日本食品安全标准体系及其监管体制初探

日本已经建立了一套比较完善的食品安全标准体系和管理体制,其食品安全标准体系以颁布食品法律、法规为主,辅之以技术标准的制定,其管理体制是通过食品安全委员会对农林水产省和厚生安全省的食品安全管理工作进行协调。日本通过法律法规的修订、安全标准的修补、管理体制的改革,夯实了其食品安全管理的法律基础,优化了其食品安全标准框架,完善了其食品安全标准体系细则,理顺了其食品安全监管的行政体制,强化了其对食品安全的管理。     

1700mm带钢平整机的机械结构分析

本文介绍了1700mm带钢平整机的原理和机械结构,对其相关的设计参数进行了研究,分析了其机械性能,得出了其具有的特性。     

小型非球面光学元件测量技术研究

非球面光学元件应用越来越广泛,其测量技术非常关键.本文研究了小型非球面光学元件的各种面形测量方法,针对其测量原理进行了分类和对比,对其优缺点和适用范围进行了讨论,同时分析了各种测量方法实现的关键技术和面临的挑战.     

Ti(C,N)基金属陶瓷的研究进展

介绍了Ti(C,N)基金属陶瓷的晶体结构和高温力学性能,综述了其主要制备方法和研究进展,详细地分析了其冶金机理和相结构特点,并讨论了环型相的形成机理及缺点,最后指出了Ti(C,N)基金属陶瓷研究方向和提高其性能的基本途径,并认为系统考虑其相平衡、粉末冶金机制和加工工艺是制备性能优良的Ti(C,N)基金属陶瓷刀具和涂层的关键.     

隔气结构膜对真空绝热板热工性能及使用寿命的影响

真空绝热板具有良好的绝热性能,为节能目的,尤其是建筑领域,提供行之有效的热屏障,但其使用寿命成为诸多研究人员、制造商和用户最为关心的关键问题。隔气结构是维持真空绝热板内真空度的重要组成元件,其性能对真空绝热板的热工性能和使用寿命影响甚大。采用试验的方法只能在有限的时间内对其使用寿命研究,理论预测其使用寿命尤为重要。文章研究了气体和水蒸汽通过隔气结构膜渗透到板内对其等效导热系数的影响,采用数值分析的方法建立了相应数学模型,选取了三种典型隔气结构膜,测试了其相关性能参数指标,对其制得的真空绝热板,理论分析了导热系数变化规律,并对其使用寿命进行了评估。     

石墨烯基界面导热材料的研究现状

随着电子器件等对有效散热的需求日益迫切,石墨烯基界面导热材料由于其优异的热性能成为近年来研究的热点。综述了石墨烯基界面导热材料的组成成分,介绍了其热导率的预测模型和测定方法。并且了结合热导率模型,分析了填料本质导热性,填料添加量及其在基体中的分布,界面耦合强度等因素对其导热性的影响。最后,对其今后的研究和发展进行了分析和展望。     

表面改性处理对ZnO电化学性能的影响

将ZnO浸泡在镁和钙的醋酸盐溶液中,通过蒸发、高温等处理得到了表面改性的ZnO样品.采用XRD、SEM对其结构和形貌进行了表征,同时用恒电流充放电等技术研究了其充放电特性和循环稳定性.实验结果表明:通过对氧化锌进行表面改性处理,改进了其电化学性能,并提高了其电化学循环稳定性.     

纸质家具及其未来发展

文章阐述了发展纸质家具不仅可以节约木材资源、稳定家具市场,亦能够降低消费成本、提高人民生活质量.纸质家具相对于其它材料的家具而言,具有其自身的优点和不足,本文对其优点进行了概括和阐述,也针对其不足提出了自己的观点和建议,亦即其未来的发展方向.     

遥控多轴航拍器的使用及其效果

文章介绍遥控多轴航拍器,对其原理、结构、特点等进行了讨论,同时对其优缺点和使用其进行航拍所要注意的事项进行了总结,对其使用效果、使用领域和广阔前景也作了说明。     

浅谈无人值守变电站设备巡视与维护

无人值守变电站设备在运行过程中由于没有设置管理和维护人员,主要是利用远程监控系统对其运行状态进行监测,所以为了确保其正常运行,就必须加强对其的巡视和维护工作的开展。本文正是基于这一背景,首先分析了加强对其巡视和维护的必要性;其次就如何做好巡视和维护工作提出了几点浅见;最后对全文进行了简单的总结。旨在与同行进行业务之间的交流,以不断强化其运行的高效性。     

Advanced Photoacoustic Imaging Applications of Near‐Infrared Absorbing Organic Nanoparticles

Progress of nanotechnology in recent years has stimulated fast development of nanoparticles in biomedical research. Photoacoustic (PA) imaging as an emerging non‐invasive technique in molecular imaging has improved imaging depth relative to conventional optical imaging, demonstrating great potential in clinical applications. The convergence of nanotechnology and PA imaging has enabled a broad spectrum of new opportunities in fundamental biology and translation medicine. This review focuses on the recent advances of organic nanoparticles in PA imaging applications. Near‐infrared absorbing organic nanoparticles are classified and discussed according to their different imaging applications, which include tumor imaging, gastrointestinal imaging, sentinel lymph node imaging, disease microenvironment imaging and real‐time drug imaging. The chemistry and PA properties of organic nanoparticles are discussed in details to highlight their own merits, and their challenges and perspectives in PA imaging are also discussed.     

