蓝宝石衬底上输出功率密度为4.69W/mm的InAlN/GaN HEMT

We report high performance InAlN/GaN HEMTs grown on sapphire substrates. The lattice-matched InAlN/GaN HEMT sample showed a high 2DEG mobility of 1210 cm²/(V·s) under a sheet density of 2.6 × 10¹³ cm^-2. Large signal load-pull measurements for a (2 × 100 μm) × 0.25 μm device have been conducted with a drain voltage of 24 V at 10 GHz. The presented results confirm the high performances reachable by InAlN-based technology with an output power density of 4.69 W/mm, a linear gain of 11.8 dB and a peak power-added efficiency of 48%. This is the first report of high performance InAlN/GaN HEMTs in mainland China.     

MOCVD方法在蓝宝石衬底上生长无应变InAlN/GaN异质结材料研究

In Al N/Ga N heterostructures were grown on sapphire substrates by low-pressure metal organic chemical vapor deposition.The influences of NH3 flux and growth temperature on the In composition and morphologies of the In Al N were investigated by X-ray diffraction and atomic force microscopy.It’s found that the In composition increases quickly with NH3 flux decrease.But it’s not sensitive to NH3 flux under higher flux.This suggests that lower NH3 flux induces a higher growth rate and an enhanced In incorporation.The In composition also increases with the growth temperatures decreasing,and the defects of the In Al N have close relation with In composition.Unstrained In Al N with In composition of 17% is obtained at NH3 flux of 500 sccm and growth temperature of790 °C.The In Al N/Ga N heterostructure high electron mobility transistor sample showed a high two-dimensional electron gas(2DEG) mobility of 1210 cm2/(V s) with the sheet density of 2.31013cm2 at room temperature.     

铜包铝线的选择与使用

介绍了铜包铝线的基本特性，在此基础上论述了铜包铝线的的类型、状态、线径和质量的选择方法，以及线缆加工过程中铜包铝线的正确使用方法。     

新型型材定尺飞锯控制系统

针对冷弯型钢连续生产线的特点，提出采用PLC与直流调速器相结合的方式构成定尺飞锯控制系统。并给出控制系统流程图。实践证明，该系统具有适用性广泛、操作方便、控制精度高、可靠性好等特点。     

大型石化建设工程（福建LNG）项目管理信息系统建设实战剖析

1 项目概况 福建LNG(Liquefied Natural Gas)项目是对外合作的国家能源发展战略项目,由接收站和输气干线项目,运输项目,莆田、晋江和厦门三个燃气电厂以及福州、莆田、泉州、漳州、厦门五个城市燃气利用工程共10个分项目组成.工程分两期建设,一期工程规模为260万吨LNG/年,总投资约240亿元,2007年底建成投产.     

氯盐侵蚀钢筋混凝土锈胀模型的动态修正

针对现有预测模型中参数难以确定,导致预测精度不足的问题,采用分布式光纤传感技术对混凝土锈胀全过程进行实时监测,并基于监测数据对解析模型中的关键参数——铁锈膨胀率进行反演算,建立了可动态更新的钢筋混凝土锈胀全过程预测模型.     

脱脂工艺对热镀锌钢板表面特性的影响

分别采用水、有机溶剂和碱性脱脂剂水溶液对热镀锌涂油钢板进行脱脂清洗处理,并通过三维显微镜、辉光光谱仪和电化学研究了不同脱脂工艺对热镀锌钢板表面形貌、元素成分及表面反应活性的影响。结果显示,不同脱脂工艺对热镀锌板表面形貌无影响,且三种脱脂工艺均能够有效清洁热镀锌板表面油污。水和有机溶剂脱脂工艺能够保留热镀锌板表面氧化层,但碱脱脂工艺会破坏其表面氧化层,因此会影响热镀锌钢板表面的反应活性。电化学数据表明,采用有机溶剂脱脂工艺可以保持热镀锌板表面的氧化膜状态不发生变化,因此其表面反应活性相对较低;采用碱脱脂工艺会改变热镀锌板表面氧化膜结构,提高热镀锌表面反应活性。     

高耐蚀型热镀铝锌钢板冲压后表面特性及耐蚀性研究

为改善家电用普通热镀铝锌耐指纹钢板普遍存在的冲压加工后耐蚀性劣化问题,开发出一种新型高耐蚀热镀铝锌表面处理钢板,并利用扫描电子显微镜(SEM)、辉光放电光谱仪(GDS)、电化学交流阻抗法(EIS)以及盐雾试验机等对其表面冲压特性及耐蚀性进行了研究。结果表明,该高耐蚀型热镀铝锌表面处理钢板经冲压加工成零件后,其表面皮膜得以完整保留,未出现犁痕、划伤和加工发黑等不良现象,且零件整体耐蚀性较普通耐指纹钢板有显著提升。     

四川省待复垦矿山分类及复垦对策研究

四川省矿山众多，因地制宜地划分矿山类型，对开展矿山土地复垦具有重要的意义。提出了四川省面向土地复垦的矿山分类原则和依据，指出四川省矿山分类的主导因素是矿山开采方式和矿区地形条件，据此将全省矿山分为2个大类和6个基本类型，即山地地下矿山、盆地丘陵地下矿山、高原露天矿山、山地露天矿山、盆地丘陵露天矿山和河谷露天矿山。分析了各类矿山对土地破坏的特点，并对各类型矿山的复垦对策进行了探讨。     

A study on La2Mo2O9 decomposition process

The present paper reports the first stage of the study by the present group on the thermal decomposition of La₂Mo₂O₉ under lower oxygen partial pressure. The stability of La₂Mo₂O₉ at 1473 K in an oxygen partial pressure $ (p_{{{\rm O}_{2} }} ) $ ranges from 2.44 × 10^?5 to 4.33 × 10^?9 Pa was studied by XRD. The results showed that La₂Mo₂O₉ could remain stable in a $ p_{{{\rm O}_{2} }} $ range greater than 2.44 × 10^?5 Pa. While below this $ p_{{{\rm O}_{2} }} $ , the formation of several reduced and crystallized molybdates were found. By means of XRD, TEM, SAED, and EDS, the decomposition process of La₂Mo₂O₉ at 1473 K under $ p_{{{\rm O}_{2} }} $ of 9.75 × 10^?7 Pa was investigated. The intermediate and final products formed during the thermal decomposition were characterized. It was found that the La₂Mo₂O₉ decomposition consisted of two steps. La₂Mo₂O₉ first decomposed to intermediate products like LaMo₂O₅, La₅Mo₄O₁₄, and La₁₂Mo₆O₃₅ and then to final products like La₅Mo₃O₁₆ and a new Mo-rich compound. Tilt series of SAED patterns of this new structure were recorded. These measurements were used for the reconstruction of the reciprocal space. The cell attained was monoclinic with parameters: a ≈ 1.195 nm, b ≈ 4.133 nm, c ≈ 1.314 nm, and β ≈ 95°.