A Study of the Relationship between Air Pollutants and Inversion in the ABL over the City of Lanzhou

By analyzing the pollutant concentrations over the urban area and over the rural area of the city of Lanzhou, Gansu Province, China, the relationships between the daytime inversion intensity and the pollutant concentration in the atmospheric boundary layer （ABL） are studied with the consideration of wind speed and direction, potential temperature, specific humidity profiles, pollutant concentration in the ABL, the surface temperature, and global radiation on the ground. It was shown that the daytime inversion is a key factor in controlling air pollution concentration. A clear and positive feedback process between the daytime inversion intensity and the air pollutants over the city was found through the analysis of influences of climatic and environmental factors. The mechanisms by which the terrain and air pollutants affect the formation of the daytime inversion are discussed. The solar radiation as the essential energy source to maintain the inversion is analyzed, as are various out-forcing factors affecting the inversion and air pollutants. At last, a physical frame of relationships of air pollution with daytime inversion and the local and out-forcing factors over Lanzhou is built.

The harmonious relationship between land use and environment in Xi’an

In this paper we adopt annual land use conditions change data, land sifting data, social, economic and population data and environment information of nine districts and four counties in Xi＇an city from 1980 to 2000 to analyze its structural and degree change of land use since the 1980s, and calculate the benefits and transformation of land use type. The results show that the non-agricultural land increased rapidly, especially the urban and rural residential spots and industrial and mining （RIM） land use increased mostly rapidly, an increase of 64%. Meanwhile, the intensity of land exploitation was accelerating, land was transformed to industries with better benefit and areas experiencing faster urbanization process. By analyzing the harmonious degree of land exploitation in economic and environmental aspects, we find out that the land use imbalance mainly existed in the municipal area of Xi＇an, and the imbalance index of land use based on GDP and non-agricultural population were respectively 12.37 and 14.67 in 2000, which were far higher than those in other regions. Nevertheless the environmental harmonious degree in the municipal area of Xi＇an ranges between 0.6 and 0.8, which was better than that of suburban area. Some proposals addressing to the problems of harmonious level in all scales, resources utilization, projects management and feasibility analysis and intensive urbanization are also put forward.

New Trends in the Relationship Between Major Western Countries and Africa

With the deep-going development of globalization and enhanced African unity for self-improvement, the international community is paying more and more attention to the standing of Africa and the role it plays. The United States, Japan, Russia, India and the European Union (EU), are strengthening and upgrading, out of their own needs, their political and economic relations with African countries in a bid to consolidate their strategic interests in the continent.

A Comparative Study of Humanistic Exchange and Cooperation between China and Southeast Asian in the Perspective of "the Belt and Road" Initiative

In the exchanges between different countries,apart from enhancing political mutual trust and strengthening pragmatic cooperation,it is of great importance to forging humanistic exchange.With a long history of exchanges between China and all the countries in South-east Asia,the humanistic exchange between China and South-east Asia has been continuing since the founding of the People's Republic of China.After the establishment of China-ASEAN dialogue relations,the strategic position of humanistic exchange has been rapidly improved.By means of the case study of Confucius Institute,sister cities,and tourism cooperation,the author has found that humanistic exchange between China and South-east Asia has enjoyed a long history and embodied profound and extensive meaning.It is the ancient Maritime Silk Road that helped to form the exchanges between China and South-east Asia.In the meantime,it is the 21st-Century Maritime Silk Road that has deepened this friendship.The successful experience of humanistic exchange and cooperation between China and South-east Asia has not only consolidated the China-ASEAN strategic partnership but also provided a conducive reference for people-to-people ties in the implementation of the Belt and Road Initiative.In addition,it has added dynamics and confidence to the building of a community with a shared future for mankind which is propelled by China's humanistic diplomacy.

