In order to investigate the behavior characteristics of asphalt components during the process of nano-cracks temperature self-healing(NTS),molecular simulation technology was used to simulate the temperature self-heal...In order to investigate the behavior characteristics of asphalt components during the process of nano-cracks temperature self-healing(NTS),molecular simulation technology was used to simulate the temperature self-healing of asphalt.Based on the determination of asphalts(virgin asphalt and aged asphalt),the proportional changes of asphalt components were confirmed.The distribution characteristics of asphalt components were obtained by marking different components in the process of NTS.At the same time,the rationality of the micro simulation findings was confirmed by asphalt performance tests and infrared spectroscopy results.The results show that different asphalt components have different behavior characteristics in the process of NTS.The content of asphaltene and resin plays a key role in the process of NTS,while saturation and aromatics play an active role in the temperature self-healing before and after aging.The NTS is the result of the comprehensive action of different components,and the self-healing efficiency is proportional to the relative molecular mass.The effect of aging on the NTS is also realized by changing the proportion of asphalt components.展开更多
In order to enhance the accuracy of Air Traffic Control(ATC)cybersecurity attack detection,in this paper,a new clustering detection method is designed for air traffic control network security attacks.The feature set f...In order to enhance the accuracy of Air Traffic Control(ATC)cybersecurity attack detection,in this paper,a new clustering detection method is designed for air traffic control network security attacks.The feature set for ATC cybersecurity attacks is constructed by setting the feature states,adding recursive features,and determining the feature criticality.The expected information gain and entropy of the feature data are computed to determine the information gain of the feature data and reduce the interference of similar feature data.An autoencoder is introduced into the AI(artificial intelligence)algorithm to encode and decode the characteristics of ATC network security attack behavior to reduce the dimensionality of the ATC network security attack behavior data.Based on the above processing,an unsupervised learning algorithm for clustering detection of ATC network security attacks is designed.First,determine the distance between the clustering clusters of ATC network security attack behavior characteristics,calculate the clustering threshold,and construct the initial clustering center.Then,the new average value of all feature objects in each cluster is recalculated as the new cluster center.Second,it traverses all objects in a cluster of ATC network security attack behavior feature data.Finally,the cluster detection of ATC network security attack behavior is completed by the computation of objective functions.The experiment took three groups of experimental attack behavior data sets as the test object,and took the detection rate,false detection rate and recall rate as the test indicators,and selected three similar methods for comparative test.The experimental results show that the detection rate of this method is about 98%,the false positive rate is below 1%,and the recall rate is above 97%.Research shows that this method can improve the detection performance of security attacks in air traffic control network.展开更多
Al Si10Mg porous protective structure often produces different damage forms under compressive loading,and these damage modes affect its protective function.In order to well meet the service requirements,there is an ur...Al Si10Mg porous protective structure often produces different damage forms under compressive loading,and these damage modes affect its protective function.In order to well meet the service requirements,there is an urgent need to comprehensively understand the mechanical behavior and response mechanism of AlSi10Mg porous structures under compressive loading.In this paper,Al Si10Mg porous structures with three kinds of volume fractions are designed and optimized to meet the requirements of high-impact,strong-energy absorption,and lightweight characteristics.The mechanical behaviors of AlSi10Mg porous structures,including the stress-strain relationship,structural bearing state,deformation and damage modes,and energy absorption characteristics,were obtained through experimental studies at different loading rates.The damage pattern of the damage section indicates that AlSi10Mg porous structures have both ductile and brittle mechanical properties.Numerical simulation studies show that the AlSi10Mg porous structure undergoes shear damage due to relative misalignment along the diagonal cross-section,and the damage location is almost at 45°to the load direction,which is the most direct cause of its structural damage,revealing the damage mechanism of AlSi10Mg porous structures under the compressive load.The normalized energy absorption model constructed in the paper well interprets the energy absorption state of Al Si10Mg porous structures and gives the sensitive location of the structures,and the results of this paper provide important references for peers in structural design and optimization.展开更多
