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1.
喷杆式喷雾机全面喷雾作业雾量分布均匀性分析   总被引:1,自引:0,他引:1  
本文介绍了喷杆式喷雾机在不同高度下全面喷雾雾量分布均匀性的分析方法,并用这种方法确定了最佳喷雾高度.  相似文献   

2.
为了研究缸内直喷汽油机多孔喷油器的碰壁喷雾特性,建立了定容碰壁喷雾试验装置,对不同喷油压力和不同环境压力条件下的碰壁喷雾过程进行了拍摄,同时考虑壁面与喷嘴的距离和壁面倾角对碰壁喷雾特性的影响.结果表明:增加喷油压力可以使碰壁喷雾高度和半径增大,但是碰壁喷雾高度的增加率随喷油压力的增加而减小;随着环境背压的增大,碰壁喷雾高度和半径均减小,进一步增大环境背压,则碰壁喷雾高度增大;加大撞击壁面与喷嘴的距离和壁面倾角,碰壁喷雾高度和喷雾半径均增大,当壁面倾角进一步增大,碰壁液滴总动能减少,而且受到喷雾油束边缘的运动阻力,碰壁喷雾半径减小.  相似文献   

3.
设计一种新型无针式碟形静电纺丝喷头用以制备亚微米纤维。建立不同圆周倾角的碟形喷头几何模型,利用ANSYS Maxwell 3D电磁学分析软件模拟无针式碟形喷头的电压及电场强度分布,探究无针式碟形喷头不同圆周倾角对亚微米纤维直径及产量的影响。结果表明:碟形喷头边缘处的电场强度最大,在施加电压一致时,圆周倾角越大则碟形喷头边缘的电场强度越大;纺丝液与水平面夹角随着圆周倾角的增大而增大;利用不同质量分数的聚丙烯腈(PAN)溶液进行纺丝,随着PAN质量分数的增加,亚微米纤维直径增加;随着碟形喷头圆周倾角的增加,亚微米纤维直径减小,产量增加。  相似文献   

4.
为分析金属矿山多中段高溜井喷头雾化特性及其降尘效果,建立高溜井喷雾降尘实验平台。采用激光粒径分析仪及喷雾实验设备对新型气-水喷头雾化特性、冲击气流对喷雾捕尘能力影响规律进行研究分析。研究结果表明:气、水流量比是影响新型气-水喷头雾化效果的关键因素;当喷头工作时气、水流量比为100~150时,雾化效果最佳,最佳气压和水压区间分别为[0.4, 0.6] MPa和[0.3, 0.5] MPa,雾滴粒径分布在15~35μm范围内;在最佳气压和水压区间内,雾化角度随气压的增加而增大,随水压先增大后减小,最大雾化角度为40°,调整气压是优化雾化角度的主要手段;溜井卸矿冲击气流对喷雾雾滴粒径影响较大,喷雾捕尘能力与冲击气流速度呈负相关。  相似文献   

5.
高压静电喷洒机的试验   总被引:5,自引:0,他引:5  
运用高压静电喷雾技术和控制技术对原有的喷洒机具进行了改进,以适应有毒药剂的大面积高效喷洒问题.改进后的机具以皮卡车为载具,车厢上安装独立汽油发电机,在驾驶室内可控制喷雾的启停、喷头的俯仰及旋转运动.在试验室内对喷雾系统进行试验,得出了雾滴平均直径和雾滴沉积量的分布特性。两者在试验喷幅内均呈现一致的双峰分布.进行了整机现场试验,对比了荷电与非荷电、不同药液及不同药液喷量下的灭蝗效果.结果表明,荷电工况优于非荷电工况;随着药液喷量的提高。近距离喷洒区域内的杀灭效果较好;锐劲特药剂对荷电的适应性能明显优于菊马乳油药剂.  相似文献   

