33 results
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2. Evolution of Structure Characteristics and Network Effects of Railway Passenger Transport Network in Chengdu-Chongqing Economic Circle.
- Author
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XU Jin, CHEN Hu, and CAO Weiwei
- Subjects
SOCIAL network analysis ,CIRCLE ,CITIES & towns ,JOINTS (Engineering) ,GEOGRAPHIC information systems - Abstract
The analysis of the spatial connection and structural characteristics evolution of the railway passenger transport network in Chengdu-Chongqing Economic Circle is of great significance to the future network construction and layout optimization. This paper constructs the railway passenger transport network of Chengdu-Chongqing Economic Circle based on the 46 863 617 railway passenger transport data, and uses GIS spatial analysis and social network analysis methods to analyze the space-time evolution of railway passenger transport links, the evolution of structure characteristics and the impact of network structure on economy and population in continuous time series. The results show that the polarization of railway passenger transport links in Chengdu Chongqing Economic Circle is obvious, and the passenger transport flow is mainly concentrated in Chengdu, followed by Mianyang, the main districts of Chongqing and Deyang, and other cities account for less than 20% of the passenger transport flow. The density of railway passenger transport network in Chengdu-Chongqing Economic Circle is increasing year by year, but it is still at a low level. The railway passenger transport network has a low average path length and a high average clustering coefficient, and it is characterized by a small world. The degree centrality and betweenness centrality of Chengdu and the main districts of Chongqing are far more than those of other cities. The accessibility of railway passenger transport in Chengdu-Chongqing Economic Circle is largely due to the intermediary role of Chengdu and the main districts of Chongqing. There is no railway passenger transport connection between most cities. The degree centrality, proximity centrality and intermediate centrality have positive effects on GDP, and pass the 1% significance level test. The degree centrality and intermediate centrality have negative impacts on the population, and pass the significance level tests of 5% and 10% respectively. Cities in the central position are not conducive to the permanent residence of the population. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
3. 顾及公共交通转换自由度的城市行人路网连通性分析 ———以成都市中心城区为例.
- Author
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郑 雪 姣, 杨 雪, 余 建 华, 赵 一 凡, 杨 鸿 海, and 唐 炉 亮
- Subjects
PUBLIC transit ,URBAN planning ,NEIGHBORHOODS ,LOCAL transit access ,SIDEWALKS ,PEDESTRIANS - Abstract
Copyright of Geography & Geographic Information Science is the property of Geography & Geo-Information Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
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4. 400 km/h 高速铁路大跨度桥梁轨道 静态长波不平顺验收标准研究.
- Author
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李国龙, 高芒芒, 杨飞, 杨静静, 魏子龙, and 孙宪夫
- Subjects
HIGH speed trains ,LONG-span bridges ,FINITE element method ,RAILROAD bridges ,VERTICAL motion ,PROBLEM solving - Abstract
Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
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5. 考虑公众风险的多目标医疗废物选址路径问题及樽海鞘算法求解.
- Author
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鲍秀麟, 张惠珍, 马良, and 张博
- Subjects
- *
MEDICAL wastes , *WASTE treatment , *HEALTH facilities , *COMPARATIVE method , *MATHEMATICAL models , *MEDICAL waste disposal - Abstract
For the location-routing problem of medical waste treatment centers, this paper proposed a multi-objective optimization model considering the public risk. Firstly, from the perspective of the government, the public and the processing center contractor, this paper established the mathematical model which simultaneously considered the operation cost, public risk and transportation cost.Secondly, according to the characteristics of the constructed model, this paper designed an improved multi-objective salp swarm algorithm to solve the problem. Finally, taking the planning projects of the medical waste treatment center in Chengdu, Sichuan province as an example, this paper verified the feasibility of the model and the effectiveness of the algorithm through the method of comparative analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. 基于图卷积网络的交通路口流量预测模型.
