城市生活垃圾焚烧飞灰的工程性质表征

分析测定了城市生活垃圾焚烧飞灰与收集、运输和处置相关的工程性质.测定结果表明,飞灰具有含水率低(0.08%～1.15%)、堆积密度小(0.646×103～0.776×103 kg·m-3)、渗透能力强(8.71×10-5～1.16×10-4 cm·s-1)、易吸水等特点;飞灰粒径均值为79μm,d50为56μm,其中38.5～74 μm粒径段飞灰约占总量的50%;在含水率＜25%时,飞灰含水率越高,流动性越差,含水率＞25%时,含水率越低,流动性越差;含水率为20%时,飞灰的压缩系数达到最小值,承载力最大,与击实曲线中含水率20%时干密度最大的结果一致;飞灰加水后孔隙率减小,但中孔比例增加,与水接触过程中,放热效应较强烈,24 h累积放热量可达到51 J·g-1;从填埋作业角度分析,飞灰含水率宜控制在20%,同时,要注意飞灰与水接触时的热效应.     

高通量空气隙膜蒸馏系统的实验研究

该文提出一种高通量的新型膜组件,它采用热液旋转切向湍流入流以冲刷膜面,减小温度和浓度边界层,改善温度和浓度极化,提高传热传质效率,并采用小间隙及膜与冷壁部分接触以减小空气隙的传热传质阻力,从而显著提高蒸馏通量。实验结果表明:最佳切向入流角为30,°膜面接触率为75%~80%。采用这种膜组件的空气隙膜蒸馏系统,当用自来水作为热溶液、间隙为1mm、冷热水温差为65℃时,蒸馏通量可高达120 kg.m-2.h-1,而传统的空气隙膜蒸馏系统(间隙为4mm以上)的最大蒸馏通量仅为28 kg.m-2.h-1。热溶液为15%的浓盐水的蒸馏通量实验也得到类似结果。     

第二焦化厂循环氨水余热采暖的研究与应用

介绍了循环氨水产生、冷却煤气的机理,阐述了循环氨水余热采暖在实际生产中的利用过程。     

一点红提取物抑菌活性研究

采用滤纸片法测定了一点红乙醇提取物对各种供试菌种的抑菌圈直径,同时就一点红提取物浓度以及加热处理对一点红提取物抑菌效果的影响进行了初步研究.结果表明:一点红乙醇提取物对G~-和G~-细菌有较强的抑制作用,而对霉菌抑菌效果不明显一点红提取物抑菌作用因菌种不同而最低抑菌质量浓度有所不同,大肠杆菌为0.05g·ml~(-1)、金黄色葡萄球菌为0.0625g·ml~(-1)、枯草芽孢杆菌为0.125g·ml~(-4),其抑菌圈直径分别为:大肠杆菌12.1mm、金黄色葡萄球菌15.3mm、枯草芽孢杆菌14.9mm,表明对常见细菌有较好的抑制作用,其在7h时抑菌效果最好.而对于真菌,黑根霉和米曲霉的最佳抑菌质量浓度分别为0.125g·ml~(-1)和0.05g·ml~(-1).在111℃湿热条件下20min后一点红提取物抑菌效果基本不变,说明一点红提取物具有良好的热稳定性.     

高比转速混流泵叶轮正反问题计算

基于Ωu=0的二元设计理论,用Fortran语言编程实现了高比转速混流泵叶轮的水力设计,讨论了轴面流道形状、速度矩分布规律、排挤系数对设计计算结果的影响。基于Navier-Stokes方程,在贴体坐标系和交错网格中,采用SIMPLEC算法,对依据不同设计参数设计出的两个叶轮内部流场进行了数值模拟,并将计算得到的流场压力分布和轴面速度分布进行了对比,同时对两个叶轮进行性能预估。结果表明,轴面流道形状和速度矩分布规律影响叶轮内部压力场和速度场的均匀性,导致两个叶轮性能预估值存在约2%的差别。     

论高校跆拳道运动员赛前减控体重与膳食搭配

从分析高校跆拳道运动员赛前减控体重的方法入手,阐述了高校跆拳道运动员既能以“优势体重“参赛,又不危害身体健康和竞技水平的观点,通过查阅部分相关文献,提出了一套办法和推荐食谱以供参考。     

Meteorological observations on Mount Everest in 2005

Mount Everest,the highest point on the Earth is often referred to as the earth's third pole as such the place is relatively inaccessible and little is known about its meteorology.In April 2005,an automatic weather station was installed at the mountain's North Col(6523 m a.s.l.).According to the observational 10-minute mean and daily records,the meteorological characteristics were analyzed. All the meteorological elements displayed obvious diurnal variations during May 1 to July 22,2005.The monthly variation of daily meteo- rological elements on Mount Everest coincided with that on Dingri,the closest routine meteorological station,with the high correlation co- efficients of 0.928,0.877,0.682,0.755,0.826 and 0.676(n=83,p<0.001)for mean temperature,minimum temperature,max- imum temperature,relative humidity,pressure and wind speed,respectively.Furthermore,the vertical mean gradient of temperature was above 0.6℃/100 m,especially for the daily maximum temperature.Most weather events on Mount Everest prominently appeared on the same day as those on Dingri,especially those from daily mean pressure,temperature and relative humidity with the cross-correlation coeffi- cients of 0.673,0.485 and 0.487(n=83,p<0.001),respectively.Some other weather events on Mount Everest lagged one-day be- hind those on Dingri.Furthermore,forecasting of the weather events on Mount Everest from pressure on Dingri was more reliable than those from the other meteorological elements.The conclusions are much important for research on meteorology and climate changes in the region.     

Daily variation of carbon flux in soils of Populus euphratica forests in the middle and lower reaches of the Tarim River

In order to lucubrate the daily variation of respiration in soils of Populus euphratica forests and analyze its relationship with environmental factors in the middle and lower reaches of the Tarim River, the LI-8100 instrument of soil CO2 flux system was used to measure the parameters of soil carbon flux and air temperature 10 cm above ground surface along the profiles of Usyman, Archy River, Yengisu and Karday, and the relationships between the soil carbon flux and the soil moisture content were analyzed. The nonlinear regression analysis was carried out with the software SPSS13.0. We observed that: (1) soil respiration began to be restrained when the air temperature was up to 30℃10 cm above the ground surface; (2) the rates of soil respiration under the forests of Populus euphratica were significantly different at various moisture contents, the soil carbon flux was high along the Usyman profile, which has a high soil moisture content, and it was low along the profiles of Archy River, Yengisu and Karday, which has a low soil moisture content; (3) the exponential model can be used to explain the relationship between soil respiration and air temperature 10 cm above the ground surface. The average Q10 values along the profiles of Usyman, Archy River, Yengisu and Karday are 0. 61, 0.16, 0. 22 and 0. 35 respectively, much lower than the average of the world; (4) there is a positive correlation between the soil carbon flux and the soil moisture content.     

连通热管太阳能技术研究

在分析了目前热管太阳能热水器的基础上,提出了克服目前热管太阳能热水器缺点的一种新的设计方案,从而使热管太阳能热水器的使用寿命、效率得到了很大的提高,而且经济效益比较明显。     

高职《金属材料与热处理》教学探讨

《金属材料与热处理》课程是机械专业的必修课,与生产实际联系比较密切,但该课程比较枯燥,学生学习兴趣低。在教学实践中,教师应从抓住教学重点、采用计算机辅助教学、善于归纳总结、加强学生技能训练等五个方面着手,激发和培养学生的学习兴趣,以求取得良好的教学效果。