Detailed studies on Late Devonian to Early Carboniferous carbonate rocks in central Hunan, southern China have led to the recognition of 25 lithofacies which can be grouped into： （I） inner ramp peritidal platform, ...Detailed studies on Late Devonian to Early Carboniferous carbonate rocks in central Hunan, southern China have led to the recognition of 25 lithofacies which can be grouped into： （I） inner ramp peritidal platform, （2） inner ramp organic hank and mound, （3） mid ramp, （4） outer ramp, and （5） shelf basin facies associations. The peritidal platform facies association dominates the Zimenqiao Formation （Namurian A or late Datangian） and is characterized by gypsum and dolostone-containing sequences, indicating a peritidal platform environment. The other four facies associations dominate the Menggongao Formation （late Famennian）, Liujiatang Formation （Tournaisian or Yangruanian）, Shidengzi Formations （early Visean or early Datangian）. Five upward-shallowing cycles were distinguished in these three Formations. The predominant facies associations developed in each Formation demonstrate an overall transgression-regression cycle in the Late Devonian to Early Carboniferous in central Hunan. The overall transgressive sequence was preserved in the Shaodong, Menggongao, and Liujiatang Formations, and the overall regressive sequence was preserved in the Liujiatang, Shidengzi, Ceshui and Zimenqiao Formations.展开更多
The plasma current ramp-up is an important process for tokamak discharge,which directly affects the quality of the plasma and the system resources such as volt-second consumption and plasma current profile.The China F...The plasma current ramp-up is an important process for tokamak discharge,which directly affects the quality of the plasma and the system resources such as volt-second consumption and plasma current profile.The China Fusion Engineering Test Reactor(CFETR)ramp-up discharge is predicted with the tokamak simulation code(TSC).The main plasma parameters,the plasma configuration evolution and coil current evolution are given out.At the same time,the volt-second consumption during CFETR ramp-up is analyzed for different plasma shaping times and different plasma current ramp rates dIP/dt with/without assisted heating.The results show that the earlier shaping time and the faster plasma current ramp rate with auxiliary heating will enable the volt-second to save 5%-10%.At the same time,the system ability to provide the volt-second is probably 470 V·s.These simulations will give some reference to engineering design for CFETR to some degree.展开更多
Overemphasizing the value of reefs in oil and gas exploration, reef-oriented geologists explain all carbonate platform deposits using the Wilson model. In their eyes, rimmed shelves are more valuable than carbonate ra...Overemphasizing the value of reefs in oil and gas exploration, reef-oriented geologists explain all carbonate platform deposits using the Wilson model. In their eyes, rimmed shelves are more valuable than carbonate ramps. However, organic banks are excellent reservoirs generated by carbonate ramps in the study area, as verified beyond doubt through petroleum exploration, such as this thesis, which investigates the genesis, types, and distribution of carbonate deposition in the north zone of the Amu-Darya Basin. Monoclinal palaeogeomorphology and rudists suggest shallow environments. Given that oolite shoals and rudist patch reefs were observed in the study area, the depositional system is interpreted to be a carbonate ramp. The Callovian-Oxfordian stage consists of nine lithofacies: oolitic limestone, skeletal limestone, micritic limestone, bioturbated limestone, and crystalline limestone, which are grouped into three facies associations presenting outer ramp, mid-ramp, and inner ramp facies associations. Five depositional sequences can be distinguished in the Callovian-Oxfordian stage. Each third-order depositional sequence is composed of transgressive systems tracts (TST) and highstand systems tracts (HST). The TST consists of mudstones with a higher response to natural gamma rays, whereas the HST contains various types of grainstone, with subordinate dolostone. The vertical and lateral distributions of sedimentary facies, and their interpreted depositional environments, revealed a ramp exhibiting a gradual southeast-northwestward environmental change from outer ramp, mid ramp, and inner ramp carbonate facies.展开更多
Two-dimensional structure of density fluctuations is examined during the current jump phase, indicating a change from the open magnetic fields to the closed ones. During the smooth current ramp-up phase the two-dimens...Two-dimensional structure of density fluctuations is examined during the current jump phase, indicating a change from the open magnetic fields to the closed ones. During the smooth current ramp-up phase the two-dimensional contour of the LiI intensity shows vertically alignment, consistent with the magnetic surfaces. At the inflection point in Ip ramp-up the LiI intensity contour becomes flat in the observation regime and then suddenly a steep gradient and higher intensity regime are formed in the vertical direction. This higher intensity corresponds to a burst of LiI waveform. According to these changes in the contour, it is found that, within ~1 ms around the burst of LiI, a low frequency coherent wave with a long wavelength rapidly grows. The relations with other signals （magnetic flux and microwave stray power） are discussed with respect to the topological change in the magnetic configuration and mode conversion of the incident electromagnetic waves.展开更多
