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以对苯二酚为原料合成2,5-二异丙氧基-4-吗啉基-硫酸氢根重氮苯重氮盐感光剂.具有感光速度快、相容性好、反差大、稳定性、安全性好等优点. 相似文献
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本文研究了4′-甲氧基-4-重氮二苯胺(VB)金属复盐的稳定性,提出红外密度比值(D),热分解温度和光、热分解指数作为稳定性的量度。本文认为,4′-甲氧基-4-重氮二苯胺盐的分解为异裂反应。感光性能试验指出,感光胶片保存性参数与重氮盐稳定性参数之间有良好的相关性。 相似文献
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重氮氨基苯类化合物的合成 总被引:1,自引:0,他引:1
1886年Strefeild提出重氮氨基化合物中亚氨基上的氢原子可被金属置换。但是,如何提高亚氮基上氢原子的活性以及作为显色剂在分析化学中的应用,却没有引起注意。重氮氨基化合物的骨架为两个游离价键可连接不同的基团,形成为数众多的化合物。经初步研究发现,两个游离价键只有连接两个芳环,且芳环上有强吸电子基如硝基、磺酸基、卤素等,才可用作显色剂。此类试剂于苛性钾溶液中的玫瑰红色可被汞(Ⅱ)、镉(Ⅱ)、钯(Ⅱ)等离子减退,用分光光度法测定痕量镉、汞、银、钯等元素具有较高的灵敏度。而这类试剂的合成方法,迄今似尚未被重视。我们经过试验,摸索出一种操作简便、反应快、收率好的合成方法。用该法合成了4,4′-二硝基重氮氨基苯(DNAAB)、2,4,4′-三硝基重氮氨基苯(TNAAB)、2,4,4′-三硝基-2′-氯重氮氨基苯(2-Cl TNAAB)、2,2′-二氯-4,4′-二硝基重氮氨基苯(2,2′-D ClDNAAB》、2,4-二硝基-4′-磺酸基重氮氨基苯(DNSAAB)等显色剂。 相似文献
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概述以间氨基苯甲酸为原料,经溴代、重氮、水解等三步反应合成2,4,6-三溴-3-羟基苯甲酸.在实验过程中深入探讨了硫酸用量、亚硝酸钠用量及温度对重氮硫酸盐合成的影响;水解过程中酸浓度及重氮硫酸盐滴加时间对产物产率的影响.在最佳条件下合成,产率可达97.3%,纯度99.7%,并采用了IR、1H NMR和13C NMR对产物结构进行了表征. 相似文献
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用2,2′-二氯-4,4′-二硝基重氮氨基苯分光光度测定痕量镉 总被引:1,自引:0,他引:1
光度测定痕量镉,用常推荐的双硫腙法,需用大量的氰化钾,手续较繁。4-(4-硝基苯重氮氨基)-偶氮苯-Triton X-100法,虽有些特色,但仍需用氰化物作掩蔽剂。结晶紫法,空白波动较大。5-Br-PADAP萃取光度法、OP-PAN法、OP-5-Br-DMPAP法。等均需预先分离。且上述这些方法的灵敏度还不够高。4,4′-二硝基重氮氨基苯(DNAAB)的苛性碱溶液呈玫瑰红色,它可被汞(Ⅱ)、 相似文献
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建立了高效液相色谱法测定6-硝基-1,2-重氮氧基萘-4-磺酸及其中杂质1,2-重氮氧基萘-4-磺酸、8-硝基-1,2-重氮氧基萘-4-磺酸含量的方法,测定结果经生产检验,对提高产品质量有明显的效果,是一切实可行的测定方法. 相似文献
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<正> 直接染料、食用色素的中间体4,4′-二氨基-二苯胺-2-磺酸在空气中易被氧化生成紫红色的化合物。单边氨基被氧化将使染料色光发生变化;两边氨基都被氧化,化合物因不能发生重氮化反应而不能作为重氮组分。4,4′-二氨 相似文献
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N-甲基-1,2-苯并异噻唑啉-3-酮的合成研究 总被引:1,自引:1,他引:0
N-甲基-1,2-苯并异噻唑啉-3-酮是一种广谱高效的杀菌剂,以邻氨基苯甲酸为原料,经重氮二硫代、酰氯化、氮酰化、Zincke二硫化物分裂以及碱性条件下环合五步反应制得目标产物,总收率为53.5%,产品含量≥99%,产品结构经红外、核磁得到确认。 相似文献
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应用结晶紫染色法测定干扰素效价 总被引:13,自引:1,他引:12
根据活细胞能吸收结晶紫染料的原理 ,建立了测定干扰素效价的结晶紫染色法 ,并用线平行线定量法计算干扰素含量。经试验测定 ,该方法与用常规法测得的结果有很好的相关性 (r =0 .9387,P >0 .0 5 ) ,且重复性较好 ,用 A值表示细胞的病变程度比打分法能够更准确地反应细胞的状态 ,因此所得结果更精确、客观 ,表明该方法可用于干扰素类制品的效价测定。 相似文献
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三水硝酸铜测定的化工行业标准采用以紫脲酸铵作指示剂的EDTA络合滴定法,该方法快速、简单,但终点不易判断,准确度和精密度不高。对该方法进行了改进,以PAN代替紫脲酸铵为指示剂。结果表明,与紫脲酸铵法相比,PAN法具有终点易判断、准确度和精密度高、重现性和再现性好等优点,值得推广应用。 相似文献
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A reduced model by proper orthogonal decomposition (POD) and Galerkin projection methods for steady‐state heat convection is established on a nonuniform grid. It was verified by thousands of examples that the results are in good agreement with the results obtained from the finite volume method. This model can also predict the cases where model parameters far exceed the sample