期刊文献+
共找到69,249篇文章
< 1 2 250 >
每页显示 20 50 100
What diameter?What height?Influence of measures of average tree size on area-based allometric volume relationships
1
作者 Yilin Wang John A.Kershaw +2 位作者 Mark J.Ducey Yuan Sun James B.McCarter 《Forest Ecosystems》 SCIE CSCD 2024年第1期100-109,共10页
Volume is an important attribute used in many forest management decisions.Data from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and he... Volume is an important attribute used in many forest management decisions.Data from 83 fixed-area plots located in central New Brunswick,Canada,are used to examine how different measures of stand-level diameter and height influence volume prediction using a stand-level variant of Honer's(1967)volume equation.When density was included in the models(Volume=f(Diameter,Height,Density))choice of diameter measure was more important than choice of height measure.When density was not included(Volume=f(Diameter,Height)),the opposite was true.For models with density included,moment-based estimators of stand diameter and height performed better than all other measures.For models without density,largest tree estimators of stand diameter and height performed better than other measures.The overall best equation used quadratic mean diameter,Lorey's height,and density(root mean square error=5.26 m^3·ha^(-1);1.9%relative error).The best equation without density used mean diameter of the largest trees needed to calculate a stand density index of 400 and the mean height of the tallest 400 trees per ha(root mean square error=32.08 m^(3)·ha^(-1);11.8%relative error).The results of this study have some important implications for height subsampling and LiDAR-derived forest inventory analyses. 展开更多
关键词 Allometric relationships Stand structure Volume estimation Stand-level attributes
下载PDF
Three anti-inflammatory polysaccharides from Lonicera japonica Thunb.:insights into the structure-function relationships
2
作者 Yu Liu Hongjing Dong +5 位作者 Dongxiao Sun-Waterhouse Wenwen Li Bin Zhang Jinqian Yu Zhichang Qiu Zhenjia Zheng 《Food Science and Human Wellness》 SCIE CAS CSCD 2024年第4期2197-2207,共11页
This study demonstrates the feasibility of producing three polysaccharides(neutral LJP-1,acidic LJP-2 and acidic LJP-3)with significant in vitro and in vivo anti-inflammatory activities from the flowers of Lonicera ja... This study demonstrates the feasibility of producing three polysaccharides(neutral LJP-1,acidic LJP-2 and acidic LJP-3)with significant in vitro and in vivo anti-inflammatory activities from the flowers of Lonicera japonica.The three polysaccharides differed in chemical composition,molecular weight(Mw)distribution,glycosidic linkage pattern,functional groups and morphology.They exhibited excellent protective effects(in a dose-dependent manner)in lipopolysaccharide-injured RAW264.7 macrophages and Cu SO4-damaged zebrafish via reducing NO production and inhibiting the overexpressions of inflammation-related transcription factors,inflammatory proteins and cytokines in the NF-κB/MAPK signaling pathways.Their antiinflammatory effects varied owing to their different molecular characteristics and chemical compositions.Overall,LJP-2 at 400μg/m L was the most effective.LJP-2 consisted mainly of→5)-α-L-Araf(1→,→4)-α-LGalp A(1→and→2)-α-L-Rhap(1→residues with terminal T-β-D-Glcp.Thus,honeysuckle flowers are good sources of anti-inflammatory polysaccharides,and precise fractionation enables the production of potent antiinflammatory agents for the development of functional foods and healthcare products. 展开更多
关键词 Honeysuckle polysaccharides FRACTIONATION Molecular characteristics Anti-inflammatory properties Structure-function relationship
下载PDF
Floristic composition and edaphic relationships in ferruginous campo rupestre reference ecosystems
3
作者 G.Wilson FERNANDES Letícia RAMOS +3 位作者 Dario C.PAIVA Jéssica CUNHA-BLUM Vanessa Matos GOMES Daniel NEGREIROS 《Journal of Mountain Science》 SCIE CSCD 2024年第3期719-733,共15页
Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the planet.Some environments with high economic relevance,such as the ferrugin... Land use change and occupation have led to modifications in the environment causing loss of biodiversity and ecosystem services throughout the planet.Some environments with high economic relevance,such as the ferruginous campo rupestre(rupestrian grassland known as Canga in Brazil),are even more susceptible to severe impacts due to their extreme habitat conditions and low resilience.The determination of reference ecosystems based on the intrinsic characteristics of the ecosystem is essential for conservation as well as to the implementation of ecological restoration.We proposed the reference ecosystem of the three main types of habitats of the ferruginous campo rupestre based on their floristic composition.We described the floristic composition of each habitat and evaluated the physicochemical properties of the soils and the relationship between plants and soils.All three habitats showed high diversity of plant species and many endemic species,such as Chamaecrista choriophylla,Cuphea pseudovaccinium,Lychnophora pinaster,and Vellozia subalata.The distribution of vegetation was strongly related with the edaphic characteristics,with a set of species more adapted to high concentration of base saturation,fine sand,organic carbon,and iron,while another set of species succeeded in more acidic soils with higher S and silt concentration.We provide support for the contention that the ferruginous campo rupestre is a mosaic of different habitats shaped by intrinsic local conditions.Failure to recognize the floristic composition of each particular habitat can lead to inappropriate restoration,increased habitat homogenization and increased loss of biodiversity and ecosystem services.This study also advances the knowledge base for building the reference ecosystem for the different types of ferruginous campo rupestre habitats,as well as a key database for highlighting those species contribute most to community assembly in this diverse and threatened tropical mountain ecosystem. 展开更多
关键词 Canga Ecological restoration Extreme ecosystem Non-forest ecosystems Rupestrian grassland Taxon environment relationships
下载PDF
Different mechanisms underlie similar species-area relationships in two tropical archipelagoes
4
作者 Shengchun Li Tieyao Tu +5 位作者 Shaopeng Li Xian Yang Yong Zheng Liang-Dong Guo Dianxiang Zhang Lin Jiang 《Plant Diversity》 SCIE CAS CSCD 2024年第2期238-246,共9页
Despite much research in the field of island biogeography,mechanisms regulating insular diversity remain elusive.Here,we aim to explore mechanisms underlying plant species-area relationships in two tropical archipelag... Despite much research in the field of island biogeography,mechanisms regulating insular diversity remain elusive.Here,we aim to explore mechanisms underlying plant species-area relationships in two tropical archipelagoes in the South China Sea.We found positive plant species-area relationships for both coral and continental archipelagoes.However,our results showed that different mechanisms contributed to similar plant species-area relationships between the two archipelagoes.For coral islands,soil nutrients and spatial distance among communities played major roles in shaping plant community structure and species diversity.By contrast,the direct effect of island area,and to a lesser extent,soil nutrients determined plant species richness on continental islands.Intriguingly,increasing soil nutrients availability(N,P,K)had opposite effects on plant diversity between the two archipelagoes.In summary,the habitat quality effect and dispersal limitation are important for regulating plant diversity on coral islands,whereas the passive sampling effect,and to a lesser extent,the habitat quality effect are important for regulating plant diversity on continental islands.More generally,our findings indicate that island plant species-area relationships are outcomes of the interplay of both niche and neutral processes,but the driving mechanisms behind these relationships depends on the type of islands. 展开更多
关键词 Coral and continental islands Plant diversity Soil nutrients Species-area relationships The sampling effect
下载PDF
Mediating role of physical activity in the relationship between psychological distress and intimate relationships among stroke patients 被引量:1
5
作者 Chang-Yue Luo Peng Jiao +2 位作者 Shu-Min Tu Lin Shen Yong-Mei Sun 《World Journal of Psychiatry》 SCIE 2023年第12期1096-1105,共10页
