The Damage Performance of Uncarbonated Limestone Cement Pastes Partially Exposed to Na2SO4 Solution

Pore structure and composition of cement paste are the main two factors in controlling the sulfate attack on concrete, but the influence of carbonization on pore structure and composition is often ignored in sulfate attack. Therefore, will the damage performance of concrete partially exposed to sulfate solution be different avoiding the alterations of pore structure and composition due to carbonation? In this paper, the cement pastes were partially immersed in 5 wt. % sodium sulfate solution, with N₂ as protective gas to avoid carbonation (20 ± 1°C, RH 65 ± 5%). Pore structures of cements were changed by introducing different contents of limestone powders (0 wt. %, 10 wt. %, 20 wt. %, and 30 wt. %) into cement pastes. The damage performance of the specimens was studied by ¹H NMR, XRD and SEM. The results showed that the immersion zone of pure cement paste under N₂ atmosphere remained intact while serious damage occurred in the evaporation zone. However, the damage of cement + limestone powders pastes appeared in the immersion zone rather than in the evaporation zone and cement pastes containing more limestone were more severely damaged. Compositional analysis suggested that the damage of the evaporation zone or the immersion zone was solely caused by chemical attack where substantial amount of gypsums and ettringites were filled in the pore volumes. Introduction of limestone powders led to the increase of the pore sizes and porosity of cement pastes, causing the damage occurred in the immersion zone not in the evaporation zone.     

Effect of Layered Double Hydroxides on the Deterioration Process of Cement Paste under Sulfate Attack

This study investigated the effect of layered double hydroxides (LDHs) on the deterioration process of cement paste in the sulfate environment. Cement pastes with the addition of original and calcined LDHs at 2.5 wt.% and 5.0 wt.% of cement were exposed to Na₂SO₄ solution for 360 days. The macroscopic performance of the cement paste was assessed based on mass variation, porosity, compressive strength, and content of sulfate ions. Furthermore, the microhardness, microstructures, and composition of the degraded pastes were examined using Vickers hardness (HV), mercury intrusion porosimetry (MIP), scanning electron microscope (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The results indicate that cement paste incorporated with LDHs can mitigate the corrosion caused by sulfate effectively, especially in the case of calcined LDHs (C-LDHs), which primarily increase the adsorption of sulfate. Compared with the control specimen, the 180 d compressive strength loss ratio of specimens with 2.5 wt.% and 5.0 wt.% of C-LDHs decreased by 63.66% and 80.51%, respectively. Moreover, LDHs can reduce the amount of ettringite crystals, densify the microstructure, and refine the pore structure to mitigate the cement paste’s sulfate corrosion significantly. Compared with the control specimen, the 180 d harmful pore volume fraction of specimens laced with 2.5 wt.% and 5.0 wt.% C-LDHs decreased by 43.77% and 54.51%, respectively. In terms of the content of C-LDHs, an optimal content of C-LDHs could ensure the dominant effect of adsorption, while excessive C-LDHs could refine pores. In addition, Vickers hardness has an excellent correlation with compressive strength, which could precisely predict the compressive strength. Moreover, by combining the Vickers hardness distribution and content distribution of sulfate ions, the cross-section of the paste could be classified into four regions to evaluate the deterioration process accurately: the degraded zone, the strengthened zone, the invaded zone, and the intact zone.     

双助益肠汤配合中药贴脐热敷治疗脾肾两虚型慢性结肠炎83例

[目的]观察双助益肠汤配合中药贴脐热敷治疗脾肾两虚型慢性结肠炎疗效。[方法]对83例患者内服自拟"双助益肠汤"水煎服,配合中药贴脐热敷,观察60天判定疗效。[结果]治愈22例(26.51%),显效29例(34.94%),好转26例(31.33%),无效6例(7.23%),总有效率为92.77%。[结论]双助益肠汤配合中药贴脐热敷治疗慢性结肠炎,内外合治,相互补充,标本兼顾,疗效确切,值得推广应用。     

中药坐浴治疗肛周湿疹临床观察

目的观察中药坐浴治疗肛周湿疹的临床疗效。方法将80例肛周湿疹的患者随机分成治疗组(40例)和对照组(40例),治疗组根据辨证分型分别选用清热利湿药物和益气养血、活血祛风药物坐浴,每日两次;对照组选用派瑞松乳膏外涂患部,每日两次。治疗3周后比较两组临床症状积分和主要症状情况,评价临床综合疗效。结果两组在治疗前后SCORAD评分、瘙痒程度、皮损面积、皮损形态方面,各项积分变化差异有统计学意义(P<0.05)。治疗后两组比较,瘙痒影响程度改善方面治疗组优于对照组(P<0.05)。治疗组皮损改善程度优于对照组(P<0.05)。治疗组痊愈率和显效率为32.5%和42.5%,对照组痊愈率和显效率为10.0%和17.5%,两组患者临床疗效比较差异有统计学意义(P<0.05)。结论中药坐浴治疗肛周湿疹较派瑞松乳膏疗效显著,能有效改善瘙痒症状及皮损表现,疗效可靠。     

