安徽池州马头铜钼矿地质特征及蚀变分带     

肖娥  马春  顾连兴 《江苏地质》2014,38(2):187-199

安徽池州马头铜钼矿是长江中下游成矿带中安庆—贵池矿集区内一个典型的铜钼矿床。通过野外地质祥查和系统的岩相学、矿相学工作,对该矿床的蚀变特征及分带进行了深入研究。识别出马头铜钼矿的蚀变类型主要有硅化、绢云母化、钾长石化,其次为黏土化、绿泥石化和碳酸盐化等。矿区围岩蚀变在空间上往往重叠,但具有一定的水平及垂向分带特征,自岩体深部至浅部、自内向外总体表现为面型石英钾长石化带、线型石英钾长石化带和石英绢云母化带。矿（化）体以脉状矿化为主,其中分布较广的石英脉带矿化主要产在石英绢云母化带中,以石英细（网）脉为主,受节理和裂隙控制;而品位较富的细脉浸染状矿化则主要产在面型钾长石化带中。通过研究认为,马头铜钼矿在成矿过程的早期阶段,由于高温、富钾和高pH值的热液流体作用,形成大面积的钾长石化,伴生与面型钾长石化有关的细脉、浸染状矿化;热液演化中期阶段,随着温度持续下降、K＋活度和流体pH值的降低,形成硅化、绢云母化等蚀变类型,并伴随范围较大的细脉-网脉状矿化;热液演化晚期阶段,主要形成碳酸盐化,而相应的矿化作用不显著。通过与部分典型斑岩型铜钼矿床的对比研究认为,马头铜钼矿在蚀变类型等方面与斑岩型铜钼矿大体相同,可归至斑岩型成矿体系。  相似文献   

黑河日径流量混沌变化特性的研究—Ⅱ相空间嵌入维数的确定     

陈引锋  李继伟 《地下水》2010,32(6):143-144

通过对黑河日径流量变化规律的探索,重点论述相空间嵌入维数的确定方法。计算结果表明：黑河日径流量时间序列的关联维数为2.1,是低维分数;另外,采用饱和关联积分法,得到黑河日径流量序列的嵌入维数为9。  相似文献   

X射线光电光谱表征金属氧化物的酸碱性     

B.H.W.S.de Jong 《地球化学》2010,39(3):280-295

本文探讨了氧配位的八面体及四面体的金属配合物中氧原子的价态变化及其酸碱性差异之间的关系。首先利用X射线光电光谱（XPS）分别推导出了氧原子在碱及碱土铝酸盐、铬酸盐、高铁酸盐、钼酸盐及钨酸盐中的价态,随后对氧原子的价态及氧化物的酸碱性质进行了比较。研究结果表明,氧原子的价态在这两种配位构型的化合物中没有显著的差别,其酸碱性的不同在于四面体配位的金属化合物中O2p态在非成键和成键的电子密度中高价带的分裂。  相似文献   

冻融作用对饱和粉质黏土抗剪性能的影响   总被引：4，自引：0，他引：4  

于琳琳  徐学燕  邱明国  闫自利  李鹏飞 《岩土力学》2010,31(8):2448-2452

为研究季节冻土地区冻融作用对道路边坡土体抗剪性能的影响规律,在不同冻结和融化温度、不同冻融循环次数、开放和封闭体系条件下对冻融饱和原状粉黏土试样进行了不固结、不排水剪切试验。试验结果表明:饱和原状粉质黏土冻融后,黏聚力降低,内摩擦角增大,冻结温度越低,冻融作用对黏聚力和内摩擦角的影响越小,随着冻融循环次数的增加,5～7次冻结循环后二者的变化逐渐趋于稳定。水分补给会强化冻融作用对试验土抗剪性能的影响;融化温度对试验土的抗剪性能影响很小。  相似文献   

华庆地区长6储层四性关系及有效厚度下限研究   总被引：4，自引：1，他引：3  

刘溪  李文厚  韩伟 《西北地质》2010,43(1):124-129

华庆地区长6储层主体为三角洲相沉积,储层主要为细砂岩。本次研究通过薄片鉴定、压汞、测井等资料,对研究区目的层位的"四性"关系进行了研究,认为长6储层属于典型的低孔低渗油层,岩性、物性的差异控制了储层油藏的富集程度,确定了储层物性下限的标准:孔隙度为8%,渗透率为0.08×10-3μm2;电性下限电阻率为16Ω.m,声波时差为215μs/m。通过对储层参数定量解释模型的优化,提高了储层参数计算精度,避免了有效厚度的漏失;并利用测井方法、压汞资料和密闭取心方法综合确定了长6油藏含油饱和度储量计算取值为71%。  相似文献   

