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991.
李莹  肖克炎  陈建平 《地质通报》2010,29(10):1547-1553
在成矿预测理论的指导下,利用已有的商业三维地质建模软件,建立了研究区地质、构造、钻孔、矿体的空间三维模型。在此基础上进行矿体品位估算与插值,建立了研究区立方体预测模型。从三维的角度分析矿体分布的不均匀性,以立方体预测模型为基础,应用三维矿体轮廓提取和品位描述算法,对矿体三维外部形态和内部品位的分布特征进行了详细分析,为今后矿区找矿指出了新方向。  相似文献   
992.
解决边坡稳定性问题的关键是确定最危险滑动面(潜在最危险滑动面)和边坡的稳定系数。将蚁群算法用于求解土质的边坡稳定性问题。针对蚁群算法在演化过程中存在停滞和过早收敛的现象,对基本蚁群算法的结构形式和蚂蚁转移概率的计算进行了改进。构建了一种新的蚁群算法——元胞蚁群算法(CA-AA)。在文武坡边坡稳定性判别中,利用CA-AA法计算得到其稳定系数为1.37,略小于《岩土工程勘察规范》不平衡推力法计算值,弥补了不平衡推力法的不足,更接近实际。算例结果表明:元胞蚁群算法(CA-AA)总能搜索到问题的全局最优解,且搜索效率也有较大的提高。  相似文献   
993.
在多波地震勘探中,转换点位置的求取精度直接影响共转换点道集的抽取,进而影响转换波速度分析的精度。利用DSR方程,对比了用不同的转换点计算方法进行转换波速度分析,分析其计算精度。  相似文献   
994.
<正>The thermo-electric coefficients of twenty-six magnetite samples,formed either by magmatism or metamorphism,were tested by the thermo-electric instrument BHET—06.Results showed that the coefficient is of a constant value of about -0.05 mV/℃.It is emphasized that because every magnetite grain was tested randomly,the coefficient is independent of the crystallographic direction.This fact means the thermal voltage generated from a single magnetite crystal can be accumulated,and as a result a new thermo-electric field can arise when a gradient thermal field exists and is active within the earth's crust.Because magnetite is widespread in the earth's crust(generally appearing more in the middle-lower crust),there is more-than-random probability that the additional thermo-electric field can be generated when certain thermal conditions are fulfilled.We,therefore,used the thermo-electric effect of magnetite to study the mechanism responsible for the presence of abnormal geo-electric fields during earthquake formation and occurrence, because gradient thermal fields always exist before earthquakes.The possible presence of additional thermo-electric fields was calculated under theoretical seismological conditions,using the following calcu-lation formula:E= - 0.159(σ×△T×φ×ρ_2×[(h~2-2x~2)cosα+ 3hxsinα]/ρ_1(h~2 +x~2)~(5/2)).In the above formula,σis thermo-electric coefficient of magnetite,△T is the temperature difference acting on it,φis a sectional area on a block of magnetite vertically perpendicular to the direction of the thermal current.ρ_1 andρ_2 are the respective resistivities of magnetite and the crust,and h,α,and x,respectively,h is the depth of embedded magnetite block,αmeans the angle created by the horizontal line and ligature of the two poles of magnetite block,and x is the distance from observation point to projective center point of the magnetite block on earth surface.According to simulations calculated with this formula,additional thermo-electric field intensity may reach as high as n to n×10~2 mV/km.This field is strong enough to cause obvious anomalies in the background geo-electric field,and can be easy probed by earthquake monitoring equipment. Therefore,we hypothesize that geo-electric abnormalities which occur during earthquakes may be caused by the thermo-electric effect of magnetite.  相似文献   
995.
