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61.
62.
WANGWei-wu ZHULi-zhong WANGRen-chao SHIYong-jung 《中国地理科学(英文版)》2003,13(1):39-47
Urban heat environmental quality(UHEQ) is affected by the interacting of weather condition and underlying surface framework of urban area .In the last two decades,many researchers from domestic and overseas have studied many problems at the aspect of urban heat environment such as urban heat islands ,urban air temperature and their rela-tion with urban land cover,city population,air pollution etc,In the recent years,Hangzhou,acting as a center city of Zhejiang Province in China,its urbanization quantum and quantity have both changed greatly,in particular ,representing as business affairs building,resident real property and all kins of specialty market having arisen in built-up zone,Based on Landsat TM images data in 1991 and 1999,urban underlying surface temperature value and Normalized Difference Vegetation Index (NDVI) were calculated using image interpreting and supervised classification technique by remote sensing software ERDAS image 8.4,The relation model between urban underlying surface temperature (UUST )and urban air temperature was setup according to the certain correlation patten .Reference to the relational standard of assessing human comfort and other meteorology data of Hangzhou City in summer,the spatial distribution characteristic and the spatial varia-tion degree of human comfort of heat environmental quality are estimated and mapped on a middle scale,that is ,in six districts of Hangzhou City .Then the paper reveals the main characteristic of spatial variation from 1991 to 1999.Lastly,the change mechanism is analyzed and discussed from the viewpoint of city planning,construction and environmental protec-tion. 相似文献
63.
64.
HUANGGuoqiang DONGShuanglin WANGFang 《中国海洋大学学报(英文版)》2005,4(1):56-60
Attractabilities of different diets and dietary selectivity of Chinese shrimp, Fenneropenaeus chinensis were studied through behavior observation and feeding experiment, respectively. The five diets used in the experiment are: Fish Flesh (FF), Shrimp Flesh (SF), Clam Foot (CF), Polychaete Worm (PW), and Formulated Diet (FD). No significant differences of attractability exist between any two different diets when every two natural diets or all five diets are provided simultaneously. On the other hand, significant differences of attractability exist between FD and every single natural diet when they are provided simultaneously. Results of behavioral observation indicate that natural diets are more attractive than FD. In feeding experiment, Chinese shrimp has distinct selectivity on different diets. It positively selects CF and PW, negatively selects FF and SF, and excludes FD absolutely. The results of the present studies indicate that the dietary selectivity of shrimp was based not only on the attractabilities of the diets, but also on the responses such as growth and food conversion. 相似文献
65.
Tourmaline mineralization in the Barberton greenstone belt,South Africa: early Archean metasomatism by evaporite-derived boron 总被引:1,自引:0,他引:1
Tourmaline-rich rocks are common in the lowgrade, interior portions of the Barberton greenstone belt of South Africa, where shallow-marine sediments and underlying altered basaltic and komatiitic lavas contain up to 50% tourmaline. The presence of tourmaline-bearing rip-up clasts, intraformational tourmalinite pebbles, and tourmaline-coated grains indicates that boron mineralization was a low-temperature, surficial process. The association of these lithologies with stromatolites, evaporites, and shallow-water sedimentary structures and the virtual absence of tourmaline in correlative deep-water facies rocks in the greenstone bels strengthens this model.Five tourmaline-bearing lithologic groups (basalts, komatiites, evaporite-bearing sediments, stromatolitic sediments, and quartz veins) are distinguished based on field, petrographic, and geochemical criteria. Individual tourmaline crystals within these lithologies show internal chemical and textural variations that reflect continued growth through intervals of change in bulk-rock and fluid composition accompanying one or more metasomatic events. Large single-crystal variations exist in Fe/Mg, Al/Fe, and alkali-site vacancies. A wide range in tourmaline composition exists in rocks altered from similar protoliths, but tourmalines in sediments and lavas have similar compositional variations. Boron-isotope analysis of the tourmalines suggest that the boron enrichment in these rocks has a major marine evaporitic component. Sediments with gypsum pseudomorphs and lavas altered at low temperatures by shallow-level brines have the highest 11B values (+2.2 to-1.9); lower 11B values of late quartz veins (-3.7 to-5.7) reflect intermediate temperature, hydrothermal remobilization of evaporitic boron. The 11B values of tourmaline-rich stromatolitic sediments (-9.8 and-10.5) are consistent with two-stage boron enrichment, in which earlier marine evaporitic boron was hydrothermally remobilized and vented in shallow-marine or subaerial sites, mineralizing algal stromatolites. The stromatolite-forming algae preferentially may have lived near the sites of hydrothermal discharge in Archean times. 相似文献
66.
Frank Stefan Tautz Volker Heine Martin T. Dove Xiaojie Chen 《Physics and Chemistry of Minerals》1991,18(5):326-336
A molecular dynamics simulation of quartz at different temperatures both in the a and in the phase has been conducted. The - phase transition could be observed. A phonon analysis of the -phase confirms and rounds out in a quantitative way the origin of the incommensurate (ic) modulated phase. In particular it traces the optic soft mode at becoming (to a good approximation) a so-called rigid unit mode (RUM) at q0, and elucidates its coupling to the transverse acoustic mode which precipitates the incommensurate transition. This success underpins and illuminates the concept of RUMs and their role in structural phase transitions. 相似文献
67.
