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51.
52.
高标准农田建设的冷思考 总被引:1,自引:0,他引:1
高标准农田建设是发展现代农业、从根本上提高粮食生产保障水平的重大前举措。各地在政策配套、资金保障、体制运行上已经进行了深入的研究和推进,已然产生了一批丰硕的成果和丰富的实践经验。但就农业综合开发而言,在思想观念、建设模式、推进机制上均未完全作出适应性调整。对此,我们应保持高度的警醒,及早作出谋划,制定出适应高标准农田建设内在规律的方案和模式并加以推进,才能确保其建设过程的科学和顺畅.也才能防止在造势上轰轰烈烈,在实际成效上却与中低产田改造并无二致的局面出现。 相似文献
53.
利用世界动物卫生组织(OIE)推荐的4对引物(389F/R、392F/R、77012F/77353R 和309F/R),通过普通 PCR 方法,对本实验室2011?2012年采集于国内不同地区的对虾样品进行 IHHNV(Infectious hypodermal and hematopoietic necrosis virus)检测,并对国内存在的 IHHNV 检出类型进行初步分析。检测结果显示,在凡纳滨对虾、斑节对虾、中国对虾、宽沟对虾中均检测出了 IHHNV,而在脊尾白对虾中未检出。其中凡纳滨对虾阳性率最高,中国对虾阳性检测率最低。对虾样品2011年阳性率高于2012年,华东地区高于华北、华南两地。此外,根据4对引物的检测结果,得到国内 IHHNV 的4种 PCR 检出类型。 相似文献
54.
目标:建立离子色谱-抑制电导检测法测定化学对照品中酒石酸盐的含量。方法:以酒石酸沃尼妙林对照品为例,采用DIONEX IonPac AS19(250 mm×4 mm)阴离子交换色谱柱和Ion Pac AS19保护柱(50 mm×4.0 mm),以22 mmol.L-1氢氧化钾溶液为流动相,流速为1.0 mL.min-1等度洗脱,抑制电导检测器检测,测定酒石酸盐中酒石酸的含量。结果:该方法在1.0~50 μg.mL-1浓度范围内线性关系良好(r=0.999),定量限为0.5μg.mL-1,酒石酸沃尼妙林在3个水平的加样回收率分别为98.79%、98.91%与96.50%,平均回收率为98.07% (RSD=2.20%,n=9)。用此方法测定3个厂家共5批样品,酒石酸沃尼妙林中酒石酸含量的数值与理论值基本一致。结论:本文建立的离子色谱法准确、灵敏,可用于酒石酸盐成盐比例与含量的测定。 相似文献
55.
Following rapid social and economic development over the past several decades, soil pollution by heavy metals (HMs) has been both serious and widespread in China. The Soil Environmental Quality Standards (SEQSs) in China (GB 15618-1995) have been introduced to encourage and enforce sustainable soil HM management. However, in recent years, HM contents in soils have frequently been found to exceed their associated standard values, while the crops growing on them might still meet regulatory standards, and vice versa. There is thus growing awareness that GB 15618-1995 does not effectively regulate current soil HM pollution, as it has encountered bottlenecks, and disappointing outcomes caused by poor execution along with deficiencies and gaps in the policies. However, due to the deficiency of scientific research about relationships between soil HM concentrations and their ecological or human health effects, the development of SEQSs in China is still greatly restricted. This paper discusses international SEQSs of HMs as well their development in China over time, then examines current Chinese SEQSs to demonstrate their potential regulatory deficiencies by referring to international SEQSs. The corresponding legislative policies are described, and scientific information or responses are outlined for maintaining soil environmental quality. China's experience has shown that policy and science can be linked to work in tandem to better understand and manage soil quality issues. 相似文献
56.
