中国极地科学数据库系统数据管理子系统的开发——以三层体系结构开发基于Web的数据管理子系统

随着Internet技术的不断发展和完善,新的应用系统体系结构在系统开发、数据存储、数据访问和控制等方面的先进性也在不断地应用到数据库系统的开发和建设中。三层体系结构通过建立中间层应用程序,将原先运行在每个客户端计算机上的应用程序和处理过程转移到中间层执行,并通过网络共享给用户,克服了传统客户端/服务器体系结构在应用系统开发维护、客户端配置调整等方面存在的缺陷。中国极地科学数据库数据管理子系统采用三层体系结构的网络数据库设计思想,开发位于中间层的多种数据库应用程序,充分利用了三层体系结构在开发、维护及使用等诸多方面的先进性,为极地科学数据库的有效管理提供了一种高效、直观的手段,同时利用Internet这一网络工具,为不同专业学科数据的提交、收集、整理、入库和发布提供了更为便捷的途径。     

Sea Level Rise and Its Risk Management

Sea level rise is among the most severe societal consequences of anthropogenic climate change. Significant advance has been achieved in recent years in the study of future sea level rise and its risk management practice: ①Sea level rise is considered as a kind of hazard,its future plausible scenarios and their probabilities are necessary to be predicted and estimated,and the upper limit with very low probability and high consequences should be emphasized. For this purpose,a complete probability distribution framework has been developed to predict the scenarios and probabilities of future sea level rise with Representative Concentration Pathways (RCPs) and the Shared Socioeconomic Pathways (SSPs) in recent years. ② For a high emissions scenario,it was found that Antarctic Ice Sheet might make a contribution to Global Mean Sea Level (GMSL) rise as high as 78150 cm (mean value 114 cm) by 2100. For the same scenario,the IPCC Fifth Assessment Report gave an Antarctic contribution of only -8+14 cm (mean value 4 cm). ③ Recent studies recommended a revised worst-case (Extreme) GMSL rise scenario of 2.5 m from previous 2.0 m by 2100. It is recognized that GMSL rise will not stop at 2100; rather,it will continue to rise for centuries afterwards,but the degree of uncertainty related to sea level rise will increase. ④ Approaches of combining the upper-bound scenario and a central estimate or mid-range scenario, Adaptation Pathways and robust decision-making are developed to provide a set of long-term planning envelope. These decision-making methods are used widely in coastal risk management related to future sea level rise. Sea level rise and its risk management need to enhance monitoring,analysis and simulation to predict the global,regional and local seal level rise scenarios and the probabilities with different time scales,reduce the estimate uncertainty, assess its upper limits, and enhance decision methods and their application under deep uncertain, in order to meet the needs of climate change adaptation planning,decision-making and long-term risk management in coastal regions.     

Saturn's gravitational field induced by its equatorially antisymmetric zonal winds

The cloud-level zonal winds of Saturn are marked by a substantial equatorially antisymmetric component with a speed of about 50 m s-1 which, if they are sufficiently deep, can produce measurable odd zonal gravitational coefficients ?J2 k+1, k = 1, 2, 3, 4. This study, based on solutions of the thermal-gravitational wind equation, provides a theoretical basis for interpreting the odd gravitational coefficients of Saturn in terms of its equatorially antisymmetric zonal flow. We adopt a Saturnian model comprising an ice-rock core, a metallic dynamo region and an outer molecular envelope. We use an equatorially antisymmetric zonal flow that is parameterized, confined in the molecular envelope and satisfies the solvability condition required for the thermal-gravitational wind equation. The structure and amplitude of the zonal flow at the cloud level are chosen to be consistent with observations of Saturn.We calculate the odd zonal gravitational coefficients ?J_(2k+1), k = 1, 2, 3, 4 by regarding the depth of the equatorially antisymmetric winds as a parameter. It is found that ?J_3 is-4.197 × 10~(-8) if the zonal winds extend about 13 000 km downward from the cloud tops while it is-0.765 × 10~(-8) if the depth is about 4000 km. The depth/profile of the equatorially antisymmetric zonal winds can eventually be estimated when the high-precision measurements of the Cassini Grand Finale become available.     

北冰洋海冰/气候系统及其对全球气候的影响

结合前人对北冰洋海冰、气候系统的研究成果和 1 999年 8月在北冰洋对海冰的现场观测 ,本文综述了海冰分布、厚度的变化 ,海冰表面特征、积雪变化及北冰洋天气、气候特征和分区。讨论了北极海冰与南极海冰的差异。文章认为 ,北冰洋与周围地区气候变化趋势的不一致 ,主要是由于夏季在北冰洋海冰与开阔水域的相间分布、海冰漂移、融化吸热 ,均衡了周围大气、海洋温度的变化。     

Carbon sequestration potential and its eco-service function in the karst area,China

The karst critical zone is an essential component of the carbon (C) pool, constituting the global C cycle. It is referred to as one of the “residual land sink” that remains largely indeterminate. Karst area (2.2×10⁷ km²) comprises 15% of the world’s land area, and karst area comprises 3.44×10⁶ km² of area in China. Due to the complexity of karst structure and its considerable heterogeneity, C sequestration rate estimations contain large inaccuracies, especially in relation to the different methods used in calculations. Therefore, we reevaluated rock weathering-related C sink estimations in China (approximately 4.74 Tg C yr^–1), which we calibrated from previous studies. Additionally, we stipulated that more comprehensive research on rock-soil-biology-atmosphere continuum C migration is essential to better understand C conversion mechanisms based on uncertainty analyses of C sink estimations. Moreover, we stressed that a collective confirmation of chemical methods and simulated models through a combined research effort could at least partially eliminate such uncertainty. Furthermore, integrated C cycling research need a long-term observation of the carbon flux of multi-interfaces. The enhanced capacity of ecosystem C and soil C pools remains an effective way of increasing C sink. Karst ecosystem health and security is crucial to human social development, accordingly, it is critical that we understand thresholds or potential C sink capacities in karst critical zones now and in the future.     

碎屑沉积地质体构型分级方案探讨

沉积体的层次结构是复杂地质体的内在特征。针对现有碎屑沉积体层次结构分级中的不足,按照构型规模及包含关系, 以最大自旋回与最小异旋回为衔接点,采用倒序分级原则,将已有的岩性体构型与层序构型分级整合为一体化的沉积体构 型分级方案,并与我国的沉积相分级体系进行了比较分析。在沉积盆地内划分了12 级构型单元,其中1~6 级单元为层序构型, 7~9 级单元为相构型,10~12 级单元为层理构型。这一方案有利于勘探开发一体化的地下地质研究。油气田勘探阶段构型分 布的研究级别主要为1~4 级,油气田开发阶段构型分布研究的级别主要为5~9 级。我国现有的沉积相分级体系为自成因沉积 体的分级体系,但并非层次结构分级体系,且存在相单元级次不统一的问题。微相单元一般具有层次结构意义,可作为构 型单元,而亚相一般不能作为构型单元。     

赤道式天文望远镜极轴调整分析及观测结果

天文望远镜的指向精度和跟踪精度是评判一架天文望远镜的重要指标。赤道式天文望远镜的指向精度和跟踪精度受到极轴位置准确性的影响。正确地安装好极轴位置显得非常重要。极轴校正是一项很重要的工作。介绍了用观测恒星的方法来校正极轴位置,分析了合理地选择目标恒星,得出结论:在调整极轴东西方向时选择子午圈上的恒星作为观测目标恒星,在调整极轴俯仰方向时选择90°时角圈上的恒星作为观测目标恒星。经过多次调整极轴东西方向和极轴俯仰方向并对两个方向交替进行调整,望远镜的极轴将处于相当准确的位置。     

曲流河储层构型表征研究进展

曲流河储层在我国各大油田占有很大比例,高含水期的剩余油被复杂的储层内部构型所遮档,难以应用常规油藏描述方法进行挖潜.为此,从储层构型的起源开始,分析建立储层构型定性及定量构型模式的研究方法,包括露头和现代沉积、探地雷达、高分辨率地震以及经验公式,并对各种方法和技术的优缺点进行简评.结合曲流河地下储层构型研究的实践,分3...     

Salt-Lake Basin Bedrock Weathered Crust Gas Reservoir in the Altun Mountains Front of the Qaidam Basin,Western China

The bedrock weathered crust in front of the Altun Mountains in the Qaidam Basin, western China, is different from others because this is a salt-lake basin, where saline water fluid infiltrates and is deposited in the overlying strata. A large amount of gypsum infills the bedrock weathered crust, and this has changed the pore structure. Using core observation, polarized light microscopy, electron probe, physical property analysis and field emission scanning electron microscopy experiments, the ch...     

基于GeoSurf建立绿色食品交易中心网站的可行性研究

因特网地理信息系统与电子商务的结合 ,有其独到的特点。特别是对于绿色食品的电子商务 ,具有一种地域的直观性 ,为客户提供全面完整的产品信息 ,消除客户决策中的不确定性。GeoSurf开发平台为地理空间信息的可视化表示提供了技术基础。综合多学科技术研究成果 ,提出一种新的电子商务网站的开发模式