沿江城市中小型闸控通江湖泊总磷变化特征及成因分析——以安庆市石塘湖为例

长江中下游沿江城郊闸控湖泊普遍面临总磷浓度偏高的现象,解析其总磷时空变化特征及影响驱动机制成为精准治理与修复此类湖泊前亟待解决的关键性问题。本文基于安庆市沿江城郊中小型闸控湖泊--石塘湖实测气象降雨、水文、河湖水质等数据,采用多因子相关性分析、变异系数法和主成分分析的方法,研究各指标因子与湖泊总磷浓度时空变化的响应关系。结果表明:(1)湖泊水质呈现丰(5-8月)、平(3-4月和9-10月)、枯(11-次年2月)水期聚类效果显著,但湖泊空间差异不明显;湖泊水质的季节性变化受总磷浓度变化控制,其他理化指标影响较弱。(2)高强度降雨和汛期闸站调度下的水动力变化决定污染物迁移速率,是导致湖泊总磷浓度在丰水期更容易受入湖河流输入影响而达到峰值的主要驱动因子。(3)高强度人类活动导致入湖河流季节性输入是石塘湖总磷上升的决定性因素,从单位土地利用类型产生单位总磷负荷来看,农业用地远大于城镇建设用地,林地和草地充当污染物进入湖泊的预前“汇”。因此,从治理策略和途径来看,可在控制外源输入的同时,适当调节闸站以减弱丰水期水动力强度,减少入湖河流总磷输入影响的同时,发挥湖泊营养盐的滞留净化能力。本文主要从人类活动导致的外源污染及闸站抽排调度角度分析沿江城郊闸控湖泊石塘湖总磷变化、影响因素及驱动机制,可以为此类城郊中小型沿江闸控型湖泊污染治理提供理论参考。     

Water flow velocity over frozen and nonfrozen black soil slopes

Ice‐ and snow‐melted water flow over partially thawed frozen soil of cultivated slopes causes serious soil erosion, which results in soil degradation and affects productivity in Northeast China. Water flow velocity over frozen and nonfrozen soil shows importance in understanding meltwater erosion. In this work, a series of laboratory experiments were conducted to measure water flow velocity over frozen and nonfrozen soil slopes. Experiments were performed using the electrolyte trace method under the pulse boundary model, under conditions of 4 slope gradients (5°, 10°, 15°, and 20°), 3 flow rates (1, 2, and 4 L/min), and 7 sensors positioned at 0.1, 1.0, 2.0, 3.0, 4.0, 5.0, and 6.0 m away from the electrolyte injection point. Results showed that velocities over frozen soil slopes increased with flow rate and slope gradient. Flow velocities over nonfrozen soil slopes increased with flow rate and slope gradients from 5° to 15° and stabilized at 15°. Flow velocities over frozen soil slopes were 30%, 54%, 71%, and 91% higher than those over nonfrozen ones at slope gradients of 5°, 10°, 15°, and 20°. Flow velocities over frozen soil slopes under different flow rates of 1, 2, and 4 L/min were approximately 52%, 59%, and 79% higher than those over nonfrozen soil, respectively. This study can help in assessing the erosion of partially thawed frozen soil by meltwater flow.     

阳原台石英水平摆倾斜仪数字化改造

2003年10月由张家口中心地震台和中国地震局地球物理研究所地震仪器厂,共同对阳原台SQ-70型石英摆倾斜仪进行了数字化改造。改造后的仪器,经过6个月的运行,目前,该仪器运行良好,产出资料稳定、可靠、精度高。     

利用Argo浮标定位信息估算分析赤道太平洋中层流场状况

本文利用Argo浮标的定位信息,经过较为严格的质量控制与误差估算,得到2003～2005年赤道太平洋区域中层流场信息,并对其进行较为详细的诊断与分析,得到以下几个结论:(1)棉兰老涡、赤道逆流和南赤道流在中层流场中多数时间清晰可辨,北赤道流较弱,有时不易分辨。(2)棉兰老涡、赤道逆流和南赤道流都存在明显的季节变化。一般在2、3月间最弱,8、9月间最强。(3)棉兰老涡、赤道逆流和南赤道流存在较明显的年际变化。(4)赤道逆流通常表现为两支,分别位于东赤道太平洋和西赤道太平洋,东太平洋支主轴位置大约在7～8°N附近,西太平洋支主轴位置大约在3°N附近。     

