同构造花岗岩的一种显微构造标记   总被引：5，自引：0，他引：5  

谢才富 《岩石矿物学杂志》2002,21(2):179-185

在许多同构造花岗岩中，发现一种不同于糜棱基质的微细粒矿物集合体－－微粒交生体，充填于大粒级矿物的三结点和接合缝内，体积分数一般为2％－6％，由微粒石英、斜长石、钾长石、蠕状石等组成，成分上与花岗质岩浆的晚期结晶产物相当。根据其产状、成分、岩相学特征及有关实验资料，认为它是较强应力作用下岩石所含少量残余熔体（质量分数约小于3％－5％）的结晶产物，可作为岩体同构造侵位结晶的显微构造标志。  相似文献   

基于微粒群算法的神经网络在岩性识别上的应用   总被引：1，自引：0，他引：1  

张章华  孟凡卉  王文娟 《物探化探计算技术》2007,29(2):130-133

针对前馈多层神经网络BP算法存在的易陷入局部最优的不足,采用了微粒群算法(PSO)加以改进。通过胜利油田及其它油田的岩性识别所做的实例验证,并与BP神经网络进行比较,结果表明,在同等条件下,此方法效果较为满意。  相似文献   

基于微粒群算法的大坝材料参数反分析研究   总被引：1，自引：0，他引：1  

宋志宇  李俊杰 《岩土力学》2007,28(5):991-994

将微粒群算法应用于大坝参数反分析，同时分析了群体规模对算法的搜索效率和搜索质量的影响以及微粒群反分析算法的数值稳定性。对算例的分析结果表明，基于微粒群算法的大坝参数反分析方法简便易行，收敛精度高，且具有很好的抗噪音能力，是一种新的有效、可靠的参数反分析方法。  相似文献   

双侧向测井反演的微粒群方法   总被引：1，自引：0，他引：1  

陈华  邓少贵  李智强  范宜仁 《物探与化探》2007,31(Z1):29-31

双侧向测井反演中,采用微粒群优化算法进行3参数(原状地层电阻率、侵入带电阻率、侵入半径)反演,反演结果精确度较高。由于微粒群优化算法对初值依赖性较小,从而算法也较为稳定,增加了反演结果的可信度。  相似文献   

Macro-and Micro-Structures of Heavy Fogs and Visibility in the Dayaoshan Expressway          下载免费PDF全文

吴兑  邓雪娇  毛节泰  毛伟康  叶燕翔  毕雪岩 《Acta Meteorologica Sinica》2007,21(3):342-352

Belonging to the southern subtropical moist type of monsoon climate,the Nanling mountainous area experiences heavy fogs whenever quasi-stationary fronts appear there from September to May.There can be as many as 15-18 days of heavy fogs per month.Fogs have more serious consequences in the Lechang-Ruyuan section of the Beijing-Zhuhai Expressway(the longest expressway in China)that passes through the main part of the Nanling Mts.,where the road rises from 200m to more than 800m above sea level(ASL).For a major motorway in the mountainous areas of Nanling Mts.,two multidisciplinary integrated field observations were carried out,which measured visibility by the naked eyes,visibility by instrument,spectrum of fog- drops,liquid water content(LWC)of fog,tethered sounding,dual-parameter low-level sounding,turbulence diffusion within fog layers,aerosol spectra of size and composition,sampled fog water compositions,and sampled rainwater compositions.Typical cases were probed for their analyses of synoptics,micro- and macro-structures and microphysics.It is understood that heavy fogs take place with high frequency in the area and bring about serious consequences.Being typical advection and upslope fogs,they are in essence low-lying clouds appearing at high altitudes,which are closely related with the activity of South China frontal processes,especially the South China quasi-stationary fronts,and reflect on the role of local terrain as well.The heavy fogs are characteristic of long duration,extremely low visibility,well-organized lump- shaped structure,large-size fog-drops,moderate concentration,high LWC,and stronger turbulent diffusion within the fog layers than in fine sky.They differ much from radiation fogs,which are better documented in previous study in China.It is found that fog LWC is in significant anti-correlation with visibility so that large LWC is associated with small visual range.It is also noted that one of the reasons for the fluctuation of characteristic quantities of micro-structure such as the LWC of fog in the area is,in addition to the inhomogeneous structure of the fog itself,the effect of advection and inhomogeneous underlying surface; during the translation of fog with the ambient wind,irregular upslope and cross-over movement is another reason for the inhomogeneous structure and fluctuation of fog.The spectrum of the aerosol size displays itself as the power function of monotonous descent.The concentration of submicrometer particles is even higher.The high-concentration sulfate particles found in the aerosols of Nanling Mts.are actually good nuclei for condensation,which are favorable for the formation of fog.The presence of fog can help cleanse the trace compositions in the atmosphere so that fog droplets contain high levels of polluting elements.In the meantime,compared to cloud droplets,fog droplets are easier to be captured by the vertical surfaces of objects on the land surface,such as vegetation and buildings to constitute another kird of cleansing process. In vast stretches of forest like the Nanling Mts.,this kind of cleansing may be quite important.Studying the characteristic variation of fogs in the area realistically assists in setting up a forecast and warning system for local fogs and provides basic information for fog dispersal experiments.  相似文献   

