Remote Sensing Study of Gold Biogeochemical Effects in the Western Guangdong-Hainan Region——A Case Study of the Hetai Gold Deposit

The vegetation has been poisoned by gold in the western Guangdong-Hainan region. The gold content ofthe leaves there is as high as 10-1961 times the abundance, the chlorophyll content is 10%-30% lower thanthat of the vegetation in metamorphic terrains and 10%-20% higher than that in granite terrains, and thecarotenoid content is 10%-44% lower than the background value. The water content of leaves is 10% to 20%lower than the background value. The cells of leaves are deformed and broken. The leaf surface shows colourspots and becomes yellow or dark green. The spectral reflectance of the leaf surface is 5%-30% higher than thebackground value: the spectral shape has shifted 5-15 nm to the short wavelength. The gray scales of eanopyon images of Landsat TM and airborne imaging scanner (AIS) are 10%-100% higher than the backgroundvalues. On Landsat TM and AIS false colour images, plants poisoned by gold display a yellow color, whichdisinguishes them from background plants. According to the spectral and image features of goldbiogeochemical effects, the author has constructed a gold information system and expert prediction system,and thus two gold target areas and two gold prospect areas have been identified rapidly, economically andaccurately in the western Guangdong-Hainan region which is extensively covered by vegetation.

Effect of nitrogen on deposition and field emission properties of boron-doped micro-and nano-crystalline diamond films

In this paper,we report the effect of nitrogen on the deposition and properties of boron doped diamond films synthesized by hot filament chemical vapor deposition.The diamond films consisting of micro-grains(nano-grains) were realized with low(high) boron source flow rate during the growth processes.The transition of micro-grains to nano-grains is speculated to be strongly(weekly) related with the boron(nitrogen) flow rate.The grain size and Raman spectral feature vary insignificantly as a function of the nitrogen introduction at a certain boron flow rate.The variation of electron field emission characteristics dependent on nitrogen is different between microcrystalline and nanocrystalline boron doped diamond samples,which are related to the combined phase composition,boron doping level and texture structure.There is an optimum nitrogen proportion to improve the field emission properties of the boron-doped films.

The Effect of Oxygen Partial Pressure during Active Layer Deposition on Bias Stability of a-InGaZnO TFTs

The effect of oxygen partial pressure （Po2） during the channel layer deposition on bias stability of amorphous indium-gallium-zinc oxide （a-IGZO） thin film transistors （TFTs） is investigated. As Po2 increases from 10% to 30%, it is found that the device shows enhanced bias stress stability with significantly reduced threshold voltage drift under positive gate bias stress. Based on the x-ray photoelectron spectroscopy measurement, the concentration of oxygen vacancies （Or） within the a-IGZO layer is suppressed by increasing Po2. Meanwhile, the low-frequency noise analysis indicates that the average trap density near the channel/dielectric interface continuously drops with increasing Po2. Therefore, the improved interface quality with increasing Po2 during the channel layer deposition can be attributed to the reduction of interface Ov-related defects, which agrees with the enhanced bias stress stability of the a-IGZO TFTs.

Geochemistry and environmental effect of cadmium in the super-large Jinding Pb-Zn deposit,Yunnan Province, China

The Jinding Pb-Zn deposit in Yunnan Province is the representative of a Cd-enriched area and mining activities lead to the release of Cd into the hypergenic ecosystem, resulting in Cd pollution. The concentrations of Cd vary greatly from one type to another type of rocks in the mining district. In the host rock, Cd concentrations range from 50×10-6 to 650×10-6 with an average of 310×10-6. In primary ores, Cd concentrations range from 14×10-6 to 2800×10-6 with an average of 767×10-6. However, in oxidized ores, Cd concentrations are highest, varying within the range of 110×10-6 to 8200×10-6 , averaging 1661×10-6. It is shown that the oxidized ores are the main carrier and environmental source of Cd. Leaching test showed that Pb/Zn ores are easy to oxidize and thereafter release Cd and other harmful elements. These leached elements in the leachate may be precipitated rapidly in the order of Zn>Pb>Cd. As for the concentration distribution of Cd in the Bijiang River, it is estimated to be 15.7 μg/L Cd in water, 49.3 mg/L in suspended substances, and 203.7 mg/L in sediments. The average value of Cd in soil from the polluted area is 83.0 mg/kg. Natural weathering of Cd-rich rocks and minerals imposes a potential environmental risk on the aquatic ecosystem of the Bijiang catchment.