正交试验筛选七白膏提取工艺的研究

目的:对七白膏的处方及制备工艺进行研究。方法:采用正交实验设计,以芍药苷含量为指标优化提取工艺。结果:最佳提取工艺为A2B2C1,即处方药材加10倍量水煎煮2次,每次1.5h。结论:经过优化后制备的七白膏各项指标符合药典规定,工艺重复性好,适于规模化生产。     

醋氯芬酸在nano-TiO2/[BnMIM]PF6修饰碳糊电极上的电催化氧化及电分析方法

目的:研究了醋氯芬酸(Aceclofenac,AC)在纳米二氧化钛(nano-TiO2)与离子液体1-苄基-3-甲基咪唑六氟磷酸盐([BnMIM]PF6)复合修饰碳糊电极(nano-TiO2-[BnMIM]PF6/CPE)上的电化学行为和电化学动力学性质,建立了AC电化学定量测定方法。方法:循环伏安法(CV),计时电流法(CA),计时库仑法(CC),方波伏安法(SWV)以及电化学交流阻抗法(EIS)。结果:在nano-TiO2-[BnMIM]PF6/CPE上AC发生了受扩散控制的不可逆电化学氧化过程。测得AC在nano-TiO2-[BnMIM]PF6/CPE上的电极反应过程动力学参数。用SWV法测得AC氧化峰电流与其浓度在5.0×10-5～1.0×10-3mol·L-1呈线性关系,检测限(S/N=3)为1.20×10-7mol·L-1。采用本方法对市售醋氯芬酸片进行了电化学定量测定,RSD在1.9%～3.0%之间,加标回收率在98.6%～103.7%之间。结论:nano-TiO2-[BnMIM]PF6/CPE对AC电化学氧化具有良好的催化作用,该方法可用于市售醋氯芬酸含量的电化学定量测定。     

关节镜与痹证膏联合治疗风湿性关节病235例

目的探讨评价外用药物和关节镜治疗各种风湿类关节炎。方法关节镜下清理各受累关节,术后一组开始外用痹症膏,两组病人均进行正规的DEMARDS口服药物治疗。并进行术前和术后六个月的评分,对关节功能进行评估。结果与结论关节清理和痹症膏通过经络的全身治疗往往能取得较好的疗效。     

李咏梅运用膏方调治黄褐斑经验

介绍李咏梅教授运用膏方调治黄褐斑的经验。认为本病发生与肝、脾、肾三脏有关,主要病机是气血生化乏源不能上承于面。通过膏方辨治,使气血生化有序,脏腑阴阳平衡,从而达到养颜消斑的目的。并举验案1则。     

基于AHP-熵权法结合星点设计-效应面试验优选清热除湿止痛液提取工艺

目的 优选清热除湿止痛液的提取工艺。方法 在单因素考察的基础上,以信息熵理论结合星点设计-效应面法,对浸泡时间、提取时间、加水量及提取次数进行考察,以绿原酸、龙胆苦苷、络石苷的含量及干膏得率为评价指标,采用信息熵理论对各评价指标赋予权重系数,并计算综合评分。通过Design-Expert 8.0.6.1软件分析各因素间的交互作用,得出优化的水提取工艺,并对该工艺进行验证实验。结果 依据信息熵理论,将绿原酸、龙胆苦苷、络石苷及干膏得率的权重系数分别确定为0.16、0.76、0.05、0.03;交互作用分析结果显示,浸泡时间对综合评分影响较大。清热除湿止痛液的最佳提取工艺确定为浸泡53 min,加9倍量水,提取3次,每次105 min;验证结果显示,各指标成分含量及综合评分RSD均小于3%。结论 优化的水提取工艺稳定、可行,可为清热除湿止痛液的进一步开发利用提供参考。     

蜂蜜干膏的质量研究

目的 建立蜂蜜干膏的质量标准.方法 采用文献调研、性状、检查和含量测定等方法进行研究.结果 观察了样品的性状特征,建立了样品的检查和含量测定方法.结论 所建立的标准可用于蜂蜜干膏的质量控制.