氧化铝对红壤正、负电荷的影响

用人工合成氧化铝包被土壤的方法研究了氧化铝(三水铝石)对红壤地区五种土壤的电荷性质的影响.结果发现,土壤包被氧化铝后正电荷有不同程度的增加,但其增加量随pH的升高而减少,pH7左右时几乎为零.人工氧化铝对负电荷的影响因土而异.带负电荷少的砖红壤包铝后在pH<7范围内负电荷稍有减少;带负电荷多的黄壤和红壤包铝后在低pH时负电荷明显减少,而高pH时负电荷明显增大;另外两个赤红壤包铝后负电荷也有类似的变化趋势,但变幅较小.四种土壤的负电荷由减小转变到增大时转变点的pH值各土不同,在pH3.6-6.2之间.包铝后土壤净电荷的变化趋势与该土壤的负电荷相似.包铝后土壤的ZPNC都有所升高,升高的幅度因土而异,在0.4-1pH单位之间.     

一类二阶奇异边值问题的正解

讨论了如下二阶奇异边值问题正解的存在性 {-（p（t）u′（t））′＋q（t）u（t）=f（t,u（t）） t∈（0,1） u（0）=u（1）=0其中f可能在t=0,1都有奇性.     

我国农产品出口韩国受阻原因分析及对策建议

随着我国对外开放的深入发展,我国农产品贸易结构发生了重要变化,连续多年呈现逆差并持续扩大,采取有效措施促进出口增长是关系农业国际收支平衡的重要任务。韩国是我国第四大农产品出口目标市场,我国长期对韩国保持农产品贸易顺差,但近年来我国对韩国农产品出口增长速度趋缓。以农药残留限量为典型的技术性贸易措施是阻碍和限制我国农产品出口韩国的重要因素。特别是近年来,韩国不断调整农药使用管理制度和相关进口监控检查措施,我国农产品出口韩国因农药残留问题受阻呈现增加趋势。梳理了2015年1月至2022年4月韩国通报我国出口农产品农药残留违规数据,表明我国农产品出口韩国因农药残留问题被通报的数量、涉及的农药种类和受影响的产品范围不断增加,导致受阻增加的主要原因是韩国全面实施农药肯定列表制度并扩大进口农产品农药残留监测范围,而我国农产品出口企业获取国外法规标准信息的能力不足,生产过程中农药使用管理的规范性仍有待加强。提升我国农产品应对韩国农药残留贸易壁垒的能力,需要从加强韩国法规标准信息预警、提升生产主体科学用药和质量安全控制能力、探索推动韩方建立重点贸易产品进口限量以及完善国内特色小宗作物农药登记和限量标准制定等方面综合施策。     

Winter chilling trends for deciduous fruit trees in Australia

Deciduous fruit trees require exposure to cold winter temperatures to fulfil chilling requirements allowing production of normal harvests. Trends in chill accumulation over the last 100 years were investigated at a number of important horticultural locations in Australia. Historical analysis is a necessary first step when considering potential impacts of climate change. Chill was examined using four chill models; the 0-7.2 °C, Modified Utah, Positive Utah and Dynamic models. Differences between locations were found with notable recent declines at Orange, Lenswood, Tatura, Yarra Valley and Bacchus Marsh. Other locations have remained stable with no location exhibiting a consensus increase in chill across all models. Trends in chill were shown to differ between models with results indicating that the 0-7.2 °C model frequently behaved differently to the other three chill models. These results highlight the need for multi-model analysis for chill trends, especially in a climate change context, to avoid maladaptation.     

夏南正回交后代、反回交后代及南阳牛的体重、体尺对比研究——河南省泌阳县"南阳牛导入夏洛来杂交育种"项目技术报告(二报)

本研究把夏南杂交的正回交后代、反回交后代及南阳牛的体重、体尺作了比较分析。结果表明，初生、6、12、18及24月龄，正、反回交后代公、母牛平均体重均高于同龄同性别南阳牛，差异均极显著，正回交公牛与反回交公牛相比，平均初生重差异不显著；6、12、18月龄反回交公牛平均体重明显高于正回交公牛，差异均极显著，24月平均体重差异不显著；正回交母牛与反回交母牛相比，反回交母牛平均初生体重高于正回交母,两者差异显著，但6、12、18及24月龄平均体重差异不显著。     

江苏省农村剩余劳动力的估量方法与实证研究

首先对农村剩余劳动力概念进行了界定,并介绍了几种常用的农业剩余劳动力的估算方法,然后提出一种新的计量农村剩余劳动力的方法,并利用该方法对江苏省的农村剩余劳动力数量进行了实证研究。     

Evidence‐Based Medicine: The Design and Interpretation of Noninferiority Clinical Trials in Veterinary Medicine

Noninferiority trials are clinical studies designed to demonstrate that an investigational drug is at least as effective as an established treatment within a predetermined margin. They are conducted, in part, because of ethical concerns of administering a placebo to veterinary patients when an established effective treatment exists. The use of noninferiority trial designs has become more common in veterinary medicine with the increasing number of established veterinary therapeutics and the desire to eliminate potential pain or distress in a placebo‐controlled study. Selecting the appropriate active control and an a priori noninferiority margin between the investigational and active control drug are unique and critical design factors for noninferiority studies. Without reliable historical knowledge of the disease response in the absence of treatment and of the response to the selected active control drug, proper design and interpretation of a noninferiority trial is not possible. Despite the appeal of conducting noninferiority trials to eliminate ethical concerns of placebo‐controlled studies, there are real limitations and possible ethical conundrums associated with noninferiority trials. The consequences of incorrect study conclusions because of poor noninferiority trial design need careful attention. Alternative trial designs to typical noninferiority studies exist, but these too have limitations and must also be carefully considered.     

腌制胡瓜出口如何应对日本“肯定列表制度”的影响

列举了近年来胡瓜的出口情况,比较分析了日本“肯定列表制度”和中国国家标准GB2763—2005《食品中农药最大残留限量》中针对胡瓜的农药限量指标,为嘉兴市腌制胡瓜生产企业提出病虫害防治建议,以及时应对日本“肯定列表制度”产生的影响,采取积极有效措施指导出口企业的胡瓜生产。     

柞蚕蛹蛋白溶解性与阳离子关系研究

[目的]为柞蚕蛹蛋白的提取及应用奠定基础。[方法]在分离柞蚕蛹蛋白的基础上,通过均匀设计法研究在不同pH值下不同浓度阳离子(Na+、Mg2+、Ca2+和Zn2+等)对柞蚕蛹蛋白溶解性的影响,并拟合出柞蚕蛹蛋白溶解性与阳离子的回归方程。[结果]阳离子Zn2+、Ca2+、Mg2+、Na+和pH值对柞蚕蛹蛋白的溶解性均有极显著影响。各阳离子对蛹蛋白溶解性的影响顺序为:Zn2+>Ca2+>Mg2+>Na+,且其溶解性随着离子浓度的增加呈先升后降的趋势。所得回归方程的拟合效果较好,可用于对蛹蛋白溶解性进行分析。[结论]根据该试验结果与数学模型分析,可快速算出蛹蛋白的溶解度,有利于柞蚕蛹蛋白在食品加工中的应用。