- Author
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何沁玮, 李学俊, and 廖 竞
- Subjects
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CONVOLUTIONAL neural networks , *TRAFFIC flow , *SMART cities , *PEARSON correlation (Statistics) , *ROAD interchanges & intersections , *PREDICTION models - Abstract
Traffic flow prediction is an important and challenging task in building smart city. Accurate forecasting requires consideration of spatio-temporal characteristics consisting of multiple influences such as holiday, similar node, and weather. In order to accurately capture the spatio-temporal characteristics of road network intersections, this paper proposed a prediction model based on graph convolutional neural network, temporal algorithm Prophet and Pearson correlation coefficient to achieve accurate prediction of intersection traffic considering spatial structure, similar nodes, holidays and other influencing factors. Firstly, it introduced pearson correlation coefficient to reduce the influence of similar nodes to improve the temporal algorithm for capturing temporal features. Secondly, it used the graph convolution neural network to capture spatial features; Finally, it determined the fusion weights of the graph convolutional network and the temporal algorithm by linear regression to obtain the results of spatio-temporal fusion prediction. This paper finally extracted the intersection traffic data based on the analysis of Chengdu taxi trajectory data and conducted traffic prediction experiments. The results show that the accuracy of the model proposed in this paper is better than that of most existing baseline methods, compared with the T-GCN, ASTGCN, and AGCRN models, the MAE is reduced by 1.623, 0.724, 0.161, respectively, and the accuracy is improved by 0. 144, 0. 068, and 0. 021, respectively, which verifies the effectiveness of the model in traffic intersection flow prediction. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
7. LTE-U在市域快线中综合业务承载的 应用研究.
- Author
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张 媛
- Subjects
RAILROADS ,WIRELESS communications ,DATA transmission systems ,CO-channel interference ,BANDWIDTHS - Abstract
Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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8. 成渝高铁提质改造工程列控系统方案.
- Author
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汤 骁
- Subjects
RAILROAD design & construction ,RAILROADS ,TIME management ,SPEED ,ENGINEERING ,HIGH speed trains - Abstract
Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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9. 四川盆地德阳—安岳裂陷晚震旦世—早寒武世 沉积演化特征与有利勘探方向.
- Author
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谢武仁, 姜 华, 马石玉, 汪泽成, 郝 涛, 付小东, 苏 楠, 李文正, 武赛军, 王小丹, and 黎 荣
- Subjects
DIFFERENTIAL evolution ,SEDIMENTATION & deposition ,GAS giants ,EROSION ,ROCK deformation ,RIFTS (Geology) - Abstract
Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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10. 成都市生态系统服务梯度时空特征及空间协调性演变.
- Author
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李政旸, 徐佩, and 王玉宽
- Subjects
- *
ECOSYSTEM services - Abstract
[Objective] The paper aimed to conduct quantitative calculation and localization research on ecosystem services in Chengdu, to understand the strength, spatial differentiation and impact mechanism of ecosystem services, and to provide policy ideas for the evaluation and supply of ecosystem services in rapidly urbanizing regions. [Method] Based on the gradient space theory, a spatial gradient ring and a spatial gradient transect in Chengdu were established to evaluate the value of ecosystem services, spatial differences and coordination were studied by the evaluation model of ecosystem service value, and coordination degree model in 1990, 2000, 2010 and 2020. [Result] (i) During the study period, the value of ecosystem services in Chengdu decreased by 4.737 billion yuan. (ii) The overall ecosystem service value in Chengdu showed a degrading trend, and the ‘center-periphery’ spatial circle structure radiating from the center to the periphery was obvious, mainly expanding in the southeast (ES) direction, and the northwest (WN) direction was the most stable. (iii) Chengdu has an obvious trend of expanding from the center to the two wings in the north-south direction (S) In the east-west direction (H), the ecosystem service value gradually declined in the central urban area, rapidly declined in some areas adjacent to the city, and the ecological function areas in the outer suburbs were relatively stable. (iv) From 1990 to 2020, the comprehensive coordination degree (P) on the gradient spatial transect in Chengdu decreased by 2.43. [Conclusion] (i)The value of ecosystem services and comprehensive coordination degree in Chengdu have obvious spatial and temporal differences and significant influence from the expansion of construction land. (ii)The spatial change direction and location of ecosystem services are consistent with the characteristics of urban expansion. (iii) The overall trend of comprehensive coordination (P) is downward. The construction of spatial ecosystem services has an increasingly significant impact on comprehensive coordination (P). [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
11. 多层次轨道交通规划技术体系研究.