可逆性热敏成像材料

本文全面扼要地介绍了可逆性透明／不透明的热敏成像材料和可逆性消色／生色的热变色成材料的发展情况,阐明其工作过程和成像机理,叙述了其生产 主要原材料性能,摘录了若干制备配方及其优异的特性。     

浅谈传统照相机与数码照相机的差异和共性

本文在研究传统成像系统和数码成像系统的共性和个性的基础上，将数码照相机与传统照相机独有的部件与功能以及两者相近部件与功能列表对比，并加以说明，以简明扼要的方式，表明两者的差异与共性，便于全面理解这两种成像系统的相关知识，对于原来熟悉传统成像技术的专业人员，充分运用原有的理论和实践知识，开展数码成像工作，尤其有帮助。     

计算机X线摄影（CR）系统使用的两种非银成像材料

本文简要地介绍了CR系统的特点,较系统地叙述了应用于CR系统的两种非银成像材料－IR成像板和医用干式影像胶片,分别介绍了它们的结构,成像原理,持性和应用方法。     

分子影像学研究的进展和前景

医学影像学历经百年,终于从解剖结构为成像基础的传统医学影像学发展到了建立在一细胞、分子结构和功能为基础的分子影像学时代,这代表了医学影像学的未来,将对现代和未来医学模式产生划时代的影响。本文扼要介绍近年来世界各国在分子影像学研究方面取得的丰硕成果和展望其在未来的光辉发展前景。     

Range-Doppler imaging

We review various narrow-band range-Doppler imaging methods that have been proposed for radar and highlight the difficulties in their implementation and their limitations. We also present two new imaging schemes. The first involves the transmission of multiplexed chirps, and the second involves simple frequency division multiplexing. The second approach seems to yield the most promising range-Doppler imaging methods.     

Photoacoustic Imaging: Contrast Agents and Their Biomedical Applications

Photoacoustic (PA) imaging as a fast‐developing imaging technique has great potential in biomedical and clinical applications. It is a noninvasive imaging modality that depends on the light‐absorption coefficient of the imaged tissue and the injected PA‐imaging contrast agents. Furthermore, PA imaging provides superb contrast, super spatial resolution, and high penetrability and sensitivity to tissue functional characteristics by detecting the acoustic wave to construct PA images. In recent years, a series of PA‐imaging contrast agents are developed to improve the PA‐imaging performance in biomedical applications. Here, recent progress of PA contrast agents and their biomedical applications are outlined. PA contrast agents are classified according to their components and function, and gold nanocrystals, gold‐nanocrystal assembly, transition‐metal chalcogenides/MXene‐based nanomaterials, carbon‐based nanomaterials, other inorganic imaging agents, small organic molecules, semiconducting polymer nanoparticles, and nonlinear PA‐imaging contrast agents are discussed. The applications of PA contrast agents as biosensors (in the sensing of metal ions, pH, enzymes, temperature, hypoxia, reactive oxygen species, and reactive nitrogen species) and in bioimaging (lymph nodes, vasculature, tumors, and brain tissue) are discussed in detail. Finally, an outlook on the future research and investigation of PA‐imaging contrast agents and their significance in biomedical research is presented.     

医用X线成像系统的数字化进展

医学影像技术是医学放射诊断学中最活跃的研究领域之一,而X线成像技术是医学成像的主要技术。文中介绍了医用X线成像系统由传统的成像方式向着数字化方向发展的过程中先后出现的CR、DR成像系统及其优缺点,着重论述了CR成像系统的改进和DR成像系统的关键部件-X射线探测器的种类并预测了X线成像系统的发展趋势。     

Analytic evaluation of sampled aperture ultrasonic imagingtechniques for NDE

This paper presents a theoretical comparison of three generic sampled aperture ultrasonic imaging systems for nondestructive evaluation. The imaging systems are categorized according to their source-receiver combination for data acquisition: common-source, back-scatter, and full-array imaging. First, forward modeling is performed for a point source and a point receiver. This is then used to model the received data set for each of the imaging categories. Subsequently, the inversion algorithm for each category is derived, and their performance is evaluated in terms of resolution, noise, and computation. We show that in terms of resolution, back-scatter imaging is the best, followed by full-array and common-source imaging. However, in terms of material noise, full-array imaging is the best, with back-scatter and common-source imaging having the same material noise response. Full-array imaging is the only system with inherent redundancy to reduce electronic noise, but at the expense of significantly more computation. The physical transducer is in the full-array category, allowing mechanical scanning to be traded for dynamic focusing and computational power     

Design,Properties, and In Vivo Behavior of Super­paramagnetic Persistent Luminescence Nanohybrids

With the fast development of noninvasive diagnosis, the design of multimodal imaging probes has become a promising challenge. If many monofunctional nanocarriers have already proven their efficiency, only few multifunctional nanoprobes have been able to combine the advantages of diverse imaging modalities. An innovative nanoprobe called mesoporous persistent luminescence magnetic nanohybrids (MPNHs) is described that shows both optical and magnetic resonance imaging (MRI) properties intended for in vivo multimodal imaging in small animals. MPNHs are based on the assembly of chromium‐doped zinc gallate oxide and ultrasmall superparamagnetic iron oxide nanoparticles embedded in a mesoporous silica shell. MPNHs combine the optical advantages of persistent luminescence, such as real time imaging with highly sensitive and photostable detection, and MRI negative contrast properties that ensure in vivo imaging with rather high spatial resolution. In addition to their imaging capabilities, these MPNHs can be motioned in vitro with a magnet, which opens multiple perspectives in magnetic vectorization and cell therapy research.