双电层电容器用煤基活性炭的制备与电化学性能表征

以河南永城无烟煤为原料、KOH为活化剂制备了高比表面积的煤基活性炭,采用低温N_2吸附法对活性炭的比表面积、孔容及孔径分布进行了表征,并对其用作双电层电容器电极材料的电化学性能进行了系统测试.在KOH与煤的质量比为4:1、活化温度为800℃、活化时间为1h的条件下制备出的活性炭其比表面积高达3224m~2/g,总孔容达1.76cm~3/g,中孔率为57.95%.该活性炭电极在3mol/L KOH电解液中的比电容高达324F/g,且具有良好的循环性能,当电流密度为40mA/g时,经1000次循环后,比电容保持率超过92%,且其漏电流很小.     

柚子皮基层次孔炭的制备及电化学性能

以柚子皮水热炭为前驱体,KOH为活化剂,800℃活化制备层次孔炭电极材料。采用扫描电子显微镜(SEM)、N2吸附法对活性炭的表面形貌和孔结构进行了表征,并评价了其在无机电解液体系(3mol/L KOH)中的电化学性能。结果表明,碱碳比为1∶1时制备的活性炭呈蜂窝状结构,其比表面积、总孔容分别达到1421 m2/g和0.7626cm3/g,相应的电极材料具有典型的双电层电容特性,质量比电容和体积比电容分别达到226F/g和250F/cm3(电极片密度为1.1g/cm3),1000次循环之后电容保持率达到91.45%。与柚子皮直接活化制备的电极材料相比,质量比电容和体积比电容分别增加了31.40%和37.36%。     

利用核桃壳制备高比表面积活性炭电极材料的研究

以核桃壳为原料,采用KOH活化法制备活性炭,并将其用作超级电容器电极材料。利用N2吸附和扫描电镜(SEM)表征活性炭的孔结构及表面形貌,系统研究碱炭比(KOH与核桃壳炭化料的质量比)对活性炭孔结构的影响,并采用恒流充放电及循环伏安等测定核桃壳活性炭电极材料在3mol/L KOH电解液中的电化学性能。结果表明,随着碱炭比的增大,活性炭的比表面积、总孔容及中孔比例先逐渐增大后稍有减小。当活化温度为800℃,活化时间为1h,碱炭比为4时,可制备出比表面积为2404m2/g,总孔容为1.344cm3/g,中孔比例为28.6%,孔径分布在0.7~3.0nm之间的高比表面积活性炭。该活性炭用作超级电容器电极材料具有良好的大电流放电特性和优异的循环性能,电流密度由50mA/g提高到5000mA/g时,其比电容由340F/g降低到288F/g,经1000次循环后,比电容保持率为93.4%。     

玉米芯活性炭的制备及其电化学性能研究

以玉米芯为原料,采用KOH活化法制备超级电容器用活性炭。利用低温氮气吸附及恒流充放电、循环伏安、交流阻抗等方法测定活性炭的孔结构及其用作电极材料的电化学性能。研究了脱灰对玉米芯活性炭孔结构及其电化学性能的影响。结果表明,在碱炭比3∶1、活化温度为800℃、活化时间为1h的条件下,可以制备出比表面积为2019m2/g、总孔容为1.084cm3/g、中孔率为15.6%的高比表面积活性炭。玉米芯经脱灰处理可以显著改善其所制活性炭的孔隙发达程度和中孔分布,脱灰玉米芯活性炭的比表面积、总孔容及中孔率分别可达2311 m2/g、1.246cm3/g和26.0%。玉米芯活性炭电极材料在3mol/L KOH的电解液中具有良好的电化学性能,其比电容量可达253F/g。脱灰玉米芯活性炭电极的比电容量更高(可达278F/g),比电容提高9.9%,且内阻更小。     

丝瓜络基活性炭电极材料的制备及其电化学性能表征

以丝瓜络作为前驱体,KOH为活化剂,在不同温度下炭化、活化制备活性炭,并将其作为超级电容器电极材料。采用N2吸附及电化学测试对活性炭的孔结构和电化学性能进行了表征,研究了炭化温度、碱炭比对活性炭电极材料孔结构和电化学性能的影响。结果表明:丝瓜络经过一步炭化即可制备出电化学性能优异的炭材料,经过KOH活化后比电容明显增加,在碱炭比为2时制备活性炭的比表面积、总孔容分别达到1549m2/g和0.901cm3/g,比电容达到228F/g,是未活化炭化物比电容的2.5倍,是一种理想的电极材料。活性炭作为电极材料,其比表面积存在一个最佳值,孔的容积、大小和形状对电解质离子的储存、扩散有着重要作用,对电化学性能有很大影响。     

