CBS玻璃/堇青石陶瓷复合材料制备与性能

采用电子陶瓷工艺制备了一系列钙硼硅玻璃／堇青石陶瓷复合材料，堇青石含量分别为50％，60％，70％和80％（质量分数）。对复合材料进行了X射线衍射分析、扫描电镜（SEM）观察和性能测试。结果表明：复合材料的介电常数和热膨胀系数随陶瓷含量的增加而减小，显微硬度随陶瓷含量的增加而增加。堇青石的加入抑制了钙硼硅玻璃中石英的析出，并生成了新相钙长石，其数量随堇青石和烧结温度的增加而增加，但它没有恶化复合材料的物理性能。所制得的复合材料具有高的相对密度（≥96％）、低的介电常数（～6）、低的介电损耗（0.3％～0．5％）、低的热膨胀系数（4．2×10^-6℃^-1～5．2×10^-6℃^-1）和低的烧结温度（≤950℃），有望用作介电材料和基板材料。     

ICP-OES法测定硅锰、锰铁合金中磷含量

应用ICP—OES法测定硅锰、锰铁合金中磷的含量,对试样前处理及分析方法的各种参数进行了优化,包括溶样酸的选择,分析谱线的选择,试样基体、分析酸度和干扰元素对测定结果的影响。通过各种分析参数的优化选择实现了硅锰、锰铁中磷的测定,取得了满意的效果。线性相关系数：P=0．9998,检测限为：0．030％。该分析方法准确快速,试剂用量少,线性范围宽,适用于硅锰、锰铁合金中质量分数为0．03～0．50％的磷测定。     

K2O杂质对铝型材厂工业废渣合成的堇青石材料晶相结构的影响

主要探讨K2O杂质对堇青石形成及晶相结构的影响.采用XRD和SEM确定各试样的晶相结构和显微结构.实验结果表明:K2O杂质含量从0.23~1.1wt%,形成的堇青石晶相量较多,其中K2O杂质含量为1.1wt%时,堇青石含量高达90%,当K2O含量继续增加时,形成的堇青石量开始减少,确定试样中K2O杂质最高允许含量为1.1wt%.plus软件分析结果:K2O杂质对堇青石的晶胞结构影响不大,晶胞参数变化很小.     

碘量法快速测定铁矿石中的铜和铁

通过三大强酸分解试样,考虑到在共存离子影响的情况下,提出了用碘量法同时测定铁矿石中的铜和铁的新方法：通过对反应机理的分析,得出最佳的实验条件和分析方法,利用本方法多次对铁矿石中的铜和铁进行测定分析,所得结果的相对偏差均小于4．0％。该方法具有准确,快速,简便,稳定性好等特点,适用于同时测定不同铁矿石矿种中铜和铁的含量。     

Fe0.92Mn0.08Six半导体热电性能的研究

采用快速凝固方法制备了FeSi2基热电材料Fe0.92Mn0.08Six(x=1．9、2．0、2．1、2．3、2．5)粉末，在高真空下采用热压法制备了块状热电材料。x射线衍射分析表明，所有试样热压后均达到了相平衡，而且x=1．9和2．0的试样热压后就完成了β-FeSi2相转变，随着Si含量的增加，β相逐渐减少，α相逐渐增多。热压试样经800℃退火20h后，完全转变为β半导体相。热压退火试样的致密度为93％～98％。研究发现，弥散分布的过量Si较少时，有利于提高β-FeSi2基热电材料的性能。名义成份为Fe0.92Mn0.088Si2.1的试样在高温区的无量纲优值最大，650℃时达到0．18。但是．当Si过量较多时，试样的热导率明显增加．显著降低了试样的优值。     

韩政府禁止进口石棉含量超1％的滑石粉

韩联社报道，韩国环境部决定将石棉含量超过1％的滑石粉指定为禁用物品，防止制造和进口。环境部官员表示，将从尚未办理通关手续的滑石粉开始进行石棉含量检查。一旦被查出石棉含量超过1％，就会被禁止进口。     

研究大豆异黄酮苷元含量的检测方法

目的建立大豆异黄酮苷元含量测定方法。方法采HPLC法,DiamonsilC18柱（250mm×4．6mm,5μm）,流动相：甲醇-0．3％磷酸溶液（体积比48：52）,流速0．7mL／min,测定波长260nm,柱温25℃。结果制备的大豆异黄酮苷元总含量为70．98％;大豆苷元、黄豆黄素和染料木素平均回收率分别为98．7％、98．9％和99．2％,RSD分别为2．1％、1．6％和1．4％。结论所建立的测定方法重现性好、可靠,可用于3种大豆异黄酮苷元的含量测定。     

碘量法测定锌精矿中的砷

试样以硝酸、氯酸钾分解、硫酸冒烟,再以碘量法测定锌精矿中的砷含量。方法准确、简便,加标回收率为98．20％-101．6％,RSD〈2．0％,方法测定范围0．20～3．00％。     

