74 resultados para Brill, Paulus, 1554-1625.


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从计算机技术的角度出发,对植物形态学信息处理和应用,构成本文的思想,文中简略同顾了植物形态学术语的标准化的历史发展过程,对当前世界范围内在此领域的工作也作了概要般的总结,论述了计算机技术用十植物学应用和研究的重要性并提出了我国在此领域内开展工作的紧迫性和必要性。计算机的资源限制及植物信息特有的复杂性是这一领域发展的困难。因此,如何贮存植物信息?如何操作加工应用?才能充分利用计算机资源和植物信息资源成为本领域的核心问题。 本文基于上面的考虑,对植物形态学信息从基本的信息单位植物形态学术语出发,探求其分类结构,并从计算机技术的编码理论方面进行探讨.力图求得一个标准化的植物形态学描述分类群的术语编码集,提供一种实现描述的方法,并试验性地给出一种描述规范和格式,简单讨论一下实现语言处理,机器鉴定、数量分类的可能性,最后简单分析和对比了本工作和国际上的类似工作,并对本领域进行了简单的展望。

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目的研究曲拉通一一, 是否会改变脑内递质及合成酶免疫组织化学定位特征, 及是 否与其浓度有关。材料与方法观察了高、低浓度预处理脑切片, 对胆碱乙酞化酶、物质和羊氨基丁酸样免 疫反应神经元胞体及终末, 在树晌内侧隔核、斜带核及海马, 免疫组化定位的影响。并在树殉和猫脑探索了缓冲的 低浓度梯度酒精替代的可能性。结果在树的脑, 当为时, 内侧隔核、斜带核三类神经元胞体染色 变浅, 数量减少, 甚至消失, 而海马及内侧隔核、斜带核的物质同及一氨基丁酸阳性终末明显增加。当为。 时, 以上情况正好相反。以酒精替代, 在树动和猫的海马及 内侧隔核、斜带核能相当好地同时显示不氨基丁酸和物质阳性神经元胞体和终末。结论不同浓度的处理 脑切片, 可能对脑内众多神经活性物质的免疫组化定位特征产生不同影响。提高或降低浓度, 分别有助于显 示神经元终末或胞体。上述梯度酒精替代, 在免疫组化光、电镜研究中, 有助于同时显示阳性神经元胞体和终 末。

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黄花蒿精油对米象、玉米象、绿豆象和蚕豆象等 4种仓库害虫具有很强的熏杀活性 ,其甲醇和乙醇提取物对小菜蛾、菜青虫、大菜粉蝶、银纹夜蛾和斜纹夜蛾幼虫也具有一定的杀虫活性。

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通过实验现场采样及室内测试方法,对复合垂直流人工湿地-池塘养殖复合系统中的物理、化学、生物和生化指标进行因子分析,并在养殖周期、日变化上对碱性磷酸酶活性进行了研究。结果表明,循环池的水质明显好于对照池,影响系统水质的主要因子在循环池和对照池中是不同的,其中循环池主要影响因子是生物指标细菌,对照池主要影响因子是氮、磷等化学因子;碱性磷酸酶存在明显的日变化规律,20时达到一天的最高;循环池和对照池的碱性磷酸酶活性以及叶绿素a含量等方面存在显著性差异,其中循环池碱性磷酸酶的日变化范围是2.81~6.83mmol

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8月中旬挑选体长12 cm以上的泥鳅作为亲本进行秋季人工繁殖,经过25 d强化培育,90%以上的亲鳅发育良好,催产雌鳅19.3 kg,催产率在86%,受精率83%,孵化率96%,共获得仔鱼约340 万尾。以丰年虫无节幼体作为开口饵料,3 d后鳅苗平均全长达0.8 cm,成活率高达99%以上;半个月后体长达2cm左右;到10月中旬,鳅苗平均全长5.0 cm左右,体重达3~4 g,成活率为60%,共计获得鳅苗约200多万尾。

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A 2-year investigation of growth and food availability of silver carp and bighead was carried out using stable isotope and gut content analysis in a large pen in Meiliang Bay of Lake Taihu, China. Both silver carp and bighead exhibited significantly higher delta 13C in 2005 than in 2004, which can probably be attributed to two factors: (i) the difference between isotopic compositions at the base of the pelagic food web and (ii) the difference between the compositions of prey items and stable isotopes. The significantly positive correlations between body length, body weight and stable isotope ratios indicated that isotopic changes in silver carp and bighead resulted from the accumulation of biomass concomitant with rapid growth. Because of the drastic decrease in zooplankton in the diet in 2005, silver carp and bighead grew faster in 2004 than in 2005. Bighead carp showed a lower trophic level than silver carp in 2005 as indicated by stable nitrogen isotope ratios, which was possibly explained by the interspecific difference between the prey species and the food quality of silver carp and bighead.

