氧化钙—HD—1型除氟剂处理含氟废水的研究

本文研究应用氧化钙—HD-1型除氟剂对磷肥厂的含氟废水进行了处理,通过一系列条件选择实验,确定了最佳反应条件。大量实验结果表明:本除氟体系可将含氟28～40mg/L的废水降至10mg/L以下,符合我国工业废水排放标准。除氟后的废水可循环使用,处理后产生的沉淀可以作肥料,不产生二次污染。用本法处理含氟废水工艺简便,操作方便,成本低廉,较有实用价值。

光固化型氢氧化钙间接盖髓的疗效观察

深龋窝洞制备近髓后间接盖髓,对维持牙髓正常的生理功能至关重要。目前可选用的盖髓剂种类较多,选择合适得盖髓剂是深龋治疗成功的关键。氢氧化钙是应用最为广泛的制剂,将其覆盖于已经暴露或即将暴露的牙髓,隔离外界刺激,促使牙髓形成牙本质桥,从而保全牙髓生理功能。我们选用光固化型氢氧化钙作间接盖髓剂,对其临床应用效果进行观察。

Dycal氢氧化钙和粉剂型氢氧化钙盖髓的临床疗效比较

目的比较Dycal氢氧化钙和粉剂型氢氧化钙盖髓的临床疗效。方法将63例患者的63颗惠牙分成3组，第一组选择深龋近髓20颗忠牙，第二组选择深龋穿髓20颗患牙，第三组选择意外穿髓23颗患牙。3组病例分别用Dycal氢氧化钙和粉剂型氢氧化钙盖髓。结果盖髓治疗3个月后追踪观察，深龋近髓的患牙用Dycal氢氧化钙盖髓的成功率（90．0％）与用粉剂型氢氧化钙盖髓的成功率（80．0％）比较，二者无显著性差异（P〉0．05）；深龋穿髓的惠牙用Dycal氢氧化钙盖髓的成功率（75．0％）明显高于用粉荆型氢氧化钙盖髓的成功率（50．0％），二者比较具有显著性差异（P〈0．05）；意外穿髓的患牙用Dycal氢氧化钙盖髓的成功率（84．6％）与用粉剂型氢氧化钙盖髓的成功率（60．0％）比较。二者具有显著性差异（P〈0．05）。结论Dycal氩氧化钙对深龋穿髓和意外穿髓惠牙的盖髓疗效明显优于粉刺型氢氧化钙。Dycal氢氧化钙凝固快，操作方便，盖髓疗效好，是一种较理想的盖髓材料。

光固化型氢氧化钙间接盖髓治疗深龋的临床观察

深龋是临床中比较常见的牙齿疾病，而且一个患者常常有多颗牙齿出现深龋，因为牙髓具有防御、修复、营养牙齿的重要功能，所以临床治疗过程中要尽量保护牙髓。当龋齿发展至牙本质深层时，牙髓极易被外界的物理、温度、化学和龋坏牙本质的细菌及代谢产物所激惹，临床症状明显。2013年，笔者对深龋患牙采用光固化型氢氧化钙间接盖髓后进行充填治疗，其中部分患者采用一次性充填治疗，效果满意，现总结报告如下。

注射型碘仿氢氧化钙糊剂治疗乳牙根尖炎疗效观察

目的 :探讨注射型碘仿氢氧化钙充填治疗乳牙根尖周炎的临床效果。方法 :2 1 0例乳牙根尖周炎随机分成两组 ,用注射型碘仿氢氧化钙及丁香油氧化锌进行充填治疗 ,随访观察 1～ 2年。结果 :注射型碘仿氢氧化钙充填 1 2 4例中成功 1 1 7例 ,成功率 94.3 % ;对照组氧化锌丁香油充填的86例 ,成功 70例 ,成功率 81 .4% ,两组差异有显著性 (P<0 .0 0 5 )。结论 :注射型碘仿氢氧化钙充填治疗乳牙根尖炎 ,操作简便 ,疗效显著 ,值得临床广泛推广应用。

改良型氢氧化钙糊剂在一次性根管充填治疗中的疗效评价

目的探讨改良型氢氧化钙糊剂在根管治疗中的可行性及疗效。方法比较改良型糊剂与传统型糊剂在充填后72h及1年后的疗效。结果改良型氢氧化钙糊剂一次性根管充填治疗术后72h及1年后疗效优于传统型糊剂,两者差异有显著性。结论改良型氢氧化钙糊剂用于一次性根管治疗操作简便,术后反应轻微,远期疗效稳定。

