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Application Strategies of Spatial Refinement Design in Ancient Cities Supported by Digital Te-Zhaoyu Ancient City in Qixian County as an Example
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作者 BAI Zhao-yi FANG Yu-xin WEN Jia-hao 《Journal of Literature and Art Studies》 2024年第6期474-490,共17页
Digital technology provides a method of quantitative investigation and data analysis for contemporary landscape spatial analysis,and related research is moving from image recognition to digital algorithmic analysis,pr... Digital technology provides a method of quantitative investigation and data analysis for contemporary landscape spatial analysis,and related research is moving from image recognition to digital algorithmic analysis,providing a more scientific and macroscopic way of research.The key to refinement design is to refine the spatial design process and the spatial improvement strategy system.Taking the ancient city of Zhaoyu in Qixian County,Shanxi Province as an example,(1)based on obtaining the integrated data of the ancient city through the drone tilt photography,the style and landscape of the ancient city are modeled;(2)the point cloud data with spatial information is imported into the point cloud analysis platform and the data analysis is carried out from the overall macroscopic style of the ancient city to the refinement level,which results in the formation of a more intuitive landscape design scheme,thus improving the precision and practicability of the landscape design;(3)Based on spatial big data,it starts from the spatial aggregation level,spatial distribution characteristics and other evaluation index system to achieve the refinement analysis of the site.Digital technology and methods are used throughout the process to explore the refined design path. 展开更多
关键词 digital technology Zhaoyu Ancient city tilt photography point cloud data
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Enhanced Cooling Efficiency of Urban Trees on Hotter Summer Days in 70 Cities of China
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作者 Limei YANG Jun GE +4 位作者 Yipeng CAO Yu LIU Xing LUO Shiyao WANG Weidong GUO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第11期2259-2275,共17页
Increasing the urban tree cover percentage(TCP) is widely recognized as an efficient way to mitigate the urban heat island effect. The cooling efficiency of urban trees can be either enhanced or attenuated on hotter d... Increasing the urban tree cover percentage(TCP) is widely recognized as an efficient way to mitigate the urban heat island effect. The cooling efficiency of urban trees can be either enhanced or attenuated on hotter days, depending on the physiological response of urban trees to rising ambient temperature. However, the response of urban trees' cooling efficiency to rising urban temperature remains poorly quantified for China's cities. In this study, we quantify the response of urban trees' cooling efficiency to rising urban temperature at noontime [~1330 LT(local time), LT=UTC+8] in 17summers(June, July, and August) from 2003–19 in 70 economically developed cities of China based on satellite observations. The results show that urban trees have stronger cooling efficiency with increasing temperature, suggesting additional cooling benefits provided by urban trees on hotter days. The enhanced cooling efficiency values of urban trees range from 0.002 to 0.055℃ %-1 per 1℃ increase in temperature across the selected cities, with larger values for the lowTCP-level cities. The response is also regulated by background temperature and precipitation, as the additional cooling benefit tends to be larger in warmer and wetter cities at the same TCP level. The positive response of urban trees' cooling efficiency to rising urban temperature is explained mainly by the stronger evapotranspiration of urban trees on hotter days.These results have important implications for alleviating urban heat risk by utilizing urban trees, particularly considering that extreme hot days are becoming more frequent in cities under global warming. 展开更多
关键词 urban trees cooling efficiency China's cities EVAPOTRANSPIRATION suMMER hot days
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Constructing a standard system of city sustainable development assessment technology based on the SDGs
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作者 Maomao Yan Feng Yang +1 位作者 Chao Li Dehua Guo 《Chinese Journal of Population,Resources and Environment》 2024年第3期275-290,共16页