- Author
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潘昭宇
- Subjects
SUSTAINABLE urban development ,METROPOLITAN areas ,PUBLIC transit ,ECONOMIC demand ,GOVERNMENT policy ,NETWORK hubs - Abstract
Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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12. 街头的魅力:成都城市社区 更新中的公共空间营造之道.
- Author
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赵炜, 李春玲, and 石杨
- Subjects
WATERFRONTS ,PUBLIC spaces ,STANDARDIZATION - Abstract
Copyright of Architectural Journal / Jian Zhu Xue Bao is the property of Architectural Journal Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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13. A Research on the Effects of the Digital Governance Pattern with "Integration of Data and Decision-making" by the Government.
- Author
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Li Guihua
- Subjects
INTERNET in public administration ,DECISION making ,POLITICAL science ,DATA integration - Abstract
Digital governance requires the government to transform its ability in dealing with data to the ability in governance, which depends heavily on the change of organizational mechanism. The digital governance pattern with the "integration of data and decision-making" is innovated by the local government in our country. A case study is carried out by taking the practice of digital governance by Chengdu government as the research object and taking the analysis framework in technical execution as the research method in this paper. The research shows that, by establishing a new type of pattern with the "integration of data and decision-making" as its feature, the digital governance by Chengdu government has promoted the transformation of technological value and finally achieved the benign change in the governance ecosystem Besides, this paper analyzes the logical in which data should serve for governance, and draws the conclusion that the transformation from its ability in dealing with data to the ability in governance should be promoted by the dual paths: "data serving governance decision" and "data serving government affairs." Finally, it is proposed that the digital governance pattern with the "integration of data and decision-making" is an evolution on the basis of "Internet plus Government Service", which is, on the one hand, helpful in strengthening social trust and confidence, coordinating behaviour and in promoting the innovative motivation for governance; On the other, there still exist potential risks of debris response and conformal governance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
14. 李實孔師:略論劉止唐、劉氏家族及 槐軒門人對四川道教發展的貢獻.
- Author
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歐福克
- Subjects
SACRED space ,QING dynasty, China, 1644-1912 ,TAOISM ,MODERN history ,TWENTIETH century ,CIVIL society ,SONS - Abstract
Copyright of Daoism: Religion, History & Society is the property of Chinese University Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
15. 农户土地承包经营权退出意愿影响因素及退出模式研究.
- Author
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牛海鹏 and 孙壹鸣
- Subjects
ABSOLUTE value ,URBAN planning ,LAND title registration & transfer ,SOCIAL security ,LOGISTIC regression analysis ,HOUSEHOLDS ,RURAL families - Abstract
Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
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16. 高速动车组被动式压力保护系统 舒适性测试与优化.
- Author
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孙玉昆 and 陈 垒
- Subjects
PRESSURE control ,TUNNELS ,PASSENGER trains ,VALVES ,DATA analysis ,HIGH speed trains ,RAILROAD tunnels - Abstract
Copyright of Rolling Stock (1002-7602) is the property of Rolling Stock Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
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17. Health Status Assessment of Metro Switch Machine Based on Real-Time Monitoring Data and Variable Weight Fuzzy Comprehensive Evaluation.
- Author
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YU Ting, ZHANG Yadong, JIANG Lei, and GUO Jin
- Subjects
CONDITION-based maintenance ,MEMBERSHIP functions (Fuzzy logic) ,MACHINERY ,SOLAR stills - Abstract
Aiming at the online assessment of the health status of metro ZDJ9 switch machines, a health status assessment method of metro switch machines based on real-time monitoring data and variable weight fuzzy comprehensive evaluation is proposed. Firstly, considering the electrical and mechanical characteristics and the external environment of the ZDJ9 switch machine during operation, a hierarchical evaluation index system for health status is established. Secondly, the constant weight of the switch machine evaluation index is determined based on the AHP and the weight is modified according to the relative deterioration degree of the index monitoring data based on the variable weight theory. Finally, the health status is divided into 4 levels, and the membership degree of the index monitoring data to each health level is calculated by the established membership function, and then a hierarchical evaluation model of the switch machine health status based on fuzzy comprehensive evaluation is constructed. Taking the monitoring data of the switch machine of a certain line of Chengdu Metro as an example, the method is verified and compared with the constant weight evaluation method. The results show that, for the serious deterioration of the indicators, the evaluation results of the constant weight method show that the switch machine is still in a "healthy" state, while the evaluation results of the method in this paper are more sensitive to the changes of the index data, and the evaluation result of the health state is "severe", which accords with the actual health condition and can provide the theoretical basis for condition-based maintenance. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
18. 新冠疫情影响下中国城市网络特征时空变化研究.
