基于GIS的土地储备业务管理系统的研究与实现     

曹铁朋 《测绘与空间地理信息》2021,44(4):84-87

土地是支撑城市社会经济发展和基础设施建设的空间基础,作为自然物的土地具有价值属性。土地储备涉及市土地开发中心前期部、征地部、出让部、工程部、合同部、计财部等内部职能部门,涉及测绘、规划、房管、农业、城市更新、发改、人民政府等外部单位,交互业务较多,因此土地的规划、审批、征收、出让、工程等流程复杂、管理困难。本文介绍了土地储备业务管理系统的实现思路,系统实现建立业务审批体系。规范资金使用和管理,达到海量数据高效处理、图属档一体化、实时信息在线共享、流程优化协同办理、短信督办提醒的目标,满足对土地储备情况的宏观监管和微观审批,形成完善的土地储备业务管理体系。  相似文献   

Seasonal variability in somatic and reproductive investment of the bivalve Scrobicularia plana (da Costa, 1778) along a latitudinal gradient     

Sílvia Santos  Joana F.M.F. Cardoso  Célia Carvalho  Pieternella C. Luttikhuizen  Henk W. van der Veer 《Estuarine, Coastal and Shelf Science》2011

Monthly investment in soma and gonads in the bivalve Scrobicularia plana is described for three populations along its distributional range: Minho estuary, Portugal; Westerschelde estuary, The Netherlands and Buvika estuary, Norway. Seasonal cycles in body mass (BMI), somatic mass (SMI) and gonadal mass (GMI) indices were observed for all populations. In Portugal, BMI and SMI peaked in mid-autumn, while in The Netherlands both indices were at their highest in mid-spring. Norway showed a different pattern with two distinct peaks: one in mid-autumn and a second peak in spring. GMI reached maximum values in July in Portugal and Netherlands and in June in Norway. Overall, mean BMI and SMI were lower in Portugal while mean GMI was lower in Norway. The spawning period lasted the whole summer in Portugal, but was shorter (only two months) in The Netherlands and Norway. The reproductive investment in The Netherlands was significantly higher than in Portugal and Norway, with the lowest values being observed in Norway. Differences in annual cycles between populations were attributed to environmental factors, namely temperature and food availability. Temperature seems important in shaping the reproductive pattern with more northern populations showing shorter reproductive periods starting later in the year, and a lower reproductive output. In addition, winter water temperatures can explain the lower mean body and somatic mass values observed in Portugal. Food availability influenced the physiological performance of the species with peaks in somatic mass coinciding with phytoplankton blooms. This relation between physiological performance and environmental factors influences S. plana distribution, densities and even survival, with natural consequences on its commercial importance.  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987114000917     

Miyuki Tahata  Yusuke Sawaki  Yuichiro Ueno  Manabu Nishizawa  Naohiro Yoshida  Toshikazu Ebisuzaki  Tsuyoshi Komiya  Shigenori Maruyama 《地学前缘(英文版)》2015,6(1):121-136

Important ecological changes of the Earth(oxidization of the atmosphere and the ocean) increase in nutrient supply due to the break-up of the super continent(Rodinia) and the appearance of multi-cellular organisms(macroscopic algae and metazoan) took place in the Ediacaran period,priming the Cambrian explosion.The strong perturbations in carbon cycles in the ocean are recorded as excursions in carbonate and organic carbon isotope ratio(δ~(13)C_(carb) and δ~(13)C_(org)) from the Ediacaran through early Cambrian periods.The Ediacaran-early Cambrian sediment records of δ~(13)C_(carb) and δ~(13)C_(org),obtained from the drill-core samples in Three Gorges in South China,are compared with the results of numerical simulation of a simple one-zone model of the carbon cycle of the ocean,which has two reservoirs(i.e.,dissolved organic carbon(DOC) and dissolved inorganic carbon(DIC).The fluxes from the reservoirs are assumed to be proportional to the mass of the carbon reservoirs.We constructed a model,referred to here as the Best Fit Model(BFM),which reproduce δ~(13)C_(carb) and δ~(13)C_(org) records in the Ediacaran-early Cambrian period noted above.BFM reveals that the Shuram excursion is related to three major changes in the carbon cycle or the global ecological system of the Earth:(1) an increase in the coefficient of remineralization by a factor of ca.100,possibly corresponding to a change in the dominant metabolism from anaerobic respiration to aerobic respiration,(2) an increase of carbon fractionation index from 25‰ to 33‰,possibly corresponding to the change in the primary producer from rock-living cyanobacteria to free-living macro algae,and(3) an increase in the coefficient of the organic carbon burial by a factor of ca.100,possibly corresponding to the onset of a biological pump driven by the flourishing metazoan and zooplankton.The former two changes took place at the start of the Shuram excursion,while the third occurred at the end of the Shuram excursion.The other two excursions are explained by the tentative decrease in primary production due to cold periods,which correspond to the Gaskiers(ca.580 Ma) and Bikonor(ca.542 Ma) glaciations.  相似文献   

