999 resultados para Attila, d. 453
Resumo:
The velocity components across tidal fronts are examined using the Blumberg and Mellor 3-D nonlinear numerical coastal circulation model incorporated with the Mellor and Yamada level 2.5 turbulent closure model based on the reasonable model output of the M-2 tide and density residual currents. In the numerical experiments, upwelling motion appears around all the fronts with different velocity structures, accounting for surface cold water around the fronts. The experiments also suggest that the location and formation of fronts are closely related to topography and tidal mixing, as is the velocity structure around the front.
Resumo:
以青海果洛黄河源区高寒退化草甸生态系统为对象,应用静态密闭箱-气相色谱法对高寒退化草甸生态系统CO_2释放进行了初步研究.结果表明:所选4种不同退化程度高寒草甸,即未退化草甸(A)、轻度退化草甸(B)、中度退化草甸(C)和重度退化草甸(D),其CO_2释放速率有明显的日变化特征,日最大排放速率在15:00-17:00左右出现,最低值出现于清晨7:00-9:00左右,释放白天大于夜晚;(2)CO_2释放速率具有明显的季节性变化特征,生长期CO_2释放速率明显高于枯黄期,8月为CO_2释放高峰期,1月或2月为CO_2释放低谷期;(3)CO_2释放速率的日变化主要受地表温度和5cm地温制约,季节动态与5cm地温呈显著正相关关系(P<0.01),本研究为进一步进行高寒退化草甸生态系统源江效应的准确估测提供科学依据.
Resumo:
牦牛的起源与属级分类学地位至今仍然存在一定的争议.我们测定了家养牦牛和野生牦牛线粒体控制区(D-loop)序列,并以此构建牦牛和牛属、野牛属、水牛属以及非洲水牛属相关种的系统发育树.研究结果表明线粒体D-loop区与Cyt b基因序列在构建牛族的系统发育具有同样重要的价值.系统发育关系显示野牛属的灭绝种草原野牛与现存种美洲野牛先聚合为一单系群,然后再和牦牛形成一单系分支,表明牦牛与野牛属的草原野牛、美洲野牛亲缘关系最近,具有最近的共同祖先,而与牛属的其它亚洲物种亲缘关系较远.因此,本研究不支持将牦牛独立为牦牛属--Poephagus,牛属与野牛属在分类上也应合并为一个属.基于上述研究结果和化石证据,我们进一步对牦牛起源的历史背景进行了讨论,认为牦牛与野牛属的分化是由于第四纪气候变化在欧亚大陆发生的,野牛通过白令陆桥进入北美;冰期结束后,由于欧亚大陆其它地区温度升高,牦牛只能局限分布在较为寒冷的青藏高原;而野牛属在北美先后分化为草原野牛和美洲野牛,前者可能是后者的直接祖先.
Resumo:
2002年4-8月份,在中国科学院海北高寒草甸生态系统定位站附近,采用标志流放、直接观察法和解剖法对青藏高原特有的植食性小哺乳动物——高原鼠兔(Ochotona curzoniae)的行为时间分配、繁殖特征和后代存活率等方面进行了研究.结果表明,雌、雄成体平均地面活动时间占总时间的比例分别为88.67%和89.88%,在不同的繁殖时段,成体的各种行为时间分配存在显著的变化,并影响后代的存活率.幼体从出生到15 d存活率和雌、雄性成体的每次移动距离以及雌性成体的地面活动强度都显著的正相关;从15 d45 d存活率和雄性成体的地面活动强度、观望强度显著的正相关.在相同的观察时期,高原鼠兔雌、雄成体的一些行为时间分配存在显著差异,如雄性成体地面移动距离、频次在繁殖前期显著的高于雌性成体;雄性成体的观望强度在6、7月份显著高于雌性成体.说明雄性成体在领域防卫中较雌性成体承担更多的责任,雌、雄成体在育幼活动中的繁殖投入存在互补性。
Resumo:
针对江河源退化草地治理与示范项目要求,在果洛州玛沁县大武乡格多牧委会人工和半人工草场上,使用D肉毒杀鼠素对高原鼠兔Ochotona curzoniae进行现场药效试验和大面积灭鼠。结果表明,0.1%和0.2%D内毒杀鼠素毒饵时鼠兔具有良好的灭杀效果,且不污染环境,无二次中毒,对保护鼠粪天敌,维持生态平衡,控制害鼠种群数量回升,减少扩散,使治理后的草场植被再次免遭破坏等方面均具良好作用.
