Purpose: The aim of this paper is to develop a standardized and reliable measurement tool for assessing information-seeking behavior of undergraduate students.Design/methodology/approach: Based on information literacy...Purpose: The aim of this paper is to develop a standardized and reliable measurement tool for assessing information-seeking behavior of undergraduate students.Design/methodology/approach: Based on information literacy and information-seeking behavior theories, expert advice and students' interview, items of undergraduates' informationseeking behavior indicators were selected. With the analysis of homogeneity reliability, item analysis and factor analysis, this study constructs an assessment system to evaluate reliability and validity of the scale.Findings: The information-seeking behavior scale for undergraduates has divided undergraduates' information-seeking behavior into seven dimensions, which include 46 items. The reliability analysis of Cronbach's α was 0.910, and the coefficient of split-half reliability was0.817. The results of factor analysis showed that Kaiser-Meyer-Olkin(KMO) was 0.864,which indicates 55.536% of the total variation could be explained by the above seven dimensions.Research limitations: Due to a small sample size and limited sample distribution, further research need be conducted in an expanded sample size in order to explore the application scope of this evaluation system; in addition, the stability of the scale also need be confirmed.Practical implications: The paper sets up an information-seeking behavior evaluation system for undergraduates and explores the characteristics of their information-seeking behavior.This study provides guidance for the development of future information literacy education and the improvement of the information literacy level of undergraduates.Originality/value: An information-seeking behavior scale for undergraduates has been developed, which comprehensively covers information need, information source, information evaluation, information retrieval, information management, information utilization and information morality. The scale is proved to have good reliability, validity, popularity anddiscrimination that it is qualified to be an assessment tool of information-seeking behavior for Chinese undergraduates.展开更多
Objective This study aimed to explore the clinical value of Children Neuropsychological and Behavioral Scale-Revision 2016(CNBS-R2016)for Autism Spectrum Disorder(ASD)screening in the presence of developmental surveil...Objective This study aimed to explore the clinical value of Children Neuropsychological and Behavioral Scale-Revision 2016(CNBS-R2016)for Autism Spectrum Disorder(ASD)screening in the presence of developmental surveillance.Methods All participants were evaluated by the CNBS-R2016 and Gesell Developmental Schedules(GDS).Spearman’s correlation coefficients and Kappa values were obtained.Taking GDS as a reference assessment,the performance of the CNBS-R2016 for detecting the developmental delays of children with ASD was analyzed with receiver operating characteristic(ROC)curves.The efficacy of the CNBS-R2016 to screen for ASD was explored by comparing Communication Warning Behavior with Autism Diagnostic Observation Schedule,Second Edition(ADOS-2).Results In total,150 children aged 12–42 months with ASD were enrolled.The developmental quotients of the CNBS-R2016 were correlated with those of the GDS(r=0.62–0.94).The CNBS-R2016 and GDS had good diagnostic agreement for developmental delays(Kappa=0.73–0.89),except for Fine Motor.There was a significant difference between the proportions of Fine Motor,delays detected by the CNBS-R2016 and GDS(86.0%vs.77.3%).With GDS as a standard,the areas under the ROC curves of the CNBS-R2016 were above 0.95 for all the domains except Fine Motor,which was 0.70.In addition,the positive rate of ASD was 100.0%and 93.5%when the cut-off points of 7 and 12 in the Communication Warning Behavior subscale were used,respectively.Conclusion The CNBS-R2016 performed well in developmental assessment and screening for children with ASD,especially by Communication Warning Behaviors subscale.Therefore,the CNBS-R2016 is worthy of clinical application in children with ASD in China.展开更多
