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HL-2A装置1MW/68GHz/1s电子回旋共振加热传输系统有两条传输线，每条传输线包括波纹波导、换向波导和直流隔离器。HE11模式微波在波导中传输，微波损失小且模式纯度高。用激光校准及用热敏纸测量短脉冲微波模式分布的手段确保传输线的准直性。传输线的倾斜角度小于0.0054rad。     

Effect of hydroxyl groups on Er doped Bi2O3-B2O3-SiO2 glasses

A series of Er³⁺-doped Bi₂O₃-B₂O₃-SiO₂-Na₂O glasses with different hydroxyl groups were prepared and the interaction between the Er³⁺ ions and OH groups was investigated. Infrared spectra were measured in order to calculate the exact content of OH groups in samples. The observed increase of the fluorescence lifetime with the oxygen bubbling time has been related to the reduction in the OH content concentration evidenced by infrared (IR) absorption spectra, which confirmed that the OH groups were dominant quenching centers of excited Er³⁺ and a cause of concentration quenching of 1.5 μm band emission. Various nonradiative decay rates from ⁴I_13/2 of Er³⁺ with the change of OH content were determined from the fluorescence lifetimes and radiative decay rates, which were calculated on the basis of Judd-Ofelt theory.     

Regularity for weakly (K 1, K 2(x))-quasiregular mappings of several n-dimensional variables

The definition for weakly (K ₁,K ₂(x))-quasiregular mappings of several n-dimensional variables is given. A regularity property is obtained by using the stability result of Hodge decomposition, some analytical tools of Sobolev spaces, and differential geometry, which can be regarded as a generalization of the results due to T. Iwaniec and Hongya Gao.     

基于多孔径闪烁的湍流强度廓线反演方法研究

以多孔径闪烁方法的理论为基础,分别讨论了孔径滤波函数和光谱响应函数对权重函数的影响.根据包括边界层项的Hufnagel-Valley 5/7模型得到的闪烁指数,采用奇异值分解法反演了垂直方向的湍流强度廓线,结果的量级介于10~(-15)~10~(-17)之间,并随高度的增加不断减小,在量级和趋势上与理论模型基本一致;同时结合Shack-Hartman的实际测量结果,反演了水平方向1 km传输路径上的湍流强度分布状况.水平方向反演结果的量级在10~(-14)~10~(-15)之间,随传播距离的变化趋势与实验场地的实际情况较为符合,随时间的变化趋势与合肥地区同期的统计结果基本一致.     

Single layer graphitic carbon nitride-modified graphene composite as a fiber coating for solid-phase microextraction of polycyclic aromatic hydrocarbons

The authors describe a three-dimensional single layer graphitic carbon nitride-modified graphene composite (g-C₃N₄@G) deposited on a stainless steel wire by a sol-gel technique. The coated fiber was applied to direct immersion solid-phase microextraction of trace levels of polycyclic aromatic hydrocarbons (PAHs) from cosmetics samples prior to their determination by gas chromatography with mass spectrometry (GC-MS). Due to π stacking interaction and hydrophobic interaction between the g-C₃N₄@G coating and the analytes (naphthalene, acenaphthene, fluorene, phenanthrene, fluoranthene and pyrene), the fiber displays an excellent adsorption capability for the analytes. Under optimized conditions, the method has a wide linear range, low LODs (from 1.0 to 2.0 ng L⁻¹), good repeatability and high recoveries. It was successfully applied to the determination of PAHs in cosmetics. The g-C₃N₄@G fiber also exhibited good durability.

Schematic of a three-dimensional single layer graphitic carbon nitride-modified graphene composite (g-C₃N₄@G) that was coated onto a stainless steel wire for the direct-immersion solid phase microextraction of trace levels of polycyclic aromatic hydrocarbons prior to gas chromatography-mass spectrometric detection.

     

酶解-离子色谱法测定烟草中的果胶

建立了一种测定烟草中果胶含量的酶解-离子色谱法,并对酶解条件进行了优化.即样品经快速溶剂萃取仪用80%乙醇除糖后,在47℃、pH4条件下用果胶酶酶解2 h,用离子色谱测定酶解液中的半乳糖醛酸含量.该法的线性相关系数为0.999 3,回收率98.3%～100.8%,RSD为3.43%.     

Application of ultrasound-assisted emulsification microextraction for the determination of triazine herbicides in soil samples by high performance liquid chromatography

Ultrasound-assisted emulsification microextraction was applied to extract the herbicides simazine, atrazine, prometon, ametryn and prometryn from soil samples. They then were determined by HPLC with diode-array detection. Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, emulsification time and addition of salt, were optimized. Under the optimum conditions, the following analytical figures of merits are found: enrichment factors between 145 and 222, limits of detection between 0.1 to 0.5 ng g^?1, analytical linearity in the range from 1.0 to 200 ng g^?1, correlation coefficients (r) between 0.9989 and 0.9998, relative standard deviations from 2.8% to 3.6% (at n?=?5, intraday) and 3.7% to 4.3% (interday), and recoveries (at spiking levels of 5.0 and 50.0 ng g^?1) from 82.6% to 92.0%. The technique is simple, practical, rapid, and environmentally friendly.     

有机液芯光纤拉曼谱测量的研究

我们选用CCl4和CS2混合溶液作为芯液制作了有机液芯光纤,采用后向泵浦的方式测量了光纤的拉曼光谱.实验中发现,随着溶质浓度和光纤长度的变化,拉曼谱强度也随之变化,并存在溶质最佳浓度和最佳光纤长度,这与理论分析值相符,并发现随着溶质浓度的降低,拉曼光谱线宽变窄.     

基于多种小波分解方法综合判决的低误报率分布式光纤围栏入侵监测系统

针对相位敏感光时域反射计型分布式光纤围栏入侵监测系统对外界干扰敏感、误报率高的问题进行了深入研究,比较了多种小波提取入侵信号突变特征方法,并提出一种基于多个小波分解结果进行综合判决来降低分布式光纤围栏误报率的方法.实验结果表明,多种小波分解可以分别提取不同层次的突变细节信息,为综合决策提供更完备的信息和条件,比单一判决...     

几种环状分子的拉曼光谱研究

通过实际检测获得了环己烷、四氢呋喃、1,4-二氧己环（二恶烷）几种环状分子的拉曼光谱。并应用密度泛函理论对几种环状分子的拉曼振动峰进行了详细的分析。研究结果表明：几种环状分子最强拉曼振动峰均由环呼吸运动引起,但它们的波数值差异较大,可以作为鉴定此类分子的判断依据。应用拉曼光谱检测技术可以对此类有毒物质进行快速的鉴定与分析。