滇东南都龙锡锌多金属矿床矿物学及年代学

都龙锡锌多金属矿床位于云南省马关县都龙镇，是我国最大的锡石硫化物矿床之一。在野外地质和岩矿鉴定基础上,本文对该矿床的绿泥石、鲕状黄铁矿、磁黄铁矿异构交生体、铁闪锌矿的“黄铜矿疾病”等矿物和特殊组构，开展了比较系统的电子探针、拉曼光谱和X光衍射等微束分析，结合对该矿床的黑云母Ar-Ar年代学、锡石TIMS法U-Pb年代学研究，基本明确了矿床各个成矿期次的具体成矿特点，丰富和完善了该矿床的成矿模式。论文取得的主要认识有： （1）绿泥石与锡矿化同为燕山期岩浆热液作用的产物。绿泥石的形成温度（231~304oC）和环境（还原环境）表明，岩浆热液叠加成矿环境为中、低温的还原环境。 （2）鲕状黄铁矿为热水沉积期的特征矿物，是Fe、Zn、S等成矿元素的主要物源。 （3）磁黄铁矿主要在区域变质晚期，由黄铁矿（主要为鲕状黄铁矿）变质脱硫而成。辣子寨矿段单斜磁黄铁矿的出现，说明燕山期岩浆热液叠加成矿温度在该矿段以中低温为主。 （4）铁闪锌矿的“黄铜矿疾病”主要是黄铜矿交代铁闪锌矿的结果，其中的Fe主要来自变质期形成的铁闪锌矿和磁黄铁矿，而Cu主要来自岩浆热液。 （5）自然铋、自然银、锡石、黄铜矿、方铅矿等矿物广泛共生，且交代、穿切其他矿物，表明岩浆热液期的成矿元素组合主要为Bi+Ag+Sn+Cu+Pb。在该矿床首次发现的自然铋和自然银，指示岩浆热液期为低硫、中低温的还原环境。 （6）利用远红外（IR-Laser）阶段加热技术，获得黑云母的低温段和高温段坪年龄，分别为179.0± 5 .0Ma和195.7± 6.6Ma。在黑云母组构显微分析的基础上，认为179.0± 5 .0Ma大致代表了变质成矿作用的年龄。 （7）都龙锡锌多金属矿床属于多成因复成矿床，其形成主要经历了热水沉积、变质改造和岩浆热液叠加三个过程。热水沉积成矿作用形成的鲕状黄铁矿，可能是后期成矿作用中Fe、Zn、S等成矿元素的主要物源。变质改造成矿作用与印支期晚期区域变形-变质作用有关，形成了大量铁闪锌矿、磁黄铁矿，可能对应于造山后伸展事件。岩浆热液叠加成矿作用与燕山晚期老君山花岗岩有关，发生大规模的锡、铜、银、铅、铋矿化。 另外，本次研究在该矿床中首次发现了自然铋、自然银等自然元素，其矿床成因意义有待进一步研究。

浙江天台-嵊县地区火山岩型银（金）矿床地质地球化学特征

浙江天（天台）-嵊（嵊县）地区是东南沿海中生代火山岩区Au、Ag及多金属成矿带的一部分，近年来发现多处具有工业意义的贵金属矿床。其矿床特征可以同世界上以火山岩为主岩的冰长石-绢云母型浅成低温热液贵金属矿床类比。具有高Ag、Pb、Zn（Au、Cu）丰度的前震旦纪陈蔡群变质岩和早白垩纪朝川组火山岩系是矿源层。矿床产于火山岩系中；围岩蚀变发育，硅化、绢云母化、伊利石化、菱锰矿化、冰长石化以及似青盘岩化与矿化有关。矿床元素垂直分带由浅部至深部为Au、Ag、Zn-Ag、Pb、Zn-Pb、Zn、Cu。菱锰矿的含Fe、Ca量与Ag矿化具有消长关系，菱锰矿含Fe高对Ag（Au）矿化有利。成矿流体为低盐度的NaCl-H_2O体系，富Na酸性（pH = 4.5）是该体系的特征。成矿流体来源以火山岩浆热液为主，有大气降水加入形成混合流体。硫、碳质来自火山岩浆。而成矿有用元素则来自大陆地壳的Ag、Pb、Zn （Au、Cu）高丰度值的陈蔡群或早白垩纪朝川组。成矿温度195 ℃ ～ 250 ℃及135 ℃±；成矿时代74 * 10~6年 ～ 105 * 10~6年，属晚白垩纪；成矿压力350 ～ 500 bar。成矿构造环境为大陆裂谷发展初期。矿床成因类型可确定为浅成中低温火山岩浆混合热液贵金属矿床。

Determination of sialic acids in the serum of cancer patients by capillary electrophoresis

A novel method for the determination of N-acetylneuraminic acid (NANA) and N-glycolylneuraminic acid (NGNA) was developed by using high-performance capillary electrophoresis (HPCE) with UV detection at 195 nm. NANA and NGNA were separated directly and analyzed without pre- or postcolumn derivation. The detection limit of NANA is 9.6 x 10(-6) mol L-1 and for mass 3.879 x 10(-14) mol (39 fmol). This method was applied for the determination of NANA in 30 normal human and 72 cancer patients. The results demonstrated that NANA in the sera of cancer patients increased significantly as compared with the normal human (P < 0.001). The new method is simple and sensitive, and is suitable for basic research and clinical application to malignant tumors.

