不同移栽群体和水分调控对水稻分蘖成穗的影响

为了控制水稻无效分蘖的发生,提高水稻的成穗率,采用盆栽实验,对比了不同的水稻移栽群体下不同的水分控制对水稻分蘖动态、成穗率、营养生长状况、根系活力的影响。结果表明：采取控蘖措施后,双本移栽、深水控蘖较单本移栽、搁田控蘖分蘖增长率减少了3.79%~7.06%,叶片中叶绿素含量也相对稳定,根系活力高出5.25个单位和5.95个单位,根系伤流强度提高29.04%和21.17%,最终成穗率比分别提高了9.09%和10.53%,双本移栽较单本移栽能更好的控制无效分蘖的发生。双本移栽、深水控蘖更有利于提供水稻较好的营养生长,控制无效分蘖的发生、提高成穗率。     

黄曲霉毒素去毒中试装置视察与现场讨论会

一九七八年十一月十二日,美日自然资源研究有毒微生物委员会第十二次联席会议,美方全体委员在日方罔部会长,粟饭原委员、办事厅中岛技术员陪同下,抵达茨城县猿岛的旭化成工业食品研究所,视察了黄曲霉素去毒的中间规模实验装置。这个装置是该研究所从基础理论开始     

中间堰麦草与小麦杂交后代的细胞遗传学及性状特点的研究

中间偃麦草作父本与小麦品种烟农15杂交,杂交结实率为71.72%,杂种F1在套袋自交和开放授粉条件下的自交结实率分别为32.05%和69.66%。以7个杂种世代为材料,对其细胞遗传学及性状特点进行研究。结果表明,F1 PMC MI染色体的联会频率较高,细胞内二价体数目平均为13.73个;F2和F3两个自交世代的染色体数目显著多于双亲和F1的42     

核桃早实性相关的SCAR标记在母本和F_1代上的分析

本文研究目的是对与新疆核桃早实性相关的SCAR标记在母本和F1代上进行分析。通过对与核桃早实性相关的SCAR标记片段的扩增并测序,获得与早实性相关的SCAR标记片段,大小为762bp。用该特异性引物对新疆五个核桃实生品种母本和F1代进行扩增,在母本和F1代上得到了以下的结果:四个母本材料出现了该标记片段,各品种实生F1代单株出现该标记的比率分别为92.68%,97.92%,96.43%,93.10%和97.73%,分析表明核桃早实性是遗传力较高的性状。本研究可为进一步研究新疆核桃早实性相关基因的克隆及功能提供一定的研究基础。     

水稻闭颖授粉QTL的初步定位分析

水稻闭颖授粉遗传位点的发掘旨在研究其闭颖授粉机制。本研究利用闭颖水稻品系RV2429为母本,开颖授粉水稻品系Koshihikari为父本杂交得到F1代,F1自交得到F2,以双亲本及F2为研究材料,对双亲本的粒型及花器官结构进行比较,推测出浆片体积增加较小是RV2429闭颖授粉的原因。统计F2群体的开花表型和基因型,通过QTL IciMapping 4.1软件分析,初步定位到4个与闭颖授粉相关的QTLs,qCL4.1(4.75%),LOD值为2.559 3、qCL6.1 (5.12%),LOD值为2.999 1、qCL11.1 (5.06%),LOD值为2.799 6和qCL12.1(4.77%),LOD值为3.052 1,分别在4、6、11、12染色体上。本研究结果明确了控制水稻闭颖授粉的新基因位置,为以后的精细定位提供了实验依据,为加快闭颖授粉的育种进程提供帮助,对抑制基因漂流具有重要意义。     

组合斜叶桨作用下多相流数值分析

运用Fluent流体分析软件,以菜籽油、辣椒颗粒和花生粒构成的多相流属性为研究对象,结合Eulerian多相流模型,研究了单斜叶桨和组合斜叶桨搅拌作用下的速度场、密度场和各单相体积分数的分布状况。结果表明:当旋转速度为5 rad/s时,在组合斜叶桨作用下,多相流的紊流特性强度增加,整体流动速度提高;近壁区的高密度聚集现象得到明显改善,混合密度均匀化程度提高;各单相的体积分数分布值与初始设定值较为接近,可以实现多相流物料的均匀性混合。计算结果对相应的多相流混合特性机理分析具有一定的理论意义和参考价值。     