SUBSTRATE EFFECT ON HYDROGENATED MICROCRYSTALLINE SILICON FILMS DEPOSITED WITH VHF-PECVD TECHNIQUE

Raman spectra and scanning electron microscope （SEM） techniques were used to determine the structural properties of microcrb＇stalline silicon （μc-Si：H） films deposited on different substrates with the very high frequency plasma-enhanced chemical vapor deposition （VHF-PECVD） technique. Using the Raman spectra, the values of crystalline volume fraction Xc and average grain size d are 86%, 12.3nm; 65%, 5.45nm; and 38%, 4.05nm, for single crystalline silicon wafer, coming 7059 glass, and general optical glass substrates, respectively. The SEM images further demonstrate the substrate effect on the film surface roughness. For the single crystalline silicon wafer and Coming 7059 glass, the surfaces of the μc-Si：H films are fairly smooth because of the homogenous growth or h＇ttle lattice mismatch. But for general optical glass, the surface of the μ-Si： H film is very rough, thus the growing surface roughness affects the crystallization process and determines the average grain size of the deposited material. Moreover, with the measurements of thickness, photo and dark conductivity, photosensitivity and activation energy, the substrate effect on the deposition rate, optical and electrical properties of the μc-Si：H thin films have also been investigated. On the basis of the above results, it can be concluded that the substrates affect the initial growing layers acting as a seed for the formation of a crystalline-like material and then the deposition rates, optical and electrical properties are also strongly influenced, hence, deposition parameter optimization is the key method that can be used to obtain a good initial growing layer, to realize the deposition of μc-Si：H films with device-grade quality on cheap substrates such as general glass.

Influence of Mineral Admixtures on the Electrodeposition Healing Effect of Concrete Cracks

Two types of solutions（Zn SO4, Mg SO4） were selected to study the influence of mineral admixtures on the electro-deposition healing effect of concrete cracks. Four parameters（i e, rates of weight gain, surface coating, crack closure and crack filling depth） were measured. The mineral composition of electro-deposits in the cracks was analyzed. The study shows that the healing effect of mortar specimens with 10% fly ash is the worst, while the healing effect of mortar specimens with 20% fly ash is better than that of the specimens without fly ash. The rates of weight gain, surface coating, crack closure and crack filling depth decrease with increasing content of the ground granulated blast-furnace slag（GGBS）. The mineral admixtures have no influence on the composition of deposits.

The effect of deposition temperature on the intermixing and microstructure of Fe/Ni thin film

The physical vapour deposition of Ni atoms on α-Fe（001） surface under different deposition temperatures were simulated by molecular dynamics to study the intermixing and microstructure of the interracial region. The results indicate that Ni atoms hardly penetrate into Fe substrate while Fe atoms easily diffuse into Ni deposition layers. The thickness of the intermixing region is temperature-dependent, with high temperatures yielding larger thicknesses. The deposited layers are mainly composed of amorphous phase due to the abnormal deposition behaviour of Ni and Fe. In the deposited Ni-rich phase, the relatively stable metallic compound B2 structured FeNi is found under high deposition temperature conditions.

