新疆内生矿产成矿规律

本文简要地介绍了新疆主要内生矿产的成矿基本特征及主要成因类型.并在此基础上结合区域地质构造特征、地质发展历史、成矿作用特征及地球化学场特征等基本因素,将新疆划分出15个综合性成矿(区)带,其中包括44个蕴矿带、14个矿田带,最后对新疆内生矿产的主要成矿规律进行了总结.讨论了新疆内生矿产的形成与板块构造发展演化历史的密切并系,指出了它们在时、空上的分布规律及分带性和主要控矿因素.     

Adsorption of phosphate on tidal flat surface sediments from the Yangtze Estuary

Adsorption of phosphate (PO₄-P) by sediments of nine sites taken from the Yangtze Estuarine and coastal tidal flats were studied in a laboratory. The results indicate that the process of phosphorus adsorption onto sediments mainly occurred within 0-10 h, and then reached a dynamic equilibrium. This experimental finding has shown maximum adsorption rates (ad-R) occurred within 0-0.5 h, ranging from 10.40-56.40 mg/kg h with regional differences. The adsorption rates were obviously related to concentrations of fine particles (<63 µm) in the sediments. Adsorption isotherm curves were fitted to the modified Langmuir equation. Adsorption capacities (ad-C) varied from 26.32 to 204.08 mg/kg, and showed good affinities for Fe³⁺ and TOC concentrations. The adsorption efficiency (ad-E) of phosphate on sediments ranged from 21.55 to 248.30 L/kg, showing a close correlation with TOC concentrations. A correlation between environmental factors and phosphate adsorption is presented in this experiment. Phosphate adsorption is susceptible to changes in pH, temperature and salinity conditions.     

Behavior of mercury in an urban river and its accumulation in aquatic plants

The characteristics of mercury in the aquatic environment have been intensively studied in mining areas with heavy mercury pollution but little work has been conducted in urban areas, with no significant Hg source. This paper presents a study of the Haihe River, which flows through an urban area in North China. The concentrations of total mercury (THg) and methylmercury (MeHg) in the river water were 3.6–31.2 and 0.12–3.21 ng/l, and the corresponding values in river sediment were 22.9–374.8 and 0.03–0.46 μg/kg. These values are lower than the reported values from mining areas. The THg concentration in sediment samples collected from the urban areas was higher than that from the rural areas and the global background levels, indicating the influence of urbanization on mercury contamination. Samples of typical riparian and floating plants, reed and hornwort, were collected. Correlation analysis showed that sediment is the major source of THg and MeHg in reed and water is the major source of MeHg in hornwort. The higher bioaccumulation factor of reed indicates its higher potential to accumulate MeHg from the environment.     

堆积的地球及其初始不均一性

从天体化学和地球科学的研究成果出发，认为地球是在一较窄的类地行星区域内，主要由硅酸盐质星子随机吸积而成。在星子形成之前，初始太阳星云已经历了挥发性元素的强烈亏损事件，同时也已发生了硫化物、金属和硅酸盐成分之间的分馏作用，随着行星的形成，行星内部的分馏作用将会持续进行。在形成地球的独立吸积区内，混合作用不彻底，星子群之间的化学成分不均一，因此，构成地球的将是一套具有各自独立化学成分组成的星子群，而不同于地球上现已发现的任何陨石或者它们的组合。     

大量采沙对东江下游及东江三角洲河床地形和潮汐动力的影响

The sand dredging and its impacts on riverbed evolution and tidal dynamic change in the lower reaches and delta of the Dongjiang River are examined in this paper. The large amount of sand, totally 3.32 billion m^3 from 1980 to 2002, was mined from the riverbeds of the lower reaches and delta of the Dongjiang River. Increasing of the channel capacity, lowering of the average riverbed elevation, deepening of the water depth and decreasing of the longitudinal riverbed gradient are the main effects on the riverbed evolution brought by the large amount of sand dredging. Under the strong sand dredging and associated significant riverbed deformation, the notable changes of the tidal dynamic in the lower reaches and delta of the Dongjiang River occurred, including： （1）in the upper reaches of the Dongjiang River delta and lower reaches of the Dongjiang River, tidal level dropped apparently, tidal range widened, flood tidal duration became longer, amplitudes for major tidal components became bigger and tidal dynamics intensified; （2） tidal wave spread faster; and （3） the limits of the tidal level, tidal current and salt water moved upstream.     

