Small-scale turbulent fluctuations beyond Taylor's frozen-flow hypothesis

The space-time cross-correlation function C-T(r, tau) of local temperature fluctuations in turbulent Rayleigh-Benard convection is obtained from simultaneous two-point time series measurements. The obtained C-T(r, tau) is found to have the scaling form C-T(r(E), 0) with r(E)=[(r-U tau)(2)+ V-2 tau(2)](1/2), where U and V are two characteristic velocities associated with the mean and rms velocities of the flow. The experiment verifies the theory and demonstrates its applications to a class of turbulent flows in which the requirement of Taylor's frozen flow hypothesis is not met.

固液黏着功的Berthelot平均规则的推广及应用

以固液黏着功的Berthelot几何平均规则及其推广为基础的Zisman方程、Fowkes方程和Owens-Wendt方程是固体表面张力测定的基础.对Berthelot几何平均规则进行了进一步的推广,并以此为基础,对Zisman方程中的参数给出了推广的表示式,并对Fowkes方程和Owens-Wendt方程进行了进一步的推广.

Knotlike chi disclinations in the cholesteric liquid crystals

We investigate the topological properties of N(N >= 1) disclination lines in cholesteric liquid crystals. The topological structure of N disclination lines is obtained with the Hopf index and Brouwer degree. Furthermore, the knotted x disclination loops is proposed with the Hopf invariant. And we consider the stability of such configuration based on the higher order interaction. At last, the evolution of the disclinations is discussed.

CSR磁场测量系统的建立及运行

CSR磁场测量系统是国家大科学工程兰州重离子加速器冷却储存环（HIRFL-CSR）的一个重要组成部分，它的建立对工程建设有着重要的现实意义。磁场测量数据是加速器束流动力学模拟、磁铁准直安装以及调束参数预置的根本依据，准确可靠的磁场参数测量更是加速器运行的一个重要保证。本论文从磁场测量的基本理论出发介绍了用于加速器磁铁各个方面参数测量的基本方法，并根据CSR对于磁铁参数的具体要求，结合国内外许多同类实验室的经验，制定了CSR磁铁测量方案；组建了三套用于不同目的的测量系统：Hall点测系统、积分测量系统和谐波测量系统。文中介绍了各测量系统的具体构成和运行模式，并对系统中主要元件的结构和参数设计以及实际加工工艺和质量检测的情况作了详细论述。通过理论分析和实际测量，讨论了CSR测磁系统中各种测量探头系统误差产生的原因和大小，以及测量中使用到的电子设备的误差和稳定性。在系统建成后，通过对不同环境下同一数据的长期重复性测量，认为各个测量系统是具有长期稳定性和重复性的。论文最后介绍了新组建的测磁系统在CSRJn注入线二极磁铁和四极磁铁的测量方面的实际应用，在对测磁数据结果分析的基础上讨论了CSR原型磁铁的设计和加工过程中存在的问题，以及CSRIn磁铁加工中应做出的改进和注意事项。

