非倍测度下Marcinkiewicz积分交换子在Hardy空间中的有界性

在测度μ仅满足多项式增长性条件的假设下,证明了Marcinkiewicz积分算子M与Lipβ(μ)函数b生成的交换子Mb具有(H1(μ), Ln/(n?β)(μ))有界性,同时得到Mb的(Ln/β(μ), RBMO(μ))有界性.     

截断调和Bergman空间上的Toeplitz算子

截断调和Bergman空间b_n~2=L_a~2{w,w~2,…,w~n}~v是Hilbert空间L~2的闭子空间.研究了单位圆盘上的截断调和Bergman空间上的Toeplitz算子的乘积问题,完整地刻画了具有有界调和符号的两个Toeplitz算子的有限秩与紧的半换位子或换位子.     

Krein空间上J-正常算子的可定化性

对于Krein空间上J-正常算子 的各种可定化性进行了研究. 利用可定化J-正常算子的谱函数, 给出了临界线的概念, 得到了可定化的J-正常算子成为强可定化算子和一致可定化算子的充要条件.     

广义直觉模糊指标的构造及其应用

针对现有广义直觉模糊指标的构造并未利用直觉模糊集广义补算子的不足,本文首先利用直觉模糊广义补算子给出了一种新的广义直觉模糊指标的构造法,其次对广义直觉模糊指标所具有的性质进行了严格证明,最后将其用于图像阈值化分割并给出其直觉模糊广义补算子参数的选取方法.实验结果表明,本文所提出的广义直觉模糊指标构造法是有效的,对于光照不均匀图像能获得满意的分割效果.     

一类板弯曲方程的辛本征函数展开方法

本文研究一边简支对边滑支边界条件的矩形板方程的无穷维Hamilton算子本征函数系,证明该无穷维Hamilton算子广义本征函数系在Cauchy主值意义下是完备的,为应用辛本征函数展开法求解该平面弹性问题提供理论基础.进而推导出原方程的通解,并对该平面弹性问题指出什么样的边界条件可按此方法求解.最后应用具体的算例说明所得结论的合理性.     

多层结构下石墨烯的可见性研究

石墨烯-氮化硅光电器件在光电集成方面具良好的性能,但在氮化硅上转移石墨烯的可见度通常不佳,导致难以判断转移石墨烯的效果,因此研究石墨烯在氮化硅上的可见性具有重要意义。基于菲涅耳公式,推导出石墨烯在多层结构下的光学反射率和对比度理论计算公式,使用MATLAB仿真并分析石墨烯/氮化硅/二氧化硅/硅多层结构下不同二氧化硅厚度对光学对比度的影响。仿真结果表明,在特定的二氧化硅层厚度下,石墨烯的光学对比度能显著增加,从而使石墨烯在显微镜下清晰可见,能更好地判断石墨烯的转移效果,当二氧化硅厚度为2547 nm时,使用500 nm的青绿色光源作为背景光,石墨烯与周围介质的对比度能够超过0.3。最后对二氧化硅厚度为2330 nm和2690 nm的石墨烯/氮化硅/二氧化硅/硅多层结构的样品进行对比度实验,实验结果与理论预测有一定差异,分析表明主要原因为材料沉积厚度和光源波长存在偏差,这对后续改进器件制作工艺以及完善测试方式具有指导意义。     

Four distributed feedback laser array integrated with multimode-interference and semiconductor optical amplifier

Monolithic integration of four 1.55-μm-range InGaAsP/InP distributed feedback (DFB) lasers using varied ridge width with a 4×1-multimode-interference (MMI) optical combiner and a semiconductor optical amplifier (SOA) is demonstrated. The average output power and the threshold current are 1.8 mW and 35 mA, respectively, when the injection current of the SOA is 100 mA, with a side mode suppression ratio (SMSR) exceeding 40 dB. The four channels have a 1-nm average channel spacing and can operate separately or simultaneously.     

Dynamic thermal modeling and parameter identification for a monolithic laser diode module

We improved the thermal equivalent-circuit model of the laser diode module(LDM) to evaluate its thermal dynamic properties and calculate the junction temperature of the laser diode with a high accuracy.The thermal parameters and the transient junction temperature of the LDM are modeled and obtained according to the temperature of the thermistor integrated in the module.Our improved thermal model is verified indirectly by monitoring the emission wavelength of the laser diode against gas absorption lines,and several thermal parameters are obtained with the temperature uncertainty of 0.01 K in the thermal dynamic process.     

Θ-type Calderón-Zygmund operators with non-doubling measures

Let µ be a Radon measure on ? ^d which may be non-doubling. The only condition that µ must satisfy is µ(B(x, r)) ≤ Cr ⁿ for all x∈? ^d , r > 0 and for some fixed 0 < n ≤ d. In this paper, under this assumption, we prove that θ-type Calderón-Zygmund operator which is bounded on L ²(µ) is also bounded from L ^∞(µ) into RBMO(µ) and from H _atb ^1,∞ (µ) into L ¹(µ). According to the interpolation theorem introduced by Tolsa, the L ^p (µ)-boundedness (1 < p < ∞) is established for θ-type Calderón-Zygmund operators. Via a sharp maximal operator, it is shown that commutators and multilinear commutators of θ-type Calderón-Zygmund operator with RBMO(µ) function are bounded on L ^p (µ) (1 < p < ∞).