APPLICATION OF CLAYS TO REMOVAL OF RED TIDE ORGANISMS Ⅱ.COAGULATION OF DIFFERENT SPECIES OF RED TIDE ORGANISMS WITH MONTMORILLONITE AND EFFECT OF CLAY PRETREATMENT   总被引：14，自引：1，他引：14  

俞志明  邹景忠  马锡年 《中国海洋湖沼学报》1994,12(4):316-324

Study on the coagulation of four species of red tide organisms(Nitzschia pungens,Skeletonema costatum,Prorocentrum minimum and Noctiluca scintillans)with montmorillonite,and the effect ofmontmorillonite pretreatment on the coagulation shows that the capability for montmorillonite to coagu-late with them is in the order:N.pungens>S.costatum>P.minimum>N.scintillans.Thecoagulation is discussed from the aspects of the structure,shape,size,movement,habit,etc.of differ-ent species and the results are explained theoretically.The experimental results also indicate that the treat-ment of montmorillonite with acid can enhance its coagulating capability.This is due to the fact that Al(OH_2)_6~(+3),exchanged from the clay lattice by hydrogen ion H~+,forms hydroxy-aluminum polymers on thesurface of the montmorillonite.The hydroxy-aluminum polymers positively charge and increase the positivecharacteristic of the clay surface,and also serves as a bridge between adjacent surfaces of particles.Thesetwo functions enhance  相似文献   

Multifacetted study of a cretaceous coal with algal affinities—II. Composition of liquefaction products     

Z. Mudamburi  P.H. Given 《Organic Geochemistry》1985,8(3):221-231

Two hydrogen-rich lithobodies of highly alipathic character from a coal occurring in southwest Utah, have been studied. Bituminite (>50%), vitrinite (25–30%) and liptodetrinite (7–12%) are the principal macerals. The hexane-soluble products of hydrogenating the lithotypes at 400° with tetralin and hydrogen have been analyzed by GC-MS. Products identified include homologous series of alkylated naphthalenes, phenols, furans, cyclohexenones and hydroxy-pyridines. In the case of furans, the alkyl groups extend beyond C₃₀. Materials released by Soxhlet extraction with pyridine consist chiefly of homologous series of fatty acids and their methyl esters and of methyl alkyl ketones, which were not found in the hydrogenation products. The long alkyl chains in these substances can account for about 75% of the alkanes found in the hydrogenation products but not in the extracts. Most of the compounds mentioned in the foregoing are thought to be physically held or trapped in the coal, rather than chemically combined in its macromolecular network. Except for the fatty acids, the origins of these substances are difficult to identify.  相似文献   

Pyrolysis of immature Torbanite and of the resistant biopolymer (PRB A) isolated from extant alga Botryococcus braunii. Mechanism of formation and structure of torbanite     

C. Largeau  S. Derenne  E. Casadevall  A. Kadouri  N. Sellier 《Organic Geochemistry》1986,10(4-6)

Immature Torbanite and the resistant biopolymer (PRB A) isolated from extant B. braunii were previously compared using bulk spectroscopic methods. In the present work, analysis of 400°C pyrolysis products and pyrolysis residues provided further information on their structure and possible relationships. It appears that such polymers are based upon unbranched, saturated, cross-linked hydrocarbon chains up to C₃₁. In addition to these bridging structures, a substantial part of the alkyl chains is singly bound, as esters of unbranched, saturated or cis unsaturated, even fatty acids. These esters are sterically protected, against chemical degradations, by the network of the bioand geopolymer.Quantitative and qualitative observations derived from 400°C pyrolysis confirm that the chemical structure of PRB A and immature Torbanite are closely related. The pyrolysis residues show a similar evolution and numerous common features are noted, with respect to the nature and the distribution of the major constituents of the pyrolysates (hydrocarbons and fatty acids). Accordingly, Botryococcus provides what seems to be the first example of a close structural relationship between a biopolymer produced in large amounts by an extant alga and the geopolymer of an immature kerogen. The essential role of PRB A in Torbanite formation is ascertained. Moreover, it is found that the resistant biopolymer does not undergo important structural changes during the first stages of diagenesis. Thus, owing to steric protection, the esters of immature Torbanite show a distribution quite close to the one of PRB A esters, with exclusively even constituents and a large contribution of unsaturated acids.Recent observations pointed to the possible genesis of some algal kerogens principally by selective preservation of resistant macromolecules. Such a type of formation is clearly predominant in Torbanite, where the bulk of the fossil organic matter corresponds to a selectively preserved and weakly altered, resistant biopolymer, while incorporation of lipids into the kerogen structure during diagenesis seems to play a minor role.  相似文献   

Grand canyon—a quantitative approach to the erosion and weathering of a stratified bedrock     

Gunnar Aronsson  Krister Linde 《地球表面变化过程与地形》1982,7(6):589-599

A new method is proposed for solving a differential equation arising from weathering-limited development of a valley. Allowance is made for horizontal stratification and overhang can be allowed to develop. The model is applied to the Grand Canyon and comments are included on its relevance.  相似文献   

Characteristics of seasonal and spatial variations of primary production over the southeastern Bering Sea shelf   总被引：3，自引：1，他引：3  

TaeKeun Rho  Terry E. Whitledge 《Continental Shelf Research》2007,27(20):2556-2569

In situ primary production data collected during 1978–1981 period and 1997–2000 period were combined to improve understanding of seasonal and spatial distribution of primary production in the southeastern Bering Sea. Mean daily primary production rates showed an apparent seasonal cycle with high rates in May and low rates in summer over the entire shelf of the southeastern Bering Sea except for oceanic region due to lack of data. There was also an increasing trend of primary production rates in the fall over the inner shelf and the middle shelf. There was a decreasing trend of primary production rates between late April and mid-May over the inner shelf while there was an abrupt increase between late April and mid-May over the middle shelf and the outer shelf. In the shelf break region, there was an increasing pattern in late May. These suggest that there was a gradual progression of the development of the spring phytoplankton bloom from the inner shelf toward the shelf break region. There was also a latitudinal variability of primary production rate over the middle shelf, probably due to either spatial variations of the seasonal advance and retreat of sea ice or horizontal advection of saline water in the bottom layer. Annual rates of primary production across the southeastern Bering Sea shelf were 121, 150, 145, 110, and 84 g C m⁻² yr⁻¹ in the inner shelf, the middle shelf, the outer shelf, the shelf break, and oceanic region, respectively. High annual rates of primary production over the inner shelf can be attributed to continuous summer production based on regenerated nitrogen and/or a continuous supply of nitrogen at the inner front region, and to fall production. There were some possibilities of underestimation of annual primary production over the entire shelf due to lack of measurement in early spring and fall, which may be more apparent over the shelf break and oceanic region than the inner shelf, the middle, and the outer shelf. This study suggests that the response of primary production by climate change in the southeastern Bering Sea shelf can be misunderstood without proper temporal and seasonal measurement.  相似文献   

钾长石粉酸浸除铁的实验研究   总被引：8，自引：1，他引：8  

郑骥  马鸿文等 《地球科学》2001,26(6):657-660

在利用钾长石粉合成沸石分子筛和制取碳酸钾技术中，铁的存在会降低沸石的白度。对北京平谷、天津蓟县、内蒙白云鄂博三地钾长石粉进行硫酸酸浸除铁实验，获得最大铁浸出率分别为88．6％、93．2％和64．6％，且前两地钾长石粉中铁的浸出行为相似，酸浸除铁效果均优于白云鄂博钾长石粉。采用正交实验法研究硫酸浓度、酸浸温度和时间对除铁效果的影响，表明三者对不同地区钾长石粉酸浸除铁效果的影响程度各不相同。钾长石酸浸除铁反应开始时，铁的溶解极快，反应速率主要由化学反应控制；其后溶解相对缓慢，反应速率则由扩散作用控制。  相似文献   

藻类勃发—湖相油源岩形成的一种重要机制   总被引：38，自引：0，他引：38       下载免费PDF全文

刘传联  徐金鲤等 《地质论评》2001,47(2):207-210

浮游藻类是重要的湖相生油母质，本文以渤海湾盆地济阳坳陷早第三纪湖相生油岩为例，研究了其中藻类（主要是颗石藻和沟鞭藻＿化石的分布特征，并通过与现代水体中藻类生产和沉积作用的比较，探讨了生油湖泊中藻类生产和沉积方式及其对油源岩形成所起的控制作用，结果显示，藻类勃发现象在早第三纪生油湖泊中相当普遍，而且贯穿于各类油源岩的形成过程，这类快速事件性沉积是湖相油源岩形成的一种重要机制。  相似文献   

燃煤烟气中SO2治理方法综述   总被引：2，自引：0，他引：2  

余江  陈攀江  龙炳清  宋薇薇  赵仕林 《地质灾害与环境保护》2001,12(2):45-48

对燃煤烟气中SO2的脱除方法进行综述和分析。  相似文献   

The generation of phytoplankton patchiness by mesoscale current patterns   总被引：1，自引：0，他引：1  

Katja Fennel 《Ocean Dynamics》2001,52(2):58-70

 Elken et al. (1994) suggested that phytoplankton patchiness can be generated by mesoscale eddies in light-limited, nutrient-replete environments. This hypothesis is explored using two ecological models of different physical complexity. The model results support the idea that the coupling of mesoscale eddy circulation and phytoplankton growth leads to differential growth rates and thus generates variability in phytoplankton distributions. The specific circulation of a cyclonic eddy isolates a phytoplankton population in its core. Due to the reduced vertical mixing, a higher growth rate is supported in the core, and phytoplankton concentrations increase compared to the surrounding environment. A one-dimensional model is used to explore the hypothesis in general and to perform sensitivity studies. A more realistic simulation uses a coupled three- dimensional model for the western Baltic Sea. Starting from vertically and horizontally homogeneous distributions for nutrients and plankton, the models generate patchiness due to the proposed mechanism. The described mechanism may apply for other mesoscale variable environments during light-limited growth periods as well, e.g., the frontal region of the Southern Ocean. Received: 31 March 2001 / Accepted: 31 August 2001  相似文献   

湘黔地区震旦纪菌藻硅质岩特征及形成机理探讨   总被引：7，自引：0，他引：7  

夏文杰  彭军 《矿物岩石》1993,13(3):21-28

湘黔地区震旦纪菌藻硅质岩化学成分纯净,硅质矿物含量95%以上,几乎都为泥晶—微晶石英,石英结晶度平均为6.35。岩石具菌藻生物结构,以纹层状构造为主。其中丰富的菌藻生物化石,按形态可划分为三种类型。岩石属原生沉积成因,二氧化硅的聚沉一方面通过菌藻有机体的硅化作用,另一方面是菌藻生物化学作用引起微环境变化而导致二氧化硅的聚沉。  相似文献