期刊文献+
共找到7,412篇文章
< 1 2 250 >
每页显示 20 50 100
Correlation and Pathway Analysis of the Carbon,Nitrogen,and Phosphorus in Soil-Microorganism-Plant with Main Quality Components of Tea(Camellia sinensis)
1
作者 Chun Mao Ji He +3 位作者 Xuefeng Wen Yangzhou Xiang Jihong Feng Yingge Shu 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第3期487-502,共16页
The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.Howev... The contents of carbon(C),nitrogen(N),and phosphorus(P)in soil-microorganisms-plant significantly affect tea quality by altering the main quality components of tea,such as tea polyphenols,amino acids,and caffeine.However,few studies have quantified the effects of these factors on the main quality components of tea.The study aimed to explore the interactions of C,N,and P in soil-microorganisms-plants and the effects of these factors on the main quality components of tea by using the path analysis method.The results indicated that(1)The contents of C,N,and P in soil,microorganisms,and tea plants were highly correlated and collinear,and showed significant correlations with the main quality components of tea.(2)Optimal regression equations were established to esti-mate tea polyphenol,amino acid,catechin,caffeine,and water extract content based on C,N,and P contents in soil,microorganisms,and tea plants(R^(2)=0.923,0.726,0.954,0.848,and 0.883,respectively).(3)Pathway analysis showed that microbial biomass phosphorus(MBP),root phosphorus,branch nitrogen,and microbial biomass carbon(MBC)were the largest direct impact factors on tea polyphenol,catechin,water extracts,amino acid,and caffeine content,respectively.Leaf carbon,root phosphorus,and leaf nitrogen were the largest indirect impact factors on tea polyphenol,catechin,and water extract content,respectively.Leaf carbon indirectly affected tea polyphenol content mainly by altering MBP content.Root phosphorus indirectly affected catechin content mainly by altering soil organic carbon content.Leaf nitrogen indirectly affected water extract content mainly by altering branch nitrogen content.The research results provide the scientific basis for reasonable fertilization in tea gardens and tea quality improvement. 展开更多
关键词 Soil-microorganisms-plant system CARBON NITROGEN PHOSPHORUS tea quality path analysis
下载PDF
Path Analysis of High-Quality Development of Regional Economy The Role and Impact of Industrial Policies
2
作者 Nan Zhou 《Proceedings of Business and Economic Studies》 2024年第2期198-204,共7页
With China’s economic development entering a new normal,high-quality regional economic development has become an important goal of current economic development.As one of the important means to promote high-quality de... With China’s economic development entering a new normal,high-quality regional economic development has become an important goal of current economic development.As one of the important means to promote high-quality development of the regional economy,industrial policies are increasingly receiving attention in terms of their role and impact.This article mainly conducts an in-depth analysis of the mechanism and impact path of industrial policies,exploring the role and impact of industrial policies in promoting high-quality regional economic development.Firstly,industrial policies play an important role in promoting high-quality regional economic development.Secondly,the impact path of industrial policies on the high-quality development of the regional economy mainly includes promoting industrial structure upgrading,promoting technological innovation,guiding resource allocation,and enhancing enterprise competitiveness.Therefore,it is necessary to increase research and practice on industrial policies,continuously optimize policy measures,and promote high-quality development of the regional economy. 展开更多
关键词 Industrial policy Regional economy High-quality development path analysis
下载PDF
Feasibility and Path Analysis of Integrating Innovation and Entrepreneurship Education into“One-Stop”Student Communities
3
作者 Yuming Zhang 《Journal of Contemporary Educational Research》 2024年第5期200-206,共7页
