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《中国渔业质量与标准》2015,(5)
参照ISO/IEC Guide98-3-2008《测量不确定度表示指南》、CNAS-GL05:2011《测量不确定度要求的实施指南》及CNAS-GL06:2006《化学分析中不确定度的评估指南》,对气相色谱法测定水产预混合饲料中肌醇含量的测量不确定度进行了评定。通过建立测量模型、分析确定水产预混合饲料中肌醇的不确定度来源,其不确定度主要来源于标准溶液、最小二乘法线性拟合曲线、定容体积、试样称量、回收率和重复测定等因素。对测量过程中的不确定度分量进行逐层分析与合成,当水产预混合饲料中肌醇含量为762 mg/kg时,得到其合成不确定度和扩展不确定度分别为81和162 mg/kg。结果表明,实验回收率、样品重复测定引入的不确定度分量对合成标准不确定度的贡献最大,样品称量引入的不确定度最小,标准曲线拟合带来的不确定度也不容忽视。本研究可为使用该方法测定水产预混合饲料中的肌醇含量的质量控制提供参考。 相似文献
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当水产品中恩诺沙星残留量接近最高残留限量时,为准确判断产品是否符合要求,开展测量不确定度评定便十分重要。基于此,本文建立了液相色谱法测定水产品中恩诺沙星残留量的不确定度分析和评定方法。依据JJF 1059.1—2012《测量不确定度评定与表示》和CNAS—GL06:2006《化学分析中不确定度的评估指南》规定的基本方法和程序,建立恩诺沙星残留量的测量不确定度数学模型,分析不确定度的来源,对主要不确定度分量进行计算和合成,最终得到扩展不确定度。当样品中恩诺沙星测量值为97.1μg/kg时,其扩展不确定度为5.6μg/kg。分析结果表明,测定结果的不确定度主要来源于样品前处理和标准溶液。 相似文献
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《中国渔业质量与标准》2015,(3)
[目的]探讨离子色谱法测定杭州湾水样中硝酸盐氮的质量浓度及测定结果的不确定度。[方法]建立离子色谱法测定水样中硝酸盐氮质量浓度的不确定度模型,分析测量不确定度来源。检测杭州湾水样中硝酸盐氮的质量浓度,确定水样测定中的不确定度。[结果]用离子色谱法测定水中硝酸盐氮的质量浓度,其不确定度主要来源于标准溶液配制、标准曲线拟合、重复测量和进样体积等4个方面,其中标准曲线拟合和重复测量引起的不确定度的主要来源,分别约占总不确定度的42%和47%。杭州湾水样中硝酸盐氮含量1.36 mg/L,其扩展不确定度为0.13 mg/L,因此硝酸盐氮含量为(1.36+0.13)mg/L。[结论]建立的不确定度分析和计算方法,适用于离子色谱法测定水中硝酸盐氮质量浓度的不确定度评估。 相似文献
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测量不确定度是判断测量结果的依据和评定测量水平的指标,现今不确定度在世界各国许多实验室和计量机构使用。中国合格评定国家认可委员会对实验室采用测量不确定度描述测量结果质量已提出明确的要求,测量不确定度在检测、校准实验室中已得到越来越广泛的重视和应用,测量不确定度在检测工作中的正确使用可以衡量实验室科学管理和检测技术的水平。通过对鱼粉中油脂酸检测的测量不确定度进行分析,找出影响不确定度的因素,对不确定度进行评定,如实反映测量的置信度和准确度。 相似文献
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不确定度是一个合理表征测量结果分散性的参数,具有广泛的应用性和实用性。不确定度的评估对实际检测工作的质量控制具有重要意义。本文研究了荧光分光光度计法测定贝类产品石油烃含量过程中所产生的不确定度。分别考虑了油标准储备液本身、储备液稀释过程、标准曲线拟合、样品的称量、皂化过程、样品的溶解及重复测定过程等各方面因素。评估了各项因子的不确定度、合成不确定度以及扩展不确定度。结果表明,在现场特定情况下,当贝类产品中石油烃的浓度为9.08mg/kg时,其相对合成不确定度为11.1%,扩展不确定度为2.02mg/kg(k=2)。贝类产品石油烃测定的不确定度主要由样品的皂化反应处理过程中的损失所致。因此减少皂化反应过程中的损失,提高皂化样品的回收率,可以有效的减少测量过程中的不确定度,从而提高检测结果的正确度。 相似文献
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气相色谱质谱法测定养殖水体中丁香酚含量不确定度评定 总被引：1，自引：0，他引：1
根据测量不确定度评定的基本程序,对本实验室研究建立的气相色谱质谱法测定养殖水体中丁香酚含量结果进行不确定度评定。分析检测过程中引入的不确定度分量,包括标准工作液、样品称量、样液定容、仪器测定、样品前处理重复性等。计算各分量结果并合成相对标准不确定度,在95%置信水平下,包含因子k=2,扩展方法不确定度。结果表明:该检测方法不确定度主要来源于样品前处理过程重复性和仪器测定。因此要确保检测结果的准确可靠,应规范操作、严控工作环境条件,增加平行检测样本数以降低检测方法不确定度。 相似文献
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《中国渔业质量与标准》2016,(4)
为验证检验机构的毛细管电泳检测能力及进行毛细管电泳检测能力比对,按照JJF 1059.1—2012《测量不确定度评定与表示》、CNAS-GL05:2011《测量不确定度要求的实施指南》及CNAS-GL06:2006《化学分析中不确定度的评估指南》,对新开发的毛细管电泳电化学发光检测鱼露中的L-羟脯氨酸含量的不确定度进行评定。不确定度来源主要有标准溶液、移取定容体积、试样重复测定、回收率和最小二乘法拟合标准曲线。结果表明,该方法中最小二乘法拟合标准曲线求试样含量引入的不确定度u_c对合成标准不确定度的贡献最大,其次为试样重复测定引入的不确定度u_(rep),而L-羟脯氨酸标准溶液配制过程中引入的不确定度u_s也不容小觑。上述3个方面应该在实验过程中加以注意,以提高实验的准确度。本研究对各个不确定度分量进行量化,得出鱼露中的L-羟脯氨酸含量为(50.44±8.80)mg/L,k=2.576。研究结果为L-羟脯氨酸含量测定新方法的质量控制提供了理论依据。 相似文献
