玉米雄穗几何造型研究

通过对玉米雄穗形态结构的观测分析,提出了基于雄穗形态特征参数的三维形态数学模型及其实现方法。雄穗模型的建立过程包括拓扑结构设计、分枝造型和小穗造型三个阶段。模型具有较高的真实感效果,可控性强,可满足雄穗数字化设计的需要。     

药物动力学系统的参数辨识

本文采用现代控制理论的方法研究药物动力学系统的模型参数辨识问题,以白鼠口服氟的实验数据,得到五室模型的参数.     

A framework for environmental management planning — A landscape-ecological approach

Framework, concepts, and methods of Environmental Management Planning (EMP) are discussed. A landscape-ecological approach was taken to integrate the environmental indices. EMP focuses on regional factors- natural, social, amenity related — and becomes more sensitive as the scale of study increases. The processes of EMP include a vertical aspect, dealing with pollution, conservation, and amenities, and a more general horizontal component which involves zoning and land use planning. Environmental impacts may be assessed by modeling exercises using all available data and considering all land use options. To keep up with the rapid change of environment and its perception, EMP should be process-oriented rather than purpose-oriented. The concepts of EMP were applied to the middle basin of the Tamagawa River and it was shown that mulvariate analysis is useful for the regional subdivision and environmental modeling.     

PV—CSMA/CD协议支持下的话音和数据综合业务通信

本文讨论优先级CSMA/CD协议支持下,类似以太局部网中的话音和数据综合业务通信性能.文中根据建立的协议模型,模拟分析了话音和数据负载、话音质量等性能参数.     

Quantitative analysis of animal model lens anatomy: accommodative range is related to fiber structure and organization

Purpose The results of a recent study on accommodation in humans and baboons has revealed that lens fiber structure and organization are key components of the mechanism of accommodation. Dynamic focusing involves the controlled displacement and replacement, or realignment, of cortical fiber-ends at sutures as the mechanism of accommodation at the fiber level. This emended explanation of the mechanism of accommodation raises the following question: as the structure of crystalline lenses are only similar, not identical between species, is accommodative amplitude related to differences in the structure and organization of fibers between species? To address this question, we have quantitatively examined the structure and organization of fibers in a number of the more commonly used animal models (mice, cattle, frogs, rabbits and chickens) for lens research. Materials and methods Lenses (a minimum of 12–18 lenses/species) from mice, cattle, frogs and rabbits were used for this study. Prior to fixation for structural analysis, measurements of the gross shape of the lenses (equatorial diameter, anterior and posterior minor radii [anterior + posterior minor radius = polar axis]) were taken directly through a stereo surgical dissecting microscope equipped with an ocular reticle. Lenses were then prepared for and examined by light (LM), transmission (TEM) and scanning electron microscopy (SEM). Scale computer-assisted drawings (CADs) of lenses and lens fibers were then constructed from quantitative data as described above and from quantitative data contained in micrographs. Results The differences in fiber structure and organization that effect accommodative range arise early in development and are continued throughout lifelong lens growth. In umbilical suture lenses (avian) secondary fibers develop with almost completely tapered anterior ends (85–90% reduction of their measures of width and thickness at the equator). By comparison, in lenses with line sutures (e.g. frogs and rabbits) secondary fibers develop with just a 50–60% reduction in anterior fiber taper. In lenses with Y sutures (mice and cattle), fiber width taper is only 25–40%. However, in all cases, while the taper of the posterior end width of fibers is just slightly less (approx. 15–20%) than that of anterior ends, posterior end thickness is only reduced by one half that of anterior thickness. Conclusions In humans, the mechanism of accommodation at the fiber level involves the controlled realignment of very flattened and flared, rather than tapered fiber-ends at sutures. In this manner, the simultaneous increase in lens thickness and surface curvature in the accommodated state is the result of fiber-ends being overlapped along multiple (9–12) suture branches covering the majority of the anterior and posterior surfaces. The results of this animal study strongly suggest that accommodative range is directly related to quantitative differences in fiber structure and organization in the different suture types. The very broad accommodative range in birds is made possible, at least in part, by the almost complete tapering of fiber-ends at umbilical sutures. In contrast, the essentially negligible accommodative range of animals that have line- and Y-suture lenses is at least partially the result of the fact that these lenses have fibers with very little end taper. Thus, the blunt ends of fibers in line- and Y-suture lenses precludes any significant overlap of end segments to effect accommodation.     