BACKGROUND Stroke patients often experience psychological distress,which can impact their intimate relationships with spouses,subsequently influencing their treatment and recovery.Physical activity is considered a key... BACKGROUND Stroke patients often experience psychological distress,which can impact their intimate relationships with spouses,subsequently influencing their treatment and recovery.Physical activity is considered a key rehabilitation method for stroke patients.This paper aims to analyze whether psychological distress affects intimate relationship between spouses through physical activity.AIM To explore the mediating effect of physical activity between psychological distress and intimate relationship in stroke patients.METHODS A total of 256 stroke patients who underwent treatment at the First People’s Hospital of Shangqiu between July 2021 and July 2022 were enrolled in this study.The participants completed questionnaires,including the Kessler Psychological Distress Scale(K10),the Quality of Relationship Index(QRI),International Physical Activity Questionnaire,and a general information questionnaire.Data analysis were performed using SPSS 23.0.The Harman test was employed to detect common method deviations,and Spearman correlation was used for correlation analysis.The mediating effect was assessed using Process 3.4.1,with significance testing of the regression coefficients conducted using the bias-corrected percentile Bootstrap method(5000 iterations,95%confidence interval).Statistical significance was set at P<0.05.RESULTS The results showed that patients scored an average of 21.61±6.44 points on the K10,32.40±6.19 points on the QRI;the median physical activity level according to the International Physical Activity Questionnaire was 1861(566,2846)MET·min/w.The level of physical activity(the physical activity intensity of the patients reflected by the Interna-tional Physical Activity Questionnaire-Long Form scale)negatively correlated with psychological distress and intimacy(P<0.05),and positively correlated with each other(P<0.05),with the correlation stronger at lower physical activity levels compared to higher ones.The mediating effect of physical activity between psychological distress and intimate relationship was calculated to be 40.23%.Bootstrap analysis further validated the results.The mediating effect of psychological distress on intimate relationships through physical activity level was-0.284,with a confidence interval of-0.409 to-0.163,excluding 0,confirming a significant mediating effect of psychological distress on intimate relationships.CONCLUSION Physical activity significantly affects relationship between psychological distress and intimate relationships among stroke patients.Addressing the role of physical activity may have implications for improving patient outcomes and rehabilitation strategies. 展开更多
关键词 STROKE Cross-sectional study Psychological distress Intimate relationship Mediating effect Physical activity level
下载PDF
Structure-guided Capacitance Relationships in Oxidized Graphene Porous Materials Based Supercapacitors
6
作者 Srinivas Gadipelli Hanieh Akbari +4 位作者 Juntao Li Christopher A.Howard Hong Zhang Paul R.Shearing Dan J.L.Brett 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第4期58-69,共12页
Supercapacitors formed from porous carbon and graphene-oxide(GO)materials are usually dominated by either electric double-layer capacitance,pseudo-capacitance,or both.Due to these combined features,reduced GO material... Supercapacitors formed from porous carbon and graphene-oxide(GO)materials are usually dominated by either electric double-layer capacitance,pseudo-capacitance,or both.Due to these combined features,reduced GO materials have been shown to offer superior capacitance over typical nanoporous carbon materials;however,there is a significant variation in reported values,ranging between 25 and 350 F g^(−1).This undermines the structure(e.g.,oxygen functionality and/or surface area)-performance relationships for optimization of cost and scalable factors.This work demonstrates important structure-controlled charge storage relationships.For this,a series of exfoliated graphene(EG)derivatives are produced via thermal-shock exfoliation of GO precursors and following controlled graphitization of EG(GEG)generates materials with varied amounts of porosity,redox-active oxygen groups and graphitic components.Experimental results show significantly varied capacitance values between 30 and 250 F g^(−1)at 1.0 A g^(−1)in GEG structures;this suggests that for a given specific surface area the redox-active and hydrophilic oxygen content can boost the capacitance to 250–300%higher compared to typical mesoporous carbon materials.GEGs with identical oxygen functionality show a surface area governed capacitance.This allows to establish direct structure-performance relationships between 1)redox-active oxygen functional concentration and capacitance and 2)surface area and capacitance. 展开更多
