The spatial form of urbanization in China has developed from single-core city expansion to a multi-center metropolitan area.However,little attention has been paid to the growth process of the emerging metropolitan are...The spatial form of urbanization in China has developed from single-core city expansion to a multi-center metropolitan area.However,little attention has been paid to the growth process of the emerging metropolitan area situated in major grain producing locations in the central China.Taking the Zhengzhou metropolitan area(ZZMA)as a case study,we developed an inverse S-shape model to characterize the spatial distribution of urban land density,and constructed an urban expansion core index,urban expansion intensity index,and urban compactness index to quantify the spatial structure change that has taken place from 1978 to 2017 during the process of urban expansion.Moreover,cropland contribution rate(CR)was constructed to evaluate the impacts of urban expansion on croplands.We uncovered four key findings.First,over the past 40 yr,the ZZMA has experienced dramatic expansion,and the central city of Zhengzhou expanded faster than other cities.The gravity centers of urban expansion of surrounding cities were moving toward to Zhengzhou City.Second,the urban land density decreased with the distance from the city center to the outskirts.As the only large city,Zhengzhou has experienced the fastest and most compact centralized urban expansion,especially after 2000,while other medium-and small-sized cities have experienced low-intensity decentralized expansion.Third,the urban core has been gradually expanding outward.From 1978 to 2017,the hot-zone of urban growth has moved progressively with the acceleration of urbanization.All cities except Jiaozuo had a single peak in different periods.Forth,the cities in national core grain-producing areas has higher cropland contribution rates and lower urban expansion areas,which was closely related to cropland protection.Further analysis showed that large city was relatively better positioned than smaller cities in the efficiency of their urban infrastructure and the effectiveness of wealth creation efficiency in the urbanized area could be tested in all cities,and the policy factor seeme展开更多
Paleoclimate record was revealed in Core MZ01 covering the mid-Holocene in age,located in the mud area of the inner continental shelf of the East China Sea. The ancient environment featured low-energy shallow sea shel...Paleoclimate record was revealed in Core MZ01 covering the mid-Holocene in age,located in the mud area of the inner continental shelf of the East China Sea. The ancient environment featured low-energy shallow sea shelf deposition formed mainly by coastal currents. The results show that temporal variation in geochemistry corresponds with the climate changes inferred from historical record. Relatively low MgO/Al 2 O 3,CaO/K 2 O and high Al 2 O 3 /Na 2 O,K 2 O/Na 2 O,MnO/CaO values reflected a warm and humid climate in general,and vice versa. Therefore,these chemical indices could be applied to identify the variation of palaeoclimate in eastern China. The authors reconstructed the history of mid-Holocene climatic variation of the inner continental shelf of the East China Sea. From 8 300 a BP to 4 200 a BP,the climate was moderately warm and humid. From 4 200 a BP to 2 000 a BP,the climate turned cool and dry,and the regional climate frequently fluctuated in alternation of cool-dry periods（3 700 a BP,2 850 a BP and 2 400 a BP） and warm-wet periods（3 250 a BP and 2 650 a BP） . After 2 000 a BP,the climate of the study area gradually turned warm again,while the Little Ice Age,a cold event centered at around 250 a BP was indicated by those geochemical indices as mentioned above.展开更多
Background:Major depressive disorder(MDD)has different clinical presentations in males and females.However,the neuroanatom-ical mechanisms underlying these sex differences are not fully understood.Objective:The purpos...Background:Major depressive disorder(MDD)has different clinical presentations in males and females.However,the neuroanatom-ical mechanisms underlying these sex differences are not fully understood.Objective:The purpose of present study was to explore the sex differences in brain cortical thickness(CT)and surface area(SA)of MDD and the relationship between these differences and clinical manifestations in different gender.Methods:High-resolution T1-weighted images were acquired from 61 patients with MDD and 61 healthy controls(36 females and 25 males,both).The sex differences in CT and SA were obtained using the FreeSurfer software and compared between every two groups by post hoc test.Spearman