数字传播时代的时空异化及其消弭

数字技术的发展与应用促使传播行业发生变革,内容、渠道、传受双方的数字化在为信息传递带来便利的同时,也从根本上改变了社会运行的逻辑,重塑了人类的日常生活。在此过程中,作为表达事物演化秩序的时间和空间发生了异化,空间的泛化与扩张、时间的加速与失序引发了社会环境的内卷、数字信息的资本收割、个体权利的让渡等系列风险。面对数字传播时代的时空异化,应该倡导公正公平、共建共享的传播理念,践行以人为本的数字技术运行模式,构建健康有序、为我所用的数字心态。

基于铁路需求侧温度响应的供热系统节能运行策略研究

目的为了解决铁路站区供热系统供热量与各功能建筑需求热量不平衡而导致的能源严重浪费问题,方法提出铁路站区供热系统热源侧与建筑物联动调节的时空差异化运行策略,以响应站区内各建筑室内温度变化需求。首先,分析常规热源侧和建筑物侧运行调节策略,在此基础上研究时空差异化运行策略;其次,以大同某铁路站区供热系统为例,利用Simulink建立供热系统仿真模型;最后,在验证模型有较高准确性的基础上,对比分析3种不同运行策略下系统室内温度动态响应和能耗。结果与热源气候补偿质调节和建筑量调节运行策略相比,热源侧与建筑物联动调节的时空差异化运行策略不仅实现了不同建筑分时分温供热的需求,还有效减小了正常供热时间段和低温供热时间段室内温度波动幅度,提高了室内热舒适性。同时与系统无运行调节相比,热源质调节运行策略节能率为20.7%,建筑物量调节运行策略节能率仅为17.5%,时空差异化运行策略节能率达38.5%。结论本文提出的热源侧与建筑物联动调节的时空差异化运行策略能够满足铁路站区内不同功能建筑的室内变温需求,减小室内温度波动幅度,具有良好的节能效果。

辽宁省黑土区土壤养分时空差异化及其与气象因子的关系

通过对2004-2019年辽宁省黑土地进行野外采样及分析,测定土壤碱解氮、速效磷、速效钾和pH值4个指标,利用GIS和统计分析方法,研究黑土区土壤养分指标时空特征及其与气象因子的相关性。结果表明,年际间,碱解氮含量整体上无明显变化,速效磷、速效钾含量和pH值呈增长趋势。空间上,碱解氮和速效磷含量呈东高西低分布,速效钾含量呈西南向东北升高分布,pH值呈东低西高分布。降水量对碱解氮的影响最大,风速对速效磷、速效钾和pH值的影响最大,且与速效磷和速效钾呈显著相关。风速对土壤养分的影响最大,应注重土壤养分的变化监测及风速的影响,严格控制氮磷钾肥的施用量,提升粮食综合生产能力。

Tempo-Spatial Variations in Stomatal Conductance, Aperture and Density of Ligustrum sinense Acclimated to Different Light Environments

There was heterogeneous distribution in stomatal conductance (g-s) and stomatal aperture for both high- and low-light leaves of Ligustrum sinense Lour. in four designated positions within a leaf. Linear or exponential or polynomial relationships between g-s and stomatal aperture were found when regression of g-s and stomatal aperture was established. Statistical analysis revealed that the relationship between g-s and stomatal aperture for high-light leaves was more significant than that of low-light leaves. A linear relationship between g-s and stomatal aperture existed in both positions 1 and 3 for both high- and low-light leaves. The stomatal density of the low-light leaves was much lower than that of the high-light leaves. The sensitivity of stomata to changing environment for high-light leaves was higher than that for low-light leaves, which may also relate to the higher stomatal density for the high-light leaves.

Characteristics of Spatial and Temporal Variations of Monthly Mean Surface Air Temperature over Qinghai-Tibet Plateau

The recorded meteorological data of monthly mean surface air temperature from 72 meteorological stations over the Qinghal-Tibet Plateau in the period of 1960-2003 have been analyzed by using Empirical Orthogonal Function （EOF） method, to understand the detailed features of its temporal and spatial variations. The results show that there was a high consistency of the monthly mean surface air temperature, with a secondarily different variation between the north and the south of the plateau. Warming trend has existed at all stations since the 1960s, while the warming rates were different in various zones. The source regions of big rivers had intense warming tendency. June, November and December were the top three fast-warming months since the 1960s; while April, July and September presented dramatic warming tendency during the last decade.

