Effects of environmental factors such as climate,topography,vegetation and soil in shelter forests in Three Gorges Reservoir Region on runoff and sediment yields were monitored to identify dominant environmental facto...Effects of environmental factors such as climate,topography,vegetation and soil in shelter forests in Three Gorges Reservoir Region on runoff and sediment yields were monitored to identify dominant environmental factors controlling runoff and sediment yields in 15 runoff plots in study area by soil sampling,laboratory analysis,stepwise regression analysis and path analysis,and to establish the main control environmental factors that affect runoff and sediment yields. The results showed that soil bulk density,herbaceous cover,slope,and canopy density were the significant factors controlling runoff,and the direct path coefficient of each factor was ranked as canopy closure(-0. 628) > litter thickness(-0. 547) > bulk density( 0. 509) > altitude( 0. 289). The indirect path coefficient was ranked as soil bulk density( 0. 354) >litter thickness(-0. 169) > altitude( 0. 126) > canopy closure(-0. 104). Therefore,canopy closure and litter thickness mainly had direct effects on runoff,while soil bulk density mainly had indirect effects through their contributions to other factors. Herbaceous cover,litter thickness,slope,canopy density,and altitude were the significant factors controlling sediment yields. The direct path coefficient of each factor was ranked as herbaceous cover(-0. 815) > litter thickness(-0. 777) > canopy closure(-0. 624) > slope( 0. 620). The indirect path coefficient was ranked as slope( 0. 272) > litter thickness(-0. 131) > canopy closure(-0. 097) > herbaceous cover(-0. 084). Therefore,herbaceous cover and litter thickness mainly had direct effects on sediment yields,while slope mainly had indirect effects through their contributions to other factors. All the selected environmental factors jointly explained 85. 5% and 78. 3% of runoff and sediment yield variability,respectively. However,there were large values of remaining path coefficients of other factors influencing runoff and sediment yields,which indicated that some important factors are not included and should be taken into account.展开更多
The necessity of rebuilding Chinese rural financial supervision system is expounded. Rebuilding rural financial supervision system is conducive to normalizing rural financial order and forming the benign competitive s...The necessity of rebuilding Chinese rural financial supervision system is expounded. Rebuilding rural financial supervision system is conducive to normalizing rural financial order and forming the benign competitive situation; to clarifying the role played by rural financial organization and providing better financial services for "three agriculture";to forming safe rural financial environment to promote the development of rural economy and national economy. The restricting factors of rebuilding Chinese rural financial supervision system are analyzed. The major reasons are that rural financial legislation is relatively backward and the supervision department lacks the necessary legal basis. The administrative supervision is insufficient, which lead to the mal-position, administrative offside and vacancy of rural financial supervision;rural financial organization mechanism is unreasonable and the internal supervision mechanism is relatively bad;supervision organization of rural financial industry is imperfect and the function is imperfect; public's supervision awareness is weak and social supervision mechanism develops slowly. The paths for rebuilding Chinese rural financial supervision system are put forward including accelerating rural financial legislation to provide perfect legal evidence for rural financial supervision system; clarifying the position on governmental functions and fully displaying the leading role of rural financial supervision; establishing specialized rural financial supervision organization to perfect its supervision functions; vigorously cultivating people's supervision awareness to promote the development of social supervision mechanism.展开更多
Runoff formation is a complex meteorological-hydrological process impacted by many factors,especially in the inland river basin.Based on the data of daily mean air temperature,precipitation and runoff during the perio...Runoff formation is a complex meteorological-hydrological process impacted by many factors,especially in the inland river basin.Based on the data of daily mean air temperature,precipitation and runoff during the period of 1958-2007 in the Kaidu River watershed,this paper analyzed the changes in air temperature,precipitation and runoff and revealed the direct and indirect impacts of daily air temperature and precipitation on daily runoff by path analysis.The results showed that mean temperature time series of the annual,summer and autumn had a significant fluctuant increase during the last 50 years（P 0.05）.Only winter precipitation increased significantly（P 0.05） with a rate of 1.337 mm/10a.The annual and winter runoff depthes in the last 50 years significantly increased with the rates of 7.11 mm/10a and 1.85 mm/10a,respectively.The driving function of both daily temperature and precipitation on daily runoff in annual and seasonal levels is significant in the Kaidu River watershed by correlation analysis.The result of path analysis showed that the positive effect of daily air temperature on daily runoff depth is much higher than that of daily precipitation in annual,spring,autumn and winter,however,the trend is opposite in summer.展开更多
In this paper,we give a necessary and sufficient condition for the existence of P3-factors in the line graph of a tree.Then we present an algorithm to determine whether the line graph of a tree has a P3-factor.
