摘要：生态集约化是指通过强化生态系统服务实现以补充或替代人为输入来维持或增加产量的目标。生态集约化具有提高农业环境可持续性的潜力,例如通过降低对环境不利的管理活动而又维持产量。生态集约化基于生态过程,而这些过程受到生物多样性的影响。本文综述了多空间尺度下生物多样性,特别是维管植物多样性如何调节与生态集约化相关的生态过程。在植物个体基因型水平上,功能性状的互补性直接影响生产力;在田块内种群水平上,作物混合类型具有抗灾能力,以减少病虫害的发生和传播的风险;尺度转换到田间水平,非作物植物类型(如杂草)的多样性为田块内的功能过程提供了必要的资源,包括地下(碳输入、分解)和地上(传粉媒介和天敌的资源连续性)。在景观尺度上,半自然和管理的植被嵌合体通过减轻洪涝和干旱风险、改善气候和调节虫害种群,为抵御极端事件提供缓冲。总体而言,上述强调了尺度异质性在农田维持生态系统功能的重要性。本综述的主要研究挑战包括:1)将植物功能多样性(从性状到栖息地尺度)更好地整合到种植系统设计中;2)量化植物多样性相对于其他管理选项对有效生态集约化的可能互动贡献,3)并通过有针对性的管理优化生物多样性的系统功能优势,以实现具有弹性、高效和高产的农业生态系统。

摘要：确定弹塑性材料结构的极限承载能力是结构设计中极其重要的一个问题,它通常是采用弹塑性非线性有限元方法来进行分析的。本文提出了利用基于一系列线弹性有限元解来获得弹塑性材料结构的极限承载能力的试验误差法,并将它与切线法和割线法进行了比较和讨论。在计算的每一步中,根据应力松弛系数降低杨氏弹性模量,并将结构的应力松弛系数和作为误差指标。当结构的误差指标小于给定的误差容限时就得到收敛解。本文方法可计算出结构受载后直到崩溃时应力、应变和载荷-变形曲线。数值实验表明,本文方法是有效的和可行的。

摘要：研究岩粉尺寸（10-30μm）和质量分数（5%-15%）对搅拌铸造法制备6061铝合金/岩粉复合材料密度、硬度和干滑动磨损行为的影响。在不同载荷、不同滑动速率和滑动距离条件下在销盘摩擦试验机上对复合材料进行干滑动摩擦磨损试验。采用Taguchi法进行正交试验（L27）设计,并对实验结果进行方差分析。结果表明,载荷和增强相（岩粉）尺寸是影响复合材料样品比摩损率的主要因素,其次为增强相的质量分数、滑动速率、滑动距离,且其影响程度分别为47.61%、28.57%、19.04%、9.52%和4.76%。对所得回归方程的预测精度进行实验论证,结果显示,此回归方程能用于复合材料的磨损率的预测且预测误差很小。复合材料磨损表面的SEm结果表明,以岩粉作为增强相能改善铝合金材料的耐磨性能。

摘要：melt extrusion-based additive manufacturing(mE-Am)is a promising technique to fabricate porous scaffolds for tissue engi-neering ***,most synthetic semicrystalline polymers do not possess the intrinsic biological activity required to control cell *** of biomolecules on polymeric surfaces of Am scaffolds enhances the bioactivity of a construct;however,there are limited strategies available to control the surface ***,we report a strategy to tune the surface density of bioactive groups by blending a low molecular weight poly(ε-caprolactone)5k(pCL5k)containing orthogonally reactive azide groups with an unfunctionalized high molecular weight pCL75k at different *** porous three-dimensional(3D)scaf-folds were then fabricated using a high weight percentage(75 wt.%)of the low molecular weight pCL *** a proof-of-concept test,we prepared films of three different mass ratios of low and high molecular weight polymers with a thermopress and reacted with an alkynated fluorescent model compound on the surface,yielding a density of 201-561 pmol/cm^(2).Subsequently,a bone morphogenetic protein 2(Bmp-2)-derived peptide was grafted onto the films comprising different blend compositions,and the effect of peptide surface density on the osteogenic differentiation of human mesenchymal stromal cells(hmSCs)was *** two weeks of culturing in a basic medium,cells expressed higher levels of Bmp receptor II(BmpRII)on films with the conjugated *** addition,we found that alkaline phosphatase activity was only significantly enhanced on films contain-ing the highest peptide density(i.e.,561 pmol/cm^(2)),indicating the importance of the surface *** together,these results emphasize that the density of surface peptides on cell differentiation must be considered at the cell-material ***,we have presented a viable strategy for mE-Am community that desires to tune the bulk and surface functionality via blending of(m

