扬子陆块北缘上两地区二长花岗岩成因：锆石U-Pb年代学、Hf同位素及地球化学制约

本文通过对扬子陆块北缘上两地区二长花岗岩年代学、Hf同位素及地球化学研究,限定其形成时代、物质来源以及所处的大地构造环境。LA-ICP-MS锆石U-Pb测年结果表明上两地区二长花岗岩形成于新元古代早期,年龄为909±5Ma。锆石Hf同位素显示二长花岗岩的ε_(Hf)(t)既有正值也有负值,在-6~+3.4之间,变化较大。tDM2变化于1570~2156Ma,平均值为1802Ma,当ε_(Hf)(t)为最小负值-6.0时,tDM2为2156Ma。表明其物源主要是约1800Ma新生地壳的部分熔融,混染了部分古老地壳。地球化学显示,二长花岗岩的SiO_2含量较高,平均值达75.46%,均属亚碱性系列,且均为铝质过饱和(A/CNK=0.93~1.29);轻稀土富集,微量元素原始地幔蛛网图中显示富集大离子亲石元素(LILE)、具有明显的Nb、Ta负异常,并具有与上部陆壳非常相似的蛛网图曲线,在花岗岩的构造环境判别图解中落入弧花岗岩区,其应是扬子陆块北缘大陆边缘弧岩浆的产物。     

东南亚大地构造特征与成矿作用

东南亚地区位于全球特提斯成矿域、环太平洋成矿域与印度-澳大利亚成矿域的交汇地带。构造演化独特,先后经历了原-古-中-新特提斯增生造山、印度-欧亚陆陆碰撞造山、太平洋俯冲等多期次构造-岩浆事件,形成了多条火山弧带、蛇绿混杂带以及同碰撞和后碰撞岩浆岩带。本文在总结前人大地构造研究成果基础上,将东南亚地区划分为6个一级构造单元、32个二级构造单元和57个三级构造单元。伴随着原-古-中-新特提斯构造演化、印度-欧亚大陆碰撞、太平洋俯冲等多期次构造域事件,以构造单元划分为基础,将东南亚地区划分为3个一级成矿域,6个二级成矿省,21个三级成矿带,并结合构造演化初步探讨了主要成矿事件。     

我国西北地区盐湖中的铀234U/238U比值示踪研究

内蒙古二连盆地、鄂尔多斯盆地典型含铀碳酸型盐湖水、岩两相234U/238U综合分析表明,碳酸型盐湖铀来源于大气降水和潜水对盐湖盆地周围中生代到现代富铀沉积物的溶滤、浸出,具有快速、近源物质来源特点。盐湖卤水和对应沉积物234U/238U值一般为0.8～1.2,湖卤水和潜卤水（晶间卤水）-岩两相中的铀处于沉积平衡状态。早白垩世～上新世含膏盐地层对比研究证实了富铀岩层234U/238U值随铀含量增大而减小,并趋近于1。室内盐湖水蒸发模拟实验发现残余卤水、沉积物234U/238U具有随蒸发程度增大逐渐减小的变化特征。盐湖现代沉积物物相研究发现铀主要以碳酸铀酰和吸附形式赋存在富含有机物和碎屑成分的含盐粘土沉积中,铀在盐类晶体中含量极少,仅存在于封闭水和结晶水中。卤水和沉积物ARu值是盐湖铀源及铀含量水平的指示标志之一。     

Advances in Coccolithophore laboratory culture and their application research

This paper summarizes previous studies of coccolithophores laboratory culture with emphasis on the application of cultured coccolithophores in the ecology, paleoceanography and petroleum. Because of the particular biology and physiology characteristics, coccolithophorid bloom can influence marine and atmosphere environment deeply , play an important roal in global carbon cycle and geological evolution. In the aspect of culture, we introduce the cultural method, the influence of cocolithophores growth by setting different environment parameters, the principle of suitable culture meduim depending on different research purpose. In the aspect of application, firstly, this paper discusses the physiological responses of coccolithophorids about ocean acidification. Then, coccolithophorid is high producer of DMSP(dimethylsulphoniopropionate)which can be divides into gas DMS, which can influence marine and atmosphere environment deeply through some chemical course. Further, another important application is the element geochemistry of coccoliths which is very meaningful in paleoceanography and paleoclimatology study. Finally, this paper also discusses the application of coccolithophores hydrocarbon generation to petroleum geology.     

