基于傅里叶变换轮廓术的动态液膜测量

动态液膜三维形貌的高速测量及重建,对于能源动力领域的工业过程优化十分重要。基于傅里叶变换轮廓术,对缓变表面和非缓变表面分别进行了模拟仿真,研究了物体表面形貌重建精度的影响因素,包括物体表面高度变化率、环境随机噪声以及条纹频率。并根据模拟结果对实验参数进行了优化,研发构建了高速三维结构光测量系统,对竖直壁面下降液膜表面形貌进行了动态测量。实验结果表明:随着液膜沿竖直壁面向下流动,液膜厚度呈现先增大后减小的趋势,高度方向的平均误差为0.1 mm,傅里叶变换轮廓术能够精确地应用于动态液膜高速测量。     

落水洞上覆路堤土工加筋设计新方法

为了改变由于土工织物的存在抑制了落水洞上覆路堤土不均匀变形,使得路堤中的土拱效应和剪应力不能完全发展的问题,提出了基于不完全发展的土拱效应的设计方法.首先根据Handy的土拱为最小主应力拱的假设,利用摩尔圆推导出了在土工织物不同挠曲变形时土中剪应力的计算方法.然后将其与土拱效应的计算理论相结合提出了不完全发展的土拱效应计算公式.最后考虑不同的填土高度,以不完全发展的土拱效应计算理论为基础得到土拱高度确定方法.利用数值分析和本文方法以及现有的设计方法分别计算同一算例,结果表明,所提出的方法与数值分析计算结果更为接近.这证明在用土工织物加固落水洞上覆路堤时考虑土中剪应力的不完全发展更符合工程的实际情况.     

水分胁迫及复水对香蒲生长和光合参数的影响

以香蒲为研究对象,通过盆栽试验,分析了其主要生长时期内在水分胁迫(水分处理由轻到严重分别为W1、W2、W3、W4以及对照CK)及复水条件下净光合速率(Pn)、气孔导度Gs、蒸腾速率Tr、水分利用效率(WUF)、株高PH、生物量等指标的变化特征。结果表明,以上指标随着水分胁迫程度加剧而降低;水分利用效率在7月底出现了较大差异,在试验结束时其大小为W2W3W1CK,W4处理下水分利用效率不增反减,适度水分胁迫提高了水分利用效率;复水使受水分胁迫处理的香蒲生长和光合作用有所恢复,但都不能恢复到对照水平。W4处理恢复幅度最大,但由于其背景值最小,最好只能恢复到W3处理水平;30%的土壤含水量可能是香蒲受水分胁迫的阈值,当低于该值时复水后香蒲很难恢复到较好状态;复水后,由于香蒲增加了水分吸收使鲜重比干重增加更多。     

Some families of combinatorial and other series identities and their applications

The main object of this presentation is to show how some simple combinatorial identities can lead to several general families of combinatorial and other series identities as well as summation formulas associated with the Fox-Wright function _pΨ_q and various related generalized hypergeometric functions. At least one of the hypergeometric summation formulas, which is derived here in this manner, has already found a remarkable application in producing several interesting generalizations of the Karlsson-Minton summation formula. We also consider a number of other combinatorial series identities and rational sums which were proven, in recent works, by using different methods and techniques. We show that much more general results can be derived by means of certain summation theorems for hypergeometric series. Relevant connections of the results presented here with those in the aforementioned investigations are also considered.     

