56 results
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52. The Zhuwajie Bronzes.
- Author
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Sun Hua
- Subjects
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ANTIQUITIES , *INTERMENT , *BRONZE sculpture , *FUNERALS - Abstract
For the first half of the first millennium Bc, the most notable find of elite artifacts in the Chengdu Plain is a pair of hoards of bronzes found at Zhuwajie in Pengxian (now Pengzhou City) in 1959 and 1980. The present paper is a comprehensive study examining and discussing the circumstances and the date of the burials, the styles and the dates of the bronzes, and their casting technology and likely place of manufacture. It also situates the Zhuwajie bronzes in the context of the bronze cultures in the Chengdu Plain as well as the general historical background of the Western Zhou period. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
53. Is e-shopping likely to reduce shopping trips for car owners? A propensity score matching analysis.
- Author
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Shi, Kunbo, Shao, Rui, De Vos, Jonas, Cheng, Long, and Witlox, Frank
- Subjects
- *
PROPENSITY score matching , *AUTOMOBILES , *ONLINE shopping , *SHOPPING , *TRAFFIC congestion - Abstract
Reducing car use is commonly considered as a potential strategy to reduce transport-related problems such as traffic congestion and air pollution. The increasing use of online shopping may potentially replace shopping trips, thus possibly reducing car use. However, car owners – compared to non-car owners – can more easily visit physical stores and transport goods. Therefore, it can be assumed that online shopping is less likely to reduce shopping trips for car owners. Using 653 structured face-to-face interviews in Chengdu (China) in 2016, an empirical study is conducted. The results show that 44.0% of respondents indicated a decrease in shopping trip frequency after they started to purchase online, while only 14.4% indicated an increase in the frequency. This confirms that online shopping tends to be a substitute for shopping trips. Applying a propensity score matching approach, this paper further compares the likelihoods of changes in shopping trips caused by online buying between car owners and non-car owners, while considering sociodemographic factors, internet experiences, spatial attributes, and online shopping attitudes as covariates. The results indicate that – due to online buying – shopping trip frequency is less likely to decrease for car owners compared to non-car owners, while there is no significant difference in the likelihood of increasing shopping trip frequency between owners and non-owners. These findings imply that online shopping may not effectively reduce driving, thus unlikely being a valid solution for transportation problems resulting from the increasing use of cars. • Propensity score matching is applied to infer causality; • Shopping trips can be partly replaced by e-shopping; • E-shopping is less likely to replace shopping trips for car owners; • E-shopping may not effectively reduce driving. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
54. Research on the Spatio-Temporal Dynamic Evolution Characteristics and Influencing Factors of Electrical Power Consumption in Three Urban Agglomerations of Yangtze River Economic Belt, China Based on DMSP/OLS Night Light Data.
- Author
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Zhong, Yang, Lin, Aiwen, Xiao, Chiwei, Zhou, Zhigao, and ZHIZHIN, Mikhail
- Subjects
- *
CITY dwellers , *STANDARD deviations , *FACTOR analysis , *DISPOSABLE income , *RANDOM forest algorithms - Abstract
In this paper, based on electrical power consumption (EPC) data extracted from DMSP/OLS night light data, we select three national-level urban agglomerations in China's Yangtze River Economic Belt(YREB), includes Yangtze River Delta urban agglomerations(YRDUA), urban agglomeration in the middle reaches of the Yangtze River(UAMRYR), and Chengdu-Chongqing urban agglomeration(CCUA) as the research objects. In addition, the coefficient of variation (CV), kernel density analysis, cold hot spot analysis, trend analysis, standard deviation ellipse and Moran's I Index were used to analyze the Spatio-temporal Dynamic Evolution Characteristics of EPC in the three urban agglomerations of the YREB. In addition, we also use geographically weighted regression (GWR) model and random forest algorithm to analyze the influencing factors of EPC in the three major urban agglomerations in YREB. The results of this study show that from 1992 to 2013, the CV of the EPC in the three urban agglomerations of YREB has been declining at the overall level. At the same time, the highest EPC value is in YRDUA, followed by UAMRYR and CCUA. In addition, with the increase of time, the high-value areas of EPC hot spots are basically distributed in YRDUA. The standard deviation ellipses of the EPC of the three urban agglomerations of YREB clearly show the characteristics of "east-west" spatial distribution. With the increase of time, the correlations and the agglomeration of the EPC in the three urban agglomerations of the YREB were both become more and more obvious. In terms of influencing factor analysis, by using GWR model, we found that the five influencing factors we selected basically have a positive impact on the EPC of the YREB. By using the Random forest algorithm, we found that the three main influencing factors of EPC in the three major urban agglomerations in the YREB are the proportion of secondary industry in GDP, Per capita disposable income of urban residents, and Urbanization rate. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