科学家构建出云雨动态新模型     

《浙江气象》2011,32(4):47-47

一群瞪羚和一团云有什么共同点?人类产生的空气悬浮微粒又是怎样影响着降雨方式?据每日科学网近日报道,以色列魏茨曼环境科学研究所和美国国家海洋和大气管理局地球系统研究实验室科学家合作,共同构建了一种新的数  相似文献   

贵州铜厂河铜矿上升气流微粒     

曹建劲  刘昶  熊志华  覃廷荣 《中国科学:地球科学》2011,(8):1109-1115

在贵州铜厂河铜矿隐伏矿体上方土壤中采集上升气流微粒并用透射电子显微镜分析,发现上升气流有自然铜、自然铜铁合金和自然铬铁铜合金微粒,它们一般呈微粒聚合体存在,单个微粒大小在5~40nm之间,形状为近圆形、椭圆形、较规则多边形或长条状.聚合体大小在20~150nm之间,形状接近圆形或椭圆形.上升气流还发现含有成矿元素的氯化物、氧化物、硫酸盐、氢氧化物微粒,这些微粒的元素一般是以高价态存在,反映它们形成于接近于地表的氧化环境.上述上升气流微粒的发现不仅为深部隐伏矿体预测提供了有力的依据,而且可以说明在地表之下自然铜、自然铜铁合金、自然铬铁铜合金、氯化物、氧化物、硫酸盐、氢氧化物等能以微粒形式由气体搬运迁移.  相似文献   

南秦岭西坝岩体的壳-幔相互作用:岩相学和锆石饱和温度计制约     

汪欢  王建平  刘必政  刘家军  曹瑞荣  程建军 《矿物学报》2011,(Z1)

花岗质岩石作为大陆地壳的重要组成部分是研究大陆地壳生长和演化的有效工具,其携带的包体在探讨壳-幔相互作用和地球深部过程中亦具有重要意义。西坝花岗质岩体是南秦岭印支期花岗质岩带的重要组成部分,岩体中分布有较多的暗色微粒包体,具有明显的岩浆混合特征。本文通过研究寄主岩和包体的岩相学特征及岩体的锆石饱和温度,以期对西坝岩体的源区  相似文献   

华南花岗岩暗色微粒包体的岩石化学组成特征及其意义   总被引：2，自引：0，他引：2       下载免费PDF全文

彭卓伦  Rodney Grapes  庄文明  张献河 《地学前缘》2011,18(1):74-81

对华南诸多花岗岩体暗色微粒包体的野外调查表明, 非均一包体是包体中最普遍的类型,常具有暗色基性边.岩石化学分析结果表明,包体边缘的岩性为二长岩-石英二长岩-二长闪长岩,中心则为石英二长闪长岩-英云闪长岩.从包体中心到边缘,具有Si、Ca含量和Na/K比值降低,K、Al、Ti、P和Fe+Mg含量升高的变化趋势,揭示包体应...  相似文献   

基于HPSO算法的岩石非定常蠕变本构模型辨识     

刘文彬 《岩土工程技术》2011,25(4):168-172

复合微粒群优化(HPSO)是一类随机全局优化技术,具有搜索能力强、收敛速度快、搜索精度高的优点.针对岩石蠕变本构模型非定常参数的辨识问题,利用FLAC软件自带的fish语言实现了HPSO算法对非定常参数的辨识.该方法从非定常参数的随机值出发,以蠕变过程中试件变形的实验值与计算值的误差大小作为适应度函数来评价参数的品质,...  相似文献