用SPring-8同步辐射研究流体水银的结构变化和金属-非金属转变

随着从液态到气态的连续体积膨胀，在临界点附近，典型的液态金属水银经历了金属-非金属（M-NM）。在Spring-8的BL04B1高温高压实验站，利用同步辐射白光，采用能量色散X射线衍射（EDXD）方法，我们研究了流体水银从液体到稠密气态的宽广密度范围中的结构变化。实验方面，我们成功地开发出一个新的高压容器，它具有7个出射窗口用于收集散射X射线，测量的温度和压力上限分别是1700℃和2000bar，适合于在高温和高压下对流体物质进行能量色散X射线衍射测量。结果表明，流体水银的结构因子S(k)的精确性和可靠性有了很大的提高，并获得了流体水银的配位数和配位距离与密度变化之间的准确关系。我们发现，除了存在由配位数减少所导致的非均匀膨胀阶段之外，在水银的金属-非金属转变时还存在一新的均匀膨胀现象，即配位距离随密度减少呈线性增长阶段。基于这些新的结果，我们提出了流体水银的膨胀模型，并讨论了流体水银的金属-非金属转变与结构的关系。     

Dyeing Properties of Reactive Cationic Dyes Containing a Vinyl-sulphonvl Group on Acrylic Fibre Blends

The preparation of reactive azo cationic dyes containing a vinylsulphonyl group derived from 2-aminobenzothiazole and its derivatives is described. Their dyeing properties on blends of acrylic–cellulosic, polyester–cellulosic fibre and on cotton and synthetic fibres are investigated. The relationship between absorption spectra and pH of dye solution is assessed.     

Performance of the Helical Screw Rheometer for Fluid Food Suspensions

The Helical Screw Rheometer (HSR) consists of a helical screw enclosed in a tight fitting cylinder. When the screw is rotated with the system closed it generates a linearly increasing pressure differential along the axis of the screw. The pressure is proportional to the viscosity of a Newtonian fluid. Viscosity of standard Newtonian fluids measured using the HSR correlated well with measurements on a rotational rheometer with cone and plate fixtures. HSR data on non-Newtonian suspensions analyzed with a power law model (σ= mγ^a) did not agree as well with results from cone and plate fiiures on the rotational rheometer.     

Economic Analysis of Hybrid Battery Energy Storage Systems Applied to Frequency Control in Power System

The battery energy storage system (BESS) is prospective energy storage in the smart grid, and the hybrid energy storage system (HESS), using two different kinds of battery, is also being studied to achieve better performance and the lower cost than the single‐battery‐type BESS. However, the cost issue has not yet been evaluated explicitly. On the other hand, BESS has been studied and offers promise for ancillary service, although HESS has not been applied to frequency control in power systems. This paper focuses on the application of HESS to frequency control and its economic analysis. In this paper, the important battery characteristics in the application to a power system are introduced and two kinds of HESS are evaluated in terms of their cost when applied to frequency control. In addition, the cost HESS is used for peak shift as well as frequency control is analyzed.     

A self-organizing time-optimal controller†

A kind of self-organizing controller is proposed, which can accomplish time-optimal control of the unknown plant through adaptation. The self-organizing controller consists of the controller which has a variable switching surface and the adaptation logic net which observes the state of the controlled plant and the control signal yielded by the controller. It can improve the parameters of the controller according to the adaptation algorithm. The proposed method required neither information on the plant dynamics nor its identification. Adaptation is carried out on line. Computer simulation shows the effectiveness of the method.     

Heuristics free group method of data handling algorithm of generating optimal partial polynomials with application to air pollution prediction†

In this paper a revised GMDH (Group Method of Data Handling) algorithm is developed in which heuristicsare not required such as dividing the available date. into training data and checking data, predetermining the structure of the partial polynomials, or predetermining the number of intermediate variables. In this algorithm the prediction error criterion, such as PSS (Prediction Sum of Squares) or AIC (Akaike's Information Criterion) evaluated from all the available data, in used as a criterion for generating optimal partial polynomials, for selecting intermediate variables and for stopping the multilayered iterative computation. This heuristics freeGMDH algorithm is applied to non-linear modelling for short-term prediction of air pollution concentration. By using the time series data of SO₂, concentration, the wind velocity and the wind direction in Tokushima; Japan, a suitable model for predicting SO₂concentration at a few hours in advance is developed. The predicted results obtained by the revised GMDH model are compared with the results obtained by a linear regression model, a linear autoregressive model and a. basic GMDH model.     

二甲醚氧化反应及其添加剂效应

采用加速量热仪（ARC）测定了二甲醚（DME）氧化反应温度变化和活化能（Ea）,考察了添加剂对DME热稳定性效应,分析热分解产物,探讨氧化反应机理. 结果表明,DME热氧化反应初始温度（To）为120 ℃,反应活化能Ea=167.3 kJ•mol-1.氧的存在是导致DME热稳定性下降重要因素,在氧化反应体系中添加Fe、Fe2O3、Al等时, To和Ea值减小,它们有促进氧化反应作用,特别是有过氧化物存在下,由于自由基的引发,显著降低DME热反应初始温度和反应活化能,抗氧剂能提高热稳定性.     

RAPID MESOCARP CELL ELONGATION ENHANCES GUMMING SYNDROME IN JAPANESE APRICOT (PRUNUS MUME SIEB. ET ZUCC.) FRUIT

ABSTRACT

Japanese apricot (Prunus mume Sieb. et Zucc.) ‘Benisashi’ fruit tends to show the physiological disorder of a gumming syndrome, while the fruit known as ‘Nanko’ rarely show this. The accumulated gum becomes a solid gel during the processing period and the commercial value of the mume pickle is consequently decreased. In the present experiment, gum accumulation in the mesocarp tissue and the cell size of the tissue during fruit growth were observed in the two cultivars. In mid‐May, the initiation of the gum duct was observed in vascular bundles in the mesocarp tissue of the two cultivars and plant gum was then observed to accumulate in the duct. No difference in these phenomena was observed between the cultivars until late May. Thereafter, ‘Benisashi’ developed a gum lump visible to the naked eye during Stage III, while the gum lump of ‘Nanko’ did not develop to the visible size as shown in ‘Benisashi’; the lumps could not be confirmed with the naked eye until the mature stage. ‘Benisashi’ showed more rapid fruit growth compared with ‘Nanko’ during Stage III due to explosive mesocarp cell elongation close to the endocarp. Moreover, the rate of gumming fruit of ‘Benisashi’ was higher in bigger fruits than smaller ones. These results indicate that the peculiar cell growth of ‘Benisashi’ fruit may accelerate gum lump formation.

PRACTICAL APPLICATIONS

Gumming syndrome affects the quality of mume pickle. In this experiment, we investigated the mechanisms of gum accumulation in fruit flesh. ‘Benisashi’, which frequently shows the gumming syndrome, presented rapid inner mesocarp cell growth on fruits developing Stage III. This peculiar cell growth may accelerate gum lump formation. Therefore, we have to prevent the cultivational misconduct that induces rapid fruit growth in this period to suppress the gumming syndrome and to increase the commercial value of mume pickle. Moreover, this knowledge is also important in order to breed the new cultivars which do not contain the gumming syndrome.

     

State feedback stabilization of cascaded nonlinear systems with discontinuous connection

In practical engineering, many phenomena are described as a discontinuous function of a state variable, and the discontinuity is usually the main reason for the degradation of the control performance. For example, in the set-point control problem of mechanical systems, the static friction （described by a sgn function of velocity of the contacting faces） causes undesired positioning error. In this paper, we will investigate the stabilization problem for a class of nonlinear systems that consist of two subsystems with cascaded connection. We will show the basic idea with a special case first, and then the result will be extended to more general cases. Some interesting numerical examples will be given to demonstrate the effectiveness of the proposed design approach.     

流体硒的同步辐射结构研究

液体硒是典型的半导体，在高温高压下临界点邻近发生半导体金属—绝缘体（SC—M—I）转变。为了研究高温高压下流体硒在SC—M—I转变过程中结构的变化，利用SPring—8的同步辐射光对高温高压下流体硒进行了能量色散X射线衍射测量和小角X射线散射测量。测量范围包括液态区、超临界区和稠密气态区域。在衍射实验中，我们获得了精确的结构因子S(k)和偶分布函数g(r)。结果证实了在金属液体区域中流体硒仍保持两配位的链结构和共价键轻微地收缩，还发现随着流体硒的金属特性的增强g(r)的第一极小值发生了显著的增加，即Se链的链问相互作用增强。小角散射结果表明在临界密度邻近，密度的涨落显著，相干长度存在极大值。这些结果表明Se链的共价键的特性和Se链问的相互作用是理解流体硒中的SC—M—I转变的机制的关键。