盐碱地低盐水池塘网箱套养漠斑牙鲆技术研究

根据漠斑牙鲆(Paralichthys lethostigma)适广温、广盐和较强的抗逆性等优良生态习性,采用地下卤水、盐碱地渗水,通过合理淡水配兑使其适合漠斑牙鲆生理生长需求,在我国中纬度地区利用盐碱地低盐水养殖过洋、暖温性漠斑牙鲆。2004-2005年,利用盐碱地低盐水池塘虾池设置网箱套养漠斑牙鲆349.5m2,产鱼3.749t,产虾55.065t,其中2005年虾池设置网箱套养漠斑牙鲆306m2,产鱼3.245t,平均10.6kg/m2,平均全长34.0cm,体重527.4g,养殖成活率为90.5%,产虾49.003t,平均408.4kg/亩,平均规格11.9cm,养殖成活率为71.23%。虾池设置网箱套养漠斑牙鲆,可充分利用水体空间,促使池塘高产高效,提高养殖经济效益。     

奶牛抗热应激中草药添加剂对小鼠热耐力的影响

试验研究奶牛抗热应激中草药添加剂对热应激小鼠机体耐力的影响。试验分A、B、C、D4个处理,每个处理20只小鼠,分别喂以不同添加剂浓度的饲料21d[A组:0.5g/(10g体重)、B组:0.25g/(10g体重)、C组:0.13g/(10g体重)、D组0g/(10g体重)],每日光暗节律各12h,自由摄食与饮水。试验结果表明,A、B组体重增加显著高于C、D组(P<0.01),A、B、C组小鼠死亡数显著少于D组(P<0.05),受热90min后,A、B、C组小鼠肛温比D组分别低0.3℃、0.3℃、0.5℃(P<0.05),说明该添加剂具有一定的提高小鼠热耐力作用。     

Growth and proximate composition of the Chaetoceros calcitrans f. pumilus under different temperature, salinity and carbon dioxide levels

The marine diatom Chaetoceros calcitrans f. pumilus has been examined for its potential source as live feed in aquaculture. The present study investigated effects of temperature (20, 25 and 30 °C), salinity (25 and 35) and carbon dioxide addition (air+CO₂) on the growth and proximate composition of C. calcitrans under laboratory conditions. The growth and biomass of C. calcitrans were primarily affected by carbon dioxide addition, and to a lesser extent by temperature and salinity. In general, lipid and carbohydrate contents were higher at lower temperatures (20 and 25 °C), while the protein content was unaffected. Carbon dioxide addition increased protein, while lowering carbohydrates, but had no effect on lipid content. Carbohydrates were increased while lipids and protein decreased at the highest salinity (35±0.9). These results should be taken into consideration when evaluating the dietary value of this micro alga for aquaculture.     

低温弱光对西葫芦幼苗渗透调节物质的影响

以西葫芦品种早青一代为试材,研究了不同低温弱光组合及低温弱光持续时间对西葫芦幼苗渗透调节物质的影响。结果表明:可溶性蛋白质含量随低温弱光逆境程度加剧和持续时间延长持续减少;在15℃/5℃以上,弱光处理渗透调节物质游离脯氨酸、可溶性糖含量增加,但增加幅度随着弱光逆境加剧和持续时间延长而减弱;但在15℃/5℃下,弱光逆境导致游离脯氨酸、可溶性糖含量先增加后降低。     

A discussion on and alternative to the Penman-Monteith equation

The Penman-Monteith (PMe) equation that estimates evaporation from leaf/canopy surfaces is based on a few approximations. Several authors discussed ensuing errors and suggested improvements. This paper reminds those discussions which ended in the early nineties. It compares linearized PMe− with non-linear iterative solutions and illustrates resulting deviations. It differentiates between deviations for daily and hourly evaporation rate estimates. The latter are found to be higher. It also demonstrates deviations obtained at two different altitudes above sea level. Considering present tendencies to refine evaporation estimates for practical purposes and making use of easily available methods for solving non-linear equations this paper offers a new method to estimate evaporation.In a first step, a simple algebraic term, the surface temperature control sum, is introduced to find approximate differences between air and evaporating surface (leaf, canopy) temperatures. It suggests to concentrate research on the r_s/r_a ratio. A new formula is derived for estimating leaf/canopy surface temperatures for non-water stressed plants.In a second step, the estimates of temperature differences are used to calculate evaporation estimates. This two-step approximation leads to appreciably smaller errors as compared to the PMe-solution over the full range of input parameters of agro-meteorological relevance. It is, however, less accurate than some of methods proposed in literature. The method is meant for practical application in agricultural water management.     

华北地区冬季温室植物冠层温度建

基于温室内植物冠层能量平衡关系,建立了与温室内、外气象条件和温室结构相关的冠层温度模拟机理模型,并在华北地区文洛型温室内对该模型进行了试验验证.结果表明:模型能较好地模拟冬季温室内植物冠层温度,模拟值和实测值之间的相关系数为0.797 5,均方根误差为1.3℃.建立了冠层温度的BP神经网络模型,模型相关系数为0.783 5,均方根误差为0.6℃.在所建神经网络模型基础上,运用敏感性分析法对影响冠层温度的各因素进行重要性分析和排序,得出影响冠层温度的最重要因子是室内温度,其次为蒸腾速率、室外太阳辐射和室内相对湿度.     

一种采用无线数据传输方式的储粮仓群测温系统

基于无线收发芯片和1-Wire总线数字温度传感器,实现了可进行无线数据传输的大型储粮仓群温度监测系统。该系统包括主机和信号采集分机,主机负责管理每个粮仓的温度信号采集分机,定时或根据操作者指令向分机发出数据传输指令,各个粮仓分机根据收到的指令进行温度数据的传输。该系统在继承了全数字粮仓测温系统硬件结构简单、安装及维修方便等优点的基础上,实现了测温数据的无线传输,适于在大型分散式储粮仓群以及不便于布线的粮库中应用。     

基于C8051F单片机的温度采集系统

基于C8051F的340SOC芯片的固有硬件特性,提出一种系统温度采集测控软硬件实现方法。该系统通过采用基于单总线技术的温度传感器并利用USB通信技术,提高了系统的实时性,减小了数据传输系统的复杂性,达到了系统温度测控目的。     

果蜡处理对低温贮藏下采后菠萝果实激素的影响

以菠萝品种‘巴厘’的果实为试材,研究果蜡处理对低温贮藏下采后菠萝激素的影响,结果表明：果蜡处理降低了冷藏菠萝果实脱落酸(ABA)、赤霉素(GA)和玉米素(ZR)含量,增加了吲哚乙酸(IAA)含量,并且ABA 和GA含量均与冷害指数极显著相关(P＜0.01),相关系数分别是0.879和0.909。表明低温胁迫下采后菠萝的ABA和GA与抗冷性密切相关,果蜡处理降低了ABA和GA含量,从而提高菠萝抗冷性。     

近三十年来厦门市气候的变化

依据厦门市1971—2004年34年的基本气象资料,研究分析了该市年均气温和年降水量的年际变化特征,并确定了各自的气候突变点,据此分析了该市的气候类型。结果表明：（1）从20世纪80年代以来,该市年均气温以每年0．0631℃的速度在升高,年均气温出现2个气候突变点,分别为1981和1998年;（2）年降水量多年变化趋势不明显,呈随机变化,年降水量出现2个气候突变点,分别为1977和1990年;（3）34年的气候类型分为暖湿、暖干、冷湿和冷干4种类型。