超临界二氧化碳微乳液法制备纳米微粒材料进展

简述了超临界二氧化碳-微乳液法制备纳米微粒材料的基本机理、制备工艺及影响因素,介绍了目前取得的一些研究成果,讨论了未来需要解决的问题。     

超临界CO_2微乳液法制备纳米氧化锆

采用超临界CO2微乳液法制备了纳米ZrO2颗粒,利用XRD、TEM、BET、TG-DSC、激光粒度分析等方法对所得的样品进行表征。结果表明:经超临界CO2微乳液过程可制得非晶相ZrO2前躯体,前躯体经550℃煅烧后转变为四方相ZrO2,900℃煅烧后转变为单斜相ZrO2,ZrO2颗粒分布均匀,粒径为40 nm左右。     

微乳液法制备纳米铜粉及其在润滑油中的应用研究

研究了以微乳液法制备纳米铜粉。以CuSO4·5H2 O、NaHBO4、PVP、AES等为主要原料 ,制得粒度可控、经透射电镜检测粒径在 30～ 5 0nm、经X衍射分析为单质铜的铜粉。该铜粉和其他润滑油添加剂进行复配后添加在 5 0 0SN基础油中 ,可以大大提高润滑油的抗磨减摩性能、氧化安定性 ,以 3%的比例加入到润滑油中 ,可以节省燃油达 1 8 71 %。     

微乳液法制备纳米球形SiO2的正交实验研究

在W/O微乳液体系下,采用TritonX-100作非离子表面活性剂,正丁醇作助表面活性剂、环己烷作油相,正硅酸乙酯为硅源、氨水为催化剂制备了纳米球形SiO2粒子。通过正交试验,采用L9（33）正交表,并运用正交设计的极差分析、方差分析确定各主要原料对制备球形纳米SiO2的影响,找出了对粒径影响显著的因素。实验结果表明：水和表面活性剂摩尔比对粒径影响最显著,并随之增大而增大;正硅酸乙酯浓度、氨水浓度增大,SiO2粒径也随之增大,但影响不显著。实验制取的SiO2粒子粒径在40-120 nm,单分散性好,粒度窄,球形率高。     

W/O微乳液法制备表面修饰纳米氟化镧润滑油添加剂

采用聚异丁烯丁二酰亚胺T152/S-80复合表面活性剂(w(Span80)∶w(Tween20)=2∶3(质量比))/异丁醇/500SN基础油/氟化铵水溶液W/O微乳液体系构建微反应器,通过原位表面修饰制备了含纳米LaF3粒子的液体润滑油添加剂,同时,采用洗涤法制备了干粉纳米LaF3。采用X-射线衍射仪(XRD)和透射电镜(TEM)分析了纳米LaF3粒子的结构和形貌。分别将液体添加剂和干粉加入基础油中,采用离心沉降法考察了不同后续分离方法得到的纳米粒子在基础油中的分散稳定性,用四球机考察了它们的摩擦学性能,最后采用扫描电子显微镜(SEM)观察了磨斑表面形貌。结果表明:所构建的微反应器制备的颗粒状纳米LaF3平均粒径在10~15 nm之间;纳米粒子在基础油中的分散稳定性对其摩擦学性能影响很大,液体添加剂中的纳米粒子在基础油中的分散稳定性和摩擦学性能大大高于干粉粒子;液体添加剂中的表面活性剂不仅有利于纳米粒子在基础油中的稳定分散而且有减摩作用。     

微乳液一步法制备Fe3O4 磁流体及其性能研究

对油包水(W／O)型微乳液的制备进行了研究,探明了一定条件下W／O型微乳液中的最大增溶水量,进而利用此W／O型微乳液作为“微乳反应器”,采用一步法合成了Fe3O4磁流体。应用古埃磁天平对所制备磁流体的磁性进行研究,并分析了制备条件对磁流体磁性的影响及磁流体良好的抗电解质浸扰能力。     

影响微乳液萃取分离稀土元素的因素

文章以镧、钆和镥为例 ,对微乳液萃取稀土元素进行研究 ,考察硫酸铵浓度和偶氮胂 浓度对萃取相行为及萃取率的影响。     

原位制备CaCO3微纳米流体及摩擦学性能研究

选用菜籽油、失水山梨糖醇脂肪酸酯(Span 80)、壬基酚聚氧乙烯醚(TX-7)、正丁醇制备W/O型微乳液，并将其作为微反应器原位合成CaCO₃微纳米粒子。对CaCO₃粒子形貌的表征表明，随含水量增加，CaCO₃粒子由球形转变为梭形薄片状，CaCO₃粒子尺寸也可受含水量控制。通过四球摩擦磨损试验机评价CaCO₃微纳米流体的摩擦学性能，结果表明，该微乳液体系相较于基础油的摩擦因数降低了约55.74%,CaCO₃粒子使微乳液P_B值提高了约10.88%,摩擦面粗糙度降低了约16.01%。在摩擦过程中，胶团在表面活性剂的作用下平行吸附于摩擦面且易于剪切，实现优异的减摩效果；梭形薄片状的CaCO₃微纳米粒子可以抑制表面微凸体之间的直接接触，减少黏着磨损与磨粒磨损，从而发挥极压作用并显著改善表面质量。     

