二元光学分束器的设计

系统地阐述了几种二元光学分束器的基本设计理论，比较其算法以及衍射效率和再现误差，并提供了设计实例。     

Synthesis and properties of cross‐linked polymers from epoxidized rubber seed oil and triethylenetetramine

A series of epoxidized oils were prepared from rubber seed, soybean, jatropha, palm, and coconut oils. The epoxy content varied from 0.03 to 7.4 wt %, in accordance with the degree of unsaturation of the oils (lowest for coconut, highest for rubber seed oil). Bulk polymerization/curing of the epoxidized oils with triethylenetetramine (in the absence of a catalyst) was carried out in a batch setup (1 : 1 molar ratio of epoxide to primary amine groups, 100°C, 100 rpm, 30 min) followed by casting of the mixture in a steel mold (180°C, 200 bar, 21 h) and this resulted in cross‐linked resins. The effect of relevant pressing conditions such as time, temperature, pressure, and molar ratio of the epoxide and primary amine groups was investigated and modeled using multivariable nonlinear regression. Good agreement between experimental data and model were obtained. The rubber seed oil‐derived polymer has a T_g of 11.1°C, a tensile strength of 1.72 MPa, and strain at break of 182%. These values are slightly higher than for commercial epoxidized soybean oil (T_g of 6.9°C, tensile strength of 1.11 MPa, and strain at break of 145.7%). However, the comparison highlights the potential for these novel resins to be used at industrial/commercial level. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42591.     

环向裂纹缺陷压力管道塑性极限载荷安全性分析

采用正交试验法,编制了25种不同管道尺寸、不同缺陷尺寸的正交实验图,对20号钢管道进行非线性计算。研究了单一载荷及组合载荷下含环向表面裂纹缺陷管道的塑性极限载荷,并用公式计算不同载荷工况下管道的塑性极限载荷,将有限元分析值与理论值进行对比,验证有限元计算的准确性。分析了裂纹环向长度、轴向长度、深度及管径4个因素对塑性极限载荷的影响,从而得到这4个因素对不同载荷工况下管道承载能力的影响规律以及相同裂纹尺寸的管道在不同载荷工况下的等效应力图。     

Synthesis of Higher Fatty Acid Starch Esters using Vinyl Laurate and Stearate as Reactants

This paper describes the synthesis of long‐chain fatty esters of corn starch (starch laurate and starch stearate) with a broad range in degree of substitution (DS = 0.24−2.96). The fatty esters were prepared by reacting the starch with vinyl laurate or vinyl stearate in the presence of basic catalysts (Na₂HPO₄, K₂CO₃, and Na acetate) in DMSO at 110°C. The yellowish products were characterized by ¹H‐, ¹³C‐NMR and FT‐IR. The DS of the products is a function of the carbon number of the fatty acid chain, vinyl ester to starch ratio and the type of catalyst. When performing the reactions using Na₂HPO₄ as the catalyst, the DS for the starch laurate compounds is higher than for the corresponding starch stearates. For low vinyl ester to starch ratios, an increase in the vinyl ester concentration leads to higher product DS values. At higher ratios, the DS decreases, presumably due to a reduction of the polarity of the reaction medium. K₂CO₃ and Na acetate are superior catalysts with respect to activity compared to Na₂HPO₄ and products with DS values close to 3 were obtained.     

沙葱总黄酮水洗组分的体外抗炎活性

本实验在体外应用脂多糖（lipopolysaccharides,LPS）诱导小鼠腹腔巨噬细胞建立炎症模型的基础上,探讨沙葱总黄酮水洗组分的体外抗炎活性。应用CCK-8法检测0、50、100、200、400、800 μg/mL沙葱总黄酮水洗组分对小鼠腹腔巨噬细胞增殖活力的影响;将细胞分为空白对照组、LPS应激模型组及不同质量浓度沙葱总黄酮水洗组分预处理组,采用Griess法及酶联免疫吸附测定法分别测定各处理组细胞上清液中NO浓度和肿瘤坏死因子-α（tumor necrosis factor-α,TNF-α）、白细胞介素（interleukin,IL）-1β、IL-6、IL-10的质量浓度,反转录实时荧光定量聚合酶链式反应法检测各处理组细胞中诱导型一氧化氮合酶（inducible nitric oxide synthase,iNOS）、TNF-α、IL-1β、IL-6、IL-10、髓样分化蛋白（myeloid differential protein,MyD）88、核因子 κB（nuclear factor κB,NF-κB）mRNA的表达水平。结果显示：与对照组相比,沙葱总黄酮水洗组分在50～800 μg/mL时对小鼠腹腔巨噬细胞无明显细胞毒性作用。与LPS应激模型组相比,沙葱总黄酮水洗组分能够极显著抑制促炎介质NO、TNF-α、IL-1β、IL-6质量浓度及其mRNA的表达（P＜0.01或P＜0.001）;高度显著提高抗炎细胞因子IL-10质量浓度及其mRNA的表达（P＜0.001）,且呈剂量依赖效应;极显著降低MyD88、NF-κB mRNA的表达水平（P＜0.01或P＜0.001）。由此得出,沙葱总黄酮水洗组分对LPS诱导的小鼠腹腔巨噬细胞具有抗炎作用,其抗炎活性可能是通过抑制促炎性介质NO、TNF-α、IL-1β、IL-6的分泌并提高抗炎性细胞因子IL-10的质量浓度实现的,其作用机制可能与NF-κB信号通路有关。     

