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Mapping and measuring urban-rural inequalities in accessibility to social infrastructures
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作者 Chenmeng Guo Weiqi Zhou +1 位作者 Chuanbao Jing Dawa Zhaxi 《Geography and Sustainability》 CSCD 2024年第1期41-51,共11页
Equal access to social infrastructures is a fundamental prerequisite for sustainable development,but has long been a great challenge worldwide.Previous studies have primarily focused on the accessibility to social inf... Equal access to social infrastructures is a fundamental prerequisite for sustainable development,but has long been a great challenge worldwide.Previous studies have primarily focused on the accessibility to social infras-tructures in urban areas across various scales,with less attention to rural areas,where inequality can be more severe.Particularly,few have investigated the disparities of accessibility to social infrastructures between urban and rural areas.Here,using the Changsha-Zhuzhou-Xiangtan urban agglomeration,China,as an example,we investigated the inequality of accessibility in both urban and rural areas,and further compared the urban-rural difference.Accessibility was measured by travel time of residents to infrastructures.We selected four types of social infrastructures including supermarkets,bus stops,primary schools,and health care,which were funda-mentally important to both urban and rural residents.We found large disparities in accessibility between urban and rural areas,ranging from 20 min to 2 h.Rural residents had to spend one to two more hours to bus stops than urban residents,and 20 min more to the other three types of infrastructures.Furthermore,accessibility to multiple infrastructures showed greater urban-rural differences.Rural residents in more than half of the towns had no access to any infrastructure within 15 min,while more than 60%of the urban residents could access to all infrastructures within 15 min.Our results revealed quantitative accessibility gap between urban and rural areas and underscored the necessity of social infrastructures planning to address such disparities. 展开更多
关键词 ACCESSIBILITY Social infrastructures urban-rural difference INEQUALITY regional sustainability
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The Solar Upper Transition Region Imager(SUTRI)Onboard the SATech-01 Satellite 被引量:7
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作者 Xianyong Bai Hui Tian +56 位作者 Yuanyong Deng Zhanshan Wang Jianfeng Yang Xiaofeng Zhang Yonghe Zhang Runze Qi Nange Wang Yang Gao Jun Yu Chunling He Zhengxiang Shen Lun Shen Song Guo Zhenyong Hou Kaifan Ji Xingzi Bi Wei Duan Xiao Yang Jiaben Lin Ziyao Hu Qian Song Zihao Yang Yajie Chen Weidong Qiao Wei Ge Fu Li Lei Jin Jiawei He Xiaobo Chen Xiaocheng Zhu Junwang He Qi Shi Liu Liu Jinsong Li Dongxiao Xu Rui Liu Taijie Li Zhenggong Feng Yamin Wang Chengcheng Fan Shuo Liu Sifan Guo Zheng Sun Yuchuan Wu Haiyu Li Qi Yang Yuyang Ye Weichen Gu Jiali Wu Zhe Zhang Yue Yu Zeyi Ye Pengfeng Sheng Yifan Wang Wenbin Li Qiushi Huang Zhong Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第6期153-171,共19页
The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the... The Solar Upper Transition Region Imager(SUTRI)onboard the Space Advanced Technology demonstration satellite(SATech-01),which was launched to a Sun-synchronous orbit at a height of~500 km in 2022 July,aims to test the on-orbit performance of our newly developed Sc/Si multi-layer reflecting mirror and the 2k×2k EUV CMOS imaging camera and to take full-disk solar images at the Ne VII 46.5 nm spectral line with a filter width of~3 nm.SUTRI employs a Ritchey-Chrétien optical system with an aperture of 18 cm.The on-orbit observations show that SUTRI images have a field of view of~416×416 and a moderate spatial resolution of~8″without an image stabilization system.The normal cadence of SUTRI images is 30 s and the solar observation time is about16 hr each day because the earth eclipse time accounts for about 1/3 of SATech-01's orbit period.Approximately15 GB data is acquired each day and made available online after processing.SUTRI images are valuable as the Ne VII 46.5 nm line is formed at a temperature regime of~0.5 MK in the solar atmosphere,which has rarely been sampled by existing solar imagers.SUTRI observations will establish connections between structures in the lower solar atmosphere and corona,and advance our understanding of various types of solar activity such as flares,filament eruptions,coronal jets and coronal mass ejections. 展开更多
关键词 Sun:transition region Sun:UV radiation Sun:activity space vehicles:instruments
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Geological characteristics and accumulation mechanisms of the "continuous" tight gas reservoirs of the Xu2 Member in the middle-south transition region,Sichuan Basin,China 被引量:12
