水轮发电机定子磁固耦合电磁激发的分岔与混沌

为研究水轮发电机定子系统磁固耦合电磁激发非线性振动，以双壳系统模型作为水轮发电机定子系统的数学模型，应用非线性多尺度法分析水轮发电机定子双壳系统在电磁力作用下的主共振问题，并进行数值计算．结果表明，随着激励幅值的增大和阻尼的减小，系统主共振稳态响应的振幅增大．按照奇异性方法得到系统主共振分岔响应方程在开折参数和物理参数平面的转迁集和分岔图．利用Melnikov方法得到系统可能出现混沌运动的临界值．     

Primary Sn-rich titianite in the Qitianling granite, Hunan Province, southern China: An important type of tin-bearing mineral and its implications for tin exploration

The Qitianling calc-alkaline granite in Hunan Province (South China) has attracted much attention since the discovery of the Furong super-large tin deposit. The present study provides new mineralogical data to address their implications for exploration of tin deposits. In the Taoxiwo granite in the southeastern part of the Qitianling granite body, Sn-rich titanite was identified as an important type of Sn-bearing mineral. The titanite commonly occurs with biotite as euhedral crystals, exhibiting typical envelope-like shape and sector-zoning texture. These indicate that the titanite most likely crystallized in the magmatic stage. Electron-microprobe analyses show that the titanite is enriched in tin up to 1.12 wt% SnO₂, with an average of 0.43 wt%. With the crystallization of the granite, primary minerals undertook hydrothermal alteration by magma-derived fluids. Subsequently, in the hydrothermal stage, the primary Sn-bearing titanite was altered (at least partially), but still preserved its typical envelope-shaped outline. Micro-scale cassiterite is a representative product of such alteration; other secondary minerals include fluorite, ilmenite, Sn-bearing rutile and quartz. Therefore, the titanite, commonly present in the calcalkaline granites, can be treated as an important Sn-carrying mineral in the Qitianling granite, reflecting the primary magmatic environment with tin enrichment. The hydrothermal alteration of the primary titanite and subsequent crystallization of cassiterite recorded a process of leaching and accumulation of tin in magmatic-hydrothermal evolution of the Sn-bearing granite. Thus, this titanite has important implications for tin exploration. Supported by National Natural Science Foundation of China (Grant Nos. 40730423 and 40221301) and Project of China Geological Survey (Grant No. 1212010632100)     

Morphologic characteristics and growth interface stability of nano-micron FeS2 whiskers

Micromorphology is further studied on the basis of our previous researches concerned with the nano-micron FeS2 whisker. There are obvious differences in the intensive degree, diameter and micro- morphology among the FeS2 whiskers growing in different stages. From the early to late stage, the intensive degree increases, the diameter decreases, and the surface micro-morphology changes following the regularity： protrusive nodulation → coarse → smooth → flat. According to the theory of crystal growth, the geological setting and processes of whisker formation, we discuss the stability and evolution of crystal growth interface of FeS2 whisker occurring in Gengzhuang gold deposit （Shanxi Province, China）. The results suggest that the negative temperature gradient and the supercooling appear in the early stage of the whisker growth, whereas the positive temperature gradient of reposeful state appears in the late stage. In the whisker growth stage, the component concentration changes through the three stages： severely nonhomogeneous in the early stage, relatively homogeneous in the middle stage, more homogeneous in the late stage. The general changing process of the interfacial state is from unstable to stable. Micromorphology of FeS2 whisker in Gengzhuang is the result of synergism of temperature, component concentration and stability of crystal interface phase in hydrothermal system. The micromorphology not only reflects the physical and chemical characteristics of the hydrothermal system during the whisker growth, but also indicates the stability characteristics of the interface phase and records the changing process of the whisker growth.     

