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991.
Fulong Wu 《Urban geography》2018,39(8):1177-1194
Housing privatization seems to suggest a process of state retreat. However, this is not always the case in China. This paper examines an estate that is mixed with work-unit housing and municipal public housing to understand its changing governance. It is intriguing to observe that the state has had to return to this neighborhood to strengthen its administration following housing privatization, because the attempt to transfer responsibility to commercial property management failed. The neighborhood governance, however, has transformed from one based on work-units to a government-funded administrative agency. The return of the state has been achieved through professional social workers, and it is struggling to operate, leading to the alienation and disempowerment of former state work-unit residents. The side effect of this approach to governance is that, through encouraging market provision and commercial operation which is not fully working, reciprocal activities are restrained. Since housing privatization, the neighborhood has deteriorated from a brand-new estate into an ‘old and dilapidated neighborhood’ in less than 25 years. 相似文献
992.
Bin Wu Qiusheng Wu Zuoqi Chen Shenjun Yao Yan Huang 《International journal of geographical information science》2018,32(3):450-475
Detailed and precise information on urban building patterns is essential for urban design, landscape evaluation, social analyses and urban environmental studies. Although a broad range of studies on the extraction of urban building patterns has been conducted, few studies simultaneously considered the spatial proximity relations and morphological properties at a building-unit level. In this study, we present a simple and novel graph-theoretic approach, Extended Minimum Spanning Tree (EMST), to describe and characterize local building patterns at building-unit level for large urban areas. Building objects with abundant two-dimensional and three-dimensional building characteristics are first delineated and derived from building footprint data and high-resolution Light Detection and Ranging data. Then, we propose the EMST approach to represent and describe both the spatial proximity relations and building characteristics. Furthermore, the EMST groups the building objects into different locally connected subsets by applying the Gestalt theory-based graph partition method. Based on the graph partition results, our EMST method then assesses the characteristics of each building to discover local patterns by employing the spatial autocorrelation analysis and homogeneity index. We apply the proposed method to the Staten Island in New York City and successfully extracted and differentiated various local building patterns in the study area. The results demonstrate that the EMST is an effective data structure for understanding local building patterns from both geographic and perceptual perspectives. Our method holds great potential for identifying local urban patterns and provides comprehensive and essential information for urban planning and management. 相似文献
993.
采用问卷调查的方式,对气象、交通、公安等多部门公路交通决策气象服务关注的气象要素、产品类型和时段、服务改进方向等需求进行了调研。利用专家评分法对调查内容进行评估分析,并提出提升公路交通决策气象服务能力的相关建议。结果表明:专家对现有公路交通决策气象服务工作总体满意度较高,普遍认为公路交通决策气象服务在公路运输、运行调度、应急救援等方面发挥作用明显;行业领域不同需求的气象要素有所不同,交通部门专家对公路积雪、降雪、霾等要素给出的需求权重值明显高于气象部门专家给出的;不同类型的决策服务产品关注的气象要素和时效也有所不同,其中,监测类产品对低能见度、道路积雪要素最为关注;预报类产品对雨雪和大雾要素最为关注;预警类产品对大雾最为关注;而影响评估类产品对低能见度最为关注。监测类产品主要关注逐小时时段;预报和预警类产品重点关注未来3—12 h时段;而影响评估类产品主要关注日、月、季度时段。 相似文献
994.
为探讨地表温度初始场在台风暴雨模拟中的重要性,以2015年第13号台风"苏迪罗"为例,分别用FY-2G卫星反演的陆表温度、海表温度产品替换NCEP资料初始场,进行数值模拟试验。对模拟结果进行分量级降水TS评分和预报正确率检验,并对比分析了各试验方案2 m温度场、感热通量和潜热通量场、900 h Pa流场和850 h Pa垂直速度场间的差异。结果表明:使用FY-2G卫星反演的陆、海表温度产品作模式初始场均能不同程度地改善降水模拟效果,但改善程度随时间降低,24 h后其改善作用已较小;陆表温度试验对小雨和中雨量级的预报质量均有提高,而海表温度试验仅提高了小雨量级的预报质量。进一步分析表明,陆表温度试验主要通过改善陆表温度初始场影响感热通量和潜热通量的分布,进而减小台风东北部低层温度正异常,使该区域气旋性环流减弱、垂直速度减小,有效抑制了虚假对流出现,最终达到改善降水预报质量的效果;海表温度试验原理与陆表温度试验类似,但对降水预报质量改善不明显,仅在广东南部沿海地区降水模拟效果较好。 相似文献
995.