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作者 Zou Caineng Gong Yanjie +1 位作者 Tao Shizhen Liu Shaobo 《Petroleum Science》 SCIE CAS CSCD 2013年第2期171-182,共12页
"Continuous" tight gas reservoirs are those reservoirs which develop in widespread tight sandstones with a continuous distribution of natural gas. In this paper, we summarize the geological features of the source ro... "Continuous" tight gas reservoirs are those reservoirs which develop in widespread tight sandstones with a continuous distribution of natural gas. In this paper, we summarize the geological features of the source rocks and "'continuous" tight gas reservoirs in the Xujiahe Formation of the middle- south transition region, Sichuan Basin. The source rocks of the Xul Member and reservoir rocks of the Xu2 Member are thick (Xul Member: 40 m, Xu2 Member: 120 m) and are distributed continuously in this study area. The results of drilled wells show that the widespread sandstone reservoirs of the Xu2 Member are charged with natural gas. Therefore, the natural gas reservoirs of the Xu2 Member in the middle-south transition region are "continuous" tight gas reservoirs. The accumulation of "continuous" tight gas reservoirs is controlled by an adequate driving force of the pressure differences between source rocks and reservoirs, which is demonstrated by a "one-dimensional" physical simulation experiment. In this simulation, the natural gas of"continuous" tight gas reservoirs moves tbrward with no preferential petroleum migration pathways (PPMP), and the natural gas saturation of"continuous" tight gas reservoirs is higher than that of conventional reservoirs. 展开更多
关键词 Geological characteristics accumulation mechanism "continuous" tight gas reservoir Xu2Member middle-south transition region Sichuan Basin
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Influence of the deposition parameters on the transition region of hydrogenated silicon films growth 被引量:2
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作者 雷青松 吴志猛 +2 位作者 耿新华 赵颖 奚建平 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第11期2342-2347,共6页
Hydrogenated microcrystalline and amorphous silicon thin films were prepared by very high frequency plasmaenhanced chemical vapour deposition (VHF PECVD) by using a mixture of silane and hydrogen as source gas. The ... Hydrogenated microcrystalline and amorphous silicon thin films were prepared by very high frequency plasmaenhanced chemical vapour deposition (VHF PECVD) by using a mixture of silane and hydrogen as source gas. The influence of deposition parameters on the transition region of hydrogenated silicon films growth was investigated by varying the silane concentration (SC), plasma power (Pw), working pressure (P), and substrate temperature (Ts). Results suggest that SC and Ts are the most critical factors that affect the film structure transition from microcrystalline to amorphous phase. A narrow region in the range of SC and Ts, in which the rapid phase transition takes place, was identified. It was found that at lower P or higher Pw, the transition region is shifted to larger SC. In addition, the dark conductivity and photoconductivity decrease with SC and show sharp changes in the transition region. It proposed that the transition process and the transition region are determined by the competition between the etching effect of atomic hydrogen and the growth of amorphous phase. 展开更多
关键词 microcrystalline silicon amorphous silicon transition region VHF PECVD
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The heating of the solar transition region 被引量:1
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作者 Wen-Bin Song Xue-Shang Feng Fang Shen 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2010年第6期529-532,共4页
The temperature curve in the solar chromosphere has puzzled astronomers for a long time. Referring to the structure of supergranular cells, we propose an inductive heating model. It mainly includes the following three... The temperature curve in the solar chromosphere has puzzled astronomers for a long time. Referring to the structure of supergranular cells, we propose an inductive heating model. It mainly includes the following three steps. (1) A small-scale dynamo exists in the supergranulation and produces alternating small-scale magnetic fluxes; (2) The supergranular flow distributes these small-scale fluxes according to a regular pattern; (3) A skin effect occurs in the alternating and regularly-distributed magnetic fields. The induced current is concentrated near the transition region and heats it by resistive dissipation. 展开更多
关键词 SUN transition region -- Sun GRANULATION
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A Novel Fast Algorithm of Mono Transition Region Determination with Gray Image 被引量:1
