Temporal and spatial differences in human activities performed in Urban Green Spaces of Vilnius(Lithuania)

Urban green spaces(UGS)are relevant to city well-being,as recognized by the United Nations’Sustainable Development Goals(SDGs).However,few studies have studied the temporal use of UGS.This work assessed the seasonal,weekly,and daily use of three urban green spaces(Vingis Park,Bernardino Garden,and Jomantas Park)in Vilnius(Lithuania).The study is based on an on-site observation-based survey,which recorded users’characteristics,activities,and weather conditions during summer and winter.The results showed that UGS’s seasonal,weekly,and daily use differed according to park and users’characteristics.Parks with a higher diversity of facilities had a high seasonal difference in the number of observed activities.User numbers were higher in the summer for activities with children,social activities,sports,and water activities than in the winter.Jomantas Park had the lowest variability in user characteristics.Weather variables were linked to changes in users’activities.Higher precipitation and lower temperature were associated with reducing the number of users and the diversity of registered activities.Most of the stationary activities were observed during summer.The diversity of the observed activities was associated with the available facilities rather than the park size.The distribution of stationary activities was spatially correlated with facility/equipment(benches,playgrounds,sports,and fitness equipment)and proximity to water features.The results of this study are relevant for UGS design,planning,and management.

Spatial and Temporal Differences of Urban Land Comprehensive Carrying Capacity in Guangxi

The comprehensive carrying capacity of urban land can reflect the re- source level, economic scale, social development and environmental pressure of ur- ban land carrying. The assessment indicator system of urban land comprehensive carrying capacity was constructed from the 4 aspects of resource, economy, society, environment, and principal component analysis and cluster analysis were used to evaluate the urban land comprehensive carrying capacity of Guangxi and the 14 cities in 2005-2014, and analyzed its spatial and temporal characteristics as well as the driving forces, with the aim to provide references for improving the urban land comprehensive carrying capacity. The results showed that, the overall urban land comprehensive carrying capacity in Guangxi increased in 2005-2014, and there were significant differences in the land comprehensive carrying capacities among the cities in Guangxi in 2005-2014, in which Liuzhou, Guilin, Nanning belonged to the regions with the highest carrying capacity, while Beihai, Yulin, Wutong belonged to the regions with high carrying capacity, and the carrying capacities of the other cities changed with the changes of time. The economic development degree was an important factor influencing urban land comprehensive carrying capacity, but could not directly represent the urban land comprehensive carrying capacity level.

TEMPORAL AND SPATIAL DIFFERENCES OF THE INDUSTRIAL RESTRUCTURING OF GUANGDONG PROVINCE IN THE 1990S

This paper focuses on the temporal and spatial change of industrial structure in Guangdong Province since the 1990s. The attention is initially paid to the change of industrial structure through analyzing the structure change of the three sectors, and the change of internal structures of agriculture, industry and tertiary sector respectively. Then the spatial differences of industrial restructuring are analyzed based on the four economic regions which have been agreed in the academic field: the Zhujiang(Pearl) River Delta, northern mountain region, east and west wings. Thirdly, the reasons for the spatial differences of industrial restructuring are examined. Finally a short conclusion is drawn and some suggestions for the regional integration are put forward.

Spatial-temporal differences in in-stream flow requirement based on GIS： A case study of Yan＇an region, northern Shaanxi

Although water has the central function of the bloodstream in the biosphere especially in arid or semi-arid regions such as Yah＇an region in northwestern China, yet the very limited attention is paid to the role of the water-related processes in ecosystem. In this research, based on continuous nearly 50-year data including runoff volume, sediment discharge as well as sediment accretion from hydrographic stations, and 10-year information of water quality from pollution monitoring stations, the method for measuring in-stream flow requirement has been put forward supported by experiential models and GIS spatial analysis. Additionally, the changes of in-stream flow requirement for environment and economic development have been addressed from spatial-temporal dimensions. The results show that： （1） According to the central streams in Yan＇an region, mean annual in-stream flow requirement reaches 1.0619 billion m^3, and the surface water for economic exploitation is 0.2445 billion m3 （2） Mean annual in-stream flow requirement for sediment transfers in flood period occupies over 80% of the integrated volume in a year. （3） From the 1950s to 1970s, in-stream flow requirement for sediment transfers is comparatively higher, while from the 1980s to 1990s, this requirement presents a decreasing tendency.