氢氧化钙与Vitapex糊剂治疗慢性窦道型乳牙根尖周炎的比较研究

目的比较分析应用注射型碘仿氢氧化钙(Vitapex)糊剂与氢氧化钙糊剂治疗慢性窦道型乳牙根尖周炎的效果和安全性。方法 88例慢性窦道型乳牙根尖周炎患者随机分成对照组和观察组,各44例。对照组患者应用氢氧化钙糊剂进行治疗,观察组患者应用Vitapex糊剂进行治疗,所有患者均随访1年,比较两组患者治疗后疼痛发生率以及治疗成功率。结果对照组患者治疗后疼痛率为20.5%,高于观察组的9.09%,差异有统计学意义(P<0.05)。治疗后随访1年,对照组患者治疗成功率为84.1%,低于观察组的95.5%,差异有统计学意义(P<0.05)。结论慢性窦道型乳牙根尖周炎应用Vitapex糊剂进行治疗与氢氧化钙糊剂相比较,具有相容性好、操作简单方便、杀菌作用强、疼痛反应轻以及治疗成功率高的技术优势,更适于慢性窦道型乳牙根尖周炎的根充治疗,在基层医院具有更广泛的应用前景。

抗水化型氧化钙的水化过程

用X—射线衍射仪对含Al_2O_3的氧化钙熟料在不同条件下放置过程中水化产物进行了鉴定;用电子探针分析了Al_2O_3等在CaO基体中的分布.结果进一步证实了这种熟料抗水化的原因在于其极低的显气孔率和发育良好的CaO晶粒自身水化活性的降低,C_3A分布在CaO晶粒周围也起到了保护CaO晶粒免于水化的作用.

自固化型氢氧化钙Dycal与光固化型氢氧化钙Calcimol LC对间接盖髓术的疗效对比

目的:探讨自固化型氢氧化钙Dycal与光固化型氢氧化钙Calcimol LC对间接盖髓术的疗效。方法:选取2018年1月—2021年1月在本院接受治疗的50例深龋患牙患者,经随机数字表法分为两组。对照组(25例)采用自固化型氢氧化钙Dycal实施间接盖髓术,观察组(25例)采用光固化型氢氧化钙Calcimol LC实施间接盖髓术。分析两组患者盖髓成功率、牙周健康指标、咬合指数及舒适度。结果:观察组深龋近髓、去龋穿髓、意外穿髓成功率高于对照组;治疗后观察组牙齿硬率高于对照组,软、非常软率及牙髓炎发生率低于对照组,且观察组咬合时间更短,左右两侧咬合力平衡度更低,舒适度评分更高(P<0.05)。结论:将光固化型氢氧化钙Calcimol LC作为深龋患牙患者的间接盖髓剂,不仅能够提高盖髓成功率,避免患者引发牙髓炎,还能促进其咬合能力及舒适度的进一步提升,有助于提高患者的牙齿硬度。

膨胀剂对水泥基灌浆材料性能的影响

为提高水泥混凝土的机械强度,避免产生裂缝,指出了水泥基灌浆材料的性能缺陷。以氧化镁基膨胀剂为例,分析了其在水泥基灌浆材料中的水化作用机理,探讨了不同类型膨胀剂对水泥基灌浆材料性能的影响,以提高水泥基灌浆材料结构的延展性及耐久性。

两种不同剂型氢氧化钙对间接盖髓术疗效的影响

探究自固化型氢氧化钙Dycal(美国登士柏公司)与光固化型氢氧化钙 TheraCal LC(美国BISCO公司)对间接盖髓术(indirect pulp capping,IPC)的疗效。方法 选取2021年3月—2022年3月南京市溧水区人民医院口腔科收治的深龋患牙患者80例,经随机数字法分为对照组(n40)与观察组(n40),对照组行Dycal治疗,观察组行TheraCal LC治疗,观察两组患者盖髓治疗效果、牙周健康度及牙齿咬合能力。结果 治疗6个月后,两组治疗成功率比较无统计学意义(P>0.05);治疗6个月后,两组牙周健康度比较无统计学意义(P>0.05);治疗前,两组患者咬合时间、左右两侧咬合力无差异(P>0.05);治疗后6个月,两组咬合时间、左右两侧咬合力均降低,其中观察组低于对照组(P<0.05)。结论 盖髓术应用TheraCal LC治疗深龋患牙,可缩短患者咬合时间,增强咬合能力,降低患者痛苦,具有积极意义。

Catalytic removal of volatile organic compounds using ordered porous transition metal oxide and supported noble metal catalysts

Most of volatile organic compounds （VOCs） are harmful to the atmosphere and human health. Cata‐lytic combustion is an effective way to eliminate VOCs. The key issue is the availability of high per‐formance catalysts. Many catalysts including transition metal oxides, mixed metal oxides, and sup‐ported noble metals have been developed. Among these catalysts, the porous ones attract much attention. In this review, we focus on recent advances in the synthesis of ordered mesoporous and macroporous transition metal oxides, perovskites, and supported noble metal catalysts and their catalytic oxidation of VOCs. The porous catalysts outperformed their bulk counterparts. This excel‐lent catalytic performance was due to their high surface areas, high concentration of adsorbed oxy‐gen species, low temperature reducibility, strong interaction between noble metal and support and highly dispersed noble metal nanoparticles and unique porous structures. Catalytic oxidation of carbon monoxide over typical catalysts was also discussed. We made conclusive remarks and pro‐posed future work for the removal of VOCs.

