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71.
DharmalingamVENUGOPAL 《山地科学学报》2004,1(1):74-80
The Nilgiri Mountains of south India is considered unique by anthropologists, geologists, climatologists, botanists as well as tourists. It has remained a subject of constant study and research over the last two centuries. Man-nature balance had continued undisturbed in the Nilgiris for thousands of years until the early 19th century when it became a British colony attracting, in due course, various developmental activities. Subsequently, the Nilgiris and its popular hill stations emerged as favourite places for the British population in India for rest and recuperation, game and for raising commercial plantations. In the process, the traditional indigenous crops were replaced by “English“ vegetables and the natural forests gave way to commercial plantations of coffee, tea and other exotic species of trees. 相似文献
72.
高从堦 《中国海洋湖沼学报》2003,21(1):40-45
Seawater desalination has been people‘s fond dream since ancient times,the dream is now becoming a reality.This paper presents a brief development history of reverse osmosis.Much attention was paid to innovative development in mebranes,modules.equipments and applied technology,including asymmetric and composite membranes,spiral-wound element and hollow fiber module,energy recovery equipments and different technological processes.The extension of reverse osmosis,such as desalination,pre-concentration,integrated processes and nanofiltration,is also briefly mentioned. 相似文献
73.
74.
INTRODUCTIONTheSubeiShoalandtheChangjiangRiverestuarineareainthewestoftheHuanghaiandEastChinaSeasisoneofthemarginalseasintheworld ,wheresuspendedmatterisextremelyhigh .Here ,notonlyistheretheTaiwanWarmCurrentoneoftheKuroshio’sbranchesintheEastChinaSea,butalsotheHuanghaiCoastalCurrent,andChangjiangDilutedWater.Sothestrongmixingbetweenthecoastalandoffshorewaterscomplicatessuspendedmatterdistributioninthisarea.HowthesuspendedmatterdischargedfromtheChangjiangRiverandtheabandonedHuan… 相似文献
75.
FUZZY COMPREHENSIVE EVALUATION OF CONTAINER TRANSPORTATION MODES ALONG THE CHANGJIANG RIVER MAIN LINE AND ITS DELTA AREA 总被引:1,自引:0,他引:1
ZHANGShi-yu XIAOHan-liang 《中国地理科学(英文版)》2003,13(3):259-261
The Changjiang River (Yangtze) is one of the fastest growth areas of container transportation in Chi-na. Rail, road and water transportation have competed against each other for container transportation in the Chang-jiang River main line and its delta area. It is of significance to assess these different transportation modes scientifi-cally in order to organize container transportation efficiently in this area and make decision for integral plan and construction of transportation system in this area. This paper outlines application of fuzzy comprehensive evaluation to appraise different modes of typical direction of containers. Twelve assessment indexes were decided. Membership functions were formulated. Evaluation results indicated that road transportation was optimal mode in the Changjiang River delta area, however water transportation was the primary way in the Changjiang River main line. 相似文献
76.
77.
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
78.
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
79.
The Mangala Valles system is an ∼
∼900 km fluvially carved channel system located southwest of the Tharsis rise and is unique among the martian outflow channels
in that it heads at a linear fracture within the crust as opposed to a collapsed region of chaos as is the case with the circum-Chryse
channels. Mangala Valles is confined within a broad, north–south trending depression, and begins as a single valley measuring
up to 350 km wide that extends northward from a Memnonia Fossae graben, across the southern highlands toward the northern
lowlands. Approximately 600 km downstream, this single valley branches into multiple channels, which ultimately lose their
expression at the dichotomy boundary. Previous investigations of Mangala Vallis suggested that many of the units mapped interior
to the valley were depositional, related to flooding, and that a minimum of two distinct periods of flooding separated by
tens to hundreds of millions of years were required to explain the observed geology. We use infrared and visible images from
the THermal EMission Imaging System (THEMIS), and topographic data from the Mars Orbiting Laser Altimeter (MOLA), to investigate
the nature of the units mapped within Mangala Vallis. We find that the geomorphology of the units, as well as their topographic
and geographic distribution, are consistent with most of them originating from a single assemblage of volcanic flow deposits,
once continuous with volcanic flows to the south of the Memnonia Fossae source graben. These flows resurfaced the broad, north–south
trending depression into which Mangala Vallis formed prior to any fluvial activity. Later flooding scoured and eroded this
volcanic assemblage north of the Mangala source graben, resulting in the present distribution of the units within Mangala
Vallis. Additionally, our observations suggest that a single period of catastrophic flooding, rather than multiple periods
separated by tens to hundreds of millions of years, is consistent with and can plausibly explain the interior geology of Mangala
Vallis. Further, we present a new scenario for the source and delivery of water to the Mangala source graben that models flow
of groundwater through a sub-cryosphere aquifer and up a fracture that cracks the cryosphere and taps this aquifer. The results
of our model indicate that the source graben, locally enlarged to a trough near the head region of Mangala, would have required
less than several days to fill up prior to any spill-over of water to the north. Through estimates of the volume of material
missing from Mangala (13,000–20,000 km3), and calculation of mean discharge rates through the channel system (∼
∼5 × 106 m3 s−1), we estimate that the total duration of fluvial activity through the Mangala Valles was 1–3 months. 相似文献
80.
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