9 research outputs found

    构建我国新能源产业税收政策体系研究

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    发展战略性新兴产业已成为世界主要国家抢占新一轮经济和科技发展制高点的重大战略。新能源产业作为战略性新兴产业之一,对于解决环境污染和资源(特别是化石能源)枯竭问题具有重要意义。我国针对新能源产业已出台多项税收激励政策,但这种支持并未形成制度体系。有鉴于此,本文针对我国现行有关能源税收优惠政策存在的缺失与不足,借鉴发达国家经验,提出引导和激励新能源产业投资、生产、研发及消费等环节的税收政策建议

    Ti-Al_2O_3金属陶瓷热爆合成的动力学

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    研究了不同动力学工艺参数对热爆合成Ti Al2 O3金属陶瓷过程和热爆产物显微结构的影响。结果表明 :升温速率越快 ,起爆温度越低 ,热爆产物显微形貌中晶粒生长得越不均匀 ;预热温度越高 ,热爆产物显微形貌中晶粒越小 ;原料粒度越小 ,起爆温度越低 ,热爆产物显微形貌中晶粒越小 ;并计算出该体系的表观活化能E为 585.6kJ/mol

    Long-term trends of macrobenthos in Changjiang Estuary, China in relation to environmental changes

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    根据近30年来的长江口大型底栖动物群落的历史资料;以及2009年和2010年的现场调查数据;从长江口底栖动物群落结构变化特征出发;分析了其长期演变的过程和规律;旨在阐明底栖动物群落的演变趋势;识别其重要演变时段。同时结合长江口海域近50~60年来的入海径流量和携沙量变化、营养盐和DO等水质特征变化;分析底栖动物群落的变化原因。分析结果表明;长江口底栖生物群落的变化可大体分为3个阶段;第一阶段是20世纪90年代之前;底栖生物群落无论物种数、生物量都维持相对较高的水平;第二阶段发生在20世纪90年代初至2005年;由于受到气候变化和人类活动的综合影响;底栖生物群落的上述指标都有所降低;表明受到自然和人为因素干扰的加剧;第三阶段是2005年之后至现在;由于长江口水域的各项生态环境保护措施加强;底栖生物群落得到一定程度的恢复。通过对长江口海域各种环境因素的分析表明;底栖生物群落变化受到长江口区域生物因素和非生物因素的共同影响;变化趋势也与环境因素的变化比较吻合

    A systematic review of adolescents' self-control researches

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    青少年的自我控制能力与其各方面发展均存在密切联系,是自控研究领域里的热点话题.本文检索并筛选了近10年(2010-2020年)Web of Science核心合集中有关青少年自我控制的文献1587篇,利用VOSviewer(1.6.13)软件关键词共现分析功能,总结了领域内的主要研究方向,系统综述了评价方法和干预研究成果.未来可以进一步研究积极冒险行为对青少年身心健康的促进作用,同时选择合适的评估方法,提高研究结果的可信度.</p

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

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    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 pνˉK+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 pνˉK+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 9.6×10339.6 \times 10^{33} years, competitive with the current best limits on the proton lifetime in this channel

    JUNO sensitivity on proton decay pνK+p → νK^{+} searches

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

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    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 pνˉK+ 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 pνˉK+ p\to \bar{\nu} K^+ is 36.9% ± 4.9% with a background level of 0.2±0.05(syst)±0.2\pm 0.05({\rm syst})\pm 0.2(stat) 0.2({\rm stat}) events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 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
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