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归来庄金矿金矿物主要为自然金、碲铜金矿和银金矿，多呈角粒状产出，粒间金较常见，属细粒—微细粒金。载金矿物以脉石英、黄铁矿、褐铁矿及方解石为主。二者标型特征表明：该金矿属浅成中低温热液型金矿床，泰山群变质岩系为其主要矿源层，并且有来自地球深部的金质参与成矿。文中提出了与金矿化相关的元素变化特征和宏观找矿标志。 相似文献
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本文阐述了A村金矿点的地质环境及其金矿化特征和矿化类型，认为该金矿点是与花岗岩类岩石有关的金矿化类型。关在研究其成矿条件的基础上，提出了若干寻找同类型金矿的找矿标志。 相似文献
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随着易选金矿资源的日益枯竭，难处理金矿则成了专家们研究的热点。作者对栾川潭头高硫难浸金精矿工艺矿物学进行了详细的研究，其难浸的原因是由于黄铁矿中存在着大量的晶格金，并发现交互连生金以及金包裹其他矿物的金的赋存状态，这是该金精矿的独有特征 相似文献
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黑色岩系金矿床具有重要的经济价值，滩间山金矿床为多因复成成因，黄铁矿是其最主要的矿石矿物。穆斯堡尔诺分析和金的浸取实验表明：滩间山金矿的黄铁矿中除存在大量金矿物（自然金或银金矿）外，尚存在１．２７％的晶格金，这部分金是一种潜在的金矿资源。此外，文中还探讨了晶格金的形成机理。 相似文献
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以山东平度旧店金矿床中金矿物作为研究对象,通过对金矿物的形态、物性、主成分及微量元素等特征的研究,认为旧店金矿中主要金矿物为银金矿、自然金,主要载金矿物为石英、黄铁矿、黄铜矿、方铅矿、闪锌矿等。金主要以银金矿形式产出,金银矿少量,自然金很少。金矿物赋存状态主要为裂隙金、包体金、晶隙金等,呈粒状、板状、针状产出,银金矿与石英、黄铁矿依存关系最为密切。旧店金矿金的成色集中在600～800之间,平均744.13,说明旧店金矿经历了中温成矿环境,且成矿时间较短,是以金石英多金属硫化物阶段为主成矿期。 相似文献
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应用GIS研究中国原生金矿与砂金矿的关系 总被引：2，自引：0，他引：2
参阅近千件文献建立中国金矿数据库(ACCESS)及构造格架、地层、火成岩等图层与属性表(ArcInfo、ArcView)，对其进行时空分析。中国砂金矿主要形成在第四纪，而原生金矿则主要形成在侏罗-白垩纪(占原生金总储量64．6％)。空间分析发现，超过半数的原生金矿金储量(52．5％)分布在砂金矿0～40km缓冲域中，其中5～25km缓冲域中为33．2％，而0～5km缓冲域中仅3％，表明原生金矿主要为5～25km内砂金矿提供矿质。此外，中国砂金矿金储量916．9t，占总储量的11．6％，明显少于澳大利亚的25．2％。认为与后者原生金矿主要形成在太古代和古生代有关；中国东部中新生代(尤其第三纪)地壳减薄导致此前形成原生金矿的掩埋，可能是造成砂金较少的另～原因，这两种推测与中国缺乏古砂金相吻合。量化分析结合地质背景研究表明，西秦岭、松潘-甘孜地块、拉萨附近为依据砂金找原生金的远景区。 相似文献
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义县红石砬子金矿，金以裂隙金、晶隙金和包体金产于载金矿物黄铁矿和石英等矿物内部及其间隙中。辽西中生代义县旋回酸性火山岩系发育地区具有线状火山机构并有次火山岩分布地段是寻找该类型金矿的有利地段，在上述火山岩中的硅化、黄铁矿化面型蚀变或褐铁矿染等是该类型金矿的找矿标志． 相似文献
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桃园金矿成因比较复杂．岩广测试和电镜扫描研究表明，金矿矿物组合可划分为金－石英－细粒黄铁矿－毒矿四，金－石英－银－多金属硫化物型；金－石英－自形黄铁广３种类型．通过对矿石的矿物组分和化学成分，以及金、银的赋存状态研究，认为桃园全矿的矿石属于金矿矿物极细，而矿物组成比较复杂的矿石类型． 相似文献
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知识型企业中创造型团队的管理 总被引：1，自引：0，他引：1
主要对知识型企业中团队问题进行了研究。从团队领导、团队结构以及团队协作与企业家精神的关系等方面讨论了在知识型企业中建立创造型团队的重要性，并相应提出了人力资源政策建议。 相似文献
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Flume experiments and numerical simulation were conducted to characterize the hydrodynamics of a trapezoid artificial reef. Measurements in particle image velocimetry were conducted to observe the formation of upwelling and vortices; and forces for the reef model were measured by load cell. The results of flume experiments agree well with the numerical data. In addition, the flow structure around a reef combining trapezoidal and cubic blocks was simulated numerically under two deployment schemes, showing a more complicated flow structure than that of a stand-alone reef. Relationship between drag coefficient and Reynolds number suggest that the degree of turbulence can be assessed from the value of drag coefficient downstream from the reef. The role of the reef in water flow is to reduce flow velocity and generate turbulence. 相似文献
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《山地科学学报》2021,(8)
A tunnel-type anchorage(TTA) is one of the main components in suspension bridges: the bearing mechanism is a key problem. Investigating the deformation characteristics, development law, and failure phenomenon of a TTA under load can provide the theoretical basis for a robust design. Utilizing the TTA of the Jinsha River suspension bridge at Lijiang Shangri-La railway as a prototype, a laboratory model test of the TTA was carried out for three different contact conditions between the anchorage body and the surrounding rock. The stress and deformation distribution law of the anchorage body and its surrounding rock were studied, and the ultimate bearing capacity and failure mode of the TTA were analyzed. The test results show that the compressive stress level is highest at the rear part of the anchorage body. Moving away from the rear portion of the