紫外分光光度法测定橙汁中维生素C的含量

[目的]为市售饮料中维生素C(Vc)的科学测定提供参考.[方法]利用Cu2+催化溶解氧氧化Vc,建立紫外分光光度法测定橙汁中还原型Vc的方法,并对测定条件进行优化.[结果]采用磷酸和醋酸混酸溶液(3∶7,V∶V)作稳定剂,Cu2+为催化剂,70 ℃恒温水浴中,测定市售橙汁饮品中Vc的含量,标准曲线方程为y=0.071 4x+0.135 0,线性相关系数为0.999 5.该方法精密度RSD(n=5)为0.35%,加标回收率为98.5%.[结论]建立了紫外分光光度法测定橙汁中Vc的方法,该方法简单、快速,结果令人满意.     

分光光度法测定伏牛山荷叶中微量元素锌

[目的]测定荷叶(FOLIUM NELUMBINIS)中微量元素锌的含量,为荷叶在医药及食品工业的深度开发利用提供科学依据.[方法]采用直接分光光度法,以1-(2-吡啶偶氮)-2-萘酚(PAN)为显色剂、锌标准液为对照品,在562 nm波长处测定吸光度.[结果]Zn(Ⅱ)与PAN形成红色的络合物,在0.48～5.03 μg/ml范围内,吸光度值与含量线性关系良好(r=0.999 9);平均回收率为99.8%,RSD为0.34%.伏牛山荷叶中锌元素的平均含量为87.44 μg/g,RSD为1.02%.[结论]该方法简便、准确、重现性好,稳定性高,可用于荷叶中微量元素锌含量的测定.     

荧光分光光度法测定木香花中的总黄酮含量

[目的]测定木香花中的总黄酮含量.[方法]通过正交试验选择最佳提取条件,以芦丁为标样,用荧光分光光度法测定木香花中总黄酮的含量.[结果]在激发波长和发射波长为430和497 nm下,芦丁浓度与荧光强度呈良好的线性关系,标准曲线的相关系数为0.997 8,平均回收率为98.7%.RSD为0.19%.木香花中总黄酮的含量为1.09%.[结论]该方法简便、快速、准确,可用于植物及其制品中总黄酮含量的定量测定.     

不同产地短葶飞蓬中总黄酮含量的比较

[目的]研究了不同产地短葶飞蓬中总黄酮含量异同.[方法]以紫外分光光度法(UV)对云南省9个不同地点的野生短葶飞蓬含量进行测定,并对结果进行方差分析.[结果]短葶飞蓬中总黄酮单株最高含量达18.539%,最低含量为3.653%;腾冲芒棒乡1平均含量最高,禄劝县雪山乡最低.同一产地点不同植株间含量差异明显,最大变异系数为25.6%,最小变异系数为9.7%.不同产地短葶飞蓬间总黄酮含量方差结果显示,F=19.467,P=0.000 1<0.01,LSD最小显著差数多重比较表明,不同地点短葶飞蓬中总黄酮含量差异性显著.[结论]短葶飞蓬中总黄酮含量的高低是内在遗传和外在生长环境共同作用的结果,该研究结果可为云南短葶飞蓬良种选育提供依据.     

微波消解-石墨炉原子吸收法测定豆腐花中的铅

[目的]建立一种简便、快速测定豆腐花中铅含量的方法.[方法]采用微波消解法处理豆腐花样品,石墨炉原子吸收光谱法测定豆腐花中铅含量,并通过正交试验设计方法对微波消解参数进行了优化.[结果]测定铅的标准曲线相关系数为0.9994,相时标准偏差在0.32%～2.17%,加标回收率在95%～104%,检出限为1.454μg/L.[结论]用微波消解作为预处理手段,以石墨炉原子吸收分光光度法测豆腐花中铅的含量是一种可行的方法,具有精密度高、准确度好等优点.     