School-based universal screening for behavioral/emotional risk is a necessary first step to providing services in an educational setting for students with emotional and behavioral disorders (EBDs). Psychometric proper...School-based universal screening for behavioral/emotional risk is a necessary first step to providing services in an educational setting for students with emotional and behavioral disorders (EBDs). Psychometric properties are critical to making decisions about choosing a screening instrument. The purpose of the present study was to examine the psychometric properties of the student risk screening scale for internalizing and externalizing behaviors (SRSS-IE). Participants included 3145 students and their teachers. Item-level analyses of the current sample supported the retention of all items. The internal consistency of the SRSS items ranged from 0.83 to 0.85. Convergent validity between the SRSS-IE and a well-established screening tool, the strength and difficulties questionnaire (SDQ), was found for the total score (r = 0.70). Additionally, the results of this study demonstrate strong social validity, suggesting the SRSS-IE to be a useful and functional screening tool. We conclude that the SRSS-IE is a valid and reliable instrument for assessing the level of emotional and behavioral difficulties among elementary students.展开更多
Unlike monocrystalline cubic boron nitride(CBN), polycrystalline CBN(PCBN) shows not only higher fracture resistance induced by tool-workpiece interaction but also better selfsharpening capability;therefore, efforts h...Unlike monocrystalline cubic boron nitride(CBN), polycrystalline CBN(PCBN) shows not only higher fracture resistance induced by tool-workpiece interaction but also better selfsharpening capability;therefore, efforts have been devoted to the study of PCBN applications in manufacturing engineering. Most of the studies, however, remain qualitative due to difficulties in experimental observations and theoretical modeling and provide limited in-depth understanding of the self-sharpening behavior/mechanism. To fill this research gap, the present study investigates the self-sharpening process of PCBN abrasives in grinding and analyzes the macro-scale fracture behavior and highly localized micro-scale crack propagation in detail. The widely employed finite element(FE) method, together with the classic Voronoi diagram and cohesive element technique,is used considering the pronounced success of FE applications in polycrystalline material modeling.Grinding trials with careful observation of the PCBN abrasive morphologies are performed to validate the proposed method. The self-sharpening details, including fracture morphology, grinding force, strain energy, and damage dissipation energy, are studied. The effects of maximum grain cut depths(MGCDs) and grinding speeds on the PCBN fracture behavior are discussed, and their optimum ranges for preferable PCBN self-sharpening performance are suggested.展开更多
The Kibble-Zurek (KZ) effect offers an overarching description of dynamical scaling behavior near a critical point.[1,2] Originally proposed in a classical setup,the KZ effect has been generalized to quantum phase tra...The Kibble-Zurek (KZ) effect offers an overarching description of dynamical scaling behavior near a critical point.[1,2] Originally proposed in a classical setup,the KZ effect has been generalized to quantum phase transitions[3-5] and is actively explored on quantum simulation platforms.[6-9] Exploring how the KZ effect fares across different criticalities has proven to be a rewarding pursuit,significantly enriching our understanding of nonequilibrium quantum dynamics.[3-5,10-23]展开更多
It is of great theoretical and practical significance to understand the rules of the differences in pesticide use behaviors between large-scale and small-scale farmers,so as to regulate the behavior of farmers differe...It is of great theoretical and practical significance to understand the rules of the differences in pesticide use behaviors between large-scale and small-scale farmers,so as to regulate the behavior of farmers differently and improve the quality and safety of rice.The overall pesticide use behavior of large-scale farmers was characterized by large doses and high application frequency,while that of small-scale farmers was characterized by small doses and low application frequency.The econometric test showed that(i)the proportion of staple food ration has a significant negative impact on the single dose exceeding the standard and pesticide application frequency of small-scale farmers,and the increase of the proportion of staple food ration will reduce the demand among small-scale farmers for pesticides;(ii)yield effect has a greater impact on the frequency of pesticide application by large-scale farmers,and the large yield effect will increase the frequency of pesticide application among large-scale farmers.Therefore,in pesticide use behaviors,large-scale farmers should reduce pesticide quantity and increase efficiency,while small-scale farmers improve the level of plant protection.展开更多
