浮床种植草坪草对富营养化水体的净化作用研究

采用浮床种植草坪草技术,研究了高羊茅Festuca arundinacea、匍匐翦股颖Agrostis stolonifera 2种草坪草对富营养化水体的净化能力.试验结果表明,2种草坪草对富营养化水体中的氮(N)、磷(P)、化学需氧量(CODcr)等具有明显的净化效果,尤其对总磷(TP)的净化能力最强,能有效改善富营养化水体的水质;2种草坪草之间,匍匐翦股颖对TP的去除效果显著高于高羊茅对TP的去除效果.研究结果显示浮床种植草坪草技术可能是一条有效的修复富营养化水域的新途径.     

THE WAYS FOR IMPROVING INDOOR ENVIRONMENT AND AIR-CONDITIONING SYSTEMS IN DANCLING HALLS

Since 1988, air temperature, humidity, air quality, noise level and intensity of illumination in lots of dancing halls in China have been investigated and tested. This paper introduces the present situation of indoor environment and air conditioning systems in dancing halls of China. The design indexes of cooling load for room and ontside air are recommended. The reasons for indoor environment deterioration have been found out. From the actual situation of China, the ways for imoroving indoor environment and approach of energy conservation in air conditioning systems are explored.     

具脱层的正交各向异性梁-板的屈曲分析

根据非线性理论，假定脱层为贯穿梁幅的一维脱层，且脱层位置任意，建立了轴向压力作用下含脱层的正交各向异性梁－板的非线性控制方程，对结构进行了分区处理，通过使控制方程适当线性化，利用脱层前缘的连续性条件、平衡条件及相容条件，导出了夹支边界情况下的具脱层的正交各向异性梁－板关于屈曲荷载的无量纲化的特征方程，确定了临界压力荷载，并讨论了脱层尺寸及位置对临界荷载的影响。     

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。     

空心胶合木-钢插板螺栓节点承载力试验研究

为研究空心胶合木-钢插板螺栓连接节点承载力及延性性能,探讨了不同胶合木宽度和螺栓直径对破坏模式的影响,分析了不同宽径比、承压宽度对节点承载力、延性等的影响。结果表明:增加宽径比及承压宽度,可有效提高节点延性。宽径比12.5~16.4的节点延性较佳;宽径比10.0~10.9是单、双塑性铰破坏模式的临界点,可作为工程设计参考值。     

人工浮岛种植水生植物对包头南海湿地水质净化效果研究

【目的】解决包头南海湿地氮磷等营养元素富集的问题,提升包头南海湿地的水质。【方法】于2017年7—9月,在包头南海湿地构筑了一段由3种水生植物单独或混合种植的人工浮岛,并对浮岛的水质进行跟踪监测。【结果】经过92 d的试验处理,风车草对TN的去除效果最好,去除率为36.02%,可以使水体中TN质量浓度提高到地表水Ⅴ类标准;风车草+水葱+千屈菜对TP的去除效果最好,去除率为41.61%,可以使水体中TP质量浓度从地表水Ⅴ类标准提高到Ⅳ类标准;对CODcr去除效果最好的是风车草+水葱+千屈菜,去除率为27.01%。对浮游藻类抑制效果最好的是风车草,可以有效抑制水华束丝藻。【结论】混合植物人工浮岛比单一型人工浮岛去除氮磷等有机物的效果要好,尤以风车草、水葱、千屈菜3种植物混合组成的人工浮岛对氮磷等有机物的效果最好。风车草、水葱、千屈菜可以作为包头南海湿地水体富营养化防治的浮岛栽培植物来进行推广应用。     

DEVELOPMENT AND EXPERIMENTAL ANALYSIS OF HYDRAULIC LOCK OF THE THINNEST COAL SEAM SHEARER

The structure and work theory of a new type of hydraulic lock of the thinnest coal seam shearer is described in this paper. Its performance tests have been done the test results show that the performance of hydraulic lock is satisfactory and can be fit for the needs of locking and floating of the cutting drum of the thinnest coal seam shearer     

结构参数对增压器浮环轴承润滑特性和环速比的影响

基于以往对增压器的浮环轴承润滑分析中大都忽略浮环的环速比影响,或将润滑性能和环速比独立分析。该文采用数值分析方法研究了增压器浮环轴承的润滑特性和环速比,分析中考虑了转轴、浮环、轴承座之间的传热因素,基于Reynolds方程和浮环平衡方程,建立了浮环轴承润滑模型,对比分析了浮环内、外层间隙,内、外圆半径4个结构参数对浮环轴承润滑特性和环速比的影响。结果表明,实际设计浮环时,需综合考虑结构参数对浮环润滑特性和环速比的影响及影响程度;浮环内层间隙增加,环速比降低,与内层间隙0.02 mm时相比,转速60 000 r/min时,内层间隙0.04 mm时的环速比减幅达23%,内层间隙增加,内、外膜温度减小,摩擦功耗略有增加,内层间隙0.03 mm时,浮环具有较理想的润滑性能和环速比;外层间隙0.06 mm的环速比均比外层间隙0.04 mm的环速比增加30%以上,外层间隙增加,外膜温度减小,且转速越高,外膜温度减幅越大;浮环内圆半径越小,环速比越小,内、外膜温度和摩擦功耗越小,浮环润滑性能越好;浮环外圆半径增加,环速比降低,但内膜温度、外膜温度、总摩擦功耗和总端泄流量变化幅度均在5%以内,外圆半径对浮环润滑性能影响不显著;浮环实际设计时,调整内圆半径比调整外圆半径对改善浮环润滑性能更有效。     

Inheritance studies of characters associated with floating habit and their linkage relationship in rice

Summary Deep water rice varieties in general have certain peculiar characters which are associated with floating habit. These characters are (i) early nodal differentiation, (ii) nodal rooting, (iii) spreading habit, (iv) awned grains, (v) brown hull colour, (vi) red pericarp (red rice), and (vii) seed dormancy. Inheritance of these characters and linkage relationship of genes governing these characters were studied in a cross between Pankaj (non floating) and Nageribao (floating) rice varieties. Nageribao, a cultivar from Assam possesses these characters.Early nodal differentiation was observed to be controlled by a single dominant gene, designated as Nd. Nodal rooting was controlled by two dominant complementary genes, designated as Nr ₁ and Nr ₂. We found an inhibitory factor for spreading habit and one for brown hull colour in Pankaj; the operation of two dominant duplicate genes An ₁ and An ₂ for controlling awning characters, a single dominant gene Rd for red pericarp colour and a single dominant gene Gd for grain dormancy. Joint segregations between these characters resulted in the assignment of genes in the X linkage group of indica rices with estimated map distances based on the cross-over values. The genes An (awning), Es (spreading habit), Nr (nodal rooting) and Nd (nodal differentiation) were observed to be associated with each other. The gene for red pericarp (Rd) was observed to be linked with the grain dormaney gene Gd.