热压温度对热压过程中板坯芯层温度变化影响的研究

纤维板热压过程中板坯芯层温度是否能迅速达到胶的固化温度是影响产品质量和生产率的重要因素之一。板坯热压过程中的传热速率受很多因素影响,如热压温度、板坯含水率、密度和厚度等,其中热压温度是生产中较易控制的工艺参数之一。通过探讨热压过程中板坯芯层温度变化规律与热压温度的关系,研究不同热压温度对板坯芯层温度变化的影响,为优化热压工艺条件提供理论依据。     

在EnergyPlus中建立单盘管、双风机空调系统的模型

概述了用于建筑节能的单盘管、双风机的空调（SCTF）在整个建筑模拟程序EnergyPlus中的模拟模型的概念及发展。     

有效微生物菌群在蛋鸡生产中的应用试验

有效微生物菌群(EV)是一种复合高效微生物制剂,在养殖业上使用EM具有改善饲养环境、降低发病率、提高饲料报酬、增加养殖效益等作用。本研究进行了EM对产蛋鸡应用效果试验。试验表明:EM对蛋鸡生产具有明显促进作用,10周试验表明,以10%比例将EM发酵饲料添加于蛋鸡日粮中,并配合饮用EM发酵水,日均产蛋量提高4.70%,产蛋率提高2.90%,料蛋比下降4.73%,毛利润提高12.79%。     

长沙蓉园园林造景研究

指出了湖南长沙的蓉园是长沙近代园林史上保存下来比较完整也是不可多得的优秀实例,经过多方资料查阅、对比与研究,梳理了蓉园的历史沿革,在对蓉园建筑及景观进行整理的基础上,对长沙蓉园园林进行了一些初步的研究。     

灌溉对心底土积盐层的溶解作用

1.心底土积盐层是引起土壤次生盐渍化不可忽略的原因土壤次生盐渍化是干旱、半干旱地区作物正常生长和发展农业生产的一个重要限制因素,综合目前的研究资料,人们对土壤次生盐渍化的发生和防治作了大量的研究工作,但对心底土积盐层与土壤次生盐渍化研究得较少,忽略了这个问题。正如罗赞诺夫指出:“人们往往忽略了土壤以及底土的原始含盐量在灌区土壤次生盐渍化中的作用,因此,我们愿意再一次强调指出,必须重视自然条件特别是土壤的原生盐渍化在次生盐渍化中的重大意义和作     

实验动物房消毒试验研究

选用５种常用消毒药物进行消毒试验,抑菌试验。结果表明实验动物房选择消毒药物的顺序为：乳酸、醋酸钠、百毒杀、卫康、过氧乙酸,消毒间隔以３个月为宜。     

鸡舍真菌气溶胶潜在危害的定量评估

本文采用6级Andersen生物空气采样器和常用真菌计数培养基,在鸡舍入口处收集气溶胶真菌,经培养和纯化鉴定出78种真菌,其中包括黄曲霉、烟曲霉、黑曲霉及镰刀菌等在内的50余种真菌。研究表明鸡舍入口处空气真菌污染程度与鸡舍内没有显著差异。早晨气溶胶真菌浓度明显低于中午(P=0.07)和晚间(P=0.05)的浓度,且夏秋季节浓度相对较高,峰值在7月份。鸡舍内气溶胶真菌的年平均浓度为2.3×103 CFU/m3。黄曲霉、烟曲霉、黑曲霉在鸡舍空气中的浓度相对较高,分别超过真菌气溶胶组成平均浓度77.7 CFU/m3、63CFU/m35、7.1 CFU/m3,而镰刀菌是常见的空气真菌,其总平均浓度为74.6 CFU/m3,比平均值高出45.3 CFU/m3。平均CMD值分别为3.1μm;GSD分别为2.1。每分钟可沉积到支气管和直接侵入肺泡的活性真菌量分别是居室的3.4倍和3.3倍。本研究探讨了真菌气溶胶不同时间和季节的变化规律,并从其组成、浓度及粒子大小定量评估采样点鸡舍真菌气溶胶的危害,为有效控制禽类真菌病的流行提供科学依据和预警资料。     

不同锌源对蛋鸡产蛋性能和蛋品质的影响

将300日龄伊莎蛋鸡135只,随机分为3组,在基础日粮中分别添加50mg/kg锌的蛋氨酸锌、氧化锌,基础日粮为对照组,研究不同锌源对蛋鸡产蛋性能和蛋品质的影响。试验期30d。结果表明,日粮补锌对蛋鸡产蛋率、蛋壳质量及蛋黄锌含量有提高作用,但未发现不同锌源的显著差异。     

饼粕发酵蛋白饲喂蛋鸡试验

将70%棉仁饼和30%菜籽饼混合发酵后制成饼粕发酵蛋白, 完全取代蛋鸡饲料配方中的豆饼或鱼粉进行蛋鸡饲喂试验。结果表明：在基础日粮中添加饼粕发酵蛋白分别替代豆饼和鱼粉后，平均产蛋率试验组比对照组分别降低了2.22%和2.21%，平均蛋重分别增加了2.31和2.03 g，投入产出比较对照组分别提高了3.6%和1.68%。     

Dam and Sire Effects on Sperm Penetration of the Perivitelline Layer of Eggs Produced by Two Strains of Commercial Turkeys

The reproductive performance of 2 commercial turkey breeder lines was examined using reciprocal crosses between sires and dams of each line. One line had been selected using artificial inseminations performed at biweekly intervals, whereas the second line had been selected using inseminations performed at weekly intervals. The hypothesis was proposed that sires and dams of the 2 lines differ because of different abilities for sperm to penetrate the inner perivitelline layer (IPVL) and fertilize eggs.Fertilized eggs to hatch poults for the experiment were obtained from the primary breeders and were incubated using conditions recommended by the industry. Hens (n = 72) and toms (n = 15) from each strain were identified and reared in preparation for a reproductive cycle using commercially accepted standards. Beginning just prior to the onset of egg production and at weekly intervals thereafter, half of the hens were inseminated with semen from males of the same line, whereas the remaining half received semen from the opposite line. Eggs were collected from the pens daily and set in incubators to determine fertility and embryo survival. At biweekly intervals 3 eggs per pen were used for counting sperm penetration holes in the IPVL. Data were collected for fertility, hatchability, and time that embryos died for each of the pens. Dam and sire affected IPVL penetration independently. A dam by sire interaction influenced fertility, whereas hatchability was affected only by dam. Thus, it is concluded that selection of dam and sires for commercial breeders alters IPVL sperm penetration ability of hens as well as egg-binding ability of sires.