We propose a catalysis-select migration driven evolution model of two-species（A-and B-species） aggregates,where one unit of species A migrates to species B under the catalysts of species C,while under the catalysts ...We propose a catalysis-select migration driven evolution model of two-species（A-and B-species） aggregates,where one unit of species A migrates to species B under the catalysts of species C,while under the catalysts of species D the reaction will become one unit of species B migrating to species A.Meanwhile the catalyst aggregates of species C perform self-coagulation,as do the species D aggregates.We study this catalysis-select migration driven kinetic aggregation phenomena using the generalized Smoluchowski rate equation approach with C species catalysis-select migration rate kernel K（k;i,j） = Kkij and D species catalysis-select migration rate kernel J（k;i,j） = Jkij.The kinetic evolution behaviour is found to be dominated by the competition between the catalysis-select immigration and emigration,in which the competition is between JD0 and KC0（D0 and C0 are the initial numbers of the monomers of species D and C,respectively）.When JD0 KC0 〉 0,the aggregate size distribution of species A satisfies the conventional scaling form and that of species B satisfies a modified scaling form.And in the case of JD0 KC0 〈 0,species A and B exchange their aggregate size distributions as in the above JD0 KC0 〉 0 case.展开更多
Aiming to develop materials for construction of the set-up and electrode of high-temperature molten salt reactors, the effect of Al and Y on the high-temperature oxidation behavior of Ni-11Fe-10Cu at 750 and 950 °...Aiming to develop materials for construction of the set-up and electrode of high-temperature molten salt reactors, the effect of Al and Y on the high-temperature oxidation behavior of Ni-11Fe-10Cu at 750 and 950 °C in air were investigated. The oxidation kinetics of Ni-11Fe-10Cu alloy followed parabolic law at 750 °C without spallation and linear law at 950 °C with severe spallation, while that of Ni-11Fe-10Cu-6Al-3Y alloy followed parabolic law at 750 and 950 °C without spallation. The parabolic rate constant （kp） of Ni-11Fe-10Cu was smaller than that of Ni-11Fe-10Cu-6Al-3Y at 750 °C. The oxide scale formed on Ni-11Fe-10Cu at 750 °C was composed of a CuO outer layer, a NiFe2O4 middle layer and a NiO inner layer. The oxide scale formed on Ni-11Fe-10Cu-6Al-3Y at 750 °C was also composed of the similar triplex layers in addition to an internal oxidation zone containing Al, Ni and Cu oxide and the microstructure of the scale changed with increasing temperature. Although the doping Al and Y could improve the adherence of oxide scale, it could aggravate the extent of internal oxidation. Based on the combination of X-ray diffraction （XRD）, scanning electron mi-croscopy/energy dispersive spectroscopy （SEM/EDX） analysis, the microstructure and growth mechanism of the multi-layer oxide scale was studied and the effect of doping Al and Y on the oxidation behavior of Ni-11Fe-10Cu alloy was also discussed.展开更多
In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the sc...In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P ( S ) ∝ e ?αS, where S represents nucleotide cluster size. The cluster-size distribution P(S1+S2) with the total size of sequential C-G cluster and A-T cluster S1+S2 were also studied. P(S1+S2) follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L(n) and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.展开更多
Despite extensive researches on the motion of polymer chains on lipid membranes,the effect of membrane fluctuations on polymer chain dynamics remains poorly understood.Here we report single molecule tracking experimen...Despite extensive researches on the motion of polymer chains on lipid membranes,the effect of membrane fluctuations on polymer chain dynamics remains poorly understood.Here we report single molecule tracking experiments that allow for comparable measurements of polymer chain diffusion dynamics on nanotubular and planar phospholipid membranes.We observe a super-diffusion behavior and no apparent chain-length-dependent mobility of polymer chains on nanotubular membranes,while a Brownian motion and apparent chain-lengthdependent mobility of polymer chains on planar membranes.We suggest the super-diffusion nature of polymer chains may be due to the thermal-fluctuations of lipid nanotubes,which can be described from a statistical thermodynamic phenomenon coupling of polymer chain dynamics and surface thermal fluctuations.We suggest that the existence of surface environment fluctuations should influence the dynamics of the adsorbed polymer chains.This study provides previously uncharacterized insights into polymer diffusion dynamics on thermal-fluctuating flexible surfaces,which is essential to understanding the effect of environment fluctuations on polymer chain behaviors.展开更多
