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101.
On the basis of its geological characteristics, the Gushan iron deposit should be assigned to volcano-hydrothermal type with hematite-quartz as its principal mineral assemblage. Iron concentration of the ore solution has been estimated from the ratio of hematite to quartz in the ore. By using experimental and thermodynamic data, the solubility of ferro-minerals at elevated temperatures and pressures have been calculated in the system FeO?Fe2O3?NaCl?HCl?H2O. The effects ofT, P, pH,f O 2 and total Cl concentration on the solubility of ferrominerals are discussed. Thermodynamic calculations based on presumed physico-chemical conditions for the ore solution are in good agreement with geological observations. The calculation shows that ferro-minerals were deposited at logf O 2=?21~?25, log(mHCl+mH+)=?2.5~?3,P=1?0.75 (or 0.5) kb, andT=400°?350°C. It is believed that the original solution was an acid NaCl-bearing solution of magmatic derivation. However, iron in the solution was enriched with falling temperatures by dissolving pre-existing ferro-minerals in consolidated rocks rather than extracting directly from the magma. Either temperature (below 400°C) or pressure decrease may result in the precipitation of ferro-minerals from the solution, but the Fe/Si ratio in the ore is dependent mainly upon pH. The widespread siliceous veins of later stages are a reflection of decreasing acidity of the solution. An increase inf O 2 will also favor the deposition of ferro-minerals. The hypabyssal occurrence and the existence of the Huangmaqing sandy shale have contributed greatly to the formation of hematite. 相似文献
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104.
当代造山带研究中值得重视的若干前沿问题 总被引:18,自引:4,他引:18
当代造山带研究正从以往以阐明板块运动历史和板块边界相互作用为主,转向并进入到了阐明造山带岩石圈及其之下地幔系统中各层圈相互作用过程和动力学的新阶段,大陆动力学正成为造山带研究的主要指导思想。在这种形势下,造山带研究正围绕着下列前沿问题展开工作:(1)碰撞后的造山过程:拆沉作用、伸展垮塌和深变质岩剥露;(2)造山带之下地幔的结构和演化;(3)壳内软层的性质和动力学作用;(4)造山带地壳的精细构造和演化;(5)巨量花岗岩的成因和侵位动力学;(6)沉积作用与造山过程:根据沉积特征对造山过程、造山事件的恢复再造;(7)新元古代超大陆。 相似文献
105.
A case of mesoscale convective complex(MCC)which evolved into a vortex is documented in this paper.As theMCC entered into the dissipating phase,a well-defined spirally banded structure became visible in the satellite image.The blackbody temperature(TBB)of the residual cold-cloud-shield indicates the vortex existed in the layer from 400 to250 hPa.According to the upper air analysis,the upper level vortex was an anticyclone.The MCC-generated vortex wasvisualized in the satellite images because it was located in the subtropical high where the wind field was very weak. 相似文献
106.
A DIAGNOSTIC EXPERIMENTAL STUDY OF EFFECTS OF CO_2 ENRICHMENT ON COTTON GROWTH,DEVELOPMENT AND YIELD 下载免费PDF全文
A series of experiments were conducted about the effects of different CO_2 concentrations andventilating time on cotton using OPT-1 open top chambers.The results show that.for all theventilating treatments,the development stages of cotton were advanced,plant height increased,thebiomass of root and stalk increased when CO_2 concentration increased: the number of bolls formed insummer was more than 85% of the total for the treatment of 700 ppm CO_2 concentration; single bollweight,the number of bolls per plant,ginned and unginned cotton weights,and stalk weightincreased obviously when CO_2 concentration increased,but the influences of CO_2 enrichment on theratio of ginned weight to the total weight of ginned and unginned cotton,fibre length and ginnedweight of 100-seed were small. 相似文献
107.
Tao Zuyu Wang Hongqing Bai Jie Zhu Wenqin Shi Dingpu Yang Hongmei 《Acta Meteorologica Sinica》1995,9(2):184-189
A case of mesoscale convective complex(MCC) which evolved into a vortex is documented in this paper.As the MCC entered into the dissipating phase,a well-defined spirally banded structure became visible in the satellite image.The blackbody temperature(TBB) of the residual cold-cloud-shield indicates the vortex existed in the layer from 400 to 250 hPa.According to the upper air analysis,the upper level vortex was an anticyclone.The MCC-generated vortex was visualized in the satellite images because it was located in the subtropical high where the wind field was very weak. 相似文献
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109.
三江平原湿地消长与区域气候变化关系研究 总被引:34,自引:0,他引:34
以遥感手段为主,提取近20年来多个时期三江平原湿地变化动态数据。将湿地动态数据与历年气象数据相对变化比较处理后,再作灰色关联分析,可以发现它们之间的相互关系。研究表明三江平原湿地面积减小迅速,三江平原区域气候环境变化剧烈,超过全球气候变化速度。通过灰色关联分析可以发现,湿地在维持区域"冷湿"效应中作用突出,三江平原湿地的变化与气温变化成负相关,与降水、湿度变化成正相关。湿地消长与气候要素中的降水因子的相关关系最大,与日照因子相关关系较低,与降雪因子几乎无关。 相似文献
110.
在已完成的包括16个构件的等位移循环加载钢筋混凝土柱的系列试验中,通过在其中3根柱的塑性铰区沿混凝土受力方向安设位移计,较准确测定了混凝土测试标距内的平均应变在一个加载循环内的变化规律及其随周数增长的变化规律;发现了单周最大压应变随周数的增长而持续增大,单周最大名义拉应变随周数增长而持续减小的重要现象;并与柱顶水平力-水平位移滞回规律实测结果相对应,结合截面受力特征对所得单周和多周应变变化规律的成因作了分析。 相似文献