The properties of nonadiabatic trapping models of the reaction NH+H -N+H, are investigated in a collinear model as \veil as a non-collinear thermal reaction on the basis of theintrinsic reaction coordinate (IRC) intbr...The properties of nonadiabatic trapping models of the reaction NH+H -N+H, are investigated in a collinear model as \veil as a non-collinear thermal reaction on the basis of theintrinsic reaction coordinate (IRC) intbrmation obtained by ah initio calculations at QCISD/631 IG** ie\el. Using the unitied statistical theory fornonadiabatic trapping models. the thermal rateconstants over the temperature range of 2000-3000K are computed which are in excellent agreementwith the experiment results.展开更多
High-k metal gate stacks are being used to suppress the gate leakage due to tunneling for sub-45 nm technology nodes.The reliability of thin dielectric films becomes a limitation to device manufacturing,especially to ...High-k metal gate stacks are being used to suppress the gate leakage due to tunneling for sub-45 nm technology nodes.The reliability of thin dielectric films becomes a limitation to device manufacturing,especially to the breakdown characteristic.In this work,a breakdown simulator based on a percolation model and the kinetic Monte Carlo method is set up,and the intrinsic relation between time to breakdown and trap generation rate R is studied by TDDB simulation.It is found that all degradation factors,such as trap generation rate time exponent m,Weibull slope β and percolation factor s,each could be expressed as a function of trap density time exponent α.Based on the percolation relation and power law lifetime projection,a temperature related trap generation model is proposed.The validity of this model is confirmed by comparing with experiment results.For other device and material conditions,the percolation relation provides a new way to study the relationship between trap generation and lifetime projection.展开更多
Earlier investigators have numerically carried out performance analysis of the invert trap fitted in an open channel using the stochastic discrete phase model(DPM) by assuming the open channel flow to be closed condui...Earlier investigators have numerically carried out performance analysis of the invert trap fitted in an open channel using the stochastic discrete phase model(DPM) by assuming the open channel flow to be closed conduit flow under pressure and assuming zero shear stress at the top wall.This is known as the fixed lid model.By assuming the top wall to be a shear free wall,they have been able to show that the velocity distribution looks similar to that of an open channel flow with zero velocity at the bottom and maximum velocity at the top,representing the free water surface,but no information has been provided for the pressure at the free water surface.Because of this assumption,the validation of the model in predicting the trap efficiency has performed significantly poorly.In addition,the free water surface subject to zero gauge pressure cannot be modeled using the fixed lid model because there is no provision of extra space in the form of air space for the fluctuating part of the water surface profile.It can.however,be modeled using the volume of fluid(VOF) model because the VOF model is the appropriate model for open channel or free surface flow.Therefore,in the present study,three-dimensional(3D) computational fluid dynamics(CFD) modeling with the VOF model,which considers open channel flow with a free water surface,along with the stochastic DPM.was used to model the trap efficiency of an invert trap fitted in an open rectangular channel.The governing mathematical flow equations of the VOF model were solved using the ANSYS Fluent 14.0 software,reproducing the experimental conditions exactly.The results show that the 3D CFD predictions using the VOF model closely fit the experimental data for glass bead particles.展开更多
At present the Eocene reservoir is the focus of exploration in the west sag of the beach area,Liaohe Depression,and lithologic and stratigraphic traps are the most important in the future work.The regional geological ...At present the Eocene reservoir is the focus of exploration in the west sag of the beach area,Liaohe Depression,and lithologic and stratigraphic traps are the most important in the future work.The regional geological background indicated that lithologic and stratigraphic traps might be created in the study area. Studies on creation conditions and distribution pattern of lithologic and stratigraphic traps are展开更多
In this paper, we apply an unstructured grid coastal ocean model to simulate variations in the sea level and currents forced by two typhoons in the northwestern South China Sea(SCS). The model simulations show distinc...In this paper, we apply an unstructured grid coastal ocean model to simulate variations in the sea level and currents forced by two typhoons in the northwestern South China Sea(SCS). The model simulations show distinct differences for the two cases in which the typhoon paths were north and south of the Qiongzhou(QZ) Strait. In both cases, coastal trapped waves(CTWs) are stimulated but their propagation behaviors differ. Model sensitivity simulations suggest the dominant role played by alongshore wind in the eastern SCS(near Shanwei) and southeast of Hainan Island. We also examine the influence of the Leizhou Peninsula by changing the coastline in simulation experiments. Based on our results, we can draw the following conclusions: 1) The CTWs stimulated by the northern typhoon are stronger than the southern CTW. 2) In the two cases, the directions of the current structures of the QZ cross-transect are reversed. The strongest flow cores are both located in the middle-upper area of the strait and the results of our empirical orthogonal function analysis show that the vertical structure is highly barotropic. 3) The simulated CTWs divide into two branches in the QZ Strait for the northern typhoon, and an island trapped wave(ITW) around Hainan Island for the southern typhoon. 4) The Leizhou Peninsula plays a significant role in the distribution of the kinetic energy flux between the two CTW branches. In the presence of the Leizhou Peninsula, the QZ branch has only 39.7 percent of the total energy, whereas that ratio increases to 72.2 percent in its absence.展开更多
