摘要：介绍了一种结合MEMS开关实现多频带PA的方法,通过电磁场分析软件对RFMEMS串联开关进行模拟和仿真,在此基础上设计实现了一种双频带PA电路,在所设计的两个频带内,功放都有较高效率及输出功率,这种多频带PA可用于未来多频带应用的移动终端中。

摘要：RF MEMS开关具有低损耗、低功耗、尺寸小和易于集成等优点而被广泛应用于各种可重构射频电路及系统中。通过分析比较电容并联式和串联式RF MEMS开关两种电路结构的射频性能,设计了一种基于RF MEMS开关的新型功率放大器,使用RF MEMS开关控制匹配网络来实现双工作频带的转换。结果表明,设计的功率放大器在2.35GHz和1.25GHz两个工作频带下,功率附加效率(PAE)和输出功率(Pout)可分别达到72%、67%及40.8、42.7dBm。该功率放大器具有较高的功率附加效率和输出功率,适用于多频带的射频系统,对RF MEMS器件在可重构系统中的应用具有一定参考价值。

摘要：We hypothesized that neuroprotective agents targeting various pathways involved in cerebral ischemia/reperfusion(I/R)injury might be superior to that targeting single ***,we prepared a fusion protein(B-I)by combining anti-apoptotic Bcl-x L(B)and anti-inflammatory IL-10(I).B-I could cross blood brain barrier by its N-terminal TAT domain,and be cleaved into separate B and I by Caspase-1.B-I treatment significantly reduced the cerebral infarct volume,better than B or I treatment alone,and equivalent to B and I treatment(B+I).Treatment with B or B-I significantly attenuated I/R-induced neuronal apoptosis as shown by the decrease in apoptotic rate and the inhibition of caspase-3 ***,all recombinant proteins,especially B-I,remarkably attenuated I/R-induced up-regulation of TNF-α.These results suggested that fusion protein B-I inhibiting both inflammation and apoptosis provided better neuroprotective effects than inhibiting either one *** study suggested that multiple pathways targeting brain I-R injury could enhance the neuroprotective effect,and it provided a new idea for the study of neuroprotective drugs for ischemic stroke.

摘要：We hypothesized that thrombolysis in combination with neuroprotection might have better therapeutic effects for ischemic stroke compared with thrombolysis *** order to verify such hypothesis,we designed a protein TBN by fusing NR6and BH4,which possibly had dual functions of thrombolysis and ***6was obtained by introducing two RGD motifs to thrombolytic protein AcAP5to target ***4is the key domain of anti-apoptotic protein Bcl-xL. The DNA fragments encoding TBN and NR6were synthesized and cloned into pET30a and pET16b vectors,*** proteins were expressed in ***21(DE3),mainly in the form of inclusion *** His-tag,NR6was purified by nickel affinity chromatography,while TBN was purified by ion exchange *** proteins were refolded by dialysis *** thrombolytic activity of both proteins was evaluated by the rat arteriovenous bypass *** NR6and TBN significantly reduced thrombus weight at higher dose (24nmol/kg),TBN showed similar effect to *** results suggested that NR6was a thrombolytic protein,and fusion protein TBN reserved the thrombolytic activation of *** effects of both proteins were also evaluated in thromboembolic middle cerebral artery occlusion (eMCAO)in *** exhibited better effect on reducing infarction volume and inhibiting apoptosis of cells than NR6,indicating that the introduction of BH4increased the protective effect of *** hemorrhagic side effects of the two proteins were evaluated by tail bleeding in mice,and it was found that NR6and TBN showed shorter bleeding time compared with *** conclusion,we designed and prepared the two novel proteins,and testified that they *** thrombolytic effect and protective effect on cerebral IR *** protective effect of TBN was more potent than *** bleeding side reaction might be weaker than *** results suggested that these two novel proteins deserved to be further investigated as new thro

