复杂裂缝网络内支撑剂运移及铺置规律分析

水力压裂技术目前已广泛应用于页岩油气的开采中,为了提高产量,将支撑剂和携砂液按照不同的质量比混合注入裂缝,可形成支撑剂的有效铺置,从而提高裂缝的导流能力。支撑剂在复杂裂缝网络中的输送距离和铺置范围是衡量水力压裂效果的重要指标。采用室内模型实验,研究砂比、主裂缝与分支裂缝夹角以及支撑剂种类对支撑剂在复杂裂缝网络中运移和铺置规律的影响。结果表明:①随着砂比从3.0%增大到4.2%,主裂缝内支撑剂铺置高度与裂缝高度之比从0.44增大到0.465,分支裂缝内支撑剂质量与复杂裂缝网络中支撑剂质量之比从21%增大到25%。②随着主裂缝与分支裂缝夹角从90°减小到30°,分支裂缝内支撑剂质量与复杂裂缝网络中支撑剂质量之比从22%增大到30%。③支撑剂进入复杂裂缝网络的质量与实验所用支撑剂总质量之比随实验时间与总实验时间之比呈先快速增加后缓慢增加的趋势,当实验时间与总实验时间之比为0.6时,支撑剂进入复杂裂缝网络的质量与实验所用支撑剂总质量之比为65%~80%。④陶粒和自悬浮支撑剂在裂缝入口处的铺置效果不好,支撑剂铺置高度在主裂缝与分支裂缝相交处以及裂缝高度变化处有明显突变

水灰比对高水材料力学特性影响的试验研究

充填开采是实现矿山绿色开采的有效方式,研究量大适宜的充填材料成为充填开采技术应用的关键。高水材料是一种新型矿山充填材料,其受压后的物理力学性能直接影响采空区充填体的稳定性。固体颗粒和水作为高水材料主要的组成物质,其相对含量直接影响高水材料的物理力学特性。利用宏观与微观相结合的综合试验方法,对高水材料在不同水灰比条件下的基本物理性能和强度特性进行了系统研究,结果表明:高水材料结石体微观结构呈网状结构,且具有稀疏多孔等特点,使其可以吸附自身重量数倍的水。水灰比越大,网状结构中孔隙越稀疏,从而形成更大的孔隙结构。高水材料具有与岩石类似的应力应变曲线,但高水材料塑性极高,达到峰值强度后仍能保持较好的完整性。单轴压缩条件下,高水材料会出现明显的析水现象,水灰比越大,析水现象越严重。在单轴压缩条件下,高水材料有"X"型共轭剪切破坏、单斜剪切破坏和拉伸破坏等几种典型的破坏类型。水灰比较高时,高水材料常呈"X"型剪切破坏;水灰比较低时,常为劈裂破坏。高水材料单轴峰值强度和残余强度均随水灰比的增大而减小,水灰比越小其应力应变曲线峰值处越陡峻,峰后强度下降得越快,但其残余强度仍保持较高水平。该种材料塑性较好,残余强度较高,适合作为地下矿山采空区的永久充填材料B。ackfill mining has been an effective way of realizing green mining, and the key part of its application is to research the filling materials. The high-water material is a new kind of filling material, the physical and mechanical properties of high-water material directly affect the filling stability. Solid particles and water are the main components of high-water material, the relative content of which directly affect its physical and mechanical properties. Based on a series of macroscopic and microscopic tests, the basic physical properties and uniaxial compressive strength characteristics of high-water material with different water cement ratio were studied. The results indicated that 1) The microstructure of high-water material stone exhibited a network structure and was very porous, so it could absorb quantities of water which was greater than its weight. The greater the water cement ratio was, the sparser the fissures in reticular formation would be and thus the larger the reticular formation would be. The phenomenon of dehydration become much more evident when the high-water material's water cement ratio got larger and when it was under the action of uniaxial compression. 2) The stress-strain curve of high-water material was similar to that of rock material, however, the high-water material exhibited high plasticity and could maintain better integrity after reaching peak strength. 3) Under uniaxial compression, the high-water material often showed “X ” type shear failure when the water cement was relatively high, but it often showed splitting failure when the water cement was relatively low. The uniaxial peak strength and residual strength of high-water material reduced with the increase of its water cement ratio. With the decrease of water cement ratio, the stress-strain curve at the peak strength become much steeper and the strength after the peak stage reduced much faster while its residual strength remained a higher level. 4) The high-water material displays excellent plastic properties and high residual strength, which is suitable for filling material. © 2017, Editorial Department of Advanced Engineering Sciences. All right reserved

Rotor-bearing system based on test aerodynamic properties of device for rolling bearing

本发明属于轴承的动力特性测试技术领域，特别涉及一种基于转子‑轴承系统测试滚动轴承动力特性的装置。包括底板及设置于底板上的电机组件、联轴器、加速器、待测轴承组件、轮盘、传动轴、转速传感器、位移传感器及同轴度传感器，其中传动轴两端由对称分布的两个待测轴承组件支撑、且传动轴的一端通过联轴器与加速器和电机组件相连，轮盘套设于传动轴上、且随传动轴一起转动，转速传感器和位移传感器分别用来测量转子‑轴承系统的转速和传动轴的位移，同轴度传感器用于测量传动轴上各部件的同轴度。本发明结构简单、易于操作可准确测算出待测轴承的动力特性，并作为建立滚动轴承动力特性数据库的基本手段

Effects of Long-term Application of Chemical Fertilizer on Food Production and Soil Quality Attributes

结合世界各地长期试验的资料 ,从土壤质量的角度综述了施用化肥对小麦、玉米、水稻产量影响 ,并对长期施用化肥条件下土壤有机碳积累、剖面硝态氮累积和土壤理化性状的演变进行了分析