Geochemical Characteristics and Sources of Ore-forming Fluids of the Mayuan Pb-Zn Deposit,Nanzheng,Shaanxi,China

The Mayuan stratabound Pb-Zn deposit in Nanzheng,Shaanxi Province,is located in the northern margin of the Yangtze Plate,in the southern margin of the Beiba Arch.The orebodies are stratiform and hosted in breciated dolostone of the Sinian Dengying Formation.The ore minerals are primarily sphalerite and galena,and the gangue minerals comprise of dolomite,quartz,barite,calcite and solid bitumen.Fluid inclusions from ore-stage quartz and calcite have homogenization tempreatures from 98 to 337℃ and salinities from 7.7 wt%to 22.2 wt%（NaCl equiv.）.The vapor phase of the inclusions is mainly composed of CH_4 with minor CO_2 and H_2S.The δD_（fluid） values of fluid inclusions in quartz and calcite display a range from-68‰ to-113‰（SMOW）,and the δ^（18）O_（fluid）values calculated from δ^（18）O_（quartz） and δ^（18）O_（calcite） values range from 4.5‰ to 16.7‰（SMOW）.These data suggest that the ore-forming fluids may have been derived from evaporitic sea water that had reacted with organic matter.The δ^（13）C_（CH4） values of CH_4 in fluid inclusions range from-37.2‰ to-21.0‰（PDB）,suggesting that the CH_4 in the ore-forming fluids was mainly derived from organic matter.This,together with the abundance of solid bitumen in the ores,suggest that organic matter played an important role in mineralization,and that the thermochemical sulfate reduction（TSR） was the main mechanism of sulfide precipitation.The Mayuan Pb-Zn deposit is a carbonate-hosted epigenetic deposit that may be classified as a Mississippi Valley type（MVT） deposit.

Influences of Low-Temperature Hydrothermal Fluids on the Re-distributions and Occurrences of Associated Elements in Coal——A Case Study from the Late Permian Coals in the Zhijin Coalfield, Guizhou Province. Southern China

The occurrences of associated elements and their genetic factors in the No. 30 coal seam in the Zhijin Coalfield were studied using instrumental neutron activation analysis, inductively coupled plasma-atomic emission spectroscopy, and a scanning electron microscope equipped with an energy-dispersive X-ray analyzer. And, a microscope photometer system (Leitz MPV-Ⅲ) was used to observe the characteristics of coal petrology. According to the influence degree by the siliceous low-temperature hydrothermal fluids, the organic matter is divided into four types: A, B, C, and D of the hydrothermally-altered organic matter (HAOM). The study shows that the high content of Fe (2.31%) is not from pyrite, but mostly from the siliceous low-temperature hydrothermal fluids. The occurrences of the associated elements in the four organic matter types are different. The contents of Fe, Si, and Al are decreasing, but S and Cu are increasing in the order of the HAOM-A, HAOM-B, HAOM-C, and HAOM-D. The losing rate of sulfur in organic matter is 0.35% and the content of Fe taken from the low-temperature hydrothermal fluids into the organic matter is 0.794% during the siliceous low-temperature hydrothermal fluids invading the coal seam. The above facts indicate that the low-temperature hydrothermal fluids play a crucial role in the re-distributions and occurrences of associated elements in coal.

Geochemistry, Paleoenvironment and Mechanism of Organic-Matter Enrichment in the Lower Silurian Longmaxi Formation Shale in the Sichuan Basin, China

