With abundant wind resources and high pressure imposed on en-vironmental protection, wind power development has a promising future. Butdue to intermittent nature, wind power can bring into full play only if being con-...With abundant wind resources and high pressure imposed on en-vironmental protection, wind power development has a promising future. Butdue to intermittent nature, wind power can bring into full play only if being con-nected into power grid to ensure its supply reliability and continuity, aswell as operational economy. However, technical and market barriers haveprevented wind power from integrating into power grid. To foster wind powerdevelopment, these barriers should be removed by both government incentivepolicies and sophisticated technologies.展开更多
Based on the decoupiing theory and method, an indicator system was built for the relation between economic development level and resource and environment carrying capacity. And the study was carried out on decoupling ...Based on the decoupiing theory and method, an indicator system was built for the relation between economic development level and resource and environment carrying capacity. And the study was carried out on decoupling degree and temporal changes of economic development level and resource and environment carrying ca- pacity in the central area of Yunnan Province. Results indicated that （i） the economic development level and resource and environment carrying capacity in the central area of Yunnan Province mainly experienced strong decoupling, weak decoupling, and ex- pansive negative coupling, and in general it was strong decoupling, and it took on re- verse ＂N＂ in temporal changes. （ii） Change rate of economic development level in the central area of Yunnan Province was greater than zero, but the amplitude of change was not large, while the change rate of resource and environment carrying capacity was negative in 2007-2008, and it was positive in the rest years; from 2007, it took on gradual expansion trend, and scissors difference gradually increased after experi- encing reverse ＂V＂ change. （iii） The strong decoupling was the main situation and it reached the peak value in T5 period and T6 pedod.展开更多
Many studies have established the role of radiofrequency (RF) ablation as a minimally invasive treatment for liver metastases. Although relatively safe, several complications have been reported with the increased use ...Many studies have established the role of radiofrequency (RF) ablation as a minimally invasive treatment for liver metastases. Although relatively safe, several complications have been reported with the increased use of RF ablation. We describe here a case of unexplained liver laceration after a RF procedure. A woman who presented a solitary metachronous liver metastasis underwent RF ablation treatment for this lesion. Six hours later the patient displayed fatigue and pallor. Emergency blood tests showed a haemoglobin level of < 7 g/dL and markedly elevated transaminase levels. A computed tomography examination revealed two areas of liver laceration with haematoma, one of them following the path of the needle and the other leading away from the f irst. Following a blood transfusion, the patient was haemodynamically stable and completely recovered 24 h later. The patient remained in bed for 1 wk. No surgical intervention was required, and she was discharged 1 wk later.展开更多
The current crisis has revealed the weaknesses of the global financial in general and its banking system in particular and puts forward a requirement for assessing the effectiveness and stability of the banking sector...The current crisis has revealed the weaknesses of the global financial in general and its banking system in particular and puts forward a requirement for assessing the effectiveness and stability of the banking sectors across countries. Based on available data from 64 countries over the world, the author tried to evaluate the effectiveness of the banking sectors in those countries through the view point of the data envelopment analysis approach to define how the global banking systems is under the effect of the current crisis. Findings from the research showed that banking systems in advanced economies are still more effective than in developing countries. Moreover, it explained the effect of the current financial crisis, the role of public finance （and the government）, and the development of the （privately） commercial banks to the effectiveness of the banking sectors. The research also explained some determinants that can affect the effectiveness of the banking system, including inflation, bank concentration, and level of economic development.展开更多
This paper focuses on the state space modeling approach and output torques prediction of torsional vibrations for variable speed wind turbines. The multi-body system model under study is mainly comprised of a wind tur...This paper focuses on the state space modeling approach and output torques prediction of torsional vibrations for variable speed wind turbines. The multi-body system model under study is mainly comprised of a wind turbine, a three stage planetary gear box and an induction generator. The masses-springs approach of shaft system differential equations is developed from Newton＇s law and Lagrange formulas. For an easy comprehension for electrical engineers and tutorial purpose, an electrical equivalent circuit of the system is proposed by using mechanical and electrical components similarities. Extensive numerical simulations are performed to investigate system mechanical resonances and impacts of damping factors on the system dynamic and stability.展开更多
Metacognitive strategy, as one of the branches of learning strategy, can help students to consciously plan, monitor and evaluate their language learning, thus facilitate it. As a matter of fact, listeuing has long bee...Metacognitive strategy, as one of the branches of learning strategy, can help students to consciously plan, monitor and evaluate their language learning, thus facilitate it. As a matter of fact, listeuing has long been regarded as an important linguistic skill to be developed in college English teaching. However, there are still some misunderstandings which exist among teachers and students. With the development of second language acquisition and listening comprehension, it becomes clear that listening is an active process in which the listener negotiates meanings in a conscious way. Therefore, if teachers can train students in metacognitive strategies in college English listening teaching, students can consciously plan, monitor and evaluate the entire listening process and become an active listener, thus improve their listening proficiency.展开更多