The construction of fully closed check dam (CD) is a conventional flood prevention mechanism implemented on rivers. Fully closed CDs trap large amounts of sediments in rivers to stabilize the river slopes and control ...The construction of fully closed check dam (CD) is a conventional flood prevention mechanism implemented on rivers. Fully closed CDs trap large amounts of sediments in rivers to stabilize the river slopes and control erosion. However, fully closed CDs cannot selectively trap sediment and may easily overflow, causing them to losing their ability to mediate and hold sediments. Previous studies proposed the concept of “breathable CDs”. The researcher introduced metal slit dam (SD) that could be assembled and disassembled quickly and conveniently. Once a CD reaches maximum capacity, operators must ensure that the water channels of the dam are free from blockage. Moreover, they must inspect the internal accumulation conditions of the dam periodically or immediately following heavy typhoon rains. When necessary, either the sediment buildup in the upriver blockage must be cleared, or the transverse structure of the dam must be removed to allow fine particles to be discharged along with a moderate amount of water. These actions can free up the sediment-storing capacity of the dam for the next heavy typhoon rains. In addition, operators should also inspect the damages inflicted on the dam, such as erosion, wear and tear, and deformation conditions. Damaged components should be disassembled and repaired if possible, or recycled and reused. The present study performed channel tests to simulate closed CDs, SDs, steel pipe dam (SPDs), and steel pipe plus slit dam (SPSDs) for 50-year and 100-year frequency floods. Results were then analyzed to determine the sediment trapping (ST) effects of various CDs, the effects of “adjustable CDs”, and the changes of moderated riverbeds.展开更多
以2014—2019年珲春地区红外相机拍摄的东北虎数据为基础,基于XGBoost算法构建了虎出没区域风险等级划分模型。由模型检验可知:模型的准确率为93.51%,精确率为93.85%,召回率为93.08%,F1值为93.31%,Cohen s Kappa统计系数为90.2%。研究...以2014—2019年珲春地区红外相机拍摄的东北虎数据为基础,基于XGBoost算法构建了虎出没区域风险等级划分模型。由模型检验可知:模型的准确率为93.51%,精确率为93.85%,召回率为93.08%,F1值为93.31%,Cohen s Kappa统计系数为90.2%。研究结果表明:基于XGBoost算法构建的人-虎共存区域风险等级划分模型分类效果好、预测准确度高,运用该模型对人-虎共存区域进行风险等级划分是可行的。展开更多
This article analyses the procedure of exploration of the Tertiary subtle trap in Jiyang depression and divides the Tertiary subtle trap into 3 types (lithologic reservoir, stratigraphic reservoir and fractured reserv...This article analyses the procedure of exploration of the Tertiary subtle trap in Jiyang depression and divides the Tertiary subtle trap into 3 types (lithologic reservoir, stratigraphic reservoir and fractured reservoir) and 8 groups, then summarizes the common feature and founding discipline of the subtle trap and finds 4 accumulating modes including steep slope mode, depression mode, center anticline mode and gentle slope mode. Its main exploration methods are explicated from the viewpoint of reservoir geological modeling, description of recognizing traps and comprehensive evaluation of reservoir and so on.展开更多
The precise seismic substructural interpretation of the Turkwal oil field in the Central Potwar region of district Chakwal of Pakistan has been carried out. The research work was confined to the large fore-thrust that...The precise seismic substructural interpretation of the Turkwal oil field in the Central Potwar region of district Chakwal of Pakistan has been carried out. The research work was confined to the large fore-thrust that serves as an anticlinal structural trap through ten 2 D seismic lines. A precise seismic substructural model of the Eocene Chorgali Limestone with precise orientation of thrust and oblique slip faults shows the presence of a huge fracture, which made this deposit a good reservoir. The abrupt surface changes in dip azimuth for the Eocene Chorgali Limestone verifies the structural trends and also the presence of structural traps in the Turkwal field. The logs of three wells(Turkwal deep X-2, Turkwal-01 and Fimkassar-01) were analyzed for petrophysical studies, well synthetic results and generation of an Amplitude Versus Offset(AVO) model for the area. The AVO model of Turkwal deep X-2 shows abrupt changes in amplitude, which depicts the presence of hydrocarbon content. Well correlation technique was used to define the overall stratigraphic setting and the thickness of the reservoir formation in two wells, Turkwal-01 and Turkwal deep X-2. The Eocene Chorgali Limestone in Turkwal-01 is an upward thrusted anticlinal structure and because of the close position of both wells to the faulted anticlinal structure, its lesser thickness differs compared to Turkwal deep X-2. The overall results confirm that the Turkwal field is comparable to several similar thrust-bound oil-bearing structures in the Potwar basin.展开更多
文摘The properties of nonadiabatic trapping models of the reaction NH+H -N+H, are investigated in a collinear model as \veil as a non-collinear thermal reaction on the basis of theintrinsic reaction coordinate (IRC) intbrmation obtained by ah initio calculations at QCISD/631 IG** ie\el. Using the unitied statistical theory fornonadiabatic trapping models. the thermal rateconstants over the temperature range of 2000-3000K are computed which are in excellent agreementwith the experiment results.
