Since the United Nations launched the Sustainable Development Goals(SDGs)in 2015,global implementation has steadily advanced,yet prominent challenges persist.Progress has been uneven across regions and countries,with ...Since the United Nations launched the Sustainable Development Goals(SDGs)in 2015,global implementation has steadily advanced,yet prominent challenges persist.Progress has been uneven across regions and countries,with Tajikistan representing a typical example of such disparities.Based on 81 SDG indicators for Tajikistan from 2001 to 2023,this study applied a three-level coupling network framework:at the microscale,it identified synergies and trade-offs between indicators;at the mesoscale,it examined the strength and direction of linkages within four SDG-related components(society,finance,governance,and environment);and at the global level,it focused on the overall SDG interlinkages.Spearman’s rank correlation,sliding window method,and topological properties were employed to analyze the coupling dynamics of SDGs.Results showed that over 70.00%of associations in the global SDG network were of medium-to-low intensity,alongside extremely strong ones(|r|value approached 1.00,where r is the correlation coefficient).SDG interactions were generally limited,with stable local synergy clusters in core livelihood sectors.Network modularity fluctuated,reflecting a cycle of differentiation,integration,and fragmentation,while coupling efficiency varied with the external environment.Each component exhibited distinct functional characteristics.The social component maintained high connectivity through the“poverty alleviation-education-healthcare”loop.The environmental component shifted toward coordinated eco-economic governance.The governance-related component broke interdepartmental barriers,while the financial component showed weak links between resource-based indicators and consumption/employment indicators.Tajikistan’s SDG coupling evolved through three phases:survival-oriented(2001–2012),policy integration(2013–2018),and shock adaptation(2019–2023).These phases were driven by policy changes,resource industries,governance optimization,and external factors.This study enriches the analytical framework for understanding the dynamic coupling of SDGs in mountainous resource-dependent countries and provides empirical evidence to support similar countries in formulating phase-specific SDG promotion strategies.展开更多
The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The ...The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The present study constructed the 2023Cross-City Patient Mobility Network in China using one million patient mobility data records obtained from online healthcare platforms. We applied urban network analysis to uncover mobility patterns and used the coupling coordination degree model to assess healthcare supply-demand relationships before and after patient mobility. Explainable machine learning further revealed the impact of supply-demand coupling on patient mobility. The results indicated the following: Patient mobility followed administrative boundaries, although megacities serve areas beyond provincial borders;The scale of healthcare supply and demand displayed a multi-centric spatial pattern with a general decline from east to west, and these characteristics of demand distribution were further solidified by patient mobility;Cities with low supply-demand coupling and undersupply experienced patient outflows, while cities with high coupling and oversupply attracted them. In turn, patient mobility helped balance healthcare supply and demand, optimising the coupling relationship across cities. Thus, this research not only provides a methodological reference for understanding the interaction between patient mobility and healthcare systems but also offers empirical insights for public health policy.展开更多
Within the prefrontal-cingulate cortex,abnormalities in coupling between neuronal networks can disturb the emotion-cognition interactions,contributing to the development of mental disorders such as depression.Despite ...Within the prefrontal-cingulate cortex,abnormalities in coupling between neuronal networks can disturb the emotion-cognition interactions,contributing to the development of mental disorders such as depression.Despite this understanding,the neural circuit mechanisms underlying this phenomenon remain elusive.In this study,we present a biophysical computational model encompassing three crucial regions,including the dorsolateral prefrontal cortex,subgenual anterior cingulate cortex,and ventromedial prefrontal cortex.The objective is to investigate the role of coupling relationships within the prefrontal-cingulate cortex networks in balancing emotions and cognitive processes.The numerical results confirm that coupled weights play a crucial role in the balance of emotional cognitive networks.Furthermore,our model predicts the pathogenic mechanism of depression resulting from abnormalities in the subgenual cortex,and network functionality was restored through intervention in the dorsolateral prefrontal cortex.This study utilizes computational modeling techniques to provide an insight explanation for the diagnosis and treatment of depression.展开更多
Climate change brings new challenges to the sustainable development of agriculture in the new era.Accurately grasping the patterns of climate change impacts on agricultural systems is crucial for ensuring agricultural...Climate change brings new challenges to the sustainable development of agriculture in the new era.Accurately grasping the patterns of climate change impacts on agricultural systems is crucial for ensuring agricultural sustainability and food security.Taking the Loess Plateau(LP),China as an example,this study used a coupling coordination degree model and spatial autocorrelation analysis to portray the spatial and temporal features of crop-cropland coupling relationship from 2000 to 2020 and explored the impact law of climate change through geographically and temporally weighted regression(GTWR).The results were as follows:1)the crop-cropland coupling coordination degree of the LP showed a gradual upward trend from 2000 to 2020,forming a spatial pattern with lower values in the central region and higher values in the surrounding areas.2)There was a positive correlation in the spatial distribution of cropcropland coupling coordination degree in the LP from 2000 to 2020,and the high value-low value(H-L)and low value-low value(L-L)agglomerations continued to expand eastward,while the spatial and temporal evolution of the high value-high value(H-H)and low value-high value(L-H)agglomerations was not obvious.3)The impacts of climatic elements on crop-cropland coupling coordination degree in the LP showed strong heterogeneity in time scales.The inhibitory impacts of summer days(SU)and frost days(FD)accounted for a higher proportion,while the annual average temperature(TEM)had both promoting and inhibiting impacts.The impacts proportion and intensity of extreme heavy precipitation day(R25),continuous drought days(CDD),and annual precipitation(PRE)all experienced significant changes.4)In space,the impacts of SU and FD on the crop-cropland coupling coordination degree varied with latitude and altitude.The adaptability of the LP to R25 gradually strengthened,and the extensions of CDD and increase of PRE led to the increasing inhibition beyond the eastern region of LP,and TEM showed a promoting impact in the Fenwei Plain.As an important grainproducing area in China,the LP should actively deal with the impacts of climate change on the crop-cropland coupling relationship,vigorously safeguard food security,and promote sustainable agricultural development.展开更多
This article reports 21 AFT （apatite fission track） data from the West Shandong （山东） rise （WSR） and Jiyang （济阳） depression, and mainly studies their Cenozoic uplifting/subsidence history and the relationsh...This article reports 21 AFT （apatite fission track） data from the West Shandong （山东） rise （WSR） and Jiyang （济阳） depression, and mainly studies their Cenozoic uplifting/subsidence history and the relationship between them. Furthermore, we improve our insights into the Bohai Bay Basin （BBB）. Our AFT analysis and AFT T-t modeling indicates that the WSR was uplifted at ca. 65 Ma with apparent uplift rate of 0.019 mm/a; it underwent two relatively rapid uplifting events at 43-33 and 16-0 Ma with rates of 0.097 and 0.052 mm/a, respectively. Meanwhile, the Jiyang depression subsided at rate of 0.032 mm/a at 52-43 Ma, and the rate increased to 0.13 mm/a at ca. 42-33 Ma; finally the subsidence rate increased to 0.053 mm/a in 16-0 Ma. They all underwent a uplift in time of 23-16 Ma with rate of 0.04-0.07 mm/a. A careful comparison shows that the Cenozoic uplifting of the WSR coupled well with the subsidence of the Jiyang depression. Our research also suggests that the uplift- basin coupling events are part of the couplings between the Bohai Bay Basin and its peripheral moun- tains. This intraplate mountain-basin coupling is a reflection of global tectonic events.展开更多