奶牛性控冻精人工授精效果的研究

为研究奶牛性控冻精人工授精效果并合理制定人工授精方案,采用流式细胞仪制备性控冻精,对3 947头健康荷斯坦牛进行人工授精。结果表明:①性控冻精和常规冻精的受胎率、产犊率差异不显著(P0.05),但性控冻精的雌犊率和繁殖率分别达到92.01%和50.03%,对照组仅为51.13%和34.97%,差异极显著(P0.01)。②青年牛的情期受胎率达到55.25%,极显著高于经产牛(P0.01);青年牛的产犊率达到98.31%,显著高于经产牛(P0.05);青年牛的繁殖率为51.84%,经产牛为42.12%,存在极显著差异(P0.01)。③采用第1次人工授精后10~11 h重复授精1次,每次1支性控冻精的授精方案,其情期受胎率为55.17%,繁殖率达到55.81%,同其他方案相比,差异极显著(P0.01)。应用性控冻精进行人工授精可以显著提高母牛的繁殖效率。     

百合品种粉美与多安娜杂交F1代主要性状遗传分析

研究了亚洲百合品种粉美和多安娜杂交F1代与亲本各性状的遗传差异性,并对F1代的主要性状进行了相关分析和主成分分析。结果显示,在14个性状中,花冠直径在F1与母本中达5%显著差异水平,与父本达1%极显著差异水平;F1内轮花被片宽与母本达1%极显著差异水平,与父本达5%显著差异水平;外轮花被片的长与宽在F1代与亲本之间差异不显著;其余10个性状与双亲均达1%极显著差异水平;相关性研究表明,各性状之间存在较复杂的关系,不宜对单个性状进行选择。     

马氏珠母贝选系F4遗传结构和亲缘关系建分析

为了有效避免因近交引起性状退化,本实验利用微卫星标记分析了选系F4的遗传结构,并估计了其有效亲本的数量。2010年9月,从快速生长系F3选择亲本进行子代繁殖,雌雄亲本数量分别为42和38个,人工解剖授精,按照常规技术进行幼体培育和海区养殖。2011年6月,从选系F4随机选取90个个体,利用45对微卫星引物进行遗传结构分析和有效亲本数量的推断。结果表明：45个微卫星位点共检测到186个等位基因,每个位点的等位基因数在2~9之间,平均每个位点有4.13个等位基因。平均观察杂合度为0.543;平均期望杂合度为0.542;平均Shannon多样性指数为1.012;平均PIC值为0.491。根据基因频率的似然率算法成功的推断出该群体含有30个全同胞家系,用于繁殖选系F4有效亲本数量为60个,有75%的亲本参与了繁殖。世代之间近交系数增量△F=0.83%,F4代群体的近交系数F=3.27%。本研究结果表明：（1）该选系F4具有较高的遗传变异;（2）利用微卫星标记能有效推算选系的有效亲本数量,同时为构建继代群体提供技术支持。     

白菜抽薹相关性状遗传分析

研究与白菜抽薹相关性状的遗传特性,为白菜类作物晚抽薹育种应用提供理论依据。试验以抽薹指数、开花时间和薹长5 cm时间分别作为抽薹早晚的评价标准,应用植物数量性状主基因+多基因混合遗传模型,对晚抽薹大白菜高代自交不亲和系(P1)和易抽薹欧洲白菜型油菜自交系(P2)及杂交所获得的F1、B1、B2和F2各世代群体进行联合遗传分析。结果表明,抽薹指数性状和薹长5 cm时间性状均受2对加性-显性-上位性主基因控制（B-1模型）,开花时间性状受1对加性-显性主基因+加性-显性-上位性多基因控制（D模型）。与抽薹相关的3个性状各分离世代(B1、B2、F2)均未检测到多基因遗传,其主基因遗传率分别为抽薹指数96.22%(B1)、93.33%(B2)、93.55%(F2);开花时间70.68%(B1)、70.68%(B2)、70.64% (F2);薹长5 cm时间79.44%(B1)、79.55%(B2)、79.38%(F2),环境条件对白菜抽薹性状影响较大。由此可知,对白菜抽薹性状的遗传改良应以主基因为主,适宜在早期世代进行选择并注意环境条件影响。     

An experimental investigation of a single jet into fluid flow in a pipe

An experimental investigation is performed on a single jet issuing into a flow in a pipe. The pressure of the flow in pipe is measured under the condition when there is a right angle between the jet and the mainstream and the velocity of the jet is 1 to 6 times of the mainstream. The results show that, there exists a jet core with skewing downstream near the entrance port; the pressure in that core increases slightly with the fluid incidence. Outside the core, the pressure of the flow inside the pipe increases significantly; the pressure increment is correlated with the velocity of the jet quadratic dependence.     

