Quantification constraints on time gap for comagmatic gold deposits:Evidence from chronological statistics

The time gap between diagenesis and mineralization (TGDM) for comagmatic gold deposits (CGD) plays an important role in confirming the genetic relationship between gold deposits and their related intrusions. With the help of preciously published isotopic ages of some typical gold deposits and their related rocks in China,the authors have discussed and quantified the distribution characteristics and scope of the TGDM. Statistical analyses and Kolmogorov tests showed that mineralizing events are either contemporaneous with or slightly postdate their cognate magma. The TGDM conforms with normal distributions at a 0.05 confidence level and clusters between 0 and 16.0 Ma with a mean of 7.0 Ma. Thus,if the TGDM of CGD is less than 16.0 Ma,it is reasonable to consider,with the aid of other evidence,the possibility of its comagmatic genetic affiliation. The authors also emphasized that to get a precise time gap it is necessary to strengthen the diagenesis-mineralization geological background of the deposits studied,and to pay attention to the study of time gap in combination with trace elements and isotope tracing.

Hydraulic mechanism and time-dependent characteristics of loose gully deposits failure induced by rainfall

Failure of loose gully deposits under the effect of rainfall contributes to the potential risk of debris flow.In the past decades, researches on hydraulic mechanism and time-dependent characteristics of loosedeposits failure are frequently reported, however adequate measures for reducing debris flow are notavailable practically. In this context, a time-dependent model was established to determine the changesof water table of loose deposits using hydraulic and topographic theories. In addition, the variation inwater table with elapsed time was analyzed. The formulas for calculating hydrodynamic and hydrostaticpressures on each strip and block unit of deposit were proposed, and the slope stability and failure risk ofthe loose deposits were assessed based on the time-dependent hydraulic characteristics of establishedmodel. Finally, the failure mechanism of deposits based on infinite slope theory was illustrated, with anexample, to calculate sliding force, anti-sliding force and residual sliding force applied to each slice. Theresults indicate that failure of gully deposits under the effect of rainfall is the result of continuouslyincreasing hydraulic pressure and water table. The time-dependent characteristics of loose depositfailure are determined by the factors of hydraulic properties, drainage area of interest, rainfall pattern,rainfall duration and intensity.

Influence of multi-deposition multi-annealing on time-dependent dielectric breakdown characteristics of PMOS with high-k/metal gate last process

A multi-deposition multi-annealing technique （MDMA） is introduced into the process of high-k/metal gate MOSFET for the gate last process to effectively reduce the gate leakage and improve the device＇s performance. In this paper, we systematically investigate the electrical parameters and the time-dependent dielectric breakdown （TDDB） characteristics of positive channel metal oxide semiconductor （PMOS） under different MDMA process conditions, including the depo- sition/annealing （D＆A） cycles, the D＆A time, and the total annealing time. The results show that the increases of the number of D＆A cycles （from 1 to 2） and D＆A time （from 15 s to 30 s） can contribute to the results that the gate leakage current decreases by about one order of magnitude and that the time to fail （TTF） at 63.2% increases by about several times. However, too many D＆A cycles （such as 4 cycles） make the equivalent oxide thickness （EOT） increase by about 1A and the TTF of PMOS worsen. Moreover, different D＆A times and numbers of D＆A cycles induce different breakdown mechanisms.

基于分子束外延技术可控制备Ga原子团簇的研究

本研究基于分子束外延(Molecular Beam Epitaxy,MBE)技术在Si(100)衬底表面成功制备金属Ga原子团簇.通过控制变量法,研究其尺寸形貌与工艺参数之间的关系.第一组对照实验分别在940℃、970℃、1000℃的Ga源温度下制备Ga原子团簇.实验结果表明,Ga源温度的升高导致Ga的蒸发量增加,进而沉积在Si衬底表面的Ga原子增多,Ga原子自组装成团簇,最终表现为Ga原子团簇的高度升高.第二组对照实验分别在3 s、6 s、10 s、40 s、50 s、60 s的沉积时长下制备Ga原子团簇.实验结果表明,沉积时长增加导致团簇的高度逐渐增加,主要由新吸附原子和竞争效应驱动.第三组对照实验分别在0 s、60 s、300 s的退火时长下制备Ga原子团簇.实验结果表明,退火时长的增加导致团簇的高度下降和团簇内的原子重新排列和分布有关.第四组对照实验分别在420℃、500℃的退火温度下制备Ga原子团簇.实验结果表明,升温至500℃退火会促进Ga原子团簇呈现有序排列,是表面原子的热运动和Ga原子团簇与Si(100)的晶格匹配度的共同作用的结果.