咔唑法测定中华鲟软骨中硫酸软骨素的含量

[目的]建立分光光度法测定中华鲟软骨中硫酸软骨素含量的方法、[方法]采用碱提-酶解法提取中华鲟软骨中硫酸软骨素,采用咔唑法,以D-萄萄糖醛酸为标准品,在硼砂-浓硫酸介质中经咔唑显色后,以蒸馏水为空白,于波长530 nm处分别测定对照品溶液和供试品溶液的吸光度,按标准曲线计算葡萄糖醛酸含量,进而转换为硫酸软骨素含量.[结果]D-葡萄糖醛酸在10～50 μg/ml范围内线性关系良好,回归方程为Y=0.015X-0.037(r=0.9997),3个不同浓度的加样回收率分别为100.87%、100.73%和101.29%(n=5),RSD值分别为2.74%、2.56%和2.22%.[结论]该方法快速,重现性好,可用作中华鲟软骨中硫酸软骨素含量的测定.     

火焰原子吸收光谱法测定牛奶中锌含量的研究

[目的]为牛乳中微量元素营养价值的研究提供参考.[方法]采用稀释法处理纯牛奶样品,并采用火焰原子分光光度法测定了纯牛奶中锌元素的含量.[结果]纯牛奶中锌元素的含量为6.25 g/ml.该方法的加标回收率为104.0%,精密度(样品相对标准偏差RSD)为0.61%.[结论]该法样品前处理简便、快捷,测定结果准确,适用于纯牛奶中锌含量的测定.     

大枣多糖铁的合成及其铁含量测定

[目的]从大枣中提取大枣多糖,然后与铁(Ⅲ)合成大枣多糖铁配合物(JPC),建立JPC中铁含量的测定方法.[方法]采用热水浸泡法提取大枣多糖;在碱性条件下,大枣多糖水溶液与三氯化铁反应合成JPC;采用邻菲罗啉分光光度法和原子吸收光谱法测定JPC中铁(Ⅲ)的含量.[结果]JPC是深棕红色无定型粉末,JPC中铁(Ⅲ)的含量:邻菲罗啉分光光度法测定结果为19.76%,原子吸收光谱法测定结果为20.37%.[结论]邻菲罗啉分光光度法和原子吸收光谱法的测定结果基本一致.     

高山绿茶浸出液中金属元素含量的测定

[目的]测定高山绿茶浸出液中金属元素的含量,为其进一步的研究利用提供参考依据.[方法]湿法消化处理和去离子水浸泡后处理高山绿茶样品,利用火焰原子吸收分光光度法(FAAS)测定Mg、Fe、Mn、Cu、Zn、Ni和cr元素的含量.[结果]高山绿茶样品中金属元素含量多少顺序为Mn>Mg>Fe>Zn>Cu>Ni>Cr;各元素的加标回收率为95.05%～101.63%;相对标准偏差为1.67%～4.07%, 准确度和精密度符合要求;不同浸泡时间茶水中金属元素含量不同,30min浸泡液含量较高.[结论]FAAS法测定高山绿茶中金属元素含量及溶出特性的方法可行, 结果可靠.     

银杏叶黄酮提取工艺的优化

[目的]优化银杏叶总黄酮的提取工艺,为银杏黄酮的精制提供前提条件.[方法]采用紫外分光光度法测定银杏叶中总黄酮的含量;用单因素试验考察乙醇浓度、回流温度、提取时间对银杏黄酮收率的影响,优化提取条件.[结果]银杏叶中总黄酮含量为1.502 6mg/ml;最佳提取条件:70%乙醇为提取剂,回流温度为80℃,提取时间为3.0 h.[结论]该研究得到银杏黄酮最佳的提取工艺,为银杏叶黄酮的精制提供了前提条件.     

转炉炉壳热应力分析

根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。     

焦炭热性能指标意义浅析

通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。     

Results of treatment of cancer of the cardia

Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.     

The effect of amount of possession of the trait of hostility on accuracy of perception of hostility in others.

Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of rates of infection of two methods of emergency ventricular drainage

The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.     

浅析《野草》的版画特征

鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".     

四辊破碎机车刀架的改造

针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。     

Effect of antibiotics of chemotaxis of human leukocytes

The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed.