基于可见/近红外光谱的乙烯利催熟西瓜与正常成熟西瓜分类试验研究

针对国内常有瓜农采摘远离成熟期的西瓜,采用高浓度乙烯利处理,诱导其快速成熟的现象,对未经乙烯利处理和经乙烯利处理的西瓜进行了可见/近红外漫透射光谱的分类试验研究,在判别分析中,提出一种简单的透过率之比判别分析法,对未经乙烯利处理样品的误判率为32.5%,经乙烯利处理样品的误判率为20%;采用马氏距离判别分析和偏最小二乘法判别分析都可以取得理想的判别结果,一阶微分光谱经Norris微分滤波处理后, 利用马氏距离判别,判别结果为未经乙烯利处理样品校正集误判率1.67%,经乙烯利处理样品校正集、预测集均没有出现误判的情况;二阶微分光谱利用偏最小二乘法判别,没有误判情况发生。在使用这两种判别方法进行判别分析时,光谱预处理方法影响判别效果,应根据采用的判别方法决定所需采用的光谱预处理方法。     

用傅立叶变换红外光谱法研究核辐照对人参粉成分的影响

本文采用傅立叶变换红外光谱(吸收光谱、二阶导数谱及差谱)法对经不同剂量核辐照的人参粉进行了对比研究.辐照剂量不高于9 kGy时,人参粉样品的化学成分几乎没有发生变化;人参粉样品经15kGy及以上的辐照剂量辐照后,可能产生新的化学成分,表明采用辐照剂量不高于9 kGy的核辐照杀灭人参粉污染的微生物和各种寄生虫卵是可行的;...     

As2S8玻璃条形波导的光激励法制备技术研究

为了在As2S8薄膜中制备条形波导,实验研究了As2S8薄膜光致折射率变化和密度变化的现象,采用棱镜耦合、X线衍射和远红外反射光谱等测试技术,确认了As2S8薄膜经紫外光辐照后薄膜密度增高、折射率增大的现象。采用可见光吸收谱测试技术,确认了经紫外光辐照的As2S8薄膜不发生黑化现象。在归纳了实验规律的基础上,提出并采用紫外光激励的方法试制了As2S8条形波导,采用自动调芯端面耦合的方法激励As2S8条形波导的导模,结果显示该波导具有良好的导波特性。     

柚皮素的制备方法研究

采用直接用水加热提取柚皮苷,再酸水解得到柚皮素.经核磁共振鉴定所得苷元为高纯度的柚皮素.     

溶胶-凝胶SiO2薄膜氨热两步后处理

 以正硅酸乙酯为前驱体,氨水作催化剂,采用溶胶-凝胶法提拉镀制SiO₂双面膜,对薄膜进行氨处理和热处理。采用椭偏仪、分光光度计、红外光谱、扫描探针显微镜、静滴接触角测量仪表征薄膜的特性。研究表明：经氨热两步后处理,膜厚持续减小,折射率经氨处理先增大了0.236,再经热处理又减小了0.202,膜层透光性变好,透过率峰值持续向短波方向移动;经两步后处理的膜面平整度明显变好,与水的接触角先增大到58.92°后减小到38.07°。     

ICP-AES测定彩涂前处理表面调整转化层中Ti、Ni含量及钝化膜中Cr含量

采用电感耦合等离子体-原子发射光谱法同时测定彩涂前处理表面调整转化层中Ti、Ni含量及钝化膜中Cr含量.以表征表面调整转化层厚度及钝化膜厚度,采用本方法准确度高、快速简便,经试验结果令人满意.     

傅里叶变换红外光谱法研究核辐照对三七总皂苷粉成分的影响

采用傅里叶变换红外光谱(卷积谱)法对经不同剂量y-射线核辐照的三七总皂苷粉进行了对比研究.辐照剂量不高于9kGy时,三七总皂苷粉样品的化学成分几乎没有发生变化;三七总皂苷粉样品经15kGy及以上的辐照剂量辐照后,可能产生新的化学成分;经21kGy的剂量辐照,三七总皂苷粉产生了人参、三七粉所含的普通成分(非三七总皂苷成分...     

用于煤矿信集闭系统车号传感器的研究

研制了一种新型非接触式机车车号传感器。通过红外线发射与接收实现信号检测,利用导线将信号传回调度室,经译码后用于车号显示及机车调度。为了提高系统抗干扰性能,红外光线经40kHz的调制器调制后发射,光电转换信号以电流方式传输,传输线的两端经光电耦合隔离,译码时采用软件纠错。传感器最多可对64辆机车实现车号检测。结果表明,这种新型非接触式机车车号传感在实际使用中没有出现过丢码和错码现象。     

一种基于NSCT变换的红外与可见光图像融合算法

针对红外与可见光图像融合,提出了一种基于NSCT变换的图像融合方法。对经NSCT变换的低频子带系数采用基于区域能量自适应加权的融合规则,对高频子带系数采用混合的融合方法,即对于低层,采用基于区域方差选大的融合方法,对于高层采用像素点的绝对值选大的融合方法。实验结果表明,该融合算法可以获得更多的细节信息,能获得较理想的融合图像。     

电感耦合等离子体-质谱法测定土壤中的有效钼

样品经草酸-草酸铵浸提,不经分离富集,振荡0.5h后放置过夜,干过滤后采用电感耦合等离子体-质谱法直接测定土壤中的有效钼。方法检出限(3s)为0.015μg/g,RSD(n=12)为2.91%—06.41%。经国家一级标准物质验证,测定值与标准值基本一致。     

Identification of the magnetic island structure in the HL-2A tokamak

The identification of the magnetic island structure in the HL-2A tokamak is presented. First, the perturbation current as a source for the perturbation flux can be determined by using Mirnov probe measurements. By superposing the perturbation flux and the equilibrium flux reconnected by equilibrium fitting, the structure and the width of the magnetic islands can be estimated. The method has been used in the HL-2A experiments.     

