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The influence of environment temperatures on single crystalline and polycrystalline silicon solar cell performance

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Science China(Physics,Mechanics & Astronomy) 2012年第2期55卷 235-241页

作者： WEN Cai FU Chao TANG JinLong LIU DeXiong HU SiFu xing zhigang School of Science Laboratory for Extreme Conditions Matter PropertiesSouthwest University of Science and TechnologyMianyang 621010China Epilight Technology Co. Ltd.Shanghai 201203China

The influence of the cell temperature (named interior environment temperature) and ambient air temperature (named exterior environment temperature) on the open-circuit voltage,short-circuit current,and output power has been carefully studied for the Si solar *** results show that one of the environment temperatures plays the major role,and the temperature dependence of device performance parameters is different for single crystalline and polycrystalline Si solar ***,the ambient air temperature builds a bridge for the comparison of the effect between the cell temperature and the illumination intensity on solar cell *** on the experimental results,the reasons which cause the difference of the environment temperatures dependence are analyzed.

关键词： Si solar cell cell temperature ambient air temperature illumination intensity cell performance

The impact of nanoporous SiN_x interlayer growth position on high-quality GaN epitaxial films

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Chinese Science Bulletin 2011年第25期56卷 2739-2743页

作者： MA ZiGuang xing zhigang WANG XiaoLi CHEN Yao XU PeiQiang CUI YanXiang WANG Lu JIANG Yang JIA HaiQiang CHEN Hong Beijing National Laboratory of Condensed Matter Institute of Physics Chinese Academy of Sciences Beijing 100190 China

The impact of nanoporous SiN x interlayer growth position on high-quality GaN epitaxial film was elucidated from the behavior of dislocations. The best quality GaN film was achieved when a nanoporous SiN x interlayer was grown on a rough layer, with the high-resolution X-ray diffraction rocking curve full width at half maximum for ( 1102 ) reflection decreasing to 223 arcs, and the total dislocation density reduced to less than 1.0×10 8 cm 2 . GaN films were grown on sapphire substrates by metal organic chemical vapor deposition. The quality of these films was investigated with high-resolution X-ray diffraction, atomic force microscopy, and cross-sectional transmission electron microscopy. A preference for the formation of half-loops to reduce threading dislocations was observed when an SiN x interlayer was grown on a rough layer. A growth mechanism is proposed to explain this preference.

关键词：氮化硅外延片多孔层间氮化镓 GaN薄膜化学气相沉积法透射电子显微镜

Recent progress in single chip white light-emitting diodes with the InGaN underlying layer

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Science China(Physics,Mechanics & Astronomy) 2010年第3期53卷 445-448页

作者： WANG XiaoLi, WANG XiaoHui, JIA HaiQiang, xing zhigang & CHEN Hong Beijing National Laboratory of Condensed Matter, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China Beijing National Laboratory of Condensed Matter Institute of Physics Chinese Academy of Sciences Beijing China

Tremendous progress has been achieved in white light-emitting diodes (LEDs). To further improve the quality of white light and simplify the fabrication process, a single chip white-light LED with the InGaN underlying layer (UL) was studied and fabricated. The turn-on voltage of this type of LED was 2.7 V, and the spectrum at a forward bias current of 20 mA was comprised of blue (443 nm) and yellow (563 nm) lights. The intensity ratio of blue to yellow light was almost constant with the in- creasing injection current in a certain scope, most important for the solid state illumination. The useful life test showed the light output level remained at a 90% light output level at the driving current of 40 mA after 300 h, meanwhile, the UV and blue LEDs combined with phosphor reached a 20% value after 144 h within 300 h.