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采用L25(56)正交试验法测定了不同pH(6、7、8、9、10)、温度(10、15、20、25、30℃)和盐度(15、20、25、30、35)对体质量为(71.2±8.5)g的单环刺螠肠蛋白酶、淀粉酶、纤维素酶和脂肪酶活力的影响,以及不同盐度对单环刺螠血液溶菌酶活力的影响。试验结果表明,单环刺螠肠消化酶活力的最适环境条件分别为,蛋白酶:pH 8、温度30℃、盐度35;淀粉酶:pH 9、温度25℃、盐度25;纤维素酶:pH6、温度30℃、盐度35;脂肪酶:pH 6、温度25℃、盐度30。盐度15和20两组单环刺螠血液溶菌酶活力均先降后升再降,而盐度30和35两组则先升后降。至处理第4d,各试验组溶菌酶活力依次为:盐度3025352015,盐度15和20两组溶菌酶活力显著低于盐度较高试验组(P0.05)。盐度25~35、pH 6~9为单环刺螠适宜的环境条件,高温(25~30℃)下其消化酶活力较高,而低盐度(15~20)下其消化酶活力和免疫能力明显降低。 相似文献
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Aquatic food security: insights into challenges and solutions from an analysis of interactions between fisheries,aquaculture, food safety,human health,fish and human welfare,economy and environment 
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下载免费PDF全文 Simon Jennings Grant D Stentiford Ana M Leocadio Keith R Jeffery Julian D Metcalfe Ioanna Katsiadaki Neil A Auchterlonie Stephen C Mangi John K Pinnegar Tim Ellis Edmund J Peeler Tiziana Luisetti Craig Baker‐Austin Mary Brown Thomas L Catchpole Fiona J Clyne Stephen R Dye Nathan J Edmonds Kieran Hyder Janette Lee David N Lees Owen C Morgan Carl M O'Brien Birgit Oidtmann Paulette E Posen Ana Ribeiro Santos Nick G H Taylor Andrew D Turner Bryony L Townhill David W Verner‐Jeffreys 《Fish and Fisheries》2016,17(4):893-938
Fisheries and aquaculture production, imports, exports and equitability of distribution determine the supply of aquatic food to people. Aquatic food security is achieved when a food supply is sufficient, safe, sustainable, shockproof and sound: sufficient, to meet needs and preferences of people; safe, to provide nutritional benefit while posing minimal health risks; sustainable, to provide food now and for future generations; shock‐proof, to provide resilience to shocks in production systems and supply chains; and sound, to meet legal and ethical standards for welfare of animals, people and environment. Here, we present an integrated assessment of these elements of the aquatic food system in the United Kingdom, a system linked to dynamic global networks of producers, processors and markets. Our assessment addresses sufficiency of supply from aquaculture, fisheries and trade; safety of supply given biological, chemical and radiation hazards; social, economic and environmental sustainability of production systems and supply chains; system resilience to social, economic and environmental shocks; welfare of fish, people and environment; and the authenticity of food. Conventionally, these aspects of the food system are not assessed collectively, so information supporting our assessment is widely dispersed. Our assessment reveals trade‐offs and challenges in the food system that are easily overlooked in sectoral analyses of fisheries, aquaculture, health, medicine, human and fish welfare, safety and environment. We highlight potential benefits of an integrated, systematic and ongoing process to assess security of the aquatic food system and to predict impacts of social, economic and environmental change on food supply and demand. 相似文献
