Analysis of the Stretch and Curvature Effects on Premixed Flame Parameters

本文假设简单流场和一步化学反应机理,采用渐进分析法计算了三种特定的拉伸或曲面预混火焰(平面火焰、管式火焰和球面火焰)的火焰速度和火焰温度。火焰速度和火焰温度可以通过两个耦合的非线性代数方程用简单的数值方法求解。基于火焰曲面效果的物理分析,将得到的分析结果拓展到一般曲面火焰,给出了曲面拉伸火焰的火焰速度和火焰温度的曲率效果关联式。通过关联式对平面拉伸火焰的参数进行修正,可以得到任意曲面拉伸火焰的火焰速度和火焰温度。Based on a simple flow assumption and one-step high-activation energy chemistry,the flame speed and flame temperature of three specific stretched and curved premixed flames(the planar flame,the tubular flame,and the spherical flame) are predicted by asymptotic analysis.The expressions for flame speed and flame temperature are two coupled nonlinear equations and they can be solved easily with a simple numerical method.To extend the asymptotic solutions to generally curved flames,correlations on flame speed and flame temperature of the stretched and curved flame are given.With these correlations,the flame speed and flame temperature of any curved and stretched flame can be predicted from information of stretched planar flames.国家自然科学基金资助项目(No.51106131); 中央高校基本科研业务费专项资金资助(No.2010121045

Island instantaneous coastline extraction based on the characteristics of regional statistics of multispectral remote sensing image

本研究采用IkOnOS遥感图像,选取波谱特征区,通过区域像元统计并计算各波段权重系数,将影像进行波谱归一化处理,使归一化的影像岛陆与海水特征更明显。在此基础上,采用最大类间方差法确定最佳分割阈值,对归一化的影像进行二值化,从而提取海岛岸线。该方法采用特征曲线法进行水陆分离,得到的二值图像保持了原图的有效边缘,采用二值形态学提取的海岸线连续可靠、信噪比高。结果表明,该方法简单、快速,能有效提取海岸线,具有实用价值。This study adopted IKONOS remote sensing images and selected spectral characteristic areas, through regional pixel statistics and calculating weight coefficients of each band, processed the images with the spectral normalized method, which made the features of islands, land and water features more obviously in the images.On this basis, the OTUS was used to determine the optimal segmentation threshold, and the normalization image binarization was made, thus the island coastline was extracted.This method used the characteristic curve method to separate the land and water, obtained the binarization images and maintained the original edge effectively.The coastline that was extracted by Binary Morphology was continuous, reliable and high signal-to-noise ratio.The results showed that this method could extract the coastline fast, simply and effectively, which had the practical value

Analysis on the land use and cover change in Tianjin Binhai New Area based on the remote sensing

采用全国土地分类系统,基于lAndSAT卫星TM遥感影像与天津滨海新区1:50,000地形图,进行相应数据处理,编制出2000年、2005年、2010年三期滨海新区土地利用/覆盖分类图,并运用土地利用转移矩阵对近10年来天津滨海新区土地利用/覆盖变化进行定量分析。在此基础上,进一步分析了经济、人口等驱动因子对土地利用/土地覆盖的影响。结果表明:十年间,滨海新区的建筑用地面积增加显著,而绿地、湿地、滩涂等高生态价值的土地向建筑用地、未利用地等开发建设用地大幅度转化,后五年变化尤为显著。This paper carries out quantitative analysis on the land use/cover(LU/C) change of Tianjin Binhai New Area in recent 10 years through using land use transition matrix from the three-stage LU/C classification maps of 2000, 2005 and 2010 drafted by means of the National Land Classification System of China based on Landsat TM satellite remote sensing image and the Tianjin Binhai New Area 1:50 000 relief maps.On this basis, the impact of such driving factors as the economy and population on LU/C is further analyzed.The results show that the area of the building land in Binhai New Area has increased significantly over the ten years, and the greenland, wetland, and shoals of high ecological value have been dramatically transformed into the building land and unused land for the development and construction, and the change is more significant in the later five years

Comparison of Wushu Pattern Athletes' Score Ability in the 10~(th) National Sports Games

以参加2005年十运会武术套路比赛的运动员为研究对象,就运动员在动作质量、演练水平和难度动作方面的得分情况进行统计分析。结果显示:(1)十运会套路比赛反映出了运动员良好的竞技能力,运动员的得分能力普遍增强;(2)套路运动员在得分能力和得分手段上存在着较大的性别差异;(3)高水平男子套路运动员的竞争,已由新规则实施之初的难度动作的竞争转变为动作质量和演练水平的竞争,而女子运动员得分能力的差异则较为分散。但与男子运动员相比,难度动作对于女子运动员得分的影响则明显高于其对男子运动员的影响。This paper analyzes the players of their movement quality,practice level and difficulty movement in the matches of the 10~(th) National Sports Games.The result shows: pattern matches reflect good competitive ability and score ability of players;sexual difference existing between pattern players' score ability and method;the competition of high level man pattern players has changed from difficulty to movement quality and practice level.Compares with man player,the influence of difficulty is obviously to women player

design and implementation of a multiservice broadband access network switch

在接入网中提供多业务可以有效地降低运营维护成本和网络铺设费用,同时提高网络利用率.采用组播技术和具有多项服务质量(QoS)选择的多层以太网交换机,可以实现能提供QoS保证的多业务宽带接入网.该文介绍了一种多业务宽带接入交换机的设计与实现,按功能模块分述并讨论了其中的难点和要点