基金supported by the National High Technology Research and Development Program of China(Grant No.SS2015AA010601)the National Natural Science Foundation of China(Grant Nos.61176091 and 61306129)the Opening Project of Key Laboratory of Microelectronics Devices&Integrated Technology,Institute of Micro Electronics of Chinese Academy of Sciences
文摘High-k metal gate stacks are being used to suppress the gate leakage due to tunneling for sub-45 nm technology nodes.The reliability of thin dielectric films becomes a limitation to device manufacturing,especially to the breakdown characteristic.In this work,a breakdown simulator based on a percolation model and the kinetic Monte Carlo method is set up,and the intrinsic relation between time to breakdown and trap generation rate R is studied by TDDB simulation.It is found that all degradation factors,such as trap generation rate time exponent m,Weibull slope β and percolation factor s,each could be expressed as a function of trap density time exponent α.Based on the percolation relation and power law lifetime projection,a temperature related trap generation model is proposed.The validity of this model is confirmed by comparing with experiment results.For other device and material conditions,the percolation relation provides a new way to study the relationship between trap generation and lifetime projection.
文摘Earlier investigators have numerically carried out performance analysis of the invert trap fitted in an open channel using the stochastic discrete phase model(DPM) by assuming the open channel flow to be closed conduit flow under pressure and assuming zero shear stress at the top wall.This is known as the fixed lid model.By assuming the top wall to be a shear free wall,they have been able to show that the velocity distribution looks similar to that of an open channel flow with zero velocity at the bottom and maximum velocity at the top,representing the free water surface,but no information has been provided for the pressure at the free water surface.Because of this assumption,the validation of the model in predicting the trap efficiency has performed significantly poorly.In addition,the free water surface subject to zero gauge pressure cannot be modeled using the fixed lid model because there is no provision of extra space in the form of air space for the fluctuating part of the water surface profile.It can.however,be modeled using the volume of fluid(VOF) model because the VOF model is the appropriate model for open channel or free surface flow.Therefore,in the present study,three-dimensional(3D) computational fluid dynamics(CFD) modeling with the VOF model,which considers open channel flow with a free water surface,along with the stochastic DPM.was used to model the trap efficiency of an invert trap fitted in an open rectangular channel.The governing mathematical flow equations of the VOF model were solved using the ANSYS Fluent 14.0 software,reproducing the experimental conditions exactly.The results show that the 3D CFD predictions using the VOF model closely fit the experimental data for glass bead particles.
文摘At present the Eocene reservoir is the focus of exploration in the west sag of the beach area,Liaohe Depression,and lithologic and stratigraphic traps are the most important in the future work.The regional geological background indicated that lithologic and stratigraphic traps might be created in the study area. Studies on creation conditions and distribution pattern of lithologic and stratigraphic traps are
基金the National Natural Science Foundation of China(Nos.41266002,41406031,41406044)the Special Fund for Basic Scientific Research Business of Central Public Research Institutes(No.2015P02)the Fund of Key Laboratory of Global Change and Marine-Atmospheric Chemistry,SOA(No.GCMAC1308)for their support
文摘In this paper, we apply an unstructured grid coastal ocean model to simulate variations in the sea level and currents forced by two typhoons in the northwestern South China Sea(SCS). The model simulations show distinct differences for the two cases in which the typhoon paths were north and south of the Qiongzhou(QZ) Strait. In both cases, coastal trapped waves(CTWs) are stimulated but their propagation behaviors differ. Model sensitivity simulations suggest the dominant role played by alongshore wind in the eastern SCS(near Shanwei) and southeast of Hainan Island. We also examine the influence of the Leizhou Peninsula by changing the coastline in simulation experiments. Based on our results, we can draw the following conclusions: 1) The CTWs stimulated by the northern typhoon are stronger than the southern CTW. 2) In the two cases, the directions of the current structures of the QZ cross-transect are reversed. The strongest flow cores are both located in the middle-upper area of the strait and the results of our empirical orthogonal function analysis show that the vertical structure is highly barotropic. 3) The simulated CTWs divide into two branches in the QZ Strait for the northern typhoon, and an island trapped wave(ITW) around Hainan Island for the southern typhoon. 4) The Leizhou Peninsula plays a significant role in the distribution of the kinetic energy flux between the two CTW branches. In the presence of the Leizhou Peninsula, the QZ branch has only 39.7 percent of the total energy, whereas that ratio increases to 72.2 percent in its absence.
