地球物理学及地球动力学研究与计算数学

地球物理学是20世纪,特别是在其中叶以后迅速发展起来的一门边缘科学.它以物理学、数学和信息科学为依托,并与地质学、地球化学密切结合;以研究和探索地球内部介质的属性、结构变异和深部物质与能量的交换、深层过程和动力学响应.这在促进社会与经济的发展和科学与技术的进步中占有重要地位,因为大量资源的需求和自然灾害的防范在人类生活和生存空间以及可持续发展中乃核心所在.在研究和探索这一系列的地球科学问题的进程中,首先必须通过地表进行高精度的地球物理探测、观测和高分辨率的数据采集,进而利用不同的数学方法反演计算地球内部介质的精细结构和其物理—力学过程与动力学响应.基于此,本文主要讨论了：1）地球物理学和地球动力学的发展趋势及特点;2）地球物理学的发展对计算数学的需求;3）地球动力学和数值模拟与计算地球物理学.最后对这些问题和基本导向进行了讨论.     

中国大陆典型沉降区垂直形变图数据集

2015—2019年,由中国地震局第一监测中心牵头,自然资源部大地测量数据处理中心和武汉大学等单位共同完成科技部科技基础性工作重点专项,系统拯救、整编共享20世纪50年代以来全国垂直形变测量数据,编制不同时空尺度的地壳垂直形变图,为强震中长期预测、地壳动力学研究、地形变灾害研究与防控及相关的国民经济建设服务。本数据集内容为中国大陆典型沉降区垂直形变图,展示特定沉降区的地表垂直形变分布,为制定地面沉降防控措施提供依据。本文对数据集的数据采集和处理情况、数据要素项和时空范围、数据输出质量和准确度,以及数据的应用前景进行了介绍。     

新型冠状病毒肺炎胸部CT影像学特征及检查优选策略初探

目的:通过对6例已确诊新型冠状病毒肺炎(COVI-19)患者的确诊过程以及当前疫情防控进行分析和思考,增强民众和医院对新型冠状病毒肺炎和突发公共卫生事件的认识和防控能力;方法:对患者的流行病学史、既往病史、本次疾病诊治过程进行详细调查和记录,查阅相关文献资料,调查疫情对个人及公共卫生的影响。结果:患者经实验室检查、胸部CT检查及咽拭子核酸检查,确诊为新型冠状病毒肺炎,及时对患者进行隔离治疗,多名接触医务人员进行隔离观察。结论:此次疫情发病急、流行快,人群普遍易感;从个人、医院及公共卫生多个方面均应提高对疫情的认识,加强防控措施,保障公共卫生安全。      

The Kings River Experimental Watersheds: Infrastructure and data

The Kings River Experimental Watersheds (KREW) were established in 2002 to expand our knowledge of catchment physical, chemical, and biological processes in Sierra Nevada headwater forests, and to better understand the impacts of prescribed burning and forest thinning on these processes. Two elevation strata (high and low) were selected for the KREW sites, with four independent catchments and one nested catchment within each stratum. Both high and low elevation study areas were instrumented for continuous measurements of meteorology, streamflow, and turbidity. Atmospheric and stream chemistry, suspended sediment concentration, and bedload sediment delivery were measured on a regular schedule. Soil chemical and physical properties and vegetation were systematically sampled before and after the initial thinning and prescribed burning treatments, which were implemented between 2012 and 2016. Post-treatment data collection continues today as we explore opportunities for the second round of possible treatments. The critical research infrastructure and long-term baseline data collection has been instrumental in building partnerships with downstream managers, end users, non-governmental organizations, academic researchers, and national research programmes. Contributions to date include fundamental understanding of magnitude and variability of nutrient deposition; carbon, nutrient, and major ion dynamics in headwater streams; aquatic algae and macroinvertebrate populations; vegetation composition and structure; and streamflow responses to precipitation in the two elevation strata. Data from the experimental watersheds also support calibration and validation of diverse hydrologic models used for water resources planning.     