The snap-through behaviors and nonlinear vibrations are investigated for a bistable composite laminated cantilever shell subjected to transversal foundation excitation based on experimental and theoretical approaches....The snap-through behaviors and nonlinear vibrations are investigated for a bistable composite laminated cantilever shell subjected to transversal foundation excitation based on experimental and theoretical approaches.An improved experimental specimen is designed in order to satisfy the cantilever support boundary condition,which is composed of an asymmetric region and a symmetric region.The symmetric region of the experimental specimen is entirely clamped,which is rigidly connected to an electromagnetic shaker,while the asymmetric region remains free of constraint.Different motion paths are realized for the bistable cantilever shell by changing the input signal levels of the electromagnetic shaker,and the displacement responses of the shell are collected by the laser displacement sensors.The numerical simulation is conducted based on the established theoretical model of the bistable composite laminated cantilever shell,and an off-axis three-dimensional dynamic snap-through domain is obtained.The numerical solutions are in good agreement with the experimental results.The nonlinear stiffness characteristics,dynamic snap-through domain,and chaos and bifurcation behaviors of the shell are quantitatively analyzed.Due to the asymmetry of the boundary condition and the shell,the upper stable-state of the shell exhibits an obvious soft spring stiffness characteristic,and the lower stable-state shows a linear stiffness characteristic of the shell.展开更多
A soil water retention curve (SWRC) is an essential soil physical property for analyzing transport and retention of water in a soil layer. A SWRC is often described as a single-valued function that relates the soil wa...A soil water retention curve (SWRC) is an essential soil physical property for analyzing transport and retention of water in a soil layer. A SWRC is often described as a single-valued function that relates the soil water potential ψ to volumetric water content θ of the soil. However, an in-situ ψ − θ relation should show soil water hysteresis, though this fact is often neglected in analyses of field soil water regimes while long-term in-situ soil water hysteresis is not well characterized. This study aimed at probing and characterizing in-situ ψ − θ relations. The developments of large hysteresis in the in-situ ψ − θ relations were observed only a few times during the study period of 82 months. Any of the large hysteretic behaviors in the ψ − θ relations began with an unusually strong continual reduction in ψ. The completion of a hysteresis loop required a recorded maximum rainfall. Because the study field had very small chances to meet such strong rainfall events, it took multiple years to restore the fraction of soil water depleted by the unusually strong continual reduction in ψ. While wetting-drying cycles had occurred within a certain domain of ψ, hysteretic behaviors tended to be so small that the in-situ ψ − θ relation can be approximated as a single-valued function of θ(ψ). These observed patterns of the in-situ ψ − θ relations were characterized by kinds of difference in dθ/dψ between a drying process and a wetting process at a given ψ. Thus, more amounts of experimental facts about wetting SWRCs in parallel with drying SWRCs should be needed for correct modelling, analyzing, and predicting soil water regimes in fields. It is also necessary to increase our understandings about the long-term trends of occurrences of extreme weather conditions associated with possible change in climate.展开更多
BACKGROUND The main treatment methods for cancer include surgery,radiotherapy,chemotherapy,targeted drug therapy and so on.Patients often feel anger,anxiety,depression,and other negative psychological reactions in the...BACKGROUND The main treatment methods for cancer include surgery,radiotherapy,chemotherapy,targeted drug therapy and so on.Patients often feel anger,anxiety,depression,and other negative psychological reactions in the process of treatment.AIM To explore the effects of cognitive behavioral therapy on the personality characteristics of cancer patients.METHODS According to the matching design requirements,150 cancer patients were divided into 3 groups based on sex,age,condition,and cultural background.Patients in the control group received conventional treatment.Patients in experimental group 1 received an intervention based on conventional treatment combined with cognitive behavioral therapy.Patients in experimental group 2 received family members'participation in addition to the treatment given in experimental group 1.An Eysenck personality questionnaire was used to investigate all the patients before and after the intervention,and the scores for psychosis,introversion,neuroticism,and concealment degree were analyzed.RESULTS Compared with the control group,for experimental group 1 and experimental group 2 before and after the intervention,the four dimensions of mental quality,neuroticism,introversion and concealment degree all decreased,and the difference was statistically significant(P<0.05).After the intervention,there were no obvious or statistically significant differences(P>0.05)among the control group,experimental group 1,and experimental group 2 for two personality traits,psychoticism and neuroticism,both inside and outside degree and all four dimensions.CONCLUSION Simple cognitive behavioral therapy could not change the personality characteristics of cancer patients quickly,but the patients’personality characteristics were significantly improved after treatment.展开更多
In this paper, the inherent rdationships between the running regulations and behavior charactcristics of cellular automata are presented; an imprecise taxonomy of such syseros is put forward; the three extreme cases o...In this paper, the inherent rdationships between the running regulations and behavior charactcristics of cellular automata are presented; an imprecise taxonomy of such syseros is put forward; the three extreme cases of slablc sysems are discussed; and the illogicalness of evolutional strategies of cellular automata is analyzed. The result is suilable for the emulation and prediction of behavior of discrete dynamics sys terns; especially it can be taken as an important analysis means of dynamic performance of complex networks.展开更多
