Biological risk and pollution history of polycyclic aromatic hydrocarbons (PAHs) in Nansha mangrove,South China

Chinese government has taken various measures to alleviate pollution caused by polycyclic aromatic hydrocarbons (PAHs) in the region of Pearl River Delta since the economic reform in 1978, but the effectiveness of these measures remains largely unknown. This study aimed to elucidate the biological risk and pollution history of PAHs by measuring the concentrations of 28 PAHs in the surface and core sediments, respectively, in Nansha mangrove. Results found that the biological risk of PAHs was low without obvious spatial variation. The PAH concentration along the depth gradient indicated that PAH pollution was stabilized since the early 1990s while the source of PAHs has gradually changed from combustion of coal to petroleum products. This implied that the mitigation measures taken by the Chinese government were effective. Compared to marine bottom sediment, we propose that using mangrove sediment can provide a more accurate and precise estimate of pollution history of PAHs.     

Runoff forecast of drainage basin based on matter element analysis

Runoff from drainage basins is a nonlinear process subject to the comprehensive influences of various factors, such as rainfall characteristics and underlying surface conditions. Matter element analysis is endowed with forecast function by using prior forecast factors. By repeatedly adjusting the grade division value (classical domain and joint domain) of each factor, the fitting rate of the calculation grade of the drainage basin to the actual grade is maximized, which results in more accurate results. The results demonstrate that this technique is a new and effective method of forecasting runoff in drainage basins.     

2014 年云南盈江Ms 6.1 地震震源机制研究

利用中国数字地震台网记录的区域宽频带波形,通过频率域和时间域多步反演,研究了2014年云南盈江Ms6.1地震基于点源模型的震源机制解和有限断层模型.考虑到使用不同的波形资料类型和简化的一维速度模型等因素对震源参数反演结果的影响,进行了大量的测试比较.结果表明,使用近震波形和本区域简化一维速度模型M1,波形拟合误差最小.基于点源模型的震源机制解显示此次地震发震断层面参数分别为:走向176°/倾角84°/滑动角-173°,表现为一次右旋走滑错动为主的事件.矩心在水平方向上位于震中(24.99°N,97.84.E)北东向约7km,最佳波形拟合矩心深度7km.平均总标量地震矩M0为7.56×1017N·m,计算成矩震级为Mw5.8.进一步模拟高达0.5Hz的高频波形,获得了盈江地震的有限断层模型,结果显示此次地震未表现出明显的破裂方向性.破裂半径约10km,整个破裂面积为267.2km2,平均滑动量约0.05m,破裂在5 s内释放了大多数能量.震后0～2s内,破裂以孕震点为中心向四周同时扩展,在深度7～ 17km内释放了部分能量.2s后,破裂朝断层面顶部和沿走向两侧进一步延伸,约5s后破裂基本停止.     

A hybrid inversion method of damped least squares with simulated annealing used for Rayleigh wave dispersion curve inversion

Surface wave methods are becoming increasingly popular in many geotechnical applications and in earthquake seismology due to their noninvasive characteristics.Inverse surface wave dispersion curves are a crucial step in most surface wave methods.Many inversion methods have been applied to surface wave dispersion curve inversion,including linearized inversion and nonlinearized inversion methods.In this study,a hybrid inversion method of Damped Least Squares(DLS) with Very Fast Simulated Annealing(VFSA) is developed for multi-mode Rayleigh wave dispersion curve inversion.Both synthetic and in situ fi eld data were used to verify the validity of the proposed method.The results show that the proposed method is superior to the conventional VFSA method in aiming at global minimum,especially when parameter searching space is adjacent to real values of the parameters.The advantage of the new method is that it retains both the merits of VFSA for global search and DLS for local search.At high temperatures,the global search dominates the runs,while at a low temperatures,the local search dominates the runs.Thus,at low temperatures,the proposed method can almost directly approach the actual model.     

松辽盆地梨树断陷页岩气资源潜力评价

松辽盆地梨树断陷纵向上发育白垩系沙河子组和营城组两套主力泥页岩烃源岩层系,其沉积环境有利、厚度大、分布广。沙河子组以Ⅱ段页岩气地质条件最好,其w(TOC)分布范围为0.11%~8.20%(平均值1.45%);营城组发育两段优质泥页岩,Ⅰ段w(TOC)为0.26%~12.01%(平均值1.96%),Ⅱ段w(TOC)为0.06%~5.03%(平均值1.06%)。有机质类型以Ⅱ₁-Ⅲ型为主,含少量I型。沙河子组R_o普遍较高,断陷西部基本进入过成熟阶段,缓坡带处于成熟-高成熟阶段。营城组R_o变化范围较大,小城子、孤家子和十屋地区R_o达到2.00%以上。两套泥页岩脆性矿物体积分数为32.10%~62.90%,具有较好的储集性能。断陷内有多口探井在沙河子组和营城组的厚层泥页岩段钻遇高气测显示。营城组I段泥页岩含气量为0.62~3.09 m³/t。采用概率法初步预测出沙河子组和营城组页岩气资源量为6 645.34× 10⁸ m³。秦家屯地区和苏家屯次洼为页岩气勘探的有利目标区,桑树台深洼带为较有利目标区。     