Accidental spills at sea - Risk, impact, mitigation and the need for co-ordinated post-incident monitoring

A fully integrated and effective response to an oil or chemical spill at sea must include a well planned and executed post-incident assessment of environmental contamination and damage. While salvage, rescue and clean-up operations are generally well considered, including reviews and exercises, the expertise, resources, networks and logistical planning required to achieve prompt and effective post-spill impact assessment and monitoring are not generally well established.The arrangement and co-ordination of post-incident monitoring and impact assessment need to consider sampling design, biological effects, chemical analysis and collection/interpretation of expert local knowledge. This paper discusses the risks, impacts and mitigation options associated with accidental spills and considers the importance of pre-considered impact assessment and monitoring programmes in the wider response cycle. The PREMIAM (Pollution Response in Emergencies: Marine Impact Assessment and Monitoring; www.premiam.org) project is considered as an example of an improved approach to the planning, co-ordination and conduct of post-incident monitoring.     

川滇地区井水位潮汐响应特性分析

利用Baytap-G潮汐分析软件对川滇地区12口观测井数字化水位的长时序数据进行计算, 提取井水位潮汐响应特征参数(振幅比和相位差), 分析其形态、 阶段变化等特征, 探讨地震前后井水位潮汐响应特征参数的变化情况, 为深入分析井水位与固体潮、 气压之间响应关系的研究提供新的方法和途径。 结果表明, 泸沽湖井等10口受固体潮影响的井水位振幅比和相位差变化相对稳定; 而南溪井和大姚井受到气压-固体潮综合作用影响的井水位振幅比和相位差变化则比较离散。 其中江油川10井、 泸沽湖井、 东川井等3口井水位振幅比和相位差对大震的响应显著, 并给出了地震能量密度与这三口井水位M₂波相位差和振幅比的变化关系。     

Assuring fish safety and quality in international fish trade

International trade in fishery commodities reached US 58.2 billion dollars in 2002, a 5% improvement relative to 2000 and a 45% increase over 1992 levels. Within this global trade, developing countries registered a net trade surplus of US 17.4 billion dollars in 2002 and accounted for almost 50% by value and 55% of fish exports by volume. This globalization of fish trade, coupled with technological developments in food production, handling, processing and distribution, and the increasing awareness and demand of consumers for safe and high quality food have put food safety and quality assurance high in public awareness and a priority for many governments. Consequently, many countries have tightened food safety controls, imposing additional costs and requirements on imports. As early as 1980, there was an international drive towards adopting preventative HACCP-based safety and quality systems. More recently, there has been a growing awareness of the importance of an integrated, multidisciplinary approach to food safety and quality throughout the entire food chain. Implementation of this approach requires an enabling policy and regulatory environment at national and international levels with clearly defined rules and standards, establishment of appropriate food control systems and programmes at national and local levels, and provision of appropriate training and capacity building. This paper discusses the international framework for fish safety and quality, with particular emphasis on the United Nation's Food and Agricultural Organization's (FAO) strategy to promote international harmonization and capacity building.     

中国空间天气研究进展

空间天气指太阳、行星际空间和地球空间(地球磁层、电离层、热层和中高层大气)的状态及其变化,它能够影响到天基和地基技术系统的运行和可靠性,危及人类的生存.空间天气计划包括观测和资料分析,研究和数值建模,预报和服务.本文评述了近十年来我国空间天气研究中的一些重要成果.     

Equipment for the studies of the acoustic properties of hydrate-containing samples in laboratory conditions

Equipment for simulation in laboratory conditions of hydrate-containing artificial samples and measuring their acoustic properties (wave velocities, absorption and attenuation) at different temperature and pressures is designed and constructed. The plant consists of a high-pressure chamber (up to 45 MPa), a measuring system intended for the excitation and reception of acoustic waves, systems for temperature and pressure control (axial and lateral) and for gas/liquid delivery into the sample. The measurements are performed on cylindrical samples with a 30-mm diameter and height of 10–50 mm. A set of successful test experiments was performed, including measurements of acoustic velocities of consolidated (plexiglas, sandstone, and frozen sand) and unconsolidated (dry and wet quartz sand) samples and formation of methane-hydrate bearing samples.     

基于波前面三角形网格剖分的波前重建法三维射线追踪

在许多地震反演和偏移成像方法中,都要涉及到射线路径和旅行时的计算.本文将波前面三角形网格剖分和三维波前重建法射线追踪技术结合使用,实现了射线路径和旅行时的准确快速计算.三维波前重建法射线追踪过程中可以保证稳定合理的射线密度,克服了常规射线追踪方法存在阴影区的问题.波前面三角形网格剖分在描述和拆分波前面时更加准确有效,而且不需太多的网格数目,从而提高了射线追踪的精度和效率.该方法在三维复杂构造成像方面有独特的优势,目前在实际的Kirchhoff 偏移中的已经有相关应用.     

