CARBOXYMETHYLPACHYMAN(Ⅰ),A NEW WATER SOLUBLE POLYSACCHARIDE WITH MARKED ANTITUMOUR ACTIVITY

Carboxymethylpachyman(Ⅰ)was formed by carboxymethylation of β-pachyman.The antitumour activity of carboxymethylpachyman(Ⅰ)against S_(180)、EAC、 MA、U_(14)was measured.The structure of carboxymethylpachyman(Ⅰ)was proved by IR ^(13)CNMR spectroscopy.

A New Simulation of Track Structure of Low-Energy Electrons in Liquid Water:Considering the Condensed-Phase Effect on Electron Elastic Scattering

A new Monte Carlo simulation of the track structure of low-energy electrons （〈10keV） in liquid water is presented. The feature of the simulation is taken into consideration of the condensed-phase effect of liquid water on electron elastic scattering with the use of the Champion model, while the dielectric response formalism incorporating the optical-data model developed by Emfietzoglou et al. is applied for calculating the electron inelastic scattering. The spatial distributions of energy deposition and inelastic scattering events of low-energy electrons with different primary energies in liquid water are calculated and compared with other theoretical evaluations. The present work shows that the condensed-phase effect of liquid water on electron elastic scattering may be of the influence on the fraction of absorbed energy and distribution of inelastic scattering events at lower primary energies, which also indicate potential effects on the DNA damage induced by low-energy electrons.

Fetching the First Bucket of Water In a New Year in Kamba

Tibetans in Kamba (referring to Qamdo and Tibetan areas in Sichuan, Yunnan and Qinghai) have developed many habits and customs unique to themselves. Fetching the First Bucket of Water in a New Year is a case in point.

A New Concept for Regulatory Water Monitoring Via High-Performance Liquid Chromatography Coupled to High-Resolution Mass Spectrometry

A combined approach of target,suspected target and non-target screening using liquid chromatography-high-resolution mass spectrometry(LC-HRMS)was used to develop a new concept for water monitoring.With the current LC-MS/MS target approach for water monitoring,all targets can be quantified,but no additional information about the sample is collected.With the new concept,it is possible to detect 97%of the target compounds with a simplified quantification method without losing accuracy.Furthermore,a suspect target screening can be performed to get broader qualitative information about the water samples.In addition,the non-target screening offers the possibility to identify unknown micropollutants.All three evaluation steps depend on the same analytical measurement so that a lot of measurement and quality assurance effort can be saved.This concept could change water monitoring and assessment,and make it much more efficiently without losing information.There is a chance to measure less but learn more about the water bodies.

A NEW NUMERICAL MODEL FOR THREE DIMENSIONAL SURFACE WATER FLOWS

A three dimensional numerical model based on the Reynolds equations is presented that can be used to predict the surface water flow in open channels.The model uses a computational mesh that conforms to the free water sur- face and the bottom of the channel so that the accuracy of boundary condition application,code complexity,and e- conomy could be enhanced.The k-ε turbulence model is used to estimate the eddy viscosity coefficient.Instead of using the“rigid-lid”approximation a 2-D equation derived from integrating the continuity equation over the total depth is adopted to determine the elevation of the free water surface.A new algorithm is presented based on the conventional SIMPLE procedure.The block correction technique is employed to enhance rate of convergence. The model presented is applied to a bottom discharge into a rectangular straight channel for three dimensional phenomena to obtain the free water surface configuration,velocities and pressure.The computed results are in good agreement with the previous experimental values.