关键词 electric double-layer capacitance graphene-oxide PSEUDOCAPACITANCE structure-performance relationships SUPERCAPACITORS
下载PDF
Four new orientation relationships of Mg_(17)Al_(12) phase with magnesium matrix in Mg-8Al-0.5Zn alloys
7
作者 Feiya Liu Renlong Xin +2 位作者 Xin Wen Xinfu Gu Qing Liu 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第12期4689-4695,共7页
Although the non-basal precipitates, those not parallel to the basal plane, are more effective to block basal slip in Mg-Al alloys, the crystallographic orientation relationship(OR) between these precipitates and the ... Although the non-basal precipitates, those not parallel to the basal plane, are more effective to block basal slip in Mg-Al alloys, the crystallographic orientation relationship(OR) between these precipitates and the α-Mg matrix has not been well established. In this work, the crystallography of the non-basal Mg_(17)Al_(12) precipitates in AZ80 alloy was systematically investigated by transmission electron microscopy(TEM). By tilting to a suitable electron beam direction, different kinds of non-basal precipitates were recognized in TEM, and the following four new ORs between the non-basal Mg_(17)Al_(12) precipitates and the matrix were revealed: ■, and ■.Furthermore, these ORs and their habit planes were explained using the edge-to-edge matching model. The findings in this work can provide some guidelines for designing the microstructure of Mg-Al alloys to enhance their precipitation hardening potential. 展开更多
关键词 Mg alloys PRECIPITATE Orientation relationship CRYSTALLOGRAPHY Edge-to-edge matching model
下载PDF
Optimizing Spatial Relationships in GCN to Improve the Classification Accuracy of Remote Sensing Images
8
作者 Zimeng Yang Qiulan Wu +3 位作者 Feng Zhang Xuefei Chen Weiqiang Wang XueShen Zhang 《Intelligent Automation & Soft Computing》 SCIE 2023年第7期491-506,共16页
Semantic segmentation of remote sensing images is one of the core tasks of remote sensing image interpretation.With the continuous develop-ment of artificial intelligence technology,the use of deep learning methods fo... Semantic segmentation of remote sensing images is one of the core tasks of remote sensing image interpretation.With the continuous develop-ment of artificial intelligence technology,the use of deep learning methods for interpreting remote-sensing images has matured.Existing neural networks disregard the spatial relationship between two targets in remote sensing images.Semantic segmentation models that combine convolutional neural networks(CNNs)and graph convolutional neural networks(GCNs)cause a lack of feature boundaries,which leads to the unsatisfactory segmentation of various target feature boundaries.In this paper,we propose a new semantic segmentation model for remote sensing images(called DGCN hereinafter),which combines deep semantic segmentation networks(DSSN)and GCNs.In the GCN module,a loss function for boundary information is employed to optimize the learning of spatial relationship features between the target features and their relationships.A hierarchical fusion method is utilized for feature fusion and classification to optimize the spatial relationship informa-tion in the original feature information.Extensive experiments on ISPRS 2D and DeepGlobe semantic segmentation datasets show that compared with the existing semantic segmentation models of remote sensing images,the DGCN significantly optimizes the segmentation effect of feature boundaries,effectively reduces the noise in the segmentation results and improves the segmentation accuracy,which demonstrates the advancements of our model. 展开更多
关键词 Remote sensing image semantic segmentation GCN spatial relationship feature fusion
下载PDF
Solubility study of hydrogen in direct coal liquefaction solvent based on quantitative structure–property relationships model
9
作者 Xiao-Bin Zhang A.Rajendran +1 位作者 Xing-Bao Wang Wen-Ying Li 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第12期250-258,共9页