微乳液增敏分光光度法测铜的研究

研究了以溴化十六烷基三甲基铵 /正丁醇 /正庚烷 /水组成的微乳液为介质 ,水杨基荧光酮为显色剂 ,Cu(Ⅱ )的光度测定体系。其表观摩尔吸光系数ε =1 .1 4× 1 0 5 L .mol 1.cm 1与CTMAB胶束体系相比较 (ε=9.3× 1 0 4L .mol 1.cm 1)灵敏度提高 2 2 %。方法用于锌白铜和水样分析 ,结果令人满意。     

雾滴微反应器法制备纳米氧化铝粉体

以硫酸铝铵和碳酸氢铵为原料,用新技术--雾滴微反应器法制备了纳米氧化铝粉体,并与用传统沉淀法制备的纳米氧化铝粉体进行比较,用SEM和TEM等方法对制备的前驱体和最终粉体进行表征,用XRD法对最终粉体进行物相分析.结果表明:雾滴微反应器法制备的纳米氧化铝粉体比传统沉淀法制备粉体的颗粒尺寸较小,粒径分布窄,分散性好,比表面积达到138.1cm2·g-1;前驱体在1 150℃煅烧20 min可完全转化为α-Al2O3.     

计算机辅助红外解谱的研究

本文主要讨论利用计算机方法进行红外谱图的初步解析的原理,介绍了两种解谱方法:一是对红外谱进行数据库检索,另一种是模拟红外光谱专家的解谱思路,以流程图问答的方式,最终给出初步的解析结果。本文着重介绍后者的实现方法。     

对二乙氨基苯甲醛二苯甲酮偶氮宁的合成与光谱分析

本文报道对二乙胺基苯甲醛二苯甲酮偶氮宁合成步骤及其红外光谱、紫外光谱,在此基础上顺利完成该化合物的结构确定。并分析红外光谱、紫外光谱各主要谱带及归属。     

采用计算化学方法解析苯和甲苯红外谱图

本研究应用量子计算化学软件Gaussian 03W HF方法中的3-21G基组优化苯和甲苯分子结构,预测苯和甲苯分子的红外光谱。找到苯环振动吸收峰分别是苯红外图中的1658 cm~(-1)与甲苯红外图中的1667 cm~(-1)。与苯和甲苯文献检索红外谱图相对应(特征吸收峰分别是1478和1485 cm~(-1)),符合较好。还找到苯环C-H拉伸振动吸收峰3080cm~(-1)(苯)和3040 cm~(-1)(甲苯)。能够实用于红外法检测环境中苯和甲苯。     

The role of Poisson's binomial distribution in the analysis of TEM images

Frank's observation that a TEM bright-field image acquired under non-stationary conditions can be modeled by the time integral of the standard TEM image model [J. Frank, Nachweis von objektbewegungen im lichtoptis- chen diffraktogramm von elektronenmikroskopischen auf- nahmen, Optik 30 (2) (1969) 171–180.] is re-derived here using counting statistics based on Poisson's binomial distribution. The approach yields a statistical image model that is suitable for image analysis and simulation.     

超光谱成像仪光谱温度漂移计算分析

为了为超光谱成像仪光谱温度漂移修正提供依据和指导其光机结构设计,介绍了光谱成像的基本原理,研究了温度变化对超光谱成像仪光机结构尺寸稳定性的影响,通过面型拟合,将MSCNastran的分析结果代入Zemax光学设计软件,计算了光谱漂移量。在＋30℃均匀温升栽荷下,光谱在x方向漂移量为-31μm,小于2pixel（CCD像元为18μm）,y方向漂移量为-29μm,小于2pixel。计算结果表明各波长光线光谱为整体漂移,光谱温度漂移对光谱分辨力和线色散率无影响,光谱漂移随温度呈线性变化。     

Fast thickness prediction and blank design in sheet metal forming based on an enhanced inverse analysis method

In sheet metal forming process, inverse analysis codes serve a useful purpose at the early product design stage when an approximate analysis is required to determine if the initial concept part can be made and where the failures and defects will occur. In this paper, a robust energy-based 3D mesh mapping algorithm is used to obtain the initial solution and is followed by a reverse deformation method to improve its accuracy. The novel initial solution scheme can consider the material and the process parameters, and thus lead to fewer Newton–Raphson iterations. The actions of the punch, die, blank holder and the drawbead are fully considered. A fast and reliable boundary condition treatment method is implemented to workpiece without binder and addendum information. Contact treatment between punch and die is an essential issue which greatly affects the convergence of Newton–Raphson iterations. A reliable contact treatment based on topological relations of workpiece is proposed to define the force direction between die and punch. Equivalent drawbead forces are also considered with a simplified model. With the improved aspects, the in-house inverse analysis code InverStamp is developed. Application to a square box and a clover-shaped cup are presented with demonstrations of the validity of the code and the efficiency of the proposed modified approaches.     

