瘦肉型猪杂交组合的筛选研究

本试验研究了早籼稻饲粮中添加NSP酶对生长猪作用效果的影响。结果表明，与对照组比较，早灿稻饲粮中添加NSP酶制剂使生长猪日增重提高了11．18％（P＜0．05），料重比降低了9．42％（P＜0．05）；粗蛋白、粗脂肪和粗纤维的表观消化率分别提高了18．76％（P＜0．01）、16．04％（P＜0．05）、108．57％（P＜0．05）；腹泻率、粪便大肠杆菌数分别下降了37．00％（P＜0．05）、81．29％（P＜0．05）。     

以大麦作基础饲料对猪胴体及肉质的影响

选择日龄、体重相近的健康去势约×荣杂交仔猪作为试验对象,研究在日粮消化能、粗蛋白质、赖氨酸及钙磷水平相近的条件下,以大麦替代玉米作基础饲料对猪胴体性状及肉质有何影响.结果发现,①饲喂大麦型日粮猪只的胴体性状优于饲喂玉米型日粮猪只,表现在胴体瘦肉率增加(试验组53.01%,对照组50.01%,提高3.00个百分点),背膘厚度降低(6～7肋膘厚试验组3.82cm,对照组4.22cm,降低9.48%;肩、腰、荐三点均膘试验组4.03cm,对照组4.18cm,降低3.59%),但差异均未达显著性水准(P＞0.05);②在肉质方面,饲喂大麦型日粮猪只的大理石纹评分、肌肉粗脂肪含量及肌肉干物质含量均稍低于饲喂玉米型日粮猪只.大理石纹评分试验组为2.75分,对照组为3.08分(sig=0.110);肌肉粗脂肪含量试验组为2.61%,对照组为3.47%(sig.=0.281);肌肉干物质含量试验组为26.61%,对照组为27.63%(sig.=0.083).但差异均未达显著性水准(P＞0.05).     

撒坝猪及其杂交组合的肉质研究

本研究测定了撒坝猪及以它为母本的两个杂交组合（长×撒二元杂、杜×长撒三元杂）肥育猪22头（♂10头、♀12头）的PH值、肉色、大理石纹、熟肉率、失水率、贮存损失、嫩度、化学成分、组织学特性等9项13个指标。测定结果表明，撒坝猪肉质优良，是食用和肉品加工的上乘原料。与撒坝猪相比，两个杂交组合的肉质在PH值、保水性、嫩度、化学成分等项指标上有不同程度下降。但未见PSE肉和DFD劣质猪肉。     

不同杂交组合生长育肥猪肉质性状变化规律的研究

分别选择体重在20kg左右的杜×长×大及长×荣2个杂交组合的健康去势仔猪48头(公母各半),每个杂交组合6个重复(公母各3个重复),每个重复以8头猪起试。分别测试20kg、35kg、50kg、80kg及100kg左右时的肉质性状,研究西南地区典型杂交组合生长育肥猪肉质性状随体重的变化规律。结果表明,随着体重增加,杜×长×大肉色评分无明显变化,而长×荣则呈直线上升趋势;杜×长×大肌肉pH1呈直线下降趋势;肌肉失水率2个杂交组合均有升高趋势;肌肉水分含量杜×长×大无明显变化,而长×荣则呈直线下降趋势;肌内脂肪含量2个杂交组合均呈直线上升趋势。2个杂交组合间肉质差异明显,肉色评分、肌肉水分含量及肌内脂肪含量均有显著或极显著的不同(P<0.05或P<0.01),综合各指标看,长×荣猪肉质优于杜×长×大,特别是在肉色和肌内脂肪含量方面有着明显优势,杜×长×大达100kg时肌内脂肪为2.84%,长×荣则为5.35%。     