基于分子束外延技术可控制备Bi原子团簇的研究

本研究基于分子束外延(MBE)技术在Si(111)衬底表面成功制备金属Bi原子团簇.首先,分别在100℃、125℃、150℃、175℃、200℃的生长温度下,制备了大小均一、密度不同的Bi原子团簇.实验结果表明,可以通过改变生长温度来精细控制Bi原子团簇的密度,当温度升高100℃,密度从1.05×10^(11)cm^(-2)降低至2.5×10^(7)cm^(-2),实现对团簇密度4个数量级的可控调节,并且发现Bi原子团簇密度对生长温度的依赖性符合经典成核理论.其次,分别在10 s、15 s、20 s的沉积时长下,制备了密度相同、尺寸各异的Bi原子团簇.实验结果表明,可以通过改变沉积时长来精细控制Bi原子团簇的尺寸:当沉积时长增加10 s,高度和直径分别从8.5 nm和65 nm增大到13.7 nm和100 nm,实现对团簇尺寸在10 nm高度、80 nm直径范围的可控调节,并且发现Bi原子团簇尺寸对沉积时长的依赖性符合晶体生长动力学.与分子束外延制备传统的Ⅲ族(Al,Ga,In)原子团簇做对比,这些结果可以为制备Ⅴ族原子团簇提供实验参考和指导,从而促进纳米级含Bi材料的制备.

Microfacies and Depositional Environments of Miocene Isolated Carbonate Platforms from Central Luconia, Offshore Sarawak, Malaysia

The Luconia Province-offshore Sarawak-is a key geological unit for understanding the distribution of hydrocarbon resources in Malaysia. Nevertheless, little effort has been made to address the palaeoenvironmental characteristics of the Tertiary carbonates in the key sector of Central Luconia.We study the sedimentology and petrography of core samples from a well in Central Luconia, for which thirteen microfacies have been identified reflecting different depositional settings. This is the first microfacies scheme elaborated for Luconian carbonates. Lithofacies and microfacies distribution are compatible with deposition in a reef complex, originating around a framework reef, within the euphotic zone. Sediments were deposited in environments of backreef, reef crest, and forereef. The fair weather wave base is marked by the presence of coralline red algae, foraminifera, decreasing degree of bioclast fragmentation and other microfacies features. As a result, a depositional-environmental model is constructed, depicting a reef complex built around a framework reef developed on the margin of an isolated platform. In addition, an innovative, preliminary time series analysis of facies, microfacies and depositional environment data reveal the existence of seasonal cycles in the stacking patterns of facies and microfacies.

Rb-Sr Dating of Pyrite and Quartz Fluid Inclusions and Origin of Ore-forming Materials of the Jinshan Gold Deposit, Northeast Jiangxi Province, South China

The Jinshan gold deposit is located in the Northeast Jiangxi province,South China,which related to the ductile shear zone.It contains two ore types,i.e.the alteration-type ore and the goldbearing quartz vein ore.Rb-Sr age dating is applied to both gold-bearing pyrite in the alteration-type ore and fluid inclusion in the gold-bearing quartz vein to make clear the time of the gold mineralization of the Jinshan deposit.Analytical results of this study yielded that the age of the alteration-type ore bodies is about 838±110Ma,with an initial 87Sr/86Sr value of 0.7045±0.0020.However,the age of the gold-bearing quartz vein-type ore is about 379±49Ma,and the initial 87Sr/86Sr is 0.7138±0.0011.Based on the age data from this work and many previous studies,the authors consider that the Jinshan gold deposit is a product of multi-staged mineralization,which may include the Jinninian,Caledonian,Hercynian,and Yanshanian Periods.Among them,the Jinninian Period and the Hercynian Period might be the two most important ore-forming periods for Jinshan deposit.The Jinninian Period is the main stage for the formation of alteration-type ore bodies,while the Hercynian Period is the major time for ore bodies of gold-bearing quartz vein type.The initial values of the 87Sr/86Sr from this study,as well as the previous isotope and trace element studies,indicate that the ore-forming materials mainly derived from the metamorphic wall rocks,and the ore-forming fluids mainly originated from the deep metamorphic water.