- Author
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施 泓 羽, 唐 炉 亮, 郑 枭 于, 杜 韵 琦, and 吴 悦 然
- Subjects
CITIES & towns ,SPATIOTEMPORAL processes ,COVID-19 pandemic ,POPULATION density ,BIG data ,URBAN growth - Abstract
Copyright of Geography & Geographic Information Science is the property of Geography & Geo-Information Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
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19. 适应不同编组列车的地铁站台门系统改造设计.
- Author
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陈 晖
- Subjects
SPATIAL arrangement ,SPATIAL systems ,URBAN growth ,TRAINING of engineers ,RAILROADS ,URBAN transit systems - Abstract
Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
- Full Text
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20. 融合高分一号、风云四号及葵花-8的光合有效辐射遥 感方法及产品研究.
- Author
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张海龙, 李丽, 辛晓洲, 闻建光, 王保清, 唐勇, 仲波, 吴善龙, 余珊珊, and 柳钦火
- Subjects
STANDARD deviations ,PHOTOSYNTHETICALLY active radiation (PAR) ,MIE scattering ,RAYLEIGH scattering ,ARTIFICIAL satellites ,REMOTE sensing ,EARTH stations - Abstract
Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2023
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21. 成都市休闲旅游资源空间分布特征及影响因素.
- Author
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李莉, 侯国林, 夏四友, and 黄震方
- Subjects
HIERARCHICAL clustering (Cluster analysis) ,CENTRAL business districts ,URBAN tourism ,CULTURAL centers ,LEISURE industry ,STREETS - Abstract
Copyright of Journal of Natural Resources / Ziran Ziyuan Xuebao is the property of Journal of Natural Resources and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2020
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22. 基于分区FA-MLP-CA模型的城市扩张模拟 --以成渝地区双城经济圈为例.
- Author
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李娥, 刘明皓, 陈春, and 李俊仪
- Subjects
URBAN growth ,K-means clustering ,FACTOR analysis ,QUALITY factor ,CELLULAR automata ,CIRCLE - Abstract
Copyright of Geography & Geographic Information Science is the property of Geography & Geo-Information Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
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23. 旅游发展与居民幸福:基于系统动力学视角.
- Author
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张俊 and 程励
- Subjects
SUSTAINABLE urban development ,CITY dwellers ,TOURIST attractions ,URBAN tourism ,SUSTAINABLE tourism - Abstract
Copyright of Tourism Tribune / Lvyou Xuekan is the property of Tourism Institute of Beijing Union University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
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24. 四川省伏旱及驱动因子多尺度分析.
- Author
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卢晓宁, 曾德裕, 黄 玥, 杨柳青, and 孟成真
- Subjects
GLACIAL landforms ,GRASSLAND soils ,WAVELETS (Mathematics) ,MIXED forests ,INNER cities ,CONIFEROUS forests ,REMOTE sensing - Abstract
Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
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25. 旅游增长与碳排放脱钩状态及其驱动因素研究——一个新的脱钩分析框架.
- Author
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查建平, 戴家权, 刘珂吉, 余 乔, and 周志坚
- Subjects
CARBON emissions ,SUSTAINABLE tourism ,DECOMPOSITION method ,AUTOREGRESSIVE models ,CLIMATE change ,TOURISM - Abstract
Copyright of Tourism Tribune / Lvyou Xuekan is the property of Tourism Institute of Beijing Union University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2022
- Full Text
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26. 背包客与“众”不同吗?: ——中国背包客与大众游客核心自我评价比较研究.
- Author
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陈钢华, 师慧敏, 赵丽君, and 黄松山
- Subjects
MASS tourism ,PLACE marketing ,EMOTIONAL stability ,BACKPACKERS ,GROUP identity ,TOURISM ,TOURIST attractions - Abstract
Copyright of Tourism Tribune / Lvyou Xuekan is the property of Tourism Institute of Beijing Union University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2021
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27. 成都平原地区梯棱羊肚菌人工栽培 生态环境参数范围及变化规律.