Temporal-spatial change and driving mechanism for regional difference of domestic tourism in China

By using the variation coefficient,Gini coefficient and Theil coefficient,this paper makes preliminary exploration of temporalspatial change features and driving mechanism for regional differences of domestic tourism in China from 1995 to 2009.According to the results,we drew the following conclusions:(1)The regional difference of domestic tourism in China tends to be narrowing generally,and is less than that of inbound tourism,playing an important role in narrowing the overall gap of regional tourism in China.(2)The regional internal difference features:inter-provincial difference in the eastern region and difference among the eastern,central and western regions are comparatively obvious and demonstrate a significantly shrinking tendency,the change tendency is consistent with the change tendency of overall difference and exercises a decisive role in overall difference,whereas the inter-provincial difference in the central and western regions is small and relatively stable,having less influence on the overall difference.(3)The temporal-spatial change in regional difference is featured by:low-level provinces occupy a majority and are concentrated in the central and western regions,showing a tendency of narrowing difference;high-level provinces are concentrated in the eastern region,showing a tendency of spreading to the central and western regions;spatial pattern of regional difference demonstrates 4 types,i.e."proliferation type","polarization type","quiescence type"and"collapse type."(4)The driving force for regional difference of domestic tourism in China comes down to 3 aspects:regional socio-economic attribute,regional transport accessibility level and regional development policy.

Temporal and spatial study of differently charged ions emitted by ns-laser-produced tungsten plasmas using time-of-flight mass spectroscopy

Tungsten(W)is an important material in tokamak walls and divertors.The W ion charge state distribution and the dynamic behavior of ions play important roles in the investigation of plasma–wall interactions using laser-ablation-based diagnostics such as laser-induced breakdown spectroscopy and laser-induced ablation spectroscopy.In this work,we investigate the temporal and spatial evolutions of differently charged ions in a nanosecond-laser-produced W plasma in vacuum using time-of-flight mass spectroscopy.Ions with different charge states from 1 to 7(W+to W7+)are all observed.The temporal evolutions of the differently charged ions show that ions with higher charge states have higher velocities,indicating that space separation occurs between the differently charged ion groups.Spatially-resolved mass spectroscopy measurements further demonstrate the separation phenomenon.The temporal profile can be accurately fitted by a shifted Maxwell–Boltzmann distribution,and the velocities of the differently charged ions are also obtained from the fittings.It is found that the ion velocities increase continuously from the measured position of 0.75 cm to 2.25 cm away from the target surface,which indicates that the acceleration process lasts through the period of plasma expansion.The acceleration and space separation of the differently charged ions confirm that there is a dynamic plasma sheath in the laser-produced plasma,which provides essential information for the theoretical laser-ablation model with plasma formation and expansion.

Exploration on Temporal-spatial Difference of Cultivated Land Pressure and Influence Factor Analysis: A Case Study of Guangxi

Based on related statistical data during 1980-2014,change rule of Guangxi cultivated land pressure level was studied. Taking each municipal administrative division as evaluation unit,temporal-spatial change trend of cultivated land pressure level was explored by establishing pressure index model of cultivated land,and principal component analysis was used to explore the driving force of cultivated land pressure. Results showed that from 1980 to 2014 in Guangxi,cultivated land pressure was at level one in 12 years,level two in 19 years and level three in 4 years; mean of cultivated land pressure in each city during 2005-2014 was taken as average level of cultivated land pressure in the city,in which cultivated land pressure values of Chongzuo City,Baise City,Laibin City,Liuzhou City,Fangchenggang City,Nanning City,Hechi City and Guigang City were all lower than average level in Guangxi at the same period. Driving factors of cultivated land pressure index mainly contained urbanization rate,Engel coefficient of rural households(ECRH),per capita cultivated land area,total population and rural per capita net income(RPFI).

Regional Differences of China′s Urban Expansion from Late 20th to Early 21st Century Based on Remote Sensing Information

This study investigated the regional differences of China′s urban land expansion from the late 1980s to the year of 2008, based on the spatio-temporal analysis of CLCD (China′s land cover/land use database) datasets which were mainly produced from remote sensing imagery data. A newly defined urbanization level index (UI), based on urban land area, is proposed to describe Chinese urban expansion process at 1 kilometer, provincial, regional, and na-tional scales, together with the absolute urban expansion index (UEa) and the relative urbanization expansion index (UEr). The results indicate that the percentages of total land area occupied by urban in the late 1980s, 1995, 2000, 2005, and 2008 were approximately 0.25%, 0.32%, 0.33%, 0.43% and 0.52% of China′s total land area, respectively. Between the late 1980s and 2008, the total urban expansion in the mainland of China was 2.645 × 104 km2, resulting in an annual urban expansion area of about 1322.7 km2/yr, with the UEr of 111.9%. This study also finds that there has been an obvious spatial gradient of urbanization ratio running from the east coast to the west inland, and the urbanization gaps among different regions have persisted over the past two decades. The study also reveals obvious temporal varia-tions of the urbanization rates. There was very little urban growth during the period of 1995-2000 due to the governmental policy factors.

Driving factors and spatio-temporal features underlying industrial SO_(2) emissions in“2+26”in North China and extended cities

As one of the largest global emitters of sulfur dioxide(SO_(2)),China faces increasing pressure to achieve sustainable economic and social development.Using panel data of 58 prefecture-level cities in North China between 2003 and 2017,this paper considers the dynamic spatio-temporal characteristics of industrial SO_(2) emissions in the"2+26"in North China and extended cities in North China and decomposes the determinants of industrial SO_(2) emissions into eight effects using the Generalized Divisia Index Model(GDIM).The contributions of each effect on changes in emissions are assessed on regional,provincial,and prefectural levels,as well as according to various stages.The results indicate the following.First,industrial SO2 emissions in the"2+26"cities in North China and extended cities in North China exhibit spatial autocorrelation and agglomeration effects.Cities with high-high(HH)and low-low(LL)agglomeration patterns were concentrated in Shanxi and Henan provinces,respectively.Second,industrialization,energy consumption,and economic development were the main factors that increased industrial SO2 emissions,while technology,energy sulfur intensity,and economic sulfur intensity were the key factors that reduced them.Third,13 cities,induding Tangshan,were the most important regions where further emissions regulations need to be implemented.These cities were divided into three types and different corresponding measures for reducing their emissions are suggested.Based on the conclusions of this study,this paper puts forward some targeted policy recommendations for reducing industrial SO_(2) emissions according to different categories of cities.

中国四大城市群碳排放驱动因素时空分解研究

城市群是中国经济发展和能源消耗的集聚区域,也是碳排放的主要来源。研究中国典型城市群碳排放的时空演变特征及其影响因素对实现“双碳”目标具有重要意义。文中应用ST-IDA模型(时空指数分解分析法)和LMDI(对数平均迪氏指数法)分解法,分析2000—2019年京津冀、长三角、珠三角和成渝城市群的碳排放驱动因素(人口规模、经济水平、产业结构、能源强度和能源结构)。研究发现:2000—2019年间,四大城市群能源活动碳排放总体趋势均由高速增长阶段步入平稳增长阶段,其中成渝城市群已基本实现碳达峰;能源强度效应是影响碳排放空间差异的主要因素;人口规模扩张、经济发展水平提高和能源强度上升是促进碳排放增长的主要因素,产业结构和能源消费结构优化起到抑制作用;四大城市群碳排放的时空演变主要取决于工业部门。鉴于四大城市群呈现出不同的碳排放特征,未来应探索差异化、多元化的城市群减排路径,促进城市群碳减排。

中国城市碳排放绩效:动态分解、空间差异与影响因素

以非径向方向距离函数为框架,构造全要素碳排放绩效指数对中国2006—2019年城市碳排放治理绩效进行测度。在此基础上从经济含义、跨期动态变化、区域均衡等层面对全要素碳排放绩效指数进行多维分解,检验中国城市碳排放绩效的影响因素。结果表明:第一,样本期内全国城市平均全要素碳排放绩效指数总体呈波动上升态势,动态分解结果显示,中国各地的平均碳排放绩效水平不断改进,创新效应对其贡献逐年增大但赶超效应贡献不足;第二,空间分异方面,珠三角、长三角、粤闽浙沿海、长江中游等东部地区城市群不仅平均碳排放绩效水平普遍较高,且碳排放绩效的增长速度较快,中西部地区仅成渝城市群碳排放绩效表现较好,中原、京津冀等城市群近年来碳排放绩效的改善速度较快;第三,基尼系数测度及其分解显示,近年中国城市碳排放绩效指数的分异程度逐步加深,分异成因主要为城市群组间差异,城市群内部差异贡献度较低;第四,Lasso分析及双固定面板模型分析结果显示,经济发展水平、清洁能源使用、金融发展、绿色环保和科技支持能够有效改善城市层面的碳排放绩效,能源消耗强度和第二产业就业人员比重对碳排放绩效具有负面影响;最后,城市群因子探测结果显示,各城市群间的驱动因子存在一定差异。