North China Plain(NCP) is the primary winter wheat production region in China, characterized by smallholder farming systems. Whereas the winter wheat average yield of smallholder farmers is currently low, the yield po...North China Plain(NCP) is the primary winter wheat production region in China, characterized by smallholder farming systems. Whereas the winter wheat average yield of smallholder farmers is currently low, the yield potential and limiting factors driving the current yield gap remain unclear. Therefore, increasing the wheat yield in NCP is essential for the national food security. This study monitored wheat yield, management practices and soil nutrient data in 132 farmers’ fields of Xushui County, Baoding City, Hebei Province during 2014–2016. These data were analyzed using variance and path analysis to determine the yield gap and the contribution of yield components(i.e., spikes per hectare, grain number per spike and 1 000-grain weight) to wheat yield. Then, the limiting factors of yield components and the optimizing strategies were identified by a boundary line approach. The results showed that the attainable potential yield for winter wheat was 10 514 kg ha^–1. The yield gaps varied strongly between three yield groups(i.e., high, middle and low), which were divided by yield level and contained 44 farmers in each group, and amounted to 2 493, 1 636 and 814 kg ha^–1, respectively. For the three yield components, only spikes per hectare was significantly different(P<0.01) among the three yield groups. For all 132 farmers’ fields, correlation between yield and spikes per hectare(r=0.51, P<0.01), was significantly positive, while correlations with grain number per spike(r=–0.16) and 1 000-grain weight(r=–0.10) were not significant. The path analysis also showed that the spikes per hectare of winter wheat were the most important component to the wheat yield. Boundary line analysis showed that seeding date was the most limiting factor of spikes per hectare with the highest contribution rate(26.7%), followed by basal N input(22.1%) and seeding rate(14.5%), which indicated that management factors in the seeding step were the most important for affecting spikes per hectare. For desired spikes per hectare(>6.598×10^6 ha^–1),the seeding rate should range from 210–300 kg ha^–1, seeding date should range from 3th to 8th October, and basal N input should range from 90–180 kg ha^–1. Compared to these reasonable ranges of management measures, most of the farmers’ practices were not suitable, and both lower and higher levels of management existed. It is concluded that the strategies for optimizing yield components could be achieved by improving wheat seeding quality and optimizing farmers’ nutrient management practices in the NCP.展开更多
This paper presents a new proof of a charaterization of fractional (g, f)-factors of a graph in which multiple edges are allowed. From the proof a polynomial algorithm for finding the fractional (g, f)-factor can be i...This paper presents a new proof of a charaterization of fractional (g, f)-factors of a graph in which multiple edges are allowed. From the proof a polynomial algorithm for finding the fractional (g, f)-factor can be induced.展开更多
Phyllostachys edulis plays an important role in maintaining carbon cycling.We examined the effects of soil properties on organic carbon content in a P.edulis forest on Dagang Mountain,Jiangxi Province,China.Based on c...Phyllostachys edulis plays an important role in maintaining carbon cycling.We examined the effects of soil properties on organic carbon content in a P.edulis forest on Dagang Mountain,Jiangxi Province,China.Based on correlation and stepwise multiple regression analyses,the effects of seven soil factors on organic carbon and their sensitivities to change were studied using path and sensitivity analyses.The results revealed differences in the interconnections and intensities of soil factors on organic carbon.Soil porosity,field capacity,and ammonium nitrogen levels were the main factors affecting organic carbon in the ecosystem.Soil porosity had a strong direct effect on organic carbon content and a strong indirect effect through field capacity.Field capacity and ammonium nitrogen levels mainly affected organic carbon directly.Field capacity,soil porosity,and ammonium nitrogen content,as well as bulk density,b-glucosidase activity,and invertase activity,were sensitive factors.Polyphenol oxidase activity was insensitive.Our study provides a theoretical basis for understanding the effects of soil factors on organic carbon,which can be utilised to improve P.edulis forest management strategies and promote carbon sequestration capacities.展开更多