Given the rapid development of China’s new urbanization,cities with different locations and varying functional positioning,resource endowments,and development stages have insufficient scientific and applicable techni... Given the rapid development of China’s new urbanization,cities with different locations and varying functional positioning,resource endowments,and development stages have insufficient scientific and applicable technical tools for implementing the United Nations Sustainable Development Goals(SDGs).City managers and policymakers must urgently establish SDG benchmarks to diagnose city development.Moreover,successful experiences from similar cities regarding sustainable development and self-improvement must be learned from to promote diversified,sustainable development across the country.Furthermore,emerging technologies such as artificial intelligence,the Internet of Things,big data and 5G are widely used in smart cities.Therefore,there is a growing need for“knowledge-based,personalized and intelligent”technologies to support monitoring,evaluation,and decision-making processes facilitating sustainable development in cities.This paper uses standardization as the theoretical support and technical basis.This approach can help clarify the sustainable development processes in China and clarify the evaluation results of and provide data on horizontal city comparisons,which can be used to develop evaluation technology for sustainable development in cities and construct a standardized system.The results provide a standard framework for intelligent assessment and decision-making regarding cities’sustainable development capabilities in China.Evaluating major international standardization institutions reveals that the practices of Chinese national standards should be fully absorbed and integrated to guide the evaluation of smart,resilient,and low-carbon cities.To this end,an indicator library of city sustainable development is proposed to provide standard evaluation technology methods.Finally,analyzing the response relationship of the indicator library to SDGs reveals the need for a standardized knowledge map of sustainable development assessment techniques and methods from the perspective of integrated management for sustainable development in cities. 展开更多
关键词 sustainable Development Goals city sustainable development Standard system Indicator library
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Subsurface multi-physical characterization of mountain excavation and city construction in loess plateau with a fiber-optic sensing system
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作者 Jie Liu Bin Shi +3 位作者 Kai Gu Meng-Ya Sun Jun-Cheng Yao He-Ming Han 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第8期2935-2946,共12页
Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the ar... Mountain excavation and city construction(MECC)projects being launched in the Loess Plateau in China involve the creation of large-scale artificial land.Understanding the subsurface evolution characteristics of the artificial land is essential,yet challenging.Here,we use an improved fiber-optic monitoring system for its subsurface multi-physical characterization.The system enables us to gather spatiotemporal distribution of various parameters,including strata deformation,temperature,and moisture.Yan’an New District was selected as a case study to conduct refined in-situ monitoring through a 77 m-deep borehole and a 30 m-long trench.Findings reveal that the ground settlement involves both the deformation of the filling loess and the underlying intact loess.Notably,the filling loess exhibits a stronger creep capability compared to underlying intact loess.The deformation along the profile is unevenly distributed,with a positive correlation with soil moisture.Water accumulation has been observed at the interface between the filling loess and the underlying intact loess,leading to a significant deformation.Moreover,the temperature and moisture in the filling loess have reached a new equilibrium state,with their depths influenced by atmospheric conditions measuring at 31 m and 26 m,respectively.The refined investigation allows us to identify critical layers that matter the sustainable development of newly created urban areas,and provide improved insights into the evolution mechanisms of land creation. 展开更多
关键词 Mountain excavation and city construction Fiber-optic monitoring Multi-physical characterization Compacted loess
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Ensemble Deep Learning Based Air Pollution Prediction for Sustainable Smart Cities
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作者 Maha Farouk Sabir Mahmoud Ragab +2 位作者 Adil O.Khadidos Khaled H.Alyoubi Alaa O.Khadidos 《Computer Systems Science & Engineering》 2024年第3期627-643,共17页