Design standards for experimental and field studies to evaluate diagnostic accuracy of tests for infectious diseases in aquatic animals 下载免费PDF全文
E Laurin K K Thakur I A Gardner P Hick N J G Moody M S J Crane I Ernst 《Journal of fish diseases》2018,41(5):729-749
Design and reporting quality of diagnostic accuracy studies (DAS) are important metrics for assessing utility of tests used in animal and human health. Following standards for designing DAS will assist in appropriate test selection for specific testing purposes and minimize the risk of reporting biased sensitivity and specificity estimates. To examine the benefits of recommending standards, design information from published DAS literature was assessed for 10 finfish, seven mollusc, nine crustacean and two amphibian diseases listed in the 2017 OIE Manual of Diagnostic Tests for Aquatic Animals. Of the 56 DAS identified, 41 were based on field testing, eight on experimental challenge studies and seven on both. Also, we adapted human and terrestrial‐animal standards and guidelines for DAS structure for use in aquatic animal diagnostic research. Through this process, we identified and addressed important metrics for consideration at the design phase: study purpose, targeted disease state, selection of appropriate samples and specimens, laboratory analytical methods, statistical methods and data interpretation. These recommended design standards for DAS are presented as a checklist including risk‐of‐failure points and actions to mitigate bias at each critical step. Adherence to standards when designing DAS will also facilitate future systematic review and meta‐analyses of DAS research literature. 相似文献
57.
为建立黎药海巴戟药材质量标准,为其质量控制及资源开发利用提供科学依据。依据《中国药典》2015 年版中药质量标准研制的要求,对药材性状、鉴别、检查、浸出物、含量测定等进行研究。明确了海巴戟药材性状和显微结构特征,并建立了其专属性薄层色谱鉴别方法;规定海巴戟药材多糖含量不得少于 6.0%、东莨菪内酯含量不得低于 0.017%、水分不得超过 10.0%、总灰分不得超过 6.0%以及醇溶性浸出物不得少于 20.0%。本研究制定的黎药海巴戟药材质量标准,可为该药材的质量控制提供依据。 相似文献
58.
通过对《地理标志产品六堡茶》标准与《六堡茶》标准在编写依据和方法、适用范围、术语和定义、分类、等级、要求、试验方法、检验规则等方面的对比,指出两标准的异同。结果显示,《地理标志产品六堡茶》是在《六堡茶》基础上增加六堡茶地理标志产品保护的内容制定而成,增加的内容主要有产品保护范围、原料种植的立地条件和气候条件、茶树品种、栽培技术、采摘、毛茶感官品质和理化指标等,产品等级从7个等级缩减至5个等级,前者比后者要求更宽广、更严格。《地理标志产品六堡茶》标准对保证六堡茶质量特色、提高质量水平,推动六堡茶产业持续健康发展具有引领作用。 相似文献
59.
Simon J. More Angus R. Cameron Matthias Greiner Richard S. Clifton-Hadley Sandra Correia Rodeia Douwe Bakker Mo D. Salman J. Michael Sharp Fabrizio De Massis Alicia Aranaz M. Beatrice Boniotti Alessandra Gaffuri Per Have Didier Verloo Michael Woodford Martin Wierup 《Preventive veterinary medicine》2009,90(3-4):254-267
Within the European Union (EU), detailed legislation has been developed for cattle, but not deer, to minimise disease risks associated with trade in animals and animal products. This legislation is expressed as input-based standards, providing a detailed outline of the activity required (for example, testing of animals and application of defined control measures), on the expectation that an adequate output (for example, confidence in freedom) will be achieved. Input-based standards are at odds with the increasing shift towards output-based standards, particularly in OIE rules governing international trade. In this paper, we define output-based standards to achieve and maintain freedom from tuberculosis (TB) in farmed deer, with reference to EU member states. After considering the probability of freedom achieved for cattle under existing EU legislation, we defined a ‘free farmed deer holding’ as one with a probability of freedom from infection of at least 99%. We then developed an epidemiological model of TB surveillance systems for deer holdings, incorporating different surveillance strategies, including combinations of diagnostic tests, and a variety of different scenarios relating to the potential for introduction of infection. A range of surveillance strategies were identified to achieve and maintain a free farmed deer holding, and worked examples are presented. The surveillance system sensitivity for varying combinations of screening and confirmatory tests in live animals, animals at slaughter and on-farm deaths is also presented. Using a single test at a single point in time, none of the TB tests routinely used in farmed deer is able to achieve an acceptable probability of TB freedom. If repeat testing were undertaken, an acceptable probability of TB freedom could be achieved, with differing combinations of the surveillance system sensitivity, frequency of testing and risk of introduction. The probability of introduction of infection through the importation of infected deer was influenced by the use of a pre-movement test (assumed 90% test sensitivity and negative test results), the TB prevalence in the source herd and the number of animals imported. A surveillance system sensitivity of at least 81% was achieved with different combinations of annual live animal surveillance and surveillance of animals at slaughter or on-farm deaths. This methodology has broad applicability and could also be extended to other diseases in both deer and other species with relevance to trade in animals and animal products. 相似文献
60.