测定葡萄糖酸钙钙片中钙含量的方法比较

详细论述了EDTA滴定法与高锰酸钾间接滴定法测定钙片中钙含量的方法比较,从理论上来说,高锰酸钾法具有更高的准确度。通过对样品的测定结果表明,用EDTA滴定法测得钙含量为8.07%,用高锰酸钾间接滴定法测得钙含量为8.29%。经显著性检验,两种方法间不存在显著性差异,可以用EDTA配位滴定法代替高锰酸钾法进行钙含量的测定。     

电感耦合等离子体发射光谱仪测定水溶肥中EDTA螯合态钙

水溶肥中的中量元素钙为了保证其在肥料中的稳定性和作物吸收上的高效性部分存在于EDTA的螯合态下,这部分钙不能采用EDTA滴定法测定,实验室主要检测方法为高锰酸钾滴定法,较为繁琐,也不能直接采用ICP-OES法直接测定,因为酸性环境会导致固体析出,堵塞毛细管,利用本文中提出的酸解后,再加入10mL EDTA进行充分螯合,及时调整p H值到9.0～10.0之间,碱性环境下,钙在EDTA螯合下不会形成沉淀,经测定相对标准偏差小于2%,加标回收率在98.5%～102.25%之间,ICP-OES测定的结果和高锰酸钾滴定法基本一致。表明这种简单的处理方法对ICP-OES快速测定水溶肥中EDTA螯合态钙准确、有效。     

EDTA容量法测定饲料级磷酸三钙中的钙含量

研究了以三乙醇胺及磺基水杨酸消除干扰离子的影响,在pH≈13的条件下,以钙黄绿素 甲基百里香酚蓝为指示剂,用EDTA标准溶液滴定,快速测定钙含量的方法。经试验,用该方法测定饲料级磷酸三钙中的钙含量,相对标准偏差为0.14%～0.35%,回收率为99.6%～100.4%。该法简便、快速、准确,能满足饲料级磷酸三钙中钙含量的快速测定。     

化学镀镍-磷合金镀层中磷的测定

准确、简便地测定镍-磷合金镀层的磷对化学镀镍工艺具有重要作用.采用浓硝酸退镀镍-磷合金镀层→高锰酸钾氧化→亚硝酸钠还原→加水定容的方法制备实验溶液,然后分别用磷钼钒黄分光光度法、磷钼酸铵容量法分析试液中的磷,再换算出镀层中磷的质量分数,并与标准方法测定结果对比.结果表明:光度法测定的相对误差为7.93％,相对标准偏差为4.38％;容量法测定的相对误差为-1.83％,相对标准偏差为0.82％.容量法具有准确、简便的优点,可在生产实际和实验研究中推广应用.     

镍磷合金中磷含量的测定方法比较

磷含量对镍磷合金的物理化学性质影响很大,快速、准确地测定镍磷合金中的磷含量,对监测、控制合金的质量有重要作用。首先按适当工艺规范制备镍磷合金（镀层）,然后分别采用EDTA滴定镍间接换算法、磷钼钒黄分光光度法、磷钼酸铵容量法测定合金中的磷含量,并与采用标准方法测定的结果进行对比,从测定结果的准确性、测定数据的精密性、测定方法的简便性3方面考察每种方法的优劣;结果表明：EDTA滴定镍间接换算法具有简便、快捷、准确、精密的优点,值得在生产过程和实验研究中推广应用。     

高锰酸钾滴定法测定钙片中钙的含量

为了准确测定钙片中钙的含量,建立了高锰酸钾容量滴定法测定钙片中钙含量的方法。实验样品经湿法消化后,在酸性溶液中,钙与草酸生成草酸钙沉淀。沉淀洗涤后,加入硫酸溶解,将草酸游离出来,在70—80℃条件下,用高锰酸钾标准溶液滴定与钙等当量结合的钙含量。测定结果的回收率（R）在98．40％-109．74％。用高锰酸钾滴定法测定钙片中的钙含量,简单、快捷、准确、干扰小。     

工业生产中钙和磷同时存在的快速测定法

在韦耳奇尔(F.J.WeIcher)的“乙二胺四乙酸在分析化学中的应用”一书中,关于钙和磷同时存在时应用EDTA 的快速滴定法,总结了沉淀分离及离子交换分离等方法。由于我们在生产上经常需要同时测定这二个元素的量,因此对其分析测定,在操作上作一些改进,以达到快速准确的目的。当磷存在时测定钙,柯里尔(R.E.Collier)在70毫升溶液中钙含量高达0.1克,而磷与钙之比为30∶1时用紫尿酸铵及铬黑T 为指示剂以标准EDTA 直接滴定钙并不引起可觉察的干扰。作者根据柯里尔所述的方法做了一些实验,当磷与钙的克分子比小于0.5时可以按照一般的方法进行钙的直接滴定。随着磷与     

