红板岩材料隐式本构模型的建立及其应用研究

针对红板岩材料在岩土工程中所表现的大量模糊的和不确定的因素等特点,基于人工神经网络的学习能力,借助于室内岩石力学试验,进行了对该材料的力学本构特性进行了神经网络模拟研究,提出了隐式本构模型的思想和方法,并通过该方法对该岩石的流变试验结果进行学习,获得了以网络权值结构保存的力学特性知识,由此得到了表征红板岩应力应变本构关系的隐式本构模型。应用结果表明,该方法对岩土类材料本构关系的模拟研究具有很好的应用前景。     

相态研究在化探异常评价中的应用——以马架子水系沉积物异常评价为例

利用相态研究可确定异常元素的赋存状态,马架子水系沉积物综合异常强度高,浓集中心明显,经过几次异常检查及查证,未获得良好的找矿效果,引起异常的成因机制不清。对异常样品中元素在氧化物相、结合相及硫化物相中分配的综合研究证实,Ph、Zn元素主要是以均匀分散形式存在于岩石中,为非矿致异常,从而节省了大量的人力、财力及物力,为异常查证及评价提供了一套新的思路。     

流速逆变张量隐式求解方法及其在航道港池流场计算中的应用

运用高分辨率的边界适应网格进行流体动力学数值计算时,如何提高计算稳定性和减少计算量成为数值求解的关键性问题.在非正交的边界适应坐标系中,每个动量方程中同时出现了两个交叉方向的水位偏导数项,给隐式求解带来困难,而显式格式下的时间步长由于受与空间步长有关的Courant-Friedrichs-Lewy条件限制,计算量成倍增加.本文从广义曲线坐标系下浅海动力学方程组出发,导出了流速的逆变张量所满足的动量方程组,使方程中的水位偏导数项变成了沿某一协变基向量方向占优的形式,方便地采用了交替方向隐式差分格式,从而提高了计算稳定性并减小了计算量.本文通过对澳门海域航道和港池中流场的计算,证实了该模式是一种进行高分辩率数值计算的有效方法.     

亚洲夏季风区中尺度地形降水结构及分布特征

采用高分辨率TRMM、AIRS卫星实测资料, 从气候态的降水微物理过程角度分析了亚洲夏季风期间中尺度山脉对不同性质降水垂直结构和水平分布的影响。研究表明, 中尺度山脉迎风、背风坡均以层云降水为主, 层云降水强度在迎风坡强于背风坡; 对流降水在迎风坡主要为浅对流, 背风坡主要为深对流, 对流降水强度在背风坡强于迎风坡。沿西南季风推进方向依次经过的中尺度山脉, 其两侧发生降水像素个数、 降水微物理特征等差异逐渐减小, 其中, 对流降水迎风坡向背风坡转变明显, 而层云降水背风坡向迎风坡转变明显。大气稳定度与对流降水在迎风、背风坡的分布相一致。另外, 对中尺度地形降水的研究为区域气候模式模拟高精度地形降水分布提供了实测依据。     

地面总辐射的异常减少对气候影响的数值试验

在与实际台风场近似一致的环境流场条件下，应用柱会标中的正压无辐散模式，讨论了台风中扰动的稳定性问题。研究表明，台风暖心结构的台风外围适当强度的冷空气活动有利限台风中扰动发展，且台风愈强，台风中扰动愈易发展。     

Geodynamic setting,structure, and composition of continuous trachybasalt-trachyandesite-rhyolite series in the north of Altai-Sayan area: the role of crust-mantle interaction in continental magma formation