Direct coal liquefaction(DCL)is an important and effective method of converting coal into high-valueadded chemicals and fuel oil.In DCL,heating the direct coal liquefaction solvent(DCLS)from low to high temperature an... Direct coal liquefaction(DCL)is an important and effective method of converting coal into high-valueadded chemicals and fuel oil.In DCL,heating the direct coal liquefaction solvent(DCLS)from low to high temperature and pre-hydrogenation of the DCLS are critical steps.Therefore,studying the dissolution of hydrogen in DCLS under liquefaction conditions gains importance.However,it is difficult to precisely determine hydrogen solubility only by experiments,especially under the actual DCL conditions.To address this issue,we developed a prediction model of hydrogen solubility in a single solvent based on the machine-learning quantitative structure–property relationship(ML-QSPR)methods.The results showed that the squared correlation coefficient R^(2)=0.92 and root mean square error RMSE=0.095,indicating the model’s good statistical performance.The external validation of the model also reveals excellent accuracy and predictive ability.Molecular polarization(a)is the main factor affecting the dissolution of hydrogen in DCLS.The hydrogen solubility in acyclic alkanes increases with increasing carbon number.Whereas in polycyclic aromatics,it decreases with increasing ring number,and in hydrogenated aromatics,it increases with hydrogenation degree.This work provides a new reference for the selection and proportioning of DCLS,i.e.,a solvent with higher hydrogen solubility can be added to provide active hydrogen for the reaction and thus reduce the hydrogen pressure.Besides,it brings important insight into the theoretical significance and practical value of the DCL. 展开更多
关键词 Hydrogen solubility Liquefied solvents Predictive model Density generalized function theory Quantitative structure-property relationship
下载PDF
The Relationship between Father-Love Absence and Loneliness:Based on the Perspective of the Social Functionalist Theory and the Social Needs Theory
10
作者 Yaping Zhou He Zhong +1 位作者 Xiaojun Li Yanhui Xiang 《International Journal of Mental Health Promotion》 2024年第2期139-148,共10页
Fathers play an important role in adolescents’development,which is significant for their development and influences their mental health,including feeling of loneliness.However,the effects and mechanisms of father-lov... Fathers play an important role in adolescents’development,which is significant for their development and influences their mental health,including feeling of loneliness.However,the effects and mechanisms of father-love absence on individual loneliness are not clear.Based on the social functionalist theory and the social needs theory,this study examines the influence of individual fatherlove absence on loneliness and its underlying mechanisms.A questionnaire survey was administered to 319 junior high school students and 1,476 high school students.The results showed that adolescents with father-love absence had higher levels of loneliness,and that father-love absence affected loneliness levels through mediating pathways of individual gratitude,peer relationships,and gratitude to peer relationships.This study not only confirms the negative effects of father-love absence on adolescents’loneliness,but also explains the mediate roles of individual gratitude and peer relationships.It enriches the theoretical system related to family education and has important theoretical and practical implications for further interventions on adolescents’mental health from the perspective of fatherless parenting. 展开更多
关键词 Father-love absence LONELINESS GRATITUDE peer relationships
下载PDF
A Large-Scale Group Decision Making Model Based on Trust Relationship and Social Network Updating
11
作者 Rongrong Ren Luyang Su +2 位作者 Xinyu Meng Jianfang Wang Meng Zhao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期429-458,共30页
With the development of big data and social computing,large-scale group decisionmaking(LGDM)is nowmerging with social networks.Using social network analysis(SNA),this study proposes an LGDM consensus model that consid... With the development of big data and social computing,large-scale group decisionmaking(LGDM)is nowmerging with social networks.Using social network analysis(SNA),this study proposes an LGDM consensus model that considers the trust relationship among decisionmakers(DMs).In the process of consensusmeasurement:the social network is constructed according to the social relationship among DMs,and the Louvain method is introduced to classify social networks to form subgroups.In this study,the weights of each decision maker and each subgroup are computed by comprehensive network weights and trust weights.In the process of consensus improvement:A