Background:Recently,cognitive behavioral therapy interventions have been extensively applied in the field of nursing education.However,no consensus has been reached on whether these interventions can reduce negative e...Background:Recently,cognitive behavioral therapy interventions have been extensively applied in the field of nursing education.However,no consensus has been reached on whether these interventions can reduce negative emotions in nursing students.Objective:This meta-analysis was designed to systematically discuss the effect of cognitive behavioral therapy interventions on levels of anxiety,fear of denial,social avoidance and social distress for nursing students.Methods:The following Chinese and English databases were searched for relevant articles:PubMed,Embase,Cochrane library,Web of Science,China National Knowledge Infrastructure,Wangfang Database,VIP Database and Chinese Biomedical Literature Database.The search encompassed the establishment of these databases up until May 2021.Two reviewers separately entered the data into Review Manager Software 5.3.Results:A total of 6 studies were reviewed.It was found that cognitive behavioral therapy interventions significantly lowered levels of anxiety(SMD=−0.98,95%CI:−1.46 to−0.50,P<0.001),fear of denial(MD=−3.22,95%CI:−5.60 to−0.84,P<0.01),social avoidance(MD=−1.74,95%CI:−2.32 to−1.16,P<0.001),and social distress(MD=−2.15,95%CI:−2.81 to−1.49,P<0.001)in nursing students.Conclusion:Cognitive behavioral therapy could effectively decrease anxiety,fear of negation,and social negative emotions of nursing students as well as enhance their mental health level.However,more studies are needed to verify whether internet-based cognitive behavioral therapy has an impact on nursing students’negative emotions.展开更多
In this work, a waveguide structure consisting of a new artificial negative index material (NIM) surrounded by a nonlinear cover and a ferrite (YIG) substrate has been designed and investigated. We apply the boundary ...In this work, a waveguide structure consisting of a new artificial negative index material (NIM) surrounded by a nonlinear cover and a ferrite (YIG) substrate has been designed and investigated. We apply the boundary conditions and impose the condition of negative effective permeability of the ferrite slab to derive the dispersion relation related to the proposed structure. The NIM permittivity and permeability are not constant and depend on the operating frequency. The dispersion properties of the nonlinear electromagnetic surface waves (NEM) are analyzed and the associated propagation index is calculated. Results show that the dispersion could be tuned and controlled by selecting the NIM film thickness and the film-cover interface nonlinearity. The proposed structure is supporting unusual types of NEM surface waves having a non-reciprocal behavior widely used in designing optoelectronic devices.展开更多
High-density polyethylene/carbon black foaming conductive composites were prepared from acetylene black(ACEY) and super conductive carbon black(HG-1P) as conductive filler, low-density polyethylene(LDPE) as the ...High-density polyethylene/carbon black foaming conductive composites were prepared from acetylene black(ACEY) and super conductive carbon black(HG-1P) as conductive filler, low-density polyethylene(LDPE) as the second component, ethylene-vinyl acetate(EVA) and ethylene propylene rubber(EPR) as the third component, azobisformamide(AC) as foamer, and dicumyl peroxide(DCP) as cross-linker. The structure and resistivity-temperature behavior of high-density polyethylene(HDPE)/CB foaming conductive composites were investigated. Influences of carbon black, LDPE, EVA, EPR, AC, and DCP on the foaming performance and resistivity-temperature behavior of HDPE/CB foaming conductive composites were also studied. The results reveal that HDPE/CB foaming conductive composite exhibits better switching characteristic; ACET-filled HDPE foaming conductive composite displays better positive temperature coefficient(PYC) effect; whereas super conductive carbon black(HG-1P)-filled HDPE foaming conductive composite shows better negative temperature coefficient(NTC) effect.展开更多
Tracheal stents are an important form of treatment for benign or malignant central airway obstruction.However,the mechanical behavior of current tracheal stents is significantly different from that of the native trach...Tracheal stents are an important form of treatment for benign or malignant central airway obstruction.However,the mechanical behavior of current tracheal stents is significantly different from that of the native trachea,which leads to a variety of serious complications.In this study,inspired by the structure of the native trachea,a wavy non-uniform ligament chiral tracheal stent is proposed,in which J-shaped stress-strain behavior and negative Poisson's ratio response are achieved by replacing the tangential ligament of tetrachiral and anti-tetrachiral hybrid structure with a wavy non-uniform ligament.Through the combination of theoretical analysis,finite element analysis and experimental tests,a wide range of desired J-shaped stress-strain curves are explored to mimic the native porcine trachea by tailoring the stent geometry.Besides,the negative Poisson’s ratio and auxetic diameter curves versus axial strain of the stent are also studied in detail,thus contributing to the enhancement of cross-section ventilation and reducing the migration of the stent.This novel tracheal stent with a unique microstructure shows a potential to perfectly match the physiological activities of the native trachea and thereby reduce potential complications.展开更多
The latest global cancer burden data released by the International Agency for Research on Cancer of the World Health Organization in 2020 shows that there were 19.29 million new cancer cases worldwide,with 4.57 millio...The latest global cancer burden data released by the International Agency for Research on Cancer of the World Health Organization in 2020 shows that there were 19.29 million new cancer cases worldwide,with 4.57 million in China,ranking first.The number of cancer survivors is increasing,with a 5-year survival rate exceeding 85%,but there are emotional disorders.Cognitive behavioral therapy(CBT)can improve negative emotions and has significant effects on patients.However,there is a limited number of physicians and high costs,so internet interventions have become a solution.The feasibility of web-based interventions for breast cancer patients has been proven.Research on internet-delivered CBT is also increasing.The purpose of this study was to review the concept of web-based CBT and its application status in cancer survivors,in order to provide relevant intervention for scholars and provide reference and supplement for patients to provide psychological therapy.展开更多
We report the investigation on the low-temperature oxidation of cyclohexane in a jet-stirred reactor over 500-742 K. Synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) was used for identify...We report the investigation on the low-temperature oxidation of cyclohexane in a jet-stirred reactor over 500-742 K. Synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) was used for identifying and quantifying the oxidation species. Major products, cyclic olefins, and oxygenated products including reactive hydroperoxides and high oxygen compounds were detected. Compared with n-alkanes, a narrow low-temperature window (-80 K) was observed in the low-temperature oxidation of cyclohexane. Besides, a kinetic model for cyclohexane oxidation was developed based on the CNRS model [Combust. Flame 160, 2319 (2013)], which can better capture the experimental results than previous models. Based on the modeling analysis, the 1,5-H shift dominates the crucial isomerization steps of the first and second O2 addition products in the low-temperature chain branching process of cyclohexane. The negative temperature coefficient behavior of cyclohexane oxidation results from the reduced chain branching due to the competition from chain inhibition and propagation reactions, i.e. the reaction between cyclohexyl radical and O2 and the de- composition of cyclohexylperoxy radical, both producing cyclohexene and HO2 radical, as well as the decomposition of cyclohexylhydroperoxy radical producing hex-5-en-l-al and OH radical.展开更多
Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy(XRD) and transmissi...Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy(XRD) and transmission electron microscopy(TEM). The electrooxidation behaviors of ethanol on the Pd/C electrode in alkaline media were investigated using cyclic voltammetry(CV), chronoamperometry(CA), electrochemical impedance spectroscopy(EIS) and single cell performance methods. Pd/C electrode for ethanol oxidation showed high electro-catalytic activity and long term stability. However, it is observed that the current density decreases with the increasing of the potential and negative impedance presents in the potential from-0.1 to0.1 V. The decreasing current density and the negative impedance could be due to the adsorbed intermediates species that inhibited the further oxidation of ethanol. Based on the chemical reaction analysis and EIS spectra, equivalent circuits relating to various potential zones have been obtained. These results reveal the dynamic adsorption of intermediates species on Pd surfaces. Significantly, it is clarified that the adsorption behavior begins from the maximum catalysis of electro-catalysis and ends in the formation of the palladium(II) oxide layer on the electrode surface.展开更多
We investigate the giant magnetoresistance of composites (La1-xAgzMnO3)1-υ(MnO2/Mn2O3)υ. The magnetoresistive property of the composites shows the characteristics of intergranular tunnelling. A conductivity leap...We investigate the giant magnetoresistance of composites (La1-xAgzMnO3)1-υ(MnO2/Mn2O3)υ. The magnetoresistive property of the composites shows the characteristics of intergranular tunnelling. A conductivity leap has been observed around y = 0.7. The composite (La0.926Ag0.074MnO3)0.698(MnO2/Mn2O3)0.302 has been found to show the greatest magnetoresistance in the samples. Its room-temperature MR ratio reaches 24% under a field of 1.8T. These phenomena suggest a percolation transformation and a kind of field-induced fluctuation in percolation in the samples investigated.展开更多
