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161.
为合成肝胆显像剂IODIDA,以活泼芳香胺为原料,经改进的直接碘化法,选择性碘代芳香胺。在吡啶与醋酐存在下,用相应的碘代芳香胺与氮三乙酸反应,可得所需产物,产率较好。 相似文献
162.
有机化学传统实验的改进 总被引:1,自引:1,他引:0
以基础有机化学实验中肉桂酸的制备和肉桂酸的酯化反应为例,对该课程的传统教学方法进行了改革研究,将这两个实验项目整合成一个大型的系列性实验,让学生在实验过程中能够更加自主地实验,有利于学生重视实验操作,增强学习兴趣,提高实验技能,同时,减少了实验废弃物,节省了实验成本。 相似文献
163.
采用索氏提取方法提取柞蚕蛹油,用KOH/CH,OH酯交换法甲酯化处理,以气相色谱/质谱方法测定脂肪酸的组成.共鉴定出13种脂肪酸成分,其中以亚麻酸(LNA)、棕榈酸(P)、硬脂酸为主,柞蚕蛹油中不饱和脂肪酸含量占总脂肪酸总量的66.63%. 相似文献
164.
以柴胡种子为材料,经6-BA、60℃、KMnO4和对照4种方法进行萌发处理,测定了萌发处理过程中不同处理时间的柴胡种子中氨基酸和蛋白质含量的变化,初步探讨了在萌发过程中的生理生化变化规律.结果表明:氨基酸的变化总体呈现先升高再降低的趋势.在萌发0-6d之间氨基酸含量迅速升高,6d以后迅速降低,这种变化对柴胡种子的萌发是有利的.在不同处理下,柴胡种子在萌发期间,蛋白质的含量要经历一个迅速升高的过程,这种升高与氨基酸的变化一致. 相似文献
165.
以铝型材碱洗废渣为原料,采用酸溶——聚合一步法工艺,制得符合行业标准的工业聚合氯化铝产品。推导得产品盐基度B与外加酸量nHY及产品Al2O3含量nAl之间的经验式B%=(1-nny/6nAl)*100%,可用于产品设计和产品质量改进的指导。通过正交试验确定了适宜的制备工艺条件,每114g铝渣用浓盐酸83ml、酸浓度4mol/1、在80℃下反应3h。制得产品盐基度47.1%、Al2O3%11.2%、密度1.23g/cm^3。 相似文献
166.
杨树 《昆明师范高等专科学校学报》2008,30(4):95-97
合成了复合固体超强酸SO4^2-/ZrO2-Ce2O3,研究了Ce2O3的最佳添加量,并将其应用于催化合成丁酸异戊酯的反应,探索到了最佳反应条件.Ce2O3的最佳添加量为2.0%,最佳反应条件为0.10mol丁酸使用1.0g复合固体超强酸催化剂,醇酸摩尔比2.0,反应时间为2.5h,丁酸的酯化率可达96%以上,并且不污染环境. 相似文献
167.
Chitra Upadhyaya Sandhya Mishra P. P. Singh Praveen Sharma 《Indian journal of clinical biochemistry : IJCB》2005,20(1):30-34
Serum antioxidant status and peroxidative stress was estimated in 30 pregnant women, their newborn infants and 25 non-pregnant
women. Serum Ascorbic acid, α-tocopherol, retinol & β-carotene levels were found to be significantly reduced and peroxidative
stress was significantly higher in mothers as compared to matched non-pregnant women. Newborn had significantly higher levels
of ascorbic acid as compared to their mother but had significantly lower levels of lipid soluble vitamins. The peroxidative
stress in newborn was found to be significantly less as compared to their mothers. A positive correlation of ascorbic acid
and α-tocopherol levels between mother and newborn reflects that their status in mother does influence the newborn status. 相似文献
168.
Anita R. Bijoor S. Geetha T. Venkatesh 《Indian journal of clinical biochemistry : IJCB》2004,19(2):20-22
Malabsorption syndromes causing steatorrhoea are quite common in India. Estimation of faecal fat is an important non-invasive
investigation, which provides vital information regarding the occurrence of malabsorption. The aim of this study was to estimate
the fat excretion per day in stools of apparently healthy adults on an unrestricted diet in random spot stool samples using
the Acid Steatocrit Method, which provides an alternate, simpler and yet reliable method of stool fat estimation. Several
studies have proved the correlation of the acid steatocrit method with the conventional methods. In India, however, there
has been no published data regarding the normal levels of fat in the stools, by the acid steatocrit method. We follow the
normal range values, as set by the United States and the European countries, not having a range for the Indian population.
Hence, we took up a preliminary study, to estimate stool fat in a section of normal and healthy Indian population. The result
obtained after screening 600 healthy and normal adults, showed the mean of stool fat to be 8.72 gms/24 hours, which is much
higher than that, defined by Western literature (7 gms/24 hours). This can be accounted for, by the cultural and ethnic variations
in dietary and food habits. Further studies are required in the same direction, involving larger population groups, and in
different malabsorptive conditions. 相似文献
169.
Gora Dadheech Sandhya Mishra Shiv Gautam Praveen Sharma 《Indian journal of clinical biochemistry : IJCB》2006,21(2):34-38
A disturbance in the antioxidant defense system including α-tocopherol, ascorbic acid and reduced glutahtione metabolism due
to free radical induced oxidative injury has been implicated in various neuro-psychiatric disorders. The roles of these antioxidants,
changes in their blood levels and correlation with oxidative stress were studied in a common psychiatric illness Schizophrenia.
Fifty-eight subjects of either sex ranging in age from 18–60 years divided into two age groups (≤40 and >40 years) diagnosed
for schizophrenia, and forty age and sex-matched normal subjects as controls were included in the study. Blood samples were
analyzed for malondialdehyde (MDA), α-tocopherol, total ascorbic acid (TAA), dehydro ascorbic acid (DHAA), reduced ascorbic
acid (RAA), leucocyte ascorbic acid (LAA) and reduced glutathione (GSH). A decrease in the levels of α-tocopherol, total ascorbic
acid and reduced glutathione was found in schizophrenics compared to normal controls. Further a significant rise in oxidative
stress and decreased antioxidant status was observed in the chronic stage of schizophrenia as compared to those in acute condition.
A significant rise in dehydroascorbic acid with concomitant fall in reduced ascorbic acid suggests scavenging action of ascorbic
acid and its utilization with increased oxidative stress as indicated by high blood malondialdehyde levels. Leucocyte ascorbic
acid, a better index of ascorbic acid status was also found to be reduced in schizophrenics, suggesting depletion of body
stores of ascorbic acid and the condition worsened with advancing age. 相似文献
170.
柠檬酸溶胶凝胶法制备铈锆固溶体的物性和氧化还原特性研究 总被引:1,自引:0,他引:1
以柠檬酸作为胶凝剂,采用溶胶凝胶法制备了一系列CeXZr1-XO2复合氧化物,分别经600℃和900℃焙烧,应用XRD检测,发现均已形成铈锆固溶体。并应用BET、XRD和TPR对其表相、晶相结构和氧化还原性质进行了分析,发现随着固溶体中铈比例的增加,固溶体稳定性降低;其储氧量测定显示铈锆固溶体用作三效催化剂助剂的最佳比例为1:1。经900℃高温焙烧以后,固溶体晶粒增大不明显,表明本方法适合制备高比表面积和高储氧量的铈锆固溶体;TPR还原峰温度降低,推测可能在于柠檬酸络合物完全分解所致。 相似文献