Big data and information and communication technologies can be important to the effectiveness of smart cities.Based on the maximal attention on smart city sustainability,developing data-driven smart cities is newly ob... Big data and information and communication technologies can be important to the effectiveness of smart cities.Based on the maximal attention on smart city sustainability,developing data-driven smart cities is newly obtained attention as a vital technology for addressing sustainability problems.Real-time monitoring of pollution allows local authorities to analyze the present traffic condition of cities and make decisions.Relating to air pollution occurs a main environmental problem in smart city environments.The effect of the deep learning(DL)approach quickly increased and penetrated almost every domain,comprising air pollution forecast.Therefore,this article develops a new Coot Optimization Algorithm with an Ensemble Deep Learning based Air Pollution Prediction(COAEDL-APP)system for Sustainable Smart Cities.The projected COAEDL-APP algorithm accurately forecasts the presence of air quality in the sustainable smart city environment.To achieve this,the COAEDL-APP technique initially performs a linear scaling normalization(LSN)approach to pre-process the input data.For air quality prediction,an ensemble of three DL models has been involved,namely autoencoder(AE),long short-term memory(LSTM),and deep belief network(DBN).Furthermore,the COA-based hyperparameter tuning procedure can be designed to adjust the hyperparameter values of the DL models.The simulation outcome of the COAEDL-APP algorithm was tested on the air quality database,and the outcomes stated the improved performance of the COAEDL-APP algorithm over other existing systems with maximum accuracy of 98.34%. 展开更多
关键词 suSTAINABILITY smart cities air pollution prediction ensemble learning coot optimization algorithm
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The Distribution of Surnames in Xiantao City through Isonymy
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作者 ZHANG Jingjing ZHU Yan XIAO Hong 《Journal of Geodesy and Geoinformation Science》 CSCD 2024年第2期52-65,共14页
The population migration in Hubei Province was frequent in history,accompanied by the migration of surnames,so it is important to study their population surnames.We take Xiantao City as an example to explore the isony... The population migration in Hubei Province was frequent in history,accompanied by the migration of surnames,so it is important to study their population surnames.We take Xiantao City as an example to explore the isonymic structure of small and medium-sized cities in Hubei.The surname distributions of 223327 residents registered in 2013 were analyzed in 5 towns and 105 villages of Xiantao.The number of different surnames found was 422.As for surnames,theα-value reflects the influence of ethnic composition on the abundance of surnames.The correlation between the isonymic distance and the geographic distance between villages was calculated and indicated that Euclidean distance was weakly correlated with the geographic distance(r=0.177±0.012),and the isonymic distance increased with the geographical distance.Furthermore,the dendrogram and PCA built from the matrix of Euclidean distances between villages identified a main surname differentiation between the urban and rural areas. 展开更多
关键词 Xiantao city surname distribution isonymy isolation by distance urban and rural areas
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Development Status and Countermeasures of Farmers' Professional Cooperatives in Shangqiu City
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作者 Xiaofan XIAO 《Agricultural Biotechnology》 2024年第3期41-44,共4页
Farmers' professional cooperatives develop in various forms,and with the continuous improvement of development level,social effects have gradually appear.Based on the specific situation of farmers' professiona... Farmers' professional cooperatives develop in various forms,and with the continuous improvement of development level,social effects have gradually appear.Based on the specific situation of farmers' professional cooperatives in Shangqiu City,this paper expounded the development status of farmers' professional cooperatives in Shangqiu City,analyzed and discussed various problems encountered in the development process of farmers' professional cooperatives,and put forward some countermeasures and suggestions,such as establishing and perfecting cooperative rules and regulations,financing from multiple channels,introducing technical talents in various ways,breaking the information asymmetry restriction by various means,and giving full play to government functions,aiming to further promote standardized,large-scale,healthy and sustainable development of farmers' professional cooperatives. 展开更多