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作者 ZhangAi-hua 《Wuhan University Journal of Natural Sciences》 EI CAS 2004年第3期309-312,共4页
There is a transition region between objects and background in any gray image. Many valuable applications of image segmentation and edge detection based on transition region determination have been developed in recent... There is a transition region between objects and background in any gray image. Many valuable applications of image segmentation and edge detection based on transition region determination have been developed in recent years. But, the complexity of calculation for determining transition region is too high. It results in the very limitation of applications based on transition region. A new novel fast method for transition region determination is presented in this paper, which will reduce the complexity of calculation dramatically. Many experiments have showed that this algorithm is effective and correct and will lay a good foundation for applications based on transition region. Key words image segmentation - transition region - maximum point - efficient average gradient (EAG) CLC number TP 391.4 Biography: Zhang Ai-hua (1965-), male, Ph. D candidate, research direction: image processing. 展开更多
关键词 image segmentation transition region maximum point efficient average gradient (EAG)
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The Emission Heights of Transition Region Lines in an Equatorial Coronal Hole and the Surrounding Quiet Sun 被引量:1
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作者 Hui Tian Li-Dong Xia +2 位作者 Jian-Sen He Bo Tan Shuo Yao 《Chinese Journal of Astronomy and Astrophysics》 CSCD 2008年第6期732-742,共11页
Using the correlation between the radiance or Doppler velocity and the extrapolated magnetic field, we determined the emission heights of a set of solar transition region lines in an equatorial coronal hole and in the... Using the correlation between the radiance or Doppler velocity and the extrapolated magnetic field, we determined the emission heights of a set of solar transition region lines in an equatorial coronal hole and in the surrounding quiet Sun region. We found that for all of the six lower-transition-region lines, the emission height is about 4-5 Mm in the equatorial coronal hole, and around 2 Mm in the quiet Sun region. This result confirms the previous findings that plasma with different temperature can coexist at the same layer of transition region. In the quiet Sun region, the emission height of the upper-transition-region line Ne VIII is almost the same that of the lower-transition-region line, but in the coronal hole, it is twice as high. This difference reveals that the outflow of Ne VIII is a signature of solar wind in the coronal hole and is just a mass supply to the large loops in the quiet Sun. 展开更多
关键词 Sun: transition region Sun: magnetic fields Sun: solar wind Sun: UV radiation
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Probing the solar transition region: current status and future perspectives 被引量:4
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作者 Hui Tian 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2017年第11期1-18,共18页
The solar transition region (TR) is the temperature regime from roughly 0.02 MK to 0.8 MK in the solar atmosphere. It is the transition layer from the collisional and partially ionized chromosphere to the collisionl... The solar transition region (TR) is the temperature regime from roughly 0.02 MK to 0.8 MK in the solar atmosphere. It is the transition layer from the collisional and partially ionized chromosphere to the collisionless and fully ionized corona. The TR plays an important role in the mass and energy transport in both the quiet solar atmosphere and solar eruptions. Most of the TR emission lines fall into the spectral range of far ultraviolet and extreme ultraviolet (~400/^-1600/~). Imaging and spec- troscopic observations in this spectral range are the most important ways to obtain information about the physics of the TR. Static solar atmosphere models predict a very thin TR. However, recent high- resolution observations indicate that the TR is highly dynamic and inhomogeneous. I will summarize some major findings about the TR made through imaging and spectroscopic observations in the past 20 years. These existing observations have demonstrated that the TR may be the key to understanding coronal heating and origin of the solar wind. Future exploration of the solar TR may need to focus on the upper TR, since the plasma in this temperature regime (0.1 MK-0.8 MK) has not been routinely imaged before. High-resolution imaging and spectroscopic observations of the upper TR will not only allow us to track the mass and energy from the lower atmosphere to the corona, but also help us to understand the initiation and heating mechanisms of coronal mass ejections and solar flares. 展开更多