关键词： GaN InGaN white light LED MOCVD

Characterization of different-Al-content AlGaN/GaN heterostructures on sapphire

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Science China(Physics,Mechanics & Astronomy) 2010年第1期53卷 49-53页

作者： DING GuoJian , GUO LiWei, xing zhigang, CHEN Yao, XU PeiQiang, JIA HaiQiang, ZHOU JunMing & CHEN Hong Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China Beijing National Laboratory of Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing China

Al x Ga 1-x N/GaN high-electron-mobility transistor (HEMT) structures with Al composition ranging from x = 0.13 to 0.36 are grown on sapphire substrates by low-pressure metalorganic chemical vapor deposition (LP-MOCVD). The effects of Al content on crystal quality, surface morphology, optical and electrical characteristics of the AlGaN/GaN heterostructures have been analyzed. Although high Al-content (36%) heterostructure exhibits a distinguished photoluminescence peak related to recombination between the two-dimensional electron gas and photoexcited holes (2DEG-h), its crystal quality and rough surface morphology are poor. 2DEG mobility increases with the Al content up to 26% and then it apparently decreases for high Al-content (36%) AlGaN/GaN heterostructure. The increase of sheet carrier density with the increase of Al content has been observed. A high mobility at room temperature of 2105 cm 2 /V s with a sheet carrier density of n s = 1.10 × 10 13 cm -2 , for a 26% Al-content AlGaN/GaN heterostructure has been obtained, which is approaching state-of-the-art for HEMT grown on SiC. Sheet resistance as low as 274 Ω/□ has also been achieved.

关键词： AlGaN Hall-effect luminescence

焊后热处理对Q235钢熔覆层组织和耐磨性的影响

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热加工工艺 2015年第8期44卷 200-202页

作者：王向杰行志刚湖北理工学院机电工程学院湖北黄石435003 河南理工大学工程训练中心河南焦作454000

利用药芯焊丝对Q235钢进行堆焊,堆焊后分别采取直接空冷和焊后450℃×3h回火处理,并对回火前后熔合线两侧的热影响区和熔覆层进行了显微组织、显微硬度梯度以及熔覆层的耐磨性能试验。试验结果表明:焊后空冷条件下,靠近熔合线的热影响... 详细信息

利用药芯焊丝对Q235钢进行堆焊,堆焊后分别采取直接空冷和焊后450℃×3h回火处理,并对回火前后熔合线两侧的热影响区和熔覆层进行了显微组织、显微硬度梯度以及熔覆层的耐磨性能试验。试验结果表明:焊后空冷条件下,靠近熔合线的热影响区存在大量的魏氏组织,熔覆层为粗大的片状马氏体和大量残余奥氏体,且基体与熔覆层显微硬度梯度较大;堆焊后经回火处理,热影响区的魏氏组织基本消失,熔覆层组织转变为回火屈氏体+少量残余奥氏体,硬度较高,耐磨性较好,相比焊后空冷熔覆层的耐磨性提高约24%,同时基体与熔覆层间的最大显微硬度梯度值减小了约70HV。

关键词：堆焊 Q235钢显微组织硬度梯度耐磨性

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多层熔敷堆焊各区域组织及性能研究

热加工工艺 2015年第11期44卷 233-235页

作者：肖新华行志刚湖北理工学院机电工程学院湖北黄石435003 河南理工大学工程训练中心河南焦作454000

利用Fe基药芯焊丝对失效的5CrNiMo模具进行多层堆焊修复,之后对堆焊试样进行空冷处理。利用显微观察及硬度分析方法研究了各层堆焊合金的显微组织形貌及显微硬度分布。结果表明:焊后空冷处理条件下各层显微组织形貌及硬度分布差异较大,... 详细信息

利用Fe基药芯焊丝对失效的5CrNiMo模具进行多层堆焊修复,之后对堆焊试样进行空冷处理。利用显微观察及硬度分析方法研究了各层堆焊合金的显微组织形貌及显微硬度分布。结果表明:焊后空冷处理条件下各层显微组织形貌及硬度分布差异较大,堆焊合金由第一层到第三层细小的板条回火马氏体逐渐减少,粗大的板条回火马氏体逐渐增多,最外表层堆焊合金组织主要为粗大的片状马氏体,同时堆焊合金的显微硬度由第一层到外表层逐渐升高,出现梯度分布,最外层堆焊合金显微硬度平均值达到了540 HV。堆焊时后层堆焊对前层进行了高温回火是各层显微组织及硬度分布出现差异的主要原因。

关键词：多层堆焊 Fe基堆焊合金显微组织硬度分布

焊后回火对ZG15MnMoVCu堆焊熔合区组织及硬度梯度的影响

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热加工工艺 2015年第7期44卷 203-205页

作者：肖新华行志刚湖北理工学院机电工程学院湖北黄石435003 河南理工大学工程训练中心河南焦作454000

采用Cr基药芯焊丝对ZG15MnMoVCu基体进行堆焊,焊后分别对堆焊试样进行空冷及不同温度回火处理。对比分析了焊后不同处理条件下的显微组织、合金元素Cr在熔合线两侧的分布以及熔合线两侧的显微硬度梯度。试验结果表明:焊后直接空冷条件... 详细信息