Effective energy deposition and latent track formation of swift heavy ions in solids

In the present paper, latent track formation in yttrium iron garnet (YIG) produced by high energy Ar ions is briefly reported at first. Then, in the framework of thermal spike model, a phenomenological parameter describing the effective energy transfer from excited electrons to lattice atoms, effective energy deposition Qeff, is deduced. Qeff is a function of ion velocity, electronic energy loss (Se) and mean free path λ of excited electrons in the matter, and is a time moderate term initialized by Waligorski’s function of spatial energy deposition of secondary electrons ejected by incident ions. Size of ion latent track is proportional to Qeff value. From Qeff obtained by use of realistic λ values, the sizes of latent tracks in SiO2, YIG, Ti and Zr produced by given swift heavy ion irradiations are deduced and com- pared with experimental results. It is found that, from the fits to experimental results, the best λ values for SiO2, YIG, Ti and Zr are (6±1), (8±2), (6.1±1.0) and (9.6±1.0) nm, respectively. Moreover, the relationship between experimental damage and Qeff is discussed.

Effects of Implant Copper Layer on Diamond Film Deposition on Cemented Carbides

The deposition of high-quality diamond films and their adhesion on cemented carbides are strongly influenced by the catalytic effect of cobalt under typical deposition conditions. Decreasing Co content on the surface of the cemented carbide is often used for the diamond film deposition. But the leaching of Co from the WC-Co substrate leading to a mechanical weak surface often causes a poor adhesion. In this paper we adopted an implant copper layer prepared by vaporization to improve the mechanical properties of the Co-leached substrate. The diamond films were grown by microwave plasma chemical vapor deposition from CH4:H2 gas mixture. The cross section and the morphology of the diamond film were characterized by scanning electron microscopy (SEM). The non-diamond content in the film was analyzed by Raman spectroscopy. The effects of pretreatment on the concentrations of Co and Cu near the interfacial region were examined by energy dispersive spectrum (EDS) equipped with SEM. The adhesion of the diamond on the substrate was evaluated with a Rockwell-type hardness tester. The results indicate that the diamond films prepared with implant copper layer have a good adhesion to the cemented carbide substrate due to the recovery of the mechanical properties of the Co-depleted substrate after the copper implantation and the formation of less amorphous carbon between the substrate and the diamond film.

若羌库木苏铜矿地质特征及成因初探

库木苏铜矿产于红柳沟-喀腊大湾裂谷带东部卓阿布拉克杂岩体中,为近年来在阿尔金东段奥陶纪辉长岩建造内发现的铜矿产地。通过对库木苏铜矿区成矿地质背景、化探异常、蚀变带及矿体特征的研究,分析成矿环境和控矿因素,初步认为该矿属岩浆硫化物型铜矿床,具良好的找矿潜力。

Effect of Pulse Parameters on Deposition in Concrete Crack using Pulse Current Electro-deposition

To evaluate the effect of pulse parameters on the formation of electrodeposits in concrete cracks, five different types of pulse current were set up, and ZnSO_4 and MgSO_4 solutions were used as the electrolytes. The rate of weight gain, rate of surface coating, rate of crack closure and crack filling depth were measured. Scanning electron microscopy was used to assess the morphology of the electrodeposits, and energy dispersive spectroscopy was used to analyze the mineral composition of the electrodeposits in the cracks. The experimental results demonstrate that, among five different pulse parameters, when T_（on）/T_（off）=0.8 ms/0.8 ms, the healing effect of electro-deposition is the best. The pulse mode hardly affects the mineral composition of the electrodeposits but changes the micromorphology. In addition, for both ZnSO_4 and MgSO_4 solutions, when T_（on）/T_（off）=0.8 ms/0.8 ms, the crystal structure of the electrodeposits is the most uniform and the densest.

