986 resultados para T1-TOPOLOGIES
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The disequilibrium between supply and demand the east part of North China accelerated natural gas exploration in Bohai bay basin. Exploration practice showed that coal-derived gas is important resource. In searching of big to middle scaled coal derived gas field, and realize successive gas supply, the paper carried out integrated study on structural evolution of Pre-Tertiary and evaluation of reservoir forming condition of coal-derived gas. Study work of the paper was based on the following condition: available achievement in this field at present, good understanding of multiphase of tectonic movement. Study work was focused on geological evolution, source rock evaluation and dissection key factors controlling reservoir forming. Based on analysis of seismic data, drilling data, tectonic style of Pre-Tertiary was subdivided, with different tectonic style representing different tectonic process. By means of state of the art, such as analysis of balanced cross section, and erosion restoration, the paper reestablished tectonic history and analyzed basin property during different tectonic phase. Dynamic mechanism for tectonic movement and influence of tectonic evolution on tectonic style were discussed. Study made it clear that tectonic movement is intensive since Mesozoic including 2 phase of compressional movement (at the end of Indo-China movement, and Yanshan movement), 2 phase of extensional movement (middle Yanshan movement, and Himalayan movement), 2 phase of strike slip movement, as well as 2 phase of reversal movement (early Yanshan movement, and early Himalayan movement). As a result, three tectonic provinces with different remnant of strata and different tectonic style took shape. Based on afore mentioned study, the paper pointed out that evolution of Bohai bay basin experienced the following steps: basin of rift valley type (Pt2+3)-craton basin at passive continental margin (∈1-2)-craton basin at active continental margin (∈3- O)-convergent craton basin (C-T1+2)-intracontinental basin (J+K). Superposition of basins in different stage was discussed. Aimed at tectonic feature of multiple phases, the paper put forward concept model of superposition of tectonic unit, and analyzed its significance on reservoir forming. On basis of the difference among 3 tectonic movements in Mesozoic and Cenozoic, superposition of tectonic unit was classified into the following 3 categories and 6 types: continuous subsidence type (I), subsidence in Mesozoic and uplift for erosion in Cenozoic (II1), repeated subsidence and uplift in Mesozoic and subsidence in Cenozoic (II2), repeated subsidence and uplift in Mesozoic and uplift for erosion in Cenozoic (II3), uplift for erosion in Mesozoic and subsidence in Cenozoic (II4), and continuous uplift (III). Take the organic facies analysis as link, the paper established relationship between sedimentary environment and organic facies, as well as organic facies and organic matter abundance. Combined information of sedimentary environment and logging data, the paper estimated distribution of organic matter abundance. Combined with simulation of secondary hydrocarbon generation, dynamic mechanism of hydrocarbon generation, and thermal history, the paper made static and dynamic evaluation of effective source rock, i.e. Taiyuan formation and Shanxi formation. It is also pointed out that superposition of tectonic unit of type II2, type II4, and type I were the most favorable hydrocarbon generation units. Based on dissection of typical primary coal-derived gas reservoir, including reservoir forming condition and reservoir forming process, the paper pointed out key factors controlling reservoir forming for Carboniferous and Permian System: a. remnant thickness and source rock property were precondition; b. secondary hydrocarbon generation during Himalayan period was key factor; c. tectonic evolution history controlling thermal evolution of source rock was main factor that determine reservoir forming; d. inherited positive structural unit was favorable accumulation direction; e. fault activity and regional caprock determined hydrocarbon accumulation horizon. In the end, the paper established reservoir forming model for different superposition of tectonic units, and pointed out promising exploration belts with 11 of the first class, 5 of the second class and 6 of the third class.
