Technology Research of The Chemical Vapor Deposition Thick Tungsten Coating

传统的制备钨涂层方法包括：等离子喷涂、热喷涂、熔盐电镀、物理气相沉积、化学气相沉积等。其中，化学气相沉积以钨涂层纯度和致密度高的优点格外引人关注。近年来在国际热核聚变堆中将钨用于面向等离子体第一壁涂层材料已引起了世界范围内的关注和重视，其厚度要求大于1mm，且需要承受高能粒子及高热量冲击，对纯度和致密度的要求很高，化学气相沉积无疑是最具有潜力的方法。根据可掌握的资料，对化学气相沉积厚钨涂层的原料制备、涂层制备、涂层抗热负荷性能检测等系统性研究还开展得较少。 本文研究了六氟化钨的制备方法，并以自制高纯六氟化钨为原料，采用化学气相沉积方法成功得到了厚钨涂层。研究了沉积工艺对涂层的沉积速率、微观组...The traditional methods of preparing tungsten coatings comprise plasma spraying, thermal spraying, molten salt electroplating, physical vapor deposition, chemical vapor deposition, etc. Among them, chemical vapor deposition of tungsten coating is particularly concerned with the advantages of its high purity and high density. In recent years,using tungsten as plasma facing first wall coating materi...学位：工程硕士院系专业：材料学院材料科学与工程系_材料工程学号：X200719300

a joint decision-making scheme for groups with members having different superiorities

公平性、透明性是联合决策的基本安全需求.结合多机构商务合作背景,利用具有同态性质的Paillier公钥密码系统和门限密码技术,提出了面向有差异群体的联合决策策略与方案,并对其安全性进行了分析和证明

Preparation and Electrocatalytic Oxygen Reduction Performance of Self-Doped Sludge-Derived Carbon

开发低成本、高性能的阴极催化剂是燃料电池商业化应用的关键. 本文以剩余污泥为前驱体，在碳化前通过连续添加苯酚来对污泥进行驯化，热解后得到自模板、自活化及N、P、Fe自掺杂的多孔类石墨烯碳材料. 结果表明，污泥经苯酚驯化后，微生物得到富集，含碳量显著提高，N、P、Fe等元素大大增加. 热解温度升高能提高材料的石墨化程度，但过高的温度会使杂原子掺杂量减少，从而降低氧还原催化活性. 其中，800 ℃下煅烧得到的污泥碳（PSC-800）比表面积为402.4 m2·g-1，远高于未驯化污泥碳（SC-800）的262.4 m2·g-1. 光电子能谱（XPS）数据表明，PSC-800具有较高的杂原子掺杂量及含铁量，形成了吡啶氮、石墨氮等氧还原活性位点. 在碱性条件下催化4电子的氧还原反应，初始电位为0.93 V，高于SC-800的0.89 V及其他温度煅烧的污泥碳（PSC-600：0.75 V，PSC-700：0.87 V， PSC-900：0.91 V）. 极限电流密度与商业铂碳相当，具有良好的稳定性及抗甲醇毒性.The development of low-cost, high-performance cathode catalysts is critical for practical application of fuel cells. Here, the N, P-doped porous graphene-like carbon with outstanding oxygen reduction reaction (ORR) performance was synthesized by pyrolysis of surplus sludge, which functioned as a self-doped, self-activated, and self-templated precursor by acclimation with continuous feedings of phenol. The results show that the amounts of microorganisms were enriched after acclimation, with increasing contents of N, P, Fe, as well as C atoms. The increasing pyrolysis temperature resulted in the formation of an ordered graphitic structure, however, the excessively high temperature induced the drop in the amounts of the heteroatoms that are doped in the carbon framework. The phenol-acclimated sludge pyrolyzed at 800 ℃(PSC-800) featured a BET surface area as high as 402.4 m2·g-1, which was much higher than that of the raw sludge carbon (SC-800) (262.4 m2·g-1). X-ray photoelectron spectroscopic (XPS) data suggests that the PSC-800 had higher levels of heteroatom doping, which was conductive to the formation of oxygen reduction active sites such as pyridinic nitrogen and graphitic nitrogen. The obtained PSC-800 exhibited excellent ORR activity in alkaline media with the onset potential of 0.93 V, higher than 0.75, 0.87, 0.91, and 0.89 V for PSC-600, PSC-700, PSC-900 and SC-800, respectively. In comparison to the commercial Pt/C catalyst, the PSC-800 showed comparable catalytic activity in terms of the close onset potential, kinetic-limiting current and four-electron transfer process, and higher tolerance to methanol toxicity and superior stability.国家自然科学基金项目（No. 21577041）资助作者联系地址：华南理工大学环境与能源学院，工业聚集区污染控制与生态修复教育部重点实验室， 广东 广州 510006Author's Address: School of Environment and Energy, the Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, South China University of Technology, Guangzhou 510006, China通讯作者E-mail：[email protected]

绿洲农业高效用水技术集成与示范

简要技术说明： 该成果围绕棉花、葡萄、小麦3大作物,从干旱绿洲区作物高效用水和提高作物水分生产效率的目标出发,研究形成了棉花高效用水技术模式3套、葡萄高效用水技术模式1套、小麦优化灌溉节水及配套栽培技术模式1套、干旱绿洲区农业高效用水管理技术模式1套,开发了15项农业节水关键技术和1套“农业灌溉决策支持系统”,筛选出节水配套抗旱小麦品种2个、抗旱棉花品种1个,制定了农业高效用水技术规程7项,研发了专利产品1项、软件著作权登记1项,人才培养12名、发表论文45篇。通过对高效灌溉技术、农艺高效用水技术、高效用水管理技术等3方面的关键技术的集成与创新,研究形成了干旱绿洲区特色作物(棉花、葡萄、..

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