石油产品中硫的测定方法及其在石油化工厂的应用

对目前各种石油产品中硫含量的测定方法进行了介绍,结合本石油化工厂石油产品中硫含量测定方法和仪器等,对测定方法的适用范围、测定范围、分析目的、优缺点以及仪器价等进行了比较和论述。不同石油产品硫含量测定方法具有各自的优缺点和适用范围。因此,对硫含量测定方法进行选择时,应结合样品的基本性质、硫含量、检出限、测定要求、适用范围、仪器成本价格及每次分析成本等众多因素来选择较为高效、准确、经济的测定方法。     

涂料黏度不同测定方法的讨论

根据被测对象、测量区间、试验条件不同,黏度测定方法也有区别.介绍了涂料黏度不同测定方法及各自的优劣势,并给出了不同黏度单位的标准及由不同测定方法所得黏度数据的换算方法.     

几种灰霉病测定方法在新化合物筛选中应用

简述了几种灰霉病测定方法,提出在化合物筛选中应采用花器接种测定方法和幼苗接种测定方法.     

铬的分析方法研究进展

本文概述了近年来铬的测定方法,包括总铬、三价铬、六价铬、三价铬与六价铬的同时测定方法,并对今后的发展进行了展望。     

测定推进剂中金属含量的研究

研究了推进剂配方中多种金属元素组分的新测定方法，并对样品分解、测定及测量精度进行了探讨，证明本文的测定方法简单、快速、可靠     

食品中亚硝酸盐的测定

对食品中亚硝酸盐的测定方法进行了综述。介绍了化学分析方法、光学分析法、色谱法、电化学分析法等,并对这些方法进行了比较。提出了亚硝酸盐测定方法的研究方向。     

不溶性硫磺总硫含量和热稳定性测定方法概述

介绍了不溶性硫磺总硫含量和热稳定性的测定方法,并对6种总硫含量测定方法和3种热稳定性测定方法进行分析比较.指出红外分光光度法是测定不溶性硫磺中总硫含量的最佳方法,在热稳定性的测定中推荐使用石蜡油-硅油二浴法.建议进一步完善测定方法,以适应今后对不溶性硫磺性能、质量的更高要求.     

氨基酸测定方法的研究进展

氨基酸的分析研究是工业、农业和生命科学中的重要课题。对氨基酸测定方法进行了综述,主要介绍了化学法、分光光度法、色谱法和电化学法等氨基酸测定方法。     

超低醇解度聚乙烯醇聚合度的测定

介绍了超低醇解度聚乙烯醇聚合度的测定方法,讨论了处理剂、处理温度、样品干量、甲醇碱、处理时间等对测定方法的影响。该方法重现性好。     

液体黏度测定方法及装置的研究现状和发展趋势

综述了当前液体黏度测定方法和测定装置的研究现状,分析了典型测定方法的工作原理、试验装置、优越性以及存在的问题,同时指出了液体黏度测定新技术及发展趋势。     

原子荧光光度法测定重整原料油中的微量砷

讨论了重整原料油试样消解的前处理过程，提出了消解时间短、反应温和、重现性好的前处理方法，采用氢化物原子荧光光度法测定砷含量，检出限为0．02ng／mL。实验结果表明，该方法在灵敏度、重现性、分析速度，尤其是批量分析等方面具有卓越的表现。     

催化动力学光度法测定痕量亚硝酸根的研究进展

综述了近年来催化动力学光度法测定痕量亚硝酸根的研究进展。具体内容包括:催化褪色动力学光度法测定痕量亚硝酸根的研究进展;催化荧光法测定痕量亚硝酸根的研究进展。评述内容包括指示反应及其条件、方法的检出限、线性范围、应用及干扰情况等,并探讨和展望了催化动力学光度法未来的研究方向和发展趋势。     

一阶导数紫外光谱法测定脂质体中维生素E的含量

为测定包裹维生素E（VE）的脂质体中VE的含量,比较了荧光法、一阶导数紫外光谱法这两种方法。结果表明一阶导数紫外光谱法测量范围大,可测定较大浓度样品,并可消除膜脂材料对VE测量的影响。一阶导数紫外光谱法是一种简便、难确、有效的测定脂质体中维生素E含量的方法：平均回收率为98.17％,重复性好,日内变异系数为1.78％。     

加入EDTA改进硫化氢吸收液的方法探讨

在分析硫化氢的方法中,稳定地保存捕集在捕集液里的硫化氢的硫离子是很重要的.对加入EDTA隐蔽铁等金属离子来防止氢氧化钠溶液中硫离子氧化的方法进行了讨论.结果是在1.0×10-5mol·L-1硫化氢标准溶液里,如果加入10mmol·L-1浓度的EDTA,硫化氢标准溶液放置在暗处至少可以稳定地保存一周.结论是通过在氢氧化钠...     

光度法测定结晶紫含量

采用荧光光度法测定水产品中结晶紫残留量。样品在pH=5．00的H3PO4-NaOH缓冲液中,激发波长为530nm、吸收波长为600nm的条件下测定荧光值,在1．00×10^-6g／mL～1．00×10^-11g／mL范围内,有良好的线性,相关系数R=0．9996;检出限为1．58×10^-12g／mL;回收率在95．0％-98．0％之间。本法具有操作方便、检出限低、较高的重现性及准确性等特点,是一种良好的分析检测方法。     

Selective Extraction and Detection of Hg2+ in Aqueous Solution by using Rhodamine Dye-Modified Silica Gel

Novel silica gel-immobilized rhodamine (SGR) anchored by hydrazinium hydrate was synthesized. The selectivity and adsorption ability of the SGR for metal cations were investigated with fluorophotometry and atomic absorption spectrophotometery, respectively. The SGR exhibits high selectivity and adsorption capacity for Hg²⁺. The maximum static adsorption capacity of the SGR for Hg²⁺ was 25.8 μmol g^?1. The linear response range covers a concentration range of Hg²⁺ from 20 ppb to 2000 ppb and the detection limit is 10 ppb. The determination of Hg²⁺ in real water samples displays satisfactory results, and the SGR can be used repeatedly by treating with a solution of tetrabutylammonium hydroxide.     

