998 resultados para 346.01


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Trichloroisocyanuric acid (TCCA) is a cheap, safe and readily available alternative to the commonly used hydrogen peroxide and hypochlorite for the phase-transfer catalytic epoxidation of alpha,beta-enones under non-aqueous conditions. A variety of chalcone derivatives give the corresponding epoxides with quantitative conversion and satisfactory yields in just a few hours under mild conditions. An asymmetric variant of the epoxidation can be carried out in the presence of chiral N-anthracenylmethylcinchonidine bromide catalyst giving 73-93% ees and 76-94% yields.

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N-Arylamides were exclusively obtained in moderate to good yields from selenium-catalyzed reactions of nitroaromatics with amides in the presence of CO and mixed organic bases Et3N and DBU.

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采用XRD、FESEM-EDS、ICP及EIS等方法研究了Ti0.17Zr0.08V0.34Nb0.01Cr0.1Ni0.3氢化物电极合金微观结构和电化学性能。X射线衍射分析表明:该合金由体心立方结构(bcc)的V基固溶体主相和少量六方结构的C14型Laves相组成;FESEM及EDS分析表明:V基固溶体主相形成树枝晶,C14型Laves相呈网格状围绕着树枝晶的晶界,元素在两相中的分布呈现镜像关系。电化学性能测试结果表明:该合金的氢化物电极在303 ̄343K较宽的温度区间内,表现出较高的电化学容量,在303K和343K时,电化学容量分别为337.0mAh·g-1和327.9mAh·g-1。在303K循环100周后,容量为282.7mAh·g-1。ICP分析结果表明,氢化物电极在充放电循环过程中,V及Zr元素向KOH电解质中的溶出较为严重。EIS研究表明,金属氢化物电极表面电化学反应的电荷转移电阻(RT)随循环次数的增加而增加,相应的交换电流密度则随循环次数的增加而降低。氢化物电极循环过程中RT的增大以及V和Zr元素的溶解,可能是导致电极容量衰减的主要原因。

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介绍了GH -0 1双组分、室温固化环氧树脂超低温胶粘剂的某些性能 ,说明这种胶粘剂能粘接多种材料 ,尤其是在液氮温度下仍有良好的粘接性能 ,并且真空放气量小 ,是在超低温环境下使用的良好胶粘剂

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本文报导了用于热缩电缆附件中间连接的一种新型填充段电应力疏散胶的配方,研究了电性能调节剂,增粘剂,填料,氨酸橡胶等对产品性能的影响.

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The species composition and abundance of microzooplankton at 10 marine and five coastal stations (Hongdao, Daguhe, Haibohe, Huangdao and Hangxiao) in the Jiaozhou Bay (Qingdao, China) were studied in 2001. The microzooplankton community was found to be dominated by Tintinnopsis beroidea, Tintinnopsis urnula, Tintinnopsis brevicollis and Cvdonellopsis sp. The average abundance of microzooplankton was highly variable among stations. Specifically, the abundance of microzooplankton was higher at inshore stations and lower in the center of the bay (St. 5), bay mouth (St. 9) and outside the bay (St. 10). The highest average annual densities (346 ind./L) was observed at St. 3, while the lowest (55 ind./L) was at St. 10. Two abundance peaks were recorded in May (324 ind./L) and February (300 ind./L). The distribution of microzooplankton in three sampling layers at the 10 stations was relatively homogenous and the abundance decreased slightly as the water depth increased. At coastal stations, the highest average annual density was recorded at Hongdao Station (677 ind./L), followed by Daguhe Station (616 ind./L), Haibohe Station (400 ind./L), Huangdao Station (275 ind./L) and Hangxiao Station (73 ind./L). Furthermore, a 24-h sampling analysis conducted at Hangxiao Station revealed that the microzooplankton assemblages were characterized by a bimodal diel vertical migration pattern, with the highest densities occurring at dusk (154 ind./L), followed by dawn (146 ind./L), noon (93 ind./L) and midnight (77 ind./L). The density of microzooplankton in the Jiaozhou Bay was in the middle range of the densities of temperate coastal waters worldwide.

