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排序方式: 共有262条查询结果,搜索用时 31 毫秒
1.
基于手机信令数据的长春市活动空间特征与社区分异研究   总被引:2,自引:0,他引:2  
居民时空行为成为透视城市空间的重要视角,本文基于手机信令数据研究长春市活动空间及其社区分异,轮廓性的揭示居住空间、就业空间和消费休闲空间的分布规律,从人地互动的过程与格局的视角认识城市空间。研究发现,居住活动对中心城区依赖明显高于就业和消费休闲活动,就业活动呈现多中心连片发展格局,近郊的欧亚卖场和郊区的净月潭成为人们消费休闲活动的重要选择。就业-居住距离和消费休闲-居住距离的社区分异显著,折射出三类活动空间关系复杂,由此感知城市生活空间质量和社会空间结构。通过对社区分异的空间聚类分析明晰各地域自身问题,从而有针对性的对长春的空间调整优化和居民行为引导提出建议,构建和谐宜居的城市空间。  相似文献   
2.
Ancient mortars played a crucial role in the construction of historical architectures due to their physical and chemical compatibility with traditional building materials such as stones and bricks. Therefore, the analysis and optimization of the ancient mortar formula are significant in the restoration and preservation of historical sites. In this work, 20 mortar samples selected from five ancient stone pagodas in Zhejiang Province, China, were analyzed. The results showed that mud, lime-soil mortar, lime-sand mortar, and lime-gypsum mortar were used as binders in these pagodas. The Ca(OH)2/aggregate ratio ranging from 0.3 to 2.7 was usually used to prepare lime mortar. Protein and polysaccharide were also found in some samples.  相似文献   
3.
L. Jiang  W. Pan  C. Cai  L. Jia  L. Pan  T. Wang  H. Li  S. Chen  Y. Chen 《Geofluids》2015,15(3):483-498
Permian hydrothermal activity in the Tarim Basin may have been responsible for the invasion of hot brines into Ordovician carbonate reservoirs. Studies have been undertaken to explain the origin and geochemical characteristics of the diagenetic fluid present during this hydrothermal event although there is no consensus on it. We present a genetic model resulting from the study of δ13C, δ18O, δ34S, and 87Sr/86Sr isotope values and fluid inclusions (FIs) from fracture‐ and vug‐filling calcite, saddle dolomite, fluorite, barite, quartz, and anhydrite from Ordovician outcrops in northwest (NW) Tarim Basin and subsurface cores in Central Tarim Basin. The presence of hydrothermal fluid was confirmed by minerals with fluid inclusion homogenization temperatures being >10°C higher than the paleo‐formation burial temperatures both in the NW Tarim and in the Central Tarim areas. The mixing of hot (>200°C), high‐salinity (>24 wt% NaCl), 87Sr‐rich (up to 0.7104) hydrothermal fluid with cool (60–100°C), low‐salinity (0 to 3.5 wt% NaCl), also 87Sr‐rich (up to 0.7010) meteoric water in the Ordovician unit was supported by the salinity of fluid inclusions, and δ13C, δ18O, and 87Sr/86Sr isotopic values of the diagenetic minerals. Up‐migrated hydrothermal fluids from the deeper Cambrian strata may have contributed to the hot brine with high sulfate concentrations which promoted thermochemical sulfate reduction (TSR) in the Ordovician, resulting in the formation of 12C‐rich (δ13C as low as ?13.8‰) calcite and 34S‐rich (δ34S values from 21.4‰ to 29.7‰) H2S, pyrite, and elemental sulfur. Hydrothermal fluid mixing with fresh water in Ordovician strata in Tarim Basin was facilitated by deep‐seated faults and up‐reaching faults due to the pervasive Permian magmatic activity. Collectively, fluid mixing, hydrothermal dolomitization, TSR, and faulting may have locally dissolved the host carbonates and increased the reservoir porosity and permeability, which has significant implications for hydrocarbon exploration.  相似文献   
4.
姜萌 《史学月刊》2007,(3):79-85
《陈寅恪的最后二十年》、《顾颉刚和他的弟子们》、《束星北档案》等著作,代表了当前历史传记写作的一种趋势。《陈寅恪的最后二十年》的文本近似历史叙事散文;《顾颉刚和他的弟子们》的文本更接近史学论文;而《束星北档案》则类同电视记录片的文稿。这些著作共有的特点是:在修撰方式上,大量运用了第一手材料;在文本风格上,力求作品深入浅出、雅俗共赏;在写作理念上,坚持真实第一,尊重历史。这一趋势非常值得重视。  相似文献   
5.
近年来,为配合城市、厂矿企业的基本建设,经文物部门勘探,在朝阳市区内发现并发掘清理了大量的古代墓葬,其中包括三燕时期的墓葬.  相似文献   
6.
蔡磊 《民俗研究》2007,(1):55-262
2006年12月16日至17日,"民族志·民俗志的理论与实践学术研讨会"在北京师范大学成功召开.这次大会由北京师范大学文学院民俗学与文化人类学研究所、北京师范大学民俗文化普查与研究中心、北京民间文艺家协会联合主办.  相似文献   
7.
This study uses service area–based coverage and various count regression methods to assess neighbourhood-level healthy and unhealthy food environments, and food access associated with different socio-economic groups in Edmonton, Canada. We identify three types of vulnerable neighbourhoods according to different food environments: food deserts (i.e., neighbourhoods lack sufficient access to healthy foods); food swamps (i.e., neighbourhoods have excess access to unhealthy foods); and those with overlaps of food swamps and food deserts. We also identify neighbourhoods with superior access to healthy foods (i.e., food oases). Additionally, our results from regression analyses indicate: (1) child population is negatively associated with both healthy and unhealthy food resources; (2) good access to public transportation is associated with good coverage of all healthy food outlets and convenience stores; and (3) deprived neighbourhoods with higher percentages of minority populations have better coverage of both healthy and unhealthy foods in general. The results from this study can help the City of Edmonton identify the key neighbourhoods with high potential for local business and the hotspot neighbourhoods that require particular support. Tailored strategies are proposed to effectively and efficiently improve food environments with limited resources.  相似文献   
8.
贵州最早的骨制装饰品出自距今一万二千年至一万五千年前的普定白岩脚洞旧石器时代晚期遗址。装饰品有1件骨笄和1件穿孔兽牙。它们是贵州的首次发现,也体现了贵州远古人类最早的爱美意识。从装饰品本体携带的信息,探索其制作技能,反映出当时人类加工技术的复杂和进步,即对不同用途的装饰品采用不同的加工方式和对同一制品的制作技术逐步改良的处理能力。这既是思维进化指导行为的结果,亦是原始人类迈向更加文明时代的一大进步。  相似文献   
9.
经济行为与环境变化:清前期台湾野生鹿消失探析   总被引:3,自引:0,他引:3  
鹿曾经是台湾数量最庞大的野生动物群之一。明末以来,随着台湾贸易交流的活跃,鹿成为大宗出口商品,土著居民由原先捕鹿作为民生用品逐渐发展至为市场服务;清前期大陆移民入台的农业垦殖又破坏了鹿原有的生态环境。人类经济行为引发的环境变化,最终导致了野生鹿在台湾渐趋消失。  相似文献   
10.
在一二八、八一三事变中,上海两次惨遭日军炮火蹂躏,尤其是闸北的繁华地带东北、西南两处,先后因日军轰炸使三十年的建设成就荡然无存。日本的侵华战争不但中断了闸北的现代化建设,还直接导致了该地区的长期沉沦。  相似文献   
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