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Alum is found to catalyze efficiently the one-pot, three-component condensation of aldehydes, α/β-naphthol, and dimedone to afford various 12-substituted-8,9,10,12-tetrahydrobenzoxanthen-11-ones in excellent yields. The use of alum catalyst and the solvent-free conditions make this method simple, convenient, eco-friendly, and cost-effective. 相似文献
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Coagulation-crossflow microfiltration of domestic wastewater 总被引:1,自引:0,他引:1
The effect of using alum, polyaluminum silicate sulfate (PASS), and lime as coagulants on the performance of crossflow microfiltration of domestic wastewater was investigated. The primary membrane used throughout the study was made of woven polyester, while the dynamic membrane was formed by circulating MnO2 precipitate. Slug doses of the coagulants were added to the circulation tank of the experimental setup at the beginning of each run. Doses of 20 to 120 mg/l of alum were investigated at pH of 7. The results showed an improvement in flux values with the increase in alum dose until an optimum dose beyond which no significant improvement was seen. Flux improvement was attributed to the agglomeration of particles which can be easily swept away by the shearing actions created by the crossflow velocity. Permeate quality was not found to be significantly affected by the increase in alum dose. PASS, which is an aluminum salt, was seen to behave in the same manner as alum when used as a coagulant. Lime was not found to be a suitable coagulant under these conditions. 相似文献
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Minoo Dabiri Peyman Salehi Mostafa Baghbanzadeh Mahboobeh Bahramnejad 《Monatshefte für Chemie / Chemical Monthly》2007,138(12):1253-1255
Summary. Alum (KAl(SO4)2 · 12H2O) catalyzed the efficient synthesis of mono- and disubstituted 1,3,4-oxadiazoles by the condensation of acyl hydrazides with
orthoesters under solvent-free conditions at 100°C. This methodology offers significant improvements for the synthesis of
oxadiazoles with regard to the yield of products, simplicity in operation, inexpensive reagents, and green aspects by avoiding
toxic catalysts and solvents. 相似文献
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A simple and efficient procedure for the synthesis of spirooxindole has been described that employs a three-component condensation reaction in one pot using isatin, active methylene reagent, and 1,3-dicarbonyl compounds in an aqueous medium. 相似文献
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An efficient green protocol for the preparation 3,4,6-trisubstituted 2-pyridone of employing a condensation reaction of cyanoacetamide and acetylacetone in the presence of KAl(SO4)2·12H2O in water has been described.The present procedure offers advantage such as shorter reaction time,simple workup,and excellent yields. 相似文献
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改性明矾浆和滤食性动物控制月湖的蓝藻水华 总被引:7,自引:0,他引:7
2000年初夏宁波月湖发生大面积蓝藻水华。同年8月1m^2水面喷洒55.6g改性明矾浆应急除藻后,蓝藻水华基本消失。2000年底和2001年初,1 hm^2水面放养尾均重25.6g鲢、鳙鱼种3500尾和平均体长7.5cm的三角帆蚌蚌种6700尾。2001和2002年不再出现蓝藻水华,水体表观质量明显提高,透明度保持在100cm以上。2001年8月份月湖浮游蓝藻数量比2000年同期下降87.5%,总氮下降26.0%,总磷下降70.0%。 相似文献
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Maged H. Zohdy Abdel Wahab M. El-Naggar Nisreen M. Ali 《European Polymer Journal》2009,45(10):2926-2934
A novel coating formulation to impart ultraviolet (UV) protection property to cotton, Polyethylene trephethalate (PET) and cotton/PET fabrics was prepared and gamma rays as an ionizing radiation was utilized for surface curing. Natural occurring aluminum potassium sulfate (Alum) was used individually and in binary coat with Zinc Oxide (ZnO), to induce the UV-blocking properties. It was found that using Alum (0.3 g/ml) caused a prompt increase in ultraviolet protection factor (UPF) over the uncoated fabrics. Moreover, the incorporated ZnO in the binary coat increased the UPF for two to threefold than the stand-alone Alum coating, specially in case of PET coated fabric. Water absorbance and moisture regain of ZnO and Alum/ZnO coated fabrics showed a decrease over the blank samples, due to the usage of oligomer/monomer combination. On contrary, Alum showed a hydrophilic effect with the increase in its content in the formulation. Surface Electron Microscope showed the homogenous coating of fibers. X-ray diffraction (XRD), energy dispersive X-ray (EDX) and water vapor permeability were also tested for coated samples. 相似文献
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《Journal of heterocyclic chemistry》2017,54(3):2085-2089
4‐Nitro‐2,3‐dihydrospiro[imidazo[1,2‐a ]indeno[2,1‐e ]pyridine‐5,3′‐indoline]‐2′,6(1H )‐dione derivatives have been synthesized in good yields in a one‐pot four‐component, and efficient process by reaction of corresponding isatins, 1,3‐indandione, diamine, and nitro ketene dithioacetal in the presence of KAl(SO4)2.12H2O (Alum) as a nontoxic and easily available heterogeneous green catalyst. 相似文献
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