浅析发酵乳霉菌零星污染来源及控制方法

霉菌在自然环境中普遍存在,而且以孢子形态随空气、水等媒介进行扩散。对食品原辅料及生产环境均可造成污染,是造成发酵乳变质的主要原因。发酵乳作为保质期较短且需冷链储运、销售的产品,零星的霉菌污染不会引起食品安全问题,但由于部分销售终端及三四线市场冷链运输缺失,造成霉菌生长,发酵乳呈现明显霉斑,导致消费者体验差,给企业品牌造成极坏影响,也影响了食品安全。本文概述了发酵乳中来自原辅料、环境、水中霉菌零星污染来源、验证方法以及相应控制措施,以期为发酵乳中霉菌控制提供参考。     

MM5模式对阿勒泰地区2005—2008年汛期降水预报检验

利用MM5中尺度数值预报模式检验了阿勒泰地区2005—2008年汛期(5-9月)的降水预报效果。结果表明,MM5模式对阿勒泰地区区域性降水的定性预报有较好的指导意义;就该地区定量降水的预报而言,对小雨的预报准确率较高,其次是中雨和微雨,对大雨、暴雨基本无预报能力。     

Verification of identities in global cacao germplasm collections

The ex situ conservation of cacao genetic resources is in the form of field genebanks. Misidentified trees though, represent a serious problem to (i) curators, who need to capture genetic diversity, and (ii) users of germplasm material, who must be certain of the identities of the accessions for proper evaluation of their results. The presence of mislabelled trees was assessed from data compiled in the International Cocoa Germplasm Database (ICGD) 2000 v4.1CD-ROM, which contains the published records of cacao accessions in global holdings. Circumstantial evidence revealed that many germplasm collections, especially those in Brazil (CEPEC), Colombia (ICA), Costa Rica (CATIE), Côte d'Ivoire, Mexico, Malaysia, Togo, Trinidad (ICG,T) and Venezuela (EEC) probably possessed misidentified material. The severity of the problem ranged from 15–44 % and is suggested as an area for immediate resolution. Based upon the morphological data provided by the ICGD CD-ROM, several accessions were highly suspect, including 'EET 19 [ECU]', 'EET 48 [ECU]', 'EET 162 [ECU]', 'ICS 1', 'ICS 6', 'ICS 43', 'ICS 89', 'ICS 100', 'IMC 67', 'PA 121 [PER]', 'POUND 7 [POU]', 'SCA 6', 'SPA 9 [COL]', 'UF 29', 'UF 613' and 'UF 667'. However, the identification of mislabelled trees should depend ultimately on molecular analysis. Hence, the use of voucher specimens for verification is forwarded and the concept of a public domain database for microsatellite analyses of germplasm holdings is raised.     

青海气候模式解释预报产品的开发及其检验

基于1982—2016 年的气候模式数值预测产品资料,整理分析生成未来45 天北半球500 hPa 高度场和本地气温、降水资料,应用降尺度方法和PP、MOS预报工具建立了预报模型及其业务系统平台。结果表明：业务系统平台构建必须考虑系统结构和功能的先进性、数据存储传输备份的经济性、系统管理的可维护性;此外,还要兼顾前瞻性、开放性、稳定性、安全性和拓展性。系统模块编制采用前端网页、后端程序、模型—视图—控制器的模式和通用的通信协议技术。适合青海高原气候模式解释应用的降尺度方法是车氏多项式、EOF经验正交函数分解和预报量的分区。2012—2016 年青海35 个样本的月降水量、51 个样本的月平均气温预报建模试验的平均评分分别为64%和75%,预报试验获得较高评分的关键是选择最好的因子构建方案和制作预报的回归预报方法。     

关于《潜水电泵试验方法》标准中性能判定的讨论

探讨了ISO 9906和GB/T 12785标准中有关流量、扬程和效率值的判定问题。以标准中性能保证值判定为基础,分析了标准中性能满足的保证条件,提出了流量、扬程和效率判定的数学表达式,解决了计算机辅助试验中计算机判定的技术难题。同时,比较了新、旧标准优缺点。     