炭化温度对酚醛树脂基活性炭孔结构及电化学性能的影响研究

以酚醛树脂为炭前驱体,KOH作活化剂,通过调节炭化温度在相同活化条件下制备了具有不同孔隙结构的活性炭材料.N_2吸附测试表明随着炭化温度降低,活性炭材料比表面积先增大后减小,孔容则不断增大.其中,550℃炭化样品与KOH反应活性最佳,可制得比表面积为2983m~2/g,总孔容为1.58cm~3/g,中孔孔容达到0.59cm~3/g的活性炭材料.采用直流充放电法、交流阻抗法和循环伏安法测定以上述多孔炭为电极材料的双电层电容器的电化学性能,结果表明,PF550活性炭材料电容性能最佳,在有机电解液中100mA/g充放电时,比电容达到160F/g,电流密度增大50倍容量保持率达到82%,显示出良好的功率特性;活性炭材料中存在一定比例的中孔不仅可以改善电极材料的功率特性,而且可以提高微孔的利用率.     

活化剂用量对无烟煤基高比表面积活性炭电容特性的影响

以云南小发路煤矿低灰无烟煤为原料，KOH为活化剂制取双电层电容器用高比表面积活性炭电极材料。考察了活化剂与无烟煤的配比对活性炭收率、孔结构及比电容的影响，初步探讨了以无烟煤基高比表面积活性炭作电极的模拟双电层电容器的充放电特性。研究结果表明：随着KOH/无烟煤（质量比：1-5）增加，所得活性炭的收率下降，比表面积、总孔容积和比电容则不断增加。控制适宜的活化工艺条件可制得双电极比电容达73.6F/g的无烟煤基高比表面积活性炭，以该活性炭作电极的模拟双电层电容器具有良好的充放电性能。     

梯级孔生物质活性炭的制备及其电容特性研究

以柚子皮为原料,采用预先炭化-KOH活化工艺制备生物质活性炭,并将其用作超级电容器电极材料。采用低温氮气吸附、扫描电镜(SEM)、透射电镜(TEM)及X射线光电子能谱(XPS)等方法表征生物质活性炭的孔结构、表面形貌等微观结构和表面化学性质,利用恒流充放电、循环伏安、漏电流等手段探究生物质活性炭用作电极材料的电化学特性。研究表明:柚子皮经预先炭化-KOH活化处理可以制备出比表面积为1 347~2 269m~2/g,总孔容达0.642~1.283cm~3/g,中孔比例为23.83%~48.90%的高品质生物质活性炭。该生物质活性炭具有发达的比表面积、"大孔-中孔-微孔"三维贯通梯级孔结构,且表面富含羰基、酚羟基及羧基等含氧官能团,是一种比较理想的超级电容器电极材料。生物质活性炭电极材料在KOH电解液中具有优异的电容特性,在50mA/g电流密度下的比电容最高可达243F/g,5 000mA/g电流密度下的比电容仍可保持为175F/g,且具有优异的循环稳定性,循环1 000次后比电容保持率高达93.34%,漏电流仅为0.006 3mA。生物质活性炭优异的电化学特性与其发达的比表面积、"大孔-中孔-微孔"三维贯通梯级孔结构、合理的孔径分布及独特的富氧表面化学性质密切相关。     

超级电容器用活性炭的制备与电化学表征

以煤焦油沥青为前驱体,采用化学活化法制备了超级电容器用高比表面活性炭和活性炭电极.考察了活化温度对活性炭电极比电容量的影响,研究了活性炭材料的比表面积和孔结构与活性炭电极的充放电性能之间的关系,并对活性碳电极进行了电化学表征.结果表明,在500～700℃,随着活化温度的提高,活性炭电极的比电容量显著增大,当活化温度超过700℃时,活性炭电极材料的比电容量变化不明显.700℃活化温度下所制备的活性炭材料呈现明显的多孔结构,孔容为1.038cm3/g,比表面积为1959m2/g;所制成的活性炭电极比电容量为210F/g,等效内阻为0.9Ω/cm2,10mA/cm2充放电500次后保持90%以上电容量,交流阻抗谱在频率低于转化点时表现出纯粹的电容行为,循环伏安曲线显示出良好的可逆特性.     

