一次特大暴雨的观测与数值模拟分析

采用美国环境预报中心(NCEP)提供的全球最终分析格点资料和地球环境静止卫星资料对2006年7月27日威海地区暴雨成因进行了观测分析。发现0605号台风格美东侧和副高西侧的急流携带大量水汽的暖湿空气,与西北小槽前的干冷空气在山东半岛上空交汇,引发了该地区的特大暴雨。分析表明水汽输送对该暴雨的形成起着重要的作用。采用区域大气模式(RAMS)对该降水过程进行了数值模拟,模拟结果合理地反映了降水范围和降水量。模拟结果表明,山东半岛附近强烈的辐合上升运动为暴雨的爆发提供了直接的动力学条件。     

一个新的矿物面扫描分析方法开发和地质学应用

LA-ICP-MS面扫描分析近些年来发展的新兴技术,相对于其他面扫描仪器,其具有样品制样流程简单、仪器购置和分析成本低、分析时间短、检测限低、多元素表面分析(5μm)、近乎无损等分析优势,在地球科学和生物学领域有着大量的应用。本文系统介绍了作者应用Photon Machines激光剥蚀系统与安捷伦ICP-MS新开发矿物元素面扫描分析方法。该方法基于近些年来开发的双室样品仓技术和Matlab软件,通过自主开发的LaIcpMsSoftware(LIMS)进行数据处理来完成的。本次研究开发的激光面扫描分析技术可以在短时间内(2小时)分析3mm×3mm区域,并同时给出多组元素(包括稀土元素等)在二维平面的分布特征。论文详细描述了LIMS工作原理和特点,相对于国外同类型软件,LIMS具有操作简单,并具有多种数据显示模式和剖面切割展示,元素比值面分布分析等优势,便于后期数据分析与解译。同时,还展示了对斜长石、白钨矿和石榴子石进行面扫描分析的初步结果。研究表明,通过LA-ICP-MS面扫描,可以获得比点分析更为准确的元素分布特征,并能够更为直观的展示不同元素在矿物分布特征和相关关系,更好的开展矿物地球化学研究。     

山东夏季空中水汽分布和水汽输送特征

利用山东省气象站的降水量资料和JRA-55、NCEP/NCAR再分析资料,分析了1962-2016年山东夏季整层大气可降水量、降水转化率、水汽通量及输送路径的分布特征和变化规律,探讨了夏季降水与水汽通量及其散度的相关性和多雨年的水汽来源。结果表明:从常年值来看,山东平均夏季降水量为401.2 mm,大气可降水量为3478.8 mm,降水转化率为11.5%。降水转化率和降水量的时空演变特征更加一致,经向水汽输送和局地水汽通量散度与地面有效降水的关系更加密切,当大气可降水量充沛、外部水汽输送充足并出现局地水汽辐合时,更加有利于山东南部地区降水的发生发展,从而形成夏季降水量和降水转化率气候特征表现出东南地区大于西北地区的空间分布型态。西北太平洋、南海、孟加拉湾和鄂霍茨克海至日本海是造成山东夏季降水异常偏多的重要水汽源地,巴尔喀什湖至贝加尔湖地区是重要的冷空气输送区域;当山东上游盛行偏西风时,自新疆和青藏高原至内蒙古的狭长带出现异常水汽扰动并发展,是由水汽异常引起的水汽通量异常对山东局地降水异常贡献的主要条件。     

深度语义分割支撑下的尾矿库风险检测

尾矿库是矿山企业选矿的必要设施,同时对周围环境也是一个重大的危险源.为研究流域范围内尾矿库的溃坝路径以及对矿区地表造成的风险,以赤城县为例,利用GF-1高分辨率遥感影像,基于遥感RS(Remote Sensing)及地理信息系统GIS(Geographic Information System)手段对尾矿库的流域风险进...     

