纳米铈-钨发射材料的结构与热发射性能研究

以纳米Ce—W粉末为原料制备了纳米Ce—W发射材料,利用扫描电镜和原位俄歇电子能谱等现代分析技术研究了材料的形貌、铈的分布和高温扩散、以及材料的表面性能,并采用自行研制的微机控制全自动电子发射测量装置测量了材料热发射性能。研究表明,纳米Ce-W材料晶粒细小,稀土元素铈的分布更弥散均匀,铈向表面扩散的能力增强。高温下材料表层形成了含有超额铈的活性层,纳米Ce-W材料的活性层厚度增大,超额铈的含量增多,Ce／O的活性层更厚,因此热发射性能更优异。     

纳米CeO_2/PMMA杂化材料的制备与表征

采用在位分散聚合法制备了纳米CeO2 /PMMA杂化材料.XRD分析表明,杂化材料是无定形的.SEM分析表明,杂化材料中CeO2 含量不同,材料的断面形貌明显不同,随CeO2 含量的增加,杂化材料由韧性断裂向脆性断裂转变.EDS面分析表明,Ce在杂化材料中分布均匀.实验表明,随CeO2 含量的增加,杂化材料的透过率和溶解性降低     

纳米CeO2/PMMA杂化材料的制备与表征

采用在位分散聚合法制备了纳米CeO2/PMMA杂化材料。XRD分析表明，杂化材料 是无定形的。SEM分析表明，杂化材料中CeO2含量不同，材料的断面形貌明显不同 ，随CeO2含量的增加，杂化材料由韧性断裂向脆性断裂转变。EDS面分析表明，Ce 在杂化材料中分布均匀。实验表明，随CeO2含量的增加，杂化材料的透过率与溶解 性降低。     

Measurement of water by oven evaporation using a novel oven design.

Using an automated oven evaporation technique combined with the coulometric Karl Fischer method, the mass fraction of water has been measured in cement, coal, and refined oil samples. The accuracy of this method was established by using SRM 2890, water-saturated 1-octanol that was added to white oil. The samples were analyzed for total reactive Karl Fischer reagent (KFR) material, for interfering materials, and for material that does not react with the aldehyde–ketone KFR. All of the samples yielded volatile material that reacted with the standard KFR. None of the samples contained significant masses of material that reacted with iodine. The cement and coal SRMs contained no material that reacted with methanol and very little material that did not volatilize at 107°C. The refined oils contained some material that was volatile at 107°C and some at 160°C. However, none of this material reacted with the aldehyde–ketone reagent. These results show that the material in the solid samples is water and that the material in the refined oils is a material other than water which reacts with methanol to form water.     

芳砜纶增强的新型摩擦材料研究

研究了芳砜纶纤维增强新型摩擦材料。采用分步干式开松法解决了芳砜纶的散问题，应用正交设计法优化芳砜纶磨擦材料的配方。研究表明该摩擦材料性能优于半金属摩擦材料和石棉摩擦材料。     

Optical analysis of polymer powder materials for Selective Laser Sintering

This study increases the basic understanding of optical material properties of polymer powders used in selective laser sintering (SLS). Therefore, different polymer powder materials were analyzed regarding their optical material properties with an integration spheres measurement setup. By the measurements a direct connection between the absorption behavior of the solid material and the overall optical material characteristics of the same material in powdery form could be shown. The results were used to develop an advanced explanation model for the optical material properties of powders. At present, existing explanation models only consider the occurring of multiple reflections in the gaps between the particles to explain the overall optical material properties of powder materials. Thus, by also considering the absorption behavior of the single particles, the basic understanding of the beam-matter interaction and their effect on the optical material properties of powder materials can be expanded.     

