农村金融资源配置效率实证研究——以黑龙江省为例

应用随机边界前沿分析法(SFA)对农村金融资源配置效率及影响因素进行了实证分析。结果表明,黑龙江省农村金融资源配置效率偏低,农村金融发展结构、农村金融中介效率和农村金融市场集中度是农村金融资源配置效率的主要影响因素;提高农村金融资源配置效率的关键在于构建多元化的农村金融体系,优化农村信贷资金结构。     

Detection of Frozen-Thawed Cycles for Frozen Tilapia (Oreochromis) Fillets Using Near Infrared Spectroscopy

Due to the ambient temperature fluctuation during the process of storage, transportation, and sale, frozen fillets may go through frozen-thawed cycles that result in quality changes. In order to detect the frozen-thawed cycles in frozen tilapia fillets, near infrared spectroscopy was applied. The thawing loss, cooking loss, moisture content, total volatile basic nitrogen, and texture profile of fillets in seven frozen-thawed cycles were analyzed to reflect the change of quality. A total of 60 fillets were used to collect the spectra on both dorsal and belly flesh in frozen and thawed state from the first to the seventh cycle. The results showed that there is a better discrimination among the once and the repeated frozen-thawed samples in the frozen state than the thawed state. Frozen samples were still conducive to the differentiation and had higher classification accuracy, ranging from 80% to 93.33%. Dorsal flesh was more beneficial for the differentiation than belly flesh and had the highest accuracy, ranging from 86.67% to 93.33% in the frozen state. These results showed that the nondestructive and fast detection of repeated frozen-thawed cycles in frozen tilapia fillets can be accomplished by near infrared spectroscopy, which has enormous potential for practical application.     

Pocono mesic till barrens in retreat: topography,fire and forest contagion effects

The Pocono mesic till barrens (PMTB) are a unique assemblage of fire-maintained shrub communities that support numerous rare species. Historically these barrens covered a large area in the vicinity of Long Pond, Pennsylvania, USA. However, due largely to regional fire suppression instituted in the early 1960s, over 70% of the area covered by barrens succeeded to fire-intolerant forest that does not support the rare species. We investigated the influence of forest proximity on barrens succession across three geomorphic types during periods of high fire frequency and fire suppression, testing the hypothesis that forest processes such as seed rain, shading, and detrital enrichment of soils enhances barrens succession through a contagion effect. Evidence of a forest contagion effect should be shown by increased rates of barrens succession with increasing proximity to the nearest forest edge. In order to detect a forest contagion effect, barrens persistence and barrens succession were modeled in proximity zones of 0-50 m, 50-100 m, 100-200 m, and greater than 200 m from the nearest forest edge. We used existing GIS data layers for fire, geomorphology, and vegetation distribution in 1938, 1963, and 1992. The layers were modified and overlain using ArcView software to determine persistence and succession rates for each unique combination of layers in each proximity zone from 1938 to 1963 (pre-fire suppression) and 1963 to 1992 (post-fire suppression). ANCOVA results indicate that proximity to the nearest forest edge significantly affected barrens persistence rates in both time periods, but succession rates were significantly affected in 1938 to 1963 only. Twenty-eight percent of the 1938 barrens succeeded to forest by 1963; 56% of the 1963 barrens became forest by 1992. Results support previous findings that barrens persistence is enhanced by increased fire frequency, and that barrens persist longer where they overlie flat glacial till than on other geomorphology types.     

电子商务案例分析课程教学改革的实践

根据教学工作的实践,对电子商务案例分析课程的教学模式、案例研究方法、教学方法、教学内容及考核方式等提出了一些看法。     

深厚覆盖层上高心墙堆石坝坝顶开裂特征及原因研究

国内多座深厚覆盖层上兴建的高心墙土石坝坝顶均出现不同程度的开裂,对坝体的长期安全稳定构成威胁,受到业内广泛关注。通过地质雷达、高密度电法等物探技术确定某高心墙堆石坝顶裂缝时空分布情况,根据变形实测资料分析了其变形破坏特征,并结合工程建设情况、结构特征、运行情况等对开裂原因进行分析。结果表明坝顶裂缝产生的根本原因是土体承受的应力超过其抗拉强度或抗剪强度后而发生的破坏,直接原因为坝顶的不均匀沉降,其中水荷载、湿化变形、蓄水速度、坝顶材料特性是坝顶不均匀沉降的关键影响因素。     

两型社会建设背景下生态效率评价研究——以湖南省为例

基于两型社会建设的目标与内涵,选取了湖南省生态效率综合评价指标,以2003—2012年湖南省数据为样本,采用DEA数据包络分析法计算各年份的生态效率,并对不同年份的能源消耗量、水资源消费量以及三废的排放量进行深入分析。结果表明,随着湖南省GDP的增长,生态效率也不断在提高。针对不同的资源产出率和环境产出率,湖南省应树立可持续发展理念,实现经济由粗放型发展向集约型发展转变;发展创新技术,推进湖南省两型社会的发展;完善法律法规体系,加大宣传力度,改变保守观念,提高人们的环保意识。     

基于数据包络分析的灌区农业生产综合效率评价与分析

为评价中国灌区农业生产综合效率的空间差异性,采用数据包络分析(Data envelopment analysis,DEA)方法对全国440个灌区2010年的农业生产综合相对效率进行评估,并基于不同区域灌区农业生产投入及其冗余状况对生产效率提升途径进行探索。结果表明,8个灌区的相对效率为1.000,达到DEA有效;灌区间农业生产效率差异显著,绝大部分(327个)不足0.300,省区尺度生产效率无明显空间分布规律;各投入指标对应存在冗余灌区个数分别为319(有效灌溉面积)、369(绿水)、155(蓝水)、298(化肥)及207(农业机械);非DEA有效灌区5个投入指标的可减少量占所有评价单元投入总量的比例分别为23.8%、39.2%、18.1%、29.0%以及19.9%。综上可知,各非DEA有效灌区应根据自身投入指标冗余状况优化配置和管理资源以提高区域综合农业生产效率,其中绿水资源高效利用是全国范围内广泛面临的问题;东北和西北地区需注重水土资源配置效率提升,而南方粮食主产区应注重水肥高效利用机制的研究与实践。     

Cost analysis of a satellite terminal for forest fuel supply in Finland

As forest fuel demand increases, new logistical solutions are needed. Most of the increase in use is expected to take place in large heat and power production units which set special requirements for the supply as both procurement volumes and transport distances increase. Biomass fuel terminals broaden the spectrum of available supply options by offering cost-effective large-scale biomass storage and processing options for securing the fuel supply in all conditions. This study aimed to study different costs of a satellite terminal and to produce important concept and cost information for developing forest fuel logistics based on future terminals. The figures indicate that terminals do not create direct cost benefits per se: direct supply chains are more economical compared to supply through terminals. However, there are several indirect benefits that can be reached via fuel supply through terminals: regional fuel procurement can be widened to a national scale, security of supply increases through easily available storages, large supply volumes can be delivered by an individual operator, prices remain more stable and a more even quality of delivered fuel can be achieved.