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排序方式: 共有133条查询结果,搜索用时 15 毫秒
1.
复方单硝酸异山梨酯-阿司匹林双缓释微丸胶囊的研制(Ⅱ) 总被引:2,自引:0,他引:2
以乙基纤维素、丙烯酸树脂Ⅱ和丙烯酸树脂Ⅲ为骨架材料分别制备单硝酸异山梨酯和阿司匹林混合骨架缓释微丸,并通过包薄膜衣进一步控制药物的释放。通过测定微丸的释放度对处方工艺进行评价,选择最佳微丸灌装胶囊.胶囊中两种药物均达到良好的缓释效果。符合中国药典对缓释制剂的要求.其体外释放过程同时符合Higuchi方程和一级释药方程,R^2值均在0.995以上。 相似文献
2.
Orewczyk J. Jasieńska S. Iwanczenko S. 《Journal of Thermal Analysis and Calorimetry》1998,54(1):79-84
This paper presents applications of thermal analysis to observe the course of reduction of acidic pellets, metallurgical substances
whose reducibility and strength are basic parameters of use in blast furnace processes. Both parameters depend on the mineral
composition of the samples. The investigations included determination of the chemical and phase compositions of the initial
samples and reduction products.
Research was conducted on acidic pellets from Połtawa (Poland), applied in the T. Sendzimir Steelworks (Poland), in comparison
with pellets from Brazil, Canada and Lebedyn (Russia).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
A series of approaches have been assayed for FTIR determination of Mancozeb in several solid commercial fungicides using different calibration strategies. The simplest procedure was based on the use of the ratio between the absorbance of a characteristic band of Mancozeb and that of a KSCN internal standard measured in the FTIR spectra obtained from KBr pellets. It was employed the quotient between peak height absorbance values at 1525 cm−1 for Mancozeb and 2070 cm−1 for KSCN. In these conditions a precision as relative standard deviation (RSD) of 0.6% and a relative accuracy error of 0.8% (w/w) were found. For complex formulations, containing other compounds with characteristic absorption bands at different wavenumbers than Mancozeb, one of them was used as internal reference being employed the standard addition approach. In this case, the Mancozeb bands at 1525 cm−1 or at 1289 cm−1 were employed, being used the ferrocyanide band at 2075 cm−1 as internal reference. RSD values between 0.7-1.4% and a relative accuracy error of 3% (w/w) were found. A third strategy was based on the use of partial least squares (PLS) calibration. A reference set was prepared mixing Mancozeb, Kaolin, Cymoxanil and KBr, being predicted the Mancozeb concentration in pesticide formulations by using the quotient between absorbance bands of Mancozeb and those of Cymoxanil. In these conditions a relative accuracy error of 0.6% (w/w) and a relative standard deviation of 1.3% were found. 相似文献
4.
《Particuology》2022
This work investigates the proportion of generated fines in a pilot-scale experiment using a belt conveyor and commercial fuel pellets. For this, a belt conveyor with a length of 3.1 m was used and operated at varying conditions: speeds, percentages of material loading on the belt, two combinations of the inclination angle of the belt and the falling height, and a different number of handling steps. We considered a design of experiments approach based on response surface methodology to investigate the effect of different conditions on the potential of fines generation. Moreover, a comparison between the results of the belt conveyor and three common benchmark experimental approaches (tumbling box, rotary impact tester, and mechanical compression test) was made. Results show that the number of handling steps and the combined effect of drop height and inclination angle directly affected the fines generation. However, the tested belt speed range and the level of loading were of lower significance. A polynomial quadratic model was derived based on the regression analysis and showed a high accuracy to predict the proportion of fines. Moreover, the tumbling box method showed good potential to predict the proportion of fines in a belt conveyor when transported several times. 相似文献
5.
