Inheritance studies of characters associated with floating habit and their linkage relationship in rice

Summary Deep water rice varieties in general have certain peculiar characters which are associated with floating habit. These characters are (i) early nodal differentiation, (ii) nodal rooting, (iii) spreading habit, (iv) awned grains, (v) brown hull colour, (vi) red pericarp (red rice), and (vii) seed dormancy. Inheritance of these characters and linkage relationship of genes governing these characters were studied in a cross between Pankaj (non floating) and Nageribao (floating) rice varieties. Nageribao, a cultivar from Assam possesses these characters.Early nodal differentiation was observed to be controlled by a single dominant gene, designated as Nd. Nodal rooting was controlled by two dominant complementary genes, designated as Nr ₁ and Nr ₂. We found an inhibitory factor for spreading habit and one for brown hull colour in Pankaj; the operation of two dominant duplicate genes An ₁ and An ₂ for controlling awning characters, a single dominant gene Rd for red pericarp colour and a single dominant gene Gd for grain dormancy. Joint segregations between these characters resulted in the assignment of genes in the X linkage group of indica rices with estimated map distances based on the cross-over values. The genes An (awning), Es (spreading habit), Nr (nodal rooting) and Nd (nodal differentiation) were observed to be associated with each other. The gene for red pericarp (Rd) was observed to be linked with the grain dormaney gene Gd.     

漂浮植物对富营养化景观水体的净化效果研究

利用软隔离小区试验研究了凤眼莲(Eichhornia crassipes)、黄花水龙(Jussiaen repens L.)、空心莲子草(Alternanthera philoxeroides(Mart.)Griseb.)、水鳖(Hydrocharis dubia(Bl.)Backer.)和四角菱(Trapaquadrispinosa Roxb.)5种不同漂浮植物对富营养化景观水体的净化效果,研究结果表明,经过100天植物处理,5种飘浮植物对水体中总氮的去除率为黄花水龙(63)%>凤眼莲(57%)>水鳖(46%)>四角菱(42%)>空心莲子草(34%),对总磷的去除率为凤眼莲(52%)>黄花水龙(50%)>水鳖(45%)>四角菱(31%)>空心莲子草(22%),其中凤眼莲、黄花水龙处理围区的水质净化效果最好,水体中总氮和总磷的去除率也最高,这与植物自身吸收同化污染水体中氮素、磷素的能力大小及植物根系微生物的作用都有关。凤眼莲、黄花水龙在提高水体透明度方面表现最佳,试验围区在处理40天后水质透明度即可达到1 m以上,而空心莲子草、水鳖和四角菱的试验围区则需要处理60天以后透明度才能达到1 m以上。5种漂浮植物对富营养化景观水体都有较好的净化效果,且易于成活,容易管理,可在今后的水质净化中推广应用。     

DEVELOPMENT AND EXPERIMENTAL ANALYSIS OF HYDRAULIC LOCK OF THE THINNEST COAL SEAM SHEARER

The structure and work theory of a new type of hydraulic lock of the thinnest coal seam shearer is described in this paper. Its performance tests have been done the test results show that the performance of hydraulic lock is satisfactory and can be fit for the needs of locking and floating of the cutting drum of the thinnest coal seam shearer     

镂空方型增殖礁上升流特性的粒子图像测速试验

利用粒子图像测速技术（particle image velocimetry）对镂空方型增殖礁单体礁和组合礁的上升流流场特性进行分析,按照海区实测流速和礁区选址要求,设定5个不同的来流速度0.2、0.4、0.6、0.8、1.0 m/s,并计算出试验流速分别为0.045、0.090、0.135、0.180、0.225 m/s。结果表明：单体礁在任何一种迎流方式下,上升流的规模都随来流速度的增加而增大;而相同来流速度下,主视面90o迎流时,上升流规模最大;单体俯视面45o迎流时,上升流规模最小;礁体横向组合排列时,礁体间距在0.5L～1.0 L时所产生的上升流规模最大,礁体间的协同作用最强;礁体纵向组合排列时,在0.5L～1.5 L倍的间距时,礁体间的相互作用较强,形成的上升流规模最大。     

基于双输出电流传输器的模拟浮地电感

由于电感不易集成，利用有源器件模拟电感一直是研究的热点．本文提出了一种新的模拟浮地电感，分析了该电感在理想情况和考虑有源器件非理想特性情况下的电感值，并把它应用到椭圆滤波器中．PSPICE仿真证实了此模拟浮地电感符合设计要求．该电感仅由2个第二代正电流传输器(简称CCⅡ )，1个双输出电流传输器(简称DOCCⅡ)和2个电阻，1个电容组成，结构简单；电感值可由无源元件参数控制．     

外浮顶罐ZYPS新型中央排水装置的应用

分析比较了钢质外浮顶油罐的回转接头式、枢轴式和挠性管式3种常用中央排水装置的结构与性能.介绍了钢质外浮顶罐ZYPS新型中央排水装置的结构与特点.实际应用效果证明,ZYPS新型中央排水装置能够快捷、彻底地排出罐顶的积水,并且具有结构简单、可靠性强、抗疲劳性能高、成本较低、适应性强等优点.     

油罐浮顶焊缝断裂原因分析及整治

通过浮顶油罐浮顶焊缝断裂漏油的实例，从油罐设计、施工、检修和油罐运行管理四个方面对浮顶焊缝断裂的原因，作了较详细的分析，同时提出了防止焊缝断裂的整治措施，主要从油罐设计、大修时的补救及油罐的日常运行管理等三个方面进行了探讨。     

浮顶罐刮蜡机构损坏的力学分析

从力学角度分析了浮顶罐刮蜡机构压筑大量断裂的原因：未按设计图安装压簧，导致其实际挠度超过设计挠度的８８％，使压簧根部的最大弯矩处正应力超出了许用应力值，应力集中使压簧折角处两边产生微裂纹；罐壁焊缝及施工中遗留的凸出焊点和残留物对刮蜡板产生卡阻和冲击荷载，压簧经长时间运行后发生疲劳断裂。针对上述原因，提出了具体维修方案。     

水体表面浮植水蕹菜养鱼

随着草食性鱼类养殖的迅速发展,青饲料供不应求和青饲料地十分紧缺等问题日益突出。为寻求解决这些问题,作者于1985—1988年进行了水体表面浮植水蕹菜养鱼的研究工作。现将主要研究结果报道如下。