光电式指纹采集图像装置及其分类算法

介绍了基于CMOS图像传感器的便携式指纹采集装置的设计,利用全反射原理,并通过对指纹图像全局的方向分布获取特征向量.实验证明,特征向量融合方法使分类的准确率达到93.7%.     

一类特定全方位摄像头外极曲线计算

研究了由双曲面镜面与球面镜面共同组成折反射系统并结合普通透视摄像头所构成的一类特定全景视觉系统,推导了该全方位摄像头成像模型以及外极曲线的计算过程,分析了外极曲线特性,最后通过实验进行理论验证.实验结果表明,本文所提出的计算方法可快速准确地得到外极曲线,有利于全景图像立体匹配过程中对应点的搜索匹配.     

基于自主配置的系统生存性增强算法研究

在系统冗余前提下，提出动态配置原子组件来增强系统生存性方法；根据中心极限定理和系统运行历史数据，获取原子组件生存性变化曲线，并结合系统服务效率以及服务质量等，设计了基于自主配置的生存性增强算法。通过实验验证了生存性计算方法在原子组件不同失效率下的正确性和有效性。仿真实验表明，该算法在原子组件遭受攻击和服务能力下降情况下都能有效保证关键服务的生存性。     

NGN的互联互通模型

针对现有两两互联互通网络模型的不足，提出了一种用于NGN的中心型互联互通网络模型，解决了现有网络模型的不足，并对该中心型网络模型的商用作进一步的探讨。     

综合康复措施治疗脊髓损伤中枢性疼痛的临床观察

目的:探讨综合康复治疗措施对脊髓损伤后中枢性疼痛的治疗效果.方法:对31例脊髓损伤后中枢性疼痛患者采用阿米替林、按摩、心理治疗及经皮神经电刺激(TENS)进行治疗.采用McGill疼痛问卷(McGill pain questionnaire,MPQ)、疼痛视觉模拟评分法(Visual Analogous Score,V...     

雷达目标特征提取的一种方法

针对雷达高分辨率距离像（HRRP）方位敏感性和平移敏感性的问题,在对一维距离像进行预处理的基础上,提取两个平移不变特征：中心矩和熵,并将二者形成组合特征,采用Karhunen—Loeve变换进一步进行特征压缩,运用并比较了最大最小距离判别法和SVM分类器的识别性能．实验结果表明中心矩一熵组合特征提取方法能够显著增强目标的可分性,大大提高识别率。     

固体介质间隔层激光标准具性能的影响因素研究

针对固体介质间隔层的镀膜标准具, 以1 064 nm激光镀膜标准具为例, 首先研究了反射膜堆数对反射带宽、基底厚度以及对自由光谱区的影响:标准具的带宽随着膜层堆数增加而减小, 自由光谱区随着基板厚度的增加而减小;其次研究了基底误差对标准具中心波长定位和透过率的影响, 通过定量数值计算证明了基底误差可通过标准具的使用角度补偿;针对典型的H(LH)^m/Substrate/(HL)^mH和L(LH)^m/Substrate/(HL)^mL两个膜系结构, 研究了入射激光发散角对标准具中心波长偏移、通带半宽度、中心波长透过率和最大透过率的影响。随着激光发散角的增加, 中心波长向短波方向移动, 通带半宽度、中心波长透过率和最大透过率呈现下降的趋势, 并且第二个膜系结构的标准具性能优于第一个膜系结构的标准具。     

Nitrogen doped nano porous graphene as a sorbent for separation and preconcentration trace amounts of Pb,Cd and Cr by Ultrasonic assisted in‐syringe dispersive micro solid phase extraction

Nitrogen doped nano porous graphene was used as an efficient sorbent in solid‐phase extraction process for simultaneous separation and pre‐concentration of metal ions lead (II), cadmium(II), and chromium(III)) in biological samples. Ultrasonic assisted in‐syringe dispersive micro solid phase extraction coupled with micro sampling atomic absorption spectrometry was utilized for the determination of metal ions. Nitrogen doped nano porous graphene was synthesized as a nano sorbent by chemical vapour deposition method. Methane and aniline were used as carbon and nitrogen sources. The characterization of sorbent was performed by field emission scanning electron microscope, transmission electron microscopy, atomic force microscope, fourier transform infrared, chemical element analysis and raman analysis. Effective parameters on the extraction efficiency such as pH, sorbent dosage, eluent volume and eluent concentration were optimized by central composite design and desirability function. Experimental results indicate that the optimal conditions for this extraction were pH = 6.4, 1.42 mg of sorbent, 100 μL of eluent, and 0.84 mol L^‐1 of eluent concentration. The detection limits are as low as 1.5, 0.3 and 0.9 μg L^‐1 for lead, cadmium, and chromium, respectively. The intra‐day precisions were 3.6, 4.38 and 2.94 and Inter‐day precision were 4.83, 5.26 and 4.52 for lead, cadmium, and chromium, respectively. Method performance was investigated by determination of mentioned heavy metals in complicated biological matrixes such as human plasma, urine and saliva samples with good recoveries.     

Oligothiophene-based small molecules with 3,3′-difluoro-2,2′-bithiophene central unit for solution-processed organic solar cells

Two new oligothiophene-based small molecules, namely DRCN6T-F and DRCN8T-F, with 3,3′-difluoro-2,2′-bithiophene as the central building block and 2-(1,1-dicyanomethylene)-rhodanine as end groups, were designed and synthesized. Compared to their non-fluorinated counterparts DRCN6T and DRCN8T, DRCN6T-F and DRCN8T-F exhibit enhanced intermolecular interactions and lower HOMO energy levels. However, PCEs of 2.26% and 5.07% were obtained for DRCN6T-F and DRCN8T-F based optimized devices, respectively, lower than those of non-fluorinated molecules DRCN6T and DRCN8T. The relatively poor performance for the DRCN6T-F and DRCN8T-F were mainly caused by their low short-circuit current densities, due to their unfavorable morphologies and low charge carrier mobilities.     

Optimization of solid phase dispersive field‐assisted ultrasonication for the extraction of auramine O and crystal violet dyes using central composite design

Simultaneous preconcentration and determination of auramine o (AO) and crystal violet (CV) dyes from aqueous solution was conducted by ultrasound assisted (dispersive) solid phase microextraction (UASPME) based on SnO₂/SnS composite loaded activated carbon (SnO₂/SnS‐NCs‐AC). The prepared of SnO₂/SnS‐NCs‐AC was characterized by FESEM and XRD analysis. Main and interaction influences of operational parameters such as pH, sonication time, amounts of sorbent, and type of eluent on extraction efficiency were investigated by central composite design and optimized with desirability function approach (DFA). ANOVA was conducted and shows that optimized values were found at 15.33 min sonication time, 0.019 g SnO₂/SnS‐NCs‐AC mass, pH 5.46 and among different solvents, dimethyl formamide was selected as an efficient eluent. Under this conditions recoverees percentage were obtained 82.85% and 86.70% for AO and CV, respectively. Based on F‐test under ANOVA all main effect and interaction effect of understudy parameters has the significant effect on the responses. At optimum conditions, limit of detection (0.0015 and 0.001 mg/l), limit of quantitation (0.4 and 0.4 mg/l), limit of linearity (9.0 and 9.0 mg/l), enrichment factor (33.48 and 83.71) and percent relative standard deviation (3.44 and 4.20) were found to be for auramine o and crystal violet dyes, respectively. Finally, the method was successfully applied for the preconcentration and determination of AO and CV in water samples and ER% of 89.0‐97.0 and 96.2–98.0% as acceptable range were found to be for AO and CV samples, respectively.