Tourists are the subject of tourism activity,and it is conducive to promoting sustainable development of tourism destination by studying their behavior characteristics and tourism perception.Mugecuo Scenic Area in Kan...Tourists are the subject of tourism activity,and it is conducive to promoting sustainable development of tourism destination by studying their behavior characteristics and tourism perception.Mugecuo Scenic Area in Kangding City,Ganzi Tibetan Autonomous Prefecture,Sichuan Province is taken as research case,and visitors and managers in the scenic area are surveyed by using semi-structured interview method.Based on survey data,the research aims to put forward corresponding policy suggestions for sustainable development of Mugecuo Scenic Area by deeply analyzing tourists’ access to information of scenic area,tourists’ travel purpose,tourists’ satisfaction with services of scenic area and willingness to revisit.展开更多
The objective of this study is to look at the understanding and perceptions of public health nurses (PHNs) related to behavioral characteristics of fathers that contribute to emotional instability in mothers by review...The objective of this study is to look at the understanding and perceptions of public health nurses (PHNs) related to behavioral characteristics of fathers that contribute to emotional instability in mothers by reviewing abuse cases involving infants and very young children. A qualitative descriptive design was applied to the data analysis, based on a semi-structured interview administered to three experienced PHNs who had been in charge of maternal and child health services for at least five years at a public health department or health center;with the data obtained in the interview narratives analyzed. In the observations of the experienced PHNs, the behavioral characteristics of fathers who are instigators of child abuse can be classified into five categories, fathers who are: “Talking to others about marital problems without attempting to solve these by themselves”, “Working on learning about childcare seeking to correct childcare methods”, “Taking the initiative in childcare at cross purposes with mothers”, “Stressing the effort they (the fathers) put into childcare”, and “Failing to notice the own family situation and problems”. The findings of the study suggest the necessity for PHNs to understand fathers, to be aware of the difficulty of building a supportive relationship with fathers, and to improve skills enabling the PHNs to help fathers form good relationships with other family members.展开更多
Objective:This study explored the characteristics,causality,and suicidal behavior among family members with suicide history in Wonogiri,Central Java,Indonesia.Methods:Qualitative semistructured interviews were conduct...Objective:This study explored the characteristics,causality,and suicidal behavior among family members with suicide history in Wonogiri,Central Java,Indonesia.Methods:Qualitative semistructured interviews were conducted with 15 family members who had made suicide attempts.The interviews directly explored the relationships among characteristics,causality,and suicidal behavior.The research data were analyzed using the Miles and Huberman approach.Results:The results indicate that there are relationships among characteristics,causality,and suicidal behaviors.The characteristics contributing to suicide attempts were male gender,age(adolescence and old age),lack of religious activities,introvert nature,low economic status,chronic diseases,unemployment,and a history of family members with suicide attempts.The causality of suicide was joblessness,economic crisis,unemployment,family conditions,personality disorder,depression,sickness,and suicide ideation.Conclusions:The findings highlight the relationships among characteristics,causality,and suicidal behaviors.Suicide occurs when individuals have some problems that they cannot solve because of the lack of family support.The causal factors were related to one another,which caused the suicidal behavior.One of the most effective suicide prevention strategies is educating the community on how to identify suicidal signs and increase social supports.展开更多
The waterfront space is a specific and perfect open space for people to experience the city.Daily entertainment,leisure,shopping,sports and other activities can be carried out in the waterfront slow-motility space.The...The waterfront space is a specific and perfect open space for people to experience the city.Daily entertainment,leisure,shopping,sports and other activities can be carried out in the waterfront slow-motility space.There are three types of slow-mover in urban waterfront space namely walking,stop or stay,and riding.Analysis of their behavioral characteristics and the difference of different people can help to clarify the design requirements and produce a waterfront space that will better meets people’s functional needs.展开更多
Based on the investigation and analysis of the social behavior characteristics of post-95undergraduates, this paper puts forward the principle of sharing and building e-class platform and analyzes thedevelopment of th...Based on the investigation and analysis of the social behavior characteristics of post-95undergraduates, this paper puts forward the principle of sharing and building e-class platform and analyzes thedevelopment of the functions of the four platforms such as the teacher-student service system, instant interactionsystem, SNS community system and vertical segmental pushing system and the realization of the function of modularoperation. Finally, in order to ensure the stable operation of the E-class platform, four measures are put forward suchas the systematic construction of the system, the innovation of team work, the assessment of key performances and thecomprehensive guarantee, thus providing an external guarantee for the stable operation of the E-class platform.展开更多
