基于FPGA的USB主控芯片软硬件协同设计与验证

设计了一款采用PowerPC架构的USB1.1主机控制器芯片,并对该芯片进行软硬件协同验证。通过内嵌PowerPC和USB主机IP核的FPGA系统,辅以外部收发器电路、驱动、应用程序和文件系统,完成了对U-Disk和HID两类典型USB应用的测试,验证结果表明该USB主机芯片设计可以符合USB技术规范,并能和其他厂家的设备兼容

pH-Induced Simultaneous Synthesis and Self-Assembly of 3D Layered beta-FeOOH Nanorods

Higher-ordered architectures self-assembly of nanomaterials have recently attracted increasing attention. In this work, we report a spontaneous and efficient route to simultaneous synthesis and self-assembly of 3D layered beta-FeOOH nanorods depending oil a pH-induced strategy, in which the continuous change of pH is achieved by hydrolysis of FeCl3 center dot 6H(2)O in the presence of urea under hydrothermal conditions. The electron microscopy observations reveal that the square-prismic beta-FeOOH nanorods are self-assembled ill a side-by-side fashion to form highly oriented 2D nanorod arrays, and the 2D nanorod arrays are further stacked in a face-to-face fashion to form the Final 3D layered architectures. Oil the basis of time-dependent experiments, a multistage reaction mechanism for the formation of the 3D layered beta-FeOOH nanorods architecture is presented, involving the fast growth and synchronous self-assembly of the nanorods toward I D, 213, and 3D spontaneously. The experimental evidence further demonstrates that the urea-decomposition-dependent pH continuously changing in the Solution, spontaneously altering the driving force competition between the electrostatic repulsive force and the attractive van der Waals force among the nanorods building blocks, is the essential factor to influence the self-assembly of the beta-FeOOH nanorods from 1D to 3D.NSFC,20525103,20801045,20531050,20725310 973 Program 2007CB81530

From Self-Assembled Microspheres to Self-Templated Nanotubes: Morphologies and Properties of Sulfur-Bridged Fluoranthene-Based Organic Materials

The inability to controllably synthesize organic nanomaterials with desired morphologies and properties is a major barrier that prevents the scientific development of organic nanomaterials. A controllable method by means of adjusting the solubility of organic reactant has now been applied to Construct sulfur-bridged fluoranthene-based materials with desired spherical or tubular morphologies, based on the Williamson type of reaction starting from perchlorinated fluoranthene and disodium salt of 2,5-dimercapto-1,3,4-thiadizaole. A disubstituted fluoranthene derivative is proved as the basic building block for the organic materials by the data of mass spectrometry, X-ray photoelectron spectroscopy, as well as crystallography. Through quenching the intermediates toward the fluoranthene-based microspheres or nanotubes, the routes of self-assembly via a vesicle pathway and self-template from perchlorinated fluoranthene rods are proposed for the growth of the microspheres and the nanotubes, respectively. The proposed routes can be extended for synthesis of other aromatic molecular materials with controllable morphologies. On the basis of the reaction with thiol groups retained on the surface of the as-synthesized materials, functional groups or noble metal nanoparticles have been facilely linked to the fluoranthene-based materials for potential applications. Morphology-dependent properties of the fluoranthene-based materials have been demonstrated, on the basis of the experimental evidence about strong near-infrared absorption exhibiting in the microspheres but lacking in the nanotubes.The National Natural Science Foundation of China (Grant 20525103, 20721001, and 20531050) and the 973 Program (Grant 2007CB815301)

Chlorofullerenes featuring triple sequentially fused pentagons

通讯作者地址: Tan,YZ(通讯作者),Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 地址: 1. Xiamen Univ, State Key Lab Phys Chem Solid Surfaces, Xiamen 361005, Peoples R China 2. Xiamen Univ, Coll Chem & Chem Engn, Dept Chem, Xiamen 361005, Peoples R China 电子邮件地址: [email protected], [email protected] triple sequentially fused pentagons (TSFP) motif is one of the basic subunits that could be used for constructing fullerenes, but it violates the isolated pentagon rule (IPR) and has not been found in carbon cages to date. The properties of TSFP-incorporating fullerenes are thus poorly explored both theoretically and experimentally. Reported herein are four chlorinated derivatives of three different fullerene cages, all with the TSFP motif. X-ray crystallographic analyses indicate that the molecular strain inherent to the pentagon adjacency of a TSFP is significantly relieved upon exohedral chlorination, leaving one of the four pentagon fusion sites unsaturated and rendering the present derivatives chiral. This unique reactivity, in stark contrast to that of previously reported non-IPR fullerenes containing double fused pentagons or triple directly fused pentagons, can be rationalized by density functional theory calculations, and are expected to stimulate further studies of these new members of the fullerene family, both theoretically and experimentally.NNSF of China 20525103,20531050,20721001,20423002 20673088 973 Program 2007CB81530

