浮选药剂的量子化学研究

介绍了量子化学ＨＭＯ法的基本原理，采用ＱＢＡＳＩＣ语言和数据库技术，设计了实用的ＨＭＯ法量子化学计算程序。用ＨＭＯ法对常用浮选药剂的基团进行了计算，讨论了取代原子和不同分子状态对浮选药剂性能的影响。     

Prediction of the Sensory Quality of Canned Beer as Determined by Oxygen Concentration, Physical Chemistry Contents, and Storage Conditions

ABSTRACT: The objective of this research was to predict any sensory characteristics of canned beer related to its oxygen concentration, composition, temperature, and time intervals of storage. The initial content of oxygen and content of carbon dioxide, pH, color, turbidity, thiobarbituric acid, and bitterness were instrumentally evaluated during 16 wk and 3 storage temperatures. Simultaneously, 8 trained panelists evaluated the degree of oxidation, quality of bitterness, and sensory stability. Principal components regression adjusted models explained the 85% to 86% ( P < 0.01) variability of the sensory characteristics. The results suggest that sensory characteristics of canned beer can be predicted by instrumental measures of its composition and storage conditions.     

PBTCA与铜、锌、镉、镍离子间的配位化学研究

采用电位滴定方法，运用先进的配位常数计算程序，通过恰当配位化学模型的建立，研究了水溶液中2－膦基丁烷－1，2，4－三羧酸（PBTCA）自身的解离以及与Cu^2 、Zn^2 、Cd^2 、Ni^2 离子间的配位化学作用，测定了相应的解离常数和配合物稳定常数，并得到了各配合物物种在不同pH值条件下的形态分布，从溶液配位化学的角度对PBTCA的阻垢作用机理进行了讨论。     

稠油破乳作用机理的量子化学和分子力学研究

 采用半经验量子化学和分子力学方法，全优化计算了稠油中胶质模型化合物(SG)、双层结构胶质模型化合物 (DG)和含磺酸基团的破乳剂分子插入双层胶质形成的超分子模型(DGHB)的结构，探讨了破乳作用机理。结果表明， DG模型化合物分子间存在氢键，其作用能为 22.8416kJ/mol；含磺酸基团的破乳剂插入胶质双层结构后，破坏了胶质分子间的氢键。计算结果预示，含有强亲水基团的磺酸盐和带支链烷基的破乳剂可破坏稠油中胶质分子间的氢键，起到稠油破乳之功效。     

Spectral response and field enhanced reverse current in a-Ge:H nip photodiodes

We demonstrate the effectiveness of using a high Ar+H₂ dilution of GeH₄, high pressure, and low substrate temperatures in producing device-grade a-Ge:H through standard radio-frequency glow discharge deposition. The enhanced plasma chemistry encourages the production, heating, and incorporation of nanoparticles to increase order, while the low substrate temperature encourages hydrogen incorporation to saturate dangling bonds. We utilize the material in nip photodiodes illuminated through the n-side, and demonstrate a device with an i-layer thickness of only 60 nm showing J_SC=20.6 mA/cm² (AM1.5 Efficiency=2.1%). Temperature-dependent conductivity and bias-dependent spectral response measurements suggest that a non-uniform field distribution and a defect-rich region near the i–p interface are currently the limiting factors for the device performance.     

Robust Parameter Estimation in Dynamic Systems

In this paper we present a practical method for robust parameter estimation in dynamic systems. In our study we follow the very successful approach for solving optimization problems in dynamic systems, namely the boundary value problem (BVP) approach. The suggested method combines multiple shooting for parameterizing dynamics, a flexible realization of the BVP principle, with a fast Gauss-Newton algorithm for solving the resulting constrained l ₁ problem. We give an overview of the theoretical background as well as the details of a numerical implementation. We discuss why the Gauss-Newton algorithm, which is known to perform well mainly on well-conditioned problems, is appropriate for parameter estimation problems, while quasi-Newton methods have only limited use for parameter estimation. The method is implemented on the basis of the direct multiple shooting method as implemented in PARFIT, thus inheriting all basic properties of PARFIT such as numerical stability, reliability and efficiency. The new code has been successfully applied to real-life parameter estimation problems in enzyme and chemical kinetics.     

Electroless deposition of Cu on multiwalled carbon nanotubes

Copper has been deposited on the surface of multiwailed carbon nanombes （MWNTs） and inside MWNTs by electroless deposition. The as-prepared Cu-MWNT composite materials have been characterized by X-ray diffractometer （XRD）, transmission electron microscopy （TEM）, and electrochemical measurement. XRD analyses showed that Cu was a face-centered cubic （fcc） structure. The average size of Cu was calculated by Scherrer＇s formula from XRD data, and it was 11 nm. TEM revealed that Cu grains on the surface of MWNTs were uniform with the sizes of about 30-60 nm. The electrochemical measurement indicated that Cu-MWNT composite materials possessed fine electron conductivity.     

扩链反应在高分子材料合成中的应用

扩链反应在高分子材料的合成与改性中日趋引人注目。介绍近年应用于高分子材料合成中各种扩链反应的研究进展 ,着重介绍使用二异氰酸酯类、二恶唑啉类扩链剂在高分子材料合成中的扩链增粘与共混增容作用