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41.
P.A. Balykin G.V. Polyakov A.E. Izokh Tran Trong Hoa Ngo Thi Phuong Tran Quoc Hung T.E. Petrova 《Russian Geology and Geophysics》2010,51(6):611-624
The Jinping–Song Da rift structure in the Emeishan Large Igneous Province is composed of Permian high- and low-Ti volcanic and volcanoplutonic ultramafic-mafic associations of different compositions and genesis. High-Ti picrites, picrobasalts, basalts, and dolerites are enriched in LREE and depleted in HREE and show low Al2O3/TiO2 ratios (~4), commensurate εNd(T) values (+0.5 to +1.1), and low (Th/Nb)PM ratios similar to those of OIB-enriched mantle source. The established geochemical characteristics evidence that the parental melts of these rocks were generated from garnet lherzolite at the depths of garnet stability (~200 to 400 km). Later, high-Mg low-Ti volcanics (komatiites, komatiitic basalts, and basalts) and associating small peridotite-gabbro massifs and komatiite-basalt dikes were produced as a result of ~20% partial melting of depleted water-poor (≤0.03 wt.% H2O) peridotite substratum from the hottest upper part of mantle plume at relatively shallow depths (100–120 km). The LREE-depleted komatiites and komatiitic basalts are characterized by low (Ce/Yb)CH values, 187Re/188Os = 0.05–1.2, 87Sr/86Sr = 0.704–0.706, positive εNd(T) values (+3 to +8), γOs = –0.5 to +0.9, and strong negative anomalies of Ba, K, and Sr on the spidergrams. The scarcer LREE-enriched komatiites, komatiitic basalts, and basalts vary greatly in chemical composition and values of εNd(t) (+6.4 to –10.2), 87Sr/86Sr (0.706–0.712), and γOs (+14.8 to +56), which is due to the different degrees of crustal contamination of parental magmas. The Rb-Sr isotopic age of basaltic komatiite is 257 ± 24 Ma. The Re-Os age determined by analysis of 12 komatiite samples is 270 ± 21 Ma. These data agree with the age of flood basalts of the Emeishan Large Igneous Province. The komatiite-basalt complex of the Song Da rift is still the only Phanerozoic PGE-Cu-Ni-complex of this composition. The geochemistry of accompanying Cu-Ni-PGE-ores confirms their relationship with komatiite-basaltic magmatism. 相似文献
42.
Replacement of Dietary Fish Oil with Vegetable Oils Improves the Growth and Flesh Quality of Large Yellow Croaker (Larmichthys crocea) 总被引:2,自引:1,他引:1
DUAN Qingyuan MAI Kangsen SHENTU Jikang AI Qinghui ZHONG Huiying JIANG Yujian ZHANG Lu ZHANG Chunxiao GUO Sitong 《中国海洋大学学报(英文版)》2014,13(3):445-452
We investigated the effect of the replacement of dietary fish oil with vegetable oils on the growth and flesh quality of large yellow croaker(Larmichthys crocea). The basal diet(FO) was formulated to contain 66.5% fish meal and 6.4% menhaden fish oil; whereas the other 3 experimental diets were formulated by replacing the fish oil with 50% soybean oil(SO50), 100% soybean oil(SO100) and 100% palm oil(PO100), respectively. The 4 diets were randomly assigned to 4 floating sea cages(3.0 m × 3.0 m × 3.0 m), and each was stocked with 250 fish individuals with an initial average weight of 245.29 g ± 7.45 g. The fish were fed to apparent satiation twice a day at 5:00 and 17:00, respectively, for 12 weeks. Experimental analysis showed that the specific growth rate of fish fed SO50 or PO100 were significantly higher than that of fish fed FO or SO100(P0.05), and crude lipid contents of ventral muscle and viscera were significantly lower in fish fed FO than in those fed the other 3 diets(P0.05). No significant differences in condition factor, viscerosomatic index, hepatosomatic index, gutted yield and colorimetric values of fish among the dietary treatments were observed(P0.05). Compared to FO diet, SO50, SO100 and PO100 diets led to substantial decreases in the liquid loss and water loss from fresh fillets(1 d, 4℃)(P0.05). Similarly, thiobarbituric acid reactive substance(TBARS) values of fillets under different storage conditions(1 d, 4℃; 7 d, 4℃; 4 weeks,-20℃; 8 weeks,-20℃) decreased significantly after partial or complete replacement of fish oil with vegetable oils. These findings indicated that the growth performance and selected flesh quality properties(liquid holding capacity and TBARS value) of large yellow croaker were substantially improved by replacing dietary fish oil with vegetable oils. 相似文献
43.
