4 research outputs found

    改良非创伤性修复技术对部队龋病患者的防治效果评价

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    目的:探讨适宜于部队官兵龋病防治可行性和实用性的方式。方法:应用非创伤性标准器械和Carisolv工具及凝胶以非创结合微创的方法对某部官兵206牙,进行去腐充填,并对修复体完好率进行1年的随访。结果:3、6、12个月后成功率分别为97.6%、95.2%、92.1%。结论:改良非创伤性修复技术适合于基层部队龋病防治,效果良好

    Reduction of Black Carbon Emissions in the Context of Sustainable Development      

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    黑碳气溶胶是环境大气中浓度较低的一种气溶胶粒子组分,因其对光的吸收作用,及其对空气质量和人体健康的影响,而成为当前国际气候变化和环境研究中关注的热点问题之一.本文围绕黑碳的减排问题,介绍黑碳的来源、全球分布,讨论全球温室气体减排和区域空气质量控制对黑碳减排的影响,综述控制和改善燃烧条件、减少开放式生物质燃烧和黑碳封存等减排黑碳的措施.文章还分析了黑碳未能成为全球减排共识的原因,并对中国有关黑碳减排的政策选择提出了建议

    Performance Evaluation of Visual Noise Imposed Stochastic Resonance Effect on Brain-Computer Interface Application: A Comparison Between Motion-Reversing Simple Ring and Complex Checkerboard Patterns

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    Adding noise to a weak input signal can enhance the response of a non-linear system, a phenomenon known as stochastic resonance (SR). SR has been demonstrated in a variety of diverse sensory systems including the visual system, where visual noise enhances human motion perception and detection performance. The SR effect has not been extensively studied in brain-computer interface (BCI) applications. This study compares the performance of BCIs based on SR-influenced steady-state motion visual evoked potentials. Stimulation paradigms were used between a periodically monochromatic motion-reversing simple ring and complex alternating checkerboard stimuli. To induce the SR effect, dynamic visual noise was masked on both the periodic simple and complex stimuli. Offline results showed that the recognition accuracy of different stimulation targets followed an inverted U-shaped function of noise level, which is a hallmark of SR. With the optimal visual noise level, the proposed visual noise masked checkerboard BCI paradigm achieved faster and more stable detection performance due to the noise-enhanced brain responses. This work demonstrates that the SR effect can be employed in BCI applications and can achieve considerable performance improvements.</p

    增温、刈割对高寒草甸地上植被生长的影响/Effects of Warming and Clipping on the Growth of Aboveground Vegetation in An Alpine Meadow[J]

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    近些年由于气候变化和土地利用方式变化的双重影响,高寒草甸植被逐渐表现出退化现象。探讨高寒草甸植被生长特征在气候变化和人类活动中的动态变化规律,对高海拔地区植被的保护和合理利用,防止草地退化和沙漠化发生具有重要意义。以青藏高原高寒草甸为研究区,利用增温实验模拟气候变暖、刈割实验模拟人类放牧,采用随机区组设计,设置对照、增温、刈割、增温+刈割交互作用四种实验处理,于2012─2013年植被生长季调查高度、盖度和地上生物量,研究高寒草甸地上植被生长特征对增温、刈割的响应,以此探讨青藏高原高寒草甸地上植被在气候变化和人类活动中的变化趋势。结果表明:(1)夏季是高寒草甸植被生长的最佳季节,其中7月是其生长的最佳月份;高寒草甸地上植被生长特征年内生长季和年际间的变化趋势差异较大,表现为植被高度在生长季中期高于初期和末期(P&lt;0.05),植被盖度和地上生物量在生长季中期和末期高于初期(P&lt;0.05);2012年的植被高度和地上生物量略高于2013年(P&gt;0.05),但植被盖度略低于2013年(P&gt;0.05)。(2)植被高度、盖度和地上生物量在增温第2年(2012年)的各实验处理间均未出现显著差异(P&gt;0.05),而在第3年(2013年)开始出现显著差异(P&lt;0.05),其中2年刈割显著降低植被高度和地上生物量(P&lt;0.05),3年增温和2年刈割的交互作用显著降低植被盖度和地上生物量(P&lt;0.05)。以上结果表明,增温、刈割对高寒草甸地上植被生长的影响在短期和长期尺度上存有差异,初期并不显著,但随着时间推移,影响开始加强
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