60°镜面光泽测量值不确定度的评定

本文采用光泽度仪对漆膜的60°镜面光泽进行了测量,对产生测量不确定度的因素进行了分析,并对其A类和B类不确定度进行了分别评定,最终获得其测量结果的扩展不确定度。     

In-situ synthesis of TiO2 nanostructures on Ti foil for enhanced and stable photocatalytic performance

TiO_2 nanostructures with strong interfacial adhesion and diverse morphologies have been in-situ grown on Ti foil substrate through a multiple-step method based on conventional plasma electrolytic oxidation(PEO) technology, hydrothermal reaction and ion exchange process. The PEO process is critical to the formation of TiO_2 seeding layer for the nucleation of Na_2Ti_3O_7 and H_2Ti_3O_7 mediates that are strongly attached to the Ti foil. An ion exchange reaction can finally lead to the formation of H_2Ti_3O_7 nanostructures with diverse morphologies and the calcination process can turn the H_2Ti_3O_7 nanostructures into TiO_2 nanostructures with enhanced crystallinity. The morphology of the TiO_2 nanostructures including nanoparticles(NP), nanowhiskers(NWK), nanowires(NW) and nanosheets(NS) can be easily tailored by controlling the NaOH concentration and reaction time during hydrothermal process. The morphology, composition and optical properties of TiO_2 photocatalysts were analyzed using scanning electron microscope(SEM), X-ray diffraction(XRD), photoluminescence(PL) spectroscopy and UV–vis absorption spectrum. Photocatalytic tests indicate that the TiO_2 nanosheets calcined at 500?C show good crystallization and the best capability of decomposing organic pollutants. The decoration of Ag cocatalyst can further improve the photocatalytic performance of the TiO_2 nanosheets as a result of the enhanced charger separation efficiency. Cyclic photocatalytic test using TiO_2 nanostructures grown on Ti foil substrate demonstrates the superior stability in the photodegradation of organic pollutant, suggesting the promising potential of in-situ growth technology for industrial application.     

取代酚对日本长腿蛙蝌蚪急性毒性的QSAR研究

用Hartree-Fock(HF)和DFT-B3LYP方法,分别在较高基组6-31G**和6.311G**水平下,全优化计算了21种取代酚化合物.从中获得分予最高占用和最低空轨道能(EHOMO和ELUMO)、前线轨道能级差(△E＝EHOMO-ELUMO)、分子总能量(ET)、氧原了所带的最高正电荷(QH+)、最负原子的静电荷(Q-)、分子偶极矩(μ)和分子体积(V)等描述符.结合文献中标题化合物对日本长腿蛙蝌蚪的毒性值(-logLC50)和辛醇/水分配系数(logKow),由线性同归方法成功建立包含10gKow、ELUMO和Q-的三参数QSAR模型.其中,模型(5)的复相关系数R2=0.944 8,交叉验证系数Q2=0.920 5,标准偏差SE=0.187,Fisher检验值F=98.390,故其预测能力较好.由此推断,标题物对日本长腿蛙蝌蚪的毒性作用分为2步,首先穿过细胞壁在细胞内富集,以logKow和Q-描述;其次与亲核试剂发生亲电反应,以风ELUMO表示.     

Real-time foveation filtering using nonlinear Mipmap interpolation

In recent years, several techniques have been proposed to simulate the gaze effect of the Human Visual System (HVS). It is believed that this effect is due to the foveation filtering. Current techniques to simulate the foveation filtering in computer graphics are either slow or suffer from artifacts and limitations. In this paper, we present a new approach of foveation filtering based on the Mipmap Pyramid of the current view by considering the relationship between the Gaussian kernel and Mipmap level. Due to the nonlinear Mipmap interpolation under the Bilateral Filtering scheme, we are able to simulate the foveation filtering more naturally and efficiently than in previous work. Moreover, a detail enhancement method based on the Cornsweet illusion is proposed to augment the gazing effect. We demonstrate our new approach with a variety of examples and provide comparisons with recent approaches.     

Dynamically modulated intensity interrogation scheme using waveguide coupled surface plasmon resonance sensors

An electro-optically modulated intensity interrogation method based on tunable waveguide coupled surface plasmon resonance sensors has been proposed. It has been theoretically and experimentally demonstrated that the proposed scheme can enable sensitive measurement of measurand variations. By modulating the refractive index in the waveguide layer, this interrogation method yields modulated signal whose amplitude is related to measurand's refractive index. This amplitude modulated signal offers a higher signal to noise ratio and eliminates additive noise in the sensor system. A preliminary investigation using saline buffers with different NaCl concentrations shows a resolution of 2.3 × 10^?6 refractive index unit by our approach. Resolution can be controlled by the amplitude of the applied modulation voltage and can be further enhanced by optimizing the device structure or improving the electro-optical (E-O) coefficient of the E-O material. This approach is simple, stable, and promising for low-cost or multi-channel SPR biosensor applications.     

Piecewise Pseudo-Maximum Likelihood Estimation for Risk Aversion Case in First-Price Sealed-Bid Auction

In the literature, more and more clues show that the bidders indeed tend to risk averse. But as a good structure estimation procedure in first-price sealed-bid auctions, the traditional PPMLE (Piecewise Pseudo-Maximum Likelihood Estimation) approach is only applicable to the risk neutrality case. This study generalizes this approach to the risk aversion case, and obtains a simple estimation procedure for the Pareto family of private costs. In the procedure, the estimation order of distribution parameters of private costs is not important, which is different from the traditional PPMLE method. Though there is no unique estimator for θ ₁ and γ, some guidance is given for real-world applications on the basis of our Monte Carlo simulation experiments. What’s more, this procedure can be reduced further, if one is only interested in estimating the private costs. Extensive simulation experimental results indicate that our approach outperforms or matches at least the traditional one in the case of risk neutrality, and is applicable to the risk aversion case.     

飞思卡尔推出一站式32位工业连接解决方案简化嵌入式开发

<正>嵌入式开发人员面临着用更少资源做更多事情的压力,他们不但要增强性能应用和连通性,而且要降低成本,加快产品上市。为了帮助开发人员成功应对设计     

对pSFLASH扰动公钥密码的一个实际攻击

通过对SFLASH的中心映射进行扰动,最近Wang等人提出了一个新的多变量公钥系统pSFLASH.pSFLASH的设计者认为,扰动后的中心映射可以破坏SFLASH公钥潜在的数学结构,从而抵抗针对SFLASH的差分代数攻击[2-3].然而对于以(T-1,U-1,β,γ)为私钥的任一pSFLASH实例,一定存在一个可逆仿射...     

无线传感器网络中基于树的动态多路径容错路由协议

多路径路由对无线传感器网络的负载均衡和容错能力等方面都有一定改善作用。在研究一些多路径路由算法的基础上,对分层的无线传感器网络路由进行探索,提出了一种基于树的动态多路径路由的生成方法,快速获得当前节点的主路径与备用路径。仿真结果表明,该方法可有效地均衡网络负载、减少时延、提高网络的可靠性。