重大毒气泄漏事故应急预警通知接收端优化与实现

从毒气泄漏事故预防和应急处置的国内外现状分析出发,指出了目前我国预警通知方法的不足及发展趋势。论述了毒气泄漏事故中安全疏散的时间构成以及预警通知接收端低功耗模式的种类,从提高预警通知系统响应时间的角度分析了不同的低功耗方案的优劣,并给出了实现方法和适用的条件,不仅实现了不同使用条件下的最佳低功耗模式,还保证了系统有较好的实时响应速度。响应时间的优化有利于提高系统报警通知的效能,在保证较好响应时间的前提下应用低功耗模式则有利于降低成本,同时提高受灾群众安装该预警系统的积极性性,对于报警器在不同地区的推广具有指导意义,从而为对系统的优化与改进提供依据。     

降低污水池外排含油量的有效措施

针对污水池外排含油量超标，加强污水池管理实施有效技术改造，降低外排水含油量，消除环境污染事故。     

Experimental and numerical analysis of a helical coil solar cavity receiver: Thermal oil as the heat transfer fluid

The paper presents the novel design of double glazing helical coil solar cavity receiver for solar thermal applications. Performance model has been developed for the experimental setup based on energy balance equations. The results obtained were compared with horizontal tube receiver for the same experimental setup. The result shows that the 87.96% improvement in the convective heat transfer coefficient for the double glazing helical coil solar cavity receiver. Maximum conversion efficiency achieved is 21% more than that would be obtained for horizontal tube receiver. This paper also investigates how the quality of vacuum degraded with the temperature of the glass cover.     

卫星导航接收机高低温工作环境试验与评定方法研究

为了完善适用于实验室的卫星导航接收机高低温环境适应性测试与评定方法,提出了实验室条件下模拟接收机实际工作状态的适应性测试条件、评估方法和标准流程。该方法能够获得接收机预期使用情况,剔除产品早期故障,弥补了现有卫星导航接收机环境试验及评定方法的不足,提高了设备检测的可靠性。     

造粒合成沸石滤料对污水中磷的净化与回收

以粉煤灰为原料,采用水热合成法制备沸石,造粒后合成沸石填充至滤柱中. 研究了不同运行条件下合成沸石对污水中磷的净化与回收效果. 结果表明:合成沸石对模拟污水和城市生活污水经二级生化处理后的排放水中磷的去除能力相近,且在磷含量低的情况下后者高于前者;与造粒前相比,造粒后的合成沸石仍具有良好的固磷能力. 水力负荷明显影响滤柱中磷的去除效果,其在177.9 L/(m2·h)以下时,磷的去除效果较好. 此外,进水pH也明显影响合成沸石的除磷效果,当进水pH调至酸性或碱性范围时,合成沸石的除磷能力显著提高. 该滤柱能够长期有效地净化与回收污水中的磷,达到饱和时合成沸石的w(磷)达20.04 g/kg(以磷元素计),可实际应用于农田改良.      

水生植物压滤液厌氧发酵条件试验

以沉水植物伊乐藻(Elodeanuttalli)和微齿眼子菜(Potamogetonmaackianus)以及挺水植物喜旱莲子草(Al ternantheraphiloxeroides)的压滤液为发酵原料,在中温批量液态发酵条件下,研究厌氧污泥接种量和不同氮添加水平对产气能力的影响。结果表明:在发酵时间为10d,污泥接种量为200mL·L-1时,获得的产气量最大,为863.2mL,所产气体中甲烷含量为720～750mL·L-1,发酵液的CODCr最大去除率为90%。添加1g·kg-1尿素-氮可促进3种水生植物压滤液的发酵产气,使微齿眼子菜、伊乐藻和喜旱莲子草的压滤液发酵产气量分别提高2%,10%和30%,说明尿素-氮对喜旱莲子草压滤液发酵产气的促进最大。     

战场电磁兼容预测中的接收机建模研究

目的建立战场电磁兼容预测分析的接收机数学模型,包括接收机频率选择性模型、敏感度门限模型、互调模型及与接收机有关的修正系数计算模型等。方法在分析接收机干扰类型的基础上,建立上述数学模型,并探讨模型中的参数获取方法。结果给出了频率选择性模型分段折线斜率常数的获取方法,并对相关的互调系数、保护比等重要参数的实验测量方法进行了分析。结论建模结果可支持战场电磁接收装备仿真,为战场电磁兼容预测分析奠定基础。     

Enhancing sewage sludge dewaterability by bioleaching approach with comparison to other physical and chemical conditioning methods

The sewage sludge conditioning process is critical to improve the sludge dewaterability prior to mechanical dewatering. Traditionally, sludge is conditioned by physical or chemical approaches, mostly with the addition of inorganic or organic chemicals. Here we report that bioleaching, an efficient and economical microbial method for the removal of sludge-borne heavy metals, also plays a significant role in enhancing sludge dewaterability. The effects of bioleaching and physical or chemical approaches on sludge dewaterability were compared. The conditioning result of bioleaching by Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans on sludge dewatering was investigated and compared with the effects of hydrothermal (121℃ for 2 hr), microwave (1050 W for 50 sec), ultrasonic (250 W for 2 min), and chemical conditioning (24% ferric chloride and 68% calcium oxide; dry basis). The results show that the specific resistance to filtration (SRF) or capillary suction time (CST) of sludge is decreased by 93.1% or 74.1%, respectively, after fresh sludge is conditioned by bioleaching, which is similar to chemical conditioning treatment with ferric chloride and calcium oxide but much more effective than other conditioning approaches including hydrothermal, microwave, and ultrasonic conditioning. Furthermore, after sludge dewatering, bioleached sludge filtrate contains the lowest concentrations of chroma (18 times), COD (542 mg/L), total N (TN, 300 mg/L), NH₄⁺-N (208 mg/L), and total P (TP, 2 mg/L) while the hydrothermal process resulted in the highest concentration of chroma (660 times), COD (18,155 mg/L), TN (472 mg/L), NH₄⁺-N (381 mg/L), and TP (191 mg/L) among these selected conditioning methods. Moreover, unlike chemical conditioning, sludge bioleaching does not result in a significant reduction of organic matter, TN, and TP in the resulting dewatered sludge cake. Therefore, considering sludge dewaterability and the chemical properties of sludge filtrate and resulting dewatered sludge cakes, bioleaching has potential as an approach for improving sludge dewaterability and reducing the cost of subsequent reutilization or disposal of dewatered sludge.     

微滤膜技术及应用研究*

随着膜制造技术的发展,微滤膜在油田采出水处理中具有越来越大的优势。文章对微滤膜的特点和过滤分离原理进行了阐述,对比分析了有机高分子微滤膜、无机陶瓷微滤膜和复合微滤膜各自的优缺点、制备工艺以及在油田中的应用情况,针对微滤膜在采油污水处理中膜通量下降快,使用周期短等弱点提出了防止膜污染和膜清洗的措施,并对微滤膜的发展及今后在油田中的应用提出了建议和展望。