流程工业过程数据的多粒度分析方法及应用研究

现代流程工业产生了大量与生产状态相关的过程数据，其庞大的规模凸显了传统数据分析方法运算复杂度过高、分析规模受限的不足。同时，流程工业生产过程中所包含的一些复杂性，如传感器数据中的高噪音以及异步采样所导致的数据时标不统一等，都增加了过程数据分析的难度。 为了应对上述挑战，本文将粒度计算的思想引入流程工业中的过程数据分析领域。粒度计算是信息处理领域中一种新兴的概念和计算范式，其核心思想是通过适度放松精度要求，在较大粒度上进行分析以提高方法整体的效率和鲁棒性。 本文重点研究了面向过程数据的粒度化分析方法，并围绕该方法的关键性质展开了深入细致的论证，在此基础上给出了选择粒度的方法和准则，最后我们还通过具体实例对上述方法的有效性进行了应用验证。 论文的主要贡献体现在： (1)将粒度计算的思想和过程数据分析方法相结合，提出了一种粒度化的过程数据分析方法，并证明了在特定条件下粒度化的数据分析能够得到原问题解的下界或下确界，为粒度化过程数据分析方法奠定了坚实的理论基础。 (2)深入探讨了不同粒度下过程数据分析的计算复杂性变化情况，提出了一种利用多粒度分析挑选最佳分析粒度的方法。该方法针对现有数据分析方法难于应对海量数据的缺点，可以根据具体应用的精度需求灵活地调整分析粒度，从而降低数据分析的总体计算复杂性。 (3)针对过程数据分析中面临的稳态周期评估问题，提出了一种基于多粒度分析的过程数据稳态周期检测算法。该算法基于我们提出的过程数据质量评估指标，能够灵活地调整查询周期，提供符合应用系统质量需求的数据，同时尽量减少运行开销。 (4)针对大规模软测量面临的计算效率问题，提出了一种基于多粒度分析的软测量方法。该方法通过构建一组粒度化的软测量模型，并依次在多个粒度中求解，最终确定一个既能满足特定精度需求又能确保运算效率最高的粒度。该方法已经得到实践检验并取得良好的效果。

流程工业过程数据的多粒度分析方法与应用研究

现代流程工业产生了大量与生产状态相关的过程数据，其庞大的规模凸显了传统数据分析方法运算复杂度过高、分析规模受限的不足。同时，流程工业生产过程中所包含的一些复杂性，如传感器数据中的高噪音以及异步采样所导致的数据时标不统一等，都增加了过程数据分析的难度。 为了应对上述挑战，本文将粒度计算的思想引入流程工业中的过程数据分析领域。粒度计算是信息处理领域中一种新兴的概念和计算范式，其核心思想是通过适度放松精度要求，在较大粒度上进行分析以提高方法整体的效率和鲁棒性。 本文重点研究了面向过程数据的粒度化分析方法，并围绕该方法的关键性质展开了深入细致的论证，在此基础上给出了选择粒度的方法和准则，最后我们还通过具体实例对上述方法的有效性进行了应用验证。 论文的主要贡献体现在： (1)将粒度计算的思想和过程数据分析方法相结合，提出了一种粒度化的过程数据分析方法，并证明了在特定条件下粒度化的数据分析能够得到原问题解的下界或下确界，为粒度化过程数据分析方法奠定了坚实的理论基础。 (2)深入探讨了不同粒度下过程数据分析的计算复杂性变化情况，提出了一种利用多粒度分析挑选最佳分析粒度的方法。该方法针对现有数据分析方法难于应对海量数据的缺点，可以根据具体应用的精度需求灵活地调整分析粒度，从而降低数据分析的总体计算复杂性。 (3)针对过程数据分析中面临的稳态周期评估问题，提出了一种基于多粒度分析的过程数据稳态周期检测算法。该算法基于我们提出的过程数据质量评估指标，能够灵活地调整查询周期，提供符合应用系统质量需求的数据，同时尽量减少运行开销。 (4)针对大规模软测量面临的计算效率问题，提出了一种基于多粒度分析的软测量方法。该方法通过构建一组粒度化的软测量模型，并依次在多个粒度中求解，最终确定一个既能满足特定精度需求又能确保运算效率最高的粒度。该方法已经得到实践检验并取得良好的效果。

In vivo mineralization and osteogenesis of nanocomposite scaffold of poly (lactide-co-glycolide) and hydroxyapatite surface-grafted with poly(L-lactide)

Nanocomposite of hydroxyapatite (HAP) surface-grafted with poly(L-lactide) (PLLA) (g-HAP) shows a wide application for bone fixation materials due to its improved interface compatibility, mechanical property and biocompatibility in our previous study. In this paper, a 3-D porous scaffold of g-HAP/poly (lactide-co-glycolide) (PLGA) was fabricated using the solvent casting/particulate leaching method to investigate its applications in bone replacement and tissue engineering. The composite of un-grafted HAP/PLGA and neat PLGA were used as controls. Their in vivo mineralization and osteogenesis were investigated by intramuscular implantation and replacement for repairing radius defects of rabbits. After surface modification, more uniform distribution of g-HAP particles but a lower calcium exposure on the surface of g-HAP/PLGA was observed. Intramuscular implantation study showed that the scaffold of g-HAP/PLGA was more stable than that of PLGA, and exhibited similar mineralization and biodegradability to HAP/PLGA at the 12-20 weeks post-surgery.

