Sustainability Evaluation of Different Systems for Sea Cucumber(Apostichopus japonicus) Farming Based on Emergy Theory

Emergy analysis is effective for analyzing ecological economic systems. However, the accuracy of the approach is af- fected by the diversity of economic level, meteorological and hydrological parameters in different regions. The present study evalu- ated the economic benefits, environmental impact, and sustainability of indoor, semi-intensive and extensive farming systems of sea cucumber （Apostichopus japonicus） in the same region. The results showed that A. japonicus indoor farming system was high in input and output （yield） whereas pond extensive farming system was low in input and output. The output/input ratio of indoor fann- ing system was lower than that of pond extensive farming system, and the output/input ratio of semi-intensive farming system fell in between them. The environmental loading ratio of A.japonicus extensive fanning system was lower than that of indoor farming sys- tem. In addition, the emergy yield and emergy exchange ratios, and emergy sustainability and emergy indexes for sustainable devel- opment were higher in extensive farming system than those in indoor farming system. These results indicated that the current exten- sive farming system exerted fewer negative influences on the environment, made more efficient use of available resources, and met more sustainable development requirements than the indoor farming system. A. japonicus farming systems showed more emergy benefits than fish fanning systems. The pond fanning systems ofA. japonicus exploited more free local environmental resources for production, caused less potential pressure on the local environment, and achieved higher sustainability than indoor farming system.

Case Study:Promoting Sustainable Energy Greenhouse Heating Systems to Small-Scale Local Farms

Biomass energy generated from livestock manure,other agricultural by-products and food waste can be an affordable greenhouse-heating energy source for those seeking lower energy costs.Appalachian State University,North Carolina(NC),USA,has built a 6.1 m×9.1 m greenhouse,called the“Nexus”to test the integrated sustainable energy heating system for growing season extension with less energy cost.This is done by using on-farm biomass resources/wastes such as agricultural waste and wood chips to produce energy coupled with solar water heating to store and supplement required thermal inputs.Growing season extension with heated greenhouses increases the availability of local food throughout the year,expands available markets and increases farmers’profits.Nexus includes an above ground 5,680-L water storage tank and an aquaculture pond.It is supported by a small-scale pyrolysis system,an anaerobic digestion system,solar thermal and compost heating.The preliminary result showed that compared to a conventional space heating system,about 30%of energy was saved to keep the greenhouse temperature available for growing by radiation from the water storage tank.The main purpose of this study was to test the proposed greenhouse heating systems developed at Nexus by implementing pilot systems on two local farms.Pyrolysis and solar thermal system in conjunction with heat storage and delivery system for each farm were built and tested in order to demonstrate how to reduce greenhouse energy use.This paper describes the results of the case study,which showed significant energy savings that can promote the resource-limited farmers’interest.

Enhancing Access to Bank Credit for Small-Scale Farmers in Kisumu and Kiambu Districts, Kenya Through Public-Private Partnership Initiative

In Kenya, small-scale fanning has immense potential in poverty reduction. The growth of farming activities requires sustainable access to affordable credit to boost and sustain production. This study is initiated to investigate factors influencing access to bank credit by small-scale farmers in Kisumu and Kiambu Districts, Kenya. It is necessitated by lack of a comprehensive study documenting the effectiveness of the partnership initiative in improving access to credit for small-scale farmers. The study seeks to address the following concerns： what factors influence access to bank credit by small-scale farmers under the initiative？ Are small-scale farmers in various parts of the country accessing bank credit equally？ Through which sources do farmers get to know about credit products provided through the initiative？ Primary data was collected from 144 farmers in Kiambu and 127 farmers in Kisumu, sampled using systematic random procedure. The cross-sectional survey design was applied to guide the research process. Quantitative analysis generated cross-tabulations with chi-square and binary logistic regression. The study found that out of 144 credit applicants in Kiambu about 56.3% were successful, while in Kisumu only 37.8% were successful. Access to bank credit was significantly associated with farmers＇ gender, education level, income level, farm size, and farming experience. Besides, women were 1.3 times less likely to access bank credit than men. In terms of regional variation, a Kiambu farmer was 2.7 times more likely to obtain bank credit than a Kisumu farmer. The initiative is an innovative approach for enhancing access to bank credit; however, its potential has not been fully exploited. The study recommends the need： to inform farmers about credit products to clear misconceptions and myths associated with bank credit; develop innovative financing packages for small-scale farmers that are also gender-sensitive; and to initiate a training program targeting farmers with appropriate information.

