豫西南周庄铅锌银矿床地质和成矿流体地球化学

豫西南周庄铅锌银矿床是最近在豫西南铅锌银矿集区新发现的一处矿产地。矿床形成于印支期造山后板内构造-岩浆地质环境,工业矿体主要是东秦岭二郎坪群中充填于垂直造山带走向的断裂构造中的石英-铅锌银硫化物矿脉,热液成矿作用经历了石英-黄铁矿、石英-铅锌银硫化物、石英-方解石等早、中、晚3个不同阶段。矿石中以石英为主的脉石矿物捕获...     

On the radiative properties of ice clouds: Light scattering,remote sensing,and radiation parameterization

Presented is a review of the radiative properties of ice clouds from three perspectives: light scattering simulations, remote sensing applications, and broadband radiation parameterizations appropriate for numerical models. On the subject of light scattering simulations, several classical computational approaches are reviewed, including the conventional geometric-optics method and its improved forms, the finite-difference time domain technique, the pseudo-spectral time domain technique, the discrete dipole approximation method, and the T-matrix method, with specific applications to the computation of the singlescattering properties of individual ice crystals. The strengths and weaknesses associated with each approach are discussed.With reference to remote sensing, operational retrieval algorithms are reviewed for retrieving cloud optical depth and effective particle size based on solar or thermal infrared(IR) bands. To illustrate the performance of the current solar- and IR-based retrievals, two case studies are presented based on spaceborne observations. The need for a more realistic ice cloud optical model to obtain spectrally consistent retrievals is demonstrated. Furthermore, to complement ice cloud property studies based on passive radiometric measurements, the advantage of incorporating lidar and/or polarimetric measurements is discussed.The performance of ice cloud models based on the use of different ice habits to represent ice particles is illustrated by comparing model results with satellite observations. A summary is provided of a number of parameterization schemes for ice cloud radiative properties that were developed for application to broadband radiative transfer submodels within general circulation models(GCMs). The availability of the single-scattering properties of complex ice habits has led to more accurate radiation parameterizations. In conclusion, the importance of using nonspherical ice particle models in GCM simulations for climate studies is proven.     

Geochemical compositions of soluble salts in aeolian sands from the Taklamakan and Badanjilin deserts in northern China, and their influencing factors and environmental implications

Two large sandy seas in northern China, the Taklamakan and Badanjilin deserts, were investigated for geochemical variations of soluble salts in aeolian sands. The aim was to explore factors influencing the composition and distribution of soluble salts in aeolian sands and their environmental implications. The total concentrations of soluble salt in the aeolian sands range between 0.14 and 1.32‰, with pH ranging between 8.4 and 9.6, indicating a primary degree of salt accumulation and alkaline soil conditions in these regions. Sodium chloride and bicarbonate are the major salts. High inter-regional homogenization and small local differences in the chemical compositions and distributional patterns of salt occur in the two deserts. The spatial variations in salt content correlate with regional climatic parameters, such as precipitation and temperature. This suggests that the regional air temperature and moisture conditions of climate have a significant influence on the soluble salts in aeolian sands. The domination of sedimentation of soluble salts in aeolian sands deposited via atmospheric processes, which is heavily associated with dry deposition, is discussed. Case studies from the two deserts suggest that variations in salt content in sedimentary sequences, interlaid by aeolian and lacustrine sediments, should be interpreted with care if the aim is to reveal palaeo-environmental changes. To a certain extent, the two deserts, as inferred from the carbon-bearing salts and the alkalinity of the sandy soils, appear to have potential to provide a significant contribution to the global carbon cycle.     

Formation and evolution of sand deserts in Xinjiang,Northwest China：Ⅱ. The palaeo-environmental reconstruction

