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微生物降解及自团聚作用对鄱阳湖流域瑶湖水中不同粒径胶体荧光物质变化的影响
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作者 黄娴 聂明华 +3 位作者 丁明军 晏彩霞 刘慧慧 吕泽兰 《湖泊科学》 EI CAS CSCD 北大核心 2020年第6期1695-1706,共12页
了解城市内湖水中胶体的环境行为对研究湖泊水环境中污染物的迁移转化意义重大.微生物降解及自团聚过程是湖泊水体中胶体转化的重要途径,然而目前有关不同粒径胶体在微生物降解及自团聚作用下荧光特性变化的报道还非常少.基于此,本文选... 了解城市内湖水中胶体的环境行为对研究湖泊水环境中污染物的迁移转化意义重大.微生物降解及自团聚过程是湖泊水体中胶体转化的重要途径,然而目前有关不同粒径胶体在微生物降解及自团聚作用下荧光特性变化的报道还非常少.基于此,本文选取南昌市内最大的湖泊(瑶湖)及其支流水体,通过切向超滤技术、三维荧光光谱法及平行因子分析法(PARAFAC),分析了在灭菌及微生物存在下两种水样含不同粒径胶体的水体(即W原水、W 1μm、W 0.45μm和W 1 kDa)中荧光特性的变化情况.通过PARAFAC模型共解析出3个类腐殖质组分(C1~C3)和1个类蛋白质组分(C4).初始时刻所有水样均以类腐殖质组分含量更高,且大都集中在1 kDa^0.45μm粒径胶体中.两种水样荧光物质的减少为微生物降解及自团聚作用共同主导,自团聚作用约占50%.相较于小粒径(W 1 kDa)胶体,微生物降解对大(W原水)、中(W 1μm)粒径胶体中荧光物质减少的影响更大.此外,类蛋白物质主要以微生物降解占主导,并出现类蛋白物质从大粒径向小粒径胶体转移的现象;而类腐殖物质的降解以自团聚作用为主,并出现类腐殖物质由小粒径向大粒径胶体的转移. 展开更多
关键词 微生物降解 自团聚 胶体 荧光特性 粒径 瑶湖
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热解法制备氧化铁纳米晶及其表征 被引量:1
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作者 李东平 车成彬 赵春山 《哈尔滨理工大学学报》 CAS 2003年第5期3-5,共3页
利用柠檬酸盐热解法制备了单相(纯态γ相)的Fe2O3纳米晶,平均晶粒度13.4nm,应用DTA,XRD,BET,SEM,磁滞回线及磁性分析等表征手段,研究了氧化铁晶体结构及相转变温度,n级粒子比表面积及粒子尺寸、表面状况、粉末的磁化强度、剩磁、矫顽力... 利用柠檬酸盐热解法制备了单相(纯态γ相)的Fe2O3纳米晶,平均晶粒度13.4nm,应用DTA,XRD,BET,SEM,磁滞回线及磁性分析等表征手段,研究了氧化铁晶体结构及相转变温度,n级粒子比表面积及粒子尺寸、表面状况、粉末的磁化强度、剩磁、矫顽力,发现了该超细粉表现出超顺磁效应和较强的自团聚现象,并对其可能的机理做了初步探讨. 展开更多
关键词 热解法 氧化铁纳米晶 柠檬酸盐 超顺磁效应 自团聚现象 晶体结构 剩磁 矫顽力 相转变温度
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Self-magnetization of pyrite and its application in flotation 被引量:2
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作者 Xi-qing WU Xin XIE Yang-fan CAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第12期3238-3244,共7页
Pyrite is a special weakly magnetic mineral containing Fe(II). Its self-magnetization only by adjusting slurry temperatureand pH value was able to enhance its magnetism, producing the so-called the magnetized pyrite, ... Pyrite is a special weakly magnetic mineral containing Fe(II). Its self-magnetization only by adjusting slurry temperatureand pH value was able to enhance its magnetism, producing the so-called the magnetized pyrite, which was further used as magneticseeds in the flotation of pyrite ore to promote flotation recovery. Tests, such as self-magnetization, vibrating sample magnetometer(VSM), XPS, size analysis and flotation were carried out. The optimal conditions of the pyrite self-magnetization were pulp pH of11.81 and temperature of 65 °C. The magnetized pyrite was characteristic of the valence change of elemental iron, resulting instronger magnetism of the magnetized pyrite than that of the original pyrite. Then, this magnetized pyrite was applied to the magneticseeding flotation (MSF) of pyrite ore. It was found that the recovery of pyrite flotation grew with the increase of magneticsusceptibility of the magnetic seeds?the magnetized pyrite; and the proper dosage of the magnetized pyrite was 100 g/t. The reasonbehind the increased recovery lies in that the magnetized pyrite promoted the magnetic agglomeration between fine pyrite particles;and the fact that the stronger the magnetism of the magnetized pyrite, the larger the aggregate size, indicates that the agglomeration issomewhat in line with the flotation, also confirming that the MSF is more suitable for fine particles than traditional flotation. 展开更多
关键词 PYRITE self-magnetization magnetized pyrite magnetic agglomeration magnetic seeding flotation
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A Method for Directly Counting and Quantitatively Comparing Aggregated Structures during Cluster Formation
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作者 Xi Yang Zhong-yuan Lu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2021年第2期137-148,I0001,共13页
Assembling of a few particles into a cluster commonly occurs in many systems.However,it is still challenging to precisely control particle assembling,due to the various amorphous structures induced by thermal fluctuat... Assembling of a few particles into a cluster commonly occurs in many systems.However,it is still challenging to precisely control particle assembling,due to the various amorphous structures induced by thermal fluctuations during cluster formation.Although these structures may have very different degrees of aggregation,a quantitative method is lacking to describe them,and how these structures evolve remains unclear.Therefore a significant step towards precise control of particle self-assembly is to describe and analyze various aggregation structures during cluster formation quantitatively.In this work,we are motivated to propose a method to directly count and quantitatively compare different aggregated structures.We also present several case studies to evaluate how the aggregated structures during cluster formation are affected by external controlling factors,e.g.,different interaction ranges,interaction strengths,or anisotropy of attraction. 展开更多
关键词 SELF-ASSEMBLY Cluster formation Aggregated structures Quantitative analysis
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