“City-Scene” Characteristics and Optimization Strategies Research on Three Gorges Reservoir Area of the Post-Three Gorges Era

In the long-term symbiotic evolution process,the town areas along the Yangtze River and its natural and cultural landscapes have presented a sound "city-scene" landscape form. But with the implementation of the Three Gorges project,the town relocation as well as the flooding in the natural and human landscape area,the original harmonious "city-scene" pattern started to collapse and fell into the situation of "fragmentation" and "islanding". The differentiation between city and landscape,uncoordinated scale and fractured urban context become pressing issues that affect the integral form optimization of the town areas. This paper aims at responding to the call of the government about proceeding the construction of the Yangtze River economic belt under the ecological and green strategy and seeking an attuned "cityscene" relationship of the town area. Based on the analysis of the dynamic evolution of the "city-scene" relationship,the paper also pointed out that the urban construction around the reservoir area in the postThree Gorges era was the key stage of "scene-city" integration and symbiosis while the maintenance of scenery pattern,the harmony of space scale and the protection of living culture should be applied as the vital strategies.

City Networks of Online Commodity Services in China:Empirical Analysis of Tmall Clothing and Electronic Retailers

City networks have been a critical topic in the fields of urban geography and regional economics. Numerous studies have explored city networks, focusing mainly on infrastructure and industrial networks. Unlike traditional urban network of which the major measuring indexes are population sizes and entity industries, online commodity service networks could reflect well the influencing of emerging economies, especially the Internet economy, on city networks. This study analyzes and reveals structural features of China's city networks through online commodity services, providing the internet economic approach on city networks. Results indicate that the core cities of online commodity service networks are mainly concentrated in eastern coastal areas. In addition, spatial polarization and layer structure of network connections are obvious, descending from the centers in eastern China to peripheral cities in central and western China. Online commodity services of different cities show apparent differences and uncertainties in terms of specialization rates of international connection, which presents a tendency toward diversification. Online commodity service networks are not only associated with goods production, supply, and consumption in physical space but also reflect virtual information, capital, and technology flows, thus providing a new empirical approach for understanding city networks in information and internet economic age.

Changing Concepts of City and Urban Planning Practices in Guangzhou(1949–2010): An Approach to Sustainable Urban Development

By focusing on Guangzhou, this paper examines how different concepts of city in terms of urban-rural relationships are shaped in transforming China since 1949, and explores how they influence the way in which urban planning are practiced. In the pre-reform era, the city was defined as a productive space under the system of urban-rural segregation established for securing rapid industrialization. Urban planning was thus only concerned with the development of urban areas. In the 1980 s and 1990 s after the reform, institutional change and economic transformation mobilized the urban-rural linkages. The development of suburban areas was then considered by urban planning, but this consideration was a passive response to urban problems such as population explosion and water resources protection. Since the new millennium, the agenda for sustainable development and problems of uneven urban-rural development have called for the development of urban-rural integration. In this context, the city is conceptualized as a complex of mountain, city, river, farmland and sea, reconstructing the ideology of urban-rural division in defining urban development. Urban planning has therefore sought in an active way to develop a sustainable city embracing rural and natural elements, and to balance economic growth and environmental protection. It is argued that developing the concept of city as a complex of urban and rural elements contributes to the urban planning for sustainable urban development, while this conceptualization relies on the recognition of the integrated urban-rural relationship.

Molecular Diversity of the Human Immunodeficiency Virus Type 1 in Metropolitan Cities in Central Africa: An Update of Data

