It has been observed that farmers adopt only a small number of the “improved” cultivars. A nationwide germplasm collection exercise in February 2018 provided the opportunity to collect indigenous technical knowledge...It has been observed that farmers adopt only a small number of the “improved” cultivars. A nationwide germplasm collection exercise in February 2018 provided the opportunity to collect indigenous technical knowledge (ITK) of the diversity of cassava varieties in terms of: their morphology, growth characteristics, uses (of tubers and leaves) and desirable characteristics. The objective is to see to what extent the objectives of the plant breeders are consistent with what farmers’ value. We performed 405 structured and semi-structured interviews with informants who were selected based on “purposive household sampling”. We found a considerable turn-over in cassava varieties, just over a third (45) have been in cultivation for at least 40 years, however, since the end of the civil war an additional 25 varieties are cultivated, while others varieties seem to have disappeared. One major issue with estimating turnover of varieties is whether the same variety might have several local names, and conversely the same name may be applied to different cultivars. Farmers overwhelmingly use ITK to select and preserve cassava germplasm for future use. Farmers have a clear preference for: sweet taste, high yield, early maturity and easy cooking and preferentially adopt cultivars that have those qualities. Cassava is primarily a human food eaten boiled or fried, some are processed into fufu and gari, and uses as livestock feed and medicine are reported but at low levels. The information produced during this study could help plant breeders choose selection criteria that will ensure their efforts are adopted and sustainable, the importance of preserving the genetic resources of local cultivars is also highlighted.展开更多
Smallholder farmers in Ahafo Ano North District,Ghana,face multiple climatic and non-climatic issues.This study assessed the factors contributing to the livelihood vulnerability of smallholder farmers in this district...Smallholder farmers in Ahafo Ano North District,Ghana,face multiple climatic and non-climatic issues.This study assessed the factors contributing to the livelihood vulnerability of smallholder farmers in this district by household surveys with 200 respondents and focus group discussions(FGDs)with 10 respondents.The Mann–Kendall trend test was used to assess mean annual rainfall and temperature trends from 2002 to 2022.The relative importance index(RII)value was used to rank the climatic and non-climatic factors perceived by respondents.The socioeconomic characteristics affecting smallholder farmers’perceptions of climatic and non-climatic factors were evaluated by the binary logistic regression model.Results showed that mean annual rainfall decreased(P>0.05)but mean annual temperature significantly increased(P<0.05)from 2002 to 2022 in the district.The key climatic factors perceived by smallholder farmers were extreme heat or increasing temperature(RII=0.498),erratic rainfall(RII=0.485),and increased windstorms(RII=0.475).The critical non-climatic factors were high cost of farm inputs(RII=0.485),high cost of healthcare(RII=0.435),and poor condition of roads to farms(RII=0.415).Smallholder farmers’perceptions of climatic and non-climatic factors were significantly affected by their socioeconomic characteristics(P<0.05).This study concluded that these factors negatively impact the livelihoods and well-being of smallholder farmers and socioeconomic characteristics influence their perceptions of these factors.Therefore,to enhance the resilience of smallholder farmers to climate change,it is necessary to adopt a comprehensive and context-specific approach that accounts for climatic and non-climatic factors.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
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
After analysis of location feature of the south of lower reaches of Yangtze River and its construction of urban and rural integration,the paper pointed out harmonious combination between natural and artificial factors...After analysis of location feature of the south of lower reaches of Yangtze River and its construction of urban and rural integration,the paper pointed out harmonious combination between natural and artificial factors had been neglected in planning and design of farmers' residential area at the south of lower reaches of Yangtze River,"regional characteristic" losing,residential area in the form of "city community" and buildings in European style.In view of these problems,relevant planning and design thoughts and methods had been proposed as to how to create "regional characteristic" from the perspective of planning,architecture and landscape design.It discussed with emphasis the importance of construction base type and combination of environment with residential area construction;inspirations and design methods obtained from traditional architectures;and the content of landscape overall planning and specific design.It was hoped to enlighten designers to shoulder social and historical responsibility,make exploration unremittingly,and construct beautiful homelands for people.展开更多
On the basis of questionnaires and field investigation,behavior characteristics of tourists in Liuxihe National Forest Park were analyzed,and the results showed that tourists in the study area mainly come from the Pea...On the basis of questionnaires and field investigation,behavior characteristics of tourists in Liuxihe National Forest Park were analyzed,and the results showed that tourists in the study area mainly come from the Pearl River Delta for sightseeing,mostly 21-45 years old,with higher revisit rate but less residence time.And meanwhile,key tourist source markets of Liuxihe National Forest Park were classified on the basis of spatial distance features,social and economic features,and behavior characteristics of tourists,specifically,The Pearl River Delta Sightseeing Tourist Market,The Pearl River Delta Vacationing Tourist Market,The Pearl River Delta Business Tourist Market,and The Pearl River Delta Special-interest Tourist Market.Moreover,corresponding development strategies were proposed according to actual conditions of each market.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
