Influence of smoking in traditional and industrial conditions on polycyclic aromatic hydrocarbons content in dry fermented sausages (Petrovská klobása) from Serbia

The aim of this study was to determine the content of 13 polycyclic aromatic hydrocarbons (acenaphthylene, fluorene, phenanthrene, anthracene, pyrene, benz[a]anthracene, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene and benzo[ghi]perylene) from Environmental Protection Agency list (US-EPA PAHs) in traditional dry fermented sausage Petrovská klobása. Sausages, stuffed in collagen and natural casings, were smoked in traditional (A1, A2, B1 and B2 - direct smoking) and industrial (B3 and B4 - indirect smoking) conditions.The highest total content of 13 US-EPA PAHs was determined in sausages stuffed in natural casings and smoked in traditional conditions at both examined periods, at the end of drying, as well as at the end of storage period (220 μg/kg and 495 μg/kg, respectively). The lowest content of these compounds was determined in sausages stuffed in collagen casings and smoked in industrial conditions, also at both examined periods (31.3 μg/kg; 54.1 μg/kg respectively). Phenanthrene (A1-120; A2-119; B2-37.6 and B4-13.1 μg/kg) and acenaphthylene (B1-45.0 and B3-18.3 μg/kg) were the most abundant PAHs in all examined sausage samples at the end of drying period, while at the end of storage period the most abundant PAHs were phenanthrene (A1-201; A2-107; B2-49.4 and B3-38.7 μg/kg) and anthracene (B1-34.4 and B4-20.1 μg/kg). Benzo[a]pyrene, whose maximum allowed content in smoked meat products is 5 μg/kg (EC No. 1881/2006), was below the limit of detection in all examined samples. Also, PAH4 (sum content of benz[a]anthracene, chrysene, benzo[b]fluoranthene and benzo[a]pyrene) a more suitable indicator for the occurrence of PAHs, with maximum allowed content in smoked meat products of 30 μg/kg (EC No. 835/2011), was below the limit of detection in all examined samples.According to the results obtained in this study, traditional dry fermented sausage Petrovská klobása, smoked in traditional and industrial conditions was safe for its consumers regarding European regulation on PAHs content.     

基于PC系统构成的虚拟仪器技术

随着计算机和多媒体技术、仿真技术以及虚拟技术的发展,可以应用于测控领域的软件比较多,如Visual C++、Power Builder,还有更为高级的HP VEE、DT VEE、LabVIEW等。实际证明,其中美国National Instrument公司推出的LabVIEW语言是比较优秀的软件开发平台,特别适于数据采集和控制方面的开发。此平台提供了一些外挂工具如PID控制及模糊控制模块[20],与远程数据库的连接功能等,可以构成了一个完整的测控系统开发平台[,主要用于过程控制、数据采集、数据分析和数据显示等方面。NI公司提出的“Software Is the Instrument”是基于计算机软件技术的测试、控制仪器。测试仪器不再是功能单一的专用仪器,而是由基本的数据采集硬件和软件的柔性组合,与传统的测试仪器相比其智能化程度、性能价格比、可靠性及可操作性等方面都具有明显的优势。     

湖南传统戏场建筑研究

湖南位于长江中游,拥有悠久的戏曲历史和深厚的戏曲文化。特别是清代和民国时期,当地的演戏活动非常活跃,大量戏场建筑也随之兴建。这些戏场建筑是中国古代观演类建筑的重要组成部分,是中华戏曲文化的重要载体。该文在实地调查以及查阅文献资料的基础上,重点分析和研究湖南清代和民国时期戏场建筑的发展沿革、留存情况、典型实例、建筑形式、空间特征等。     

山东清代戏场建筑研究

清代时山东戏曲艺术得到蓬勃发展,演戏活动非常活跃。与之相应,作为演出场所的戏场建筑也陆续兴建。但是,由于自然损坏和人为破坏,大部分戏场建筑已被毁,现存者寥寥无几。该文根据实地调查的结果,分析了山东清代戏场建筑的基本情况,并选择现存有代表性的戏场建筑,分析了其建筑形式、空间特征、艺术成就等,最后总结了山东清代戏场建筑的主要类型和建筑特征。     

旅游开发对传统村落风貌的利弊影响——以大理市环洱海区域为例

该文以大理市环洱海区域为例,通过对参与旅游方式不同的村落的对比研究,认为在我国旅游对村落形态的影响,不能简单地用“利弊并存”来概括,而是“利大于弊”的．指出如果没有旅游,随着经济的发展,传统村落风貌的建设性破坏会更严重。     

上海清代晚期戏园研究

清道光二十三年（1843年）后,上海开放为商埠,并很快发展成为国际性商业大城市。与之相应的是,各种戏曲剧种也纷纷涌入上海,在社会生活中发挥着极为重要的影响力。随着戏曲的发展,以商业赢利为目的的戏园逐渐兴起,成为上海清代晚期最为重要的演出场所。清代晚期的上海戏园达百余座,数量居全国之首,在中国剧场史上具有重要的意义。该文根据大量文献史料以及当时的写实性画报中的形象资料,分析了上海清代晚期戏园的历史沿革、空间特征、建筑形式、观演形式等。     

心桥无止甘肃省天水市大滩村无止桥建设与实践

文章介绍了甘肃省天水市大滩村无止桥的设计及建设过程。项目在扶助贫困的同时,运用生态可持续技术为发扬地方传统文化做出有益的尝试,并藉此措建起联系内地和香港两地的“心桥”。     

Numerical Study on Bubble Formation of a Gas‐Liquid Flow in a T‐Junction Microchannel

Bubble emergence in a gas‐liquid flow in a T‐junction microchannel of 100 μm diameter, operated under a squeezing regime, was simulated with the computational fluid dynamics method. In general, bubble formation in channels includes three stages: expansion, collapse and pinching off. After analyzing and comparing quantitatively the three forces of pressure, surface tension and shear stress acting on the gas thread in the whole process, their effects in the different stages were identified. The collapse stage was the most important for bubble formation and was investigated in detail. It was found that the collapse process was mostly influenced by the liquid superficial velocity, and the rate and time of collapse can be correlated with empirical equations including the liquid superficial velocity, the capillary number and the Reynolds number.     

传统红木家具的传承与创新

我们处在一个改革开放、科学技术迅猛发展的时代,当今社会人们的生活需要和审美要求联系得越来越紧密,与明清时期相比,二者都产生了巨大的变化,这就要求传统红木家具必须在继续延传统国粹的基础上进行创新。     

Fully developed thermal behaviors for parallel flow microchannel heat exchanger

The hydrodynamics and thermal behaviors of the flow in micro-heat exchanger parallel-plate are investigated numerically. The model that combines both the continuum approach and the possibility of slip at the boundary is adopted in the study. Effects of different parameters, such as, Knudsen number (Kn), heat capacity ratio (Cr), the effectiveness (e) and number of transfer units (NTU) are investigated. It is found that both the velocity slip and the temperature jump at the walls increase with increasing Kn. On the other hand, at low values of Kn, the NTU increases with increasing Cr, but at high values of Kn the NTU decreases with increasing Cr. With regard to the effect of Cr on e, it is found that increasing Cr leads to a reduction in e and for all Kn.