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Unlike Escherichia coli, the cyanobacterium Synechocystis sp. strain PCC 6803 is insensitive to chill (5 degrees C) in the dark but rapidly losses viability when exposed to chill in the light (100 mu mol photons m(-2) s(-1)). Preconditioning at a low temperature (15 degrees C) greatly enhances the chill-light tolerance of Synechocystis sp. strain PCC 6803. This phenomenon is called acquired chill-light tolerance (ACLT). Preconditioned wild-type cells maintained a substantially higher level of alpha-tocopherol after exposure to chill-light stress. Mutants unable to synthesize alpha-tocopherol, such as slr1736, slr1737, slr0089, and slr0090 mutants, almost completely lost ACLT. When exposed to chill without light, these mutants showed no or a slight difference from the wild type. When complemented, the slr0089 mutant regained its ACLT. Copper-regulated expression of slr0090 from P-petE controlled the level of et-tocopherol and ACLT. We conclude that alpha-tocopherol is essential for ACLT of Synechocystis sp. strain PCC 6803. The role of a-tocopherol in ACLT may be based largely on a nonantioxidant activity that is not possessed by other tocopherols or pathway intermediates.

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We have investigated the optical properties of single CdSe/ZnS nanocrystals by conducting combinations of experiments on antibunching and photoluminescence intermittence under different experimental conditions. Based on photoluminescence in an antibunching experiment, we analyzed the emission lifetime of QDs by using stretched exponentials. The difference between the parameters obtained from average lifetimes and stretched exponents were analyzed by considering the effect of nonradiative emission. An Auger-assisted tunneling model was used to explain the power law exponents of off time distribution. The power law exponent under high excitation power was correlated with a higher Auger ionization rate. Using the parameters obtained from stretched exponential function and power law, the antibunching phenomena at different time and under different excitation intensity were analyzed.

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提出了一个组件级的细粒度属性证明方案,用于向远程依赖方证明用户平台满足某种安全属性.与现有的远程证明方案相比,组件属性远程证明具有一定的语义和属性表述性等优势.该方案不但证明粒度细和扩展性强,而且属性证书的颁发、验证和撤销实现简单;本方案以组件承诺的方法保证属性证明的真实性,采用零知识证明实现平台组件的隐私性.基于强RSA假设,在Random Oracle模型下可被证明是安全的.实现的原型系统实验结果表明,组件属性证明是一种灵活、实用、高效的证明,对系统性能没有影响.

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TRISO-Model(tridimensional integrated software development model)是为处理软件开发的复杂性和动态性而提出的三维集成软件开发方法学,其中,多维模型之间的语义一致性维护以及对模型应用中公共操作部分的重用,提出了基于一致语义进行模型管理的需求.给出了基于MDA(model driven architecture)进行模型管理的方法MDA-MMMethod(MDA based model management method),应用MDA的4层模型管理结构,基于MDA核心标准MOF(meta object facility)所提供的公共语义基础管理模型和元模型,MDA-MMMethod支持各种MDA模型操作标准实现在TRSIO-model应用中的重用.开发了相应的支持系统MDA-MMSystem(MDA based model management system),应用于SoftPM的项目实践中.与传统方法相比,模型应用的开发效率得到了显著提高,同时降低了开发成本.最后,给出了模型融合的应用实例介绍.

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现有的发布/订阅系统不能根据事件的语义来进行事件与订阅的匹配,且不能支持具有复杂结构(如图状结构)的事件.将语义Web技术引入发布/订阅系统中,提出一种基于本体的发布/订阅系统.该系统采用本体来表示事件的概念模型,采用RDF图来表示事件,采用图模式来表示订阅条件.它能较好地解决现有的发布/订阅系统的上述问题.实验结果表明,该系统具有较高的订阅匹配效率.

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针对水合物形成过程中存在成核诱导期长、过冷度大,形成速度慢的问题,本文以HCFC-141b(1,1-dichloro-1-flooroethane)作为研究工质,将超声波引入水合物形成过程中,研究超声波对水合物形成的影响。建立了包括超声波水合反应系统、数据采集和图像采集系统的可视化低温实验系统。利用这套实验系统,分别实验研究了频率为20kHz和15kHz,功率为0-1000w的超声波对HCFC-141b水合物的形成影响。实验结果表明,超声波对水合物的形成有明显的影响。水合物形成过程主要分为三阶段:冷却期、