R G Rastogi H Chandra P Janardhan Thai Lan Hoang Louis Condori T K Pant D S V V D Prasad B Reinisch 《Journal of Earth System Science》2014,123(6):1273-1285
The paper describes the results of spread-F at low latitude stations around the world during the magnetic storm starting at 0130 UT on 22 January 2004. The storm can be divided into two phases, first phase up to 1000 UT when interplanetary magnetic field IMF-Bz was highly fluctuating around a small positive value and the second phase after a sudden large southward turning of IMF-Bz at 1030 UT. The first phase produced strong spread-F at Jicamarca, Sao Luis, and Ascension Island and caused complete inhibition of spread-F at Thumba and Waltair in India. It generated weak spread-F at Ho Chi Minh City in Vietnam and strong spread-F at Hainan and Chung Li. The strong spread-F at Hainan and Chung Li were caused by the positive IMF-Bz during the first phase of the storm and not by the negative pulse of IMF-Bz at 1000 UT. 相似文献
44.
E.F. Van Dishoeck W.F. Thi G.A. Blake V. Mannings A.I. Sargent D. Koerner L.G. Mundy 《Astrophysics and Space Science》1997,255(1-2):77-82
Preliminary results are presented of observations of the pure rotational lines of H2 toward T Tauri and Herbig Ae stars using
the Short Wavelength Spectrometer (SWS) on the Infrared Space Observatory (ISO). The sources are selected to be isolated low-
and intermediate-mass young stellar objects, for which the presence of a circumstellar disk has been established by millimeter
interferometry. The lowest H2 S(0) and S(1) lines are detected in 3 out of 5 objects. The measured intensities indicate ∼
0.01 M⊙ of warm (T ≈ 150 K) gas in the ISO beam. It is argued that for at least one case (HD 163296), the emission is probably
dominated by the warm gas in the circumstellar disk rather than by shocked- or photon-heated gas in the surrounding envelope.
Such observations can provide important constraints on the radial and vertical temperature profiles in circumstellar disks.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
45.
Lopatin A. V. Golovachev I. V. Serdyuk N. V. Maschenko E. N. Vislobokova I. A. Dac Le Xuan Phuong Pham Mai Parkhaev P. Yu. Syromyatnikova E. V. 《Doklady Earth Sciences》2022,504(2):372-379
Doklady Earth Sciences - Speleological, geological and paleontological characteristics of the Lang Trang cave in northern Vietnam are presented. Primates Gigantopithecus blacki von Koenigswald,... 相似文献
46.
H. Jean Thiébaux 《大气与海洋》2013,51(4):291-305
Abstract Data assimilation in numerical weather forecasting corrects current forecast values by subtracting a portion of interpolated forecast‐minus‐observation differences at the points of a three‐dimensional grid. Deviations used in updating a forecast data field are forecast errors obtained or derived from observations available at update time. When observations are missing at mandatory levels, construction of full vertical soundings by interpolation introduces extraneous errors. The present paper is concerned with determination of the error in vertical extrapolations of surface winds, and of aircraft and satellite cloud‐tracked winds. In addition it examines the effect on accuracy of using location‐specific statistics compared to averaged statistics as the basis for the interpolation weighting scheme and compares errors of one‐ and two‐variable interpolations. Interpolation accuracy tests demonstrate the influence of the interpolation scheme on the quality of interpolated information used in forecast updating. The results show that the level of accuracy exceeds the benchmark provided by monthly mean forecast error values only with bivariate interpolation of wind components from off‐level data sources. 相似文献
47.
