豆粕标准检测方法与快速测定法的对比研究

本实验采用凯氏定氮法、直接干燥法、索氏抽提法及近红外分析仪对豆粕的粗蛋白质、水分、脂肪进行分析测定,旨在将传统检测方法与快速测定法进行对比,分析其测定误差,确定最优测定方法.试验结果表明,2种方法的测定结果差异不显著(p>0.05),均可用于豆粕测定;其中近红外分析仪测定可以节省试剂,减少实验经费,能快速、精准的出具数...     

Aggregation of Price Risk over Commodities: An Economic Index Number Approach

This article extends the economic theory of index numbers to the aggregation of price risk over commodities in production. Superlative indexes of aggregate price risk are related to Tornqvist and Fisher−type output quantity indexes. An application to major crops in Manitoba illustrates the empirical importance of the analysis.     

粮食金融化背景下投机行为与国际粮价波动——以大豆期货为例

利用CFTC公布的COT持仓报告数据检验了2006年6月至2013年7月大豆期货价格和投机性持仓两者间的关系,通过构造投机多头头寸变化率、投机多头头寸占比和投机净头寸3种度量投机力量的指标,发现3种指标均与大豆期货价格正相关,其中投机多头头寸变化率能更好地预测大豆价格的变动.由于投机行为有推高粮食价格的潜在危害,监管机构应当加强监管防止投机资金对粮食衍生品市场的过度投机.     

碱性蛋白酶提取杜仲籽粕蛋白的工艺优化

采用二次通用旋转组合设计实验优化超声波辅助碱性蛋白酶提取杜仲籽粕蛋白工艺。在单因素实验基础上,选择pH值、碱性蛋白酶用量、酶解温度与酶解时间为考察因素,以杜仲籽粕蛋白提取率为响应值建立回归数学模型,对杜仲籽粕蛋白提取工艺条件进行优化。结果表明,最佳提取工艺条件为：pH10,碱性蛋白酶用量320u／g,酶解温度55℃,酶解时间115rain。在此优化条件下,杜仲籽粕蛋白提取率可迭74．28％。     

Alternative Methods for Estimating Price Elasticities of Imports

Abstract

This article compares three commonly-used methods for estimating import price elasticities: (1) trade-weighted price elasticities of domestic demand and supply along with price transmission; (2) direct estimates based on ad hoc import demands; and (3) Armington model estimates. Using data from El Salvador's grain markets (white maize, red beans, and rice), the results indicate that the second method provides the most reliable estimates and that the Armington procedure may not be appropriate for estimations of this type. However, the first method offers the best guesstimates to assess potential rather than historical import response as trade is liberalized.     

Pre-Harvest Price Expectations for Corn: The Information Content of USDA Reports and New Crop Futures

This article examines the puzzle of why futures prices continue to react to USDA crop reports despite the fact that reports appear to be no longer newsworthy, that is, provide no better production estimates than private forecasts. The information value of reports is measured in terms of their influence on rational agents' harvest-time corn price expectations, which are uncovered using a Hamilton-type modeling approach. Results show that reports are still newsworthy, as they would contribute to agents' price expectations if released a day early. Thus futures price reactions, which closely reflect price expectations, are rational and consistent with efficient markets hypothesis.     

资源性产品价格改革对经济转型升级作用的再认识

资源性产品对经济结构优化升级、空间优化布局、发展和转型升级方向、国家（地区）经济转型升级战略的制定具有重要的基础性影响。资源性产品市场化程度不高造成过度依赖资源性产品高投入的经济结构,对资源型产业经济结构、加工型产业经济结构造成约束。必须再认识资源性产品价格改革对经济转型升级的重大作用：第一,资源性产品价格改革已成为经济转型升级进程中的薄弱环节,第二,资源性产品价格改革是矫正要素价格机制扭曲的迫切需要;第三,完善资源性产品价格形成机制已成为经济结构转型升级的基础条件。     

采空区分类及概预算价格依据探讨

矿山采空区的调查工作需要一套标准体系,其中更为重要的是对其进行合理分类,并制定科学的概预算标准。根据目前我国采空区现状,结合实际情况,对采空区调查工作中出现的分类及概预算方面的问题,进行了初步探讨。经过分析,提出了相应的分类标准,同时参考相关行业内规范的概预算标准,提出了采空区概预算的价格参考标准。     

林业项目投资风险管理对策分析

项目风险管理是现代项目管理中的一个重要组成部分。林业项目投资面临自然风险、社会风险和政策风险。规避风险,可以从改变风险后果的性质和降低风险发生概率等方面采取多种对策,主要可采取风险减轻、预防、转移、回避、接受和储备等6项措施。     

Resource Management under Production and Output Price Uncertainty: Implications for Environmental Policy

Various environmental policies have been proposed to control agricultural runoff of nutrients and pesticides. The impacts of these policies on input use are complicated because of the various sources of uncertainty farmers face and the precise nature of farmers' risk attitude. A risk–averse farmer's response to changed profit , input , and output taxes under output price and production uncertainty is examined. The impact of these policies on input use depends on the form of production uncertainty, risk–input relationships, risk attitudes, and degrees of output price and production uncertainty. These results have implications for the design and implementation of environmental and other production–related policies.     