行包货物实时验放CT智能解决方案

自X射线成像技术应用于安检领域行包货物的查验以来,CT成像技术占据越来越重要的角色和地位。传统安检CT应用模式难以满足海关和民航等交通物流枢纽中心行包货物实时验放的应用需求和公共场所疫情防控要求,查得快、验得准、拦得住的CT智能解决方案得以蓬勃发展,有效提高行包货物的查验效率和旅客的通行效率,有力保障国境安全、人身安全和财产安全,具有巨大的发展潜力和广阔的市场前景。      

Identification, definition and quantification of goods and services provided by marine biodiversity: implications for the ecosystem approach

This paper identifies and defines ecosystem goods and services provided by marine biodiversity. Case studies have been used to provide an insight into the practical issues associated with the assessment of marine ecosystem goods and services at specific locations. The aim of this research was to validate the definitions of goods and services, and to identify knowledge gaps and likely difficulties of quantifying the goods and services. A validated theoretical framework for the assessment of goods and services is detailed, and examples of the goods and services at a variety of case study areas are documented. These results will enable future assessments of marine ecosystem goods and services. It is concluded that the utilisation of this goods and services approach has the capacity to play a fundamental role in the Ecosystem Approach, by enabling the pressures and demands of society, the economy and the environment to be integrated into environmental management.     

与地震有关的水文及地球化学变化

简要回顾了几十年来对地震发生前、地震过程中和震后地下流体和地球化学变化的研究和成果,这些研究一般都是以探索地震预报可能性为目的的。论述了与地震有关的地下水文及地球化学变化的机理,这些地下流体(包括地下水和气体诸如氢、氧和惰性气体)的起源和迁移流动现象以及详细介绍了早期和近代对有关地震的地下流体和地球化学变化的观测成果。同时指出了对地下流体和地球化学作为地震前兆来观测研究的困难所在以及为了克服这些困难而应该采取的地震前兆观测研究的方向,例如多种手段和多种原理方法,开发有效的地球物理和地球化学模型以及适当的数据分析统计方法等。     

天然有机质及其在地表环境中的重要性

天然有机质是地表各种环境介质中的重要化学组分,分布广泛.越来越多的研究已经表明:它在地表生态系统的物理、化学和生物过程中都起着十分重要的作用;它与生态系统的各个重要环节密切相关,是生态系统中能量与物质循环的重要途径.因此,天然有机质不仅是生物地球化学、生态学和环境科学等研究领域的重要内容之一,而且也是环境污染的评价、预测和治理研究中的基础理论问题,是目前环境质量、毒理学、环境立法和管理研究共同关注的科学问题.本文主要以陆地地表淡水湖泊与河流水环境为例,对天然有机质的来源、化学结构、循环特征,与养分循环的耦合关系,对有毒金属元素和有机污染物迁移转化和毒性影响机理等几个方面的研究进展进行了简要的总结;针对我国水体富营养化和环境污染等重要环境问题,阐述当前应该采取的研究思路和存在的主要科学内容,并对现代有机环境与生物地球化学学科的研究趋势进行了展望.     

基于能量密度的自解耦互相关成像条件

基于能量密度构建的弹性波能量成像条件，可以准确提取弹性波场的能量信息，并可以有效压制背向散射.但是该成像条件得到的成像结果将所有弹性波场能量信息耦合在一起，难以区分纯波模式的能量信息.为此，我们从势能及动能两方面将能量场解耦，得到纯纵波（PP）、纯横波（SS）、转换波（C）能量场.根据能量守恒定律，基于Helmholtz原理对位移场的空间导数进行因式分解，将弹性势能自解耦得到纯纵波、纯横波及转换波势能；引入体应力构建得到P波及S波速度，将弹性动能分解为纯纵波、纯横波和转换波动能.从而，构建基于能量密度自解耦得到纯波能量互相关成像条件.数值实验表明自解耦成像条件可实现弹性波场能量的分解，并得到背向散射压制、振幅有效保持的PP波、SS波和C波成像结果.     