榆林黄土区梨枣树生理生长对土壤水分的响应研究

本文通过对国内外相关研究现状及存在问题进行分析和总结，在陕北红枣节水示 范基地，以小区内三年生梨枣为研究对象，监测不同土壤水势处理条件下土壤性质、 枣树茎直径微变化、冠层结构、叶片生理、光合生产等梨枣树生长生理指标的变化， 并结合气象要素分析梨枣树适宜的栽培气象环境，茎直径微变化的主成分气象影响因 子。通过分析土壤&mdash;植物&mdash;大气连续体各界面的指标数量关系与内在联系，最后综合 探讨陕北梨枣树栽培水分优化调控问题。设置四个土壤水势处理，即：T1：土壤水势 控制在-41～-51kPa 范围内；T2：土壤水势控制在-68～-84kPa 范围内；T3：土壤水势 控制在-96～-135kPa；T4：土壤水势控制在-311～果实萎蔫～-311kpa。初步得出以下 结论： （1）陕北气象环境对于枣树栽培利弊共存。陕北太阳辐射值高，辐射时间长， 试验期间Rs 日均值为226.80wat/m2，长时间高辐射对梨枣后期果实着色、成熟度等 具有重要作用。陕北昼夜温差较大，试验期间日温差日均值为13.88℃，而较大的日 温差可以改善果实品质。试验区日平均降雨量1.71mm，日均参考作物腾散量6.77mm， 栽培环境相对干旱，降雨集中连续，从第160 天到第220 天（开花坐果期到果实膨大 前期）是饱和水汽压亏缺与温度较高时段。试验确定梨枣树果实膨大期与开花期为主 要亏水时期，需要进行合理的人为补灌，确保梨枣树健康的生长。 （2）茎直径日变化可以分为平衡型、亏缺型和增长型三种类型。平衡型茎直径 日生长量（DI）为正值，亏缺型DI 为负值，增长型没有明确的DI。茎直径日变化过 程与气温具有负向的，与空气相对湿度具有正向的相似变化趋势，茎直径日最大值 MXTD 一般出现在早上8 点左右，茎直径日最小值MNTD 一般出现在下午3 点左右。 （3）通过对气象因子关于茎直径日最大收缩量（MDS）的通径分析得出，Rs、 Tmd 是影响MDS 的主要决策变量。ET0 是MDS 的主要限制变量。分析认为大气蒸腾 强度与辐射是影响MDS 的主要因素，由于计算中误差项的直接通径系数与决策系数较高，表明除了气象因子外还有其他重要因素影响着MDS 的变化。 （4）枣树茎直径的日动态变化以及生育期内生长速度与土壤水分有密切的关系。 高水分处理枣树茎直径微变化（MXTD 与MNTD）比较稳定，数值要小于低水分处理 的，茎秆由快速生长进入缓慢生长的时间要比低水分处理的迟，生长速率转折点要滞 后于低水分处理的。因此，对枣树进行灌溉可以延长植株生长的周期。枣树茎直径的 生长变化能很好的被Slogistic1 曲线方程拟合。 （5）试验得出：叶面积指数与土壤水分处理成正相关，而冠层透光率和树高与 土壤水分处理成负相关。中等水分处理可以使枣树冠层透光率长期处在25%～35%适 宜范围内，水分处理对枣树叶片叶绿素相对含量、气孔导度、胞间CO2 浓度等特性 影响较大。土壤水分高，枣树叶片叶绿素相对含量低，气孔导度大，胞间CO2 浓度 高，气孔限制值低。在经过复水后，叶片叶绿素相对含量有降低的趋势，但不同程度 的水分胁迫复水后，叶绿素降低程度不同。适当灌溉可以提高枣树叶片净光合速率、 蒸腾速率，但会降低叶片水分利用效率。通过灌溉可以显著提高枣树的初期坐果率、 保果率、坐果枝条数和收获果实数，并同时增加枣树总枝条数、坐果枝平均坐果率和 坐果枝率，但不显著。适当灌水可以显著提高单果重与总产量，但水分过多，枣树生 长会受到水涝胁迫，单果重与总产量会有所降低。 （ 6）梨枣树栽培适宜的灌溉土壤水势为-68~-84kpa，相对田间持水量的 60%~65%；适宜灌溉时期为开花坐果期与果实膨大期；梨枣树水分亏缺敏感性指标 为茎直径微变化（MDS、MXTD、MNTD）、气孔导度、净光合速率和蒸腾速率。 关键词：梨枣树；土壤水分；气象因子；生理生长；生产；水分亏缺；茎直径； 水分优化</p

