农户减少化肥用量和采用有机肥的意愿研究——基于洱海流域上游面源污染防控的视角

[目的]过量施用化肥导致水体富营养化是造成洱海流域上游面源污染的主要原因之一,调查分析农户减少化肥用量和采用有机肥的意愿有助于了解其调整施肥结构的行为。当前研究忽视了农户减少化肥施用强度和采用有机肥的意愿间的替代性,未能开展联立研究。[方法]基于洱海流域上游397个水稻种植户的问卷调查数据,通过Bivariate-Probit模型对农户减少化肥用量和采用有机肥两种意愿进行分析。[结果]年龄负向影响农户减少化肥量的意愿,农户对有机肥好处的认知正向影响其减少化肥量的意愿,农户参加农业社会化服务对其减少化肥用量和采用有机肥的意愿均产生正向影响,相比之下,对农户采用有机肥意愿的促进作用更大。[结论]引导农户参加农业社会化服务以及加强宣传和培训,提高农户对有机肥作用的认知可能是加强其减少化肥用量和增加有机肥施用量意愿的有效途径。     

水源地突发水污染政府应急预留水量需求预测

近年来,随着工业化和产业化的快速发展,水源地突发水污染事件频发。为应对紧急情况下的水资源非常规需求,保障经济社会稳定发展,政府需要安排一部分应急预留水量。如何合理预测政府应急预留水量的规模是一个值得探讨的课题。提出了一种基于案例推理技术的政府应急预留水量需求预测方法,具体思路是:借助于案例库,利用主成分分析法从众多影响水源地突发水污染事件的因素中提取出两两不相关的因子,以此作为案例的特征属性,基于加权曼哈顿距离测算相似度,依此得到匹配案例,进而测算政府应急预留水量。以太湖流域常州地区水源地为例,进行政府预留水量需求量的预测与分析。该方法可以为政府应急预留水量的配置、储备等提供相关理论知识。     

Agriculture–nutrition linkages with heterogeneous,unobserved returns and costs: Insights from Tajikistan

Agriculture–nutrition linkages (ANLs) have been increasingly investigated in the literature. However, nutritional returns and costs of household agricultural production practices (APPs) in semisubsistence settings are poorly understood. We fill these knowledge gaps using pooled cross-section data sets in Tajikistan, where semisubsistence farming and undernutrition coexist despite relatively good agricultural infrastructure and education systems. Agricultural diversification, yield enhancement, production expansion are positively associated with various nutritional outcomes, particularly in areas with poor food market access. Decomposition exercises suggest that nutritional returns and costs of these APPs vary across households, and the adoption of APPs is driven by the expected nutritional returns. In Tajikistan, improving nutrition through household ANLs requires growing the smallholder agricultural sector in multiple dimensions, including diversification, intensification, and expansion, while also understanding better the pathways of ANLs and addressing bottlenecks at appropriate stages of such pathways.     

农户生态耕种行为及其影响因素研究——以江西省为例

[目的]为清晰识别影响农户生态耕种行为的主要因素,以期为加强耕地生态保护、保障农作物质量安全、提升农户耕种收益、实现农业现代化目标提供参考。[方法]基于江西省11市47县(区)1488份农户微观调查数据,在分析农户生态耕种特征基础上,运用二元Logistic和Probit模型对农户生态耕种行为影响因素开展实证研究。[结果]农户生态耕种10种具体行为的采纳情况差异明显,其中施用有机肥采纳程度最高,生态农业模式采纳程度最低。农户采纳生态耕种整体水平不高,但仍具备进一步推广的潜力。家庭劳动力比重、生态耕种成本认知、新型农业经营主体、法律法规认知、生态耕种收益认知、生计分化和生态环境认知等解释变量是影响农户生态耕种行为的主要内部因素,政府补贴、农田基础设施、生产交流程度、耕地质量变化和生态耕种信息获取难度等则是主要的外部影响因素。[结论]政府及基层管理部门应在推动农户非农就业生计、大力培育新型农业经营主体、加强生态耕种宣传与推广、完善政策扶持与管控机制等方面制定针对性的政策措施。     

中国酒店餐饮中的食品营养问题研究

随着我国社会的不断进步,经济的不断发展,人民群众的生活水平逐渐提高,人民的生活节奏也越来越快,生活方式也逐渐发生改变.因为各方面原因,现在越来越多的人喜欢在外就餐,但是目前我国酒店餐饮中的食品依然存在营养问题,例如,酒店为了追求菜品的色香味,破坏了食物的营养,忽略了膳食平衡.为了人们的健康饮食,急需解决这些问题.本篇文章以中国酒店餐饮中的食品营养为例,对存在的问题进行深入分析,供大家参考.     

