高质量矿床的勘查战略

邮我国矿产勘查应以高质量矿床作为目标矿床的战略;认为勘查高质量矿床需要加强矿床模式的研究和ＧＩＳ技术的推广应用;确保高质量矿床战略成功实施的思路包括：（１）以高质量金矿床作为勘查目标;（２）加强对典型高质量矿床的研究,寻找同类型高质量矿床;（３）从构造环境发展演化的机理进行成矿分析,制定高质量矿床勘查战略;（４）打破地域限制,促进勘查队伍之间的竞争机制。     

太湖梅梁湾藻类生态模拟与蓝藻水华治理对策分析

根据目前对太湖梅梁湖生态环境的认知,建立该湖区藻类生态动力学模型进行生态模拟,基于模拟结果对太湖富营养化中最严重的蓝藻水华治理与污染物排放控制和清淤工程进行了分析。结果显示;太湖污染物排放达标将极大改善富营养水平;但应结合经济分析和效益分析,通过组合各类污染物控制总量来达到最优治理效果,模拟分析表明,单一清淤工程对于富营养化中蓝藻水华治理意义有限。     

中国湖泊现状及面临的重大问题与保护策略

我国湖泊数量多、类型全、分布广,湖泊的形成演化不仅受流域自然环境因素及变化的影响,而且还深受人类活动的干扰,呈现出不同的区域演变特征和生态环境问题.近几十年来,我国湖泊数量、面积和分布都发生了较为显著的变化,并面临着湖泊萎缩与调蓄能力减少、水质下降与富营养化加重、生物多样性减少与生态退化、河湖水力和生态联系阻隔以及湖岸线和环湖地带过度开发等问题,引发一系列生态与环境后果,严重影响流域居民日常生活和经济的可持续发展.本文通过大量湖泊野外考察和调查,查清了我国面积大于1km2湖泊的数量、面积和分布状况,结合历史湖泊调查和相关研究资料,系统分析了近几十年我国湖泊面临的重大生态环境问题及区域特征,提出了我国湖泊保护的策略.     

基于局部采样MCMC方法的时移探地雷达反演

马尔科夫链蒙特卡洛方法(MCMC)是一种启发式的全局寻优算法,可以用来解决概率反演的问题.基于MCMC方法的反演不依赖于准确的初始模型,可以引入任意复杂的先验信息,通过对先验概率密度函数的采样来获得大量的后验概率分布样本,在寻找最优解的过程中可以跳出局部最优得到全局最优解.MCMC方法由于计算量巨大,应用难度较高,在地...     

Source-independent wave-equation based microseismic source location using traveltime inversion

A new source location method using wave-equation based traveltime inversion is proposed to locate microseismic events accurately. With a sourceindependent strategy, microseismic events can be located independently regardless of the accuracy of the source signature and the origin time. The traveltime-residuals-based misfit function has robust performance when the velocity model is inaccurate. The new Fréchet derivatives of the misfit function with respect to source location are derived directly based on the acoustic wave equation, accounting for the influence of geometrical perturbation and spatial velocity variation. Unlike the mostly used traveltime inversion methods, no traveltime picking or ray tracing is needed.Additionally, the improved scattering-integral method is applied to reduce the computational cost. Numerical tests show the validity of the proposed method.     

国产海底地震仪的时间记录与原始数据精细校正

海底地震仪(OBS)的时间记录对数据处理是至关重要的.实践发现,部分国产便携式OBS的数据记录存在较大的内部时间误差,并且实测地震剖面异常的同相轴"断阶"、"倾斜"现象时有发生.我们通过自激自收试验,对这些异常现象进行了验证,确认其来源于OBS数据文件内部时间漂移,以及数据处理程序存在的缺陷.统计表明,A、B型OBS内部时间漂移量在250Hz的预设采样率下为0～40ms,L、S型OBS在100Hz下为0～90ms.这个量级的时间漂移,会对OBS数据处理、计算模拟产生影响.进一步,我们采用计算实际采样间隔、调整采样间隔、数据重采样的方法,对这种误差进行校正,并且改进了相关的OBS数据处理程序.本文的研究加深了对OBS数据时间记录误差的认识,得到了OBS数据文件内部时间漂移的分布规律,使得中等及较大程度的内部时间漂移的精细校正得到重视,进而完善了OBS数据处理步骤和流程,对OBS数据的有效利用进行了重要补充,为国产OBS的广泛使用、仪器研发提供了重要参考.     