Fabrication of Titanate Barium Films by Electrophoretic Deposition Technique

EPD （electrophoretic deposition） technique has been shown as an effective method to produce thin ore thick layers at voltage 5-100 V onto Ni conductive substrate. The aim of this study is to use the EPD method to fabricate films from suspensions BaTiO3. The effects of the EPD process parameters such as the suspension concentration, deposition time, electrical field strength on the specific EPD deposited weight, morphology particles were used. The surface microstructures of the as-deposited films were investigated by SEM （scanning electron microscopy）. A homogeneous microstructure was obtained at applied electric field of 100 V and I min of deposition time at an electrode distance of 1.0 cm.

Deposition of BaTiO3 Films from EthanoI-PVB Medium

EPD （electrophoretic deposition） of barium titanate from organic medium ethanol-PVB （polyvinyl butyral） was performed on Ni, Ti, steel substrate. Stable BaTiO3 suspensions with concentration of 2 wt.% have been prepared for the deposition. A uniform and dense layer was obtained for films deposited from ethanol with PVB of 0.1%. The surface topology of deposited films can be controlled via the applied voltage. This method allows to obtain crack-free and smooth layers BaTiO3 from organic medium with thickness of 4-20 μm.

Numerical Investigation on Influence of Wire Dimension on Energy Deposition Stage in Single Wire Electrical Explosion

The initial stage of wire array Z-pinch,i.e.the energy deposition stage in single wire electrical explosion,plays a very important role in the performance of the whole Z-pinch process.In this paper,this stage was modeled and simulated.Based on a mathematic model coupled with external circuit,the influence of wire dimension on the waveforms of current and voltage and the voltage-peak time in the energy deposition stage was studied.The calculated specific power indicates that time of the energy deposition extends with wire length quadratically.For normal wire dimension of wire array Z-pinch,the energy deposition time decreases slowly with the decreasing wire diameter,until approaches a minimum depended on the wire length.

新疆中亚造山带铁矿床地质特征、时空分布和找矿方向

在前人研究和野外调查基础上,文章综述了新疆中亚造山带铁及铁多金属矿地质特征、时空分布规律、构造环境和找矿方向。铁及铁多金属矿主要为岩浆型、海相火山岩型、矽卡岩型、IOCG型、岩浆热液脉型、沉积变质型和沉积型,其中海相火山岩型和矽卡岩型是主要类型,主要分布于南阿尔泰、东天山和西天山,少量分布在准噶尔、北山和西南天山。6个主要成矿期:新元古代青白口纪、中-晚志留世、泥盆纪(376~411 Ma)、石炭纪(301~337 Ma)、早-中二叠世(262~295 Ma)和晚三叠世—中侏罗世,其中泥盆纪和石炭纪为主要成矿期。新疆中亚造山带在前寒武纪陆块、洋-陆俯冲增生、陆-陆碰撞、后造山伸展和陆内等地质过程形成了不同类型的铁矿床。泥盆纪—石炭纪为与板块俯冲有关的大洋岛弧和陆缘弧环境,主要形成海相火山岩型和矽卡岩型;二叠纪为后碰撞环境,主要形成岩浆型和矽卡岩型;晚三叠世—中侏罗世为陆内伸展环境。今后的找矿部署是主攻西天山阿吾拉勒,深化南阿尔泰、东天山阿齐山-雅满苏-沙泉子和梧桐沟-天湖矿集区,加快评价准噶尔北缘、伊什基里克和莫托沙拉-库米什矿集区。