Several software network models are constructed based on the relationships between classes in the object-oriented software systems.Then,a variety of well-known open source software applications are statistically analy...Several software network models are constructed based on the relationships between classes in the object-oriented software systems.Then,a variety of well-known open source software applications are statistically analyzed by using these models.The results show that: (1) Dependency network does play a key role in software architecture;(2) The exponents of in-degree and total-degree distribution functions of different networks differ slightly,while the exponent of out-degree varies obviously;(3) Weak-coupling relationships have greater impact on software architecture than strong-coupling relationships.Finally,a theoretically analysis on these statistical phenomena is proposed from the perspectives of software develop technology,develop process and developer’s habits,respectively.展开更多
Depending on the analysis of the coeval sedimentary geometry and subsidence mechanism in the Longmen Shan foreland basin,three models about the coupling relationship between Longmen Shan uplift and foreland basin subs...Depending on the analysis of the coeval sedimentary geometry and subsidence mechanism in the Longmen Shan foreland basin,three models about the coupling relationship between Longmen Shan uplift and foreland basin subsidence since the Indosinian have been proposed:(1)crustal shortening and its related wide wedge-shaped foreland basin,(2)crustal isostatic rebound and its related tabular foreland basin,and(3)lower crustal flow and its related narrow wedge-shaped foreland basin.Based on the narrow wedge-shaped foreland basin developed since 4 Ma,it is believed that the narrow crustal shortening and tectonic load driven by lower crustal flow is a primary driver for the present Longmen Shan uplift and the Wenchuan(Ms 8.0)earthquake.展开更多
Based on the theory of sustainable development,using the theory and method of coupling relationship,the main city of Aiby Lake basin——Jinghe County in Xinjiang is selected. Based on the analyses of natural condition...Based on the theory of sustainable development,using the theory and method of coupling relationship,the main city of Aiby Lake basin——Jinghe County in Xinjiang is selected. Based on the analyses of natural condition,population growth,land use type and ecological environment,the comprehensive evaluation index systems of socio-economic development level and eco-environment quality in Jinghe County are constructed. Using principal component analysis,a comprehensive evaluation of socio-economic development level and ecological environment quality in Jinghe County is conducted by combining with Excel. Their coupling relationship is studied,and quantitative coordination degree between social economy and ecological environment in Jinghe County is obtained. The results show that in recent 50 years,socio-economic development level in Jinghe County is rising,but the ecological environment quality is falling. Their coupling degree C changes during [- 1. 260, ＋ 0. 482],in other words,their coupling relationship is changing between ＂ reluctant coordination＂ and ＂ not coordination＂. After entering into the 21 stcentury,their coupling relationship is basically ＂ reluctant coordination＂. On this basis,the existing problems in the process of sustainable development in Jinghe County are analyzed,and the suggestions about promoting coordinated development between social economy and ecological environment are put forward.展开更多
The 14th Five-Year Plan period is a critical period for China to achieve high-quality development. Based on super-efficiency slacks-based measure(SBM) model, grey-related analysis(GRA) and other models, this paper stu...The 14th Five-Year Plan period is a critical period for China to achieve high-quality development. Based on super-efficiency slacks-based measure(SBM) model, grey-related analysis(GRA) and other models, this paper studies the heterogeneity of the coupling relationship among technological innovation, industrial transformation and environmental efficiency in the Huaihai Economic Zone during the period of 2005-2019. In addition, it analyzes the coupling mechanism of single and binary systems to the ternary system, which is of great significance for the collaborative symbiosis among systems. The findings are as follows. 1) The technological innovation, industrial transformation and environmental efficiency(TIE) systems of the Huaihai Economic Zone had significant spatial-temporal heterogeneity. Although their evaluation value fluctuated, the development trends are all positive. Ultimately, technological innovation is characterized by being high in the northeast and low in the southwest around Xuzhou, while other systems are relatively staggered in space. 2) The coupling of TIE systems is in transition, lack of orderly integration and benign interaction. However, the developing trend of interaction is also upward, and a spatial pattern driven by Xuzhou and Linyi as the dual cores has gradually formed. Moreover, the coupling is mostly manifested as outdated technological innovation and industrial transformation. Except for the final coordination of regenerative cities, the other resource types are all in transition. Cities in all traffic locations are still in transition. The overall system interaction of cities on Longhai Line(Lanzhou-Lianyungang Railway) is relatively optimal, and cities on Xinshi Line(Xinxiang-Rizhao Railway) are accelerating toward synergy. 3) The coupling status of TIE systems depends on the development of the single system and the interaction of the binary(2E) system. The coupling is closely related to technological innovation and Technology-Industry system,and is hindered by the inefficient interaction of Technology-Environment system. Specifically, the synergy of regenerative cities is attributed to the advantage of a single system and the effective integration of 2E systems. Beneficial from the advantages of environmental efficiency, the cities on Xinshi Line promote the synergy of the 2E and TIE systems. Therefore, while the Huaihai Economic Zone stimulates the development potential of the single and 2E systems, it is necessary to amplify the superimposition effect of systems in accordance on the basis of resource and location.展开更多
Rural industrial development and ecological civilization transformation are crucial to China's comprehensive advancement of rural revitalization. However, many regions still face the issue of a conflict between ec...Rural industrial development and ecological civilization transformation are crucial to China's comprehensive advancement of rural revitalization. However, many regions still face the issue of a conflict between economic development and ecological protection. Symbiosis theory provides a new perspective for understanding the interactive relationship of rural industry and ecology(RIE). Jiangxi Province, one of China's first national pilot zones for ecological conservation, exemplifies rural areas' typical challenges in balancing industrial development and ecological protection, and has been selected as the study area. By integrating the characteristics of RIE with symbiosis theory, a comprehensive RIE assessment framework was constructed. The comprehensive model, spatial autocorrelation method, and symbiosis theory model were employed to address the spatio-temporal evolution characteristics of RIE, reveal the symbiotic relationship(SR) and the symbiosis types of RIE, and explore the path of symbiotic development between RIE. Results indicated that:(1) Since 2015, RIE has shown an upward trend, with regional differences in ecological development levels gradually shrinking. Significant spatial correlation and agglomeration characteristics exist, but a coordinated regional development pattern has not yet emerged.(2) Overall, the symbiosis degree(SD) between RIE showed a positive trend with narrowing gaps, the symbiosis coefficient(SC) of industry to ecology converged to 0.5 under a positive asymmetric mutualism(PAM) mode, suggesting that their relationship tended to be coordinated. Specifically, rural ecology grew increasingly influential on industry in most counties.(3) Rural areas were classified into different types led by industry-dominated PAM, and various optimization paths were proposed. Future efforts should promote the equalization of the interaction forces between RIE according to local conditions.展开更多
The Taihang Mountains in North China are an important carbon-water ecosystem service supply area.Understanding the coupling effect and influencing mechanisms of mountain carbon sequestration as well as water conservat...The Taihang Mountains in North China are an important carbon-water ecosystem service supply area.Understanding the coupling effect and influencing mechanisms of mountain carbon sequestration as well as water conservation is essential for regional eco-logical restoration and sustainable development.In this study,we utilized models such as the coupled coordination degree model,the random forest and Geodetector to analyze the spa-tio-temporal changes as well as driving factors of carbon sequestration-water conservation coupling coordination in the Taihang Mountains.The results show that:(1)From 1990 to 2020,the carbon sequestration and water conservation capacity of the Taihang Mountains exhibited a spatial pattern with higher values in the southeast and central regions,while lower values in the northwest region.(2)The average coupling coordination degree from 1990 to 2020 was O.23,which was overall low,with a fluctuating decreasing-rising-decreasing trend over time.The coupling coordination degree exhibited a pattern that is high in the middle and low in the periphery,with a fluctuating distribution that initially decreases and then increases with the increasing altitude.The overall trend of coupling coordination is degradation,with concen-trated degradation in the northwest mountainous regions.(3)Precipitation and soil texture were identified as the main driving factors influencing coupling coordination,with the interac-tion between precipitation and soil sand content showing the strongest explanatory power,while that among topography,vegetation and human activities had relatively low explanatory power.Therefore,enhanced protection and the continuous monitoring of vegetation and soil environments in the Taihang Mountains are essential,with particular emphasis on ecological restoration in areas experiencing a persistent degradation of carbon-water coupling.This study can provide assistance in monitoring and managing carbon sink and water resources in the mountains,meanwhile mitigating potential adverse impacts on human well-being.展开更多
