我国羊肉市场价格波动研究

本文利用季节调整法和H-P滤波法分析了2002年至2013年我国羊肉市场价格波动周期及产生的原因,并提出稳定羊肉价格的对策和建议。     

十一届三中全会后农村经济改革成功的五大因素分析

论及十一届三中全会后农村经济改革成功的文章,无不将其归功于家庭联产承包制的实行和推广,毫无疑问,这是促使农村经济改革成功的首要因素。但,长久以来,学界却忽视了其他几个重要因素:即,国家在这一时期还采取提高粮食收购价、限定粮食征购数量,以及扩大进口粮食等特殊政策,给农民生产的积极性提供了持续的推动力和可行条件。另外,从生产力决定生产关系的基本原理考察,"四三方案"引进大化肥厂的投产,成倍地扩大了单位化肥施用量;籼型杂交水稻和高产小麦的研制成功和推广,这两项先进科技的引进和进步使得粮食亩产大幅度增加,从而为农村经济改革的成功提供了可靠的保证。这五个不可或缺的因素共同促使新时期农村经济改革顺利进行并最终取得成功。     

On 'variability' as a sampling artefact: the case of Sardinella in north-western Africa

Objective evaluation of the global impact of fisheries on ocean ecosystems may be hampered by various biases suggesting natural variability of exploited species to be stronger and more widespread than is really the case. One of these is reporting biases: papers are usually not published which show that nothing has changed. Another such bias is that much variability is fishery-induced, i.e. due to the truncation by fishing of the age composition of exploited populations. A third source of bias, emphasized here, is that resulting from sampling a migrating population with a fixed device. This bias is illustrated by contrasting the relatively stable echo-acoustic estimates of biomass of Sardinella spp. along the north-west African coast, i.e. from Morocco and Mauritania to Senegal (data from 1992–98), with the more variable estimates of biomass in the waters of each of these countries. We conclude that published reports of 'variability' in exploited species should explicitly account for the effect of migrations and other movements, especially when such reports are to be used for contrasting fisheries-induced with environmental impacts on biomass.     

Variation in abundance of Norwegian spring-spawning herring (Clupea harengus, Clupeidae) throughout the 20th century and the influence of climatic fluctuations

A long-term (1907–98) virtual population analysis (VPA) was made for Norwegian spring-spawning herring (NSSH), which is a huge pelagic fish stock in the north-east Atlantic. It shows that this herring stock has had large fluctuations during the last century; these fluctuations have mainly been determined by variations in the temperature of the inflowing water masses to the region. The spawning stock biomass (SSB) increased from a rather low level in the early years of this century and reached a high level of around 14 million tons by 1930. The spawning stock biomass then decreased to a level of around 10 million tons by 1940, but increased again to a record high level of 16 million tons by 1945. The stock then started to decrease and during the next 20-year period fell to a level of less than 50 000 tons by the late 1960s. Through the 1970s and 1980s, the stock slowly recovered and after the recruitment of strong year classes in 1983 and 1990–1992 the stock recovered to a spawning stock biomass of about 10 million tons. The long-term fluctuation in spawning stock biomass is caused by variations in the survival of recruits. It is found that the long-term changes in spawning stock abundance are highly correlated with the long-term variations in the mean annual temperature of the inflowing Atlantic water masses (through the Kola section) into the north-east Atlantic region. The recruitment is positively correlated with the average temperature in the Kola section in the winter months, January–April, which indicates that environmental factors govern the large-scale fluctuations in production for this herring stock.     

1998～2005年《南京农业大学学报》(自然科学版)载文、引文统计分析与评价

用文献计量学方法对《南京农业大学学报》1998～2005年所刊登的论文及引文进行了统计分析。结果表明：8年共发表论文839篇，引文率99．30％，平均篇引文量10．22，引文语种中文占52.04％，英文占47．61％；其它语种占0．35％。引文在英文期刊的聚集度高于中文期刊。引文种类中期刊占78、39％，图书占17．06％。引文6～10篇的频率占44．03％，11～15篇的占32.70％。年度获得基金项目总教与发表论文篇数的均值为112．87％。平均普赖斯指数为28.23％     

高等教育实行价格歧视的可行性研究

在研究我国高等教育收费现状的基础上,依据价格歧视原理分析了高等教育实施价格歧视的充要条件,指出我国高等教育收费已具有实施价格歧视的理论和现实可行性,并提出具体的实施策略。     

区域间农用地价格的协调

分析了区域间农用地价格差异的成因,阐述了区域间农用地价格差异的类型,对区域间农用地价格差异产生的影响进行了评估。并提出区域间农用地价格差异的协调办法。     

2014年辽宁省生猪生产形势分析及2015年预测

2014年,辽宁省乃至全国生猪生产遭遇寒冬,出现量价齐跌现象,小规模养殖户被迫退出生产,大中规模养殖场艰难运营,全年亏损严重。本文从价格、效益、生产三方面分析了2014年辽宁省生猪生产形势变化情况,并综合多方因素对2015年生猪生产形势进行预测,希望能给养猪人士带来启示。     

我国蔬菜市场预测预警研究浅析

在探讨蔬菜预测、预警理论发展情况的基础上,介绍了蔬菜市场预测预警的核心内容即蔬菜价格监测和蔬菜价格预警理论体系的概况,着重从蔬菜价格监测的概念、蔬菜价格监测的品种及范围、蔬菜价格监测体系3个方面介绍了蔬菜价格监测的主要内容;并分别从数量供应、需求、贮藏库、市场价格4个角度总结蔬菜预测预警现状,最后进行了展望。     

火龙果周年成花结果观测及产期调节策略分析

【目的】为掌握火龙果周年成花结果及市场价格规律以便制定出最优的产期调节方案,【方法】本研究以“桂红龙1号”红肉火龙果为对象,通过观测各批次花果的物候、单产、等级比例、批发售价等进行关联性分析,【结果】研究显示红肉火龙果全年可结果3个造次(结果周期),每个造次包括5～6个批次,在自然产期全年可结果13～15个批次,加上产期调节提早及延后批次周年可结果约18～20个批次;在自然产期单造产量峰高值与售价呈相反走向,7～8月成熟的批次同级别鲜果售价最低,且小果比例最高,大果比例越低。【应用范围】因此提出了火龙果周年产期调节要“抓两头、调中间”的基本策略,供生产者安排制定周年各批次的产期、产量生产计划方案提供参考依据。