放射性废物概述

全世界许多国家都在着手于核废物的管理任务．目前，还不能认为这个极其困难的问题在任何国家中真正得到了解答，然而又必须得出解答．本文中概括地说明了有关核废物各方面的常识     

治理塑料废弃物新技术途径探讨--专论可降解塑料的研究开发

综述了可降解塑料的研究开发现状及其进展。可降解塑料的降解时控性研究，合成，加工工艺改进以及降低成本的研究，可控光－生物降解的合成降解性研究和一次性使用塑料实用性研究，仍是今后需要深入探讨的重要研究课题。     

电化学方法用于氯代芳烃污染物去除的研究

本文介绍了电化学方法用于氯代芳烃污染物去除的原理、反应历程及影响因素,分析了进一步实用化应考虑的主要问题,展望了该方向今后的发展趋势。     

纳米尺寸聚苯乙烯-丙烯酸彩色高分子微球的合成与表征

以苯乙烯、丙烯酸、分散蓝染料为原料,采用分步聚合的方法合成了彩色具有核–壳结构的分散蓝/聚苯乙烯–丙烯酸高分子微球。通过TEM测得其颗粒尺寸约为200nm,分散均匀;通过FTIR对颗粒的组成结构进行表征,并对其合成过程进行探讨。     

Oxidation behaviour of uranium and neptunium in stabilised zirconia

Yttria stabilised zirconia (YSZ) based (Zr,Y,U)O_2−x and (Zr,Y,Np)O_2−x solid solutions with 6 and 20 mol% actinide were prepared with Y/Zr ratios ranging from 0.2 to 2.0 to investigate uranium and neptunium oxidation behaviour depending on the oxygen vacancies in the defect fluorite lattice. Sintering at 1600 °C in Ar/H₂ yields a cubic, fluorite-type structure with U(IV) and Np(IV). Annealing (Zr,Y,U)O_2−x with Y/Zr=0.2 at 800 °C in air results in a tetragonal phase, whereas (Zr,Y,U)O_2−x with higher Y/Zr ratios and (Zr,Y,Np)O_2−x retain the cubic structure. XANES and O/M measurements indicate mixed U(V)-U(VI) and Np(IV)-Np(V) oxidation states after oxidation. Based on X-ray diffraction, O/M and EXAFS measurements, different oxidation mechanisms are identified for U- and Np-doped stabilised zirconia. In contrast to U, excess oxygen vacancies are needed to oxidise Np in (Zr,Y,Np)O_2−x as the oxidation process competes with Zr for oxygen vacancies. As a consequence, U(VI) and Np(V) can only be obtained in stabilised zirconia with Y/Zr=1 but not in YSZ with Y/Zr=0.2.     

高放废物处置库选址中低渗透介质地质研究的几个问题

低渗透介质是阻碍有害物质在地下迁移良好的天然屏障, 因此成为高放废物处置库围岩类型的首选。本文通过对高放废物处置库选址中地质研究的回顾, 阐述了低渗透介质地质研究的特点, 对地质参数测定、取样、水流模拟、地球化学模拟进行了重点介绍。     

激发态Cs2和H2的电子-振转能级的碰撞转移

利用相干反斯托克斯拉曼光谱(CARS)探测技术, 研究了激发态Cs2与H2间的电子-振转能级的碰撞转移。用波长为532 nm和中心波长为716 nm的两束激光同时聚焦到样品池中, 扫描CARS谱确认了H2分子的S支(△v =1, △J=2)仅在v=1, J=4,5及v=2, J=3,4能级上有布居, 用n1、n2、n3、n4分别表示(2,4)、(2,3)、(1,4)及(1,5)上的粒子数密度。从CARS线的峰值得到n2/n1、n3/n1、n4/n1分别为6.34±1.27、3.66±0.73和1.45±0.29。转移能配置到振动、转动和平动的比例分别为0.44、0.06和0.50, 能量主要分配在振动和平动上。在T=523 K和PH2=2.5×103 Pa条件下, 通过求解速率方程组和对时间分辨CARS线轮廓的分析, 得到碰撞转移速率系数k1=(6.0±1.2)×10-14 cm-3s-1和k2=(4.0±0.8)×10-13cm-3 s-1。     

上海浦东新区垃圾堆放场地的适宜性评价

本文概括地介绍了浦东新区垃圾堆放的地质环境特征之后, 运用综合指数法和层次分析法对区内现有30个典型垃圾堆场的地质环境适宜性和综合适宜性分别作了评价。     

On Vaporizing Water Flow in Hot Sub-Vertical Rock Fractures

Water injection into unsaturated fractured rock at above-boiling temperatures gives rise to complex fluid flow and heat transfer processes. Examples include water injection into depleted vapor-dominated geothermal reservoirs, and emplacement of heat-generating nuclear wastes in unsaturated fractured rock. We conceptualize fractures as two-dimensional heterogeneous porous media, and use geostatistical techniques to generate synthetic permeability distributions in the fracture plane. Water flow in hot high-angle fractures is simulated numerically, taking into account the combined action of gravity, capillary, and pressure forces, and conductive heat transfer from the wall rocks which gives rise to strong vaporization. In heterogeneous fractures boiling plumes are found to have dendritic shapes, and to be subject to strong lateral flow effects. Fractures with spatially-averaged homogeneous permeabilities tend to give poor approximations for vaporization behavior and liquid migration patterns. Depending on water flow rates, rock temperature, and fracture permeability, liquid water can migrate considerable distances through fractured rock that is at above-boiling temperatures and be only partially vaporized.     

Mode Specificity,Bond Selectivity,and Product Energy Disposal in X + CH4/CHD3 (X=H,F, O(3P), Cl,and OH) Hydrogen Abstraction Reactions: Perspective from Sudden Vector Projection Model

Reactions between methane and various radicals have become the workhorse in our understanding of mode specificity and bond selectivity in bimolecular reactions. In this work, the recently proposed Sudden Vector Projection (SVP) model is used to gain insight into the existing experimental and theoretical data on these reactions. The SVP model attributes mode specificity and bond selectivity to the coupling of reactant modes/bonds with the reaction coordinate at the transition state. In the sudden limit, the strength of the coupling can be simply computed by projecting the corresponding reactant normal mode vector onto that of the imaginary frequency mode at the saddle point. In addition, the SVP model can be used to predict energy disposal in the products, thanks to microscopic reversibility. It is shown that most of the mode‐specific and bond‐selective chemistry in X + CH₄/CHD₃ (X=H, F, O(³P), Cl, and OH) reactions can be reasonably understood with this simple model.