Vapor Pressures of Di-n-Butyl Phthalate and Di-iso-ButylHexahydrophthalate at Reduced Pressures     

齐欣  徐立勇  高正红  刘志华 《天津大学学报(英文版)》2004,10(3):229-232

In this paper the measured values of the vapor pressures by ebulliometer method of two important maleic anhydride recovery solvents, di-n-butyl phthalate (DBP) and di-iso-butyl hexahydrophthalate (DIBE),between 0. 63-17. 79 kPa and 0. 49-30. 95 kPa,are reported respectively. A comparison of the data of DBP with the published data has been made, which shows good consistency. For the convenient use of these vapor pressures, Cragoe equation, Antoine equation and Kirchhoff equation are selected to correlate them. The correlating results show that Antoine equation is the best one of the three equations to fit for the vapor pressures of the two solvents. According to Clausius-Clapeyron equation, the linear relationship between natural logarithm of pressure and reciprocal of temperature is used to calculate the molar latent heats of evaporation of the two organic solvents. The molar latent heats of evaporation of DBP and DIBE are 75.1 kJ/mol and 67.7 kJ/mol, respectively.  相似文献   

Gel time of calcium acrylate grouting material     

韩同春 《Journal of Zhejiang University. Science. B》2004,(8)

INTRODUCTION One of the main advantages of chemical groutsis easy control of gel time (Mollamahmutoglu andLittlejohn, 1996; ?nupárek and Soucek, 2000).Calcium acrylate is a chemical grout usually used ingeotechnical engineering (Zelanko and Karfakis,1997), and is a water-soluble monomer that po-lymerizes in an aqueous solution. The rate of po-lymerization is controlled by the concentration ofcatalyst and activator. The polymerization of cal-cium acrylate is free radical chain pol…  相似文献   

工业废渣在NH600t/d五级旋风预热器窑上的应用   总被引：2，自引：0，他引：2  

李香玲 《洛阳工业高等专科学校学报》2003,13(2):29-30

利用高碳粉煤灰、电石渣等工业废渣代替粘土和部分石灰石配料，优化操作参数、强化煅烧，使NH600t/d五级旋风预热器窑产量达到28t/h以上，熟料标号达到60MPa，熟料热耗2400KJ/kg，取得了优质、高产低能耗的效果．  相似文献   

Expression and proteolytic activity of calpain in lens epithelial cells of oxidative cataract     

徐雯  姚克  孙朝晖  王凯军  申屠形超 《浙江大学学报(A卷英文版)》2004,5(6):743-748

Objective: To study the role of calpain in the mechanism of oxidative cataract through detecting the level of intracellular free Ca2 , the expression and proteolytic activity of calpain in the lens epithelial cells (LECs) of H2O2-induced cataract. Methods: Rat lenses were cultured in vitro and cataract was induced by H2O2. The level of intracellular free Ca2 was measured by fluorescence determination with fura-2/AM. The expression of m-calpain protein in LECs was detected with immunohistochemical method. The proteolytic activity in LECs was measured using a fluorogenic synthetic substrate. Results: There were significant differences of the level of intracellular free Ca2 (P=0.001, 0.000, 0.000), the expression of m-calpain (P=0.001, 0.000, 0.000) and the proteolytic activity of calpain (P=0.001, 0.000, 0.000) between H2O2-induced and control group at 6, 12 and 24 h, respectively. Conclusions: H2O2 can increase intracellular free Ca2 , then enhance the expression and proteolytic activity of calpain which may play a role in the mechanism of oxidative cataract of rat.  相似文献   

TiO2悬浮态体系光催化降解邻苯二甲酸乙酯的研究     

程沧沧刘立  万昆周菊香  胡德文 《培训与研究》2005,22(2):6-8

研究了以悬浮态TiO2为催化剂，在波长为365nm的125W紫外灯照射下加入H2O2对邻苯二甲酸乙酯(DEP)光催化降解，分别讨论了pH值、H2O2的加入量、邻苯二甲酸乙酯的初始浓度及光照时间对DEP的降解效果。结果表明：在pH=2、浓度为50mg/l的H2O2中对初始浓度为50mg／L的邻苯二甲酸乙酯溶液光照120分钟有较好的降解效果。  相似文献   

燃煤型氟骨症患者血清钙、磷及碱性磷酸酶的变化   总被引：1，自引：0，他引：1  

陈应康  田培燕  叶劲松  莫开勇  杨小军  余跃生 《河北北方学院学报(医学版)》2008,25(4)

