SN/T 2980-2011在动物源性成分检测中的适用性分析

目的 探讨行业标准SN/T 2980-2011《动物产品中牛、山羊和绵羊源性成分三重实时荧光PCR检测方法》在动物源性成分检测中的适用性。方法 基于中华人民共和国出入境检验检疫行业标准SN/T 2980-2011和国家标准GB/T 25165-2010《明胶中牛、羊、猪源性成分的定性检测方法实时荧光PCR法》对鲜肉组织及加工肉制品进行动物源性成分检测实验, 建立依托上述标准的动物源性成分检测能力。结果 SN/T 2980-2011中牛源性成分检测特异性不佳, 山羊源性成分检测特异性良好, 绵羊探针仅适用于单通道实时荧光PCR检测; GB/T 25165-2010中的牛、羊源性成分检测均展示出良好的特异性。结论 建议SN/T 2980-2011行业标准的起草单位及起草人重新设计适用于三重实时荧光PCR的牛、绵羊引物及探针,既要保证引物和探针的特异性也要保证适用性。     

Performance and design of shear connectors in composite beams with parallel profiled sheeting at elevated temperatures

This paper describes an extensive experimental and numerical study conducted to evaluate the thermo-structural response of shear connectors embedded in composite slabs with steel sheeting parallel to the steel beam, with particular focus on opentrapezoidal profiles. For this purpose, eight push-out tests were carried out at different levels of temperature. A threedimensional finite element model was developed in Abaqus and its accuracy was validated against the experimental measurements collected as part of this study. The model was then used to perform a parametric study to gain insight into the structural response at different temperatures. The experimental and numerical results were then used to evaluate the accuracy of available European guidelines for predicting the capacity of shear connectors at elevated temperatures (when embedded in composite slabs with the profiled sheeting parallel to the steel beam). Finally, a new design equation was proposed to calculate the degradation factor defining the resistance of shear connectors for different levels of temperature.     

逝者的仪式:柏林鲍姆舒伦韦格火葬场设计理念

本文介绍了阿克塞尔·舒尔特斯建筑设计事务所设计的柏林鲍姆舒伦韦格火葬场,介绍了设计者试图在作品中继承一种自古至今一脉相承的建筑精神的构思,以及如何通过材料与光线的对比达到建筑空间的塑造。     

The surface properties of aluminated meso–macroporous silica and its catalytic performance as hydrodesulfurization catalyst support

Aluminated mesoporous silica was prepared by multiple post-grafting of alumina onto uniform mesoporous SiO_2 ,which was assembled from monodisperse SiO_2 microspheres.Hydrodesulfurization(HDS)catalyst was prepared by loading Ni and Mo active components onto the aluminated uniform mesoporous SiO_2 ,and its HDS catalytic performance was evaluated using hydrodesulfurization of dibenzothiophene as the probe reaction at 300°C and 6.0 MPa in a tubular reactor.The samples were characterized by N_2 physisorption,scanning electronic microscopy,Fourier transform infrared spectrum,X-ray diffraction(XRD),temperature-programmed desorption of ammonia(NH_3-TPD),~(27)Al nuclear magnetic resonance(~(27)Al-NMR)and high-resolution transmission electron microscopy(HRTEM).The results showed that the Si–OH group content of SiO_2 was mainly dependent on the pretreatment conditions and had significant influence on the activity of the Ni Mo catalyst.The surface properties of the aluminated SiO_2 varied with the Al_2O_3-grafting cycles.Generally after four cycles of grafting,the aluminated SiO_2 behaved like amorphous alumina.In addition,plotting of activity of Ni Mo catalysts supported on aluminated meso–macroporous silica materials against the Al_2O_3-grafting cycle yields a volcano curve.     

通过廉价硅源制备二氧化硅微球及其粒径控制

将廉价的硅酸钠作为硅源生产二氧化硅微球有着重要的意义。以硅酸钠为硅源,聚乙二醇（PEG）为结构导向剂,在超声波辅助下,成功合成出高分散的二氧化硅微球。探索了PEG及超声波对产物形貌的影响,讨论了反应温度、pH、PEG相对分子质量与产物粒径的关系。结果表明,PEG能够引导产物成球,超声波可以提高产物的分散性,升高温度及pH会降低产物粒径,增加PEG的相对分子质量会提升产物粒径。当控制温度为40 ℃、pH为3.5、聚乙二醇相对分子质量为2 000时,所得的产品分散性较好,粒径为6.34 μm。     

Orthogonal analysis and optimization of a K4-rating auto-lifting anti-ram bollard system

The anti-ram bollard system (ABS) is installed around the perimeter of buildings and infrastructures to prevent the penetration of unauthorized vehicles and reduce the blast and debris caused by the vehicle-borne improvised explosive devices (VBIED). Comparing with the fixed anti-ram bollard system (FABS), the auto-lifting anti-ram bollard system (AABS) has the advantage to be set down automatically to allow authorized vehicles passing on. In this paper, a configuration of K4-rating AABS is proposed and a finite-element model is developed to simulate its performance. Differences between vehicle model and real vehicle, effects of boundary conditions are both taken into account. The effectiveness and accuracy of the numerical simulation are validated through predicting the results of relevant experiments. Based on the verified numerical model, 32 groups of numerical experiments of K4-rating AABS are investigated using an orthogonal array L₃₂ (4⁸×8¹). The order and significant levels of nine affecting factors are identified on the basis of the range analysis and variance analysis, respectively. It shows that gaps between substructure and outer sleeve, wall thickness of substructure, wall thickness of steel tube, diameter of steel tube and thickness of stiffening ribs have significant influences on the behavior of AABS. The optimal design is proposed according to the orthogonal analysis.     

自由表面光学系统对白光LED色温角分布的影响

基于非成像光学设计的自由表面光学系统,对提高以LED为核心的固态半导体照明的性能起着至关重要的作用。文章提出了简化模型模拟一次封装白光LED光源的色温角分布特性,并研究了自由表面光学系统对该色温角分布特性的影响。仿真与实验结果都表明,自由表面光学系统可以明显改善白光LED光源的色温角分布不均匀特性。     

新生儿缺氧缺血性脑病与血清及脑脊液葡萄糖水平变化的研究

目的研究新生儿缺氧缺血性脑病(HIE)与血清及脑脊液葡萄糖水平的变化,为HIE临床分度与治疗提供参考依据。方法对HIE患儿于急性期及恢复期各测定1次血清及脑脊液葡萄糖的含量,并以正常新生儿作为对照组。结果轻、中、重度HIE组患儿急性期血清及脑脊液葡萄糖水平分别为:(1)血清葡萄糖:(4.50±0.20);(3.80±0.21);(3.20±0.22),低于对照组:(4.80±0.25)(P值分别<0.05、0.01、0.01);(2)脑脊液葡萄糖:(4.30±0.20);(4.00±0.21);(3.50±0.20),低于对照组(4.50±0.25)(P值分别<0.05、0.01、0.01)。且临床分度愈重,血清及脑脊液葡萄糖水平降低愈明显,HIE各组间差异显著(P<0.05)。HIE各组患儿恢复期血清及脑脊液葡萄糖水平上升。结论测定HIE患儿血清及脑脊液葡萄糖含量,有助于对HIE的分度,及指导临床治疗。     

广东棉纺织业现状特点及发展趋势

总结了广东棉纺织业目前的三大特点：一是纺织产业集群优势显著,二是高新技术广泛应用,三是纺织行业成为解决“三农问题”的龙头产业。指出了广东棉纺织业“高速、自动化、智能化”、“工艺环保型”和“信息化”的三大发展趋势。并提出加快区域结构调整、拓展可持续发展空间、完善加工、信息化、品牌三大体系的建设,迎接新一轮发展机遇。     

聚合物乳胶粉水分散性影响机理的研究进展

可再分散聚合物乳胶粉是一种绿色环保、便于运输和贮存的新型粉体功能材料.介绍了可再分散聚合物乳胶粉在建筑材料中的强化作用机理,综述了母乳液功能性单体、乳液粒子结构、喷雾液预处理、保护胶体、喷雾干燥温度、雾化器转速和进料速度对聚合物乳胶粉水再分散性的影响机理,并阐述了乳胶粉研究现状及展望.