The Human Immunodeficiency Virus (HIV) has a diversity that is equal to the complexity of its management. The group M (Major) is the dominant group in Sub-Saharan Africa and its distribution is very heterogeneous;the diversity of the virus is more heterogeneous in this region than elsewhere in the world which follows a complex and specific algorithm because of geographical positions and countries. This distribution is very dynamic, evolving and unpredictable. This review aimed to expose the specifics of the HIV Type 1 epidemic in Central Africa, in terms of the different molecular variants of HIV published for the region compared to the geographic location. Both Type 1 and Type 2 of HIV are prevalent in sub-Saharan Africa due to distinct geographical contexts. HIV-2 is mainly documented in West and Central Africa, particularly in Cameroon, Guinea-Bissau, Gambia, Senegal, Ivory Coast and Burkina-Faso however HIV-1 infection is widely distributed across the continent. The HIV-1 epidemic in Sub-Saharan Africa is dominated by the Group M. The different subtypes respect a certain geographical distribution across the continent. West Africa is dominated by subtype A, East and South Africa are dominated by subtype C, while Central Africa is dominated by strains A, C, D, F, H, J, CRF01-AE and CRF02-AG. This review is the first to present de molecular diversity of HIV-1 in metropolitan cities in all central African countries. The Circulating Recombinant Form (CRF02_AG) and subtypes A and G are present in all Central African countries and are also the most commonly encountered;followed by the subtypes D, F, G, C, B, J, K and several Circulating Recombinant Forms that are not represented in all Central African countries.

Cities and Country Today-Full of Colorful Life

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Projected Rainfall Intensity Duration Frequency Relationships under Climate Change:A Case Study Thane City

Climate change is the most important factor to increase in short-duration high-intensity rainfall and consequent flooding.Intensity-Duration-Frequency(IDF)curves are commonly used tools in Stormwater design,so a method to derive future IDF curves including climate change effect could be necessary for the mainstreaming climate change information into storm water planning.The objective of the present study is to define a mechanism to reflect the effect of climate change into the projected rainfall IDF relationships.For this,the continuously observed hourly rainfall data from 1969 to 2018 were divided into five subgroups.Then the IDF curve of each subgroup is defined.The rainfall intensity for the next 30 years was then estimated using a linear regression model.The obtained result indicates that for the same duration and for the same return period,the rainfall intensity is likely to increase over time:17%(2019-2028),25%(2029-2038)and 32%(2039-2048).However,the findings presented in this paper will be useful for local authorities and decision makers in terms of improving stormwater design and future flood damage will be avoided.

Seismic Risk Assessment and Maximum Magnitudes of Potential Earthquakes on Active Faults near Lanzhou City

The Zhuanglang river and Baiyin Baiyangshu river faults are late Quaternary faults near Lanzhou city,which pose a threat to the safety of the city. However,the cause of medium-strong earthquakes along the fault is rather complicated and even uncertain. It is important for us how to assess the magnitudes of maximum potential earthquakes and the seismic risk of the faults. The authors make reference to the method that Wen Xueze,et al.(2007) developed to assess the magnitudes of maximum potential earthquakes in sub-areas of moderately and weakly active faults in the eastern Chinese Mainland,and brought forward an empirical relationship between the maximum magnitudes M_max and the a_t/b values of the sub-areas' frequency-magnitude relationships in the Lanzhou area. By using this empirical relationship,the authors have estimated the upper-limits M_u of the Zhuanglang river and Baiyin Baiyangshu river active faults near Lanzhou city as M_S6.9 and 6.3,respectively. In addition,they have assessed the average interval recurrence time and the probabilities of destructive earthquakes on the faults.

石家庄市县域科技创新与经济发展耦合协调关系时空演变

选取石家庄市13个县域单元作为研究区域,构建科技创新能力和经济发展水平评价指标体系,计算评价指数,测算两者的耦合协调度,使用ArcGIS绘制空间分布图,深入剖析科技创新能力、经济发展水平以及两者耦合协调关系的时空演变特征。研究发现:全市县域科技创新能力和经济发展水平呈现较强的正相关性,且都在2010—2017年间提升速度较快,而在2019年之后提升速度呈减慢的趋势。2010—2021年经济发展水平指数均高于科技创新能力指数,但后者提升速度高于前者,表明石家庄市各县域科技创新能力滞后于经济发展水平,但科技创新能力的发展势头较好。2010年以来,全市县域耦合协调度呈现上升趋势,但耦合协调度与科技创新能力和经济发展水平的变化趋势相似,即2018年之前的提升速度要快于2018年之后。2021年,全市县域耦合协调度等级为“勉强协调发展”,协调发展水平较低,有待进一步提升。