In this paper,a series of major policy decisions used to improve the power grid reliability,reduce the risk and losses of major power outages,and realize the modernization of 21st century power grid are discussed. The...In this paper,a series of major policy decisions used to improve the power grid reliability,reduce the risk and losses of major power outages,and realize the modernization of 21st century power grid are discussed. These decisions were adopted by American government and would also be helpful for the strategic development of Chinese power grid. It is proposed that China should take precaution,carry out security research on the overall dynamic behaviour characteristics of the UHV grid using the complexity theory,and finally provide safeguard for the Chinese UHV grid. It is also pointed out that,due to the lack of matured approaches to controll a cascading failure,the primary duty of a system operator is to work as a "watchdog" for the grid operation security,eliminate the cumulative effect and reduce the risk and losses of major cascading outages with the help of EMS and WAMS.展开更多
To improve the defense capability of military equipment under extreme conditions,impact-resistant and high-energy-consuming materials have to be developed.The damping characteristic of entangled porous metallic wire m...To improve the defense capability of military equipment under extreme conditions,impact-resistant and high-energy-consuming materials have to be developed.The damping characteristic of entangled porous metallic wire materials(EPMWM)for vibration isolation was previously investigated.In this paper,a study focusing on the impact-resistance of EPMWM with the consideration of ambient temperature is presented.The quasi-static and low-velocity impact mechanical behavior of EPMWM under different temperatures(25℃-300℃)are systematically studied.The results of the static compression test show that the damping energy dissipation of EPMWM increases with temperature while the nonlinear damping characteristics are gradually enhanced.During the impact experiments,the impact energy loss rate of EPMWM was between 65%and 85%,while the temperatures increased from 25℃to 300℃.Moreover,under the same drop impact conditions,the overall deformation of EPMWM decreases in the temperature range of 100℃-200℃.On the other hand,the impact stiffness,energy dissipation,and impact loss factor of EPMWM significantly increase with temperature.This can be attributed to an increase in temperature,which changes the thermal expansion coefficient and contact state of the internal wire helixes.Consequently,the energy dissipation mode(dry friction,air damping,and plastic deformation)of EPMWM is also altered.Therefore,the EPMWM may act as a potential candidate material for superior energy absorption applications.展开更多
C f/SiC composites were prepared by precursor pyrolysis hot pressing, and the effect of fiber characteristics on the fracture behavior of the composites was investigated. Because the heat treatment temperature of fibe...C f/SiC composites were prepared by precursor pyrolysis hot pressing, and the effect of fiber characteristics on the fracture behavior of the composites was investigated. Because the heat treatment temperature of fiber T300 (below 1?500?℃) was much lower than that of fiber M40JB (over 2?000?℃), fiber T300 had lower degree of graphitization and consisted of more impurities compared with fiber M40JB, suggesting that T300 exhibits higher chemical activity. As a result, the composite with T300 showed a brittle fracture behavior, which is mainly ascribed to a strongly bonded fiber/matrix interface as well as the degradation of fibers during the preparation of the composite. However, the composite with M40JB exhibits a tough fracture behavior, which is primarily attributed to a weakly bonded fiber/matrix interface and higher strength retention of the fibers.展开更多
Layered backfill is commonly used in mining operations,and its mechanical behavior is strongly influenced by delamination parameters.In this study,13 specimens with different numbers of delamination and delamination a...Layered backfill is commonly used in mining operations,and its mechanical behavior is strongly influenced by delamination parameters.In this study,13 specimens with different numbers of delamination and delamination angle were prepared to investigate the anisotropic mechanical behavior,energy dissipation characteristics and crack development of backfill.P-wave velocity,uniaxial compression,scanning electron microscope(SEM),and acoustic emission(AE)experiments were conducted.The results indicate that:(1)The P-wave velocity has linear and elliptical relationships with the number of delamination surface and delamination angle,respectively;the strength,delamination parameters and P-wave velocity show a high degree of coincidence in terms of their function relationship,which can realize the rapid prediction of strength.(2)The microstructure of the delaminated surface is looser than that of the matrix,leading to a decrease in strength and an increase at the pore-fissure compaction stage.The number and angle of delamination increase linearly with the anisotropy coefficient.(3)The energy evolution in angle-cut backfill can be divided into four stages,with a decrease in the proportion of elastic energy at the initiation stress and peak stress with increasing number of delamination planes and delamination angle.(4)Crack development increases with the number of delamination surface and delamination angle,resulting in a decrease in energy dissipation coefficient and peak AE energy.These findings provide valuable insights for the design of filling materials and processes in mining operations.展开更多
In order to understand the travel characteristics and behavior patterns of women in Wangjing area and explore whether the existing situation can meet women's needs for the use of street space,the area around Wangj...In order to understand the travel characteristics and behavior patterns of women in Wangjing area and explore whether the existing situation can meet women's needs for the use of street space,the area around Wangjing South Station of Metro Line 14 was taken as an example for analysis and research.Wangjing area was classified to the following six use attributes:company enterprise,transportation hub,education and culture,residential area,municipal facilities,leisure and entertainment.The proportion of each use attribute was evaluated according to four levels:A 25%and above(including 25%),B 15%-25%,C 15%-5%,D 5%and below(including 5%).Finally,whether the plot had composite functions was judged,and the spatio-temporal laws and behavior patterns of surrounding women were analyzed from the perspectives of time and space.展开更多