<strong>Objective:</strong> To understand the influencing factors of job burnout among nurses in Haikou 3A hospital and explore its direct and indirect effects, so as to provide a scientific basis for the ...<strong>Objective:</strong> To understand the influencing factors of job burnout among nurses in Haikou 3A hospital and explore its direct and indirect effects, so as to provide a scientific basis for the work efficiency of nursing staff. <strong>Methods:</strong> Between November 2, 2015 and November 2015, using multi stage random sampling, self-administered questionnaire survey was conducted among 1049 nursing staff, using the path analysis method to study the effect of direct and indirect factors effect. <strong>Results:</strong> The total score of job burnout of nurses was 38.44 ± 7.55, high occupational burnout was 0.9%, moderate occupational burnout was 66.5%, and low occupational burnout was 32.6%. The scores of job burnout were compared among the nurses with different titles, and less achievement (F = 8.342, P < 0.001) and depersonalization (F = 3.12, P = 0.025) were statistically significant. Nurses’ Job Burnout and job stressors were the first, and the canonical correlation coefficient was 0.4397 (F = 20.54, P < 0.0001), indicating that the more problems existed in patient care, the greater the degree of emotional exhaustion. The first canonical correlation coefficient of job burnout and job satisfaction of nurses was 0.3791 (F = 12.8, P < 0.0001), indicating that the better the family and work balance, the less individualized nurses were. The path analysis results showed that the 4 dimensions of job stressors (management and interpersonal problems) is positive, the direct effect of the strongest (0.219), the total effect of sort of work pressure source of 4 dimensions (0.245) > 5 dimensions of work pressure source (0.125) > title (<span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>0.112) job satisfaction scores (<span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>0.097). <strong>Conclusion:</strong> Job stress, job satisfaction and job title are the factors that affect job burnout. The 4 and the direct and indirect effects of job stressors are the strongest, and measures should be taken to solve these problems.展开更多
This paper presents nonmonotonic quasi-Newton algorithms via two pre-conditional curvilinear paths, the preconditional modified gradient path and the precon-ditional optimal path, for unconstrained optimization proble...This paper presents nonmonotonic quasi-Newton algorithms via two pre-conditional curvilinear paths, the preconditional modified gradient path and the precon-ditional optimal path, for unconstrained optimization problem. We employ the stableBunch-Parlett factorization method to form two curvilinear paths very easily. Thenonmonotone criterion is used to speed up the convergence progress in the contoursof objective function with large curvature. Theoretical analyses are given which provethat the proposed algorithms are globally convergent and have a local superlinear con-vergence rate under some reasonable conditions. The results of numerical experimentsare reported to show the effectiveness of the proposed algorithms.展开更多
Ler G = （ V, E） be a finite simple graph and Pn denote the path of order n. A spanning subgraph F is called a { P2, P3 }-factor of G if each component of F is isomorphic to P2 or P3. With the path-covering method, i...Ler G = （ V, E） be a finite simple graph and Pn denote the path of order n. A spanning subgraph F is called a { P2, P3 }-factor of G if each component of F is isomorphic to P2 or P3. With the path-covering method, it is proved that any connected cubic graph with at least 5 vertices has a { P2, P3 }-factor F such that｜P3（F）｜P2（F）｜, where P2（F） and P3（F） denote the set of components of P2 and P3 in F, respectively.展开更多
Glacier shape factors （area, length, and thickness）, climatic factors （annual temperature and precipitation）, mass balance, and other influence factors, of the Qiyi glacier velocity and their intensity were analyz...Glacier shape factors （area, length, and thickness）, climatic factors （annual temperature and precipitation）, mass balance, and other influence factors, of the Qiyi glacier velocity and their intensity were analyzed with the application of the path analysis method during 1958-2007. Results indicate that glacier velocity was mainly influenced by glacier shape, followed by mass balance and climatic conditions. Among the influence factors, glacier area and thickness are most significant, and direct and indirect path coef- ficients are respectively 6.56, 4.71, 19.29 and 13.57. This research provides information for further understanding glacier velocity and its influencing factors.展开更多
基金Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China(2015BAD07B04)Key Science and Technology Program of Henan Province,China(152102110059)
