防辐射孕妇服电磁防护性能的测试与仿真

在分析防辐射孕妇服的基础上,通过实验测得2件防辐射孕妇马甲的电磁防护性能,并且根据实验条件利用三维电磁仿真软件Ansoft HFSS建立测试仿真模型,获得服装的屏蔽效能.利用该仿真模型分析了孕妇不同孕期体型变化对服装电磁防护性能的影响.研究结果表明,服装电磁屏蔽效能测试模型的仿真结果与实际测定结果比较一致,该模型能够用...     

防电磁辐射服装的屏蔽效能

文章对不同款式的防电磁辐射服装进行效能测试和评估。在防电磁辐射服装屏蔽电磁波的机制基础上,设计了相应的模拟实验。分析辐射源、辐射距离、防电磁辐射面料、服装加工缝隙和服装上孔洞的大小对服装防辐射性能的影响,以这些因素为变量建立了服装屏蔽效能的数学模型,并对这个模型进行了稳定性和实用性的验证。验证结果表明:所建立的数学模型用于实际计算服装的屏蔽效能是可行的。     

防电磁辐射纺织品及测试标准和方法的探讨

介绍了电磁辐射及防电磁辐射作用机理,分析了电磁辐射对人体影响,探讨了常见抗电磁辐射织物品种和优缺点,并对防电磁辐射纺织品测试标准和方法进行综述。文章表明,新型防辐射纤维增强屏蔽效果以及采用新型纳米材料技术应用于防电磁辐射领域将成为未来发展的方向。对防电磁辐射服装屏蔽效能的评价方式和考核指标进行统一有利于未来消费者选购防辐射服装和评价防电磁辐射性能好坏。文章对于人们了解防辐射纺织品和对防辐射纺织品的后续研究有现实意义。     

防电磁辐射服装暴露面积对其屏蔽效能的影响

由于防电磁辐射面料制成服装后的屏蔽效能会因款式和暴露面积有所下降,研究服装暴露面积对屏蔽效能的影响可以为防电磁辐射类服装的研发提供参考。利用依据“开窗法”原理自行研制的独特防电磁辐射服装屏蔽效能测试系统,对不同款式的防电磁辐射服装进行效能测试和评估。结果表明：电磁屏蔽服装的屏蔽效能与服装款式和面料屏蔽效能这2个因素直接相关;在面料屏蔽效能相同的条件下,服装款式对防电磁辐射服装的屏蔽效能影响很大;西装类等暴露面积较大的屏蔽服装其屏蔽效能不佳,暴露面积过大的屏蔽服装几乎没有屏蔽效果。     

两种防辐射面料的性能研究

使用有效的防护材料可以显著降低电磁辐射对人体的伤害。通过模拟试验对防电磁辐射织物——镀银纤维面料和金属纤维面料的屏蔽效能进行测试分析比较。研究结果显示:屏蔽效能与辐射频率密切相关;当频率较大时,防辐射性能较好;信号接收距离和反射距离越近,屏蔽效能越佳。     

防电磁辐射服装的屏蔽效能数学模型

在防电磁辐射服装屏蔽电磁波的机制基础上,设计了相应的模拟实验,分析辐射源、辐射距离、防电磁辐射面料、服装加工缝隙和服装上孔洞的大小对服装防辐射性能的影响。并就这些因素对服装整体屏蔽效能的影响显著性进行了检验,最后以这些因素为变量建立了服装屏蔽效能的数学模型,并对这个模型进行了稳定性和实用性的验证。验证结果表明,所建立的数学模型用于实际计算服装的屏蔽效能是可行的。     

防电磁辐射毛服装屏蔽效能的研究

从电磁辐射的屏蔽机理入手,详细论述和分析了开发和设计防电磁辐射毛服装时,主要有辐射源、辐射源距离、防辐射毛服装的面料选择以及服装结构设计等因素对屏蔽效能的影响,并针对性地提出设计和开发防电磁辐射毛服装的重点.     