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Chitosan (CS) with two different molecular weights was modified by reacting with 4-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride or 2-hydroxyl-5-chloride-1,3-benzene-disulfo-chloride to give new 2-(4(or 2)-hydroxyl-5-chloride-1,3-benzene-di-sulfanimide)-chitosan (2-HCBSAHCS, 2-HCBSALCS, 4-HCBSAHCS, 4-HCBSALCS). The structure of the derivatives was characterized by FT-IR and C-13 NMR spectroscopy. The antioxidant activities of the derivatives were investigated employing various established systems, such as hydroxyl radical ((OH)-O-center dot)/superoxide anion (O-2(radical anion)) scavenging/reducing power and chelating activity. All the derivatives showed stronger scavenging activity on hydroxyl radical than chitosan and ascorbic acid (Vc), and IC50 of 4-HCBSAHCS, 4-HCBSALCS, 2-HCBSAHCS and 2-HCBSALCS was 0.334, 0.302, 0.442, 0.346 mg/mL, respectively. The inhibitory activities of the derivatives toward superoxide radical by the PMS-NADH system were strong. The results showed that the superoxide radical scavenging effect of 2-(4(or 2)-hydroxyl-5-chloride-1,3-benzene-disulfanimide)-chitosan was higher than chitosan. The derivatives had obviously reducing power and slight chelating activity. The data obtained in in vitro models clearly establish the antioxidant potency of 2-(4(or 2)-hydroxyl-5-chloride-1,3-benzene-disulfanimide)-chitosan. (C) 2007 Elsevier Masson SAS. All rights reserved.

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The applicability of capillary electrophoresis/frontal analysis (CE/FA) for determining the binding constants of the drugs propranolol (PRO) and verapamil (VER) to human serum albumin (HSA) was investigated. After direct hydrodynamic injection of a drug-HAS mixture solution into a coated capillary (32 cm x 50 mu m i.d.), the basic drug was eluted as a zonal peak with a plateau region under condition of phosphate buffer (pH 7.4; ionic strength 0.17) at 12 kV positive running voltage. The unbound drug concentrations measured from the plateau peak heights had good correlation coefficients, r > 0.999. Employing the Scatchard plot, the Klotz plot and nonlinear regression, the drug protein binding parameters, the binding constant and the number of binding sites on one protein molecule, were obtained. The binding constant obtained was compared to a reported equilibrium dialysis result and they are basically in good agreement.

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To study the relationship between mental-physical health and coping behavior,job stress and job motivation in medical laboratory scientists and technicians. A cross-section survey was conducted,using the anxiety rating scale(SAS), depression rating scale(SDS), coping behavior rating scale,self-rating subhealth scale,self-rating stress scale,and self-rating job motivation scale among 289 medical laboratory scientists and technicians with analysis of ANOVA and Regression. The study was carried out in three steps:step1 is to analyze the general situation of the mental-physical health.Step 2 is to analyze the features of the main influencial facotors.Step 3 is to study the influence of the relative factors on mental-physical health.The following are the results: 1.The anxiety and depression scores of the medical researchers and technicians were 30±6 and 37±8 respectively,both significantly lower than those of the national norm(34±6 and 42±11 respectively,both P<0.01),which are of significant difference. The depression score of the associate chief technician was 42±7, significantly higher than those of the medical researchers and technicians with any other professional titles (all P<0.05), and the anxiety score of the associate chief technicians was 32±7, significantly higher than that of the research fellows(28±4, P<0.05),with no significant difference to the score of the medical researchers and technicians with other professional titles. The depression score,anxiety score and the subhealth score of the age group of 36~49 were 39±9,31±7 and 32±9 respectively, both higher than that of the age group of 20~35 (36±8,29±6 and 29±7 respectively,both P<0.05),while there is much diference among other age groups. And the subhealth status has nothing to do with marital status,education background and professional titles. 2.The coping behaviors,job stress and motivation of the military medical laboratory scientists and technicians. 1)Coping behaviors:The seeking help score of the associate chief technicians was 2.8±0.5,not significantly different from that of the associate research fellows(2.8±0.5),but significantly lower than those of the medical researchers and technicians with other professional titles(all P<0.01),and whose self-blame score was higher than that of the research fellows,which is of significant difference.The self-blame score and the imagination score of the associate research fellows were 2.0±0.5 and 2.4±0.5 respectively, significantly higher than that of the research fellows(1.6±0.4, 2.1±0.4,both P<0.01). The seeking help score of the females was 3.1±0.5, significantly higher than that of the males(2.9±0.5, both P<0.01),and the solving problem score was 3.4±0.6,significantly lower than the male(3.6±0.7, both P<0.01).There is no any significant difference in coping behaviors among researchers and technicians of different marital status,education background and age groups. 2)Job stress: The score of job stress of the age group of 35~49 and 50~60 were 23±8 and 25±6 respectively,significantly higher than that of the 20~35(21±7,both P<0.05). There is no any significant difference in job stress among researchers and technicians of different marital status,gender,professional titles and education background. 3)The score of meeting personal desire for reputation and interests of the males was 19.6±5.4,significantly higher than that of the females(18.4±5.0, both P<0.05), while there is no significant difference in job motivation among researchers and technicians of different titles,education,age and marital status. 3.The relationship of the mental-physical health of the military medical laboratory scientists and technicians with their coping behaviors,job stress and motivations 1) Coping behaviors:Regression analysis showed that, the best predictors of subhealth were anxiety,depression and escaping (β=-0.40,β=0.23, β=0.14, both P<0.01).the best predictors of anxiety and depression were active coping behaviors and negative coping behaviors (β=-0.40,β=0.40, both P<0.01).The moderate(rational) coping behaviors is the best predictor only of anxiety and of significant difference. 2)job stress : Regression analysis demonstrated that anxiety,depression,job stress 2 and job stress 4 are the best predictor for subhealth;job stress 12 is the best retro-predictor for depression; job stress 3 and 8 are the best predictor for depression;and job stress 2 and 9 are the best predictor for anxiety ,which are of significant difference. 3)Motivation:Regression analysis demonstrated that depression is the best predictor for subhealth while motivation itself doesn't predict subhealth;with respect to the specific contents of motivation,"probing unknown rules and making contributions to the human society "is the best retro-predictor for depression and has nothing to do with anxiety prediction. 4) The combined influences of coping behaviors,job stress and motivations: Regression analysis showed that, the best predictors for subhealth were anxiety,depression and job stress(β=0.41,β=0.24, β=0.19, both P<0.01).the best predictors for anxiety and depression were active coping behaviors and negative coping behaviors (β=-0.40,β=0.40, both P<0.01).The moderate(rational) coping behaviors is the best predictor only for anxiety and of significant difference. CONCLUSIONS: Regression analysis showed that the best predictors for anxiety and depression were active coping behaviors and negative coping behaviors, the best predictors for subhealth were anxiety,depression and job stress.Coping behaviors, job stress and motivations have significant influences on the mental-physical health of the military medical researchers and and technicians. Among them,coping behavior is the most important factor while job stress and motivation follow. Seeking help more often,less self-blame ,imagination and job stress could help release the anxiety, depression and improve the subhealth of the medical researchers and technicians. The findings of this study indicate we should address the physical and mental health of the military laboratory researchers and technicians.