With rapid development of industrialization in Zhejiang Province, surplus rural labor forces move to the secondary and tertiary industries. Farmers of Zhejiang Province are no exception. They turn to industrial worker...With rapid development of industrialization in Zhejiang Province, surplus rural labor forces move to the secondary and tertiary industries. Farmers of Zhejiang Province are no exception. They turn to industrial workers and their income source has great changes. Wage income becomes their major source of income. Accordingly, farmers' consumption behavior has great changes. Apart from satisfying basic production and living demands, farmers start to pursue living quality and their life style tends to urbanization. Nevertheless, under the influence of rural physical environment, policies and systems, the existing consumption environment fails to follow farmers' urban lifestyle any more. In line with how to optimize rural consumption environment, improve farmers' consuming capacity, continue to expand farmers' consumption and promote urbanization development of rural areas, this paper presents pertinent countermeasures and recommendations.展开更多
In order to investigate the failure mechanism of rock joint,a series of laboratory tests including cyclic direct shear tests under constant normal load(CNL)conditions were conducted.Morphology parameters of the rock j...In order to investigate the failure mechanism of rock joint,a series of laboratory tests including cyclic direct shear tests under constant normal load(CNL)conditions were conducted.Morphology parameters of the rock joint surface were precisely calculated by means of a three-dimensional laser scanning machine.All test results were analyzed to investigate the shear behavior and normal displacement behavior of rock joints under CNL conditions.Degradation of rock joint surface during cyclic shear tests was also analyzed.The comparison results of the height parameters and the hybrid parameters of the joint surface during cyclic tests show that the degradation of the surface mostly happens in the first shear and the constant normal loads imposed on the joints have significant promotion effects on the morphology degradation.During cyclic shear tests,joints surfaces evolve from rough state to smooth state but keep an overall undulation.Dilatancy of rock joints degrades with the degradation of joint surface and the increase of normal loads.The closure deformation of joint is larger than that of the intact rock,and the normal stiffness increases with the increase of shearing times.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 this study,using the PRA method,we conduct a questionnaire survey on 525 farmers in 10 typical villages in Yunnan Province,and study the farmers' farmland abandonment behavior as well as their perception. Studi...In this study,using the PRA method,we conduct a questionnaire survey on 525 farmers in 10 typical villages in Yunnan Province,and study the farmers' farmland abandonment behavior as well as their perception. Studies have shown that there are some common problems for the villages in the inner suburbs and the villages in the outer suburbs such as small scale of rural land,dispersed plots and land fragmentation,and the scale and fragmentation problems are more prominent in the villages in the inner suburbs while the dispersed plot problems are more obvious in the villages in the outer suburbs; the levels of farmland abandonment vary in different sample villages,the farmland abandonment is more prevalent in the villages in the outer suburbs,the abandonment behavior involves more farmers,and farmers tend to abandon small plots of farmland; the proportion of the abandoned farmland perceived by the farmers in the villages in the inner and outer suburbs( especially in the inner suburbs) is significantly lower than the actual proportion,and farmers' perception greatly deviates from the actual reality; some farmers have wrong perception of farmland abandonment behavior,and even if there are farmers with correct perception,they also abandon farmland.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 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
In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption characteristics...In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption characteristics.Several characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second phase.Compressive tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous Mg-Zn-Y.The experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second phase.When the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),W-phase(Mg_(3)Zn_(3)Y_(2)),and LPSO phase(Mg_(12)ZnY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 MJ/m^(3)to 10.97 MJ/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second phase.However,the average energy absorption efficiency is independent of the Y content.In addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing temperature.The compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the struts.The deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.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
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
China's extensive development model of pig industry gives rise to serious resource and environment bottleneck restriction,it is urgent to transform the existing development model into ecological farming model. In ...China's extensive development model of pig industry gives rise to serious resource and environment bottleneck restriction,it is urgent to transform the existing development model into ecological farming model. In this process,farmers' behavior will play a key role. On the basis of summarizing development connotation and characteristics of ecological agriculture,using survey data of 323 pig farmers in 6 provinces,based on the Theory of Planned Behavior( TPB) it introduced individual characteristics and external environment constraint variables,and made an empirical analysis on factors influencing intention and behavior of pig farmers' ecological farming using the Structural Equation Model( SEM). Results indicate:( i) ecological farming intention of pig farmers has the largest direct effect on their ecological farming behavior;( ii)ecological farming cognition of pig farmers has significant positive effect on their ecological farming behavior;( iii) external environment has the largest indirect effect on their ecological farming behavior,followed by the overall effect,and external environment has significant positive effect on ecological farming attitude and cognition of pig farmers;( iv) individual characteristics( educational level and income level) of pig farmers influence ecological farming behavior of pig farmers through their ecological farming attitude and intention,but the degree of influence is limited.展开更多