关键词 Sun: transition region -- Sun: corona -- Sun: flares -- Sun: coronal mass ejections --instrumentation: spectrographs
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Addressing inclusion,innovation,and sustainability challenges through the lens of economic geography:Introducing the hierarchical regional innovation system
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作者 Iván Tartaruga Fernanda Sperotto Luís Carvalho 《Geography and Sustainability》 CSCD 2024年第1期1-12,共12页
The world is facing dramatic challenges related to environmental sustainability at an accelerating pace.In this context,the field of economic geography(EG)has been playing an important role in understanding both the s... The world is facing dramatic challenges related to environmental sustainability at an accelerating pace.In this context,the field of economic geography(EG)has been playing an important role in understanding both the socioeconomic and technological dimensions of these challenges,as it deals with a variety of complementary notions and perspectives.Departing from this lens,our aim is to explore a conceptual framework that can help us to understand environmental changes relating to multi-dimensional territorial development,notably in eco-nomic contexts where inequality is high,and stratification based on hierarchies regulate social and economic life.Based on the territory concept,we propose the original notion of a hierarchical regional innovation system(HRIS)that emphasises the pervasive role of hierarchies(powers)in regional innovation systems and illustrate its value with evidence and case studies from extant literature on sustainability transitions.The HRIS can help us understand and promote development paths considering the contribution of inclusive eco-innovations(another original conceptual amalgam).Through some empirical cases from other studies in low-carbon transitions,we show the application of the HRIS(and inclusive eco-innovation)framework.In conclusion,we provide incen-tives to explore new regional innovation systems,alongside the HRIS,adapted to different regions worldwide and centred on the inclusiveness of people and places. 展开更多
关键词 Inclusive eco-innovation Inclusive innovation Hierarchical regional innovation system(HRIS) Territorial development Sustainable development Sustainability transitions
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Analyzing Land-use Change in Farming-pastoral Transitional Region Using Autologistic Model and Household Survey Approach 被引量:3
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作者 ZHU Likai MENG Jijun MAO Xiyan 《Chinese Geographical Science》 SCIE CSCD 2013年第6期716-728,共13页
Land change science(LCS)strives to understand and model land-use change,which will further advance the understanding of multiple issues in the socio-ecological systems.Based on GIS/RS techniques,autologistic model,and... Land change science(LCS)strives to understand and model land-use change,which will further advance the understanding of multiple issues in the socio-ecological systems.Based on GIS/RS techniques,autologistic model,and household survey method,this study investigated major land use changes and their causes from 1978 to 2008 in Uxin Banner(county-level),Inner Mongolia in China and then developed an understanding of the relationships between household livelihood and land-use pattern.Results showed that cultivated land increased from 1988 to 2000,and leveled off after 2000.Built-up land increased stably for the period 1978–2008.The change of grassland and bare land differed among the three periods.From 1978 to 1988,grassland increased by 23.3%,and bare land decreased by 20.48%.From 1988 to 2000,bare land expanded by 1.7%,but grassland declined by 1.3%.From 2000 to 2008,an increase in grassland area by 1.8%was observed,but a decrease in bare land area by 9.0%was witnessed.The autologistic models performed better than logistic models as indicated by lower Akaike Information Criterion(AIC)values.Factors associated with human activities significantly correlated with the change of cultivated land,forest land,grassland,and built-up land.The produce prices and extensive cultivated land use are major issues in the farming area.This study suggests that completing land circulation systems and maintaining the stability of price are effective solutions.By contrast,reclamation and overgrazing are major concerns in the pastoral areas.Implementing environmental policies effectively,transferring population out of rural pastoral areas,and developing modern animal husbandry are effective ways to address these issues. 展开更多
关键词 LOGISTIC模型 土地利用变化 统计调查方法 农牧交错地区 AUTO 住户 社会生态系统 土地利用格局
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A NEW ALGORITHM FOR DETECTING THE TRANSITION REGION ON NOISE IMAGE 被引量:1