基于长江雨课堂的矿床学课程教学实践

长江雨课堂作为一种线上教学工具,在全国范围内得到广泛的好评。雨课堂是基于PowerPoint运行的智慧教学方案,可以通过三步式“课前—课中—课后”为学生和老师提供全方位服务。该文立足矿床学课程教学实践,主要探讨长江雨课堂为传统线下教育教学带来的影响,雨课堂的三步式方案显著提高教学质量,打造高效课堂。

押金制度下参考质量/价格效应的产品定价策略

为研究顾客在押金制度下参考质量/价格对制造商定价决策的影响,构建了以制造商利润最大化为目标的产品定价模型。运用斯坦伯格博弈理论和最优化方法求出产品最优定价,通过解析方法和数值分析方法分别进行了灵敏度分析及模型比较。结果表明,参考价格/质量效应下再制造品的接受程度、产品的耐用性及押金等参数影响了制造商的最优利润,决定了制造商是否采用押金制度;制造商利润随着参考质量效应程度的增加而减少,随着参考价格效应程度的增加而增加;合理使用押金制度下参考价格效应可使制造商达到更高的期望利润。

非岩浆后生热液矿床构造—流体耦合成矿作用研究现状综述

构造—流体耦合成矿作用是矿床学研究的核心问题之一。本文聚焦非岩浆后生热液矿床成矿系统的构造—流体耦合成矿作用研究成果,从构造对流体作用、流体对构造作用两个方面,总结了构造活动与流体作用同步进行且相互影响的机制。通过典型实例分析,认为构造—流体耦合成矿作用研究要从时间、空间、物质方面的耦合关系阐明构造与流体成矿作用过程及其“矿源—输运—聚集”过程,揭示构造活动与流体成矿作用机理。在此基础上,提出了构造—流体耦合成矿作用研究的主要方向及发展趋势。该研究对丰富热液矿床成因理论研究和成矿规律的认识具有重要意义。

黄河三角洲近岸潮汐动力对地貌演变的响应及其沉积效应

近年来自然过程和人类活动显著改变了黄河入海流路以及近岸地貌格局,而剧烈的地貌演变对近岸水动力环境的影响尚未得到充分研究。为厘清近30年来黄河三角洲近岸水文动力格局对地貌演变的响应过程,本文基于Landsat系列遥感影像和多期测深数据,分析了1992-2020年黄河三角洲岸线和地形变化,并采用TELEMAC-2D建立了多套覆盖整个渤海的数值模型,研究了地貌演变对黄河三角洲邻近海域潮汐动力的影响及其沉积效应。结果表明,黄河三角洲近岸冲淤格局呈现显著的时空异质性,分布多个淤积和侵蚀中心,且2000-2020年南侧老清水沟外侵蚀中心向南移动9.6 km,1992-2015年北侧刁口河口外侵蚀中心东移6.4 km。中长时间尺度黄河三角洲岸线和地形变化主导了潮汐动态,三角洲北部刁口河口近岸潮差减小,清水沟河口外潮差增大,5 m水深处的潮差变化增大幅度达0.27 m;黄河口近岸K_1分潮振幅显著增加,M_2分潮振幅明显减小,东营港附近无潮点向东迁移3.8 km。刁口河口和老河口外高流速区持续减弱,现行河口外逐渐发育形成另一高流速区,持续稳定的高流速区造成了水下三角洲的冲刷,南北侧高流速区沉积物粗化。

油水乳化胶凝作用对蜡沉积影响的定量表征

通过对乳液黏温曲线变化规律进行挖掘,对凝油团形成过程定量表征,推导得出凝油团形成的数学关系表达式,将胶凝过程细化为凝油团形成和黏附两个阶段。通过蜡沉积的温度条件,发现随着沉积管壁的温度降低,凝油团形成系数逐渐增大,胶凝作用逐渐显著,即在沉积初期蜡沉积的厚度迅速增加,这与蜡沉积实验结果相吻合。