The results from a number of investigations and fire experiments are presented and analyzed in order to characterize the fire behavior of mining vehicles in underground hard rock mines. The analysis also includes fire...The results from a number of investigations and fire experiments are presented and analyzed in order to characterize the fire behavior of mining vehicles in underground hard rock mines. The analysis also includes fire safety and fire protection measures with respect to the mining vehicle fire behavior.Earlier studies on fires in underground hard rock mines have shown that vehicles or mobile equipment are the dominant sources of fire. A better knowledge about the fire behavior of vehicles in underground hard rock mines is therefore needed. During the analysis the direction and flow rate of the ventilation in a drift was found to have a significant impact on the fire behavior, causing for example flame tilt with rapid fire spread. The shielded sections of a vehicle will be less affected by the ventilation flow resulting in for example a decreased flame spread. It was also found that spray fires may result in considerable heat release rate but are generally of shorter duration and will not make any significant contributions to the overall heat release rate of the fully developed vehicle fire. The fire duration of a loader tire from a full-scale fire experiment was found to be at least 200 min and will largely determine the total fire duration of the vehicle. A different scenario with different conditions with for example a slower flame spread resulted in an even longer fire duration. The radiative and convective fraction will be a key factor when determining the heat transfer mechanisms involved in a fire and will vary from material to material.Calculations show that the radiative fraction of the tire fires on two mining vehicles is significantly lower than found in earlier experiments. The design and construction of the mining vehicle will have an important impact on the fire behavior and could possibly mitigate the consequences of a fire and allow fire personnel to extinguish a fire that otherwise would have had a too high heat release rate.展开更多
Analysis of freight rate volatility characteristics is a hot topic after year 2008 due to the effect of financial crisis in marine transportation.In this paper,we analyze the bulk freight rate index by detrended fluct...Analysis of freight rate volatility characteristics is a hot topic after year 2008 due to the effect of financial crisis in marine transportation.In this paper,we analyze the bulk freight rate index by detrended fluctuation analysis(DFA) method and discover the scaling behavior.Switching points(SPs),as the indicators of scaling behavior,can be eliminated after Vondr′ak noise reduction technique.Therefore,we conclude that highfrequency noise is the cause of SP.展开更多
基金supported by the National Social Science Foundation of China(Grant No.:11BTQ044)the Innovative Training Program for College Students in Changsha University(Grant No:CW11255)
文摘Purpose: The aim of this paper is to develop a standardized and reliable measurement tool for assessing information-seeking behavior of undergraduate students.Design/methodology/approach: Based on information literacy and information-seeking behavior theories, expert advice and students' interview, items of undergraduates' informationseeking behavior indicators were selected. With the analysis of homogeneity reliability, item analysis and factor analysis, this study constructs an assessment system to evaluate reliability and validity of the scale.Findings: The information-seeking behavior scale for undergraduates has divided undergraduates' information-seeking behavior into seven dimensions, which include 46 items. The reliability analysis of Cronbach's α was 0.910, and the coefficient of split-half reliability was0.817. The results of factor analysis showed that Kaiser-Meyer-Olkin(KMO) was 0.864,which indicates 55.536% of the total variation could be explained by the above seven dimensions.Research limitations: Due to a small sample size and limited sample distribution, further research need be conducted in an expanded sample size in order to explore the application scope of this evaluation system; in addition, the stability of the scale also need be confirmed.Practical implications: The paper sets up an information-seeking behavior evaluation system for undergraduates and explores the characteristics of their information-seeking behavior.This study provides guidance for the development of future information literacy education and the improvement of the information literacy level of undergraduates.Originality/value: An information-seeking behavior scale for undergraduates has been developed, which comprehensively covers information need, information source, information evaluation, information retrieval, information management, information utilization and information morality. The scale is proved to have good reliability, validity, popularity anddiscrimination that it is qualified to be an assessment tool of information-seeking behavior for Chinese undergraduates.
基金This study was supported by Emergency Technology Research Project of Huazhong University of Science and Technology(No.2020kfyXGYJ020).
