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采用水热法,以P25(TiO2)粉体和NaOH溶液为反应原料,水热反应制备出TiO2纳米管.采用透射电镜(TEM)、X-射线衍射(XRD)等手段对制得的纳米管的形貌、结构、组成进行了表征,并研究了其光催化性能.实验结果表明:实验所得产物为TiO2纳米管,晶型为锐钛矿型,呈多管壁结构,外径为10~30纳米,长度为几百纳米至几微米.在紫外光照射下,TiO2纳米管对亚甲基蓝(MB)的光催化降解率高于P25粉,80分钟后降解率达到60%. 相似文献
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采用电化学阳极氧化法在含氟溶液中制得结构规则、有序核-壳结构的TiO2纳米管,再以上述TiO2纳米管为基质,在一定条件下水热合成制得TiO2/ZnO纳米复合材料,对所制备的纳米复合材料进行表征。在阳极氧化电压为60 V、反应时间9 h、溶液pH=6时制得的TiO2纳米管形貌最佳,当锌浓度为0.2 mmol/L时制得TiO2/ZnO纳米复合材料的包覆明显且清晰;同等条件下采用SDS制得的纳米材料尺寸比用CTAB的小。 相似文献
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分别以无机酸性溶液(氟化铵和硫酸)和有机中性溶液(氟化铵和丙三醇)作为电解液,采用阳极氧化法在钛板表面制备出二氧化钛纳米管阵列,并以制得的纳米表面作为换热壁面,对其强化传热的性能进行实验研究。通过场发射扫描电镜表征其微观结构形貌,利用接触角测量仪检测表面的静态接触角。结果表明,有机中性溶液制备出的纳米管管径大、管壁厚,两种方法得到的纳米表面均具有亲水特性,接触角明显减小。池沸腾实验中,与未处理的钛板相比,纳米表面能够产生更多的汽化核心,有利于提高传热系数及临界热流密度。其中有机中性溶液条件下制备的纳米表面的传热系数和临界热流密度分别达到了10 kW/(m~2·℃)和330 kW/m~2,相比于未处理的钛板分别提高了66.7%和15.8%。 相似文献
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《合成纤维工业》2021,44(4)
对熔点为105.67℃的低熔点聚对苯二甲酸乙二醇酯(LPET)与普通聚对苯二甲酸乙二醇酯(PET)的熔体流变性能进行了分析,研究了两种熔体的流变性能和不同皮芯比对纺丝工艺和纤维性能的影响。结果表明:PET熔体在292~300℃、LPET在260~270℃时,两者的结构黏度指数非常接近;PET熔体的黏度较LPET对温度的依赖性更低;细旦LPET/PET皮芯复合纤维的最佳纺丝工艺为卷绕速度1 000 m/min,纺丝温度292℃,皮芯质量比为4:6,皮层与芯层单孔流量分别为2.36,3.54 mm~3/s,此工艺条件下制得的LPET/PET皮芯复合初生纤维成形完好,该初生纤维在110℃下进行3.25倍拉伸,制得的细旦LPET/PET皮芯复合纤维的单丝线密度为1.38 dtex、断裂强度为3.42 cN/dtex、断裂伸长率为22.36%。 相似文献
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主要对碳纳米管制备及活化处理改善电化学性能进行研究。以二茂铁为催化剂前驱体,环己烷为碳源,采用CVD方法制备碳纳米管。采用KOH活化的方法对碳纳米管进行活化处理,有效地的改善了其电化学容量性能。考察了在制备活性碳纳米管时的三个主要影响因素:KOH/CNTs配比、活化温度和活化时间对活性碳纳米管的电化学容量的影响。通过对比研究,KOH/CNTs比例为3∶1所制得的活性碳纳米管作为电极材料时的电化学容量较理想;当活化温度为875℃时,所制得的活性碳纳米管作为电极材料时的电化学容量出现峰值;当活化时间为1.5h,活性碳纳米管的电化学容量达到最大值。同时对未活化及活化后的碳纳米管的形态和结构进行SEM和TEM表征,并对活化机理进行初步讨论。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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我厂3号回转窑(Φ4m×60m)生产线在1996年年底由SP窑(产量912t/d)改为NSP窑(产量1320t/d),预分解系统为四级旋风预热器带离线式分解炉 相似文献
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The objective of the study was to explore the effect of the degree of deacetylation (DD) of the chitosan used on the degradation rate and rate constant during ultrasonic degradation. Chitin was extracted from red shrimp process waste. Four different DD chitosans were prepared from chitin by alkali deacetylation. Those chitosans were degraded by ultrasonic radiation to different molecular weights. Changes of the molecular weight were determined by light scattering, and data of molecular weight changes were used to calculate the degradation rate and rate constant. The results were as follows: The molecular weight of chitosans decreased with an increasing ultrasonication time. The curves of the molecular weight versus the ultrasonication time were broken at 1‐h treatment. The degradation rate and rate constant of sonolysis decreased with an increasing ultrasonication time. This may be because the chances of being attacked by the cavitation energy increased with an increasing molecular weight species and may be because smaller molecular weight species have shorter relaxation times and, thus, can alleviate the sonication stress easier. However, the degradation rate and rate constant of sonolysis increased with an increasing DD of the chitosan used. This may be because the flexibilitier molecules of higher DD chitosans are more susceptible to the shear force of elongation flow generated by the cavitation field or due to the bond energy difference of acetamido and β‐1,4‐glucoside linkage or hydrogen bonds. Breakage of the β‐1,4‐glucoside linkage will result in lower molecular weight and an increasing reaction rate and rate constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 3526–3531, 2003 相似文献
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Conclusions It is significant that the purification on a single passage of viscose through porous ceramic corresponds to the result of a two-stage filtration of it in industrial filter-presses with standard fillings.Kiev Combine. Kiev Technological Institute of Light Industry. Translated from Khimicheskie Volokna, No. 3, pp. 20–22, May–June, 1969. 相似文献
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A refined nonlinear value of the main parameter of a material, i.e., the elongation modulus versus the instant temperature value, was suggested for introduction into the computational algorithm of tempering stresses. 相似文献