Screening of cold-resistant seedlings of a Chinese wild grape (Vitis piasezkii Maxim var. pagnucii) native to loess plateau of eastern Gansu province,China, as rootstocks

Seedlings of a Chinese wild grape (Vitis piasezkii Maxim var. pagnucii) native to loess plateau of Eastern Gansu province, China, were evaluated to screen cold-resistant rootstocks in Lanzhou area. After 14-year investigation two selections of LDP-191and LDP-294 were screened as rootstocks for two table grape cultivars, ‘Fujiminori’ and ‘Red Globe’, respectively. The two graft unions demonstrated very high cold-resistance as well as good graft compatibility. Furthermore, they could survive through low temperatures in winter without soil coverage together with good fruit quality of the cultivars grafted.     

大蒜高产栽培技术及病虫害防治

大蒜为百合科葱属植物蒜的鳞茎。大蒜的幼苗、花茎、鳞茎均为广大群众所喜食,不仅可以生食和做成调味品,还可以做成糖醋蒜、罐头和大蒜油等产品出口创汇。大蒜栽培历史有2000多年,大蒜是人们日常生活不可缺少的辛香类蔬菜。大蒜含有丰富的糖类、蛋白质、脂肪、粗纤维,数量元素、维生素和大蒜素,营养与保健价值极高,被誉为“天然广谱杀菌素”。     

苹果主要病虫害的发生与防治

1、苹果腐烂病 1.1为害症状苹果树腐烂病有溃疡型、枝枯型两种.溃疡型病斑是冬春发病盛期和夏季在极度衰弱树上发生的典型症状.病斑最初在外表,不易被发现,揭开枝干表皮后,可见暗褐色湿润状小斑或黄褐色干斑,当环境条件适宜时,在夏秋落皮层上出现稍带红褐色、稍湿润的小溃疡斑.     

海水育苗锅炉的节能降耗

海水养殖业中耗能较大的环节是海水育苗,因为育苗企业鼓风机天天转、锅炉天天烧、水泵天天抽,既是耗煤大户又是耗电大户,所以海水育苗行业如何在保证正常生产的前提下把能耗降下来是今后育苗生产中的一个重要工作。在此,笔者就本行业锅炉的一些使用方法略做说明。     

基于响应面法的板料成形工作模面几何参数优化

阐述了以响应面法建立板料成形参数与有限元模拟结果的代理模型的基本原理;介绍了板料成形中的设计变量、目标函数、约束条件,多目标优化的处理方法;基于响应面法.以汽车后桥悬架内板零件为研究对象,成形后最小板料厚度为优化目标,成形极限图为约束条件,建立了模面几何参数优化模型;对模面几何参数进行优化并获得最优参数组合;以最优几何参数组合进行了实际的冲压试验,验证了优化结果.     

驱动圆盘犁的研究与设计

驱动圆盘犁对土堡侧面和底部的土壤进行旋转滑切,将土垡底部的土壤由沟底撕裂开形成土垡,并利用圆盘的旋转将土垡抬升并翻转.为此,以研究驱动圆盘犁为目标,分析了驱动圆盘犁各几何参数和工作参数对其工作过程的影响,为驱动圆盘犁的研制提供了可靠的理论依据.通过理论分析,阐明了驱动圆盘犁的运动学特性,推导了残耕高度的计算公式.     

封闭式蛋鸡舍环境控制系统的设计

针对全封闭的蛋鸡舍结构特点和室内环境因子不同于外界环境等问题,设计开发了全封闭蛋鸡舍环境调控系统.该系统以单片机LPC2132为微控器,由上位机和智能监控点构成监控硬件系统,其执行机构由湿帘风机、喷雾等设施组成.该系统根据智能监控点传来的传感器所采集信息数据,通过一定算法分析决策,能够实现鸡舍内的温度、湿度、光照度、二氧化碳、氨气和硫化氢按照设定值自动调控.夏季试验结果表明:在封闭式蛋鸡舍试用的环境调控系统,对蛋鸡舍环境因子中的温度和湿度进行了调控试验,试验期间的蛋鸡的产蛋率比对照组高出约15%,说明设计的蛋鸡舍环境控制系统具有推广价值.     

