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1.
总结一次野外重大活动饮食卫生保障的针对性做法和经验,为以后遂行多样化任务提供参考。从食谱审查、从业人员卫生管理及培训、采购保管、加工制作、餐饮具消毒以及留样备检等环节严格把关,强化常态食品卫生监督;科学分析餐饮环节容易导致疫情传播的风险点,从人、物、环境和预案4个方面开展督导;针对野外食品加工及人员大规模长时间野外就餐,指导餐饮单元选址开设、做好环境卫生管理、保障加工用水及食材安全、保障运输前送环节的食品安全及人员就餐过程卫生、指导智能化餐厨设备使用。提高餐饮单位负责人及从业人员的食品安全意识;提高保障人员的卫生法律素质和专业技术能力,关注新的风险点。加强保障人员自身管理及从业人员的卫生管理,树立良好形象。  相似文献   
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为研究碳粉粒度对腰果壳油改性酚醛树脂(PF)基摩擦材料性能的影响,采用热压成型工艺制备出4种不同碳粉粒度(48,25,18,9μm)的PF基摩擦材料,分别对摩擦材料的密度、硬度、压缩强度、冲击强度、热性能和摩擦磨损性能进行了测试。结果表明,碳粉粒度越小,摩擦材料的密度和硬度越高,力学性能越好,高温下的摩擦系数越稳定,且磨损率及200℃时的热膨胀系数越小,热稳定性能越好;当碳粉粒度为9μm时,摩擦材料密度为1.725 g/cm3,洛氏硬度值为92,压缩强度为109.8 MPa,冲击强度为3.72 k J/m2,350℃下的磨损率为1.12×10–7 cm3/(N·m),200℃下的线膨胀系数为1.55×10–5/℃,失重速率最大时的温度为441.3℃,750℃质量保持率为88.6%。摩擦材料中碳粉适宜的粒径为9μm。  相似文献   
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针对氧化铝生产过程中的母液,采用碳酸化方法回收其中的金属镓进行了回收工艺试验,并对试验结果进行讨论。  相似文献   
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As a traditional soybean product with good quality and a healthy food with many functional components, tofu is increasingly consumed in people's daily life. Traditional tofu processing consists of numerous steps, including the soaking and grinding of soybean seeds, heating of the soybean slurry, filtering, and addition of coagulants, and others. The properties of soybean seeds, processing scale, soaking and heating conditions, type and concentration of coagulant, and other factors collectively impact the processing steps and the final tofu quality. The generation of whole soybean tofu with more nutritive value comparing with traditional tofu has been successfully reported by several studies. As one of the most important functional component, isoflavones and their presence in tofu are also influenced by the above-mentioned factors, which influence the nutritive value of tofu. Research investigating the influence of tofu processing conditions on the quality and isoflavone profiles of tofu are the subject of this review. Issues that should be further studied to investigate the influence of processing conditions on the quality and nutritive value of tofu are also introduced.  相似文献   
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表面增强拉曼光谱(SERS)是基于探针分子的指纹信息(分子振动、转动信息等),可应用于具有灵敏度和特异性分子结构研究的分析技术.SERS借助具有优异的等离子体性能的贵金属纳米材料作为基底,可对单组分或复杂多组分的痕量农药残留物进行分析检测.其中,柔性SERS基底具有孔隙率高、制备成本低、柔韧可折叠弯曲等特点,在复杂样品体系中提取、过滤、浓缩探针分子等应用中具有刚性SERS基底不可比拟的优势.柔性SERS基底主要是由基于生物基材料、聚合物和碳材料的3类材料来支撑和固定修饰表面提供光谱增强作用的贵金属纳米材料.重点综述了这3种类型的柔性SERS基底常用制备方法及应用,充分利用SERS的"指纹图谱"分析优势,介绍了柔性SERS基底应用于不同农药残留的最新研究进展.最后,对SERS技术发展和应用提出了亟待解决的问题.  相似文献   
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The performance prediction of wireless system over κ?μ shadowed fading channels was a challenging problem of wireless communications,which affects transmission scheme design seriously.To solve this problem,a novel method of quantifying the κ?μ shadowed fading channels performance based on nondata-aided error vector magnitude (NDA-EVM) was proposed.NDA-EVM was considered as a new metric to evaluate the change of the channels.The unified model to calculate different modulation order of NDA-EVM was analytically derived by maximum likelihood criterion.Moreover,the relationship between the κ?μ distribution and the NDA-EVM was built by using the attenuation factor of the channel as intermediate variable.Thereafter,the lower bounds of the NDA-EVM over the κ?μ shadowed fading channels were formulated,which was also simplified for various typical channels.The theoretical analysis was taken,moreover,numerical results were also conducted to verify the effectiveness of the derived formulation.It shows that NDA-EVM estimation has the lest root mean square error than data-aided signal to noise ratio (DA-SNR) estimation and error vector magnitude (DA-EVM) estimation over the κ?μ shadowed fading channels.The derived lower bounds closely match the theoretical values,especially at low SNR.In addition,the lower bounds are negatively related to all of the parameters of the κ?μ shadowed fading channels,which make it sensitive to the change of the fading channels.  相似文献   
8.