To investigate the mechanism of the organic-matter enrichment in the Lower Longmaxi Formation shale,the geochemistry and total organic carbon(TOC)of the Longmaxi Formation black shales in the Jiaoshiba,Zhaotong,and Weiyuan areas of the Sichuan Basin were analyzed.Paleoproductivity proxy parameters(Babio,Siex,and Ni/Al),clastic influx proxies(TiO2 and Ti/Al),redox indices(V/Cr,Ni/Co,V/(V+Ni),and U/Th),and hydrothermal indicators(Fe,Mn,and Y concentrations;Fe/Ti ratio and a Ni-Zn-Co diagram)were employed to decipher the paleoenvironment of the Lower Longmaxi Formation shales.TiO2 and Ti/Al indicated low terrigenous detrital influx in all three areas.However,Babio,Siex,and Ni/Al indicated high productivity in the Jiaoshiba area.V/Cr,Ni/Co,and U/Th indicated higher oxygen content with larger fluctuations in the Zhaotong and Weiyuan areas.Fe,Mn,and Y concentrations and the Fe/Ti ratio implied greater active hydrothermal activity in the Weiyuan area.These heterogeneities were considered to be closely related to the paleoenvironment and paleogeography,and the large basement faults that developed during the Chuanzhong paleo-uplift could have provided vents for deep-hydrothermal-fluid upwelling.The redox indices(V/Cr,Ni/Co,and U/Th)and a paleoproductivity proxy(Ni/Al)displayed a significant correlation with the TOC,suggesting that both excellent preservation conditions and high paleoproductivity were the controlling factors for the enrichment of organic matter in the Longmaxi Formation shale.There was no obvious correlation between the clastic influx proxy(Ti/Al)and the TOC due to the extremely low supply of terrigenous debris.The hydrothermal indicator(Fe/Ti)was negatively correlated with the TOC in the Weiyuan area,indicating that hydrothermal activity may have played a negative role in the accumulation of organic matter.This study suggests that the enrichment of organic matter in the Longmaxi Formation marine shale varied according to the paleogeography and sedimentary environment.

Thin Film Flow of a Second Grade Fluid over a Stretching/Shrinking Sheet with Variable Temperature-Dependent Viscosity

Effects of variable viscosity on the flow and heat transfer in a thin film on a horizontal porous stretching sheet are analyzed. The steady boundary layer equations for momentum and thermal energy are simplified by using similarity transformations. The resulted and coupled nonlinear differential equations are solved by Homotopy analysis method. The results are presented graphically to interpret various physical parameters appearing in the problem.

The characteristics and significance of pure nitrogen fluid inclusions in Xikuangshan copper deposit,Dongchuan,Yunnan of China

Nitrogen is an important gas-phase element in geological fluid,and normally hosted in mineralizing fluid,in which the content is very low.Nearly 100% mol pure nitrogen inclusion was discovered in copper-bearing quartz vein from Xikuangshan copper deposit,Dongchuan,Yunnan Province in this research.It is between 3 and 5 μm,in shape of ellipse,occurring in group or independence without obvious orientation,and co-existed with primary gas-liquid inclusions.Inclusion analysis by using laser Raman spectroscopy shows its composition is dominated by nitrogen with minor H2O.High concentration of N2 may be the necessary and sufficient condition for forming this kind of inclusion.It is suggested that there are two genesis modes of pure N2 inclusion in the deposit,oxida-tion-devolativation of mantle matter and trap of metasomatic fluid in organic matter decomposition in Luoxue For-mation dolomite.In conclusion,pure N2 inclusion hardly presents in the ore-forming fluids,which providing a new evidence for the genesis of Xikuangshan type copper deposit.

应用计算流体动力学方法估测医院急诊大厅颗粒物分布特征的研究

目的基于室内场所的空间几何构型、风速、颗粒物浓度和环境温度测量值,阐述空气中颗粒物浓度、悬浮时间等分布规律。方法现场测量医院急诊大厅的空间及其中大型设施的尺寸,测量环境中颗粒物数量浓度、温度、风速,场所空间尺寸用于构建模型,环境检测参数用于确定模型的边界条件和验证模型的正确性。基于格子波尔曼方法(Lattice Boltzmann Method,LBM)计算颗粒物运动,应用对流扩散方程计算空调送风系统出风口处颗粒物浓度的变化,离散相模型(discrete phase model,DPM)用于计算颗粒物在流场的运动情况。结果环境检测表明空调送风系统出口风速与室内颗粒物数量浓度呈负相关,人群聚集的候诊区颗粒物数量浓度高于诊室(P值均<0.05)。通过建立的数学模型进行仿真计算,仿真相对浓度未超过实测相对浓度的x±s范围,候诊人群使局部颗粒物浓度升高,候诊区人员咳嗽呼出气中的颗粒物可以在15 s内传播给周围的人,呼出气中60%的颗粒物悬浮时间可持续几分钟或更长时间。结论改变模型中的空间几何尺寸和环境检测参数可以用于计算不同室内场所中颗粒物的分布情况,仿真结果与实测结果具有可比性,数学计算结果可支持环境呼吸危害防控管理措施的制定。

