工厂化立体式兰州百合鳞片埋植条件下不同基质对小鳞茎繁殖效果的影响

为完善工厂化立体式条件下兰州百合鳞片埋植繁育技术,研究兰州百合不同层次鳞片小鳞茎繁殖效果对于添加不同基质的响应,优选出更具有生产应用价值的基质类型和鳞片层次,为工厂化立体式兰州百合鳞片繁育技术的示范和推广提供科学数据支撑。结果表明,蛭石处理的鳞片疑似发病率最低,25 d到50 d,鳞片疑似发病率快速上升,50 d到75 d,鳞片疑似发病率缓慢下降。外层鳞片疑似发病率最高,内层鳞片疑似发病率最低。蛭石处理中,在75 d时中层鳞片分化率最高达到93.23%,中层、内层鳞片分化率高于外层。在75 d时,蛭石中层鳞片小鳞茎分化数最高为2.21粒/片,内层和中层鳞片分化的小鳞茎数差异较小。小鳞茎繁殖效果指标均表现为蛭石处理最高,蛭石+营养土次之,营养土效果最差。蛭石单个鳞片小鳞茎鲜重平均为0.68 g,根数平均为0.77根,单个鳞片生子球数为4.03个,周径＞2 cm 鳞茎数量占比为60.33 %,繁殖系数为2.68。     

龙牙百合小鳞茎离体诱导与脱毒培养研究

将龙牙百合种球鳞片当做外植体,进一步分析了龙牙百合小鳞茎离体诱导与脱毒培养,以推进无病毒百合种苗的应用,减少龙牙百合组培苗的生产费用。     

四良配套种百合

1良田 适宜种百合的田,必须具备无污染、高燥、肥沃、沙性、杂草少、特别是恶性草少。 2良制 百合栽培目的是鳞茎,而鳞茎长在地下,常遭受病虫而不知;生育期长,播收季节要求严格,作物搭配不当,既影响百合收成,又波及系统生产力,减少收益。所以耕作制度就成了百合生产的前提条件,其中最关键的是： 　　(1)复种方式 在江西各地均适用的"百合--晚稻"复种方式,有季节衔接好、病虫少、系统产量高、产品质量好等特点。 　　(2)轮作 百合忌连作,因为连作病、虫严重。轮作,是一种不费工本、不用农药、没有污染和残毒而能有效地防…     

深施型液态施肥机扎穴机构优化设

为实现液态施肥机高速作业,设计了一种结构简单、运动平稳的椭圆齿轮行星系作为液态施肥机的扎穴机构.对该机构进行运动学分析,建立了数学模型,以穴距200mm和入土深度120～150mm为寻优目标,应用Visual Basic 6.0软件编程得出满足机构运动要求的最优参数范围为:喷肥针尖和行星轮轴连线与行星架的初始夹角-45°～-40°、行星架初始角位移40°～50°、喷肥针尖与行星轮轴心距离280～300mm,此时椭圆齿轮长半轴29.364mm、齿数23、短半轴与长半轴比0.958,正圆齿轮半径25mm.从优化工作参数中选择一组参数设计扎穴机构,应用Pro/E软件进行仿真.结果表明,根据优化参数设计的扎穴机构能够满足穴距和入土深度的设计要求.     

负水头条件下水质对湿润体运移及水盐分布的影响

通过室内试验,分析了负水头供水条件下,灌溉水钠吸附比和盐分浓度对湿润体运移及水盐分布的影响.结果表明,湿润体的最大水平湿润距离、最大垂直湿润距离以及累积入渗量均与时间呈幂指数关系,并随着灌溉水盐分浓度的增加和钠吸附比的减小而增加;湿润体内土壤含水率和电导率的分布近似为一组同心椭球面,并与湿润体半椭圆在水平方向的半轴平方呈线性关系,随着半轴的增加,土壤含水率减小,而电导率增加;灌溉水盐分浓度一定的条件下,随着钠吸附比的增加,湿润体内的平均含水率减小,平均电导率增加,在钠吸附比一定的条件下,灌溉水盐分浓度对两者的影响较小.     

不同时期覆膜对兰州百合产量及土壤温湿度的影响

在兰州百合种植区进行秋覆膜、顶凌覆膜和不覆膜3种栽培模式试验,结果表明,在兰州百合生长的每一个生育期,株高、茎粗、叶长、叶宽、根重均是秋覆膜(A)>顶凌覆膜(B)>不覆膜(CK);0～20cm土壤含水量、土壤温度不同生育时期秋覆膜、顶凌覆膜均高于传统不覆膜栽培;百合鳞茎产量秋覆膜栽培较传统不覆膜栽培高21.2%,顶凌覆膜栽培较传统不覆膜栽培高4.5%。     

土壤水力参数对点源入渗湿润体形状的影响

为探究点源积水入渗的运移机理,以达西定律和质量守恒原理为基础,利用HYDRUS软件对点源积水入渗过程进行数值模拟分析与验证,分析点源积水入渗条件下土壤水平湿润锋与垂直湿润锋的比值(湿润锋比)和土壤水力参数(进气吸力、形状系数以及饱和导水率)之间的关系,并基于土壤饱和扩散率建立水平湿润锋运移模型。结果表明:细质土壤(进气吸力大于11 cm)的湿润体形状近似为以积水中心为椭圆心、以垂直湿润锋和水平湿润锋为长半轴和短半轴的椭圆体,而粗质土壤(进气吸力小于8.7 cm)湿润体的椭圆心位于积水中心下方,从而导致短半轴大于水平湿润锋、长半轴小于垂直湿润锋;细质土壤的湿润锋比随时间变化较小,可近似为常数,土壤湿润锋比与形状系数和饱和导水率之间无显著的函数关系,但与进气吸力呈线性递增关系,决定系数R^2为0.999;湿润锋运移过程可以采用入渗时间的幂函数进行拟合,且幂函数系数和指数可以分别用土壤饱和扩散率的一次多项式和二次多项式进行估计,经验证得到的模型在误差允许范围内具有较好的效果。本研究可为分析点源积水水盐运移等问题提供机理性依据,也为我国北方干旱半干旱地区合理规划设计滴灌系统、提高农业灌溉用水效率提供科学依据。     

半轴为啥滚键

一台新的小四轮拖拉机使用不到半年,左半轴就滚键了,在半轴原键槽的对面铣一键槽,工作了4个月,又发生了滚键故障。在更换半轴和制动鼓时,发现半轴壳体上固定驱动轮挡泥板的3个螺栓中,有一个螺栓与制动鼓对应的     

汽车后桥总成的维修

1.桥壳与半轴套管的检修。桥壳是驱动桥的基础件,其作用是支承主减速器、差速器和半轴等零部件,固定左右驱动轮的相对位置,支承汽车重量,传递车架与车轮之间的各种作用力。桥壳按结构分为整体式桥壳和分段式桥壳。东风EQ1092型汽车为整体式桥壳的结构。它用球墨铸铁铸造而成,两端压入无缝钢管制成的半轴套管。     

运输车后桥故障的诊断

一、运输车后半轴易断,且易断半轴的那一侧轮胎有锯齿形异常磨损. 1、检查过程 (1)在拆卸半轴紧固螺栓螺母时,锥形衬套有自动向外弹出的现象.(2)将半轴紧固螺栓螺母及锥形衬套全部卸掉后,在将半轴凸缘平面与后轮毂平面靠拢时,发现前侧约有O.70衄的缝隙.(3)在将半轴装入半轴套管时,装到最后约10咖时很难装进.     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。