低屈强比X65M管线钢的研制

对X65M管线钢在不同调质处理工艺下的组织性能进行了研究。结果表明,在900℃淬火,660～670℃回火条件下,达到最佳性能匹配,X65M管线钢具有良好的综合性能,可获得低的屈强比(0.85)。     

地下车库电气设计浅谈

通过工程实例探讨不同规模地下车库的电气设计,重点探讨地下车库的供电负荷等级、安防管理以及消防设计。     

Optimized power simulation of AlGaN/GaN HEMT for continuous wave and pulse applications

An optimized modeling method of 8 × 100 μm AlGaN/GaN-based high electron mobility transistor (HEMT) for accurate continuous wave (CW) and pulsed power simulations is proposed. Since the self-heating effect can occur during the continuous operation, the power gain from the continuous operation significantly decreases when compared to a pulsed power operation. This paper extracts power performances of different device models from different quiescent biases of pulsed current-voltage (I-V) measurements and compared them in order to determine the most suitable device model for CW and pulse RF microwave power amplifier design. The simulated output power and gain results of the models at V_gs = -3.5 V, V_ds = 30 V with a frequency of 9.6 GHz are presented.     

14份紫叶紫苏叶片营养综合评价及精油型分析

为筛选优质药食兼用型紫叶紫苏资源,本研究对源于贵州、湖南、山西和黑龙江的14个紫叶紫苏品系（编号C01～C14）叶片的基本营养品质、主要活性成份和微量矿物质含量进行了测定,并利用因子分析和系统聚类分析对紫苏叶营养品质进行评价,同时分析了各紫苏叶片的精油型。结果显示,不同紫苏的粗蛋白、粗脂肪、粗纤维、可溶性蛋白、总游离氨基酸和可溶性糖含量依次为12.87～19.52、2.07～4.19、6.59～9.84 g/100 g、0.99～2.49、0.17～1.57、28.90～61.54 g/kg,黄酮、总酚和维生素C等活性物质含量分别为13.28～24.35 g/kg、59.26～99.18 mg/kg、1.16～8.17 mg/100 g。Fe、Zn、Mn和Cu四种矿物质含量依次为13.96～27.86、5.60～8.94、4.63～19.74和0.52～2.61 mg/kg。因子分析显示,紫叶紫苏叶片营养成分可以提取出“糖和矿质元素”、“活性物质”、“蛋白质”和“脂肪”4个公因子,综合品质表现最优的为C05,其次为C12、C11、C06和C10。利用系统聚类分析将14份紫苏划分为“高糖...     

基于共价/非共价结合的蛋白质与花色苷相互作用研究进展

蛋白质是生命活动的物质基础,是食品营养的重要成分。花色苷是广泛存在于自然界的植物色素,具有抗氧化、抗炎、抗衰老、抗癌等生理活性。花色苷对环境十分敏感,容易发生降解或分解,但通过与蛋白质的共价和非共价相互作用可以改善这一现象,同时也可以改善蛋白质的功能特性和营养品质。该文综述了花色苷与蛋白质的相互作用形式和影响因素,分别分析了二者的相互作用对花色苷和蛋白质性质的影响,为开发富含花青素的蛋白质食品或功能性配料提供理论依据。     

A Ka-band 22 dBm GaN amplifier MMIC

A Ka-band GaN amplifier MMIC has been designed in CPW technology,and fabricated with a domestic GaN epitaxial wafer and process.This is,to the best of our knowledge,the first demonstration of domestic Kaband GaN amplifier MMICs.The single stage CPW MMIC utilizes an AlGaN/GaN HEMT with a gate-length of 0.25μm and a gate-width of 2×75μm.Under V_ds=10 V,continuous-wave operating conditions,the amplifier has a 1.5 GHz operating bandwidth.It exhibits a linear gain of 6.3 dB,a maximum output power of 22 dBm and a peak PAE of 9.5%at 26.5 GHz.The output power density of the AlGaN/GaN HEMT in the MMIC reaches 1 W/mm at Ka-band under the condition of V_ds=10 V.     

Load-pull measurement analysis of AlGaN/GaN HEMT taking into account number of gate fingers

This paper investigates load-pull measurement of AlGaN/GaN high electron mobility transistors (HEMTs) at different numbers of gate fingers. Scalable small-signal models are extracted to analyze the relationship between each model''s parameters and the number of device''s gate fingers. The simulated S-parameters from the small-signal models are compared with the reflection coefficients measured from the load-pull measurement system at X-band frequencies of 8.8 and 10.4 GHz. The dependency between the number of device''s gate fingers and load-pull characterization is presented.     

一种完全生物可降解塑料的制备研究

将分散均匀的明胶、甲壳素、复合无机填料和复合增塑剂的水溶液用流延法成膜,并通过耐水测试、孔隙率测试、以及降解测试表征了蛋白质基可降解塑料薄膜的性能。实验结果表明：当增塑剂质量分数小于10％时,对蛋白质基塑料薄膜的耐水性的影响不大;无机填料的质量分数的改变没有太大的影响薄膜的耐水性。材料的孔隙率随增塑剂的质量分数的增大而增大,随复合无机填料的质量分数减小,然后达到一个动态的平衡;蛋白质基塑料薄膜具有生物降解性,在20天内降解度为1．9％,在使用期内基本可以保持其使用性,在使用后可以降解处理。     

8GHz带有RC稳定网络的AlGaN/GaN HEMTs内匹配功率合成放大器的设计

设计了工作在8GHz的基于AIGaN/GaN HEMTs的内匹配功率合成放大器.输入和输出匹配电路制作在0.381mm厚的氧化铝陶瓷基片上,为了提高整个电路的稳定因子K,在电路输入端增加了片上RC有损网络.在8GHz测出连续波ldB压缩点时的输出功率为PldB=43dBm(20W),线性增益7.3dB,最大PAE为38.1%,合成效率达到70.6%.