In the low aspect ratio torus experiment （LATE） device, plasma current is initiated and ramped up to 20 kA solely by microwave power at the electron cyclotron （EC） range of frequency with a ramp of the external ve...In the low aspect ratio torus experiment （LATE） device, plasma current is initiated and ramped up to 20 kA solely by microwave power at the electron cyclotron （EC） range of frequency with a ramp of the external vertical field By for the radial equilibrium of plasma torus at larger currents. Measurements suggest that an energetic electron tail in the energy range of about 200 keV carries the current. The line averaged electron density is higher than the plasma cutoff density, suggesting that tail electrons might be driven by electron Bernstein waves modeconverted from the launched electromagnetic waves.展开更多
With the increasing penetration of renewable energy in power system,renewable energy power ramp events(REPREs),dominated by wind power and photovoltaic power,pose significant threats to the secure and stable operation...With the increasing penetration of renewable energy in power system,renewable energy power ramp events(REPREs),dominated by wind power and photovoltaic power,pose significant threats to the secure and stable operation of power systems.This paper presents an early warning method for REPREs based on long short-term memory(LSTM)network and fuzzy logic.First,the warning levels of REPREs are defined by assessing the control costs of various power control measures.Then,the next 4-h power support capability of external grid is estimated by a tie line power predictionmodel,which is constructed based on the LSTMnetwork.Finally,considering the risk attitudes of dispatchers,fuzzy rules are employed to address the boundary value attribution of the early warning interval,improving the rationality of power ramp event early warning.Simulation results demonstrate that the proposed method can generate reasonable early warning levels for REPREs,guiding decision-making for control strategy.展开更多
THE Chinese Government released a range of reform and opening up policies, as is custom- ary. ahead of the Third Plenary Session of the 18th Central Committee of the Communist Party of China （CPC）, which ran from No...THE Chinese Government released a range of reform and opening up policies, as is custom- ary. ahead of the Third Plenary Session of the 18th Central Committee of the Communist Party of China （CPC）, which ran from November 9 to 12. This year. the corporate registration system was included in the reform package.展开更多
Ensuring adequate access to truck parking is critical to the safe and efficient movement of freight traffic. There are strict federal guidelines for commercial truck driver rest periods. Rest areas and private truck s...Ensuring adequate access to truck parking is critical to the safe and efficient movement of freight traffic. There are strict federal guidelines for commercial truck driver rest periods. Rest areas and private truck stops are the only places for the trucks to stop legally and safely. In locations without sufficient parking areas, trucks often park on interstate ramps, which create safety risks for other interstate motorists. Historically, agencies have employed costly and time intensive manual counting methods, camera surveillance, and driver surveys to assess truck parking. Connected truck data, available in near real-time, offers an efficient alternative to practitioners to assess truck parking patterns and identify areas where there may be insufficient safe parking spaces. This paper presents a case study of interstate I-70 in east central Indiana and documents the observed spatiotemporal impacts of a rest area closure on truck parking on nearby interstate ramps. Results showed that there was a 28% increase in parking on ramps during the rest area closure. Analysis also found that ramps closest to the rest area were most impacted by the closure, seeing a rise in truck parking sessions as high as 2.7 times. Parking duration on the ramps during rest area closure also increased drastically. Although it was expected that this would result in increased parking by trucks on adjacent ramps, this before, during, after scenario provided an ideal scenario to evaluate the robustness of these techniques to assess changing parking characteristics of long-haul commercial trucks. The data analytics and visualization tools presented in this study are scalable nationwide and will aid stakeholders in informed data-driven decision making when allocating resources towards improving the nations commercial vehicle parking infrastructure.展开更多
