检索结果-南通市图书馆

电加工与模具 2024年第S1期 26-32,38页

作者：夏斯伟刘志东吴小川曾熊辉郑宁黄静南京航空航天大学机电学院江苏南京210016 江苏省机械工程学会特种加工专业委员会江苏南京211100

回顾了电火花精密加工工艺的提出及其实现四类技术条件和回转式电火花加工的发展演变过程,着重介绍了共轭回转式电火花精密加工工艺的基本原理及其工艺特点,展示了应用回转式电火花精密加工的典型零件,并对回转式电火花精密加工进行技... 详细信息

回顾了电火花精密加工工艺的提出及其实现四类技术条件和回转式电火花加工的发展演变过程,着重介绍了共轭回转式电火花精密加工工艺的基本原理及其工艺特点,展示了应用回转式电火花精密加工的典型零件,并对回转式电火花精密加工进行技术展望。

关键词：电火花精密加工共轭回转式工艺原理技术条件与展望

脱盐水系统极高回收率工艺包的设计及工程应用

在线全文

学校读者我要写书评

暂无评论

山西化工 2024年第6期44卷 242-246页

作者：胡俊辉安康李建华曾雄辉陈然汇信盈(嘉兴)环保技术有限公司浙江嘉兴314201

针对脱盐水系统中水的利用率普遍较低的问题[1],设计了一种提高回收率的脱盐水工艺包,通过采用优质的高回收率超滤单元和对预处理工艺段的高浊排放水进行降浊处理回用[2],同时对脱盐水工艺段的高盐排放水进行深度除硬脱盐回用[3],使系... 详细信息

针对脱盐水系统中水的利用率普遍较低的问题[1],设计了一种提高回收率的脱盐水工艺包,通过采用优质的高回收率超滤单元和对预处理工艺段的高浊排放水进行降浊处理回用[2],同时对脱盐水工艺段的高盐排放水进行深度除硬脱盐回用[3],使系统水的利用率大于92%。运行结果表明,通过采用高强度、耐污染的超滤膜产品,经过优化其运行模式,可以使超滤单元做到95%以上的回收率,并通过回用超滤排放的高浊排污水能使预处理段的回收率做到99.5%;通过对RO浓水的深度软化,再用浓水RO进行脱盐回用,可以把脱盐段的回收率做到92%,这样整个脱盐水系统就能轻松实现92%以上的极高回收率。产水水质能满足高温高压锅炉补给水电导率<0.2μS/cm,ρ(SiO_(2))<0.02 mg/L的水质标准[4],可作为厂区锅炉补给水使用。成本分析表明,该脱盐水工艺包的吨水运行成本约13元(含税及其它全部费用),具有较好的经济性。

关键词：脱盐水系统极高回收率工艺包优质超滤降浊除硬

Luminescence mechanism and energy level structure of Eu-doped GaN powders investigated by cathodoluminescence spectroscopy

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2014年第4期57卷 628-631页

作者： WANG XiaoDan zeng xionghui XU Ke MAO HongMin MA ChunLan Department of Physics Suzhou University of Science and Technology Suzhou Institute of Nano-tech and Nano-bionics Chinese Academy of Sciences

1.5at% Eu-doped GaN powders were prepared by a co-precipitation *** X-ray diffraction(XRD)results shows that there is only the wurtzite *** spectra were measured at room temperature and liquid nitrogen temperature,*** band-to-band luminescence of GaN was shifted from 373 nm to 368 nm with the temperature decreasing from room temperature to liquid nitrogen *** luminescence peaks at 537,557,579,590,597,614,653 and 701 nm are attributed to the Eu ions related transitions in the host of GaN powders and the peak positions were not influenced by the variation of *** the increase of accelerating voltage,the intensity of all luminescence peaks was *** strongest luminescence peak at 614 nm shows non-symmetrical shape and is composed of 612,615 and 621 nm through Lorentzian fitting,which indicates there are oxygen and nitrogen environments of the Eu3+ions in the Eu-doped GaN powders.

关键词：发光机理发光光谱 GaN 能级结构阴极铕掺杂液氮温度粉体

Practices on rockburst prevention and control in headrace tunnels of Jinping II hydropower station

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2012年第3期4卷 258-268页

作者： Jimin Wang xionghui zeng Jifang Zhou Ertan Hydropower Development Company Ltd. Chengdu 610051 China

Rockburst problems induced by high in-situ stresses were prominent during construction of the headrace tunnels of Jinping II hydropower station. The rockbursts occurred in various forms, and it is necessary to take pertinent measures for integrated prevention and control of rockbursts. In view of the rockburst characteristics during tunnel construction of Jinping II hydropower station, the engineering geological conditions were presented, and the features, mechanisms and forms of rockbursts observed during construction were analyzed in detail. A large number of scientific researches, experiments and applications were conducted. Multiple measures were adopted to prevent and control rockbursts, including the prediction and early warning measures, stress relief by blasting in advance, optimized blasting design and optimized tunnel support in the tunnel sections prone to strong rockbursts. The effectiveness of these prevention and control measures was evaluated. Experiences have been accumulated through a great number of helpful explorations and practices for rockburst prevention and control. A comprehensive rockburst prevention and control system has been gradually established.