Opening Flow Coefficient and its Effect on Fire Smoke Flow

The flow coefficient of the typical doors and windows in different states between opening and closing was tested in a high rise experimental fire tower. It can be used for the prediction calculation of the fire smoke flow and the calculation of the positive air supply as well as for the ventilation. Using the prediction software of the fire smoke flow properties in the building, the effect of the flow coefficient on the fire smoke flow was also studied.     

Numerical Simulation of Turbulent Flow Flow Over a Tiny Rearward facing Step on Circular Cylinder

Results of numerical simulation for viscous incompressible turbulent flow field over a tiny rearward facing step on circular cylinder are presented.The Domain Subdividing and Matching method and the Simplified SOLA solution are engaged in the simulation. The effects of the step's height,installed position and Reynolds number on the flow field are obtained and discussed. The results show that, if the rearward facing step is installed on the cylinder surface at a suitable point, a reattached boundary layer will be produced at the downstream of the step lagged in a small distance on the cylinder s surface and will re separate from the cylinder s surface.The reattachment point and the re separated point will exchange as the step's height and installed point exchanging.There is an effective reattachment region. If the fluid flow separated from the sharp edge of the rearward step reattaches in the effective region, the re separated point will occur at the downstream of the cross section of the cylinder and the drag will be reduced. This pattern is not directly connected with the flow in laminar nor in turbulent.[WT5HZ]     

Optimization Model of Non-rhythm Flow Process and the Dynamic Programming Algorithm

The flowing sequence has important effect to the flow ste Pdistance and the period of non-rhythm flowing construction,algorithmic research of ordering and step distance calculation are always difficult point of non-rhythm flowing construction optimizes studying.An optimization model of non-rhythm flow process is founded,and a common method for confirming the length of flow step was put forward.In order to find the solution of the optimization model conveniently,the optimization problem is transformed to shortest path problem skillfully.A dynamic programming algorithm is given to make the construction project period as shorter as possible,to reduce cost and improve economic efficiency.     

OPTIMAL REACTIVE POWER FLOW BY SENSITIVITY METHOD

A new approach based on sensitivity method for the optimal power flow is presented in the paper. This method has the following advantages: it is suitable to solve a 200-node power system on the microcomputer; the convergence is easy to reach and the computation speed is quick; it is possible to reduce 8-14% power loss and to get maximum economic benefit by using this method; in power system dispatch center it can be used as an on-line voltage and reactive power control program to keep good voltage level. The proposed method has been proved successful by IEEE 118-node test system and the several real power systems such as 49-node, 61-node, 99-node and 200-node systems.     

Experiments and Numerical Simulation of Flow Distribution with Larger Flux in Multi-branch Pipe

Many heating process with smoking gas involves the uniformity problem of flow distribution with larger flux in multi-branch pipe. The authors do the experiments and numerical simulation of flow distribution with larger flux in multi-branch pipe, which gets flow regulation in distributing pipe and the methods to improve flow distribution uniformly. Experiments have shown that improving the frame of distributing pipe may realize the flow distribution uniformly to the pipe with larger flux and multi-branch.     

POD analysis of flow structures in thermally stratified flow in a confined space with the effects of horizontal wind

PIV measurements are carried out on the thermally stratified flows under different horizontal shear intensities in a confined space. Proper orthogonal decomposition (POD) is used to analyze the structures of these thermally stratified flows. Results show that, at the conditions without forced horizontal airflow, the low-order POD mode constitutes a high proportion of the total energy of the flow, and the horizontal flow is the dominant flow structure. The horizontal shear drives the energy to dissipate from large structure to smaller structures. Relative to the conditions without forced horizontal airflow, the ratios of vertical kinetic energy to horizontal kinetic energy become higher for each order of POD mode in the conditions with forced horizontal airflow. This indicates that horizontal shear can result in stratification instability and enhance the mass exchange in the vertical direction.     

Experimental Technology on Dynamic Wind Loads on a Tall Building

The wind load is a major load on tall buildings from side directions. It is of considerable necessity to building engineering that the static and dynamic wind load and the dynamic wind response can be achieved accurately. Therefore, the model of a tall building in Chongqing is made and tested in wind tunnel by using the high frequency balance used widely home and abroad at present. The characteristics of wind load are studied. This paper gives the coefficients of base force of the building produced by wind load in different wind directions, and offers reference for wind-resistant design of the building.