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作者 Wang Hui Luo Jianping(Faculty of Information Eng., Shenzhen University, Shenzhen 518060) 《Journal of Electronics(China)》 2003年第4期279-284,共6页
An algorithm of ramp width reduction based on the gray information of neighborhood pixels is proposed, which can sharpen the ramp edge effectively Then, a new gray-weighted gradient operator and the automatic method t... An algorithm of ramp width reduction based on the gray information of neighborhood pixels is proposed, which can sharpen the ramp edge effectively Then, a new gray-weighted gradient operator and the automatic method to determine its parameter are introduced when detecting the transition region of images. Gray-weighted gradient operator can not only make the correlation of gradient and gray information as big as possible, but also resist the noise in the images. Some experiments show that the algorithm in this paper can extract the transition regaon more effectively. 展开更多
关键词 斜面边际 宽度缩减 过度区 图像处理
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Transition-region explosive events produced by plasmoid instability
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作者 Dong Li 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2019年第5期43-52,共10页
Magnetic reconnection is thought to be a key process in most solar eruptions. Thanks to highresolution observations and simulations, the studied scale of the reconnection process has become smaller and smaller. Spectr... Magnetic reconnection is thought to be a key process in most solar eruptions. Thanks to highresolution observations and simulations, the studied scale of the reconnection process has become smaller and smaller. Spectroscopic observations show that the reconnection site can be very small, which always exhibits a bright core and two extended wings with fast speeds, i.e., transition-region explosive events.In this paper, using the PLUTO code, we perform a 2-D magnetohydrodynamic simulation to investigate small-scale reconnection in double current sheets. Based on our simulation results, such as the line-of-sight velocity, number density and plasma temperature, we can synthesize the line profile of SiIV 1402.77? which is a well known emission line used to study transition-region explosive events on the Sun. The synthetic line profile of Si IV 1402.77? is complex with a bright core and two broad wings which can extend to nearly 200 km s^(-1). Our simulation results suggest that the transition-region explosive events on the Sun are produced by plasmoid instability during small-scale magnetic reconnection. 展开更多
关键词 Sun:transition region line:profiles methods:numerical magnetohydrodynamics(MHD)
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Evapotranspiration of an oasis-desert transition zone in the middle stream of Heihe River, Northwest China 被引量:18
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作者 LiWen ZHAO WenZhi ZHAO 《Journal of Arid Land》 SCIE CSCD 2014年第5期529-539,共11页
As a main component in water balance, evapotranspiration is of great importance for water saving and irrigation-measure making, especially in arid or semiarid regions. Although studies of evapotranspiration have been ... As a main component in water balance, evapotranspiration is of great importance for water saving and irrigation-measure making, especially in arid or semiarid regions. Although studies of evapotranspiration have been conducted for a long time, studies concentrated on oasis-desert transition zone are very limited. On the basis of the meteorological data and other parameters(e.g. leaf area index(LAI)) of an oasis-desert transition zone in the middle stream of Heihe River from 2005 to 2011, this paper calculated both reference(ET0) and actual evapotranspiration(ETc) using FAO56 Penman-Monteith and Penman-Monteith models, respectively. In combination with pan evaporation(Ep) measured by E601 pan evaporator, four aspects were analyzed:(1) ET0 was firstly verified by Ep;(2) Characteristics of ET0 and ETc were compared, while the influencing factors were also analyzed;(3) Since meteorological data are often unavailable for estimating ET0 through FAO56 Penman-Monteith model in this region, pan evaporation coefficient(Kp) is very important when using observed Ep to predict ET0. Under this circumstance, an empirical formula of Kp was put forward for this region;(4) Crop coefficient(Kc), an important index to reflect evapotranspiration, was also analyzed. Results show that mean annual values of ET0 and ETc were 840 and 221 mm, respectively. On the daily bases, ET0 and ETc were 2.3 and 0.6 mm/d, respectively. The annual tendency of ET0 and ETc was very similar, but their amplitude was obviously different. The differences among ET0 and ETc were mainly attributed to the different meteorological variables and leaf area index. The calculated Kc was about 0.25 and showed little variation during the growing season, indicating that available water(e.g. precipitation and irrigation) of about 221 mm/a was required to keep the water balance in this region. The results provide an comprehensive analysis of evapotranspiration for an oasis-desert transition zone in the middle stream of Heihe River, which was seldom reported before. 展开更多