This paper analyzes the structural design of an urban interchange ramp bridge from four aspects,which are the superstructure,pier structure,foundation structure,and deck structure design to summarize the structural de...This paper analyzes the structural design of an urban interchange ramp bridge from four aspects,which are the superstructure,pier structure,foundation structure,and deck structure design to summarize the structural design ideas of this urban interchange ramp bridge,which can be used as a reference for future construction of the same bridge.展开更多
This article explores the fundamentals of small-radius curved ramp bridges.It covers the selection of box girder spans,support methods,and forms,along with design optimization techniques for this type of bridge struct...This article explores the fundamentals of small-radius curved ramp bridges.It covers the selection of box girder spans,support methods,and forms,along with design optimization techniques for this type of bridge structure.The purpose of this paper is to provide robust support for enhancing the design quality of these bridges and ensuring their efficacy in real-world applications.展开更多
基金supported by the National Natural Science Foundation of China(No.41030213)the Major National S&T Program of China(2011ZX05009-002)
文摘Detailed studies on Late Devonian to Early Carboniferous carbonate rocks in central Hunan, southern China have led to the recognition of 25 lithofacies which can be grouped into： （I） inner ramp peritidal platform, （2） inner ramp organic hank and mound, （3） mid ramp, （4） outer ramp, and （5） shelf basin facies associations. The peritidal platform facies association dominates the Zimenqiao Formation （Namurian A or late Datangian） and is characterized by gypsum and dolostone-containing sequences, indicating a peritidal platform environment. The other four facies associations dominate the Menggongao Formation （late Famennian）, Liujiatang Formation （Tournaisian or Yangruanian）, Shidengzi Formations （early Visean or early Datangian）. Five upward-shallowing cycles were distinguished in these three Formations. The predominant facies associations developed in each Formation demonstrate an overall transgression-regression cycle in the Late Devonian to Early Carboniferous in central Hunan. The overall transgressive sequence was preserved in the Shaodong, Menggongao, and Liujiatang Formations, and the overall regressive sequence was preserved in the Liujiatang, Shidengzi, Ceshui and Zimenqiao Formations.
基金Project supported by the National Key Research and Development Program of China(Grant Nos.2017YFE0300500 and 2017YFE0300501)the National Natural Science Foundation of China(Grant Nos.11875290 and 11875253)the Fundamental Research Funds for the Central Universities of China(Grant No.WK3420000004).
文摘The plasma current ramp-up is an important process for tokamak discharge,which directly affects the quality of the plasma and the system resources such as volt-second consumption and plasma current profile.The China Fusion Engineering Test Reactor(CFETR)ramp-up discharge is predicted with the tokamak simulation code(TSC).The main plasma parameters,the plasma configuration evolution and coil current evolution are given out.At the same time,the volt-second consumption during CFETR ramp-up is analyzed for different plasma shaping times and different plasma current ramp rates dIP/dt with/without assisted heating.The results show that the earlier shaping time and the faster plasma current ramp rate with auxiliary heating will enable the volt-second to save 5%-10%.At the same time,the system ability to provide the volt-second is probably 470 V·s.These simulations will give some reference to engineering design for CFETR to some degree.
文摘Overemphasizing the value of reefs in oil and gas exploration, reef-oriented geologists explain all carbonate platform deposits using the Wilson model. In their eyes, rimmed shelves are more valuable than carbonate ramps. However, organic banks are excellent reservoirs generated by carbonate ramps in the study area, as verified beyond doubt through petroleum exploration, such as this thesis, which investigates the genesis, types, and distribution of carbonate deposition in the north zone of the Amu-Darya Basin. Monoclinal palaeogeomorphology and rudists suggest shallow environments. Given that oolite shoals and rudist patch reefs were observed in the study area, the depositional system is interpreted to be a carbonate ramp. The Callovian-Oxfordian stage consists of nine lithofacies: oolitic limestone, skeletal limestone, micritic limestone, bioturbated limestone, and crystalline limestone, which are grouped into three facies associations presenting outer ramp, mid-ramp, and inner ramp facies associations. Five depositional sequences can be distinguished in the Callovian-Oxfordian stage. Each third-order depositional sequence is composed of transgressive systems tracts (TST) and highstand systems tracts (HST). The TST consists of mudstones with a higher response to natural gamma rays, whereas the HST contains various types of grainstone, with subordinate dolostone. The vertical and lateral distributions of sedimentary facies, and their interpreted depositional environments, revealed a ramp exhibiting a gradual southeast-northwestward environmental change from outer ramp, mid ramp, and inner ramp carbonate facies.