Eu3+、Dy3+和Er3+对制备堇青石晶相转变的对比表征

以菱镁矿风化石、工业Al2O3和SiO2微粉为原料,固相反应烧结合成制备堇青石.通过在反应物中分别加入不同含量的Eu2O3、Dy2O3和Er2O3,研究分析和对比了Eu3+、Dy3+和Er3+对堇青石晶相组成、晶粒大小、晶胞常数、结晶度及显微结构的影响.采用XRD和SEM表征试样中的晶相和显微结构,利用X'Pert Plus 软件对结晶相的晶胞参数和结晶度进行分析,采用半定量法对试样晶相组成进行计算,利用Scherrer公式计算堇青石的晶粒大小.结果表明:由于Eu2O3、Dy2O3和Er2O3的加入,通过固相反应烧结所得堇青石试样中出现了莫来石相,Eu3+、Dy3+和Er3+对Mg2+的置换作用改变了堇青石相晶格常数和晶胞体积.随着添加剂含量的增加,堇青石结构中液相量增加,相对结晶度降低,常温致密度提高,堇青石晶粒粒径减小.综合对比分析,Eu2O3对堇青石晶相转变的影响程度最弱,Er2O3对堇青石晶相转变的影响程度最强,对提高合成堇青石的烧结性和热震稳定性效果最好.     

低温合成堇青石

采用废玻纤和高纯Ａｌ＿２Ｏ＿３、ＳｉＯ＿２、ＭｇＯ，在常压下＜１２００℃、４～８ｈ人工合成高纯堇青石．废玻纤中的几种金属氧化物能参与堇青石的晶体结构，类似于砂化剂，对堇青石的致密化有利，并能有效地扩大烧结范围，降低热膨胀系数．文中讨论了试样的配方组成、合成温度、保温时间和冷却条件等对堇青石的合成量和晶粒大小的影响．     

Investigative studies for the use of an inactive asbestos mine as a disposal site for asbestos wastes

Although, according to European legislation the use of Asbestos Containing Materials is forbidden, many buildings in Greece still contain asbestos products, which must be removed at some point in the near future. Therefore, suitable disposal sites must be found within Greece, so that the unverified disposal of asbestos waste in municipal waste Landfills is brought to an end. In the present work, an innovative approach to the disposal problem of asbestos wastes in Greece has been examined, through a risk assessment analysis of the inactive asbestos mine of Northern Greece and an evaluation of its suitability as a disposal site for asbestos wastes in the future. According to the research carried out, two areas (Site 1 and Site 2) inside the mine area are suitable for the construction of a disposal site for asbestos wastes. The geological investigations showed that in Site 1 and Site 2 ultrabasic rocks of ophiolite complex were prevalent, which have been intensely serpentinized and converted into the fibrous shape of serpentine (asbestos). Concentrations of hazardous substances such as heavy metals in the soil of Site 1 and Site 2 oscillate at low levels, with the exception of the concentrations of nickel and chrome which are high. The investigative work also included the collection of meteorological data and the monitoring of the water level of the artificial lake, which has developed inside the open mine. The main aim is to safely dispose asbestos wastes inside the mine, to minimize any pollution of the wider vicinity of the mine, as well as to engage in restoration activities.     

Microwave thermal inertisation of asbestos containing waste and its recycling in traditional ceramics

Asbestos was widely used as a building material prior to the 1970's. It is well known that asbestos is a health hazard and its progressive elimination is a priority for pollution prevention. Asbestos can be transformed to non-hazardous silicate phases by microwave thermal treatment. The aim of this investigation is to describe the microwave inertization process of asbestos containing waste (ACW) and its recycling in porcelain stoneware tiles, porous single-fired wall tiles and ceramic bricks following industrial manufacture procedure. Inertised asbestos powder was added in the percentages of 1, 3, and 5 wt.% to commercially available compositions and then fired following industrial thermal cycles. Water absorption and linear shrinkage of the obtained industrial products do not present significant variations with additions up to 5 wt.% of microwave inertised ACW.     

An electrical study of chrysotile asbestos

The dielectric constant (K) and dielectric loss (tan ) of preheated chrysotile asbestos up to 900°C were measured in the frequency range 10² to 10⁵ Hz. TheK and tan values were also measured as a function of temperature for hot pressed powdered pellets of chrysotile asbestos. The d.c. conductivity of hot pressed powdered pellets of chrysotile asbestos was also measured as a function of temperature. Dynamic d.c. conductivity was measured in the temperature range 58 to 580° C. The results have been discussed and attempts made to establish a correlation between the structural changes with the variation of dielectric properties.     

