Dissolved chromium in the St. Lawrence estuary

A study of dissolved chromium in the St. Lawrence estuary and Gulf of St. Lawrence has been carried out. A chromium concentration of 0·7 μg l^?1 was found in the St. Lawrence River. In the turbidity maximum of the upper estuary, chromium is removed from solution onto fine-grained resuspended sediments and internally produced organic-rich floccules. A simple flux calculation shows that these processes remove ～50% of the total dissolved chromium input of the river. At salinities greater than 5‰ dissolved chromium mixes conservatively.     

新疆棉花"矮密早"栽培技术的气候条件

简要论述了新疆棉花“矮密早”栽培技术形成的气候条件和依据。     

辽,金,元测绘史考（下）

概述辽、金、元三代有关测绘的管理和机构,职官设置,各类测绘状况及成果,着重介绍了元代的测绘技术,发明创造及著述。     

McSEIS—170f浅层地震勘探仪数据格式

日本ＯＹＯ公司生产的ＭｃＳＥＩＳ－１７０ｆ瞬时浮点浅层地震勘探仪野外观测数据具有软盘专用格式。本文对磁盘上文件部信息段与数据段存放方式作出了详细的解释,并且对文件头记录内容逐一进行了解剖和说明。本文还提供了读取文件关信息和数据的标准Ｃ语言程序实例。些项工作补充了仪器说明书中缺少的内容。     

吉林东部延吉地区中生代火山岩地球化学特征

吉林东部延吉地区大面积出露的中生代火山岩,根据岩性特征可分为三个火山喷发旋回。各旋回火山岩均属ＳｉＯ２过饱和的中基性—中酸性岩类。从第一旋回至第三旋回岩石碱度变化较大,岩浆分异明显,特别是第三旋回分异作用明显高于第一、二旋回。火山岩中金、铜微量元素的平均含量普遍高于同类岩石的克拉克值几倍至几十倍,而且随着岩浆分异程度的升高,其平均含量有明显升高的趋势,为本区金、铜矿床的形成提供了物质来源。     

贡嘎山东坡海螺沟的河川径流特征

对贡嘎山高山水文观测试验系统进行了简要介绍，并对海螺沟冰川河以及黄崩溜沟的径流特征进行了初步探讨。由于大气降水同是冰川河及黄崩溜沟径流的重要补给来源，故其径流量的季节变化明显带有大气降水过程的烙印，显得丰、枯分明。在冰川河，冰雪融水和地下水在枯水季节的稳定补给改变了大气降水对冰川河径流的年内分配过程；在黄崩溜沟，由于冰雪融水和地下水对其径流的补给非常有限，大气降水过程对其径流过程的影响便明显大过冰川河。     

水库汛期限制水位控制理论与观念的更新探讨

传统的水库汛限水位的控制,只利用了洪水的统计信息,使水库在汛期要时刻预防设计与校核洪水事件的发生,致使一些水库在汛期不敢蓄水而汛后又无水可蓄,造成洪水资源的浪费。提出水库汛限水位动态控制的新理念及其综合推理模式,适应当前预报技术的发展水平,考虑降雨径流洪水预报与一定时间内的短期降雨预报,排除不可能发生的洪水事件,预报可能发生的洪水,实施水库汛限水位的动态控制。但预报不可避免地存在误差,当小概率预报误差事件发生时,仍可采取弥补措施以确保大坝的防洪安全。     

山东地质环境中砷的分布特征

山东地质环境砷含量一般为(10^-6)：各类岩石4．87～7．89，土壤10．89，水系底泥6．23。根据砷的分布特点。总体上可将山东分为鲁中南-鲁东山地丘陵区、鲁西北-鲁西南平原区2个大的砷的地质环境(背景)区及7个亚区。每个亚区内，山地丘陵区砷的地球化学背景较低，而平原区砷的背景相对高些。但总体上，全省处于正常的和相对比较低的背景，还未发现原生地质环境形成高砷背景对人体危害的案例。     

A layered model of the upper crust in the Aigion region of Greece,inferred from arrival times of the 2001 earthquake sequence

The western part of the Gulf of Corinth attracts attention due to its seismically active fault system and considerable seismic hazard. Detailed studies of the seismic activity of the region have been carried out especially as part of the so-called Corinth Rift Laboratory (CRL) Project. For standard earthquake locations, the CRL uses the HYPO algorithm and a special structural model that is composed of homogeneous layers (Rigo et al., 1996). This model was derived from a passive seismic experiment in a broader area around the western part of the Gulf. A significant part of the seismic activity is concentrated close to the town of Aigion, which was damaged by a strong earthquake in 1995. A sequence of smaller earthquakes occurred to the south of this town in the year 2001. In the present paper, we have used this sequence to derive an improved structural model for the region in the vicinity of the town of Aigion. This new model is based on the minimization of travel-time residuals. In particular, we used arrival times from a subset of 88 events recorded by at least 5 stations of the southern part of the CRL network, had magnitudes of over 2.3, and were recorded at the nearest station (station code AIO). A variant of the method of conjugate gradients has been used for this purpose. In comparison with the model derived by Rigo et al. (1996), the new model is characterized by a higher ν_P/ν_S velocity ratio and by higher velocities to a depth of about 7 km. The new model was derived with the aim to get more accurate locations of future events in the vicinity of the town of Aigion.