Synthesis of a high-permeance NaA zeolite membrane by microwave heating

Zeolite membranes with high permeance and separation factors are highly desirable for practical applications. Although, in the past, very good separation factors have been obtained, it has proved difficult to achieve a high permeance. Ken a comparative study of microwave versus conventional heating in the hydrothermal synthesis of NaA zeolite membranes is made. It is demonstrated that membranes prepared by microwave heating have not only a higher permeance but also a considerably shorter synthesis time. These observations are rationalized by examining the mechanism of membrane formation.

Rentabilidade econômica do cultivo da pupunheira (Bactris gasipaes Kunth), destinada à produção de palmito no Litoral de Santa Catarina.

2010

Análise da variabilidade intra-espécie dos genes pld e rpoB de Corynebacterium pseudotuberculosis por meio de marcadores PCR-RFLP.

Corynebacterium pseudotuberculosis é o agente etiológico da linfadenite caseosa em ovinos e caprinos, uma doença infectocontagiosa crônica caracterizada por abscessos em linfonodos superficiais ou internos. Os animais acometidos podem apresentar lesões internas ou externas, o que representa perdas econômicas graves na caprinovinocultura, como o comprometimento da produção de lã em ovinos, deficiência reprodutiva, condenação da carne ou morte do animal. Uma vez estabelecida a infecção no rebanho, torna-se difícil sua erradicação. Com o objetivo de avaliar a variabilidade genética intra-espécie em C. pseudotuberculosis, 31 isolados provenientes de seis municípios do Estado de Pernambuco, sendo 23 de caprinos e oito de ovinos, tiveram os seus DNAs genômicos extraídos e analisados por reação em cadeia da polimerase e análise de polimorfismos por tamanho de fragmentos de restrição (PCR-RFLP). Os locis escolhidos foram os genes pld e rpoB, cujas seqüências dos oligonucleotídeos amplificaram fragmentos de 924 e 447 pares de bases (pb), respectivamente. Os produtos da amplificação foram digeridos com as enzimas Pst I e Msp I (gene pld) e HpyCh4 IV e Msp I (gene rpoB). Os fragmentos de restrição foram corridos em gel de poliacrilamida a 15%, os quais foram corados com brometo de etídeo. Para o gene pld, digerido com a enzima Pst I, foram obtidos fragmentos de 566, 195, 91 e 72 pb; e com a enzima Msp I, fragmentos de 395, 369, 108 e 52 pb. O gene rpoB digerido com a enzima HpyCh4 IV apresentou fragmentos de 235, 126 e 86 pb; e com a enzima Msp I apresentou fragmentos de 222, 93, 78 e 54 pb. O padrão de bandas obtido para os 31 isolados de C. pseudotuberculosis, analisados neste estudo, foi monomórfico, não havendo, portanto, polimorfismo entre os diferentes isolados, independentes da espécie hospedeira ou da área geográfica estudada, o que corrobora com o padrão homogêneo da infecção para a região.

Análise econômica mensal sobre o setor de mandioca e derivados: março/2010.

Mandioca: Preços recuam após três meses de alta ? A oferta de mandioca seguiu elevada para a indústria de fécula das regiões acompanhadas pelo Cepea em março. Este quadro foi atribuído aos preços favoráveis da cultura e também pelo clima favorável ao longo do período. Por conta destes fatores, as cotações que vinham se valorizando expressivamente em meses anteriores, passaram a ter elevações menos intensas. Em março, a tonelada da raiz destinada às fecularias foi cotada à média de R$ 249,71 (R$ 0,4343/ grama de amido, considerando a balança hidrostática de 5 kg), subindo 5,4% frente à de fevereiro (R$ 236,89/t). Esta alta é pouco expressiva quando comparada com a de meses anteriores, que foi de até 15%. Comparando o preço médio de R$ 236,89/t da última semana de fevereiro com o de R$ 243,23 em igual período de março, a desvalorização é de 4,0% entre os períodos. Entre os estados acompanhados pelo Cepea, o maior preço foi registrado no Paraná, de R$ 269,13/t, aumento de 6,5% frente ao valor do mês anterior. No Mato Grosso do Sul, no mesmo período, houve valorização de 4,6%, com o produto cotado a R$ 231,48/t. O estado de São Paulo teve a variação mais expressiva, de 11,9%, com a mandioca comercializada a R$ 195,81/t (Figura 1). Em âmbito regional, os preços tiveram alta em todas as regiões em março. A mais expressiva ocorreu na região de Assis (SP), de 11,9%, porém a mesma área teve a menor média do período (R$ 195,81/t). Já o maior preço do mês ocorreu no noroeste paranaense (R$ 272,17/t), onde a valorização foi de 5,5%. A alta menos expressiva foi observada no sudeste do Mato Grosso do Sul, de 4,0%, com o produto cotado à média de R$ 234,06/t (Figura 2).