feedback mechanism with four identification and two direction rules is designed to guide the consensus of the improvement process.Based on the trust relationship among DMs,the preferences are modified,and the corresponding social network is updated to accelerate the consensus.Compared with the previous research,the proposedmodel not only allows the subgroups to be reconstructed and updated during the adjustment process,but also improves the accuracy of the adjustment by the feedbackmechanism.Finally,an example analysis is conducted to verify the effectiveness and flexibility of the proposed method.Moreover,compared with previous studies,the superiority of the proposed method in solving the LGDM problem is highlighted. 展开更多
关键词 Large-scale group decision making social network updating trust relationship group consensus feedback mechanism
下载PDF
Nonlinear Relationship and Its Evolutionary Trace between Node Degree and Average Path Length of China Aviation Network Based on Complex Network
12
作者 Cheng Xiangjun Zhang Xiaoxuan Li Yangqi 《Journal of Traffic and Transportation Engineering》 2024年第1期11-22,共12页
In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the node degree and the average path length of China aviation network in 1988,1994,2001... In order to reveal the complex network characteristics and evolution principle of China aviation network,the relationship between the node degree and the average path length of China aviation network in 1988,1994,2001,2008 and 2015 was studied.According to the theory and method of complex network,the network system was constructed with the city where the airport was located as the network node and the airline as the edge of the network.On the basis of the statistical data,the node average path length of China aviation network in 1988,1994,2001,2008 and 2015 was calculated.Through regression analysis,it was found that the node degree had a logarithmic relationship with the average length of node path,and the two parameters of the logarithmic relationship had linear evolutionary trace.Key word:China aviation network,complex network,node degree,average length of node path,logarithmic relationship,evolutionary trace. 展开更多
关键词 China aviation network complex network node degree average length of node path logarithmic relationship evolutionary trace.
下载PDF
Male/Female Relationships in Strange Interlude
13
作者 康晓亚 夏霁 《教育教学论坛》 2012年第9期219-220,共2页
Strange Interlude has been considered the most complicated play ever written by Eugene O'Neill,not only because of it's great length,but also because of the complex in structure.The play conversal most the ent... Strange Interlude has been considered the most complicated play ever written by Eugene O'Neill,not only because of it's great length,but also because of the complex in structure.The play conversal most the entire life of a woman,right from her girlhood to old age.This paper intends to analyze diverse male/fem ale relationships that are evident in thisplay. 展开更多
关键词 male/female relationships Oedepus Complex Electra Complex
下载PDF
Relationships between Regional Indian Summer Monsoon Rainfall and Eurasian Snow Cover 被引量:7
14
作者 B. Parthasarathy Song Yang 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1995年第2期143-150,共8页
RelationshipsbetweenRegionalIndianSummerMonsoonRainfallandEurasianSnowCoverB.Parthasarathy(Indianinstituteof... RelationshipsbetweenRegionalIndianSummerMonsoonRainfallandEurasianSnowCoverB.Parthasarathy(IndianinstituteofTropicalMeteorolo... 展开更多
关键词 REGIONAL INDIAN raipfall Eurasian SNOW COVER INTERANNUAL relationship
下载PDF
Vegetation-environment relationships in the forests of Chitral district Hindukush range of Pakistan 被引量:8
15
作者 Nasrullah Khan Syed Shahid Shaukat +1 位作者 Moinuddin Ahmed Muhammad Faheem Siddiqui 《Journal of Forestry Research》 SCIE CAS CSCD 2013年第2期205-216,共12页