correlation analysis was also performed to explore the relationships between these regions and clinical characteristics.Results:In male patients with MDD,the CT of the right precentral was thinner compared to female patients,although this did not survive Bonferroni correction.The SA of several regions,including right superior frontal,medial orbitofrontal gyrus,inferior frontal gyrus triangle,superior temporal,middle temporal,lateral occipital gyrus,and inferior parietal lobule in female patients with MDD was smaller than that in male patients(P<0.01 after Bonferroni correction).In female patients,the SA of the right superior temporal(r=0.438,P=0.008),middle temporal(r=0.340,P=0.043),and lateral occipital gyrus(r=0.372,P=0.025)were positively correlated with illness duration.Conclusion:The current study provides evidence of sex differences in CT and SA in patients with MDD,which may improve our understanding of the sex-specific neuroanatomical changes in the development of MDD.展开更多
There are abundant coal and coalbed methane(CBM)resources in the Xishanyao Formation in the western region of the southern Junggar Basin,and the prospects for CBM exploration and development are promising.To promote t...There are abundant coal and coalbed methane(CBM)resources in the Xishanyao Formation in the western region of the southern Junggar Basin,and the prospects for CBM exploration and development are promising.To promote the exploration and development of the CBM resources of the Xishanyao Formation in this area,we studied previous coalfield survey data and CBM geological exploration data.Then,we analyzed the relationships between the gas content and methane concentration vs.coal seam thickness,burial depth,coal reservoir physical characteristics,hydrogeological conditions,and roof and floor lithology.In addition,we briefly discuss the main factors influencing CBM accumulation.First,we found that the coal strata of the Xishanyao Formation in the study area are relatively simple in structure,and the coal seam has a large thickness and burial depth,as well as moderately good roof and floor conditions.The hydrogeological conditions and coal reservoir physical characteristics are also conducive to the enrichment and a high yield of CBM.We believe that the preservation of CBM resources in the study area is mainly controlled by the structure,burial depth,and hydrogeological conditions.Furthermore,on the basis of the above results,the coal seam of the Xishanyao Formation in the synclinal shaft and buried at depths of 700-1000 m should be the first considered for development.展开更多
At present,there are still many problems in language teaching in rural primary schools,which will affect the quality of teaching if we don't pay much attention to them.This article focuses on the existing flaws in...At present,there are still many problems in language teaching in rural primary schools,which will affect the quality of teaching if we don't pay much attention to them.This article focuses on the existing flaws in current language teaching and provides some solutions.展开更多
The scaling relationship between leaf area and total mass of plant has important implications for understanding resource allocations in the plant.The model of West,Brown and Enquist(WBE model)considers that a 3/4 scal...The scaling relationship between leaf area and total mass of plant has important implications for understanding resource allocations in the plant.The model of West,Brown and Enquist(WBE model)considers that a 3/4 scaling exponent of metabolic rate versus total mass to be optimal for each plant and has been confirmed numerous times.Although leaf area is a better proxy of the metabolic rate than leaf mass,few studies have focused on the scaling exponent of leaf area versus total mass and even fewer have discussed the diversification of this scaling exponent across different conditions.Here,I analyzed the scaling exponent of leaf area versus total mass of sample plots across world plants.I found that as the plant grows,it allocates fewer resources to photosynthetic tissues than expected by the WBE model.The results also empirically show that this scaling exponent varies significantly for different plant leaf habit,taxonomic class and geographic region.Therefore,leaf strategy in response to environmental pressure and constraint clearly plays a significant role.展开更多