Toxicity evaluation for the broad area of the asbestos mine of northern Greece

The existing data regarding the quality of the environment in the asbestos mine of northern Greece (MABE) region related to the presence of asbestos are insufficient to determine the current pollution problem. In the present work, a first approach to this problem has been taken through a toxicity risk assessment. The environmental quality of an open air asbestos mine was evaluated over a long period of time by measuring and monitoring the concentration of asbestos fibres in air, soil and water. Air measurements were made to determine the concentration of asbestos fibres in the atmospheric air of the mine, the depositions and the nearby villages. The asbestos fibre concentration was also specified inside the building facilities of MABE. Analyses of soil, dust and water samples were carried out showing the presence of enormous quantities of chrysotile asbestos. The concentration of asbestos fibres in the atmospheric air was compared to older measurements that were taken at the same sampling points during the operation of the mine. The results of this work, in conjunction with individual researches that have been carried out in the past and with the evaluation of international standards of scientific and experience-based findings, provide a reliable framework with which to estimate the threat of MABE to its surrounding environment, and help to determine a basic criterion for the remediation and rehabilitation of the region. In addition, mathematical models based on human and animal studies were used to estimate the probability of a person developing cancer from breathing air containing asbestos fibres in the wider vicinity of the mine in order to define appropriate procedures for evaluating asbestos-related risk.     

Wear behaviour of organic asbestos based and bronze based powder metal brake linings

Bronze based brake linings, were produced by powder metallurgy technique and their wear behaviour was investigated and compared to that of asbestos ones. Bronze powders were compacted under 350, 500 and 600 MPa pressures and sintered at 810 °C in ammonia atmosphere for 75 min. For the same friction distance, it was determined that temperature increase in the bronze based brake linings was lower than that of asbestos based ones. However, higher wear rate was observed in the bronze based brake linings. Moreover, thermal conductivity was decreased with high porosity level with low densities. Although, friction coefficient remained the same during breaking, an increase in wear resistance was observed.     

Asbestos real-time monitor in an atmospheric environment

The concentration of asbestos fiber aerosols can be monitored by measuring the polarization of laser light scattered by asbestos fibers. The principle of discriminating asbestos fibers is based on the theoretically expected difference in polarization at a scattering angle of 170 deg between cylindrical and spherical airborne particles; polarization at this scattering angle should be positive for cylindrical particles such as asbestos fibers but should be negative or close to zero for spherical mineral particles. We constructed an experimental asbestos real-time monitor that uses a strong electric field to align the airborne particles, that uses lasers having linear polarization with an equal amplitude in parallel and perpendicular components to the aligned long axis of particles, and that simultaneously detects the two components of the linear polarization of light scattered at 170 deg, i.e., close to the backscatter. Experiments that were performed to detect the light scattered from airborne standard asbestos fibers showed that the measured polarization fits theoretical prediction. The concentrations of airborne asbestos fibers obtained by the asbestos real-time monitor were consistent with those estimated by the standard phase contrast microscope method.     

石棉检测方法综述

本文根据《2009年香港国际安全与环境无害化拆船公约》,介绍了石棉的种类、应用、危害及国内外石棉检测方法和标准,综述了用X射线衍射法、偏光显微镜、电子显微镜及红外光谱等多种测试技术,提出了比较适当的石棉检测方法建议。     

电化学CO2去除方法的可行性研究

以Ｐｔ／Ｃ作电极，石棉作电池隔膜，组装成去除ＣＯ２用单电池，试验了各种工作条件对电池性能的影响。实验证明了电化学方法去除空气中ＣＯ２的可行性。     

Studies on Mechanical, Friction, and Wear Characteristics of Kevlar and Glass Fiber-Reinforced Friction Materials

Asbestos possesses properties that are ideally suitable for use as a friction material in automotive and a number of other applications. Animal and human studies carried out since the early 1900s have established that asbestos is carcinogenic and that exposure to especially asbestos dust causes a large number of diseases. Realizing the health hazards posed by asbestos, many countries started phasing out asbestos from all asbestos-containing products since the 1980s. Some of them imposed a total ban in the 1990s on the use of asbestos-containing friction products. This situation forced many manufacturers to look for alternatives to asbestos. But the efforts have only been partly successful. The search is, therefore, still on to find suitable substitutes for asbestos. Though steel wool, Kevlar, glass, and a number of other mineral fibers have been tried out on an experimental basis over the last two decades, glass and Kevlar fibers, in particular, have shown promise as potential substitutes for asbestos. These days, therefore, studies on polymer-based friction materials reinforced with glass, Kevlar, and ceramic fibers are being pursued with much fervor. However, conflicting views are prevailing even today as to the suitability of asbestos-free composites for automotive applications and freedom from the concomitant health risks posed by them. In the present work, therefore, phenolic resin matrix samples reinforced with different amounts of glass and Kevlar fibers were produced and characterized for their mechanical, physical, friction, and wear properties to assess their suitability for light passenger car applications. The study establishes that composites based on glass and Kevlar fibers show good mechanical, physical, friction, and wear characteristics, enhancing thereby their suitability for automotive applications. The property improvements achieved are correlated to the composition, microstructure, and the changes taking place on the surface of the friction composites.