千里岩湿沉降中的营养盐特征、来源及生态效应研究

本研究基于2020年3月—2021年2月黄海千里岩岛雨水中营养盐(NH_(4)^(+)、NO_(3)^(-)、NO_(2)^(-)、PO_(4)^(3-)、SiO_(3)^(2-)、DON、DOP)浓度,利用后向轨迹聚类分析和浓度权重轨迹分析法(CWT)解析气团主要传输路径和营养盐潜在源区,并讨论湿沉降对黄海生态系统的影响。结果表明,NH_(4)^(+)、NO_(3)^(-)和DON是雨水营养盐的主要组成,平均浓度分别为(48.2±118.8)、(30.8±97.2)和(22.1±147.7)μmol/L。NO_(2)^(-)、PO_(4)^(3-)、DOP和SiO_(3)^(2-)的浓度较低,平均仅为(0.24±0.40)、(0.87±5.5)、(0.12±0.17)和(0.13±0.23)μmol/L。影响雨水的气团来自南方陆海混合源(41%)、北方陆源(41%)、东南海源(10%)和西北陆源(8%),陆源气团影响的雨水中营养盐浓度普遍高于混合源和海源。不同营养盐组分潜在源区的分布特征不同。NH_(4)^(+)、NO_(3)^(-)和PO_(4)^(3-)的潜在源区集中在山东,DON的潜在源区分布在河北、山东、河南、安徽和俄罗斯的贝加尔湖附近,DOP的潜在源区在长江入海口附近的上海和浙江沿岸地区,SiO_(3)^(2-)的潜在源区分别位于山东河北交界处、安徽江苏交界处、安徽江西交界处和黄海部分海域。总体而言,对营养盐高贡献的潜在源区位于周边陆地地区,海源较少。黄海大气TDN的全年湿沉降通量为103.0 mmol·m^(-2)·a^(-1),对新生产力的贡献可达29.9%。

CSAMT在危机矿山深边部勘查中的应用——以湖南稻草湾矿区锑矿为例

近年来,我国许多大中型有色金属矿山经过多年开采后,出现资源严重不足.文章主要针对危机矿山——湖南省锡矿山锑矿的现状,探讨寻找接续资源的问题,以期在危机矿山深边部取得找矿突破.在锡矿山北部的稻草湾矿区共布设11条可控源音频大地电磁测深法(CSAMT)剖面,通过对探测数据进行预处理、静态校正以及二维反演计算等方法,研究该区受断裂和地层联合控制的隐伏锑矿体的存在状态.研究成果突显了稻草湾矿区控矿断裂的分布特征,并由此推断出隐伏矿体的标高位置.经后期钻孔验证可知:CSAMT的解译结果与断裂构造和矿体的位置吻合,表明CSAMT法在该区找锑具有较好的效果,可为今后类似的危机矿山深边部找矿提供科学依据.

黔西南赖子山背斜区成矿结构面特征及其对卡林型金矿控矿作用

赖子山背斜位于黔西南卡林型金矿矿集区中部,成矿条件优越。通过对赖子山背斜区内成矿结构面特征的归纳总结,对区内卡林型金矿的控矿作用进行剖析。结果表明:研究区主要发育原生成矿结构面和次生成矿结构面,成矿结构面对金矿的控制作用表现在对金矿体产出、规模、形态、厚度和品位的控制,并指出赖子山背斜区卡林型金矿成矿主要受次生成矿结构面控制。

NiO外延薄膜的显微结构与光学、电学性能研究

本文利用脉冲激光沉积技术在MgO(100)和Al_(2)O_(3)(0001)衬底上生长了NiO薄膜,并应用高分辨X射线衍射仪、X射线光电子能谱仪和透射电子显微镜表征了两种薄膜的物相、化学成分和显微结构。结果表明,MgO衬底上的NiO薄膜为单晶外延薄膜,薄膜内部存在位错和由衬底扩散来的Mg元素,Al_(2)O_(3)衬底上的NiO薄膜为多晶外延薄膜。采用霍尔效应测试系统和紫外分光光度计测量了NiO薄膜的电阻、可见光透过率和能隙。结果表明,单晶NiO薄膜具有较低的电阻,更高的可见光透过率和更大的能隙。本研究表明可以通过选择不同的衬底来调控NiO薄膜的显微结构、光学和电学性质。