ZnO压敏陶瓷最佳掺杂含量的理论计算

从对电子薄膜材料研究中得到的最佳掺杂含量定量理论推广到ZnO陶瓷材料。该理论建立了电子薄膜材料的某一物理性能与晶体结构、制备方法和掺杂剂含量之间的联系，给出了一个能够拟合实验曲线的具有确定物理意义的抛物线方程。该方程的极值点确定了最佳掺杂含量与晶体结构和制备方法之间的定量关系，进而得到了一个掺杂最佳含量的表达式。系统地分析了ZnO压敏陶瓷的掺杂改性的实验结果，应用此表达式定量计算了ZnO压敏陶瓷的最佳掺杂含量，定量计算的结果与实验数据相符合。该理论也适用于其他薄膜材料最佳掺杂含量的理论计算。     

ZnS掺杂技术研究及应用现状

对现阶段国内外在ZnS及ZnS基材料掺杂改性方面的研究成果作一概述性介绍，综述了纳米级ZnS发光材料掺杂改性的基本机理，主要的掺杂技术、方法，并对多种掺杂元素的效果进行了分析比较。     

溶胶—凝胶法制备基于荧光猝灭原理的光纤氧传感器在线监测水中溶解氧

利用氧分子对金属钌化合物的荧光具有猝灭作用的特性,构造出基于荧光猝灭原理的光纤氧传感器。就用于水中溶解氧在线监测的光纤光谱仪的搭建、传感器探头的设制及传感膜的制作过程进行探索,并对传感器的响应性能进行考察。结果表明以联吡啶钌等作为荧光指示剂以溶胶-凝胶法制备的传感膜对溶解氧的响应具有良好的可逆性,稳定性,较快的响应时间和较长的使用寿命。与标准法相对照,用本仪器系统测定了不同盐度的人工海水中的溶解氧浓度,两种方法在不同浓度水平下的溶解氧测定值均无显著性差异。本法的日内和日间RSD在1.7％～5.0％之间。     

Oxidation of porous nanocrystalline titanium nitride. II. Scale structure and composition

We have used x-ray phase analysis to study the composition of the products of reaction between oxygen and nanocrystalline powders with particle sizes 15, 40, 55, and 80 nm, and also specimens pressed (and sintered) from them. The powders were oxidized in air at 100°C (400 h) to 500°C (5 min), while the sintered specimens were oxidized at 600–900°C for 15, 120, and 240 min. In all cases, in the initial oxidation step the oxynitride Ti(O_xN_y) is formed, which over time is oxidized to TiO, Ti₂O₃, Ti₃O₅, TiO₂ (anatase) and TiO₂ (rutile). In the range 600–800°C, formation of a continuous oxide layer and conversion of anatase to rutile slows down diffusion of oxygen in the scale. We have established that at 900°C, the growth rate of the scale thickness increases and so the reflections from the oxynitride are barely noticeable on the diffraction patterns taken from the surface of the oxidized specimen. In these diffraction patterns, along with strong reflections from the rutile, we also observed weak reflections from lower oxides and anatase, which may be due to reaction between oxygen and the titanium ions diffused to the scale surface. We have concluded that at T > 850°C, the mechanism for oxidation of TiN changes. This is due to superposition of counterdiffusion of titanium ions on the diffusion of oxygen. __________ Translated from Poroshkovaya Metallurgiya, Nos. 3–4(448), pp. 72–78, March–April, 2006.     