Groundwater pollution containing ammonium,iron and manganese in a riverbank filtration system: Effects of dynamic geochemical conditions and microbial responses

Bench-scale experiments were conducted to investigate the effect of hydraulic loadings and influent concentration on the migration and biotransformation behaviour of three groundwater pollutants: ammonium (NH₄⁺), iron (Fe²⁺) and manganese (Mn²⁺). Columns packed with aquifer media collected from a riverbank filtration (RBF) site in Harbin City, NE China were introduced synthetic groundwater (SGW) or real groundwater (RGW) were at two different constant flow rates and initial contaminant concentrations to determine the impact of system conditions on the fate of the target pollutants biotransformation. The results showed that the biotransformation rate of Fe²⁺ Mn²⁺ and NH₄⁺ decreased by 8%, 39% and 15% under high flow rate (50 L d⁻¹) compared to low flow rate (25 L d⁻¹), which was consistent with the residence-time effect. While the biotransformation rate of Fe²⁺ Mn²⁺ and NH₄⁺ decreased by 7%, 14% and 9% under high influent concentration comparing with original groundwater. The 16S rRNA analysis of the aquifer media at different depths after experiments completion demonstrated that the relative abundance of major functional microbes iron-oxidizing bacteria and manganese-oxidizing bacteria under higher flow rate and higher influent concentration decreased 13%, 14% and 25%, 24%, respectively, whereas the ammonium-oxidizing bacteria and nitrite-oxidizing bacteria exhibited minimal change, compared to the lower flow rate. Above all results indicated that both high flow rate and high concentration inhibit the biotransformation of NH₄⁺, Fe²⁺ and Mn²⁺. The biotransformation of Fe²⁺ and Mn²⁺ occurs primarily in the 0–40 cm and 20–60 cm depth intervals, respectively, whereas the NH₄⁺ biotransformation appears to occur relatively uniformly throughout the whole 110 cm column. The biotransformation kinetics of NH₄⁺ in RGW and SGW, Mn²⁺ in RGW at different depths accords with the first order kinetics model, while Fe²⁺ in RGW and SGW, Mn²⁺ in SGW presented more complicated biotransformation process. The results should improve understanding of the transport and fate of common groundwater pollutants in RBF and other groundwater recharge environments.     

耕地保护主体的行为方式及其特征分析

耕地保护主体具有基于逐利驱动下的理性思考,从而直接影响耕地保护的效果。在耕地保护行为过程中,地方政府掌握耕地的实际支配权,主导耕地的规划布局,而农民对待耕地保护的积极性则受经济利益的影响较大。现行制度框架下,耕地保护政策具有"委托-代理"关系、政策公平偏好、信息不对称、投入产出不对等、多方面利益干扰等特征。转型时期耕地保护与经济建设之间的矛盾容易凸显,应理性地正视耕地一定程度上的减少,但耕地保护的力度不容放松,需加强制度建设和耕地管理方式的创新,深化国家土地管理宏观调控。     

山地城市道路景观设计手法解析

阐述了山地城市关于护坡、商业街道的几种设计手法。     

国际行业温室气体减排方法最新进展评述

由于《巴厘行动计划》中明确提出"合作的行业方法"以及发达国家的积极推动,所谓国际行业减排方法正受到越来越多的关注。在对此类方法的定义、分类和提出背景进行简要介绍的基础上,总结了该类方法的最新进展和发展动向。最后对近期发展的特点进行了归纳与评述,指出了发展中国家尤其是我国在国家和行业发展层面所面临的挑战和亟待解决的问题。     

Is atmospheric carbon dioxide removal a game changer for climate change mitigation?

The ability to directly remove carbon dioxide from the atmosphere allows the decoupling of emissions and emissions control in space and time. We ask the question whether this unique feature of carbon dioxide removal technologies fundamentally alters the dynamics of climate mitigation pathways. The analysis is performed in the coupled energy-economy-climate model ReMIND using the bioenergy with CCS route as an application of CDR technology. BECCS is arguably the least cost CDR option if biomass availability is not a strongly limiting factor. We compare mitigation pathways with and without BECCS to explore the impact of CDR technologies on the mitigation portfolio. Effects are most pronounced for stringent climate policies where BECCS is a key technology for the effectiveness of carbon pricing policies. The decoupling of emissions and emissions control allows prolonging the use of fossil fuels in sectors that are difficult to decarbonize, particularly in the transport sector. It also balances the distribution of mitigation costs across future generations. CDR is not a silver bullet technology. The largest part of emissions reductions continues to be provided by direct mitigation measures at the emissions source. The value of CDR lies in its flexibility to alleviate the most costly constraints on mitigating emissions.