- Author
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谭 昊, 苗人云, 刘天海, 唐 杰, 杜大兵, 韩海涛, 杨海军, 林松, 黄忠乾, and 彭卫红
- Subjects
- *
SOIL moisture , *SOIL temperature , *ATMOSPHERIC temperature , *WATER temperature , *SOIL air - Abstract
[ Objective) This paper aimed to the quantification of the detailed ranges and dynamics of the environmental factors of the light, temperature, air and moisture in morel cultivation. ( Methods ] Environmental factors in greenhouses for Morchella importuna cultivation were collected in Chengdu plain area using Internet of Things (IoT) technologies. Illumination intensity, air temperature, air relative humidity, oxygen percentage in the air, carbon dioxide concentration in the air, soil temperature and soil water content were recorded every ten mi nutes, in greenhouses with different layers of sunshade-net. Fluctuation models in 24-hour cycle were established for the environmental fac tors at different stages. [ Results] The sunlight in the greenhouses showed a dynamic that indirectly regulated the fluctuating features of the ox Oxygen percentage, relative humidity and temperature in the air, while the average illumination intensity in the greenhouse with the highest mo rel yield were about 2500 - 3500 ks at the noon of sunny days. Sunshade-net effectively prevented over-heating during daytime and over-chill ing during night., diminishing the occurrence of extreme values of air temperature and soil temperature, whereas the cumulative temperatures of the air and the soil, as well as the cumulative values of the relative humidity. oxygen percentage and carbon dioxide concentration in the air, and the soil water content, showed no significant difference between the regimes of different sunshade net layers. The effects of the sunshade-net layers were attenus ting the fluctuations of the environmental factors, The air tem perature was either higher than or similar to the soil temperature during the fruiting stage. (Conclusion) Field conditions ideal for morel cultivation were summarized from the analytical results of the environmental factors, for the reference of field management of morel cul tivation in plain area of southwestern China, which further provided some inspirations for the engineers hoping to develop factory-mode tech nologies of morel production. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
28. 成都平原-山地过渡带不同高程下耕地土壤养分变异特征分析--以彭州市为例
- Author
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钟文挺, 李浩, 谢丽红, 孙娟, 何玉亭, and 王科
- Subjects
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HUMUS , *MOUNTAIN soils , *KRIGING , *SOIL protection , *ANALYSIS of variance , *STATISTICAL correlation , *LAND resource - Abstract
[Objective] This paper aimed to investigate the variation characteristics of soil nutrients of cultivated land at different elevation in the transition zone between plain and mountain of Chengdu. [Method] Pengzhou city as the study area was chosen, 1142 topsoil samples at different elevation were collected, and the nutrient data were analyzed with traditional statistics, correlation analysis, variance analysis, semi-variogram model optimization and Co-kriging interpolation. [Result] The correlation relationship between available potassium(AK), soil organic matter(SOM) and elevation were overwhelmingly positive, and the correlation relationship between alkali-hyclrolyzable nitrogen(AN), available phosphorus(AP) and elevation were overwhelmingly negative. The content of AN and AP decreased with elevation increasing and then obviously rebounded at the area above 913 m, the content of AK and SOM increased with elevation. The area with relatively low content of AN, AP and SOM was mainly concentrated in the zone of the most transitional elevation. [Conclusion] The result of this study could be helpful for the improvement of the productivity of cultivated land, soil utilization and protection in the transition zone between plain and mountain of Chengdu, which was of great significance for promoting the sustainable utilization of the resource of cultivated land and ensuring southwest China’s grain security. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
29. 成都地区3种桉树叶挥发油成分与体外抗肿瘤活性的初步研究.