基于雨课堂的混合教学模式在“食品分析与检验”教学中的应用探索

“食品分析与检验”是食品专业学生的一门必修课,专业性强,传统教学采用教师单方面讲授方式,存在师生互动不充分、学生学习自主性较低等问题。雨课堂为混合式教学的一种新型工具,结合了传统教学与网络教学的优势,体现了以学生为主体、教师为主导的教学理念,利用“微信和Powerpoint”能够实现课前学生预习,课堂上师生互动、弹幕交流和课后大数据分析等功能,使教学始终在线。分析了目前“食品分析与检验”传统教学中存在的问题,并对雨课堂在“食品分析与检验”教学中的应用进行了探索,教学效果良好,为食品专业教师改进教学方式、创新教学理念提供了新思路。     

Monitoring and verification of soil carbon changes under Article 3.4 of the Kyoto Protocol

Abstract. The Marrakech Accords allow biospheric carbon sinks and sources to be included in attempts to meet emission reduction targets for the first commitment period of the Kyoto Protocol. Forest management, cropland management, grazing land management and re-vegetation are allowable activities under Article 3.4 of the Kyoto Protocol. Soil carbon sinks and sources can therefore be included under these activities. The Kyoto Protocol states that sinks and sources of carbon should be accounted for 'taking into account uncertainties, transparency in reporting, verifiability'. At its most stringent, verifiability would entail the sampling of each geo-referenced piece of land subject to an Article 3.4 activity at the beginning and end of a commitment period, using a sampling regime that gives adequate statistical power. Soil and vegetation samples and records would be archived and the data from each piece of land aggregated to produce a national figure. Separate methods would be required to deliver a second set of independent verification data. Such an undertaking at the national level would be prohibitively expensive. At its least stringent, verifiability would entail the reporting of areas under a given practice (without geo-referencing) and the use of default values for a carbon stock change for each practice, to infer a change for all areas under that practice. A definition of verifiability between these extremes would allow simple methods, such as those derived from IPCC default values for CO₂ fluxes from soil, to be used for estimating changes in soil carbon. These may enable low-level verifiability to be achieved by most parties by the beginning of the first commitment period (2008–2012).     

水稻肥料配方验证研究

[目的]为制定土壤节肥高产施肥制度和提高其生产效益提供技术指导。[方法]通过开展肥料试验,采用随机区组设计,对水稻肥料配方进行验证。[结果]配方肥处理的水稻苗数、叶面积系数、产量均高于常规施肥处理和不施肥处理;与常规施肥处理相比,配方肥处理可节本300元/hm2,增效2 520元/hm2;施用配方肥处理的土壤养分变化并不明显。[结论]N∶P2O5∶K2O施用量18∶4∶9的肥料配方符合当地水稻生长过程中的营养需求。     

紫花苜蓿品种鉴定的RAPD分子标记技术研究

试验分别以中苜一号(Medicago sativa L. cv.Zhongmu No.1)、肇东(M.sattva L. cv.Zhodong)、甘农三号(M.sativa L. cv.Gannong No.3)、公农一号(M.satzva L. cv.Gongnong No.1)紫花苜蓿品种的混合DNA(由各品种60个单株的DNA等量混合)为模板筛选RAPD特异性引物,分析比较品种鉴定的特异性谱带.结果表明:从120条随机引物中筛选出S1、S78、S89和S¨5共4条随机引物,可以通过特异性分子标记位点反映品种间的差异;另外,筛选出的RAPD标记引物对各品种60个单株DNA的测试显示品种内部存在特异性标记的单株比例较高;通过RAPD分子标记引物的筛选、标记程序的完善,确定品种特异性标记谱带,可以进行紫花苜蓿(Medicago sativa)品种的鉴定.     

茄子ISSR-PCR反应体系优化及验证

以茄子为试验材料,采用改良CTAB法提取茄子嫩叶总DNA,结合单因素设计和正交设计L9(34)的优点,探讨Mg2+、dNTP、引物及TaqDNA聚合酶等因素对茄子ISSR-PCR反应体系的影响,利用16份广西茄子主要栽培品种对最优处理组合进行验证。结果表明,在25μL反应体系中,含2.5μL10×buffer、2.0～3.0mmol·L-1Mg2+、0.32～0.36mmol·L-1dNTP、0.4μmol·L-1引物、50ng模板DNA、0.6UTaqDNA聚合酶等成分,可以获得比较稳定、清晰和丰富的条带。