The Research about Single-crystal Casts Made by the Technology of Directional Solidification

Single-crystal casts are obtained with the technology of directional solidification, The reasonable technique is discussed and the growing process of single crystal is analyzed.     

地面灌水技术优化组合节水高产机理研究

对不同地面灌水技术进行优化组合应用,根据全年作物连作的需水特点实施调亏灌溉使土壤水分消长过程在节水高产调控范围内,提高了水分效应,小麦和棉花水分生产效率达１．５３ｋｇ／ｍ３和０．４１ｋｇ／ｍ３的较高水平。同时还对其节水高产机理进行了探讨,为节水高产的地面灌水技术优化组合应用提供了科学依据。     

冬雪蜜桃早期丰产栽培技术研究

冬雪蜜桃具有成熟晚、耐贮藏、效益高的特点,是一种较好的水土保持经济植物.为使这一品种得到推广,自1995年春开始,进行了冬雪蜜桃早期丰产优质栽培技术的研究.经两年多的研究,取得了当年栽植半成苗,当年成花,第二年平均株产5.3kg、最高株产12.3kg的好效果.研究结果表明,改传统的一穴栽植1株为一穴定植3～4株,主枝角度由传统的60°～65°开张到70°～80°,并在生长季节喷生长延缓剂促花,是实现早期丰产的关键.     

应用模糊优选技术预报棉花苗期棉蚜发生程度

根据山东省曲阜市植保站１９８２～１９９４年对棉花苗期棉蚜的系统观测资料和相应年份的气象资料,应用模糊优选技术,建立了棉花苗期棉蚜发生程度的模糊优选预报模型。对历史资料进行回代验证,其历史拟合率达１００％。将１９９５年的气象观测数据作为独立样本进行试报,预测结果与实际一致。     

田间喷-管结合灌水技术体系的研究

该文在总结以往经验基础上,分析了喷灌与管灌在粮田灌溉中的优点和缺点,针对北方地区管灌面积甚广,亟待配套完善的现状,提出了“喷－管结合,扬长避短,择优施灌”的田间灌水新技术体系,通过配套部件研制、测试及田间对比试验和投资、能耗分析,这一体系在技术上是可行的,经济上是合理的。并已在北京等地推广应用。     

杜仲优树苗木水分生理状况的研究

本文利用Ｐ─Ｖ技术,对从湘、黔、川、陕四省选出的１８个杜仲无性系优树进行了水分生理状况测定,结果表明：在充分吸胀时和膨压为零时具有较低渗透势的耐旱品系依次为湘１１号、黔９号、黔１号、略４１号、略２７号、略３３号、黔８号、略１６号、湘１８号、略４９号、略７号、略１４号、灌３号、湘３号、灌２号、黔１１号、略１号、灌１号;依据膨压（ＰＶＡＴ）、细胞弹性模量（ε）和细胞体积比（ＲＣＶ）的相互关系,将１８个杜仲优树分成两大类型：具有较大ＰＶＡＴ、ε值和较小ＲＣＶ值的为一类,具有较小ＰＶＡＴ、ε值和较大ＲＣＶ值的为另一类,显示了它们在抗旱机制中的差异性。     

Zum Einsatz von TRIME-TDR zur Messung der Bodenfeuchte auf leichten Sandböden

Using TRIME-TDR for the determination of soil water dynamics on sandy soils In this study the suitability of the TRIME-TDR system for the determination of soil water content was analysed. For this purpose a period of three years with continuous data of soil water contents, measured by TRIME-TDR, and soil water suction measured by tensiometer were available. Additionally soil samples at different times were taken for gravimetric moisture analysis. The determinations of soil moisture with the TRIME-TDR is based on a new measuring technique. The soil water contents measured by TRIME-TDR were analysed by comparison with corresponding soil moisture values from gravimetric measurements of soil samples. The soil water contents determined by TRIME-TDR in comparison with gravimetric soil moisture values show an absolute mean error of 7.9 Vol%. In most cases the soil water contents measured by TRIME-TDR were distinctly higher than the corresponding soil moisture values from gravimetric measurements. After correcting the TRIME-TDR the absolute mean error was reduced to 2.5 Vol%. Due to the results of this study soil water contents measured by TRIME-TDR-technique cannot be used in hydrological or ecological studies without a check based on the comparison with gravimetric soil moisture values.     

麦茬移栽稻生育中期烤田技术研究初报

从烤田始期、烤田历时天数两个关键烤田要素着手研究,初步提出了麦茬移栽稻生育中期烤田技术的定量化指标。研究表明：烤田始期指标为田间茎蘖数等于计划穗数,即“够苗烤田”为宜;烤田历时天数宜掌握在１４天左右。并从稻作生产实际操作的角度,粗浅地讨论了灵活应用定量化指标的原则。     

池养青虾的高产技术

按青虾摄食、栖息生态习性设计池塘青虾养殖工艺,养殖实践表明：（１）采用虾苗一次放养,每１０００ｍ＾２池塘面积投放４．５－７．５万尾虾苗,饲养期间采用地分期分批捕捞的方法,青虾养殖池塘每１０００ｍ＾２净产为９０－１５０ｋｇ,其中６０－７０％的商品虾规格可达２．０－２．５ｇ以上。（２）采用一年二茬养殖青虾的方式,每１０００ｍ＾２净产可达２０４．３ｋｇ左右,但操作较为复杂。（３）青虾高产养殖池塘以面积６     

稻田甲烷排放机理和调控技术

分别在温室和田间进行甲烷排放测定。结果表明：稻田土壤氧化还原电位低于－１８０ｍＶ时,甲烷排放量明显上升;稻田甲烷排放途径：３／４从水稻排出,１／４从土壤排出;宽窄行“双龙出海”插秧＋养萍、垄畦栽水稻＋养萍可分别比常规稻作减少甲烷排放量２１．８％和４２．３％;稻田放养一定量的革胡子鲶能提高土壤氧化还原电位,减少甲烷排放,放养量以２２５０ｋｇ·ｈｍ＾－２为宜。放养量过大会增加甲烷排放;稻田放养鱼、萍,