连续信息基

D.Scott在20世纪60年代引入了domain理论,并给出了两种等价形式——信息系统和邻域系。在型论(typetheory)基础上,G.Sambin提出了形式拓扑(Formal topology)理论,并证明了一元形式拓扑与代数Scott domain等价,从而推出代数信息基的概念,同时作为信息系统与邻域系的推广。本文从信息基的观点出发,提出了连续信息基的概念,证明了它与连续Scott domain的等价性。     

Fast Fourier Continuous Cyclic Voltammetry at Gold Ultramicroelectrode in Flowing Solution for Determination of Ultra Trace Amounts of Penicillin G

In this work, for the first time a fast continuous cyclic voltammetry was used as a highly sensitive detection method for Penicillin G in a flow‐injection system. A special computer‐based numerical calculation method (using Fast Fourier Transformation) is introduced here for enhancing the analyte signal and noise reduction. During the measurements, the potential waveform (consists of potential steps for cleaning, stripping and potential ramp) was continuously applied on an Au disk microelectrode (with a radius 12.5 μm in radius). The stripping time was less than 200 ms. Effects of rest potential, sweep rate, and delay time on the sensitivity of the method were investigated. The limit of detection of the method was 1.0 × 10^?11 M. The detection limit of the method is 660 times lower than the most sensitive reported method. The relative standard deviation of the method at 1.0×10^?7 M of Penicillin G was 2.7% for 10 runs.     

Design of recursive least-squares fixed-lag smoother using covariance information in linear continuous stochastic systems

This paper newly designs the recursive least-squares (RLS) fixed-lag smoother and filter using the covariance information in linear continuous-time stochastic systems. It is assumed that the signal is observed with additive white observation noise and the signal is uncorrelated with the observation noise. The estimators require the covariance information of the signal and the variance of the observation noise. The auto-covariance function of the signal is expressed in the semi-degenerate kernel form.     

On characterizing the bivariate exponential and geometric distributions

In this note, a characterization of the Gumbel's bivariate exponential distribution based on the properities of the conditional moments is discussed. The result forms a sort of bivariate analogue of the characterization of the univariate exponential distribution given by Sahobov and Geshev (1974) (cited in Lau and Rao ((1982), Sankhy Ser. A, 44, 87)). A discrete version of the property provides a similar conclusion relating to a bivariate geometric distribution.     

为2800对母婴上门提供保健服务的体会

主要介绍了深圳市妇幼保健院在国内率先推出的产后家庭保健服务项目,总结了为2 800对母婴上门提供保健服务的临床意义和社会效益.     

A Kinetic Evidence for the Nitroxyl Radicals Recycling Mechanism in the Photostabilizing Process of HALS

The photoinduced bulk polymerization of a reactive-hindered amine fight stabilizers(r-HALS), 4-acryloyl-2, 2, 6, 6-tetramethylpiperidinyl (ATMP), was performed at 80℃ by using a DPC technique. An unique periodic exponential attenuation-type oscillating curve was found when the polymerization was carried out in air, but this phenomenon was not found in nitrogen.It is supposed that this unique kinetic performance may be attributed to nitroxyl radicals that are produced in situ from the oxidation of ATMP. ATMP polymer with narrow polydispersity (d =1.03) can be obtained by photoinduced solution polymerization of ATMP. The signal detected in ESR may be assigned to the nitroxyl radicals in the matrix of ATMP polymer. Since this kind of recycling of nitroxyl radicals is well documented for the photostabilizing mechanism of HALS, the present results may serve as a kinetic evidence for this mechanism.     

The separation of synthetic mixtures of glucose and fructose and also inverted sucrose feedstocks using countercurrent chromatographic techniques

Summary A pilot scale semi-continuous countercurrent chromatographic Refiner (SCCR4) unit packed with a Zerolit 225 resin in the Ca²⁺ form has been used to separate synthetic mixtures of glucose and fructose and also inverted sucrose feedstocks into glucose-rich and fructose-rich products.For the same process conditions less pure fructose-rich products were found when using inverted sucrose feedstocks than with synthetic mixtures of glucose and fructose. However, anion-exchange resins Duolite A113 in the (HSO ₃ ^– ) form did not produce any variation in product purities with change of feed source.     

连续流动注射法测定土壤和植物中全磷

应用AA3型连续流动分析仪测定了土壤和植物中全磷.结果表明:对于采用高氯酸-硫酸消解的土壤样品以及硫酸-过氧化氢消解的植物样品,在测定时调节反应混合液的酸度使其在显色的适宜范围内,磷的质量浓度在6 mg·L-1(土壤)和7.5 mg·L-1(植物)以内呈线性,相关系数分别为0.999 2(土壤)和0.999 6(植物);加标回收率98.5%～100.5%,相对标准偏差小于2%,检出限分别为0.010 mg·L-1(土壤)和0.013 mg·L-1(植物).     

Independent exponential feeding of glycerol and methanol for fed-batch culture of recombinant Hansenula polymorpha DL-1

As a novel feeding strategy for aptomizing human epidermal growth factor (hEGF) production with a recombinant Hansenula polymorpha DL-1 using the methanol oxidase (MOX) promoter in H. polymorpha DL-1, independent exponential feeding of two substrates was used. A simple kinetic model considering the cell growth on two substrates was established and used to calculate the respective feeding rates of glycerol and methanol. In the fedbatch culture with methanol-only feeding, the optimal set point of specific growth rate on methanol was found to be 0.10 h⁻¹. When the fed-batch cultures were conducted by the independent feeding of glycerol and methanol, the actual specific growth rate on glycerol and methanol was slightly lower than the set point of specific growth rate. By the uncoupled feeding of glycerol and methanol the volumetric productivity of hEGF increased from 6.4 to 8.0 mg/(L·h), compared with methanol-only feeding.