泰乐菌素在提取工艺中溶液中的稳定性研究

为探讨泰乐菌素在提取工艺中溶液中的稳定性,取提取工艺中不同环节的泰乐菌素溶液,采用高效液相色谱法测定在一定时间内检测泰乐菌素的含量,观察不同环节的泰乐菌素溶液的降解情况。结果显示,在提取工艺中不同环节的泰乐菌素溶液,均较稳定,结果证明,提取工艺中不同环节的泰乐菌素溶液稳定,基本上不降解。     

Sp7 Transgenic Mice with a Markedly Impaired Lacunocanalicular Network Induced Sost and Reduced Bone Mass by Unloading

The relationship of lacunocanalicular network structure and mechanoresponse has not been well studied. The lacunocanalicular structures differed in the compression and tension sides, in the regions, and in genders in wild-type femoral cortical bone. The overexpression of Sp7 in osteoblasts resulted in thin and porous cortical bone with increased osteoclasts and apoptotic osteocytes, and the number of canaliculi was half of that in the wild-type mice, leading to a markedly impaired lacunocanalicular network. To investigate the response to unloading, we performed tail suspension. Unloading reduced trabecular and cortical bone in the Sp7 transgenic mice due to reduced bone formation. Sost-positive osteocytes increased by unloading on the compression side, but not on the tension side of cortical bone in the wild-type femurs. However, these differential responses were lost in the Sp7 transgenic femurs. Serum Sost increased in the Sp7 transgenic mice, but not in the wild-type mice. Unloading reduced the Col1a1 and Bglap/Bglap2 expression in the Sp7 transgenic mice but not the wild-type mice. Thus, Sp7 transgenic mice with the impaired lacunocanalicular network induced Sost expression by unloading but lost the differential regulation in the compression and tension sides, and the mice failed to restore bone formation during unloading, implicating the relationship of lacunocanalicular network structure and the regulation of bone formation in mechanoresponse.     

Possible Role of Crystal-Bearing Cells in Tomato Fertility and Formation of Seedless Fruits

Crystal-bearing cells or idioblasts, which deposit calcium oxalate, are located in various tissues and organs of many plant species. The functional significance of their formation is currently unclear. Idioblasts in the leaf parenchyma and the development of crystal-bearing cells in the anther tissues of transgenic tomato plants (Solanum lycopersicon L.), expressing the heterologous FeSOD gene and which showed a decrease in fertility, were studied by transmission and scanning electron microscopy. The amount of calcium oxalate crystals was found to increase significantly in the transgenic plants compared to the wild type (WT) ones in idioblasts and crystal-bearing cells of the upper part of the anther. At the same time, changes in the size and shape of the crystals and their location in anther organs were noted. It seems that the interruption in the break of the anther stomium in transgenic plants was associated with the formation and cell death regulation of a specialized group of crystal-bearing cells. This disturbance caused an increase in the pool of these cells and their localization in the upper part of the anther, where rupture is initiated. Perturbations were also noted in the lower part of the anther in transgenic plants, where the amount of calcium oxalate crystals in crystal-bearing cells was reduced that was accompanied by disturbances in the morphology of pollen grains. Thus, the induction of the formation of crystal-bearing cells and calcium oxalate crystals can have multidirectional effects, contributing to the regulation of oxalate metabolism in the generative and vegetative organs and preventing fertility when the ROS balance changes, in particular, during oxidative stresses accompanying most abiotic and biotic environmental factors.     

The Effects of Immunosuppressive Treatment during Pregnancy on the Levels of Potassium,Iron, Chromium,Zinc, Aluminum,Sodium and Molybdenum in Hard Tissues of Female Rats and Their Offspring

The ideal immunosuppressive regimen should provide for excellent immunosuppression with no side effects. Yet, current immunosuppressive therapy regimens commonly used in clinical applications fail to meet this criterion. One of the complications caused by immunosuppressive drugs is mineralization disorders in hard tissues. In this study, we evaluated the effects of three immunosuppressive therapies used after transplantation on the levels of potassium, iron, chromium, zinc, aluminum, sodium and molybdenum in the bones and teeth of female rats and their offspring. The study was conducted on 32 female Wistar rats, subjected to immunosuppressive regimens (cyclosporine A, mycophenolate mofetil and prednisone; tacrolimus, mycophenolate mofetil and prednisone; and cyclosporine A, everolimus and prednisone). The hard tissues of rats were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES, ICAP 7400 Duo, Thermo Scientific) equipped with a concentric nebulizer and a cyclonic spray chamber. All the immunosuppressive regimens included in the study affected the concentrations of the studied minerals in hard tissues of female rats and their offspring. The therapy based on cyclosporine A, everolimus and prednisone led to a decline in the levels of iron in bone, zinc in teeth, and molybdenum in the bone and teeth of mothers, while in the offspring, it caused a decline of bone potassium, with a decrease in iron and increase of molybdenum in teeth. Moreover, the regimen caused an increase in aluminum and chromium in the teeth and aluminum in the bones of the offspring, and consequently, it seems to be the therapy with the most negative impact on the mineral metabolism in hard tissues.