影响异戊二烯大气光解形成二次有机气溶胶的环境因素研究

通过自制的烟雾腔系统研究羟基启动的异戊二烯光解形成二次有机气溶胶(SOA)过程中环境因素的影响.使用气溶胶粒径光谱仪测量了SOA的粒径分布,通过光解实验研究了光照时间、反应物浓度以及CH3ONO浓度对异戊二烯光解形成SOA的影响.结果表明,异戊二烯光解形成的SOA空气动力学直径在0.4 mm～1.4 mm之间,这些粒子的直径小于2.5μm的微细粒子很容易沉积在人体肺泡内,对人体健康产生很大危害;不管是SOA粒子的粒子数浓度还是质量数浓度都随着反应时间的增长、光照强度的增强和反应物浓度的增加而增加.该研究为大气颗粒物排放源的外场测量提供了非常有用的信息.     

级联弧放电氦等离子体特性研究

采用另加偏压的单阴极弧氦放电直线等离子体装置对氦等离子体的基本特性进行了研究。对氦轴向输运规律做了描述并与光谱测量数据做了定性地比较。实验结果表明,氦等离子体的电子温度与电子密度均随放电电流、约束磁场的增加而增加。氦原子与氦离子的辐射光谱随放电电流、偏压、磁场的变化规律进行了测量分析,同时氦离子对钨靶积分辐照效应进行了观察。这些结果不但提供了氦等离子体的基本特性,对于研究氦离子与面向等离子材料相互作用导致产生气泡、肿胀、脆化损伤等的评估,特别是对将来伴有(n, α)反应时具有一定的参考价值。     

TiVI真空紫外光谱

用1m法向入射光谱仪观察三电极真空火花发射的Ti五次离化光谱。在24～200nm波段内观察到157条TiVI的新谱线。根据新归属的TiVI谱线定出11个新能级,并对5个有疑问的能级值作了修正。     

基于二极管阵列检测器的色谱峰纯度的快速直观鉴定

基于二极管阵列检测器（DAD）得到的色谱-光谱图,通过去噪、归一化、计算欧氏距离,聚类分析等方法,建立了一种快速直观的评价色谱峰纯度的有效方法：可直观的判断色谱峰的纯度,并判断存在干扰峰的位置,为色谱工作者评价色谱峰,进行下一步工作提供了依据。     

Learning to short-time Fourier transform in spectrum sensing

The future wireless communication will come up with a strict requirement on high spectral efficiency, developing novel algorithms for spectrum sensing with deep sensing capability will be more challenging. However, traditional expert feature-based spectrum sensing algorithms are lack of sufficient capability of self-learning and adaptability to unknown environments and complex cognitive tasks. To address this problem, we propose to build up a deep learning network to learn short time-frequency transformation (STFT), a basic entity of traditional spectrum sensing algorithms. Spectrum sensing based on the learning to STFT network is supposed to automatically extract features for communication signals and makes decisions for complex cognitive tasks meanwhile. The feasibility and performances of the designed learning network are verified by classifying signal modulation types in deep spectrum sensing applications.     

黄芩素稳定性研究

用紫外光谱研究了光、温度、pH、Na2SO3、FeSO4及抗坏血酸对黄芩素稳定性的影响.在室温条件下,黄芩素溶液的吸光度值在6h内强度有明显的下降;当温度升高或在避光条件下,偏酸性黄芩素溶液的吸光度值在6h内强度不变,而碱性条件下依然有下降趋势;但黄芩素溶液加入抗坏血酸或Na2SO3后,吸光度值可稳定不变.本文研究提示:黄芩素对光和pH稳定性差;抗坏血酸和Na2SO3具有提高黄芩素溶液稳定性的作用.     

红外光谱预处理中去噪的研究

红外(IR)光谱由于包含了噪声等各种外界干扰因素.应该先进行光谱预处理,以便降噪,提高分析准确度.本文采用了一种基于最优小波包基的信号去噪算法,该算法根据最小代价原理,采用不同的阈值算法对光谱的高频和低频信号进行量化处理,用量化后的系数重构得到去噪信号,从而达到较好的去噪效果.实验表明,本方法处理后光谱曲线非常光滑、噪声消除效果明显.     

高离化态硫离子光谱的理论分析

 在考虑组态相互作用的基础上,利用包含相对论修正的Hartree-Fock(HFR)理论对S⁸⁺-S¹³⁺离子的谱线波长及加权振子强度等有关原子参数进行了系统计算,并与最新的实验观测和其它理论计算结果进行了比较。计算结果表明：S⁸⁺-S¹¹⁺的各个原子态在LS耦合下纯度很高,随着离化度的增大,S¹²⁺和S¹³⁺离子的部分原子态能级出现混合,组态相互作用逐渐增强。通过对实验结果的分析,识别出32条实验谱线,其中大多数谱线来自S⁸⁺-S¹³⁺离子的2s²2p^k-2s2p^k+1和2s2p^k+1-2s2p^k+2(k=0,1,2,3,4)之间的跃迁,理论计算结果与实验谱线波长之间的绝对误差大多数都在实验的有效分辨力以内。     

双酚A人工抗原的光谱表征及免疫鉴定研究

双酚A(bisphenol A,BPA)是一种酚类环境雌激素,即使极低剂量残留对人类健康也有危害。为了建立其简单快速并适应现场检测的免疫分析方法,必须先合成它的人工抗原并进行鉴定。通过对双酚A进行结构修饰,用碳二亚胺将结构修饰了的双酚A与牛血清蛋白相偶联,经透析得到纯的双酚A人工抗原并冷冻干燥备用。然后用紫外光谱、红外光谱和免疫方法对人工抗原进行鉴定。结果表明,合成的人工抗原紫外光谱图中具有蛋白质和双酚A的特征吸收峰;人工抗原红外光谱图中呈现双酚A和牛血清蛋白的红外特征吸收峰;通过竞争ELISA试验表明用合成的人工抗原免疫的Balb/c小鼠血清中产生了双酚A的抗体。三种方法综合鉴定结果表明双酚A人工抗原合成成功,该人工抗原可以进一步用于制备抗双酚A的单克隆抗体。     

Acoustic Measures and Self-reports of Vocal Fatigue by Female Teachers

This study investigated the relation of symptoms of vocal fatigue to acoustic variables reflecting type of voice production and the effects of vocal loading. Seventy-nine female primary school teachers volunteered as subjects. Before and after a working day, (1) a 1-minute text reading sample was recorded at habitual loudness and loudly (as in large classroom), (2) a prolonged phonation on [a:] was recorded at habitual speaking pitch and loudness, and (3) a questionnaire about voice quality, ease, or difficulty of phonation and tiredness of throat was completed. The samples were analyzed for average fundamental frequency (F0), sound pressure level (SPL), and phonation type reflecting alpha ratio (SPL [1-5 kHz]-SPL [50 Hz-1 kHz]). The vowel samples were additionally analyzed for perturbation (jitter and shimmer). After a working day, F0, SPL, and alpha ratio were higher, jitter and shimmer values were lower, and more tiredness of throat was reported. The average levels of the acoustic parameters did not correlate with the symptoms. Increase in jitter and mean F0 in loud reading correlated with tiredness of throat. The results seem to suggest that, at least among experienced vocal professionals, voice production type had little relevance from the point of view of vocal fatigue reported. Differences in the acoustic parameters after a vocally loading working day mainly seem to reflect increased muscle activity as a consequence of vocal loading.