The“one-stop”student community provides new support for innovation and entrepreneurship education in universities.Integrating innovation and entrepreneurship education into the“one-stop”student community work enri... The“one-stop”student community provides new support for innovation and entrepreneurship education in universities.Integrating innovation and entrepreneurship education into the“one-stop”student community work enriches course materials,integrates teacher resources,improves students’participation in innovation and entrepreneurship,and solves problems such as low student participation,lack of course resources,insufficient teacher resources,and single evaluation methods in traditional classrooms.Through various means such as exploring course resources,innovating management models,and strengthening team construction,the role of“one-stop”student communities in innovation and entrepreneurship education has been fully utilized,promoting the development of innovation and entrepreneurship education. 展开更多
关键词 Innovation and entrepreneurship “One-stop”student community FEASIBILITY path analysis
下载PDF
Correlation and Path Analysis for Growth Traits in F_1 Population of Pearl Oyster Pinctada martensii 被引量:34
4
作者 邓岳文 杜晓东 +2 位作者 王庆恒 符韶 黄荣莲 《Marine Science Bulletin》 CAS 2008年第2期68-73,共6页
120 pearl oysters (Pinctada martensii) were randomly sampled from F1 population, and shell length, shell width, shell height, shell weight and total weight of each sample were measured. Correlation and path analysis... 120 pearl oysters (Pinctada martensii) were randomly sampled from F1 population, and shell length, shell width, shell height, shell weight and total weight of each sample were measured. Correlation and path analysis were conducted on the basis of measurement data. The results showed that shell length, shell width, shell height, shell weight and total weight were significantly correlated (P 〈 0.05). Total weight was significantly and positively correlated with shell weight (r = 0.8970), shell height (r = 0.6974), shell width (r = 0.6521) and shell length (r = 0.5486). Shell weight, shell height, shell width and shell length had positive and direct effects on total wet weight, with the values of 0.6356, 0.1872, 0.1814 and 0.0599, respectively. The results indicated that growth traits (shell length, shell width, shell height, shell weight and total wet weigh) of the F1 population could be improved by direct or indirect selection. 展开更多
关键词 Pinctada martensii selected line F1 growth traits CORRELATION path analysis
下载PDF
Correlation and path coefficient analysis for phenotypic traits of noble scallop Chlamys nobilis 被引量:2
5
作者 李俊辉 杜晓东 +1 位作者 邓岳文 王庆恒 《Marine Science Bulletin》 CAS 2010年第2期55-60,共6页
In April of 2006, a base population of the noble scallop Chlamys nobilis was established by collecting parental breeders from the stocks in Wushi, Zhanjiang. In December of 2006, 200 individuals were randomly sampled ... In April of 2006, a base population of the noble scallop Chlamys nobilis was established by collecting parental breeders from the stocks in Wushi, Zhanjiang. In December of 2006, 200 individuals were randomly sampled from the base population and subjected for correlation and path coefficient analysis. It was found that there were statistically significant phenotypic correlations among the traits (P 〈 0.01). Total weight was significantly and positively correlated with the shell length (r = 0.934 3), shell height (r = 0.895 9), shell width (r = 0.899 1 ), muscle weight (r = 0.882 0) and shell weight (r = 0.937 9), respectively. Shell length, shell width, muscle weight, shell height and shell weight had positive and direct effects on the total weight, with values of 0.397 1, 0.321 9, 0.172 1, 0.089 6 and 0.066 9, respectively. Shell length, shell width and muscle weight had higher direct effects on the total weight than shell height and shell weight. A combined evaluation of correlation, direct effects and indirect effects showed that direct selection for shell length, shell width, muscle weight, shell height and shell weight would be effective to improving the total weight. It was concluded that these traits could be regarded as the selection criteria in breeding programs of the species. 展开更多
关键词 Chlamys nobilis phenotypic traits CORRELATION path coefficient analysis
下载PDF
Correlation Analysis and Path Analysis between Yield and Yield-Related Traits of Yunmai 52 被引量:1
6
作者 赵红 刘琨 +7 位作者 李宏生 崔永祯 田玉仙 顾坚 李绍祥 杨木军 浦秋红 丁明亮 《Agricultural Science & Technology》 CAS 2017年第3期407-410,431,共5页