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O Município de Machadinho d´Oeste, em Rondônia foi escolhido para um estudo de longo prazo. Já são 10 anos de acompanhamento de mais de 450 pequenas propriedades rurais e cerca de 250 variáveis biofísicas, sócio-econômicas e ambientais. A duração deste projeto é de 100 anos. Os estudos pedológicos da área do "Projeto de Assentamento Machadinho" teve como objetivos identificar os solos das Glebas e implementar uma base de dados do meio físico em escala municipal, através do uso de técnicas de geoprocessamento (SIG´s); bem com o caracterizar e avaliar química, física e morfologicamente os perfis de solos representativos das principais unidades identificadas, a fim de promover o desenvolvimento agrícola da região e fornecer subsídios para estudos em áreas semelhantes na Amazônia.

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An approach towards shape description, based on prototype modification and generalized cylinders, has been developed and applied to the object domains pottery and polyhedra: (1) A program describes and identifies pottery from vase outlines entered as lists of points. The descriptions have been modeled after descriptions by archeologists, with the result that identifications made by the program are remarkably consisten with those of the archeologists. It has been possible to quantify their shape descriptors, which are everyday terms in our language applied to many sorts of objects besides pottery, so that the resulting descriptions seem very natural. (2) New parsing strategies for polyhedra overcome some limitations of previous work. A special feature is that the processes of parsing and identification are carried out simultaneously.

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Identificacao dos sintomas de fitotoxicidade; Decisao quanto a semeadura; Importancia da manutencao da tecnologia do tratamentodesementes de soja com fungicidas; Outros problemas que tem ocorrido simultaneamente nas lavouras.

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Agronegócio da soja no Brasil; Exigências climáticas; Rotação de culturas; Manejo do solo; Correção e manutenção da fertilidade do solo; Cultivares; Cuidados na aquisição e na utilização de semente; Tratamento com fungicidas, aplicação de micronutrientes e inoculação de sementes de soja; Instalação da lavoura; Controle de plantas daninhas; Manejo de pragas; Doenças e medidas de controle; Retenção foliar (Haste verde); Colheita; Tecnologia de sementes.