The distribution of igneous rocks is closely related to hydrocarbon resources.This study utilized high-precision gravity,magnetic,and rock physical property data,employing gravity-magnetic field fusion technology and ...The distribution of igneous rocks is closely related to hydrocarbon resources.This study utilized high-precision gravity,magnetic,and rock physical property data,employing gravity-magnetic field fusion technology and Euler deconvolution technology.The objective was to identify the distribution of igneous rocks in the China Seas and neighboring regions and investigate their relationships with petroliferous basins.Our results reveal that igneous rocks are widely scattered throughout the China Seas and neighboring regions,with the highest concentration in the northwest(NW)and the second highest concentration in the east-northeast(ENE).The largest-scale igneous rocks are those with a north-south(N-S)orientation,followed by those with northeast(NE),NW,and ENE orientations.The depths of igneous rocks within petroliferous basins typically range from 3 km to 9 km and are associated with hydrocarbon resource distributions characterized by deep oil and shallow gas.The proportions of igneous rocks in different types of basins exhibit varying correlations with the total hydrocarbon resources.In particular,the proportion of igneous rocks in rift-type basins in the China Seas exhibits a strong linear correlation with the total hydrocarbon resources.These research findings provide valuable guidance for studying the relationship between igneous rock distribution and petroliferous basins,offering insights that can inform future hydrocarbon exploration endeavors.展开更多
This study investigates the coupling and coordination relationship between tourism industry development and the level of green consumption across 30 provinces in China's mainland(excluding Xizang).An analytical fr...This study investigates the coupling and coordination relationship between tourism industry development and the level of green consumption across 30 provinces in China's mainland(excluding Xizang).An analytical framework for evaluating the coupling and coordination between tourism development and green consumption is constructed,employing a modified coupling model and exploratory spatial analysis to examine their interactive dynamics as well as their spatiotemporal characteristics.The findings indicate that:(1)From 2011 to 2022,the national level of tourism development exhibited wave-like growth,while the overall level of green consumption remained stable.Significant regional disparities exist between the two,presenting a spatial pattern of“higher in the east and lower in the west.”(2)The coupling coordination degree between the two systems increased steadily from 0.562 to 0.604,reaching an overall coordinated state.A non-equilibrium pattern has emerged,characterized by“leading in the eastern region,catching up in the central region,improving in the western region,and under pressure in the northeastern region.”Inter-provincial differences remain evident but show signs of convergence.(3)Five major influencing factors-energy consumption,urbanization,population size,transportation infrastructure,and government regulation-exhibit significant spatiotemporal heterogeneity,with their effects showing clear regional adaptability in both magnitude and direction.Based on these findings,it is recommended to promote regionally differentiated development strategies,strengthen cross-provincial coordination mechanisms,and implement precise regulatory policies aligned with local development stages to foster high-level coordination between tourism development and green consumption.展开更多
At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascert...At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascertain its potential development of gas hydrates. This paper reviewed pertinent literature on gas hydrates in the Tibetan Plateau. Both geological and ge- ographical data are synthesized to reveal the relationship between gas hydrate formation and petroleum geological evo- lution, Plateau uplift, formation of permafrost, and glacial processes. Previous studies indicate that numerous residual basins in the Plateau have been formed by original sedimentary basins accompanied by rapid uplift of the Plateau. Ex- tensive marine Mesozoic hydrocarbon source rocks in these basins could provide rich sources of materials forming gas hydrates in permafrost. Primary hydrocarbon-generating period in the Plateau is from late Jurassic to early Cretaceous, while secondary hydrocarbon generation, regionally or locally, occurs mainly in the Paleogene. Before rapid uplift of the Plateau, oil-gas reservoirs were continuously destroyed and assembled to form new reservoirs due to structural and thermal dynamics, forcing hydrocarbon migration. Since 3.4 Ma B.P., the Plateau has undergone strong uplift and extensive gla- ciation, periglacier processes prevailed, hydrocarbon gas again migrated, and free gas beneath ice sheets within sedi- mentary materials interacted with water, generating gas hydrates which were finally preserved under a cap formed by frozen layers through rapid cooling in the Plateau. Taken as a whole, it can be safely concluded that there is great temporal and spatial coupling relationships between evolution of the Tibetan Plateau and generation of gas hydrates.展开更多
Due to the interactions among coupled spatio-temporal subsystems and the constant bias term of affine chaos, it is difficult to achieve tracking control for the affine coupled spatiotemporal chaos. However, every subs...Due to the interactions among coupled spatio-temporal subsystems and the constant bias term of affine chaos, it is difficult to achieve tracking control for the affine coupled spatiotemporal chaos. However, every subsystem of the affine coupled spatio-temporal chaos can be approximated by a set of fuzzy models; every fuzzy model represents a linearized model of the subsystem corresponding to the operating point of the controlled system. Because the consequent parts of the fuzzy models have a constant bias term, it is very difficult to achieve tracking control for the affine system. Based on these fuzzy models, considering the affine constant bias term, an H∞ fuzzy tracking control scheme is proposed. A linear matrix inequality is employed to represent the feedback controller, and parameters of the controller are achieved by convex optimization techniques. The tracking control for the affine coupled spatio-temporal chaos is achieved, and the stability of the system is also guaranteed. The tracking performances are testified by simulation examples.展开更多
There is a certain coupling relationship among the main circuit parameters of a single-phase shunt active power filter(SAPF),which has a great influence on the reasonable selection of various parameter values.By analy...There is a certain coupling relationship among the main circuit parameters of a single-phase shunt active power filter(SAPF),which has a great influence on the reasonable selection of various parameter values.By analyzing the calculation methods of the inductance of alternating current(AC)side and the voltage and capacitance values of direct current(DC)side in the existing single/three-phase SAPF main circuit,a specific single-phase SAPF circuit parameter analytical expression was obtained.Aiming at the coupling relationship among the variables in the resulting expression,the model was optimized and analyzed in MATLAB,and a complete set of parameters design scheme was obtained,which ensure the comprehensive optimization target of the post-harmonic content below 2%is compensated under a specific load.The simulation and experimental procedures verify the correctness of the selected parameters.展开更多
Spatio-temporal relationship of the phytophagons Clania miniscula （Butler） and garden spiders was examined through analysis of their niche and distribution as they occur in sasanqua orchard in Southern Anhui, China ...Spatio-temporal relationship of the phytophagons Clania miniscula （Butler） and garden spiders was examined through analysis of their niche and distribution as they occur in sasanqua orchard in Southern Anhui, China from June 2003 to May 2004. The dynamic relationships between Clania minuscula and garden spiders were seasonal in time and space. Spatio-temporal niche breadth was high for the two groups, ranging from 0.57 to 0.98; niche overlap was also high between the two groups from 0.76 to 0.96 during the seasons of June 2003 to May 2004. Geostatistical results indicated that Clania minuscula and garden spiders were aggregated during the emergence periods. The pest Clania minuscula was spatially dependent to a range from 33.48 to 46.84 m while spatial dependence from 30.93 to 51.11 m for garden spiders. The correlation analysis of distribution maps further illustrate the distribution of garden spiders always coincided with that of Clania minuscula. These results showed spatio-temporal synchrony of Clania minuscula and garden spiders at different periods. Adequate knowledge of spatio-temporal correlation between Clania minuscula and garden spiders contributed to provide information for biocontrol at different periods in sasanqua orchard.展开更多
