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111.
112.
文章应用常规资料,从天气环流形势演变、物理量等方面,对2000年1月10—11日包头地区普降大雪过程作了客观的分析,揭示了大雪过程的发生、发展机制,对今后分析大雪过程具有一定指导意义。 相似文献
113.
Using benthic macrofauna to assess environmental quality of four intertidal mudflats in Hong Kong and Shenzhen Coast 总被引:4,自引:0,他引:4
Cai Lizhe Nora F. Y. Tam Teresa W. Y. Wong Ma Li Gao Yang Yuk-Shan Wong 《海洋学报(英文版)》2003,22(2):309-319
Abstract-Intertidal zone is a significant wetland between land and ocean. It plays an important rolein maintaining local ecological balance. Both Mai Po and Futian intertidal mudflats are located in Shen-zhen Bay and are important "refueling" point along the East Asian/Australian flyway of migratory birds.The environmental quality of Mai Po and Futian mudflats have aroused great concern due to rapid eco-nomic developments in Hong Kong and Shenzhen in recent decades. Microinfauna of Mai Po and Futianmudflats was investigated in December 2000 and the faunal data were used to assess their environmentalquality. Two other mudflats, namely Ma Wan Typhoon Shelter (a more disturbed area) and Luk Kengintertidal mudflat (a place with relatively less human disturbance), were also sampled for macroinfaunaand used as reference mudflats. Shannon-Weaver species diversity index (I_(sd)), biotic coefficient (C_b)and macrofaunal pollution index (I_(mp)) of the macrofauna community on four intertidal mudflats wereused to 相似文献
114.
首次对浙北潮下带(0~-5m)水域生物学调查表明:共鉴定底栖生物222种,隶属103科170属;该区生物数量较高(生物量为80.88g/m2,栖息密度为655个/m2),以软体动物为主要类群;群落结构可划分为五个类型。底栖生物的分布与水域盐度、温度、底质性质、海湾屏蔽度有密切的关系。 相似文献
115.
<正>On 21 April 2021 local time(20 April UTC), the Indonesian Navy submarine(KRI Nanggala-402) sank near the Lombok Strait, ~100 km north of the Bali Island(see magenta star in Fig. 1a),with 53 crew members dead. On the basis of Moderate Resolution Imaging Spectroradiometer(MODIS) satellite images(Jackson, 2007), 相似文献
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This paper calculates the structural parameters, electronic and optical properties of orthorhombic distorted perovskite-type TbMnO3 by first principles using density functional theory within the generalised gradient approximation. The calculated equilibrium lattice constants are in a reasonable agreement with theoretical and experimental data. The energy band structure, density of states and partial density of states of elements are obtained. Band structures show that TbMnO3 is an indirect band gap between the O 2p states and Mn 3d states, and the band gap is of 0.48 eV agreeing with experimental result. Furthermore, the optical properties, including the dielectric function, absorption coefficient, optical reflectivity, refractive index and energy loss spectrum are calculated and analysed, showing that the TbMnO3 is a promising dielectric material. 相似文献
118.
对大亚湾3种重要经济鱼类包括黑鲷Sparusmacrocephalus、平鲷Rhabdosargussarba和细鳞Theraponjarbua的多项温度指标进行室内热效应模拟研究。结果表明:在驯化温度为25—33℃条件下,黑鲷、平鲷和细鳞3种鱼类的起始致死温度分别为34.96─36.42,34.78─35.62,38.75─39.39℃;最高起始致死温度分别为36.35,35.52℃和39.32℃;临界热最大值分别为38.08─40.50,38.28─40.40℃和42.40─43.64℃;最适生长温度分别为28,28℃和32℃;生长的最高周平均温度分别为30.78,30.51℃和34.44℃;短期暴露最高温度分别为34.04,33.57℃和37.90℃。根据黑鲷、平鲷和细鳞的多项温度指标,结合这些鱼类的生活习性分析和大亚湾基本环境特征的调查资料,就大亚湾核电站温排水对渔业资源影响的热效应问题进行初步探讨。 相似文献
119.
Distribution characteristics of size-fractionated chlorophyll a and primary productivity in Beibu Gulf 总被引:1,自引:1,他引:1
The distribution of the abundance of phytoplankton, chlorophyll a (Chl.a) concentration and primary productivity in the Beibu Gulf were observed from May 23 to June 4, 1994.The results show that there were marked featares of spatial zonation in the survey area due to the differences between the geographic environment and the hydrological conditions.Chlorophyll a and primary productivity were higher in the inshore than in the middle area and higher in the north than in the south of the Beibu Gulf.The average concentration of Chl.a, primary productivity and the abundance of phytoplankton were 0.94±0.45 μg/dm3, 351±172 mg/(m2·d) (C) and 0.97×104-10.050×104 ind./m3 in the area, respectively.There were 176 species belonging to 4 phyla and 56 genera based on microscope identification.The results of the size-fractionation show that the contribution of nanoplankton and picoplankton was 77% to total Chl.a and 91% to total primary productivity, which proved their importance to phytoplankton communities in the Beibu Gulf. 相似文献
120.
Chunfang Cai Zengye Xie Richard H. Worden Guoyi Hu Lansheng Wang Hong He 《Marine and Petroleum Geology》2004,21(10):1265-1279
New sour pools have recently found in the Lower Triassic Feixianguan Fm carbonate reservoirs in the East Sichuan Basin in China with H2S up to 17.4% by volume. A recent blowout from a well drilled into this formation killed hundreds of people as a result of the percentage concentrations of H2S. In order to assess the origin of fatal H2S as well as the cause of petroleum alteration, H2S concentrations and the isotopes, δ34S and δ13C have been collected and measured in gas samples from reservoirs. Anhydrite, pyrite and elemental sulphur δ34S values have been measured for comparison. The high concentrations of H2S gas are found to occur at depths >3000 m (temperature now at 100 °C) in evaporated platform facies oolitic dolomite or limestone that contains anhydrite nodule occurrence within the reservoirs. Where H2S concentrations are greater than 10% its δ34S values lie between +12.0 and +13.2‰ CDT. This is within the range of anhydrite δ34S values found within the Feixianguan Fm (+11.0 to +21.7‰; average 15.5±3.5‰ CDT). Thus H2S must have been generated by thermochemical sulphate reduction (TSR) locally within the reservoirs. Burial history analysis and fluid inclusion data reveal that the temperature at which TSR occurred was greater than about 130–140 °C, suggesting that the present depth-temperature minimum is an artifact of post-TSR uplift. Both methane and ethane were actively involved in TSR since the petroleum became almost totally dry (no alkanes except methane) and methane δ13C values become significantly heavier as TSR proceeded. Methane δ13C difference thus reflects the extent of TSR. While it is tempting to use a present-day depth control (>3000 m) to predict the distribution of H2S in the Feixianguan Fm, this is an invalid approach since TSR occurred when the formation was buried some 1000–2000 m deeper than it is at present. The likelihood of differential uplift across the basin means that it is important to develop a basinal understanding of the thermal history of the Feixianguan Fm so that it is possible to determine which parts of the basin have been hotter than 130–140 °C. 相似文献