无人经济趋势下的未来城市空间创新与规划应对

聚焦无人化趋势下的城市新型人地关系,结合无人化趋势带来的业态创新和就业模式变化,推演未来可能出现的无人化场景及其对规划技术提出的新挑战,由此得出如下新趋势并提出相应的规划应对设想:在无人化趋势下,以人定地的空间规模预测方式的适用性会降低,需要在系统考虑机器换人对各类用地影响的基础上确定城镇空间发展规模;无人化生产和劳动力替代将在一定程度上重构现有的产城空间格局,未来需要加强对无人化产业空间的学术研究和规划技术研究;未来城市会出现大量“人—机”共存交互的空间场景并产生相应的治理难题,急需从时空行为活动导控方面探索提升建成空间利用效率的规划新理论和新方法。

武汉市城市快速扩张与生态系统服务价值权衡/协同的交互作用

研究城市快速扩张区域各类生态系统服务的相互关系和驱动因素,对于协调区域社会、经济与生态的可持续发展具有重要意义。以处于快速城市化进程的武汉市为研究对象,基于多源数据,分析研究区11种生态系统服务价值的空间分异特征、权衡/协同关系及其多重因子交互影响。结果表明:①2000―2020年武汉市城市化率增长25.43%,土地利用结构显著变化,其中建设用地面积增长最大,增加了25.86%,湖泊和耕地面积显著减少。②武汉市生态系统服务总价值呈现下降趋势,减少了6.70亿元,调节服务价值占主导地位,达到总量65.75%以上,其中水文调节服务价值总量最高,主要来源于湖泊。③2000―2020年武汉市11种生态系统服务间的关系以协同关系为主导,占比80.00%,权衡关系主要存在于食物生产与其他服务之间。④地理探测器结果表明社会经济因素对生态系统服务价值空间分异的解释度高于自然因素,农村住户人均纯收入、粮食产量和人口密度对其影响强度最大。

On the Strategic Relationship between China and Islamic Countries in the Middle East

The relationship between China and the Islamic countries has been of strategic significance;mutual understanding and mutual respect in their political ties has been the mainstream in the bilateral relationship.Since the founding of new China,their relationship has undergone two phases:from bilateral to multilateral relations and from mainly in the political field to comprehensive ties in the economic and trade,resources,security,culture and other fields.For future development of bilateral relationships,issues such as misjudgment and misunderstanding,trade imbalance and conflicts of interest must be resolved.To do so,strategic significance must be attached to bilateral relationships so as to uplift the strategic position of the Middle East in the overall Chinese diplomacy,establish a Middle East strategy with Chinese characteristics and strengthen China's cultural diplomacy including religious communication with the Islamic countries in the Middle East.

An Analysis of the Relationship Between the Education Attainment and Economic Status of the Elderly Population in the Towns and Cities of China

Viewed from a macro scope,the cultureof a community is closely related to its econ-omy.Economy being the basis,the level ofeconomic growth determines the level ofcultural development.Conversely,culturecan act as the precursor and cultural devel-opment enhances economic growth.Likewise,the education attainment of an in-dividual reflects the same sort

航运中心与城市经济互动关系分析——上海与新加坡比较

港口与城市经济的协调发展有助于提高港口竞争力和城市影响力。以上海和新加坡为比较对象,采用熵权-灰色关联模型探究港口与城市经济的关联度。通过构建向量自回归模型,从对外贸易、生产总值和产业结构探究港城互动关系。结果表明,城市经济与航运中心存在较强关联。新加坡对外贸易与港口间具有稳定的双向促进效应,上海市外向型经济对航运中心的驱动作用较弱。上海市生产总值能为港口发展提供有力的腹地支撑,港口对城市生产总值的辐射带动效应并不明显。上海市第三产业与港口间存在长期的潜在拉动力,但现阶段上海市第二产业对航运中心的发展仍起主导作用。从长期效果看,第三产业扩张政策对航运中心的促进作用强于第二产业。针对上述结论,分析原因并提出增强港口韧性、促进“港产城”融合发展等建议。

