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   

Microbial life in martian ice: A biotic origin of methane on Mars?     

P. Buford Price 《Planetary and Space Science》2010,58(10):1199-1206

Despite the fact that microbial cells are unlikely to be found in the Martian soil in the near future, this paper is written on the assumption that some of the seasonally varying concentration of Martian methane is due to ongoing methanogenesis. It is first pointed out that life might have arisen on Mars first and been transported to Earth later. A case is made that an icy origin of life is more likely than a hot origin, especially if biomolecules take advantage of the high encounter rates and stability against hydrolysis, and that microorganisms feed on the ions that comprise eutectic solutions in ice. Although certain difficulties are avoided if RNA and DNA grow while adsorbed on clay grains, double strand-breaks of microbial DNA due to alpha radioactivity are a far greater threat to microbial survival on clay or other rock types than in ice. Developing a relation between the rate of microbial metabolism in ice and the experimentally determined rate of production of trapped gases of microbial origin, one can estimate the concentration of methanogens that could account for the methane production rate as a function of temperature of their habitat. The result, of order 1 cell cm⁻³ in the Martian subsurface, seems an attainable goal provided samples are taken from at least 1 or 2 m below the hostile surface of Mars. Instruments on NASA’s 2011 Mars Science Lab will measure stable isotopes for methane, water, and carbon dioxide, which on Earth served to distinguish abiotic, thermogenic, and microbial origins. Future measurements of chirality of biomolecules might also provide evidence for Martian life.  相似文献   

Marine debris review for Latin America and the wider Caribbean region: from the 1970s until now, and where do we go from here?   总被引：1，自引：1，他引：0  

Ivar do Sul JA  Costa MF 《Marine pollution bulletin》2007,54(8):1087-1104

The available literature on marine debris from Latin America and the Wider Caribbean Region was collected and linked, reviewing their methodologies and principal results (quantities, composition and spatial-temporal patterns). The study region comprises 52 coastal countries of which only 14 had registers of works on marine debris. A total of 70 works were available and 69 had their full contents accessed. Brazil dominated the available literature with 70% of the documents. Beaches were the most studied environment, and plastics the prevalent form of contamination in the whole region. The exposure of marine biota (species, type of contact, consequences) was highlighted. The studied region, although still little exploited by this sort of research, shows the same contamination patterns observed world-wide. We also contacted 40 researchers in the area, collecting scientific contributions, opinions and suggestions for improvement of this research field. Further advances and new (urgently needed) lines of research are also discussed.  相似文献   

Early development of Silvetia babingtonii (Fucales,Phaeophyceae)     

Gaoge Wang  Xiaojiao Wei  Limei Shuai  Bojun Lu  Shasha Wang  Dongdong Kang 《中国海洋大学学报(英文版)》2014,13(4):677-682

Silvetia babingtonii is a potentially economic brown alga for sources of food and high-value added utilization. So far, sporeling nursery and field cultivation has not been successful. The lack of knowledge on development and life cycle of this alga hinder the development of techniques for the sporeings and cultivation. In this study, internal structure of oogonium and antherium of S. babingtonii was observed with hematoxylin and eosin staining and through microscope. Meanwhile, early development from zygotes to juvenile sporelings was studied at 20℃ under 60–100 μmol photons m-2 s-1. Zygotes germinated and divided into thallus and rhizoid cells. The larger thallus cells further divided and developed into juvenile sporelings; while the smaller rhizoid cells divided and elongated into rhizoid hairs. These findings documented the life cycle of S. babingtonii and provided fundamental knowledge for sporeling nursery in the near future.  相似文献   

深水钢悬链立管疲劳寿命评估分析     

董永强  宋儒鑫  孙丽萍 《海洋工程》2014,32(2):119-124

在时域内分析深水钢悬链立管在平台运动和波流载荷共同作用下的非线性动力响应;采用雨流计数法处理立管节点应力的时间历程,选用DoE.E型S-N曲线分析立管在单一海况和平台运动联合作用下的疲劳损伤;将各方向含概率分布的疲劳损伤进行叠加,得到立管整体的全方向疲劳损伤及疲劳寿命。平台的运动为六自由度的运动预报数据,波流载荷由某海域实际的波浪统计数据采用Morison公式计算所得。计算结果表明钢悬链立管疲劳寿命的极值点分别位于悬挂点附近和触地点附近,对立管疲劳寿命极值点各方向疲劳损伤分布情况进行了分析。所提方法为钢悬链立管疲劳分析提供了新思路,给出的结论对钢悬链立管设计分析有一定借鉴意义。  相似文献   

Enhanced Multi-Layer Fatigue-Analysis Approach for Unbonded Flexible Risers     

杨和振  姜豪  杨启 《海洋工程》2014,28(3):363-379

This paper proposes an enhanced approach for evaluating the fatigue life of each metallic layer of unbonded flexible risers. Owing to the complex structure of unbonded flexible risers and the nonlinearity of the system, particularly in the critical touchdown zone, the traditional method is insufficient for accurately evaluating the fatigue life of these risers. The main challenge lies in the transposition from global to local analyses, which is a key stage for the fatigue analysis of flexible pipes owing to their complex structure. The new enhanced approach derives a multi-layer stress-decomposition method to meet this challenge. In this study, a numerical model validated experimentally is used to demonstrate the accuracy of the stress-decomposition method. And a numerical case is studied to validate the proposed approach. The results demonstrate that the multi-layer stress-decomposition method is accurate, and the fatigue lives of the metallic layers predicted by the enhanced multi-layer analysis approach are rational. The proposed fatigue-analysis approach provides a practical and reasonable method for predicting fatigue life in the design of unbonded flexible risers.  相似文献   