采用Cr基药芯焊丝对ZG15MnMoVCu基体进行堆焊,焊后分别对堆焊试样进行空冷及不同温度回火处理。对比分析了焊后不同处理条件下的显微组织、合金元素Cr在熔合线两侧的分布以及熔合线两侧的显微硬度梯度。试验结果表明:焊后直接空冷条件下靠近熔合线的基体侧为形状不规则的针状魏氏组织,熔覆层表现为粗大的针状马氏体,Cr元素在熔合线两侧的分布量差异较大,且熔合线两侧显微硬度梯度较大;焊后随回火温度提高,靠近熔合线基体侧针状魏氏组织逐渐减少,粒状珠光体和铁素体逐渐增多,熔覆层由粗大的针状马氏体逐渐转变为细小的板条状回火马氏体,组织明显发生改善,同时Cr在熔合线两侧的分布量逐渐均匀化,且熔合线两侧的显微硬度梯度逐渐减小。

关键词： ZG15MnMoVCu 显微组织 Cr元素分布硬度梯度

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基于平移不变多小波变换的齿轮故障诊断

机械传动 2016年第2期40卷 142-145页

作者：华伟行志刚荆双喜中国矿业大学机电与信息工程学院北京100083 河南理工大学机械与动力工程学院河南焦作454003

机械设备发生故障时,反映设备故障特征的振动信号常淹没在背景噪声中,直接做频谱分析,很难提取其故障特征。将平移不变多小波降噪方法应用到仿真加噪冲击信号,提取出隐藏在噪声中的冲击特征。然后将该方法应用于齿轮箱试验台信号分析中... 详细信息

机械设备发生故障时,反映设备故障特征的振动信号常淹没在背景噪声中,直接做频谱分析,很难提取其故障特征。将平移不变多小波降噪方法应用到仿真加噪冲击信号,提取出隐藏在噪声中的冲击特征。然后将该方法应用于齿轮箱试验台信号分析中,试验结果表明,平移不变多小波降噪方法能够有效地提取出齿轮箱断齿故障的冲击特征频率,诊断出齿轮箱的断齿故障,为故障诊断提供了准确的依据。仿真与试验分析验证了平移不变多小波降噪方法在故障诊断中的有效性。

关键词：多小波平移不变信号降噪故障诊断

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采用信标的大型可展开天线指向控制方法

中国空间科学技术 2012年第3期32卷 1-6,14页

作者：邢志钢刘丽坤郑钢铁周志成清华大学航天航空学院北京100084 中国空间技术研究院通信卫星事业部北京100094

为提高大型可展开天线的指向控制精度,并适应喷气卸载等在轨工况,基于Craig-Bampton法建立了表征柔性天线指向的动力学模型,在此基础上提出了一种采用信标的大天线指向控制方法。该方法先基于卡尔曼滤波,对大天线的振动状态进行检测,若... 详细信息

为提高大型可展开天线的指向控制精度,并适应喷气卸载等在轨工况,基于Craig-Bampton法建立了表征柔性天线指向的动力学模型,在此基础上提出了一种采用信标的大天线指向控制方法。该方法先基于卡尔曼滤波,对大天线的振动状态进行检测,若天线未出现明显振动,则通过信标敏感器修正天线指向偏差,同时引入星本体姿态敏感器以保证稳定性;若天线振动超过阈值,则仅引入星本体敏感器以衰减振动,直至天线未出现明显振动。最后利用瑟拉亚(Thuraya)卫星的在轨实测热变形数据进行了仿真验证。结果表明,在未受到喷气扰动时,大天线指向精度优于±0.02°,在受到喷气扰动后,系统可正确检测并切换跟踪输入。这说明,该指向控制方法在保证稳定性的同时,可以有效修正大天线指向偏差,并能适应在轨位保、卸载喷气工况。

关键词：信标敏感器天线指向控制姿态动力学指向精度大型可展开天线