The distribution of dissolved aluminum in the Yellow and East China Seas

Water samples containing dissolved aluminum were collected from the Yellow and East China Seas in October-November 2000. The average concentrations of dissolved AI in the Yellow Sea （YS） and East China Sea （ECS） were 0.042 and 0.056 μ molL^-1, respectively. The concentration of dissolved aluminum decreased gradually across the continental shelf. The lower concentrations appeared in the YS cold water center and in the bottom layer at the shelf edge of the ECS, where they were 0.016 and 0.011 μmolL^-1, respectively. The distribution of dissolved Al was controlled by physical mixing processes rather than biological uptake processes. The impact of different water masses along the PN transect was calculated based on the mass balance model. The results show that the impact of the Changjiang River was mainly concentrated on the coastal area and the top thermocline water on the ECS shelf, where the impact percentage decreased from 12.6% to 1.1% in the surface water, while the contribution of the Kuroshio water was dominant on the ECS shelf in this survey, increasing from 77.6% to 97,8% along the PN transect from the Changjiang River Estuary to the Ryukyu Islands. It is concluded that aluminum can serve as a proper tracer for studying the impact of Changjiang terrestrial matter on the ECS shelf water.     

大巩山金矿床构造控矿作用分析

大巩山金矿床在大地构造上处于中朝地块东南缘的蚌埠隆起东段,郯庐断裂带的两条次级断裂——朱顶-石门山断裂和五河-红心铺断裂所夹持的部位.矿区内出露五河群最下部的西堆组,并构成蚌埠复背斜的核部,断裂有北北东向、南北向、北西西向和北东向4组.南北向断裂在宏观上控制金矿体的产状和规模.向西缓倾的南北向断裂控制石英脉型金矿体的发育和产出,而向东陡倾的南北向断裂控制构造蚀变岩型金矿体的产出,这是与不同时期南北向断裂成生演化和岩浆活动作用密切相关的,也与该区及邻区成矿年代学研究成果相一致.     

渤海湾盆地新生代各坳陷沉降的时空差异性

渤海湾盆地的成因机制主要与坳陷的构造位置、边界条件及深部因素有关。各坳陷沉降的时空差异性是这种复杂性的一种表现形式。本文通过渤海湾盆地主要坳陷的沉降史和各坳陷沉降差异对比,发现时空差异具体表现在下列3方面。1)在几个主要的裂陷幕构造沉降(或总沉降)均具有越往东部沉降量越大的趋势,如孔店组和沙河街组四段裂陷主要分布在济阳坳陷、昌潍坳陷和大型断裂部位,这与新生代盆地演化的开始阶段有关,并叠加有大型断裂(如郯庐断裂)的左行走滑作用。2)构造沉降量分析表明在经历沙河街组三段沉积期的主裂陷幕后,除了沙河街组一段沉积期沉积中心往西(黄骅坳陷)迁移外,沙河街组一段至东营组沉积期总体表现为随时间向东北部递进渐变式迁移,新近纪又回迁至渤中地区。3)与该区沉降规律相异的是冀中坳陷和临清坳陷(昌潍坳陷因特殊的构造位置除外),表现为在整体沉降过程中局部挤压或抬升反转的沙河街组二段沉积期,这两者的沉降量及沉降速率反而变大,不但比同时期其它坳陷大,亦比坳陷本身的其它裂陷期大。控制各坳陷发育差异间的主要原因,一是有北东东向的新生构造发育,二是有北西西向的变换断层影响。     

西吉—中卫地震测深剖面及其解释

通过对南北向的西吉－中卫宽角反射／折射剖面测探资料的二维处理、计算和解释，研究了中宁、中卫和同心一带弧形构造及两侧的壳幔速度结构和深部构造的基本特征。结果表明，3个区域的壳幔速度结构在纵向和横向上均具有明显的非均匀性，标志壳幔深部构造存在着差异，地壳厚度变化大，弧形构造带中部为一莫霍面隆起（深45．0km)，弧形构造带南北两侧上地壳中存在不同的低速块体。     

围岩质量分级的模糊综合评判研究

岩体本身具有许多不确定性和随机性,围岩质量分级取决于许多因素。选择岩石单轴饱和抗压强度Re、岩体完整程度（RQD）、平均节理裂隙间距d、不连续面状态系数f、结构面方位φ以及地下水状态w六个指标,采用模糊数学方法,引入模糊数学隶属函数的概念,建立边坡岩体质量综合评判模型,并将其应用于黄河上游某电站引水隧洞围岩岩体质量评价。评判结果显示,该模型使用模糊综合评价的评价结果与现场定性判断及报告中RMR分类结果基本一致。