文摘Objective This study aimed to explore the clinical value of Children Neuropsychological and Behavioral Scale-Revision 2016(CNBS-R2016)for Autism Spectrum Disorder(ASD)screening in the presence of developmental surveillance.Methods All participants were evaluated by the CNBS-R2016 and Gesell Developmental Schedules(GDS).Spearman’s correlation coefficients and Kappa values were obtained.Taking GDS as a reference assessment,the performance of the CNBS-R2016 for detecting the developmental delays of children with ASD was analyzed with receiver operating characteristic(ROC)curves.The efficacy of the CNBS-R2016 to screen for ASD was explored by comparing Communication Warning Behavior with Autism Diagnostic Observation Schedule,Second Edition(ADOS-2).Results In total,150 children aged 12–42 months with ASD were enrolled.The developmental quotients of the CNBS-R2016 were correlated with those of the GDS(r=0.62–0.94).The CNBS-R2016 and GDS had good diagnostic agreement for developmental delays(Kappa=0.73–0.89),except for Fine Motor.There was a significant difference between the proportions of Fine Motor,delays detected by the CNBS-R2016 and GDS(86.0%vs.77.3%).With GDS as a standard,the areas under the ROC curves of the CNBS-R2016 were above 0.95 for all the domains except Fine Motor,which was 0.70.In addition,the positive rate of ASD was 100.0%and 93.5%when the cut-off points of 7 and 12 in the Communication Warning Behavior subscale were used,respectively.Conclusion The CNBS-R2016 performed well in developmental assessment and screening for children with ASD,especially by Communication Warning Behaviors subscale.Therefore,the CNBS-R2016 is worthy of clinical application in children with ASD in China.
文摘School-based universal screening for behavioral/emotional risk is a necessary first step to providing services in an educational setting for students with emotional and behavioral disorders (EBDs). Psychometric properties are critical to making decisions about choosing a screening instrument. The purpose of the present study was to examine the psychometric properties of the student risk screening scale for internalizing and externalizing behaviors (SRSS-IE). Participants included 3145 students and their teachers. Item-level analyses of the current sample supported the retention of all items. The internal consistency of the SRSS items ranged from 0.83 to 0.85. Convergent validity between the SRSS-IE and a well-established screening tool, the strength and difficulties questionnaire (SDQ), was found for the total score (r = 0.70). Additionally, the results of this study demonstrate strong social validity, suggesting the SRSS-IE to be a useful and functional screening tool. We conclude that the SRSS-IE is a valid and reliable instrument for assessing the level of emotional and behavioral difficulties among elementary students.
基金the financial support provided by the National Natural Science Foundation of China (No. 51775275 and No. 51575270)the Fundamental Research Funds for the Central Universities of China (No. NP2018110)+1 种基金Top Six Talents Project in Jiangsu Province of China (No. JXQC-002)the Foundation of Postgraduate Research & Practice Innovation Program of Jiangsu Province of China (KYCX18_0264)
文摘Unlike monocrystalline cubic boron nitride(CBN), polycrystalline CBN(PCBN) shows not only higher fracture resistance induced by tool-workpiece interaction but also better selfsharpening capability;therefore, efforts have been devoted to the study of PCBN applications in manufacturing engineering. Most of the studies, however, remain qualitative due to difficulties in experimental observations and theoretical modeling and provide limited in-depth understanding of the self-sharpening behavior/mechanism. To fill this research gap, the present study investigates the self-sharpening process of PCBN abrasives in grinding and analyzes the macro-scale fracture behavior and highly localized micro-scale crack propagation in detail. The widely employed finite element(FE) method, together with the classic Voronoi diagram and cohesive element technique,is used considering the pronounced success of FE applications in polycrystalline material modeling.Grinding trials with careful observation of the PCBN abrasive morphologies are performed to validate the proposed method. The self-sharpening details, including fracture morphology, grinding force, strain energy, and damage dissipation energy, are studied. The effects of maximum grain cut depths(MGCDs) and grinding speeds on the PCBN fracture behavior are discussed, and their optimum ranges for preferable PCBN self-sharpening performance are suggested.