Oligocene(fan)delta-associated coal measures and marine source rocks are the main gas-generating source rocks in the Qiongdongnan Basin,and(fan)delta sand bodies are the dominant types of reservoirs.By comprehensively...Oligocene(fan)delta-associated coal measures and marine source rocks are the main gas-generating source rocks in the Qiongdongnan Basin,and(fan)delta sand bodies are the dominant types of reservoirs.By comprehensively utilizing a large amount of 2D and 3D seismic data and new drilling data,the distribution of(fan)deltas and three types of Oligocene fault fan systems were systematically identified;these are thought to have had joint control over the development of hydrocarbon source rocks and reservoirs.The three types of Oligocene fault fan coupling relationships in the Qiongdongnan Basin were found to be fault bend,fault gully,and fault tip.The fault bend type of(fan)delta developed at the bend of the fault and was distributed in the downthrown block of Fault Nos.5 and 2.The fault tip type developed where the fault died out toward the source direction and was distributed near the eastewest faults on the north and south sides of Baodao and Changchang Sags.The fault gully type developed along the fault trend in the downthrown block and was mainly distributed in areas including the northern part of Ya'nan Sag and the Fault No.3 downthrown block.The fault bend(fan)delta is surrounded by a relatively closed bay environment,and the terrigenously dominated marine source rocks in the still water bay environment were developed with a high hydrocarbon generation index and high hydrocarbon generation potential.Fault tip and fault gully types of(fan)delta plain facies have a wide distribution of plain subfacies,which is conducive to the development of coal-measure source rocks that have excellent gas potential.During sedimentation of the fault gully and the fault tip delta,the terrain was relatively flat,with sand bodies strongly reworked by hydrodynamic force;the reservoir quality of the sand bodies in the underwater distributary channel and estuary dam are good,and the sand bodies have wide distribution.The sand bodies of the fault bend type of(fan)delta were deposited rapidly near the source kitchen,and the degree of sorting and rounding was poor,which resulted in the poor physical properties of the plain subfacies.In the southern and northern step-fault zones of Baodao Sag in the eastern part of this basin,the fault bend,fault tip,and fault trench(fan)deltas were inherited and further developed,and the source-reservoir configuration conditions were favorable.Exploration deployment was carried out in the Baodao 21 area in the northern step-fault zone and the Yongle 10 area in the southern step-fault zone,where new discoveries in natural gas exploration have been realized.In the eastern part of this basin,the fault bend,fault tip,and fault gully(fan)deltas in the southern and northern fault step zones of Baodao Sag were successively developed,which were beneficial for favorable sourceereservoir configuration conditions.The natural gas exploration successes in the Baodao-21 area in the northern fault step zone and the Yongle-10 area in the southern fault step zone are beneficial for new discoveries in natural gas exploration in the Qiongdongnan Basin.展开更多
The spatio-temporal variability of Northern Hemisphere Sea Level Pressure （SLP） and precipitation over the mid-to-low reaches of the Yangtze River （PMLY） is analyzed jointly using the multi-taper/singular value de...The spatio-temporal variability of Northern Hemisphere Sea Level Pressure （SLP） and precipitation over the mid-to-low reaches of the Yangtze River （PMLY） is analyzed jointly using the multi-taper/singular value decomposition method （MTM-SVD）. Statistically significant narrow frequency bands are obtained from the local fractional variance （LFV） spectrum. Significant interdecadal （i.e., 16-to-18-year periods） and interannual （i.e., 3-to-6-year periods） signals are identified. Moreover, a significant quasi-biennial signal is identified but only for PMLY data. The spatial joint evolution of patterns obtained for peaks in the LFV spectrum sheds light on relationships between SLP and PMLY： the Arctic Oscillation （AO） modulates the variability of the PMLY while the interannual variability of PMLY is in phase with the Northern Atlantic Oscillation （NAO） and the Northern Pacific Oscillation （NPO）.展开更多
For mankind’s survival and development,water,energy,and food(WEF)are essential material guarantees.In China,however,the spatial distribution of WEF is seriously unbalanced and mismatched.Here,a collaborative governan...For mankind’s survival and development,water,energy,and food(WEF)are essential material guarantees.In China,however,the spatial distribution of WEF is seriously unbalanced and mismatched.Here,a collaborative governance mechanism that aims at nexus security needs to be urgently established.In this paper,the Yellow River Basin in China with a representative WEF system,was selected as a case.Firstly,a comprehensive framework for WEF coupling coordination was constructed,and the relationship and mechanism between them were analyzed theoretically.Then,we investigated the spatiotemporal characteristics and driving mechanisms of the coupling coordination degree(CCD)with a composite evaluation method,coupling coordination degree model,spatial statistical analysis,and multiscale geographic weighted regression.Finally,policy implications were discussed to promote the coordinated development of the WEF system.The results showed that:1)WEF subsystems showed a significant imbalance of spatial pattern and diversity in temporal changes;2)the CCD for the WEF system varied little and remained at moderate coordination.Areas with moderate coordination have increased,while areas with superior coordination and mild disorder have decreased.In addition,the spatial clustering phenomenon of the CCD was significant and showed obvious characteristics of polarization;and 3)the action of each factor is self-differentiated and regionally variable.For different factors,GDP per capita was of particular importance,which contributed most to the regional development’s coupling coordination.For different regions,GDP per capita,average yearly precipitation,population density,and urbanization rate exhibited differences in geographical gradients in an east-west direction.The conclusion can provide references for regional resource allocation and sustainable development by enhancing WEF system utilization efficiency.展开更多
文摘Since the United Nations launched the Sustainable Development Goals(SDGs)in 2015,global implementation has steadily advanced,yet prominent challenges persist.Progress has been uneven across regions and countries,with Tajikistan representing a typical example of such disparities.Based on 81 SDG indicators for Tajikistan from 2001 to 2023,this study applied a three-level coupling network framework:at the microscale,it identified synergies and trade-offs between indicators;at the mesoscale,it examined the strength and direction of linkages within four SDG-related components(society,finance,governance,and environment);and at the global level,it focused on the overall SDG interlinkages.Spearman’s rank correlation,sliding window method,and topological properties were employed to analyze the coupling dynamics of SDGs.Results showed that over 70.00%of associations in the global SDG network were of medium-to-low intensity,alongside extremely strong ones(|r|value approached 1.00,where r is the correlation coefficient).SDG interactions were generally limited,with stable local synergy clusters in core livelihood sectors.Network modularity fluctuated,reflecting a cycle of differentiation,integration,and fragmentation,while coupling efficiency varied with the external environment.Each component exhibited distinct functional characteristics.The social component maintained high connectivity through the“poverty alleviation-education-healthcare”loop.The environmental component shifted toward coordinated eco-economic governance.The governance-related component broke interdepartmental barriers,while the financial component showed weak links between resource-based indicators and consumption/employment indicators.Tajikistan’s SDG coupling evolved through three phases:survival-oriented(2001–2012),policy integration(2013–2018),and shock adaptation(2019–2023).These phases were driven by policy changes,resource industries,governance optimization,and external factors.This study enriches the analytical framework for understanding the dynamic coupling of SDGs in mountainous resource-dependent countries and provides empirical evidence to support similar countries in formulating phase-specific SDG promotion strategies.