关键词 Farmers'professional cooperatives Shangqiu city Development status Existing problems Countermeasure analysis
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Accessibility and Fairness of Public Service Facilities from the Perspective of Supply and Demand Coordination: A Case Study of Old Urban Area of Guangzhou City
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作者 CHEN Xu LI Xin 《Journal of Landscape Research》 2024年第3期21-26,共6页
The accessibility and fairness of public service facilities are important manifestations of the convenience and equality of urban public service resource allocation.Optimizing the layout of urban public service facili... The accessibility and fairness of public service facilities are important manifestations of the convenience and equality of urban public service resource allocation.Optimizing the layout of urban public service facilities is an inevitable requirement for promoting the construction of people centered cities.This paper takes the old urban area of Guangzhou as the research area,measures the accessibility of multiple types of public service facilities based on an improved two-step floating catchment method,and combines Palma Ratio and location quotient methods to explore the fairness of urban public service facilities from two dimensions:social equity and spatial equity,with supply and demand relationship analysis as the main line.Research has shown that:①there is a significant spatial difference in the accessibility of public service facilities in the old urban areas of Guangzhou,and the comprehensive accessibility is generally higher in the central and southeastern regions of the old urban areas with fewer residential populations;②from the perspective of social equity,the resource allocation of public service facilities in the old urban areas of Guangzhou is in a seriously unfair state(with a fairness index of 2.99),and there are also varying degrees of unfairness within the streets;③from the perspective of spatial equity,the location quotient of public service facilities in the old urban areas of Guangzhou shows a pattern of multil center circles decreasing,indicating a significant spatial mismatch between the accessibility supply side of public service facilities and the demand side of the residential population.The research conclusion will provide scientific basis for optimizing the allocation of urban public service facilities and ensuring the equalization of public services. 展开更多
关键词 Public service facilities ACCESSIBILITY Social equity Space equity Guangzhou city
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Harm of Hail to Crops and Countermeasures of Artificial Hail Suppression in Ulanqab City
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作者 Pei WANG Tengge'er WU Jinhua LIU 《Meteorological and Environmental Research》 2024年第2期62-63,70,共3页
Hail is one of meteorological disasters affecting crop growth in Ulanqab City.It happens frequently from May to September,and this period is also the main growing season of crops.In this period,hail will cause damage ... Hail is one of meteorological disasters affecting crop growth in Ulanqab City.It happens frequently from May to September,and this period is also the main growing season of crops.In this period,hail will cause damage to crops,make farmland soil harden,and bring varying degrees of harm to agricultural production.Artificial hail suppression is an important scientific and technological means for disaster prevention and mitigation.It is necessary to strengthen the monitoring,analysis and forecast of severe convection weather,intensify the release of early warning information of hail weather,provide accurate and reliable real-time information for the implementation of artificial hail suppression operations,strengthen the implementation of artificial weather modification,effectively carry out artificial hail suppression operations,and avoid and reduce the impact of hail disaster. 展开更多
关键词 HAIL CROPS HARM Artificial hail suppression Ulanqab city
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Impact of coupling coordination development of port and city environments on urban economic competitiveness:Evidence from the coastal port cities in eastern China
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作者 LI Zhen-qiang YI Ying +2 位作者 LI Jia-li YOU Xiao-yue ZHOU Qiu-yang 《Ecological Economy》 2024年第1期53-71,共19页