文摘The Kibble-Zurek (KZ) effect offers an overarching description of dynamical scaling behavior near a critical point.[1,2] Originally proposed in a classical setup,the KZ effect has been generalized to quantum phase transitions[3-5] and is actively explored on quantum simulation platforms.[6-9] Exploring how the KZ effect fares across different criticalities has proven to be a rewarding pursuit,significantly enriching our understanding of nonequilibrium quantum dynamics.[3-5,10-23]
基金the financial supports from the National Natural Science Foundation of China (71573261)the Agricultural and Rural Resources Monitoring and Statistical Funds Project, Ministry of Agriculture and Rural Affairs, China (12190201)the Agricultural Science and Technology Innovation Program, Chinese Academy of Agricultural Sciences (ASTIP-IAED-2019-01)
文摘It is of great theoretical and practical significance to understand the rules of the differences in pesticide use behaviors between large-scale and small-scale farmers,so as to regulate the behavior of farmers differently and improve the quality and safety of rice.The overall pesticide use behavior of large-scale farmers was characterized by large doses and high application frequency,while that of small-scale farmers was characterized by small doses and low application frequency.The econometric test showed that(i)the proportion of staple food ration has a significant negative impact on the single dose exceeding the standard and pesticide application frequency of small-scale farmers,and the increase of the proportion of staple food ration will reduce the demand among small-scale farmers for pesticides;(ii)yield effect has a greater impact on the frequency of pesticide application by large-scale farmers,and the large yield effect will increase the frequency of pesticide application among large-scale farmers.Therefore,in pesticide use behaviors,large-scale farmers should reduce pesticide quantity and increase efficiency,while small-scale farmers improve the level of plant protection.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10875086 and 10775104)
文摘We propose a catalysis-select migration driven evolution model of two-species（A-and B-species） aggregates,where one unit of species A migrates to species B under the catalysts of species C,while under the catalysts of species D the reaction will become one unit of species B migrating to species A.Meanwhile the catalyst aggregates of species C perform self-coagulation,as do the species D aggregates.We study this catalysis-select migration driven kinetic aggregation phenomena using the generalized Smoluchowski rate equation approach with C species catalysis-select migration rate kernel K（k;i,j） = Kkij and D species catalysis-select migration rate kernel J（k;i,j） = Jkij.The kinetic evolution behaviour is found to be dominated by the competition between the catalysis-select immigration and emigration,in which the competition is between JD0 and KC0（D0 and C0 are the initial numbers of the monomers of species D and C,respectively）.When JD0 KC0 〉 0,the aggregate size distribution of species A satisfies the conventional scaling form and that of species B satisfies a modified scaling form.And in the case of JD0 KC0 〈 0,species A and B exchange their aggregate size distributions as in the above JD0 KC0 〉 0 case.
基金supported by the National Natural Science Foundation of China(51325102)the International Science and Technology Cooperation Program of Ministry of Science and Technology(2015DFA90750)
文摘Aiming to develop materials for construction of the set-up and electrode of high-temperature molten salt reactors, the effect of Al and Y on the high-temperature oxidation behavior of Ni-11Fe-10Cu at 750 and 950 °C in air were investigated. The oxidation kinetics of Ni-11Fe-10Cu alloy followed parabolic law at 750 °C without spallation and linear law at 950 °C with severe spallation, while that of Ni-11Fe-10Cu-6Al-3Y alloy followed parabolic law at 750 and 950 °C without spallation. The parabolic rate constant （kp） of Ni-11Fe-10Cu was smaller than that of Ni-11Fe-10Cu-6Al-3Y at 750 °C. The oxide scale formed on Ni-11Fe-10Cu at 750 °C was composed of a CuO outer layer, a NiFe2O4 middle layer and a NiO inner layer. The oxide scale formed on Ni-11Fe-10Cu-6Al-3Y at 750 °C was also composed of the similar triplex layers in addition to an internal oxidation zone containing Al, Ni and Cu oxide and the microstructure of the scale changed with increasing temperature. Although the doping Al and Y could improve the adherence of oxide scale, it could aggravate the extent of internal oxidation. Based on the combination of X-ray diffraction （XRD）, scanning electron mi-croscopy/energy dispersive spectroscopy （SEM/EDX） analysis, the microstructure and growth mechanism of the multi-layer oxide scale was studied and the effect of doping Al and Y on the oxidation behavior of Ni-11Fe-10Cu alloy was also discussed.