Resumo:
A simple, sensitive, and mild method for the determination of amino compounds based on a condensation reaction with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC-HCI) as the dehydrant with fluorescence detection has been developed. Amines were derivatized to their acidamides with labeling reagent 2-(2-phenyl-1H-phenanthro-[9,10-d]imidazole-1-yl)-acetic acid (PPIA). Studies on derivatization conditions indicated that the coupling reaction proceeded rapidly and smoothly in the presence of a base catalyst in acetonitrile to give the corresponding sensitively fluorescent derivatives with an excitation maximum at lambda(ex) 260nm and an emission maximum at lambda(em) 380nm. The labeled derivatives exhibited high stability and were enough to be efficiently analyzed by high-performance liquid chromatography. Identification of derivatives was carried out by online post-column mass spectrometry (LC/APCI-MS/MS) and showed an intense protonated molecular ion corresponding m/z [MH](+) under APCI in positive-ion mode. At the same time, the fluorescence properties of derivatives in various solvents or at different temperature were investigated. The method, in conjunction with a gradient elution, offered a baseline resolution of the common amine derivatives on a reversed-phase Eclipse XDB-C-8 column. LC separation for the derivatized amines showed good reproducibility with acetonitrile-water as mobile phase. Detection limits calculated from 0.78 pmol injection, at a signal-to-noise ratio of 3, were 3.1-18.2 fmol. The mean intra- and inter-assay precision for all amine levels were < 3.85% and 2.11%, respectively. Excellent linear responses were observed with coefficients of > 0.9996. The established method for the determination of aliphatic amines from real wastewater and biological samples was satisfactory. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
The reservoir of Zhongerbei region in Gudao Oilfield is a typical fluvial facies deposit, its serious heterogeneity of the reservoir caused the distribution of remaining oil in mature reservoirs is characterized by highly scattered in the whole field, and result to declination of production, tap potential and stabilize production is more difficult. Reservoir modeling based on lay scale can not fulfill requirement. How to further studied reservoir heterogeneity within the unit and establish the finer reservoir modeling is a valid approach to oil developing. The architectural structure elements analysis is the effectively method to study reservoir heterogeneity. Utilize this method, divide the reservoirs of Gudao Oilfield into ten hierarchies. The priority studying is sixth, seven hierarchies, ie single sand layers sand bodies By the identification of sixth, seven hierarchies, subdivide the reservoir to the single genetic unit. And to subdivide by many correlation means, such as isometry and phase transition, accomplish closure and correlation of 453 wells.Connectting fluvial deposit pattern, deposition characteristic with its log, build the inverting relation between “sedimentary facies” and “electrofacies” The process emphasize genetic communication and collocation structure of genetic body in space. By detailed architecture analyses sandbodies’ structure, this paper recognize seven structure elements, such as major channel, abandoned channel, natural levee, valley flat, crevasse splay, crevasse channel and floodplain fine grain.Combination identification of architectural structure elements with facieology and study of deposition characteristic, can further knowing genesis and development of abandoned channel. It boost the accuracy to separation in blanket channel bodies distribution, and provide reference to retrieving single channel boundary. Finally, establish fine plane and section construction. On basis architectural structure map, barrier beds and interbeds isopach map and mini-structure map, considering single thin layers to be construction unit, the main layer planimetric maps have drawn and the inner oil-water boundary have revealed. All account that architectural structure elements control remaining oil distribution in layer, and develop the study on architectural structure elements to direct horizontal well is succesful.
