Continuous Separation of Inclusions from Aluminum Melt Flowing in a Circular Pipe using a High Frequency Magnetic Field

The continuous separation of inclusions from aluminum melt flowing in a circular pipe using a high frequency magneticfield was investigated both theoretically and experimentally The separation efficiency was calculated based on thetrajectory method and compared with experimental results. It is found that the separation efficiency is a functilnondimensional parameters t_i·d_p~2B_e~2/μ_fμ_eα~2 and α/δ.The effective way to improve the separation efficiency is to increasethe effective magnetic flux density and decrease the pipe radius. and the value of α/δ should be kept about 2 in orderto obtain the optimum separation efficiency.     

提高热采注汽系统热效率的研究

为了降低热采成本和提高经济效益 ,建立了热采注汽系统热效率的数学模型。根据实测数据计算了 9个注汽系统的热效率。提出了改进注汽系统热效率的行之有效的措施。根据排烟的氧含量的大小 ,可以确定注汽锅炉热效率改进程度 ;按管线允许热损失量和保温材料种类 ,设计保温层厚度 ,可大大提高输汽管线热效率。仅此两项 ,即可使大部分注汽系统热效率提高 7%以上 ,井底蒸汽干度提高 10 %以上。     

3D圆阀塔板性能研究

介绍了3D圆阀塔板的结构特点和实验研究情况。以空气和水为工质进行了冷模实验,研究了3D圆阀塔板的塔板压降、雾沫夹带量和泄漏量等流体力学性能。利用氧解吸法测定其塔板效率,并在相同条件下与F1浮阀塔板进行了对比实验。结果表明,在相同条件下,3D圆阀塔板比传统F1浮阀塔板的塔板效率提高5%~15%,塔板压降约低100 Pa,泄漏量和雾沫夹带量与F1浮阀塔板基本相当,是一种综合性能优良的新型浮阀塔板。     

水库发电运行的计算机仿真

介绍了用VB语言编写的一个简便、实用的适合洞坪水库发电运行的计算机仿真程序.     

矿山空压机设备的经济运行

空压机设备是煤矿耗电量较大的设备之一。如何提高空压机设备的运行效率,对节约电能和降低生产成本有着非常重要的意义。文章论述了提高空压机运行效率的措施及方法,提出了合理化建议。     

Water and Radiation Effect on Sweet Sorghum Productivity

Suitability of sweet sorghum in Greece, where irrigation supply during crop development is limited as rainfall is scarce and evapotranspiration loss is high, is examined in relation with radiation availability. A two-year field experiment was conducted, in central Greece, imposing four soil water regimes via different irrigation treatments: (1) Highly irrigated, (2) Highly irrigated till anthesis when irrigation stopped, (3) Medium irrigated, and (4) Low irrigated. It was found that above-ground dry biomass production from non-water-stressed sweet sorghum plants suggests a high productivity potential among C₄ crops. Under water shortage, radiation use efficiency may be significantly lower. Radiation use efficiency seems to be linearly related to water consumption. Stressed plants (probably except severely stressed) seem to use available water more efficiently than unstressed plants. The slope of the line relating dry matter produced and water evapotranspired increases the sooner the stress is sensed. Yield reduction resulting from post-anthesis irrigation stopage is very little. High water use efficiency values tend to be related with low radiation use efficiency values.     

稠油井注汽系统的热效率分析

建立了热采注汽系统热效率的计算模型。根据XX油田数据计算了2个注汽系统的热效率。提出了提高注汽系统热效率的三项措施：（1）降低锅炉的过剩空气系数；（2）按最大允许热损失设计地面输汽管线的保温层厚度；（3）使用视导热系数小的隔热油管，按箍增加隔热结构，防止热封隔器的泄漏等。     

童氏标准公式的校正及应用

在童标准公式中引入校正系数，提出了童氏校正公式，应用该校正公式可对水驱断块油田以及标定采收集较低的油田进行早期含水率预测和采收率预测，应用实例表明，与实际生产数据对比，校正公式计算值比标准公式计算值的误差小得多。     

利用大流量液压支架控制顶板事故的发生

通过对工作面端面冒顶原因及支护系统的分析得出，加大液压支架的流量可以加快移架速度，降低冒顶事故率，提高生产效率。     

The smooth fractionator

A modification of the general fractionator sampling technique called the smooth fractionator is presented. It may be used in almost every situation in which sampling is performed from distinct items that are uniquely defined, often they are physically separated items or clusters like pieces, blocks, slabs, sections, etc. To each item is associated a ‘guesstimate’ or an associated variable with a more‐or‐less close – and possibly biased ? relationship to the content of the item. The smooth fractionator is systematic sampling among the items arranged according to the guesstimates in a unique, symmetric sequence with one peak and minimal jumps. The smooth fractionator is both very simple to implement and so efficient that it should probably always be used unless the natural sequence of the sampling items is equally smooth. So far, there is no theory for the prediction of the efficiency of smooth fractionator designs in general, and their properties are therefore illustrated with a range of real and simulated examples. At the cost of a slightly more elaborate sampling scheme, it is, however, always possible to obtain an unbiased estimate of the real precision and of some of the variance components. The only real practical problem for always obtaining a high precision with the smooth fractionator is specimen inhomogeneity, but that is detectable at almost no extra cost. With careful designs and for sample sizes of about 10, the sampling variation for the primary, smooth fractionator sampling step may in practice often be small enough to be ignored.