碘仿电解合成的工艺研究

开发了一种以石墨为阳极、铅为阴极、采用旋转阳极和离子膜分隔电解槽的碘仿电解合成的先进工艺 ,经过 5因素 4水平的正交试验 ,发现影响电流效率的各工艺因素中 ,阳极电流密度的影响最大 ,其次分别为阳极液温度 ,阳极液 p H值 ,阳极液中碘化钾的浓度和阳极转速。优化得到碘仿电合成的最佳工艺条件为 :碘化钾浓度 2 0 0 g· L- 1 ,阳极电流密度 2 5 A· dm- 2 ,阳极液温度为 2 0℃ ,阳极液 p H值为 9.5,阳极转速为2 0 0 r· min- 1 ,在此最佳工艺条件下 ,电流效率可达 97.2 3%。     

Water Bloom Precursor Analysis Based on Two Direction S-Rough Set

In the field of water quality management, it is vital to determine the main precursory anomalies from the precursor of intricate water bloom in the context of a given area. In this paper, a water bloom precursor analysis method, based on two direction singular rough set, was proposed. This approach was produced on the basis of the different sections and pre-water bloom of water bloom precursor anomalies and characteristic of elements transferred in singular rough set. For testing the validity of two direction singular rough set application in water bloom precursor analysis, Xiangxi River, which is one of the typical tributaries of Three Gorges Reservoir in China, was selected as study area. The result showed that compared with other indexes, pH and dissolved oxygen (DO) are the most valuable indicators of water bloom in the precursory anomalies. Furthermore, regarding with water bloom precursory anomalies in Xiangxi River, most of the nutrient loading and biological community are the key indicators. Hence, this method can determine the main precursory anomaly for water bloom in the study area, which provides powerful knowledge support to water quality specialists for them to comprehensively analyze precursory anomaly so as to find out its relationship with occurrence law of water bloom.     

药用中间体苯丙酮含量的气相色谱/质谱分析

苯丙酮是合成利胆药苯丙醇的重要中间体。本文建立了用气相色谱 /质谱法 (GC/MS)测定苯丙酮含量的方法。组分的定性依靠GC/MS联用技术和NIST谱库标准质谱图对照分析。以苯乙酮为内标 ,苯丙酮含量在 1.0× 10 -5～ 2 .0× 10 -4g/mL范围内呈线性 ,线性相关系数r =0 .994 9,苯丙酮最低检测浓度为 1.0× 10 -8g/mL。该法操作简便、快速 ,结果准确可靠 ,且具有很好的实用价值     

High-g impact resistance for epoxy molding compound

The behavior of resistance high-g impact of EMC (epoxy molding compound) with two package models, small outline package (POS) and Globtop, was evaluated by experimental method used Hopkinson bar. At 120,000 g (generated in the Hopkinson bar with widths about 70 μ s) no damage in either the POS devices or the Globtop devices was observed. In order to enhance the EMC’s ability of resistance high-g impact, buffering effect of epoxy resin was also studied. The experimental results above all show that EMC has a better performance of impact resistance at about 120,000 g, and epoxy resin can absorb the stress wave to have the protected ability. The study of this paper could serve as a basis for selection packaging materials and enhance its reliability in high-g impact environment.     

光照变化条件下的光流估计

目的 为了提高光流法在处理光照变化和大位移方面的稳健性。提出一种结合结构纹理分解预处理和加权中值滤波的光流场模型。方法 该方法数据项采用灰度守恒假设和梯度守恒假设相结合、局部约束与全局约束相结合的思想。同时采用结构纹理分解、加权中值滤波、金字塔结构等高效的光流估计技术,进一步增强了光流算法的精确性与实用性。结果 分别通过Middlebury光流数据库图像和真实场景图像对提出的光流估计算法进行了大量实验验证。实验结果表明,改进的光流估计法在处理光照变化方面表现不错,不仅获得稠密的光流场,而且提高了光流场准确提取目标边缘的能力。结论 和传统光流方法相比,所提方法在光照变化情况下能获得更加理想的结果,降低了实际场景中光线变化的干扰,能更好地适用于实际场景中。     