We investigated the composition of plant communities to quantify their relationships with environmental parameters in the Chitral Hindukush range of Pakistan. We sampled tree vegetation using the Point Centered Quarte... We investigated the composition of plant communities to quantify their relationships with environmental parameters in the Chitral Hindukush range of Pakistan. We sampled tree vegetation using the Point Centered Quarter (PCQ) method while understory vegetation was sampled in 1.5-m circular quadrats. Cedrus deodara is the national symbol of Pakistan and was dominant in the sampled communities. Because environmental variables determine vegetation types, we analyzed and evaluated edaphic and topographic factors. DCA-Ordination showed the major gradient as an amalgam of elevation (p<0.05) and slope (p<0.01) as the topographic factors correlated with species distribution. Soil variables were the factors of environmental significance along DCA axes. However, among these factors, Mg2+ , K + and N2+ contributed not more than 0.054% 0.20% and 0.073%, respectively, to variation along the first ordination axis. We conclude that the principal reason for weak or no correlation with many edaphic variables was the anthropogenic disturbance of vegetation. The understory vegetation was composed of perennial herbs in most communities and was most dense under the tree canopy. The understory vegetation strongly regulates tree seedling growth and regeneration patterns. We recommend further study of the understory vegetation using permanent plots to aid development of forest regeneration strategies. 展开更多
关键词 environmental relationship MULTIVARIATE ANALYSIS cluster ANALYSIS ORDINATION ANTHROPOGENIC factors forest Hindukush RANGE
下载PDF
Relationships between moment magnitude and fault parameters:theoretical and semi-empirical relationships 被引量:4
16
作者 王海云 陶夏新 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2003年第2期201-211,共11页
Fault parameters are important in earthquake hazard analysis. In this paper, theoretical relationships between moment magnitude and fault parameters including subsurface rupture length, downdip rupture width, rupture ... Fault parameters are important in earthquake hazard analysis. In this paper, theoretical relationships between moment magnitude and fault parameters including subsurface rupture length, downdip rupture width, rupture area, and average slip over the fault surface are deduced based on seismological theory. These theoretical relationships are further simplified by applying similarity conditions and an unique form is established. Then, combining thc simplified theoretical relationships between moment magnitude and fault parameters with seismic source data selected in this study, a practical semi-empirical relationship is established. The seismic source data selected is also to used to derive empirical relationships between moment magnitude and fault parameters by the ordinary least square regression method. Comparisons between semi-empirical relationships and empirical relationships show that the former depict distribution trends of data better than the latter. It is also observed that downdip rupture widths of strike slip faults are saturated when moment magnitude is more than 7.0, but downdip rupture widths of dip slip faults are not saturated in the moment magnitude ranges of this study. 展开更多
关键词 earthquake HAZARD analysis fault PARAMETERS scismic MOMENT MOMENT MAGNITUDE scmi-empirical relationships.
下载PDF
Relationships Between Tidal Prism and Throat Area of Tidal Inlets Along Yellow Sea and Bohai Sea Coasts 被引量:4
17
作者 Zhang Renshun and Wang Yaping Professor, Dept. of Geography, Nanjing Normal University, Nanjing 210024 Lecturer, Nanjing Normal University, Nanjing 210024 《China Ocean Engineering》 SCIE EI 1996年第2期229-238,共10页
The relationship between P (spring tidal prism) and A (throat area below mean sea level) is statistically analysed in terms of 29 tidal inlets or bays along the Huanghai Sea (Yellow Sea) and Bohai Sea coasts. For 15 o... The relationship between P (spring tidal prism) and A (throat area below mean sea level) is statistically analysed in terms of 29 tidal inlets or bays along the Huanghai Sea (Yellow Sea) and Bohai Sea coasts. For 15 of these tidal inlets, the best regression equation is A(km2) = 0.845 /】(km3)1.20. The analysis shows that C and n are little different from those in the P-A relationship for the inlets of the South China Sea and East China Sea coasts. It is noted that the relationship between P and A is unstable because of the difference in sediment abundance. The study shows that a united P-A relationship can be obtained for the tidal inlets of lagoon type and bay-drowned-valley type, not containing some half-circle shape bays which confront deep water. These half-circle bays do not belong to tidal inlets because they do not have enough sediment abundance and are fairly open. 展开更多
关键词 TIDAL INLET P-A relationship HUANGHAI SEA (Yellow Sea) Bohai SEA
下载PDF
Relationships between Rainy Days,Mean Daily Intensity and Seasonal Rainfall in Normal,Flood and Drought Years over India 被引量:1