6.
滴头间距对线源滴灌土壤湿润均匀度的影响   总被引:1,自引:0,他引:1  
通过室内试验研究了滴头间距对线源滴灌土壤湿润均匀度的影响。试验中滴头间距设为10、30、40、50和70cm5个处理,滴头流量和滴水量恒定,分别观测分析了滴头连线方向的土壤湿润均匀度、垂直该连线方向的湿润均匀度、交汇区的湿润均匀度以及地表湿润带的均匀度。结果表明:在试验范围内壤土沿滴头连线方向、垂直滴头连线方向以及交汇区的湿润均匀度均不受滴头间距的影响;滴头间距大于30cm时,沙土沿滴头连线方向的湿润均匀度减小,而垂直滴头连线方向和交汇区的湿润均匀度基本不随滴头间距而变化,但其交汇区土壤含水量却随滴头间距增大而明显降低;滴头连线方向的土壤湿润均匀度是评价线源滴灌质量的最主要指标。以上结果可以为滴头间距和滴灌带间距设计提供参考。  相似文献   

7.
通过高速风洞测试系统,模拟飞行时产生的高速气流,开展了气流大小和喷头结构参数对雾滴粒径及其分布的影响研究.研究结果表明:在喷头型号一定的情况下,3种航空喷头产生的雾滴粒径都随着风速的增大而减小;在喷雾压力一定、同一风速条件下,雾滴粒径均随着孔径的增大而增大;风洞条件下,3种航空喷头的雾滴谱相对宽度均较小,表明雾滴分布较均匀;空拖CP-03喷头结构多样,可以灵活调节流量,用于不同条件的农药喷洒作业;相比其他喷头,GP-81A喷头流量大,雾滴粒径较大,应结合飞机作业参数进一步优化喷头结构,以实现低量喷雾,减少农药浪费;直升机旋流喷头结构单一,需要根据直升机喷雾特点对雾化装置做进一步优化改进.  相似文献   

8.
基于压力变量喷雾的雾化特性及其比较   总被引:6,自引:1,他引:5  
讨论了基于压力变量喷雾的流量调节范围、雾量分布、喷雾角、雾滴粒径、速度及喷雾动态特性等雾化特性随流量的变化规律,定量比较了PWM连续式、PWM间歇式和基于压力的变量喷雾的雾化特性.结果表明,压力变量喷雾流量调节范围约为2;随流量的减小,雾量分布向中央集中剧烈,雾滴粒径增大明显,喷雾角、雾滴粒径随流量的变化率分别为1.08°/%,-1.562 μm/%;雾滴速度显著减小;动能中值直径(KEMD)和比能(SE)随流量的变化率分别为-1.50 μm/%, 0.228 7(J/kg)/%,压力变量喷雾的能量利用率低.比较3种变量喷雾的雾化特性,基于压力变量喷雾的流量调节范围最小,对雾化特性的影响最大;PWM连续式变量喷雾的流量调节范围最大;PWM间歇式变量喷雾流量控制对雾化特性的影响最小.  相似文献   

9.
为提高光学头力矩器在大规模生产条件下的性能一致性,研究了力矩器生产过程中7种工艺因素误差对力矩器动态性能参数的影响。以有限元仿真并结合田口实验设计方法和数学统计原理,分析得出:悬线竖直预变形量对扭转共振频率的影响贡献率为72.4%,永磁铁轴向安装误差对扭转共振峰值和偏转共振峰值的影响贡献率分别为51.9%和58.1%,永磁铁水平安装误差对物镜倾角的影响贡献率为93.6%。结果表明,悬线竖直预变形量与永磁铁水平、轴向安装误差属于关键工艺因素,生产中应重点控制。  相似文献   

10.
为提高光学头力矩器在大规模生产条件下的性能一致性,研究了力矩器生产过程中7种工艺因素误差对力矩器动态性能参数的影响。以有限元仿真并结合田口实验设计方法和数学统计原理,分析得出:悬线竖直预变形量对扭转共振频率的影响贡献率为72.4%,永磁铁轴向安装误差对扭转共振峰值和偏转共振峰值的影响贡献率分别为51.9%和58.1%,永磁铁水平安装误差对物镜倾角的影响贡献率为93.6%。结果表明,悬线竖直预变形量与永磁铁水平、轴向安装误差属于关键工艺因素,生产中应重点控制。  相似文献   

11.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

12.
There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.  相似文献   

13.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

14.
本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。  相似文献   

15.
Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with  相似文献   

16.
The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to  相似文献   

17.
18.
The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.  相似文献   

19.
R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).  相似文献   

20.
The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.  相似文献   

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