LD泵浦Nd:GdVO4晶体LBO三倍频紫外激光器

报道了二极管(LD)端面泵浦Nd：GdVO4晶体腔外三倍频紫外激光器。利用声光调Q获得脉宽为25ns、重复频率为20kHz的355nm紫外准连续激光输出。当泵浦功率为16W时,用Ⅰ类相位匹配LBO晶体进行二倍频获得822mW的绿光输出;此时用Ⅱ类相位匹配LBO晶体进行三倍频获得266mw的355nm紫外激光输出,三倍频效率(1064-355nm)达到5．9％,输出功率抖动低于1．7％。     

云安21井127mm超短尾管固井技术

云安21井是川东开发公司在云安厂红家湾潜伏构造上的一口超深开发井,该井设计井深为5709m;实钻过程中钻遇断层,导致井深增加,实际井深钻达5858．00m,裸跟井段73．00m,属于典型的“深井、小尺寸、短尾管”固井范畴。介绍了该井的固井技术难点,固井技术措施、水泥浆体系的优选、现场应用及认识与体会。     

武装直升机与空地导弹系统相容性分析

针对武装直升机与空地导弹的机-弹相容性问题,提出一种综合多因素的系统分析方法.从直升机旋翼下洗气流对初始弹道的影响、直升机飞行速度对初始弹道的影响、导弹发射过程中导弹弹道与直升机的相对位置关系、发动机喷流对直升机的影响等多角度,综合分析各种因素对载机和空地导弹的影响.该方法完善了直升机载空地导弹与载机相容性分析体系,可...     

利用NetFlow技术构建网络异常监测及分析系统

随着互联网的不断普及,网络已经跟人们的日常生活密不可分,使用者在享受网络所带来的便利的同时,网络上的许多问题也陆续衍生而出,运营商网络正面临着日益严重的安全威胁.作为网络管理者,如何迅速有效地监测网络异常情况,同时准确地掌握整个网络的业务流量模型,供市场部门作决策分析,已成为一项重要的课题.介绍了利用NetFlow技术,构建网络异常监测及分析系统,利用本系统可随时监测网络运行情况,以达到网络稳定顺畅运作及节省经费、人力的目的.     

不同退火温度下Mo/4H-SiC肖特基接触界面特性分析

为研究退火温度对肖特基接触界面特性的影响,在不同温度下测试了不同退火温度处理的Mo/4H-SiC肖特基接触的I-V及C-V特性.根据金属-绝缘层-半导体(MIS)结构二极管模型理论,认为在金属与半导体间存在薄介质层,通过估算介质层电容值,得到了肖特基接触界面态密度(N88)的能级分布情况,N8s约为1012 eV-1·cm-2量级.退火温度升高,N8s的能级分布靠近导带底;测试温度升高,Ns8增加且其能级分布远离导带底.利用X射线光电子能谱(XPS)分析表征肖特基接触界面态化学组分,分析结果证实接触界面存在SiO.SiO组分随退火温度的升高而减少,在退火温度为500℃及以上时检测到Mo-C成分,说明Mo与4H-SiC发生反应.     

Nonfullerene Electron Transporting Material Based on Naphthalene Diimide Small Molecule for Highly Stable Perovskite Solar Cells with Efficiency Exceeding 20%

This study reports a new nonfullerene electron transporting material (ETM) based on naphthalene diimide (NDI) small molecules for use in high‐performance perovskite solar cells (PSCs). These solar cells simultaneously achieve high power conversion efficiency (PCE) of over 20% and long‐term stability. New NDI‐ID (N,N′‐Bis(1‐indanyl)naphthalene‐1,4,5,8‐tetracarboxylic diimide) consisting of an N‐substituted indane group having simultaneous alicyclic and aromatic characteristics is synthesized by a low‐cost, one‐step reaction, and facile purification method. The partially flexible characteristics of an alicyclic cyclopentene group on indane groups open the possibility of low‐temperature solution processing. The conformational rigidity and aromaticity of phenyl and alicyclic groups contribute to high temporal stability by strong secondary bonds. NDI‐ID has herringbone packed semiconducting NDI cores that exhibit up to 0.2 cm² V^?1 s^?1 electron mobility in field effect transistors. The inverted PSCs based on CH(NH₂)₂PbI_3–xBr_x with NDI‐ID ETM exhibit very high PCEs of up to 20.2%, which is better than that of widely used PCBM (phenyl‐C61‐butyric acid methyl ester) ETM‐based PSCs. Moreover, NDI‐ID‐based PSCs exhibit very high long‐term temporal stability, retaining 90% of the initial PCE after 500 h at 100 °C with 1 sun illumination without encapsulation. Therefore, NDI‐ID is a promising ETM for highly efficient, stable PSCs.     

An Improved LEACH Routing Algorithm for Wireless Sensor Network

Optimization of energy consumption is major concern for the design and planning of wireless sensor networks (WSNs). Recent research has demonstrated that organizing nodes in clusters has higher energy efficiency. LEACH is the most popular routing protocol for cluster-based in WSNs, and FCM algorithm is used for the optimum number of the clusters and their location. Aiming at the shortcomings of LEACH and FCM-LEACH, which including inaccurate cluster centers, unreasonable clustering and sole data transmission mode. This paper proposes a new energy efficient routing algorithm (NF-LEACH). In the new algorithm, There are many factors have considered to prolong the network life cycle that they are the degree of membership, residual energy, base station distance and data transmission mode. Finally, the comparison among LEACH, FCM-LEACH, and NF-LEACH has been done. The results show that the NF-LEACH has the longest lifetime and the most evenly distributed amongst three algorithms.     

利用旧厂房改造微模块数据中心的问题及对策

本文主要介绍在旧厂房（仓库）改造微模块数据中心时,可能遇到的部分问题,以及针对这些问题的解决思路和解决方案。     

2D Black Phosphorus–Based Biomedical Applications

Black phosphorus (BP) has increasingly attracted scientific attention since its first applications in biomedicine due to its unique properties and excellent biocompatibility. In particular, its layer‐dependent bandgap, moderate carrier mobility, large surface‐area‐to‐volume ratio, biodegradability, intrinsic photoacoustic properties, and biocompatibility make it an ideal candidate for use in photothermal therapy, photodynamic therapy, drug delivery, 3D printing, bioimaging, biosensing, and theranostics, which are reviewed here. In addition, the article discusses strategies to overcome challenges related to surface instability due to chemical degradation, a major obstacle for its application. This review not only provides a comprehensive summary on BP preparation and biomedical applications but also summarizes recent research and future possibilities.