Temporal and spatial differences and imbalance of China's urbanization development during 1950-2006

A better understanding of the regional disparity and imbalance characteristics of China's urbanization development is the important premise for constituting correct policy and strategy and promoting the healthy and sustainable development of urbanization in the 21st century. The regional differences of China's urbanization level have close relations with natural conditions of landform and climate etc.,the urbanization level reduces with the eleva-tion of topography and decrease of precipitation. According to the statistical data set of ur-banization in 1950-2006,the temporal change course of inter-provincial disparity of Chinese urbanization level since the founding of New China in 1949 was studied,and then the inter-regional and intra-regional disparities of urbanization development were analyzed by the Theil index and its nested decomposition method,to grasp the dynamic change of spatial disparities of China's urbanization level on the whole. Using the imbalance index model,the imbalance status of urban population distribution relative to total population,grain output,total agricultural output value,gross output value of industry,tertiary industrial output value as well as gross regional product was discussed,to hold the balance characteristics of urbanization development relative to the regional development conditions from the macroscopic scales.

SPATIAL-TEMPORAL CHANGES AND TRENDS OF AGEING IN CHINA

This study focuses on the development stages of ageing and its regional differences in China based on examination of official statistics and documents. The development of ageing in China has experienced three major stages. Firstly, in the 1950s, low coefficient of elderly population (over 65 years) paced up to primary adult type. Secondly, there was a deeply drop of the elderly population because of natural disaster and political factors in the 1960s. Thirdly, from the 1970s to the end of 20th century, the constant increasing of elderly coefficient made China close to elderly society. With statistic data of population, Logistic model is used to simulate the future development of ageing, and two characteristics of development of ageing are presented. Firstly, as for ageing from 2005 to 2050, the elderly coefficient will grow up significantly from 8.48% to 16.30%. Secondly, after 2025, the increasing rate of elderly coefficient will slow down gradually. The regional differences of elderly population in China can be summarized as follows: 1) the eastern China possesses higher elderly coefficient and huger elder population than the western China; 2) about 47.4% of municipalities and provinces in the eastern China become elderly especially Shanghai, Zhejiang Province, Jiangsu Province, Beijing, Tianjin and Shandong Province; 3) ageing intensity is higher in rural area than urban area but getting close each other, and there are more elderly people in rural area than in urban area. Therefore, these will arose aged care problems, and it becomes important issue to establish the social security system in rural areas as soon as possible for elderly people.

Spatio-temporal Variation of Landscape Heterogeneity under Influence of Human Activities in Xiamen City of China in Recent Decade

Xiamen is an economically competitive and highly urbanized city along the coastal area of Fujian Province, China. The research on spatio-temporal variation of landscape heterogeneity under the influence of human activities is of great importance to the further study on the relationship of landscape pattern and ecological process. It is also crucial to the discovery of spatial variation and intensity distribution of human activities. The research analyzed the intensity of human impacts and the spatial variation features and dynamics of landscape patterns by introducing statistical theories and approaches. We analyzed spatio-temporal variation of landscape heterogeneity using the geostatistical techniques, such as semivariogram and Kriging interpolation.Results show that there is a higher correlation between landscape heterogeneity indexes and human impact index. Both the indexes show a moderate spatial autocorrelation as well as an obvious characteristic of anisotropy. From 1998 to 2008, the spatial differentiation of the changes in the intensity of human activities and the changes in landscape heterogeneity shows that the landscape patterns in Xiamen are closely related with the urban land utilization methods, the condition of traffic and geographical location and the physical geographical condition such as the terrain and the ecological environment. The process of urbanization has a significant impact on the urban landscape pattern.