论经典平差模型的几何统一

为了更直观、深入地理解参数平差与条件平差的本质区别并找出它们的内在联系,在参数平差、条件平差、具有参数的条件平差、附有限制条件的条件平差和具有条件的参数平差模型中引入线性泛函,构建其统一的几何模型,从几何角度统一经典平差模型.     

iGPS测量原理及其精度分析

iGPS测量技术采用类似于GPS的空间定位原理,通过测量两台以上发射器发射的红外激光信号,解算得到接收传感器的空间三维坐标。在分析iGPS角度测量原理的基础上,进一步分析iGPS的系统平差原理和在线控制程序开发技术,最后分析iGPS的测量精度及其应用,提出完全测量空间概念。     

基于城镇二维地籍数据快速构建城市三维模型研究

对城镇大比例数据进行归类,提取适合三维建模的点、线、面要素,然后对要素进行重新组织,利用Arc Scene,依据三维表达的要求,对地形背景建立DEM并与DOM叠加处理,界址点、控制点等点状地物建立三维独立地物符号库,一般建筑物按高度进行拉伸,而对标志性建筑物采用三维建模软件按二维轮廓进行精细模型制作。利用2D GIS中城镇地籍数据信息建立城市三维模型方法可行有效,有利于推进三维地籍的发展。     

甘肃西秦岭北麓与青海共和盆地干热岩赋存条件的对比分析

发展新能源和建立清洁能源大基地是甘肃省“十三五”规划纲要中的“六大支柱”之一。笔者在广泛收集分析青海干热岩已有勘探资料及研究成果的基础上,结合甘肃西秦岭北麓地热异常（温泉、地热井）有限的勘探测试数据,分析研究了甘肃西秦岭北麓和青海共和盆地所处的区域地质构造背景,从干热岩形成条件和热储赋存特征两个方面进行了对比分析。研究认为甘肃西秦岭北麓与青海共和盆地具有相同的地质构造背景;西秦岭北麓规模较大的酸性岩体大部分直接裸露地表,属开启式地热田类型,岩浆岩侵入时代相对较早;岩体中放射性元素U、Th、K含量及放射性生热率略低于青海共和盆地;地层增温率6. 0℃／100 m左右,温度随深度基本上呈现线性增加,表现出以热传导为主的热源特征,推测在甘肃西秦岭北麓4 000 ～ 5 000 m深度热储温度可达180℃ ～ 200℃以上,具备干热岩赋存条件。     

河北丰宁撒岱沟门钼矿床成岩成矿年代学及成矿岩体地球化学特征

撒岱沟门钼矿床是位于华北克拉通北缘的一个大型斑岩型钼矿床。前人获得的成矿岩体的年龄与成矿年龄差别较大, 为此本研究对矿区内不同特征的花岗岩开展了锆石U-Pb测年和与辉钼矿伴生的白云母40Ar/39Ar测年, 并对这些岩石开展了岩石地球化学和Sr-Nd-Hf同位素地球化学测试, 以及成矿岩体磷灰石EPMA主量元素成分测试, 旨在进一步厘定成矿岩体, 以便加深对成岩成矿演化过程的认识。结果表明: 撒岱沟门钼矿白云母40Ar/39Ar坪年龄为(237±2) Ma, 与赋矿白色黑云母二长花岗岩锆石U-Pb年龄(240±1) Ma和前人获得的辉钼矿Re-Os年龄在误差范围内一致, 成岩成矿作用发生在中三叠世, 而赋矿的另外一种岩体, 即红色黑云母二长花岗岩的年龄为(248±1) Ma, 说明其是成矿前的侵入体。赋矿红色和白色黑云母二长花岗岩均为高硅、富碱、富钾的I型花岗岩, 属于准铝质到弱过铝质、高钾钙碱性至钾玄岩系列, 并在Sr-Nd-Hf同位素组成上显示同源特征, 表明其主要来源于古元古代壳源物质的部分熔融, 与华北克拉通2.3~1.9 Ga的构造演化密切相关。成矿岩体中的岩浆磷灰石具高F、低Cl特征, 反映F在撒岱沟门钼矿的形成过程中扮演了重要角色。