Anisotropic Open Cosmological Models of Spin Matter with Magnetic Moment

We have derived a set of field equations for a Weyssenhoff spin fluid including magnetic interaction among the spinning particles prevailing in spatially homogeneous, but anisotropically cosmological models of Bianchi type V based on Einstein Cartan theory. We analyze the field equations in three different equations of states specified by p =(1/3)ρ, p =ρ and p =0. The analytical solutions found are non singular provided that the combined energy arising from matter spin and magnetic interaction among particles overcomes the anisotropy energy in the Universe. We have also deduced that the minimum particle numbers for the radiation ( p =(1/3)ρ ) and matter ( p =0) epochs are 10 88 and 10 108 respectively, the minimum particle number for the state p =ρ is 10 96 , leading to the conclusion that we must consider the existence of neutrinos and other creation of particles and anti particles under torsion and strong gravitational field in the early Universe.

活塞风对地下平台颗粒物动态分布的影响分析

随着地铁客流量的急剧增加,地铁乘车环境面临严重的污染问题。现有相关文献研究只注重地铁站台整体颗粒物平均浓度,局部位置颗粒物浓度研究较少。通过实测数据,分析地铁站台颗粒物分布规律,利用CFD模拟软件模拟分析列车进站时,活塞风产生的诱导气流对颗粒物分布特征影响。结果表明:随着列车进站,站台颗粒物浓度明显上升,不同位置颗粒物浓度动态变化规律有所不同。地铁站台在不同时空条件下的颗粒物浓度与屏蔽门上方风口诱导气流的变化存在一定的相关性,靠近列车进站一侧的颗粒物浓度偏高且变化较大。了解颗粒物浓度在不同位置的浓度变化,能够针对局部通风提出更好的颗粒物控制策略。

Photon orbits and phase transition for Letelier AdS black holes immersed in perfect fluid dark matter

We obtain an exact solution for spherically symmetric Letelier AdS black holes immersed in perfect fluid dark matter(PFDM).Considering the cosmological constant as the positive pressure of the system and volume as its conjugate variable,we analyze the thermodynamics of our black holes in the extended phase space.Owing to the background clouds of strings parameter(a)and the parameter endowed with PFDM(β),we analyze the Hawking temperature,entropy,and specific heat.Furthermore,we investigate the relationship between the photon sphere radius and phase transition for the Letelier AdS black holes immersed in PFDM.Through the analysis,with a particular condition,non-monotonic behaviors are found between the photon sphere radius,impact parameter,PFDM parameter,temperature,and pressure.We can regard the changes in both the photon sphere radius and impact parameter before and after phase transition as the order parameter;their critical exponents near the critical point are equal to the same value,1/2,similar to that in ordinary thermal systems.This indicates that a universal relation of gravity may exist near the critical point for a black hole thermodynamic system.

T2WI-FLAIR脑白质高信号与脑梗死机械取栓治疗预后的相关性

目的分析T2WI-FLAIR脑白质高信号与脑梗死机械取栓治疗患者预后的相关性。方法选取2021-03—2023-01于喀什地区第一人民医院卒中中心接受机械取栓治疗的100例脑梗死患者为研究对象。随访3个月后,根据mRS评分分为预后良好组(n=59例)和预后不良组(n=41例)。采用单因素与多因素Logistic回归分析影响脑梗死机械取栓治疗预后的相关因素,采用预测模型受试者工作特征(ROC)曲线与曲线下面积(AUC)分析评估效能。结果单因素分析显示,预后良好组患者的年龄、发病到医院就诊时间、发病2周NIHSS评分、Fazekas脑白质高信号评分均低于预后不良组,差异有统计学意义(P<0.05)。多因素Logistic回归分析显示,年龄≥60岁、发病到医院就诊时间≥6 h、发病2周NIHSS评分≥12.5分、Fazekas脑白质高信号评分≥3分是影响脑梗死机械取栓患者预后的独立危险因素,差异有统计学意义(P<0.05)。Fazekas脑白质高信号评分预测脑梗死机械取栓患者预后的ROC曲线AUC值为0.882。结论T2WI-FLAIR脑白质高信号与脑梗死机械取栓治疗患者的预后密切相关,可作为预测脑梗死机械取栓治疗患者预后的重要指标,同时也要综合考虑年龄、发病到医院就诊时间、神经功能缺损程度等多种因素,从而为临床诊断和治疗提供更有价值的参考。

