容量法测定铜镍锰钎料合金中镍元素

本文采用丁二酮肟—EDTA容量法测定铜镍锰钎料合金中镍元素含量,该方法适用于测定元素镍含量为20％～50％,其RSD为0.06％,加入回收率为99.88％～100.08％,试验表明:方法的精密度与准确度令人满意,可满足铜镍锰钎料合金中镍元素分析的要求.     

酚醛树脂及其涂料——用于封闭的滑动元素及其制备工艺：EP1433766[欧洲专利申请，英]／日本：Eagle Industry Co．,Ltd．（Hosoe，Takeshi等）．

本发明描述的是一种封闭的陶瓷滑动元素，其主要含有25％～75％碳聚集体和20％～50％热固性合成树脂基料(如酚醛树脂)。该滑动元素在1200℃被烧结。该元素的球形孔直径范围是1～100μm。这些小孔独立分散在元素中。     

电感耦合等离子质谱法测定钛白粉中的砷、铌、锑、铅

采用电感耦合等离子质谱(简称ICP-MS)法测定钛白粉中的砷、铅、铌、锑杂质。讨论了钛基体的谱线干扰,引入内标元素In,有效补偿了墓体元素对待测元素的抑制效应。方法的检出限为0．07～0．15μg／t,加标回收率90％～105％,RSD为1．9％～4．8％。     

硫在中国非农业方面中的应用

自８０年代以来中国元素硫产量保持在３１０～３３０ｋｔ，在整个含硫原料比例中占５．２９％～６．９３％。元素硫的消费领域主要集中于某些产品的生产，包括硫酸、食糖、农药、粘胶纤维、染料、橡胶、特种硫磺、冶金选矿药剂以及其他产品等。中国元素硫的消费预测年平均增长率将达到３％～４％，到２０００年需求量将达到４００～４３０ｋｔ。     

熔融制样-X射线荧光光谱法测定矿石中的锡

通过人工配制和化学分析方法定值作为标准样品,扩大了锡元素标准曲线的测量范围.采用理论a系数和经验系数法校正基体干扰,锡的测定范围0.01％ ～5.00％,相对标准偏差(RSD)为0.850％ ～1.471％.本方法的测定结果与碘酸钾容量法测定结果基本一致,能满足矿石中低品位锡元素的检测.     

水泥窑烟气脱硝催化剂V2O5/TiO2中杂质元素的发射光谱研究

建立了水泥窑烟气脱硝催化剂V2O5/TiO2中杂质元素的分析方法.选择硝酸+氢氟酸为混合消解溶剂,V2O5/TiO2经微波消解后采用电感耦合等离子体发射光谱(ICP-OES)法直接测定其中杂质元素(Na、K、Ca、Mg、As、Zn、Pb).通过对仪器工作参数和待测元素分析谱线的选择,确定了仪器的最优工作条件,详细地研究了基体元素Ti产生的基体效应以及共存元素对待测元素的光谱干扰,利用同步背景扣除技术消除光谱干扰,以In为内标元素并结合基体匹配法消除基体效应.7个元素的检出限为1.72～ 41.60 μg/L,回收率为93.82％ ～ 105.58％,相对标准偏差(RSD)为0.87％～3.43％ (n=11).方法可用于V2O5/TiO2中杂质元素的检测,为水泥窑烟气脱硝催化剂的质量评价提供了新的技术手段.     

褐煤超临界醇解萃余物组成分析

通过工业分析、元素分析、灰成分分析和热值分析对褐煤超临界醇解萃余物进行了研究,结果表明,褐煤醇解萃余物水分含量为6.93％～11.35％,灰分含量高达22.10％～24.46％,挥发分为39.75％～45.53％,无黏结性和结焦性:褐煤醇解萃余物碳含量为66.74％～76.03％,氢含量为4.51％～5.06％,氮含量...     