Based on the survey data and statistical information on farmers,we conduct comparative analysis of land use behavior of farmers in the Jianghan Plain and the hilly areas of Xianning City in Hubei Province.We find that...Based on the survey data and statistical information on farmers,we conduct comparative analysis of land use behavior of farmers in the Jianghan Plain and the hilly areas of Xianning City in Hubei Province.We find that the utilization rate of agricultural land and level of agricultural labor output in the plain areas are higher than in the hilly areas;at the same time,the degree of mechanization of agricultural land utilization and farmers'land use scale are larger in the plain areas.But the crop type in the plain areas is single,and the decline rate of the growing area of food crops is higher in recent twenty years;meanwhile,the material input costs and opportunity cost of labor for the agricultural land utilization in the plain areas are greater than in the hilly areas.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
Crop straw has huge resource potential. It has an important significance for realizing waste recycling and improving eco-environment to prefect straw marketization system and sufficiently stimulate farmers’ straw mar...Crop straw has huge resource potential. It has an important significance for realizing waste recycling and improving eco-environment to prefect straw marketization system and sufficiently stimulate farmers’ straw marketization behavior. Based on 427 copies of investigation data on farmers,influence mechanism framework of farmers’ straw marketization behavior is constructed,and key factors of farmers’ straw marketization behavior are analyzed. Results show that farmers joining in straw marketization account for 42. 1%; in influence factors of farmers’ straw marketization behavior,cultivated land area,market price level,logistics satisfaction and air quality perception have significantly positive impacts on farmers’ straw marketization behavior,while education degree,agricultural income proportion and traffic convenience have significantly negative impacts on farmers’ straw marketization behavior. Therefore,it needs strengthening propaganda intensity,carrying out reasonable subsidies and support,encouraging and breeding new type of organization,and establishing and improving the price mechanism of straw marketization to perfect straw marketization construction.展开更多
文摘It has been observed that farmers adopt only a small number of the “improved” cultivars. A nationwide germplasm collection exercise in February 2018 provided the opportunity to collect indigenous technical knowledge (ITK) of the diversity of cassava varieties in terms of: their morphology, growth characteristics, uses (of tubers and leaves) and desirable characteristics. The objective is to see to what extent the objectives of the plant breeders are consistent with what farmers’ value. We performed 405 structured and semi-structured interviews with informants who were selected based on “purposive household sampling”. We found a considerable turn-over in cassava varieties, just over a third (45) have been in cultivation for at least 40 years, however, since the end of the civil war an additional 25 varieties are cultivated, while others varieties seem to have disappeared. One major issue with estimating turnover of varieties is whether the same variety might have several local names, and conversely the same name may be applied to different cultivars. Farmers overwhelmingly use ITK to select and preserve cassava germplasm for future use. Farmers have a clear preference for: sweet taste, high yield, early maturity and easy cooking and preferentially adopt cultivars that have those qualities. Cassava is primarily a human food eaten boiled or fried, some are processed into fufu and gari, and uses as livestock feed and medicine are reported but at low levels. The information produced during this study could help plant breeders choose selection criteria that will ensure their efforts are adopted and sustainable, the importance of preserving the genetic resources of local cultivars is also highlighted.
文摘Smallholder farmers in Ahafo Ano North District,Ghana,face multiple climatic and non-climatic issues.This study assessed the factors contributing to the livelihood vulnerability of smallholder farmers in this district by household surveys with 200 respondents and focus group discussions(FGDs)with 10 respondents.The Mann–Kendall trend test was used to assess mean annual rainfall and temperature trends from 2002 to 2022.The relative importance index(RII)value was used to rank the climatic and non-climatic factors perceived by respondents.The socioeconomic characteristics affecting smallholder farmers’perceptions of climatic and non-climatic factors were evaluated by the binary logistic regression model.Results showed that mean annual rainfall decreased(P>0.05)but mean annual temperature significantly increased(P<0.05)from 2002 to 2022 in the district.The key climatic factors perceived by smallholder farmers were extreme heat or increasing temperature(RII=0.498),erratic rainfall(RII=0.485),and increased windstorms(RII=0.475).The critical non-climatic factors were high cost of farm inputs(RII=0.485),high cost of healthcare(RII=0.435),and poor condition of roads to farms(RII=0.415).Smallholder farmers’perceptions of climatic and non-climatic factors were significantly affected by their socioeconomic characteristics(P<0.05).This study concluded that these factors negatively impact the livelihoods and well-being of smallholder farmers and socioeconomic characteristics influence their perceptions of these factors.Therefore,to enhance the resilience of smallholder farmers to climate change,it is necessary to adopt a comprehensive and context-specific approach that accounts for climatic and non-climatic factors.