目的:了解燃煤型氟骨症患者血清Ca、P和ALP的变化。方法:分别测定99例燃煤型氟骨症患者和61例非病区健康人群血清Ca、P和ALP水平。结果:氟骨症患者血清Ca(2.12±0.24mmol/L)明显低于健康对照组(2.51±0.14mmol/L),血清P(1.24±0.41mmol/L)和ALP(90.22±29.21U/L)明显高于对照组(分别为1.09±0.28mmol/L和73.64±23.93U/L),差异均具有统计学意义(P<0.01)。结论:在排除其他代谢性骨病的条件下,血清Ca、P和ALP可作为氟骨症辅助诊断的生化指标。  相似文献   

Oxidative stress and calcium-phosphorus levels in Rheumatoid arthritis     

S. D. Walwadkar  A. N. Suryakar  R. V. Katkam  K. M. Kumbar  R. D. Ankush 《Indian journal of clinical biochemistry : IJCB》2006,21(2):134-137

Generation of reactive oxygen species is an important factor in the development and maintenance of rheumatoid arthritis (RA) in humans. This study was undertaken to investigate interplay among oxidants, antioxidants and pathogenesis of Rheumatoid arthritis. Serum levels of lipid peroxides, nitric oxide, vitamin E and ratio of calcium/phosphorus in RA patients were determined and compared with normal healthy controls. Significant increases in lipid peroxides (p<0.001) and nitric oxide (p<0.001) levels were found in patients presenting with RA as compared to controls. Whereas significant decrease in vitamin E (P<0.001) and calcium/phosphorus ratio (p<0.001) were found in Rheumatoid arthritis patients as compared to controls. Positive correlation was found between lipid peroxides and nitric oxide as well as between vitamin E and calcium. While lipid peroxides and nitric oxide were correlated negatively with vitamin E. whereas negative correlation was observed between MDA and Calcium/Phosphorus ratio in patients with rheumatoid arthritis. Our findings suggest that there is a close association between bone loss and oxidative threat in patients presenting with Rheumatoid arthritis.  相似文献   

复方血栓通软胶囊联合阿托伐他汀钙片治疗老年高脂血症的临床观察     

韦尚珠 《大众科技》2016,(7)

目的:观察复方血栓通软胶囊联合阿托伐他汀钙片治疗老年高脂血症的临床疗效。方法:将64例符合纳入标准的高脂血症患者随机分为对照组和观察组,对照组应用阿托伐他汀钙片治疗,观察组应用复方血栓通软胶囊联合阿托伐他汀钙片治疗,两组治疗前后进行疗效比较。结果:治疗后观察组与对照组比较,血清总胆固醇、甘油三脂、低密度脂蛋白明显降低,高密度脂蛋白明显升高,差异均具有统计学意义(P0.05);观察组总有效率为,对照组总有效率为,两组比较差异有统计学意义(P0.05)。结论:复方血栓通软胶囊联合阿托伐他汀钙片治疗老年高脂血症能够迅速降低总胆固醇、甘油三脂、低密度脂蛋白,具有较好的临床疗效,值得广泛推广。  相似文献   

Expression and proteolytic activity of calpain in lens epithelial cells of oxidative cataract     

徐雯  姚克  孙朝晖  王凯军  申屠形超 《Journal of Zhejiang University. Science. B》2004,(6)

INTRODUCTION The association between oxidative stress andcataract formation is well known from both clinicaland experimental data. The mechanism throughwhich oxidative stress causes cataract has not yetbeen established. It is known that many kinds ofcataract are related to increased levels of calcium.This has raised interest in the involvement of cal-cium-activated proteases. Calpains are non-lysosomal, cysteine prote-ases activated by calcium, which are found in mostmammalian…  相似文献   

钙浸种对盐胁迫下鸡冠花种子萌发的影响     

张雪平  王雪娟  周玉丽  王成正 《安徽科技学院学报》2012,26(1):27-31

研究CaCl2浸种处理对NaCl胁迫下鸡冠花种子萌发的缓解效应。结果表明,NaCl胁迫抑制了鸡冠花的萌发和生长,NaCl浓度高于100mmol/L时,抑制作用显著加强;较低浓度的CaCl2浸种能缓解鸡冠花种子受到的盐胁迫伤害,而浓度过高,缓解作用减弱甚至消失;试验中CaCl2以80mmol/L的浸种效果最好,在各种浓度盐胁迫下,均能提高种子的发芽率、发芽指数、活力指数,促进胚轴和胚根的生长。适宜浓度的CaCl2浸种能够缓解盐胁迫对鸡冠花种子萌发和生长的抑制作用。  相似文献