The geologic positions and geochemical and isotope parameters of the Ordovician-early Silurian and Early-Middle Devonian continuous volcanic series of the Minusa basin and its mountainous framing are compared. Both series are composed mostly of moderately alkaline rocks with variations in SiO₂ contents from 45 to 77 wt.%. The Ordovician-early Silurian series differs from the Early-Middle Devonian one in lower contents of TiO₂ (< 1.7 wt.%) and Fe₂O_3tot and higher contents of Al₂O₃ in all rock varieties and in the more fractionated REE patterns of trachybasalts. The compositions of both series reflect two simultaneous mechanisms of magma evolution. The main process was fractional crystallization leading to the formation of rocks from trachybasalts to trachyrhyodacites. The accessory mechanism was the contamination of fractionated melts by crustal material, anatectic melting of crust, and mixing of deep-seated magmas with crustal melts. These processes had specifics at each stage and were controlled by the composition of the sources of parental melts. Their geochemical and isotopic parameters (high alkalinity, high contents of lithophile elements, negative anomalies of Nb, Ta, and Ti, and enrichment in radiogenic Sr) point to the interaction of mantle plumes with the lithospheric mantle that was metasomatically transformed during the preceding Vendian-early Cambrian subduction processes.     

云南元阳大坪金矿矿床成因讨论

金矿位于哀牢山构造变质岩带、金（贵金属）成矿带南部西侧,含金石英脉分布于小新街断裂两侧的次级构造裂隙中,矿脉严格受次级压扭性断裂控制.     

惠民凹陷南坡石炭二叠系煤层二次生气模式

利用开放体系程序升温热模拟实验方法,对惠民凹陷南坡石炭—二叠系煤岩样品的热演化规律进行了研究,建立了该区石炭二叠系含煤地层有机质的生气模式,探讨了影响二次生气潜力的各种主控因素,为准确评价其资源潜力和计算远景资源量奠定了基础,对渤海湾盆地其他类似地区煤型气勘探具有指导意义。     

Effects of adjusting cropping systems on utilization efficiency of climatic resources in Northeast China under future climate scenarios

Quantitatively evaluating the effects of adjusting cropping systems on the utilization efficiency of climatic resources under climate change is an important task for assessing food security in China. To understand these effects, we used daily climate variables obtained from the regional climate model RegCM3 from 1981 to 2100 under the A1B scenario and crop observations from 53 agro-meteorological experimental stations from 1981 to 2010 in Northeast China. Three one-grade zones of cropping systems were divided by heat, water, topography and crop-type, including the semi-arid areas of the northeast and northwest (III), the one crop area of warm–cool plants in semi-humid plain or hilly regions of the northeast (IV), and the two crop area in irrigated farmland in the Huanghuaihai Plain (VI). An agro-ecological zone model was used to calculate climatic potential productivities. The effects of adjusting cropping systems on climate resource utilization in Northeast China under the A1B scenario were assessed. The results indicated that from 1981 to 2100 in the III, IV and VI areas, the planting boundaries of different cropping systems in Northeast China obviously shifted toward the north and the east based on comprehensively considering the heat and precipitation resources. However, due to high temperature stress, the climatic potential productivity of spring maize was reduced in the future. Therefore, adjusting the cropping system is an effective way to improve the climatic potential productivity and climate resource utilization. Replacing the one crop in one year model (spring maize) by the two crops in one year model (winter wheat and summer maize) significantly increased the total climatic potential productivity and average utilization efficiencies. During the periods of 2011–2040, 2041–2070 and 2071–2100, the average total climatic potential productivities of winter wheat and summer maize increased by 9.36%, 11.88% and 12.13% compared to that of spring maize, respectively. Additionally, compared with spring maize, the average utilization efficiencies of thermal resources of winter wheat and summer maize dramatically increased by 9.2%, 12.1% and 12.0%, respectively. The increases in the average utilization efficiencies of precipitation resources of winter wheat and summer maize were 1.78 kg hm⁻² mm⁻¹, 2.07 kg hm⁻² mm⁻¹ and 1.92 kg hm⁻² mm⁻¹ during 2011–2040, 2041–2070 and 2071–2100, respectively. Our findings highlight that adjusting cropping systems can dominantly contribute to utilization efficiency increases of agricultural climatic resources in Northeast China in the future.