Journal of Oceanology and Limnology - The red swamp crayfish, Procambarus clarkii, is an economically important species especially in China. Their exoskeleton places serious constraints on growth... 相似文献
996.
Roberto Soria Kinwah Wu Duncan K. Galloway 《Monthly notices of the Royal Astronomical Society》1999,309(2):528-532
We carried out I , R , V and B photometric observations of the neutron star X-ray binary RXTE J2123−058 shortly after the end of the X-ray outburst in mid-1998. We adopt the low-mass binary model to interpret our observations. After folding our data on the 0.24 821‐d orbital period, and correcting for the steady brightness decline following the outburst, we observed sinusoidal oscillations with hints of ellipsoidal modulations which became progressively more evident. Our data also show that the decline in brightness was faster in the V band than in the R and I bands. This suggests both the cooling of an irradiation-heated secondary star and the fading of an accretion disc over the nights of our observations. 相似文献
997.
13mm低温制冷谱线接收系统和星际水分子观测研究 总被引:2,自引:0,他引:2
为了开拓短厘米波单天线星际分子的观测和研究,在乌鲁木齐天文站25m射电望远镜13mm低温制冷接收机的基础上,配置了声表面波频谱仪和谱线数据采集系统,组成了13mm低温致冷谱线接收机.接收机前端是一个工作在低温20K的低噪声放大器,本振是22GHz的锁相源.接收机的平均噪声温度为50K.后端是一个宽带的(40MHz)高分辨率(40kHz)的声表波频谱仪.利用这套系统观测了一批已知的水脉泽源,观测系统正常,结果合理.观测结果表明,乌鲁木齐天文站良好的站址和25m射电望远镜给厘米波段星际分子谱线观测提供了一个很好的条件. 相似文献
998.
Helen M. Johnston Robert Fender Kinwah Wu 《Monthly notices of the Royal Astronomical Society》1999,308(2):415-423
We present new optical and infrared (IR) observations of Cir X-1 taken near apastron. Both sets of spectra show asymmetric emission lines. Archival optical observations show that an asymmetric H α emission line has been in evidence for the past 20 years, although the shape of the line has changed significantly. We present an eccentric ( e ∼0.7–0.9) low-mass binary model, where the system consists of a neutron star orbiting around a (sub)giant companion star of 3–5 M⊙ . We suggest that the broad components of the emission lines arise in a high-velocity, optically thick flow near the neutron star, while the narrow components of the optical and the IR lines arise near the companion star and a heated ejecta shell surrounding the binary respectively. In this model, the velocity of the narrow component reflects the space velocity of the binary; the implied radial velocity (+430 km s−1 after correcting for Galactic rotation) is the highest velocity known for an X-ray binary. 相似文献
999.
中国南方山地的土地荒漠化初探 总被引:4,自引:0,他引:4
我国的土地沙漠化已不仅仅在北方干旱、半干旱、包括部分半湿润地区, 而且在我国不少湿润和半湿润地带的东部平原(如黄淮海平原等)、沿海地区以及南方山地区也有发生, 其环境退化过程所包括的内容已不局限于"风沙化", 还包括了"砂石化"的类似砾质荒漠景观和山地丘陵斜坡的流水侵蚀造成的劣地景观, 内容较为丰富, 因此对我国南方山区的环境趋向于类似荒漠条件的退化过程, 我们采用了较广义的土地荒漠化的含义。 相似文献
1000.
东胜煤田矿区绿化初见成效 总被引:4,自引:0,他引:4
本文介绍了矿区荒漠化土地对东胜煤田开发的危害, 东胜露天矿开发对该区荒漠化土地的影响, 以及为了保证东胜煤田顺利开发, 对矿区荒漠化土地的综合治理现状。 相似文献