Promoting the coupling coordination development of port and its hinterland city environments is an important way to improve urban economic competitiveness.Based on relevant data of 13 coastal port cities in eastern Ch... Promoting the coupling coordination development of port and its hinterland city environments is an important way to improve urban economic competitiveness.Based on relevant data of 13 coastal port cities in eastern China from 2000 to 2018,this study explores the coupling coordination development of port and city environments and its impact on urban economic competitiveness by constructing the coupling coordination degree model and the panel threshold model.The research results show that:(1)In terms of the coupling coordination development of port and city environments,most coastal ports and their hinterland cities are in a state of moderate or serious disorder.Overall,the degree of coupling coordination of port and city environments needs to be further improved;(2)The coupling coordination degree of port and city environments has a significant impact on urban economic competitiveness,and this effect gradually increases with the development of the ports and the urban economy.Among the variables that impact the urban economic competitiveness,fixed assets investment and foreign trade are significant factors that can enhance urban economic competitiveness.(3)At present,there is a“U-shaped”relationship between the coupling coordination degree of port-city environments and the urban economic competitiveness.This relationship lies on the right side of the inflection point of the“U-shaped”curve.Therefore,following the concept of assigning priority to ecological development,expanding fixed assets investment and actively developing foreign trade can further enhance the urban economic competitiveness. 展开更多
关键词 coastal ports city environments coupling coordination degree urban economic competitiveness threshold effect
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Influence of Lightning Disaster on Cities and Lightning Defense Measures
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作者 Pei WANG Tao ZHANG +1 位作者 Tengge'er WU Xiangjun ZHANG 《Meteorological and Environmental Research》 2024年第3期65-67,共3页
Under the influence of special terrain and climatic conditions,lightning weather in Ulanqab City is more frequent from June to August,and lightning disaster has become one of the important tasks of disaster prevention... Under the influence of special terrain and climatic conditions,lightning weather in Ulanqab City is more frequent from June to August,and lightning disaster has become one of the important tasks of disaster prevention and mitigation.In this paper,based on the characteristics of lightning weather in Ulanqab City,the impact of lightning disaster on the city was analyzed,and lightning protection measures,such as strengthening supervision of lightning protection safety,establishing a long-term lightning protection mechanism,doing a good job in lightning protection construction and detection in key places,and further improving public awareness of lightning protection,were put forward to reduce and avoid urban lightning disasters as much as possible and ensure urban safety. 展开更多
关键词 Lightning characteristics Disaster impact city Lightning protection measures
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Measurement and Strategy Research on the Green Development Level for the New Energy Vehicle Industry in Chongqing City
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作者 HE Qian 《Journal of Literature and Art Studies》 2024年第3期247-264,共18页
This article takes 2016-2022 as the inspection period to construct an evaluation index system for the green development level of the new energy vehicle industry.The entropy method and comprehensive index are used to m... This article takes 2016-2022 as the inspection period to construct an evaluation index system for the green development level of the new energy vehicle industry.The entropy method and comprehensive index are used to measure the green development level of the new energy vehicle industry in Chongqing,and compared with neighboring provinces such as Yunnan,Guizhou,and Sichuan.Policy recommendations are proposed to promote the development of the new energy vehicle industry in Chongqing City. 展开更多
关键词 Chongqing city new energy vehicle industry green development level
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Heritage Communities in Consumer Contexts Spatial Production of Tourism Research-Take Qixian Zhao Yu Historical City as an Example