Epoxidation of styrene on Si/Ti/SiO2 catalysts prepared by chemical grafting

Titania-silica (Ti/SiO2) and silica-titania-silica (Si/Ti/SiO2) catalysts were:prepared by chemical grafting using TiCl4 and tetraethyl orthosilicate (TEOS) as precursors and SiO2 as support. The prepared catalysts were characterized by UV Raman and visible Raman spectroscopies, XRD and the epoxidation of styrene; Ti/SiO2: catalyst grafted with only titanium species is not very active for epoxidation using H2O2 (30%), but is active and-selective when one uses tert-butyl hydroperoxide (TBHP). The catalyst grafted at high temperatures shows better epoxide selectivity. Si/Ti/SiO2 catalyst, the titanium-silica grafted further with TEOS, is active and selective for the epoxidation of styrene using either dilute H2O2 or TBHP, possibly due to the fact that the grafting of Ti/SiO2 with TEOS modifies the coordination structure of titanium and makes the titanium sites of Si-O-Ti-O-Si species less hydrophilic. A characteristic band at 1085cm(-1) due to Ti-O-Si species is detected for the grafted catalysts by UV resonance Raman spectroscopy. Reaction between TiCl4 and SiO2 at high temperatures favors the formation of Ti-O-Si species. Better activity and selectivity to epoxide,is found for the catalysts with more Ti-O-Si species. It is assumed that the active sites are the highly isolated Ti-O-Si species. For Si/Ti/SiO2 catalyst, the gas phase O-2 can participate in the catalytic oxidation of styrene when H2O2 is present ana:ii causes the formation of benzaldehyde. (C) 2000 Elsevier Science B.V. All rights reserved.

Learning and Example Selection for Object and Pattern Detection

This thesis presents a learning based approach for detecting classes of objects and patterns with variable image appearance but highly predictable image boundaries. It consists of two parts. In part one, we introduce our object and pattern detection approach using a concrete human face detection example. The approach first builds a distribution-based model of the target pattern class in an appropriate feature space to describe the target's variable image appearance. It then learns from examples a similarity measure for matching new patterns against the distribution-based target model. The approach makes few assumptions about the target pattern class and should therefore be fairly general, as long as the target class has predictable image boundaries. Because our object and pattern detection approach is very much learning-based, how well a system eventually performs depends heavily on the quality of training examples it receives. The second part of this thesis looks at how one can select high quality examples for function approximation learning tasks. We propose an {em active learning} formulation for function approximation, and show for three specific approximation function classes, that the active example selection strategy learns its target with fewer data samples than random sampling. We then simplify the original active learning formulation, and show how it leads to a tractable example selection paradigm, suitable for use in many object and pattern detection problems.

A System for Representing and Using Real-World Knowledge

This report describes a knowledge-base system in which the information is stored in a network of small parallel processing elements ??de and link units ??ich are controlled by an external serial computer. This network is similar to the semantic network system of Quillian, but is much more tightly controlled. Such a network can perform certain critical deductions and searches very quickly; it avoids many of the problems of current systems, which must use complex heuristics to limit and guided their searches. It is argued (with examples) that the key operation in a knowledge-base system is the intersection of large explicit and semi-explicit sets. The parallel network system does this in a small, essentially constant number of cycles; a serial machine takes time proportional to the size of the sets, except in special cases.

Titanium species in titanium silicalite TS-1 prepared by hydrothermal method

The titanium species existing in titanium silicalite TS-1, which is prepared by hydrothermal method, were investigated using chemical analysis, XRD, FT-IR, Si-29 MAS NMR, UV-VIS, ESR. It has been observed that several kinds of titanium species may exist in titanium silicalite. The form that titanium atoms incorporate into the framework of titanium silicalite synthesized using tetrapropylammonium bromide (TPABr) as template differs from that using the classical method. But, the symmetry of titanium silicalite, changes from monoclinic to orthorhombic with the increase of titanium content in both methods. The Ti-O-2(-) originated from framework titanium and H2O2 has the moderate stability and may be active site in oxidation reaction. TS-1 synthesized using TPABr as template does not contain anatase, but contains a kind of partly condensed titanium species with six-fold coordination. The titanium species may correspond to 270-280 mn band in UV-VIS spectra and also can form Ti-O-2(-). But, this kind of Ti-O-2(-) is very stable and cannot be catalytic active site. So, the six-fold coordination titanium species may be inactive in both the oxidation reaction and the decomposition of H2O2. The hypothesis has been further proved by the phenomena that the titanium species is easily washed off using acid, and acid treating will not influence the catalytic performance of TS-1. (C) 2001 Elsevier Science B.V. All rights reserved.

Informações meteorológicas de Passo Fundo, RS: julho de 2006.

2006