综述了甲醇制烯烃(MTO)/甲醇制丙烯(MTP)工艺技术的进展情况,介绍了烯烃分离技术,汇总了MTO/MTP的工业应用进程,并对MTO/MTP行业进行了展望。MTO/MTP工艺技术已成功地进行了商业化工业规模的应用,我国MTO工艺技术水平和产业进程已居世界前列,尤其是中国科学院大连化学物理研究所的DMTO技术和中国石化上海石油化工研究院的SMTO技术已达到世界领先水平。已经建成和正在建设以及规划筹建的MTO/MTP项目烯烃总产能将达到15.19 Mt/a,MTO/MTP装置全部建成后将占乙烯/丙烯总烯烃产能的1/4以上份额,与2012年底蒸汽热裂解装置乙烯产能16.00 Mt/a相当。今后需要进一步优化MTO/MTP催化剂的性能和烯烃分离工艺以提高烯烃的收率并降低项目工程投资和装置综合能耗。  相似文献   
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Currently, wavelet-based coding algorithms are popular for synthetic aperture radar (SAR) image compression, which is very important for reducing the cost of data storage and transmission in relatively slow channels. However, standard wavelet transform is limited by spatial isotropy of its basis functions that is not completely adapted to represent image entities like edges or textures, which means wavelet-based coding algorithms are suboptimal to image compression. In this paper, a novel tree-structured edge-directed orthogonal wavelet packet transform is proposed for SAR image compression. Inspired by the intrinsic geometric structure of images, the new transform improves the performance of standard wavelet by filtering along the regular direction first and then along the orthogonal direction with directional lifting structure. The cost function of best basis selection is designed by textural and directional information for tree-structured edge-directed orthogonal wavelet packet transform. The new transform including speckle reduction can be used to construct SAR image coder with the embedded block coding with optimal truncation for transform coefficients, and arithmetic coding for additional information. The experimental results show that the proposed approach outperforms JPEG2000 and Fast wavelet packet (FWP), both visually and item of PSNR values.  相似文献   
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Most mobile video applications are often deployed on battery-operated devices. With limited power supply, it is a challenging issue to support video applications with high resolution due to the complex functionality and high resource requirements. Thus, power-efficient design is important in computation intensive applications especially for mobile video terminals. Previous works on power-efficient control in video encoding systems focus on the low complexity design while typically ignoring the impact of scalable design by considering various power consumption involved in the encoding process. This paper is dedicated to developing a power-scalable video encoding (PSVE) strategy for energy-limited mobile terminals. PSVE can help the video encoding terminal to adjust its power consumption budget efficiently so as to enhance the power-scalable capability in mobile video terminals. This paper first establishes game theoretical analysis to model the power consumption problem as a bargaining problem. Then, the tradeoff between encoding effect and power consumption achieved by the use of game theory. The scalable and low power video encoding system based on Nash equilibrium solution is derived through the analysis on the power consumption and encoding effect. Experimental results demonstrate the efficiency of the proposed approach.  相似文献   
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