ICP-OES法测定汽油中的铁锰铅及硅元素

本实验采用ICP-OES法直接稀释进样,以航空煤油作为稀释剂对样品进行稀释,同步测定车用汽油中的Fe、Mn、Pb和Si元素.通过加标回收实验与方法精密度计算,验证了该方法所得数据的可靠性,各元素测定结果的相对标准偏差在0.3％～2.1％(n=11)之间,加标回收率在92.0％～103.0％之间.结果显示,该法高效简便、...     

ICP—AES法测定矿泉水中多种元素

本文研究了ＩＣＰ－ＡＥＳ法测定矿泉水中多元素，相对标准偏差为１．２％～６．２％，回收率９７％～１１０％，结果令人满意。     

ICP—AES法测定不锈钢中铬的精密度研究

进行了电感耦合等离子体发射光谱法（ICP-AES）测定不锈钢中铬元素的精密度研究,运用排除法确定了导致不锈钢中测量铬元素精密度稳定性较差的主要原因是仪器自身的波动。不锈钢中铬元素的激发状态、溶液黏度、酸度以及操作过程对方法精密度的影响不明显。加入内标钪元素后,不锈钢中铬元素测量的相对标准偏差（RSD）由原来的0．60％～1．60％降低到≤0．50％,精密度明显提高。同时,不锈钢中铬元素测定的准确度也得到提高。     

The measurement of toughness of ABS and high-impact polystyrene by the falling dart impact test

Falling Dart Impact, FDI, toughness is used extensively to characterize the response of plastics to potential abuse. A critical study shows FDI toughness is highly variable with only 68 percent of the test pieces of a typical material failing within ±35 percent of the mean break energy, MBE. If no adjustment for this variability is made, the ASTM accepted “up/down” testing procedure leads to erroneous MBE values. A statistical analysis was carried out which defines the confidence which can be placed in measured MBE's as a function of the number of pieces tested. This analysis shows, for example, that 60 pieces must be tested so that a measured 20 percent difference in MBE's will be significant 90 percent of the time; while if 20 pieces are tested, as is suggested by ASTM, a 35 percent difference is needed before the same level of significance is reached.     

集装箱箱底涂料流变性能的研究

为提高厚防腐涂层的流变性能,在涂料中加入不同种类及含量的触变剂,优选出最佳触变剂,即2%改性聚酰胺和1%膨润土,通过不同剪切速率下的涂料粘度的测量,推导出Casson公式。结果表明,触变剂的加入能满足集装箱底涂料对流变性的要求。     

PVA／PS共混改性及对拉伸性能的影响

对不同配比的聚乙烯醇／聚苯乙烯（PVA／PS）共混物进行共混改性研究。使用拉力试验机测试了PVA／PS共混物的拉伸强度,使用扫描电镜（SEM）分析试样的断口,并分析共混物的分散性及相容性。实验结果表明：PVA含量在10％以内对共混物的拉伸强度影响不大,主要表现为PS的拉伸强度;而PVA含量在10％～50％的范围内,扛伸强度明显下降,在50％时达到最小值。     

苏嵯输油管道混合原油凝点计算方法

对呼伦贝尔与塔木察格原油不同混合比例下进行凝点测试实验,并根据已有的混合原油凝点模型进行计算,优选了凝点计算模型。通过分析实验数据,采用曲线拟合和最小二乘法进行模型修正两种方法得出苏嵯输油管道混合原油凝点计算公式,并对修正后模型和拟合出的曲线进行验证。实验数据表明修正后的模型较曲线拟合公式对于计算混合原油凝点结果更精准,可使原油的凝点较已有模型计算值的最小平均绝对偏差减小75%,较最大平均绝对偏差减小99%,较最小标准偏差减小45.77%,较最大标准偏差减小75.26%。     

傅立叶变换红外光谱仪在水中油定量分析中的应用

采用红外光谱法对污水中油含量进行测试,并对傅立叶变换红外光谱仪的应用机理和实际工作中遇到的问题进行了研究分析。通过实验确定了用PE-2000傅立叶变换红外光谱仪测定水中油的最佳实验条件。该方法分析准确度较高,回收率在97%～103%之间。     