[Objective] This study was tween yield-related traits and yield of conducted to understand the relationship be- Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety, and make contribution of ... [Objective] This study was tween yield-related traits and yield of conducted to understand the relationship be- Yunmai 52 which is a high-quality high-yield multi-resistant new wheat variety, and make contribution of yield-related traits to the yield of Yunmai 52 clear. [Method] Wheat variety regional trial data in Yunnan Province in 2005-2007 were subjected to correlation analysis and path analysis in the paper. [Result] Correlationanalysis showed that the yield of Yunmai 52 was in- very significant positive correlation with spikelet number per ear, maximum tiller number and grains per ear (r=0.726^**, 0.717^** and 0.695^**, respectively), in signif- icant positive correlation with 1 000-grain weight (r=0.491^*), but in significant nega- tive correlation with sterile spikelet number per ear, and in non-significant correlation with basic seedlings, effective ears and percentage of ear bearing tillers. Partial correlation analysis showed that the yield of Yunmai 52 was in very significant posi- tive correlation with spikelet number per ear (r=0.711^**), significant positive correla- tion with 1 000-grain weight (r=0.641 =), but in non-significant correlation with other 6 traits. Path analysis showed that spikelet number per ear (P=-0.595), maximum tiller number (P=0.462) and t 000-grain weight (P=0.263) had more contribution to yield of Yunmai 52. [Conclusion] Therefore, in extension and application of Yunmal 52 that is a high-quality high-yield multi-resistant new wheat variety, supply of fertilizer and water should be increased in tillering stage and jointing stage, to ensure its characteristics of high tilledng ability and large ear, as well as high 1 000-grain weight, and coordinated development of other yield-related traits is beneficial to im- provement of yield of Yunmai 52. 展开更多
关键词 Yunmai 52 YIELD Yield-related traits Correlation analysis path analysis
下载PDF
Path Analysis on the Meteorological Factors Impacting Soil Respiration Rate of Wheat Field 被引量:2
7
作者 江晓东 李永秀 《Agricultural Science & Technology》 CAS 2009年第1期74-76,156,共4页
[Objective]The experiment aimed to study the effects of meteorological factors under different weather conditions on soil respiration. [ Method] The path analysis was used to analyze meteorological factors which influ... [Objective]The experiment aimed to study the effects of meteorological factors under different weather conditions on soil respiration. [ Method] The path analysis was used to analyze meteorological factors which influenced soil respiration of wheat field under different weather condition and at jointing stage. [ Result] In sunny day, the correlations between ground temperature at 5 cm, solar radiation, air relative humidity, air temperature and soil respiration were all at significant level while solar radiation and ground temperature at 5 cm were the major factors which influenced soil respiration. In cloudy day, solar radiation was a major factor which influenced soil respiration.[ Conclusion] The soil respiration and surplus path coefficient in sunny day were all higher than these in cloudy day, which demonstrated that except influenced by ground temperature, air temperature, solar radiation and air relative humidity, the soil respiration was also influenced by other factors especially biological factor. 展开更多
关键词 Soil respiration Wheat meteorological factors path analysis
下载PDF
Research on the Current Status, Paths and Countermeasures of Family Farm Development in China——Investigation and Analysis of Hubei Province 被引量:2
8
作者 曾靖 《Agricultural Science & Technology》 CAS 2017年第11期2188-2192,共5页
The Chinese family farm is the most important new micro subject in the construction and development of modern agriculture in China. The investigation and analysis of the actual situation of Hubei Province showed that ... The Chinese family farm is the most important new micro subject in the construction and development of modern agriculture in China. The investigation and analysis of the actual situation of Hubei Province showed that since the implementation of the household contract management system in rural areas, the family farm has followed the track of gradual development, breakthrough development and normal standardization development. In order to promote the family farm to develop rapidly, orderly and healthily, work must be well done to land circulation, scale management, financial support, financial subsidy, cultivation of leading talents and professional farmers, and providing all-round services. 展开更多
关键词 Chinese family farm Hubei Province Development overview Typical analysis path design
下载PDF
Impact of climate factors on runoff in the Kaidu River watershed:path analysis of 50-year data 被引量:10
9
作者 XueMei LI LanHai LI +3 位作者 LingPeng GUO FeiYun ZHANG Suwannee ADSAVAKULCHAI Ming SHANG 《Journal of Arid Land》 SCIE 2011年第2期132-140,共9页
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
关键词 climate factors runoff formation inland river Kaidu River watershed path analysis
下载PDF
Using Path Analysis to Identify the Influence of Climatic Factors on Spring Peak Flow Dominated by Snowmelt in an Alpine Watershed 被引量:16
10
作者 ZHANG Fei-Yun LI Lan-Hai +1 位作者 AHMAD Sajjad LI Xue-Mei 《Journal of Mountain Science》 SCIE CSCD 2014年第4期990-1000,共11页
Spring snowmelt peak flow (SSPF) can cause serious damage. Precipitation as rainfall directly contributes to the SSPF and influences the characteristics of the SSPF, while temperature indirectly impacts the SSPF by ... Spring snowmelt peak flow (SSPF) can cause serious damage. Precipitation as rainfall directly contributes to the SSPF and influences the characteristics of the SSPF, while temperature indirectly impacts the SSPF by shaping snowmelt rate and determining the soil frozen state which partitions snowmelt water into surface runoff and soil infiltration water in spring. It is necessary to identify the important and significant paths of climatic factors influencing the SSPF and provide estimates of the magnitude and significance of hypothesized causal connections between climatic factors and the SSPF. This study used path analysis with a selection of five factors - the antecedent precipitation index (API), spring precipitation (SP), winter precipitation as snowfall (WS), 〈0℃ temperature accumulation in winter ([ATNI), and average 〉0℃temperature accumulation in spring (AT) - to analyze their influences on the SSPF in the Kaidu River in Xinjiang, China. The results show that {ATN}, AT and WS have a significant correlation with the SSPF, while API and SP do not show a significant correlation. AT and WS directly influence the SSPF, while as the influence of[ATN] on SSPF is indirect through WS and AT. The indirect influence of [ATN[ on SSPF through WS accounts for 69% of the total influence of [ATN] on SSPF. Compared to the multiple linear regression method, path analysis provides additional valuable information, including influencing paths from independent variables to the dependent variable as well as direct and indirect impacts of external variables on the internal variable. This information can help improve the description of snow melt and spring runoff in hydrologic models as well as the planning and management of water resources. 展开更多
关键词 SNOWMELT Peak flow path analysis Alpine watershed
下载PDF
Correlation and path analysis of morphological and weight traits in marine gastropod Glossaulax reiniana 被引量:11
11
作者 赵力强 何阳阳 +2 位作者 杨凤 聂鸿涛 闫喜武 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第4期821-827,共7页
Using correlation and path analysis, the genetic correlation between weight traits and morphological traits was determined in the marine gastropod Glossaulax reiniana. A total of 100 G. reiniana individuals from a wil... Using correlation and path analysis, the genetic correlation between weight traits and morphological traits was determined in the marine gastropod Glossaulax reiniana. A total of 100 G. reiniana individuals from a wild population were used. Shell width (X1), shell height (X2), umbo-callus height (X3), body width (X4), operculum length (X5), operculum width (X6), body weight (Y1) and soft-tissue weight (Y2) were measured, and the correlation coefficient matrix calculated. Morphological traits were used as independent variables and weight traits as dependent variables for path coefficient analysis. Path coefficients, correlation indices and determination coefficients were also determined. Results indicate that the correlation coefficients associated with each morphological and weight trait were all highly significant (P〈0.01). After deleting redundant independent variables, the following optimum multiple regression equations were obtained using stepwise multiple regression analysis: Y1=-29.317+0.362X2+0.349X4+ 1.190)(5 for body weight; and Y2=-17.292+0.166X1+0.171X2+0.703X5, for soft-tissue weight. Operculum height had the highest positive direct correlation with both body weight and soft-tissue weight, which was in accordance with the test results obtained from determinate coefficient analysis. The indication of high genetic correlations between weight traits and morphological traits will provide valuable information for G. reiniana breeding programs. 展开更多
关键词 Glossaulax reiniana correlation and path analysis morphological traits weight traits
下载PDF
Optimal yield-related attributes of irrigated rice for high yield potential based on path analysis and stability analysis 被引量:4
12