Divorce can have a significant effect on children’s health emotionally and practically.It can be crucial for the whole family to deal with divorce.There are many factors that come about when this situation is discuss...Divorce can have a significant effect on children’s health emotionally and practically.It can be crucial for the whole family to deal with divorce.There are many factors that come about when this situation is discussed,for example,its effect on children,the possible probability of transmission of depression from parent to children,and its effect on children’s school achievements.This paper focuses on the discussion of the answers to two questions.Firstly,how does divorce affect the school achievement of children whose parents are divorced?Secondly,how does divorce affect depression levels among children?The research finds interesting facts that children’s schools achievements get affected due to divorce but also reveals that gender plays a role as a factor,such as boys are more likely to suffer an effect on their school achievement more than girls.On the other hand,it is also found that children,especially girls,can experience depression transmitted from their depressed mothers but divorce in parents is not the only reason for children’s depression.展开更多
By using a combined method of density functional theory and non-equilibrium Green's function formalism,we investigate the electronic transport properties of carbon-doped armchair phosphorene nanoribbons(APNRs).The ...By using a combined method of density functional theory and non-equilibrium Green's function formalism,we investigate the electronic transport properties of carbon-doped armchair phosphorene nanoribbons(APNRs).The results show that C atom doping can strongly affect the electronic transport properties of the APNR and change it from semiconductor to metal.Meanwhile,obvious negative differential resistance(NDR) behaviors are obtained by tuning the doping position and concentration.In particular,with reducing doping concentration,NDR peak position can enter into m V bias range.These results provide a theoretical support to design the related nanodevice by tuning the doping position and concentration in the APNRs.展开更多
We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckion...We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckions. These material particles interact indirectly, and have very strong restoring forces keeping them a finite distance apart from each other within their respective species. Because of their mass compensating effect, the vacuum appears massless, charge-less, without pressure, net energy density or entropy. In addition, we consider two varying G models, where G, is Newton’s constant, and G<sup>-1</sup>, increases with an increase in cosmological time. We argue that there are at least two competing models for the quantum vacuum within such a framework. The first follows a strict extension of Winterberg’s model. This leads to nonsensible results, if G increases, going back in cosmological time, as the length scale inherent in such a model will not scale properly. The second model introduces a different length scale, which does scale properly, but keeps the mass of the Planck particle as, ± the Planck mass. Moreover we establish a connection between ordinary matter, dark matter, and dark energy, where all three mass densities within the Friedman equation must be interpreted as residual vacuum energies, which only surface, once aggregate matter has formed, at relatively low CMB temperatures. The symmetry of the vacuum will be shown to be broken, because of the different scaling laws, beginning with the formation of elementary particles. Much like waves on an ocean where positive and negative planckion mass densities effectively cancel each other out and form a zero vacuum energy density/zero vacuum pressure surface, these positive mass densities are very small perturbations (anomalies) about the mean. This greatly alleviates, i.e., minimizes the cosmological constant problem, a long standing problem associated with the vacuum.展开更多
Let X and Y be positive weakly negatively dependent (WND) random variables with finite expectations and continuous distribution functions F and G with heavy tails, respectively. The asymptotic behavior of the tail o...Let X and Y be positive weakly negatively dependent (WND) random variables with finite expectations and continuous distribution functions F and G with heavy tails, respectively. The asymptotic behavior of the tail of distribution of XY is studied and some closure properties under some suitable conditions on F(x) = 1-F(x) and G(x) = of XY when X and Y are WND random variables 1- G(x) are provided. Moreover, subexponentiality is derived.展开更多
