竖直式HVPE反应系统的理论模拟与GaN厚膜生长

根据流体动力学模型,研究了反应气体在反应室内的浓度分布,以及反应室的温场分布.NH3浓度在衬底附近分布均匀,而GaCl浓度在衬底中心区域较大,周边较小.实验结果表明,外延层在中心区生长速率为260μm/h,周边为140/μm/h.X射线摇摆曲线半高宽为141".O杂质的引入,使得样品具有较强的黄光发射.     

Versatile Antibacterial Materials: An Emerging Arsenal for Combatting Bacterial Pathogens

Antibacterial materials that prevent bacterial infections and mitigate bacterial virulence have attracted great scientific interests. In recent decades, the bactericidal polymers have been presented as promising candidates to combat bacterial pathogens, mainly based on the construction of bactericidal cationic polymers, functionalization with biocidal agents, and formation of bacterial‐repelling layers. However, these established strategies have inherent disadvantages because they often overlook important features such as their biocompatibility and biosafety, especially for biomedical applications. In recent years, many efforts have been made focusing on the development of multifunctional antibacterial materials to meet the elaborate requirements for medical devices and public hygiene products. Herein the recent advances in developing multifunctional materials for their antibacterial activities together with other functions including “kill‐and‐release” capability, hemocompatibility, cell proliferation promoting properties, and coagulation promoting ability for wound dressing are highlighted. In addition, the outlooks on the remaining challenges that should be addressed in the field of multifunctional antibacterial materials are also described.     

Modulating Blue Phosphorene by Synergetic Codoping: Indirect to Direct Gap Transition and Strong Bandgap Bowing

The structural and electronic properties of synergistically modified blue phosphorene (BP) is investigated. The inversion and threefold rotational symmetries of BP are broken. The codoping of group IV and VI impurities can turn monolayer BP into direct bandgap semiconductors. The underlying physical mechanism is that group IV and VI impurities tailor the valence band maximum and conduction band minimum, respectively, and move them to Γ. All the bandgaps of monolayer, nanoribbons, and quantum dots of BP can be modulated in a wide range, and the strong bandgap bowing is found. In addition, the Coulomb interactions between the screened impurities are revealed. Lower formation energies indicate the fabricating practicability of synergeticly modified BP. Spin–orbit coupling (SOC) can also be tuned by the introduction of impurities.     

A 5 mW and 5% efficiency 210 GHz InP-based heterostructure barrier varactor quintupler

This letter reviews the design, construction, and measurement of a 210 GHz heterostructure barrier varactor frequency quintupler. The quintupler utilizes planar heterostructure barrier varactors (HBVs) based on the InGaAs/InAlAs/AlAs material system and has produced a measured output power of 5.2 mW with 5.2% conversion efficiency at 210 GHz. This performance is comparable to the state-of-the-art results reported in the literature for HBV frequency triplers operating at millimeter and submillimeter wavelengths.     

嵌入式系统软件模拟及硬件接口设计的快速验证

该文提出了一种面向宿主机器代码编译的嵌入式软件功能验证方法,该方法从系统行为级验证系统功能,通过建立RTOS软件模拟器,实现嵌入式软件功能及硬件接口设计的快速验证,并以椭圆滤波器为例,阐述如何使用该方法验证嵌入式系统软件和硬件接口功能。     

Matrix unit cell scheduler (MUCS) for input-buffered ATM switches

This paper presents a novel matrix unit cell scheduler (MUCS) for input-buffered asynchronous transfer mode (ATM) switches. The MUCS concept originates from a heuristic strategy that leads to an optimal solution for cell scheduling. Numerical analysis indicates that input-buffered ATM switches scheduled by MUCS can utilize nearly 100% of the available link bandwidth. A transistor-level MUCS circuit has been designed and verified using HSPICE. The circuit features a regular structure, minimal interconnects, and a low transistor count. HSPICE simulation indicates that using 2-μm CMOS technology, the MUCS circuit can operate at clock frequency of 100 MHz     

几种CO2激光切雕机光开关的设计与研究

设计与研究了几种用于CO2激光切雕机的光开关,并对其性能进行了讨论和比较。     

锥形有源条半导体光放大器增益和饱和特性分析

以行波半导体光放大器速度方程为基础，采用传输矩阵方法，对锥形结构半导体光放大器的增益和饱和特性进行理论研究。讨论了不同锥形长度，不同结构时的增益和饱和特性差异。理论研究表明，锥形结构能改善半导体光放大器的偏振灵敏度。在同一锥度下，长锥形长度能提高饱和增益，降低偏振度。在进行半导体光放大器有源条结构设计时要综合考虑锥度及锥形长度的影响，以实现结构优化 。     

C／Ku双波段馈源系统的研究

本文介绍C／KU双波段馈源系统的一种设计方法，对其设计思想和实现的技术措施进行了较为详细的阐述，最后给出测试结果。