机载指控系统仿真环境与评估研究

机载指控系统是一类复杂大系统，如何有效地分析和评估机载指控系统一直是研究领域里的一个难点，基于HLA的分布式仿真技术的发展为这一问题的解决提供了一个新途径．采用了一种基于HLA的通用机载指控系统仿真环境框架，该框架的实现将大大促进机载指控系统的研制开发和作战使用研究。     

基于数字相关技术的铝合金航天结构件缝隙测量研究

对铝合金航天结构件受载情况下端框铆接缝隙变化测量进行研究,搭载静力试验模拟航天器飞行过程中的典型最严酷的载荷环境,采用三维数字相关技术进行测试某铆接界面缝隙变形情况,并将三维数字相关技术测量数据与塞尺进行对比,试验数据表明:三维数字相关技术用于缝隙测量,精度高,且测量可实现实时监测。     

掺铕稀土配合物的光学树脂荧光光谱研究

报道了将多种稀土铕配合物复合于苯乙烯(ST)／甲基丙烯酸(HMA)的共聚体系,研究了含稀土配合物透明光学树脂的光学性能。发现其具有发光效率高,光谱呈现尖锐的线状谱带及相对于纯稀土配合物粉末来说掺有稀土配合物的光学树脂的发射产生光谱红移等特点。特别是用电子云重排效应(当中心稀土离子与不同配体结合时,其相同的J能级间的跃迁谱带位置略有移动的现象)解释了掺有稀土配合物的光学树脂发射光谱红移现象。并推断出在含稀土配合物复合于光学树脂后。稀土中心离子和配位原子间距离有所减小。     

推进高清晰度电视需要解决的问题

高清电视的发展应该在具备一定的条件下进行,统一的规划和指导以及一些必要的标准和规范应该尽早制定,只有这样才能使得高清电视科学、有序、协调、稳定地向前推进。     

导高职学生走进健身广场提升运动技能的探析

学校体育工作不仅是教育事业的有机组成部分,而且是全民健身事业的重要内容,还是全体公民终身体育的教育基础,为了使学生全面适应社会的发展,跟上时代的步伐,我们必须开发有效的学习手段来增强学生的学习能力,以适应现代教学需要和社会的需求。     

A GaN/InGaN/AlGaN MQW RTD for versatile MVL applications with improved logic stability

To improve the logic stability of conventional multi-valued logic (MVL) circuits designed with a GaN-based resonate tunneling diode (RTD),we proposed a GaN/InGaN/AlGaN multi-quantum well (MQW) RTD.The proposed RTD was simulated through solving the coupled Schrodinger and Poisson equations in the numerical non-equilibrium Green's function (NEGF) method on the TCAD platform.The proposed RTD was grown layer by layer in epitaxial technologies.Simulated results indicate that its current-voltage characteristic appears to have a wider total negative differential resistance region than those of conventional ones and an obvious hysteresis loop at room temperature.To increase the Al composite of AlGaN barrier layers properly results in increasing of both the total negative differential resistance region width and the hysteresis loop width,which is helpful to improve the logic stability of MVL circuits.Moreover,the complement resonate tunneling transistor pair consisted of the proposed RTDs or the proposed RTD and enhanced mode HEMT controlled RTD is capable of generating versatile MVL modes at different supply voltages less than 3.3 V,which is very attractive for implementing more complex MVL function digital integrated circuits and systems with less devices,super high speed linear or nonlinear ADC and voltage sensors with a built-in super high speed ADC function.     

Ice-Templated,Large-Area Silver Nanowire Pattern for Flexible Transparent Electrode

Flexible transparent electrodes are critically important for the emerging flexible and stretchable electronic and optoelectronic devices. To this end, transparent polymer films coated with silver nanowires (AgNWs) have been intensively studied in the past decade. However, it remains a grand challenge to achieve both high conductivity and transmittance in large-area films, mainly due to the poor alignment of AgNWs and their high junction resistance. Here, the successful attempt to realize large-area AgNW patterns on various substrates by a 2D ice-templating approach is reported. With a relatively low dosage of AgNWs (4 µg·cm⁻²), the resulted flexible electrode simultaneously achieves high optical transmittance (≈91%) and low sheet resistance (20 Ω·sq⁻¹). In addition, the electrode exhibits excellent durability during cyclic bending (≈10 000 times) and stretching (50% strain). The potential applications of the flexible transparent electrode in both touch screen and electronic skin sensor, which can monitor the sliding pressure and direction in real-time, are demonstrated. More importantly, it is believed that the study represents a facile and low-cost approach to assemble various nanomaterials into large-area functional patterns for advanced flexible devices.     

Ultrafast Electrochemical Growth of Lithiophilic Nano-Flake Arrays for Stable Lithium Metal Anode

Lithium dendrites caused by nonuniform Li⁺ flux leads to the capacity fade and short-circuit hazard of lithium metal batteries. The solid electrolyte interface (SEI) is critical to the uniformity of Li⁺ flux. Here, an ultrafast preparation of uniform and vertical Cu₇S₄ nano-flake arrays (Cu₇S₄ NFAs) on the Cu substrate is reported. These arrays can largely improve the lithiophilicity of the anode and form Li₂S-enriched SEI due to the electrochemical reduction of Cu₇S₄ NFAs with lithium. A further statistical analysis suggests that the SEI, with a higher content of Li₂S, is more effective to inhibit the formation of lithium dendrites and yields less dead lithium. A quite stable coulombic efficiency of 98.6% can be maintained for 400 cycles at 1 mA cm^–2. Furthermore, at negative to positive electrode capacity ratio of 1.5 (N/P = 1.5), the full battery of Li@Cu₇S₄ NFAs||S shows 83% capacity retention after 100 cycles at 1 C, much higher than that of Li@Cu||S (33%). The findings demonstrate that high Li₂S content in the SEI is crucial for the dendrite inhibition to achieve better electrochemical performance.     

Colorless ONU implementation for WDM-PON using direct-detection optical OFDM

A novel architecture for the colorless optical network unit (ONU) is proposed and experimentally demonstrated with direct-detection optical orthogonal frequency division multiplexing (DDO-OFDM). In this architecture, polarization-division multiplexing is used to reduce the cost at ONU. In optical line terminal (OLT), quadrature amplitude modulation (QAM) intensity-modulated OFDM signal with x-polarization at 10 Gbit/s is transmitted as downstream. At each ONU, the optical OFDM signal is demodulated with direct detection, and y-polarization signal is modulated for upstream on-off keying (OOK) data at 5 Gbit/s. Simulation results show that the power penalty is negligible for both optical OFDM downstream and the on-off keying upstream signals after over 50 km single-mode fiber (SMF) transmission.     

8mm波导结环行器的仿真设计

介绍一种8mm波导结环行器的仿真设计方法,分析了环行器内部的电磁场,在仿真时采用了Ansofl Hfss和Ansofi Maxwell软件实现电磁联合仿真,有效的保证了仿真的准确性.在32.5GHz-36GHz频段,实测结果为驻波小于1.2,损耗小于0.4dB,隔离大于20dB.