地下介质和物流运移的综合成像方案

目的：借鉴描述冷暖气流等多科参数(气压、温度和湿度、风速、风向、水蒸汽密度等)的动态三维显示,初步解决了暴雨和天气预报的难题,促进了天气预报的成功,在地球科学中起到了示范作用。从而联想到在地下介质和物流运移过程的综合成像。资料和方法本文总结了地面和地下探测手段的多样性,列举了天然地震CT的精度已能达到l～5km的量级,地震人工曝破作勘探可以达到10～20米的成像分辨率,地下电阻率和电磁成像可以分辨到l—2米的量级;将磁共振(MRI)用于地下成像可得到地下水分布的动态观测深度,概括了这三方面的前沿性进展,并与震源的空间分布和地应力相结合,进而设计出综合性的观测系统。发展地下水、岩浆、地应力和活断层结构和地震破裂面等多种参数的动态显示,设计出一套观测系统,并阐述言的科学意义。结果和结论：将以上三方面的观测方法综合起来;可在有火山喷发危险的区域,具有诱发地震危险的大型水库地区,和在发生了强烈地震的地区,为了抗震救灾,有必要同时进行以上三个系统的观测,引入可视化数字科技,便于了解地下水和岩浆的过移过程及相关参数的变化,并配合当前已有的综合监测系统（震源空间分布、地震应力和其他前兆等）,服务于保障大型水库的安全、促进强震预测,及对火山喷发、矿井塌陷、突出的监测预报。     

“韧性”的词义解析及其应用

英文“Resilience”和汉语“韧性”这两个词汇被广泛应用在不同的学科领域。在中国的生态学和工程学领域“Resilience”一词常被翻译成“恢复力、弹性、韧性和韧弹性”等,正确的理解和解析英文“Resilience”和汉语“韧性”十分必要。本文主要依据现有英文和汉语辞典、辞书以及相关的中外科技文献,对英文“Resilience”和汉语“韧性”这两个词汇的含义进行全面的词义辨析和清理,认为英文“Resilience”翻译成汉语“韧性”比较合适,符合汉语的词义和语言环境,韧性在一定程度上涵盖了恢复、弹回和弹性的含义;在此基础上,总结和厘定了韧性的起源、定义和内涵;比较全面的梳理和评述了“Resilience”和“韧性”这两个词在不同学科领域的发展和演化。这一研究工作对正确的使用英文“Resilience”和汉语“韧性”有重要意义,对从事韧性城市研究、城市规划、城市抗震韧性研究和建筑抗震韧性研究的科技人员有一定的参考价值。     

装配式钢模块柱-柱和梁-梁组合的框架结构及其抗震性能分析

钢模块装配式框架形成模块柱-柱和梁-梁分离的框架结构,模块之间除了节点连接之外、柱-柱和梁-梁没有连接形成结构整体的柱和梁,模块和模块协同工作并提高结构柱、梁和整体承载与抗震能力的性能没有充分利用和发挥,是这类结构仍需研究和发展的重要方面.本文提出了一种外包钢板柱-柱组合和垫板螺栓连接梁-梁组合的结构形式,并进行了设计...     

浅水湖泊湖沼学与太湖富营养化控制研究

自2007年无锡暴发饮用水危机事件以来,太湖经历了前所未有的高强度、大规模治理,各种治理措施累计投资已经超过千亿元.监测显示,在治理初期太湖的氮、磷浓度下降明显,水质有所好转,但最近几年关键水质指标总磷与浮游植物叶绿素α浓度出现了波动,蓝藻水华有所反弹.研究表明,太湖的外源负荷并没有减少,这与城镇用水量增加、污水排放标准偏低、面源污染削减不足有很大的关系;同时,内源负荷也因为蓝藻水华的持续而加重,浅水湖泊水深浅、扰动强的特点强化了磷的循环利用效率,加剧了内源负荷对湖泊富营养化和蓝藻水华的影响.气候变暖叠加营养盐富集的复合效应、流域风速下降以及暴雨事件频次和强度增加等气象水文条件变化,都促进了太湖蓝藻水华的暴发;蓝藻水华的时空分布特征则受湖泊水动力的决定性影响.太湖治理的曲折过程,凸显了大型浅水湖泊湖沼学研究的不断深入与发展,未来需要继续加强多学科交叉研究,特别是基于湖泊-流域系统的气象水文、生物地球化学和生物生态学的学科交叉.对于太湖生态环境的综合治理和管理,既要注重湖泊与流域相结合,更需要重视自然科学和人文科学的有机融合,才能真正达到控制太湖富营养化、维护流域水环境安全与社会经济可持续发展的目标.