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作者 BAI Zhao-yi ZHU Jun-jie WEN Jia-hao 《Journal of Literature and Art Studies》 2024年第1期95-108,共14页
Taking Zhaoyu Historical City in Qixian County as an example,this paper explores the production process of tourism space in Zhaoyu Historical City in the context of consumption,based on Lefebvre's triadic dialecti... Taking Zhaoyu Historical City in Qixian County as an example,this paper explores the production process of tourism space in Zhaoyu Historical City in the context of consumption,based on Lefebvre's triadic dialectic theory.The study reveals that,driven by the development of tourism,subjects such as the government and planners possess absolute dominance over spatial representations,while residents demonstrate receptive and adaptive action strategies and social relations are reproduced,presenting a harmonious state.Further exploring the tourism community in the environmental performance of the subject of action,social relations,consumption demand,daily life practice,cultural capital,etc.,the daily life practice of the tourism community has transcended the original logic of tourism spatial production and has a certain extension.The mechanism analysis in this paper can help guide the healthy development of tourism space in the neighboring historical cities or communities and achieve the dual purpose of promoting the economic development of the community and heritage protection. 展开更多
关键词 spatial production theory tourism space consumption context heritage community ZhaoYu Historical city
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改进YOLOv5su模型检测桃树缩叶病
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作者 姚凌云 周俊峰 李丽 《农业工程学报》 EI CAS CSCD 北大核心 2024年第14期109-117,共9页
为实现自然环境下桃树缩叶病的检测,该研究提出了一种基于YOLOv5su的桃树缩叶病识别改进模型DLLYOLOv5su。首先,针对桃树缩叶病目标特征变化较大的问题,在骨干网络最后一层C3模块中加入可变形自注意力模块(deformable attention,DA),使... 为实现自然环境下桃树缩叶病的检测,该研究提出了一种基于YOLOv5su的桃树缩叶病识别改进模型DLLYOLOv5su。首先,针对桃树缩叶病目标特征变化较大的问题,在骨干网络最后一层C3模块中加入可变形自注意力模块(deformable attention,DA),使模型更加关注目标区域,降低背景对模型的影响,提高模型在复杂背景下的拟合能力。其次在SPPF(fast spatial pyramid pooling)模块中引入LSKA(large separable kernel attention)结构,大核卷积增大了模型的感受野,使模型能够关注更多信息。最后,提出了LAWD(lightweight adaptive weighted downsampling)模块,使用轻量化的下采样结构替换卷积模块,减少计算开销。在桃树缩叶病数据集上进行试验,结果显示,DLL-YOLOv5su模型权重大小为17.6 MB,检测速度为83帧/s。识别准确率P、召回率R和平均精度均值mAP_(50)分别达到了80.7%、73.1%和80.4%,相较于原始YOLOv5su分别提高了4.2、2.4和4.3个百分点。与YOLOv3-tiny、Faster R-CNN、YOLOv7和YOLOv8相比mAP_(50)分别高出了28.5、11.8、2.1和4.1个百分点。改进模型识别精度高,误检、漏检率低,检测速度满足实时检测的要求,可以为桃树缩叶病的实时监测和预警提供参考。 展开更多
关键词 图像处理 病害 缩叶病 目标检测 YOLOv5su 可变形自注意力 大核卷积 轻量化
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小麦SUS基因家族鉴定与生物信息学分析 被引量:1
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作者 孔斌雪 李娜 +5 位作者 马靖福 窦佳欣 陈涛 张沛沛 刘媛 杨德龙 《云南农业大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第1期1-8,共8页
【目的】对小麦蔗糖合成酶(sucrose synthase,SUS)基因家族进行鉴定和生物信息学分析,为探究小麦SUS(TaSUS)基因家族的作用机制提供理论参考。【方法】采用生物信息学方法在小麦全基因组上鉴定TaSUS基因家族成员,并对其系统进化关系、... 【目的】对小麦蔗糖合成酶(sucrose synthase,SUS)基因家族进行鉴定和生物信息学分析,为探究小麦SUS(TaSUS)基因家族的作用机制提供理论参考。【方法】采用生物信息学方法在小麦全基因组上鉴定TaSUS基因家族成员,并对其系统进化关系、染色体位置、基因结构、保守结构域、启动子顺式作用元件和基因表达模式进行分析。【结果】在小麦基因组中共鉴定到分布于14条染色体上的24个TaSUS基因,可分为3个亚组。TaSUS基因含有多个外显子,但部分基因缺失非翻译区结构。TaSUS基因家族成员启动子区域包含45种顺式作用元件,涉及植物生长发育和逆境胁迫响应。大多数TaSUS基因在小麦穗中显著表达,在叶、茎和根中的相对表达量较低。【结论】研究结果有助于了解小麦SUS基因家族的进化,为后期小麦SUS基因家族的生物功能研究奠定理论基础。 展开更多
关键词 小麦 蔗糖合成酶(suS) 生物信息学分析 基因表达
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文旅融合:“Citywalk”热潮下的冷思考
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作者 赵欣 《河北旅游职业学院学报》 2024年第1期60-64,共5页
“Citywalk”(城市漫步)强调慢节奏和沉浸式体验,是深受年轻人追捧的文旅消费新范式。“Citywalk”火爆出圈的背后,也存在着产品辨识度不高、利润低、专业性不强、产品更迭慢等问题。“文旅融合”的有效健康发展,需要在资源供给、产品... “Citywalk”(城市漫步)强调慢节奏和沉浸式体验,是深受年轻人追捧的文旅消费新范式。“Citywalk”火爆出圈的背后,也存在着产品辨识度不高、利润低、专业性不强、产品更迭慢等问题。“文旅融合”的有效健康发展,需要在资源供给、产品创新、服务品质等方面开展全方位、多领域的合作联动,成果共享才能形成互利共赢新格局。 展开更多
关键词 文旅融合 休闲游 城市旅游
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Measurement and Interpretation of Connectivity of Chinese Cities in World City Network,2010 被引量:48
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作者 Ben DERUDDER Peter J TAYLOR +5 位作者 Michael HOYLER NI Pengfei LIU Xingjian ZHAO Miaoxi SHEN Wei Frank WITLOX 《Chinese Geographical Science》 SCIE CSCD 2013年第3期261-273,共13页