body, the stress decays in a negative exponential function. Based on the load transfer curve, the calculation formula for the shear stress on the contact surface between the anchorage body and the surrounding rock was derived, which shows that the distribution of the shear stress along the axial direction of the anchorage body is not uniform. The distance from the maximum value to the loading surface is approximately 1/3 of the length of the anchorage body, and the stress decreases as the distance from the loading surface increases. Furthermore, the contact condition between the anchorage body and surrounding rock has a great influence on the bearing capacity of the TTA. The increase in the anti-skid tooth ridge and radial anchor bolt can improve the cooperative working capacity of the anchorage body and the surrounding rock, which is approximately 50% higher than that of the flat contact condition. The main function of the anchor bolt is to increase the overall rigidity of the TTA. The contact condition between the anchorage body and the surrounding rock will lead to a change in the failure mode of the TTA. With an increase in the degree of contact, the failure mode will change from shear sliding along the interface to trumpet-shaped inverted cone-shaped failure extending into the surrounding rock. 相似文献
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This study aimed to produce a high-quality landslide susceptibility map for Teziutlán municipality, a landslide-prone region in Mexico, which is characterised by a depositional pyroclastic ramp. The heterogeneous quality of available topographic information(i.e. higher resolution digital elevation model only for a sub-region) encouraged to confront modelling results based on two different study area delineations and two raster resolutions. Input data was based on the larger modelling region L15(163 km2) and smaller S(70 km2; located inside L15) with an associated raster cell size of 15 m(region L15 and S15) and 5 m(region S5). The resulting three data sets(L15, S15 and S5) were included into three differently flexible modelling techniques(Generalized Linear Model-GLM, General Additive Model-GAM, Support Vector Machine-SVM) to produce nine landslide susceptibility models. Preceding variable selection was performed heuristically and supported by an exploratory data analysis. The final models were based on the explanatory variables slope angle, slope aspect, lithology, relative slope position, elevation, convergence index, distance to streams, distance to springs and topographic wetness index. The ability of the models to classify independent test data was elaborated using a k-fold cross validation procedure and the AUROC(Area Under the Receiver Operating Characteristic) metric. In general, all produced landslide susceptibility maps depicted the hillslopes of the ravines, which cut the pyroclastic ramp, as prone to landsliding. The modelling results showed that predictive performances(i.e. AUROC values) slightly increased with an increasing flexibility of the applied modelling technique. Thus, SVM performed best, while the GAM outperformed the GLM. This tendency was most distinctive when modelling with the largest landslide sample size(i.e. data set L15; n = 662 landslides). Non-linear classifiers(GAMs, SVMs) performed slightly better when trained on the basis of lower raster resolution(data set S15) compared to the 5 m counterparts(data set S5). Highest predictive performance was obtained for the model based on data set L15 and the SVM classifier(median AUROC: 0.82). However, SVMs also indicated the highest degree of model overfitting. This study indicates that the decision to delineate a study area, the selection of a raster resolution as well as the chosen classification technique can affect varying aspects of subsequent modelling results. The results do not support the assumption that a higher raster resolution(i.e. a more detailed digital representation of the terrain) inevitably leads to better performing or geomorphically more plausible landslide susceptibility maps. 相似文献