作者 Ganghua Li Jun Zhang +5 位作者 Congdang Yang Yunpan Song Chengyan Zheng Shaohua Wang Zhenghui Liu Yanfeng Ding 《The Crop Journal》 SCIE CAS 2014年第4期235-243,共9页
Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New... Improvement of yield in rice(Oryza sativa L.) is vital for ensuring food security in China. Both rice breeders and growers need an improved understanding of the relationship between yield and yield-related traits. New indica cultivars(53 in 2007 and 48 in 2008) were grown in Taoyuan,Yunnan province, to identify important components contributing to yield. Additionally, two standard indica rice cultivars with similar yield potentials, II You 107(a large-panicle type) and Xieyou 107(a heavy-panicle type), were planted in Taoyuan, Yunnan province and Nanjing,Jiangsu province, from 2006 to 2008 to evaluate the stability of yield and yield-related attributes.Growth duration(GD), leaf area index(LAI), panicles per m2(PN), and spikelets per m2(SM) were significantly and positively correlated with grain yield(GY) over all years. Sequential path analysis identified PN and panicle weight(PW) as important first-order traits that influenced grain yield. All direct effects were significant, as indicated by bootstrap analysis. Yield potential varied greatly across locations but not across years. Plant height(PH), days from heading to maturity(HM), and grain weight(GW) were stable traits that showed little variation across sites or years, whereas GD(mainly the pre-heading period, PHP) and PN varied significantly across locations. To achieve a yield of 15 t ha-1, a cultivar should have a PH of 110–125 cm, a long GD with HM of approximately 40 days, a PN of 300–400 m-2, and a GW of 29–31 mg. 展开更多
关键词 IRRIGATED rice GRAIN YIELD Yield-related attributes SEQUENTIAL path analysis Stability analysis
下载PDF
Correlation and Path Coefficient and Chi-square Distance Cluster Analysis for Several Characteristics in Tobacco Germplasm Resource 被引量:1
13
作者 LI Wenping ZHU Lieshu +3 位作者 ZHAO Songyi LIANG Qizheng WANG Yuchao TAN Xi 《Journal of Northeast Agricultural University(English Edition)》 CAS 2010年第1期10-15,共6页
Correlation and path coefficient analyses were conducted for 10 characteristics of 24 pure lines of flue-cured tobacco such as plant height, knot distance, leaf number, the central leaf length and width, ratio of the ... Correlation and path coefficient analyses were conducted for 10 characteristics of 24 pure lines of flue-cured tobacco such as plant height, knot distance, leaf number, the central leaf length and width, ratio of the length to width, stem girth, dates of budding, leaf yield and ratio of the prime-medium tobacco. The leaf number and the central leaf length showed a positive or a strong positive correlation with the yield per plant. And the leaf number and leaf yield per plant showed a strong positive correlation with the ratio of prime-medium tobacco. The results showed that the leaf yield per plant among these characteristics played a major role in determining the ratio of prime-medium tobacco while the others were less related with the ratio. Square sum of deviation method cluster analyses showed that 24 pure lines of flue-cured tobacco were clustered into two groups. Of the pure lines, Line T1706 and Line T1245 had a far relationship with all other lines, and also had a heterosis when crossed with the other lines. Lines Guangdonghuang 1 and R72(3)B-2-1 were closely related. 展开更多
关键词 flue-cured tobacco correlation analysis path coefficient analysis cluster analysis
下载PDF
Transfer Path Contribution to Floor Vibration of Metro Vehicles Based on Operational Transfer Path Analysis Method 被引量:1
14
作者 Laixian Peng Jian Han +2 位作者 Jiaxing Nie Xinbiao Xiao Caiying Mi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2022年第2期228-238,共11页
Operational transfer path analysis(OTPA)is an advanced vibration and noise transfer path identification and contribution evaluation method.However,the application of OTPA to rail transit vehicles considers only the ex... Operational transfer path analysis(OTPA)is an advanced vibration and noise transfer path identification and contribution evaluation method.However,the application of OTPA to rail transit vehicles considers only the excitation amplitude and ignores the influence of the excitation phase.This study considers the influence of the excitation amplitude and phase,and analyzes the contribution of the secondary suspension path to the floor vibration when the metro vehicle runs at 60 km/h,using an analysis based on the OTPA method.The results show that the vertical direction of the anti-rolling torsion bar area provides the maximum contribution to the floor vibration,with a contribution of 22.1%,followed by the longitudinal vibration of the air spring area,with a contribution of 17.1%.Based on the contribution analysis,a transfer path optimization scheme is proposed,which may provide a reference for the optimization of the transfer path of metro vehicles in the future. 展开更多