Rotating minidisk-disk electrodes

Rotating minidisk-disk electrode (RMDDE) was developed by replacing ring electrode of rotating ring-disk electrode (RRDE) with a minidisk electrode. Its applications were demonstrated by studying electrochemical reactions of ferricyanide and divalent copper. The replacement of ring electrode by minidisk electrode results in following advantages. First, the fabrication of RMDDE is easier than that of RRDE with the same electrode material. Second, there is more freedom in choosing electrode materials and sizes, since it is difficult to make thin ring electrodes of RRDE with fragile materials. Third, the replacement of ring electrode by minidisk electrode saves electrode materials, especially rare materials. Finally, the substitution of minidisk electrode for ring electrode allows using multiple minidisks for simultaneous monitoring of multiple components. Therefore, RMDDE is a promising generator-collector system, especially when special generator-collector systems are not commercially available, such as corrosion study and electrocatalysis study of new electrode materials.

PEG-supported dipyridyl ligand for palladium-catalyzed Suzuki and Suzuki-type reactions in PEG and aqueous media

An air- and water-stable PEG-supported bidentate nitrogen ligand is prepared and its applications in the palladium-catalyzed Suzuki reaction of aryl halides with arylboronic acids in PEG and Suzuki-type reaction of aryl halides with sodium tetraphenylborate in aqueous media are reported. The homogeneous catalyst system is environmentally friendly and offers the advantages of high activity, reusability and easy separation.

Calculation of the thermal expansion coefficient for Bi2Sr2CaCu2O8

An estimation method of thermal expansion coefficient in term of lattice energy which was developed earlier for simple materials is extended to a complex material of Bi2Sr2CaCu2O8 (Bi-2212). The calculation of the chemical bond property and thermal expansion coefficient of Bi-2212 has been carried out and the theoretical values were in good agreement with the corresponding experimental results. The dependence of the thermal expansion coefficient on the different structures and on the flexible oxidation states of Bi and Cu are investigated. The results indicate that the thermal expansion coefficients of Bi-2212 are insensitive to the low lattice distortion of the average structure and the changes of formal valences of Bi and Cu ions.

Chemical bond properties and Mossbauer spectroscopy in REBa2Cu3O7 (RE = Eu, Y)

By using the chemical bond theory of complex crystals, the chemical bond properties of REBa2Cu3O7 (RE = Eu, Y) were calculated. The calculated covalencies for Cu(1)-O and Cu(2)-O bond in REBa2Cu3O7 compounds are 0.41 and 0.28 respectively. Mossbauer isomer shifts of Fe-57 doped, and Sn-119 doped in REBa2Cu3O7-x were calculated by using the chemical environmental factor, h(e), defined by covalency and electronic polarizability. Four valence state tin ion and iron ion sites were identified in Fe-57 and Sn-119 doped REBa2Cu3O7-x superconductors.

Organic phase enzyme electrodes based on organohydrogel

A dimethylformamide-polyhydroxyl cellulose organo-hydrogel has been prepared, and its applications for enzyme immobilization in construction of organic phase biosensors have been exploited. With horseradish peroxidase, tyrosinase, and bilirubin oxidase immobilized in the organohydrogel, enzyme electrodes can be operated in various situations, including aqueous buffer, oil/water mixtures, and anhydrous organic solvents, and even in dimethylformamide, to determine analytes of different solubilities, e.g., organic peroxides, phenolic compounds and bilirubin. Biosensing has no restrictions in terms of measuring media and solubilities of analytes.