如何搞好实验室仪器设备的期间核查

根据GB/T 15481-2000 idt ISO/IEC 17025-1999<检测和校准实验室能力的通用要求>第5.6.3.3条<期间核查>的要求"应根据规定的程序和日程对参考标准,基准,传递标准或工作标准以及标准物质(参考物质)进行核查,以保持其标准状态的置信度".这就要求检测和校准实验室的仪器设备应建立期间核查的程序文件并实施,其目的是为了及时发现运行的仪器设备是否有问题,防止使用不符合技术规范要求的仪器设备,以及可以缩短失效后的追溯时间.     

Experimental and Modeling Studies on the Synthesis and Properties of Higher Fatty Esters of Corn Starch

This paper describes a systematic study on the synthesis of higher fatty esters of corn starch (starch laurate and starch stearate) by using the corresponding vinyl esters. The reactions were carried out in DMSO using basic catalysts (Na₂HPO₄, K₂CO₃, and Na‐acetate). The effect of the process variables (vinyl ester to starch ratio, catalyst intake, reaction temperature and type of the catalyst) on the degree of substitution (DS) of the starch laurate and starch stearate esters was determined by performing a total of 54 experiments. The results were adequately modeled using a non‐linear multivariable regression model (R²≥0.96). The basicity of the catalyst and the reaction temperature have the highest impact on the product DS. The thermal and mechanical properties of some representative product samples were determined. High‐DS products (DS = 2.26‐2.39) are totally amorphous whereas the low‐DS ones (DS = 1.45‐1.75) are still partially crystalline. The thermal stability of the esterified products is higher than that of native starch. Mechanical tests show that the products have a tensile strength (stress at break) between 2.7–3.5 MPa, elongation at break of 3–26%, and modulus of elasticity of 46–113 MPa.     

光催化剂TiO2改性的研究进展

TiO₂具有光催化性能好、化学性质稳定、毒性低、价格低廉等优点,但由于禁带较宽,只对紫外光有响应,且电子和空穴容易复合,导致光催化活性和效率降低。本文介绍了TiO₂的几种主要改性方法的最新研究进展。表面沉积贵金属、半导体复合、染料敏化可以降低TiO₂的禁带宽度,增加其响应波长,提高太阳光的利用率。离子掺杂可使得TiO₂晶体表面产生缺陷,抑制光生电子和空穴的复合,增加表面活性中心的数量。碳纳米管和石墨烯掺杂则能够提高TiO₂对可见光的吸收率,扩大光响应范围,同时加快电子传输,减少载流子复合,提高催化效率。指出石墨烯作为新型掺杂材料具有很大的发展潜力,TiO₂基多组分复合型光催化剂可获得比单种组分表面改性或者掺杂TiO₂更好的效果。最后介绍了TiO₂表面的亲/疏水改性研究进展。     

SbVO4 doped ZnO–V2O5-based varistor ceramics: microstructure, electrical properties and conductive mechanism

The effects of SbVO₄ addition on the microstructure, electrical properties and characteristics of grain and grain boundary of ZnO–V₂O₅ based varistor ceramics were studied using SEM, E–J measurements and impedance spectroscopy. XRD analysis revealed that all the samples consist of main phase of ZnO and the second phase of BiVO₄ and Zn₇Sb₂O₁₂. The microstructural homogeneity of the ceramic was improved through adding SbVO₄. With an increase of SbVO₄, the average grain sizes decrease from 16.1 to 6.1 μm. The resistivity of grain boundary is approximately constant (~10³ Ω). The ZnO–V₂O₅-based varistor ceramics added with 0.3 mol % SbVO₄ sintered at 940 °C for 4 h exhibited good nonlinear properties of α = 51, J = 13.4 μA/mm² and E _1mA = 416 V/mm.