基于生物炭的生态浮床设计

根据生物炭的强吸附特性,对传统生态浮床进行改进,构建了由浮床框体、床体、内外双环圆柱结构种植单元、沉水植物生长袋4个部分组成的新型组合生态浮床,结合水下空间和水面景观重点描述了浮床的构建过程,为生态浮床的发展提供了新的思路。     

不同材料铺垫苗盘底孔的砂培漂浮育苗初探

摘要：采用不同种材料铺垫苗盘底孔,上层装砂的砂培漂浮育苗试验。结果表明：与常规基质育苗相比,用腐熟过的锯木屑铺垫育苗盘底孔处理的烟苗的存苗率、成苗率、生育期一致,生长速度一致,育苗管理过程比砂培育苗更加省工省时,方便易操作。     

3种方法检测仔猪球虫卵囊的比较研究

[目的]为有效检测仔猪球虫卵囊提供参考。[方法]通过对检测仔猪球虫病的3种方法(直接涂片镜检法、饱和盐水漂浮法和Teleman法)进行比较,研究检测仔猪球虫卵囊的有效方法。[结果]比较3种方法分别对仔猪球虫卵囊阳性检出的效果,结果表明,Tele-man法能观察到较清楚的圆形球虫卵囊,是检测效果最好的方法。对仔猪球虫卵囊检出率的比较结果表明,Teleman法和饱和盐水漂浮法是较好的仔猪球虫卵囊检出方法,而检出比率Teleman法最高。饱和盐水漂浮法、直接镜检法都由于粪便中存在脂肪颗粒等异物而影响检测效果。对检测的结果进行分析可知近年来乐山仔猪球虫病发病率有所升高。[结论]Teleman法是最有效的卵囊检出方法。     

Evaluation of the structural strength and failure for floating collar of a single-point mooring fish cage based on finite element method

Deep-water fish cage floating collar also referred to as float, bears a load in the form of waves, fishing nets, and moorings, in which the longitudinal wave force is the main type of loading. The long-term continuous effects caused by wave force could cause reduction in strength, or vibration failure in the floating collar. In this study, the peak responses of a single-point mooring (SPM) cage floating collar, due to either static or vibration loadings, were calculated by the finite element method (FEM) based on an elastic model. In this model, the float exhibited macro-plastic deformation when the stress of 26.1 MPa, generated under 100 kN load, was greater than the yield limit (25 MPa). With the increase in order modes from 1 to 18 (1.2–7.9 Hz), the stress increased. Moreover, the harmonic stress corresponding to 8 and 0.1 Hz was clearly higher than that for 0 Hz under 100 kN loads, due to structural resonance. The range of stress values due to the random vibration was 16.0–63.7 MPa, when the angular velocities (k) were in the range of 0.01–16 rad s^―1. Moreover, the transient response (34.4 MPa) was maximum when the angular velocity was 10 rad s^―1 (range 1–100 rad s^―1). The reliability rate of the entire body was 53.1% and 97.0% after 10⁸ loading cycles for 100 kN and 10 kN loads, respectively. Furthermore, the fatigue modes of the key components were determined from the outer triangular tops and inner hexagonal intersections. In short, static analysis, vibration analysis, and fatigue analysis of FEM could be used as reliable ways to evaluate structural strength and failure for floating system. Finally, the floating parts could be strengthened with partially double pipes or optimized by increasing the stiffness, and appropriate damping could be widely used.     

RH—XF型糠醛分批精馏装置

本文分析了习用夹套蛇管釜微分蒸馏糠醛,精制率低、能耗高的问题。改用热虹吸式再沸器减轻热破坏,旋浮塔(the cyclonic floating tray)分批精馏提高一次精制率及回收率。生产应用表明,本装置可使总精制率从84％提高到87.5％以上,且投资不多,简单易行。     

浮顶油罐举升工艺的研究及应用

针对浮顶油罐结构特点,讨论了浮顶油罐举升方案与举升原理.结合20 000 m3浮顶油罐现场举升试验,介绍了举升工艺的技术要求、浮顶油罐举升的工艺流程及必要的安全和加固措施,并根据试验结果,提出了举升工艺完善和改进的建议.     

Fuller双中间轴变速器结构特点分析

美国Fuller 双中间轴变速器是我国已引进生产技术尚未批量生产的新型产品。此种新结构变速器为大扭矩容量的变速器设计开辟了一条新路,其设计构思有许多独到之处,对于开拓思路颇多启迪。由于它采用双中间轴功率分流,输出轴和轴上齿轮浮动、主箱无同步器与拉型离合器配合换档等独特结构,使之具有很多突出的优点,解决了传统变速器无法解决的问题,而且其结构较简单,设计与制造技术易于掌握,敌对它进行研究是有实用意义的。本文对其结构特点进行了较详细的理论分析。     

基于风洞平台实验的内浮顶罐油气泄漏扩散数值模拟

研究内浮顶罐油气泄漏扩散规律,对于加强环境污染控制、保障罐区安全具有重要意义。建立风洞实验平台,测试小型内浮顶罐风速及浮盘位置对蒸发损耗速率的影响,并考察了风场、浓度场分布规律。基于CFD数值模拟,使用UDF导入环境风,建立了内浮顶罐油气泄漏扩散的数值模型,并通过风洞实验数据验证其模拟的可行性。重点讨论了内浮顶罐外风场及风压分布规律、风速对内浮顶罐油气流场分布及油气扩散浓度的影响。结果表明:浮盘位置越低、风速越大,蒸发速率越快;罐壁的静压力分布规律为迎风侧最大、背风侧居中、罐两侧最小;不同风速下,罐内油气分布整体呈现对称状态;风速越小,油气质量浓度越高,浮盘缝隙处的油气质量浓度最高,并存在安全和环境污染隐患。研究成果对于内浮顶罐设计及运行维护、环保安全管理具有参考价值。     

关于污水处理厂生物浮沫问题的分析

针对污水处理厂生物浮沫现象,总结了生物浮沫的危害,分析了生物浮沫的形成原因,提出了解决办法。