A New Exact Evaluation Formula for Loop Subdivision Surfaces

利用控制网格拓扑结构的对称性,通过将奇异点周围12环和22环的控制顶点进行离散Fourier 变换(DFT) 得到分块对角阵,将其进行特征分解及排序之后,再通过离散Fourier 逆变换( IDFT) 和截断等操作得到细分矩阵的 高次幂的表达式,从而得到Loop 细分曲面新的精确参数化公式1国家自然科学基金(10571145

Catmull-Clark 细分曲面的误差分析

运用引入相邻点的方法和计算控制点的一阶差分的新的技术, 研究CatmullClark 曲面细分过程的误差估计 问题. 证明了CatmullClark 曲面的控制网格按指数速率收敛于极限曲面; 并给出关于CatmullClar k 曲面误差估计的一个计算公式. 本文的技术亦可适用于Doo-Sabin 曲面等细分曲面.福建省自然科学基金( A0210004) 资

三向四次箱样条曲面的差分界

研究了三向四次箱样条曲面与控制网格中心三角平面片间的距离和该距离的界. 借助三向四次箱样条曲 面的分片表示,应用该曲面片控制顶点的一阶和二阶方向差分, 给出了该曲面片与控制网格中心三角平面片之间的 逐点距离. 通过该距离的分片表达式, 给出了该距离的界.国家自然科学基金(10571145

雌激素的非基因组途径在哺乳动物雌性生殖过程中的作用机制

雌激素的非基因组调节模式在雌性生殖系统中广泛存在．雌激素通过基因组、非基因组及两种调节模式的整合在不同 组织中行使多种生理功能．卵巢中雌激素能通过非基因组效应对卵细胞起到保护作用．子宫中雌激素对多种基因的表达都是 通过非基因组模式．对雌激素非基因组效应的研究将有利于进一步了解雌激素的作用机制．国家自然科学基金重点资助项目(30930013

Generalized Subdivision of Bézier Surfaces

将矩形和三角形bzIEr曲面的基于直线的细分推广到基于曲线的细分.运用多项式曲线细分矩形和三角形bzIEr曲面,并以参数变换和多项式开花为工具,计算出细分后每个子曲面片的bzIEr控制顶点.曲线细分使细分方式的选择更灵活,细分后的子曲面片及其边界的形状更丰富多彩,而且该方法能推广到有理情况.The subdivision of rectangular and triangular Bézier surfaces is generalized from with line to with polynomial curve in domain.By using of parameter transformation and blossoming of polynomial,each subpatch's Bézier control points are evaluated.The subdivision method based on curve makes more choices for the style of subdivision and the shape of the subpatches and their sides.This method is also working for rational cases.国家自然科学基金(10571145);安徽大学数学科学学院创新团队项

Synthesis optimization,characterization and electrochemical performance of Li[Li_(0.2)Mn_(0.54)Ni_(0.13)Co_(0.13)]O_2 as cathode material of lithium ion battery

采用共沉淀法合成锂离子电池用富锂正极材料lI[lI0.2Mn0.54nI0.13CO0.13]O2。通过X射线衍射光谱法(Xrd)、扫描电子显微镜法(SEM)和电池充放电测试方法来考察高温烧结时间和烧结温度对所合成材料的结构和性能的影响。结果表明:900℃烧结15 H合成的样品材料具有较好的层状结构和较优越的综合电化学性能;在1.0 C充放电时,首次放电比容量高达181.6 MAH/g(2.0~4.6 V),充放电效率为68.2%,80圈循环后的放电比容量为176.5 MAH/g,具有较高的容量保持率(97.2%);同时,该富锂正极材料表现出较好的倍率性能,在3.0 C充放电时还有148.8 MAH/g的放电比容量。The conditions of sintering time and sintering temperature were optimized to prepare the cathode material Li [Li0.2Mn0.54Ni0.13Co0.13]O2 with co-precipitation method.The prepared materials were characterized and tested by means of XRD,SEM and electrochemical measurements.It is found that the material synthesized by sintering at 900 ℃ for 15 h exhibits the best electrochemical performance,including high initial discharge capacity & coulombic efficiency and good cycling stability in the first 80 charge/discharge cycles at 1.0 C rate in comparison with materials synthesized under other conditions.Meanwhile,the material synthesized at the optimized condition also shows good rate capability,delivering high specific discharge capacity of 148.8 mAh/g at 3.0 C.深港创新圈合作项目(SG200810200106A