一种基于非残差估计线性表示模型的人脸识别

Dantzig selector利用样本与残差之间的相关向量的L!范数来约束线性表示模型,为了克服传统的线性表示在处理表示残差时依赖于一个对残差特定的似然估计这一缺陷将这样一种处理残差的思路用于人脸识别,提出了一种基于Dantzig selector模型的人脸识别算法,并对Dantzig selector的一种有效的求解方法进行研究。在常用人脸库上实验表明,基于Dantzig selector人脸识别算法在不需要对残差进行估计的情况下也能取得了很好的识别效果。     

Defect formation and its effect on the thermodynamic properties of Pu2Zr2O7 pyrochlore: a first-principles study

In the past decades, pyrochlores, such as Gd₂Zr₂O₇, have demonstrated great potential to immobilize nuclear wastes such as Pu, which results in the production of Pu₂Zr₂O₇. Due to the high radioactivity of Pu, it is difficult to investigate the radiation response behavior of Pu₂Zr₂O₇ and its physical properties of the damaged state experimentally. Consequently, few related data have been reported in the literature thus far. In this study, first-principles calculations have been carried out to investigate the defect formation and its effect on the thermodynamic properties of Pu₂Zr₂O₇. It reveals that Pu_Zr antisite and O_8a interstitial defects are very easy to form in Pu₂Zr₂O₇. In particular, the O_8a interstitial defect can be formed spontaneously, while it is mechanically unstable. When vacancy, interstitial or antisite defects are formed in Pu₂Zr₂O₇, and the elastic moduli and Debye temperature are decreased. Besides, better ductility is resulted. As compared with other zirconate pyrochlores, such as Gd₂Zr₂O₇, the Pu₂Zr₂O₇ is suggested to be less resistant to radiation-induced amorphization. This study demonstrates that the created defects due to self-radiation from actinide decay have remarkable influences on the thermophysical properties of Pu₂Zr₂O₇.     

Effect of IR-laser treatment parameters on surface structure,roughness, wettability and bonding properties of fused deposition modeling-printed PEEK/CF

In this study, laser surface treatment was applied to alter the surface texturing and chemical compositions of fused deposition modeling (FDM)-printed PEEK/CF samples to improve the deficiency of inert surface of PEEK as adherend substrate. The influence of IR-laser parameters including treatment gaps, single pulse energy and pulse widths on surface properties and shear bond strength were discussed. The results indicated that surface roughness was enhanced with decreasing treatment gap or increasing pulse energy, which reached the highest value of Ra = 32.44 μm at 0.4*0.4 mm² treatment gap and 300 mJ single pulse energy. By adjusting laser pulse width, surface wettability changed from hydrophobicity to hydrophilicity. After micro-second laser ablation, the texturing structure was changed and acted as mechanical interlocking effect, and therefore make the shear bond strengths improve from 3.28 to 6.42 MPa compared with the untreated groups. On the other hand, functional groups on substrate surface were activated after nano-second laser ablation, which contributes to an enhancement of shear bond strength through chemical interaction between adhesives and substrates. Therefore, our work highlights an efficient method of laser surface treatment on the adhesion property of FDM-printed substrates.     

BNi—2钎焊条的真空吸铸工艺

研究了ＢＮｉ－２钎焊条真空吸铸原理，并由试验得出：当ＢＮｉ－２合金加热到１５００℃，真空控制阀门开口为φ６ｍｍ以上，真空度５０ｋＰａ，铸型预热温度５００℃，并用φ内２ｍｍ×５００ｍｍ石英管进行真空吸铸时，吸铸高度可达到４０ｃｍ以上。     

Extraction and separation of Ga(Ⅲ) and T1(Ⅰ) or In(Ⅲ) and T1(Ⅰ) from chloride media with CA-12 in sulphonating kerosene

The extraction behavior and mechanism of gallium(Ⅲ) and thallium(Ⅰ) or indium(Ⅲ) and thallium(Ⅰ) with Sec-octylphenoxy acetic acid (CA-12) from hydrochloric acid solution in sulphonating kerosene were studied. Optimum extraction conditions were evaluated from critical study of various experimental parameters and the probable composition of the extracted species is ascertained from lg D-lg C plots. The effects of different ions on the determination of these ions were examined.