Surface tension of sodium aluminate solution and the contact angle between Al(OH)3 particles and aluminate solution were measured, then the dependence of Al(OH)3 solubility on its particle size was calculated and ...Surface tension of sodium aluminate solution and the contact angle between Al(OH)3 particles and aluminate solution were measured, then the dependence of Al(OH)3 solubility on its particle size was calculated and thus the variation of the critical nucleus sizes was determined based on the Ostwald ripening formula. The results show that the Al(OH)3 solubility in sodium aluminate solution decreases with the increment of particle size, and the critical nucleus sizes increase with the rise of alkali concentration, caustic ratio and precipitation temperature. The results also imply that the presence of small particles in seeded precipitation system is an important factor to limit the depth of precipitation.展开更多
基金Project(51274242)supported by the National Natural Science Foundation of China
文摘Surface tension of sodium aluminate solution and the contact angle between Al(OH)3 particles and aluminate solution were measured, then the dependence of Al(OH)3 solubility on its particle size was calculated and thus the variation of the critical nucleus sizes was determined based on the Ostwald ripening formula. The results show that the Al(OH)3 solubility in sodium aluminate solution decreases with the increment of particle size, and the critical nucleus sizes increase with the rise of alkali concentration, caustic ratio and precipitation temperature. The results also imply that the presence of small particles in seeded precipitation system is an important factor to limit the depth of precipitation.
文摘目的探讨小剂量来氟米特配合甲氨蝶呤治疗老年首发类风湿关节炎(rheumatoid arthritis,RA)患者的效果。方法选取2020年2月至2023年2月西安市第五医院收治的120例老年首发RA患者进行随机对照试验。采用随机数字表法将其分为配合组及参考组,各60例。配合组男37例,女23例,年龄(70.22±5.29)岁,体质量指数(body mass index,BMI)(22.87±1.55)kg/m^(2),病程(4.76±0.85)年。参考组男38例,女22例,年龄(70.31±5.34)岁,BMI(22.94±1.58)kg/m^(2),病程(4.82±0.87)年。参考组采用甲氨蝶呤治疗,配合组则于参考组的基础上采用小剂量来氟米特治疗。两组均治疗90 d。对比两组临床疗效,临床症状改善情况,治疗前后骨代谢指标水平和血清壳多糖酶3样蛋白1(chitinase 3-like protein1,CHI3L1)、可溶性基质裂解素2(soluble suppression of tumorigenicity 2,sST2)、白细胞介素-32(interleukin-32,IL-32)水平,不良反应。采用χ^(2)检验和t检验。结果配合组总有效率高于参考组[96.67%(58/60)比83.33%(50/60)](χ^(2)=5.926,P=0.015)。配合组关节压痛数目、关节肿胀数目分别为(5.23±1.05)个、(4.18±0.66)个,均少于参考组的(7.45±1.36)个、(6.39±0.82)个,晨僵时长为(34.58±4.68)min,短于参考组的(50.40±8.21)min,双手握力为(14.03±2.55)kPa,高于参考组的(11.28±2.09)kPa(t=10.008、16.263、12.967、6.461,均P<0.001)。治疗后,配合组骨钙素(bone gla protein,BGP)、骨保护素(osteoprotectin,OPG)及总Ⅰ型胶原氨基端延长肽(total type I collagen amino terminal extension peptide,T-PⅠNP)水平分别为(27.48±5.02)ng/L、(5.02±0.74)ng/L、(43.17±8.59)μg/L,均高于参考组的(24.16±4.19)ng/L、(4.45±0.66)ng/L、(36.92±7.33)μg/L(t=3.933、4.453、4.287,均P<0.001)。治疗后,配合组血清CHI3L1、sST2、IL-32水平分别为(50.82±6.12)μg/L、(28.45±4.11)μg/L、(14.32±2.01)ng/L,均低于参考组的(78.45±8.39)μg/L、(33.05±5.24)μg/L、(16.85±2.77)ng/L(t=20.609、5.350、5.726,均P<0.001)。两组不良反应发生率对比,差异无统计学意义(P>0.05)。结论小剂量来氟米特配合甲氨蝶呤应用于老年首发RA患者中的效果较佳,可改善患者骨代谢指标及血清CHI3L1、sST2、IL-32水平。