AN ADAPTIVE ITERATION METHOD FOR STRUCTURAL STATIC REANALYSIS of TOPOLOGICAL MODIFICATIONS

基于guyAn缩减和EPSIlOn算法,提出了结构拓扑修改静态重分析的自适应迭代方法。首先将新增加的自由度通过guyAn缩减方法凝聚到原结构自由度上,形成缩减方程。其次,根据刚度矩阵增量,利用nEuMAnn级数建立基向量,采用向量EPSIlOn算法对基向量部分和系列进行迭代加速,并给出了控制迭代收敛精度的误差计算方法,可以根据结构改变的大小自适应选择迭代次数,从而快速求出原结构自由度的位移。新增加自由度的位移可从缩减方程恢复得到。给出了一个数值算例,将该方法与组合近似法(CA)进行比较。数值计算结果表明,该方法可以根据精度要求自动选择迭代次数,且计算效率比CA方法高。Based on the Guyan reduction and epsilon algorithm, an adaptive iteration method for structural static reanalysis of topological modification is presented.In this process, the equations of the newly added degree of freedoms(DofS)(if any) are condensed to the original structure by means of Guyan reduction.And then, the basis vector is formed using Neumann serial according to the increment of the stiffness matrix, and the epsilon algorithm is used to accelerate the convergence of the partial sum of the basis vectors.An error evaluation method is introduced to control the accuracy of the iteration adaptively.A numerical example is given to compare the computational cost and approximation accuracy between the combined approximation and the presented method, the numerical results show that the present method is effective and easy to integrate into a general optimization approach.国家自然科学基金项目(50905033);中国博士后科学基金项目(20070420761);广东省自然科学基金项目(8451009001001414);广州市科技计划项目(2006Z2-D9061);广东省科技计划项目(2009B010900032);粤港招标项目(20070103-1

数字微流控技术及其在生物分析中的应用

数字微流控技术是一种基于微电极阵列来实现离散液滴精确控制的新型液滴操纵技术。这种基于介电润湿现象实现的液滴电操纵体系,相比于传统微流控芯片具有自动化、可寻址、可动态配置、易集成等特点。该文介绍了数字微流控技术液滴驱动原理,总结了芯片的结构和常用的制作方法,举例阐述了现阶段该技术在生物分析化学领域的应用,并对其应用前景做了展望。国家自然科学基金资助项目(21735004,21435004,21775128,21705024,21521004);;长江学者和创新研究团队项目(IRT13036

MnO/Nitrogen-doped graphene composite cathode for high performance lithium oxygen batteries

本文采用水热法制备了MnO/氮掺杂石墨烯复合材料. 作为非水锂空气电池的正极催化剂, 该复合材料表现出了优异的电化学性能以及循环稳定性.; 在充放电电流密度为0.05 mA cm~(-2)时, 其能量效率高达84.6%, 远高于目前文献所报道的非贵金属催化剂的能量效率,; 也超过了基于贵金属的催化剂. 其氧还原反应(ORR)和氧析出反应(OER)的过电势分别仅为0.11和0.41 V.; 扫描电子显微镜(SEM)和透射电子显微镜(TEM)结果表明, 所制备的MnO纳米颗粒能够均匀地分散在氮掺杂石墨烯的表面.; 密度泛函理论(DFT)计算揭示, MnO(100)面是主要的催化活性面, 其理论ORR和OER的过电势分别仅为0.21与0.24 V,; 充放电电势差为0.45 V, 与实验结果0.52 V相当.MnO/nitrogen-doped graphene (MnO/NG) composite cathode was fabricated by; a facile one-pot method as cathode catalyst for non-aqueous lithium; oxygen batteries. It exhibited superior electrochemical performance with; higher round-trip efficiency and better cyclic stability. It showed a; high round-trip efficiency of 84.6% at the current density of 0.05 mA; cm~(-2) with the discharge and charge overpotentials of 0.11 and 0.41 V,; respectively. Through scanning electron microscopy, transmission; electron microscopy and X-ray photoelectron spectroscopy, it was; confirmed that MnO nanoparticles were homogeneously dispersed on NG; surface. The density functional theory calculations demonstrated that; the superior electrochemical performance of MnO/NG might be attribute to; the exposure of stoichiometric MnO (100) surface, with the ORR and OER; overpotential only to be 0.21 and 0.24 V, respectively. The; discharging-charging voltage gap is 0.45 V, in good agreement with the; experimental value of 0.52 V.国家重点基础研究发展计划; 国家自然科学基金; 国家基础科学人才培养基

SPECIATION ANALYSIS OF TRACE ELEMENTS IN GANODERMA ATRUM

研究黑灵芝中微量元素含量及溶出特性对黑灵芝质量控制、灵芝产品的合理开发利用有重要作用。用ICP-MS法同时测定黑灵芝中十余种微量元素的初级形态含量及分布,考察了黑灵芝中微量元素在不同极性溶剂中的浸出率,并通过国家一级标准物质验证了分析结果的准确性。结果表明,随着溶剂极性增大,大部分元素的溶出率增大。水提取黑灵芝,铜、锰、铁、锌等元素的提取率均小于40%,对黑灵芝样品进行了加标回收试验,回收率在88.2%~110.6%。It is important to study the trace element contents and transference characteristics and element speciation in the extract of Ganoderma atrum for the quality control and reasonable exploitation. In this experiment the contents and speciation of more than ten elements in Ganoderma atrum were simultaneously determined with microwave assisted digestion of sample combined with inductively coupled plasma mass-spectrometry (ICP-MS). The dissolution percentage of trace element in different solvents were also studied and the veracity of the analytical results were validated with CRMs′ under the same conditions.The results indicated that the dissolution percentage of most elements in solvents were increased with its polarities. In the aqueous solution of the Ganoderma atrum, the extraction percentage of Cu, Mn, Fe, Zn were all lower than 40%. The recoveries of the elements were ranged from 88.2% to 110.6%