基于BP神经网络的血液荧光光谱识别分类研究

光谱技术在生物和医学检测方面具有积极的应用前景。由于血液成分的复杂性和类同性,有关不同动物血液光谱识别分类的技术研究尚未出现较为完善的结论。基于机器学习理论, 以BP神经网络为工具, 建立了对不同动物血液荧光光谱进行特征提取和识别分类的方法。实验采用Cary Eclipse光谱仪分别采集了鸽、鸡、鼠、羊四种动物不同浓度(1%和3%)的全血与红细胞荧光光谱数据(每个类型样本各50组数据);基于移动平滑算法对原始数据进行了平滑处理,以减少实验仪器噪声对特征提取和识别分类的影响;进一步根据血液光谱数据的特性, 该文出了“组合放大”的特征提取方法, 并建立了BP神经网络分类器进行训练和识别。相比于常用的光谱数据(单一)特征, 提出的“组合放大”特征和所设计的BP神经网络能对不同动物、不同类型(全血与红细胞)、不同浓度(1%和3%)的血液荧光光谱实现100%的准确分类, 同时神经网络测试误差均远小于设定的允许误差值。研究的动物血液光谱特征提取及识别技术具有较好的普适性和可靠性, 在农业、食品检查、以及生物医学检测等方面均可发挥重要作用。     

Waveguides induced by steady-state gray solitons in biased photorefractive-photovoltaic crystals

We carry out a theoretical investigation of the properties of waveguides induced by photorefractive one-dimensional steady-state gray spatial solitons (i.e., screening solitons, photovoltaic solitons, and screening-photovoltaic solitons). We demonstrate that waveguides induced by photorefractive steady-state gray spatial solitons are only a single guided mode for both all soliton graynesses and all values of ρ, where ρ is the ratio between the soliton peak intensity and the dark irradiance, and moreover, waveguides induced by gray photovoltaic solitons for closed-circuit condition are also only a single guided mode for all electric current densities. We find that the confined energy near the center of a photorefractive steady-state gray spatial soliton increases with ρ and decreases with an increase in the soliton grayness. We also find that the confined energy near the center of a gray photovoltaic soliton for closed-circuit condition increases with the electric current density. On the other hand, waveguides induced by gray screening-photovoltaic solitons are gray screening soliton-induced waveguides when the bulk photovoltaic effect is neglectable and are gray photovoltaic soliton-induced waveguides when the external bias field is absent.     

Degradation of azo dye Acid black 1 using low concentration iron of Fenton process facilitated by ultrasonic irradiation

A combination of ultrasonic and low concentration iron (<3 mgL(-1)) of Fenton process (US/Fenton) has been used to treat wastewater containing Acid black 1 (AB1). The results show that the oxidation power of low concentration iron of Fenton could be significantly enhanced by ultrasonic irradiation. The degradation of AB1 in aqueous solution by US/Fenton can receive better results compared with either Fenton oxidation or ultrasonic alone. Many operational parameters, such as ultrasonic power density, the pH value, the Fe(2+) dosage, the H(2)O(2) dosage, AB1 concentration and the temperature, affecting the degradation efficiency were investigated. Also, the effects of various inorganic anions (such as Cl(-), NO(3)(-), CO(3)(2-), etc.) on the oxidation efficiency of US/Fenton were studied. Under the given test conditions, 98.83% degradation efficiency was achieved after 30 min reaction by US/Fenton. The effect of various inorganic anions was in the following decreasing order: SO(3)(2-)>CH(3)COO(-)>Cl(-)>CO(3)(2-)>HCO(3)(-)>SO(4)(2-)>NO(3)(-). The results show that the US/Fenton can be an effective technology for the treatment of organic dyes in wastewater.     

