The effect of transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investi...The effect of transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investigated.PANI was synthesized by co-polymerization of aniline in the presence of different transition metal ions by using potassium dichromate in acidic medium. It was found that the ion doping of PANI showed a certain catalytic activity for the regeneration of traditional iodide/triiodide(I^-/I_3^-) redox couples. The power conversion efficiency(η) of PANI CEs doped with Mn^(2+),Ni^(2+),Co^(2+) (4.41%, 2.36% and 2.10%, respectively) were higher than 1.94%, the value measured for PANI CE without doping. Doping with Cu^(2+)decreased the power conversion efficiency of PANI CE(PANI-Cu^(2+) η = 1.41%). The electrical properties of the PANI, PANI-Ni^(2+), PANI-Co^(2+),PANI-Mn^(2+) and PANI-Cu^(2+) were studied by cyclic voltammetry(CV), impedance(EIS), and Tafel polarization curve. The experimental results confirmed that PANI was affected by the doping of different transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)). These results indicate a potential application of ion doped PANI as counter electrode in cost-effective DSSCs.展开更多
Vishay推出新的功率等级达10W且采用2818外形尺寸的汽车级Power Metal Strip电阻WSHP2818。Vishay Dale WSHP2818在较小的占位面积内具有与尺寸更大电阻相当的高功率,在汽车、工业、消费和计算机产品中能节省空间,减少元器件数量,而且...Vishay推出新的功率等级达10W且采用2818外形尺寸的汽车级Power Metal Strip电阻WSHP2818。Vishay Dale WSHP2818在较小的占位面积内具有与尺寸更大电阻相当的高功率,在汽车、工业、消费和计算机产品中能节省空间,减少元器件数量,而且用表面贴装替换引线电阻能大大加快组装速度。新发布的器件采用独有的结构,这种结构改进了热管理设计,使这颗10W电阻在2818封装尺寸内还能保持Power Metal Strip结构的优良电气特性。展开更多
Vishay宣布,发布新的汽车级Power Metal Strip?电池旁路电阻——WSBS8518...14。该电阻的功率密度达到36W,采用8518外形尺寸,在接头上镀锡。Vishay Dale WSBS8518...14的电阻值低至50μΩ,测量精度比霍尔效应的电流检测方案高,而成本更...Vishay宣布,发布新的汽车级Power Metal Strip?电池旁路电阻——WSBS8518...14。该电阻的功率密度达到36W,采用8518外形尺寸,在接头上镀锡。Vishay Dale WSBS8518...14的电阻值低至50μΩ,测量精度比霍尔效应的电流检测方案高,而成本更低,镀锡的接头便于PCB组装,同时也提高了耐腐蚀能力。展开更多
In a bid to deal with international price increases and meet domestic demand, China is diversifying its sources of iron ore Wugang (Wuhan Iron & Steel Group Corp.), one of China's top 10 iron and steel enterpr...In a bid to deal with international price increases and meet domestic demand, China is diversifying its sources of iron ore Wugang (Wuhan Iron & Steel Group Corp.), one of China's top 10 iron and steel enterprises, has begun to tap an iron ore belt with reserves of almost 2 billion tons in central China's Hubei Province. The belt was detected as early as 1959, but has lain idle due to its high展开更多
The effect of frequencies of AC power supply on the quality of the electroslag-melted ingot is studied. The results show that with a decrease in the frequency, electromagnetic force becomes more violent, and the tempe...The effect of frequencies of AC power supply on the quality of the electroslag-melted ingot is studied. The results show that with a decrease in the frequency, electromagnetic force becomes more violent, and the temperature in the slag bath becomes more homogeneous, and therefore, the depth of molten metal pool is decreased; electrochemical reactions occur with the decrease in the frequency, and the atomic oxygen electrolyzed dissolves in the molten metal pool; the nonmetallic inclusions, which are distributed dispersively in the ingot, have an increased content, and their size is approximately in the range of 2--3 μm.展开更多
High intensity power ultrasound was respectively introduced into three different solidification stages of Al–8%Si hypoeutectic alloy, including the fully liquid state before nucleation, the nucleation and growth proc...High intensity power ultrasound was respectively introduced into three different solidification stages of Al–8%Si hypoeutectic alloy, including the fully liquid state before nucleation, the nucleation and growth process of primary α(Al) phase and L →(Al) +(Si) eutectic transformation period. It is found that both the primary α(Al) phase and(Al + Si) eutectic structure were refined by different degrees with various growth morphologies depending on the ultrasonic treatment stage. Based on the experimental results,the cavitation-induced nucleation due to the high undercooling caused by the collapse of tiny cavities was proposed as the major reason for refining the primary α(Al) phase. Meanwhile, obvious eutectic morphological change was observed only when ultrasound was directly introduced in the eutectic transformation stage, in which typical divorced eutectics and(Al + Si) eutectic cells with symmetrical flower shape were formed at the top of the alloy sample. The introduction of ultrasound in each solidification stage also improves the yield strength of Al–8% Si alloy to a diverse extent.展开更多