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4种沉水植物断枝再生能力研究 总被引：1，自引：0，他引：1
比较研究了4种长江中下游湖泊常见的沉水植物(金鱼藻、伊乐藻、黑藻和穗花狐尾藻)断枝在投掷和扦插的移植方式下,生物量、株高、节数的变化及不定根和新芽形成的时间.结果表明,在试验期间,各种断枝均发生了明显的变化,除金鱼藻外,其他3种沉水植物均有不定根产生;除穗花狐尾藻外,其他3种沉水植物断枝均有新芽产生.投掷和扦插对金鱼藻断枝生物量、节数和新芽的产生无明显影响,对株高影响显著;对黑藻和伊乐藻断枝生物量、株高、节数、不定根和新芽的产生影响显著;对穗花狐尾藻断枝的生物量、株高影响显著,对节数影响不明显,而对不定根的产生有一定的影响.研究结果为退化水体的修复、恢复和重建提供了参考. 相似文献
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Salmonid fishes may reside within or migrate between stream and lake habitats, or undergo anadromous migrations between freshwater and the ocean. While the degree of anadromy of salmonids has been thoroughly compared, no analogous review has examined the degree of lake use. To assess the extent of reliance on lake habitat in this family, we considered 16 species of salmon, trout and charr from the genera Oncorhynchus, Salmo and Salvelinus, comparing their (a) use of lakes as spawning habitat, (b) rearing strategies in lakes, and (c) occurrence and diversity of lacustrine trophic polymorphism. In identifying the primary life‐history patterns of each species and exploring the lesser‐known lacustrine behaviours, we found that the extent of reliance on lakes exhibits a negative association with the degree of anadromy. Oncorhynchus rely least on lakes, Salmo to an intermediate level and Salvelinus the most, opposite of the general prevalence of anadromy among these genera. Lakes are critical to adfluvial and lake‐resident salmonids, but they also support anadromous and fluvial life histories by providing spawning, rearing, overwintering and/or summer refuge habitat. Adfluviality, although a non‐anadromous life history, consists of similar migration‐related traits and behaviours as anadromy, including the parr–smolt transformation, sex‐biased patterns of migration and residency, and the presence of precocious males. Lakes support life‐history variants, reproductive ecotypes and trophic morphs unique to lacustrine habitat. Therefore, conservation of salmonids is dependent on maintaining the diversity and quality of their habitats, including lakes. 相似文献
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采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)和荧光定量-聚合酶链式反应(Q-PCR)技术分析高体重(high weight,HW)和低体重(low weight,LW)斑点叉尾(鮰)(Ietalurus punetaus)皮肤、鳃和胃肠道菌群多样性,为斑点叉尾(鮰)微生态研究及筛选斑点叉尾(鮰)源益生菌提供理论依据.结果显示,斑点叉尾(鮰)菌群丰富度由低到高依次为鳃、皮肤、前肠、后肠和胃.肠杆菌科(Enterobacteriaceae)和气单胞菌属(Aeromonas)是皮肤的优势菌群;肠杆菌科(Enterobacteriaceae)、气单胞菌属(Aeromonas)和肠球菌属(Enterococeus)是水体、鳃和胃的优势菌群;肠杆菌科(Enterobacteriaceae)、拟杆菌属(Bacteroidetes)、气单胞菌属Aeromonas)和酵母菌属(Saccharomyces)是肠道的优势菌群.HW斑点叉尾(鮰)鳃菌群的香农多样性指数、均匀度和丰富度及前肠菌群的丰富度显著高于LW斑点叉尾(鮰)(P＜0.05).皮肤的黄杆菌属(Flavobacterium),胃的肠杆菌科(Enterobacteriaceae),前肠的拟杆菌属(Bacteroidetes)和双歧杆菌属(Bfidobacterium及后肠的拟杆菌属(Bacteroidetes)、双歧杆菌属(Bifidobacterium)和酵母菌属(Saccharo-myces)的拷贝数分别是101 97、107.69、106.19、103.83、106.13、103.92和104 26,均显著高于LW斑点叉尾(鮰)(P＜0.05).结果表明,斑点叉尾(鮰)皮肤、鳃、胃肠道均形成独特的菌群结构,LW和HW斑点叉尾(鮰)菌群结构存在明显差异,HW斑点叉尾(鮰)菌群多样性增加. 相似文献
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The status of marine biodiversity in the Eastern Central Atlantic (West and Central Africa) 下载免费PDF全文
下载免费PDF全文 Beth A. Polidoro Gina M. Ralph Kyle Strongin Michael Harvey Kent E. Carpenter Rachel Arnold Jack R. Buchanan Khairdine Mohamed Abdallahi Camara Bruce B. Collette Mia T. Comeros‐Raynal Godefroy De Bruyne Ofer Gon Antony S. Harold Heather Harwell Percival A. Hulley Tomio Iwamoto Steen W. Knudsen Jean de Dieu Lewembe Christi Linardich Kenyon C. Lindeman Vanda Monteiro Thomas Munroe Francis K.E. Nunoo Caroline M. Pollock Stuart Poss Barry Russell Catherine Sayer Aboubacar Sidibe William Smith‐Vaniz Emilie Stump Mor Sylla Luis Tito De Morais Jean‐Christophe Vié Akanbi Williams 《水产资源保护:海洋与淡水生态系统》2017,27(5):1021-1034
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水域生态牧场从水域生态学和景观生态学角度出发，高度重视生态系统的整体性和连通性，是拓展渔业空间、推动业态融合发展的重要场景。为了实现我国渔业的健康高质量发展，生态经济和数字经济将共同驱动水域生态牧场的模式创新和产业发展。本文详述了水域生态牧场建设的必要性、发展理念和应对策略，阐述了数字赋能从关键技术、无人装备和智能管理三方面助力水域生态牧场的体系化、数字化建设，提出了四场联动、陆海贯通、牧养互动和业态融合的发展模式，以期为更好地利用数字技术，科学、规范建设水域生态牧场提供参考。 相似文献
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Guanlin Ye Wucai Zhang Xiaohui Dong Beiping Tan Shuang Zhang 《Aquaculture Research》2020,51(2):584-594
The objective of the present study is to preliminarily clarify the mechanism of carbohydrates metabolism in cobia (Rachycentron canadum) (85 ± 3 g) receiving injection of glucose solution. We examined plasma glucose (GLU), total protein (TP), triglyceride (TG), cholesterol (CHOL), insulin, liver glycogen and muscle glycogen, activities of hepatic hexokinase (HK), phosphofructokinase (PFK) and pyruvate kinase (PK), as well as relative expressions of glucose transporter 1 (GLUT1), GLUT2, GLUT3, GLUT4, GLUT5 and GLUT9 in hemocyte, liver and muscle of R. canadum when fish were injected with 200 μl of glucose solution (255 mg/ml) after 0, 1, 2, 4, 8, 12, 24 and 48 hr. Fish received injection of 0.68% saline served as control. Results indicated that the plasma GLU, TG and CHOL increased and reached peak at 1, 8 and 48 hr postinjection (hpi) respectively. The hepatic glycogen increased from 1 hpi, and reached peak at 8 hpi, plasma insulin increased at 1 hpi, and reached peak at 2 hpi, and activity of hepatic PK peaked at 8 hpi. Furthermore, the relative expressions of GLUT1, GLUT2, GLUT3, GLUT4 and GLUT5 in hemocytes reached peak at 1,4, 8, 4 and 8 hpi, respectively, relative expressions of GLUT2, GLUT3, GLUT5 and GLUT9 in liver reached peak at 24, 24, 12 and 24 hpi, respectively, and relative expressions of GLUT1 and GLUT3 in muscle were significantly higher at 2 and 2–4 hpi, respectively compared with those in controls. In conclusion, low ability of utilizing glucose in R. canadum may be attributed to insufficient insulin secretion, low activities of key glycolytic enzymes (HK, PFK and PK) regulated by glucose injection and slow increase of GLUTs. 相似文献
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K. LORENZEN 《Fisheries Management and Ecology》1995,2(1):61-73
Abstract The population dynamics of culture-based fisheries are studied by means of a mathematical model, which incorporates explicit sub-models for density-dependent individual growth and size-dependent mortality. The model applies to populations of carps, i.e. common carp, Chinese carps, and Indian major carps, and coregonids.
The effects on production of stocking density and size of seed fish, fishing mortality, and size at harvesting are studied in a model population of carp. Management implications of the modelling results are emphasized. An adaptive approach to management, involving judicious experimentation with stocking and harvesting regimes, is proposed to gain information on the dynamics of actual fisheries, and to optimize their production. 相似文献
The effects on production of stocking density and size of seed fish, fishing mortality, and size at harvesting are studied in a model population of carp. Management implications of the modelling results are emphasized. An adaptive approach to management, involving judicious experimentation with stocking and harvesting regimes, is proposed to gain information on the dynamics of actual fisheries, and to optimize their production. 相似文献
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邻苯二甲酸二丁酯（dibutyl phthalate,DBP）作为增塑剂,已被中国列入优先控制的污染物名单,其对海洋生物的影响已引起人们的广泛关注。为研究邻苯二甲酸酯类化合物（phthalic acid esters,PAEs）对海洋贝类抗氧化防疫系统的影响,本文以厚壳贻贝（）为受试生物,研究了不同质量浓度DBP（0 mg/L、100 mg/L、200 mg/L、280 mg/L、360 mg/L）胁迫以及清水释放对其鳃和内脏团中抗氧化系统相关指标超氧化物歧化酶（superoxide dismutase,SOD）、过氧化氢酶（catalase,CAT）活性以及丙二醛（malondialdehyde,MDA）含量变化的情况。结果表明：厚壳贻贝鳃和内脏团SOD、CAT活性以及MDA含量呈现不完全相同的变化规律。DBP胁迫阶段,鳃和内脏团中SOD活性基本呈先诱导后抑制再诱导的趋势,CAT活性则先抑制后诱导,MDA含量基本呈不断升高趋势;清水释放阶段,鳃和内脏团中SOD活性基本呈先抑制后诱导的趋势,CAT活性基本处于诱导状态,之后内脏团CAT活性被抑制,MDA含量处于先升高,之后内脏团MDA含量出现降低的趋势,浓度-效应和时间-效应较为明显。研究表明,在DBP胁迫下,厚壳贻贝鳃和内脏团产生了氧化损伤,可诱导机体产生脂质过氧化现象,且15 d清水释放期间不足以让厚壳贻贝恢复到正常水平。本研究旨在为海洋贝类的健康养殖和风险评价提供科学依据。 相似文献