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评述了分散元素镓的应用和成矿作用的研究现状并剖析了镓的成矿研究存在的主要问题。论证了铝土矿床中的镓主要赋存于其中的一水硬铝石且以GaO(OH)形式存在;以晶体化学理论分析,认为中高温热液条件形成的闪锌矿(主要包括铁闪锌矿、黑闪锌矿及富铜铅锌矿中的闪锌矿)是Ca的富集载体,Ca最可能以GaAs、GaxIn1-xAs和三元硫化物M^IGaS2(M^I=T1,Cu,Ag)分子的形式赋存,并可能于后期温度降低的条件下以单矿物(如硫镓铜矿)析出;镓在岩浆岩中的主要富集载体为长石类矿物、尖晶石型矿物以及具反尖晶石型结构的磁铁矿。对峨眉山大火成岩省中的重要矿床类型—攀枝花式超大型钒钛磁铁矿矿床中的代表性矿石进行镓含量分析并阐述了该类型矿床中Ca的成矿效应,初步评估了攀西地区钒钛磁铁矿工业储量中伴生的镓为34.8万t,远景资源量为43.5万t,认为该区超大型钒钛磁铁矿矿床亦属超大型镓矿床,具潜在的重要经济价值。呼吁加强对我国磁铁矿矿床中镓的成矿效应及综合利用的系统研究。
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T1虽然是一种分散元素,但在一定条件下也是可以富集的,甚至形成独立矿体。笔者在分析滇黔桂地区富铊矿床的地球化学特征后,认为T1在低温阶段富信,并提出T1的富集与沉积盆地局部高地球化学背景有关;促使T1富集万丈和的主要条件是矿化剂和沉淀富集剂,卤素和有机质是主要的成矿化剂,富硫流体和热液改造的有机质是主要的沉淀富集剂,在此基础上进一步探讨铊的二期三阶段成矿模式。
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贵州省兴仁县滥木厂铭矿床是世界上唯一的铭的独立矿床。多年来,由于对蛇矿产资源的开发,大量未及时提取和利用的含佗矿石堆积于地表,经过风化淋滤作用,进入当地的水源和土壤,并通过食物链进入人体。20世纪60-70年代,滥木厂地区有近1000名村民患有不同程度的铂中毒,轻者脱发、视力减退,重者失明、丧失劳动力,至今在该地区仍可见到铭中毒患者。该区成为世界上唯一爆发过大规模馆中毒的病发区。馆又是人体的非必需元素,体内任何含量的馆都会对人体造成危害。饮用水的安全标准中,铭的含量不得超过1μg/L。因此对表生条件下,含铂矿物的氧化溶解动力学以及反应性迁移的实验研究具有重要的现实意义。通过对滥木厂铭矿床中的主要含铭矿物(红铭矿)在酸性矿水条件下的氧化溶解过程、光照旧光照射和汞弧灯照射)对铭价态改变的影响,以及酸性矿水条件下铁对蛇吸附的实验研究,得到如下几点认识:1.红铭矿的氧化溶解动力学实验表明:红铂矿的氧化溶解速率受到温度、氧化剂中阴离子种类及氧化剂浓度的影响。随着温度的升高,红蛇矿的氧化速率增高;Cl-离子的存在更有助于红锭矿的氧化溶解,表现为氧化溶解速率的增高;随着氧化剂浓度的升高,红铭矿的氧化速率逐渐降低,这主要是由于高铁浓度下,红佗矿表面形成了一层厚约2nm的铁硫化合物的膜,减缓了红铭矿进一步溶解。红铭矿表面形态和成分的电镜分析表明,红铭矿表面具有较多的活性点,因此含铭矿石在初露地表时对环境的污染比较强烈,经过风化淋滤作用后,红铭矿表面的活性点减少,加之硫铁化合物膜的形成,阻止了其对环境的进一步污染。但这并不排除一旦环境介质改变,红铭矿表面氧化形成的膜被破坏,红铭矿的新鲜表面暴露出来,活性点增多,溶解性加强,继续对周围环境造成强烈的污染。从红蛇矿24小时溶解的总馆量来看,酸性矿水条件下红佗矿的氧化溶解是贵州省兴仁县滥木厂地区佗污染的一个重要来源。2.铭的光致氧化实验结果表明:无论日光还是汞弧灯照射,水溶液中的T1(I)均可被氧化成T1(III)。州值越低、光照强度越大,铭的光氧化速率越快,UVB区的紫外光对铭的光氧化起着主要作用,微生物作用在本实验条件下,相对于光氧化作用并不明显。3.铁对铭的吸附实验表明:铁的水合氧化物对水溶液中铭的吸附除受溶液的pH值和吸附剂的阴离子种类的影响外,主要与佗的价态有直接关系。铁的水合氧化物对Tl(I)具有一定的吸附能力,阴离子种类对T1(I)吸附的作用稍有差别,C1-离子存在时,铁对Tl(I)的吸附更强一些吸附率达到50%左右,而S叮一离子存在条件下,铁对Tl(I)的吸附率小于20%。碱性(pH=10左右)条件下,铁对T1(I)的吸附较中胜条件更明显一些。T1(III)由于自身的水解作用很强,在不同pH值和不同阴离子存在条件下,与Fe(III)均可发生共沉淀作用而被完全从水溶液中脱除。利用光照将Tl(I)氧化成Tl(III),再利用T1(III)易被沉淀或共沉淀吸附的特性,将Tl以Tl(OH)3,的形式吸附固定下来,降低了铭的活动性,进而可以减少铭对环境的影响,为锭污染的环境治理提供了重要的理论依据。
Resumo:
Touros jovens da raça Nelore (n=6) foram mantidos em pasto formado de Brachiaria brizantha desde a desmama em dietas com diferentes níveis de zinco. Foram formados aleatoriamente dois grupos que receberam diariamente, durante dois anos, diferentes concentrações de zinco no sal mineral: T1 (n=4), os animais não receberam suplemento com zinco e T2 (n=2), 60 mg/kg/dia de Zn inorgânico suplementar. A concentração de Zn na pastagem variou de 17,8 (águas) a 12,8 mg/kg (seca), respectivamente. A partir dos 14 meses de idade, os animais foram submetidos quinzenalmente a exame de sêmen e colheita de sangue. A morfologia espermática foi estimada, incluindo a mensuração da cabeça espermática a partir de esfregaços coradas pelo método de Fuelgen, em imagens captadas digitalmente e processadas pelo software Kontron Eletronik Imaging System, KS 400-2.0. A concentração de zinco no plasma foi dosada por spectrofotometria de absorção atômica. Os resultados mostraram que os touros do T1 tiveram qualidade seminal inferior (P<0,05) em relação ao T2. Observou-se variação das características seminais em função da data da colheita, evidenciando efeito estacional sobre a qualidade do sêmen. Os defeitos mais encontrados foram de peça intermediária e cauda. A concentração de Zinco (Zn) na circulação sangüínea foi maior (P<0,01) no T1 em comparação ao T2 (0,72 ±0,01 x 0,66 ±0,01, respectivamente). A área da cabeça espermática de espermatozóides morfologicamente normais e com defeitos de cabeça, peça intermediária e cauda foi maior (P<0,01) para os touros do T1 em relação aos do T2. Ademais, espermatozóides com fragmentação nuclear apresentaram forma mais alongada quando comparados àqueles sem alterações morfológicas. As correlações encontradas sugerem a importância do Zn na qualidade seminal, especialmente pelos efeitos deletérios que sua deficiência (subclínica) causa na morfologia espermática.