Food, energy and mineral resources appeared to be available in limitless quantities. The accelerated growth in global population during recent centuries brought about a new situation. We reached the resource limits of Spaceship Earth. This, along with the dawning awareness of the extent of environmental damage to date, have made it necessary to turn to new attitudes as to the use of renewable and non-renewable resources.IRM (Integrated Resource Management) is proposed as a way to rationally balance the use and conservation of natural resources. A databank based on the Geographic Information System (GIS) concept, bringing together all relevant resources of a nation, is the centerpiece of IRM and will make it possible to establish strategies to optimize the long term use of resources, including all relevant environmental factors. 相似文献
68.
Martin Beech 《Astrophysics and Space Science》1986,122(1):57-61
We perform a Monte Carlo analysis of the eclipse probabilities of short-period binary systems in an attempt to estimate the distribution of ellipsoidal variable system with Main-Sequence components. Our results suggest that possibly as many as one in four of the non-eclipsing, spectroscopic binaries withP(d)10, and Main-Sequence components withM
v
10 could be ellipsoidal variable systems. This result, while an upper limit, would seem to hold irrespective of primary spectral type (B5 to G5). 相似文献
69.
Martin Beech 《Astrophysics and Space Science》1985,114(2):345-350
In the standard cosmological model symmetry breaking in grand unified theories will occur at times 10–39 s after the initial singularity when the Universe has cooled to a temperature 1016 GeV. We investigate here whether it is possible for a uniform, large-scale, magnetic field present in the early universe to delay significantly the time at which symmetry breaking occurs. Given the present magnitude of the intergalactic B-field (10–11–10–9 G) it is found that no significant effects are introduced. 相似文献
70.
Andreas G. Mueller Gregory C. Hall Alexander A. Nemchin Holly J. Stein Robert A. Creaser Douglas R. Mason 《Mineralium Deposita》2008,43(3):337-362
The Granny Smith (37 t Au production) and Wallaby deposits (38 t out of a 180 t Au resource) are located northeast of Kalgoorlie,
in 2.7 Ga greenstones of the Eastern Goldfields Province, the youngest orogenic belt of the Yilgarn craton, Western Australia.
At Granny Smith, a zoned monzodiorite–granodiorite stock, dated by a concordant titanite–zircon U–Pb age of 2,665 ± 3 Ma,
cuts across east-dipping thrust faults. The stock is fractured but not displaced and sets a minimum age for large-scale (1 km)
thrust faulting (D2), regional folding (D1), and dynamothermal metamorphism in the mining district. The local gold–pyrite
mineralization, controlled by fractured fault zones, is younger than 2,665 ± 3 Ma. In augite–hornblende monzodiorite, alteration
progressed from a hematite-stained alkali feldspar–quartz–calcite assemblage and quartz–molybdenite–pyrite veins to a late
reduced sericite–dolomite–albite assemblage. Gold-related monazite and xenotime define a U–Pb age of 2,660 ± 5 Ma, and molybdenite
from veins a Re–Os isochron age of 2,661 ± 6 Ma, indicating that mineralization took place shortly after the emplacement of
the main stock, perhaps coincident with the intrusion of late alkali granite dikes. At Wallaby, a NE-trending swarm of porphyry
dikes comprising augite monzonite, monzodiorite, and minor kersantite intrudes folded and thrust-faulted molasse. The conglomerate
and the dikes are overprinted by barren (<0.01 g/t Au) anhydrite-bearing epidote–actinolite–calcite skarn, forming a 600-m-wide
and >1,600-m-long replacement pipe, which is intruded by a younger ring dike of syenite porphyry pervasively altered to muscovite
+ calcite + pyrite. Skarn and syenite are cut by pink biotite–calcite veins, containing magnetite + pyrite and subeconomic
gold–silver mineralization (Au/Ag = 0.2). The veins are associated with red biotite–sericite–calcite–albite alteration in
adjacent monzonite dikes. Structural relations and the concordant titanite U–Pb age of the skarn constrain intrusion-related
mineralization to 2,662 ± 3 Ma. The main-stage gold–pyrite ore (Au/Ag >10) forms hematite-stained sericite–dolomite–albite
lodes in stacked D2 reverse faults, which offset skarn, syenite, and the biotite–calcite veins by up to 25 m. The molybdenite
Re–Os age (2,661 ± 10 Ma) of the ore suggests a genetic link to intrusive activity but is in apparent conflict with a monazite–xenotime
U–Pb age (2,651 ± 6 Ma), which differs from that of the skarn at the 95% confidence level. The time relationships at both
gold deposits are inconsistent with orogenic models invoking a principal role for metamorphic fluids released during the main
phase of compression in the fold belt. Instead, mineralization is related in space and time to late-orogenic, magnetite-series,
high-Mg monzodiorite–syenite intrusions of mantle origin, characterized by Mg/(Mg + FeTOTAL) = 0.31–0.57, high Cr (34–96 ppm), Ni (22–63 ppm), Ba (1,056–2,321 ppm), Sr (1,268–2,457 ppm), Th (15–36 ppm), and rare earth
elements (total REE: 343–523 ppm). At Wallaby, shared Ca–K–CO2 metasomatism and Th-REE enrichment (in allanite) link Au–Ag mineralization in biotite–calcite veins to the formation of the
giant epidote skarn, implicating a Th + REE-rich syenite pluton at depth as the source of the oxidized hydrothermal fluid.
At Granny Smith, lead isotope data and the Rb–Th–U signature of early hematite-bearing wall-rock alteration point to fluid
released by the source pluton of the differentiated alkali granite dikes. 相似文献