广东长坑金银矿床成矿流体成分及来源探讨

对广东长坑金银矿床流体包裹体的研究表明 ,该矿床矿石中流体包裹体种类较多 ,以富气态烃包裹体与盐水溶液包裹体为主 ,包裹体相对含量统计表明 ,富气态烃包裹体占包裹体总数的大多数 ,表明成矿流体为富含气态烃的水溶液。金、银矿石均一温度测定主要集中在 16 0～ 2 6 0℃区间。单个包裹体的拉曼光谱分析结果证明 ,成矿流体成分与赋矿围岩有密切关系。

高温低伤害压裂液性能优化与应用

中原油田应用的压裂液存在着残渣含量高、表面活性差、地层损害程度严重等问题。针对深井高温地层压裂改造的要求,采取了降低成胶剂残渣含量、提高液体表面活性、稳定地层粘土矿物、改善交联体系以及实行分段破胶等技术措施,使压裂液具有良好的高温稳定性与地层保护能力。新的压裂液体系主要由低残渣羟丙基胍胶、HY-605和HF-605高活性复合表面活性剂体系、新型油溶性树脂、复合型粘土稳定剂和高温延迟交联剂OB-99组成。高温低伤害压裂液体系在现场3井次应用表明,该压裂液保证了高砂比、大排量和复杂工艺条件下的压裂施工顺利进行,取得了显著的增产效果,压后初期日增油量为51.3 t,累计增油量为4900 t;日增天然气量为8300 m^3,累计增气量为124.5×10~4m^3。

云南省富宁县者桑金矿床成矿流体特征

通过云南者桑金矿床中流体包裹体岩相学、显微测温、稀土元素、氢氧同位素的分析,探讨了成矿流体特征。研究表明:存在液体包裹体、纯液体包裹体、纯气体包裹体和含液体CO2包裹体4种流体包裹体类型;液体包裹体均一温度为83.4~248.2℃,盐度为0.18%~6.45%,密度为0.85~1.0 g/cm3,成矿压力为10.9~59.4 MPa,成矿深度为0.2~2.2 km;各成矿阶段石英及方解石稀土元素特征表明,其成矿物理化学条件为还原环境。δ18OH2O值为-6.1‰~4.9‰;δDV-SMOW值为-40.3‰^-74.8‰,表明成矿流体来源为大气降水,岩矿石有机碳含量达到0.12%~0.45%,金品位与有机质含量呈正相关,黄铁矿及毒砂δ34SV-CDT值为9.2‰~10.2‰,表明者桑金矿床成矿热液中硫化物沉淀所需硫源为围岩中有机质与硫酸盐反应提供的还原硫。成矿热液在下渗过程中混合建造水,受到岩浆烘烤作用及地温梯度影响后再向上循环,金矿化发生在成矿流体的热循环与赋矿围岩的相互作用过程中,并在构造有利部位沉淀富集。

新疆蒙其古尔铀矿床成矿流体研究

文章对新疆蒙其古尔铀矿床成矿流体中的包裹体、酸解烃和镜质体反射率进行了分析研究。结果表明：该矿床的成矿流体主要为层间含氧含铀水和还原性烃类;石英裂隙中存在的流体包裹体主要是次生的富液盐水包裹体和液烃包裹体。测得流体包裹体的均一温度为50-67℃,平均66℃;w（NaCleq）为1.40%-14.04%,平均4.49%;成矿流体密度为0.98-1.04 g/cm^3,平均1.01 g/cm^3;说明成矿流体为低温低盐度流体,有机质热演化形成的甲烷等烃类参与了成矿过程。

江西金山金矿床成矿流体地球化学及矿床成因讨论

对金山韧性剪切带型金矿床石英及方解石中流体包裹体的研究表明:成矿流体具有中低温、低盐度和低密度的特征;富含Ca2+,Mg2+,SO2-4,CO2等;主要来源有变质热流体、富含有机质的大气降水形成的热流体和深源流体;流体的性质在时间和空间上都有一定的变化,矿床的形成主要是两期流体成矿作用的结果,是热液与构造的耦合;不同种类流体的混合、单一流体不混溶分离作用和盐水体系中有机质的参与是矿床形成的关键因素。