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As multiprocessor system size scales upward, two important aspects of multiprocessor systems will generally get worse rather than better: (1) interprocessor communication latency will increase and (2) the probability that some component in the system will fail will increase. These problems can prevent us from realizing the potential benefits of large-scale multiprocessing. In this report we consider the problem of designing networks which simultaneously minimize communication latency while maximizing fault tolerance. Using a synergy of techniques including connection topologies, routing protocols, signalling techniques, and packaging technologies we assemble integrated, system-level solutions to this network design problem.
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Electrical circuit designers seldom create really new topologies or use old ones in a novel way. Most designs are known combinations of common configurations tailored for the particular problem at hand. In this thesis I show that much of the behavior of a designer engaged in such ordinary design can be modelled by a clearly defined computational mechanism executing a set of stylized rules. Each of my rules embodies a particular piece of the designer's knowledge. A circuit is represented as a hierarchy of abstract objects, each of which is composed of other objects. The leaves of this tree represent the physical devices from which physical circuits are fabricated. By analogy with context-free languages, a class of circuits is generated by a phrase-structure grammar of which each rule describes how one type of abstract object can be expanded into a combination of more concrete parts. Circuits are designed by first postulating an abstract object which meets the particular design requirements. This object is then expanded into a concrete circuit by successive refinement using rules of my grammar. There are in general many rules which can be used to expand a given abstract component. Analysis must be done at each level of the expansion to constrain the search to a reasonable set. Thus the rule of my circuit grammar provide constraints which allow the approximate qualitative analysis of partially instantiated circuits. Later, more careful analysis in terms of more concrete components may lead to the rejection of a line of expansion which at first looked promising. I provide special failure rules to direct the repair in this case.
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O sistema de cultivo em consórcio de fruteiras com outras culturas, sejam anuais, semiperenes ou perenes, constitui uma boa alternativa para propriedades rurais e uma importante forma de recuperação de áreas degradadas. O objetivo deste trabalho foi avaliar o comportamento de bananeira, cv. D'Angola, em monocultivo e consorciada com açaizeiro, Euterpe precatoria, em diferentes espaçamentos, no primeiro ciclo de produção. Para tanto, foi instalado um experimento seguindo um delineamento em blocos casualizados completos com quatro repetições e seis plantas por parcela. Os tratamentos foram: T1 ? bananeira em 3 m x 3 m (1.111 plantas ha-1); T2 ? bananeira em 3 m x 2 m (1.666 plantas ha-1) com açaizeiro em 3 m x 4 m (833 plantas ha-1); T3 ? bananeira em 3 m x 3 m (1.111 plantas ha-1) com açaizeiro em 3 m x 4 m (833 plantas ha-1); T4 ? bananeira em 4 m x 2 m x 2 m (1.666 plantas ha-1) com açaizeiro em 6 m x 3 m (555 plantas ha-1) e T5 ? bananeira em 4 m x 2 m x 2 m (1.666 plantas ha-1) com açaizeiro em 4 m x 2 m x 3 m (1.111 plantas ha-1). O sistema de cultivo da bananeira terra consorciada com açaizeiro em diferentes espaçamentos pode ser considerado como boa alternativa no primeiro ciclo, pois não apresentou interferência nas características de desenvolvimento, de produção e qualidade física dos frutos. Os plantios mais adensados propiciaram maiores produtividades no primeiro ciclo da cultura.