摘要：基于Kinect体感感应技术,设计了一套温室果蔬采摘运输自动跟随平台。通过体感感应系统获取图片上像素点的深度信息,结合图像处理算法,逐行扫描确定人体图像并实时获取人体骨骼信息,计算了人体当前的三维坐标并记录人体走过的路径轨迹。系统采用自调整函数对路径进行优化,避免了剧烈转向行为,并对优化后的路径以模糊算法动态确定纯追踪模型的前视距离,从而实时调整转向和转角,实现了精准跟随和稳定跟随。试验结果表明,该跟随系统能在避免剧烈转向的前提下以较高的精度跟随,横向最大跟踪偏差不超过10.0 cm,最大深度偏差为5.5 cm,且系统性能不受光照条件影响,满足温室采摘运输要求。

摘要：The rapid development in the digital circuit design enhances the applications on very large scale integration era. Encoders are one among the digital circuits found in all communication systems. The polar encoding is mainly meant for its channel achieving property. It finds its application in communications, sensing and information theory. This coding proposed by Erdal Arikan is significant because of its zero error floors and simple architecture for hardware implementation. In this paper, a folded polar encoder is designed to start from the fully parallel architecture and proceeds with its data flow graph, delay requirement calculation, lifetime analysis and register allocation, which results in a very large scale integration architecture with minimum hardware utilization. The results are simulated for 4 and 8 parallel folded 32-bit polar encoder using Xilinx 14.6 ISIm and implemented in Virtex 5 field programmable gate array. A comparison is made on fully parallel and various folding techniques based on their resource utilization.

摘要：为了深入研究灯泡贯流泵装置内部流动与水力特性之间的联系,采用数值计算、性能试验与pIV流场测试方法,获得了灯泡贯流泵装置在大流量、小流量和最优工况下的流动和水力特性.采用RNG紊流模型和SImpLEC算法,基于多旋转坐标系模型,计算了灯泡贯流泵内部定常流动.分析了泵装置内部流动,指出小流量工况下泵叶轮的进口有较大范围的旋涡区,出水灯泡体内流态较为紊乱;而在最优工况及大流量工况下,泵装置内未见明显回流区.研究表明,灯泡贯流泵进水流道水力损失符合传统管道内局部水力损失规律,而出水流道的水力损失表现为与泵装置运行工况相关的规律,最优工况点附近损失最小,小流量和大流量工况点水力损失均较大.计算结果与二维pIV流动测试结果均表明在小流量下进口近泵壳侧有明显的回流区,而在叶轮出口靠近轮毂处有大面积的脱流.因此,灯泡贯流泵装置优化水力设计应当重视小流量工况下叶轮和导叶处的流动特性.

摘要：斑马贻贝是引起大损坏到淡水依赖者工业的一个重要水的害虫，由于这里讨论的工程的主要目标是开发改进答案控制这种的 ***。三条途径在一次尝试被探索了为存在 bio-cides 设计创新应用程序策略：毒素的(i) 封装；(i i ) 毒素的联合；(iii ) 硬币到毒素的忍耐的季节的变化的调查。在这篇论文，在每个话题的这些途径和主要结果后面的原则被介绍。采用一个化学产品工程的好处在进行这个工程来临也被讨论。

摘要：In this study,waste tire was used as raw material for the production of activated carbons through *** char was first produced by carbonization at 550℃ under nitrogen.A two factorial design was used to optimize the production of activated carbon from tire *** effects of several factors controlling the activation process,such as temperature(850-950 ℃),time(2-6 h) and percentage of carbon dioxide(70%-100%) were *** production was described mathematically as a function of these three *** order modeling equations were developed for surface area,yield and mesopore *** was concluded that the yield,BET surface area and mesopore volume of activated carbon were most sensitive to activation temperature and time while percentage of carbon dioxide in the activation gas was a less significant factor.

摘要：Ipm-pmASR电机的设计实质上是磁体材料用量和转子结构各向异性之间的折中。各向异性设计的越好,需要的磁体材料就越少。磁体材料的增加总是有利于功率因数和电机转矩性能。不过,当需要大范围恒功率调速时,较少的磁体材料也能保证高速区的安全运行,只是逆变器发生故障时会出现短时过电压。因此,应该使转子各向异性达到最大。