有机质热演化过程中地层压力的作用与影响

压力对有机质演化的影响长期以来争论不断,共有3种不同意见:压力对有机质演化没有影响,压力促进有机质的演化,压力抑制有机质的演化。通过对前人所做实验的实验设备、实验样品及实验结果的分析对比发现:不同实验结果主要是由于不同实验条件引起的,特别是实验系统和加压方式的不同,对实验结果影响最大,所代表的地质意义也不同。综合分析结果表明,当压力的增加表现为沉积有机质受到的有效应力增加时可以促进有机质生烃;当压力的增加表现为孔隙流体压力增加时,有机质生烃过程将受到抑制;另外,这两种情况都可能使干酪根的镜质组反射率降低,易使人得出压力增加抑制有机质演化的结论。进一步对压力影响有机质演化的成因机制进行了分析,发现在有机质演化的不同阶段因异常压力的增压机制不同,压力在有机质演化过程中所表现出来的作用也有差异。

利用产量数据动态跟踪地层压力的新方法

地层压力是计算气藏储量、评价气井产能、进行动态分析等必不可少的重要参数。根据定容性封闭气藏物质平衡方程，在已知天然气组分、地层温度、井底流压及产量等条件下，通过偏差因子程序计算得到地层温度恒定条件下井底流压对应的气体偏差因子，从而做累计产气量与井底视地层压力关系曲线并做其拟合直线，再通过已知视地层压力，做拟合直线的平行线，得到任意时刻累计产气量对应气藏视地层压力的关系曲线，利用此曲线预测在一定生产制度下地层压力变化趋势。应用表明该方法简单实用，计算地层压力接近实测地层压力，减轻现场测试工作量。

拉曼光谱在油气地质应用中的研究进展

拉曼光谱具有简单、快速、原位、微区、无损、高分辨率和高灵敏度等优点,可以分析物质的成分与分子结构信息,是开展地质研究的有力工具。通过回顾近年来拉曼光谱的研究进展,结合实际的油气地质研究工作及分析测试经验,对拉曼光谱在油气地质研究中的应用进行总结,并讨论现阶段应用过程中存在问题及未来的发展方向。拉曼光谱在油气地质中的应用主要分为三个方面:(1)矿物与流体包裹体分析,可以确定成岩-成藏流体类型及组成、成岩-成藏作用过程,包括岩矿鉴定、流体包裹体中流体体系分析、水-岩相互作用过程研究、地质样品同位素研究等;(2)不同类型有机质成熟度分析,可以用于恢复热史、油气成藏期次约束;(3)流体包裹体压力恢复,可以研究油气藏的形成与演化过程。主要方式为利用流体包裹体中气体的拉曼特征峰位移变化量、气体溶解度恢复流体包裹体内压及捕获压力。在实际油气地质研究中,多种因素制约拉曼光谱的定量/半定量应用,主要包括:地质样品复杂性与特殊性、样品处理方式、拉曼测试参数与测试环境、拉曼光谱数据处理与分析方式。拉曼光谱分析测试流程标准化、挑选和制备校准标样;拉曼光谱与冷热台、水热金刚石压腔(HDAC)、高压可视反应腔(HPOC)、扫描电镜(SEM)、电子探针(EPMA)等仪器联用,开展复杂体系原位、实时、不同温压条件下测试,是进一步将拉曼光谱应用到油气地质中的研究方向。

造山运动对变质流体及深部有机质演化的控制

对深部岩层应变速率在超临界阈值状态下形成的变质流体中有机质的化学物理反应进行剖析，认为地壳深部的高温高压条件是有机质生油的另一种地质特殊环境。讨论了碰撞造山过程中垂向增生应变、水平挤出应变、极限拉升应变与深部有机质的生、运、聚之间的相关性，认为中国西部新构造运动控制着成盆、成烃、成藏的全过程。深部有机质成烃是中国西部盆地新生代陆相油气藏的重要组成部分。

有机成矿流体研究进展

介绍了有机成矿流体的概念、研究意义、研究方法及其发展趋势。由于有机成矿流体是在金属矿床成矿过程中起重要或主要作用的、经过一定距离迁移的、含有机质的流体或呈流体状态的有机质，因此“异源有机质”对于金属成矿的作用特别重要，从而大大拓展了生物成矿学的研究领域。