A Study on Optical Emission of CF4＋CH4 Plasma and Deposition Mechanisms of a-C ： F, H Films

Fluorinated amorphous carbon (a-C : F, H) films were deposited by inductively coupled plasma using CH4 and CF4 gases. Actinometrical optical emission spectroscopy (AOES) was used to determine the relative concentrations of various radicals, CF, CF2 CH, C2, H and F, in the plasma as a function of gas flow ratio R, R=[CH4]/([CH4] [CF4]). The structural evolution of the films were characterized by Fourier transform infrared transmission (FTIR) spectroscopy. The relationship between the film deposition and the precursor radicals in the plasma was discussed. It was shown that CH radical, as well as CF, CF2, C2 radicals are of the precursors, contributing to a-C : F, H film growth.     

核分析技术在环境和医学研究中的应用

通过对汽车尾气颗粒物、同一污染源的不同粒径飞灰样品的分析,以及稀土元素对人和动物的毒性研究,获得了环境监测和方面的特定信息,展现了核分析技术在环境和医学中的广泛应用。     

棒束通道内定位格架搅混特性PIV可视化研究

定位格架作为燃料组件中重要的组成部件之一,不仅在结构上固定燃料棒,而且在燃料组件内热工水力性能同样显著,特别是对工质的搅混性能直接关系到反应堆的经济性和安全性,因此有必要对燃料组件内定位格架搅混特性进行研究。本文通过粒子图像测速（PIV）技术开展了棒束通道内定位格架上下游流场的可视化研究,对比了有无格架棒束通道内流场的分布特征,定量分析了定位格架对棒束通道流场搅混的贡献。对不同流速下定位格架下游横纵速度的沿程变化特性进行研究,发现了不同流速作用下定位格架对横向、轴向速度的促进和抑制规律。另外,通过速度均方根对下游的湍流特性进行了评估。实验结果可为数值计算提供全场的数据验证,并可为定位格架设计和优化提供基础。     

3-三甲基硅苄胍的合成及其125I标记

以3-溴甲苯为起始物，通过5步反应合成可用于放射性碘（砹）标记的3-三甲基硅苄胍，并用核磁共振（NMR）、质谱（MS）、高效液相（HPLC）等对产物进行了表征。以此化合物为前体，对其进行了¹²⁵I标记。¹²⁵I MIBG的标记率达66.7%，放化纯度＞98%。标记物在室温下放置3d后，放化纯度无明显变化，表明¹²⁵I MIBG具有较高的体外稳定性。     

基于网络数据统计的食品欺诈研究分析

目的 建立符合我国国情的食品欺诈数据库, 补充国际上已建立的经济利益驱动型掺假(economically motivated adulteration, EMA)数据库空白。方法 搜集2001~2019年发生的食品欺诈行为, 初步建立具有中国国情的食品欺诈数据库。对数据库中信息完备的454条欺诈数据进行分析。结果 媒体报道数据占食品欺诈信息总数的71.6%; 食用农产品、酒类、乳制品、肉制品等11类产品是欺诈事件发生较多的食品类别; 产品欺诈(72.2%)高居食品欺诈类型的首位; 2001~2019年食品欺诈事件数量呈现出先上升后降低, 再上升再降低的“M”状趋势; 目前食品欺诈检测技术主要以理化分析技术为主, 针对的食品类别还有限; 食品欺诈信息以中国为主(89.0%), 涉及到世界各个地区。结论 食品欺诈是广泛存在的全球性问题, 本研究建立的食品欺诈数据库为预防食品安全风险起到了重要的技术支撑作用。     

Ten complementary measures to assist with environmental watering programs in the Murray–Darling river system,Australia

Restoration programmes for degraded aquatic ecosystems frequently focus on flow restoration or reinstatement, including recovery targets for volumes of water to be used for environmental benefit. Australia's Murray–Darling Basin is an example of a major system undergoing substantial water reform to balance the needs of competing users, including the environment, within the constraints of an arid climate. This reform revolves around accounting for finite volumes of water that have been shared amongst water users. We argue that while recovering water will provide good outcomes, as a sole intervention, it is not enough to deliver the desired environmental benefits of the reform given the significantly altered state of the catchment. Here, we present 10 measures that could be used to complement planned water recovery actions. These “complementary measures” integrate recovery actions, which when strategically combined with water delivery would significantly enhance water reform efforts to generate environmental outcomes in a highly modified system.