基金Project supported by the National Natural Science Foundation of China (No. 20574052)Program for New Century Excellent Talents in University,and the Natural Science Foundation of Zhejiang Prov-ince (Nos. R404047 and Y405011),China
文摘In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P ( S ) ∝ e ?αS, where S represents nucleotide cluster size. The cluster-size distribution P(S1+S2) with the total size of sequential C-G cluster and A-T cluster S1+S2 were also studied. P(S1+S2) follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L(n) and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.
基金financially supported by the National Natural Science Foundation of China(No.22173070)the Youth Talent Support Program from Wuhan University of Technology。
文摘Despite extensive researches on the motion of polymer chains on lipid membranes,the effect of membrane fluctuations on polymer chain dynamics remains poorly understood.Here we report single molecule tracking experiments that allow for comparable measurements of polymer chain diffusion dynamics on nanotubular and planar phospholipid membranes.We observe a super-diffusion behavior and no apparent chain-length-dependent mobility of polymer chains on nanotubular membranes,while a Brownian motion and apparent chain-lengthdependent mobility of polymer chains on planar membranes.We suggest the super-diffusion nature of polymer chains may be due to the thermal-fluctuations of lipid nanotubes,which can be described from a statistical thermodynamic phenomenon coupling of polymer chain dynamics and surface thermal fluctuations.We suggest that the existence of surface environment fluctuations should influence the dynamics of the adsorbed polymer chains.This study provides previously uncharacterized insights into polymer diffusion dynamics on thermal-fluctuating flexible surfaces,which is essential to understanding the effect of environment fluctuations on polymer chain behaviors.
文摘The results from a number of investigations and fire experiments are presented and analyzed in order to characterize the fire behavior of mining vehicles in underground hard rock mines. The analysis also includes fire safety and fire protection measures with respect to the mining vehicle fire behavior.Earlier studies on fires in underground hard rock mines have shown that vehicles or mobile equipment are the dominant sources of fire. A better knowledge about the fire behavior of vehicles in underground hard rock mines is therefore needed. During the analysis the direction and flow rate of the ventilation in a drift was found to have a significant impact on the fire behavior, causing for example flame tilt with rapid fire spread. The shielded sections of a vehicle will be less affected by the ventilation flow resulting in for example a decreased flame spread. It was also found that spray fires may result in considerable heat release rate but are generally of shorter duration and will not make any significant contributions to the overall heat release rate of the fully developed vehicle fire. The fire duration of a loader tire from a full-scale fire experiment was found to be at least 200 min and will largely determine the total fire duration of the vehicle. A different scenario with different conditions with for example a slower flame spread resulted in an even longer fire duration. The radiative and convective fraction will be a key factor when determining the heat transfer mechanisms involved in a fire and will vary from material to material.Calculations show that the radiative fraction of the tire fires on two mining vehicles is significantly lower than found in earlier experiments. The design and construction of the mining vehicle will have an important impact on the fire behavior and could possibly mitigate the consequences of a fire and allow fire personnel to extinguish a fire that otherwise would have had a too high heat release rate.
基金the MOE(Ministry of Education in China)Project of Humanities and Social Sciences(Nos.12YJCGJW001 and 14YJC630008)the Interdiscipline Foundation of Social Science and Engineering of Shanghai Jiao Tong University(No.15JCMY11)+2 种基金the Fund of Center for Teaching and Learning Development of Shanghai Jiao Tong University(No.CTLD16B3002)the National Students Innovation Program of China(Nos.201610248001 and IPP12002)the National Natural Science Foundation of China(No.51409157)
文摘Analysis of freight rate volatility characteristics is a hot topic after year 2008 due to the effect of financial crisis in marine transportation.In this paper,we analyze the bulk freight rate index by detrended fluctuation analysis(DFA) method and discover the scaling behavior.Switching points(SPs),as the indicators of scaling behavior,can be eliminated after Vondr′ak noise reduction technique.Therefore,we conclude that highfrequency noise is the cause of SP.