关键词 EVAPOTRANSPIRATION pan evaporation water requirement arid region oasis-desert transition zone
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Study of crust-mantle transitional zone along the northeast margin of Qinghai-Xizang plateau 被引量:1
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作者 LAI Xiao-ling(赖晓玲) +3 位作者 ZHANG Xian-kang(张先康) FANG Sheng-ming(方盛明) 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第2期144-151,共8页
This study deals with complexity, frequency spectrum and velocity model of the crust-mantle transitional zone in different tectonic units along the northeast margin of Qinghai-Xizang plateau, based on PmP waveform dat... This study deals with complexity, frequency spectrum and velocity model of the crust-mantle transitional zone in different tectonic units along the northeast margin of Qinghai-Xizang plateau, based on PmP waveform data from two deep seismic sounding profiles passing through the area. It reveals that Moho has stable tectonic features in Ordos and Lingzhong basins, where crust and mantle are coupled as first-order discontinuity. Moho shows obvious signs of activity in Haiyuan seismic region and in the contact zone between Bayanhar block and Qaidam block. Crust and mantle in these two areas are coupled as complicated crust-mantle transitional zone consisting of multiple laminae with alternate high and low velocities, totaling 20 km in thickness. The difference between Moho of different tectonic units reflects heterogeneity of the coupled crust-mantle zone; the difference between fine structures of Haiyuan seismic region and Maqin fault zone reflects different deep material composition of the two continent-continent collision zones and the interaction between blocks. 展开更多
关键词 crust-mantle transitional zone tectonic units Haiyuan seismic region Maqin fault zone
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Quantifying the parameter dependent basin of the unsafe regime of asymmetric Lévy-noise-induced critical transitions 被引量:1
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作者 Jinzhong MA Yong XU +3 位作者 Yongge LI Ruilan TIAN Shao juan MA J.KURTHS 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第1期65-84,共20页
In real systems,the unpredictable jump changes of the random environment can induce the critical transitions(CTs)between two non-adjacent states,which are more catastrophic.Taking an asymmetric Lévy-noise-induced... In real systems,the unpredictable jump changes of the random environment can induce the critical transitions(CTs)between two non-adjacent states,which are more catastrophic.Taking an asymmetric Lévy-noise-induced tri-stable model with desirable,sub-desirable,and undesirable states as a prototype class of real systems,a prediction of the noise-induced CTs from the desirable state directly to the undesirable one is carried out.We first calculate the region that the current state of the given model is absorbed into the undesirable state based on the escape probability,which is named as the absorbed region.Then,a new concept of the parameter dependent basin of the unsafe regime(PDBUR)under the asymmetric Lévy noise is introduced.It is an efficient tool for approximately quantifying the ranges of the parameters,where the noise-induced CTs from the desirable state directly to the undesirable one may occur.More importantly,it may provide theoretical guidance for us to adopt some measures to avert a noise-induced catastrophic CT. 展开更多
关键词 tri-stable model asymmetric Lévy noise critical transition(CT) escape probability absorbed region parameter dependent basin of unsafe regime(PDBUR)
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Chaotic motions of the L-mode to H-mode transition model in tokamak
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作者 陈芳启 周良强 +1 位作者 王霞 陈予恕 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第7期811-820,共10页
The chaotic dynamics of the transport equation for the L-mode to H-mode near the plasma in a tokamak is studied in detail with the Melnikov method. The transport equations represent a system with external and parametr... The chaotic dynamics of the transport equation for the L-mode to H-mode near the plasma in a tokamak is studied in detail with the Melnikov method. The transport equations represent a system with external and parametric excitation. The critical curves separating the chaotic regions and nonchaotic regions are presented for the system with periodically external excitation and linear parametric excitation, or cubic parametric excitation, respectively. The results obtained here show that there exist uncontrollable regions in which chaos always take place via heteroclinic bifurcation for the system with linear or cubic parametric excitation. Especially, there exists a controllable frequency, excited at which chaos does not occur via homoclinic bifurcation no matter how large the excitation amplitude is for the system with cubic parametric excitation. Some complicated dynamical behaviors are obtained for this class of systems. 展开更多