目的探讨儿童行为特点及其家庭管理方式对儿童哮喘控制水平影响路径。方法采用便利抽样法选取82例哮喘患儿,应用一般资料问卷、适应行为量表(AAMR)、家庭管理测量量表(FaMM)及儿童哮喘控制测试表(Childhood asthma control test,C-ACT)...目的探讨儿童行为特点及其家庭管理方式对儿童哮喘控制水平影响路径。方法采用便利抽样法选取82例哮喘患儿,应用一般资料问卷、适应行为量表(AAMR)、家庭管理测量量表(FaMM)及儿童哮喘控制测试表(Childhood asthma control test,C-ACT)进行问卷调查,分析其影响路径。结果患儿AAMR适应行为量表得分(84.87±9.16)分,FaMM量表得分(188.77±19.01)分,C-ACT得分(15.20±4.66)分。Pearson相关分析结果显示,适应性行为分别与家庭管理、哮喘控制呈正相关关系(r=0.580、0.219,P<0.05),家庭管理与哮喘控制呈正相关关系(r=0.401,P<0.05)。结构方程模型结果表明,家庭管理在哮喘患儿适应性行为和哮喘控制有部分中介调节作用,效应占比为45.95%。结论儿童行为特点能够通过家庭管理方式对患儿哮喘控制水平产生影响,临床护理人员应重视对患儿家属的健康教育管理,提升家属对疾病的认知度及家庭管理能力,以改善患儿的行为方式,达到有效控制患儿疾病的目的。展开更多
基金Funded by the Fundamental Research Funds for the Central Universities(No.2572021AW10)。
文摘In order to investigate the behavior characteristics of asphalt components during the process of nano-cracks temperature self-healing(NTS),molecular simulation technology was used to simulate the temperature self-healing of asphalt.Based on the determination of asphalts(virgin asphalt and aged asphalt),the proportional changes of asphalt components were confirmed.The distribution characteristics of asphalt components were obtained by marking different components in the process of NTS.At the same time,the rationality of the micro simulation findings was confirmed by asphalt performance tests and infrared spectroscopy results.The results show that different asphalt components have different behavior characteristics in the process of NTS.The content of asphaltene and resin plays a key role in the process of NTS,while saturation and aromatics play an active role in the temperature self-healing before and after aging.The NTS is the result of the comprehensive action of different components,and the self-healing efficiency is proportional to the relative molecular mass.The effect of aging on the NTS is also realized by changing the proportion of asphalt components.
基金National Natural Science Foundation of China(U2133208,U20A20161)National Natural Science Foundation of China(No.62273244)Sichuan Science and Technology Program(No.2022YFG0180).
文摘In order to enhance the accuracy of Air Traffic Control(ATC)cybersecurity attack detection,in this paper,a new clustering detection method is designed for air traffic control network security attacks.The feature set for ATC cybersecurity attacks is constructed by setting the feature states,adding recursive features,and determining the feature criticality.The expected information gain and entropy of the feature data are computed to determine the information gain of the feature data and reduce the interference of similar feature data.An autoencoder is introduced into the AI(artificial intelligence)algorithm to encode and decode the characteristics of ATC network security attack behavior to reduce the dimensionality of the ATC network security attack behavior data.Based on the above processing,an unsupervised learning algorithm for clustering detection of ATC network security attacks is designed.First,determine the distance between the clustering clusters of ATC network security attack behavior characteristics,calculate the clustering threshold,and construct the initial clustering center.Then,the new average value of all feature objects in each cluster is recalculated as the new cluster center.Second,it traverses all objects in a cluster of ATC network security attack behavior feature data.Finally,the cluster detection of ATC network security attack behavior is completed by the computation of objective functions.The experiment took three groups of experimental attack behavior data sets as the test object,and took the detection rate,false detection rate and recall rate as the test indicators,and selected three similar methods for comparative test.The experimental results show that the detection rate of this method is about 98%,the false positive rate is below 1%,and the recall rate is above 97%.Research shows that this method can improve the detection performance of security attacks in air traffic control network.
基金financially supported by the National Natural Science Foundation of China(Nos.12272356,12072326,and 12172337)the State Key Laboratory of Dynamic Measurement Technology,North University of China(No.2022-SYSJJ-03)。
文摘Al Si10Mg porous protective structure often produces different damage forms under compressive loading,and these damage modes affect its protective function.In order to well meet the service requirements,there is an urgent need to comprehensively understand the mechanical behavior and response mechanism of AlSi10Mg porous structures under compressive loading.In this paper,Al Si10Mg porous structures with three kinds of volume fractions are designed and optimized to meet the requirements of high-impact,strong-energy absorption,and lightweight characteristics.The mechanical behaviors of AlSi10Mg porous structures,including the stress-strain relationship,structural bearing state,deformation and damage modes,and energy absorption characteristics,were obtained through experimental studies at different loading rates.The damage pattern of the damage section indicates that AlSi10Mg porous structures have both ductile and brittle mechanical properties.Numerical simulation studies show that the AlSi10Mg porous structure undergoes shear damage due to relative misalignment along the diagonal cross-section,and the damage location is almost at 45°to the load direction,which is the most direct cause of its structural damage,revealing the damage mechanism of AlSi10Mg porous structures under the compressive load.The normalized energy absorption model constructed in the paper well interprets the energy absorption state of Al Si10Mg porous structures and gives the sensitive location of the structures,and the results of this paper provide important references for peers in structural design and optimization.