Raman spectroscopic of osteoporosis model in mouse tibia in vivo

In this work, we correlate Raman spectroscopy in vivo which is performed in healthy bone tibia, 3-month-old mice with osteoporotic bone, within two groups: OVX (ovariectomized) and sham (lumbar access, no ovariectomy group control). Laser beam was applied directly in a punch of skin in the distal medial part of tibia. To access bone quality, we calculate mineral/matrix ratio, relative lipid and proteoglycan content as well as the crystallinity using normalized spectrum within the integrated area method. The variables obtained for bone quality were statistically verify by ANOVA and tested for normality, where differences were considered to be significant for P < 0.05. In osteoporotic bone (OVX) we found a decreasing ratio between mineral to matrix and relative proteoglycan content, followed by a relative increasing lipid content when comparing with healthy bone (Sham) with statistical significance. The crystallinity showed higher value for OVX group but without statistical significance. Our Confocal Raman Spectroscopy provides a well-controlled environment to differentiate osteoporotic bone from healthy bone by decreasing calcium and glycosaminoglycans and increasing the amount of lipids in the cortical tibia of the mouse in vivo.     

Theoretical study of the electrokinetic and electrochemical behaviors of two-layer composite membranes

A theoretical study concerning the effect of structure (porosity, pore radius and layer thickness) and surface characteristics (zeta potential) of two-layer composite membranes on global streaming potential (SP_g), membrane potential (Em_g) and membrane conductivity (λ_g) is presented. To this end, each layer of the composite membrane (composed of a support layer and a filtering layer) was modeled as a bundle of identical capillary tubes with connections between pores of the two layers (the pores in the filtering layer being smaller than those of the support layer). The global parameters SP_g, Em_g and λ_g were calculated by using the theory of thermodynamics of irreversible processes and a space charge model. SP_g, Em_g and λ_g were expressed as a function of the individual parameters of each layer SP⁽ⁱ⁾, Em⁽ⁱ⁾ and λ⁽ⁱ⁾, respectively, the length fraction of the support layer, the porosity and pore radius ratios. It was shown that the electrokinetic (streaming potential and membrane conductivity) and electrochemical (membrane potential) behaviors of such composite membranes vary between that of single layers. For streaming potential, the results indicate that the contribution of the filtering layer to the global streaming potential is very little influenced by zeta potentials of both types of pores. It appears that the individual streaming potential of the filtering layer greatly dominates the global streaming potential. This is due to the fact that the streaming potential of the filtering layer is weighted by the pore radius ratio which is a predominant parameter in determining the global streaming potential. In contrast to the streaming potential, the contribution of the filtering layer to the global membrane potential (Em_g) or membrane conductivity (λ_g) depends more or less on the zeta potentials of both kinds of pores and the corresponding electrokinetic radii as well. As to the membrane potential, the contribution of the filtering layer to Em_g is all the more sensitive to the zeta potentials than the electrokinetic radii are small. The filtering layer greatly dominates the global membrane potential when its pores are narrow (with regard to the Debye length) and strongly charged. For the electrolyte conductivity inside pores, the smaller pores (inside the filtering layer) have an effect all the more dominant on the apparent membrane conductivity than their zeta potential is low and that of larger pores (inside the support layer) is high.     

Lanthanide nitrate complexes of diphenylmethylphosphine oxide: synthesis and spectroscopic studies. Crystal structures of [La(Ph2MePO)3(NO3)3], [La(Ph2MePO)4(NO3)3]·xMe2CO and [Yb(Ph2MePO)4(NO3)2]PF6