上海松江播种红花油茶的试验研究

通过容器、露地和槽式苗床播种的方法,在上海松江对来自不同地源的3种红花油茶种子进行播种试验。研究显示全南野生和九江大果红花油茶的出苗率高于德兴红花油茶;在苗高、地径方面,容器播种的全南野生红花油茶极显著高于其它播种方式的品种,德兴红花油茶的3种播种方式中,容器播种的苗高显著高于其它方式、而露地播种苗的地径极显著大于其它方式。本研究还对上海地区红花油茶的播种和管理进行了探讨。     

含ACC脱氨酶PGPR菌株的分离及其对燕麦耐盐性的影响

本文采用富集筛选法,以1-氨基环丙烷-1-羧酸(1-aminocyclopropane-1-carboxylate,ACC)为唯一氮源,从白城农科院实验地燕麦根际土壤中分离出2株具有ACC脱氨酶活性的细菌。其中菌株7ACC9-1的ACC脱氨酶酶活性较高,并用此菌株处理燕麦种子,在不同浓度的碳酸氢钠溶液的碱胁迫下进行燕麦种子的萌发实验和初生苗的生长试验,测定燕麦种子的发芽率、燕麦初生苗的根长和苗高。结果表明:燕麦种子用菌株处理后,发芽率显着提高;同时,在各浓度的碱胁迫下,燕麦处理组的初生苗根长和苗高均显着地优于对照组。说明具ACC脱氨酶活性的7ACC9-1能够有效地缓解燕麦种子在盐碱胁迫下萌发及其在初生苗生长阶段所受到的危害。     

Modelling of turbulent lifted jet flames using flamelets: a priori assessment and a posteriori validation

This study focuses on the modelling of turbulent lifted jet flames using flamelets and a presumed Probability Density Function (PDF) approach with interest in both flame lift-off height and flame brush structure. First, flamelet models used to capture contributions from premixed and non-premixed modes of the partially premixed combustion in the lifted jet flame are assessed using a Direct Numerical Simulation (DNS) data for a turbulent lifted hydrogen jet flame. The joint PDFs of mixture fraction Z and progress variable c, including their statistical correlation, are obtained using a copula method, which is also validated using the DNS data. The statistically independent PDFs are found to be generally inadequate to represent the joint PDFs from the DNS data. The effects of Z–c correlation and the contribution from the non-premixed combustion mode on the flame lift-off height are studied systematically by including one effect at a time in the simulations used for a posteriori validation. A simple model including the effects of chemical kinetics and scalar dissipation rate is suggested and used for non-premixed combustion contributions. The results clearly show that both Z–c correlation and non-premixed combustion effects are required in the premixed flamelets approach to get good agreement with the measured flame lift-off heights as a function of jet velocity. The flame brush structure reported in earlier experimental studies is also captured reasonably well for various axial positions. It seems that flame stabilisation is influenced by both premixed and non-premixed combustion modes, and their mutual influences.     

高功率激光器喷雾冷却的实验研究

以水为冷却介质,采用Spray公司的TG0.3机械雾化实心圆锥喷嘴,在体积通量为0.044,0.049和0.053 m3/(m2·s)情况下,对刻有不同微结构槽道冷却面的无沸腾区换热性能进行实验研究。结果表明：刻有微结构的表面可明显增强换热效果;壁面刻有高为0.2 mm的微结构槽道且壁面温度为52 ℃时,体积通量为0.044 m3/(m2·s则热流可达260 W/cm2,通量为0.053 m3/(m2·s则散热功率高达376 W/cm2,完全可以满足当前高功率激光器的散热需求。对于光滑面以及槽肋高为0.1和0.2 mm的换热面,其换热能力随着体积通量的增加而增强;换热面高度为0.4 mm时,通量对换热的影响变得较微弱。微结构槽道不仅增加了换热面积,还有利于液膜扩散,减小液膜厚度,增强换热。在三种不同的流量通量下,高度为0.2 mm的微结构槽道换热性能最佳。     

倒伏量对翻驳领结构影响分析

主要研究了直线状、圆弧状和部分圆弧部分直线状3种类型翻折线与翻驳领结构的相关关系,针对翻驳领结构设计中的主要难点——倒伏量进行研究,并分析翻折线变化对其产生的重要影响。通过变换驳点高度及搭门宽度来控制翻折线倾斜度,各领型分别做出ll组试样,进而研究翻折线与倒伏量的关系,最后对理论研究的数据进行成衣验证。