考虑随机频率偏移的微波炉加热

针对微波炉加热使用的微波源具有工作不稳定的特点,本文在考虑微波炉具有随机频率偏移的情况下,模拟了微波炉对德拜介质的加热。微波炉的随机频率偏移能够非常明显的影响到整个谐振腔体的加热。因此在进行色散介质加热的仿真计算时,必须要考虑随机频率偏移的影响。本文还对在微波炉中进行的微波加热实验重复性低的原因进行了分析和猜想,并建议在研究微波化学反应机理时应该采用稳定性更高的固态源。     

ZnO-B2O3-SiO2掺杂对锆酸钙基陶瓷性能的影响

研究了ZnO-B2O3-SiO2(ZBS)玻璃掺杂量对CaZrO3陶瓷烧结性能、物相组成、微观组织形貌和介电性能的影响。结果表明:通过掺杂ZBS,可使CaZrO3陶瓷的烧结温度由1 550℃降至1 000℃,且无第二相生成,相对密度达97.8%。当ZBS添加量为质量分数15%时,CaZrO3陶瓷在1 000℃烧结3 h获得良好的介电性能:εr=25,Q·f=8 584 GHz,τf=–45×10–6/℃。     

微波消解--采用ICP-AES法对食品中铝含量测定方法的探究

采用电感耦合等离子发射光谱仪（ICP-AES）对食品中铝含量测定方法的研究。样品经全自动微波消解仪（硝酸+过氧化氢）进行预处理,消解液用ICP-AES进行检测。结果表明,采用ICP-AES对食品中铝的测定方法具有灵敏度高、检测限低、高效、稳定的优点。此方法检出限为2μg/L,相对标准偏差低于1%,在0～10.0 mg/L 范围内,线性良好（R=0.9997）,回收率为92.8%～99.6%。测定结果满意。     

新型高抑制波导滤波器设计

提出了一种新颖的波导带通滤波器设计。该滤波器是一个四阶广义切比雪夫滤波器,中心频率为9.93GHz,带宽为200 MHz,插损小于0.5 dB,带内回波损耗大于20 dB。谐振器为CQ结构,通过一个矩形波导膜片(一个不完全高度的导电杆),实现了交叉耦合,相比传统方法,产生一个额外的传输零点。由于在高端产生了两个零点,使得滤波器在阻带高端10.1 GHz处的带外抑制达到了35 dB以上。仿真实验证明了该设计方法能显著提高滤波器的带外抑制,对滤波器的小型化、高性能化有一定的意义。     

H3BO3掺杂的Ba5Nb4O15陶瓷的烧结及介电性能

采用传统的固相烧结工艺制备了H3BO3掺杂的Ba5Nb4O15陶瓷。研究了H3BO3掺杂量对Ba5Nb4O15陶瓷的相成分、微观结构、烧结以及微波介电性能的影响。结果表明:H3BO3掺杂的Ba5Nb4O15陶瓷中,除主晶相Ba5Nb4O15相外,还生成了BaNb2O6和BaB2O4相;H3BO3能够将Ba5Nb4O15陶瓷的烧结温度降低500℃左右,同时没有显著损害该陶瓷的微波介电性能;当H3BO3掺杂量为质量分数1%时,900℃烧结的Ba5Nb4O15陶瓷具有良好的微波介电性能:εr=38.8,Q×f=48 446 GHz,τf=37.0×10–6/℃。     

波束组合器微波传输特性的实验研究*

波束组合器是复合制导半实物仿真系统中的关键设备,为了分析半实物仿真系统中微波传输过程和有效地研究波束组合器对微波场的影响,利用四端口网络法对该波束组合器的结构进行了设计。针对波束组合器对微波传输特性的影响进行了实验研究,主要包括微波传输振幅的衰减和微波传输方向的变化情况。同时建立了该系统的理论模型,最后采用物理光学法对框架绕射引起的相对相位变化进行了仿真验证,仿真结果和实测结果相符合,即不同微波频率造成的波束组合器的振幅衰减和微波传播方向不同,发射天线的偏移会引起振幅和相对相位差变化。     

