基于模拟退火算法优化给水管线造价公式研究

给水管线造价公式的精确性对工程经济分析与给水管网优化的科学性和经济性有重大影响。通过五个地区的铸铁管综合单价数据,采用最小二乘法对各组数据进行多项式一至十次的拟合,确定了给水管线造价公式的最佳拟合次数为三次;进一步采用模拟退火算法对拟合的多项式参数进行优化计算,求解给水管线造价公式。结果表明:凭借模拟退火算法随机全局搜索模式以及不受函数性质影响的优势,能够克服传统算法难以求解多阶导数的困难,提高公式拟合精度。     

基于灰色关联法的小型农田水利工程建设项目绩效评价研究

运用灰色关联法原理,采用均方差法计算指标权重,根据近年来湖北省进行小型农田水利工程建设项目绩效评价的实际情况,建立了小型农田水利工程建设项目评价定性定量混合指标体系和模型,应用该模型和方法对湖北省2012年第二批20个小农水重点县工程建设项目进行了评价(作为研究,各县、市名以汉语拼音字头代替)。结果表明:LHK、SSS、ZJS、DJK、XTS等14个县为优秀,XCX、TMS、JSX等5个县为良好,CYX为一般,无及格等级的重点县。评价结果与实际基本相符。证明本文所提出的模型和方法可应用于实际,是一种快速便捷的评价工具。     

基于外碾削立式碾米机的离散元法仿真分析

引入离散元仿真技术对碾米机械进行仿真研究,旨在探索碾米机在碾白过程中的碎米机理。通过模拟大米在输送过程来获得速度、运动轨迹等数据,由图表等方式输出模拟结果,可以看到米粒群绕着碾辊做螺旋形前进的运动规律。该技术在粮食机械设计系统的研究中具有重要的推广意义,可为碾米机优化设计提供理论参考,也为其他农业物料精确定量分配提供了一种新的方法。     

基于标记的极半径极值红枣形状识别方法

形状是分级的最重要参数之一,本文采用标记法对红枣形状进行了识别。通过图像预处理获取红枣二值图像,通过边界追踪获取目标边界笛卡尔坐标,并将其转化为极坐标,对目标图像进行缩放旋转使均值圆成为基线,切割的4部分边界曲线能完整表达。对边界曲线进行多项式拟合,获取极值点坐标,将其映射回被拟合曲线上,获取对应极值点坐标。若两极小极半径差值大于阈值,则红枣畸形;若两极大极半径附近区域极半径过渡平缓,判红枣为规整,否则为较规整。取53粒红枣进行检测,其中16粒畸形,17粒较规整,20粒规整。检测结果表明:畸形枣识别准确率达100%,较规整枣的识别准确率94%,规整枣识别准确率95%,可基本满足红枣分级系统精度的要求。     

区域农业水资源恢复力可变模糊评价模型

区域农业水资源系统是与自然及人类活动紧密联系的复杂适应系统,不断与周围环境发生物质、能量和信息因素方面的交换和作用。以黑龙江省农垦红兴隆管理局12个农场为研究基点,运用主成分-相关分析法筛选评价指标,构建农业水资源恢复力评价指标体系,采用CRITIC法确定指标权重,结合可变模糊模型评价方法对其农业水资源系统恢复力进行评价,并利用ArcGIS技术对其进行分区,结果表明:双鸭山、八五三、北兴和八五二农场的农业水资源恢复力为Ⅱ级,饶河、二九一、五九七、红旗岭、友谊、江川、宝山和曙光的农业水资源恢复力为Ⅲ级。研究成果揭示了当地农业水资源系统力恢复情况,为农业水资源系统恢复力研究提供了一种新的研究模式。     

基于Z比分数的参考作物腾发量计算方法优选

参考作物腾发量(ET0)是计算作物需水量的关键,是进行农田水分管理和灌溉预报的主要参数。但不同ET0计算方法的结果存在明显差异。用能力统计量Z比分数,对FAO56Penman-Monteith、Hargreaves-Samani、Irmark-Allen拟合和Priestley-Taylor四种常用ET0计算方法在不同天气条件下的计算结果精度进行了对比分析。结果表明,Priestley-Taylor与FAO56Penman-Monteith方法的计算结果在精度上具有较高的一致性,与有关文献结果相吻合,其中前者精度略佳。且Z比分数参数受极端值的影响较小,计算简便、适用性强,克服了常规方法公式繁杂、编程实现困难的缺点,说明Z比分数法能够更好地适用于ET0计算方法的优选。研究结果可为农业水土工程领域有关参数计算与测定方法的优选提供借鉴。     

Study on the Change Rule of Egg Yolk Antibody in Laying Hens after First Immunization by Japanese Encephalitis Virus

