城区高光谱遥感数据假彩色波段组合研究

高光谱数据具有波段数目多、波段宽度窄、数据量庞大等特点，如何根据具体的应用目的，在众多的波段中选取最佳波段组合用于假彩色合成，对于有效进行高光谱数据处理、分析及信息提取至关重要。以面阵推帚式机载超光谱成像仪(PHI)获得的上海市黄浦江附近复杂地表高光谱图像数据为例，分析了图像所包含的信息量、各通道之间的相关性以及影像上各地物的光谱特征，选出了那些包含信息量大、相关性小、光谱差异大的波段子集，然后再结合协方差矩阵特征值法、最佳指数法和波段指数法波段组合方法选出了高光谱遥感图像的最佳波段组合。     

Geochronology,geochemistry and Sr–Nd–Hf isotopes of the Haisugou porphyry Mo deposit,northeast China,and their geological significance

The Haisugou Mo deposit is located in the northern part of the Xilamulun Mo–Cu metallogenic belt in northeastern China. The Mo mineralization mainly occurs as quartz-molybdenite veins within the Haisugou granite, which was emplaced into rocks of the Early Permian Qingfengshan Formation. Zircon U–Pb dating by LA–ICP-MS of the granite yields a crystallization age of 137.6 ± 0.9 Ma, suggesting emplacement during the peak time of Mo mineralization in eastern China, broadly constrained to ca. 150–130 Ma, when tectonic stresses shifted from compression to extension. Whole-rock geochemical data suggest that the granite belongs to the high-K calc-alkaline series, and is characterized by relatively high LREE; low HREE; depletion of Ti, Ba, and Nb; and a moderate negative Eu anomaly. The zircon ε_Hf(t) and whole-rock ε_Nd(t) values for the intrusion range from +4.5 to +10.0 and +0.2 to +1.6, respectively, indicating that the magma originated from the juvenile lower crust source derived from depleted mantle, with some component of ancient continental crust. The granite is also characterized by initial (⁸⁷Sr/⁸⁶Sr)_i ratios ranging from 0.7040 to 0.7074, which suggest some contamination by the upper crust during the ascent of the primitive magma. Moreover, it can be recognized from the whole-rock major and trace element data that significant fractional crystallization occurred during magmatic evolution, with the separation of plagioclase and K-feldspar. Because Mo is an incompatible element and tends to concentrate in the melt during crystallization, fractionation processes likely played an important role in the formation of the Haisugou Mo deposit.     

Inertial effects during irreversible meniscus reconfiguration in angular pores

In porous media, the dynamics of the invading front between two immiscible fluids is often characterized by abrupt reconfigurations caused by local instabilities of the interface. As a prototype of these phenomena we consider the dynamics of a meniscus in a corner as it can be encountered in angular pores. We investigate this process in detail by means of direct numerical simulations that solve the Navier–Stokes equations in the pore space and employ the Volume of Fluid method (VOF) to track the evolution of the interface. We show that for a quasi-static displacement, the numerically calculated surface energy agrees well with the analytical solutions that we have derived for pores with circular and square cross sections. However, the spontaneous reconfigurations are irreversible and cannot be controlled by the injection rate: they are characterized by the amount of surface energy that is spontaneously released and transformed into kinetic energy. The resulting local velocities can be orders of magnitude larger than the injection velocity and they induce damped oscillations of the interface that possess their own time scales and depend only on fluid properties and pore geometry. In complex media (we consider a network of cubic pores) reconfigurations are so frequent and oscillations last long enough that increasing inertial effects leads to a different fluid distribution by influencing the selection of the next pore to be invaded. This calls into question simple pore-filling rules based only on capillary forces. Also, we demonstrate that inertial effects during irreversible reconfigurations can influence the work done by the external forces that is related to the pressure drop in Darcy’s law. This suggests that these phenomena have to be considered when upscaling multiphase flow because local oscillations of the menisci affect macroscopic quantities and modify the constitutive relationships to be used in macro-scale models. These results can be extrapolated to other interface instabilities that are at the origin of fast pore-scale events, such as Haines jumps, snap-off and coalescence.     