民用防电磁辐射服装的开发及屏蔽效能评价

本文结合国内外最新防电磁辐射服装开发现状,依据面料的屏蔽原理和服装款式对各类防电磁辐射服装屏蔽效能进行了分类研究,最终根据屏蔽效能将防电磁辐射服装分为A、B、C、D四级防护服装。     

防电磁辐射服装的防护机理

从电磁波的物理性能入手,详细论述了防电磁辐射服装屏蔽电磁波的基本原理,包括防电磁辐射服装中防辐射纤维、织物等屏蔽电磁波的机理.同时结合人体特征和服装结构特点,介绍了防电磁辐射服装结构设计及影响防电磁辐射效果的一些主要因素.     

影响防电磁辐射针织服装屏蔽效能的因素研究

简述了电磁辐射的产生及其对人体的危害,分析了在开发和设计防电磁辐射针织服装中影响其屏蔽效能的一些主要因素:包括如电磁辐射源、辐射源与服装之间的距离、服装的面料、服装的结构设计等.     

ICP/MS and ICP/AES elemental analysis (38 elements) of edible wild mushrooms growing in Poland

Thirty-eight elements, including toxic cadmium, lead, mercury, silver and thallium, were determined in 18 species of wild edible mushrooms collected from several sites in Pomorskie Voivodeship in northern Poland in 1994. Elements were determined by double focused high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES), after wet digestion of the dried samples with concentrated nitric acid in closed PTFE vessels using a microwave oven. K, P and Mg were present at levels of mg/g dry matter; Na, Zn, Ca, Fe, Cu, Mn, Rb, Ag, Cd, Hg, Pb, Cs, Sr, Al and Si were present at µg/g levels, while Tl, In, Bi, Th, U, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, La, Lu and Ba were present at ng/g levels.     

茶叶加工中品质关键组分的变化与调控机制

茶树起源于中国,茶叶是世界三大饮品之一.茶叶中富含茶多酚、蛋白质及氨基酸、生物碱、芳香族化合物、糖类、类脂化合物、维生素、无机物、叶绿素、酶等多种化合物.它们经过非发酵、微发酵、半发酵、全发酵及后发酵工艺,萎凋、杀青、揉捻、发酵、干燥等处理后,由于温度、压力、酶及微生物的作用,儿茶素在多酚氧化酶、过氧化物酶等的氧化聚合下分别形成茶黄素、茶红素、茶褐素等茶色素;β-D-糖苷类等香气前驱体在β-葡萄糖苷酶、β-樱草糖苷酶的作用下水解生成相应的醇类等香气物质;蛋白质水解成氨基酸,并形成不同的手性对映体,所以赋予茶叶特有的颜色、香气、滋味、外形以及其抑菌、抗病毒、抗氧化、防衰老、增强机体免疫、防癌抗癌、预防心脑血管疾病等功效,进而形成绿茶、白茶、黄茶、青茶、红茶、黑茶六大茶系.本文从茶叶成品色、香、味等关键组分入手,阐述其在加工过程中的变化规律和关键技术调控的相关性及存在问题,并探讨它们的形成机理,为提高茶叶品质提供理论依据.     

Post-Harvest Processing and Utilization of Sweet Potato: A Review

ABSTRACT

Sweet potato is a major root crop utilized widely for diverse food applications. Processing enables the usability of sweet potato in various forms for longer durations. Post-harvest processing of sweet potato involves grading and sorting, cleaning, peeling, drying or secondary processing and storage. Commercial utility of sweet potato is comprised of conventional and composite ingredient-based foods, starch, and industrial products. This review outlines the post-harvest processing practices and utilization of sweet potato. The present status of the sweet potato industry, processes, products, and machines, have been featured. In addition, challenging issues in the small-scale processing of sweet potato are discussed.

Abbreviations: %: percentage, °C: degree Celsius, cm: centimeter, cv: Cultivar, e.g: example, g: gram, h: hour, Hg: Mercury, Hz: hertz, kg: kilogram, kGy: kilo gray, kPa: kilopascal, kV: kilovolt, L: liter, LDL-C: Low-density lipoprotein Cholesterol, m: meter, MAP: Modified Atmosphere Package, MHz: Megahertz, min: minute, mm: millimeter, mol: mole, MPa: Mega Pascal, MW: Megawatt, NaOH: Sodium hydroxide, nm: nanometer, Pa: Pascal, RH: Relative Humidity, rpm: revolutions per minute, s: second, sp: Species, t: metric ton, USA: United States of America, USDA: United States Department of Agriculture, v: volume, w: weight     

Toxic and trace elements in liver, kidney and meat from cattle slaughtered in Galicia (NW Spain)