- Author
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孟巧巧, 岳海燕, 张玉琴, and 马丹炜
- Subjects
- *
EUCALYPTUS , *EUCALYPTUS globulus , *CULTIVATED plants , *ANTINEOPLASTIC agents , *LIMONENE , *ESSENTIAL oils , *CARVONE - Abstract
[Objective] Eucalyptus globulus, E.grandis and E.robusta are green plants widely cultivated in Chengdu, and this paper aimed to exploit the utilization potential of Eucalyptus resources. [Method] The essential oils from three Eucalyptus species leaves were extracted by using the modified steam-distillation extraction method, and the chemical components were determined by gas chromatography-mass spectrometry(GC-MS). The effects of the essential oils on proliferation of human hepatoma cells(SMMC-7721) in vitro was studied by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide(MTT) assay. [Result] The oil yields of globulus, E.grandis and E.robusta were 3.67 %, 1.21 % and 0.43 %, respectively. The essential oil of E.globulus, E.grandis and E.robusta contains 34, 34 and 31 components. A total of 17 components, such as α-pinene, camphene, limonene, eucalyptol, fenchol, campholenal, borneol, carvone, alloaromadendrene, caryophyllene and o-cymene, were common components of three essential oils. The two main components were α-pinene and eucalyptol in the essential oil of E.globulus, E.grandis and E.robusta, the relative contents of α-pinene were 17.18 %, 17.89%and 41.91%, respectively;The relative contents of eucalyptol were 59.55 %, 50.49 % and 7.68 %, respectively. Three Eucalyptus essential oil significantly inhibited proliferation of human hepatoma SMMC-7721 cells and human normal liver L02 cells.SMMC-7721 cells were more inhibited than L02 by the essential oil of E.robusta, E.grandis and E.Globulus, with half maximal inhibitory concentration(IC50) values of 4.66, 7.36 and 13.53 μg·mL-1 after 24 hours treatments, respectively. The essential oil from E.robusta had a best inhibiting effect on SMMC-7721 cells. [Conclusion] These results indicated that the chemical components and contents of essential oils from different species of Eucalyptus in the same area were different, and the essential oils of Eucalyptus had the potential to be used as antitumor drugs. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
30. Invulnerability of urban transit network under different attack modes.
- Author
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HU Ping and FAN Wen-li
- Subjects
- *
PUBLIC transit , *TRAFFIC engineering , *TRAFFIC safety , *ELECTRIC network topology , *NUMBER theory - Abstract
To ensure the safety of the urban transit network so as to improve the operation efficiency of the entire traffic network, this paper took the transit network of Chengdu city for instance, it analyzed the invulnerability under random and deliberate attacks based on revealing the network topology. The simulation results show that the node number removed from the network affects the invulnerability little in both random attacks and deliberate attacks on the basis of node degree. At the same time, it finds that the less node number removed from the network, the worse invulnerability the network shows in deliberate attacks based on not only node betweeness but node efficiency. Furthermore, the impacts of deliberate attacks based on node betweeness on the network invulnerability are more remarkable than those based on node degree and efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
31. Impact on house value of distance interval to rail transit station in Chengdu.
- Author
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ZHOU Jia-zhong
- Subjects
- *
RAILROAD stations , *RAILROAD distances , *RAILROADS , *IMPACT (Mechanics) , *RESIDENTIAL real estate , *DATA analysis , *RAILROAD engineering - Abstract
To study the impact on house value of distance to stations of west extension line of metro line 2 in Chengdu within 800 meters radius area, this paper surveyed residential real estate data along the urban rail transit stations within 800 meters radius area, selected appropriate characteristics variables, and constructed semi-logarithmic equations and logarithmic equations based on hedonic price model, and then built overall equation and distance interval equation by a single distance variable and distance interval variables, and verified the impact on house value of distance to stations of west extension line of metro line 2 in Chengdu. Result shows that, within 800 meters to the metro stations, house values experience an overall downward trend with the increase of distance to the metro stations, the significance of the impact is high. But based on the different distance intervals, house values have seen a trend of "low in the two ends, high in the middle, declining in the overall". And the degree of impact on house value of distance variables, compare to other major variables (distance to the CBD, developer brand, etc.), is relatively low. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
32. 地下车库联络道出入口设计研究.
- Author
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李 尚
- Subjects
EMERGENCY management ,CENTRAL business districts ,UNDERGROUND construction ,RUNNING speed ,GARAGES ,TECHNICAL specifications - Abstract
Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
- Full Text
- View/download PDF
33. 基于浮动车轨迹数据的城市路网提取.
- Author
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王冬, 张焱, and 姜俊奎
- Subjects
NETWORK effect ,INFORMATION storage & retrieval systems ,SPLINES ,NOISE ,ALGORITHMS ,ROAD interchanges & intersections - Abstract
Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2019
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