Comparison of throttle devices to measure two-phase flowrates of wet gas with extremely-low liquid loading

The online measurement of wet gas with extremely-low liquid loading (Lockhart-Martinelli parameter lower than 0.02) remains a challenge. In this study, three types of throttle devices, Venturi, orifice plate and cone, are compared experimentally with air-water two-phase flow in a horizontal pipe of inner diameter of 50 mm. High-precision correlations are established to measure the gas and liquid flowrates via a single throttle device. Results show that the two-phase mass flow coefficient (K) of the three throttle devices all increase linearly with the liquid densiometric Froude number and the K correlations are established respectively to correct the gas mass flowrate deviation. The pressure loss ratio (δ) for Venturi is sensitive and monotonous to the liquid loading, which contributes to the high accuracy of liquid flowrate measurement. By incorporating the K correlations, both the gas and liquid mass flowrates can be predicted precisely. The relative error of the gas mass flowrate predicted by the Venturi is within ±2.0% at 95% confidence level, and that of the liquid mass flowrate is within ±15% at 90% confidence level.     

丁香酚和三卡因甲磺酸盐在大口黑鲈中代谢残留的比较

为了确定大口黑鲈成鱼适合的麻醉方式和麻醉剂量,研究了不同浓度的丁香酚和MS-222对大口黑鲈的静水麻醉效果。在最适麻醉质量浓度下模拟运输24 h,记录24 h存活率并测定麻醉0.5、4、8、16和24 h后的血清生化指标、水质p H、氨氮以及麻醉剂的残留量。结果表明:随着丁香酚和MS-222浓度增加,入麻时间缩短,复苏时间延长;丁香酚和MS-222的最适质量浓度分别为18~20 mg/L、50~60 mg/L时,两麻醉组模拟运输和复苏24 h后的成活率为100%,显著高于无麻醉运输组的80%和90%(p<0.05);随着麻醉时间延长,丁香酚和MS-222组血清中的皮质醇(COR)分别从336.83pg/m L下降到291.41pg/m L,从286.11上升到367.05pg/m L(p<0.05),丁香酚组血清中的COR显著低于对照组;葡萄糖分别从14.36、7.48 mg/dL下降到7.36、3.11 mg/dL(p<0.05),而丁香酚组中乳酸脱氢酶(LDH)、碱性磷酸酶(AKP)、谷草转氨酶(GOT)、尿素氮(BUN)的浓度显著低于MS-222组(p<0.05);残留检测结果表明在麻醉0.5h时,鱼肉中丁香酚含量达到最大值5.14mg/kg,在清水中复苏1d时丁香酚残留量为0.45mg/kg;而MS-222组在8 h残留量达到最大值为36.24 mg/kg,复苏4 d时基本消除完全。结果显示,丁香酚剂量小,代谢快,在诱发氧化应激和组织损伤时有较少的副作用。     

壳牌气化炉激冷口盘管损坏原因分析及改进

简要介绍壳牌气化炉结构及工艺流程、激冷口结构及存在问题;分析激冷口盘管损坏原因及如何避免;检修优化及取得的效果。     

Liking of food textures and its relationship with oral physiological parameters and mouth-behavior groups

Researchers have categorized people into four “mouth-behavior” groups based on their oral processing preferences, and claimed that members of those mouth-behavior groups differ in their food texture preferences. If people could be classified into groups based on their liking of different textures, food products could be targeted to specific subgroups, potentially enhancing consumer acceptability. In the first part of our study, we grouped people based on their liking ratings of a wide variety of food textures by asking 288 participants to rate their liking of 106 food texture attributes in an online survey. In the second part of our study, we further examined relationships among individuals' food texture liking ratings, mouth-behavior group membership, and measurements of four oral physiological parameters (saliva flow rate, chewing efficiency, biting force, and particle size sensitivity). One-hundred participants completed the online survey on food texture liking, classified themselves into one of four mouth-behavior groups (Chewers, Crunchers, Smooshers, and Suckers), and were measured for four oral physiological parameters. We refuted the idea that large texture-liking subgroups exist. Although our participants self-categorized themselves into the four mouth-behavior groups similarly to previous researchers, our texture liking measurements did not support the presumed preferences of those mouth-behavior groups. Clustering of participants on their oral physiological measurements produced a “low particle-size sensitivity” cluster, a “high biting force” cluster, a “high saliva flow rate” cluster, and a “low saliva flow and low chewing efficiency” cluster. Neither our texture liking nor our oral physiological measurements predicted membership in the four mouth-behavior groups.     

直线电机井口操车设备在五阳煤矿的应用

简述了传统井口操车设备在机械化、联动化方面的局限性 ;重点讲述了直线电机技术在井口操车设备机械化、联动化方面的应用及特点 ;并阐述了直线电机工作原理、基本类型 ,以及直线电机技术和悬浮技术在煤矿辅助运输机械化方面的应用前景。     

露天矿主溜井降段方法及防止堵塞跑矿的对策

露天采场内矿（岩）石溜井，随开采台阶下降须进行降段．文中评述了“空井法”、“满井法”的降段条件，介绍了防止溜井堵塞跑矿的措施。     

关于井口及油层套管泄漏问题的探讨

根据高压油气井试采中出现井口及油层套管泄漏的情况，对其原因进行了分析。并提出了解决的对策。     

双层大角度倾斜轻质混凝土外隔墙施工技术研究

双层大角度倾斜轻质砼外墙,由于其构造的特殊性,传统施工方法不能同时进行双层砼浇筑,施工延续时间长,工期较难保障。本文针对双层大角度倾斜轻质砼外墙施工技术进行研究,通过设置喇叭型混凝土浇筑口,控制内外层混凝土浇筑厚度,相互平衡内外侧模压力,从而实现双层砼同时施工,不仅保证了混凝土的浇筑质量,而且缩短了工期。     

带气液分离器自动复叠系统中节流阀开度引起的混合工质浓度偏移(英文)

Auto cascade refrigeration (ACR) cycle with phase separators is widely used in the cryogenic system. The compo-sition of mixed refrigerant has a great effect on the performance of the system. Based on the assumption of infinite volume of phase separator, ACR system with one phase separator is simulated in this paper. The variation of refrigerant composition under different valves opening is obtained. A related experimental system is set up to verify the variation. The result shows that when the valve opening connected to the evaporator increases or the valve opening under the phase separator decreases, the low-boiling component concentration of the working mixture passing through the compressor and condenser increases, while the high-boiling component concentra-tion decreases. Furthermore, the variations of condensation pressure and evaporation pressure under different valves opening are also observed. This paper is helpful to deepen the understanding of ACR system.     

长钢8号高炉大修放残铁实践

详细介绍了长钢8号高炉如何确定残铁口位置的经过,同时对放残铁的效果作了简要说明,为公司在日后的停炉放残铁工作方面积攒了一定的经验。