2~26GHzGaAs单片功率放大器

报道了一个具有低噪声性能的2~26GHz GaAs超宽带单片功率放大器的研究结果,介绍了模型提取、电路设计和单片制作的全过程.放大器采用分布式设计,在超宽带频率范围内增益为6.5±0.5dB,输入输出驻波比小于2.0.在2~20GHz内测得输出功率大于300mW,噪声系数为3.5~5.5dB.单片放大器包括所有匹配、隔直及偏置电路,芯片面积为3.2mm×1.275mm×0.1mm.     

深层高温高压气井临界产量计算模型

基于热膨胀效应和环空体积变化效应这两种环空带压机理,结合气井生产过程中井筒温度-压力分布计算方法,考虑油层套管和油管的许可压力值,建立一个深层高温高压气井临界产量计算模型.运用迭代法求解模型,编制相关程序.结果表明:环空压力与主要受温度的影响,气井产量越高,井口温度越高,环空压力越大,油套管安全系数越低,因此需要考虑管柱安全性确定临界流量.利用新疆某深层高温高压气井的实际数据进行实例计算,结果可为深层高温高压气井的合理配产提供依据.     

Hyperpolarized He diffusion MRI and histology of secreted frizzled related protein-1 (SFRP1) deficient lungs in a Murine model

Secreted frizzled related protein-1 (SFRP1) plays a key role in many diverse processes, including embryogenesis, tissue repair, bone formation, and tumor genesis. Previous studies have shown the effects of the SFRP1 gene on lung development using the SFRP1 knockout mouse model via histological and physiological studies. In this study, the feasibility of ADC (acquired via HP ³He) to detect altered lung structure in the SFRP1 knockout (SFRP1^−/−) mice was investigated, and compared to analysis by histology. This study consisted of two groups, the wild-type (WT) mice and the knockout (KO) mice with n = 6 mice for each group. ³He ADC MRI and histology were performed on all of the animals. The global L_m values of WT and KO mice were 35.0 ± 0.8 μm and 38.4 ± 3.8 μm, respectively, which translated to an increase of 9.58% in the L_m of KO mice. The mean global ADCs for the WT and KO mice were 0.12 ± 0.01 cm²/s and 0.13 ± 0.01 cm²/s, respectively, which equated to a relative increase of 8.0% in the KO mice compared to the WT mice. In the sub-analysis of the anterior, medial and posterior lung regions, L_m increased by 10.50%, 6.66% and 11.84% in the KO mice, respectively, whereas the differences in ADC between the two groups in the anterior, medial, and posterior regions were 7.3%, 8.3%, and 4.6%, respectively. These results suggest that HP MRI measurements can be used as a suitable substitute for histology to obtain valuable information about lung geometry non-invasively. This technique is also advantageous as regional measurements can be performed, which can identify lung destruction more precisely. Most importantly, this approach extends far beyond the specific pathology analyzed in this study, as it can be applied to many other pathological conditions in the lung tissue, as well to many other embryonic studies.     

聚烯烃用新型抗氧化剂分子的设计、合成及性能

在对抗氧化剂HP136结构进行分析的基础上,设计并合成一系列HP136衍生物,旨在筛选出新的碳自由基捕获剂.通过对其黄度测试和熔流指数等性能研究发现,1,1-二芳基乙酰胺型化合物的抗氧化性和颜色变化都接近HP136,其中2.(3,5-二叔丁基-2-羟基苯基)-N-烯丙基-2-苯基乙酰胺(2d)具有与HP136相当的抗氧...     

幽门螺杆菌感染胃黏膜病变中组织硒含量与p16、PCNA关系的研究

为研究幽门螺杆菌感染的胃黏膜病变中组织硒含量与p1 6、PCNA表达相互关系 ,应用免疫组化染色法检测了 1 1 4例经胃镜及病理诊断证实的五种胃黏膜病变标本中p1 6及PCNA的表达 ;应用快速脲酶试验结合Warthin -Starry银染色确定了HP感染 ;应用MK光纤压力密闭微波溶解炉及RF -1 5 0 1荧光分光光度计检测了组织硒含量。结果表明 ,各种HP感染的胃黏膜病变中 ,组织硒含量除DYS与GC无显著性差异外 (P >0 0 5 ) ,其余各组均有显著性差异 (P <0 0 5 ) ,在CSG中升高明显 ,并随病变加重相对降低 (P <0 0 5 ) ,但高于正常组 (P <0 0 5 )。硒含量与PCNA表达呈负相关 (rs=-0 9898,P <0 0 5 ) ,而与p1 6表达呈正相关 (rs=0 91 4 3 ,P <0 0 5 )。p1 6表达HP阳性标本明显低于HP阴性标本 (P <0 0 1 ) ;PCNA表达HP阳性标本明显高于HP阴性标本(P <0 0 1 )。p1 6表达与PCNA表达呈负相关 (rs=-0 60 75 ,P <0 0 1 )。提示HP感染直接或间接地促进PCNA的表达 ,抑制p1 6的表达。HP感染的胃黏膜组织中硒含量明显升高 ,可能不仅是保护性的对抗活性氧增加的反应 ,也可能与多种癌基因表达之间存在一定的关系     

基于双轴转台的惯性器件自动标定系统研制

基于Acutronic双轴转台，采用GPIB接口卡、HP34401A数字万用表、计算机工作站及VC开发平台等，开发了一套惯性器件自动标定系统。实现了对转台的实时测控，信号采集、数据处理、标定计算、标定报告的显示、打印和存贮的计算机自动完成，并提高了标定精度，为在捷联惯性导航系统中对器件进行系统级修正提供了保障。