中国数字经济发展水平时空演变及区域差异分析

数字经济作为国民经济的核心增长极之一,正在成为促进经济发展的新动能。构建数字经济发展水平指标体系,运用熵值法对2014—2020年中国省际数字经济发展水平进行测度,在此基础上进一步探究中国数字经济发展的分布动态和区域差异。研究结果表明:与2014年相比,2020年中国数字经济发展水平整体有所提升,分区域看,东部地区数字经济发展水平呈波动下降趋势,中西部地区呈上升趋势且差距较小;空间分布上,中国数字经济呈现东高西低的发展格局,而且在发展过程中逐步形成多极分化状态;东、中、西地区数字经济发展的相对差异呈不断缩小趋势,并且区域内差异是造成数字经济发展存在差异的主要原因。

中国新质生产力水平测度及其对经济高质量发展的影响效应

根据新质生产力的理论内涵,本文从实体性和渗透性两个维度构建新质生产力综合评价指标体系,借助2012—2022年省级面板数据测度了中国新质生产力水平,并进一步探讨了新质生产力对经济高质量发展的影响。研究表明:在时序演变方面,中国新质生产力的总体水平及其构成要素的分项发展水平均呈现稳步上升的趋势;在空间分布方面,中国四大地区的新质生产力发展水平存在差异性,但差距正在不断缩小;在因果关系方面,新质生产力能显著促进经济的高质量发展,在处理内生性问题后结论依然成立。此外,空间杜宾模型估计结果显示,新质生产力对经济高质量发展不仅存在直接促进作用,而且存在显著的空间溢出效应。

长江流域农业绿色发展水平评价与时空差异分析

对长江流域农业绿色发展水平进行评价与影响因素分析,能促进长江流域农业绿色高质量发展。基于2006—2020年长江流域19个省份的面板数据,从绿色生产、绿色生态、经济效益、生活水平四个维度构建了农业绿色发展水平评价指标体系;并通过熵权法对各省份农业绿色发展水平进行测度;最后应用区域差异分析法、空间自相关性分析对区域内与区域间的时空发展差异、关联度进行探讨。结果表明:(1)长江流域农业绿色发展水平整体呈现出稳步上升趋势,干流发展趋势优于支流。(2)长江流域农业绿色发展水平区域差异呈现出波动扩大的变化趋势。(3)长江流域各省份农业绿色发展水平显示出空间聚集效应,其中上海、江苏、浙江是高—高聚集模式,重庆、贵州、广西是低—低聚集模式。因此,要提高长江流域农业绿色发展水平,各省份应制定个性化政策、重视并补齐发展短板、加强区域间辐射效应。

中国县城土地利用效率时空差异及影响因素分析

运用超效率SBM模型、Malmquist指数、Tobit回归模型等分析2006—2020年我国县城土地利用效率的时空差异及其影响因素,结果表明:①研究期内我国县城土地利用效率呈“W”形波动上升态势,空间上呈东部地区>中部地区>西部地区,东部与中部地区的差距不断缩小,西部与东、中部地区的差距有所扩大;②研究期内我国县城土地利用全要素生产率年均增长率为3.4%,县城土地利用效率提高主要得益于技术进步;③县域城镇化水平、县域经济发展水平、县城建设用地规模以及产业结构升级可以促进县城土地利用效率提升,地方财政压力、交通设施水平对县城土地利用效率起抑制作用,各影响因素的作用结果存在区域异质性。今后应以创新城乡用地制度、优化建设用地配置方式和土地供给结构为保障,因地制宜优化产业结构、完善县城基础设施,促进县域经济、城镇化发展,提高县城土地综合效益,进而提升县城土地利用效率。