Do consumers view the nutrition facts panel when making healthfulness assessments of food products? Antecedents and consequences

Consumer use of the Nutrition Facts Panel (NFP) is an important topic of interest to researchers and public policymakers. Studies conducted in the United States and elsewhere find high levels of self-reported use of the NFP or its equivalent. However, data from self-reports may inflate estimated NFP use due to social desirability problems. Utilizing data from an online experiment, we examine whether consumers choose to view the NFP when assessing the nutritional properties and disease-fighting abilities of foods. We also examine the antecedents of NFP-viewing behavior and its implications for the accuracy of healthfulness judgments and the potential for overgeneralization. We conclude with a discussion of the public policy implications of our results and point to directions for future research.     

一种利用均匀圆阵对称特性的近场源酉变换估计算法

针对现有均匀圆阵的近场源三维参数估计算法运算量大的缺点，提出了一种基于均匀圆阵对称特性的近场源酉变换估计算法。该算法利用均匀圆阵对称特性将阵列导向矢量进行酉变换和对角化分离处理，消除距离参数，把三维搜索问题化简为二维搜索问题，同时把复值方向矢量转化为实值方向矢量。计算机仿真结果显示,所提算法估计性能优于相关序列降维估计方法，与三维多重信号分类算法性能相当，且通过矩阵分离降维和实值化处理，减少了运算量，有利于工程实时处理。     

烹饪专业食品营养与卫生课程教学改革

随着我国高职教育的迅速发展,以“工学结合”为特色的课程标准广泛应用于高职院校烹饪专业的教学中。食品营养与卫生课程是一门重要的课程,为进一步提升该课程的教学质量,培养学生的职业能力和职业素养。本文结合食品营养与卫生课程教学改革现状,提出教学改革途径,以期实现食品营养与卫生教学质量的进一步提升。     

Faltering fisheries and ascendant aquaculture: Implications for food and nutrition security in Bangladesh

Bangladesh has made considerable progress against human development indicators in recent years, but malnutrition resulting from poor dietary diversity and low micronutrient intakes remains entrenched. Fish is central to the Bangladeshi diet and small fish species are an important micronutrient source. Although fish consumption per capita has increased in recent years as a result of rapid expansion of aquaculture, it is likely that consumption of fish from capture fisheries (including small indigenous species particularly rich in micronutrients), has declined. This paper evaluates data on fish consumption collected in Bangladesh by the International Food Policy Research Institute in 1996/7 and 2006/7 to assess changing patterns of fish consumption and their implications for food and nutrition security. This analysis indicates that growth of aquaculture has been positive, mitigating a sharp reduction in the quantity of fish consumed from capture fisheries and smoothing out seasonal variability in consumption. However, increased availability of fish from aquaculture may not have fully compensated for the loss of fish from capture fisheries in terms of dietary diversity, micronutrient intakes and food and nutrition security, particularly for the poorest consumers. A range of approaches are recommended to sustain and enhance the contributions capture fisheries and aquaculture make to food and nutrition security in Bangladesh     

杭州湾海域水污染演变及污染源分析

以杭州湾海域水环境调查的相关数据为依据,研究杭州湾海域水污染演变及污染源情况。杭州湾海域常年以劣四类海水为主,水质状况极差,部分指标仍有恶化趋势。其主要超标污染物为无机氮和活性磷酸盐,化学需氧量浓度波动较大,但不是杭州湾水污染的主要威胁。从海域污染源来看,从富春江电站上游区域汇入的污染物占比最多;其次是杭州湾沿岸支流河道汇入的污染物;再次是从排海污水处理厂纳入的污染物。