枣镰翅小卷蛾对枣树挥发物的行为反应

【目的】研究木枣枝条和不同处理枣吊的挥发性组分和含量,分析枣镰翅小卷蛾对不同处理枣吊的行为反应,为生产上应用植物源引诱剂防治枣镰翅小卷蛾提供理论依据。【方法】利用固相微萃取技术（SPME）和GC-MS,分析木枣枝条和不同处理枣吊的挥发物成分,利用触角电位技术(EAG)和Y-嗅觉仪,测定枣镰翅小卷蛾的电生理及行为反应。【结果】木枣枝条的挥发物成分有9种,主要挥发性组分为萜类和酯类化合物;木枣不同处理枣吊共有的挥发物成分有17种,多为萜类、酯类和醇类化合物。健康枣吊、人工机械损伤枣吊和虫害枣吊相比,三者在挥发性组分组成及比例上均存在差异,并且在遭受虫害后,木枣枣吊可释放出虫害诱导型挥发物乙酸-4-己烯-1-醇酯。枣镰翅小卷蛾成虫对木枣的触角电位(EAG)反应表明,枣镰翅小卷蛾成虫对枝条有强烈的刺激反应,且雌虫的反应值显著或极显著高于雄虫。行为测试结果显示,当木枣枣吊受到机械损伤后,其对枣镰翅小卷蛾的趋向选择产生了驱避行为,而健康和虫害枣吊则具有明显的吸引作用。【结论】木枣不同部位释放的挥发物成分并不相同,在健康和虫害枣吊所释放的挥发物成分中,含有对枣镰翅小卷蛾起引诱作用的成分。     

一种基于UML的面向方面建模框架研究

从分析面向方面建模需求入手,基于UML的扩展机制提炼出一个面向方面建模元模型,构建一个基于UML的面向方面建模框架,并且提出一种简单有效的面向方面软件的动态行为建模方法。     

Quantitative impact assessment of spray coverage and pest behavior on contact pesticide performance

BACKGROUND: Standard procedures for evaluation of pesticide performance do not take into account pest behavioral response or incomplete spray coverage. In this study, a series of laboratory experiments was conducted with two non‐systemic miticides (propargite and hexythiazox) applied to cotyledon cotton plants, which were subsequently infested with spider mites. The results of these laboratory experiments are discussed through a comprehensive pest population dynamics model. RESULTS: When cotton leaves were submerged in miticide solutions, both miticides provided effective control of spider mites. In a two‐choice test it was demonstrated that propargite was repellent to spider mites, but not hexythiazox. Finally, the spray coverage on cotton plants was varied, and, for both miticides, significantly positive relationships between spray coverage and spider mite mortality were shown. However, propargite required higher spray coverage (20%) than hexythiazox (10%) to control spider mites. A theoretical model showed that, without repellency, the pesticide performance is positively correlated with target pest mobility. If the pesticide is repellent, the probability of exposure decreases, especially for a less mobile pest. CONCLUSION: With an experimental and theoretical modeling approach, it was demonstrated how the combination of behavioral avoidance and low spray coverage can markedly reduce pesticide performance. Copyright © 2012 Society of Chemical Industry     

计算机建模与仿真在液压伺服控制系统中的研究应用

计算机建模和仿真软件可协助液压控制系统对已有系统进行校验,当1种液压控制系统不能正常工作时,基于模型的控制能够提供1种精确的指示工具,其控制方法具有很大的灵活性.本文着重介绍了在液压伺服控制系统中,若结合计算机软件进行仿真,对系统的参数可进行较精确地调整,并对可靠性做进一步验证,最终可以得出比较可靠的液压伺服控制系统.     

山羊溶酶体α-AMA基因的克隆、生物信息学及组织表达谱分析

本研究旨在对山羊溶酶体α-甘露糖苷酶(α-AMA)基因进行组织表达谱和生物信息学分析。参考牛α-AMA基因序列设计引物,采用PCR技术克隆山羊α-AMA基因序列,并利用荧光定量RT-PCR进行组织表达谱分析以及进行生物信息学预测。首次获得了山羊α-AMA基因,含有完整CDS编码区3 000bp,编码999个氨基酸,其中前50个氨基酸为信号肽序列。其编码区的核苷酸序列和预测氨基酸序列与牛的α-AMA相似性最高,分别为95.93%和94.79%。组织表达谱分析表明α-AMA在山羊各组织均不同程度的表达,其中在肺脏、肝脏、小脑表达量较高。生物信息学预测发现,α-AMA蛋白属于糖苷水解酶38家族成员,有2个保守的结构域,存在9个N-糖基化位点。SWISS-MODEL同源建模山羊α-AMA具有良好的可信度。本研究为探讨酶的作用机理及疯草解毒剂的研制提供了理论依据。