方解石负载羟基磷灰石复合材料去除水中铀离子的PRB活性介质研究

铀污染地下水分布于世界多国,其危害备受关注。本文基于溶胶-凝胶法制备方解石负载羟基磷灰石复合材料(CLHC),通过静态与动态对比试验,探讨了PRB活性介质对水中铀离子的吸附机理和去除效果。试验结果表明,制备的CLHC表面被羟基磷灰石覆盖,对铀离子具有较强的吸附能力。当U的初浓度为5.0 mg/L、试验周期为2 h、溶液pH值为4、CLHC用量为0.5 g/L时,CLHC可以吸附水中所有的铀离子。CLHC对铀离子的吸附过程可以用Langmuir等温吸附模型、粒子内扩散吸附动力学模型和准二级吸附动力学模型较好地进行描述。石英砂负载羟基磷灰石与CLHC相比,后者具有更强的吸附能力,而且具有更长的使用寿命。CLHC在吸附铀的过程中没有价态变化,其对铀离子的吸附主要为离子交换的化学吸附。本研究的成果可为可渗透反应墙被应用于铀污染地下水修复提供试验依据。     

济南市新旧动能转换区浅层地下水硝酸盐污染特征

为查清济南市新旧动能转换先行区浅层地下水NO₃^-污染问题,对研究区7种污染源类型64件浅层地下水样品水质结果进行统计分析后认为:受人类活动影响,地下水中NO₃^-含量的高低往往与几种特定的水化学类型存在对应关系。4类主要污染源类型浅层地下水NO₃^-含量一般顺序为:垃圾渗滤液>禽畜养殖>生活污水>农业种植。垃圾渗滤液下渗导致的NO₃^-污染对应的主要地下水化学类型为HCO₃·Cl^-Na·Mg型,粪便渗滤液及尿液下渗主要对应产生HCO₃·SO₄-Na·Mg型、生活污水入渗对应产生HCO₃·Cl^-Na·Ca型,农业种植区主要对应HCO₃-Na·Ca型。离子相关性分析表明,NO₃^-含量与Ca²⁺、Cl^-存在相关关系。研究区以农业种植为主,大量氮素化肥和石灰等土壤改良剂的使用是导致浅层地下水NO₃^-与Ca²⁺相关的主要因素。NO₃^-与Cl^-在地下水中同属较稳定离子,由长期的人类活动排放、入渗积累或蒸发浓缩富集,是一个地区人类活动密集程度和历史长度的综合反映,提出了NO₃^-与Cl^-质量浓度联合评价地下水污染的基本方法。     

宽窄相间河道水流紊动特性试验研究

为了探索宽窄相间河道的水流紊动特性，以西南地区宝兴河上游宽窄相间河段为研究对象，基于室内概化模型试验，采用多普勒声学流速仪（ADV）测量了室内模型典型断面上的三维瞬时流速，分析典型断面上的纵向时均流速、紊动强度、雷诺切应力和紊动能的分布规律。试验结果显示：宽窄相间水槽中，扩散段边壁的紊动强度大于中心区域的紊动强度，最大值位于0.2倍水深处；扩散段两侧坡脚处紊动能最大；侧壁区的平面和立面雷诺切应力最大值出现在扩散段内，中心区域最大雷诺切应力位于两槽间的中间断面处；扩散段内水流紊乱，两侧出现旋涡和涡脱，易造成侧壁侵蚀加强，引起河道拓宽。深入分析了宽窄相间河道水流的紊动特性，可为山区河流治理和自然灾害防治提供参考。     

H~+对Cu~(2+)—Me~(2+)二元体系吸附的影响规律研究

土壤对重金属离子的吸附容量严格受H~+浓度的控制。本文通过试验探讨了H~+ 对Cu~(2+)——Pb~(2+),Cn~(2+)——Zu~(2+),Cu~(2+)——Hg~(2+)系统中Cu~(2+)吸附量的影响规律。当pHpH时,Cu~(2+)吸附量随pH值增大而减小。对于酸性土,pH=6.5(初始值)或7.0(平衡值),对碱性土,pH=5.5(初始值)或7.8(平衡值)。在pHpH_(ZPC)时,吸附模式具有完全不同的形式。     