关键词： long and deep tunnel rockburst prevention and control stress relief by blasting microseismic monitoring

GaN:Eu,Dy薄膜的结构和发光特性研究

在线全文

学校读者我要写书评

暂无评论

稀有金属 2023年第3期47卷 381-389页

作者：陈华军罗璇王晓丹毛红敏曾雄辉徐科苏州科技大学物理科学与技术学院江苏苏州215009 中国科学院苏州纳米技术与纳米仿生研究所江苏苏州215123

通过离子注入方法制备了一系列稀土Eu和Dy掺杂的GaN薄膜,研究了其结构、发光特性和能量传递机制。拉曼(Raman)光谱和X射线衍射(XRD)的研究一致表明:当Eu剂量保持不变时,随着Dy剂量增加,GaN晶格应变出现了先张应变后压应变的变化趋势。... 详细信息

通过离子注入方法制备了一系列稀土Eu和Dy掺杂的GaN薄膜,研究了其结构、发光特性和能量传递机制。拉曼(Raman)光谱和X射线衍射(XRD)的研究一致表明:当Eu剂量保持不变时,随着Dy剂量增加,GaN晶格应变出现了先张应变后压应变的变化趋势。阴极荧光(CL)光谱表明:Eu,Dy共掺GaN样品的发光峰和单掺GaN样品的发光峰基本一致,这说明Eu和Dy共掺时并没有显著改变彼此的局域晶体场环境。在GaN中,对于Eu离子,^(5)D_(0)→^(7)F_(2)跃迁所对应的625 nm发光最强;对于Dy离子,^(4)F_(9/2)→^(6)H_(13/2)对应的583 nm发光最强。在Eu离子剂量保持不变的情况下,随着Dy离子注入剂量的增加,583 nm的发光逐渐变强,而625 nm的发光变弱。进一步,结合计算分析表明Eu离子主要通过电偶极-电偶极共振方式传递能量给Dy离子。最后发现随着离子注入剂量的改变,发光颜色在白色和红色间变化,色温在3889~4839 K变化。

关键词：铕离子镝离子氮化镓离子注入发光特性结构特性

Investigation on Luminescent Properties of Eu-doped GaN Polycrystalline Prepared by Solid-state Reaction

在线全文

学校读者我要写书评

暂无评论

Journal of the Chinese Ceramic Society 2016年第2期3卷 84-90页

作者： WANG Xiaodan MO Yajuan SHI Jianping zeng xionghui WANG Jianfeng XU Ke Department of Physics Suzhou University of Science and Technology Suzhou Institute of Nano-tech and Nano-bionics Chinese Academy of Sciences Suzhou Nanowin Science and Technology Co. Ltd.

Eu-doped GaN was prepared by solid-state reaction with Ga_2O_3,Eu_2O_3 and NH_3 applied as raw *** structural and optical properties were *** to XRD results,wurtzite-type GaN powder without Eu_2O_3phase was obtained at 1000℃ and the grain size was about 20 *** to the undoped GaN powder,all the Raman peaks of Eu-doped GaN powder were shifted towards lower phonon frequency about 2-6 cm^(-1),which may be resulted from the strain caused by the Eu^(3+) *** cathodo-luminescence(CL) spectra were measured from 80 to 293 *** luminescence and Eu^(3+) luminescence were both observed when the temperature was below 200 *** the temperature was increased to 293 K,the ultraviolet luminescence ***,the intensity of Eu^(3+) luminescence was nearly not influenced by temperature.A donor-acceptor pair(DAP) model based on O_N and Mg_(Ga) was pointed out for explaining the luminescence *** cathodo-luminescence spectra of nominal 1.0%,2.0%,3.0%and 5.0%(mole fraction) Eu-doped GaN at room temperature were summarized,which suggestes the 2.0%Eu-doped GaN has the highest Eu luminescent intensity.

关键词： gallium nitride europium luminescence

Eu,Mg共掺GaN薄膜的结构和发光性能研究

在线全文

学校读者我要写书评

暂无评论

稀有金属 2020年第11期44卷 1170-1176页

作者：李祥马海王晓丹陈飞飞曾雄辉苏州科技大学数理学院江苏省微纳热流技术与能源应用重点实验室江苏苏州215009 中国科学院苏州纳米技术与纳米仿生研究所江苏苏州215123

通过离子注入,将Eu和Mg共掺杂到金属有机化学气相沉积方法生长的GaN薄膜中,Mg的注入剂量保持为5×10^(13)cm^(-2),Eu的剂量依次为1×10^(14),5×10^(14)和1×10^(15)cm^(-2)。采用X射线衍射(XRD)、Raman散射和光致发光研究了样品的结构... 详细信息