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.
文摘After analysis of location feature of the south of lower reaches of Yangtze River and its construction of urban and rural integration,the paper pointed out harmonious combination between natural and artificial factors had been neglected in planning and design of farmers' residential area at the south of lower reaches of Yangtze River,"regional characteristic" losing,residential area in the form of "city community" and buildings in European style.In view of these problems,relevant planning and design thoughts and methods had been proposed as to how to create "regional characteristic" from the perspective of planning,architecture and landscape design.It discussed with emphasis the importance of construction base type and combination of environment with residential area construction;inspirations and design methods obtained from traditional architectures;and the content of landscape overall planning and specific design.It was hoped to enlighten designers to shoulder social and historical responsibility,make exploration unremittingly,and construct beautiful homelands for people.
文摘On the basis of questionnaires and field investigation,behavior characteristics of tourists in Liuxihe National Forest Park were analyzed,and the results showed that tourists in the study area mainly come from the Pearl River Delta for sightseeing,mostly 21-45 years old,with higher revisit rate but less residence time.And meanwhile,key tourist source markets of Liuxihe National Forest Park were classified on the basis of spatial distance features,social and economic features,and behavior characteristics of tourists,specifically,The Pearl River Delta Sightseeing Tourist Market,The Pearl River Delta Vacationing Tourist Market,The Pearl River Delta Business Tourist Market,and The Pearl River Delta Special-interest Tourist Market.Moreover,corresponding development strategies were proposed according to actual conditions of each market.
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.
基金Supported by Soft Science Project of Zhejiang Province Science and Technology Department(2010C35038)
文摘With rapid development of industrialization in Zhejiang Province, surplus rural labor forces move to the secondary and tertiary industries. Farmers of Zhejiang Province are no exception. They turn to industrial workers and their income source has great changes. Wage income becomes their major source of income. Accordingly, farmers' consumption behavior has great changes. Apart from satisfying basic production and living demands, farmers start to pursue living quality and their life style tends to urbanization. Nevertheless, under the influence of rural physical environment, policies and systems, the existing consumption environment fails to follow farmers' urban lifestyle any more. In line with how to optimize rural consumption environment, improve farmers' consuming capacity, continue to expand farmers' consumption and promote urbanization development of rural areas, this paper presents pertinent countermeasures and recommendations.
基金Project(51274249)supported by the National Natural Science Foundation of ChinaProject(2015zzts076)supported by the Explore Research Fund for Graduate Students of ChinaProject(201406)supported by the Hunan Key Laboratory of Coal Resources and Safe Mining Open-end Funds,China
文摘In order to investigate the failure mechanism of rock joint,a series of laboratory tests including cyclic direct shear tests under constant normal load(CNL)conditions were conducted.Morphology parameters of the rock joint surface were precisely calculated by means of a three-dimensional laser scanning machine.All test results were analyzed to investigate the shear behavior and normal displacement behavior of rock joints under CNL conditions.Degradation of rock joint surface during cyclic shear tests was also analyzed.The comparison results of the height parameters and the hybrid parameters of the joint surface during cyclic tests show that the degradation of the surface mostly happens in the first shear and the constant normal loads imposed on the joints have significant promotion effects on the morphology degradation.During cyclic shear tests,joints surfaces evolve from rough state to smooth state but keep an overall undulation.Dilatancy of rock joints degrades with the degradation of joint surface and the increase of normal loads.The closure deformation of joint is larger than that of the intact rock,and the normal stiffness increases with the increase of shearing times.
