Holocene initiation and expansion of the southern margins of northern peatlands triggered by the East Asian summer monsoon recession

Northern peatlands represent one of the largest biospheric carbon reservoirs in the world. Their southern margins act as new carbon reservoirs, which can greatly influence the global carbon dynamics. However, the Holocene initiation, expansion and climate sensitivity of these peatlands remain intensely debated. Here we used a compilation of basal peat ages across six isolated peatlands at the southern margins of northern peatlands to address these issues. We found that the earliest initiation event of these peatlands occurred after the Younger Dryas (YD, 12,800–11,700 years ago) period. The second initiation event and rapid expansion occurred since 5 ka cal. BP. The recession of East Asian summer monsoon (EASM) during the YD period and at around 5 ka cal. BP likely played a major role in controlling the initiation and expansion of these peatlands. The rapid expansion of these peatlands possibly contributed to the significant increases in atmospheric methane concentrations during the late Holocene because of the minerotrophic fens status and rapid expansion of them. These ecological processes are different from northern peatlands, indicating the special carbon sink and source implications of these peatlands in the global carbon cycle.     

郯庐断裂带南段新活动性的初步研究

由于郯庐断裂带南段的第四纪地层不发育,尽管断裂构造岩松散而未固结成岩,也难以应用地层变位法来确定它的最新活动时代和活动方式。笔者在发育断层泥的断裂露头剖面上,采集断层泥样品9个,通过扫描电镜——石英碎砾刻蚀形貌法来确定它的新动活性。根据石英碎砾的刻蚀形貌类型判定断层的最新活动时代和活动方式;蠕滑?粘滑?从而确定郯庐断裂带南段的最新活动时代在N_2—Q_1或Q_2,活动方式以粘滑为主。     

珠江三角洲工业地域分工研究

本文从专业化部门的数量和发展水平以及专业化部门地区分布和组合两方面揭示珠江三角洲工业地域分工的基本特点。指出新形势下虽然不少县市存在专业化部门多而不精，工业结构趋同的问题，但珠江三角洲地域分工格局已开始形成。文章还讨论了形成工业地域分工特点的原因并提出了完善地域分工的措施。     

云南省传染病与太阳活动关系的考察

从日地关系的角度出发,探讨太阳活动对人类流行性疾病的影响。根据云南地区自建国以来的１５种流行性疾病每年人数的资料,对每种疾病人数的相对比率与太阳黑子相对数对应作图比较,并求其相关系数。考察结果为：猩红热、疟疾、炭疽、百日咳、白喉、流感、乙脑、痢疾、麻疹、脊髓灰质炎、姜片虫病、肝炎与太阳活动的关系不明确,伤寒、斑疹伤寒和流脑与太阳活动显著相关     

Spatial dynamics of retail structure and the venerable retail hierarchy

The retail system is continuously adapting itself to changing demographic conditions, consumer behavior and economic conditions. Existing retail units, getting larger in order to achieve economics of scale, and new forms of large-scale retailing do not fit easily in the traditional spatial pattern of retail concentrations. Neverteless the spatial distribution of retailing in urban areas, as schematized by Berry thirty-five years ago, still has its value. Through an upward hierarchical movement the retail system has adapted itself to an inflexible spatial system, in which downtown has still a dominant position. Future developments, however, may weaken the position of central shopping areas in favour of peripheral locations. This revised version was published online in July 2006 with corrections to the Cover Date.     

赤道太平洋对流活动异常对我国夏季降水和气温的影响

利用月平均ＯＬＲ、降水和气温资料,研究了ＥＮＳＯ期间赤道太平洋对流活动与我国夏季降水和气温的关系。结果表明：春季、夏季中、西太平洋对流活动异常与我国夏季江淮地区的降水有密切关系;春季和前一年冬季西太平洋对流活动异常与东北地区夏季降水有显著相关。前一年冬季中、西太平洋对流活动异常与我国降水的显著相关区是不同的,前者为华南、西南地区,后者为东北至内蒙古一带。气温与同期中、西太平洋对流活动的相关不显著。     

南海的新构造运动及其演化史

本文对南海壳块第三纪以来所发生的断裂作用、地震活动、岩浆活动与褶皱作用进行了综合研究。在此基础上,总结了南海壳块新构造运动特征并进而对其演化规律进行了探讨。     

Spatiotemporal change patterns of urban lakes in China’s major cities between 1990 and 2015

China has experienced unprecedented urbanization in the past decades, resulting in dramatic changes in the physical, limnological, and hydrological characteristics of lakes in urban landscapes. However, the spatiotemporal dynamics in distribution and abundance of urban lakes in China remain poorly understood. Here, we characterized the spatiotemporal change patterns of urban lakes in China’s major cities between 1990 and 2015 using remote-sensing data and landscape metrics. The results showed that the urban lake landscape patterns have experienced drastic changes over the past 25 years. The total surface area of the urban lakes has decreased by 17,620.02?ha, a decrease of 24.22%, with a significant increase in the landscape fragmentation and a reduction in shape complexity. We defined three lake-shrinkage types and found that vanishment was the most common lake-shrinkage pattern, followed by edge-shrinkage and tunneling in terms of lake area. Moreover, we also found that urban sprawl was the dominant driver of the lake shrinkage, accounting for 67.89% of the total area loss, and the transition from lakes to cropland was also an important factor (19.86%). This study has potential for providing critical baseline information for government decision-making in lake resources management and urban landscape design.     

北京城市边缘区非农产业活动特征与形成机制*

考察了北京主城边缘区的非农产业结构与空间特征,揭示了二者的交互演进过程:非农产业的发展是城市边缘区形成的重要标志,产业结构的升级促进了边缘区的圈层扩展和空间演进;边缘区的外移过程中,制造业具有稳定的优势,交运仓储、生产资料租赁等传统生产者服务业的优势也随之强化,但空间黏滞性较强的旅游、体育等行业则促进了边缘区产业结构的时相差异性。文章对城市边缘区"年轮式"的圈层扩展进行了定量实证分析,并将其实现的微观路径归纳为飞地式、轴向、填充式和外推式等四种扩展模式。城市规划、城郊高速公路和开发区建设、地价和综合环境的改善是城市边缘区产业空间演变的重要动力。城市空间优化和产业结构调整的结合是解决边缘区产业、空间和社会问题的有效途径。     

新疆火山岩分区及其地质意义

新疆火山活动强烈 ,火山岩类型多 ,出露广泛。依据火山岩特征和时空分布规律 ,新疆火山岩分布区域可以划分两个较大级别的火山岩分区单元 :第一级为火山岩区 ,第二级为火山岩带。全区共划分出 6个火山岩区和 30个火山岩带。火山岩分区的划分对火山岩、地质构造和矿产的研究具有重要的意义和实用价值