Spatio-temporal Variability of Soil Water at Three Seasonal Floodplain Sites: A Case Study in Tarim Basin,Northwest China

The floodplain -egetation of the Tarim River in Northwest China is strongly influenced by irrigated agriculture. The abstrac- tion of river water disturbs; the natural dynamics of the floodplain ecosystem. The human impact on the hydrological system by bank dams and the irrigation of cotton plantings have caused adverse changes of the Tarim River and its floodplains, so the current stocks of the typical Tugai vegetation show significant signs of degradation. Field studies of soils and statistical analysis of soil moisture data have shown that the vitality of the Tugai vegetation is primarily determined by its position to the riverbank and the groundwater. There exist complex interactions between soil hydrological conditions and the vitality of the vegetation. But the availability of water is not only influenced by the groundwater level and seasonal flood events. The spatial distribution of stocks at different states of vitality seems also to be decisively influenced by physical soil properties. Our results show that the water supply of plant communities is strongly in- fluenced by the soil texture. Spatial differences of soil moisture and corresponding soil water tensions may be the decisive factors for the zonafion of vegetation. Physical soil properties control the water retention and rising of capillary water from deeper soil layers and the phreatic zone and may supply the root systems of the phreatophytic vegetation with water. Keywords： soil moisture;soil texture; soil water tensions; Tarim River; water retention

Spatial and temporal variation of picoplankton distribution in the Yellow Sea, China

Seven surveys were carried out in April, September, October, December 2006 and March, May, August 2007 in the Yellow Sea, China. Variations in the spatial and temporal distribution of Synechococcus, picoeukaryotes and heterotrophic bacteria are quantified using flow cytometry. Synechococcus and heterotrophic bacteria are most abundant from late spring to autumn, while picoeukaryotes concentration is high in spring. Synechococcus and heterotrophic bacteria concentrated high in the northwest part of the Yellow Sea in spring and autumn, while picoeukaryotes distributed evenly over the whole study area except for a small frontal zone in the coastal area on the west （in spring） and central Yellow Sea （in autumn）. Under mixing conditions, the vertical distribution of the three picoplankton groups showed a well-mixed pattern. Upon a well-established stratification, the maximum abundance of picoplankton occurred above the mixed layer depth （-30 m）. Cell sizes of Synechococcus and picoeukaryotes were estimated by converting forward scatter signals （FSC） from cytometry analysis to cell diameter, showing the results of 0.65-0.82 um for Synechococcus and 0.85-1.08 um for picoeukaryotes. The average integrated carbon biomasses ranged 15.26-312.62 mgC/m2 for Synechococcus, 18.54-51.57 mgC/m2 for picoeukaryotes, and 402.63-818.46 mgC/m2 for heterotrophic bacteria. The distribution of Synechococcus and heterotrophic bacteria was temperature dependent, and picoplankton presence was poor in the Yellow Sea Cold Water Mass.

Multilevel Assessment of Spatiotemporal Variability of Vegetation in Subtropical Mountain-hill Region

The complex spatiotemporal vegetation variability in the subtropical mountain-hill region was investigated through a multi-level modeling framework. Three levels - parcel, landscape, and river basin levels- were selected to discover the complex spatiotemporal vegetation variability induced by climatic, geomorphic and anthropogenic processes at different levels. The wavelet transform method was adopted to construct the annual maximum Enhanced Vegetation Index and the amplitude of the annual phenological cycle based on the 16-day time series of a5om Moderate Resolution Imaging Spectroradiometer Enhanced Vegetation Index datasets during 2OOl-2OlO. Results revealed that land use strongly influenced the overall vegetation greenness and magnitude of phenological cycles. Topographic variables also contributed considerably to the models, reflecting the positive influence from altitude and slope. Additionally, climate factors played an important role： precipitation had a considerable positive association with the vegetation greenness, whereas the temperature difference had strong positive influence on the magnitude of vegetation phenology. The multilevel approach leads to a better understanding of the complex interaction of the hierarchical ecosystem, human activities and climate change.