Structure‐Properties Relationship in Iron Oxide‐Reduced Graphene Oxide Nanostructures for Li‐Ion Batteries

Non‐aqueous sol‐gel routes involving the reaction of metal oxide precursors in organic solvents (e.g., benzyl alcohol) at moderate temperature and pressure, offer advantages such as high purity, high reproducibility and the ability to control the crystal growth without the need of using additional ligands. In this paper, a study carried out on a series of iron oxide/reduced graphene oxide composites is presented to elucidate a structure‐properties relationship leading to an improved electrochemical performance of such composites. Moreover, it is demonstrated that the easy production of the composites in a variety of temperature and composition ranges, allows a fine control over the final particles size, density and distribution. The materials obtained are remarkable in terms of the particle's size homogeneity and dispersion onto the reduced graphene oxide surface. Moreover, the synthesis method used to obtain the graphene oxide clearly affects the performances of the final composites through the control of the restacking of the reduced graphene oxide sheets. It is shown that a homogeneous and less defective reduced graphene oxide enables good electrochemical performances even at high current densities (over 500 mAh/g delivered at current densities as high as 1600 mA/g). The electrochemical properties of improved samples reach the best compromise between specific capacity, rate capability and cycle stability reported so far.     

一种用于高功率微波合成的X波段双色板

在数值模拟的基础上,设计了一种用于高功率微波合成的X波段同频带双色板。微波斜45°入射时,该双色板在9 GHz到9.3 GHz内反射效率大于99%,在9.7 GHz到10 GHz内传输效率大于99%,可以用于实现两路高功率微波的同极化合成。利用电磁场全波分析软件,建立了双色板数值模型,分析了该双色板的场增强因子和功率容量问题。     

基于微波光电技术的未来数字阵列构想

大型数字阵列雷达的天线系统由辐射单元和成千上万个数字收发组件（DTR）组成,极其庞大与复杂,雷达的工程化和安全性是系统的难点问题,微波光子学将对未来大型数字阵列雷达产生重大影响,基于微波光电实现阵列信号远程收发与传输技术,对未来大型数字阵列雷达提出一种构想,使雷达天线系统由辐射单元和模拟光电收发模块（OTR）组成,天线系统实现轻质、低成本、远程安装,有效改善大型数字阵列雷达的架设灵活性和使用安全性,同时光电数字阵列模块（ODAM）设计空间将更加宽容,有利于雷达综合性能的提升。     

Effects of ultrasonic–microwave combination treatment on the physicochemical,structure and gel properties of myofibrillar protein in Penaeus vannamei (Litopenaeus vannamei) surimi

The objective of this study was to evaluate the effects of single ultrasound (360 W, 20 min), single microwave (10 W/g, 120 s) and ultrasonic–microwave combination treatment on shrimp surimi gel properties. The structure and physicochemical properties of myofibrillar protein (MP) were also determined. Low-field nuclear magnetic resonance showed that the fluidity of water molecules and the moisture content decreased, the stability and water holding capacity (WHC) increased after single ultrasound, single microwave and ultrasonic–microwave combination treatment. Compared with the traditional water bath treatment, ultrasound and microwave treatment reduced the total sulfhydryl content and promoted the formation of intermolecular disulfide bonds and hydrophobic interactions, which improved the compactness of the network structure of shrimp surimi gel. Moreover, Fourier transform infrared spectroscopy and sodium dodecyl sulfate–polyacrylamide gel electrophoresis analysis revealed that these treatments not only inhibited the degradation of MP, but also decreased the α-helix content and increased the β-sheet content. The three treatments also significantly reduced the particle size and decreased the solubility of MP. Overall, the effect of ultrasonic–microwave combination treatment was superior to that of either single treatment.