Study on Present Status and Development of Animal Husbandry in the Farming Region in Shigatse City

通过农户调查,并根据日喀则市1992-2009年的统计数据,对其农牧业结构及农区畜牧业现状进行分析,归纳了其主要存在如下问题:种植业结构不合理;畜群结构单一;加工体系薄弱等。针对这些问题,提出了调整措施:调整农业产业结构,即压缩粮食播种面积,增加饲料与经济作物种植面积;改进畜群结构,增加耗粮型牲畜数量;建立饲料和农畜产品加工体系;提高农机化程度,兴修水利设施

A study on application of an Organic Compound, Quickening-Supporting Curative,in larval rearing of kuruma shrimp, Penaeus japonicus

以复方有机疗效助长剂（简称Q.S.）的不同剂量和不同投喂方式对日本对虾（PEnAEuSJAPOnICuS）各期幼体培育进行三批的试验，分析了Q.S.在日本对虾幼体培育中的应用效果。在水温24~29℃，盐度22~29下，无节幼体至仔虾经15d（10月4~19日）培育，试验组和对照组的存活率、平均体长分别是52.9%（40.2%~72.4%），10.05MM（9.30~11.7MM）和31.7%与8.8MM。试验表明，在幼体培育中Q.S.以“水浴”为主，以一定比例掺进饵料为辅的方式最为有效；结果还表明，Q.S.在日本对虾各期幼体的培育中具有显著的提高存活率和促进生长的作用。本文还就提高幼体存活率、促生长与虾苗质量之间的关系进行了讨论。Three experiments in the larvalurearing of kuruma shrimp, P.japonicus with diFFerent dosages and diFFerent Feeding mode of an organic quickening-suporting curative compound were made- The application of Q.S.to the larval rearing of P.japonicus was investigated.Under this experimental condltion with 24 --29℃, 22-- 29, it took about 15d From naupliar stage to postlarval stape 8(PL8),With a survival rate of 52.9% (40.2% --72.4% ) in the experimental groups and of 31.7% in the control, with an average body length of 10.05mm (9.30-- 11.7mm ) in the expermental groups and of 8.8mm in the control.The results show that the Feeding mode of main "sea bathing" and assisst "medicinal Food" is the most eFFicient in the larval rearing and that they increase survival rate and quicken growth eFFiciency.The relation between increasing survival rate and quickening growth and larval quality is also discussed.深圳外贸勤兴工贸公司资

CFD numerical simulation of Hyshot scramjet

以HySHOT超燃冲压发动机试验为研究对象,分别对冷流和燃烧工况进行了Cfd数值模拟.冷流模拟计算得到的壁面压力与试验结果吻合良好,且数值计算压力分布对采用的湍流流动模型不敏感;但是采用不同的湍流流动模型计算的湍流参数(湍动能和耗散率)差别很大,会对氢气燃料与气流的掺混产生重要影响,进而影响燃烧模拟结果.采用SST(SHEAr STrESS TrAnSPOrT)k-ω湍流流动模型和EdM(Eddy dISSIPATIOn MOdEl)湍流燃烧模型得到的模拟结果与试验结果基本吻合,但是计算压力峰值略靠后.对8个不同氢气燃料喷射角度的工况进行数值模拟结果表明喷射角度为99°和114°时燃料和空气混合最好、燃烧效率可达到最高.CFD numerical simulation was carried out for cold flow and combustion flow of the Hyshot scramjet to test the accuracy of turbulence flow model and turbulent combustion model.For cold flow,the predicted wall pressure profile was in accurate agreement with experimental data and the simulation result was insensitive to turbulence flow model choice.However,the predicted field of turbulence variables(turbulence kinetic energy and its dissipation rate)in cold flow is strongly influenced by turbulence flow model choice;these turbulence variables affect the mixing of hydrogen fuel and air and the subsequent combustion.Indeed,the simulation of combustion flow showed strong dependence on turbulence flow model and turbulent combustion model choice.The best combustion simulation result with SSTk-ωturbulence flow model and EDM turbulence combustion model has good agreement with experimental wall pressure data,but the pressure peak location is slightly deviated.The effect of fuel injection angle was also simulated.Eight injection angles of hydrogen fuel were tested and it was shown that the scramjet has best fuel/air mixing and combustion efficiency with injection angles of 99°and 114°.国家自然科学基金(51106131;11002125;51206057); 中央高校基本业务费专项资金(2010121045

improvement and implementation of dhcp relay agent in layer 3 switch

社区宽带综合业务网络系统使用交换式以太网技术。为社区用户提供Intemet接入、电视、IP电话等服务。根据系统的实际需求，提出了一种改进的DHCP中继代理机制，并将该机制在系统的核心三层交换机SW1200的驱动程序中实现

design and implementation for integrating a switch with a router

宽带社区接入网是下一代网络研究的主要领域之一.RBISN(社区宽带综合业务网络)研究使用交换式以太网提供电视、IP电话和Internet接入服务,边缘路由设备必不可少.该文分析了该环境下的通信量,在对可用的方案进行对比的基础上,提出了将智能二层VLAN交换机和VLAN路由器一体化的方案.随后给出其模型和设计,加以实现以证明其可行性