食用花生油热值的测定

利用WZR-1A型精密微电脑量热计系统地测量了食用花生油的恒容燃烧热.准确称取一定量的基准物质,放入氧弹中充入高压纯氧,将测试样品在氧弹中完全燃烧,并记录燃烧前后时间与量热计温度变化数据,运用仪器所带的数据处理软件计算出仪器热容量,然后再准确称取一定量的食用花生油,装入已准确测定热值的燃烧胶囊中后,将测试数据用自编的计算机处理程序对测试数据处理,从而得到食用花生油的燃烧热值.此法准确、简便、实用,可用于日常检测工作.     

蜂蜜热值的测定

利用WZR-1A型精密微电脑量热计系统地测量了蜂蜜的恒容燃烧热.准确称取一定量的基准物质,放入氧弹中充入高压纯氧,将测试样品在氧弹中完全燃烧,并记录燃烧前后时间与量热计温度变化数据,运用仪器所带的数据处理软件计算出仪器热容量,然后再准确称取一定量的蜂蜜,装入已准确测定热值的燃烧胶囊中后,将测试数据用自编的计算机处理程序对测试数据处理,从而得到蜂蜜的燃烧热值.此法准确、简便、实用,可用于日常检测工作.     

基于定容燃烧法的快速煤质分析

在自制的定容氧弹燃烧装置上，测量了多种煤样在氧弹内燃烧期间气体压力随燃烧时间变化的关系。通过理论分析和试验研究，得出了发热量和挥发分与压力曲线的定量关系。同时，通过测量尾气中碳氧化物的含量求出煤中的碳含量。对本法的测量结果与标准方法的测量结果进行了比较。实验结果表明，通过定容燃烧法测量发热量、挥发分和碳含量是可行的。     

浅谈量热仪核心部件氧弹的改进

通过对量热仪氧弹整体结构、材料方面的改进,达到简化结构、节约生产成本、方便操作的目的,同时提高氧弹的热值测量范围和耐压能力。     

对JJG672-2001规程和GB／T213-2003标准中氧弹热量计计量性能要求上的差异的分析和建议

针对计量检定规程JJG672—2001和国家标准GB／T213-2003中对氧弹热量计的搅拌热、热容量测量重复性、热值误差、平衡点稳定性等计量性能要求上的一些差异进行分析,对如何看待以及在实际工作中如何处理这些差异提出了一些看法和建议,希望在以后的规程或标准修订中能考虑这些因素。     

氧弹燃烧-离子色谱法测定油基切削液中的卤素

建立了氧弹燃烧-离子色谱法测定油基切削液中卤素的分析方法。通过对氧弹燃烧装置条件优化,采用胶囊称取0.2g样品,充氧压力2.5 MPa,吸收液20mL,静置吸收时间20min。用离子色谱法测定吸收液中F-、Cl-、Br-的含量,结果表明,该方法定量检测限为5mg/kg^9mg/kg,在0.02mg/L^0.40mg/L线性范围良好,相关系数在0.9993~0.9996之间,精密度为3.6%~9.8%。不同浓度加标回收率在93.3%~104.0%之间,该方法快速、准确、回收率高,重复性好,能够满足对切削液质量控制的需求。     

氧弹燃烧灰化-酸碱滴定法测定腐植酸硼肥中的硼

介绍了一种用氧弹燃烧灰化技术和酸碱滴定法测定腐植酸硼肥中硼的方法.在高压、高纯氧环境中利用氧弹灰化技术对样品进行预处理,灰化产物利用碱液进行吸收,采用酸碱滴定法测定试样中硼含量.通过标准加入法进行验证,结果表明,本方法灵敏度高,重现性较好,回收率平均为97.5%,标准偏差为1.49%,可直接用于有机物中硼的测定.     

基于热值反馈系统的窑炉用天然气供应装置研究

为提高高等级玻璃制造质量,有必要对供给窑炉的天然气热值进行精确控制.利用对空气流加热的方法在线测量天然气热值,通过给燃气加入空气调整燃气热值,设计了燃气热值反馈调节系统.在系统设计时,了解热值控制系统特性,准确把握天然气指标和控制系统参数的相互作用,以及相应控制参数整定方法具有重要意义.在MATLAB/SIMULINK环境下进行了仿真研究,制定了前馈串级闭环控制策略.仿真研究结果有效指导控制系统设计,确保系统达到需要的控制精度.     

