一种焦炉放散管自动点火装置的工装设计

一种焦炉放散管自动点火装置,属于炼焦工艺技术领域,用于提供一种安全实用、工作可靠、操作简便、便于及时放散焦炉荒煤气的工装。     

Gill arches of some teleostean fishes of the families Girellidae,Pomacentridae, Embiotocidae Labridae and Scaridae

Summary

Streams and meander lakes in the Mato Grosso, between the Rio das Mortes and the Rio Suiá Missú, have low conductivities ranging from 12 to 50 μmho/cm/20°c, but exceptional isolated pools reach 800 μmho under the influence of evaporation.

Rainfall at the beginning of the wet season had conductivities up to 110 μmho, but the general level of conductivity fell as the wet season progressed.

Run-off water flowing over the ground during heavy rain generally had a higher conductivity than the rain.

Short-term fluctuations in the conductivity of small streams showed increases with heavy rain accompanied by surface run-off.

The rainfall had a high calcium to sodium ratio. It is estimated that during the period from 1 September to 30 November 1968 the rainfall supplied the area with at least 4 kg Ca per hectare.     

分布不定环境下具有价格干预的单产品流网络均衡

在市场需求分布不定的环境下,考虑产能限制以及政府价格干预,研究了供应链网络均衡问题.借助变分不等式理论,给出了供应链网络中各层决策者以及整体均衡条件.利用对数二次预测校正算法,进行了数值算例分析.结果证明:当需求为分布不定时,采取保守策略的零售商利润少于随机需求分布已知的情形;同时,由于信息的匮乏,容易造成制造商的盲目生产.     

激励性设计对中国电力产业的启示

通过对激励性规制价格上限和标尺竞争理论的概述,分析了西方发达国家电力产业规制的实践,探讨了激励性设计对我国电力产业的启示。     

冷放空天然气火灾爆炸事故影响范围模拟

针对冷放空作业中的意外火灾、爆炸事故,许多研究单一从冲击波超压方面考虑伤害范围,一旦发生火灾,热辐射强度也非常强,研究不同影响因素下火灾的热辐射伤害范围十分必要。首先,分析放空压力6 MPa和放空速率20×10⁴m³/h时冷放空天然气火灾的热辐射影响范围和冲击波超压影响范围,然后,模拟不同放空速率和不同放空压力下热辐射的影响范围和冲击波超压的影响范围。结果表明,在模拟工况下,放空压力对热辐射强度影响更大,热辐射导致的轻伤距离最远达到269.72 m;在模拟工况下,放空速率对冲击波超压影响更大,冲击波导致轻伤的最远距离达到198.00 m。在实际工程中,控制放空压力和放空速率对减轻意外火灾爆炸事故的后果极为重要。     

水平巷道火灾浮羽流及顶板射流积分模型

为研究矿井火灾火源区域烟流流动规律，以便对矿井火灾灾变风流的流动状态进行更详细地描述和计算机动态模拟，分析了矿井水平巷道火灾浮羽流的特性和顶板射流的形成原因，从基本物理定律和守恒方程出发，采用二维平面射流和动量积分分析方法，建立了水平巷道火灾浮羽流和顶板射流的数学模型。此模型经实验和计算检验修正后将作为矿井火灾区域模拟的理论基础。     

烟气顶蓬射流非稳态温度场的分析计算

在综合分析烟气顶蓬射流特性的基础上,利用速度场分布不随时间变化的实验结果,计算了顶蓬射流的非稳态温度场,并与参考文献的实验结果进行了比较。其计算方法简单可行,结果合理。这一结果对火灾探测器和水喷淋器的安装设计具有一定的指导意义。     

Detection of methane plumes in the water column of Losatchev hydrothermal vent field, Mid-Atlantic Ridse

During DY105-17 cruise onboard the PJV ＂Da Yang Yi Hao＂ in 2005, methane concentrations in the water column above Logachev hydrothermal vent field were measured by applying stripping/trapping-gas chromatographic （GC） and the distinct methane plumes were detected. Results show that the background methane concentration within the Logachev area is from 1.05 nmol/L to 1.68 nmol/L, significantly higher than the background level of the Atlantic abyssal plain of 0.4-0.5 nmol/L, suggesting that hydrothermal venting is a major source of dissolved methane to the ocean. The highest anomalies of methane concentrations in the water column range from 7.14 nmol/L to 113.9 nmol/L and occur just at 180-500 m above the seafloor. The distribution of methane concentration and the structural characteristics of hydrothermal plumes are strongly influenced by the supply of underlying hydrothermal fluids, the mixing process of ocean bottom currents and the microbial oxidation. Furthermore, the differences in distribution of methane plume between the station MAR-CTD3 and the other stations indicate a probable unknown hydrothermal vent site nearby. There occurs high concentration of methane along with temperature and nephelometry anomalies, which strongly confirms that the subtle measurement of methane concentration in water column is one of the effective ways to locate active sites of hydrothermal venting.     

双机共变顶高尾水洞系统水力干扰分析

采用有压管道特征线法、跟踪明满流分界点的明渠改进狭缝法和状态方程数值计算的联合算法,结合相应的边界条件,研究变顶高尾水洞方案的水力干扰问题,并与尾水调压室方案进行了比较分析,结果表明：变顶高尾水洞方案水力干扰对运行机组稳定性和调节品质的影响较尾水调压室方案小,此水力特性为变顶高尾水洞的应用提供了可靠的比选依据．     

无排气管VFD立式排气机的设计

无排气管VFD排气机是生产无排VFD的关键设备。在介绍无排气管VFD立式排气机的结构设计方案的基础上,重点讨论了真空头、封口装置、真空盒的关键技术及其特点。实践证明,新设计开发的无排气管VFD立式排气机的设计合理、制造成本低,具有推广应用前景。