关键词 OTPA Secondary suspension Contribution analysis Transfer path optimization scheme Metro vehicles
下载PDF
The Generation of a Reduced Mechanism for Flame Inhibition by Phosphorus Containing Compounds Based on Path Flux Analysis Method 被引量:1
15
作者 李山岭 蒋勇 邱榕 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第4期357-365,共9页
In order to analyze the complex chemical kinetic mechanism systematically and find out the redundant species and reactions, a numerical platform for mechanism analysis and simplification is established basing on Path ... In order to analyze the complex chemical kinetic mechanism systematically and find out the redundant species and reactions, a numerical platform for mechanism analysis and simplification is established basing on Path Flux Analysis (PFA). It is used to reduce a detailed mechanism for flame inhibited by phosphorus containing compounds, a reduced mechanism with 65 species and 335 reactions is obtained. The detailed and reduced mechanism are both used to calculate the freely-propagating premix C3H8/air flame with different dimethyl methylphosphonate doped over a wide range of equivalence ratios. The concentration distributions of free radicals and major species are compared, and the results under two different mechanisms agree well. The laminar flame speed obtained by the two mechanisms also matches well, with the maximum relative error introduces as a small value of 1.7%. On the basis of the reduced mechanism validation, the correlativity analysis is conducted between flame speed and flee radical concentrations, which can provide information for target species selection in the further mechanism reduction. By analyzing the species and reactions fluxes, the species and reaction paths which contribute the flame inhibition significantly are determined. 展开更多
关键词 mechanism reduction path flux analysis phosphorus containing compounds flame inhibition
下载PDF
The Shortest Path Analysis Based on Road Network 被引量:1
16
作者 Chaozheng DU 《Asian Agricultural Research》 2017年第6期98-100,共3页
Rational planning of agricultural product transport route from initial node to destination node can effectively reduce the cost price of agricultural products,and the calculation of shortest path between any two point... Rational planning of agricultural product transport route from initial node to destination node can effectively reduce the cost price of agricultural products,and the calculation of shortest path between any two points also affects people’s daily travel.Taking Heze Railway Station to Heze College for example,with remote sensing image data as the base map,we conduct vectorization and topological analysis on roads in the target area.With Dijkstra as theoretical basis of shortest path algorithm,we use ArcG IS network analysis method to build road network,and calculate the planning program of the shortest distance path,the shortest path by driving and the shortest path by walking. 展开更多
关键词 Shortest path Dijkstra’s algorithm Road network model Network analysis
下载PDF
Analysis of fluid vibration transfer path and parameter sensitivity of swash plate axial piston pump 被引量:1
17
作者 ZHAO Jianhua WANG Xinwei +6 位作者 LIU Hang PEI Youzhi YANG Yong WU Zhaohua WANG Jin XING Lanchun DU Guojun 《High Technology Letters》 EI CAS 2022年第2期217-226,共10页
Taking swash plate axial piston pump as the research object,the mechanism of fluid vibration and transfer rule are analyzed.The pump shell can be assumed as the ultimate recipient of vibration transmission,the path mo... Taking swash plate axial piston pump as the research object,the mechanism of fluid vibration and transfer rule are analyzed.The pump shell can be assumed as the ultimate recipient of vibration transmission,the path model and differential equations from the fluid to the shell are established.The parameters of the path model are determined by the simulation software,and the mathematical model is solved by the simulation software.And time/frequency domain analysis of vibration acceleration of shell is presented.Based on the different influence of various parameters in the transfer path model on transfer characteristics and vibrational recipients,the time-varying parameters are studied by using sensitivity analysis theory,and the influence of the structural parameters on the vibration characteristics of vibration subject is quantitatively analyzed.The research in the paper provides theoretical basis for vibration analysis and structure parameter optimization of axial piston pump. 展开更多