基于居民时空行为的社区日常活动空间测度及活力影响因素研究——以南京市沙洲、南苑街道为例

新时期人本导向的社区生活圈规划转型关注居民的日常活动对社区空间的利用情况,从而反映出居民对社区公共服务设施的使用需求。但目前研究较少关注不同类型居民的差异化时空行为特征,不能有效应对社区居民的差异化需求。论文结合行为地理学的理论,利用手机信令数据,基于居民出行活动的频率和密度测度其核心活动空间和弹性活动空间,分析不同类型人群日常活动特征。以南京市沙洲和南苑街道为例,划定不同社区中,青少年、青年、中年和老年群体的日常活动空间,并从日常活动范围和活力的视角分析居民对社区空间利用的基本特征及群体间差异。研究结果表明,居民的日常活动空间表现出层次性、共享性和方向性,且不同年龄群体的日常活动空间存在显著差异;进一步利用相关性检验分析不同群体社区活力的影响因素,提出考虑不同群体活动空间和设施需求的公共服务设施差异化供给策略。研究有助于完善基于居民时空间行为测度社区日常活动空间的方法,丰富对社区居民差异化行为需求的认知。实证研究的结论对基于居民差异化空间和设施需求的社区公共服务设施配置具有一定指导意义。

Urban Expansion and Spatiotemporal Relationships with Driving Factors Revealed by Geographically Weighted Logistic Regression

Urbanization improves our lives but also threatens human health and sustainable development. Revealing the spatiotemporal pattern of urban expansion and spatiotemporal relationships with driving forces, especially in terms of the ubiquitous and fast growing small city, is a crucial prerequisite to solving these problems and realizing sustainable development. Kunshan, China was used as a case study here. Eleven variables from four aspects covering physical, socioeconomic, accessibility and neighborhood were selected, and logistic regression and geographically weighted logistic regression modeling were employed to explore spatiotemporal relationships from 1991-2014. Results reveal that urban expansion in Kunshan shows an accelerating tendency with annual expansion from 2000-2014 four times higher than for 1991-2000. More importantly, the annual expansion rate of Kunshan of 28.42% in 2000-2014 is higher than that of a large city. Urban expansion and related factors have spatiotemporal varying relationships. From a global perspective, the closer to a city, town, main road and the higher the GDP, the more likely a region will undergo urbanization. Interestingly, the effect of population on urban expansion is decreasing, especially in developed areas, and the effect of distance to lake is enhanced. From a local perspective, the magnitude and even the sign of the coefficients vary across the study area. However, the range of the coefficient of GWLR is around that of the corresponding variable in LR, and the sign of most variables in GWLR is consistent with that of corresponding variables in LR. GWLR surpasses LR with the same explanatory variables in revealing regional differences and improving model reliability. Based on these findings, more attention should be given to small cities in China. Promoting the connotation of city culture and public services to realize New-type Urbanization and regional diversity policy in order to manage urban expansion scientifically are also recommended.

Spatiotemporal variability of ocean chemistry in the early Cambrian,South China

Following the Ediacaran metazoan radiation,the "Cambrian Explosion" set up the major framework of todays' animal phyla as well as modern marine ecosystem.Here,we present a preliminary investigation on the temporal and spatial(from shallow to deep waters) variations of the early Cambrian ocean chemistry in South China through analyzing a Fe-S-C systematic dataset integrated from literature.Our investigation indicates that the early Cambrian deep ocean in South China was still anoxic and Fe2+-enriched(i.e.,ferruginous) although its surface was oxic,and in between a metastable euxinic(anoxic and sulfidic) water zone may have dynamically developed in anoxic shelf waters with an increasing weathering sulfate supply.Furthermore,accompanying marine transgression and regression cycles in the early Cambrian,such a "sandwich" structure in ocean redox chemistry demonstrates five evolutional stages,which can be well correlated to the spatiotemporal patterns of fossil records in South China.The good correlation between metazoan fossil occurrences and water chemistry in South China suggests that early animals possibly possessed ability to inhabit anoxic but generally not euxinic environments as free H2S was fatal to most eukaryotes.This view can well explain why those small shell fauna and sponges disappeared from shelf to slope areas where sulfidic Ni-Mo-rich shales were widely deposited.Thus,we conclude that the spatiotemporal variations of ocean chemistry and its biological effects probably played a key role in the phased animal radiations and "extinctions" in the early Cambrian.