RESOURCE USE EFFICIENCY AND SOCIAL PROFITABILITY OF AN INTEGRATED AQUA-FARM,TRIPURA, INDIA

The nature of resources available and how they are combined and utilized in aquaculture largely determine its economic viability and social profitability. Using a novel Resource Cost Ratio (RCR), this study analyzes resource use efficiency and social profitability of an integrated aqua farm located in Tripura, India. RCR, a variant of the Domestic Resource Cost Ratio (DRCR), is the ratio of the net cost of non-marketable resources and the net value addition by using marketable resources. The RCR for the integrated farm was found to be ?0.24. The negative value of RCR shows positive profitability for the integrated farm. The corresponding value for a specialized farm was found to be 0.52. The difference is the greater resource use efficiency of the integrated approach. Private and social profits per unit cost for the integrated farm (0.26 and 0.08, respectively) were higher than for the specialized farm (0.11 and 0.04, respectively).     

桃蛀螟研究的历史、现状与展望

本文就国内外对桃蛀螟[Conogethes puncti feralis(Guene)]的研究历史与现状进行了综述,涉及桃蛀螟的生物学和生态学特性、性信息素组成、交尾行为、分类学、人工饲养及综合防治技术等方面。提出了今后有待进一步深入研究的问题。     

Effects of blue shrimp Litopenaeus stylirostris and goldlined rabbitfish Siganus lineatus in mono‐ and polyculture on production and environmental conditions

This study was conducted to compare the effects of shrimp and rabbitfish in mono‐ and polyculture stocked at high biomass on production and environmental conditions in a mesocosm system. Shrimp (14 g) and/or rabbitfish (19 g) were stocked in four treatments with different density but with the same total biomass (236 g m^?2), including shrimp monoculture (SM) (17 shrimp m^?2), shrimp–fish polyculture (SF) (11 shrimp and 4 rabbitfish m^?2), fish–shrimp polyculture (FS) (6 shrimp and 8 rabbitfish m^?2) and fish monoculture (FM) (12 rabbitfish m^?2). After 10 weeks of experiment, shrimp survival and biomass were low in the treatments where shrimp were dominant (SM, SF), while rabbitfish survival and biomass were high in all the treatments. Shrimp mortality was assumed to be related to an excess of the system carrying capacity (CC). Results suggested that CC is linked to shrimp biomass/density rather than the system eutrophication level. The ecosystem became heterotrophic as daily feed supply was beyond 7 g m^?2 per day. This threshold corresponded to the environmental CC of the semi‐intensive shrimp culture system. Under these conditions, the combination of high fish biomass and low shrimp biomass appeared as the most valuable in terms of system performances.     

云计算与饲料企业会计管理融合化发展探究

近年来,互联网和信息技术的快速发展使各行各业出现了深刻变革,其中云计算技术因具有成本低廉、效率高等优点,受到各行业管理者的高度重视,许多企业尝试将云计算与企业管理相结合,以此提升企业的管理水平.但从行业角度看,饲料行业起步相对较早,在经过几十年的发展后已进入相对成熟的阶段,且呈现企业数量众多和产品竞争激烈的局面.在这种...     

烟草马铃薯Y病毒病的发生与综合防治

近年来,烟草马铃薯Y病毒病已成为湖南烟区危害最为严重的病害之一。从症状表现、侵染循环和发病规律3个方面对其进行了概括,并提出综合防治措施。     

关中大蒜病虫害综合防治研究

１９９３－１９９６年对陕西关中大蒜病虫害综合防治技术进行了研究,确定了以匐柄霉叶枯病和根明为主要防治对象,锈病,病毒病害,韭蛆,蓟马,绿圆跳虫,蒜萤叶甲等为兼治对象,提出了以农业防治为基础,药剂防治为重点的综防策略,确立了一套适用防治措施和田间防治历。     

确定含水层参数的混沌序列优化算

以泰斯公式为例，将混沌序列优化算法应用于求解分析抽水试验资料，确定含水层参数的函数优化问题．就混沌序列长度、粗搜索次数和待估导水系数初值取值范围等因素对算法收敛性的影响，进行了数值实验．结果表明：1）混沌序列优化算法可以有效地应用于求解含水层参数计算问题；2）粗搜索次数的多少和序列长度的大小对算法收敛性的影响不明显；3）待估导水系数的初始取值范围对算法的收敛速度有一定的影响，但不会影响最终计算结果．与其它方法相比较，混沌序列优化算法具有原理简单、易于编程和运算、计算结果精度不受人为因素影响和应用范围较宽等优点．     

The potential of flat-bed passive integrated transponder antennae for studying habitat use by stream fishes

Abstract – Describing habitat use by stream fishes is important from both basic ecological and fisheries management points of view. The most widely used methods of measuring habitat use vary in degree of effort required, level of intrusiveness and in the level of spatial and temporal resolution. In this paper, we describe a remote monitoring technique that can provide detailed and continuous data on habitat use of individual fish in the field. The technique is based on the passive integrated transponder (PIT) system, in which a newly developed flat-bed antenna is placed on the stream bottom and simply requires a PIT-tagged fish to swim over it. We present data obtained from work using this new technology on brown trout ( Salmo trutta ) in stream enclosures, in which we describe habitat use and temporal patterns of movement by individuals and relate such data to growth rate and sex of the individual fish as well as to pool depth and time of day. In addition, we describe the range of applications of the flat-bed PIT-antenna as well as the advantages and disadvantages of using the system. ^NOTE     

我国近地面甲烷浓度分布及变化规律

利用我国业务使用的5个大气本底监测站的观测资料,分析了2009年1月至2013年12月不同地区近地面甲烷(CH_4)浓度的分布和变化规律。结果表明:这5年临安站CH_4浓度最高,其次是龙凤山站,上甸子站居中,而香格里拉站和瓦里关站CH_4浓度最低。上甸子站和龙凤山站CH_4浓度具有明显的双峰特征,最高值出现在夏季,次高值出现在冬季;且受人为活动的影响,CH_4浓度日变化幅度很大。而香格里拉站和瓦里关站由于海拔高,人为排放源少,只有1个峰值出现在自然源排放强烈的夏季。除上甸子站CH_4浓度呈逐年略下降趋势外,其余4个站的CH_4浓度都呈逐渐上升趋势。     

新疆农村一二三产业融合发展综合评价指标体系构建及应用

目的 研究针对新疆农村一二三产业发展现状,构建指标体系,对其发展进行评价,找出薄弱环节,提出推进新疆农村一二三产业融合发展措施。方法 收集相关文献资料,运用德尔菲法,聘请相关专家对评价指标进行打分,采用层次分析法和综合指数法构建评价指标体系。结果 新疆农村一二三产业融合发展即将步入成长阶段,发展的薄弱环节主要在农民组织化程度,农业的多功能性的拓展,农产品电子商务发展,农业科技投入,转移劳动力和农村公共资源短缺等方面。结论 新疆已经具备农村一二三产业融合发展的基础,以培育新型农业经营主体为核心,以科技为引领,以融合程度高、带动性强的农业产业化龙头企业为依托,推进农村一二三产业融合发展。