创新型城市试点对企业数字化转型的政策效应及其传导机制——基于双重差分方法的准自然实验

创新型城市试点政策是中国建设创新型国家的战略部署,但目前基于微观企业层面、采取定量方法对其是否以及如何影响企业数字化战略选择的相关研究缺乏。在数字经济时代下,为给中国进一步推动企业利用制度优势实现数字化转型提供经验证据,从制度层面的视角,以微观企业数字化转型为研究对象,利用Python软件对2004—2020年中国上市企业年报关键词进行文本挖掘,构建企业数字化转型评价指标,运用多时点的双重差分(DID)模型考察创新型城市试点对企业数字化转型的政策效应及其作用机制。结果发现,相较于非试点城市,试点城市内的企业更加易于开展数字化转型,且这一政策效果在非国有企业、资本密集型行业的企业以及技术密集型行业的企业中更为显著;而且,创新型城市试点能够通过缓解企业融资约束、促进科技人才集聚和优化创新环境(硬环境和软环境)对企业数字化转型产生影响。据此,提出进一步总结创新型城市试点建设的经验、因企制宜地采用差别化的激励扶持政策,以及重视资金、人才、新型基础设施建设和知识产权保护等政策传导渠道等相关政策建议。

环鄱阳湖城市群土地利用功能转型及其驱动机制

快速城镇化背景下,推进土地利用高质量转型是实现区域可持续协同发展的重要路径。该研究基于土地利用主导功能,运用综合指数法、耦合协调度模型和时空地理加权回归模型(geographically and temporally weighted regression,GTWR)等方法,分析了环鄱阳湖城市群土地利用功能转型的时空演变特征、耦合协调水平及其驱动机制。结果表明:1)2000—2020年,环鄱阳湖城市群土地利用功能指数从0.20上升到0.55,持续优化提升,但总体上处于中低水平,土地利用功能水平表现为阶段性的变化特征;土地利用功能指数逐渐呈现出中西高、东部低的空间格局。2)生产-生活-生态功能及生产-生活功能的协调度指数持续上升,其余耦合度及协调度指数均呈波动发展的趋势,耦合协调度指数呈现中部和西南部高、东北和西北部低的空间分布格局;以低质量转型为主,平均占比约为50%,功能转型质量有所提升,中西部区县的土地利用功能转型质量要明显优于北部和东部区县。3)不同影响因子的驱动作用存在显著的空间差异。人口密度和城镇化水平的正向驱动作用持续增强,二三产业占比的负向驱动作用增强,人均GDP、人均固定资产投资和人均粮食产量的影响力趋于减弱。应根据各区县土地利用功能的转型阶段,实行差别化的发展政策,补齐区县发展短板,提升功能系统间的耦合协调度。研究结果可为提高区域用地效率,促进土地利用多功能协同发展提供参考和决策依据。

山地城市公交服务感知与出行幸福感关系研究——基于获得感的调节作用

将幸福感理论与城市公共交通出行相结合,基于结构方程模型,实证检验山地城市居民公交服务质量感知与出行幸福感之间的非线性关系,以及公交资源获得感在两者之间的调节效应。结果表明:1)公交服务质量感知与出行幸福感之间存在非线性关系,且出行幸福感呈现出边际递减特征;2)山地城市居民公交资源获得感在公交服务质量感知与出行幸福感之间具有显著负向调节效应,公交服务质量感知对出行幸福感的正向影响随公交资源获得感的增强而减弱;3)山地城市公交资源获得感对出行幸福感具有正向显著影响。研究结论可为促进城市公交“满意度-获得感-幸福感”的制度改革提供启发,利于提高山地城市居民公交出行幸福感。