加权Logistic回归模型在火山岩型铜矿预测中的应用:以宁芜盆地中段为例          下载免费PDF全文

赵增玉  陈火根  潘懋  贾根  李向前  徐士银  郭刚  张祥云 《高校地质学报》2016,22(1):105

文中探讨了加权Logistic回归模型在宁芜盆地中段火山岩型铜矿预测中的应用。首先,结合研究区的成矿地质背景,提取地质体、构造、围岩蚀变三大类证据因子;其次,分析各证据因子与铜矿点之间的空间关系,认为姑山旋回、娘娘山旋回火山机构控制了本区火山岩型铜矿的空间分布,根据计算结果,选取与火山岩型铜矿密切相关的龙王山组、姑山组地层,姑山旋回粗面斑岩、娘娘山旋回二长斑岩、NW向构造1.5 km缓冲区、NE向构造1.3 km缓冲区、EW向构造4.5 km缓冲区、硅化、褐铁矿化、黄铜矿化等作为模型自变量;最后采用加权Logistic回归模型进行成矿概率计算,并结合成矿地质背景,圈定四个成矿远景区,分别为P1、P2、P3、P4,其中P1、P2、P3呈北东向展布,主要受娘娘山和姑山火山机构控制,P4为东西向分布,主要受龙王山火山机构控制,在这些预测区中,均存在已发现的铜矿体,说明预测可信度较高。  相似文献   

日本囊对虾Marsupenaeus japonicus)组织蛋白酶D基因克隆及表达分析     

张曼  程光平  苏永全  徐伊桦  冯文荣  王军  宋晓红  毛勇 《海洋学报》2016,38(8):52-61

组织蛋白酶D是溶酶体天冬氨酸蛋白酶家族的主要成员,广泛参与动物机体细胞内蛋白质的降解过程,对维持细胞稳态和正常代谢具有重要的作用。为研究组织蛋白酶D在甲壳动物非特异性免疫和幼体发育过程中的作用,本研究采用RACE技术首次克隆得到日本囊对虾组织蛋白酶D基因cDNA序列,命名为MjCatD,其中开放阅读框长为1161 bp,编码386个氨基酸残基。序列分析和同源建模显示该基因编码的蛋白含有保守的N-糖基化位点、天冬氨酸蛋白酶签名序列、酶活化位点和非消化性组织蛋白酶D的特征序列,并且呈保守的双叶形结构。同源性比较和系统进化分析发现,MjCatD与斑节对虾、美洲螯龙虾和脊尾白虾相似性较高,并且与它们紧密聚为一支。实时荧光定量PCR结果显示,MjCatD基因在日本囊对虾多个组织中均有表达,其中肝胰腺中表达量最高。在白斑综合征病毒(white spot syndrome virus, WSSV)感染后3～24 h日本囊对虾肝胰腺中MjCatD的表达量逐渐下降,而在48 h急剧上调至最高表达量并且与对照组差异极显著(P<0.01)。此外,MjCatD基因在幼体发育不同阶段中也表现出明显的变化趋势。以上研究表明,MjCatD基因可能参与日本囊对虾先天免疫反应和幼体发育过程。  相似文献   

基于海浪谱分解与重构的资料同化试验     

毛科峰  萧中乐  宋海波  钟奕飞 《海洋学报》2016,38(3):15-26

针对有效波高资料提出一种海浪谱分解与重构的资料同化方案:利用历史时段内的有效波高观测资料和模式计算波高场,采用最优插值方法得到分析波高场;在WAVEWATCH-Ⅲ模式的波浪能量密度谱和有效波高分析值之间引入一个变异系数矩阵,描述模式的误差,以此为状态向量构建卡尔曼滤波系统,对分解过的海浪谱进行修正和重构,得到同化后的海浪谱初始场。利用美国阿拉斯加湾北部海域的7个浮标站进行同化和72 h预报试验,对连续1个月的预报结果进行统计表明:采用该同化方案后24 h预报结果的有效波高均方根误差比未同化的结果降低了0.13 m;同化方案对预报效果的影响可持续36 h左右,随着预报时效延长,同化的效果减弱。  相似文献   

