二癸基次膦酸的合成与萃取性能

以混合癸烯为原料,采用自由基加成法合成二癸基次膦酸(DDPA),并研究自由基引发剂的种类、反应温度和反应时间对DDPA产率的影响,获得DDPA的最佳合成条件;通过碱洗和离心分离等手段除去产物中的单烷基次膦酸和烯烃聚合物等杂质,得到较纯的DDPA,并用核磁、质谱等方法对产物进行表征。研究产物在硫酸介质中对二价钴、镍、铜、镁、锌及锰等多种离子的萃取性能,并着重研究钴镍分离性能。结果表明:用10%DDPA(溶剂为环己烷)作萃取剂,经过二级萃取,二级洗涤,钴镍分离系数可达1.20×105。     

Influence of Rare Earth Elements on Luminescent Properties of Y_2SiO_5∶Tb

Various types of multicomponent oxide phosphorshave been widely studied for the applications in dis-play techniques , such as high definition television(HDTV) ,projection television (PTV) and flat paneldisplays (FPD) .Since the beginning of the 1990s ,anewtype of flat panel display device ,field emissiondisplay (FED) has been developed .In this device ,the phosphors are excited bythe cathode rays withlowvoltage ( <5 kV) and high current density . Due tothese excitation conditions ,the ge…     

不同条件下乌桕类可可脂结晶行为之研究

液化后的CTCBE如果在室温下自然缓慢冷却凝固则导致容器以横向力炸裂，而以冷冻方式使之快速冷却固化，则容器完好无损，CB则不会出现类似情况。为了解这一现象与CTCBE结晶行为的关系，拟用X粉末衍射和差示扫描量热法对乌桕类可可脂和天然可可脂在不同条件下的结晶行为进行了研究。结果表明过 冷度和诱导晶核对乌桕类可可脂和天然可可脂的结晶行为有不同的影响。对乌桕类可可脂而言，过冷度对有诱导晶核存在的结晶行为无明显影响，相反对无诱导晶核的结晶行为则有较大影响。天然可可脂则不然，过冷度的变化对有或没有诱导晶核存在的结晶行为均有很大影响；如果过冷度相同，则有或没有诱导晶核存在的结晶行为无太大差异。     

Structure and Electrorheological Performance of Nanosized Y2O3-Doped TiO2 Particle Materials

The nanosized particle materials of doped-TiO2 with Y2O3 were prepared by means of sol-gel technique for use in electrorheological (ER) fluids, and their crystal structures were measured by X-ray diffraction (XRD) analysis. To compare with the pure TiO2, a distinct enhancement in the shear stress under dc electric field was found by using such materials. This can be explained by the increase of the dielectric loss and dielectric constant at low frequency. The effects of the crystal structure of the particles on the dielectric property and ER performance of materials were investigated.     

直流电弧等离子体法合成金属和陶瓷纳米颗粒

介绍了直流电弧等离子体法制备纳米颗粒的原理和条件以及由此法制备的纳米颗粒的种类、结构和性能. 用直流电弧等离子体法能够合成金属、氧化物、氮化物、碳化物及氢化物等多类纳米颗粒. 合成的颗粒大小因合成条件和成份而变化，一般在10~200 nm. 这种方法的合成速度比传统的真空蒸发法快10倍以上，适合工业化生产.     

有机磷萃取剂的合成研究进展

有机磷萃取剂广泛应用于湿法冶金、原子能工业和环境科学等领域,在金属萃取方面占有重要地位。介绍和评述了国内外已商品化的有机磷萃取剂的合成工艺,展望了有机磷萃取剂的发展趋势,并指出了未来有机磷萃取剂的设计和合成方向。     

几种巧克力调温过程中的结晶特性研究

本文用X-衍射法（XRD）和差示扫描量热法（DSC）对香菇巧克力（LC）,茶叶巧克力（TC）和对照样巧克力（CC）在调温工艺过程中的结晶特性进行了研究,发现3种巧克力在调温过程中的结晶行为各有其特性,这些特性在X-衍射（XRD）谱图中和热差法（DSC）熔解曲线上得到明显反映,LC和CC有相似的变化趋势,3种巧克力在浇模时所形成的晶相之熔点各不相同,LC为29.62℃,TC为21.93℃。CC为26.05℃,促霜试验表明：香菇和茶叶均有较好的延霜效果,其中香菇效果优于茶叶。     

Photoluminescence of Cerium(Ⅲ)in Lanthanum Strontium Halophosphates

La_(1.5)Sr_(7.0)Na_(1.5)(PO_4)_6X′X″(X′and X″stand for two identical or different halide ions F~-,Cl~-,and Br~-)is anew kind matrix of phosphors.X-ray analysis shows that these crystals belong to the apatite structure ofhexagonal system with a space group of p6_(3/m).Their lattice parameters have been obtained.Subsolidus phaserelationship in the double halophosphate systems were determined by lattice parameter method.It has beenproved that in the Br-Cl and F-Cl systems there exist complete and continuous solid solutions.In the F-Br sys-tem there appears a two phase region with the bromide composition 0.75     

Luminescence enhancement of BaMgSiO4：Eu^2＋ by adding borate as flux

The luminescence of EU^2＋ in BaMgSiO4 with BaB2O4 as flux was studied. The emission spectrum of the phosphor consisted of two bands, peaking at about 398 nm and 515 nm, which were attributed to the emissions from different Eu^2＋ sites in the lattice. When the BaB2O4 flux was applied, the intensity of the 398 nm emission was not clearly affected, but the intensity of the 515 nm emission was enhanced by about ten times. Gaussian fitting showed that the emission band at around 515 nm could actually be resolved into two bands with peak wavelengths of 499 nm and 521 nm, respectively. The assignments of the emission bands to the cation sites were carried out according to the values of bond valence. The overlapping of the 398 nm emission band on the excitation band of 515 nm emission implied that energy transfer could occur from the luminescent center related to the 398 nm emission to the center related to the 515 nm emission, and the energy transfer process remarkably enhanced the intensity of the 515 nm emission band. The phosphor had strong excitation at around 350-400 nm and emitted a bright green luminescence. Thus it could have applications as a green component in solid-state lighting devices assembled by near-UV Light Emitting Diodes （LED） combined with tricolor phosphors.