关键词 transitions in tokamak CHAOS Melnikov method uncontrollable regions controllable frequency
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Analysis of the Variability of the L-H Transition Power Threshold in a Helium-4 Discharge
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作者 吴国将 张晓东 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第6期557-561,共5页
In this paper, a mechanism about the variability of the L-H transition power thresh- old PL-H is proposed which is based on the ion orbit losses. Only in the edge where there are enough ion orbit losses and the negati... In this paper, a mechanism about the variability of the L-H transition power thresh- old PL-H is proposed which is based on the ion orbit losses. Only in the edge where there are enough ion orbit losses and the negative radial electric field Er is high enough can the H-mode be triggered. The ion orbit losses are determined by the ion in the loss region under certain edge conditions. For different mass A and different charge Z, the critical loss energy E Z2/A in the loss region. In H and D charges, because the D+ loss region is larger than H+, it can be deduced that the PL-H of H is larger than that of D. In a 4He discharge, experiment finds there exist a considerable number of 4He1+ in the plasma edge. The actual ion orbit losses are determined by the mixing ratio of a He1+ and 4He2+. The 4He1+ loss region is larger than that of 4He2+, and the loss region of D+ interposes between 4He1+ and 4He2+. Different 4He1+ content can cause the edge ion losses in a 4He discharge to be greater than, less than or equal to that in a D discharge. So a 4He discharge can exhibit multiple experimental phenomena in the PL-H. 展开更多
关键词 4He discharge the L-H transition the ion orbit loss region the variability of PL-H
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A framework to create video-transition effects
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作者 卜佳俊 赵传禹 陈纯 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第B08期58-65,共8页
The paper presents a framework for developing a variety of video transition effects. The framework is designed to deal with the problem of inefficiency for programmers to generate more and more diversified video trans... The paper presents a framework for developing a variety of video transition effects. The framework is designed to deal with the problem of inefficiency for programmers to generate more and more diversified video transition, which is caused by excessive coupling between the sub-modules of the system. So the framework is designed to be modular, flexible and extensible. Based on the analysis of common features of different effects, the implementation of video transition effect is divided into 4 sub-modules, each of which can be designed and developed independently. Furthermore, these sub-modules can be easily sub- stituted, modified and reused. We present a formal description of our framework, and give typical study cases to show the exten- sive utility of the framework. 展开更多
关键词 数字摄像机 视频转换 框架结构 映射法 系统模块 目标区域
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Human Rights Organizations in Transition Countries
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作者 Elie Abouaoun 《Journal of Philosophy Study》 2014年第7期483-485,共3页
关键词 组织 人权 阿拉伯地区
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Transitional Description of Diatomic Molecules in U(4) Vibron Model
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作者 ZHANGXin PANFeng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第1期29-36,共8页
U(3)-O(4) transitional description of diatomic molecules in the U(4) vibron model is studied by usingthe algebraic Bethe ansatz, in which the O(4) limit is a special case of the theory. Vibrational band-heads of somet... U(3)-O(4) transitional description of diatomic molecules in the U(4) vibron model is studied by usingthe algebraic Bethe ansatz, in which the O(4) limit is a special case of the theory. Vibrational band-heads of sometypical diatomic molecules are fitted by both transitional theory and the O(4) limit within the same framework. Theresults show that there are evident deviations from the O(4) limit in description of vibrational spectra of some diatomicmolecules. 展开更多
关键词 双原子分子振动光谱 维布隆振动模型 代数模型 分子物理学 传输理论
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