壅塞管直径对壅塞空化器空化特性的影响

在不同壅塞管直径下,利用Fluent软件对壅塞空化器进行数值分析并采用水听器对其空化噪声信号测试,探索壅塞管直径对壅塞空化器空化特性的影响。测试结果表明：增大壅塞管直径,最大压力上升梯度值会增大,壅塞截面会向上游移动;壅塞空化器的数值分析和空化噪声信号测试结果基本吻合,壅塞管的最佳直径为10 mm。     

浅析英法哥特建筑的发展

哥特式建筑于11世纪开始登上历史舞台,它在这个舞台上闪耀了8个世纪,也影响了整个欧洲乃至全世界的建筑风格。文章就英法两国哥特式建筑风格在不同历史背景下的发展和形成原因进行对比分析,并挖掘其历史成因和文化内涵。     

Flexible and Autonomous Integrated System for Characterizing Metal Oxide Gas Sensor Response in Dynamic Environment

Characterization and calibration of gas sensor is a complex problem due to the dynamic behavior of gases and the limitations of current technology. This article reports a flexible, robust, and autonomous integrated system that is able to perform characterization on metal oxide-based gas sensors in dynamic environments. The system controls the concentration and flow of the relevant gases into the gas chamber and simultaneously measuring the sensor response. This feature allows the characterization of the sensor under continuous dynamic flow of gases similar to conditions on a robot or flow pipes. Several experiments have been performed on the system using hydrogen sulfide. The results provide information on the general characteristics of the sensor as well as its sensitivity. The noise levels were studied with different reference voltages. Overall, the results verify that the system is reliable and able to produce repeatable measurements.     

The Main Factors Affecting Isotopes of Yellow River Water in China

Abstract

Variation of δ¹⁸O, δD, and ³H in the Yellow River water were analyzed based on the isotope test results of water samples in 18 sections of the Yellow River in rainy and dry seasons. The results show the trend of the ratios of the stable isotopes increases while the ³H concentration decreases progressively from the river source to the estuary. The main factors affecting the isotopes in the river water are the mixing of foreign water bodies, evaporation, and human activities. River runoff mostly comes from the source and the middle reaches of the river. The changes of the isotopes in the river water could be served as a good indicator of the recharge of different foreign water to the Yellow River.     

A Method for Evaluating Sea Dike Safety

To implement the maintenance and management of the sea dike engineering, the qualitative factors and quantitative factors need to be combined to evaluate the sea dike safety. Firstly, the evaluation index system and evaluation grading criterions of sea dike safety are established. Secondly, a new weight structure of evaluation indexes is proposed to combine the subjective weight and objective weight. Fuzzy Analytic Hierarchy Process method is used to determine the subjective weight and implement the qualitative analysis for sea dike safety. Projection Pursuit algorithm is introduced to calculate the objective weight and implement the quantitative analysis for sea dike safety. Based on the minimum relative information entropy principle, above two weights are combined. Thirdly, an evaluation model of sea dike safety is built with the improved Set Pair Analysis method. Finally, the proposed analysis method is used to assess one sea dike safety in China. It is shown that the combined weight can describe both the subjective information of expert experience and objective variation information of samples values, the uncertainty of information can be handled by the improved Set Pair Analysis method. The evaluation model has the clear physical concepts and intuitive modeling process. The calculation result is reasonable. The proposed method can be applied to sea dike safety evaluation and other complex systems evaluation as well.     

LaNi3.8Co1.1Mn0.1/TiMn1.5贮氢合金的结构和性能

为了探索一种新的掺杂方式对AB5型贮氢合金贮氢性能的影响,采用熔炼掺杂方法制备La-Ni3.8Co1.1Mn0.1/TiMn1.5(TiMn1.5质量分数为4%、8%)贮氢合金,利用PCTPro-2000气体吸附测量仪研究了合金的气态储氢性能。XRD和SEM分析显示,熔炼掺杂后合金主相为LaNi5相,出现少量(NiCo)3Ti相。P-C-T测试结果表明,(NiCo)3Ti相的出现对合金气态贮氢性能有较大影响,熔炼掺杂后合金吸放氢平台压和滞后效应降低,贮氢容量减少。掺杂TiMn1.5使得合金的氢化物的生成焓由原始合金的-27.35kJ/mol降至-29.14kJ/mol(掺杂质量分数8%的TiMn1.5),较高温度有利于合金中氢的释放,同时掺杂形成的(NiCo)3Ti相改善了合金吸/放氢动力学性能。     

壅塞空化器设计及其处理污水的可行性研究

在分析直管中气液两相混合流的壅塞空化现象,射流泵发生极限工况时的壅塞空化现象,经过倒角的圆柱管在定常和非定常流动下的壅塞空化现象,在阶梯圆管中的稳态绝热闪蒸流中的壅塞空化现象的基础上,提出了一种新型的空化器——壅塞空化器;通过采集分析空化噪声和处理模拟污水(苯酚溶液)的实验,对壅塞空化器在污水处理应用中的可行性进行了初步研究。实验结果表明:壅塞空化器模拟处理污水的效果较好,其空化能量比振荡腔喷嘴高,从而为国内外研究空化发生器开辟了一条新途径。     

Biofouling control by quorum sensing inhibition and its dependence on membrane surface

Biofouling control by quorum sensing (QS) inhibition and the influence of membrane surface characteristics on biofilm formation and QS inhibition were investigated. Pseudomonas putida isolated from the bio-fouled reverse osmosis (RO) membranes in a real plant was used. Acylase was chosen as a model QS inhibitor. Bacteria on the membrane coupons were quantified with the heterotrophic plate count method. Cell distribution was imaged by a confocal laser scanning microscope. Results showed that biofilm formation on the membrane was reduced by acylase as it inhibits the activity of N-acylhomoserine lactone (AHL) which is a signal molecule of QS. It was also shown that membrane surface characteristics were influential factors affecting bacterial adhesion, biofilm formation, and QS inhibition.     

基于改进免疫遗传算法的电网故障诊断研究

针对电网故障的特点,应用一种改进的免疫遗传算法对电网故障进行研究。该算法能够较好地解决传统遗传算法的不足。通过引入新的交叉和变异率,更多考虑了种群的全局特征,采用动态自适应方式提取疫苗,避免了传统遗传算法收敛速度较慢的缺点。改进的算法本着优胜劣汰的思想,删除适值较低的抗体群,取而代之的是随机生成的部分新抗体,保持种群的多样性。建立一个新的目标函数,通过对一个电网的分析,验证了方法的有效性。