Small-Scale Tomato Cultivators’ Perception on Pesticides Usage and Practices in Buea Cameroon

It has been shown that farmers with limited knowledge of the use and safe handling of pesticides may suffer exposure which results in adverse health effects. In Buea, Cameroon, small-scale tomato farmers commonly use pesticides for pest control. Information was obtained from these tomato farmers to determine the extent and types of their pesticide use, their knowledge of pesticide use and effectiveness, and their perception of potential harm resulting from pesticide use. A standardized questionnaire, interviews, field observations and an analytical ranking game were used to describe the pesticide use of 93 tomato farmers. Many farmers (47.6%) used pyrethiod and organophosphorus insecticides and identified these chemicals as the most effective in pesticide control;these are WHO Class II pesticides which are the most hazardous to humans. Most farmers (83.8%) used knapsack sprayers to apply pesticides, with 76.3% using no or partial personal protective equipment (PPE). It was notable that 55.5% of farmers expressed no concern regarding the wind direction (pesticide drift) during spraying. The results showed a significant association between the method of pesticides application and farm size (P < 0.001). Most farmers (85.0%) reported at least one symptom of acute pesticide poisoning following spraying. This study revealed that the tomato farmers have a high exposure to pesticides secondary to inadequate knowledge of the safe and judicious use of pesticides. Strategies that provide training on the appropriate use of pesticides, how to reduce exposure to and health risks of pesticides and alternative options of pest management and control are required. The study also raised concerns that further control of the sale and distribution of pesticides may be indicated.

Research on Influence Factors of Pig Farmers' Ecological Farming Behavior: Based on the TPB and SEM

China's extensive development model of pig industry gives rise to serious resource and environment bottleneck restriction,it is urgent to transform the existing development model into ecological farming model. In this process,farmers' behavior will play a key role. On the basis of summarizing development connotation and characteristics of ecological agriculture,using survey data of 323 pig farmers in 6 provinces,based on the Theory of Planned Behavior( TPB) it introduced individual characteristics and external environment constraint variables,and made an empirical analysis on factors influencing intention and behavior of pig farmers' ecological farming using the Structural Equation Model( SEM). Results indicate:( i) ecological farming intention of pig farmers has the largest direct effect on their ecological farming behavior;( ii)ecological farming cognition of pig farmers has significant positive effect on their ecological farming behavior;( iii) external environment has the largest indirect effect on their ecological farming behavior,followed by the overall effect,and external environment has significant positive effect on ecological farming attitude and cognition of pig farmers;( iv) individual characteristics( educational level and income level) of pig farmers influence ecological farming behavior of pig farmers through their ecological farming attitude and intention,but the degree of influence is limited.

Study on Mooring Design and Calculation Method of Ocean Farm Based on Time-Domain Potential Flow Theory

In order to calculate the mooring force of a new semi-submerged Ocean Farm quickly and accurately,based on the unsteady time-domain potential flow theory and combined the catenary model,the control equation of mooring cable is established,and the mooring force of the platform under the wave spectrum is calculated.First of all,based on the actual situation of the ocean environment and platform,the mooring design of the platform is carried out,and the failure analysis and sensitivity analysis of the single anchor chain by the time domain coupling method are adopted:including different water depth,cycle,pretension size,anchor chain layout direction and wind speed,etc.The analysis results confirm the reliability of anchoring method.Based on this,the mooring point location of the platform is determined,the force of each anchor chain in the anchoring process is calculated,and the mooring force and the number of mooring cables are obtained for each cable that satisfies the specification,the results of this paper can provide theoretical calculation methods for mooring setting and mooring force calculation of similar offshore platforms.

Empirical Study on Formation Path of Family Farms in Different Environments from the Perspective of ANT

Family farm is an essential modern agricultural micro economic organization. With accelerated advance of rural land circulation and large-scale management,family farm gradually becomes an important choice for modern agricultural management. With ANT as theoretical basis,this paper analyzed formation of family farms in the joint action of endogenous and exogenous forces. Besides,it analyzed Fengsheng Tobacco Family Farm of Guyue Town in Zhucheng City of Shandong Province and Li Chunfeng's Family Farm in Songjiang District of Shanghai.Research indicates that different regional environments bring about different actors and also different formation paths for family farms.