基金Project supported by the National Natural Science Foundation of China(Nos.11832002 and 12072201)。
文摘The snap-through behaviors and nonlinear vibrations are investigated for a bistable composite laminated cantilever shell subjected to transversal foundation excitation based on experimental and theoretical approaches.An improved experimental specimen is designed in order to satisfy the cantilever support boundary condition,which is composed of an asymmetric region and a symmetric region.The symmetric region of the experimental specimen is entirely clamped,which is rigidly connected to an electromagnetic shaker,while the asymmetric region remains free of constraint.Different motion paths are realized for the bistable cantilever shell by changing the input signal levels of the electromagnetic shaker,and the displacement responses of the shell are collected by the laser displacement sensors.The numerical simulation is conducted based on the established theoretical model of the bistable composite laminated cantilever shell,and an off-axis three-dimensional dynamic snap-through domain is obtained.The numerical solutions are in good agreement with the experimental results.The nonlinear stiffness characteristics,dynamic snap-through domain,and chaos and bifurcation behaviors of the shell are quantitatively analyzed.Due to the asymmetry of the boundary condition and the shell,the upper stable-state of the shell exhibits an obvious soft spring stiffness characteristic,and the lower stable-state shows a linear stiffness characteristic of the shell.
文摘A soil water retention curve (SWRC) is an essential soil physical property for analyzing transport and retention of water in a soil layer. A SWRC is often described as a single-valued function that relates the soil water potential ψ to volumetric water content θ of the soil. However, an in-situ ψ − θ relation should show soil water hysteresis, though this fact is often neglected in analyses of field soil water regimes while long-term in-situ soil water hysteresis is not well characterized. This study aimed at probing and characterizing in-situ ψ − θ relations. The developments of large hysteresis in the in-situ ψ − θ relations were observed only a few times during the study period of 82 months. Any of the large hysteretic behaviors in the ψ − θ relations began with an unusually strong continual reduction in ψ. The completion of a hysteresis loop required a recorded maximum rainfall. Because the study field had very small chances to meet such strong rainfall events, it took multiple years to restore the fraction of soil water depleted by the unusually strong continual reduction in ψ. While wetting-drying cycles had occurred within a certain domain of ψ, hysteretic behaviors tended to be so small that the in-situ ψ − θ relation can be approximated as a single-valued function of θ(ψ). These observed patterns of the in-situ ψ − θ relations were characterized by kinds of difference in dθ/dψ between a drying process and a wetting process at a given ψ. Thus, more amounts of experimental facts about wetting SWRCs in parallel with drying SWRCs should be needed for correct modelling, analyzing, and predicting soil water regimes in fields. It is also necessary to increase our understandings about the long-term trends of occurrences of extreme weather conditions associated with possible change in climate.
基金Supported by Science and Technology Foundation of the Guizhou Health Department,No.GZWKJ2011-1-026National Natural Science Foundation of China,No.81760548.
文摘BACKGROUND The main treatment methods for cancer include surgery,radiotherapy,chemotherapy,targeted drug therapy and so on.Patients often feel anger,anxiety,depression,and other negative psychological reactions in the process of treatment.AIM To explore the effects of cognitive behavioral therapy on the personality characteristics of cancer patients.METHODS According to the matching design requirements,150 cancer patients were divided into 3 groups based on sex,age,condition,and cultural background.Patients in the control group received conventional treatment.Patients in experimental group 1 received an intervention based on conventional treatment combined with cognitive behavioral therapy.Patients in experimental group 2 received family members'participation in addition to the treatment given in experimental group 1.An Eysenck personality questionnaire was used to investigate all the patients before and after the intervention,and the scores for psychosis,introversion,neuroticism,and concealment degree were analyzed.RESULTS Compared with the control group,for experimental group 1 and experimental group 2 before and after the intervention,the four dimensions of mental quality,neuroticism,introversion and concealment degree all decreased,and the difference was statistically significant(P<0.05).After the intervention,there were no obvious or statistically significant differences(P>0.05)among the control group,experimental group 1,and experimental group 2 for two personality traits,psychoticism and neuroticism,both inside and outside degree and all four dimensions.CONCLUSION Simple cognitive behavioral therapy could not change the personality characteristics of cancer patients quickly,but the patients’personality characteristics were significantly improved after treatment.
文摘In this paper, the inherent rdationships between the running regulations and behavior charactcristics of cellular automata are presented; an imprecise taxonomy of such syseros is put forward; the three extreme cases of slablc sysems are discussed; and the illogicalness of evolutional strategies of cellular automata is analyzed. The result is suilable for the emulation and prediction of behavior of discrete dynamics sys terns; especially it can be taken as an important analysis means of dynamic performance of complex networks.