Effectiveness of BIOECODS for peak flow attenuation: an appraisal using InfoWorks SD

The Bio-Ecological Drainage System (BIOECODS) is a sustainable drainage system, which adopts a “control at source” approach for urban storm water management in Malaysia. This study attempts to model a small-scale BIOECODS using InfoWorks SD. New modelling techniques are used to fully integrate the surface and on-line subsurface conveyance system, in which overland flow routing is described by a storm water management model that uses a nonlinear reservoir method and the kinematic wave approximation of the St Venant equation, and subsurface flow is described by the Horton method in conjunction with the Soil Conservation Service (SCS) curve number (CN) method. The observed water levels at primary outlets are compared with those obtained from model simulation. The modelling approach has been proven successful as the hydrographs (predicted and observed) match each other closely, with a mean error in the range of 4.58–7.32%. Results from the model showed that the BIOECODS is able to attenuate peak flow by 60–75%, and increase the lag time by 20 min within an area of <28?300 m² when compared with a traditional drainage system.     

可持续发展与现代化转型

提出社会发展综合动力观 ,揭示精神文化因素是经济社会可持续发展的动力资源和“另一只看不见的手”。分析了可持续发展对现代化理论的扬弃与创新 ,批判了工具文明的弊端及负面效应 ,重审人类共同选择———现代化文明转型的价值尺度和终极目标 ,展望了中国转型的核心、主题和历史归宿 :由农业文明向工具文明、从工业文明向可持续发展文明的双重超越     

Massive stars

We describe the present state of massive star research seen from the viewpoint of stellar evolution, with special emphasis on close binaries. Statistics of massive close binaries are reasonably complete for the Solar neighbourhood. We defend the thesis that within our knowledge, many scientific results where the effects of binaries are not included, have an academic value, but may be far from reality. In chapter I, we summarize general observations of massive stars where we focus on the HR diagram, stellar wind mass loss rates, the stellar surface chemistry, rotation, circumstellar environments, supernovae. Close binaries can not be studied separately from single stars and vice versa. First, the evolution of single stars is discussed (chapter I). We refer to new calculations with updated stellar wind mass loss rate formalisms and conclusions are proposed resulting from a comparison with representative observations. Massive binaries are considered in chapter II. Basic processes are briefly described, i.e. the Roche lobe overflow and mass transfer, the common envelope process, the spiral-in process in binaries with extreme mass ratio, the effects of mass accretion and the merging process, the implications of the (asymmetric) supernova explosion of one of the components on the orbital parameters of the binary. Evolutionary computations of interacting close binaries are discussed and general conclusions are drawn. The enormous amount of observational data of massive binaries is summarized. We separately consider the non-evolved and evolved systems. The latter class includes the semi-detached and contact binaries, the WR binaries, the X-ray binaries, the runaways, the single and binary pulsars. A general comparison between theoretical evolution and observations is combined with a discussion of specially interesting binaries: the evolved binaries HD 163181, HD 12323, HD 14633, HD 193516, HD 25638, HD 209481, Per and Sgr; the WR+OB binary V444 Cyg; the high mass X-ray binaries Vela X-1, Wray 977, Cyg X-1; the low mass X-ray binaries Her X-1 and those with a black hole candidate; the runaway Pup, the WR+compact companion candidates Cyg X-3, HD 50896 and HD 197406. We finally propose an overall evolutionary model of massive close binaries as a function of primary mass, mass ratio and orbital period. Chapter III deals with massive star population synthesis with a realistic population of binaries. We discuss the massive close binary frequency, mass ratio and period distribution, the observations that allow to constrain possible asymmetries during the supernova explosion of a massive star. We focuss on the comparison between observed star numbers (as a function of metallicity) and theoretically predicted numbers of stellar populations in regions of continuous star formation and in starburst regions. Special attention is given to the O-type star/WR star/red supergiant star population, the pulsar and binary pulsar population, the supernova rates. Received 17 July 1998     

Zircon U–Pb age and geochemical constraints on the origin and tectonic implication of the Tuotuohe Cenozoic alkaline magmatism in Qinghai–Tibet Plateau