撒坝猪专门化母系及其杂种猪的生长胴体和肉质特性的研究

由云南地方猪种撒坝猪选育的专门化母系，在杂交体系应用中不仅能提高杂种优势利用效果，且本身肉质优良，肌纤维较细、肌肉脂肪丰富，生产的杂种猪亦具有较好的肉质。     

胆囊收缩素主动免疫对猪生产性能及胴体品质、肉质的影响

此试验研究胆囊收缩素(CCK)主动免疫对猪生产性能及胴体品质、肉质的影响。试验结果表明,CCK主动免疫诱发高强度的免疫应答,试验组抗体滴度在第71天比对照组高67.73%,差异极显著(P<0.01);试验组猪的日增重比对照组提高21.23%,日采食量提高16.23%,料重比降低4.86%,但均差异不显著;试验猪屠宰体重比对照组增加12.68%,背膘厚、胴体长、眼肌面积与对照组差异不显著,CCK主动免疫对猪的肉色评分、大理石纹评分、pH、滴水损失以及肌肉的脂肪/蛋白质比例没有影响。结果显示,CCK主动免疫诱发试猪高强度的免疫应答,提高猪的生产性能,但不影响猪的胴体品质和肉质。     

不同硒源对肥育猪鲜肉肉色和滴水损失的影响

占秀安等选用108头体重60kg左右的杜长大三元杂种肥育猪，按饲养试验要求分成3组．每组3个重复，每个重复12头。对照组不添加硒(基础饲粮中硒的实测值为0．045mg／kg)，亚硒酸钠组和硒代蛋氨酸组均添加硒0．30mg／kg，试验期40天。     

二花脸猪和双肌臂大约克、新丹系长白猪的选育与杂交利用研究

二花脸、双肌臀大约克、新丹系长白纯种和长·二、大·二杂种经产母猪46、389、215、34、42窝的窝总产仔数分别是15.57、11.81、11.89、14.97、15.02头,窝产活仔数分别是14.80、11.45、11.66、14.44、14.60头;前三组纯种和大×二、长×二、大×长·二、长×大·二杂种共7组每组各20头育肥猪的全期日增重分别是480.3、829.8、806.3和741.4、720.4、781.5、770.3g,料重比分别是3.89、2.81、2.83和3.26、3.29、3.23、3.26,每组各屠宰6头的平均瘦肉率分别是43.65%、65.54%、65.81%和53.93%、54.02%、58.73%、59.46%,各组母猪平均每头年产瘦肉量分别是737.15、1283.38、1282.88和1236.48、1230.43、1298.65、1368.46kg。     

半胱胺、L-肉碱对肥育猪生长性能和胴体品质的影响

选择60kg左右的杜大长三元杂种猪144头,按体重接近原则分为4组,每组3个重复,每个重复12头。对照组饲喂基础饲粮,3个试验组分别饲喂基础饲粮 L-肉碱100g/t、基础饲粮 半胱胺75g/t、基础饲粮 L-肉碱100g/t 半胱胺75g/t,饲养试验38天,饲养试验结束后每组选取6头(公母各半)进行屠宰试验。结果表明,饲粮中添加半胱胺75g/t和半胱胺75g/t L-肉碱100g/t可使肥育猪平均日增重分别提高7.83%(P<0.05)和8.55%(P<0.05),平均日采食量提高8.43%(P<0.05)和8.05%(P<0.05)。添加L-肉碱100g/t、半胱胺75g/t和L-肉碱100g/t 半胱胺75g/t可使肥育猪脂肪率分别下降11.81%(P<0.05)、9.81%(P<0.05)和17.05%(P<0.05),瘦肉率分别提高5.34%(P<0.05)、5.20%(P<0.05)和6.11%(P<0.05),眼肌面积分别提高7.41%(P<0.05)、5.44%(P>0.05)和9.49%(P<0.05),肩部背膘厚分别降低12.50%(P<0.05)、5.45%(P>0.05)和14.10%(P<0.05),最后肋骨处背膘厚分别下降24.86%(P<0.05)、7.57%(P>0.05)和27.03%(P<0.05)。添加L-肉碱对猪肉滴水损失无显著影响,但能显著改善肉色,添加半胱胺对肉质无明显影响,两者同时添加可使滴水损失下降16.08%(P<0.05)。添加半胱胺和L-肉碱具有协同作用。     