基金Sponsored by School-level Project of Sichuan Minzu College(XYZB18041SB)Project pf Sichuan Provincial Education Department(16ZB0365)
文摘Tourists are the subject of tourism activity,and it is conducive to promoting sustainable development of tourism destination by studying their behavior characteristics and tourism perception.Mugecuo Scenic Area in Kangding City,Ganzi Tibetan Autonomous Prefecture,Sichuan Province is taken as research case,and visitors and managers in the scenic area are surveyed by using semi-structured interview method.Based on survey data,the research aims to put forward corresponding policy suggestions for sustainable development of Mugecuo Scenic Area by deeply analyzing tourists’ access to information of scenic area,tourists’ travel purpose,tourists’ satisfaction with services of scenic area and willingness to revisit.
文摘The objective of this study is to look at the understanding and perceptions of public health nurses (PHNs) related to behavioral characteristics of fathers that contribute to emotional instability in mothers by reviewing abuse cases involving infants and very young children. A qualitative descriptive design was applied to the data analysis, based on a semi-structured interview administered to three experienced PHNs who had been in charge of maternal and child health services for at least five years at a public health department or health center;with the data obtained in the interview narratives analyzed. In the observations of the experienced PHNs, the behavioral characteristics of fathers who are instigators of child abuse can be classified into five categories, fathers who are: “Talking to others about marital problems without attempting to solve these by themselves”, “Working on learning about childcare seeking to correct childcare methods”, “Taking the initiative in childcare at cross purposes with mothers”, “Stressing the effort they (the fathers) put into childcare”, and “Failing to notice the own family situation and problems”. The findings of the study suggest the necessity for PHNs to understand fathers, to be aware of the difficulty of building a supportive relationship with fathers, and to improve skills enabling the PHNs to help fathers form good relationships with other family members.
文摘Objective:This study explored the characteristics,causality,and suicidal behavior among family members with suicide history in Wonogiri,Central Java,Indonesia.Methods:Qualitative semistructured interviews were conducted with 15 family members who had made suicide attempts.The interviews directly explored the relationships among characteristics,causality,and suicidal behavior.The research data were analyzed using the Miles and Huberman approach.Results:The results indicate that there are relationships among characteristics,causality,and suicidal behaviors.The characteristics contributing to suicide attempts were male gender,age(adolescence and old age),lack of religious activities,introvert nature,low economic status,chronic diseases,unemployment,and a history of family members with suicide attempts.The causality of suicide was joblessness,economic crisis,unemployment,family conditions,personality disorder,depression,sickness,and suicide ideation.Conclusions:The findings highlight the relationships among characteristics,causality,and suicidal behaviors.Suicide occurs when individuals have some problems that they cannot solve because of the lack of family support.The causal factors were related to one another,which caused the suicidal behavior.One of the most effective suicide prevention strategies is educating the community on how to identify suicidal signs and increase social supports.
基金supported by the Ministry of Education Humanities and Social Sciences Research Project(Grant No.19YJC760024).
文摘The waterfront space is a specific and perfect open space for people to experience the city.Daily entertainment,leisure,shopping,sports and other activities can be carried out in the waterfront slow-motility space.There are three types of slow-mover in urban waterfront space namely walking,stop or stay,and riding.Analysis of their behavioral characteristics and the difference of different people can help to clarify the design requirements and produce a waterfront space that will better meets people’s functional needs.
文摘Based on the investigation and analysis of the social behavior characteristics of post-95undergraduates, this paper puts forward the principle of sharing and building e-class platform and analyzes thedevelopment of the functions of the four platforms such as the teacher-student service system, instant interactionsystem, SNS community system and vertical segmental pushing system and the realization of the function of modularoperation. Finally, in order to ensure the stable operation of the E-class platform, four measures are put forward suchas the systematic construction of the system, the innovation of team work, the assessment of key performances and thecomprehensive guarantee, thus providing an external guarantee for the stable operation of the E-class platform.
文摘In this paper,a series of major policy decisions used to improve the power grid reliability,reduce the risk and losses of major power outages,and realize the modernization of 21st century power grid are discussed. These decisions were adopted by American government and would also be helpful for the strategic development of Chinese power grid. It is proposed that China should take precaution,carry out security research on the overall dynamic behaviour characteristics of the UHV grid using the complexity theory,and finally provide safeguard for the Chinese UHV grid. It is also pointed out that,due to the lack of matured approaches to controll a cascading failure,the primary duty of a system operator is to work as a "watchdog" for the grid operation security,eliminate the cumulative effect and reduce the risk and losses of major cascading outages with the help of EMS and WAMS.