Based on the palaeoclimatic and palaeoenvironmental evidences of geological history and human history periods, this paper reviews the researches and progresses on the development of the sandy deserts in Xinjiang. It pointed out that the features of tectonic structure in Xinjiang had made both the Tarim Basin and the Junggar Basin being influenced greatly by the foehn effects originated from the planetary wind system of westerly, the East Asian ocean-continental monsoon and the topographical mountain-valley winds. The regional patterns of climate and environment since the Quaternary were characterized by the overall persistent drought accompanied by fluctuations in the secondary scale. Formations of aeolian sediments in the basins and at the margins are a potential response to global climate change, particularly the aridification of the Asian hinterland deduced by the uprising of the Tibetan Plateau and its surrounding highlands. For the question about the formation time of the Taklamakan Desert, because the research methods, objects and information carriers used in previous studies are different, there are many disputes in the academic circles at present. Evidences from aeolian deposits/rocks at the edge and in the hinterland of these sandy deserts and their chronological data indicate that an arid climate and land surface aeolian processes have occurred at the edge of the Tarim Basin and its hinterland areas since the Tertiary period. However, the duration time of these processes at mass scale should have begun after the middle Pleistocene and lasted to the Holocene. Occurrence of dune fields in recent 2000 years in the oasis areas should be greatly influenced by human factors.     

中国西北部新疆地区沙漠的形成与演化——Ⅱ.古环境重建(英文)

Based on the palaeoclimatic and palaeoenvironmental evidences of geological history and human history periods, this paper reviews the researches and progresses on the development of the sandy deserts in Xinjiang. It pointed out that the features of tectonic structure in Xinjiang had made both the Tarim Basin and the Junggar Basin being influenced greatly by the foehn effects originated from the planetary wind system of westerly, the East Asian ocean-continental monsoon and the topographical mountain-valley winds. The regional patterns of climate and environment since the Quaternary were characterized by the overall persistent drought accompanied by fluctuations in the secondary scale. Formations of aeolian sediments in the basins and at the margins are a potential response to global climate change, particularly the aridification of the Asian hinterland deduced by the uprising of the Tibetan Plateau and its surrounding highlands. For the question about the formation time of the Taklamakan Desert, because the research methods, objects and information carriers used in previous studies are different, there are many disputes in the academic circles at present. Evidences from aeolian deposits/rocks at the edge and in the hinterland of these sandy deserts and their chronological data indicate that an arid climate and land surface aeolian processes have occurred at the edge of the Tarim Basin and its hinterland areas since the Tertiary period. However, the duration time of these processes at mass scale should have begun after the middle Pleistocene and lasted to the Holocene. Occurrence of dune fields in recent 2000 years in the oasis areas should be greatly influenced by human factors.     

用模糊均生函数作区域夏季旱涝预测

用模糊均生函数建模方案建立宁镇的地区夏季旱涝趋势预测模型，其拟合效果，特别是对大旱大涝的拟合十分理想。１９９４年用该模型预测宁镇地区梅雨量，结果与实况较为接近。     

A simple Monte Carlo method for estimating the chance of a cyclone impact

Natural Hazards - Cyclones endanger life and cause great financial impact on interior and coastal regions through the destruction of buildings and land. Governments need to have a way of estimating...     

福建山仔水库不同季节表层沉积物内源磷负荷分析

对山仔水库沉积物各形态磷的季节性特征以及夏、冬季磷释放速率进行研究.结果表明,该水库表层沉积物含有较丰富的磷,4个季节各采样点表层沉积物总磷含量范围为(521.23±7.60)~(1255.54±11.03)μg/g,夏季各采样断面中总磷含量及各形态磷含量均高于其他季节.表层沉积物磷以无机磷为主,且主要赋存形态为铁/铝结合态磷.活性较大的铁/铝结合态磷和有机磷占总磷量的77%~90%.柱状样模拟实验结果表明:夏季溶解性磷释放平均速率范围在1.66~2.49 mg/(m2·d),冬季溶解性磷释放平均速率范围为0.69~1.29 mg/(m2·d),夏季各采样点表层沉积物磷释放速率约为冬季的2倍.由于水温分层,夏季沉积物释放的溶解性磷主要滞留在上覆层,但夏季暴雨天气可能导致水温分层破坏,沉积物释放的溶解性磷对水体将产生重要影响;冬季由于水温分层破坏导致上、下水层混合,沉积物释放的溶解性磷被带到上层,对上覆水体水质的影响不容忽视.     

河南省新县姚冲钼矿地球化学异常特征及找矿意义

文章在1∶10 000土壤地球化学测量的基础上,分析姚冲矿区钼等元素地球化学特征,包括元素的富集与离散特征、元素组合特征、单元素异常特征、综合异常特征,确定Mo,W等元素为区内具有一定潜力的找矿指标;通过探讨地球化学异常与矿体的关系,认为该区的化探异常成果对找矿有很好的指示作用。