Spectral Properties of Black Holes in Gamma Rays     

Sandip Kumar Chakrabarti 《Astrophysics and Space Science》2005,297(1-4):131-142

Black holes are the most compact objects in the universe. Therefore, matter accreting onto them is likely to radiate photons of energy comparable to very high gravitational potential energy. We discuss the nature of the emitted radiation in X-rays and gamma-rays from black hole candidates. We present theoretical solutions, which comprise both Keplerian and sub-Keplerian components and suggest that shocks in accretion and outflows may play a major role in producing these spectra.  相似文献   

Statistical Modeling with a Hidden Markov Tree and High-resolution Interpolation for Spaceborne Radar Reflectivity in the Wavelet Domain     

Leilei KOU  Yinfeng JIANG  Aijun CHEN  Zhenhui WANG 《大气科学进展》2020,37(12):1359-1374

With the increasing availability of precipitation radar data from space, enhancement of the resolution of spaceborne precipitation observations is important, particularly for hazard prediction and climate modeling at local scales relevant to extreme precipitation intensities and gradients. In this paper, the statistical characteristics of radar precipitation reflectivity data are studied and modeled using a hidden Markov tree (HMT) in the wavelet domain. Then, a high-resolution interpolation algorithm is proposed for spaceborne radar reflectivity using the HMT model as prior information. Owing to the small and transient storm elements embedded in the larger and slowly varying elements, the radar precipitation data exhibit distinct multiscale statistical properties, including a non-Gaussian structure and scale-to-scale dependency. An HMT model can capture well the statistical properties of radar precipitation, where the wavelet coefficients in each sub-band are characterized as a Gaussian mixture model (GMM), and the wavelet coefficients from the coarse scale to fine scale are described using a multiscale Markov process. The state probabilities of the GMM are determined using the expectation maximization method, and other parameters, for instance, the variance decay parameters in the HMT model are learned and estimated from high-resolution ground radar reflectivity images. Using the prior model, the wavelet coefficients at finer scales are estimated using local Wiener filtering. The interpolation algorithm is validated using data from the precipitation radar onboard the Tropical Rainfall Measurement Mission satellite, and the reconstructed results are found to be able to enhance the spatial resolution while optimally reproducing the local extremes and gradients.  相似文献   

Optical,Radiative and Chemical Characteristics of Aerosol in Changsha City,Central China     

Xiaoyan WU  Jinyuan XIN  Wenyu ZHANG  Chongshui GONG  Yining MA  Yongjing MA  Tianxue WEN  Zirui LIU  Shili TIAN  Yuesi WANG  Fangkun WU 《大气科学进展》2020,37(12):1310-1322

Industrial pollution has a significant effect on aerosol properties in Changsha City, a typical city of central China. Therefore, year-round measurements of aerosol optical, radiative and chemical properties from 2012 to 2014 at an urban site in Changsha were analyzed. During the observation period, the energy structure was continuously optimized, which was characterized by the reduction of coal combustion. The aerosol properties have obvious seasonal variations. The seasonal average aerosol optical depth (AOD) at 500 nm ranged from 0.49 to 1.00, single scattering albedo (SSA) ranged from 0.93 to 0.97, and aerosol radiative forcing at the top of the atmosphere (TOA) ranged from ?24.0 to 3.8 W m^?2. The chemical components also showed seasonal variations. Meanwhile, the scattering aerosol, such as organic carbon, SO₄^2?, NO₃^?, and NH₄⁺ showed a decrease, and elemental carbon increased. Compared with observation in winter 2012, AOD and TOA decreased by 0.14 and ?1.49 W m^?2 in winter 2014. The scattering components, SO₄^2?, NO₃^? and NH₄⁺, decreased by 12.8 μg m^?3 (56.8%), 9.2 μg m^?3 (48.8%) and 6.4 μg m^?3 (45.2%), respectively. The atmospheric visibility and pollution diffusion conditions improved. The extinction and radiative forcing of aerosol were significantly controlled by the scattering aerosol. The results indicate that Changsha is an industrial city with strong scattering aerosol. The energy structure optimization had a marked effect on controlling pollution, especially in winter (strong scattering aerosol).  相似文献   

Effects of Aerosols on Fogs Observed in the North China Plain          下载免费PDF全文

ZHANG Jia-Wei  XUE Hui-Wen  DENG Zhao-Ze  ZHAO Chun-Sheng  ZHANG Qing-Hong 《大气和海洋科学快报》2013,6(2):79-83

fog, microphysical properties, aerosol indirect effect, visibility  相似文献   

固化滨海盐渍土路用性能的室内试验与现场测试     

王沛  柴寿喜 《工程地质学报》2011,19(3):440-446

渤海湾西海岸带地区的路堤多为填方型式,且以滨海盐渍土为主要填料.以滨海盐渍土填筑路堤,须解决土的盐胀、溶陷和吸湿软化带来的强度下降和稳定性降低问题,以进行土的改性或固化处理.为降低工程费用,固化材料应以常规的无机材料为主,辅助少量的高分子材料.为研究滨海盐渍土填筑路堤的力学性能,完成了石灰固化土和石灰+SH固土剂固化土...  相似文献