20^#钢碳氮共渗表面渗硫层组成和化学状态的AES和XPS研究

对20^#钢进行碳氮共渗,然后在溶液介质中室温下进行电解渗硫处理,采用俄歇电子谱和X射线光电子能谱对硫化层表面及深度成分进行分析。结果表明,硫化固体润滑膜主要由FeS组成,而不含低温电解渗硫处理时形成的亚硫酸亚铁,硫化层的结构比较疏松。     

光弹贴片主应变分离方法与新仪器研究

本文针对光弹性贴片法目前存在的技术困难，提出了一种分离主应变的钻孔法，利用孔边条纹级别比近似代替测点主应变比，达到了简便地分离主应变的目的。研制了一台新型小巧轻便的反射式偏光仪，便于钻孔法及野外现场试验中使用。     

深度拉伸塑性变形对0.7%碳钢耐磨性的影响

经过铅浴处理的0.7%碳钢进行冷拉变形,采用扫描电子显微镜观察分析冷拉0.7%碳钢的组织形貌,采用材料拉力试验机和显微硬度计测试0.7%碳钢丝的抗拉强度和显微硬度,采用ML-10型销-盘式磨料磨损试验机考察深度冷拉0.7%碳钢丝在不同磨料磨损工况下的磨损特性,利用扫描电子显微镜观察分析0.7%碳钢磨损表面形貌.结果表明,深度拉伸塑性变形使得0.7%碳钢的组织超细化,大幅提高0.7%碳钢的机械性能.在以氧化铝和石英为磨料工况下,随着0.7%碳钢真应变增加,耐磨性缓慢提高;在以玻璃为磨料工况下,随着0.7%碳钢真应变增加,耐磨性呈现阶段性变化,当变形达到一定程度时,0.7%碳钢的耐磨性大幅提高.在以氧化铝和石英为磨料工况下,其磨损机理以微观切削和犁沟为主;以玻璃为磨料工况下,在低应变阶段,其磨损机理以显微切削为主,在高应变阶段,磨损机理以多次塑性变形和疲劳磨损为主.     

Analysis and applications of a frequency selective surface via a random distribution method

A novel frequency selective surface （FSS） for reducing radar cross section （RCS） is proposed in this paper. This FSS is based on the random distribution method, so it can be called random surface. In this paper, the stacked patches serving as periodic elements are employed for RCS reduction. Previous work has demonstrated the efficiency by utilizing the microstrip patches, especially for the reflectarray. First, the relevant theory of the method is described. Then a sample of a three-layer variable-sized stacked patch random surface with a dimension of 260 mm x 260 mm is simulated, fabricated, and measured in order to demonstrate the validity of the proposed design. For the normal incidence, the 8-dB RCS reduction can be achieved both by the simulation and the measurement in 8 GHz-13 GHz. The oblique incidence of 30° is also investigated, in which the 7-dB RCS reduction can be obtained in a frequency range of 8 GHz-14 GHz.     

复合基底圆极化微带贴片天线建模与仿真

设计了一种用于无源射频识标签,中心谐振频率为2.45GHz的圆极化微带贴片天线。设计中引入了Rogers RO4232 (tm),Rogers RO4003 (tm)以及玻璃短纤维增强聚四氟乙稀三种材质的复合基底,利用Ansoft HFSS 10.0进行建模,并对设计模块进行仿真和优化处理,仿真结果表明天线的方向性良好,有效增益为5.534dB, 带宽>50MHz(S11<-15dB),阻抗匹配良好。驻波比、辐射效率均与理论期望吻合,各项指标达到了航空配件管理及维修记录的实际需求且易于实现,价格低廉,可靠性好。     

紧凑型宽谱高功率微波辐射器仿真设计

为了提高宽谱高功率微波辐射源的辐射因子,提出采用双路同步输出的宽谱谐振器驱动2×2宽带高功率贴片天线阵的技术思路。设计了一种双路同步输出的宽谱高功率脉冲谐振器,由两个同轴谐振腔尾尾相连,并共用一个环形对地开关,实现两路宽谱脉冲的同步产生与输出,通过对"T"形充电结构进行优化,使输出宽谱脉冲幅值达到充电电压的0.89倍。2×2宽带高功率单层贴片天线阵采用气体基底和单层贴片结构以降低重量,单层贴片设计为E形以拓展工作带宽,通过对天线阵几何参数进行全局优化,优化后的天线阵百分比带宽为47%(驻波比VSWR小于2),中心频率300 MHz的增益为11.8dB。对天线阵工作过程中的电场强度分析表明,在天线罩内填充105 Pa的SF6气体时,理论功率容量可达到7.4GW。对整个辐射系统的电性能进行了仿真分析,系统的理论辐射因子可达谐振器充电电压的2.8倍。     

Application of Ultra-Compact Single Negative Waveguide Metamaterials for a Low Mutual Coupling Patch Antenna Array Design

A novel ultra-compact single-negative waveguide metamaterial （WG-MTM） based on a complementary anti- parallel-spiral line （CAPAL） is proposed and investigated by circuit model analysis, electromagnetic simulation and extraction of the effective parameters. The cell is ultra-compact with dimensions of λ0/22.08 × λo/22.08, which advances a step further toward homogenized concept. Two band-gaps attributing to the negative permeability and negative permittivity appear when the CAPAL-WG-MTM cells response to the time-varying perpendicular E-field and parallel H-field, and thus a high decoupling efficiency is obtained. Mutual coupling reduction of about 8.27dB is realized by inserting 7 ×1 CAPSL-WG-MTM cells between two closely placed antenna elements with an edge-to-edge separation of only λ0/19.23. Moreover, the radiation characteristics are improved for both the patch element and the antenna array. A higher front-to-back ratio is obtained for the patch element and an increase of 0.64dB for the gain of the antenna array by using the CAPAL-WG-MTM structure.     

压敏胶贴片中芍药苷及残留溶剂含量的测定

建立了贴片中标示成分芍药苷含量的高效液相色谱(HPLC)法和贴片中各种残留溶剂含量的气相色谱(GC)法。样品经甲醇提取,离心分离后,以乙腈-水(含4%HAc)的体积比为16∶84作流动相,选择ODS-2HypersilC18(150×4.6mm,5μm)色谱柱,测定芍药苷含量。贴片基质经乙醚处理,离心分离,以GC内标法测定残留溶剂含量。结果表明:HPLC法的精密度、重现性和回收率良好;GC法测得乙酸乙酯、异丙醇、乙醇三种残留溶剂,贴片中残留溶剂总量为2.1×10-4,符合药典限度规定。     

宽带高功率贴片天线阵列辐射特性

 为提高宽带高功率微波辐射天线的总体功率容量和增益,研究了2×2宽带高功率贴片天线阵列的阵元互耦特性、馈电功分器设计及对宽带电磁脉冲的辐射特性。阵元采用宽带高功率双层贴片天线,分析了阵元反射和互耦系数随阵元间距的变化关系,结合增益变化曲线,选取阵元间距为30 cm。优化设计了1分4的同轴功分器,采用阻抗渐变方法,提高了功分器的带宽,使其在224~415 MHz时的反射系数小于0.1。模拟了带功分器的完整天线阵,结果表明天线阵带宽达到了57.4％,280~390 MHz频带范围内的增益大于12 dB,在360 MHz时达到最大增益14.23 dB,对中心频率320 MHz,带宽10％的宽带电磁脉冲辐射效率为868％,峰值功率增益大于11 dB。