THE SCANNING NUCLEAR MICROPROBE AT SINR

This paper describes the scanning nuclear microprobe facilities established at the Shanghai Institute of Nuclear Research. The Russion quadruplet constructed with four magnetic quadrupolets is used for microbeam formation. The long focus of the lens makes the working distance long enough to accommodate the scanning coils and the detectors for PIXE, RBS, RFS, NRA and SE experiments. A 5 μm focussed beam is scanned continously by a pair of coils. A multiparameter multidetector data system for the nuclear microprobe is based on the idea of Total quantitative scanning analysis (TQSA) suggested by Melbourne University. A digital graphic displayer is a good substitute for an ordinary storage oscilloscope for on- line scanned area monitoring. The new microprobe meets high demands of biologists and geologists on applications.     

氨基磺酸用于龙须草浆漂白

氨基横酸（SA）是一含氮助剂，可溶于水，105℃时分解。在次氨酸盐溶液中易分解成硫酸和氮气，所以不能将其直接加入漂液，应先用水溶解后再加入漂液中。氨基磺酸能使漂液保持稳定．减少重金属离子对纤维素的氧化降解。与漂液反应生成的N一氯氨基磺酸钠能对纤维素的反应基团产生固定作用，阻止纤维素的剥皮反应，从而提高了纸浆强度、白度，同时，还可依次氯酸盐漂白在pH值小于7的情况下进行，进而加快漂白速度。轮厂体用氯甚碘酸化湮内助剂，达到了预期目的。左表是漂白烧碱一首酿法龙须草浆时使用氨基磺酸前后的结果对比。加入SA时，先…     

A STUDY OF ANTINODULARIZING PROPERTIES OF Pb, Bi, Al AND Ti IN NODULAR CAST IRON BY SPM

The nodular cast iron samples were prepared with the normal nodularizing process, in which the important antinodularizing elements Pb, Bi and Al were added respectively in order to research the influence of them on the nodularization of the graphites. The nodular graphites were extracted from the nodular cast iron by the electrolytic technique. The distribution of trace elements in nodular and deformed graphite were measured by Scanning Proton Microprobe (SPM). Most of the adding elements Pb, Bi and Al existed in matrix as impurities, a part of them intruded into the nodular graphites. A new suggestion of Ti antinodularizing properties had been proposed. The influence of Pb, Bi and Al on the nodularization was indirectly performed through Ti. Therefore, Ti is one of the most important antinodularizing elements.     

两性淀粉对填料留着率的影响

两性淀粉即淀粉分子中含有阴、阳离子两种基团，与阴、阳离子症扮相比，其用量低，不需糊化而直接加入，对PH值敏感度低，使用方便。对麦草浆来说，加入0．5％两性淀粉，除对撕裂度影响不大外，耐破度、裂断长、耐折度均有提高，对填料留着率影响也较大。下表是两性淀粉对填料留着率影响的结果：14料留着率的变化从表中可以看出，两性淀粉能有效地提高填料留着率，但是随着滑石粉用量增加，填料留着率反而下降。说明一定量的两性淀粉对纤维和填料的相互吸附有一个最佳值。2纸中灰分的变化从表中可以看出，随着滑石粉用量增加，填料留着率下…     

阴离子淀粉在胶印书刊纸中的应用

SP－Ⅱ型阴离子淀粉是一种较好的浆内添加剂。在进行小试的基础上，我厂于1997年7月在新上的一台淄博产的1760mm长网双大缸纸机上添加SP-Ⅱ型阴离子淀粉生产胶印书刊纸，取得了满意的结果。1质量指标外观：白色粉末；细度：100目筛全通过；白度：不低于80％；粘度≥250mPa·S；     

测量造纸废水中CODcr含量应注意的问题

ＣＯＤ反映了水中受还原性物质污染的程度,是指在一定条件下,用强氧化剂处理水样时所消耗氧化剂的量,以氧的ｍｇ／Ｌ表示。它受加入氧化剂的种类及浓度、反应溶液的酸度、反应温度和时间以及催化剂的有无而获得不同的结果。因此ＣＯＤ是一个条件性指标,应严格按操作步骤进行。 我国规定用重铬酸钾法测量工业废水的ＣＯＤ含量,测得的值称为ＣＯＤｃｒ．检测原理是基于在强酸性溶液中,一定量的重铬酸钾氧化水样中还原性物质,过量的重铬酸钾以试亚铁灵作指示剂,用硫酸亚铁筷溶液回滴,滴定终点时,溶液的颜色由黄色经绿色至红褐色。根…     

IBM-PC/XT及其兼容机硬盘常见故障恢复方法浅谈

IBM—PC/XT及兼容机,在使用DOS2.5系统时,会经常出现以下故障,从软盘上引导时会出现:Data error reading drive C:Abort, Retry, Ignore?能换提示符,但不能工作。通过DIR C:能看到部份文件名而其它的文件丢掉了。不能用