氧弹燃烧-离子色谱法测定电子产品中的卤素

本文讨论了采用氧弹燃烧-离子色谱法测定电子产品中卤素含量的前处理方法.电子产品中的卤素通过氧弹燃烧,可溶性卤素被吸收液吸收后,经离子色谱仪测定.该方法线性良好,四种离子(F-、Cl-、Br-、I-)相关系数均大于0.999,回收率范围91.2～101％.精密度(RSD,n=4)范围在0.69％～3.26％.该方法可广泛应用于电子产品的质量控制及市场商品检验.     

建筑材料燃烧热值试验问题探讨

燃烧热值试验,是GB 8624-2012中A1级、A2级建筑材料的燃烧性能分级的判定依据。本文分析了该试验最新的对应的国际标准ISO 1716:2010的技术性变更,结合日常实践,对燃烧热值试验设备规定、样品制作、试验过程、结果确认等问题进行了探讨,以规范和指导试验过程,保证试验结果的精确性和一致性。     

液相色谱串联质谱法测定谷物中二乙酸镳草镰刀菌烯醇

采用内标法，建立了液相色谱串联质谱法（LC／MS—MS）ESI＋测定谷物中的二乙酸镳草镰刀菌烯醇的方法。对比了液液革取与Micostep226、Micostep225、C185种SPE柱对样品前处理的效果，其中Micostep225SPE柱净化样品具有较好的回收率。标准工作曲线范围在0．1～100．0ng／mL之间，检出限为0．02ng／mL。对大米粉、面粉与玉米淀粉二乙酸镳草镰刀菌烯醇浓度为1．0～10．0ng／g合成样品的回收率在70．1％～82．7％之间，相对标准偏差在6．7％～9．5％之间。该方法快速、简单、灵敏度高。     

新型插杆式粮油水分传感器设计

介绍一种用于粮食、油料、油脂水分快速测定的插杆式传感器,论述了传感器的工作机理、结构和功能特点。利用这种传感器可以组成粮油水分快速测定仪和水分自动测试系统。     

气相色谱法快速测定粮谷及油籽中哒菌清残留量

采用气相色谱法对粮谷及油籽中哒菌清残留量进行测定，方法具有前处理简单、干扰因素小，对色谱系统污染小。且快速、准确、分离完全等特点。     

浅谈砝码对烘干法水分测定仪装置和测量结果的影响及不确定度评定

水分测定仪是目前实现食品、药品、谷物水分含量快速检测的唯一测量仪器。砝码是其必备的测量设备之一。根据水分测定仪的显示方式和衡量装置的不同,目前市场上的烘干法水分测定仪分为模拟显示水分测定仪和数字显示水分测定仪。本文详细阐述砝码在烘干法水分测定仪运用,进一步阐述烘干法水分测定仪测量结果不确定度评定。     

基于Pro/E的圆筒初清筛的三维建模

圆筒初清筛是粮食及饲料加工厂常用的粒料除杂设备。传统的设计方法是利用二维图形来表达三维信息,非常抽象且不便于修改。该研究利用Pro/E对圆筒初清筛各组成零件进行三维建模和虚拟装配。设计人员可以直观地观察和分析其外形、零件间的相互位置关系,且便于修改尺寸,既简化设计过程,且改善视觉效果,提高了设计效率。     

食品质地分析

质地测试是评价食品原材料及加工食品的机械物理特性的一种成熟方法,并常用于食品加工前后的质量控制。质地测试基本适用于各类食品,包括烘烤品、谷类、糖果、点心、奶制品、水果、蔬菜、凝胶、肉类、家禽、鱼类、意大利面,甚至是宠物食品。本文分别介绍了目前手动、自动化以及全程软件控制的食品质地分析测试仪器。     

An ultrastructural study of spermiogenesis in two species of Sitophilus (Coleoptera: Curculionidae).