Sr-rich apatite from the Dangzishan leucitite-ijolite xenoliths （Heilongjiang Province）： Mineralogy and mantle-fluid metasomatism

Abundant apatite grains with elevated SrO content were found in leucitite-ijolite xenoliths in the Dangzi Mountain,Heilongjiang Province.Morphological and mineralogical associations,and compositional analysis of the Sr-rich apatite,were carried out using an electron microprobe.Two principal types of apatite were distinguished.One type occurs as short-prismatic crystals with Sr-rich rims,while another type with acicular or finely columnar shapes constitutes Sr-rich apatite element maps and systematic quantitative analysis of apatite revealed great variations in SrO content (0.42%-26.79%).The calculated structural formula of the measured Sr-rich apatite is:(Ca3.15-4.963Sr0.019-1.510Ba0.00-0.030Na0.006-0.108REE0.106-0.153) (P2.84-3.028Si0.009-0.094)O12(F0.675-1.079,Cl0.000-0.256,OH0.084-0.297).Mineralogical textures of apatite implied a replacement mechanism for the Sr-rich apatite.Sr-rich rims of apatite are suggested to have formed after metasomatism (isomorphic replacement) of early fluorapatite in a Sr-,light rare-earth elements (LREE),lithophile light elements (LILE)-and volatile-rich residual melt during late magmatism.However,the acicular apatite probably directly crystallized from a Sr-rich residual melt.The Sr-Nd isotopic composition of the apatite was distinctive from that of leucitite-ijolite and its host rock.These differences,combined with mineralogical features of apatite,imply that Sr-LREE-LILE-volatile-rich components in the residual melt were derived from deep in the asthenosphere,and subsequently were enriched at a late stage in magma evolution.     

Zircon U-Pb dating confirms existence of a Caledonian scheelite-bearing aplitic vein in the Penggongmiao granite batholith, South Hunan

Granite at Penggongmiao is a large batholith in the Nanling Range, with an outcrop area of over 900 km 2 . There are many scheelite-quartz veins around the granite. LA-ICP-MS U-Pb dating was carried out for zircons from the granite. The middlecoarse-grained biotite granite has U-Pb ages of 435 to 436 Ma. Ages of 426.5±2.5 Ma were obtained for aplitic dyke cross-cutting the granite. The scheelite of magmatic origin in the aplite dyke was identified from petrographic investigation. This demonstrates that W-bearing granites of Early Paleozoic (corresponding to the Caledonian orogensis in the traditional sense) occur in the Nanling Range. This finding has important implications for the ore-forming potential of Paleozoic granites and on the extent of Mesozoic mineralization. Thus it merits performing an intensive study of Paleozoic granites in South China. The occurrences of aplite or microgranite may be an indicative of the Caledonian tungsten granites and associated W mineralization.     

环境一号B星热红外波段单通道算法温度反演

文中在考虑环境一号B星(HJ-1B)热红外波段(infrared scanner,IRS4)光谱响应函数和有效波长的基础上,通过MODTRAN4模型模拟,对Jimenez-Munoz和Sobrino(JM&S)单通道算法中的大气函数进行改进,重新计算得到了适合HJ-1B星IRS4地表温度(land surface temperature,LST)反演的3个大气函数公式,并反演了福州地区的地表温度.采用基于星上辐亮度法对反演的地表温度进行精度评价,并将反演的地表温度与JM&S算法、段四波等修正的JM&S算法反演的地表温度进行对比分析.结果表明:使用文中改进后的大气参数对HJ-1B星IRS4进行地表温度反演,可取得较好结果.     

Mantle metasomatism by P- and F-rich melt/fluids： evidence from phosphate glass in spinel Iherzolite xenolith in Keluo, Heilonsjiang Province

Spinel Iherzolite xenoliths were found in phonoliUc alkaline basalt in the Keluo area, Heilongjiang Province. Detailed electron-microprobe study revealed abundant phosphates and associated metasomatic minerals between primary phases in xenolith. The phosphates are considered special residual phases （coagulation） of P- and F-rich mantle melt/fluid, most of which were identified as glass phases based on Raman spectroscopic analyses. Such melt/fluid also further metasomatized primary minerals, thus leading to formation of reaction rims successively composed of Cr-spinel symplecUUc zone and olivine ＋ diopside zone. Therefore, the P- and F-rich melt/fluid played an important role in the upper-mantle metasomatism in the Keluo area. It is suggested that this kind of metasomstism may occur in some other places of eastern China. The present results may also have significance in studying types of metasomatic melt/fluid and its evolution in the lithospheric mantle beneath eastern China.