轴流泵叶轮进出口流场的测量

为了获得轴流泵内部流动的真实情况,设计了内部流动测量装置.运用五孔球形探针,对高效轴流泵在0.8Qopt,1.0Qopt和1.2Qopt工况下的叶轮进口和出口速度矢量分布、静压分布和总压分布进行了测量,并分析了不同工况下的轴面速度、环量、圆周方向分速度和压力分布等.测量结果表明：轴流泵模型进口在0.8Qopt至1.2Qopt工况范围内,流动稳定,进口轴向速度从轮毂到轮缘逐渐减小,且进口预旋很小,不同径向位置的静压基本相等.在最优工况下,轮毂与可调叶片间无间隙时,轴流泵叶轮出口基本呈现等环量流型,轴面速度呈现抛物线分布,且效率高.若轮毂侧存在间隙,间隙处的环量、轴面速度、压力和效率均明显下降.     

基于特征线方程N—S方程非增量型分离算法

为克服传统有限元方法求解流场时由于对流项占优而引起的求解振荡和基函数选择困难的问题,推导了基于特征线方程的粘性不可压N-S方程的增量型和非增量型分离算法的公式及求解步骤,并讨论了两者的Babuska-Brezzi条件.沿着特征线方向,N-S方程的对流项消失,方程矩阵是自伴随矩阵,可以自动满足有限单元法中能量泛函最小的要求,并可以给出合理的粘性耗散项.动量方程的求解采用非增量型分离算法,压力和速度可以采用任意阶次的插值函数,离散后的方程自动满足Babuska-Brezzi条件.为验证算法的可靠性,采用T3P3空间等阶次U-p单元计算了方柱绕流.结果表明：基于特征线方程的非增量型分离算法可以很好地应用于粘性不可压流场的计算,与目前流行的其它方法相比,该算法有明显的优势.     

Transpositional feeding rhythm of loach <Emphasis Type="Italic">Misgurnus anguillicaudatus</Emphasis> from larvae to juveniles and its ontogenesis under artificial rearing conditions

The diel feeding rhythm and ontogenesis during early life stage of loach Misgurnus anguillicaudatus were investigated under experimental conditions (light: L 06:00–18:00, D 18:00–06:00 h). Morphological and behavioral developments of loach from newly hatched to 40 days after hatching were observed. Larvae were able to prey on daphnia 3–4 days after hatching at 23 ± 0.5°C. As the larvae grew, they showed an increasing feeding capacity and a distinct feeding rhythm. Feeding intensity and incidence for day-4 larvae were highest at 10:00 and 16:00 h. The highest levels of feeding intensity for day-12 larvae occurred at 08:00, 12:00, and 18:00 h as did feeding incidence. By day 20, when the larvae metamorphosed, the highest levels of feeding intensity occurred at 06:00, 18:00, and 24:00 h and were concurrent with the highest feeding incidence. After metamorphosis, feeding capacity had again increased considerably and, in contrast to the earlier stages before day 20, feeding intensity for day-30 juveniles peaked at 05:00 and 20:00 h, about 1–2 h after the maximum feeding incidence. The feeding rhythm of loach juveniles at day 40 was almost the same as the day-30 juveniles. The estimated maximum daily feeding rates were 43.1%, 33.4%, 19.0%, 12.8%, and 5.8% of body weight on days 4, 12, 20, 30, and 40, respectively. Thus, loach was found to have different feeding rhythms in the pre- and post-metamorphosis stages, with the highest feeding activity in daytime during the larval planktonic stage before metamorphosis, and intensely nocturnal feeding behavior during the juvenile benthic stage after metamorphosis.