水热炭化-KOH活化制备核桃壳活性炭电极材料的研究

以核桃壳为原料,经水热炭化-KOH活化制备活性炭,并将其用作超级电容器电极材料。采用低温氮气吸附、扫描电镜(SEM)及X射线光电子能谱(XPS)等手段系统研究核桃壳活性炭的微观结构及表面化学性质,并利用恒流充放电、循环伏安等探讨其对应电极材料的电化学性能。研究表明,在碱碳比为3∶1、活化温度为800℃、活化时间为1h的条件下,核桃壳水热炭经KOH活化可制备出比表面积为1 236m2/g、总孔容为0.804cm3/g、中孔比例为38.3%的活性炭。该核桃壳活性炭用作电极材料在KOH电解液中具有优异的电化学特性,其在50mA/g电流密度下的比电容可达251F/g,5 000mA/g电流密度下的比电容为205F/g,且具有良好的循环稳定性,1 000次循环后比电容保持率达92.4%,是一种比较理想的超级电容器电极材料。核桃壳活性炭优异的电化学性能与其相互贯通的层次孔结构和独特的含氧表面密切相关。     

Effect of Permeable Crystalline Material on Steel Reinforcement Corrosion of Concrete

Permeable crystalline materialcan permeate into pores and cracks of concrete and catalyze the reaction between Ca(OH) 2and unhydrated cement to generate a great quantity needle non-soluble crystals, which can stop up the pores and cracks of concrete, and increase the impermeability of concrete. This paper reported the results of a study conducted to evaluate steel reinforcement corrosion of concrete specimens uncoated and coated with permeable crystalline material as well as mixed with the permeable crystalline material. The properties evaluated for corrosion test were water impermeability, water absorption, compressive strength and potential. The results of water impermeability, water absorption, compressive strength clearly showed that the permeable crystalline material could prohibit water, any soluble salts and moisture from penetrating the concrete to cause corrosion, leaking, and other problems, and it did increase the compressive strength, which was favorable for protection of corrosion of reinforcing steel. Moreover, it was concluded from the potential-time curve that the steel reinforcement of uncoated specimen was in the state of activation whereas that of other specimens coated and mixed with the permeable crystalline material was in the state of inactivation. Above all, it was indicated that the permeable crystalline materialis very effective to protect the steel reinforcement of concrete from corrosion.     

The Research and Application About "Dry Peeling Off" Technology for Airplane Surface Paint Layer

In this paper, the principle of spurting take off lacquer were introduced; and with orthogonal method the unsaturate polyester was prepared ;it was easy to peel airplane paint layer off with this material and equipment.     

Quality Study of Honeycomb Core Shaping Without Wax Stabilization

Sandwich panels utilizing honeycomb cores result in lightweight, high-strength units that are very rigid. Indeed, they give honeycomb panels the best strength-to-weight ratio of any construction type available. Conventionally, the wax is poured into the cell of the core to strengthen the structure and prevent the core from being crushed during milling. Much time and labor is required to wax, mill, and clean the cores. In this study, the process of pouring wax into the core was skipped. In other words, the cutter directly milled the core. Experiments showed that the compressive strength of the core produced without wax stabilization was only 3% lower than that of cores produced using the traditional method. In addition, the drum peel strengths of cores produced without wax stabilization were 38.4% higher than cores produced using the traditional method, in which residual wax seriously polluted the adhesive. It was also found that eliminating the wax process can reduce costs.     

In-process thermal treatment of polylactic acid in fused deposition modelling

Polylactic acid (PLA) is one of the most widely used open source fused filament fabrication materials due to its ease of extrusion, biodegradability, and mechanical strength. The mechanical strength of PLA largely depends on the proper growth of its semi-crystalline structure, which can be severely impaired by a low rate of crystallization, particularly in open source printers. This can be further aggravated by the non-uniform thermal distribution of heat that causes improper curing among the extruded beads of the printing material. As a result, PLA printed on open source printers does not achieve the best mechanical properties. This research, for the first time, proposes an additive-free solution implemented through a detailed set of experimentation to improve the curing rate through in-process temperature variations to cure the joints among the beads. Scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy is used to confirm the improvements in the bead joints. This work is conducted in two phases of experiments. In the first phase, a full factorial ANOVA is used to investigate various process parameters and the important variables are used in the second phase to print test specimens in four different sets.     

