Most proteins have amino acids with aromatic ring , so they have yellow reaction . phenylalanine is not easy to nitrify , so it is necessary to add in a little vitriol oil 多数蛋白质分子含有带苯环的氨基酸，所以都会发生黄色反应。苯丙氨酸不易硝化，需加少量浓硫酸后才能够发生黄色反应。
The temperature of the mixture can be kept at above 200 , thus the oxidation power of nitric acid can be kept at a rather high level and the non - diamond carbon can be removed completely 其做法是，将半成品与浓硫酸混合，加热到200以上，将浓硝酸缓慢滴入，进行氧化处理，这样可以使混合物保保持较高温度，从而提高了硝酸的氧化能力。
High temperature concentrated sulfuric acid fluid pump ; force diluted acid special purpose pump ; diluted acid wear - resisting special purpose pump , three items of products hich were presided by him passed through provincial level new product appraisal in 2001 主持开发研制的高温浓硫酸液下泵；强力稀酸专用泵；稀酸耐磨专用泵，三项产品2001年通过省级新产品鉴定。
In order to enhance the efficiency of usage of lignocellulosic wastes and protect the balance of ecosystem , the liquefaction of lignocellulosic wastes was studied in this paper . lignocellulosic wastes and other chemicals were put into the reaction container and then liquefied 对纤维类废弃物在浓硫酸苯酚为催化剂、乙二醇为反应介质的热化学催化液化反应中，对其各反应物的用量比例、反应条件进行优化。
The effects of catalysts , solvents , reaction time and temperature on the liquefaction were investigated . the molecular weight distributions of liquefaction products were determined by gpc . in most cases , low residue content cannot be achieved by single catalyst 实验结果表明，纤维类废弃物在浓硫酸苯酚(浓硫酸占所加物质总量的质量分数为6 )的混合催化体系中，当温度为160 ，时间为70min时的液化效果最好。
The effect of the catalysts , e . g . , concd . sulfuric acid , p - toluenesulfonic acid , dodecylbenzenesul - fonic acid on the esterification of starch was studied with cassava starch as the raw material , acetic anhydride as the esterifying agent and acetic acid as the dispersion medium 摘要以木薯淀粉为原料，用醋酸酐为酯化剂，以乙酸为分散递质，探索了以浓硫酸、对甲基苯磺酸、十二烷基苯磺酸为催化剂对淀粉醋酯化反应的影响。
By using coal pitches and green petroleum coke as starting materials , the mixture of sulfuric acid and nitric acid as oxidizing agent , effects of the properties of starting materials and the processing conditions on the yield of were aqua - mesophase have been investigated 以煤沥青和石油生焦为原料，以浓硝酸和浓硫酸混合物为氧化剂，对炭质原料性能与水性中间相的产率之间的关系以及工艺条件对水性中间相产率的影响进行了研究。
However the binary catalysts system favors low residue content . it was found that the residue content were remained at a low level with ethylene glycol as the reaction media and 6 % ( by mass ) of sulfuric acid as the catalyst in the presence of phenol . the contents of lipophilic products were investigated 经凝胶色谱法测定表明，以浓硫酸苯酚为催化剂、乙二醇为反应介质的反应体系，所得到液化产物的平均相对分子质量最低， m _ w为806 ， m _ n为799 。
Single - walled carbon nanotubes ( swnts ) were opened and oxidized in the concentrated h2so4 / hno3 mixture ( volume ratio : 3 : 1 ) , hydroxyl groups could be brought into the swnts after oxidation modification treatment , and the long - chain silane coupling agent was grafted onto swnts via hydroxyl - silanol route 摘要采用混酸体系（浓硫酸浓硝酸体积比为3 / 1 ）对单壁碳纳米管进行了氧化处理，并通过氧化处理后在单壁碳纳米管表面生成的羟基官能团与长链硅烷偶联剂进行反应，制备了表面有机修饰的单壁碳纳米管。
A recommend for basic organic chemistry experiment in university - the production of acetyl - salicylic ( aspirin ) , which takes the salicylic acid and acetic oxidecon as raw material under the atmospheric pressure condition , takes the strong sulfuric acid as catalysis , through acetoxylation , heating , dialysising , filtering , heavy crystallization , the white solid product can be made finally 摘要推荐一个大学基础有机化学实验乙酰水杨酸（阿斯匹林）的制备，即在常压条件下以水杨酸和乙酸酐为原料，在浓硫酸为催化剂下通过酰基化试剂酯化反应，经加热、析滤、重结晶，最后得白色固体产品。