1208号台风“韦森特”异常路径及其对珠三角南部暴雨影响成因分析 总被引:1,自引:0,他引:1
利用1°×1°NCEP再分析资料、全省遥测站资料、卫星云图、香港雷达图等资料,分析台风“韦森特”的环流背景场、物理量场特征,找出“韦森特”在南海中北部原地摆动和对珠三角南部强降水过程的物理成因:“韦森特”的原地摆动,与副热带高压、南海中部海温、还有台风内在的云系和风场结构的不对称有关;珠三角地区两侧附近存在弱的水汽通量辐合,在降水中心附近存在明显的上升运动,低层辐合、高层辐散,另外垂直螺旋场与降水中心的第一段降水期具有很好的对应关系. 相似文献
48.
Florence Habets Julien Boé Michel Déqué Agnès Ducharne Simon Gascoin Ali Hachour Eric Martin Christian Pagé Eric Sauquet Laurent Terray Dominique Thiéry Ludovic Oudin Pascal Viennot 《Climatic change》2013,121(4):771-785
This study presents an analysis of climate-change impacts on the water resources of two basins located in northern France, by integrating four sources of uncertainty: climate modelling, hydrological modelling, downscaling methods, and emission scenarios. The analysis focused on the evolution of the water budget, the river discharges and piezometric heads. Seven hydrological models were used, from lumped rainfall-discharge to distributed hydrogeological models, and led to quite different estimates of the water-balance components. One of the hydrological models, CLSM, was found to be unable to simulate the increased water stress and was, thus, considered as an outlier even though it gave fair results for the present day compared to observations. Although there were large differences in the results between the models, there was a marked tendency towards a decrease of the water resource in the rivers and aquifers (on average in 2050 about ?14 % and ?2.5 m, respectively), associated with global warming and a reduction in annual precipitation (on average in 2050 +2.1 K and ?3 %, respectively). The uncertainty associated to climate models was shown to clearly dominate, while the three others were about the same order of magnitude and 3–4 times lower. In terms of impact, the results found in this work are rather different from those obtained in a previous study, even though two of the hydrological models and one of the climate models were used in both studies. This emphasizes the need for a survey of the climatic-change impact on the water resource. 相似文献
49.
Ethnic Enclave Reconfiguration: A ‘new’ Chinatown in the Making 总被引:1,自引:0,他引:1
Years of past research on traditional Chinatowns were based on the assumption that Chinatown is an ethnic enclave for a single
ethnic minority, i.e. the Chinese. In recent years, one could observe significant changes over Chinatowns in terms of more
Vietnamese presence. Yet, the transition process as an object of study is much under-represented in the literature on ethnic
enclaves. Looking at ethnic business transition from Hong Kong to Vietnamese in Toronto’s Chinatown West, this paper argues
strongly that ‘multiple ethnicity’ can coexist in an enclave. For this case study, the Chinatown is being reconfigured into a ‘new’ Chinatown. Drawing upon data from the authors’ Vietnamese Business Database that covers information between
1983 and 2003, we present both spatial and temporal analyses that offer insights into how the Vietnamese businesses grow through
time. Our findings support the existence of a Vietnamization process in Toronto Chinatown West. However, its evolution is
still in an infant stage. In some aspects, the incoming Vietnamese businesses display similarities with the remaining Hong
Kong businesses. In sum, a total reconfiguration of Chinatown West in form and business nature is still unaccomplished. The
conventional enclave concept which bases on the singularity of ethnic group has to be abandoned in view of rising occurrence
of ethnic transition, particularly in this globalizing era. 相似文献
50.
Advances in the Study on Nutrient Requirements of Grouper(Epinephelus sp. ):a Review 总被引:1,自引:0,他引:1
LUOZhi LIUYongjian MAIKangsen TIANLixia 《中国海洋大学学报(英文版)》2005,4(2):93-98
The paper reviews the recent advances in studying grouper nutrition requirement for the development of cost-effective and environmentally friendly artificial diets. It consists of seven parts: protein and amino acid, lipid and essential fatty acid, carbohydrate, vitamin, mineral, alternative protein source, broodstock and larval nutrition. The review provides some basic information for further investigation of nutrient requirements of groupers. 相似文献