Constitutive model and failure locus of a polypropylene grade used in offshore intake pipes

BorECO^®™ BA212E is a polypropylene block co-polymer which has become a common material in the manufacturing of large diameter non-pressurized gravity offshore intake pipelines. These lines are used for transportation of sea water for cooling of petrochemical process plants. The pipe sections are joined by butt heat fusion welding to create the pipeline. Recently a few premature failures of such pipelines have been reported in the field. Hence, there is a need to characterize the constitutive behavior of the pipe and weld material in order to properly design these pipes. The aim of this work is to determine the material constitutive behaviors of the pipe material and the welded joint material. Uniaxial tensile tests of both the pipe and weld joint material are conducted at various strain rates. Both the pipe and weld material show a rather high strain rate dependency, with the weld material having about half the yield strength than that of the pipe material. An analytical constitutive material model is developed for both the pipe and weld material, incorporating the effect of strain rate. The failure locus, expressed in terms of the equivalent plastic strain at failure vs. the stress triaxiality, for both materials is also determined as part of the constitutive model using notched dumbbell specimens. The constitutive model and failure loci for the pipe and weld material are implemented in a finite element model (FEM) and are validated by conducting a series of independent four-point bend experiments on both material types. The validation is carried out by comparing the FEM results of the four-point bend model with the experimental results, which show a rather good agreement.     

二氧化碳中一氧化氮气体标准物质研制

研制二氧化碳中一氧化氮气体标准物质。以高纯二氧化碳和一氧化氮气体标准物质为原料,采用称量法制备二氧化碳中一氧化氮气体标准物质,用气体分析仪对制备的标准物质浓度进行检测,并对该标准物质定值结果的不确定度进行评定。研制的二氧化碳中一氧化氮气体标准物质中一氧化氮的浓度为5,25,50 μmol/mol,相对扩展不确定度为3.0% (k=2)。该气体标准物质具有良好的均匀性和稳定性,可用于食品级二氧化碳分析方法的确认和评价。     

GM3018脱硫剂在LPG深度脱硫中的开发和应用

M30 1 8脱硫剂是将原料气中的无机硫催化转化为单质硫 ,生成单质硫后沉积在脱硫剂中 ,而有机硫则被催化转化为硫和硫酸根 ,沉积在脱硫剂中。脱硫效果的好坏实际上取决于硫的转化。脱硫剂需定期更换 ,回收处理     

石墨烯材料与模拟生物膜界面相互作用的研究进展

石墨烯材料在生物领域的蓬勃发展使其纳米生物界面研究已成为纳米生物学研究的热点方向。生物膜是石墨烯材料进入生物体系环境中的第一道屏障,深入理解石墨烯材料与磷脂膜间的相互作用,对于石墨烯基生物材料的功能界面优化设计和生物学效应控制具有极为重要的意义。本文对石墨烯材料进行了简要介绍,系统总结了近几年石墨烯材料与模拟生物膜相互作用的研究进展,并对其研究方向进行了展望。     

一种新型物证摄影技术的探索

低温荧光摄影是用摄影方法记录物证在低温状态下被激发出荧光图像的一种技术，同普通荧光摄影一样，它是利用光致发光原理来显现隐性痕迹物证，但又克服了普通荧光摄影中被拍物荧光亮度低、物证细节特征无法再现等缺陷，增加了物证的反差，而且对检材不造成任何损坏，是物证摄影中非常有效的一种技术手段．着重阐述了低温荧光摄影的方法、类型，以及在物证检验中的运用，     

新型生态环境替代材料

环境材料是指与环境相协调或具有环境意识的材料,其特点是对资源和能量消耗少,环境污染小,再生利用率高,同时又具有优异使用性能.用环境负荷小的材料替代环境负荷大的材料是21世纪新型生态环境材料应用开发的重要内容.本文重点介绍替代氟里昂的制冷材料、替代含磷洗涤剂材料、替代建筑用石棉材料以及新型环境相容性材料的研究和应用进展.     

钼酸铋基气敏材料研究进展

气体传感器被广泛应用于检测工业和家庭中有毒有害气体。气体敏感材料是气体传感器中重要的组成部分,敏感材料的性质决定了气体传感器的性能。研制精度高、检测快、集成度高的气体检测器迫在眉睫。钼酸铋作为一种新型双金属氧化物气敏材料,具有高选择性、高敏感度的优势。本文从气敏机理、形貌控制、掺杂和复合材料构建方面对近年来钼酸铋作为气敏材料的研究进行了总结,并对钼酸铋基气敏材料未来的研究方向进行了展望。     