ln the context of comprehensively deepening the reform, and integration of three The first, second and third industry sectors in rural areas, the research took major grain-producing areas in Hubei as an example, analy...ln the context of comprehensively deepening the reform, and integration of three The first, second and third industry sectors in rural areas, the research took major grain-producing areas in Hubei as an example, analyzed dominant grain in-dustrialization models “leading grain enterprises＋farmers”, and revealed its character-istics, advantages, and approaches for function reinforcement. The research is so meaningful, practical y or in future.展开更多
基金Under the auspices of National Natural Science Foundation of China(No.41971274)the Innovation Research Team of Henan Provincial University(No.2021-CXTD-08,2022-CXTD-02)the Scientific and Technological Innovation Team of Universities in Henan Province(No.22IRTSTHN008)。
文摘The spatial form of urbanization in China has developed from single-core city expansion to a multi-center metropolitan area.However,little attention has been paid to the growth process of the emerging metropolitan area situated in major grain producing locations in the central China.Taking the Zhengzhou metropolitan area(ZZMA)as a case study,we developed an inverse S-shape model to characterize the spatial distribution of urban land density,and constructed an urban expansion core index,urban expansion intensity index,and urban compactness index to quantify the spatial structure change that has taken place from 1978 to 2017 during the process of urban expansion.Moreover,cropland contribution rate(CR)was constructed to evaluate the impacts of urban expansion on croplands.We uncovered four key findings.First,over the past 40 yr,the ZZMA has experienced dramatic expansion,and the central city of Zhengzhou expanded faster than other cities.The gravity centers of urban expansion of surrounding cities were moving toward to Zhengzhou City.Second,the urban land density decreased with the distance from the city center to the outskirts.As the only large city,Zhengzhou has experienced the fastest and most compact centralized urban expansion,especially after 2000,while other medium-and small-sized cities have experienced low-intensity decentralized expansion.Third,the urban core has been gradually expanding outward.From 1978 to 2017,the hot-zone of urban growth has moved progressively with the acceleration of urbanization.All cities except Jiaozuo had a single peak in different periods.Forth,the cities in national core grain-producing areas has higher cropland contribution rates and lower urban expansion areas,which was closely related to cropland protection.Further analysis showed that large city was relatively better positioned than smaller cities in the efficiency of their urban infrastructure and the effectiveness of wealth creation efficiency in the urbanized area could be tested in all cities,and the policy factor seeme
基金Coastal Investigation and Research Project of China under contract Nos 908-01-CJ12 and 908-ZC-I-05Marine Public Welfare Research Project under contract No. 200805063China Postdoctoral Science Foundation under contract No. 20100481304
文摘Paleoclimate record was revealed in Core MZ01 covering the mid-Holocene in age,located in the mud area of the inner continental shelf of the East China Sea. The ancient environment featured low-energy shallow sea shelf deposition formed mainly by coastal currents. The results show that temporal variation in geochemistry corresponds with the climate changes inferred from historical record. Relatively low MgO/Al 2 O 3,CaO/K 2 O and high Al 2 O 3 /Na 2 O,K 2 O/Na 2 O,MnO/CaO values reflected a warm and humid climate in general,and vice versa. Therefore,these chemical indices could be applied to identify the variation of palaeoclimate in eastern China. The authors reconstructed the history of mid-Holocene climatic variation of the inner continental shelf of the East China Sea. From 8 300 a BP to 4 200 a BP,the climate was moderately warm and humid. From 4 200 a BP to 2 000 a BP,the climate turned cool and dry,and the regional climate frequently fluctuated in alternation of cool-dry periods（3 700 a BP,2 850 a BP and 2 400 a BP） and warm-wet periods（3 250 a BP and 2 650 a BP） . After 2 000 a BP,the climate of the study area gradually turned warm again,while the Little Ice Age,a cold event centered at around 250 a BP was indicated by those geochemical indices as mentioned above.
基金supported by the Sichuan Science and Technology Program (No.2018JY0666)58th batch Chinese Postdoctoral Science Foundation (No.2015M582554)+4 种基金sichuan Provincial Health and Family Planning Commission (No.150251)Science and Technology Bureau of Yibin city (No.2015SF030)Open Project of Sichuan Key Laboratory of Functional and Molecular Imaging (No.SCU-HM-2021001)Project of Health Commission of Yibin city (No.2020YW085)Xinglin Scholar Project of Chengdu University of Taditional Chinese Medicine (No.YYZX2020111).
