形成优质Si＋注入SI-GaAs层的研究

在GaAs集成电路研制中需要高电激活率、高迁率的n型薄层。该文研究了Si~+注入GaAs形成的n型层光电特性与材料参量、注入和退火条件的关系。结果表明材料生长中的杂质污染和缺陷对注入层电特性有直接影响。材料或退火过程中As和Ga的原子比[As]/[Ga]稍大时,注入层中电激活率和迁移率都高。实验还证明,~(29)Si~+注入时BF~+束流的影响会使注入层电激活率和迁移率下降。指出注入时剂量不宜过大,白光快速退火时温度不宜过高,一般在960℃ 5秒退火为佳

Excavation of Laohudun Prehistoric Site in Jing'an,Jiangxi

老虎墩遗址位于江西省靖安县城西北约15公里,在高湖镇中港村邓家自然村东约200米的台地上。2009~2010年,江西省文物考古研究所、厦门大学历史系考古专业、靖安县博物馆联合对遗址进行了发掘,揭示出从史前时期到明代中期的文化内涵。本文主要对老虎墩遗址的史前遗存进行了介绍,分为下层遗存和上层遗存。下层遗存有房址、道路、灰坑等,出土有石器和陶器;上层遗存有墓葬、房址、灰坑,出土器物主要是陶器。下层文化陶器表现出较早的形态,初步推断其年代在距今6000年之前;上层文化可能是江西省一支新的古文化类型,年代距今5000~4500年。The Laohudun Site is situated on a mound about 200 m east of Dengjia Village in Gaohu Town,about 15 km northwest of the Jing'an County seat in Jiangxi Province.From 2009 to 2010,a collaborative archaeological team excavated the site.Rich cultural remains from prehistoric times to the middle of the Ming Dynasty were unearthed.This report focuses on the prehistoric remains,which were divided into lower and upper layers.In the lower layer,there are building and road remains,ash-pits,stone artifacts,and pottery.In the upper layer,there are burials,building remains,and ash-pits,with unearthed objects consisting mainly of pottery.Pottery found in the lower layer presents a relatively early form.Initial analysis suggests the culture of the lower layer dates to about 6000 years BP,and the culture of the upper layer,which may be a newly discovered ancient culture type in Jiangxi Province,dates to about 5000—4500 years BP

Electrochemical Removal of Low Concentration Pb(II) from Aqueous Solution based on PPy/α-ZrP/PTCF Electrode

采用循环伏安法在水相中制备了电活性聚吡咯/α-磷酸锆（PPy/α-ZrP）有机-无机杂化膜，通过FT-IR、XRD、XPS对电活性PPy/α-ZrP杂化膜进行表征. 将制备在碳毡（PTCF）基体上的电活性PPy/α-ZrP膜电极（聚吡咯/α-磷酸锆/碳毡电极，PPy/α-ZrP/PTCF）用于电控离子交换去除废水中的铅离子. 通过对PPy/α-ZrP膜电极施加氧化还原电位来调节电活性组分PPy/α-ZrP的氧化还原状态，使废水中的铅离子能够快速置入和释放. 在10 mg·L-1的Pb(II)水溶液中，膜电极对铅离子的去除效率为单纯离子交换的1.8倍，膜电极的吸附量为单纯离子交换的2倍，表明该膜电极在电控离子交换条件下对铅离子具有较强的去除效率和更高的吸附容量. 吸附过程符合准二级动力学模型，电控离子交换的准二级吸附速率常数k2（0.6142 g·mg-1·h-1）明显高于单纯离子交换（0.2632 g·mg-1·h-1).A novel organic-inorganic hybrid film consisting of polypyrrole/α-zirconium phosphate (PPy/α-ZrP) was prepared in an aqueous phase by cyclic voltammetry method. It was proved by FT-IR, XRD and XPS characterizations that the electroactive PPy/α-ZrP hybrid film was synthesized successfully. The PPy/α-ZrP film electrode prepared on a porous three-dimensional carbon felt (PTCF) was used for removal of a low concentration of Pb(II) ions from an aqueous solution by electrochemically switched ion exchange (ESIX). A quick uptake and release rate of Pb(II) onto the film electrode was obtained by adjusting redox state of the hybrid film. The removal efficiency and adsorption capacity of the PPy/α-ZrP/PTCF electrode for Pb(II) were about 1.8 and 2 times higher than those of traditional ion exchange (IX), respectively. Thus, the film electrode showed higher removal efficiency and adsorption capacity for Pb(II) by ESIX. The adsorption kinetics of Pb(II) could be described properly by the pseudo-second-order kinetic mode. A greater pseudo-second-order rate constant of 0.6142 g·mg-1·h-1 was achieved by ESIX, which was higher than that of 0.2632 g·mg-1·h-1 by IX.国家自然科学基金项目（No. 21276173，No. 21476156，No. 21306123）资助作者联系地址：1. 太原理工大学化学工程系，山西 太原 030024；2. 广东省国家模具产品质量监督检验中心，东莞市质量监督检测中心，广东 东莞 523808Author's Address: 1. Department of Chemical Eegineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China; 2. Guangdong Dongguan Quality Supervision Testing Center National Mould Products Quality Supervision Inspection Center, Dongguan 523808, Guangdong, China通讯作者E-mail：[email protected]

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies