免疫亲和层析净化液相色谱法检测谷物中赭曲霉毒素A

采用免疫亲和层析净化液相色谱法测定多种谷物(小麦、玉米和大米)样品中的赭曲霉毒素A。提取液提取试样中的赭曲霉毒素A,经免疫亲和柱净化后,采用高效液相色谱法荧光检测器测定,外标法定量。结果表明,不同粮食中赭曲霉毒素A在0.5~50.0ng/m L浓度范围内呈良好的线性关系,相关系数(r)0.999;样品在0.3μg/kg、5.0μg/kg和10.0μg/kg三个添加水平下的加回收率为84.4%~96.7%;方法检出限为0.3μg/kg,重复性的相对标准偏差为1.03%~3.17%。     

谷物中锗的干灰化-氢化物发生-原子荧光光谱法测定

建立一种干灰化-氢化物发生-原子荧光光谱法测定谷物中锗的方法。采用控温程序的干灰化为前处理方式,实现谷物中锗的原子荧光光谱法测定。灰化程序:第一步,200℃保持10min;第二步,500℃保持20min的条件下,称样2g的谷物样品灰化效果良好。优化仪器参数和试剂浓度条件,考察灯电流、负高压、载气、酸浓度、还原剂浓度等对锗荧光强度的影响。结果表明,锗元素浓度0～30μg/L,线性相关r为0.999,方法检出限为0.12μg/kg,方法精密度(n=7)在3.9%～5.8%,加标回收率为94.5%～104.5%。该方法操作简单、高效、稳定性良好,适用于谷物中锗的批量检测。     

河南省大豆种质资源重要性状分析

本文收集1998—2018年在河南省审定及部分适合在黄淮海南部种植的大豆新品种,共计112个。对产量、农艺性状(生育期、株高、百粒重)、蛋白质及脂肪含量、抗SMV(大豆花叶病毒病)/SCN(大豆胞囊线虫病)的情况进行统计分析。结果显示:产量变异系数10.37%,生育期变异系数3.62%,株高变异系数13.16%,百粒重变异系数13.59%,蛋白含量变异系数5.63%,脂肪变异系数6.13%,抗SC3品种(大豆花叶病毒病3号株系)占77%,抗SC7品种(大豆花叶病毒病7号株系)占58%,抗SCN品种占8.1%。本文旨在梳理近年来育成品种的特性,找出成绩与不足,为今后科学合理地开展大豆育种工作、选育优良品种提供参考。     

反应条件对面粉中多酚氧化酶活性测定的影响

目的:研究面粉中多酚氧化酶(PPO)活性测定方法。方法:在不同的料液比、反应温度、底物浓度、反应时间等测定条件下,控制pH在6.0、反应测定波长为410 nm,以邻苯二酚为底物、使用磷酸盐缓冲液、用分光光度法测定面粉中PPO活性,分析测定条件对面粉中PPO活性的影响。结果:反应料液比、底物浓度、反应时间、反应温度对面粉中PPO活性的测定有着重要影响。料液比较低时测定结果较高,误差较大;料液比大于1.0/10时测定结果较稳定。底物浓度0.12 mol/L时限制反应进行,在0.13～0.2 mol/L测定结果没有显著差异。反应时间大于15 min会影响测定结果。PPO活性测定最佳温度为35℃。     

在线固相萃取-高效液相色谱法快速测定果汁中的苯并咪唑类残留量

研究了高效液相色谱仪搭载在线固相萃取装置,对果汁样品进行在线净化并测定多菌灵、甲基硫菌灵和噻苯哒唑残留量的分析方法。果汁样品经离心后,直接进高效液相色谱仪,经萃取柱净化和富集后,采用C₁₈分析柱分离,分别用二极管阵列检测器检测和荧光检测器检测。结果表明,用二极管阵列检测器,多菌灵、甲基硫菌灵以及噻苯哒唑在0.01～2.00μg·m L^-1浓度范围内线性关系良好,检出限达到0.01μg·m L^-1;用荧光检测器,多菌灵及噻苯哒唑在0.005～2.000μg·m L^-1浓度范围内线性关系良好,检出限达到0.005μg·m L^-1。加标回收率在89.4%～106.9%,相对标准偏差在0.2%～5.4%。该方法具有简单、快速、准确度高、重复性好等优点,适用于果汁中多菌灵、甲基硫菌灵以及噻苯哒唑残留量的快速测定。     

美国大口胭脂鱼养殖技术专题讲座(五) 大口胭脂鱼人工繁殖技术——人工孵化

<正>大口胭脂鱼鱼卵的卵膜呈轴射状,厚3.5μm,膜外有绒毛,在水中绒毛长10～25μm,起黏附作用。在生产性条件下,用滑石粉和奶粉脱黏,置于8L容积的孵化器中孵化,在实验室条件下,可用黏朊酶脱黏(50mg比100mL)。一、孵化条件1.水温大口胭脂鱼的生长、发育和繁殖受水温     

高效液相色谱-串联质谱法测定植物性食品中多种有机锡化合物

样品分别经甲酸乙腈(甲酸1%)和甲酸甲醇(甲酸1%)提取,上清提取液经混合盐析试剂除水分层,上清液与水按2∶3(体积比)混合,过膜后上机检测。以0.2 g·L^-1乙酸铵水溶液(含0.1%甲酸)-0.1%甲酸乙腈为流动相,在0.3 m L·min^-1流速下梯度洗脱,采用苯基色谱柱进行液相分离,正离子模式检测,外标法定量。结果表明,在草莓、苹果、柑橘、葡萄、黄瓜5种基质中,7种有机锡化合物线性关系良好,相关系数均≥0.995;方法检出限为0.2～4μg·kg^-1,定量下限为0.5～10μg·kg^-1;在3个浓度添加水平下,7种有机锡化合物的平均回收率为68.1%～103.1%,相对标准偏差为1.00%～11.36%。该方法准确、灵敏、快捷,适用于植物源性食品中多种有机锡化合物的定量分析。     

葵花籽中水分含量测定不确定度评定

依据《食品安全国家标准食品中水分的测定》(GB 5009.3-2016)中第一法测定葵花籽中的水分。根据方法计算公式建立相应的数学模型,对葵花籽中水分的来源进行全面、细致的分析,通过对影响葵花籽中水分测定结果的4个不确定度分量μA(x)、μ(m1)、μ(m2)、μ(m3)进行量化分析,最后在实验中得出所测定葵花籽水分含量为6.82g/100g时,其扩展不确定度为0.06g/100g(k=2),进而得到了影响合成不确定度最主要的因素为μA(x),进一步保证了检测结果的准确性和稳定性。     

大棚温室内光温水气的调节方法

一、光照的调节方法要根据不同蔬菜对光强和光照时间长短的要求不同进行科学管理。喜光蔬菜有瓜类、茄果类、豆类及根菜类 ;耐弱光蔬菜有叶菜类、葱蒜类 ;喜弱光蔬菜有芥菜、食用菌等。在栽培上除了合理安排棚、室内作物布局外 ,还应采取相应调节方法。１ 提高光照强度的方法一是可用人工方法补充光照 ,在冬季或阴雨天 ,用日光灯照明 ,每平方米１００瓦 ,日光灯距苗３０ -４０厘米高 ,每天照明时间应根据蔬菜种类和天气状况而定 ,有条件的用水银荧光灯补充光照更好。二是可用反射光改善光照条件。如将温室内墙壁刷成白色 ,在温室中柱附近挂…     

超高效液相色谱-串联质谱法测定谷物和油料中10种有机磷农药残留

本文介绍了谷物和油料中甲拌磷、倍硫磷、乐果、辛硫磷、三唑磷、乙硫磷、马拉硫磷、甲基嘧啶磷、敌敌畏、毒死蜱共10种有机磷农药残留的超高效液相色谱-串联质谱(UPLC-MS/MS)测定方法。样品经乙腈提取、石墨化碳/氨基固相萃取柱净化;质谱采用电喷雾正离子源和多反应监测模式测定。结果显示,10种农药在0.1～4μg/mL范围内线性关系良好(R~20.99),方法定量限最低为0.15μg/kg,在20μg/kg、100μg/kg、400μg/kg加标水平下回收率范围为60.6%～113.2%,相对标准偏差为1.21%～14.76%。该方法灵敏度较高、准确度良好,适用于谷物和油料中有机磷农药残留的常规检测。     

The Effect of the Structural Adjustment Program on the Output,Prices and Exports of Major Agricultural Export Crops in Nigeria

The primary objective of this paper is to examine changes in the level of output, prices and exports of major export crops resulting from the Structural Adjustment Program (SAP) in Nigeria. THere two main sources of data: the Central Bank of Nigeria (CBN) through its annual reports, Economic and Financial Review, and the Nigerian Federal Office of Statistics (FOS) through its Trade Summaries. Although the SAP led to appreciable increases in output and producer prices, its effects on exports were insignificant. The implications of these for the implementation of the program are explored.     

Revealing different understandings of soil held by scientists and farmers in the context of soil protection and management

This paper aims to analyse and draw together results from similar studies in England, Switzerland and France which investigated farmers’ understanding of soil and compared it with that of scientists, researchers and advisors (collectively called scientists in this analysis). A range of methods were used across the three studies and different theoretical approaches, looking at forms of knowledge, local practice of knowledge production and conceptions of reality, were employed to explain the results. Despite the different contexts, methodologies and theoretical approaches in the three studies, the results reveal similar patterns of difference in farmer and scientist understanding of soil. In the English study, farmers demonstrate a ‘know-how’ form or intuitive working knowledge of soil while advisors rely on scientifically established forms of ‘know-why’ and seek to understand and explain soil processes. Similarly in the Swiss study farmers’ and scientists’ differing perceptions are directed and shaped by their respective aims, methods and context of work. In the French study, farmers and researchers are shown to have different conceptions of soil, they attribute different meaning to the same activities, and use different words and language to describe the same features. In all three studies understanding is shown to be cultural and contextual, as such an integrative theoretical framework is proposed.     

Towards an Integration of R & D and Marketing in Production Development

Abstract

In this paper, two approaches which are characteristic for Research & Development and Marketing departments are compared. First, R&D versus Marketing orientations are explained, then the major differences between them are presented. The integration of both approaches may improve competitive advantage of the food industry. Factors stimulating such integration are presented on the basis of data from real business circumstances. Innovation is regarded as a major source of competitive advantage of company. Therefore, integration in sensory methodology, that is commonly but differently used by R & D and Marketing departments, may contribute to the improvement of innovation practices and successful business performance. Finally, the role of consumer tests, oriented for marketing and product development, is illustrated.     

森林生物多样性评价模型的改进

针对2002年的评价模型中的不足,提出了新的改进后的森林生物多样性变化的评价模型,并在我国第六次森林资源清查(1999～2003)资料的基础上,对1973～2003年我国森林生物多样性的变化进行了补充评价。评价结果表明:我国森林生物多样性的压力越来越大,压力指数由1973年的100,上升到2003年的199.10,上升了1.99倍;森林物种多样性总体的下降趋势已有一定幅度的改变,森林物种多样性指数增加了31.12%。森林生态系统多样性和森林生物多样性先逐渐上升,尔后又下降,第六次森林资源清查时又有所恢复,并分别上升了4.67个百分点和17.90个百分点。     

Trust-A monolithic panacea in land use planning?

Although trust research has been extensive and substantial, the constitution and actual merits of trust in land use planning remain nebulous. What do participants of a local land use planning process actually mean when they say they trust the planning committee? How important is participants’ trust in the planning committee in shaping their perceptions of the planning process and their cooperation in it? To explore the everyday meaning of trust in the specific context of local land use planning, semi-structured interviews with the participants of a local planning project in Switzerland were conducted (n = 9). Based on these results, the constitution and the relevance of trust in the responsible planning committee among a wider circle of participants were assessed (n = 66). The results show that participants trust the planning committee if they perceive its members as competent, honest, open, fair, reliable, reciprocating, respectful and committed. Interestingly, a considerable part of trust in the planning committee hinges explicitly on whether the committee incorporates the personal interests of the participant. Trust is indeed vital to participants’ belief that a meaningful discussion and cooperation with the members of the planning committee is possible. However, trust is neither a guarantee for people's approval of planning decisions nor for their cooperation. One implication of the findings is that in order to evaluate trust-building practice comprehensively, it is necessary to first understand the specific everyday meaning of trust for ‘real people’ in real planning processes.     

转变地质工作发展与服务方式的实践和建议

天津市地矿局注重加快转变经济发展方式,发挥地质工作优势,推进低碳清洁能源的开发利用创新和技术进步,紧紧依托地质工作的人才、技术和行业优势,加大清洁环保资源的勘查、研究、开发、利用。针对天津市水资源缺乏的情况,积极加强后备和应紧水源勘查。按照“两种资源,两个市场”的思路,通过实施中外合作勘查项目,以境外勘查工作为载体和平台,实施引进来和走出去战略,为天津市经济社会发展提供地质技术支撑。     

Agricultural Land in Vietnam: Markets Tempered by Family, Community and Socialist Practices

Since the late 1980s, markets involving agricultural land have emerged in the Socialist Republic of Vietnam. One major reason is that collective farms, previously a central feature of the country's political economy, ended. And a major reason for that was villagers' everyday politics gnawed the underpinnings of the collectives until they collapsed. Rural households, for the most part, wanted to farm separately. Today they do. Land is not privatized, however. Farming households have land use rights, not ownership. This tempers markets, as do other conditions arising from contending schools of thought in Vietnam about how land should be used, distributed and regulated.     

Conservation agriculture (CA) in Tanzania: the case of the Mwangaza B CA farmer field school (FFS), Rhotia Village,Karatu District,Arusha

This project was initiated to promote conservation agriculture (CA) in Tanzania so as to improve the food security and rural livelihood of small- and medium-scale farmers through the scaling-up of CA as a sustainable land management (SLM) tool as well as increasing the numbers of SLM-CA farmer field schools (FFS) in communities. The project had two phases from 2004 to 2010. It was funded by a Government of Germany trust fund and implemented by the Food and Agriculture Organization of the United Nations (FAO) and the Ministry of Agriculture in Tanzania. The project pilot districts include Arumeru (Arusha and Meru Councils), Karatu, Babati, Hanang and Moshi districts. CA has been shown to offer positive elements that could contribute to fighting hunger and poverty.     

The Real of Community,the Desire for Development and the Performance of Egalitarianism in the Peruvian Andes: A Materialist–Utopian Account

The paper proposes a materialist–utopian perspective for explaining the persistence of community in the Andes by drawing upon Lacanian theory and the thought of the Peruvian Marxist José Carlos Mariátegui. What characterizes the Andean comunidad are not notions of belonging and identity, but the existence of a fundamental antagonism (what I call the ‘Real of community’). The argument unfolds ethnographically. Usibamba, a peasant comunidad in the central Peruvian Andes, is known as a highly egalitarian and disciplined comunidad. However, a disjunction exists between deep‐seated aspirations of justice and egalitarianism and the particularistic interests of families and individuals. This disjunction manifests itself in a contradictory, schizophrenic regime of discipline and negotiation that produces ‘split subjects’. Desiring development and the staging of theatrical performances of egalitarianism enables Usibambinos to deal with this disjunction and to present an image of unity and determination. I conclude that the comunidad persists through ‘impossible political acts’ brought about by a residual but growing category of landless comuneros who constitute ‘the part of no part’, the uncounted or unnamed.     

边缘旅游地开发研究——以赤峰市为例

边缘旅游地正逐渐成为旅游发展研究的热点之一;在阐述边缘旅地形成机理的基础上,分析了赤峰市旅游业边缘化的原因及表现;对边缘旅游地赤峰市的旅游业开发进行可行性分析,提出摆脱旅游业边缘化的对策和措施,强调必须紧紧依托周边京津冀辽等核心旅游地,注重区域间的优势互补,借助周围核心旅游地的优势扩大赤峰市的旅游市场,在边缘地树立大旅游观念,同时依据赤峰市自身的资源优势不断开发特色旅游产品、打造品牌,积极培养优秀的旅游人才。