文摘The construction of fully closed check dam (CD) is a conventional flood prevention mechanism implemented on rivers. Fully closed CDs trap large amounts of sediments in rivers to stabilize the river slopes and control erosion. However, fully closed CDs cannot selectively trap sediment and may easily overflow, causing them to losing their ability to mediate and hold sediments. Previous studies proposed the concept of “breathable CDs”. The researcher introduced metal slit dam (SD) that could be assembled and disassembled quickly and conveniently. Once a CD reaches maximum capacity, operators must ensure that the water channels of the dam are free from blockage. Moreover, they must inspect the internal accumulation conditions of the dam periodically or immediately following heavy typhoon rains. When necessary, either the sediment buildup in the upriver blockage must be cleared, or the transverse structure of the dam must be removed to allow fine particles to be discharged along with a moderate amount of water. These actions can free up the sediment-storing capacity of the dam for the next heavy typhoon rains. In addition, operators should also inspect the damages inflicted on the dam, such as erosion, wear and tear, and deformation conditions. Damaged components should be disassembled and repaired if possible, or recycled and reused. The present study performed channel tests to simulate closed CDs, SDs, steel pipe dam (SPDs), and steel pipe plus slit dam (SPSDs) for 50-year and 100-year frequency floods. Results were then analyzed to determine the sediment trapping (ST) effects of various CDs, the effects of “adjustable CDs”, and the changes of moderated riverbeds.
文摘以2014—2019年珲春地区红外相机拍摄的东北虎数据为基础,基于XGBoost算法构建了虎出没区域风险等级划分模型。由模型检验可知:模型的准确率为93.51%,精确率为93.85%,召回率为93.08%,F1值为93.31%,Cohen s Kappa统计系数为90.2%。研究结果表明:基于XGBoost算法构建的人-虎共存区域风险等级划分模型分类效果好、预测准确度高,运用该模型对人-虎共存区域进行风险等级划分是可行的。
文摘This article analyses the procedure of exploration of the Tertiary subtle trap in Jiyang depression and divides the Tertiary subtle trap into 3 types (lithologic reservoir, stratigraphic reservoir and fractured reservoir) and 8 groups, then summarizes the common feature and founding discipline of the subtle trap and finds 4 accumulating modes including steep slope mode, depression mode, center anticline mode and gentle slope mode. Its main exploration methods are explicated from the viewpoint of reservoir geological modeling, description of recognizing traps and comprehensive evaluation of reservoir and so on.
文摘The precise seismic substructural interpretation of the Turkwal oil field in the Central Potwar region of district Chakwal of Pakistan has been carried out. The research work was confined to the large fore-thrust that serves as an anticlinal structural trap through ten 2 D seismic lines. A precise seismic substructural model of the Eocene Chorgali Limestone with precise orientation of thrust and oblique slip faults shows the presence of a huge fracture, which made this deposit a good reservoir. The abrupt surface changes in dip azimuth for the Eocene Chorgali Limestone verifies the structural trends and also the presence of structural traps in the Turkwal field. The logs of three wells(Turkwal deep X-2, Turkwal-01 and Fimkassar-01) were analyzed for petrophysical studies, well synthetic results and generation of an Amplitude Versus Offset(AVO) model for the area. The AVO model of Turkwal deep X-2 shows abrupt changes in amplitude, which depicts the presence of hydrocarbon content. Well correlation technique was used to define the overall stratigraphic setting and the thickness of the reservoir formation in two wells, Turkwal-01 and Turkwal deep X-2. The Eocene Chorgali Limestone in Turkwal-01 is an upward thrusted anticlinal structure and because of the close position of both wells to the faulted anticlinal structure, its lesser thickness differs compared to Turkwal deep X-2. The overall results confirm that the Turkwal field is comparable to several similar thrust-bound oil-bearing structures in the Potwar basin.