Optimization of heat treatment process parameter for nickel-base superalloy X-750by nonlinear ultrasonic nondestructive evaluation method

为了获得更好的材料性能,需要对热处理工艺参数进行精确地优化。非线性超声无损检测技术是一种可以有效表征材料微观结构状态变化的评估方法,可以用来评估、优化热处理工艺参数。利用非线性超声波对热处理后的X-750合金材料进行评估,根据超声传播的非线性响应不同,对材料的性能变化做出判断,并与线性超声检测技术的评估结果进行了对比研究。研究发现经过热处理之后,材料性能显著提高,在其中传播的超声非线性响应则明显下降。材料经过热处理后性能提升越大,其声学非线性响应就会变得越小。根据超声波传播的非线性响应定性评估了3种不同的热处理工艺,明确了最优的镍基高温合金X-750退火工艺参数。研究证实了非线性超声方法的敏感度优于传统的线性超声评估方法,可以对材料的热处理效果进行无损评估,从而对热处理工艺参数进行优化与完善。It is necessary to optimize heat treatment process parameter to achieve better material properties of metallic materials.Nonlinear ultrasonic nondestructive evaluation technology is an effective approach to characterize the material's microstructural change,which can be used to evaluate and optimize heat treatment process by nonlinear ultrasonic waves.Nonlinear ultrasonic method is used to evaluate the heat treated X-750 alloy material.Material properties of specimens after heat treatments are evaluated and predicted by the acoustic nonlinear responses of ultrasonic wave propagation.Conventional linear ultrasonic approaches are also used to make comparisons.It is found that the material properties are significantly improved after heat treatment,and better material properties correspond to less nonlinear response of ultrasound propagation.The qualitative evaluation of three different heat treatment processes for X-750 alloy is provided by ultrasonic nonlinear response in the specimens and shows the optimal heat treatment process for this materials.It can be concluded that the nonlinear acoustic technique can be used to evaluate the heat treatment condition nondestructively and to optimize the process with the improved sensitivity compared with conventional linear ultrasonic approach.国家自然科学基金(51405405); 中央高校基本科研业务费专项资金(20720140511)~

Hoisting component for strong operation type underwater robot carrier

本发明涉及水下机器人，具体是一种强作业型水下机器人载体用提升 组件。包括：提升杆，竖直设有中心贯通圆孔，上部为圆柱体，通过卡环 与中继器锁栓连接；下部为带有两个相对设置的竖直平面的圆柱体，在柱 体两侧分别设连接孔；提升座为环形，在环形上表面沿一个半径方向相对 设有起吊耳座，通过提升点销轴与提升杆的柱体两侧的连接孔安装在一起； 在环形上表面沿起吊耳座连线的垂直方向设有两限位挡块；底座圈，容置 有提升座；上压盖，与底座圈外径尺寸相同，覆盖于容置有提升座的底座 圈上表面；来自中继器的系缆穿过提升杆中心的贯通圆孔，提升座内环与 潜水器载体相连。具有供强作业型水下机器人使用、能够向任意方向倾斜 的特点

致密油储集层迂曲度变化特征研究

迂曲度是刻画多孔介质中输运过程的重要参数,对致密储集层,由于流动的非线性,流动规律和常规储集层有巨大差异,迂曲度与常规储集层亦不同。本文利用孔隙网络模型,研究了由流动非线性所带来的迂曲度改变。提出2个无量纲数:1以岩心的水动力迂曲度为基础定义无量纲迂曲度Γ,用以刻画非线性效应带来的迂曲度改变;2定义流量加权平均的孔喉半径为特征孔喉半径,并以此定义无量纲压力梯度Ρ,用以刻画压力梯度状态。本文研究了Γ随Ρ的变化规律表明,Ρ-Γ曲线具有确定的形态,且不随岩心孔隙网络的任何参数发生变化。即对于任何岩石,由流动的非线性所带来的迂曲度的改变是确定的。本文给出了Ρ-Γ曲线的拟合公式,可方便计算给定压力梯度下..