白令海夏季浮游植物的群落结构与时空变化     

王雨  项鹏  叶又茵  林更铭  杨清良  林和山  林茂 《海洋学报(英文版)》2016,35(4):99-107

通过1999年和2010年夏季同期7月在白令海(169°E~166°W,50°N~67°N)获取的94份浮游植物样品分析,获得了近十年的始末两个时间节点的浮游植物群落结构与时空变化,探讨了浮游植物群落动态及其与环境因素的关联。研究结果显示,共鉴定浮游植物(>10μm)5门58属153种,分为3个生态类群。硅藻是浮游植物的主体,种类多丰度高,占总种类数目的66.7%,占总丰度的95.2%。鉴于样品属性和空间范围的不同,物种组成有细微差别,丰度有较大差异且空间分布明显不同,高丰度区受控于上层营养盐供给和表层环流系统。优势种从北方温带大洋性硅藻演变为广温广盐性与冷水性硅藻,1999年以西氏新细齿状藻为第一优势种,柔弱伪菱形藻次之;2010年以丹麦细柱藻为第一优势种,冷水性的诺登海链藻次之并在陆架和陆坡占优。浮游植物群落结构较为稳定,由深水群落和浅水群落组成。深水群落分布于太平洋西北部和白令海盆,种类组成以温带大洋性的西氏新细齿状藻、长海毛藻、大西洋角毛藻和广布性的菱形海线藻、扁面角毛藻、笔尖根管藻为主,丰度低,种间丰度分配均匀,优势种多元化,物种多样性高;浅水群落分布于白令海陆坡和陆架,主要由冷水性的诺登海链藻、叉尖角毛藻、聚生角毛藻和广布性的丹麦细柱藻、旋链角毛藻组成,丰度高,种间丰度分配不均匀,优势种突出,物种多样性低。白令海夏季浮游植物种类组成及丰度变化直接受控于表层环流、营养盐、春季冰缘线等环境因素。  相似文献   

MALBAC技术扩增微生物群落基因组的效率评估     

王勇  高兆明  徐颖  李光玉  贺丽生  钱培元 《海洋学报(英文版)》2016,35(2):131-136

环境样品的低生物量是微生物宏基因组学研究面临的首要挑战,通过基因组扩增技术来满足高通量测序对DNA样品量的需求是最常用的解决策略。MALBAC(Multiple Annealing and Looping Based Amplification Cycles)基因组扩增试剂盒最初为扩增和研究哺乳动物的单细胞基因组而研发。本文中,我们通过人工构建的微生物群落来检测该试剂盒在微生物宏基因组扩增方面的效率和应用可行性。结果表明,每个标准反应中,10 pg的DNA模板量足以满足MALBAC试剂盒对样品扩增的需要。每个标准反应DNA模板用量为10和100 pg时,所扩增DNA样品的基因组覆盖度与原始未扩增样品表现出高度的一致性,证明MALBAC试剂盒扩增效果的高度稳定性和一致性。常用的GenomePlex全基因组扩增试剂盒使我们可以在每个标准反应DNA模板量为100 pg的条件下扩增获得足够的DNA样品,但是结果表明该参照试剂盒无法有效的实现对群落中低丰度细菌菌株基因组的线性扩增。对于MALBAC试剂盒和参照试剂盒而言,在扩增高GC含量的微生物物种基因组DNA方面效率低下。我们的实验结果表明MALBAC试剂盒在高效扩增环境样品宏基因组DNA方面的可行性,但对该试剂盒在扩增环境样品中高GC含量微生物物种方面的适用性存在疑虑。  相似文献   

Numerical study on inter-tidal transports in coastal seas     

Xinyan Mao  Wensheng Jiang  Ping Zhang  Shizuo Feng 《中国海洋大学学报(英文版)》2016,15(3):379-388

Inter-tidal(subtidal) transport processes in coastal sea depend on the residual motion, turbulent dispersion and relevant sources/sinks. In Feng et al.(2008), an updated Lagrangian inter-tidal transport equation, as well as new concept of Lagrangian in- ter-tidal concentration(LIC), has been proposed for a general nonlinear shallow water system. In the present study, the LIC is nu- merically applied for the first time to passive tracers in idealized settings and salinity in the Bohai Sea, China. Circulation and tracer motion in the three idealized model seas with different topography or coastline, termed as ‘flat-bottom', ‘stairs' and ‘cape' case, re- spectively, are simulated. The dependence of the LIC on initial tidal phase suggests that the nonlinearities in the stairs and cape cases are stronger than that in the flat-bottom case. Therefore, the ‘flat-bottom' case still meets the convectively weakly nonlinear condi- tion. For the Bohai Sea, the simulation results show that most parts of it still meet the weakly nonlinear condition. However, the de- pendence of the LIS(Lagrangian inter-tidal salinity) on initial tidal phase is significant around the southern headland of the Liaodong Peninsula and near the mouth of the Yellow River. The nonlinearity in the former region is mainly related to the complicated coast- lines, and that in the latter region is due to the presence of the estuarine salinity front.  相似文献   

Identification of light-harvesting chlorophyll a/b-binding protein genes of Zostera marina L. and their expression under different environmental conditions     

Fanna Kong  Yang Zhou  Peipei Sun  Min Cao  Hong Li  Yunxiang Mao 《中国海洋大学学报(英文版)》2016,15(1):152-162

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Development of efficiently coupled thermo-hydro-mechanical model to predict hydraulic fracture morphology in heavy oil reservoirs     

Yongquan Hu  Qiang Wang  Jinzhou Zhao  Ziyi Guo  Yong Zhang  Chun Mao 《Environmental Earth Sciences》2018,77(23):778