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Martin Huelse: Generating complex connectivity structures for large-scale neural models. In: V. Kurkova, R. Neruda, and J. Koutnik (Eds.): ICANN 2008, Part II, LNCS 5164, pp. 849?858, 2008. Sponsorship: EPSRC
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Wallace, Joanne, et al., 'Body composition and bone mineral density changes during a premier league season as measured by dual-energy X-ray absorptiometry', International Journal of Body Composition Research (2006) 4(2) pp.61-66 RAE2008
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Winter, Rudolf; Heitjans, P., (2001) 'Li+ Diffusion and its Structural Basis in the Nanocrystalline and Amorphous Forms of Two-dimensionally Ion-conducting LixTiS2', Journal of Physical Chemistry B 105(26) pp.6108-6115 RAE2008
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Wydział Chemii: Zakład Chemii Fizycznej
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This paper explores reasons for the high degree of variability in the sizes of ASes that have recently been observed, and the processes by which this variable distribution develops. AS size distribution is important for a number of reasons. First, when modeling network topologies, an AS size distribution assists in labeling routers with an associated AS. Second, AS size has been found to be positively correlated with the degree of the AS (number of peering links), so understanding the distribution of AS sizes has implications for AS connectivity properties. Our model accounts for AS births, growth, and mergers. We analyze two models: one incorporates only the growth of hosts and ASes, and a second extends that model to include mergers of ASes. We show analytically that, given reasonable assumptions about the nature of mergers, the resulting size distribution exhibits a power law tail with the exponent independent of the details of the merging process. We estimate parameters of the models from measurements obtained from Internet registries and from BGP tables. We then compare the models solutions to empirical AS size distribution taken from Mercator and Skitter datasets, and find that the simple growth-based model yields general agreement with empirical data. Our analysis of the model in which mergers occur in a manner independent of the size of the merging ASes suggests that more detailed analysis of merger processes is needed.
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Recent work in sensor databases has focused extensively on distributed query problems, notably distributed computation of aggregates. Existing methods for computing aggregates broadcast queries to all sensors and use in-network aggregation of responses to minimize messaging costs. In this work, we focus on uniform random sampling across nodes, which can serve both as an alternative building block for aggregation and as an integral component of many other useful randomized algorithms. Prior to our work, the best existing proposals for uniform random sampling of sensors involve contacting all nodes in the network. We propose a practical method which is only approximately uniform, but contacts a number of sensors proportional to the diameter of the network instead of its size. The approximation achieved is tunably close to exact uniform sampling, and only relies on well-known existing primitives, namely geographic routing, distributed computation of Voronoi regions and von Neumann's rejection method. Ultimately, our sampling algorithm has the same worst-case asymptotic cost as routing a point-to-point message, and thus it is asymptotically optimal among request/reply-based sampling methods. We provide experimental results demonstrating the effectiveness of our algorithm on both synthetic and real sensor topologies.
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Effective engineering of the Internet is predicated upon a detailed understanding of issues such as the large-scale structure of its underlying physical topology, the manner in which it evolves over time, and the way in which its constituent components contribute to its overall function. Unfortunately, developing a deep understanding of these issues has proven to be a challenging task, since it in turn involves solving difficult problems such as mapping the actual topology, characterizing it, and developing models that capture its emergent behavior. Consequently, even though there are a number of topology models, it is an open question as to how representative the topologies they generate are of the actual Internet. Our goal is to produce a topology generation framework which improves the state of the art and is based on design principles which include representativeness, inclusiveness, and interoperability. Representativeness leads to synthetic topologies that accurately reflect many aspects of the actual Internet topology (e.g. hierarchical structure, degree distribution, etc.). Inclusiveness combines the strengths of as many generation models as possible in a single generation tool. Interoperability provides interfaces to widely-used simulation and visualization applications such as ns and SSF. We call such a tool a universal topology generator. In this paper we discuss the design, implementation and usage of the BRITE universal topology generation tool that we have built. We also describe the BRITE Analysis Engine, BRIANA, which is an independent piece of software designed and built upon BRITE design goals of flexibility and extensibility. The purpose of BRIANA is to act as a repository of analysis routines along with a user–friendly interface that allows its use on different topology formats.