苏北湖区户用风光互补发电系统的设计与试验分析

离网型风光互补发电系统是解决湖区电力供应短缺问题的新选择.以金湖县宝应湖为应用背景,对风光互补发电系统进行设计和试验分析,为该系统在此地区的推广提供技术依据.     

Increasing experimental approaches in stream trout research – 1987–2006

Abstract –  This review of stream trout research literature for the 1987–2006 period covered >1300 papers dealing with 22 relevant topics, when compared with <400 papers on 18 topics in the previous one (1967–1986). The percentage of experimental approaches here quantified for both research reviews was 18% in the 1967–1976 period, increased to 21% in 1977–1986, to 39% in 1987–1996, and up to 43% in 1997–2006. Particular journals in the recent two decadal period published high percentages of experimental papers ( The Journal of Animal Ecology and Canadian Journal of Fisheries and Aquatic Sciences ; 62.9% and 62.4%, respectively), others, intermediate percentages ( Nordic Journal of Fisheries Research , Transactions of the American Fisheries Society , North American Journal of Fisheries Management and Ecology of Freshwater Fish : 44.1%, 42.4%, 40.5%, and 35.6%, respectively); the remainder covered ≤33%. Research papers on stream 'trouts' published over the last two decades were classified into 22 subject areas for nine major journals separately and combined for 55 other journals. Subject areas dealing with the biology and ecology of trout redds, egg development, alevin emergence and onto fry and parr were the most heavily reported in nine major journals, as well as in all other journals combined. Habitat characteristics and cover use by trout were the next. Atlantic salmon and brown trout were the species with highest publication coverage in nearly all subject areas, with low coverage for all salvelinid (charr) species except brook charr. Research on Atlantic salmon in the UK used experimental approaches in nearly 60% of publications and in mid to high 30% for those on Atlantic salmon and brown trout in Scandinavian countries. Consideration is given to future research needs for stream trouts.     

The pond's shape matters: differential growth,physiological condition and survival of epibenthic Farfantepenaeus aztecus postlarvae

As a function of the water quality provided by square, circular and oval experimental ponds, the growth, survival and oxygen requirements in epibenthic postlarvae of Farfantepenaeus aztecus were analysed in relation to their routine metabolism and apparent heat increment. Temperature, oxygen concentration, pH and salinity were measured daily in two experimental ponds of each shape. The postlarvae oxygen consumption during two 24‐h cycles, their growth, physiological condition and survival and the productivity in the ponds were estimated. Low values of pH, oxygen concentration and phytobenthos productivity, and reduced postlarvae relative growth and survival were observed in the square ponds. We suggest that the latter results from a deficient water circulation related to the effect of the pond's shape on dissolved oxygen levels and, consequently, on growth and survival. The postlarvae routine metabolism, including feeding, varied between 1.91 and 2.25 mg O₂ h^?1 g^?1 wet weight, whereas the minimum oxygen concentration needed in the ponds is approximately 4.25 mg O₂ L^?1. These conditions were achieved in the oval ponds concurrent with higher survival and growth values, in which individuals distributed randomly, for which we suggest that oval‐shaped ponds could be the most adequate for the culture of this and other penaeid species.     

辽南山葡萄籽多酚提取工艺的初步研究

以山葡萄籽为实验材料，通过单因素法提取葡萄籽中的多酚。根据不同浸提剂在540nm处可见光吸收情况的测定，确定70％甲醇溶液为最佳浸提剂。通过单因素试验确定了提取剂浓度、提取时间、提取温度、料液比的适用范围，再利用正交试验法进行工艺优化。确定最佳工艺条件为：体积分数70％的甲醇，料液比1：20（m／v），70℃水浴，浸提20min。山葡萄籽中多酚的含量可达18．981mg／g。     

