氧化钛烧结体的氧含量测定

用电子探针X射线微分析(EPMA)方法测定了一系列氧化钛烧结体中的氧含量,并用X射线衍射(XRD)分析对其相态作了研究,所得的结果指出根据产品的氧含量与其某些物理特性之间的内在联系,即可从其表现的某些物理性质估计某一烧结产品的氧化物含量,而所得结果对下一步的镀膜工作具有指导意义.     

火焰原子吸收光谱法测定氧化铝中微量氧化铬

氧化铝是陶瓷制品中的重要原料 ,其中氧化铬对陶瓷的电性和美观都有较大的影响 ,测定其含量很有必要。由于材料中氧化铝占 98%以上 ,而铬的含量小于 0 .1 % ,处理成溶液后 ,铝离子与铬离子浓度比超过 1× 1 0 3倍以上 ,且分离较困难 ,为了较好地消除铝对试验结果的影响 ,采用标准曲线中加入铝离子作为基体。由于大量铝离子的存在 ,对铬的吸光度影响较大 ,又因铬含量较低 ,用作标准曲线的标准溶液浓度不宜太高 ,否则测量误差很大。据文献[1 ]介绍 ,加高氯酸铵或低碳链脂肪酸能增感铬的吸收信号。通过试验 ,当溶液中大量铝存在时 ,直接加入这…     

环氧乙烷环氧丙烷共聚醚的研究进展

综述了环氧乙烷环氧丙烷共聚醚的聚合机理聚合工艺及其应用.环氧乙烷环氧丙烷共聚醚的聚合按其催化剂体系的机理可以分为阴离子聚合、阳离子聚合和配位聚合三类,其中阳离子聚合应用较少.在环氧乙烷和环氧丙烷开环聚合生成共聚醚的反应中,不同的反应工艺条件对生成的聚醚有着很大的影响.同样比例的环氧乙烷和环氧丙烷,因聚合反应器设计、反应器种类、起使剂种类催化剂种类与用量温度加料方式端基结构等的不同,所合成的共聚醚会产生不同的结构和性能.环氧乙烷环氧丙烷共聚形成的聚醚可以分为嵌段共聚醚和无规共聚醚两类.其中,嵌段共聚醚可以分为EPE和PEP两类.     

氧化石墨烯水热还原前后的发光光谱

分别采用改进Hummers方法和水热还原法制备了氧化石墨烯(GO)和还原氧化石墨烯(RGO)。 GO和RGO经透射电子显微镜(TEM)、紫外-可见吸收光谱(UV-Vis)、红外光谱(IR)、荧光发射和激发光谱(PL、PLE)等技术手段进行了表征。 荧光发射光谱显示,氧化石墨烯(GO)在可见光的激发下可以得到波长在600~800 nm范围内的宽谱近红外荧光。 通过比较氧化石墨烯水热还原前后的光谱变化,发现氧化石墨烯近红外荧光起源于氧化石墨烯的表面含氧基团,如C=O、COOH。 近红外荧光穿透性好、对生物组织损坏小,非常适合于生物成像,预示着氧化石墨烯在生物成像方面的应用潜力。     

环氧乙烷环氧丙烷开环聚合反应动力学研究

环氧乙烷和环氧丙烷由于具有较高的环张力,因而容易发生开环聚合。本文综述了环氧乙烷合环氧丙烷开环聚合反应的动力学研究进展,考察了环氧乙烷和环氧丙烷开环聚合反应的机理,分别讨论了各类催化剂体系中环氧乙烷和环氧丙烷开环聚合的动力学常数、两者的竞聚率及开环聚合产物的分子量分布,并指出了开环聚合反应动力学研究对于环氧乙烷和环氧丙烷的开环聚合研究及工业应用的重要性。     

ZnO及其含锌混合氧化物薄膜的充放电性能研究

从充放电性能、晶体结构等方面考察了包括粉末状的ZnO、脉冲激光沉积方法制备的ZnO薄膜和含锌混合氧化物薄膜的电化学性质.结果表明,ZnO粉末制备的电极的嵌入容量随退火温度的升高而增大,掺入其他氧化物可以明显改善ZnO薄膜的电化学性能,在Ar气氛中,基片温度为400℃时,沉积的靶子成分为Zn:B:P:Al=1:1:0.5:0.5(摩尔比)的含锌混合氧化物薄膜具有较高的可逆容量,且循环性能良好.     

Nitrogen Oxide Fluorides

Oxyfluorides of nitrogen, i.e. compounds containing the grouping F? N? O, have been known for many years in the form of simple compounds, such as NOF and NO₂F. Detailed studies of physical, structural, and chemical aspects of this class of compounds have been conducted only in recent years, after the potential of N? F compounds as rocket propellants had been recognized. Several novel types of oxyfluorides of nitrogen, such as difluorohydroxyl amines, RO? NF₂, or trifluoroamine oxide, F₃NO, have been discovered recently. A further major development in O? N? F chemistry is indicated by the discovery that compounds of great chemical potential are formed between HF and NOF or NO₂F, respectively. The compound O₂NOF, although not an oxyfluoride of nitrogen, will also be discussed in this review, because of its particular chemical relationship to NO₂F.     

Oxide hemostatic activity

The tunable in vitro blood clotting activity of high-surface-area hemostatic bioactive glass is evaluated by Thromboelastograph, a clinical instrument for quantifying changes in blood during coagulation. The hemostatic trends associated with hemostatic bioactive glass and a new preparation of spherical hemostatic bioactive glass, along with similar Si- and Ca-containing oxides, are described and related to Si:Ca ratios, Ca2+ availability and coordination environment, porosity, DeltaHHydration, and surface area. Hemostatic bioactive glass is a new material with an excellent efficacy for inducing hemostasis and is chemically distinct from the traditional bioglass employed for bone growth.     