A large number of Eocene-Oligocene alkaline/alkali-rich igneous rocks were developed in the Tuotuohe region of the Qinghai-Tibetan Plateau.In this study,we present zircon U-Pb ages,Hf isotope data,and major and trace element compositions of the Cenozoic alkaline rocks from the Tuotuohe region in order to constraint the petrogenesis and tectonic evolution history of Qiangtang Block.Zircon U-Pb ages were measured via LA-ICP-MS to be39.6,37.6 and 32.0 Ma.The 39.6 Ma trachyte was characterized by low SiO2 and high K2O and MgO contents.The 37.6 and 32.0 Ma orthophyres show enrichment in SiO2 and K2O,but deficient in MgO.All of the samples belong to the alkaline rocks.These rocks display enrichment in REE,LREE,and LILE,depletion in HFSE,and no obvious Eu anomalies.Geological and geochemical features suggest that there were two possible mechanisms for the origin of the alkaline rocks in the Tuotuohe region:(1)the removed mafic lower crust dropped into the asthenosphere,forming the mix magma(Nariniya trachyte);(2)the upwelling asthenosphere triggered the crustal melting(Nariniya and Zamaqu orthophyre).The Eocene-Oligocene alkaline rocks in the study and adjacent areas are likely to be the result of the same tectonic-magmatic event of deep lithospheric evolution that is the crustal material melting triggered by lithospheric delamination.This conclusion extends the influence scope of lithospheric delamination eastward to the Tuotuohe region(*92°E)from Banda Co(*82°E).     

He–Ar isotope geochemistry of iron and gold deposits reveals heterogeneous lithospheric destruction in the North China Craton

The North China Craton (NCC) provides a classic example for extensive destruction of the cratonic lithosphere. The Mesozoic magmatism which contributed to the decratonization of the NCC was also accompanied by the formation of a variety of mineral deposits. In order to gain further insights into the cratonic destruction process, typical iron and gold deposits are investigated here. Helium–argon isotopic data on pyrite, from typical skarn iron deposits of the Beiminghe and Fushan in the Han-Xing district of the central NCC, and the Linglong and Canzhuang gold deposits in the Jiaodong district in the eastern NCC, are presented in this paper. The ³He/⁴He, ⁴⁰Ar/³⁶Ar and ⁴⁰Ar/⁴He ratios show generally uniform patterns within the individual deposits and reveal a complex evolutionary history of the ore-forming fluids with varying degree of crust–mantle interaction. The ore-forming fluids associated with the gold mineralization at the Jiaodong mine have higher content of fluids of mantle origin with mantle helium ranging from 1.24% to 18.02% (average 6.73%; N = 18). In contrast, the ore-forming fluids related to the iron ore deposits contain less mantle contribution with mantle helium ranging from 0.12% to 4.96% (average 1.29%; N = 10). Our results suggest complex and heterogeneous crust–mantle processes associated with the magmatism and metallogeny, where the lithosphere of the eastern NCC was subjected to more extensive thinning and destruction as compared with that in the western part, consistent with the observations from geophysical studies in the region. Our study demonstrates that fluids associated with the Mesozoic metallogenic processes in the NCC provide useful insights into the geodynamics of destruction and refertilization of the cratonic lithosphere.     

Salinité des ressources en eau: intrusion marine et interaction eaux–roches (Maroc occidental)

Résumé

Le flux migratoire de la population vers les grandes villes et la multiplication des activités industrielles et agricoles, lors des ces dernières années (1990–2006), ont provoqué un accroissement des besoins en eaux de la nappe du bassin du Rharb (ouest du Maroc). Cette forte sollicitation a produit une augmentation de la minéralisation et une dégradation de la qualité hydrochimique (salinité) des eaux souterraines. Cet article a pour objectif de suivre l'évolution spatiale de la qualité hydrochimique des eaux souterraines et de comprendre le processus de cette minéralisation en fonction de l'intrusion marine, le gradient hydraulique et l'interaction eaux–réservoirs. Les corrélations hydrochimiques réalisées dans la zone côtière révèlent une contamination par les eaux marines. L'intrusion marine et la caractérisation des complexes pré-Rifains ont été identifiées par les méthodes géophysiques électriques et sismiques.

Citation Zouhri, L., Toto, E. A., Carlier, E. & Debieche, T.-H. (2010) Salinité des ressources en eau: dilution marine et interaction eaux–roches (Maroc occidental). Hydrol. Sci. J. 55(8), 1337–1347.