含腐蚀缺陷高强钢厚壁管道压溃压力预测方法

腐蚀是管道常见的缺陷形式之一,会极大降低管道的压溃压力,同时深海环境下高静水外压易引发管道压溃失效,威胁管道的安全运行,因此准确预测管道压溃压力显得尤为重要。采用数值模拟方法研究了含腐蚀缺陷的高强钢厚壁管道压溃失效模式,分析了管材、管道径厚比、腐蚀深度、长度和宽度等参数对高强钢厚壁管道压溃压力的影响规律。分析结果表明:管道径厚比愈大,对厚壁管道的承压能力提升愈显著;腐蚀缺陷的存在对管道压溃压力具有减小作用;随着管道材料等级的提升,压溃压力有明显提高。提出了相应的压溃压力预测公式,为厚壁管道完整性评价提供了参考依据。     

中国乡镇人口分布时空变化及其影响因素

精细尺度的人口变化研究对于理解、模拟和调控人地系统具有重要参考价值,乡镇级的人口数据可以精细化揭示中国人口时空分布的演变特征。本文建立了2010年和2015年中国乡镇人口空间数据库,借助GIS空间分析方法和地理探测器模型揭示了乡镇人口时空变化特征及其影响因素。研究表明：2015年乡镇人口数量均值为2.95万、密度均值为374人/km²,乡镇人口数量和密度分布的区域差异较大;乡镇人口与土地面积分布相较县域呈现更加不均衡特征,人口密度大于150人/km²的19403个乡镇（60.81%）,人口总量占比为81.76%、国土面积占比为20.27%,近似符合“二八定律”;2010—2015年,超过70.94%的乡镇人口数量有所增加（平均增幅19.33%）,9273个乡镇人口减少（平均减幅13.33%）,其中1684个乡镇（5.28%）的减幅超过20%,主要分布在东北、内蒙古和云南的边境地区;人口密度分布受地形起伏等自然地理条件,以及夜间灯光、路网密度所反映的社会经济因素等的综合影响,其作用机制存在明显的空间异质性。研究认为,乡镇人口的大幅增减变化及其显著差异格局对人地系统的优化调控,特别是编制国土空间规划、实施乡村振兴战略和保障国防安全等带来一定挑战,应给予足够重视。     

中波红外几何标定场靶标定制问题研究

分析了物体红外辐射的发射因素和反射因素对红外成像的影响,利用不同材料的红外发射率差异和镜面反射原理,克服普通靶标在中红外波段成像的低对比度问题,考虑靶标的形状、大小,以及包括积分时间、环境温度、光照在内的拍摄条件等因素,设计了靶标定制的技术方案和使用方法。实验证明,采用油毡和锡铂两种材料组合制作靶标效果最好,在适宜的使用条件下,可以获得高对比度的靶标图像,能够满足高精度室外几何标定的需要。     

Rubber plantation and its relationship with topographical factors in the border region of China, Laos and Myanmar

Rubber plantation is the major land use type in Southeast Asia. Monitoring the spa- tial-temporal pattern of rubber plantation is significant for regional land resource development, eco-environmental protection, and maintaining border security. With remote sensing tech- nologies, we analyzed the rubber distribution pattern and spatial-temporal dynamic; with GIS and a newly proposed index of Planted Intensity （PI）, we further quantified the impacts and limits of topographical factors on rubber plantation in the border region of China, Laos and Myanmar （BRCLM） between 1980 and 2010. The results showed that： （1） As the dominant land use type in this border region, the acreage of rubber plantation was 6014 km2 in 2010, accounting for 8.17% of the total area. Viewing from the rubber plantation structure, the ratio of mature- （〉10 year） and young rubber plantation （〈 10 year） was 5：7. （2） From 1980 to 2010, rubber plantation expanded significantly in BRCLM, from 705 km2 to 6014 km2, nearly nine times. The distribution characteristics of rubber plantation varied from concentrated toward dispersed, from border inside to outside, and expanded further in all directions with Jinghong City as the center. （3） Restricted by the topographical factors, more than 4/5 proportion of rubber plantation concentrated in the appropriate elevation gradients between 600 and 1000 m, rarely occurred in elevations beyond 1200 m in BRCLM. Nearly 2/3 of rubber plantation concentrated on slopes of 8~-25~, rarely distributed on slopes above 35~. Rubber plantation was primarily distributed in south and east aspects, relatively few in north and west aspects. Rubber planted intensity displayed the similar distribution trend. （4） Comparative studies of rubber plantation in different countries showed that there was a remarkable increase in area at higher elevations and steeper slopes in China, while there were large appropriate topog- raphical gradients for rubber plantation in Laos and Myanmar which benefited China for rubber trans-boundary expansion. （5） Rubber plantation in BRCLM will definitely expend cross borders of China to the territories of Laos and Myanmar, and the continuous expansion in the border region of China will be inevitable.