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Interception of sulfate deposition from a closed canopy to a forest gap edge canopy in a subalpine dragon spruce plantation 总被引：1，自引：0，他引：1
《山地科学学报》2019,(12)
Reducing the threats of sulfate ion(SO_4~(2-))deposition to terrestrial ecosystems is a great challenge.The canopy interception effect on SO_4~(2-)deposition has been well documented,but the interception efficiency of the gap edge remains unknown.Therefore,a subalpine dragon spruce(Picea asperata) plantation was evaluated in the upper reaches of the Yangtze River.The dynamics of the SO_4~(2-) concentration in the throughfall were investigated from the gap edge to the closed canopy during the rainfall and snowfall periods from August 2015 to July 2016.The annual input of SO_4~(2-) totaled 2.56 kg/ha through rainfall and 0.69 kg/ha through snowfall.The total annual net interception fluxes(NIFs) of SO_4~(2-) at the gap edge and in the closed canopy were 1.48 kg/ha and 0.66 kg/ha,respectively,and the net interception ratios(NIRs) accounted for 45.40% and 20.25%,respectively.The NIF and the NIR of SO_4~(2-) at the gap edge were higher than those in the closed canopy.Therefore,the results suggested that a significant amount of SO_4~(2-) deposition was intercepted by the tree canopy in the subalpine plantation,with more SO_4~(2-) deposition at the gap edge than in the closed canopy,which is beneficial for improving the water quality in the upper reaches of the Yangtze River via forest management. 相似文献
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Based on the principle of turned mass damper(TMD) systems,the conceptual design of semi-submersible platform with a moveable heave-plate(MHS) has been put forward.The heave motion response amplitude operator(RAO) and viscous damping of the MHS platform are calculated by iteration,and the coupling stiffness between the MHS hull and the heave-plate is optimized to decrease the maximum heave motion response of the MHS hull under 10-year survival conditions in the South China Sea.The nu-merical results indicate that the heave motion RAO of the MHS hull can be decreased in the range of predominant wave frequencies,which may provide some reference to the heave motion control of offshore platforms. 相似文献
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A finite difference model for solving Navier Stokes equations with turbulence taken into account is used to investigate viscous liquid sloshing-wave interaction with baffles in a tank. The volume-of-fluid and virtual boundary force methods are employed to simulate free surface flow interaction with structures. A liquid sloshing experimental apparatus was established to evaluate the accuracy of the proposed model, as well as to study nonlinear sloshing in a prismatic tank with the baffles. Damping effects of sloshing in a rectangular tank with bottom-mounted vertical baffles and vertical baffles touching the free surface are studied numerically and experimentally. Good agreement is obtained between the present numerical results and experimental data. The numerical results match well with the current experimental data for strong nonlinear sloshing with large free surface slopes. The reduction in sloshing-wave elevation and impact pressure induced by the bottom-mounted vertical baffle and the vertical baffle touching the free surface is estimated by varying the external excitation frequency and the location and height of the vertical baffle under horizontal excitation. 相似文献
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Liang Qiao Xing-min Meng Guan Chen Yi Zhang Peng Guo Run-qiang Zeng Ya-jun Li 《山地科学学报》2017,14(6):1113-1123