Frontal upwelling is an important phenomenon in summer in the Yellow Sea (YS) and plays an essential role in the distribution of nutrients and biological species. In this paper, a three-dimensional hydrodynamic model is applied to investigate the characteristics and influencing factors of frontal upwelling in the YS. The results show that the strength and distribution of frontal upwelling are largely dependent on the topography and bottom temperature fronts. The frontal upwelling in the YS is stronger and narrower near the eastern coast than near the western coast due to the steeper shelf slope. Moreover, external forcings, such as the meridional wind speed and air temperature in summer and the air temperature in the preceding winter and spring, have certain influences on the strength of frontal upwelling. An increase in air temperature in the previous winter and spring weakens the frontal upwelling in summer; in contrast, an increase in air temperature in summer strengthens the frontal upwelling. When the southerly wind in summer increases, the upwelling intensifies in the western YS and weakens in the eastern YS. The air temperature influences the strength of upwelling by changing the baroclinicity in the frontal region. Furthermore, the meridional wind speed in summer affects frontal upwelling via Ekman pumping.  相似文献   
996.
We introduced the Coupled Model Intercomparison Project Phase 6 (CMIP6) Ocean Model Intercomparison Project CORE2-forced (OMIP-1) experiment by using the First Institute of Oceanography Earth System Model version 2.0 (FIO-ESM v2.0), and comprehensively evaluated the simulation results. Unlike other OMIP models, FIO-ESM v2.0 includes a coupled ocean surface wave component model that takes into account non-breaking surface wave-induced vertical mixing in the ocean and effect of surface wave Stokes drift on air-sea momentum and heat fluxes in the climate system. A sub-layer sea surface temperature (SST) diurnal cycle parameterization was also employed to take into account effect of SST diurnal cycle on air-sea heat ?uxes to improve simulations of air-sea interactions. Evaluations show that mean values and long-term trends of significant wave height were adequately reproduced in the FIO-ESM v2.0 OMIP-1 simulations, and there is a reasonable fit between the SST diurnal cycle obtained from in situ observations and that parameterized by FIO-ESM v2.0. Evaluations of model drift, temperature, salinity, mixed layer depth, and the Atlantic Meridional Overturning Circulation show that the model performs well in the FIO-ESM v2.0 OMIP-1 simulation. However, the summer sea ice extent of the Arctic and Antarctic is underestimated.  相似文献   
997.
为探究海湾扇贝(Argopecten irradians)、栉孔扇贝(Chlamys farreri)、虾夷扇贝(Patinopecten yessoensis)三种扇贝闭壳肌的挥发性风味物质差异,采用气相色谱-离子迁移谱(gas chromatography-ion mobility spectroscopy,GC-IMS)技术,对三种扇贝闭壳肌在新鲜(40℃)和加热(100℃)情况下进行挥发性成分分析。结果表明:在新鲜状态下,海湾扇贝(HWSB-F)、栉孔扇贝(ZKSB-F)、虾夷扇贝(XYSB-F)闭壳肌中,共定性出27种挥发性风味物质,其中醛类8种,醇类5种,酮类5种,酯类3种,以及醚类、苯类、酸类、烯类和噻唑等。在加热情况下,海湾扇贝(HWSB-C)、栉孔扇贝(ZKSB-C)、虾夷扇贝(XYSB-C)闭壳肌中共定性出52种挥发性风味物质,其中醛类20种,酯类5种,酮类7种,醇类8种,烯类4种,酸类2种,醚类2种,还包括吡嗪、胺类、苯类、含氧杂环等物质。对三种扇贝闭壳肌新鲜组和加热组指纹图谱进行分析,发现新鲜扇贝原有的挥发性风味物质加热后减少,且产生了新的其他种类的挥发性风味物质。扇贝闭壳肌加热组的挥发性风味物质种类较多,组成比较复杂,新鲜组的扇贝闭壳肌挥发性风味物质种类较少,组成简单。通过主成分分析,可在新鲜状态和加热状态下,有效区分三种扇贝闭壳肌组织。三种扇贝闭壳肌挥发性风味物质指纹图谱的建立,丰富了不同扇贝呈味物质的组成成分研究内容,证明GC-IMS技术可快速鉴别三种去壳扇贝闭壳肌的种类,为不同种扇贝闭壳肌以次充好提供检测依据。  相似文献   
998.