基金Humanities and Social Sciences Fund of Ministry of Education of China,No.24YJA630097National Natural Science Foundation of China,No.42471304。
文摘The uneven distribution of medical resources has led to increasingly frequent patient mobility;however, the interaction between this phenomenon and the healthcare supply-demand relationship remains underexplored. The present study constructed the 2023Cross-City Patient Mobility Network in China using one million patient mobility data records obtained from online healthcare platforms. We applied urban network analysis to uncover mobility patterns and used the coupling coordination degree model to assess healthcare supply-demand relationships before and after patient mobility. Explainable machine learning further revealed the impact of supply-demand coupling on patient mobility. The results indicated the following: Patient mobility followed administrative boundaries, although megacities serve areas beyond provincial borders;The scale of healthcare supply and demand displayed a multi-centric spatial pattern with a general decline from east to west, and these characteristics of demand distribution were further solidified by patient mobility;Cities with low supply-demand coupling and undersupply experienced patient outflows, while cities with high coupling and oversupply attracted them. In turn, patient mobility helped balance healthcare supply and demand, optimising the coupling relationship across cities. Thus, this research not only provides a methodological reference for understanding the interaction between patient mobility and healthcare systems but also offers empirical insights for public health policy.
基金supported by the Major Research Instrument Development Project of the National Natural Science Foundation of China(82327810)the Foundation of the President of Hebei University(XZJJ202202)the Hebei Province“333 talent project”(A202101058).
文摘Within the prefrontal-cingulate cortex,abnormalities in coupling between neuronal networks can disturb the emotion-cognition interactions,contributing to the development of mental disorders such as depression.Despite this understanding,the neural circuit mechanisms underlying this phenomenon remain elusive.In this study,we present a biophysical computational model encompassing three crucial regions,including the dorsolateral prefrontal cortex,subgenual anterior cingulate cortex,and ventromedial prefrontal cortex.The objective is to investigate the role of coupling relationships within the prefrontal-cingulate cortex networks in balancing emotions and cognitive processes.The numerical results confirm that coupled weights play a crucial role in the balance of emotional cognitive networks.Furthermore,our model predicts the pathogenic mechanism of depression resulting from abnormalities in the subgenual cortex,and network functionality was restored through intervention in the dorsolateral prefrontal cortex.This study utilizes computational modeling techniques to provide an insight explanation for the diagnosis and treatment of depression.
基金Under the auspices of Major Program of National Natural Science Foundation of China(No.42293271)Alliance of International Science Organizations(No.ANSO-PA-2023-16)。
文摘Climate change brings new challenges to the sustainable development of agriculture in the new era.Accurately grasping the patterns of climate change impacts on agricultural systems is crucial for ensuring agricultural sustainability and food security.Taking the Loess Plateau(LP),China as an example,this study used a coupling coordination degree model and spatial autocorrelation analysis to portray the spatial and temporal features of crop-cropland coupling relationship from 2000 to 2020 and explored the impact law of climate change through geographically and temporally weighted regression(GTWR).The results were as follows:1)the crop-cropland coupling coordination degree of the LP showed a gradual upward trend from 2000 to 2020,forming a spatial pattern with lower values in the central region and higher values in the surrounding areas.2)There was a positive correlation in the spatial distribution of cropcropland coupling coordination degree in the LP from 2000 to 2020,and the high value-low value(H-L)and low value-low value(L-L)agglomerations continued to expand eastward,while the spatial and temporal evolution of the high value-high value(H-H)and low value-high value(L-H)agglomerations was not obvious.3)The impacts of climatic elements on crop-cropland coupling coordination degree in the LP showed strong heterogeneity in time scales.The inhibitory impacts of summer days(SU)and frost days(FD)accounted for a higher proportion,while the annual average temperature(TEM)had both promoting and inhibiting impacts.The impacts proportion and intensity of extreme heavy precipitation day(R25),continuous drought days(CDD),and annual precipitation(PRE)all experienced significant changes.4)In space,the impacts of SU and FD on the crop-cropland coupling coordination degree varied with latitude and altitude.The adaptability of the LP to R25 gradually strengthened,and the extensions of CDD and increase of PRE led to the increasing inhibition beyond the eastern region of LP,and TEM showed a promoting impact in the Fenwei Plain.As an important grainproducing area in China,the LP should actively deal with the impacts of climate change on the crop-cropland coupling relationship,vigorously safeguard food security,and promote sustainable agricultural development.
基金supported by the National Natural Science Foundation of China(No.40772132)
文摘This article reports 21 AFT （apatite fission track） data from the West Shandong （山东） rise （WSR） and Jiyang （济阳） depression, and mainly studies their Cenozoic uplifting/subsidence history and the relationship between them. Furthermore, we improve our insights into the Bohai Bay Basin （BBB）. Our AFT analysis and AFT T-t modeling indicates that the WSR was uplifted at ca. 65 Ma with apparent uplift rate of 0.019 mm/a; it underwent two relatively rapid uplifting events at 43-33 and 16-0 Ma with rates of 0.097 and 0.052 mm/a, respectively. Meanwhile, the Jiyang depression subsided at rate of 0.032 mm/a at 52-43 Ma, and the rate increased to 0.13 mm/a at ca. 42-33 Ma; finally the subsidence rate increased to 0.053 mm/a in 16-0 Ma. They all underwent a uplift in time of 23-16 Ma with rate of 0.04-0.07 mm/a. A careful comparison shows that the Cenozoic uplifting of the WSR coupled well with the subsidence of the Jiyang depression. Our research also suggests that the uplift- basin coupling events are part of the couplings between the Bohai Bay Basin and its peripheral moun- tains. This intraplate mountain-basin coupling is a reflection of global tectonic events.