The reaction of Ln(NO₃)₃·6H₂O (Ln=lanthanide except Pm) with Ph₂MePO in a 1:3 or 1:4 ratio in acetone or ethanol produces [Ln(Ph₂MePO)₃(NO₃)₃] which have been characterised by analysis, IR, ¹H and ³¹P{¹H} NMR spectroscopy and conductance measurements. The [Ln′(Ph₂MePO)₃(NO₃)₃] (Ln′=Pr–Tb) exist only as tris complexes in solution and are unaffected by the presence of excess Ph₂MePO. In contrast the [Ln″(Ph₂MePO)₃(NO₃)₃] (Ln″=Ho–Lu) partially decompose in CH₂Cl₂ solution into [Ln″(Ph₂MePO)₄(NO₃)₂]⁺, and [Ln″(Ph₂MePO)₄(NO₃)₂]PF₆ are readily isolated from Ln″(NO₃)₃, Ph₂MePO and NH₄PF₆ in acetone. For lanthanum only, a neutral 1:4 complex [La(Ph₂MePO)₄(NO₃)₃] was isolated. X-ray crystal structures show that [La(Ph₂MePO)₃(NO₃)₃] contains nine-coordinate La, whilst [La(Ph₂MePO)₄(NO₃)₃]·xMe₂CO contains a ten-coordinate metal centre. The structure of [Yb(Ph₂MePO)₄(NO₃)₂]PF₆ reveals an eight-coordinate cation and all complexes contain bidentate nitrato-groups.     

Coupled Vacancy Pairs in Ni-Doped CoSe for Improved Electrocatalytic Hydrogen Production Through Topochemical Deintercalation

Vacancy engineering plays vital role in the design of high-performance electrocatalysts. Here, we introduced coupled cation-vacancy pairs in Ni-doped CoSe to achieve boosted hydrogen evolution reaction (HER) activity through a facile topochemical intercalation approach. Adjacent Co vacancy pairs and heteroatom Ni doping contribute together for the upshift of the Se 4p_z orbital, which induces larger overlap between the Se 4p and H 1s orbitals. As a result, the free energy of H adsorption can be lowered significantly. With an advanced HER activity of 185.7 mV at 10 mA cm⁻², this work provides new direction and guidance for the design of novel electrocatalysts.     

Defect modes supported by optical lattices in photovoltaic-photorefractive crystals

We study defect modes in optically induced one-dimensional lattices in photovoltaic-photorefractive crystals. These defect modes exist in different bandgaps due to the change of defect intensity. For a positive defect, defect mode branches exist not only in the semi-infinite bandgap, but also in the first and second bandgaps. When the defect mode branch is fixed, the confinement of defect modes increases with the defect strength parameter. For a negative defect, defect mode branches exist only in the first and second bandgaps. For a given defect mode branch, the strongest confinement of the defect modes appears when the lattice intensity at the defect site is not the smallest in its branch. On the other hand, when the defect strength parameter is fixed, the most localized defect modes arise in the semi-infinite bandgap for the positive defect and in the first bandgap for the negative defect.     

Modulation instability of bright photovoltaic solitons on a partially incoherent background

We present the observation of incoherent anti-dark photovoltaic solitons in LiNbO₃:Fe crystal. This new class of soliton states involves bright photovoltaic solitons on a background beam meeting ?? > 1, where ?? is the ratio of background illumination photovoltaic constant to that of soliton beam. For ?? < 1, dark photovoltaic solitons are generated. Furthermore, this novel type solitons are investigated experimentally by injecting coherent light and partially coherent background of infinite extent. In case of spatial coherence of the background lower than the threshold of incoherent modulation instability, these results indicate that bright photovoltaic solitons can propagate in a stable fashion.     

声纳信号宽容性检测指数的初步分析

自上世纪六十年代以来,信号的宽容性(Robust,Robustness)处理就开始在统计数学与信号处理领域受到关注。由于声纳使用的水声环境的特殊复杂性,从事声纳信号处理和声纳设计的学者对环境适应性处理和宽容性水声信号处理开展了大量的研究。主要的目的是探索水声环境效应以及对声纳信号处理的影响,企图寻求一种适应环境的宽容性信号处理方法。本文初步探讨水声信号处理领域宽容性检测的基本概念,给出一种度量宽容性性能的数量指标。同时推导在不同声速剖面下声纳检测宽容性指标和所使用频率的关系。对文中所提出的理论方法与国内外实际海试的某些实例进行了分析比较。