机械转子动静碰摩故障的EMD分解Hilbert包络谱分析

为避免碰摩故障对旋转机械的影响,针对转子系统局部碰摩的特征,提出一种基于EMD分解Hilbert包络谱分析方法。该珐利用EMD方法分解含有碰摩故障的振动信号,提取出的IMF分量有明显的调幅特征,再对其中突出的IMF分量进行Hilbert包络谱分析提取出故障特征频率。与倒谱分析相比,得到的碰摩故障信息更加精确;与小波分析相比,能更容易提取出真实的故障特征。     

Atomic force microscope (AFM) combined with the ultramicrotome: a novel device for the serial section tomography and AFM/TEM complementary structural analysis of biological and polymer samples

A new device (NTEGRA Tomo) that is based on the integration of the scanning probe microscope (SPM) (NT‐MDT NTEGRA SPM) and the Ultramicrotome (Leica UC6NT) is presented. This integration enables the direct monitoring of a block face surface immediately following each sectioning cycle of ultramicrotome sectioning procedure. Consequently, this device can be applied for a serial section tomography of the wide range of biological and polymer materials. The automation of the sectioning/scanning cycle allows one to acquire up to 10 consecutive sectioned layer images per hour. It also permits to build a 3‐D nanotomography image reconstructed from several tens of layer images within one measurement session. The thickness of the layers can be varied from 20 to 2000 nm, and can be controlled directly by its interference colour in water. Additionally, the NTEGRA Tomo with its nanometer resolution is a valid instrument narrowing and highlighting an area of special interest within volume of the sample. For embedded biological objects the ultimate resolution of SPM mostly depends on the quality of macromolecular preservation of the biomaterial during sample preparation procedure. For most polymer materials it is comparable to transmission electron microscopy (TEM). The NTEGRA Tomo can routinely collect complementary AFM and TEM images. The block face of biological or polymer sample is investigated by AFM, whereas the last ultrathin section is analyzed with TEM after a staining procedure. Using the combination of both of these ultrastructural methods for the analysis of the same particular organelle or polymer constituent leads to a breakthrough in AFM/TEM image interpretation. Finally, new complementary aspects of the object's ultrastructure can be revealed.     

扩频通信系统中混沌序列和 PN 序列的对比分析

本文介绍了在扩频通信系统中应用的两种序列：由线性移位寄存器(LFSR)产生的 PN 序列,如 m序列和 Gold 序列;另一种是由确定的非线性系统产生的混沌序列。通过仿真分析了 PN 序列和混沌序列各自的特性,并由此得出不同的序列在扩频通信系统中的优缺点,从而利用序列的优点来改善扩频通信系统中的信号传输。     

Combining FIB milling and conventional Argon ion milling techniques to prepare high‐quality site‐specific TEM samples for quantitative EELS analysis of oxygen in molten iron

This paper reports a procedure to combine the focused ion beam micro‐sampling method with conventional Ar‐milling to prepare high‐quality site‐specific transmission electron microscopy cross‐section samples. The advantage is to enable chemical and structural evaluations of oxygen dissolved in a molten iron sample to be made after quenching and recovery from high‐pressure experiments in a laser‐heated diamond anvil cell. The evaluations were performed by using electron energy‐loss spectroscopy and high‐resolution transmission electron microscopy. The high signal to noise ratios of electron energy‐loss spectroscopy core‐loss spectra from the transmission electron microscopy thin foil, re‐thinned down to 40 nm in thickness by conventional Argon ion milling, provided us with oxygen quantitative analyses of the quenched molten iron phase. In addition, we could obtain lattice‐fringe images using high‐resolution transmission electron microscopy. The electron energy‐loss spectroscopy analysis of oxygen in Fe_0.94O has been carried out with a relative accuracy of 2%, using an analytical procedure proposed for foils thinner than 80 nm. Oxygen K‐edge energy‐loss near‐edge structure also allows us to identify the specific phase that results from quenching and its electronic structure by the technique of fingerprinting of the spectrum with reference spectra in the Fe‐O system.