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.     

基于图型矢量距离的多点地质统计相建模算法

多点地质统计建模算法已由基于概率模拟发展到基于相似度模拟的新阶段,基于相似度模拟的算法的关键是从训练图像中选取与数据事件最为相似的训练图型。以Simpat算法为基础发展起来的最具代表性的Filtersim和DisPat算法,采取先聚类、再匹配的建模策略,在训练图型选取的计算效率上较Simpat算法具有明显改进,但其匹配数据事件与训练图型仍采用标量距离度量二者相似度的方法。标量距离度量相似度的方法虽然具有较好的图形识别功能,但对于具有地质意义的训练图型（而非单纯的几何图形）,该方法的相似度判断往往难以获取在地质含义上与数据事件最佳匹配的训练图型。考虑图型选取过程中的地质含义,兼顾实际储层的非平稳性,提出了基于图型矢量距离的多点地质统计相建模算法。新算法在训练图型和数据事件矢量距离计算的基础上,采用二次匹配方式通过矢量距离对数据事件与训练图型的相似度进行度量,最终确定与数据事件相似度最大的训练图型。以文献算例定性和定量对比了新算法和Snesim、Filtersim、DisPat算法的建模效果,并以实际油藏为例,对比了新算法与传统两点建模方法、Snesim和DisPat算法的建模效果。结果表明,新算法显著降低了训练图型选取的不确定性,所建模型更符合地质认识,从而为复杂油气藏相建模提供了一种新的方法。     

西湖凹陷深层低渗-致密气藏“甜点”类型划分及成因探讨

低渗-致密气藏开发的关键是“甜点”的识别和预测,为探索海上少井、深层低渗-致密气藏“甜点”类型及成因,指导油气田勘探开发,利用岩心观察,铸体、阴极发光、扫描电镜等薄片鉴定,粒度分析,核磁共振,高压压汞,恒速压汞,孔渗测试和元素分析等多种手段对东海陆架盆地西湖凹陷X气田“甜点”进行研究。首先对研究区“甜点”定义进行探讨,并根据理论产能、物性、孔隙结构和束缚水含量将“甜点”分为3类：Ⅰ类“甜点”为高产气藏,以Ⅰ类孔隙结构为主,束缚水饱和度大多处于22%~57%;Ⅱ类“甜点”为中产气藏,储层中主要发育Ⅱ类孔隙结构,其次为Ⅰ类孔隙结构,少见Ⅲ类孔隙结构,束缚水饱和度大多处于45%~55%;Ⅲ类“甜点”为低产气藏,主要以Ⅲ类孔隙结构为主,发育少量Ⅳ类孔隙结构,束缚水饱和度大多处于45%~55%。认为Ⅰ类和Ⅱ类“甜点”能够实现现阶段经济有效开发,Ⅲ类“甜点”为后期开发的“潜力层”。研究认为,埋深是控制“甜点”发育的决定性因素,研究区4 000 m以深基本不发育Ⅰ类和Ⅱ类“甜点”;沉积环境是控制“甜点”发育的内因;事件性沉积作用及成岩作用是Ⅰ类和Ⅱ类“甜点”的重要影响因素;溶蚀作用是Ⅲ类“甜点”的主控因素;构造运动是研究区气藏“甜点”形成和保存的必要条件。     

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。     

A new technique for boosting efficiency of silicon solar cells

A new type of photovoltaic system with higher generation power density has been studied in detail. The feature of the system is a V-shaped module (VSM) with two tilted monocrystalline solar cells. Compared to solar cells in a flat orientation, the VSM enhances external quantum efficiency and leads to an increase of 31% in power conversion efficiency. Due to the VSM technique, short-circuit current density was raised from 24.94 to 33.7 mA/cm², but both fill factor and open-circuit voltage were approximately unchanged. For the VSM similar results (about 30% increase) were obtained for solar cells fabricated by using mono-crystalline silicon wafers with only conventional background impurities.