A REACTION ENGINEERING MODEL FOR ZEOLITE A SYNTHESIS

Heat transfer and pressure drop data are presented for equilateral-triangular pitch tube bundles containing low-finned tubes with fin counts between 0.4 and 1.06 fins per mm. Two types of finned tubes were tested. The first was a 19-mm O.D. integral finned tube with a 1.65-mm fin height and with 0.75 and 1.06 fins per mm. The second was a 31.75-mm O.D. plain tube wound with 3.18-mm soldered fin stock and containing 0.4, 0.71, and 0.98 fins per mm. A new low-fin heat transfer correlation was developed which predicted these new data and additional data from five other sources within an error range from minus 20 percent to plus 31 percent. A necessary dimensionless group required to obtain this accuracy was the fin diameter/fin spacing ratio. Existing friction factor correlations were not successful in predicting these new pressure drop results. A new low-fin friction factor correlation was developed which predicted these data and additional published data within an error range from minus 19 percent to plus 27 percent.     

Ballistic performance of polycarbonate/polyester and polycarbonate/styrene-acrylonitrile microlayer sheets

Extruded microlayer sheets of Polycarbonate/Polyester (PC/PCTG) and Polycarbonate/Styrene-acrylonitrile (PC/SAN) were tested for ballistic performance. Composition of the microlayer sheets ranged from 60 to 100 percent polycarbonate. The number of layers in the approximately 3 mm thick sheets ranged from on for the blend control samples to 3713 layers in the PC/PCTG sheets. The normalized ballistic test results showed that some samples performed as well as as and slightly better than injection molded polycarbonate samples. The failure mechanism was affected by the composition and the number of layers. Increasing composition of polycarbonate and number of layers decreased the percent of brittle failures.     

Foaming properties of soap solutions

Summary This paper reports results, obtained by the “liquid drainage” method and a modified “foam time” method, on the stability of foams from solutions of soaps and detergents. The two methods gave qualitatively equivalent results. Rates of drainage of liquid from soap and detergent foams were not proportional to the volumes of liquid in the foam. The stabilities of foams from 0.1 percent solutions of soaps of most of the natural fats and oils tested were much greater than those of foams from single soaps that were sufficiently soluble to form solutions of this concentration. The foam time of a mixture of equal volumes of two 0.1 percent solutions was not equal to the average of the foam times of the separate solutions. A number of electrolytes, organic liquids, pectic materials, and vegetable gums greatly increased foam stability. Data on 0.03 percent sodium tallow and palm oil soap solutions indicated a maximum foam time at a pH of about 10.6. Increasing the concentrations of ten soaps from 0.05 to 0.1 percent more than doubled the foam time.     

A correlation for heat of vaporization of pure compounds

Twenty-seven selected equations were tested on 162 compounds with 1958 calorimetric data for their abilities to reflect the temperature influence on the heat of vaporization of pure compounds. A new equation is recommended (overall percent deviation 0.27% and percent deviation 0.59% above 0.9T _r ).     

不同温度条件下HTPB推进剂干燥恢复研究

以在30℃、RH为100%条件下湿老化5 d的丁羟(HTPB)推进剂试样为研究对象,分别进行了在10、30、50℃3种温度下的干燥恢复试验,测试了干燥恢复过程中推进剂试样的失水率和力学性能。综合分析了试验数据,得到了不同温度下干燥时初始阶段推进剂试样的失水率、抗拉强度恢复速率,以及各力学性能参量恢复度90%且伸长率比值1.2的恢复时间。对抗拉强度测试中得到的断面照片进行了对比和分析,将样品30℃干燥恢复1、4、9 d后的单向拉伸曲线绘制在一张图上进行比较寻找规律,在对试验数据和试验现象分析总结的基础上探讨了HTPB推进剂干燥恢复过程中氢键的作用规律。