Phosphorus Inputs to Lake Simcoe from 1990 to 2003: Declines in Tributary Loads and Observations on Lake Water Quality

Total phosphorus (TP) inputs to Lake Simcoe have led to hypolimnetic dissolved oxygen (DO) depletion and loss of cold water fish habitat. Since 1990, efforts have been made to reduce the total TP input to the lake below a defined target of 75 t/year, which was predicted to lead to reductions in spring TP concentration and improvements in end-of-summer hypolimnetic DO concentrations. The total TP load to the lake during the most recent period of record (1998/99-2003/04) ranged from 53 to 76 t/yr and averaged 67 t/yr, compared to an average of 114 t/yr estimated between 1990/91 and 1997/98 (range 85-157 t/yr). Reductions in TP loads from the catchment via tributary discharge (∼26 t) accounted for the majority of the decrease in total load between the two time periods. Total P concentrations decreased significantly in four out of six long-term monitored tributaries; however, concentrations in all six tributaries remain above the level recommended to avoid nuisance plant growth (30 μg/L). Although TP loads to the lake are currently below the target 75 t/yr, excessive growths of filamentous algae and macrophytes continue to be a problem in the nearshore zone. End-of-summer minimum hypolimnetic DO concentrations (average 4.3 mg/L, 1998/99-2003/04) remain substantially below the level (7 mg/L) that is considered protective of lake trout. Efforts to reduce TP loads to the lake therefore need to continue.     

An on-line microcomputer-based respiratory monitor for manual materials handling

The main objective of the present study is to develop a low cost microcomputer-based respiratory system that is capable of computing the oxygen consumption and minute ventilation of individuals engaged in manual materials handling on an on-line basis. The design, specifications, and merits of the system are given. The software package developed was written in assembly language for the IBM AT personal computer.     

Electrical and optical properties of fluorine-doped CdO films deposited by ultrasonic spray pyrolysis

The CdO:F samples have been deposited onto microscope glass substrates at 250 °C by ultrasonic spray pyrolysis method. With the incorporation of fluorine into CdO, the direct optical transition has shifted towards the shorter wavelengths, and the transparency of the material has increased at a given wavelength above the fundamental absorption edge. The shift in the absorption edge is explained by means of the Moss–Burstein effect, which is also supported with the results of the current–voltage characteristics. Here, a correlation has been established between the band broadening and the increase in conductivity due to the increase in carrier density.     

Internal-corrosion inhibitors for pipelines in heat-supply systems carrying water with a high oxygen content

The reliability of heat-supply systems is determined primarily by internal corrosion of the pipelines. The concentration of oxygen in the water exerts a major influence on the corrosion. In systems with a standard oxygen content, OéDF-Zn is a highly effective corrosion inhibitor. However, there are systems in which the quality of deaeration of the make-up water of the heat-supply system is low (or deaeration is nonexistent), and the concentration of oxygen is considerably above the standard value. Classed among these systems, for example, are the HWS systems, which are incorporated into closed heat-supply systems. The oxygen concentration in these systems is analyzed to assess the situation. __________ Translated from élektricheskie Stantsii, No. 6, June 2007, pp. 35–39.     

水浴法加温液氧泵

1　故障现象一次 ,我们用KL -1 5型制氧制氮车开机制氮 ,给一只容积为 40升、最高工作压力为1 4 7MPa的气瓶灌充氮气 ,当气瓶充气压力升高到一定值时不再上升。反复开泵 ,压力基本不变。液氧泵停止时 ,出口压力无明显下降。经分析判断导致气瓶压力升高到一定值时不再上升的原因是由于液氧泵被冻结所致。2　排除方法首先关闭液氧泵。拧开制冷机氢气放气阀 ,使压力下降到 1 0MPa。开大放气阀 ,使二级压力保持在 0 3 5MPa左右。调整正流空气调节阀 ,调节好中部温度。关闭液氮进液氧泵阀和气氮出液氧泵阀。戴棉布手套 ,拆开液氮进口接头、…     

不同粒度松散煤体的氧扩散特性实验研究

以自行研制的煤对氧扩散特性测试装置为实验手段,在常温环境条件下测试了不同粒度松散煤体对氧的自由扩散特性.实验结果表明:煤样粒度的变化对取气腔氧浓度流出曲线的影响表现出2个极限值,煤样粒度在20～100目之间时,取气腔氧气浓度梯度随煤样粒度的增大而增大;当煤样粒度<20目或>100目时,煤样粒度的再变化对氧浓度流出曲线的影响则微乎其微;取气腔氧浓度曲线流形基本符合指数曲线的变化规律.