The purpose of this experiment was to study the immunization rule of the egg yolk antibody affected by different vaccines,immunization dose and injection ways and further to discuss the optimal immunization procedures of the laying hens for the preparation of egg yolk antibody against swine Japanese encephalitis virus.180 brown laying hens without any vaccines were selected and divided into 18 groups randomly,each group of 10 hens.Groups 1,2 were the control groups,injected with the sterile saline;Groups 3 to 10 were injected with subcutaneous or intramuscular injection,and the vaccine was injected with 0.2,0.5,1.0 and 1.5 mL successively.Groups 11 to 18 were also adopted two kinds of injection,followed by the same dose of vaccine immunization.Six eggs of each experimental group were gathered before immune day and after 3,7,10,14,18,21 and 28 days,the egg yolk antibody was extracted and the titer was determined.As a result,the egg yolk antibody titers of groups 1 to 6,11 and 12 were all 0,and no significant immune response produced;The hens from 7 to 10 groups were injected with the inactivated vaccine.After 7 days,the average antibody titer reached the peak,and the duration of the antibody was 14 days.The hens from 13 to 18 groups were injected with the attenuated virus vaccine.After 14 days,the average antibody titer reached the highest value,and the duration of the antibody was 21 days.The egg yolk antibody titers were not significantly different in the two compared experiment groups with the same injection dose but with different injection ways (P>0.05).With the same injection way of each experiment group,and the difference was significant (P>0.05).Compared with some groups with the same injection and vaccine,the titer of yolk antibody was gradually increased with the increase of the immune dose,and the difference was significant (P<0.05).The results showed that,no matter intramuscular or subcutaneous injection,in order to produce a significant immune response to hens,the immune antigen dose was 1.0 mL inactivated vaccine or 0.5 mL attenuated vaccine at least.Compared with the attenuated and inactivated vaccine,inactivated vaccine stimulated the body to produce the antibody faster,but the maintenance time was shorter;The lower dose of attenuated vaccine could stimulate the body to produce antibodies,but the speed was slower,the maintenance time was longer.     

Preparation and Identification of Canine Parvovirus NY Strain VP2 Protein Polyclonal Antibody

This study was aimed to prepare canine parvovirus (CPV) VP2 protein polyclonal antibody.The recombinant expression vector pET28a-CPV-VP2 was constructed and transfromed into E.coli BL21 (DE3),the expression of recombinant proteins was induced by IPTG from which the fusion protein was identified by SDS-PAGE.The target protein was purified and emulsify with adjuvant,the prepared immunogen was inoculated into rabbit by subcutaneous injections to prepare of VP2 protein specific polyclonal antibody.The immuno-activity,titers,neutralization titers of the prepared polyclonal antibody were determined by immunoperoxidase monolayer assay (IPMA).The results showed that the expressed recombinant protein VP2 (rVP2) existed in the form of inclusion body with a molecular weight of 72 ku.The prepared polyclonal antibody titer was 1 600 dilution,the virus titer was 10⁷ TCID₅₀/mL,the neutralizing titer was 1∶2 884.The antibodies showed specific reaction with CPV.In conclusion,rVP2 specific polyclonal antibody showed wonderful immunocompetence,specificity and neutralizing activity,providing foundation for the development of genetic vaccine and clinical therapeutic method.     

Establishment and Application of a Multiplex RT-PCR Assay for Detection of PEDV,TGEV and PRoV

In this study,a multiplex RT-PCR assay was established to differentially detect porcine epidemic diarrhea virus (PEDV),porcine transmissible gastroenteritis virus (TGEV) and porcine rotavirus (PRoV) after optimization of the reaction conditions.Three pairs of primers PEDV-N,TGEV-M and PRoV-VP6 were designed for specifically amplifying PEDV N gene,TGEV M gene and PRoV VP6 gene,respectively.The assay could specifically amplify PEDV,TGEV and PRoV,but not classical swine fever virus (CSFV),porcine foot and mouth disease virus (FMDV),pseudorabies virus (PRV),porcine parvovirus (PPV) and porcine circovirus type 2 (PCV2).The detection limits of PEDV,TGEV and PRoV standard recombinant plasmids were 1.41×10³,1.41×10² and 1.41×10³ copies/μL,respectively.The repeated reaction under the same conditions obtained uniform results.The assay was used to detect a total number of 190 clinical samples,of which 42 (22.11%) samples were positive for PEDV,58 (30.53%) samples for TGEV and 34 (17.89%) samples for PRoV,and there were mixed infection among these viruses.The results indicated that this multiplex RT-PCR assay had the advantages of sensitivity,specificity and repeatability and provided a useful tool for differential detection and epidemiological investigation of PEDV,TGEV and PRoV.     

Screening of Probiotics Inhibiting E. coli K88 in vitro

The probiotics tested in the experiment were isolated from the intestinal of weaning piglets.The isolated probiotics and E.coli K88 were inoculated into the culture of intestinal porcine epithelial cell-1 (IPEC-1).The activity of lactate dehydrogenase (LDH) in the supernatant was measured after incubating for 2.5 h.At the same time, the probiotics and E.coli K88 were co-cultured in vitro, the number of E.coli K88 was counted and the probiotics which could be resistant to the E.coli K88 were selected 2.5 h later.The results showed that the Lactobacillus casei and Bacillus coagulans could significantly reduce LDH activity (P<0.05), decrease the damage of E.coli K88; Bacillus coagulans could inhibit the growth of E.coli K88.At the same time, Bacillus coagulans could resist high temperature, acid and bile salt.The results showed that Bacillus coagulans strains had great potential as the application of probiotics strains.The methods could be used as a model of screen probiotics which could inhibit the growth of E.coli K88 in vitro.