基金supported by the National Natural Science Foundation of China(grant number 51805086)the Natural Science Foundation of Fujian Province,China(grant number 2018J01763)。
文摘To improve the defense capability of military equipment under extreme conditions,impact-resistant and high-energy-consuming materials have to be developed.The damping characteristic of entangled porous metallic wire materials(EPMWM)for vibration isolation was previously investigated.In this paper,a study focusing on the impact-resistance of EPMWM with the consideration of ambient temperature is presented.The quasi-static and low-velocity impact mechanical behavior of EPMWM under different temperatures(25℃-300℃)are systematically studied.The results of the static compression test show that the damping energy dissipation of EPMWM increases with temperature while the nonlinear damping characteristics are gradually enhanced.During the impact experiments,the impact energy loss rate of EPMWM was between 65%and 85%,while the temperatures increased from 25℃to 300℃.Moreover,under the same drop impact conditions,the overall deformation of EPMWM decreases in the temperature range of 100℃-200℃.On the other hand,the impact stiffness,energy dissipation,and impact loss factor of EPMWM significantly increase with temperature.This can be attributed to an increase in temperature,which changes the thermal expansion coefficient and contact state of the internal wire helixes.Consequently,the energy dissipation mode(dry friction,air damping,and plastic deformation)of EPMWM is also altered.Therefore,the EPMWM may act as a potential candidate material for superior energy absorption applications.
文摘C f/SiC composites were prepared by precursor pyrolysis hot pressing, and the effect of fiber characteristics on the fracture behavior of the composites was investigated. Because the heat treatment temperature of fiber T300 (below 1?500?℃) was much lower than that of fiber M40JB (over 2?000?℃), fiber T300 had lower degree of graphitization and consisted of more impurities compared with fiber M40JB, suggesting that T300 exhibits higher chemical activity. As a result, the composite with T300 showed a brittle fracture behavior, which is mainly ascribed to a strongly bonded fiber/matrix interface as well as the degradation of fibers during the preparation of the composite. However, the composite with M40JB exhibits a tough fracture behavior, which is primarily attributed to a weakly bonded fiber/matrix interface and higher strength retention of the fibers.
文摘Layered backfill is commonly used in mining operations,and its mechanical behavior is strongly influenced by delamination parameters.In this study,13 specimens with different numbers of delamination and delamination angle were prepared to investigate the anisotropic mechanical behavior,energy dissipation characteristics and crack development of backfill.P-wave velocity,uniaxial compression,scanning electron microscope(SEM),and acoustic emission(AE)experiments were conducted.The results indicate that:(1)The P-wave velocity has linear and elliptical relationships with the number of delamination surface and delamination angle,respectively;the strength,delamination parameters and P-wave velocity show a high degree of coincidence in terms of their function relationship,which can realize the rapid prediction of strength.(2)The microstructure of the delaminated surface is looser than that of the matrix,leading to a decrease in strength and an increase at the pore-fissure compaction stage.The number and angle of delamination increase linearly with the anisotropy coefficient.(3)The energy evolution in angle-cut backfill can be divided into four stages,with a decrease in the proportion of elastic energy at the initiation stress and peak stress with increasing number of delamination planes and delamination angle.(4)Crack development increases with the number of delamination surface and delamination angle,resulting in a decrease in energy dissipation coefficient and peak AE energy.These findings provide valuable insights for the design of filling materials and processes in mining operations.
基金Sponsored by 2022 Beijing Undergraduate Innovation and Entrepreneurship Training PlanConstruction of Demonstration Off-campus Practice Base for Integration of Industry and Education+1 种基金Beijing Municipal Education Commission Social Science Project(KM202010009002)“Young Yu You Talents Training Plan”of North China University of Technology。
文摘In order to understand the travel characteristics and behavior patterns of women in Wangjing area and explore whether the existing situation can meet women's needs for the use of street space,the area around Wangjing South Station of Metro Line 14 was taken as an example for analysis and research.Wangjing area was classified to the following six use attributes:company enterprise,transportation hub,education and culture,residential area,municipal facilities,leisure and entertainment.The proportion of each use attribute was evaluated according to four levels:A 25%and above(including 25%),B 15%-25%,C 15%-5%,D 5%and below(including 5%).Finally,whether the plot had composite functions was judged,and the spatio-temporal laws and behavior patterns of surrounding women were analyzed from the perspectives of time and space.
文摘目的探讨儿童行为特点及其家庭管理方式对儿童哮喘控制水平影响路径。方法采用便利抽样法选取82例哮喘患儿,应用一般资料问卷、适应行为量表(AAMR)、家庭管理测量量表(FaMM)及儿童哮喘控制测试表(Childhood asthma control test,C-ACT)进行问卷调查,分析其影响路径。结果患儿AAMR适应行为量表得分(84.87±9.16)分,FaMM量表得分(188.77±19.01)分,C-ACT得分(15.20±4.66)分。Pearson相关分析结果显示,适应性行为分别与家庭管理、哮喘控制呈正相关关系(r=0.580、0.219,P<0.05),家庭管理与哮喘控制呈正相关关系(r=0.401,P<0.05)。结构方程模型结果表明,家庭管理在哮喘患儿适应性行为和哮喘控制有部分中介调节作用,效应占比为45.95%。结论儿童行为特点能够通过家庭管理方式对患儿哮喘控制水平产生影响,临床护理人员应重视对患儿家属的健康教育管理,提升家属对疾病的认知度及家庭管理能力,以改善患儿的行为方式,达到有效控制患儿疾病的目的。