Historical development of the saltmarsh at Wells,Maine

Comparisons of maps and aerial photographs dating from the late 1700s to the present document the recent development of an 8 km² saltmarsh that is situated behind a barrier spit in southern Maine. Tidal channels that were relatively narrow in 1794 became wider by 1872. The reduction of marsh bordering tidal channels is interpreted as evidence that marsh accretion could not keep pace with rising sea-level. This suggests that the rate of sea-level rise had increased, although a change in discharge or sediment load caused by extensive settlement and land clearance may also have been involved. Meander patterns of the tidal streams changed considerably throughout the time period covered by the maps, demonstrating that the streams of this marsh are more dynamic than some others that have been widely reported in the literature. These differences in stream dynamics are probably related to the differences in sedimentological structure of the marshes. Between 1872 and 1956 the barrier spit eroded on its inside (shoreward) edge, probably in response to the construction of riprapping and houses along the spit, and the subsequent reduction of overwash and aeolian transport of sediment. Modification of the tidal inlet and adjacent marsh during the 1960s, including jetty construction, dredging, and filling of portions of the marsh surface, affected the marsh only locally. One tidal stream has been migrating rapidly apparently in response to compaction of peat by dredge spoils and consequent local disruption of the marsh hydrology. Except for this migration, erosion of the marsh edge occurred immediately after the inlet modifications; planimetric changes in the marsh and its streams have been minor since then.     

Charge distribution on the atmospheric aerosol over the North Atlantic and the Indian Ocean

The distribution of electric charge on the marine aerosol was determined near the sea surface of the Indian Ocean and the North Atlantic during the final stage of the Snellius II-expedition. Mean values for small ion concentrationsn ⁺=455 cm^–3 andn ^–=340 cm^–3 were found over the Atlantic, whilen ⁺=310 andn ^–=250 cm^–3 were the mean values over the Indian Ocean. The ration ⁺/n^– increased from 1.2 to 2.0 with decreasing wind velocity. At wind velocities below 5 m/s 75% of the net space charge near the ocean surface was found to be carried by small ions.     

配位滴定法同时测定金属离子浓度的研究

将多元校正分析法应用于配位滴定中，以ＥＤＴＡ为滴定剂，玻璃电极为指示电极，饱和甘汞电极为参比电极。依据电位滴定原理，对混合三组分：Ｃｕ￣（２＋）、Ｃｄ￣（２＋）、Ｚｎ￣（２＋）、及Ｃｕ￣（２＋）、ＣＯ￣（２＋）、Ｎｉ￣（２＋）进行测定，各金属离子之间的△ｌｏｇＫ在０．０４～２．３４之间，计算误差一般小于土１０％。     

Sedimentary Features of Shallow Ancient River Channels on the Northern Shelf of the South China Sea1

Abstract Quaternary buried ancient river channels are widespread in the shallow-level sediments of the northern shelf of the South China Sea. The sedimentary sequence mainly of fluvial deposits comprise an important component part of the low-stand system tract and transgressive system tract in the study region. The plannar variation and spatial association of the sedimentary features such as incised valley fillings, deltaic foreset wedges and block slides of shelf-marginal fans reflect the palaeogeographic environment during the fall of the regional sea level in the northern part of the South China Sea. Based on the high-resolution seismic reflection data and gelogical data from boreholes, the present paper makes an integrated interpretation of the Quaternary ancient river channels in the shallow sediments of the study area, studies the sedimentary features of the ancient channels such as their spatial distribution, seismic facies reflection indicators, sedimentary facies and sand-body types, and discusses their formational setting and evolutionary model, with the main purpose to render a service to the hydrocarbon resources exploration and development and marine engineering in the northern shelf of the South China Sea.     

离子质谱计测定地质样品中镁同位素组成方法学研究

应用信通公司研制的离子质谱计（ＳＴ－ＩＭＳ），建立了地质样品镁同位素分析的实验流程和误差分析方法，为进一步分析微量地质样品中镁同位素组成和分布奠定了基础。     

地球弓激波前的低频磁流体波

一、引言 在地球弓激波前存在着低频磁流体波。这种低频磁流体波是太阳风在地球弓激波上的反射粒子和太阳风粒子之间相互作用产生的。根据人造卫星的观测资料可以得到,在地球弓激波前,Pc3-4脉动频率范围内的低频磁流体波的主频率和行星际磁场强度