基金The paper is supported by the National High Technology Research and Development Program of China （863 Program） （No.2009AA01Z439） and the National Natural Science Foundation of China （U0835001）
文摘Several software network models are constructed based on the relationships between classes in the object-oriented software systems.Then,a variety of well-known open source software applications are statistically analyzed by using these models.The results show that: (1) Dependency network does play a key role in software architecture;(2) The exponents of in-degree and total-degree distribution functions of different networks differ slightly,while the exponent of out-degree varies obviously;(3) Weak-coupling relationships have greater impact on software architecture than strong-coupling relationships.Finally,a theoretically analysis on these statistical phenomena is proposed from the perspectives of software develop technology,develop process and developer’s habits,respectively.
基金funded by China National Natural Science Foundation(No:41372114,41502116,41340005,40841010,40972083,41172162,and 41402159)geological survey from China Geological Survey(No:121201010000150004–08 and 12120115004501–01)the project of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation(No:SK–0801)
文摘Depending on the analysis of the coeval sedimentary geometry and subsidence mechanism in the Longmen Shan foreland basin,three models about the coupling relationship between Longmen Shan uplift and foreland basin subsidence since the Indosinian have been proposed:(1)crustal shortening and its related wide wedge-shaped foreland basin,(2)crustal isostatic rebound and its related tabular foreland basin,and(3)lower crustal flow and its related narrow wedge-shaped foreland basin.Based on the narrow wedge-shaped foreland basin developed since 4 Ma,it is believed that the narrow crustal shortening and tectonic load driven by lower crustal flow is a primary driver for the present Longmen Shan uplift and the Wenchuan(Ms 8.0)earthquake.
基金Supported by Natural Science Fund of Xinjiang Uygur Autonomous Region,China(2011211B18)
文摘Based on the theory of sustainable development,using the theory and method of coupling relationship,the main city of Aiby Lake basin——Jinghe County in Xinjiang is selected. Based on the analyses of natural condition,population growth,land use type and ecological environment,the comprehensive evaluation index systems of socio-economic development level and eco-environment quality in Jinghe County are constructed. Using principal component analysis,a comprehensive evaluation of socio-economic development level and ecological environment quality in Jinghe County is conducted by combining with Excel. Their coupling relationship is studied,and quantitative coordination degree between social economy and ecological environment in Jinghe County is obtained. The results show that in recent 50 years,socio-economic development level in Jinghe County is rising,but the ecological environment quality is falling. Their coupling degree C changes during [- 1. 260, ＋ 0. 482],in other words,their coupling relationship is changing between ＂ reluctant coordination＂ and ＂ not coordination＂. After entering into the 21 stcentury,their coupling relationship is basically ＂ reluctant coordination＂. On this basis,the existing problems in the process of sustainable development in Jinghe County are analyzed,and the suggestions about promoting coordinated development between social economy and ecological environment are put forward.
基金Under the auspices of National Natural Science Foundation of China(No.41971158)National Social Science Foundation of China(No.20BJL106)+1 种基金Cultural Experts and Four batches Talents Independently Selected Topic Project(No.ZXGZ[2018]86)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_0357)。
文摘The 14th Five-Year Plan period is a critical period for China to achieve high-quality development. Based on super-efficiency slacks-based measure(SBM) model, grey-related analysis(GRA) and other models, this paper studies the heterogeneity of the coupling relationship among technological innovation, industrial transformation and environmental efficiency in the Huaihai Economic Zone during the period of 2005-2019. In addition, it analyzes the coupling mechanism of single and binary systems to the ternary system, which is of great significance for the collaborative symbiosis among systems. The findings are as follows. 1) The technological innovation, industrial transformation and environmental efficiency(TIE) systems of the Huaihai Economic Zone had significant spatial-temporal heterogeneity. Although their evaluation value fluctuated, the development trends are all positive. Ultimately, technological innovation is characterized by being high in the northeast and low in the southwest around Xuzhou, while other systems are relatively staggered in space. 2) The coupling of TIE systems is in transition, lack of orderly integration and benign interaction. However, the developing trend of interaction is also upward, and a spatial pattern driven by Xuzhou and Linyi as the dual cores has gradually formed. Moreover, the coupling is mostly manifested as outdated technological innovation and industrial transformation. Except for the final coordination of regenerative cities, the other resource types are all in transition. Cities in all traffic locations are still in transition. The overall system interaction of cities on Longhai Line(Lanzhou-Lianyungang Railway) is relatively optimal, and cities on Xinshi Line(Xinxiang-Rizhao Railway) are accelerating toward synergy. 3) The coupling status of TIE systems depends on the development of the single system and the interaction of the binary(2E) system. The coupling is closely related to technological innovation and Technology-Industry system,and is hindered by the inefficient interaction of Technology-Environment system. Specifically, the synergy of regenerative cities is attributed to the advantage of a single system and the effective integration of 2E systems. Beneficial from the advantages of environmental efficiency, the cities on Xinshi Line promote the synergy of the 2E and TIE systems. Therefore, while the Huaihai Economic Zone stimulates the development potential of the single and 2E systems, it is necessary to amplify the superimposition effect of systems in accordance on the basis of resource and location.
基金supported by the National Natural Science Foundation of China (No.42361050,42201232)Humanities and Social Sciences Research Project of Jiangxi Colleges and Universities (No.JC24211)+1 种基金Science and Technology Research Project of Jiangxi Provincial Department of Education (No.GJJ2200553)Jiangxi provincial Social Science Foundation of China (No.23JL11)。
文摘Rural industrial development and ecological civilization transformation are crucial to China's comprehensive advancement of rural revitalization. However, many regions still face the issue of a conflict between economic development and ecological protection. Symbiosis theory provides a new perspective for understanding the interactive relationship of rural industry and ecology(RIE). Jiangxi Province, one of China's first national pilot zones for ecological conservation, exemplifies rural areas' typical challenges in balancing industrial development and ecological protection, and has been selected as the study area. By integrating the characteristics of RIE with symbiosis theory, a comprehensive RIE assessment framework was constructed. The comprehensive model, spatial autocorrelation method, and symbiosis theory model were employed to address the spatio-temporal evolution characteristics of RIE, reveal the symbiotic relationship(SR) and the symbiosis types of RIE, and explore the path of symbiotic development between RIE. Results indicated that:(1) Since 2015, RIE has shown an upward trend, with regional differences in ecological development levels gradually shrinking. Significant spatial correlation and agglomeration characteristics exist, but a coordinated regional development pattern has not yet emerged.(2) Overall, the symbiosis degree(SD) between RIE showed a positive trend with narrowing gaps, the symbiosis coefficient(SC) of industry to ecology converged to 0.5 under a positive asymmetric mutualism(PAM) mode, suggesting that their relationship tended to be coordinated. Specifically, rural ecology grew increasingly influential on industry in most counties.(3) Rural areas were classified into different types led by industry-dominated PAM, and various optimization paths were proposed. Future efforts should promote the equalization of the interaction forces between RIE according to local conditions.