小剪跨比格构式混凝土墙体抗震性能试验     

周静海  王鹏里  孟宪宏  朱静雯  侯延泽  张志伟 《地震工程与工程振动》2011,31(3):127-133

文章旨在研究不同剪跨比的格构式混凝土墙体抗震性能.将生产车间预制成EPS保温模块拼接成墙体模板,在横向和纵向孔洞中分别布置钢筋,然后在孔内浇筑自密实混凝土,形成“EPS新型节能”格构式混凝土墙体,然后对6个参数不同的试件进行低周反复水平荷载作用的试验.结果,墙体破坏形态为:首先墙体相邻格构柱间的连梁出现环状裂缝和“X”...  相似文献   

基于时态数据库技术的导航信息空间关系局部动态更新方法     

郭继发  毛健  崔铁军 《测绘软科学研究》2011,(4):47-50

针对目前导航电子地图生产中导航地图数据生产周期长的问题,提出了一种基于导航数据生命周期状态维护触发器的导航地图数据生产时空动态更新模型。首先基于时空数据库技术构建了导航地图数据生产时空数据模型,构建了导航数据生命周期状态维护触发器,将导航数据空间关系分为一级几何拓扑和二级逻辑拓扑。利用触发器,使得导航数据的任何变更（几何和逻辑）得到有效记录,保证了增量包的有效导出。  相似文献   

异质性农户土地流转的决定性因素与政策建议     

张淑萍 《地域研究与开发》2015,(4)

建立异质性农户土地流转行为的理论分析基础,利用Logistic回归分析方法和河南省调查数据,明确农户土地流转决策的影响因素。研究结果表明:农村信贷市场约束是纯农户、以农业收入为主的农户转入土地的需求不足的重要原因;规避就业风险和争夺土地租金是非农户和以非农业收入为主的农户转出土地的供给不足的主要原因;土地控制权偏好与生存预期造成中年、老年农户竭力排斥土地流转;农村土地流转不活跃的决定性因素是国家保护农业与有效管理兼业农户、非农户的责任缺位。  相似文献   

Environmental effects on the reproduction and fecundity of the introduced calcareous sponge Paraleucilla magna in Rio de Janeiro,Brazil          下载免费PDF全文

Emilio Lanna  Rodolfo Paranhos  Paulo C. Paiva  Michelle Klautau 《Marine Ecology》2015,36(4):1075-1087

The calcareous sponge Paraleucilla magna (Porifera, Calcarea) has been the subject of several studies in the last decade. It was first described along the Brazilian coast, where it is considered cryptogenic, and was subsequently found in the Mediterranean, where it is considered invasive. The wide artificial distribution of this species allows us to compare different aspects of the biology of an introduced species in different locations. Here, we analysed the effects of selected environmental parameters on the reproductive dynamics of P. magna in Rio de Janeiro (Brazil) over 18 months and compared our results with those obtained for the same species in the Mediterranean Sea. Specimens were collected monthly and analysed through histological methods. The density of reproductive elements in each month was calculated, and the effects of environmental parameters (photoperiod, precipitation, temperature, phytoplankton and bacterioplankton) were analysed using a regression tree analysis. Paraleucilla magna was reproductive throughout the study period. The densities of the reproductive elements (oocytes, embryos and larvae) showed no seasonality, and this species presented one of the highest reproductive efforts documented to date in the phylum Porifera (99.0 oocytes · mm^?3; 89.0 embryos · mm^?3; 319.0 larvae · mm^?3). The main environmental parameters related to the reproduction of P. magna were temperature, photoperiod and bacterioplankton. Temperature was the main driver associated with the densities of oocytes and embryos, while bacterioplankton was the main driver of larvae (positive relationships). In Rio de Janeiro, larvae were present and continuously released. This strategy is different from that observed in the Mediterranean, where a larger larval output was observed but only during the summer months. Our results show that P. magna is a species with a strong invasive potential, considering its high and continuous reproductive effort. This high fecundity stimulated by high temperatures may be a key factor contributing to the growth of P. magna populations and its invasion of new areas.  相似文献   