住宅用地基准地价的容积率系数修正新方法

容积率修正系数编制是土地评估领域探讨的热点之一。提出了先构建容积率、因素总分值与地价关系的地价模型,进而编制分级别的住宅用地容积率修正系数的新方法,并以北海市为例进行实证研究。研究表明:地理加权回归模型的拟合度明显优于最小二乘法,便于据此编制更精准的分级别容积率修正系数表;该方法引入因素总分值规避了传统区域修正方法的主观任意性问题,便于计算机进行批量快速处理,保证了编制的容积率修正系数的可靠性,在实践中行之有效。     

地质灾害风险管理研究综述及展望

地质灾害风险管理是一种寻求更加合理有效的地质灾害减灾防灾的理念和模式。国外对于地质灾害风险管理的研究,主要是通过采用现代高技术与地质灾害风险管理相结合的方式体现出来的。国内学者对我国地质灾害的类型、特征、影响因素、分布状况和区域发展规律等进行了深入的研究,提出了许多新理论、新观点。需要解决的问题:(1)如何评估灾情程度需要科学的理论与切实可行的方法;(2)需要借助现代信息技术和数值模拟仿真技术建立地质灾害风险评价与风险管理的数学模型,以进一步拓展地质灾害风险管理的研究体系;(3)需要结合具体的区域,对风险管理措施、手段及传导机制进行系统仿真和比较研究。     

意愿调查法在征地区片综合地价评估中的应用——以兰州市安宁区城市规划区征地区片综合地价评估为例

研究目的:确定能否将意愿调查法应用于城市规划区征地区片综合地价评估。研究方法:实例验证法、对比分析法和因果分析法。研究结果:(1)意愿调查法能够兼顾农民、用地单位和政府三方对征地补偿标准的受偿意愿、支付意愿和决策意愿,测算结果更具可执行性。(2)意愿调查法测算出的征地区片综合地价略高于现行的征地补偿标准,符合“适当提高现行征地补偿标准和有利于提高农民现有生活水平[1]”的原则。研究结论:意愿调查法是进行城市规划区征地区片综合地价评估的较好方法。     

Capacity Depreciation, Implicit Rental Price, and Investment Demand for Farm Tractors in Canada

Among the different factors pertaining to the demand for durable inputs in agriculture, the way the input depreciates over time is an important issue. This study investigates four alternative capacity depreciation patterns for farm tractors. While published estimates from government agencies implicitly assume convex capacity depreciation patterns, the results of this study demonstrate that the use of agricultural engineering data which depict a concave rather than convex pattern better reflect farmers' investment decisions. An implicit rental price measure is also proposed to account for the fact that the purchase price of a durable input is not an appropriate measure of the implicit rental cost of the asset.
Parmi les facteurs déterminants de la demande pour les biens durables en agriculture, la rapidité avec laquelle I'intrant se déprécie est certainement importante lors des décisions d'investissement. La présente etude analyse quatre différents scénarios de dépréciation pour les tracteurs agricoles au Canada. Bien que les données publiées par les agences gouver-nementales supposent implicitement que les biens durables se déprécient à un taux annuel constant, les résultats de cette etude montrent que I'utilisation de données basées sur la valeur productive de I'intrant telle que calculée sur une base expkrimentale donne de meil-leurs résultats statistiques dans I'estimation de la demande pour les tracteurs agricoles. De plus, une mesure du coût implicite de I'intrant est également proposée pour tenir compte du fait que le prix d'achat n'est pas une mesure appropriée dans I'analyse de la demande pour un bien durable.     

退耕还林工程风险管理机制研究

通过定性识别和分析退耕还林工程实施过程中存在各种风险的研究认为,退耕还林工程的规划设计、植被选择与林种配置、农户粮食安全、农户经济收入增长、地方政府治理、林权政策有效性、财政资金保障等实施环节均存在现实的不确定性,将有可能影响工程后续管理的有效性,进而制约工程稳步规模推进和成果的巩固。在系统评价工程风险因素的基础上,提出建立退耕还林工程风险管理机制的具体措施。     

Functional Land Management for managing soil functions: A case-study of the trade-off between primary productivity and carbon storage in response to the intervention of drainage systems in Ireland

Globally, there is growing demand for increased agricultural outputs. At the same time, the agricultural industry is expected to meet increasingly stringent environmental targets. Thus, there is an urgent pressure on the soil resource to deliver multiple functions simultaneously. The Functional Land Management framework (Schulte et al., 2014) is a conceptual tool designed to support policy making to manage soil functions to meet these multiple demands. This paper provides a first example of a practical application of the Functional Land Management concept relevant to policy stakeholders. In this study we examine the trade-offs, between the soil functions ‘primary productivity’ and ‘carbon cycling and storage’, in response to the intervention of land drainage systems applied to ‘imperfectly’ and ‘poorly’ draining managed grasslands in Ireland. These trade-offs are explored as a function of the nominal price of ‘Certified Emission Reductions’ or ‘carbon credits’. Also, these trade-offs are characterised spatially using ArcGIS to account for spatial variability in the supply of soil functions.To manage soil functions, it is essential to understand how individual soil functions are prioritised by those that are responsible for the supply of soil functions – generally farmers and foresters, and those who frame demand for soil functions – policy makers. Here, in relation to these two soil functions, a gap exists in relation to this prioritisation between these two stakeholder groups. Currently, the prioritisation and incentivisation of these competing soil functions is primarily a function of CO₂ price. At current CO₂ prices, the agronomic benefits outweigh the monetised environmental costs. The value of CO₂ loss would only exceed productivity gains at either higher CO₂ prices or at a reduced discount period rate. Finally, this study shows large geographic variation in the environmental cost: agronomic benefit ratio. Therein, the Functional Land Management framework can support the development of policies that are more tailored to contrasting biophysical environments and are therefore more effective than ‘blanket approaches’ allowing more specific and effective prioritisation of contrasting soil functions.