Individuals’risk attitudes play an important role in economic decision making and policy evaluation,particularly in the midst of unprecedented uncertainty caused by the COVID-19 pandemic.We adopt a multiple-price-lis...Individuals’risk attitudes play an important role in economic decision making and policy evaluation,particularly in the midst of unprecedented uncertainty caused by the COVID-19 pandemic.We adopt a multiple-price-list elicitation method with real money incentives to measure precisely individuals’risk attitudes at different stake levels and the extent to which they are affected by personal and social shocks following the COVID-19 outbreak in China.We find that subjects who had previously experienced negative personal shocks are more risk-averse at medium and large stakes but more risk loving at very small stakes.For our sample,COVID-19 has no significant impact on risk attitudes,as it is more likely to be regarded as a social shock.The result indicates that the impact of COVID-19 on individual risk attitudes is not as influential as expected,unless the individual’s personal life is affected directly.展开更多
文摘Background:Recently,cognitive behavioral therapy interventions have been extensively applied in the field of nursing education.However,no consensus has been reached on whether these interventions can reduce negative emotions in nursing students.Objective:This meta-analysis was designed to systematically discuss the effect of cognitive behavioral therapy interventions on levels of anxiety,fear of denial,social avoidance and social distress for nursing students.Methods:The following Chinese and English databases were searched for relevant articles:PubMed,Embase,Cochrane library,Web of Science,China National Knowledge Infrastructure,Wangfang Database,VIP Database and Chinese Biomedical Literature Database.The search encompassed the establishment of these databases up until May 2021.Two reviewers separately entered the data into Review Manager Software 5.3.Results:A total of 6 studies were reviewed.It was found that cognitive behavioral therapy interventions significantly lowered levels of anxiety(SMD=−0.98,95%CI:−1.46 to−0.50,P<0.001),fear of denial(MD=−3.22,95%CI:−5.60 to−0.84,P<0.01),social avoidance(MD=−1.74,95%CI:−2.32 to−1.16,P<0.001),and social distress(MD=−2.15,95%CI:−2.81 to−1.49,P<0.001)in nursing students.Conclusion:Cognitive behavioral therapy could effectively decrease anxiety,fear of negation,and social negative emotions of nursing students as well as enhance their mental health level.However,more studies are needed to verify whether internet-based cognitive behavioral therapy has an impact on nursing students’negative emotions.
文摘In this work, a waveguide structure consisting of a new artificial negative index material (NIM) surrounded by a nonlinear cover and a ferrite (YIG) substrate has been designed and investigated. We apply the boundary conditions and impose the condition of negative effective permeability of the ferrite slab to derive the dispersion relation related to the proposed structure. The NIM permittivity and permeability are not constant and depend on the operating frequency. The dispersion properties of the nonlinear electromagnetic surface waves (NEM) are analyzed and the associated propagation index is calculated. Results show that the dispersion could be tuned and controlled by selecting the NIM film thickness and the film-cover interface nonlinearity. The proposed structure is supporting unusual types of NEM surface waves having a non-reciprocal behavior widely used in designing optoelectronic devices.
文摘High-density polyethylene/carbon black foaming conductive composites were prepared from acetylene black(ACEY) and super conductive carbon black(HG-1P) as conductive filler, low-density polyethylene(LDPE) as the second component, ethylene-vinyl acetate(EVA) and ethylene propylene rubber(EPR) as the third component, azobisformamide(AC) as foamer, and dicumyl peroxide(DCP) as cross-linker. The structure and resistivity-temperature behavior of high-density polyethylene(HDPE)/CB foaming conductive composites were investigated. Influences of carbon black, LDPE, EVA, EPR, AC, and DCP on the foaming performance and resistivity-temperature behavior of HDPE/CB foaming conductive composites were also studied. The results reveal that HDPE/CB foaming conductive composite exhibits better switching characteristic; ACET-filled HDPE foaming conductive composite displays better positive temperature coefficient(PYC) effect; whereas super conductive carbon black(HG-1P)-filled HDPE foaming conductive composite shows better negative temperature coefficient(NTC) effect.
基金supported by the National Key Research and Development Program of China(No.2020YFC1107103)the National Natural Science Foundation of China(No.51821093)the Research Project of Public Welfare Technology Application of Zhejiang Province,China(No.LGF21H010006).