The ecological footprint concept and its calculation models are useful for the measurement of the sustainable level of social and economic development.The ecological security situation of the Three Gorges Reservoir Ar...The ecological footprint concept and its calculation models are useful for the measurement of the sustainable level of social and economic development.The ecological security situation of the Three Gorges Reservoir Area(TGRA) was evaluated using this concept in this study.The construction of the Three Gorges Reservoir has led to the change in the ecology and immigration status of TGRA.The ecological footprint method is an important means to study the regional ecological security.Our results suggested that,by excluding the areas for biodiversity conservation(12% of the total land),the ecological footprint per capita was 0.57895 ha,which exceeded the ecological carrying capacity in TGRA.The total ecological deficit was found to be 11,522,193.34 ha,accounting for 95.02% of the ecological carrying capacity.These findings suggested that the ecological security of TGRA was not good.In order to compensate for the ecological deficit,it was essential to introduce natural resources from other regions.展开更多
In the present research work, the pitch-control is carried out such that the rotor blades are rotated around their longitudinal axis while the rotor continues its normal rotation. It is really a challenge to produce a...In the present research work, the pitch-control is carried out such that the rotor blades are rotated around their longitudinal axis while the rotor continues its normal rotation. It is really a challenge to produce a clever design to pitch the rotor blades by the optimal amount so as to maximize the power output at all wind speeds. The mechanism is implemented to a three-blade, horizontal-axis, home-scale wind turbine. The mechanism is powered by a suitable DC （direct-current） motor. The tests were carried out in the open section of a delivery wind tunnel. The air speed was measured by a suitable anemometer. The corresponding rotational speed （rpm） and output voltage at different wind speeds were measured and recorded for calibration of the control system. The mechanism proved to be successful in controlling the pitch angle over a wide range of wind speeds.展开更多
By calculating the azimuth, phase angle and change rate of tidal force, and contrasting their rupture types, we find that in 6 of 11 reverse faulting earthquakes, the angles between the direction of the horizontal tid...By calculating the azimuth, phase angle and change rate of tidal force, and contrasting their rupture types, we find that in 6 of 11 reverse faulting earthquakes, the angles between the direction of the horizontal tidal force and compressive principal stress are within 33°, the vertical phase angles of all 8 strike-slip earthquakes are in the upward peak section and the vertical phase angles of two extensional normal faulting earthquakes are in the downward peak section. According to the above statistics, the mechanism of tidal force triggering of the Wenchnan Ms8. 0 Earthquake and its strong aftershocks is discussed.展开更多
Currently,technology,human resources,economic development level and resource endowment determine the spatial layout of China's strategic emerging industries,whose development is dominated by large state-owned ente...Currently,technology,human resources,economic development level and resource endowment determine the spatial layout of China's strategic emerging industries,whose development is dominated by large state-owned enterprises and leading firms.Disparities in the layout of strategic emerging industries are limited for economically developed regions in China but significant for less developed regions.In this context,the Chinese government should be alarmed of repetitive development and excessive input of industrial resources;encourage the development of private capital and prevent the monopoly of state-owned enterprises;adopt a strategy of complementary advantages,and promote industrial relocation for the multi-tiered and non-equilibrium development of strategic emerging industries in China.展开更多
文摘With abundant wind resources and high pressure imposed on en-vironmental protection, wind power development has a promising future. Butdue to intermittent nature, wind power can bring into full play only if being con-nected into power grid to ensure its supply reliability and continuity, aswell as operational economy. However, technical and market barriers haveprevented wind power from integrating into power grid. To foster wind powerdevelopment, these barriers should be removed by both government incentivepolicies and sophisticated technologies.
基金Supported by Scientific Research Foundation of Yunnan Provincial Department of Education(2015J088)~~
文摘Based on the decoupiing theory and method, an indicator system was built for the relation between economic development level and resource and environment carrying capacity. And the study was carried out on decoupling degree and temporal changes of economic development level and resource and environment carrying ca- pacity in the central area of Yunnan Province. Results indicated that （i） the economic development level and resource and environment carrying capacity in the central area of Yunnan Province mainly experienced strong decoupling, weak decoupling, and ex- pansive negative coupling, and in general it was strong decoupling, and it took on re- verse ＂N＂ in temporal changes. （ii） Change rate of economic development level in the central area of Yunnan Province was greater than zero, but the amplitude of change was not large, while the change rate of resource and environment carrying capacity was negative in 2007-2008, and it was positive in the rest years; from 2007, it took on gradual expansion trend, and scissors difference gradually increased after experi- encing reverse ＂V＂ change. （iii） The strong decoupling was the main situation and it reached the peak value in T5 period and T6 pedod.
文摘Many studies have established the role of radiofrequency (RF) ablation as a minimally invasive treatment for liver metastases. Although relatively safe, several complications have been reported with the increased use of RF ablation. We describe here a case of unexplained liver laceration after a RF procedure. A woman who presented a solitary metachronous liver metastasis underwent RF ablation treatment for this lesion. Six hours later the patient displayed fatigue and pallor. Emergency blood tests showed a haemoglobin level of < 7 g/dL and markedly elevated transaminase levels. A computed tomography examination revealed two areas of liver laceration with haematoma, one of them following the path of the needle and the other leading away from the f irst. Following a blood transfusion, the patient was haemodynamically stable and completely recovered 24 h later. The patient remained in bed for 1 wk. No surgical intervention was required, and she was discharged 1 wk later.