过磷酸钙中有效磷快速测定方法研究

以乙二胺四乙酸二钠(EDTA)为提取液,研究了过磷酸钙中有效磷含量的快速测定方法,考察了提取液用量以及提取温度和时间对有效磷提取率的影响,并采用磷钼酸喹啉容量法分析磷含量。研究结果表明:1 g过磷酸钙样品,以100 mL质量浓度为37.5 g/L的EDTA溶液作为提取液,在80℃±1℃恒温水浴振荡10 min,即可完全提取过磷酸钙中的有效磷;对过磷酸钙样品中的磷含量进行测试,测定结果与标准方法GB 20413—2006《过磷酸钙中有效磷含量测定》的测定结果相符,绝对偏差小于0.20%;精密度实验结果表明,相对标准偏差小于0.5%;新方法与标准方法相比,分析时间缩短了至少2.5 h。方法不仅有较高的准确度与精密度,还可以缩短测定时间,是一种快速、简便、准确的分析方法,完全能够满足现场生产要求的准确、快速的分析要求。     

化工铬渣浸出液中钙的测定

用水作为提取剂浸出铬渣可模拟铬渣在自然条件下中钙、镁、钠、铬等金属元素的自行溶出.处理后,铬渣含量大大减少,浸出残渣进一步处理后可用作水泥原料,实现了无渣排放.铬渣中钙的测定对铬渣污染的全面评估及环境评价水文地质勘察工作尤为重要,钙的测定一般采用EDTA容量法.但在测定过程中,铬（Ⅵ）的氧化性和较深的背景,铬（Ⅲ）于配位滴定剂的配位等均影响测定的正常进行.本实验选择氯化铬酰挥发分离法除去铬,在优化的实验条件下,结果的相对标准偏差RSD均小于0.5％.钙的加标回收率在98％以上,满足分析要求.     

高锰酸钾滴定法测定钙片中的钙含量

为了准确测定钙片中钙的含量,建立了高锰酸钾容量滴定法测定钙片中钙含量的方法.样品经湿法消化后,在酸性溶液中,钙与草酸生成草酸钙沉淀.沉淀经洗涤后,加入硫酸溶解,把草酸游离出来,然后在70～80 ℃条件下,用高锰酸钾标准溶液滴定与钙等当量结合的钙含量.测定结果的回收率(R)在98.40%～109.74%之间.结果表明,用该法测定钙片中的钙含量,简单、快捷、准确,干扰小.     

焦炭灰分,硫分数学模型的建立

应用计算机软件,从大量生产数据中统计焦炭灰分、硫分预测模型。利用工程分析的允许误差,对数据库分组段进行了极差及DIXON检验,得出了更具代表性的预测模型。     

低甲醛含量六羟基树脂植绒胶黏剂的研究

作为一种植绒胶黏剂,六羟基树脂胶黏剂因甲醛含量偏高而受到诸多限制。对六羟基树脂植绒胶黏剂的低甲醛化进行了研究。结果显示,以三聚氰胺和甲醛作为原料,采用3次投料法,并进行甲醚化可使所得胶黏剂甲醛含量降低至0.2%,含固量达到80%(质量分数),且耐干磨性、耐湿磨性及水溶性均良好。     

HANDBOOK OF INDUSTRIAL DRYING

Papermaking is a massive dehydration operation. Thermal removal of moisture which can not be removed mechanically is a key process stage in papermaking. It is well known that it is a highly energy intensive step. However, it is less readily recognized that it also influences some of the most important physical, optical or functional properties of the product. With the advent of new drying technologies- some already commercialized while some still at pilot or laboratory stage - it is increasingly important to devote attention to the interaction between the drying conditions and the final product quality as measured by generally accepted standard test results. Aside from the drying parameters one must also examine paper/pulp parameters in the hope of achieving in the long term some predictive capability as well as drying-quality effects. This bibliography is selective in coverage and is compiled to ease the task of the interested reader in locating appropriate references covering his/her areas of interest.. Some general observations are made on the basis of the literature cited.

important problem.This is influenced by the composition and characteristics of the coating colour and raw stock and also by the type and rate of drying.

The following selected bibliography covers the effect of drying on pulp, paper and paperboard properties. Some available literature on coated paper drying is also included. It is encouraging to note a trend towards considering the effect of drying on the product quality as an integral part of drying R&;D projects. Earlier, the drying work was confined to optimising only the heat and mass transfer parameters. It should be noted also that this bibliography includes a substantial number of publications which are not in english. The availability of their translations into english is not known to the authors.

It is noteworthy that an international symposium - The Helsinki Symposium on Alternate Drying Technologies will be held in Helsinki in June 1991 to discuss the competing new drying technologies from the papermakers viewpoint.     