文摘Effects of environmental factors such as climate,topography,vegetation and soil in shelter forests in Three Gorges Reservoir Region on runoff and sediment yields were monitored to identify dominant environmental factors controlling runoff and sediment yields in 15 runoff plots in study area by soil sampling,laboratory analysis,stepwise regression analysis and path analysis,and to establish the main control environmental factors that affect runoff and sediment yields. The results showed that soil bulk density,herbaceous cover,slope,and canopy density were the significant factors controlling runoff,and the direct path coefficient of each factor was ranked as canopy closure(-0. 628) > litter thickness(-0. 547) > bulk density( 0. 509) > altitude( 0. 289). The indirect path coefficient was ranked as soil bulk density( 0. 354) >litter thickness(-0. 169) > altitude( 0. 126) > canopy closure(-0. 104). Therefore,canopy closure and litter thickness mainly had direct effects on runoff,while soil bulk density mainly had indirect effects through their contributions to other factors. Herbaceous cover,litter thickness,slope,canopy density,and altitude were the significant factors controlling sediment yields. The direct path coefficient of each factor was ranked as herbaceous cover(-0. 815) > litter thickness(-0. 777) > canopy closure(-0. 624) > slope( 0. 620). The indirect path coefficient was ranked as slope( 0. 272) > litter thickness(-0. 131) > canopy closure(-0. 097) > herbaceous cover(-0. 084). Therefore,herbaceous cover and litter thickness mainly had direct effects on sediment yields,while slope mainly had indirect effects through their contributions to other factors. All the selected environmental factors jointly explained 85. 5% and 78. 3% of runoff and sediment yield variability,respectively. However,there were large values of remaining path coefficients of other factors influencing runoff and sediment yields,which indicated that some important factors are not included and should be taken into account.
文摘The necessity of rebuilding Chinese rural financial supervision system is expounded. Rebuilding rural financial supervision system is conducive to normalizing rural financial order and forming the benign competitive situation; to clarifying the role played by rural financial organization and providing better financial services for "three agriculture";to forming safe rural financial environment to promote the development of rural economy and national economy. The restricting factors of rebuilding Chinese rural financial supervision system are analyzed. The major reasons are that rural financial legislation is relatively backward and the supervision department lacks the necessary legal basis. The administrative supervision is insufficient, which lead to the mal-position, administrative offside and vacancy of rural financial supervision;rural financial organization mechanism is unreasonable and the internal supervision mechanism is relatively bad;supervision organization of rural financial industry is imperfect and the function is imperfect; public's supervision awareness is weak and social supervision mechanism develops slowly. The paths for rebuilding Chinese rural financial supervision system are put forward including accelerating rural financial legislation to provide perfect legal evidence for rural financial supervision system; clarifying the position on governmental functions and fully displaying the leading role of rural financial supervision; establishing specialized rural financial supervision organization to perfect its supervision functions; vigorously cultivating people's supervision awareness to promote the development of social supervision mechanism.
基金supported by the National Natural Sciences Foundation of China (40871027)the Initial Project of State Key Basic R & D Program of China (2009CB426309)the Knowledge Innovation Project of Chinese Academy of Sciences (KZCX2-YW-334)
文摘Runoff formation is a complex meteorological-hydrological process impacted by many factors,especially in the inland river basin.Based on the data of daily mean air temperature,precipitation and runoff during the period of 1958-2007 in the Kaidu River watershed,this paper analyzed the changes in air temperature,precipitation and runoff and revealed the direct and indirect impacts of daily air temperature and precipitation on daily runoff by path analysis.The results showed that mean temperature time series of the annual,summer and autumn had a significant fluctuant increase during the last 50 years（P 0.05）.Only winter precipitation increased significantly（P 0.05） with a rate of 1.337 mm/10a.The annual and winter runoff depthes in the last 50 years significantly increased with the rates of 7.11 mm/10a and 1.85 mm/10a,respectively.The driving function of both daily temperature and precipitation on daily runoff in annual and seasonal levels is significant in the Kaidu River watershed by correlation analysis.The result of path analysis showed that the positive effect of daily air temperature on daily runoff depth is much higher than that of daily precipitation in annual,spring,autumn and winter,however,the trend is opposite in summer.