Kinetic model for calcium sulfate decomposition at high temperature

A modified shrinking unreacted-core model,based on thermogravimetric analysis,was developed to investigate CaSO4 decomposition in oxy-fuel combustion,especially under isothermal condition which is difficult to achieve in actual experiments due to high-temperature corrosion.A method was proposed to calculate the reaction rate constant for CaSO4 decomposition.Meanwhile,the diffusion of SO2 and O2,and the sintering of CaO were fully considered during the development of model.The results indicate that the model can precisely predict the decomposition of CaSO4 under high SO2 concentration（1100×10-6）.Concentrations of SO2 and O2 on the unreacted-core surface were found to increase first and then decrease with increasing temperature,and the average specific surface area and porosity of each CaO sintering layer decreased with increasing time.The increase of SO2 and/or O2 concentration inhibited CaSO4 decomposition.Moreover,the kinetics of CaSO4 decomposition had obvious dependence on temperature and the decomposition rate can be dramatically accelerated with increasing temperature.

Photocatalytic Degradation of Water-Soluble Dyes by LaCoO_3

Pervoskite type oxides LaCoO 3 was prepared by citrate method with the granula of 20 nm-30 nm. With a fluorescent Hg lamp or sunlight as irradiator, the degradation experiments of various water soluble dyes were carried out in the suspension system of LaCoO 3 . The results show that the pervoskite type oxide LaCoO 3 has good photocatalytic activity.Studied by X ray photoelectron spectroscopy and photoacoustic spectra, its photocatalytic activity is found to be related with factors such as the d electron structure of ion Co 3+ ,Co—O binding energy and adsorbed oxygen on the surface etc.

Effect of Calcium Oxide Additive on the Performance of Iron Oxide Sorbent for High-Temperature Coal Gas Desulfurization

The effect of calcium oxide additive in iron oxide sorbent for hot gas desulfurization was investigated by XRD and TPR techniques.XRD characterization showed that CaO was highly dispersed after the calcination of sorbents.Calcium sulfate formed in the desulfurization was decomposed and regenerated to CaO by reacting with CO before the next sulfidation process.Calcium participated in every sulfidation/regeneration cycle and contributed to the enhancement of sulfur capacity.The TPR results showed that the reduction temperature of the sorbent increased with the increase of the content of calcium.Calcium played a role of retarding reduction.Therefore,the addition of calcium oxide additive will benefit the utilization of iron oxide sorbent in strongly reducing atmospheres.

Photocatalytic Degradation of Water-Soluble Dyes by LaCoO3

Pervoskite type oxides LaCoO 3 was prepared by citrate method with the granula of 20 nm-30 nm. With a fluorescent Hg lamp or sunlight as irradiator, the degradation experiments of various water soluble dyes were carried out in the suspension system of LaCoO 3 . The results show that the pervoskite type oxide LaCoO 3 has good photocatalytic activity.Studied by X ray photoelectron spectroscopy and photoacoustic spectra, its photocatalytic activity is found to be related with factors such as the d electron structure of ion Co 3+ ,Co—O binding energy and adsorbed oxygen on the surface etc.

Performance of Ni-based, Fe-based and Co-based Oxygen Carriers in Chemical-Looping Hydrogen Generation

Ni-based, Fe-based and Co-based oxygen carriers with perovskite oxides used as the supports were prepared by citric acid complexation method, The oxygen carriers were characterized by thermal analysis, H2-temperature-programmed reduction and X-ray diffraction methods. Performance tests were evaluated through Chemical-Looping Hydrogen Genera- tion in a fixed-bed reactor operating at atmospheric pressure. The characterization results showed that all samples were composed of metal oxides and perovskite oxides. Performance results indicated that CH4 conversion over the oxygen car- riers decreased in the lbllowing order： NiO/LaNiO3〉Co203/LaCoO3〉Fe203/LaFeO3. The ability of NiO/LaNiO3 and F%O3/ LaFeO3 to decompose water was stronger than that of Co203/LaCoO3 as evidenced by our experiments. H2 amounting to 80 mL upon reacting on methane in every cycle could be completely oxidized by NiO/LaNiO3 at 900℃ in the period from the third cycle to the eighth cycle.

Preparation and application of perovskite-type oxides for electrocatalysis in oxygen/air electrodes

Recent advances in the preparation and application of perovskite-type oxides as bifunctional electrocatalysts for oxygen reaction and oxygen evolution reaction in rechargeable metal-air batteries are presented in this review.Various fabrication methods of these oxides are introduced in detail,and their advantages and disadvantages are analyzed.Different preparation methods adopted have great influence on the morphologies and physicochemical properties of perovskite-type oxides.As a bifunctional electrocatalyst,perovskite-type oxides are widely used in rechargeable metal-air batteries.The relationship between the preparation methods and the performances of oxygen/air electrodes are summarized.This work is concentrated on the structural stability,the phase compositions,and catalytic performance of perovskite-type oxides in oxygen/air electrodes.The main problems existing in the practical application of perovskite-type oxides as bifunctional electrocatalysts are pointed out and possible research directions in the future are recommended.