青海省东北部地区中晚全新世人类对动物资源的获取与利用——以青海湖盆地尖嘴遗址为例

青海省东北部地区复杂多样的地貌类型,为研究史前人类适应不同自然环境下的动物资源利用提供了条件.然而,已开展的动物考古研究主要聚焦在青海省东北部的河谷农业区,对于草原地带的研究相对薄弱,其先民对草原环境中的适应策略仍未得到充分讨论.本文选择农牧过渡带的青海湖盆地尖嘴遗址出土动物骨骼为研究对象,运用AMS 14C测年方法、动物种属鉴定和可鉴定标本数(NISP)统计,确认尖嘴遗址(3.2 ka B.P.左右)是一处卡约文化早期的人类活动遗迹,其先民以狩猎活动为主要生业策略,渔猎作为辅助生计,属"初级开发型"模式.在此基础上,结合青海省东北部地区已有动物研究资料,探讨了中晚全新世(8.0~2.0 ka B.P.)以来的动物资源获取利用及家畜饲养状态.结果显示:8.0~6.0 ka B.P.,本区先民以纯粹的狩猎经济为主,其猎取对象则为中小型哺乳动物,属"依赖型"生业模式;6.0~4.0 ka B.P.,本区先民获取动物资源方式仍以狩猎为主,并开始出现一定规模的家畜饲养(猪和狗),其生业属低水平的食物生产阶段,获取肉食资源的模式处于"初级开发型"阶段;4.0~2.0 ka B.P.,史前东西方文化交流的不断增强,驯化于西亚的家畜牲畜牛羊传入至青海省东北部地区,使得该区先民利用动物资源方式呈现多元化,构成了"初级开发型"和"开发型"两种生业模式,牛羊成为家畜饲养的主流.总体来讲,中晚全新世以来青海省东北部地区先民获取肉食资源的方式大致经历了由以狩猎-采集方式到家畜饲养方式的历时性转变,不同区域的自然环境差异及史前欧亚大陆东西方文化间的交流是起决定性作用的因素.     

地震台站采购困境与应对策略 ——以内蒙古自治区地震局所属台站为例

针对内蒙古自治区地震局所属台站在采购中存在的问题,以乌加河地震台、宝昌地震台在采购中存在的问题为研究对象,利用相关政策法规,结合近几年工作经验,提出几条合理建议,以便解决内蒙古自治区地震局所辖台站采购中存在的问题。     

Characteristics of Vegetation Carbon,Nitrogen, and C/N Ratio in a Tamarix chinensis Coastal Wetland of China

Variations in carbon (C) and nitrogen (N) of the vegetation in a Tamarix chinensis coastal wetland located in Laizhou Bay, China, are analyzed. It is found that T. chinensis accumulates more C and N than the surrounding herbs, and it allocates more C and N in the aboveground parts but less in the roots. Branches store more C, whereas leaves and flowers accumulate more N than other tissues. The C and N contents in the aboveground parts of T. chinensis are mainly influenced by pH, electrical conductivity (EC), water content, and clay content in the top 100 cm of soil as well as the distance from the sea. For the herbs, their C contents vary little in the supratidal zone, but they are higher than those in the intertidal zone. However, N contents in the herbs are higher in the aboveground parts and varied among different communities. The contents of C and N in the herbs are affected by EC, water content as well as the contents of organic C and total nitrogen (TN) in the top 10 cm of soil. The findings confirm that increasing the biomass of T. chinensis is an effective way to increase C sequestration in temperate coastal wetland.     

Subsistence strategies of prehistoric hunter-gatherers on the Tibetan Plateau during the Last Deglaciation

The study of prehistoric hunter-gatherer subsistence strategies on the Tibetan Plateau is important for understanding the mechanisms and processes of human adaption to high altitude environments.But to date,only a few Paleolithic sites have been found on the Tibetan Plateau with clear stratigraphy and reliable dating.These sites are mainly distributed in the Qinghai Lake Basin on the northeastern part of the plateau,and the sporadic fauna and flora remains excavated provide limited information about the subsistence strategies of hunter-gatherers.In 2014,relatively abundant animal remains were unearthed in the Lower Cultural Layer (LCL,15400-13100 cal yr BP) of the"151 site"located in the Qinghai Lake Basin,providing important information about human subsistence strategies on the Tibetan Plateau during the Last Deglaciation.Zooarchaeological analysis of these faunal remains indicates that hunter-gatherers at the"151 site"mainly targeted large ungulates of Bos and wild horse/ass,and only brought back the most nutritious parts of animal carcasses including upper and intermediate limb bones,heads,and trunks (ribs and vertebrae).People then processed and consumed the carcasses around single hearths.Our comprehensive analyses of contemporaneous sites in the Qinghai Lake Basin show that a subsistence strategy involving opportunistic hunting of ungulates,high mobility,and short occupation of campsites was used by terminal Pleistocene huntergatherers to adapt to the high-altitude environment on the Tibetan Plateau.This subsistence strategy may have been a first step of gradual hunter-gatherer adaptation to the extreme conditions on the Tibetan Plateau after the Last Glacial Maximum,and laid the foundation for the widespread distribution of hunter-gatherers on the plateau during the Holocene.