聚乙烯纤维增强有机玻璃复合材料性能影响因素的研究

通过真空浸渍法，成功制备出聚乙烯纤维增强有机玻璃（UHMWPE/PMMA）复合材料，就纤维含量以及孔隙率等对材料性能的影响进行了初步研究，重点探讨了孔隙率对复合材料的影响。     

HPLC法测小儿氨酚黄那敏颗粒含量及含量均匀度

建立了小儿氨酚黄那敏颗粒中马来酸氯苯那敏的含量及含量均匀度测定方法。采用HPLC,以Phenom enex Luna C18为色谱柱,乙腈：0.3%十二烷基硫酸钠溶液：磷酸（60：40：0.02）（用三乙胺调节pH值至3.3±0.1）为流动相;检测波长为224nm。测得马来酸氯苯那敏在0.02019~2.0190μg（R=0.9999）范围内呈线性关系,平均回收率为98.1%（RSD=1.2%）。测定方法简便,准确,可用于该制剂的质量控制。     

PEAR DRYING PROCESS ANALYSIS: DRYING RATES AND EVOLUTION OF WATER AND SUGAR CONCENTRATIONS IN SPACE AND TIME

ABSTRACT

Dried pears are produced in Portugal by a traditional solar drying process and, because they represent unquestionable regional economic interest, some studies are being conducted in order to convert their production to industrial drying methods. In this work the main mass transfer phenomena occurring during drying of pears are investigated. Experiments were carried out to determine the time evolution of the radial profiles of water and sugar content. The drying rates were also studied at constant drying temperatures of 30, 40 and 50°C. The results enable to conclude that the concentration profiles of water and sugar, both in space and time, follow an expected pattern if one takes into account the rates of water removal and the diffusion mechanisms. These also allow to explain why the sugar concentration increases in the periphery of the fruit. The drying rate curves obtained are typical, with the drying process at 30°C being more gradual but also much slower than that at 50°C.     

高分子量聚氯乙烯树脂增塑,填充体系的物理力学性能研究

本文研究聚合度及增塑剂、填充剂用量对高分子量聚氯乙烯（ＨＭＷＰＶＣ）树脂物理力学性能的影响规律，并将国内外ＨＭＷＰＶＣ树脂以及ＨＭＷＰＶＣ与通用型ＰＶＣ树脂进行了性能对比。结果表明，ＨＭＷＰＶＣ增塑、填充体系的拉什强度、撕裂强度冲击回弹性及压缩永久形变等物理力学性能均随聚合度的提高而有所增加，而且各项性能均优于通用型ＰＶＣ树脂，可有效地用作橡胶代用品。分子量相同的国内外ＨＭＷＰＶＣ树脂物理力学性能基本相同。但是，后者随着增塑剂用量的增加，弹性比前者有所提高；随着填充剂用量的增加，性能变化比前者缓慢．增加填充剂用量以降低制品的体积成本。笔者还时两者物理力学性能的差异与颗粒形态之间的关系进行了探讨。     

PEAR DRYING PROCESS ANALYSIS: DRYING RATES AND EVOLUTION OF WATER AND SUGAR CONCENTRATIONS IN SPACE AND TIME

Dried pears are produced in Portugal by a traditional solar drying process and, because they represent unquestionable regional economic interest, some studies are being conducted in order to convert their production to industrial drying methods. In this work the main mass transfer phenomena occurring during drying of pears are investigated. Experiments were carried out to determine the time evolution of the radial profiles of water and sugar content. The drying rates were also studied at constant drying temperatures of 30, 40 and 50°C. The results enable to conclude that the concentration profiles of water and sugar, both in space and time, follow an expected pattern if one takes into account the rates of water removal and the diffusion mechanisms. These also allow to explain why the sugar concentration increases in the periphery of the fruit. The drying rate curves obtained are typical, with the drying process at 30°C being more gradual but also much slower than that at 50°C.     

重催油浆磺化制磺化沥青工艺条件研究

本实验用重催油浆经磺化、中和反应合成磺化沥青类产品。考察、优化了油浆磺化的原料、工艺条件,用中国石油天然气总公司钻井工程局企业标准《钻井液用磺化沥青-FT1》分析方法,对各种工艺条件下的油浆磺化产品的磺酸钠含量、油溶物、水溶物含量进行了测定比较,找到了油浆磺化制磺化沥青类产品的最佳工艺条件。     

不同黏土矿物种类和含量的泥粉对亚甲蓝值的影响

研究了石粉中含不同黏土矿物种类和含量的泥粉与亚甲蓝值的相互关系,探究不同黏土矿物吸附性能对亚甲蓝(MB)值的影响。结果表明:随着纯石粉含量的增加,MB值逐渐增大,但也远小于1.00,增幅较小、变化不大。纯泥粉和混合泥粉对MB值影响较大,呈现出线性关系;蒙脱土和以蒙脱土为主的混合泥粉对MB值影响最大,分别高达8.00、4.20;高岭土、伊利土的MB值最大为1.75、1.05,而以其为主要成分的2种混合泥粉MB值最大为2.10、1.95,影响相对较小;含有不同黏土矿物成分的混合泥粉较纯泥粉,能更好的减少对MB值的影响。与纯石粉相比,亚甲蓝对黏土矿物变化较为敏感,由大到小顺序为:蒙脱土、高岭土和伊利土,即蒙脱土的吸附能力最强。