文摘Background:Major depressive disorder(MDD)has different clinical presentations in males and females.However,the neuroanatom-ical mechanisms underlying these sex differences are not fully understood.Objective:The purpose of present study was to explore the sex differences in brain cortical thickness(CT)and surface area(SA)of MDD and the relationship between these differences and clinical manifestations in different gender.Methods:High-resolution T1-weighted images were acquired from 61 patients with MDD and 61 healthy controls(36 females and 25 males,both).The sex differences in CT and SA were obtained using the FreeSurfer software and compared between every two groups by post hoc test.Spearman correlation analysis was also performed to explore the relationships between these regions and clinical characteristics.Results:In male patients with MDD,the CT of the right precentral was thinner compared to female patients,although this did not survive Bonferroni correction.The SA of several regions,including right superior frontal,medial orbitofrontal gyrus,inferior frontal gyrus triangle,superior temporal,middle temporal,lateral occipital gyrus,and inferior parietal lobule in female patients with MDD was smaller than that in male patients(P<0.01 after Bonferroni correction).In female patients,the SA of the right superior temporal(r=0.438,P=0.008),middle temporal(r=0.340,P=0.043),and lateral occipital gyrus(r=0.372,P=0.025)were positively correlated with illness duration.Conclusion:The current study provides evidence of sex differences in CT and SA in patients with MDD,which may improve our understanding of the sex-specific neuroanatomical changes in the development of MDD.
基金the China Geological Survey Project of Chinese Oil and Gas Strategic Petroleum Prospects Investigation and Evaluation(Grant No.1211302108025—2 and No.DD20160204).
文摘There are abundant coal and coalbed methane(CBM)resources in the Xishanyao Formation in the western region of the southern Junggar Basin,and the prospects for CBM exploration and development are promising.To promote the exploration and development of the CBM resources of the Xishanyao Formation in this area,we studied previous coalfield survey data and CBM geological exploration data.Then,we analyzed the relationships between the gas content and methane concentration vs.coal seam thickness,burial depth,coal reservoir physical characteristics,hydrogeological conditions,and roof and floor lithology.In addition,we briefly discuss the main factors influencing CBM accumulation.First,we found that the coal strata of the Xishanyao Formation in the study area are relatively simple in structure,and the coal seam has a large thickness and burial depth,as well as moderately good roof and floor conditions.The hydrogeological conditions and coal reservoir physical characteristics are also conducive to the enrichment and a high yield of CBM.We believe that the preservation of CBM resources in the study area is mainly controlled by the structure,burial depth,and hydrogeological conditions.Furthermore,on the basis of the above results,the coal seam of the Xishanyao Formation in the synclinal shaft and buried at depths of 700-1000 m should be the first considered for development.
文摘At present,there are still many problems in language teaching in rural primary schools,which will affect the quality of teaching if we don't pay much attention to them.This article focuses on the existing flaws in current language teaching and provides some solutions.
文摘The scaling relationship between leaf area and total mass of plant has important implications for understanding resource allocations in the plant.The model of West,Brown and Enquist(WBE model)considers that a 3/4 scaling exponent of metabolic rate versus total mass to be optimal for each plant and has been confirmed numerous times.Although leaf area is a better proxy of the metabolic rate than leaf mass,few studies have focused on the scaling exponent of leaf area versus total mass and even fewer have discussed the diversification of this scaling exponent across different conditions.Here,I analyzed the scaling exponent of leaf area versus total mass of sample plots across world plants.I found that as the plant grows,it allocates fewer resources to photosynthetic tissues than expected by the WBE model.The results also empirically show that this scaling exponent varies significantly for different plant leaf habit,taxonomic class and geographic region.Therefore,leaf strategy in response to environmental pressure and constraint clearly plays a significant role.
文摘ln the context of comprehensively deepening the reform, and integration of three The first, second and third industry sectors in rural areas, the research took major grain-producing areas in Hubei as an example, analyzed dominant grain in-dustrialization models “leading grain enterprises＋farmers”, and revealed its character-istics, advantages, and approaches for function reinforcement. The research is so meaningful, practical y or in future.
