沙棘叶多酚在苹果汁保鲜中的应用

沙棘叶多酚是从沙棘叶里提取出来的一种植物多酚,由于植物多酚的结构是多样性的,所以沙棘叶多酚具备多种生物活性。在沙棘叶多酚中具备一种较为特殊的活性,这就是抑菌活性。基于其抑菌活性的特点,人们可以将沙棘叶多酚应用于苹果汁保鲜中。由于沙棘叶多酚是一种天然的植物多酚,所以对人体并不会产生副作用,人们可以将其广泛地应用于苹果汁保鲜中。本文从沙棘叶多酚的提取、沙棘叶多酚的抑菌机制及在苹果汁保鲜中的应用等角度出发说明沙棘叶多酚在食品保鲜中的价值。     

首都物流业发展的主要问题与对策研究

文章首先对当前首都物流业发展主要问题进行了分析，发现存在物流系统分散；管理人才缺乏，从业人员素质不高；企业规模小、设施落后；第三方物流落后等问题．因此，作者提出了建立统一的物流主管部门；普及物流知识，培训物流人才；抓好物流科技进步，加强基础设施建设，推进以信息化、标准化为重点的物流现代化建设；大力发展第三方物流业等针对性措施。     

Transition economies and trust building: a network perspective on EU enlargement

Many transition economies are characterised by a relativelyrudimentary institutional framework. Weak legislative structuresand the absence of effective market regulation and propertyright enforcement rules diminish the chance of mutually profitablebusiness transactions and—more generally—restrictthe chances for innovation and sustainable growth. Against thisbackground, we analyse the extent to which more efficient governancemechanisms can contribute to a more favourable business environment.In doing so, we adopt a network perspective. We argue that bothin developed market economies as well as in centrally plannedeconomies much of economic exchange takes place in networks.However, the characteristics of these networks, in particularthe concept of trust, can differ significantly. This leads usto conclude that the real challenge of the process of economictransition is connected to building new economic exchange networks.In this paper, we discuss this argument and analyse how thecurrent enlargement of the EU into Eastern Europe may favourablyaffect this process of institutional change in the accessioncountries.     

鄱阳湖区农业自然资源利用演变机制研究

鄱阳湖区农业自然资源利用演变的基本动因，是具有增长型机制并对自然资源需求无限的社会经济子系统，与具有稳定型机制的，自然资源供给有限的自然生态子系统之间的对立统一。其演变过程实质上是一个螺旋式上升的发展过程，是社会经济子系统需求与自然生态子系统供给之间动态平衡过程。1949年～1950年代中期低水平相对平衡；1960年代～1980年代社会经济迅速发展而自然生态明显失衡；1990年代尤其是1998年特大洪涝灾害后朝遵从自然力进而有效利用自然力的可持续方向发展。     

国家治理、问责机制和国家审计

沿着国家治理整体构造、问责机制到国家审计这一逻辑路径,探究国家审计的本质,并解释国家审计差异化的原因.国家治理基本构造可分为四个层次,国家审计本质上属于经济问责,问责对象是政府治理系统中的任务确定及资源配置子系统.在经济问责系统中,国家审计的基本功能是经济问责信息保障机制,由于各国的国家治理整体构造和问责机制不同,因而出现不同国家的审计差异.     

Distress rentals and the land rental market as a safety net: contract choice evidence from Tigray,Ethiopia

Rural households in the semiarid Northern Ethiopian highlands are net buyers of food. Crop failure due to erratic and unpredictable rainfall occurs frequently and leads to food shortages and income shocks. The renting out of land may be one of the coping responses of households exposed to shocks. We developed a theoretical household model for poor landlord households capturing their contract choice response to downside production shocks. We tested econometrically whether contract choice may depend on poverty, capital constraints, production risk and random shocks. The multinomial logit model estimates show that poor households experiencing random shocks are more likely to choose fixed‐rent contracts as a distress response to shocks, suggesting that fixed‐rent contracts may be used to meet immediate needs, but at the expense of future incomes. We also found that fixed‐rent contracts are preferred when ex ante production risk is low, while sharecropping is more likely where production risk is high. Finally, we found an indication that the choice of a fixed‐rent contract as a coping response to shocks comes as a last resort after all other means of coping are exhausted.     

Payments for agrobiodiversity conservation services: An overview of Latin American experiences,lessons learned and upscaling challenges

Many developing countries face a major challenge today: how to safeguard the biodiversity maintained in the fields of the rural poor - which constitute a national and global public good - whilst meeting those same people's development needs and rights? A solution to this dilemma has thus been sought in adapting the design and implementation of Payments for Ecosystem Services (PES) concepts to the conservation of agrobiodiversity.Here we review the application of nine such Payments for Agrobiodiversity Conservation (PACS) schemes that have been applied to date in four Latin American countries over the period 2010–2018. These covered 130 threatened varieties across a number of major food crops, and involved over 100 farming communities and 1,100 farmers (45 % of which were women). Conservation service offers were received through a competitive tender mechanism. Average bid offers revealed high heterogeneity, varying between US$675/ha. to ten times as much.In relation to issues identified as key to PES, such as spatial targeting, differentiated payments and conditionality, the underlying design of the PACS schemes may be considered solid. PACS-related prioritisation processes allow for the a priori identification of sites with high ecosystem service densities and high threat levels. The use of competitive tenders permits accounting for cost heterogeneity in the provision of conservation services and for payments to be differentiated. Conditionality is strong.In terms of implementation, a “back of the envelope” calculation based on the results of the competitive tenders suggests that conservation costs are modest. For a priority conservation portfolio of 100 varieties (which may be from different crops) each with a target area of five hectares, costs would amount to just under US$860,000 over twenty years or US$70,000 p.a. at a 5 % discount rate. The small-scale and one-off nature of the interventions realised to date, along with threatened crop variety seed availability constraints, have however meant that environmental effectiveness has been incomplete in the short-term (area cultivated with specific threatened varieties increased, but still below the “not at risk” threshold). The establishment of systematic monitoring systems is required to determine longer-term impacts and inform more regular PACS interventions within a dynamically evolving systems context.     

基于延伸责任的逆向供应链激励机制研究

逆向供应链作为生产者延伸责任制实施的载体,各企业间的组织协调性直接关系着生产商延伸责任制的实施效果。基于此,将逆向供应链抽象为一个制造商和一个回收商组成的价值链模型,应用委托代理理论,研究信息对称与不对称的情况下制造商和回收商之间的利益博弈,并分析不同因素对制造商和回收商期望收入的影响。     

房地产市场异常现象的行为金融学研究

房地产市场在发展的过程中出现了一些异常现象,传统金融理论面对这些异常现象无法给出令人信服的解释,现以行为金融学的噪声交易理论、反馈机制、羊群效应,对上海房地产市场出现的异常现象进行解释,并在此基础上寻求相应的对策,以促进房地产市场健康发展。     

清至民国时期黔东南苗侗族民众之田土山林诉后防御策略

清至民国时期,黔东南苗侗族民众在田土山林诉讼之后有独具特色的防御策略,即将官府判词刊刻在石碑上,立于桥头路口等众人途经之处,以警示他人以后对判决所涉田土山林不得再生觊觎之心。黔东南苗侗族民众之所以采取这种诉后防御策略,其主要有以下几个方面的原因:一是田土山林对黔东南传统苗侗族民众来说意义非常重大;二是意图减少或者避免以后的讼累;三是官府判决的权威性已经在黔东南得到显现。黔东南苗侗族民众的田土山林诉后防御策略对法制建设的启示:要加强对民众田土山林权益的保护,减轻民众的诉讼负担。