NUMERICAL PREDICTION OF TURBULENT PLANE BUOYANT JETS DISCHARGING IN A STRATIFIED STAGNANT OR FLOWING OCEAN

The discharge of sewage effluent from ports in a long diffuser pipe on the ocean bottom produces a flow pattern that may be idealized as a buoyant jet from a line source. To minimize the impact of emission of pollutants, the dispersion of wastewater should be predictable, and the prediction of the maximum height of rise is important in determining whether or not the jet will remain submerged. A buoyancy-extended K-ε model of turbulence has been developed for calculating the dynamical and thermal fields in forced plane plumes vertically discharged into a stably stratified environment. The predicted maximum height of rise for the linearly stratified quiescent ambient case is compared with available experimental data. An idealized two-layer situation is then considered in such a way as to simulate a thermocline in the upper part of the ocean. Numerical results are presented for a uniform horizontal cross-stream situation.     

纳米Al2O3协同水性环氧树脂对水泥基锚固注浆材料改性研究

锚固注浆材料性能良好,可有效提高锚固结构的服役寿命。为解决传统水泥基锚固注浆材料在边坡工程中稳定性和力学性能不足的问题,采用纳米Al₂O₃、水性环氧树脂对水泥基锚固注浆材料进行改性获得复合改性水泥浆材。通过正交试验、扫描电镜和X射线衍射测试,研究不同水灰比及配合比下复合改性水泥浆材的基本性能和改性机制。结果表明,复合改性水泥浆材的流动度、凝结时间、抗压强度受水性环氧树脂掺量的影响均大于纳米Al₂O₃掺量,而漏斗黏度、析水率受纳米Al₂O₃掺量的影响大于水性环氧树脂掺量。复合改性水泥浆材具有稳定性高、析水率低、抗压强度高等特点,有效解决了传统水泥基锚固注浆材料存在的稳定性和力学性能不足的问题,且其最佳性能配合比为水灰比0.5、纳米Al₂O₃掺量5%(质量分数,下同)、水性环氧树脂20%、固化剂掺量2.0%。     

近红外光谱仪在特香型白酒生产检测中的应用

特香型白酒生产中原料、酒醅等的检测是工艺控制的关键因素,传统检测方法存在耗时长,工作量大,数据反馈滞后等问题。建立特香型白酒原料和酒醅的近红外快速检测模型可以快速无损进行检测,及时反馈数据,在指导生产,提高工艺控制上起到了有效的作用。     

特香型白酒中甲醇和丙酸乙酯同时检测的研究

使用气相色谱仪,研究甲醇检测方法和丙酸乙酯检测方法,因国标GB/T 20823—2017《特香型白酒》中对丙酸乙酯含量有规定要求,同时国标GB 2757—2012《食品安全国家标准蒸馏酒及其配制酒》中对甲醇的含量也有明确要求。两种物质是特香型白酒检测的必备项,研究可实现两种物质的同时检测,为特香型白酒检测节约大量人力物力。