The aims of this study were to determine the levels of some toxic and trace metals in cattle meat in Spain and to compare them with concentrations in cattle elsewhere and to maximum acceptable levels. Arsenic, cadmium, lead, copper and zinc concentrations in the liver, kidney and muscle (meat) from 438 calves (6-10 months old) and 56 cows (2-16 years old) slaughtered in Galicia (NW Spain) in 1996 were quantified. The arithmetic mean fresh weight concentrations in calf liver, kidney and muscle respectively were 0.043, 0.055, 0.004mg/kg for arsenic, 0.032, 0.070, 0.001 mg/kg for cadmium, 0.053, 0.052, 0.009 mg/kg for lead, 64.6, 4.91, 0.677mg/kg for copper and 47.7, 14.4, 47.8mg/kg for zinc. In cows, these concentrations were 0.046, 0.068, 0.005mg/kg (arsenic), 0.097, 0.458, 0.001mg/kg (cadmium), 0.057, 0.066, 0.017mg/kg (lead), 60.3, 3.67, 1.26 mg/kg (copper) and 59.8, 20.0, 52.7mg/kg (zinc). Except for copper levels in the liver which were high, metal concentrations in cattle were generally low in Galicia and broadly similar to those in the rest of Europe, Australia and Canada. Arsenic, cadmium and lead concentrations in Galician cattle rarely exceeded acceptable maximum concentrations that have been adopted by many countries. Copper and zinc concentrations in Galician cattle did exceed acceptable maximum concentrations but the frequency with which this occurred depended upon which acceptable maximum concentration was used; regulatory values differ markedly between countries.     

Applications of emerging imaging techniques for meat quality and safety detection and evaluation: A review

With improvement in people's living standards, many people nowadays pay more attention to quality and safety of meat. However, traditional methods for meat quality and safety detection and evaluation, such as manual inspection, mechanical methods, and chemical methods, are tedious, time-consuming, and destructive, which cannot meet the requirements of modern meat industry. Therefore, seeking out rapid, non-destructive, and accurate inspection techniques is important for the meat industry. In recent years, a number of novel and noninvasive imaging techniques, such as optical imaging, ultrasound imaging, tomographic imaging, thermal imaging, and odor imaging, have emerged and shown great potential in quality and safety assessment. In this paper, a detailed overview of advanced applications of these emerging imaging techniques for quality and safety assessment of different types of meat (pork, beef, lamb, chicken, and fish) is presented. In addition, advantages and disadvantages of each imaging technique are also summarized. Finally, future trends for these emerging imaging techniques are discussed, including integration of multiple imaging techniques, cost reduction, and developing powerful image-processing algorithms.     

海洋生物苷肽天然铁调味汁与市售铁强化酱油的铁吸收率试验及铁高吸收率结果的机理探究

由扇贝、海带生产的海洋生物营养均衡[1]、含天然铁的调味汁,富含磺酸岩藻糖苷多肽聚合物(简称"苷肽")、扇贝多肽、牛磺酸、精氨酸、赖氨酸、硒、锰、钙、锌、镁、碘、钾、铜、钴和VA、Vc、VB12等维生素族群、以及20余种海洋生物氨基酸等营养元素.铁缺乏和缺铁性贫血是我国普遍存在的营养问题.目前市场上的铁酱油主要靠添加NaFeEDTA形成含铁酱油,其主要缺点有:肠胃不良反应、吸收率不高、口感不佳等等.就海洋生物调味汁与天然铁、均衡营养和特殊因子相结合,形成铁吸收速度较快,在血内存留时间较长的试验结果和原理做出了阐述.     

蒽醌助剂对乙二醇溶剂脱胶苎麻纤维性能的影响

为解决苎麻在乙二醇有机溶剂脱胶中纤维易被氧化而导致性能下降的问题,在乙二醇溶剂中添加助剂蒽醌对苎麻进行脱胶,并对蒽醌不同添加量下制得的纤维进行结构和性能表征。结果表明:纤维中半纤维素含量随蒽醌添加量的增加而升高,纤维的聚合度、结晶度、物理力学性能先升高后降低,纤维的残胶率和线密度先降低后升高;当蒽醌质量分数为0.3% 时,这些性能均达到最佳值,此时纤维的聚合度、结晶度、制成率、断裂强度、断裂伸长率、断裂功比不加蒽醌时分别提高了7.32%、20.53%、1.46%、9.55%、6.89%、33.33%,纤维的残胶率、线密度比不加蒽醌时分别降低了17.91%、7.24%。     

