最大特征根的极值六角链

定义了六角链的一种翻转-粘贴运算, 利用这一运算, 证明了Gutman 猜想.这一证明思想也可用于证明关于Hosoya指标和Merrifield-Simmons 指标的极值六角链的结果.     

关于矩阵相似中变换矩阵的一般形式

本利用Jordan标准形理论,给出了矩阵相似中的变换矩阵的一般表达形式。     

The reliability of measurements on electron energy distribution function in silane rf glow discharges

Electron energy distribution function (EEDF) is a key parameter of plasmas, which is directly proportional to the second derivative of the probe I-V characteristics. Because of an amplifying effect of unavoidable noises in the experimental probe I-V curves during the derivation process, the experimental I-V curves should be smoothed before performing the numerical derivation. This paper investigates the effect of adjustable factors used in the smoothing process on the deduced second derivative of the I-V curves, and an optimum group of the adjustable factors is selected to make the rms deviation of the smoothed I-V curves from the measured curves less than 1%. A simple differentiation circuit is designed and used to measure the EEDF parameter straightforwardly. It is the first time, so far as we know, to measure the EEDF parameters simultaneously by means of both numerical and circuit derivative methods under the same discharge conditions and on the same discharge equipment. The deviation between two groups of mean electron energy E and electron density n_e obtained by the above different methods is within about 7%. This apparently improves the reliability of the measurements of the EEDF parameters.     

Cell image recognition with radial harmonic Fourier moments

Various types of moments have been utilized to recognize image patterns in a number of applications. Multi-distortion invariant－radial harmonic Fourier moments were investigated in the recognition of cell smear images. Image recognition experiments showed that radial harmonic Fourier moments are not only highly concentrated image features but also have a good property of antidistortion and antinoise. They may be used in fast and accurate automatic cell recognition.     

Theoretical investigation of incomplete ionization of dopants in uniform and ion-implanted 4H-SiC MESFETs

The effects of incomplete ionization of nitrogen in 4H-SiC have been investigated. Poisson's equation is numerically analysed by considering the effects of Poole--Frenkel, and the effects of the potential on $N^+_\dd$ (the concentration of ionized donors) and $n$ (the concentration of electrons). The pinch-off voltages of the uniform and the ion-implanted channels of 4H-SiC metal-semiconductor field-effect transistors (MESFETs) and the capacitance of the gate are given at different temperatures. Both the Poole--Frenkel effect and the potential have influence on the pinch-off voltage $V_{\rm p}$ of 4H-SiC MESFETs. Although the $C$-$V$ characteristics of the ion-implanted and the uniform channel of 4H-SiC MESFETs have a clear distinction, the effects of incomplete ionization on the $C$-$V$ characteristics are not significant.     

Ni(OH)_2电极材料的XRD和Raman光谱表征

用 XRD和 Raman光谱等方法对几种典型球形 Ni( OH) 2 电极材料进行了表征 ,并分析了材料的表观形貌、掺杂元素和微观结构等对其充放电性能的影响 .结果表明 ,有较好填充性和充放电性能 Ni( OH) 2 电极材料所具有的特征为 ,颗粒的球形好且结晶完好 ,晶粒较小 ,较大的晶格参数 c,并在 51 0和 3596cm- 1 处可以生成 Raman光谱峰 ;而 XRD和 Raman光谱方法则是评价 Ni( OH) 2 电极材料性能的有效手段 .     

Ni(OH)2电极材料的XRD和Raman光谱特征

掺杂元素;Ni(OH)2电极材料的XRD和Raman光谱特征     

当归特征组分的识别与定量对比

 将高效液相色谱模式 /二极管阵列检测与自编紫外光谱库管理软件结合 ,用液相色谱 /紫外光谱以及特征参数研究同种当归多个特征组分的识别及快速定量对比。色谱 /光谱及其特征参数共同表达同种当归 2 3个特征组分 ;探讨定量对比的关键技术 ;定量比较两个同种当归相同组分的浓度差异。多指标表达当归特征组分 ,可用于它们的识别 ;定量手段的建立 ,可对比当归特征组分定量结果的差异性。不用化学对照品 ,便能识别和定量比较当归样品中的多组分。方法简便易行、快速 ,结果的代表性强、重现性良好。     

M2B5O9X：Eu，Tb（M=Ca,Sr;X=Cl,Br）荧光体的光谱特征

利用Eu^3 和Tb^3 稀土离子之间存在电子组态共轭性的特征,将其双掺于同一基质中,由于电子转移而产生Eu^2 ,使Eu^3 ,Tb^3 和Eu^2 共存于同一体系中,在空气中合成了M2B5O9X：Eu,Tb荧光粉,研究了其发光特征及影响作用。结果表明,Eu^3 ,Tb^3 和Eu^2 共存于同一基质中,且稀土离子的掺杂量对其光谱产生影响。     

地方性铝氟病

综述了地方性铝氟病的临床表现和生化特征,骨X线表现,氟与铝的关系,氟、铝与其它元素的关系,骨病理组织学基础,环境及流行病学特征和该病的防治措施与效果。