文摘Tracheal stents are an important form of treatment for benign or malignant central airway obstruction.However,the mechanical behavior of current tracheal stents is significantly different from that of the native trachea,which leads to a variety of serious complications.In this study,inspired by the structure of the native trachea,a wavy non-uniform ligament chiral tracheal stent is proposed,in which J-shaped stress-strain behavior and negative Poisson's ratio response are achieved by replacing the tangential ligament of tetrachiral and anti-tetrachiral hybrid structure with a wavy non-uniform ligament.Through the combination of theoretical analysis,finite element analysis and experimental tests,a wide range of desired J-shaped stress-strain curves are explored to mimic the native porcine trachea by tailoring the stent geometry.Besides,the negative Poisson’s ratio and auxetic diameter curves versus axial strain of the stent are also studied in detail,thus contributing to the enhancement of cross-section ventilation and reducing the migration of the stent.This novel tracheal stent with a unique microstructure shows a potential to perfectly match the physiological activities of the native trachea and thereby reduce potential complications.
文摘The latest global cancer burden data released by the International Agency for Research on Cancer of the World Health Organization in 2020 shows that there were 19.29 million new cancer cases worldwide,with 4.57 million in China,ranking first.The number of cancer survivors is increasing,with a 5-year survival rate exceeding 85%,but there are emotional disorders.Cognitive behavioral therapy(CBT)can improve negative emotions and has significant effects on patients.However,there is a limited number of physicians and high costs,so internet interventions have become a solution.The feasibility of web-based interventions for breast cancer patients has been proven.Research on internet-delivered CBT is also increasing.The purpose of this study was to review the concept of web-based CBT and its application status in cancer survivors,in order to provide relevant intervention for scholars and provide reference and supplement for patients to provide psychological therapy.
基金supported by the National Natural Science Foundation of China(No.91641205,No.51622605,No.91541201)the Shanghai Science and Technology Committee(No.17XD1402000)
文摘We report the investigation on the low-temperature oxidation of cyclohexane in a jet-stirred reactor over 500-742 K. Synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) was used for identifying and quantifying the oxidation species. Major products, cyclic olefins, and oxygenated products including reactive hydroperoxides and high oxygen compounds were detected. Compared with n-alkanes, a narrow low-temperature window (-80 K) was observed in the low-temperature oxidation of cyclohexane. Besides, a kinetic model for cyclohexane oxidation was developed based on the CNRS model [Combust. Flame 160, 2319 (2013)], which can better capture the experimental results than previous models. Based on the modeling analysis, the 1,5-H shift dominates the crucial isomerization steps of the first and second O2 addition products in the low-temperature chain branching process of cyclohexane. The negative temperature coefficient behavior of cyclohexane oxidation results from the reduced chain branching due to the competition from chain inhibition and propagation reactions, i.e. the reaction between cyclohexyl radical and O2 and the de- composition of cyclohexylperoxy radical, both producing cyclohexene and HO2 radical, as well as the decomposition of cyclohexylhydroperoxy radical producing hex-5-en-l-al and OH radical.
文摘Carbon-supported Pd nanoparticles were prepared by microwave heating-glycol reduction method, and characterized by a wide array of experimental techniques including X-ray diffraction spectroscopy(XRD) and transmission electron microscopy(TEM). The electrooxidation behaviors of ethanol on the Pd/C electrode in alkaline media were investigated using cyclic voltammetry(CV), chronoamperometry(CA), electrochemical impedance spectroscopy(EIS) and single cell performance methods. Pd/C electrode for ethanol oxidation showed high electro-catalytic activity and long term stability. However, it is observed that the current density decreases with the increasing of the potential and negative impedance presents in the potential from-0.1 to0.1 V. The decreasing current density and the negative impedance could be due to the adsorbed intermediates species that inhibited the further oxidation of ethanol. Based on the chemical reaction analysis and EIS spectra, equivalent circuits relating to various potential zones have been obtained. These results reveal the dynamic adsorption of intermediates species on Pd surfaces. Significantly, it is clarified that the adsorption behavior begins from the maximum catalysis of electro-catalysis and ends in the formation of the palladium(II) oxide layer on the electrode surface.
基金Supported by the National Natural Science Foundation of China under Grant No 20473038.
文摘We investigate the giant magnetoresistance of composites (La1-xAgzMnO3)1-υ(MnO2/Mn2O3)υ. The magnetoresistive property of the composites shows the characteristics of intergranular tunnelling. A conductivity leap has been observed around y = 0.7. The composite (La0.926Ag0.074MnO3)0.698(MnO2/Mn2O3)0.302 has been found to show the greatest magnetoresistance in the samples. Its room-temperature MR ratio reaches 24% under a field of 1.8T. These phenomena suggest a percolation transformation and a kind of field-induced fluctuation in percolation in the samples investigated.
