连锁餐饮企业食品安全管理体系过程验证工作研究

在借鉴食品加工企业、药品生产企业验证工作成功经验的基础上,对餐饮连锁企业过程验证工作进行研究,总结并提出了餐饮加工企业生产、加工过程人员能力的验证方法,物料的验证方法,加工、储存设备的验证方法,过程操作及控制措施的验证方法,生产、加工、储运、售卖环境的验证方法。为广大餐饮连锁企业管理人员正确运用过程验证工作指导质量及安全工作提供参考。     

钻井液处理剂溶液活度测量方法对比

室内通过吸附等温曲线法与饱和湿度法测定了钻井液处理剂溶液的活度。结果表明：两种方法均具有较好的重复性,测量结果基本一致,吸附等温曲线法需要的测试周期较长,饱和湿度法的测试周期明显缩短。     

工艺参数对电镀镍铜合金镀层成分及相结构的影响

采用由200 g/L NiSO4·6H2O、10 g/L CuSO4·5H2O、80 g/L Na3C6H5O7·2H2O、0.2 g/L C12H25SO4Na和0.5 g/L糖精钠组成的镀液,在10~60 mA/cm2、pH=2.5~5.0和25~50°C条件下电沉积制备了NiCu合金镀层。探讨了镀液pH、电流密度、温度等工艺参数对镍铜合金镀层相结构和组成的影响。结果表明,NiCu合金镀层的铜含量随电流密度或温度升高而增大。但随pH增大,镀层铜含量降低,pH小于4.0时,NiCu合金镀层中含有单质铜。     

缩醛/酮的无气味硫缩醛/酮化反应

在甲醇介质中,氯化乙酰存在下,易制备和稳定的2-（1,3-二噻）亚甲基-3-氧代丁酸作无气味代硫醇试剂能与缩醛/酮有效进行硫缩醛/酮化反应。该反应条件温和,操作简单,产率高,且反应和后处理过程中,无硫醇的恶臭气味。     

黏结剂对SnO_2/石墨烯负极材料电化学行为的影响

针对SnO2用作锂离子电池负极材料所存在的体积膨胀率高及导电性差的不足,考察了羧甲基纤维素钠(CMC)/丁苯橡胶(SBR)和聚偏氟乙烯(PVDF)黏结剂对SnO2、SnO2/石墨烯负极材料电化学性能的影响。结果表明:1)200 mA/g下经过30次充放电循环后,当以CMC/SBR作复合黏结剂时,SnO2的首次放电容量和容量保持率分别为581.3 mA·h/g和37.6%,明显高于PVDF作黏结剂时的电化学性能(135.3 mA·h/g、10.6%);2)200 mA/g下经过100次循环后,当以CMC/SBR作复合黏结剂时,SnO2/石墨烯复合负极材料的首次放电容量、容量保持率分别为702.3 mA·h/g和43.8%,也高于PVDF作黏结剂时的电化学性能(552 mA·h/g和32.8%)。     

氟代碳酸乙烯酯的合成方法综述

综述了氟代碳酸乙烯酯的制备方法。其制备方法主要有两种:一、直接氟化法:以氟气、氮气和碳酸乙烯酯为原料在高温高压条件下的一步合成法;二、卤素交换法:碳酸乙烯酯先经过氯代反应生成氯代碳酸乙烯酯,然后与氟化试剂进行卤素取代反应制备氟代碳酸乙烯酯。并重点介绍了卤素取代反应中使用不同的催化剂用来合成氟代碳酸乙烯酯。     

一种基于网格技术的多局域网资源调度模型的研究

在网格技术不断发展的今天,网格内部的资源调度成为人们关心的话题,但是传统的资源调度模型很大程度上加重了用户机器的负担,提出了一种新的调度模型,较为出色的解决了这一困难。     

Mechanical properties and morphology of thermoplastic polyurethane elastomer with pol(vinylidene fluoride) blends

A study on blends of thermoplastic polyurethane elastomer (TPU)/poly(vinylidene fluoride) (PVDF) is described. This investigation focused on the effects that PVDF has on the mechanical behaviors and morphological characteristics of the blends. Basic thermodynamic and structural considerations were applied to predict the blend miscibility. It was found that addition of PVDF disrupted the intermolecular chain interactions in TPU, resulting in lowering of mechanical properties in the blends. Our results showed that the 50/50 blend has the lowest mechanical strength. At higher levels of PVDF (<50%), the mechanical strength increased proportionally to PVDF. It was also found that both the breaking strain and the energy at break of these blends decreased with increased PVDF content. The lowering of the mechanical properties in the blends could be attributed to the formation of layered structures caused by the immiscibility of the polymers. It was concluded that TPU/PVDF blends were incompatible at all compositions. © 1996 John Wiley & Sons, Inc.     

Preparation and characteristics of polymer-based large adsorbent particles

Using polyvinyl alcohol (PVA) crosslinked with glutaric dialdehyde (c-PVA) as matrix and activated carbon (AC) or crosslinked polyacrylic acid (PAA) as the adsorptive constituent, large beads of c-PVA-AC and c-PVA-PAA composites were prepared via the sedimentation polymerization method. In this method, an aqueous solution of PVA, glutaric dialdehyde, and a catalyst for crosslinking (hydrochloric acid), containing activated carbon or the precursors of the crosslinked polyacrylic acid was injected dropwise with a syringe into hot mineral oil (about 80–90°C) located in a cylindrical reactor fit with a stirrer near its bottom. Partial gelation took place during the sedimentation process. This ensured that the particles arrived at the bottom of the column, where they were kept about 30–60 min to complete their polymerization, maintained their individuality without aggregation. The particle size was as large as about 3 mm. The adsorption characteristics of the two types of adsorbents were dependent on their AC or PAA content. Their adsorption capacity for four dyes was investigated. The c-PVA-AC and c-PVA-PAA had, at room temperature, saturation adsorption capacities as large as 84 and 104 mg/g for the basic Chrysoidin dye, and 70 and 72 mg/g for the basic Bismarck brown Y dye. © 1996 John Wiley & Sons, Inc.     

Cf/SiC复合材料表面沉积铱膜层工艺研究

为了进一步提高Cf/SiC复合材料的高温耐烧蚀性能,采用冷壁MOCVD工艺,对条型和管型Cf/SiC复合材料样品进行了金属铱膜层沉积。结果表明,在该工艺条件下,Cf/SiC复合材料的力学性能没有明显降低,沉积的金属铱膜呈白亮的金属色光泽。针对通氧沉积工艺中涂层氧含量较多的问题,通过对涂层进行后处理,使金属铱层的纯度大大提高,为获得高纯膜提供了新的工艺途径。