EXPERT OPTIMIZED CONTROL TECHNIQUE FOR ELECTROLYTIC DEPOSITION PROCESS OF HYDROMETALLURGY OF ZINC

ＥＸＰＥＲＴＯＰＴＩＭＩＺＥＤＣＯＮＴＲＯＬＴＥＣＨＮＩＱＵＥＦＯＲＥＬＥＣＴＲＯＬＹＴＩＣＤＥＰＯＳＩＴＩＯＮＰＲＯＣＥＳＳＯＦＨＹＤＲＯＭＥＴＡＬＬＵＲＧＹＯＦＺＩＮＣ①ＹａｎｇＣｈｕｎｈｕａ，ＧｕｉＷｅｉｈｕａ，ＹｅＷｅｎｗｕＩｎｆｏｒｍａｔｉ...

聚多巴胺修饰的Ag/AgCl参比电极的制备及其性能试验

为了适应栽培基质等非均相体系pH值的在线检测,并提供稳定的参考电位,采用磁控溅射沉积银膜、NaClO溶液氯化获得的AgCl层和多巴胺沉积修饰膜,研制了聚多巴胺修饰的Ag/AgCl固体薄膜参比电极,并在沉积时间分别为4、8、12、16 h时,对聚多巴胺修饰的参比电极在磷酸缓冲盐溶液(phosphate buffered saline,PBS)中的稳定性、可逆性和循环伏安特性曲线进行了对比测试.结果表明:参比电极在PBS溶液中电位标准差均约为1.00 mV,在不同pH缓冲溶液中均能够恢复到相对稳定的电位,且偏差小于5.00 mV,具有良好的可逆性;在50次循环伏安试验中电位漂移很小;根据参比电极的氯离子灵敏度为2.00~2.50 mV/pCl,聚多巴胺修饰的参比电极对氯离子浓度不敏感,证实聚多巴胺修饰的参比电极可以用作参比电极;沉积时间为12 h时的参比电极在各项试验中综合性能表现最优,应用试验表明该参比电极更适用于开展栽培基质pH检测.

预售模式下电商平台订货时间与定金决策研究

预售模式延长了产品整体销售周期,这为电商平台的产品订货时间决策带来了新问题。为研究对比提前与延后两种订货时间策略影响下的产品定金、产品价格与电商平台利润,建立两阶段主从博弈模型,分析定金敏感度、尾款敏感度和制造成本对订货时间选择与产品定金决策的影响。结果表明:在延后订货模式中,定金、尾款敏感度对产品订货价格影响相反;在提前订货模式中,只有定金敏感度影响产品订货价格。电商平台预售券/定金策略受消费者尾款敏感度影响。

Effect of varying spatial orientations on build time requirements for FDM process: A case study

In this research, effect of varying spatial orientations on the build time requirements for fused deposition modelling process is studied. Constructive solid geometry cylindrical primitive is taken as work piece and modeling is accomplished for it. Response surface methodology is used to design the experiments and obtain statistical models for build time requirements corresponding to different orientations of the given primitive in modeller build volume. Contour width, air gap, slice height, raster width, raster angle and angle of orientation are treated as process parameters. Percentage contribution of individual process parameter is found to change for build time corresponding to different spatial orientations. Also, the average of build time requirement changes with spatial orientation. This paper attempts to clearly discuss and describe the observations with an aim to develop a clear understanding of effect of spatial variations on the build time for Fused Deposition Modelling process. This work is an integral part of process layout optimization and these results can effectively aid designers specially while tackling nesting issues.

全球矿床数据库建设现状、应用与展望

基于大数据和人工智能技术的数据驱动科学范式推动地球科学研究发生了变革。作为地球科学的重要分支,现代矿床学经历了百余年的发展,已经积累了海量的数据资料,这些数据的流通和共享是发挥其资源价值的关键。文章介绍了中国“地质云”与全球矿产资源储量动态评估数据库、澳大利亚深部地球探测计划AuScope、美国矿产资源在线空间数据库、国际经济地质学家学会(SEG)Geofacets数据库、美国标准普尔公司SNL Metals&Mining数据库等国际主要矿床数据库的情况;同时,列举了应用大数据思维和人工智能方法在区域成矿规律、矿床成因机制、矿床类型判别、资源潜力评价、战略咨询等方面取得的若干重要进展。文章提出,未来在深时数字地球国际大科学计划的平台下,整合全球海量矿床数据,建设开放、共享、统一的矿床大数据平台势在必行。