Resumo:
Hersai porphyry copper deposit(PCD) of eastern junggar, newly discovered copper deposit, is located at the eastern segment of the Xiemisitai-Kulankazigan-Zhifang-Qiongheba Paleozoic island arc, Eastern Junggar. The Hersai PCD is developed in a intrusive complex, characterized by intensive and multiform hydrothermal alteration, including potassic alteration, silification, chloritization,sericitization,kaolinitization and carbonatization. Granodiorite, grandiorite porphyry, granite and concealed explosion breccia are hosts of the ore bodies containing veinlet and disseminated ore. Ore-bearing granite (ZK107-1-9), granodiorite (ZK107-1-9) and Ore-barren granodiorite (HES2-1) are selected to date zircon U-Pb age by SHRIMP method, and have an age of 429.4±6.4Ma ,413.0±3.4Ma and 411.1±4.8Ma, respectively, showing that they were emplaced from Late Silurian to Early Devonian. In addition, sample ZK107-1-9 has some hydrothermal zircons with a weighted mean 206Pb/238U age of 404.9±3.7Ma which is interpreted to be related to the granodiorite porphyry. Re-Os dating of five molybdenite samples yielded a weighted average model age of 408.0±2.9Ma, indicating the metallogenic epoch of the Hersai PCD. The ore-forming age is close to the petrogenic time of garnodiorite (411-413Ma), this suggests the ore-forming porphyry is most possiblely granodiorite porphyry. Systematic major - trace elements and Rb-Sr-Sm-Nd-Pb-Hf isotopic characteristics were studied. Analysis results show that these intrusives have some interesting and special characteristics, as following:1) containing both calc-alkaline rocks and high potassium calc-alkaline rocks ; 2) have some characteristics of adakite, but not totally, such as much lower La/Yb ratios and no Eu anomaly or just faint Eu anomaly; 3) have an initial 87Sr/86Sr ratios(0.703852-0.704565) similar to that of BSE, positive εNd(t) values between 6.1 and 7.4, the initial 206Pb/204Pb values (17.576-17.912), 207Pb/204Pb values (15.400-15.453) , 208Pb/204Pb values (37.252-37.466) , and high εHf(t) values (10.2-15.4) close to the value of depleted mantle. These geochemical features suggest that these igneous rocks in the Hersai area not only have some characteristics of island arc, but also some characteristics that only appear in the continental margin arc. It is suggested that Hersai PCD is formed in the subduction setting by the partial melting of young crust. These works and advancements mentioned in the paper are helpful to understand the deposit geology, geochemistry and metallogenesis of Hersai PCD. It is also significant to understand mineralization and tectonic setting in the Qiongheba area.
Resumo:
老厂矿床位于三江成矿带南段昌宁—孟连裂谷的次级澜沧断陷盆地中,昌宁—孟连裂谷是三江成矿带南段的重要成矿段之一,其大地构造位于保山―掸邦微陆块东缘,兰坪—思茅盆地、临沧地块西缘,属东特提斯构造域,是冈瓦纳古陆与欧亚大陆巨型缝合带的组成部分。 矿床开采历史悠久,始于明朝永乐二年(1404年),至今已605年。古时炼银弃铅,最高年产白银30万两。解放后主要开采古人废弃的高铅炉渣,并对深部原生矿体进行了初步勘探,90年代至今对深部银铅矿体进行了详细勘查,深部矿体是矿床主要的开采对象。它以独特的成矿地质特征、富银(铅锌矿石中平均含量为629×10-6,方铅矿中平均2069×10-6)、伴生元素多(In、Se、Te、Ga、CdBi)、规模大(In、Se、Te、Cd达大型规模)、含Sn等特征而受到广大地质工作者的关注。它是“三江”成矿带南段最具代表性的铅银矿床类型之一,也是昌宁—孟连裂谷内目前探明的唯一大型银铅锌多金属矿床,具有十分重要的研究价值。 虽然前人已从矿床地质、成矿条件、控矿因素等方面对老厂大型银铅锌多金属矿床进行过研究,但研究工作较为零散,在成矿物质与成矿流体来源、矿床成因、花岗斑岩与成矿等方面还存在较大争议。本文在深入细致的野外地质工作基础上,利用多种现代分析测试技术,对矿床进行了较为系统的矿物学、岩石学、年代学和矿床地球化学研究,进而查明了矿床成矿物质与成矿流体来源、揭示了成矿地球动力学背景、探讨了矿床的成因、初步建立了矿床成因模式。论文取得的主要成果如下: 1.查明了硫化物的物质组分及形成阶段。闪锌矿以高铁(早期平均11.51%,晚期平均8.41%)为基本特征,并伴生多种特征的微量元素,早期闪锌矿是Fe、In的主要载体,Cu、CdMn则主要富集在晚阶段闪锌矿中;方铅矿是Ag的主要载体,其早期富Ag、Te、Bi,含Se、Cu,中期主要富Ag,晚期以含As、Bi为特征;其它硫化物成分较单一。 2.揭示了伴生元素赋存状态和富集规律。矿床伴生元素含量高,闪锌矿中Cd均4293.19×10-6,In平均555.37×10-6,方铅矿中Te平均143.81×10-6,As、Se、Bi、Ga含量也很高。初步估算金属储(万吨)量分别为: Ga 0.097,Cd1.84, In0.13,Se0.06 ,Te0.15,Bi1.28,As4.31。闪锌矿是Ga、In、Cd要载体,Te、Bi主要赋存在方铅矿中,Se则主要在铅锌、黄铁矿石中富集。 3.首次获得了精确的成矿年代学数据。单颗粒闪锌矿—黄铁矿Rb-Sr法获得矿床成矿年龄t=(45±3.6)Ma,(87Sr/86Sr)i=0.70977±0.00034。证实了矿床成矿与隐伏花岗斑岩关系密切,矿床形成是三江成矿带南段对喜马拉雅碰撞造山成矿运动的响应。 4.首次系统研究了花岗斑岩的地质、地球化学特征。矿床花岗斑岩具高硅、超钾、富碱、贫钠和低镁、钙、铁、磷的特征,岩石为过铝质岩石;其轻稀土富集、Eu为弱负异常、基本无Ce异常、岩石富集大离子亲石元素,具有较高的锶初始值和较低εNd高的Nd式年龄,与三江地区富碱斑岩具有相似的地球化学特征。岩浆主要来源于加厚下地壳重熔,成岩过程中有地幔物质的加入,为同碰撞构造环境下形成。 5.首次探讨了容矿沉积建造及矿石、矿物的地球化学特征。矿床碳酸盐岩轻稀土富集、Eu正异常及Ce异常和其微量元素特征与热水沉积岩石相似,表明了碳酸盐岩的热水沉积成因,同时矿石及其硫化物微量和稀土元素特征也指示了在早石炭世矿区发生了广泛的火山喷流热水沉积成矿作用。 6.查明了成矿物质及成矿流体来源。成矿元素研究显示矿床成矿物质具有多来源的特征,Pb同位素研究表明矿床Pb可能来自不同地层岩石的淋滤, S同位素组成显示其可能主要来源于海水对下伏火山岩地层的淋滤与海水硫酸盐的还原,花岗斑岩岩浆也可能提供了部分S。C-O、H-O同位素和矿石及其硫化物稀土元素反映矿床早期成矿流体主要源于深部岩浆,晚期主要来源于喜山期花岗斑岩岩浆热液。 7.初步建立了成矿模式。老厂矿床是长期以来多种地质作用下的综合产物,具有成矿物质多来源,成矿阶段多期次特点。经历了早石炭世火山喷流热水沉积成矿和喜山期花岗斑岩岩浆热液叠加改造成矿作用,热水成矿作用下形成了以黄铁矿为主的块状硫化物矿床,喜山期富碱花岗斑岩岩浆热液流体携带了大量的Cu、Mo、Ag、Pb等成矿元素,在它的叠加改造作用下形成了老厂银多金属矿床。总之矿床为火山喷流沉积—岩浆热液叠加改造成因。
Resumo:
This paper gives a brief review of R&D researches for light olefin synthesis directly and indirectly from synthesis gas in the Dalian Institute of Chemical Physics (DICP). The first pilot plant test was on methanol to olefin (MTO) reaction and was finished in 1993, which was based on ZSM-5-type catalyst and fixed bed reaction. In the meantime, a new indirect method designated as SDTO (syngas via dimethylether to olefin) was proposed. In this process, metal-acid bifunctional catalyst was applied for synthesis gas to dimethylether(DME) reaction, and modified SAPO-34 catalyst that was synthesized by a new low-cost method with optimal crystal size was used to convert DME to light olefin on a fluidized bed reactor. The pilot plant test on SDTO was performed and finished in 1995. Evaluation of the pilot plant data showed that 190-200 g of DME were yielded by single-pass for each standard cubic meter of synthesis gas. For the second reaction, 1.880 tons of DME or 2.615 tons of methanol produced 1 ton of light olefins, which constitutes of 0.533 ton of ethylene, 0.349 ton of propylene and 0.118 ton of butene. DICP also paid some attention on direct conversion of synthesis gas to light olefins. A semi-pilot plant test (catalyst 1.8 1) was finished in 1995 with a CO conversion > 70% and a C(2)(=)-C(4)(=) olefin selectivity 71-74% in 1000 h. (C) 2000 Published by Elsevier Science B.V. All rights reserved.