文摘In this paper,we give a necessary and sufficient condition for the existence of P3-factors in the line graph of a tree.Then we present an algorithm to determine whether the line graph of a tree has a P3-factor.
基金supported by the National Basic Research Program of China (2015CB150405)the Special Fund for Agro-scientific Research in the Public Interest, China (201103003)
文摘North China Plain(NCP) is the primary winter wheat production region in China, characterized by smallholder farming systems. Whereas the winter wheat average yield of smallholder farmers is currently low, the yield potential and limiting factors driving the current yield gap remain unclear. Therefore, increasing the wheat yield in NCP is essential for the national food security. This study monitored wheat yield, management practices and soil nutrient data in 132 farmers’ fields of Xushui County, Baoding City, Hebei Province during 2014–2016. These data were analyzed using variance and path analysis to determine the yield gap and the contribution of yield components(i.e., spikes per hectare, grain number per spike and 1 000-grain weight) to wheat yield. Then, the limiting factors of yield components and the optimizing strategies were identified by a boundary line approach. The results showed that the attainable potential yield for winter wheat was 10 514 kg ha^–1. The yield gaps varied strongly between three yield groups(i.e., high, middle and low), which were divided by yield level and contained 44 farmers in each group, and amounted to 2 493, 1 636 and 814 kg ha^–1, respectively. For the three yield components, only spikes per hectare was significantly different(P<0.01) among the three yield groups. For all 132 farmers’ fields, correlation between yield and spikes per hectare(r=0.51, P<0.01), was significantly positive, while correlations with grain number per spike(r=–0.16) and 1 000-grain weight(r=–0.10) were not significant. The path analysis also showed that the spikes per hectare of winter wheat were the most important component to the wheat yield. Boundary line analysis showed that seeding date was the most limiting factor of spikes per hectare with the highest contribution rate(26.7%), followed by basal N input(22.1%) and seeding rate(14.5%), which indicated that management factors in the seeding step were the most important for affecting spikes per hectare. For desired spikes per hectare(>6.598×10^6 ha^–1),the seeding rate should range from 210–300 kg ha^–1, seeding date should range from 3th to 8th October, and basal N input should range from 90–180 kg ha^–1. Compared to these reasonable ranges of management measures, most of the farmers’ practices were not suitable, and both lower and higher levels of management existed. It is concluded that the strategies for optimizing yield components could be achieved by improving wheat seeding quality and optimizing farmers’ nutrient management practices in the NCP.
基金This work is supported by NNSF of ChinaRFDP of Higher Education
文摘This paper presents a new proof of a charaterization of fractional (g, f)-factors of a graph in which multiple edges are allowed. From the proof a polynomial algorithm for finding the fractional (g, f)-factor can be induced.
基金supported by the Science and Technology Basic Work Special(No.2014FY120700)
文摘Phyllostachys edulis plays an important role in maintaining carbon cycling.We examined the effects of soil properties on organic carbon content in a P.edulis forest on Dagang Mountain,Jiangxi Province,China.Based on correlation and stepwise multiple regression analyses,the effects of seven soil factors on organic carbon and their sensitivities to change were studied using path and sensitivity analyses.The results revealed differences in the interconnections and intensities of soil factors on organic carbon.Soil porosity,field capacity,and ammonium nitrogen levels were the main factors affecting organic carbon in the ecosystem.Soil porosity had a strong direct effect on organic carbon content and a strong indirect effect through field capacity.Field capacity and ammonium nitrogen levels mainly affected organic carbon directly.Field capacity,soil porosity,and ammonium nitrogen content,as well as bulk density,b-glucosidase activity,and invertase activity,were sensitive factors.Polyphenol oxidase activity was insensitive.Our study provides a theoretical basis for understanding the effects of soil factors on organic carbon,which can be utilised to improve P.edulis forest management strategies and promote carbon sequestration capacities.