18
作者 C.V.Singh 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1998年第3期142-150,共9页
RelationshipsbetwenRainyDays,MeanDailyIntensityandSeasonalRainfalinNormal,FloodandDroughtYearsoverIndiaC.V.S... RelationshipsbetwenRainyDays,MeanDailyIntensityandSeasonalRainfalinNormal,FloodandDroughtYearsoverIndiaC.V.SinghCentreforAtmo... 展开更多
关键词 Monsoon RAINFALL Linear relationship Logarithmic relationship Mean DAILY RAINFALL INTENSITY SEASONAL RAINFALL
下载PDF
The Role of Relationships with Teachers in Adolescent Development among a National Sample of Chinese Urban Adolescents 被引量:11
19
作者 DONGQi CHENChuan-sheng 《应用心理学》 CSSCI 2001年第2期3-10,共8页
A nationally representative sample of 1640 Chinese urban adolescents (mean age=14.5 years) and their parents and teachers were surveyed to examine the associations between relationships with teachers and parents and a... A nationally representative sample of 1640 Chinese urban adolescents (mean age=14.5 years) and their parents and teachers were surveyed to examine the associations between relationships with teachers and parents and adolescents' developmental outcomes such as academic performance, psychological well-being, altruistic behaviors, and misconduct. Results showed that the quality of adolescents' relationships with teachers was highly correlated with adolescent outcomes, in most cases more so than for relationships with parents. Furthermore, such associations were the same across both genders and three grade levels. These findings suggest that teachers may play an especially significant role in Chinese adolescent development. This study adds to the small but growing literature on the importance of teachers as well as other non-parental adults in adolescent psychosocial development. 展开更多
关键词 teacher-student relationships ADOLESCENT development CHINESE adolescents
下载PDF
Desert vegetation distribution and species-environment relationships in an oasis-desert ecotone of northwestern China 被引量:2
20
作者 ZHAO Peng QU Jianjun +3 位作者 XU Xianying YU Qiushi JIANG Shengxiu ZHAO Heran 《Journal of Arid Land》 SCIE CSCD 2019年第3期461-476,共16页
Environmental heterogeneity significantly affects the structure of ecological communities.Exploring vegetation distribution and its relationship with environmental factors is essential to understanding the abiotic mec... Environmental heterogeneity significantly affects the structure of ecological communities.Exploring vegetation distribution and its relationship with environmental factors is essential to understanding the abiotic mechanism(s)driving vegetation succession,especially in the ecologically fragile areas.In this study,based on the quantitative analysis of plant community and environmental factors in 68 plots at 10 different transects in the Minqin oasis-desert ecotone(ODE)of northwestern China,we investigated desert vegetation distribution and species-environment relationships using multivariate analysis.Two-way indicator species analysis(TWINSPAN),detrended correspondence analysis(DCA),and canonical correspondence analysis(CCA)methods were used.A total of 28 species,belonging to 27 genera in 8 families,were identified.Chenopodiaceae,Zygophyllaceae,Gramineae,and Leguminosae were the largest families.Annual and perennial herbs accounted for 28.60%of the total number of plants,while shrubs(42.90%)were the most dominant.Nitraria tangutorum was the constructive species of the desert plant community.We divided the 68 plots surveyed in this study into 7 community types,according to the results of TWINSPAN.The distribution of these 7 communities in the DCA ordination graph showed that species with a similar ecotype were clustered together.Results of CCA indicated that groundwater was the dominant factor influencing vegetation distribution,while distance between plot and oasis(Dis)and soil electrical conductivity(EC)were the local second-order factors.Our study suggests that optimizing the utilization of groundwater in oases is key to controlling the degradation of desert vegetation.The favorable topographic conditions of sand dunes should be fully utilized for vegetal dune stabilization,and the influence of soil salinity on the selection of afforestation tree species should be considered. 展开更多
关键词 TWINSPAN classification ORDINATION DESERT plant GROUNDWATER oasis-desert ECOTONE species-environment relationship Minqin
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部