Quality attributes and their relations in fresh black ripe ‘Kalamon’ olives (Olea europaea L.) for table use – phenolic compounds and total antioxidant capacity

Quality attributes were investigated in fresh Greek black table ‘Kalamon’ olives prior to processing. Fruit weight, dimensions, respiration and ethylene production rates, firmness, peel colour, moisture, oil content, total antioxidant capacity (TAC), the concentration of total phenolics (TP) and phenolic compounds (hydroxytyrosol, oleuropein, tyrosol, verbascoside, luteolin‐7‐O‐glucoside, luteolin, rutin) were determined in olives from different orchards. There was a significant effect of orchard on most attributes, but not on fruit firmness. Verbascoside, oleuropein and hydroxytyrosol were the major phenolics, and the presence of verbascoside in ‘Kalamon’ olives is revealed for the first time. Positive correlations were found among fruit weight, dimensions, respiration and ethylene. TAC was positively related mainly to TP, hydroxytyrosol, verbascoside and rutin, but inversely to oleuropein. Luteolin was inversely related to luteolin‐7‐O‐glucoside. Colour darkening was directly related to TAC, while colour parameters were positively and moderately affected by oil and moisture.     

Daily intake of trace metals through coffee consumption in India

The trace element contents of five varieties of instant coffee powder available in the Indian market have been analysed. Ca, Cr, Fe, K, Mg, Mn, Ni, Sr, Zn and Pb, Cd, Cu have been determined using atomic absorption spectrophotometry and differential pulse anodic stripping voltammetry, respectively. The metal levels in the coffee powders observed in this study are comparable with those reported for green coffee beans (Arabica and Robusta variety) reported worldwide with the exception of Sr and Zn, which were on the lower side of the reported values. Concentrations of these metals have been converted into intake figures based on coffee consumption. The daily intakes of the above metals through ingestion of coffee are 1.4mg, 1.58 mu g, 124 mu g, 41.5mg, 4.9mg, 17.9 mu g, 2.9 mu g, 3.8 mu g, 12.5 mu g, 0.2 mu g, 0.03 mu g and 15.5 mu g, respectively. The values, which were compared with the total dietary intake of metals through ingestion by the Mumbai population, indicate that the contribution from coffee is less than or around 1% for most of the elements except for Cr and Ni which are around 3% .     

采前喷施壳聚糖复合膜对猕猴桃软腐病的防控及其保鲜作用

以‘贵长’猕猴桃为试材,通过病原菌分离、致病性测定和DNA测序鉴定了修文县猕猴桃软腐病病原菌,并选用壳聚糖、钙盐和糊精分别与茶多酚、甘氨酸、柠檬酸、抗菌肽混合制备和筛选了复合膜剂,研究了采前幼果期和壮果末期果面喷施壳聚糖复合膜对猕猴桃软腐病的防控及其保鲜作用。结果表明,修文县猕猴桃软腐病病原菌为葡萄座腔菌（Botryosphaeria dothidea）和拟茎点霉菌（Phomopsis sp.）;采前喷施不同壳聚糖复合膜对其软腐病的防效均达60%以上（添加茶多酚防效86.54%、甘氨酸防效61.54%、柠檬酸防效71.15%、抗菌肽防效69.23%）,显著降低丙二醛（MDA）积累,提高果实的超氧化物歧化酶（SOD）、过氧化氢酶（CAT）和过氧化物酶（POD）活性,诱导增强果实的抗病性。同时,该复合膜能有效地增加果实单果质量和体积,显著提高果实VC、可溶性固形物、可溶性总糖、可滴定酸、叶绿素和蛋白质的含量,促进猕猴桃产量的增加和品质的改善。此外,施用该复合膜还能有效提高和维持果实硬度、降低果实呼吸强度以及果实质量损失率和营养物质的损失,明显抑制果实可溶性固形物和可溶性总糖含量的上升速率和延缓组织的衰老软化,从而提高了猕猴桃耐贮性。研究结果为猕猴桃优质栽培、病害有机防控和果实绿色保鲜提供了科学依据和新途径。