文摘<strong>Objective:</strong> To understand the influencing factors of job burnout among nurses in Haikou 3A hospital and explore its direct and indirect effects, so as to provide a scientific basis for the work efficiency of nursing staff. <strong>Methods:</strong> Between November 2, 2015 and November 2015, using multi stage random sampling, self-administered questionnaire survey was conducted among 1049 nursing staff, using the path analysis method to study the effect of direct and indirect factors effect. <strong>Results:</strong> The total score of job burnout of nurses was 38.44 ± 7.55, high occupational burnout was 0.9%, moderate occupational burnout was 66.5%, and low occupational burnout was 32.6%. The scores of job burnout were compared among the nurses with different titles, and less achievement (F = 8.342, P < 0.001) and depersonalization (F = 3.12, P = 0.025) were statistically significant. Nurses’ Job Burnout and job stressors were the first, and the canonical correlation coefficient was 0.4397 (F = 20.54, P < 0.0001), indicating that the more problems existed in patient care, the greater the degree of emotional exhaustion. The first canonical correlation coefficient of job burnout and job satisfaction of nurses was 0.3791 (F = 12.8, P < 0.0001), indicating that the better the family and work balance, the less individualized nurses were. The path analysis results showed that the 4 dimensions of job stressors (management and interpersonal problems) is positive, the direct effect of the strongest (0.219), the total effect of sort of work pressure source of 4 dimensions (0.245) > 5 dimensions of work pressure source (0.125) > title (<span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>0.112) job satisfaction scores (<span style="white-space:nowrap;"><span style="white-space:nowrap;">−</span></span>0.097). <strong>Conclusion:</strong> Job stress, job satisfaction and job title are the factors that affect job burnout. The 4 and the direct and indirect effects of job stressors are the strongest, and measures should be taken to solve these problems.
基金The author gratefully acknowledges the partial supports of the National Science Foundation Grant of China(10071050),the Science Foundation Grant(02ZA14070)of Shanghai Technical Sciences Committee and the Science Foundation Grant(02DK06)of Shanghai Educat
文摘This paper presents nonmonotonic quasi-Newton algorithms via two pre-conditional curvilinear paths, the preconditional modified gradient path and the precon-ditional optimal path, for unconstrained optimization problem. We employ the stableBunch-Parlett factorization method to form two curvilinear paths very easily. Thenonmonotone criterion is used to speed up the convergence progress in the contoursof objective function with large curvature. Theoretical analyses are given which provethat the proposed algorithms are globally convergent and have a local superlinear con-vergence rate under some reasonable conditions. The results of numerical experimentsare reported to show the effectiveness of the proposed algorithms.
文摘Ler G = （ V, E） be a finite simple graph and Pn denote the path of order n. A spanning subgraph F is called a { P2, P3 }-factor of G if each component of F is isomorphic to P2 or P3. With the path-covering method, it is proved that any connected cubic graph with at least 5 vertices has a { P2, P3 }-factor F such that｜P3（F）｜P2（F）｜, where P2（F） and P3（F） denote the set of components of P2 and P3 in F, respectively.
基金supported by the Global Change Research Program of China (2010CB951404)The National Natura Science Foundation of China (41071043)
文摘Glacier shape factors （area, length, and thickness）, climatic factors （annual temperature and precipitation）, mass balance, and other influence factors, of the Qiyi glacier velocity and their intensity were analyzed with the application of the path analysis method during 1958-2007. Results indicate that glacier velocity was mainly influenced by glacier shape, followed by mass balance and climatic conditions. Among the influence factors, glacier area and thickness are most significant, and direct and indirect path coef- ficients are respectively 6.56, 4.71, 19.29 and 13.57. This research provides information for further understanding glacier velocity and its influencing factors.
