Ternary Ta2NiSe5 Flakes for a High‐Performance Infrared Photodetector

Multielemental systems enable the use of multiple degrees of freedom for control of physical properties by means of stoichiometric variation. This has attracted extremely high interest in the field of 2D optoelectronics in recent years. Here, for the first time, multilayer 2D ternary Ta₂NiSe₅ flakes are successfully fabricated using a mechanical exfoliation method from chemical vapor transport synthesized high quality bulk and the optoelectronic properties are systematically investigated. Importantly, a high responsivity of 17.21 A W^?1 and high external quantum efficiency of 2645% are recorded from an as‐fabricated photodetector at room temperature in air; this is superior to most other 2D materials‐based photodetectors that have been reported. More intriguingly, a usual sublinear and an unusual superlinear light‐intensity‐dependent photocurrent are observed under air and vacuum, respectively. These excellent and special properties make multilayer ternary Ta₂NiSe₅ a highly competitive candidate for future infrared optoelectronic applications and an interesting platform for photophysics studies.     

凝结式湿度传感器系统设计与试验

大气湿度是地面以及高空气象观测的基本要素之一,为了设计气象业务用露点型湿度传感器,本文基于凝结法测湿原理,结合显微光学、图像识别、嵌入式系统和自动控制等技术,成功设计并研制了凝结式湿度传感器样机。重点突破了凝结镜面设计、镜面温度控制和凝结物检测识别算法等关键技术,并将样机分别与MBW373湿度标准器和HMP155a测湿传感器进行了静态和动态对比试验。测试结果显示,样机与对比仪器均有较好的一致性,与标准器相对湿度测量偏差在-2.86%RH到-0.95%RH之间,测量的平均误差为-1.66%RH,满足地面气象观测业务要求。     

一种改进的定时同步算法

离散傅立叶变化扩展的正交频分复用(DFT-S-OFDM)技术已被3GPP采用,作为长期演进项目(LTE)的上行调制方案,具有峰均比(PAPR)低等优势.该方案中接收机端现有的定时同步算法,大都不能适应低信噪比的高斯白噪声信道和多径衰落信道的恶劣环境.针对此情况,本文提出了一种改进的假设检验统计量,用来进行定时同步.理论分析与仿真表明,在AWGN信道和多径衰落信道下,低信噪比(-10dB)的工作条件,改进的算法对高速运动引起的多普勒频偏具有较强的抵抗力.接收机能快速、高准确率的同步上发送数据的帧头,改进算法对工程应用具有一定价值.     

Kinetic studies of adsorption of Pb(II), Cr(III) and Cu(II) from aqueous solution by sawdust and modified peanut husk

Sawdust and modified peanut husk were used as adsorbents to remove Pb(II), Cr(III) and Cu(II) from aqueous solution. Results of kinetic experiments demonstrated that the adsorption was effective and rapid. Three different kinds of kinetic models (i.e., intraparticular diffusion model, Lagergren-first-order and second-order equations) were used to investigate the adsorption mechanisms. The adsorption of heavy metals on sawdust and modified peanut husk is not an intraparticular diffusion control. The kinetic adsorption data can be described by the second-order equation and the adsorption might be a rate-limiting control. The suitability of the adsorbent was tested by fitting the adsorption data with Langmuir and Freundlich isotherms, which gave good fits with both isotherms.     

语用模糊的认知观

本文从认知探讨了语用视角语用模糊现象.语用模糊是说话人在特定语境或上下文中使用不确定的、模糊的或间接的话语向听话人表达数种言外行为或言外之力的现象.从认知语用的视角来看,语用模糊可分为消极语用模糊和积极语用模糊两种,前者主要源于认知、表达及意义映射的模糊;后者则主要是出于交际策略和语境效果的需要.而关联性可以对语用模糊交际起指导和解释作用.     

几种典型铁矿石烧结基础特性的实验与评价

引入了铁矿石烧结基础特性的新概念,并对几种典型铁矿石的烧结基础特性进行了测试与评价,包括铁矿石的同化性、流动性、粘结相强度、连晶性能及铁酸钙生成性能.在此研究基础上给出了烧结与球团互补性配矿建议.     

山西临汾奥陶系石膏岩的成因及形成环境

山西临汾奥陶系石膏岩可分为原地沉淀型、异地沉积型、成岩交代型和脉状充填型四种。原地沉淀型石膏岩形成于浅水台地地势相对低洼的盐湖中;成岩交代型石膏岩形成在浅水台地地形相对隆起的部位,交代作用发生于大气淡水渗流带;异地沉积型石膏岩的形成环境介于低洼的盐湖和较高的隆起之间;脉状充填型石膏岩是充填在白云岩中的石膏脉,其形成与石膏-硬石膏相互转化时,脱水产生异常高压和吸水膨胀有关。     

反应自生成AlN传质过程的研究

根据反应自生成AIN的传质及生长特征,构造出传质模型,并建立了传质方程.分析表明：整个反应过程分AlN晶体生长并伴随Si元素富集及AlN、Si_cry,晶体共生两个阶段进行;N原子的扩散传质速率是控制总反应速率的关键因素.     

中国的前陆盆地与油气聚集

由于两个板块的相互碰撞形成一系列造山带,而在稳定板块的前缘常常形成前陆盆地.由于前陆盆地的特点,使它对油气的生成、运移、聚集和保存都十分有利.中国的主要前陆盆地有:塔里木盆地库车坳陷前缘、塔西南昆仑山前缘、塔东南阿尔金山前缘;准噶尔盆地南缘、准噶尔盆地东部博格山前缘;贺兰山一六盘山前缘;南方地区的两个前陆盆地.这些前陆盆地都是寻找油气前景广阔的地区.     

间磺基偶氮氯磷光度法测定钢样及人发中铬

研究了在ＨＡｃ－ＮａＡｃ介质中间磺基偶氮氯膦（ＣＰＡｍｓ）分光光度法测定Ｃｒ（Ⅲ）的最佳条件。在ｐＨ４．６条件下,ＣＰＡｍＳ与Ｃｒ（Ⅲ）形成的配合物最大吸收位于６２２ｎｍ,摩尔吸光系数ε＿ｍａｘ＝２．９９×１０￣４,有色物质的组成为Ｃｒ（Ⅲ）：ＣＰＡｍＳ＝１：１,１～２５μｇ／２５ｍｌ的铬（Ⅲ）符合比尔定律。方法用于钢样及人发中铬的测定,得到了满意的结果。