A colluvial landslide in a debris flow valley is a typical phenomena and is easily influenced by rainfall. The direct destructiveness of this kind of landslide is small, however, if failure occurs the resulting blocking of the channel may lead to a series of magnified secondary hazards. For this reason it is important to investigate the potential response of this type of landslide to rainfall. In the present paper, the Goulingping landslide, one of the colluvial landslides in the Goulingping valley in the middle of the Bailong River catchment in Gansu Province, China, was chosen for the study. Electrical Resistivity Tomography (ERT), Terrestrial Laser Scanning (TLS), together with traditional monitoring methods, were used to monitor changes in water content and the deformation of the landslide caused by rainfall. ERT was used to detect changes in soil water content induced by rainfall. The most significant findings were as follows:(1) the water content in the centralupper part (0~41 m) of the landslide was greater than in the central-front part (41~84 m) and (2) there was a relatively high resistivity zone at depth within the sliding zone. The deformation characteristics at the surface of the landslide were monitored by TLS and the results revealed that rainstorms caused three types of deformation and failure: (1) gully erosion at the slope surface; (2) shallow sliding failure; (3) and slope foot erosion. Subsequent monitoring of continuous changes in pore-water pressure, soil pressure and displacement (using traditional methods) indicated that long duration light rainfall (average 2.22 mm/d) caused the entire landslide to enter a state of creeping deformation at the beginning of the rainy season. Shear-induced dilation occurred for the fast sliding (30.09 mm/d) during the critical failure sub-phase (EF). Pore-water pressure in the sliding zone was affected by rainfall. In addition, the sliding L1 parts of the landslide exerted a discontinuous pressure on the L2 part. Through the monitoring and analysis, we conclude that this kind of landslide may have large deformation at the beginning and the late of the rainy season. 相似文献
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The tidal asymmetry-induced siltation below tidal barriers is a worldwide problem that restricts regional socio-economic and environmental development. The hydrodynamic processes of the small mud estuary also feature a high uncertainty after estuary restoration measures. In this study, a hydrodynamic model based on the MIKE21 is used to quantify the responses of tidal asymmetry to a two-phase restoration project in Shuanglong Estuary, Bohai Bay, China. According to the numerical modeling results, the tidal flat removal in the upper estuary(first-phase restoration) induces the flood asymmetry switching to the ebb asymmetry in unrestored reach but enhances flood asymmetry in widening restored reach. Although the tidal asymmetry reverts to flood-dominated pattern after full restoration over the estuary, the imbalance between flood and ebb velocities is relieved. A possible net sediment transport pattern based on a comparison of dominant asymmetric current and actual sediment transport period shows net sediments in the upper estuary and inlet transport seaward and landward, respectively, in the first-phase restoration, whereas landward net sediment transport occurs in the whole estuary under the second-phase restoration scenario. Given these results, we assume that a switch from the flood-dominated estuary to ebb-dominated estuary can be caused by redesigning the cross-sectional profile. The quantitative comparison of Lagrangian residual currents also implies that a channel–shoal structure rather than a flat bathymetry can promote the mass transport. Therefore, reshaping the channel–tidal flat system in restoration projects can prevent the sedimentation of the estuary and improve the water environment. 相似文献