Practical Method for Designing Gas Conditions of Atomic Layer Deposition

In order to effectively develop the atomic layer deposition (ALD) reactor and process, having huge potentials and applications in the advanced technology fields, a practical design method of the gas conditions for the ALD was studied using computational fluid dynamics (CFD). The design method consisting of the following four steps was studied. 1) At a low gas pressure producing no gas recirculation, the maximum difference in the gas phase temperature from the sample stage temperature, ΔT, was obtained at various chamber wall temperatures. 2) The ΔT value was studied at various gas pressures producing the gas recirculation. 3) For determining the applicable process conditions, contour diagrams of the temperature uniformity were obtained utilizing the temperature uniformity equations consisting of various process parameters. 4) The relationships of the maximum gas residence time with the gas flow rate and the gas pressure were obtained. The process in this study is expected to be practical for designing the thermal and gas flow conditions for achieving a fast ALD.

Geology and Geochemistry of Reworking GoldDeposits in Intrusive Rocks of China──Ⅱ.Gold Deposits and Their Genesis

Gold deposits in intrusive masses include the veinlet dissemination, quartz vein andveinlet dissemination + vein types . They are distributed in fracture zones along the endocontact zone of a batholith or in the centre and edge of a stock. The metallogenic epochs are Yenshanian, Hercynian, Archean, Proteredc and Himalaysn. The gold deposits are characterizedby a big difference in time span between gold mineralization and the formation of host masses.Ore-forming materials were derived from the masses and auriferous strata and ore-forming fluidscame from meteoric and formation waters. When circulating water was heated by ascendingheat flow, gold would be extracted, concentrated and transported from auriferous rocks andthen precipitated in the masses during the late tectonic movement. Finally gold deceits wereformed in the intrusive masses.

FDM技术打印参数对成型效率的影响研究

FDM技术可用于工业领域中大型零件模型的打印,提升成型效率成为重要的研究课题。本研究通过响应面分析方法,探究了FDM打印参数对聚乳酸圆柱件成型效率的影响规律,得到了最优打印参数,并经过实际打印验证。结果表明层厚增加,成型效率提高;打印速度增加,成型效率提高;填充率增加,成型效率降低;路径规划和壁厚对成型效率影响不大。影响成型效率的因素按照顺序排列是:层厚>打印速度>填充率,其中层厚和打印速度影响显著。最优打印参数为打印速度85mm·s^(-1)、层厚0.175mm、填充率55%,预测时间为58.8min,实际时间为59min,预测精度达99.7%,为提升成型效率提供了依据。

海南岛雷鸣盆地鹿母湾组碎屑岩地球化学特征、锆石U-Pb年龄和Hf同位素组成:对物源及构造环境的启示

海南岛雷鸣盆地鹿母湾组的确切沉积时限和沉积物来源是研究的空白区域。本文选取雷鸣盆地鹿母湾组作为研究对象,通过全岩地球化学、碎屑锆石U-Pb年代学和Lu-Hf同位素分析,旨在限定其沉积时限及物质来源,并探讨其沉积构造环境。鹿母湾组碎屑沉积岩的最年轻碎屑锆石年龄峰(113.3 Ma)与侵入其中的花岗闪长岩岩体年龄(~107 Ma)限定鹿母湾组沉积时限为109.9~113.3 Ma。全岩地球化学研究表明,鹿母湾组碎屑沉积岩的分异指数(ICV)为0.78~1.52(平均值0.96)、化学风化指数(CIA)为51.11~73.45(平均值65.27),反映其源区岩石具有中等成熟度并经历了弱的化学风化作用。结合微量元素、稀土元素含量及相关比值(如La、Th、Sc、Zr、Hf、∑REE及δEu)、源区判别图和构造环境判别图解,本文认为鹿母湾组碎屑沉积岩可能沉积于活动大陆边缘相关的盆地,主要来源于同时代的长英质火山岩或火山物质,少量碎屑来自华南内陆和海南岛早古生代岩浆岩。