55. A new mass & time primary standard for natural gas in China and the uncertainty evaluation.
- Author
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Ren, Jia, Duan, Jiqin, Huang, Min, and He, Min
- Subjects
- *
UNITS of time , *OPTICAL gratings , *UNCERTAINTY , *MASS measurement , *TEST interpretation , *NATURAL gas , *ELECTROHYDRAULIC effect - Abstract
A new mass-time primary standard for high pressure natural gas, which is based on electromagnetic balance and hydraulic fast-acting valves, was set up at the beginning of 2017 in Chengdu, China. The full load of the electromagnetic balance is 3 tons and the measurement uncertainty of mass is better than 1.0g(k = 2). The opening and closing time of the hydraulic fast-acting valves can achieve 33 ms±3 ms.The operation pressure and flowrate range of the facility is (4–60)bar.a and (5–410)m3/h respectively. In accordance with the preliminary tests, the estimate uncertainty of sonic nozzles calibration is between 0.10% and 0.12%(k = 2). The operation principle, testing results and the uncertainty evaluation are presented in the paper as well as some improving ideas. • A new mass-time primary standard for natural gas based on 3t electromagnetic balance and hydraulic fast-acting valves. • Gas collecting tank, balancing tank and weights are operated automatically by PLC. • Two hydraulically-actuated valves equipped with 13 optical gratings are operated in about 33ms and "zero overlap" are achieved. • Uncertainty evaluation and one year time stability test results show that the CMC is about 0.10%-0.12%(k =2). • Inter-lab comparisons with NMI and CEESI also verify the CMC. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
56. Exploring the Associations Between Urban Form and Neighborhood Vibrancy: A Case Study of Chengdu, China.
- Author
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Lu, Shiwei, Huang, Yaping, Shi, Chaoyang, and Yang, Xiping
- Subjects
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NEIGHBORHOODS , *URBAN planning , *SOCIAL accounting , *CITIES & towns , *GEOGRAPHIC information systems , *SOCIAL status - Abstract
The design and optimization of urban form has always been a hot topic in urban planning and development research. Besides, the creation of continuous vitality in urban areas is of critical importance in the development of urbanization. However, due to the lack of data, it is difficult to measure the effects of urban form on neighborhood vibrancy. Additionally, no uniform conclusion has been drawn regarding to what degree urban form can contribute to neighborhood vibrancy. Taking advantage of emerging new data sources, the depth and breadth of related research can now be improved. Therefore, this paper uses high-precision positioning social media check-in data to approximate the vibrancy of 658 neighborhoods, and uses a geographical information system (GIS) to quantitatively measure the urban form indicators in the central area of Chengdu City, China. A quantitative exploration and analysis of the relationships between neighborhood vibrancy and urban form is conducted. The results of three regression models considering different explanatory variables show that socio-economic factors account for approximately 23% of neighborhood vibrancy. In addition, the correlation between the shape characteristics of a neighborhood and the vibrancy is weak. However, when the inner urban form indicators of neighborhoods are introduced into the regression model, the goodness of fit (R2) is nearly doubled. This finding indicates that strong associations exist between urban form and neighborhood vibrancy. Specifically, building density and functional diversity are positively correlated with neighborhood vibrancy. Unlike existing studies, this study finds that the road network within the neighborhood plays a positive role in the creation of neighborhood vibrancy. However, the impact of a road density indicator is not as powerful as the impacts of building density and functional diversity. This research can help urban designers to better design urban environments. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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