摘要：金属泡沫材料拥有优良的γ射线屏蔽能力和较低的密度,但影响其屏蔽性能的关键结构参数及作用规律尚不明确,阻碍了该材料屏蔽性能的进一步优化。本文采用蒙特卡罗方法构建了2种最密堆球模型,计算了理想铝基泡沫金属在各结构参数下的屏蔽性能。研究发现,铝基泡沫金属对能量低于0.24 MeV软γ射线屏蔽能力优于铝基块体材料。控制空心球填充率是优化该材料屏蔽性能的主要可操控方式,且在其适合辐射屏蔽能段时材料越轻性能越好。堆球方式是影响材料屏蔽^(137)Cs、^(60)Co源γ射线性能的最重要参数,实现面心立方最密堆球铝基泡沫金属的制备将弱化其在屏蔽硬γ射线时的劣势。

摘要：为研究闪电特性,设计了用于闪电实验室场景模拟的大变倍比近红外无焦激光扩束光学系统,用于模拟不同光斑尺寸的闪电单元。根据高斯光学几何法计算系统外形尺寸,合理确定了各组份的口径及光焦度;由ZEMAX软件包优化设计得到系统的光学结构参数,并对系统整体性能进行了分析评价。该系统变倍比为13,出射光束光斑均匀、无衍射环,满足研究闪电信号特性的需求。激光扩束系统的中心工作波长为777.4nm,入射光束直径为1.0mm,入射激光光束在步进电机驱动下连续可调,使得出射光束可从φ0.8mm变化到φ10.6mm。系统具有镜片少,结构简单,变焦轨迹平滑无卡滞等优点,可用于模拟不同尺寸的闪电单元。

摘要：利用平面激光诱导荧光技术(PLIF)结合数字图像处理对不同Re下液膜厚度的实时变化进行测量。通过MATLAB内建功率谱密度计算函数对液膜波动的时间序列进行进一步的处理,获得了液膜波动特性的功率谱密度(PSD)曲线,对不同Re下的液膜波动规律进行了频谱分析。结果表明:液膜波动具有显著的多频特性,且各频率有优劣之分,孤立波数量虽少,却携带液膜波动的大部分能量,对液膜波动的贡献不可忽略。液膜波动幅度与Re有关并呈现出一定的规律性:小Re时,液膜的波动幅度与Re有强烈的相关性,随Re的增大而增大;中等Re时,液膜的波动幅度基本保持稳定;大Re时,孤立波的出现使液膜波动幅度急剧增大,液膜波动不稳定性增强。

摘要：为了分析大视场高空间分辨率红外多光谱扫描仪系统误差的影响,为检校方案的确定提供依据,通过利用严格成像模型对机载摆扫红外扫描仪进行成像仿真分析。针对红外扫描仪摆扫系统中相机投影中心与稳定平台回转中心不重合的设计特点,重点研究相机安置误差与POS系统安置误差的相关关系。仿真实验表明:相机安置误差与POS系统安置误差对定位精度影响规律基本一致,两者存在较强相关性但随着摆扫角度增大而减小;在摆扫幅度小于20°时,相机安置误差可合并到POS系统安置误差。该结论可为后期的检校方案设计提供参考。

摘要：介绍了上海科技城的工程概况 ,着重介绍了蓄冰系统的组成、特点。该系统在乙二醇溶液环路上增加了一套供回液集管 ,使低温的乙二醇溶液在蓄冰和空调两种工况下各行其道 ,不产生冻结的现象。这种双集管式系统变二级泵制为单级泵制 ,溶液泵兼作蓄冰泵、融冰泵之用 ,简化了系统 ,减少了设备数量、机房面积、电耗和初投资。该工程已经运行 ,达到设计要求。

摘要：对于梯度变化较大的光学自由曲面,采用模式化方法对光学面整体重构,其重构精度受到限制,无法满足要求,而且曲面局部特性无法精确表征。针对以上问题提出了基于Zernike多项式和径向基函数的自由曲面重构方法,提高自由曲面的重构精度。将整个自由曲面分解为多个圆形子区域,在各个圆形子域中采用Zernike多项式作为基函数进行曲面局部拟合,然后利用径向基函数形成整个自由曲面。通过数值实验对5种不同类型的曲面进行重构分析,实验结果表明,自由曲面重构精度优于纳米量级,验证了所提重构方法的适应性和高精度,在现代光学系统制造和检测中具有一定的应用前景,同时对自由曲面重构中的一些关键问题进行了讨论分析。