促生长激素释放肽对肥育猪生产性能、养分消化率和胴体性状的影响

此试验研究注射促生长激素释放肽(GHRP-2)20μg/kg体重对猪生长、养分消化率和胴体组成及特性的影响。采用单因子试验设计,将10头杜长大三元杂种去势公猪(约64kg),分为对照组和试验组2个处理,每个处理5个重复,每个重复1头猪。2个处理分别为:(1)空白对照组,隔天注射和试验组相等剂量的生理盐水;(2)试验组,隔天肌肉注射GHRP-220μg/kg体重,共注射14天。试验期为4周,期间以周为单位记录增重和采食量,到28天时结束饲养试验,对所有猪进行放血屠宰。结果表明,试验组全期生产性能与对照组相比,注射GHRP-220μg/kg体重使日增重增加14.15%(P<0.05),料重比下降11.92%(P<0.05),而日采食量(kg)几乎相等(分别为3.19±0.16,3.2±0.2)。注射GHRP-220μg/kg体重对胴体组成没有显著的影响(P>0.05);对养分表观消化率影响差异不显著(P>0.05),蛋白质表观利用率提高7.46%(P<0.05);提高了血钙(P<0.05)和极低密度胆固醇水平(P<0.01),降低了甘油三脂水平(P<0.01)和乳酸脱氢酶活力(P<0.05)。结论,GHRP-2可以提高猪的生产性能,但在改善胴体组成上效果不明显。     

A comparison among different modified Priestley and Taylor equations to calculate actual evapotranspiration with MODIS data

Priestley and Taylor's (1972) equation to estimate evapotranspiration (ET) stands for its simple form and data requirement. Although the original equation was developed for saturated surfaces, it has been widely extended to unsaturated surfaces. In this paper, different hypotheses to modify Priestley and Taylor's equation for unsaturated surfaces are compared. In general, ET models for unsaturated surfaces assume that the process is ruled by the available radiant energy and surface moisture or the atmospheric conditions or both surface and air states. The results presented here suggest that both atmospheric and surface variables should be jointly parameterized in order to obtain estimates with errors lower than 20%, which are common in ground observations. While surface condition parameterizations alone, such as those proposed by Barton (1979 Barton, I.J. 1979. A parameterization of the evaporation from nonsaturated surfaces. Journal of Applied Meteorology, 18: 43–47. [Crossref] , [Google Scholar]) and Jiang and Islam (2001 Jiang, L. and Islam, S. 2001. Estimation of surface evaporation map over southern Great Plains using remote sensing data. Water Resources Research, 37: 329–340. [Crossref], [Web of Science ®] , [Google Scholar]), show errors slightly larger than 20%, unaided atmospheric parameterization results in errors of about 50% of the mean ET. Our recently proposed model, with atmospheric and surface parameters, keeps the simple form of Priestley and Taylor's original equation while benefiting from remotely sensed data. Estimates with our model would have errors lower than 20%.     

Optimal buffer allocation of serial production lines with quality inspection machines

Using Taylor series expansion and probability generating function technique, we present an approximation method for the analysis of the average steady state throughput of serial production lines with unreliable machines, finite buffers and quality inspection machines. Employing the approximation method, we propose an analytic method for the optimal buffer allocation to achieve a desired throughput. The proposed methods are validated by computer simulations.     

A comparison of Magal's service quality instrument with SERVPERF

The role of service quality has become critical to the success of organizations. Therefore, it is important to use a reliable instrument to measure information service quality. SERVQUAL is a popular instrument for doing this, but, though widely used, it has been criticized for its reliability and validity. Use of the performance measures from SERVQUAL to form SERVPERF has addressed some of these issues. However, Magal's instrument on information center success was found effective within a service context because of its service orientation.     

Sharing beliefs among agents with different degrees of credibility

This paper introduces an approach for sharing beliefs in collaborative multi-agent application domains where some agents can be more credible than others. In this context, we propose a formalization where every agent has its own partial order among its peers representing the credibility the agent assigns to its informants; each agent will also have a belief base where each sentence is attached with an agent identifier which represents the credibility of that sentence. We define four different forwarding criteria for computing the credibility information for a belief to be forwarded, and for determining how the receiver should handle the incoming information; the proposal considers both the sender’s and the receiver’s points of view with respect to the credibility of the source of the information.     