The aim of the study involves examining the effect of heavy oil viscosity on fracture geometry in detail by establishing a heavy oil fracturing model and conventional fracturing model based on thermal–hydraulic–mechanical (THM) coupled theory, Walther viscosity model, and K–D–R temperature model. We consider viscosity and density within the heavy oil fracturing model as functions of pressure and temperature while that as constants within the conventional fracturing model. A heavy oil production well is set as an example to analyze the differences between the two models to account for the thermo-poro-elastic effect. The results show that temperature exhibits the most significant influence on the heavy oil viscosity while the influence of pressure is the least. In addition, a cooling area with a width of 0–1 m and varied length is generated near the fracture. The heavy oil viscosity increases sharply in this area, thereby indicating an area of viscosity increment. The heavy oil viscosity increases faster and is closer to wellbore, and a high viscosity increment reduces the mobility of the heavy oil and prevents the fracturing fluid from entering into the reservoir. The special viscosity distribution results in significant differences in pore pressure, oil saturation, and changing trends between these two models. In the heavy oil reservoir fracturing model, the thermal effect completely exceeds the influence of pore elasticity, and the values of the fracture length, width, and static pressure exceed those calculated in the conventional fracturing model. Thus, a comparison of the measured values indicates that the results obtained by considering viscosity as a function of temperature and pressure are more accurate. Therefore, the results of this study are expected to provide good guidelines for the design of heavy oil fracturing.  相似文献   

Paleo-environment and reservoir evolution of the Middle Ordovician Kelimoli Formation in the northern Tianhuan area,Ordos Basin,China: implications for high-quality reservoir development     

S. W. Mao  J. M. Li  W. Liu  Z. C. Wang  Z. L. Huang 《Australian Journal of Earth Sciences》2018,65(4):535-555

The Middle Ordovician Kelimoli Formation carbonate reservoirs in the northern Tianhuan area, Ordos Basin, China are main exploration targets. Subsurface core samples, logging, drilling and production data from the area were used to characterise the carbonate reservoir and to construct a genetic model for exploration. The sedimentary facies identified include trough–continental rise, upper–lower slope, platform margin reef-shoal, open platform and evaporation-restricted platform. The slope and platform margin facies are potential zones for high-quality reservoirs. Porosity in the study area comprises intergrain, intercrystal, intragrain and intracrystal pores, fractures and vughs. The Sr/Ba (0.40–4.87) and V/(V + Ni) (0.64–0.97) ratios indicate deposition in a brackish water-dominated environment under reducing conditions, associated with sea-level fluctuations during the deposition of the Kelimoli Formation. The Sr/Ba, V/(V + Ni), ⁸⁷Sr/⁸⁶Sr ratios, δ¹⁸O values and crystal texture of dolomite samples suggest that meteoric water was involved in the diagenetic fluid in the near-surface depositional environment. Isotopes (δ¹³C and δ¹⁸O) and trace elements (Fe and Mn) allowed the identification of seepage-reflux and mixed-water dolomitisation. The crystal textures of the samples consist of micritic, bioclastic and reefal limestones, and dolomite with gypsum, which were easily dissolved during the early diagenetic stage. The epidiagenetic stage was the key period for the development of high-quality reservoirs because of large-scale bedding-parallel karstification from meteoric water. The reservoir zones, dominated by partially filled and unfilled vughs, and fractures, are favourable exploration targets in the northern Tianhuan area.  相似文献   

Progress in the Application of Ground Gravity Observation Data in Earthquake Prediction     

Jinglun Mao  Yiqing Zhu 《地球科学进展》2018,33(3):236-247

The mechanism of earthquake inoculation and the process of earthquake occurrence are very complicated. Additionally, earthquakes do not happen very often, and we lack enough cognition to the earth’s interior structure, activity regularity and other key elements. As a result, research progress about the theory of earthquake precursors has been greatly restricted. Ground gravity observation has become one of the main ways to study earthquake precursor information in many countries and regions. This paper briefly summarized the surface gravity observation technology and observation network in China: the surface gravity measurement instrument developed from Huygens physical pendulum in seventeenth Century to today’s high-precision absolute gravimeter, and its accuracy reached to ±1×10^-8 m/s². China has successively established the National Gravity Network, Digital Earthquake Observation Network of China,the Crustal Movement Observation Network of China Ⅰ and the Crustal Movement Observation Network of China, to provide a public platform for monitoring non tidal gravity change, seismic gravity and tectonic movement. The use of specific examples illustrated the role of gravity observation data in earthquake prediction. The gravity observation data of ground gravity can be used to capture the information of gravity change in the process of strong earthquake inoculation, and to provide an important basis for the long-term prediction of strong earthquakes. The temporal and spatial variation characteristics of the regional gravity field and its relation to strong earthquakes were analyzed: Before the earthquake whose magnitude is higher than M_S 5, generally there will be a large amplitude and range of gravity anomaly zones. Strong earthquakes occur mainly in areas where the gravity field changes violently. The dynamic change images of gravity field can clearly reflect the precursory information of large earthquakes during the inoculation and occurrence. Finally, the existing problems of surface gravity technology in earthquake precursor observation were put forward and the use of gravity measurement data in earthquake prediction research was prospected.  相似文献