基金Special Program for Survey of National Basic Scientific and Technological Resources,No.2021FY00802。
文摘The Taihang Mountains in North China are an important carbon-water ecosystem service supply area.Understanding the coupling effect and influencing mechanisms of mountain carbon sequestration as well as water conservation is essential for regional eco-logical restoration and sustainable development.In this study,we utilized models such as the coupled coordination degree model,the random forest and Geodetector to analyze the spa-tio-temporal changes as well as driving factors of carbon sequestration-water conservation coupling coordination in the Taihang Mountains.The results show that:(1)From 1990 to 2020,the carbon sequestration and water conservation capacity of the Taihang Mountains exhibited a spatial pattern with higher values in the southeast and central regions,while lower values in the northwest region.(2)The average coupling coordination degree from 1990 to 2020 was O.23,which was overall low,with a fluctuating decreasing-rising-decreasing trend over time.The coupling coordination degree exhibited a pattern that is high in the middle and low in the periphery,with a fluctuating distribution that initially decreases and then increases with the increasing altitude.The overall trend of coupling coordination is degradation,with concen-trated degradation in the northwest mountainous regions.(3)Precipitation and soil texture were identified as the main driving factors influencing coupling coordination,with the interac-tion between precipitation and soil sand content showing the strongest explanatory power,while that among topography,vegetation and human activities had relatively low explanatory power.Therefore,enhanced protection and the continuous monitoring of vegetation and soil environments in the Taihang Mountains are essential,with particular emphasis on ecological restoration in areas experiencing a persistent degradation of carbon-water coupling.This study can provide assistance in monitoring and managing carbon sink and water resources in the mountains,meanwhile mitigating potential adverse impacts on human well-being.
基金The National Key Research and Development Program of China under contract No.2017YFC0602202.
文摘The distribution of igneous rocks is closely related to hydrocarbon resources.This study utilized high-precision gravity,magnetic,and rock physical property data,employing gravity-magnetic field fusion technology and Euler deconvolution technology.The objective was to identify the distribution of igneous rocks in the China Seas and neighboring regions and investigate their relationships with petroliferous basins.Our results reveal that igneous rocks are widely scattered throughout the China Seas and neighboring regions,with the highest concentration in the northwest(NW)and the second highest concentration in the east-northeast(ENE).The largest-scale igneous rocks are those with a north-south(N-S)orientation,followed by those with northeast(NE),NW,and ENE orientations.The depths of igneous rocks within petroliferous basins typically range from 3 km to 9 km and are associated with hydrocarbon resource distributions characterized by deep oil and shallow gas.The proportions of igneous rocks in different types of basins exhibit varying correlations with the total hydrocarbon resources.In particular,the proportion of igneous rocks in rift-type basins in the China Seas exhibits a strong linear correlation with the total hydrocarbon resources.These research findings provide valuable guidance for studying the relationship between igneous rock distribution and petroliferous basins,offering insights that can inform future hydrocarbon exploration endeavors.
基金supported by the National Social Science Fund of China(Grant No.23BJY142).
文摘This study investigates the coupling and coordination relationship between tourism industry development and the level of green consumption across 30 provinces in China's mainland(excluding Xizang).An analytical framework for evaluating the coupling and coordination between tourism development and green consumption is constructed,employing a modified coupling model and exploratory spatial analysis to examine their interactive dynamics as well as their spatiotemporal characteristics.The findings indicate that:(1)From 2011 to 2022,the national level of tourism development exhibited wave-like growth,while the overall level of green consumption remained stable.Significant regional disparities exist between the two,presenting a spatial pattern of“higher in the east and lower in the west.”(2)The coupling coordination degree between the two systems increased steadily from 0.562 to 0.604,reaching an overall coordinated state.A non-equilibrium pattern has emerged,characterized by“leading in the eastern region,catching up in the central region,improving in the western region,and under pressure in the northeastern region.”Inter-provincial differences remain evident but show signs of convergence.(3)Five major influencing factors-energy consumption,urbanization,population size,transportation infrastructure,and government regulation-exhibit significant spatiotemporal heterogeneity,with their effects showing clear regional adaptability in both magnitude and direction.Based on these findings,it is recommended to promote regionally differentiated development strategies,strengthen cross-provincial coordination mechanisms,and implement precise regulatory policies aligned with local development stages to foster high-level coordination between tourism development and green consumption.
基金supported by Re-search Project No.200420140001 of China Geological Survey
文摘At present, gas hydrates are known to occur in continental high latitude permafrost regions and deep sea sediments. For middle latitude permafrost regions of the Tibetan Plateau, further research is required to ascertain its potential development of gas hydrates. This paper reviewed pertinent literature on gas hydrates in the Tibetan Plateau. Both geological and ge- ographical data are synthesized to reveal the relationship between gas hydrate formation and petroleum geological evo- lution, Plateau uplift, formation of permafrost, and glacial processes. Previous studies indicate that numerous residual basins in the Plateau have been formed by original sedimentary basins accompanied by rapid uplift of the Plateau. Ex- tensive marine Mesozoic hydrocarbon source rocks in these basins could provide rich sources of materials forming gas hydrates in permafrost. Primary hydrocarbon-generating period in the Plateau is from late Jurassic to early Cretaceous, while secondary hydrocarbon generation, regionally or locally, occurs mainly in the Paleogene. Before rapid uplift of the Plateau, oil-gas reservoirs were continuously destroyed and assembled to form new reservoirs due to structural and thermal dynamics, forcing hydrocarbon migration. Since 3.4 Ma B.P., the Plateau has undergone strong uplift and extensive gla- ciation, periglacier processes prevailed, hydrocarbon gas again migrated, and free gas beneath ice sheets within sedi- mentary materials interacted with water, generating gas hydrates which were finally preserved under a cap formed by frozen layers through rapid cooling in the Plateau. Taken as a whole, it can be safely concluded that there is great temporal and spatial coupling relationships between evolution of the Tibetan Plateau and generation of gas hydrates.
文摘Due to the interactions among coupled spatio-temporal subsystems and the constant bias term of affine chaos, it is difficult to achieve tracking control for the affine coupled spatiotemporal chaos. However, every subsystem of the affine coupled spatio-temporal chaos can be approximated by a set of fuzzy models; every fuzzy model represents a linearized model of the subsystem corresponding to the operating point of the controlled system. Because the consequent parts of the fuzzy models have a constant bias term, it is very difficult to achieve tracking control for the affine system. Based on these fuzzy models, considering the affine constant bias term, an H∞ fuzzy tracking control scheme is proposed. A linear matrix inequality is employed to represent the feedback controller, and parameters of the controller are achieved by convex optimization techniques. The tracking control for the affine coupled spatio-temporal chaos is achieved, and the stability of the system is also guaranteed. The tracking performances are testified by simulation examples.