Electron impact broadening of Si IV spectral lines: Comparison with recent experiments

Electron impact widths of eight Si IV spectral lines have been calculated using our quantum mechanical method. Semiclassical perturbation calculations using atomic data from the SUPERSTRUCTURE code have been also performed. Comparison with recent measurements shows that they are always lower than our quantum mechanical, semiclassical perturbation and all other theoretical results. A disagreement in the importance of fine structure effects between our results and the measured ones has been reported here.     

Calculation of resonant structure of a double photoionization

Using many-body perturbation theory, we give the first calculation for the resonance structure into the double photoionization continuum in the 2s → 3p resonance region in neutral sodium. This resonance structure results from the interference between the one step direct double photoionization continuum and the resonant Auger process. The coupled equation method has been improved to calculate this interference by the summation of specific classes of diagrams of perturbation theory to infinite order. We find that the dominant contribution to resonance comes from a super-Coster-Kronig decay. Theoretical results are in good agreement with experiment.     

Resonant structure due to the 3p→3d transition in the photoionization of Ca+

Many-body perturbation theory has been used to calculate the resonance structure (3p→3d) into the photoionization (4s→kp) for ion Ca⁺. This resonance structure results from the interference between a photoionization process or a photoionization with excitation process and a resonant Auger process. The coupled equation method has been improved to calculate this interference by the summation of specific classes of diagrams of perturbation theory to infinite order. The resonance structure in the region of the 3p threshold is enhanced via a super-Coster–Kronig transition. The theoretical results are in good agreement with experiment.     

Higher order Stark effect and transition probabilities on hyperfine structure components of hydrogen like atoms

A quantum-electrodynamical (QED) perturbation theory is developed for hydrogen and hydrogen-like atomic systems with interaction between bound electrons and radiative field being treated as the perturbation. The dependence of the perturbed energy of levels on hyperfine structure (hfs) effects and on the higher-order Stark effect is investigated. Numerical results have been obtained for the transition probability between the hfs components of hydrogen-like bismuth. This revised version was published online in August 2006 with corrections to the Cover Date.     

Manifestations of the roton mode in dipolar Bose-Einstein condensates

We investigate the structure of trapped Bose-Einstein condensates (BECs) with long-range anisotropic dipolar interactions. We find that a small perturbation in the trapping potential can lead to dramatic changes in the condensate's density profile for sufficiently large dipolar interaction strengths and trap aspect ratios. By employing perturbation theory, we relate these oscillations to a previously identified "rotonlike" mode in dipolar BECs. The same physics is responsible for radial density oscillations in vortex states of dipolar BECs that have been predicted previously.     

Recent progress in the theory of the complex atomic hyperfine structure

The revised analysis of the hyperfine structure of the complex atoms on several selected examples has been performed. The complete set of corrections up to the second order perturbation theory has been taken into account and the accuracy of the wave functions in the intermediate coupling scheme has been carefully checked. The still remaining discrepancies suggest that the commonly used approximate model of the hyperfine structure might require revision. This revised version was published online in August 2006 with corrections to the Cover Date.     

腔内像散扰动对正支共焦腔模式影响的数值分析

 针对激光器出光过程中腔内像差扰动带来的输出光束质量和光束能量下降问题,分析了腔内像差扰动对非稳腔模式的影响,并采用数值迭代法计算了理想情形和腔内像散扰动对无源正支共焦腔输出模式强度和相位分布的影响,进一步采用Zernike模式法对光束相位进行了像差拟合,得到了前35阶Zernike像差系数、点扩散函数(PSF)分布和环围能量曲线,计算了腔内像散扰动量与远场Strehl比的关系。结果表明：对小菲涅耳数正支共焦腔,腔内像散扰动对输出光束强度和相位分布均有明显影响,相位分布中一些高阶Zernike像差也有所增大。因此在进行腔内像差校正时,应优先考虑此类像差的校正。     

用磁探针反演磁岛二维结构的方法及其在HL-2A装置上的应用

介绍了HL-2A装置中利用磁探针数据反演磁岛极向二维结构的新方法,以及在反演基础上建立的撕裂模动态分析方法。在实验中通过磁探针测量确定作为扰动磁场来源的扰动电流。将扰动磁通与由EFIT重建的平衡磁通叠加反演出磁岛的结构,并给出磁岛的宽度。然后,按时间顺序建构二维结构图并依次记录,之后依次展现图像就可以对磁岛进行动态分析。应用此方法进行撕裂模分析,得出了磁岛旋转与电子抗磁漂移方向相同,验证了磁岛宽度与扰动场的关系及ECRH对磁岛的抑制作用。这显示了磁探针反演磁岛结构方法的直观性,对观察并控制MHD不稳定性非常有利。     

A simplified treatment of exchange and correlation in semiconducting surface inversion layers

Many-body calculations of subband structure which treat the electron-electron correlations beyond the Hartree approximation as a perturbation suffer from the shortcoming that the perturbation to the subband energies is large. We propose a new approach to calculating the subband structure which corrects this defect.