文摘Divorce can have a significant effect on children’s health emotionally and practically.It can be crucial for the whole family to deal with divorce.There are many factors that come about when this situation is discussed,for example,its effect on children,the possible probability of transmission of depression from parent to children,and its effect on children’s school achievements.This paper focuses on the discussion of the answers to two questions.Firstly,how does divorce affect the school achievement of children whose parents are divorced?Secondly,how does divorce affect depression levels among children?The research finds interesting facts that children’s schools achievements get affected due to divorce but also reveals that gender plays a role as a factor,such as boys are more likely to suffer an effect on their school achievement more than girls.On the other hand,it is also found that children,especially girls,can experience depression transmitted from their depressed mothers but divorce in parents is not the only reason for children’s depression.
基金Project supported by the National Natural Science Foundation of China(No.11274096)the University Science and Technology Innovation Team Support Project of Henan Province(No.13IRTSTHN016)+1 种基金the University key Science Research Project of Henan Province(No.16A140043)supported by the High Performance Computing Center of Henan Normal University
文摘By using a combined method of density functional theory and non-equilibrium Green's function formalism,we investigate the electronic transport properties of carbon-doped armchair phosphorene nanoribbons(APNRs).The results show that C atom doping can strongly affect the electronic transport properties of the APNR and change it from semiconductor to metal.Meanwhile,obvious negative differential resistance(NDR) behaviors are obtained by tuning the doping position and concentration.In particular,with reducing doping concentration,NDR peak position can enter into m V bias range.These results provide a theoretical support to design the related nanodevice by tuning the doping position and concentration in the APNRs.
文摘We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckions. These material particles interact indirectly, and have very strong restoring forces keeping them a finite distance apart from each other within their respective species. Because of their mass compensating effect, the vacuum appears massless, charge-less, without pressure, net energy density or entropy. In addition, we consider two varying G models, where G, is Newton’s constant, and G<sup>-1</sup>, increases with an increase in cosmological time. We argue that there are at least two competing models for the quantum vacuum within such a framework. The first follows a strict extension of Winterberg’s model. This leads to nonsensible results, if G increases, going back in cosmological time, as the length scale inherent in such a model will not scale properly. The second model introduces a different length scale, which does scale properly, but keeps the mass of the Planck particle as, ± the Planck mass. Moreover we establish a connection between ordinary matter, dark matter, and dark energy, where all three mass densities within the Friedman equation must be interpreted as residual vacuum energies, which only surface, once aggregate matter has formed, at relatively low CMB temperatures. The symmetry of the vacuum will be shown to be broken, because of the different scaling laws, beginning with the formation of elementary particles. Much like waves on an ocean where positive and negative planckion mass densities effectively cancel each other out and form a zero vacuum energy density/zero vacuum pressure surface, these positive mass densities are very small perturbations (anomalies) about the mean. This greatly alleviates, i.e., minimizes the cosmological constant problem, a long standing problem associated with the vacuum.
基金Supported by Ferdowsi University of Mashhad(Grant No.MS88076AMI)
文摘Let X and Y be positive weakly negatively dependent (WND) random variables with finite expectations and continuous distribution functions F and G with heavy tails, respectively. The asymptotic behavior of the tail of distribution of XY is studied and some closure properties under some suitable conditions on F(x) = 1-F(x) and G(x) = of XY when X and Y are WND random variables 1- G(x) are provided. Moreover, subexponentiality is derived.
文摘Individuals’risk attitudes play an important role in economic decision making and policy evaluation,particularly in the midst of unprecedented uncertainty caused by the COVID-19 pandemic.We adopt a multiple-price-list elicitation method with real money incentives to measure precisely individuals’risk attitudes at different stake levels and the extent to which they are affected by personal and social shocks following the COVID-19 outbreak in China.We find that subjects who had previously experienced negative personal shocks are more risk-averse at medium and large stakes but more risk loving at very small stakes.For our sample,COVID-19 has no significant impact on risk attitudes,as it is more likely to be regarded as a social shock.The result indicates that the impact of COVID-19 on individual risk attitudes is not as influential as expected,unless the individual’s personal life is affected directly.