基金National Natural Science Foundation of China(No.51367010)Science and Technology Program of Gansu Province(No.17JR5RA083)+2 种基金Natural Science Foundation of Gansu Province(No.1610RJZA042)Program for Excellent Team of Scientific Research in Lanzhou Jiaotong University(No.201701)Scientific Research Program of Colleges and Universities in Gansu Province(No.2016B-032)。
文摘There is a certain coupling relationship among the main circuit parameters of a single-phase shunt active power filter(SAPF),which has a great influence on the reasonable selection of various parameter values.By analyzing the calculation methods of the inductance of alternating current(AC)side and the voltage and capacitance values of direct current(DC)side in the existing single/three-phase SAPF main circuit,a specific single-phase SAPF circuit parameter analytical expression was obtained.Aiming at the coupling relationship among the variables in the resulting expression,the model was optimized and analyzed in MATLAB,and a complete set of parameters design scheme was obtained,which ensure the comprehensive optimization target of the post-harmonic content below 2%is compensated under a specific load.The simulation and experimental procedures verify the correctness of the selected parameters.
基金This work was supported by Natural Science Foundation of Anhui Province Office of Education （No.2002kj 101）.
文摘Spatio-temporal relationship of the phytophagons Clania miniscula （Butler） and garden spiders was examined through analysis of their niche and distribution as they occur in sasanqua orchard in Southern Anhui, China from June 2003 to May 2004. The dynamic relationships between Clania minuscula and garden spiders were seasonal in time and space. Spatio-temporal niche breadth was high for the two groups, ranging from 0.57 to 0.98; niche overlap was also high between the two groups from 0.76 to 0.96 during the seasons of June 2003 to May 2004. Geostatistical results indicated that Clania minuscula and garden spiders were aggregated during the emergence periods. The pest Clania minuscula was spatially dependent to a range from 33.48 to 46.84 m while spatial dependence from 30.93 to 51.11 m for garden spiders. The correlation analysis of distribution maps further illustrate the distribution of garden spiders always coincided with that of Clania minuscula. These results showed spatio-temporal synchrony of Clania minuscula and garden spiders at different periods. Adequate knowledge of spatio-temporal correlation between Clania minuscula and garden spiders contributed to provide information for biocontrol at different periods in sasanqua orchard.
基金funded by the National Natural Science Foundation of China under contract number 91528303the National Science and Technology Major Project under contract numbers 2016ZX05026,2011ZX05025,and 2008ZX05025+1 种基金the National Basic Research Program(973 Program)of China under contract number 2009CB219400the Science and Technology Project of China National Offshore Oil Corporation under contract number KJGG2022-0101.
文摘Oligocene(fan)delta-associated coal measures and marine source rocks are the main gas-generating source rocks in the Qiongdongnan Basin,and(fan)delta sand bodies are the dominant types of reservoirs.By comprehensively utilizing a large amount of 2D and 3D seismic data and new drilling data,the distribution of(fan)deltas and three types of Oligocene fault fan systems were systematically identified;these are thought to have had joint control over the development of hydrocarbon source rocks and reservoirs.The three types of Oligocene fault fan coupling relationships in the Qiongdongnan Basin were found to be fault bend,fault gully,and fault tip.The fault bend type of(fan)delta developed at the bend of the fault and was distributed in the downthrown block of Fault Nos.5 and 2.The fault tip type developed where the fault died out toward the source direction and was distributed near the eastewest faults on the north and south sides of Baodao and Changchang Sags.The fault gully type developed along the fault trend in the downthrown block and was mainly distributed in areas including the northern part of Ya'nan Sag and the Fault No.3 downthrown block.The fault bend(fan)delta is surrounded by a relatively closed bay environment,and the terrigenously dominated marine source rocks in the still water bay environment were developed with a high hydrocarbon generation index and high hydrocarbon generation potential.Fault tip and fault gully types of(fan)delta plain facies have a wide distribution of plain subfacies,which is conducive to the development of coal-measure source rocks that have excellent gas potential.During sedimentation of the fault gully and the fault tip delta,the terrain was relatively flat,with sand bodies strongly reworked by hydrodynamic force;the reservoir quality of the sand bodies in the underwater distributary channel and estuary dam are good,and the sand bodies have wide distribution.The sand bodies of the fault bend type of(fan)delta were deposited rapidly near the source kitchen,and the degree of sorting and rounding was poor,which resulted in the poor physical properties of the plain subfacies.In the southern and northern step-fault zones of Baodao Sag in the eastern part of this basin,the fault bend,fault tip,and fault trench(fan)deltas were inherited and further developed,and the source-reservoir configuration conditions were favorable.Exploration deployment was carried out in the Baodao 21 area in the northern step-fault zone and the Yongle 10 area in the southern step-fault zone,where new discoveries in natural gas exploration have been realized.In the eastern part of this basin,the fault bend,fault tip,and fault gully(fan)deltas in the southern and northern fault step zones of Baodao Sag were successively developed,which were beneficial for favorable sourceereservoir configuration conditions.The natural gas exploration successes in the Baodao-21 area in the northern fault step zone and the Yongle-10 area in the southern fault step zone are beneficial for new discoveries in natural gas exploration in the Qiongdongnan Basin.
文摘The spatio-temporal variability of Northern Hemisphere Sea Level Pressure （SLP） and precipitation over the mid-to-low reaches of the Yangtze River （PMLY） is analyzed jointly using the multi-taper/singular value decomposition method （MTM-SVD）. Statistically significant narrow frequency bands are obtained from the local fractional variance （LFV） spectrum. Significant interdecadal （i.e., 16-to-18-year periods） and interannual （i.e., 3-to-6-year periods） signals are identified. Moreover, a significant quasi-biennial signal is identified but only for PMLY data. The spatial joint evolution of patterns obtained for peaks in the LFV spectrum sheds light on relationships between SLP and PMLY： the Arctic Oscillation （AO） modulates the variability of the PMLY while the interannual variability of PMLY is in phase with the Northern Atlantic Oscillation （NAO） and the Northern Pacific Oscillation （NPO）.
基金Under the auspices of Graduate Innovation Program of China University of Mining and Technology (No.2022WLKXJ095)National Natural Science Foundation of China (No.71874192)Youth Project of Fundamental Research Funds for the Central Universities (No.2021QN1076)。
文摘For mankind’s survival and development,water,energy,and food(WEF)are essential material guarantees.In China,however,the spatial distribution of WEF is seriously unbalanced and mismatched.Here,a collaborative governance mechanism that aims at nexus security needs to be urgently established.In this paper,the Yellow River Basin in China with a representative WEF system,was selected as a case.Firstly,a comprehensive framework for WEF coupling coordination was constructed,and the relationship and mechanism between them were analyzed theoretically.Then,we investigated the spatiotemporal characteristics and driving mechanisms of the coupling coordination degree(CCD)with a composite evaluation method,coupling coordination degree model,spatial statistical analysis,and multiscale geographic weighted regression.Finally,policy implications were discussed to promote the coordinated development of the WEF system.The results showed that:1)WEF subsystems showed a significant imbalance of spatial pattern and diversity in temporal changes;2)the CCD for the WEF system varied little and remained at moderate coordination.Areas with moderate coordination have increased,while areas with superior coordination and mild disorder have decreased.In addition,the spatial clustering phenomenon of the CCD was significant and showed obvious characteristics of polarization;and 3)the action of each factor is self-differentiated and regionally variable.For different factors,GDP per capita was of particular importance,which contributed most to the regional development’s coupling coordination.For different regions,GDP per capita,average yearly precipitation,population density,and urbanization rate exhibited differences in geographical gradients in an east-west direction.The conclusion can provide references for regional resource allocation and sustainable development by enhancing WEF system utilization efficiency.