This is an empirical paper that measures and interprets the position of Chinese cities in the world city network in 2010. Building on a specification of the world city network as a′interlocking network′in which busi... This is an empirical paper that measures and interprets the position of Chinese cities in the world city network in 2010. Building on a specification of the world city network as a′interlocking network′in which business services firms play the crucial role in city network formation, information is gathered about the presence of global service firms in cities. This information is converted into data to provide the′service value′of a city for a firm′s provision of corporate services in a 526(cities)×175(firms) matrix. These data are then used as the input to the interlocking network model in order to measure cities′connectivity and its predominant geographical orientation. Here we focus on the position of some key Chinese cities in this regard, and discuss and interpret results in the context of the urban dimensions of the′opening up′of the Chinese economy. 展开更多
关键词 world city network advanced producer services SHANGHAI Hong Kong Beijing
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温度对SUS410/BNi-2/Hastelloy X钎焊接头界面组织及力学性能的影响
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作者 付伟 孙浩 +2 位作者 陈兴东 宋晓国 胡胜鹏 《精密成形工程》 北大核心 2024年第10期124-130,共7页
目的针对汽封部件的高质量制造需求,系统研究了温度对SUS410/BNi-2/Hastelloy X钎焊接头微观组织及力学性能的影响。方法将以SUS410/BNi-2/Hastelloy X搭接结构装配的试样放入真空炉中在不同温度(1060~1140℃)下进行钎焊连接,利用SEM和... 目的针对汽封部件的高质量制造需求,系统研究了温度对SUS410/BNi-2/Hastelloy X钎焊接头微观组织及力学性能的影响。方法将以SUS410/BNi-2/Hastelloy X搭接结构装配的试样放入真空炉中在不同温度(1060~1140℃)下进行钎焊连接,利用SEM和EDS等手段分析钎料与母材之间的相互作用,测试接头的力学性能并分析接头断裂行为,研究温度对接头界面组织演化和力学性能的影响。结果钎缝主要由Ni(s,s)与Cr-B相组成,B元素扩散进入两侧母材,在晶界处聚集形成硼化物相。随着钎焊温度的升高,钎缝中富Cr的硼化物和浅灰色Ni(s,s)相消失,形成均匀的Ni(s,s)组织,两侧母材中B元素扩散深度增加。随着钎焊温度不断升高,钎焊接头的抗剪强度逐渐上升,上升到某一强度后,温度继续升高,但强度反而下降,断裂位置由钎缝中心先转移至Hastelloy X基体,随着温度继续升高,断裂位置又转移至SUS410扩散区。断裂形式由脆性断裂转变为韧性断裂。结论采用BNi-2黏带钎料实现了SUS410与Hastelloy X合金的可靠连接,接头典型界面组织为SUS410/扩散区((Fe,Cr)+(Fe,Cr)-B)/钎缝区(Ni(s,s)+Cr-B+β_(1)-phases)/扩散区(γ-phase+(Cr,Ni)-B+(Cr,Ni,Mo)-B)/Hastelloy X;钎焊接头的最大抗剪强度为235.6 MPa(1100℃)。 展开更多
关键词 suS410 Hastelloy X 真空钎焊 界面组织 力学性能
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Pulsed current-assisted twelve-roll precision rolling deformation of SUS304 ultra-thin strips with exceptional mechanical properties 被引量:1
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作者 Wanwan Fan Tao Wang +3 位作者 Jinxiong Hou Zhongkai Ren Qingxue Huang Guanghui Wu 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第4期291-305,共15页
Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips.The results show that in the first rolling pass,the ro... Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin strips.The results show that in the first rolling pass,the rolling reduction rate of a conventionally rolled sample(at room temperature)is 33.8%,which can be increased to 41.5%by pulsed current-assisted rolling,enabling the formation of an ultra-thin strip with a size of 67.3μm in only one rolling pass.After three passes of pulsed current-assisted rolling,the thickness of the ultra-thin strip can be further reduced to 51.7μm.To clearly compare the effects of a pulsed current on the microstructure and mechanical response of the ultra-thin strip,ultra-thin strips with nearly the same thickness reduction were analyzed.It was found that pulsed current can reduce the degree of work-hardening of the rolled samples by promoting dislocation detachment,reducing the density of stacking faults,inhibiting martensitic phase transformation,and shortening the total length of grain boundaries.As a result,the ductility of ultra-thin strips can be effectively restored to approximately 16.3%while maintaining a high tensile strength of 1118 MPa.Therefore,pulsed current-assisted rolling deformation shows great potential for the formation of ultra-thin strips with a combination of high strength and ductility. 展开更多
关键词 pulsedcurrent-assisted suS304 ultra-thinstrip rolling reductionrate WORK-HARDENING mechanical properties
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Landscape Architecture Development Path of Water Resource-Scarcity Cities: Summary of Jinchang City's Efforts in Constructing National Garden City 被引量:1
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作者 SUN Yuhu 《Journal of Landscape Research》 2014年第6期22-24,共3页
Jinchang City, a city with scarce water resources, has developed through 32 years of efforts from a small town in the Gobi desert into a medium modern city, and green coverage ratio of the downtown area has risen from... Jinchang City, a city with scarce water resources, has developed through 32 years of efforts from a small town in the Gobi desert into a medium modern city, and green coverage ratio of the downtown area has risen from 2.6% before the founding of the city to 36.11%. This paper summarized the measures adopted by Jinchang City for building national garden city. 展开更多
关键词 Jinchang city Water resource-scarcity city LANDSCAPING Development path
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