An Analysis of Totalitarianism in Animal Farm from an Allegorical Perspective

Animal Farm is a classic novel based on history,whose author Orwell reveals the totalitarianism under the dark rule of the farm and its potential trend of destruction with his fable art form and extraordinary vision.From the perspective of Benjamin’s fable theory,this paper systematically analyzes the totalitarian rule in the language,the totalitarian rule in worship,and the totalitarian rule in strategy,so as to help people understand historical figures and events objectively.

Establishment of the "Fenlong Energy Theory" and Conjecture of the "Fenlong Dark Matter Flow"

It is the first time that the world’s first new method of farming,the"Fenlong farming technology,"has been systematically clarified,and the"Fenlong body integrating with natural science"has been created in terms of land resource activation,natural fertilization,natural water management,natural ecological improvement(including climate),and natural indirect activation of river water resources.Moreover,the"theory of Fenlong energy"has been established based on its effectiveness.The"theory of Fenlong energy"originates from the"multiplying and incremental utilization of three-dimensional spatial resources"in production practice.Its application to more than 40 kinds of crops such as rice,corn and wheat in 26 provinces including Guangxi,Xinjiang and Tibet shows that:the yield of arable land increases by 20%to 50%(the quality is improved by 5%),the yield of saline land increases by 20%to 100%,and it can retain 100%of water and resist or ease the disaster.The"theory of three-dimensional spatial resources","Fenlong science","Fenlong law"are the theoretical base for the establishment of the"theory of Fenlong energy".Based on the phenomena that the Fenlong crops have particularly developed root systems,white and more fibrous roots,and tall plants,it is proposed for the first time that Fenlong farming breaks the confinement of the bottom layer of the plow and realizes the holographic penetration of material,energy,and information flows,and there may be the speculation of"Fenlong dark matter flow".

家庭农场创业资源整合驱动因素与作用机理研究——基于扎根理论和SEM模型的融合方法

我国现有家庭农场尚处于起步阶段,因受自身弱质性、创业资源匮乏、创业环境复杂性等因素制约而面临着巨大挑战。文章基于相关文献将家庭农场创业资源整合过程界定为识别、获取、配置和运用,使用扎根理论方法分析30个家庭农场资源整合案例,形成创业资源、内在需求、整合意愿、农场主个性特征、创业环境和家庭农场创业资源整合6个维度理论构想,建立驱动因素模型。依据分析结果,借鉴相关测量量表开发创业资源整合驱动因素量表,验证量表信效度并利用结构方程模型对建构的理论模型进行实证检验。结果表明,创业资源和整合意愿直接驱动家庭农场进行创业资源整合,内在需求经由整合意愿驱动家庭农场进行创业资源整合,农场主个性特征和创业环境在内在需求与整合意愿关系中起调节作用。通过拓宽创业资源整合的研究外延,丰富家庭农场创业问题的理论与方法体系,为家庭农场破解资源约束困境提供了新思路。

基于自适应优化AP聚类与BP加权网络的多区域复合短期风电功率预测

精准的风电集群区域功率预测对电源侧的竞价上网具有重要意义。由于同一地区多个风电场受气候影响波动程度相近,可看作具有时空相关性的风电场群,并以此进行集群的合理划分。为此,提出一种基于自适应优化近邻传播(AP)聚类与反向传播(BP)加权神经网络的多区域复合短期风电功率预测模型。首先,通过粒子群优化算法(PSO)优化AP聚类方法对风电场群的历史数据进行集群的聚类与划分;然后,根据得到的最优聚类结果构建风电场群子区域样本训练集;最后,利用基于相关系数权重的BP神经网络对各子区域进行功率预测。算例结果表明:所提方法在24 h日前预测相较传统叠加法与单一BP神经网络可提高1.35%和2.62%的精度,可表明该模型具有优越的预测性能。