scope. Moreover, the calculation time needed by the model is much shorter than that needed for the finite volume method. Thus, the nonuniform POD‐Galerkin projection method exhibits high accuracy, good suitability, and fast computation. It has universal significance for accurate and fast prediction. Also, the methodology can be applied to more complex modeling in chemical engineering and technology, such as reaction and turbulence. 相似文献
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冻干魔芋胶性能的实验研究 总被引:1,自引:0,他引:1
介绍了采用冻干工艺获取的优质魔芋胶(KGM)的主要性能及其实验研究。该工艺方法具有成胶薄、韧性好、保存容易而且时间长、复水性好等优点。魔芋胶可广泛用于食品保鲜与储藏以及保健、医疗等方面;由于它价格低,可进一步拓展其应用领域,深受医疗保健人员的关注。 相似文献
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The results of measurements of unperturbed dimensions for a series of stereoregular poly(methyl methacrylates) are reported. The measurements were made by a recently developed method involving a gel permeation chromatograph coupled with an on-line low angle laser light scattering photometer. Measurements were performed in a thermodynamically good solvent, tetrahydrofuran at 25°C. The unperturbed dimensions were obtained by means of viscosity plots. Comparison of the results obtained by this method with those currently available in the literature, as well as with values predicted by statistical calculations, show good agreement. It was determined that a measurable difference occurs in the Mark-Houwink relationship between isotactic and syndiotactic poly(methyl methacrylate); isotactic poly(methyl methacrylate) is 30% more extended than syndiotactic poly(methyl methacrylate) in its unperturbed state; and isotactic poly(methyl methacrylate) exhibits a smaller degree of polymer solvent interaction than the syndiotactic form. 相似文献
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We describe a method developed to quantify the amount of foam in frying oils. In this method the foam was quantified by digitizing
photographic images that were taken continuously at 1-s intervals; spots showing more than a certain luminance were considered
as foam. The ratio of total foaming area to the whole oil surface was integrated to obtain the intergration of foam (IF) index
as a parameter of the extent of foaming. There was a good correlation between this method and the visual evaluation done by
a group of panelists. Furthermore, the foaming tendency correlated with the distribution of TG by M.W. when the IF was plotted
against the foam index of TG (FIT), which reflects the M.W. distribution. A correlation was found between the FIT value of
oil and foaming on frying, indicating that when the FIT value is small, the oil foams less. Based on the results of this investigation,
we have designed a method to obtain edible oils consisting of medium-chain FA that not only are nutritious but also have good
cooking properties. 相似文献