细分移动互联网地理信息服务,构建宜居数字世界生活     

景贵飞 《地理信息世界》2014,(6)

移动互联网的发展在短时间内为地理信息带来了数亿用户,个人用户的增加,对地理信息提出了新的技术要求;地理信息界在努力,信息领域企业也在从信息基础设施角度向地理信息应用方向拓展,形成了目前信息技术企业与地理信息企业相向开发的局面;地理信息用户和行业的快速扩张,对行业管理提出了更高要求,需要许可认证、市场范围秩序维持等新的手段;地理信息有了与能力相适应的角色需要。以服务数字世界、打造虚拟社会中的宜居生活为目标,做好粘结剂,实现现实世界与数字世界的互动。  相似文献   

动力学模型预测泥鳅(Misgurnus anguillicaudatus)半干制品的货架期   总被引：1，自引：1，他引：0  

刘卓然  翁佩芳  敖雨燕  吴祖芳 《海洋与湖沼》2014,45(2):382-386

以泥鳅(Misgurnus anguillicaudatus)半干制品为研究对象,测定和分析其在不同贮藏温度(4°C、20°C、30°C和40°C)下,菌落总数、挥发性盐基氮(TVBN)、脂肪氧化程度(TBA值)与感官评分各项指标随贮藏时间的变化。结果表明,泥鳅半干制品在不同贮藏温度下,随着贮藏时间的延长品质逐渐下降,贮藏温度越低,品质指标变化越缓慢。经Pearson相关性分析,确定影响泥鳅半干制品品质变化的关键因子为菌落总数;基于Arrhenius方程,进一步建立菌落总数与贮藏时间、贮藏温度之间的动力学模型,该模型中活化能Ea为26.5 kJ/mol,反应速率常数k0为3186.6,推算得出泥鳅半干制品货架期预测值与实测值相对误差较小,该动力学模型可准确预测泥鳅半干制品在4—40°C贮藏温度下的货架期。本研究可为泥鳅半干制品的开发、流通奠定理论基础。  相似文献   

海洋寄生性甲藻——阿米巴藻Amoebophrya spp.的研究进展     

李才文 《海洋学报》2014,36(6):1-9

寄生性甲藻阿米巴藻Amoebophrya是一类广泛寄生于纤毛虫类、放射虫类、甲藻类等海水浮游生物的原生生物,在北大西洋、北太平洋和地中海等营养盐丰富、宿主密度较高的河口和近海水环境中普遍存在,是海洋浮游食物网的重要组成部分。这类寄生性甲藻能够特异性感染海洋浮游甲藻,在有害藻华(harmful algal bloom,HAB)的发生过程中起下行控制作用,将逃脱了浮游动物摄食的浮游植物补充到微食物环(microbial loop)中去。Amoebophrya在近海海洋生态系统中的独特作用日益受到国际上越来越多研究者的关注和重视,并逐渐成为国际上海洋微型生物研究的新热点之一。近年来,已有初步调查研究表明这类寄生性甲藻在我国近海海域广泛存在;然而,目前我国尚缺乏该类寄生性甲藻的相关研究。本文系统综述了国际上该类寄生性甲藻的研究进展,针对目前研究中存在的问题并结合我国有害藻华发生机制相关研究的现状做出了分析和展望,以期推动我国该类寄生性甲藻的相关研究,为进一步阐释寄生性甲藻等海洋微型生物在有害藻华消长过程和海洋微食物环中的作用奠定基础。  相似文献   

Outstanding challenges for urban conservation research and action     

《Global Environmental Change》2014

Researchers, advocates and policymakers have proposed urban conservation as an emerging, integrative discipline that can contribute to sustainable cities by delivering co-benefits to human and non-human components of biodiversity. Given the recent growth in biodiversity-friendly designs and management schemes, there is an urgent need for a synthesis of this fragmented research base to inform planners and decision-makers. We conducted a systematic multidisciplinary literature review (787 papers) and found that the importance of urban areas for general conservation is not convincingly supported by empirical research. Only few studies demonstrated that cities can directly contribute to conservation efforts, by hosting viable populations of rare or endangered species, or by providing green corridors for the passage of natural populations. From a social perspective, while several studies demonstrated that green infrastructure could provide services for people (notably cultural services), only few studies explored the role of species diversity per se. Our review also shows strong geographical, location and taxonomic biases in urban biodiversity conservation research that make generalisations difficult. It is a disturbing paradox that while research in urban biodiversity conservation is rising exponentially, the main motivations for conserving urban biodiversity remain largely untested and unproven. We thus propose a framework for promoting integrative urban conservation research to bridge those gaps. Together, these findings warn against expanding cities under green planning and call for enhancing biodiversity experience by improving the quality of existing green spaces throughout the entire urban matrix. We provide a set of recommendations for practitioners and decision-makers to continue action.  相似文献