Investigation of the Corrosion Behaviors of HVOF-Sprayed Carbide Cernet Coatings in Molten Al-Zn-Si Alloy Bath

In continuous hot-dip galvanization process the corrosion and chemical stability of the sink roll in the galvanizing bath are important problem which effects on the quality and productivity. In order to protect the sink roll the carbide cermet and/or ceramic coatings were deposited on the surface of the sink roll. The WC-, Cr3 C2-cermet coatings were deposited by high velocity oxygen fuel (HVOF) spray, respectively. The coating samples were immersed in molten Zn-alloy containing 50 wt % aluminum at 833 K for 24 hr and 144 hr, respectively. The inter-diffusion and inter-reaction of Zn, Al and elements in coating and corrosion behaviors of these coatings were investigated by XRD, SEM and EPMA etc. The corrosion mechanisms of the carbide cermet coatings and ceramic coatings in molten High Al-Zn-alloy were approached.     

Fundamental study of adhesion of ice to cooling solid surface (Discussion on influence of copper oxide layer on ice adhesion force)

In many situations, ice often adheres to a cooling solid surface, frequently causing serious accidents. It is critical to clarify the mechanism of ice adhesion to the cooling surface in order to prevent ice adhesion. In a past study, the shearing stresses of two kinds of test plates with a copper surface having the higher thermal conductivity were measured. The shearing stress corresponds to ice adhesion force. Both shearing stresses were significantly different; however, the cause remains unclear.Therefore, the present study focuses on an oxide layer as the main factor causing the difference of both shearing stresses; the influence of the oxide layer formed on shearing stress was discussed. And in the removal and reformation processes of the oxide layer, the time variation of the shearing stress was clarified. Moreover, the relationship between the state of the copper surface and the shearing stress was also clarified by surface analysis.     

＂Three Transformations＂ and Standardization

During his inspection in Henan Province in May, Chinese President Xi Jinping stressed to ＂push forward the transformation from China Speed to China Quality, from Made in China to Created in China, and from Chinese Products to Chinese Brand＂. The ＂Three Transformations＂ are the specific requirements and goal of China＇s national development in the context that market should play a decisive role in the allocation of resources.     

重塑标准推行格局 推动LED照明的普及（英文）

正When you are enjoying the green,energy-saving and healthy lighting of IKEA LED luminaire,you may not realize that most of IKEA’s LED bulbs are produced by the LED luminaire smart manufacturing system of Hangzhou Zhongwei Photoelectricity CO.,LTD(ZVISION).No longer enclosed in the laboratory,the product standards are brought into the factory workshop and even to the entire production process.Thus,the standards are promoted and applied in a favorable way by enterprises,benefitting consumers with high quality products.     

Chinese Experts Contribute to ISO＇s New Toy Standards

正The international standard,ISO 8124-6,Safety of toys–Part 6:Certain phthalate esters in toys and children’s products,was officially issued by ISO worldwide on August 15.It was the first time for Chinese experts to lead the ISO standard development in toys industry.The standard was drafted by a group of Chinese experts from SAC/TC for toys and relevant Chinese departments and finally completed by a dedicated international group of experts.ISO 8124-6 makes a substantive breakthrough in the aspects of the scope of toys,limitation of plasticizer types,control of test cost,accuracy of test,operation convenience,etc.,offering the operational guidance for toy manufactures and testing laboratories.     

SAC Delegation Visits AENOR and Signs Cooperation Agreements

正SAC Administrator Tian Shihong led the Chinese delegation to visit the Spanish Association for Standardization and Certification(AENOR)on September 15,2014.Mrs.Begona Cristeto,the Vice-Minister of Industry,Energy and Tourism of Spain,and Mr.Avelino Brito,the President and CEO of AENOR greeted the delegation.The two sides had a deep and friendly discussion on strengthening the cooperation between China and Spain in the standardization field and promoting the standardization work to support the development of economy and trade in the two countries.