文摘The current crisis has revealed the weaknesses of the global financial in general and its banking system in particular and puts forward a requirement for assessing the effectiveness and stability of the banking sectors across countries. Based on available data from 64 countries over the world, the author tried to evaluate the effectiveness of the banking sectors in those countries through the view point of the data envelopment analysis approach to define how the global banking systems is under the effect of the current crisis. Findings from the research showed that banking systems in advanced economies are still more effective than in developing countries. Moreover, it explained the effect of the current financial crisis, the role of public finance （and the government）, and the development of the （privately） commercial banks to the effectiveness of the banking sectors. The research also explained some determinants that can affect the effectiveness of the banking system, including inflation, bank concentration, and level of economic development.
文摘This paper focuses on the state space modeling approach and output torques prediction of torsional vibrations for variable speed wind turbines. The multi-body system model under study is mainly comprised of a wind turbine, a three stage planetary gear box and an induction generator. The masses-springs approach of shaft system differential equations is developed from Newton＇s law and Lagrange formulas. For an easy comprehension for electrical engineers and tutorial purpose, an electrical equivalent circuit of the system is proposed by using mechanical and electrical components similarities. Extensive numerical simulations are performed to investigate system mechanical resonances and impacts of damping factors on the system dynamic and stability.
文摘Metacognitive strategy, as one of the branches of learning strategy, can help students to consciously plan, monitor and evaluate their language learning, thus facilitate it. As a matter of fact, listeuing has long been regarded as an important linguistic skill to be developed in college English teaching. However, there are still some misunderstandings which exist among teachers and students. With the development of second language acquisition and listening comprehension, it becomes clear that listening is an active process in which the listener negotiates meanings in a conscious way. Therefore, if teachers can train students in metacognitive strategies in college English listening teaching, students can consciously plan, monitor and evaluate the entire listening process and become an active listener, thus improve their listening proficiency.
基金supported by the National Natural Science Foundation of China (Grant Nos41201274/D010505 and 41071350/D011201)the National Basic Research Program of China (973Program,Grant No. 2010CB951704)
文摘The ecological footprint concept and its calculation models are useful for the measurement of the sustainable level of social and economic development.The ecological security situation of the Three Gorges Reservoir Area(TGRA) was evaluated using this concept in this study.The construction of the Three Gorges Reservoir has led to the change in the ecology and immigration status of TGRA.The ecological footprint method is an important means to study the regional ecological security.Our results suggested that,by excluding the areas for biodiversity conservation(12% of the total land),the ecological footprint per capita was 0.57895 ha,which exceeded the ecological carrying capacity in TGRA.The total ecological deficit was found to be 11,522,193.34 ha,accounting for 95.02% of the ecological carrying capacity.These findings suggested that the ecological security of TGRA was not good.In order to compensate for the ecological deficit,it was essential to introduce natural resources from other regions.
文摘In the present research work, the pitch-control is carried out such that the rotor blades are rotated around their longitudinal axis while the rotor continues its normal rotation. It is really a challenge to produce a clever design to pitch the rotor blades by the optimal amount so as to maximize the power output at all wind speeds. The mechanism is implemented to a three-blade, horizontal-axis, home-scale wind turbine. The mechanism is powered by a suitable DC （direct-current） motor. The tests were carried out in the open section of a delivery wind tunnel. The air speed was measured by a suitable anemometer. The corresponding rotational speed （rpm） and output voltage at different wind speeds were measured and recorded for calibration of the control system. The mechanism proved to be successful in controlling the pitch angle over a wide range of wind speeds.
基金sponsored under the Seismic Situation Tracing Directional Work Project in Contract System in 2009 (20090203012009010107),China
文摘By calculating the azimuth, phase angle and change rate of tidal force, and contrasting their rupture types, we find that in 6 of 11 reverse faulting earthquakes, the angles between the direction of the horizontal tidal force and compressive principal stress are within 33°, the vertical phase angles of all 8 strike-slip earthquakes are in the upward peak section and the vertical phase angles of two extensional normal faulting earthquakes are in the downward peak section. According to the above statistics, the mechanism of tidal force triggering of the Wenchnan Ms8. 0 Earthquake and its strong aftershocks is discussed.
基金Supported by National Natural Science Foundation of China project "Spatial layout and development path of China's strategic emerging industries"(Grant No.71273276)
文摘Currently,technology,human resources,economic development level and resource endowment determine the spatial layout of China's strategic emerging industries,whose development is dominated by large state-owned enterprises and leading firms.Disparities in the layout of strategic emerging industries are limited for economically developed regions in China but significant for less developed regions.In this context,the Chinese government should be alarmed of repetitive development and excessive input of industrial resources;encourage the development of private capital and prevent the monopoly of state-owned enterprises;adopt a strategy of complementary advantages,and promote industrial relocation for the multi-tiered and non-equilibrium development of strategic emerging industries in China.