FTIR研究不同固化程度SiO2/酚醛杂化材料官能团的变化

采用FTIR光谱吸收峰的波数位移、A/A1612表示的吸收强度和半峰宽Δ1/2(O—H)/Δ1/2(C C)表示的谱带宽度,比较不同固化程度SiO2/酚醛树脂杂化材料官能团的变化.在相同固化条件下(120℃,2 h),杂化材料的氢键作用比酚醛树脂的强得多,羟基含量更高,而且杂化材料发生邻位取代缩合反应的比例特别高.正是因为杂化材料中未反应的官能团多,作为底漆使用时能与面漆中的官能团反应,实现无层间界面交联,获得层间结合力.过固化过程(160℃,1 h)能够有效降低杂化材料中的羟基含量,但醚键含量比酚醛树脂的高得多,而且过固化过程中酚环主要发生对位取代缩合反应.杂化材料固化后的颜色比热固性酚醛树脂的淡得多,与热塑性酚醛树脂的相当.在相同氧化程度下,杂化材料中无游离酚,比酚醛树脂更环保.     

异辛烷中正十六烷溶液标准物质制备

以正十六烷和异辛烷为原料,采用重量–容量法制备异辛烷中正十六烷溶液标准物质。经过均匀性检验、稳定性考察和量值比较,结果表明该标准物质符合国家二级标准物质的研制要求,标准值为500 ng/μL(Urel=2%,k=2),可作为量值传递的标准,用于气相色谱仪的校准和检定、分析方法评价,以及正十六烷的质量控制等方面。该标准物质已取得国家二级标准物质证书,证书编号为GBW(E)130660。     

Behavior of intumescent epoxy resins in fireproofing applications

The thermal degradation process of a commercial intumescent epoxy resin for fireproofing applications was investigated. The changes in the morphology of the material during exposure to fire-like conditions were interpreted in the light of the degradation of single material components and of the overall swelling mechanism. An apparent kinetic model was developed to describe the thermally activated conversion and the weight loss of the material. The dramatic change in the key properties of the material (thermal conductivity, volume swelling, and apparent density) was investigated and linked with the thermal degradation phenomena governing the swelling process. Models were developed to describe material properties as a function of temperature and material conversion. The models provide the simulation of the fire-triggered degradation of the sample material at the heating rates of interest, allowing a detailed analysis of fireproofing performance.     

Extrusion processing for ammonia fiber explosion (AFEX)

The ammonia fiber explosion (AFEX) process, previously run only in a batch reactor, has been adapted to run on a twin-screw extruder. The sugar yield of AFEX material after enzymatic hydrolysis has been increased up to 3.5 times over that of completely untreated material. The ruminant digestibility of corn fodder has been increased up to 32% (from 54–71%) over completely untreated material, and 23% (from 63–77%) over material extruded with no ammonia. Extrusion-treated material proved more digestible by the ruminant at 48 h than material treated in the batch reactor.     

固体芯材微胶囊制备技术研究进展

文章主要介绍了微胶囊研究背景、用途及制备方法。从固体芯材料水溶性的角度,可把芯材分为亲水性和疏水性两种类型。对于水溶性芯材微胶囊的制备方法,介绍了原位聚合法、油相相分离法、喷雾干燥法和喷雾冷凝法的技术进展;对于疏水性芯材,介绍了界面聚合法、原位聚合法、水相相分离法等方法包覆微胶囊的技术进展。此外,本文还对不同类型的固体芯材所适应的制备方法及壳材料进行了探讨,从试验条件、芯材料的特性及目标产品性能等角度来选取适当的微胶囊壳材及制备方法,以期探索出更经济、实用、高效的固体芯材微胶囊化制备方法。     

有机太阳能电池材料研究新进展

介绍了有机太阳能电池研究的背景、基本原理、分类,并对有机太阳能电池材料进行了全面综述,包括小分子太阳能电池材料、大分子太阳能电池材料、D-A体系材料和有机无机杂化体系材料.     

建立食品安全中有毒(害)物标准物质体系的设想

介绍标准物质的概念,食品标准物质的重要性、种类、现状及其研制过程。提出了我国食品安全中有毒(害)物标准物质研制应从3大范围入手,全方位展开,建立并健全我国食品安全中有毒(害)物标准物质体系的设想。