木粉/PVC复合材料挤出流动性的影响因素

研究木粉的粒径、添加剂的种类及配比等因素,对木塑复合材料挤出流动性的影响.结果表明:木粉粒径越小,复合物料在挤出过程中的流动性能越差,所制备的木塑复合材料色差越大,且产品材色越深.综合考虑加工特性和制品材色,宜选用木粉粒径45～60目;并添加稀土热稳定剂及铝酸酯偶联剂,可以提高物料的挤出流动性.     

变分不等式的加性广义Schwarz算法

将加性广义Ｓｃｈｗａｒｚ算法推广到求解变不等式，并在适当条件下证明了其收敛性。     

草原蝗虫开发利用的研究

青海草原环湖及柴达木蝗区大部分地面平缓，宜于机械作业。蝗虫种群密度８０～１２０头／ｍ２者居多，面积为４０～５０万ｈｍ２，贮量小年为４８４０Ｔ，大年为６５６０Ｔ，开发前景广阔。蝗虫粉含粗蛋白７４．８８％，居我国目前优良饲料之首。经试验，作为饲料添加剂与５０％的进口鱼粉比较，京黄１号７日龄肉仔鸡饲喂４９天后成活率为８８．７１％，体重平均增长１０２０．２ｇ，二者差异不显著；星杂二八八６～８月龄蛋鸡饲喂后产蛋量提高１８．０８％，产蛋率提高７．９９％，完全可以代替鱼粉。新研制的捕蝗机捕蝗率为６５．０～７４．２％，生产率２．７４ｈｍ２／ｈ，单机捕幅４ｍ。以１９９３年的市场价格为准，机捕的经济效益为２８．６０元／ｈｍ２，且有突出的社会和生态效益。     

毛细管区带电泳测定饲料添加剂中酪蛋白磷酸肽含量的方法研究

利用毛细管区带电泳(CZE)对饲料添加剂中酪蛋白磷酸肽(CPP)样品进行分离，结果显示，用四硼酸钠缓冲溶液(20mmmol/L,pH9.2)及50cm×70μmi.d.石英毛细管柱，在工作电压30kV、检测波长200nm、柱温25℃的条件下，CPP得到较好的分离；同时，采用外标法对饲料添加剂样品中CPP各组分的含量进行了测定。     

中草药添加剂强力速补的抗应激试验研究

以中草药为主体的饲料添加剂强力速补,具有提高蛋鸡产蛋率的作用。以250%的强力速补药液0.2ml/10g给小白鼠灌胃,观察在寒冷、高温、缺氧条件和水浴中小白鼠的存活时间。结果显示试验组小白鼠存活时间明显长于对照组P<0.01或P<0.05,说明强力速补对机体具有良好的抗应激效应。     

The Influence of Genotype–Environment Interaction on the Grain Yields of 10 Pigeonpea Cultivars Grown in Kenya

To study the importance of the effects of genotype–environment interactions on the yield of pigeonpea ( Cajanus cajan L. Millsp.), 10 early-maturing genotypes were grown in a randomized complete block design with three replications in a total of seven environments spread over five regions of Kenya between 1987 and 1988. Results indicated the presence of a substantial genotype–environment interaction effect on grain yield. The observed significant genotype–environment interaction effect is discussed in relation to its importance in pigeonpea grain yield evaluation studies. It is noted that the best genotype in one environment is not always so in other environments. Results from regression analysis indicated that this method of analysis is appropriate for describing the response of pigeonpea genotypes grown in a number of locations. Analysis of variance showed significant additive and multiplicative genotype–environment interaction effects. Only the first interaction principal component axis (IPCA) was found to be important in describing the multiplicative interaction effects. The additive main effects and multiplicative effects (AMMI) model allowed the partitioning of interaction variance into agronomically important sources (genotype groups), and the specific genotype × environment patterns that are the basis of these sources of variance were examined.     

中药饲料添加剂对法国肉用鹌鹑增重及肉质的影响

用1周龄法国肉用鹌鹑120只,随机分成4组,每组3个重复,每个重复10只.第1～3组为试验组,分别在基础日粮中添加1％的党参、0.5％党参 0,5％黄芪、0.5％党参 0.5％艾叶,第4组为对照组.试验期为2～6周龄,共35d,每7d称重一次.试验结果表明,各试验组的增重与对照组相比,差异均显著(P<0.05);其中第3组效果最好(P<0.01).日粮蛋白质表观代谢率和料肉比,试验组均优于对照组(P<0.05).各组间的肌肉概略养分、pH值和胴体品质,除第1组的屠宰率略高外(P<0.05),其余差异均不显著(P>0.05).嫩度值差异极显著(P<0.01).血清总蛋白质和A/G差异不显著(P>0.05),但血糖含量差异较大(P<0.01).     

Sulphate Attack Resistance of the Concrete with Additives and Its Assessment

The influence of three kinds of additives: silica fume,slag and fly ash on the sulphate attack resistance of concrete were studied.The experiment results show that these three kinds of additives can improve sulphate attack resistance of the concrete and the order of their efficiency from high to low is silica fume,slag and fly ash;the development of mortar expansion value is closely related to the degree of sulphate attack resistance of the concrete;integrated assessing two concrete properties: mortar expansion value and compressive strength ratio can more exactly assess the sulphate attack resistance of the concrete.     

Genetic study of bolting and stem length in sugar beet (Beta vulgaris L.) using a factorial cross design

Summary The objective was to study the genetic basis of bolting and stem length in sugar beet full-sibs, developed by a factorial mating design (N.C. design II). The extent to which the inheritance of these characters can be attributed to the additive and non-dominance variation was investigated. The genetic analysis consisted of three sets (4×10, 4×8, and 3×8) of progenies. Estimates of additive genetic variance (² _A) and variance due to dominance deviations with some fractions of epistatic variance (² _D) were obtained for both characters. Bolting had a relatively large proportion of total genetic variance accounted for by ² _A. In most cases, non-additive effects were also important in determining the type of gene action in bolting. Stem length showed similar genetic variation to bolting susceptibility. Bolting resistance seemed to be dominant to the bolting susceptibility in most cases. Narrow sense heritability estimated for bolting was generally very large (0.93 to 0.96), which suggests that early generation selection for bolting resistance in a sugar beet population would be successful.     

Modified full-sib selection and best linear unbiased prediction of progeny performance in a European F2 maize population

Four cycles of modified recurrent full‐sib (FS) selection were conducted in an intermated F₂ population of European flint maize. The objectives of our study were to monitor trends across selection cycles in the estimates of population mean, inbreeding coefficients and variance components, and to investigate the usefulness of best linear unbiased prediction (BLUP) of progeny performance under the recurrent FS selection scheme applied. We used a selection rate of 25% for a selection index, based on grain yield and dry matter content. A pseudo‐factorial mating scheme was used for recombination. In this scheme, the selected FS families were divided into an upper‐ranking group of parents mated to the lower‐ranking group. Variance components were estimated with restricted maximum likelihood (REML). Average grain yield increased 1.2 t/ha per cycle, average grain moisture decreased 20.1 g/kg per cycle, and the selection index relative to the F₂ check entries decreased 0.3% per cycle. For a more precise calculation of selection response, the four cycles should be tested together in multi‐environmental trials. We observed a significant decrease in additive variance in the selection index, suggesting smaller future selection response. Predictions of FS family performance in Cn + 1 based on mean performance of parental FS families in Cn were of equal precision as those based on the mean additive genetic BLUP of their parents, and corresponding correlations were of moderate size for grain moisture and selection index.