基金Supported by the National Natural Science Foundation of China(21473048,21303039)the Natural Science Foundation of Hebei Province(B2016205161,B2015205163)the 2015 Hebei Province Undergraduate Training Programs for Innovation and Entrepreneurship
文摘The effect of transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investigated.PANI was synthesized by co-polymerization of aniline in the presence of different transition metal ions by using potassium dichromate in acidic medium. It was found that the ion doping of PANI showed a certain catalytic activity for the regeneration of traditional iodide/triiodide(I^-/I_3^-) redox couples. The power conversion efficiency(η) of PANI CEs doped with Mn^(2+),Ni^(2+),Co^(2+) (4.41%, 2.36% and 2.10%, respectively) were higher than 1.94%, the value measured for PANI CE without doping. Doping with Cu^(2+)decreased the power conversion efficiency of PANI CE(PANI-Cu^(2+) η = 1.41%). The electrical properties of the PANI, PANI-Ni^(2+), PANI-Co^(2+),PANI-Mn^(2+) and PANI-Cu^(2+) were studied by cyclic voltammetry(CV), impedance(EIS), and Tafel polarization curve. The experimental results confirmed that PANI was affected by the doping of different transition metal ions(M^(2+)=Mn^(2+),Ni^(2+),Co^(2+),Cu^(2+)). These results indicate a potential application of ion doped PANI as counter electrode in cost-effective DSSCs.
文摘Vishay推出新的功率等级达10W且采用2818外形尺寸的汽车级Power Metal Strip电阻WSHP2818。Vishay Dale WSHP2818在较小的占位面积内具有与尺寸更大电阻相当的高功率,在汽车、工业、消费和计算机产品中能节省空间,减少元器件数量,而且用表面贴装替换引线电阻能大大加快组装速度。新发布的器件采用独有的结构,这种结构改进了热管理设计,使这颗10W电阻在2818封装尺寸内还能保持Power Metal Strip结构的优良电气特性。
文摘Vishay宣布,发布新的汽车级Power Metal Strip?电池旁路电阻——WSBS8518...14。该电阻的功率密度达到36W,采用8518外形尺寸,在接头上镀锡。Vishay Dale WSBS8518...14的电阻值低至50μΩ,测量精度比霍尔效应的电流检测方案高,而成本更低,镀锡的接头便于PCB组装,同时也提高了耐腐蚀能力。
文摘In a bid to deal with international price increases and meet domestic demand, China is diversifying its sources of iron ore Wugang (Wuhan Iron & Steel Group Corp.), one of China's top 10 iron and steel enterprises, has begun to tap an iron ore belt with reserves of almost 2 billion tons in central China's Hubei Province. The belt was detected as early as 1959, but has lain idle due to its high
文摘The effect of frequencies of AC power supply on the quality of the electroslag-melted ingot is studied. The results show that with a decrease in the frequency, electromagnetic force becomes more violent, and the temperature in the slag bath becomes more homogeneous, and therefore, the depth of molten metal pool is decreased; electrochemical reactions occur with the decrease in the frequency, and the atomic oxygen electrolyzed dissolves in the molten metal pool; the nonmetallic inclusions, which are distributed dispersively in the ingot, have an increased content, and their size is approximately in the range of 2--3 μm.
基金financially supported by the National Natural Science Foundation of China (Nos. 51471134 and 51402240)the Fund of the State Key Laboratory of Solidification Processing in NWPU (No. SKLSP201735)Ao Xiang Xin Xing Foundation of NWPU
文摘High intensity power ultrasound was respectively introduced into three different solidification stages of Al–8%Si hypoeutectic alloy, including the fully liquid state before nucleation, the nucleation and growth process of primary α(Al) phase and L →(Al) +(Si) eutectic transformation period. It is found that both the primary α(Al) phase and(Al + Si) eutectic structure were refined by different degrees with various growth morphologies depending on the ultrasonic treatment stage. Based on the experimental results,the cavitation-induced nucleation due to the high undercooling caused by the collapse of tiny cavities was proposed as the major reason for refining the primary α(Al) phase. Meanwhile, obvious eutectic morphological change was observed only when ultrasound was directly introduced in the eutectic transformation stage, in which typical divorced eutectics and(Al + Si) eutectic cells with symmetrical flower shape were formed at the top of the alloy sample. The introduction of ultrasound in each solidification stage also improves the yield strength of Al–8% Si alloy to a diverse extent.