海底裸置与埋置管线自沉过程对比研究     

唐丕鑫  杨树耕  宋艾恒  刘晓峰  徐蒙  王晗 《海洋工程》2015,33(2):89-96

海底管线是海洋油气输运系统的重要组成成分,其稳定性和安全性尤为重要。通过有限元软件ABAQUS,应用Mohr-Coulomb模型,模拟海底裸置与埋置管线自沉过程。通过平衡初始地应力,设置管土接触,考虑重力和浮力作用,进行土体固结分析,计算裸置与埋置管线的土体与管线竖直位移,并进行管线悬跨研究。计算结果显示,对于裸置管线,参数的改变使土体更容易发生塑性屈服,土体的竖直位移量更大;对于埋置管线,当管线埋深较浅、管线上方土体重量不大时,参数的改变使管线平均密度与周围土体密度相差越大土体越容易发生塑性屈服,土体的竖直位移量越大。当管线悬空时,悬跨长度过大易使管线两端支撑土体被压溃,管线易产生大变形而失稳,因此在管线安装与维护过程中,一定要采取措施降低悬跨长度,保证管线运营安全。  相似文献   

冰激直立腿海洋平台疲劳寿命分析   总被引：1，自引：1，他引：0  

张大勇  刘笛  许宁  岳前进  郭龙玮 《海洋工程》2015,33(4):35-44

由于渤海特殊环境条件与油藏分布决定了该海域导管架油气平台属于典型的柔性抗冰结构。多年现场观测发现,该类结构存在显著的冰激振动现象。冰振不仅能激起较大的甲板加速度响应,还会引起明显的导管架管节点交变应力。在结构设计与安全保障中进行疲劳分析及寿命估计是必要的。对于直立腿抗冰结构,精确的冰激疲劳寿命计算方法还不成熟。基于多年的现场监测,首先分析了冰与直立腿抗冰结构相互作用过程;其次,提出了冰激直立腿平台的疲劳寿命分析流程;最后,选取渤海某典型直立腿平台,利用ANSYS数值模拟,对比了稳态冰力和随机冰力下结构的疲劳损伤,进而计算出疲劳寿命。本研究为寒区柔性结构抗冰设计与安全保障提供了理论基础。  相似文献   

辽东山地老秃顶子冰缘地貌植物群落类型及基本特征   总被引：3，自引：0，他引：3  

张华  刘剑刚  伏捷  孙明扬  罗璇  何红  祝业平  兰玉波  王颖 《冰川冻土》2015,37(2):500-510

基于48个样地的群落调查数据,运用TWINSPAN分类方法,对辽东山地老秃顶子冰缘地貌植物群落类型进行了划分,并对群落结构、种类组成和生活型谱进行了系统研究.结果表明:老秃顶子冰缘地貌植被可划分为16个森林群系、6个灌丛群系,归并为落叶阔叶林、针阔混交林、暗针叶林、矮曲林、灌丛、灌草丛6个植被型.其中,石海地貌主要发育灌丛和灌草丛,也有针阔混交林和矮曲林分布;石河地貌主要发育针阔混交林和落叶阔叶林,也有暗针叶林分布;石流坡地貌主要发育针阔混交林、落叶阔叶林和灌丛,也有矮曲林分布.老秃顶子冰缘地貌植被由68科138属193种维管束植物组成;石海与石河间植物群落物种组成属中等不相似,而石河与石流坡间属中等相似.老秃顶子冰缘地貌植物群落中高位芽植物占38.0%,隐芽植物占36.3%,地面芽植物占21.8%,地上芽植物和一年生植物均很少,反映出辽东山地冰缘地貌区具有夏季温暖多雨、冬季寒冷漫长的气候特点.相对而言,石海、石流坡地貌中隐芽植物较多,石河地貌中高位芽植物较多,表明石海、石流坡地貌具有更为冷湿的小气候环境.  相似文献