轻型木结构建筑覆板的集中静载性能

介绍轻型木结构建筑覆板集中静载结构性能试验的装置、条件和方法,并进行国产人工林落叶松胶合板作轻型木结构覆板的集中静载性能研究.结果表明:与国外胶合板覆板具有相同厚度的国产落叶松屋面板和楼面板,其集中载荷性能均优于相关标准的要求.     

衢州黑桃的生产现状与发展对策

衢州黑桃,又称乌桃,为地方良种,已有200多年的栽培历史,自然分布于浙西常山县新桥乡,衢江区举树乡及开化县林山乡,栽培地系海拔1000m左右的高山地。该品种较耐寒、耐旱、耐瘠薄,喜微酸性土壤,在石灰岩地区也能生长结果。果实营养丰富,经浙江省林业科学研究所化验中心分析,每100     

非平行直纹面的电解磨削

为解决整体叶轮扭曲叶片型面的精加工难题,本文进行了五轴联动数控展成电解磨削的基础研究.在分析平行直纹展成电解磨削整体叶轮扭曲叶片的过切误差、得到过切误差计算公式的基础上,提出用圆锥磨轮和组合式五轴联动数控方案来消除过切误差的方法.文中还介绍了数控展成电解磨床的结构与运动、经济型多轴数控系统及其联动控制方法,并建立了电解磨削非平行直纹展成曲面的数学模型,开发了五轴联动数控展成电解磨削自动数控编程系统,对航空发动机整体叶轮的叶片型面进行电解磨削.结果表明,加工效率比手工修磨、抛光提高了12倍以上.     

长翅燕蝗发生与防治初报

2001年5月末至6月上旬，在岫岩县牧牛乡河滩地上的枫杨上，发现大批蝗虫危害，每棵树上均有一千头以上蝗虫成虫在取食叶片，稍经震动即可起飞。在树冠下的草地上仍有部分蝗蝻取食杂草，经现场调查平均每平方米有幼蝻105头，多者达270多头。6月中旬枫杨树叶基本被吃光，开始转入邻近的玉米田危害，平均每株玉米有长翅燕蝗成虫38头，多者达80多头，仅一夜间邻近枫杨的玉米叶肉己被吃光，受害面积几百公顷，来势凶猛。     

Monthly model for genetic evaluation of laying hens 1. Fixed regression.

1. This paper addresses the possibility of using a monthly model for the genetic evaluation of laying hens, based on the definition of a test day model with fixed regression as used in dairy cattle, in which monthly records were treated as repeated measurements of the same trait. 2. Production records of 6450 hens, daughters of 180 sires and 1335 dams were analysed using an animal model with restricted maximum likelihood (REML). The traits considered were individual monthly egg production and cumulative egg production in 11 months. Four different models were fitted to various combinations of monthly and cumulative records. The covariates were derived from the regression of Ali and Schaeffer (1987). 3. Spearman rank correlations were computed to compare breeding values from different models. Two types of correlations were computed: between individual breeding values and between sire breeding values based on subsets of full-sib records. 4. The results indicated that a monthly model with nested covariates produced higher heritability and permanent environmental variance than the models with non-nested or without covariates. The estimates of heritability obtained from monthly model were lower than the estimates from the cumulative model. The monthly model resulted in higher correlations of sire breeding values between two subsets of full-sib records than those from cumulative models. 5. In conclusion, the monthly model with nested covariates appears to be better than the model with non-nested covariates or without covariate. Although the heritability estimates obtained from the monthly model were lower, the monthly model with nested covariates could be better than the cumulative model for genetic evaluation of laying hens in the 1st cycle of laying period when using either full or part records. The use of information from odd months of production could be of interest for the evaluation of full records.     

D-LysAsnProTyr四肽对肉仔鸡免疫及主要生产性能的影响

将体重、发育及健康状况接近的300羽7日龄肉仔鸡随机等分为5个处理，每个处理设3重复，每重复20羽。试鸡用D-LysAsnProTyr四肽＋3头份新城疫Ⅳ系疫苗生理盐水混合液滴鼻，剂量为50μl／只，D-LysAsnProTyr四肽水平为：0μg／只（对照组），15μg／只，20μg／只，25μg／只，30μg／只。测定新城疫抗体水平及淋巴细胞ANAE阳性百分率，计算全期平均日增重、采食量和料肉比。结果表明，D-LysAsnProTyr四肽在20～25μg／只鸡剂量对ND抗体有明显的提高作用，不改变抗体变化规律；显著提高肉仔鸡血液中淋巴细胞阳性百分率，10～42日龄20μg／只和25μg／只试验组分别比对照组提高2．03～9．47个百分点和2．36～9．22个百分点，淋巴细胞阳性百分率的增减变化规律与对照组相一致，说明适宜剂量D-LysAsnProTyr四肽可以显著提高肉仔鸡对ND的体液免疫和细胞免疫。20μg／只、25μg／只组试期末体重、平均日增重显著高于15μg／只、30μg／只组（P〈0．05）。与20μg／只、25μg／只组相比，对照组日增重、饲料转化率有降低趋势（P〉0．05）。各处理组对肉仔鸡日均采食量无显著影响（P〉0．05）。     

虚拟仪器技术及其在距离保护中的

介绍了虚拟仪器的发展过程以及虚拟仪器的软件与硬件的基本构成原理,设计了一套虚拟仪器系统，并在此基础上对距离保护进行了仿真实验。认为虚拟仪器在电力系统具有广泛的应用前景，是今后一段时间的发展方向。     

大尺度水文条件变化对建筑工程环

研究了大尺度水文条件变化对建筑环境的影响，分析了大尺度水文条件变化对建筑物维护、建筑设计、建筑施工、建筑材料等建筑环境的影响。依据不同的影响程度，提出了建筑物设计、运行维护与管理的对策与措施。