基金the NIFS Collaboration Research Program (NIFS07KOAR009,NIFS05KUTR012)the JSPS-CAS Core-University Program in the field of Plasma and Nuclear Fusion
文摘Two-dimensional structure of density fluctuations is examined during the current jump phase, indicating a change from the open magnetic fields to the closed ones. During the smooth current ramp-up phase the two-dimensional contour of the LiI intensity shows vertically alignment, consistent with the magnetic surfaces. At the inflection point in Ip ramp-up the LiI intensity contour becomes flat in the observation regime and then suddenly a steep gradient and higher intensity regime are formed in the vertical direction. This higher intensity corresponds to a burst of LiI waveform. According to these changes in the contour, it is found that, within ~1 ms around the burst of LiI, a low frequency coherent wave with a long wavelength rapidly grows. The relations with other signals （magnetic flux and microwave stray power） are discussed with respect to the topological change in the magnetic configuration and mode conversion of the incident electromagnetic waves.
基金supported in part by the JSPS-CAS Core University Program in the field of Plasma and Nuclear Fusion
文摘In the low aspect ratio torus experiment （LATE） device, plasma current is initiated and ramped up to 20 kA solely by microwave power at the electron cyclotron （EC） range of frequency with a ramp of the external vertical field By for the radial equilibrium of plasma torus at larger currents. Measurements suggest that an energetic electron tail in the energy range of about 200 keV carries the current. The line averaged electron density is higher than the plasma cutoff density, suggesting that tail electrons might be driven by electron Bernstein waves modeconverted from the launched electromagnetic waves.
基金funded by State Grid Shandong Electric Power Company Technology Project(520626220110).
文摘With the increasing penetration of renewable energy in power system,renewable energy power ramp events(REPREs),dominated by wind power and photovoltaic power,pose significant threats to the secure and stable operation of power systems.This paper presents an early warning method for REPREs based on long short-term memory(LSTM)network and fuzzy logic.First,the warning levels of REPREs are defined by assessing the control costs of various power control measures.Then,the next 4-h power support capability of external grid is estimated by a tie line power predictionmodel,which is constructed based on the LSTMnetwork.Finally,considering the risk attitudes of dispatchers,fuzzy rules are employed to address the boundary value attribution of the early warning interval,improving the rationality of power ramp event early warning.Simulation results demonstrate that the proposed method can generate reasonable early warning levels for REPREs,guiding decision-making for control strategy.
文摘THE Chinese Government released a range of reform and opening up policies, as is custom- ary. ahead of the Third Plenary Session of the 18th Central Committee of the Communist Party of China （CPC）, which ran from November 9 to 12. This year. the corporate registration system was included in the reform package.
文摘Ensuring adequate access to truck parking is critical to the safe and efficient movement of freight traffic. There are strict federal guidelines for commercial truck driver rest periods. Rest areas and private truck stops are the only places for the trucks to stop legally and safely. In locations without sufficient parking areas, trucks often park on interstate ramps, which create safety risks for other interstate motorists. Historically, agencies have employed costly and time intensive manual counting methods, camera surveillance, and driver surveys to assess truck parking. Connected truck data, available in near real-time, offers an efficient alternative to practitioners to assess truck parking patterns and identify areas where there may be insufficient safe parking spaces. This paper presents a case study of interstate I-70 in east central Indiana and documents the observed spatiotemporal impacts of a rest area closure on truck parking on nearby interstate ramps. Results showed that there was a 28% increase in parking on ramps during the rest area closure. Analysis also found that ramps closest to the rest area were most impacted by the closure, seeing a rise in truck parking sessions as high as 2.7 times. Parking duration on the ramps during rest area closure also increased drastically. Although it was expected that this would result in increased parking by trucks on adjacent ramps, this before, during, after scenario provided an ideal scenario to evaluate the robustness of these techniques to assess changing parking characteristics of long-haul commercial trucks. The data analytics and visualization tools presented in this study are scalable nationwide and will aid stakeholders in informed data-driven decision making when allocating resources towards improving the nations commercial vehicle parking infrastructure.
文摘This paper analyzes the structural design of an urban interchange ramp bridge from four aspects,which are the superstructure,pier structure,foundation structure,and deck structure design to summarize the structural design ideas of this urban interchange ramp bridge,which can be used as a reference for future construction of the same bridge.
文摘This article explores the fundamentals of small-radius curved ramp bridges.It covers the selection of box girder spans,support methods,and forms,along with design optimization techniques for this type of bridge structure.The purpose of this paper is to provide robust support for enhancing the design quality of these bridges and ensuring their efficacy in real-world applications.