“大国小农”格局缘何存续至今——基于马克思主义“小农消亡论”的重新考察

实现“大国小农”向“大国强农”历史性跨越是推进和拓展中国式农业农村现代化的重要理论命题。在资本“剥夺性积累”的宏观叙事中,马克思主义经典作家基于传统小农的自然经济特性阐明了其受资本主义机器大生产排挤而渐趋衰亡的历史宿命,提出社会主义国家应通过“合作社的生产和占有”实现劳动者与劳动条件重新结合的前瞻性思考。中国共产党在跨越“资本主义卡夫丁峡谷”基础上建立起社会主义全新形态范式,借助集体化改造和市场化探索帮助家户经营深度嵌入社会化大生产体系,从而在宏观背景和主体规定层面实现了对经典农户理论的突破和创新,“大国小农”格局由此存续至今。农户家庭虽被重新赋予生产环节的自定义能力和裁量自由,但商业流通资本也正从产业链上下游“迂回”获取其田间生产剩余。新征程上要继续巩固和完善土地集体所有制、严防资本下乡“跑马圈地”,重新激活村社集体统筹优势、提升小农生产组织化和社会化程度,在价值创造与价值实现的辩证统一中实现全体农民共同富裕,走出一条家户经营“渐进式”改良和转型的中国特色小农现代化之路。

现代农庄创建的驱动因素研究——一项多案例比较研究

现代农庄的出现标志着一种全面多样的,集成了农业、旅游、文化等多种功能的现代化农业经营模式的形成,能够激励企业参与市场竞争,优化营商环境,是实现乡村振兴的重要途径。基于对杨凌示范区9家农庄深度访谈,应用扎根理论研究影响现代农庄创建的驱动因素。结果表明:对现代农庄的创建,农村发展的“引力”是内驱因素,城市发展受阻的“推力”是外部情境因素,技术发展的“助力”是内部情境因素。在内驱因素影响下,经营主体产生创建现代农庄的意识,并通过内外情境因素影响主体的意识来影响其行为,最终完成现代农庄的创建。最后提出了增加资金、设施、技术支持,强化行政规范管理等促进农庄创建和发展的建议。

农户参与农耕文化保护和传承意愿研究

农耕文化作为中华文明发展的根基,对文化强国和农业强国建设具有重大意义和关键价值。基于计划行为理论剖析影响农户参与农耕文化保护和传承意愿的因素,以蚌埠市五河县刘朵村为研究区域,通过走访调查收集数据,利用二元Logistic回归模型进行实证分析。研究结果表明:农耕文化的经济价值、社会价值、邻居朋友的带动、基层政府的宣传、参与农耕文化活动的精力和能力以及受教育水平对于农户参与农耕文化保护和传承意愿有显著的正向影响。因此,在推动农耕文化发展中,要切实增强农户的主体意识,加强政府的宣传和推广力度,显现农耕文化的经济价值和社会价值,鼓励农户参与农耕文化发展事业,发挥村干部的示范带头作用,提高农户的自我效能感,调动农户的参与积极性,保障农耕文化稳步有序发展。

基于贝叶斯理论和条件协同模拟的海上风电场土体参数空间变异性表征

海上风电场土体参数的空间变异性表征对海上风电工程具有重要意义,多源土体参数融合可降低表征结果的不确定性。然而,现有方法无法利用非同位多源土体参数数据,且不考虑统计不确定性对空间变异性表征的影响。为此,提出了基于贝叶斯理论的条件协同模拟方法,该方法根据非同位多源土体参数数据,利用贝叶斯理论估计交叉变异函数,再利用条件协同模拟方法生成大量土体参数空间分布的模拟样本,表征参数空间变异性,表征过程中合理地考虑模型参数的统计不确定性。以某海上风电场为工程背景,利用提出的方法融合无侧限抗压强度(qu)和标准贯入试验(SPT)击数N值,表征qu的空间变异性。结果表明:提出的方法可以根据有限非同位的qu和N值数据,表征qu的空间变异性,合理地反映了有限数据条件下统计不确定性的影响。此外,利用强信息先验分布或者融合标准贯入数据,可以降低变异函数模型参数统计不确定性和条件协同模拟结果的不确定性。