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Supported by Supported by Program for Innovative Research Team(in Science and Technology)in University of Yunnan Province
文摘In this study,using the PRA method,we conduct a questionnaire survey on 525 farmers in 10 typical villages in Yunnan Province,and study the farmers' farmland abandonment behavior as well as their perception. Studies have shown that there are some common problems for the villages in the inner suburbs and the villages in the outer suburbs such as small scale of rural land,dispersed plots and land fragmentation,and the scale and fragmentation problems are more prominent in the villages in the inner suburbs while the dispersed plot problems are more obvious in the villages in the outer suburbs; the levels of farmland abandonment vary in different sample villages,the farmland abandonment is more prevalent in the villages in the outer suburbs,the abandonment behavior involves more farmers,and farmers tend to abandon small plots of farmland; the proportion of the abandoned farmland perceived by the farmers in the villages in the inner and outer suburbs( especially in the inner suburbs) is significantly lower than the actual proportion,and farmers' perception greatly deviates from the actual reality; some farmers have wrong perception of farmland abandonment behavior,and even if there are farmers with correct perception,they also abandon farmland.
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.
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supported by"The National Key Research and Development Program of China(No.2018 YFA0703300)""Science and Technology Project of Education Department of Jilin Province(No.JJKH20231086KJ)"Development Project of Jilin Province(No.2021C038-4)。
文摘In this study,interconnected porous Mg-2Zn-xY alloys with different phase compositions were prepared by various Y additions(x=0.4,3,and 6 wt.%)to adjust the compressive properties and energy absorption characteristics.Several characterization methods were then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second phase.Compressive tests were performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous Mg-Zn-Y.The experimental results showed that a high Y content promotes a microstructure refinement and increases the volume fraction of the second phase.When the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),W-phase(Mg_(3)Zn_(3)Y_(2)),and LPSO phase(Mg_(12)ZnY).When the Y content ranges between 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 MJ/m^(3)to 10.97 MJ/m^(3)at RT,which is mainly attributed to the phase composition and volume fraction of the second phase.However,the average energy absorption efficiency is independent of the Y content.In addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing temperature.The compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the struts.The deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.
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.
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Supported by Project of National Natural Science Foundation(41171436)Key Project of National Social Science Foundation(14AZD002)
文摘China's extensive development model of pig industry gives rise to serious resource and environment bottleneck restriction,it is urgent to transform the existing development model into ecological farming model. In this process,farmers' behavior will play a key role. On the basis of summarizing development connotation and characteristics of ecological agriculture,using survey data of 323 pig farmers in 6 provinces,based on the Theory of Planned Behavior( TPB) it introduced individual characteristics and external environment constraint variables,and made an empirical analysis on factors influencing intention and behavior of pig farmers' ecological farming using the Structural Equation Model( SEM). Results indicate:( i) ecological farming intention of pig farmers has the largest direct effect on their ecological farming behavior;( ii)ecological farming cognition of pig farmers has significant positive effect on their ecological farming behavior;( iii) external environment has the largest indirect effect on their ecological farming behavior,followed by the overall effect,and external environment has significant positive effect on ecological farming attitude and cognition of pig farmers;( iv) individual characteristics( educational level and income level) of pig farmers influence ecological farming behavior of pig farmers through their ecological farming attitude and intention,but the degree of influence is limited.
基金Supported by Humanities and Social Sciences Research Project of Ministry of Education(11YJAZH038)Research Project of South-Central University for Nationalities(CSY12043)
文摘Based on the survey data and statistical information on farmers,we conduct comparative analysis of land use behavior of farmers in the Jianghan Plain and the hilly areas of Xianning City in Hubei Province.We find that the utilization rate of agricultural land and level of agricultural labor output in the plain areas are higher than in the hilly areas;at the same time,the degree of mechanization of agricultural land utilization and farmers'land use scale are larger in the plain areas.But the crop type in the plain areas is single,and the decline rate of the growing area of food crops is higher in recent twenty years;meanwhile,the material input costs and opportunity cost of labor for the agricultural land utilization in the plain areas are greater than in the hilly areas.
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Crop straw has huge resource potential. It has an important significance for realizing waste recycling and improving eco-environment to prefect straw marketization system and sufficiently stimulate farmers’ straw marketization behavior. Based on 427 copies of investigation data on farmers,influence mechanism framework of farmers’ straw marketization behavior is constructed,and key factors of farmers’ straw marketization behavior are analyzed. Results show that farmers joining in straw marketization account for 42. 1%; in influence factors of farmers’ straw marketization behavior,cultivated land area,market price level,logistics satisfaction and air quality perception have significantly positive impacts on farmers’ straw marketization behavior,while education degree,agricultural income proportion and traffic convenience have significantly negative impacts on farmers’ straw marketization behavior. Therefore,it needs strengthening propaganda intensity,carrying out reasonable subsidies and support,encouraging and breeding new type of organization,and establishing and improving the price mechanism of straw marketization to perfect straw marketization construction.