通过离子注入,将Eu和Mg共掺杂到金属有机化学气相沉积方法生长的GaN薄膜中,Mg的注入剂量保持为5×10^(13)cm^(-2),Eu的剂量依次为1×10^(14),5×10^(14)和1×10^(15)cm^(-2)。采用X射线衍射(XRD)、Raman散射和光致发光研究了样品的结构和发光特性。X射线衍射和Raman散射揭示了GaN:Eu样品和GaN:Eu,Mg样品内部的应力随Eu注入剂量变化展现出相同的变化趋势,在Eu注入剂量从1×10^(14)cm^(-2)提高到5×10^(14)cm^(-2)后会导致GaN晶格收缩,产生张应力;当Eu注入剂量从5×10^(14)cm^(-2)提高到1×10^(15)cm^(-2),会导致晶格膨胀,产生压应力。光致发光测试结果表明,GaN:Eu,Mg样品中Mg的存在能够减少Eu周围的本征缺陷,抑制黄光发射,增强GaN基质与Eu^(3+)之间的能量传递,导致与Eu相关的发射峰强度整体增强,且Mg的存在并不改变Eu相关的发光峰峰位,也没有引入新的发光峰。随着Eu/Mg剂量比的增加,发光强度增强倍数呈现先增加后减小的趋势,且在Eu/Mg剂量比为10∶1时,此时Eu发光得到最大程度的增强,为GaN:Eu发光强度的6.6倍。

关键词：光电子学 GaN 离子注入光致发光光学特性

在线全文

学校读者我要写书评

暂无评论

农村土地污染及土壤环境保护方式分析

皮革制作与环保科技 2021年第14期2卷 24-25页

作者：曾雄辉惠州市环境科学研究所广东惠州516003

在社会整体经济水平不断提升的背景下,环境污染问题日益凸显,对农村经济发展产生了一定的制约。目前,土地污染是农村环境污染的主要类型,只有采取合理的方式解决土地污染,才能进一步提高土地的利用率,更好地保护土壤环境。基于此,本文... 详细信息

在社会整体经济水平不断提升的背景下,环境污染问题日益凸显,对农村经济发展产生了一定的制约。目前,土地污染是农村环境污染的主要类型,只有采取合理的方式解决土地污染,才能进一步提高土地的利用率,更好地保护土壤环境。基于此,本文深入分析污染的主要来源及原因,以期全面优化农村土地环境,为农村经济发展创造良好的条件。

关键词：农村土地污染土壤环境保护方式

在线全文

学校读者我要写书评

暂无评论

锦屏二级水电站引水隧洞TBM施工工法研究

岩石力学与工程学报 2011年第1期30卷 149-154页

作者：周济芳曾雄辉周春宏陈炳瑞龚秋明武汉大学水利水电学院湖北武汉430072 二滩水电开发有限责任公司四川成都610051 中国水电顾问集团华东勘测设计研究院浙江杭州310014 中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室湖北武汉430071 北京工业大学城市防灾与减灾教育部重点实验室北京100124

锦屏二级水电站引水隧洞是我国目前规模最大的水工隧洞群,特点是洞线长、埋深大、技术难度大,且沿线突水、岩爆、塌方各种地质灾害十分突出,为确保工程施工的安全与按期顺利发电,有必要选择安全快速的掘进方式,为此针对TBM工法,进行大... 详细信息

锦屏二级水电站引水隧洞是我国目前规模最大的水工隧洞群,特点是洞线长、埋深大、技术难度大,且沿线突水、岩爆、塌方各种地质灾害十分突出,为确保工程施工的安全与按期顺利发电,有必要选择安全快速的掘进方式,为此针对TBM工法,进行大量的调查研究与分析论证,研究结果表明:无论是从岩石的可钻性、耐磨性,还是从岩石的变形、破坏特性,TBM施工都是可行的,对可能遇到的地下水、岩爆、围岩大变形等不良地质条件的处理,较传统的钻爆法有一定的优势,对人员设备的安全具有更好的保护作用。结合地质超前预报和施工中不断改进的施工工艺和支护手段,可以较好地解决施工过程中可能遇到的一些工程难题。

关键词：水利工程锦屏二级水电站引水隧洞 TBM 适应性

White light emission from Er, Pr co-doped AlN films

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2019年第11期17卷 65-68页

作者：李祥王晓丹马海陈飞飞曾雄辉 Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application School of Mathematics and PhysicsSuzhou University of Science and TechnologySuzhou 215009China Suzhou Institute of Nano-Tech and Nano-Bionics Chinese Academy of SciencesSuzhou 215123China

In this work, Er-doped aluminum nitride(AlN), Pr-doped AlN, and Er, Pr co-doped AlN thin films were prepared by ion implantation. After annealing, the luminescence properties were investigated by cathodoluminescence. Some new and interesting phenomena were observed. The peak at 480 nm was observed only for Er-doped AlN. However, for Er, Pr co-doped AlN, it disappeared. At the same time, a new peak at 494 nm was observed,although it was not observed for Er-doped AlN or Pr-doped AlN before. Therefore, the energy transfer mechanism between Er^3+and Pr^3+in AlN thin films was investigated in detail. Through optimizing the dose ratio of Er^3+with respect to Pr^3+, white light emission with an International Commission on Illumination chromaticity coordinate(0.332, 0.332) was obtained. This work may provide a new strategy for realizing white light emission based on nitride semiconductors.

关键词： light films white