基于理实一体化的农事学耕读思政育人改革与实践

农事学是农学专业开设的一门专业核心必修课。农事实践是农学专业学生掌握农事生产技能、理解优秀农耕文化内涵及把专业理论知识与实践深度融合的重要途径。近年来,尽管涉农高校农学专业学生培养过程中重理论、轻实践的现状得到一定的改善,但在培养实践能力方面仍然与现代农业产业和农业强国建设的需求差距很大。山西农业大学农事学教学团队进行一系列教学改革,以耕读教育实践育人为核心,深入挖掘农事学所蕴含的丰富思政元素,创新农事实践活动的组织形式,完善多元化综合考核评价体系,探索构建基于理实一体化的农事学全过程思政育人模式。

基于Koopman理论的风电场调频动态等值建模

针对风电场动态运行条件下等值建模精度偏低、模型复杂度高的问题,提出一种基于Koopman理论的动态等值建模方法。首先,基于风电场实际运行数据,得到各风机参与调频的动态过程曲线,完成数据的采样和处理;其次,基于Koopman理论,从风机可观测量出发,考察定义在状态空间中相关函数的演化,将非线性风机系统近似转化为更高维函数空间中的线性系统,得到能描述各风机调频动态特性κ算子;然后,采用间隙测度方法对各机组的κ算子进行聚类分群,根据分群结果建立风电场的等值模型;最后,通过算例仿真表明所提方法的准确性。所提方法可有效表征风电场参与调频的复杂响应特性,提高了等值模型的精度。

西部农牧交错带互助养老服务优化路径研究

受到地区经济发展不平衡以及劳动年龄人口外流等因素的影响,我国西部农村牧区养老问题严峻,老年人的养老环境及养老模式选择问题亟待各界关注。为解决养老问题,互助养老逐步在农村牧区兴起,并得到了广泛推广。本文通过对我国西部农牧交错带老年人互助养老服务现状进行田野调查,运用扎根理论解析这一特殊区域互助养老模式运行过程中的瓶颈,归纳出3个主范畴、8个副范畴和相对应的23个子范畴。研究发现,虽然互助养老模式在不同地区的实践中成效显著,但在推进过程中面临着发展后劲不足的问题,主要存在互助服务空壳运行、基本养老资源匮乏与基层治理能力不足等三大问题范畴,范畴与范畴之间存在着内在的联系,不同维度又有各自的问题。研究认为,要从丰富互助养老服务内容、社会化运营互助养老幸福院、提升基层治理能力、涵养互助文化、养老政策向农村牧区倾斜、提升经济保障与增强服务提供等方面进行优化,从而实现西部农牧交错带互助养老服务的完善。

加入合作社对家庭农场收入的影响——基于共生理论的研究

家庭农场与合作社融合发展是完善农业生产经营体系的重要路径。为促进家庭农场与合作社融合发展,完善农业生产经营体系,基于共生理论,分析家庭农场加入合作社的增收效应及其作用机制。研究表明:加入合作社能显著提高家庭农场经营性收入,家庭农场与合作社能够共生发展;加入合作社对家庭农场经营性收入的影响存在异质性,土地经营规模较大、以种植业为主和农场主受教育程度较低的家庭农场加入合作社的增收效应更为显著;合作社主要通过为家庭农场提供信用担保和社会化服务以及与其建立股权契约合作,进而构建融资约束机制、服务联结机制和利益联结机制影响家庭农场经营性收入;在家庭农场与合作社融合发展所形成的关系中,互惠共生关系对家庭农场增收效应的影响更加显著。

An Improved Group Decision-Making Model for the Investment Options of Small-Scale Photovoltaic Systems Based on Cumulative Prospect Theory and Choquet Integral

With the development of photovoltaic(PV) industry, installing small-scale PV systems which are integrated into the buildings becomes popular. Therefore, it is important to make optimal investment decisions for investors and consumers. This paper proposes an improved group decision-making method which integrates the cumulative prospect theory and Choquet integral for the investment options of small-scale PV systems. From the perspective of sustainability, the alternatives are evaluated by four criteria, including economic benefits, solar energy condition, carbon emissions and social benefits. Since the performances of criteria are given by decision makers as linguistic variables, the proposed method measures the criteria values by intuitionistic trapezoidal fuzzy numbers. Then the alternatives are evaluated and ranked to determine the optimal option. Finally, the proposed method is implemented in a case study to illustrate its feasibility and effectiveness.