X射线荧光光谱法测定海底钴结壳的方法研究 总被引:3,自引:0,他引:3
采用粉末压片制样,X-射线荧光光谱法直接测定钴结壳中Fe、Mn、Co、Ni、Si、Al、Ca、K、Na、Ti、P、Mg、Cu、Pb、Mo、Sr、V、Zn、Zr、Y、Ba等元素。重点讨论用熔融法定值部分样品,然后用加以定值的钴结壳标准及样品、国家岩石、土壤、水系沉积物系列标准用粉末压片制样,做工作曲线,一次测量钴结壳中二十余种元素,并用定值样品做精密度与准确度试验,各元素统计结果为RSD%(n=12)除V的RSD〈4%外,其余元素的RSD均小于2%,测定结果与标准值和ICP-MS测量值相符。 相似文献
6.
王国雄 《武汉科技大学学报(自然科学版)》1991,(1)
为了解决钢铁企业粉尘污染越来越严重的问题,合理地回收和利用含铁资源,作者运用添加精矿粉和其它粘结剂成型的方法,采用回转窑预还原的工艺手段,对武钢各种含铁粉尘的回收利用进行了广泛的实验研究,探讨了回收工艺的合理性、经济性及可行性,获得了适宜于作为高炉炉料或炼钢用添加料的优质球团。 相似文献
7.
建立了制备载体催化剂干法浸渍步骤的过程模型,给出了该模型的数值解法,并用实验对模型加以检验。研究表明:吸附平衡常数、相对吸附系数、润湿角及浸渍时间等参数对载体催化剂内活性前体的浓度分布具有显著影响。 相似文献
8.
王国惠 《中山大学学报(自然科学版)》2007,46(3):112-116
自活性污泥中筛选到一株对重金属Cr(VI)有很强吸附能力的霉菌菌株G-28。结果表明,G-28菌丝球吸附铬的适宜pH为1.0~3.0,适宜温度为20~45℃。在Cr(VI)初始浓度10~60mg·L^-1范围内,G-28对Cr(VI)吸附效果明显。该菌株吸附铬的适宜摇速为150~180r·min^-1,吸附率达98.2%~98.8%。培养48h的菌丝球对Cr(VI)的吸附率最大。吸附动力学研究表明,G-28对铬的吸附0~2h是一个快速过程,而2~12h为慢吸附过程,12h后趋于平衡。G-28菌丝球灭活后,仍具有较强的吸附能力。G-28对电镀废水Cr(VI)的吸附率高达99.1%。 相似文献
9.
有机粘结剂替代膨润土制备氧化球团 总被引:1,自引:1,他引:1
为了提高球团矿铁品位,研究新型有机粘结剂D替代膨润土对球团制备的影响。研究结果表明:采用有机粘结剂D完全替代膨润土,当其用量为0.25%~0.30%(质量分数)时,即可获得满足要求的生球性能及成品球强度,但预热球强度很低,只有100 N/个左右,只能用于对预热球强度要求不高的球团生产工艺;而有机粘结剂D部分替代膨润土时,不仅可以获得良好的生球性能及成品球强度,预热球强度也可满足生产要求;在0.10%有机粘结剂D和0.50%膨润土的条件下,生球落下强度大于3次/(0.5 m),且爆裂温度大于600℃,成品球强度达到2.6~2.9 kN/个,预热球强度大于400 N/个;有机粘结剂D的应用使球团铁品位明显提高,用0.30%有机粘结剂D完全替代膨润土时,球团铁品位为64.07%,比1.0%膨润土的球团提高0.76%;采用0.10%有机粘结剂D和0.50%膨润土时,球团铁品位为63.74%,比1.0%膨润土球团提高0.43%。 相似文献
10.
基于还原炉控温还原实验,通过分析CO和H2还原球团矿过程中的反应速率模型,提出两种气体混合后还原球团矿的反应动力学模型,得到还原过程中阻力和反应速率随温度及还原度的变化规律,得出结论:CO还原球团矿时,内扩散阻力所占比例随着温度及还原度增加而变大;H2还原球团矿时,内扩散属于速率控制环节;混合气还原球团矿时,反应速率随温度升高而增大,温度低于500℃时,CO浓度增加,反应速率降低,而温度超过500℃后,反应速率则随着CO浓度的增加而增大;混合气反应速率模型的计算值与实验结果一致。 相似文献