撕扯振动式嫩板栗脱蒲机试验研究

撕扯振动式嫩板栗脱蒲机脱蒲的剥净率和损伤率受各种因素的影响,为了得到较高的剥净率和较低的损伤率,需要根据不同的工艺参数进行优化。以撕扯振动式嫩板栗脱蒲机为研究对象,研究锯齿式辊子与沟槽式辊子之间间距、柔性振动辊子转速及倒入嫩板栗个数对脱蒲率的影响,采用单因素试验和正交试验方法安排撕扯振动式嫩板栗脱蒲机脱蒲试验。结果表明:单因素试验中锯齿形辊子与沟槽式辊子间间距为50mm时脱蒲效果最好;在正交试验中,锯齿形辊子与沟槽式辊子间间距为50mm、柔性振动辊子转速为560r/min、脱蒲时倒入嫩板栗个数为40个时效果最好。     

盐酸咪唑苯脲W/O型乳剂的处方工艺筛选

旨在筛选盐酸咪唑苯脲W/O型乳剂的基础处方.采用单因素分析方法对油相、乳化剂的种类及用量、油水比例进行筛选以及采用正交试验对处方工艺进行优化;确定了盐酸咪唑苯脲W/O型乳剂的基础处方,最终筛选出白油为最佳油相、亲水性乳化剂OP-10为最佳乳化剂,初步确定白油、亲脂性乳化剂司盘-80、亲水性乳化剂OP-10为最佳处方组合,乳化剂的最佳用量为处方量的10%,油水最佳比例为7∶3.确定最佳乳化温度为50℃,最佳乳化时间为3 min,最佳乳化速度为8000 r/min.通过上述处方筛选及工艺优化,制备了2%的盐酸咪唑苯脲W/O型乳剂.     

秸秆粉碎还田回收机性能试验

在棉田对秸秆粉碎还田回收机进行机具性能试验,选定留茬高度、秸秆粉碎长度和抛送距离作为主要的性能指标,通过一系列正交试验和理论分析,用直观分析法和方差分析法揭示了影响秸秆粉碎还田机性能的主要因素.与实际生产相结合,确定了最优的参数组合,即秸秆粉碎还田回收机在刀辊的转速为1800 r/min,粉碎机具前进速度为5.4 km/h,甩刀刀刃离地最小间隙为8cm.实验结果表明,机具有较优的性能指标,为整机的设计研究提供了理论依据.     

轴流泵多目标优化正交试验

为了整体提高轴流泵的水力优化设计水平,找出影响轴流泵性能的主要几何参数,运用正交试验方法,以扬程、效率、轴功率和压力脉动作为试验评判指标,将综合频率分析法应用到轴流泵多目标优化设计中。基于L_9(3~4)正交表得到了9组方案,研究叶片数、翼型、轮毂比和叶片与导叶间距离对轴流泵的扬程、效率、轴功率和压力脉动的影响规律,并通过综合频率分析法确定了一组最佳试验方案。结果表明:该最佳试验方案在设计流量下,水流在叶轮及导叶段中的流态较好,水流流线顺畅,分布相对均匀;轴流泵模型在流量和扬程满足改型要求的同时,效率提高了5.7%;轴功率下降了1.21%;压力脉动系数降低了11%,验证了综合频率分析法在多目标正交优化中的可行性。     

高速钻削复合材料的切削力

采用多种硬质合金钻头,在高转速和不同进给速度条件下对碳纤维/环氧树脂复合材料进行孔加工正交试验,通过研究其轴向力和扭矩以分析刀具条件和切削参数的适应性.结果表明:主轴转速是影响轴向力和扭矩的最主要因素,高转速钻削时轴向力和扭矩都显著减小;减小进给速度也使轴向力和扭矩减小,但其影响小于主轴转速.此外,钻头材质对轴向力和扭矩的影响大于钻头几何形状和进给速度;进给速度对轴向力的影响较大,而钻头几何形状对扭矩的影响较大.     

多层建筑框架结构光弹性应力分析

对多层建筑框架结构在风载下的应力分布了进行了光弹性分析，通过模型梁和柱的等差线，测出其反弯点位置及剪力植，算出梁和柱端部弯矩值。同时，对该结构进行了有限元计算，并将光弹性分析，有限元计算放Ｄ值法的结果进行了比较。及