半导体激光倍频晶体硫氰酸汞镉(CMTC)显微结晶的研究

采用显微结晶,系统地观察、研究了半导体激光(LD)倍频材料CMTC晶体在KCl/H2O的溶剂体系中,不同条件下的结晶习性。结果给出：在KCl浓度为3;～10;范围,pH值为3.0～4.3范围时,结晶形态规则,各项生长速度均匀,结晶透明;pH值为2.0～3.0条件下,z轴方向生长速度变快,a轴方向生长速度变慢;杂质严重影响了结晶的质量和外形;溶液稳定性随时间的增长和温度的升高而逐渐变差。本文分析了CMTC单晶生长和定向生长适宜的溶液条件和关键。     

A One-Dimensional Model of Hydrogen Molecular Ion

We present a study on a one-dimensional hydrogen molecular ion under the Born-Oppenheimer approximation. A canonical transformation produces the classical system directlyto be a pendulum. The quantum Schrodinger equation is solved analytically and theelectronic energy curves show that the bound states of this 1D model differ from the 2D and 3DH₂⁺. The vibration spectroscopy is also obtained by employing the Morse's eigen wavefunctionsas basis vectors to diagonalize the Hamiltonian for R. The semiclassical quantization yieldselectronic energies in agreement with the quantum ones reasonably.     

新概念下的Sn掺杂(La1-xSrx)2Cu1-xSnxO4超导体的MÖssbauer谱研究 *

对新概念指导下而设计的 (La_1-xSr_x)2Cu_1-xSn_xO₄超导体进行了¹¹⁹Sn M_Össbauer谱研究 .对不同掺杂量样品的系统研究表明 ,M_Össbauer谱实验结果进一步证实了Sn以Sn⁴⁺价态存在并占据Cu晶位 ,不存在占据La晶位的Sn^{2 +}离子 .Sn⁴⁺离子附近的局域晶格畸变较小 ,但是随Sn掺杂量有增加趋势 .在对La₂ CuO₄母体进行Sr和Sn同时掺杂所引入的载流子对超导电性的影响存在新的机制 .在新的额外氧机制下 ,讨论了Sn掺杂所导致的额外氧对超导电性的影响 .     

Zero-lag chaos synchronization properties in a hierarchical tree-type network consisting of mutually coupled semiconductor lasers

Nonlinear Dynamics - Chaos synchronization properties in a novel hierarchical tree-type optical network consisting of semiconductor lasers (SLs) are investigated numerically. In such network, each...     

微波-超声波协同萃取-高效液相色谱检测鱼肉中两种沙星类药物残留

本文报道了微波-超声波协同萃取(MWUS)前处理技术处理样品,高效液相色谱法同时测定鱼肉中环丙沙星(CPFX)和恩诺沙星(ENFX)药物残留的快速分析方法。该法简化了样品的前处理过程,缩短了前处理时间。环丙沙星和恩诺沙星在5～200μg/L范围内,其回收率在76.8%～107.5%之间。     

采用自反应淬熄法的电磁波吸收剂空心化研究

分析了火焰喷射淬熄技术的工艺原理,通过实验制备了几种吸波材料的空心微珠,利用扫描电镜和X射线衍射分析了微珠的形貌和组成,微珠大都成空心结构的球形,直径分布在几个至几十个微米范围;利用网络分析仪同轴法研究了空心微珠的电磁性能,不同成分的微珠在不同的波段具有较好的电磁波吸收性能.     

A novel optical SSB modulation scheme with interfering harmonics suppressed for ROF transmission link

A novel optical SSB modulation scheme for ROF transmission link is proposed in this paper, the scheme employs two parallel MZMs to generate an SSB signal with major high-order interfering harmonics well suppressed. The SSB signal generated by conventional modulation scheme is interfered by adjacent high-order harmonics, and such interference may cause distortion on the RF signal generated at the base station (BS). As major high-order interfering harmonics are well suppressed in the proposed scheme, the power of the generated RF signal can be avoided and the transmission performance of the ROF transmission link is largely improved.     

一种基于交叉相关的类星体的红移测量方法

给出了一种新的类星体光谱的红移测量方法。首先,利用提取出的发射谱线信息确定一组红移候选;然后,按这些红移候选将静止模板光谱红移,计算所得光谱与目标光谱的相关值;最后,确定最大相关值对应的红移候选为目标光谱的红移。相对于已有的基于谱线匹配的方法,此方法的性能受谱线提取效果的影响较小。实验结果表明： 此方法的鲁棒性较好,性能优于基于谱线匹配的方法。     

感兴趣区域对羊肉pH高光谱检测模型的影响研究

感兴趣区域(regions of interest, ROIs)的选择及其光谱提取是高光谱图像无损检测分析的关键一步。为快速准确检测羊肉pH,在473～1 000 nm波段,开展了两种不同提取ROIs方法对羊肉pH高光谱检测模型的影响研究。采用“矩形区域法”和“图像分割法”两种ROIs方法分别获得相应的122条羊肉光谱,对比了不同预处理方法对建模效果的影响,并比较了两种ROIs方法下逐步多元线性回归(SMLR)、主成分回归(PCR)和偏最小二乘回归(PLSR)的模型精度。结果表明,提取光谱数据建模中SMLR和PLSR模型效果分别最优。“矩形区域法”提取ROIs对应的SMLR模型校正集的相关系数(R_cal)和均方根误差(RMSEC)分别为0.85和0.085,预测集的相关系数(R_p)和均方根误差(RMSEP)分别为0.82和0.097。“图像分割法”提取ROIs对应的PLSR模型校正集的R_cal和RMSEC分别为0.95和0.050,预测集的R_p和RMSEP分别为0.91和0.071。其次通过比较“矩形区域法”和PCR, SMLR和PLSR三个模型中,“图像分割法”提取的ROIs光谱数据建模效果较优。表明,应用高光谱图像技术结合“图像分割法”提取ROIs快速无损准确检测羊肉pH具有可行性。     

Time reversal multiple-input/multiple-output acoustic communication enhanced by parallel interference cancellation

Multiple-input/multiple-output (MIMO) techniques can lead to significant improvements of underwater acoustic communication capabilities. In this paper, receivers based on time reversal processing are developed for high frequency underwater MIMO channels. Time reversal followed by a single channel decision feedback equalizer, aided by frequent channel updates, is used to compensate for the time-varying inter-symbol interference. A parallel interference cancellation method is incorporated to suppress the co-channel interference in the MIMO system. The receiver performance is demonstrated by a 2008 shallow water experiment in Kauai, Hawaii. In the experiment, high frequency MIMO signals centered at 16 kHz were transmitted every hour during a 35 h period from an 8-element source array to a wide aperture 16-element vertical receiving array at 4 km range. The interference cancellation method is shown to generate significant performance enhancement, on average 2-4 dB in the output signal-to-noise ratio per data stream, throughout the 35 h MIMO transmissions. Further, communication performance and achieved data rates exhibit significant changes over the 35 h period as a result of stratification of the water column.