A comparison of vibrotactile thresholds on the finger obtained with different equipment

Vibrotactile thresholds on the finger have been compared using two alternative systems. One system prescribed the push force, the contact force, and the surround, while this was not defined for the other system. The experiment was performed with nine male subjects attending on three different days. It was found that the two systems yielded vibrotactile thresholds which were significantly different. The dependence of vibrotactile thresholds on the frequency of vibration, the area of contact with vibration, the conditions surrounding the contact area, the contact force, the push force, the finger temperature, and the distortion of waveform must be considered when quantifying vibrotactile thresholds.     

不同网络负载的Ad Hoc网络路由协议性能分析

通过实验对一种表驱动路由协议(DSDV)以及其中两种按需式路由协议(DSR和AODV)协议的性能进行比较和分析.利用NS-2仿真软件,设计了基于不同网络负载的多组仿真模型,并根据模型进行仿真.之后从分组投递率、时延和路由负荷三个性能指标参数对仿真结果进行了比较.实验结果表明:按需式路由协议DSR和AODV要优于基于表驱动的路由协议DSDV;在两种按需式路由协议之间,随着不同网络负载的加重,AODV协议比DSR协议的性能优势越来越明显.同时分析了造成不同协议之间性能差距的原因,针对AODV协议提出了今后的改进方向.     

Parasitic motion comparison of 3-PRS parallel mechanism with different limb arrangements

The 3-PRS parallel mechanism (PM) is an important category of lower-mobility parallel mechanisms. Because it can undergo one translational degree of freedom (DOF) and two rotational DOFs, the 3-PRS PM has great potential in practical application and has received extensive attention. Parasitic motion occurring in the constrained DOFs of a 3-PRS PM is a key issue affecting its application. First, the 3-PRS PM is classified into seven subcategories based on the geometrical arrangements of limbs. Then, parasitic motion of each subcategory is discussed in detail and case studies are presented. It is illustrated that the complexity of parasitic motion of the 3-PRS PM is determined by the limb arrangement. The architecture of the 3-PRS PM without parasitic motion is also identified.     

Performance evaluation of continuous production lines with machines having different processing times and multiple failure modes

This paper presents an approximate analytical method for the performance evaluation of asynchronous production lines with deterministic processing times, multiple failure modes and finite buffer capacity. The discrete flow of parts is approximated by a continuous flow of material. The technique developed here is based on the approximate evaluation of a K machine line by the evaluation of K−1 two-machine lines: unlike previous work on this subject, the multiple failure approach allows to consider real and virtual failure modes for each building block in which the original line is decomposed. Indeed, to reproduce in each two-machine lines the flow of material observed in the related buffer of the original line, real failures are used to take into account the reliability of the physical machines while virtual failures are introduced to model the different interruptions of flow that can arise inside the line thus preventing machines from working. To assess the accuracy of the proposed method, extensive simulation and numerical experiments have been carried out.     

二种夹套结构聚酯终缩聚釜有限元分析比较

为考察和比较整体夹套结构与半圆管夹套结构聚酯终缩聚釜内筒的径向变形,用ANSYS进行设计工况下的强度和变形分析．结果表明,虽然整体夹套结构聚酯终缩聚釜耗材较多,但内筒径向变形较小．建议采用T形加强圈提高半圆管夹套结构聚酯终缩聚釜中内筒刚度,减小内筒径向变形．     

基于图像质量加权的D-S证据理论多生物特征融合识别

对人脸和指静脉在决策层的融合识别,给出一种新的组合图像质量评价方法,并采用一种改进的基于图像质量加权的D-S证据理论融合这两种生物特征。首先,组合图像质量评价法采用清晰度和对比度、相关系数的组合方法来评价生物特征图像质量;其次,应用改进的基于图像质量的匹配值增强方法和D-S证据理论,减少了极大值图像质量指标的影响,使图像质量加权与实际情况更趋一致。实验结果表明,与没有考虑图像质量因素相比,考虑了图像质量信息的D-S证据理论融合方法提高了识别效果。