinds of rock burst. Understanding the cause, magnitude and prevention of pillar rock burst is a significant undertaking. Equations describing the bending moment and displacement of the rock beam in asymmetric mining have been deduced for simplified asymmetric beam-pillar systems. Using the symbolic operation software MAPLE 9.5 a catastrophe model of the dynamic failure of an asymmetric rock-beam pillar system has been established. The differential form of the total potential function deduced from the law of conservation of energy was used for this deduction. The critical conditions and the initial and final positions of the pillar during failure have been given in analytical form. The amount of elastic energy released by the rock beam at the instant of failure is determined as well as. A diagrammatic form showing the pillar failure was plotted using MATLAB software. This plot contains a wealth of information and is important for understanding the behavior during each deformation phase of the rock-beam pillar system. The graphic also aids in distinguishing the equivalent stiffness of the rock beam in different directions.
文摘This paper discusses the ben efits of developing cross border in tercon nection. It was writte n to promote the ben efits of interc on nectio n to facilitate ren ewable en ergy developme nt and trading. It illustrates the assessme nt of the ben efit with coupling between two power systems with an example importing renewable energy. The strategy for the development of European wide in tercon necti on to level prices is described together with the trading arrangeme nts. The process to evaluate the pote ntial for new intercon nectio n investment is outli ned together with a discussi on of the tech no logy options. The paper concludes with an illustration of the arrangements for cross border trading.
文摘A thermal power plant of Sinopec has 9 boilers, which generally have problems of high exhaust gas temperature and high flying ash carbon content. In order to improve the adaptability of coals, the stability of coal powder ignition, the burn-off rate of pulverized coals and the boiler efficiency, a series of renovation projects about importing hot air into mill exhauster are proposed. For the sake of verifying the renovation effects, an efficiency performance test is conducted on the renovated #5 boiler. The test result shows that the boiler heat efficiency has improved by 0.4% and it operates more safely and reliably after the renovation. At last, this paper recommends an optimized operation mode.
文摘Successful cases have not been rare, that is to import funds accelerate hospital building by means of raising funds, borrowing, renting, jointing, and so on. The same characteristics is raising money at first and then working, and the investor will earn high proportional benefits. 'Importing funds' has solved some practical problems, but it also causes some negative effects, such as difficulty in management, being difficult to work, inequitable benefit allocation, little benefits earned by the hospital, a big venture, and so on.By means of installment, the hospital has imported much equipment, such as very expensive Magnetic Resonating Instrument (MRI), spiral CT, straight accelerator, ECT and so on. Connecting with practice, the authors has analyzed objectively the profits and the harm of importing equipment by installment. There are four reasons for applying installment: firstly, it solves the problem of shortage of funds of the hospital; secondly, it efficiently avoids the inconvenience resulted from the management by both jointing sides together; thirdly, it raises the investing earnings of the hospital; finally, it is advantages which are as follows. Importing large-scale foreign equipment from abroad by installment has not been popular in the native hospital, and there are not relatively regular and ripe rules to be followed. Moreover, because effective institution is required to act as an economic guarantor, an extra content of work will, be added to practice.The authors prefer that attentions should be paid to the five aspects in importing equipment by means of installment; selecting the suitable importing project, selecting a favorable cooperating partner and deciding suitable cooperating items; selecting an excellent company or institution to guarantee for the hospital, and grasping the practice of the contract.