作为半封闭狭长海湾,铁山湾受风暴潮灾害的影响较为严重。根据多年观测资料和数值模型对铁山湾内的风暴潮水位特征进行了研究。观测资料表明海湾内风暴潮峰值水位受天文潮相位影响较为显著,然后基于ADCIRC风暴潮模型和1409号“威马逊”台风参数,定量评估了天文潮对风暴潮水位的影响。模拟结果表明当考虑天文潮作用时,会显著提高模拟结果精度,然后通过数值实验研究了风暴潮与不同相位天文潮相互作用时的水位变化特征。数值实验结果表明天文潮-风暴潮相互作用引起的非线性水位在涨潮阶段不明显,在高潮位时非线性水位达到负值最大;在落潮时达到正值最大。风暴潮增水峰值由于受到这种非线性效应的影响,在高潮位时数值最小。海湾内非线性作用要远大于外部,非线性效应越强,总水位峰值相对于天文潮高潮位的延迟时间也就越长。  相似文献   
999.
He  Ying  Wang  Jianing  Wang  Fan  Hibiya  Toshiyuki 《Journal of Oceanography》2022,78(1):35-48

The Mindanao Current (MC) bridges the North Pacific low-latitude western boundary current system region and the Indonesian Seas by supplying the North Pacific waters to the Indonesian Throughflow. Although the previous study speculated that the diapycnal mixing along the MC might be strong on the basis of the water mass analysis of the gridded climatologic dataset, the real spatial distribution of diapycnal mixing along the MC has remained to be clarified. We tackle this question here by applying a finescale parameterization to temperature and salinity profiles obtained using two rapid-sampling profiling Argo floats that drifted along the MC. The western boundary (WB) region close to the Mindanao Islands and the Sangihe Strait are the two mixing hotspots along the MC, with energy dissipation rate ε and diapycnal diffusivity Kρ enhanced up to?~?10–6 W kg?1 and?~?10–3 m2 s?1, respectively. Except for the above two mixing hotspots, the turbulent mixing along the MC is mostly weak, with ε and Kρ to be 10–11–10–9 W kg?1 and 10–6–10–5 m2 s?1, respectively. Strong mixing in the Sangihe Strait can be basically attributed to the existence of internal tides, whereas strong mixing in the WB region suggests the existence of internal lee waves. We also find that water mass transformation along the MC mainly occurs in the Sangihe Strait where the water masses are subjected to strong turbulent mixing during a long residence time.

  相似文献   
1000.
食物生产系统的碳排放占人类活动碳排放总量的 30%, 碳汇渔业是一种重要的面向人类社会高质量食物蛋白质供给 的低碳发展路径。本文基于常见的 11 种养殖贝类的固碳系数和蛋白质含量特性研究,系统评估了我国2019 年养殖牡蛎 、蛤 类、扇贝、贻贝和蚶类等在养殖周期内碳捕集特性以及对低碳发展的贡献。研究表明: (1) 11 种养殖贝类之间贝壳和软体 组织含碳量的差异并不明显,但干重比和出肉率差异显著。因此,贝类固碳量核算不能忽视种类差异。 (2)所选 11 种贝类 软体组织皆属于高蛋白食品,虾夷扇贝软体组织 (干重) 的蛋白质含量最高。针对单位质量贝类养殖,长牡蛎的碳封存贡献 度最大,而华贵栉孔扇贝提供的蛋白质最多,两者都是碳汇渔业的优势种。(3) 据估算,我国2019 年海水养殖贝类中牡蛎、蛤 类 、扇贝和蚶类总共吸收固定了约 117.98 万吨 C02,提供了 40.65 万吨蛋白质 。这些蛋白质相比于牛肉源蛋白质可减少 4 048.74 万吨 C02 当量的排放量。由于贝类固碳强度大,探索低碳可持续的贝类养殖是绿色渔业经济的重要引擎, 也是建立可持续高质量“蓝色粮仓”和生物固碳的重要路径, 将在我国低碳产业发展中发挥重要作用。  相似文献   
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