磁流变耗能器及其性能

磁流变换（ＭＲ）是一种智能材料,它能够在强磁场的作用下从牛顿流体变化为粘塑流体,用磁流变液制作的耗能装置简单,体积小,能耗小,可连续可逆变化,是实现半主动控制的理想控制元件,本文介绍了磁流变液的材料特征,建立了磁流变耗能器的恢复力简化模型,根据磁流变液耗器的特点,提出了制作磁流变耗器时参数设计的基本要求;最后,利用等效线性化方法,提出了磁流变耗能器总阻尼系数的计算方法,并且比较了其中的粘性阻尼系数     

"97.7"梧州连续性暴雨过程的诊断分析

利用常规的观测资料,结合天气环流形势,对"97.7"暴雨的水汽场、能量场及稳定度等作中尺度物理量场的诊断分析,以了解该类过程降雨的形成机制.     

Bioavailability of dissolved organic phosphorus compounds to typical harmful dinoflagellate Prorocentrum donghaiense Lu

The bioavailability of dissolved organic phosphorus (DOP) compounds to harmful alga Prorocentrum donghaiense Lu and its alkaline phosphatase activity (APA) were studied. Results showed that P. donghaiense could utilize the test DOP compounds such as glucose-6-phosphate (G-6-P), adenosine triphosphate (ATP) and ribonucleic acid (RNA) to sustain its growth. Nutrition between the test DOP compounds and orthophosphate was comparable. P. donghaiense could utilize intracellular phosphorus to sustain growth under depletion of dissolved phosphorus. Variation of APA in different test DOP compounds was addressed; the controlling mechanism of APA in different DOP media was discussed.     

The effects of semi-lunar spring and neap tidal change on nutrients cycling in the intertidal sediments of the Yangtze estuary

During a semi-lunar tidal cycle from full moon till new moon, tide is characterized by the periodic change in spring and neap tide. Under the in situ conditions of light and temperature, the influence of a semi-lunar spring and neap tidal cycle on nutrient cycling in intertidal flat of the Yangtze estuary was simulated in the laboratory in July 2002. Lab experiments showed that NH₄⁺ and PO₄^3– were always released into overlying waters, while NO₃^– was directed into sediments in the permanently waterlogged systems, suggesting that the long-term waterlogged sediment acts as a significant source for NH₄⁺ and PO₄^3–, and a sink for NO₃^– in water columns. In contrast, reflooding of intertidal sediments after long-term desiccation promoted the considerable effluxes of NH₄⁺, NO₃^– and PO₄^3– into overlying waters, reflecting that the long-term exposed sediment is an important source for nutrients in overlying waters. In addition, the semi-lunar tidal cycle led to the intricate depth distribution patterns of nutrients in intertidal sediments. During long-term exposure, NH₄⁺ in sediments was quickly transformed into NO₂^– and NO₃^–, while organic P pool might be converted to slightly adsorbed and iron-bound P. Therefore, it is considered that the semi-lunar tidal circulation has the significant influence on the biogeochemical cycle of nutrients in intertidal systems.     

现役导管架式海洋平台结构整体安全度评估

本文提出了一整套评估导管式海洋平台结构整体安全度的简化方法。主要工作包括：讨论了现役结构内力重分析的影响因素并提出了考虑原则和处理方法；将基本构件依受力特点和重要性程度予以分类、并通过划分层结构而将结构整体简化为层结构的串联体系；用强度储备比定义了基本构件的安全度指标、并延拓此定义于层结构和结构体系；结合专家经验并利用模糊数学原理综合结构的整体安全度指标。文章同时给出了工程应用实例