关键词 axial plunger pump fluid vibration transfer path shell vibration fault analysis
下载PDF
A path analysis of the cultivated land change in Hubei Province,China 被引量:1
18
作者 Li Chunhua Li Ning Shi Peijun 《Ecological Economy》 2007年第3期243-248,共6页
Hubei Province is one of the critical grain production regions in China with the quantitative cultivated landand good natural condition; it plays an important role in grain security in China. However, owing to rapid e... Hubei Province is one of the critical grain production regions in China with the quantitative cultivated landand good natural condition; it plays an important role in grain security in China. However, owing to rapid economicgrowth, population pressures, anthropogenic activities, and natural disasters, the quality of the cultivated land hassignificantly decreased in recent years and environmental resources are under increasing stress. In order to research onthe mechanism of the change of the cultivated land, this paper analyzes qualitatively the influencing factors of thecultivated land change in Hubei Province from 1978 to 2004, and distinguishes the direct factors from indirect influentones by means of the approach of the path analysis. The result shows that the area of the rent land in the total non-agricultural land, the total population growth and the fixed asset investment are the main factors deciding the change ofthe cultivated land. Meanwhile, the density of the transportation network, the proportion of per capita income of ruralcitizens to that of urban citizens, non-agricultural gross domestic production’s share of the total GDP has a less directeffect but a more indirect influence on the decrease of the cultivated land in Hubei Province. The result means that whilesome factors have less direct influence on the change of the cultivated land, its indirect influence are significant, viceversa. Thus it’s necessary to adopt a comprehensive measurement to protect the cultivated land. 展开更多
关键词 Cultivated land change Correlation analysis path analysis Hubei Province
下载PDF
Remote open-path laser-induced breakdown spectroscopy for the analysis of manganese in steel samples at high temperature 被引量:1
19
作者 Minchao CUI Yoshihiro DEGUCHI +4 位作者 Zhenzhen WANG Seiya TANAKA Min-Gyu JEON Yuki FUJITA Shengdun ZHAO 《Plasma Science and Technology》 SCIE EI CAS CSCD 2019年第3期52-59,共8页
A remote open-path laser-induced breakdown spectroscopy(LIBS) system was designed and studied in the present work for the purpose of combining the LIBS technique with the steel production line. In this system, the rel... A remote open-path laser-induced breakdown spectroscopy(LIBS) system was designed and studied in the present work for the purpose of combining the LIBS technique with the steel production line. In this system, the relatively simple configuration and optics were employed to measure the steel samples at a remote distance and a hot sample temperature. The system has obtained a robustness for the deviation of the sample position because of the open-path and alloptical structure. The measurement was carried out at different sample temperatures by placing the samples in a muffle furnace with a window in the front door. The results show that the intensity of the spectral lines increased as the sample temperature increased. The influence of the sample temperature on the quantitative analysis of manganese in the steel samples was investigated by measuring ten standard steel samples at different temperatures. Three samples were selected as the test sample for the simulation measurement. The results show that, at the sample temperature of 500 ℃, the average relative error of prediction is 3.1% and the average relative standard deviation is 7.7%, respectively. 展开更多
关键词 REMOTE open-path LIBS steel MANGANESE SAMPLE temperature QUANTITATIVE analysis
下载PDF
基于PathAnalysis的广东省产业创新路径研究
20
作者 陈莹莹 宁凌 《劳动保障世界》 2017年第9Z期56-58,共3页
以广东省高技术产业数据为基础,采用路径分析方法,实证分析广东省产业创新中的技术创新的主要影响因素及其对产业创新的影响效果,得出广东省产业创新路径选择的基本逻辑。其主要是:广东省产业创新当中,技术作为推动因素,起到了一定的效... 以广东省高技术产业数据为基础,采用路径分析方法,实证分析广东省产业创新中的技术创新的主要影响因素及其对产业创新的影响效果,得出广东省产业创新路径选择的基本逻辑。其主要是:广东省产业创新当中,技术作为推动因素,起到了一定的效果,但其创新水平还不够,产业创新仍然具有劳动密集型的特征;产业创新当中,研发人才对技术创新有显著影响,但政府的扶持力度过小,广东产业创新路径的选择是人才导向和引进外资模式。 展开更多
关键词 产业创新 路径 path analysis
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部