The spermiogenesis of Sitophilus zeamais and Sitophilus oryzae, the maize and the rice weevil, respectively, was studied by light microscopy and scanning and transmission electron microscopy. Sitophilus spp. is the most widespread and destructive primary pest of stored cereals in the world. The spermiogenesis occurs within cysts. There are approximately 256 germ line cells per cyst. Inside each cysts, all the spermatids are in the same stage of maturation. The ultrastructure of the spermatozoa of S. zeamais and S. oryzae is similar to that described for other beetles. The head is formed by a three-layered acrosome with the perforatorium, the acrosomal vesicle, the extra-acrosomal layer and the nucleus. The flagellum has the typical axoneme formed by a 9+9+2 microtubules arrangement, two mitochondrial derivatives and two accessory bodies. The typical pattern for Curculionidae spermatozoa described here may provide useful information for future phylogenetic analysis of the superfamily Curculionoidea.     

Interphase chromosomes and the Rabl configuration: does genome size matter?

It is now well established that the cereals share a common gene order or gene synteny. However, the cereal species encompass an enormous range of genome size, with wheat being one of the largest and rice one of the smallest. Here we describe the current state of knowledge of interphase chromosome structure within the cereal species. In wheat and its close relatives, the interphase chromosomes adopt a highly regular Rabl configuration, with the two chromosome arms lying next to each other and the centromeres and telomeres located at opposite poles of the nuclei. By contrast, the chromosomes in most rice nuclei clearly do not show a Rabl configuration. Surprisingly, the chromosomes in the endoreduplicated xylem vessel cells of rice do adopt a Rabl configuration. To explain this observation, we propose that endoreduplication may occur immediately after chromosome segregation in these cells, and that the new chromatin interactions, particularly at the centromeres, in the endoreduplicated chromosomes may stabilize the anaphase chromosome configuration.     

Mass spectrometry in the proteome analysis of mature cereal kernels

In the last decade, the improved performance and versatility of the mass spectrometers together with the increasing availability of gene and genomic sequence database, led the mass spectrometry to become an indispensable tool for either protein and proteome analyses in cereals. Mass spectrometric works on prolamins have rapidly evolved from the determination of the molecular masses of proteins to the proteomic approaches aimed to a large‐scale protein identification and study of functional and regulatory aspects of proteins. Mass spectrometry coupled with electrophoresis, chromatographic methods, and bioinformatics tools is currently making significant contributions to a better knowledge of the composition and structure of the cereal proteins and their structure–function relationships. Results obtained using mass spectrometry, including characterization of prolamins, investigation of the gluten toxicity for coeliac patients, identification of proteins responsible of cereal allergies, determination of the protein pattern and its modification under environmental or stress effects, investigation of genetically modified varieties by proteomic approaches, are summarized here, to illustrate current trends, analytical troubles and challenges, and suggest possible future perspectives. © 2011 Wiley Periodicals, Inc. Mass Spec Rev 31:448–465, 2012     

Increase of forage dryness induces differentiated anatomical response in the sheep rumen compartments

The aim of this study was to investigate how the Surface Enlargement Factor (SEF) and the epithelial keratinization degree of sheep rumen change in response to phytomass production, and to forage fiber and water content during the pasture vegetative cycle. The study used eighteen sheep nourished with dry hay and cereals during the winter season and with fresh hay during the pasture vegetative cycle. We collected samples from rumen indicative regions for two consecutive years characterized by different rainfall and pasture productivity values. We evaluated the densities (D) of rumen papillae to estimate the rumen SEF, and the keratinization percentage of the epithelial lining; these parameters showed differentiated modifications in the four ruminal analyzed compartments in response to pasture seasonal conditions. In addition, we performed Canonical Redundancy Analysis (RDA) on the “keratinization and SEF” matrix constrained by phytomass, water, and crude fiber contents of pasture at different time in the two considered years to highlight how rumen features answer to pasture conditions. Atrium (A) and ventral sac (VS) keratinization showed a strict positive correlation to crude fiber, while SEF of VS was positively related to phytomass and forage water content. The degree of keratinization of the rumen VS epithelium proved to be a useful parameter for evaluating anatomical variations in the short term period related to pasture features; in addition, its monitoring could be carried out through biopsy, thus avoiding the killing of animals. The study also leads to the application of the 3Rs (Replacement; Reduction; and Refinement). Microsc. Res. Tech. 79:738–743, 2016. © 2016 Wiley Periodicals, Inc.