人类福祉视角下城市生态效率时空差异与障碍诊断——以黑龙江省为例

基于2010-2019年黑龙江省12个地级市的面板数据,从人类福祉视角构建城市生态效率的指标体系,运用考虑非期望产出的超效率SBM模型与Malmquist指数进行分析,揭示黑龙江省12个地级市生态效率时空差异特征及其动态变化驱动力,并利用障碍度模型识别阻碍黑龙江城市生态效率提升的关键因素。结果表明:①黑龙江省12个地级市整体效率水平呈缓慢上升态势,年均增速1.313%;②城市生态效率呈高值连片空间分布特征,逐步形成中西部和东部两条高效率城市带;③纯技术效率、技术进步是促进其全要素生产率的主导驱动因素,两者变化指数平均值分别为1.070、1.035;④黑龙江省城市生态效率的主要障碍因子为全社会固定资产投资、实际地区生产总值和全社会用电量,而人类福祉对生态效率阻碍程度相对较小。据此,从区域协调发展、找准驱动路径、加快城市绿色转型等方面提出提升城市生态效率、推动黑龙江省城市可持续发展的建议。

广东省数字经济发展及时空差异特征分析

数字经济是引领经济高质量发展的新动能。为反映广东省数字经济发展水平,本文通过构建数字经济指标体系,运用熵值法,测算了广东省21个地市数字经济发展指数,反映其十年来数字经济发展变化趋势,并通过可视化处理,分析各区域数字经济发展水平的空间集聚特征。研究发现,广东省各地市数字经济发展差异明显,各区域数字经济发展水平呈现动态波动性。从数字经济发展时空分布情况来看,进入第一梯队与第二梯队的城市长期以来稳定不变,而进入第三、四、五梯队的城市有所调整变化。据此,本文从政府、产业与企业层面提出对策建议。

中国现代化金融生态系统建设及其区域差异研究

2023年10月,我国首次提出建设金融强国的战略目标,而现代化金融生态系统建设是实现该目标的重要条件。利用熵权法、泰尔指数法对八大综合经济区现代化金融生态系统建设水平进行实证研究。研究发现:现代化金融生态系统在2013—2022年之间呈现出较大的波动趋势,整体呈现“东部沿海>北部沿海、南部沿海>长江中游、黄河中游>西南地区>东北地区、西北地区”态势;上海、江苏、浙江、北京、广东排名靠前;东部沿海地区内部的联动效应高,南部沿海地区的联动效应低;八大综合经济区的组间差异对整体差异的贡献度呈上升趋势,区域间发展水平差距在逐渐扩大;东北地区、黄河中游、西南地区、西北地区内部发展水平差距波动大。最后文章提出应加强区域内和区域间现代化金融生态系统的联动效应,促进金融资源的有效配置和利用;因地制宜制定当地政策,推动本地金融科技产业的发展,打造本地金融科技创新生态圈;加强金融风险防范,提高金融市场的透明度和规范性等建议。

地表水中全氟及多氟烷基化合物(PFASs)的污染现状研究进展

近年来,全氟及多氟烷基化合物(per-and polyfluoroalkyl substances,PFASs)的大量生产使用,使得其在自然水体中的浓度日益升高.由于PFASs的生物毒性及强稳定性,环境中的PFASs严重威胁到生态环境及人类健康.目前,多个国家及相关国际组织开始对地表水中的PFASs展开检测,但目前的监测基本属于点源监测,大范围、长时间维度的监测依然缺乏,从而无法准确揭示PFASs的时空赋存特征.本文概述了PFASs在地表水中的赋存水平,同时阐述了地表水环境中PFASs的水平分布和垂直分布特征,并揭示了地表水中PFASs污染水平与组成的时间变化规律,总结了影响PFASs污染的主要因素,对后续PFASs监测提出了建议,以期为准确评估水环境中PFASs的污染状况提供依据.

基于土地利用变化的江苏省碳排放时空差异与碳平衡分区

以江苏省13个设区市为例,基于碳排放(CE)和碳吸收估算方法,分析2005—2020年江苏省市域碳收支和碳补偿率的时空演变特征,随后引入环境基尼系数(EGC)从经济和生态两个角度分析空间碳平衡特征。结果表明:2005—2020年,江苏省土地利用碳排放从14210.005×10^(4)t增至23015.325×10^(4)t,碳吸收3039.383×10^(4)t波动上升至3628.703×10^(4)t,总体表现为碳源;13个设区市的碳补偿率整体呈现下降趋势,碳排放量与经济发展水平处于比较协调状态,与其人口聚集协调性较高;根据碳平衡分析,将13个设区市划分为碳汇功能区、低碳保持区、经济发展区、碳强度控制区、高碳优化区5类,并建议前两个分区充分发挥生态优势,着重推进生态产品价值变现;其余分区优先推动产业低碳转型,能源绿色化发展。