氧化环己烯连续进料下二氧化碳-环氧丙烷-氧化环己烯三元共聚物的合成

由于氧化环己烯（CHO）与二氧化碳的共聚反应速度比其与环氧丙烷（PO）快,这种竞聚率的差异导致一锅法所得的二氧化碳-环氧丙烷-氧化环己烯三元共聚物的组成难以稳定控制。 为此本文在稀土三元催化剂下,采用氧化环己烯单体连续进料的方法合成了二氧化碳-环氧丙烷-氧化环己烯三元共聚物,催化效率可达575 g/(mol Zn h)。 三元共聚物的玻璃化转变温度随CHO含量升高而增大,当CHO的摩尔投料比从0.19增加到0.59时,玻璃化温度从44.3 ℃提高到70.1 ℃。 CHO连续进料合成的三元共聚物的组成与投料比基本相近,且连续进料法所合成的三元共聚物只有一个玻璃化转变温度,而普通的一锅法所得的三元共聚物通常存在两个玻璃化转变温度,因此连续进料法是制备组成稳定的二氧化碳-环氧丙烷-氧化环己烯三元共聚物的有效方法。     

Cationic Copolymerization of Epichlorohydrin with Styrene Oxide and with Cyclohexene Oxide

Cationic copolymerizations of epichlorohydrin (ECH) (chloro-methyl oxirane) with styrene oxide (SO) (phenyl oxirane) and with 1,2-cyclohexene oxide (CO) (7-oxabicyclo [410] heptane) were carried out at 50°C by employing the salt triphenylmethyl hexachloro-antimonate (HC) (Ph₃CSbCl₆) as initiator. NMR spectra before and after attempted extractions of the polymeric products indicated that the resulting polymeric products were true copolymers and not mixtures of the respective homopolymers. Monomer reactivity ratios for both pairs of comonomers were determined; for one pair the values were r ₁(ECH) = 3.29, r ₂(CO) = 0.16 and for the second pair r ₁(ECH) = 0.57, r ₂(SO) = 0.16.     

萃取色谱分离-原子发射光谱测定超高纯氧化铥、氧化镱和氧化镥中痕量稀土杂质

用２－乙基己基膦酸单２－乙基己酯萃取色谱分离－原子发射光谱测定超高纯Ｔｍ２Ｏ３、Ｙｂ２Ｏ３、Ｌｕ２Ｏ３中痕量稀土杂质，可用于纯度为９９．９９９９％～９９．９９９９９％（不含非稀土杂质）Ｔｍ２Ｏ３、Ｙｂ２Ｏ３、Ｌｕ２Ｏ３的纯度分析，１４个稀土杂质的回收率在６７％～１３３％之间；相对标准偏差 ５．１％～２３．２％；分离周期 １０～１３ ｈ。     

Highly Ordered Zinc Oxide Nanotubules Synthesized within the Anodic Aluminum Oxide Template

Zinc oxide (ZnO) is a wide-band-gap semiconductor, which has a broad range of applications, e.g., in pigment, rubber additives, gas sensors, varistors and transducers1. It has recently been demonstrated that nanophase zinc oxide can be used in photocells of the Gatzel type2, which results in improved current generation efficiency. The properties of high aspect ratios and small sizes of zinc oxide nanotubules or nanowires are expected to improve the luminescence efficiency of the electro-optical devices and the sensitivity of the chemical sensors3.     

硫铁矿烧渣制备氧化铁黄和氧化铁红

对利用硫铁矿烧渣制备氧化铁黄和氧化铁红进行了研究。考察了影响硫铁矿烧渣还原、酸溶、中和、氧化等过程的各种因素。结果表明,在适宜的条件下,利用烧渣可以制备出用做颜料的氧化铁黄和氧化铁红。     

游离氧化钙,氧化镁连续测定的电导法研究

研究了乙二醇对氧化钙，氧化镁的提取条件，利用乙二醇提取氧化钙后在催化剂存在下继续提取氧化镁，建立了电导法连续测定ＣａＯ，ＭｇＯ分析方法，可用于水泥熟料中游离氧化钙，氧化镁的测定。     

Liquid-Repellent Metal Oxide Photocatalysts

Metal oxide photocatalysts (MOPCs) decompose organic molecules under illumination. However, the application of MOPCs in industry and research is currently limited by their intrinsic hydrophilicity because MOPCs can be wetted by most liquids. To achieve liquid repellency, the surface needs to possess a low surface energy, but most organic molecules with low surface energy are degraded by photocatalytic activity. Herein, current methods to achieve liquid repellency on MOPCs, while preventing degradation of hydrophobic coatings, are reviewed. Classically, composite materials containing MOPCs and hydrophobic organic compounds possess good liquid repellency. However, composites normally form irregular coatings and are hard to prepare on surfaces such as those that are mesoporous or nanostructured. In addition, the adhesion of composites to substrates is often weak, resulting in delamination. Recent studies have shown that the direct grafting reaction of polydimethylsiloxane (PDMS) from silicone oil (methyl-terminated PDMS) under illumination results in a stable polymer brush. This easy and simple grafting method allows us to create stable liquid-repellent surfaces on MOPCs of various types, structures, and sizes. In particular, super-liquid-repellent drops with an underlying air layer can be created on PDMS-grafted nano-/microstructured MOPCs. Potential applications of surfaces combining liquid repellency and photocatalytic activity are also discussed; thus offering new ways of using MOPCs in a wider range of applications.