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碳粒砂——一种非硅质造型材料
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作者 孙海涛 王艳杰 +2 位作者 丛建臣 丛建滋 杨夕美 《山东机械》 1994年第1期48-48,共1页
一、前言 碳粒砂是一种极好的造型材料,它所具有的综合性能有利于提高铸件质量。选用碳粒砂作造型材料,可有效地防止铸造缺陷、减少清砂费用。利用碳粒砂或碳粒砂与普通石英砂的混合物制成的型芯和铸型,能够生产出表面光洁的高质量铸件... 一、前言 碳粒砂是一种极好的造型材料,它所具有的综合性能有利于提高铸件质量。选用碳粒砂作造型材料,可有效地防止铸造缺陷、减少清砂费用。利用碳粒砂或碳粒砂与普通石英砂的混合物制成的型芯和铸型,能够生产出表面光洁的高质量铸件,并且有利于减少机械粘砂、胀砂、渗透粘砂、结疤等铸造缺陷。 展开更多
关键词 碳粒砂 非硅质 造型材料
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左摆体的铸造工艺设计
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作者 牛群英 《企业技术开发(下旬刊)》 2014年第2期93-94,共2页
文章从左摆体铸造工艺的设计出发,分析了铸件的冷却、凝固、清理、处理等工艺过程。
关键词 铸造 铸钢 非硅质 冒口
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An analytical model to explore open-circuit voltage of a-Si:H/c-Si heterojunction solar cells 被引量:1
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作者 钟春良 耿魁伟 +1 位作者 罗兰娥 杨迪武 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第3期598-603,共6页
The effect of the parameters on the open-circuit voltage, V_(OC) of a-Si:H/c-Si heterojunction solar cells was explored by an analytical model. The analytical results show that V_(OC) increases linearly with the logar... The effect of the parameters on the open-circuit voltage, V_(OC) of a-Si:H/c-Si heterojunction solar cells was explored by an analytical model. The analytical results show that V_(OC) increases linearly with the logarithm of illumination intensity under usual illumination. There are two critical values of the interface state density(D_(it)) for the open-circuit voltage(V_(OC)), D_(it)^(crit,1) and D_(it)crit,2(a few 1010 cm^(-2)·e V^(-1)). V_(OC) decreases remarkably when D_(it) is higher than D_(it)^(crit,1). To achieve high V_(OC), the interface states should reduce down to a few 1010 cm^(-2)·e V^(-1). Due to the difference between the effective density of states in the conduction and valence band edges of c-Si, the open-circuit voltage of a-Si:H/c-Si heterojunction cells fabricated on n-type c-Si wafers is about 22 mV higher than that fabricated on p-type c-Si wafers at the same case. V_(OC) decreases with decreasing the a-Si:H doping concentration at low doping level since the electric field over the c-Si depletion region is reduced at low doping level. Therefore, the a-Si:H layer should be doped higher than a critical value of 5×10^(18) cm^(-3) to achieve high V_(OC). 展开更多
关键词 solar cells a-Si:H/c-Si heterojunctions open-circuit voltage
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Structural evolution and electronic properties of phosphorus-doped hydrogenated amorphous silicon thin films deposited by PECVD
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作者 HE Jian LI Wei +2 位作者 XU Rui QI KangCheng JIANG YaDong 《Science China(Technological Sciences)》 SCIE EI CAS 2013年第1期103-108,共6页
The relationship between structure and electronic properties of phosphorus-doped hydrogenated amorphous silicon(a-Si:H) thin films was investigated.Samples with different features were prepared by plasma enhanced chem... The relationship between structure and electronic properties of phosphorus-doped hydrogenated amorphous silicon(a-Si:H) thin films was investigated.Samples with different features were prepared by plasma enhanced chemical vapor deposition(PECVD) at various substrate temperatures.Raman spectroscopy and Fourier transform infrared(FTIR) spectroscopy were used to evaluate the structural evolution,meanwhile,electronic-spin resonance(ESR) and optical measurement were applied to explore the electronic properties of P-doped a-Si:H thin films.The results revealed that the changes in materials structure affect directly the electronic properties and the doping efficiency of dopant. 展开更多
关键词 a-Si:H PECVD RAMAN FTIR ESR
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