高压旋流除砂装置的研制

为保证在高压条件下实现连续除砂作业,从结构、工作原理、主要尺寸和技术特点方面介绍一种旋流除砂器,可以满足高压工作条件的同时有效保证连续作业和分离效率。现场应用结果表明:对于直径100μm以上的砂粒可以实现完全分离,其分离效果较好,装置安全可靠。     

物理过程参数化方案对加勒比海台风模拟的影响

针对大气模式的多个物理过程,研究不同微物理过程和积云对流参数化方案组合对WRF模拟加勒比海地区台风路径和强度的影响。结果表明：虽然台风路径模拟对于参数化方案组合的选择具有一定的“个例依赖”特性,但综合来看,WSM5-Kessler的组合方案对模拟加勒比海地区台风路径的模拟效果最好,其次是WSM6-Kessler组合。台风强度模拟“个例依赖”特征不明显,以KF积云方案为最优,微物理过程方案对强度模拟影响不明显。     

Two parametric tropical cyclone models for storm surge modeling

In this paper,the two parametric tropical cyclone models for storm surge modeling are further developed.The analytical expressions of tangential and radial velocity distribution are derived from the governing momentum equations,based on the general symmetric pressure distribution proposed by Holland and Fujita.On the basis of the data of several tropical cyclones that occurred in East China Ocean,the shape parameter in pressure model is estimated.Finally,the Fred cyclone(typhoon 199417)is calculated,and comparisons of measured and calculated air pressures and wind speed are presented.     

热带气旋生成的预报现状与船舶实用监测信息

介绍了目前对热带气旋发生及发展研究的最新理论及预报业务,指出目前热带气旋发生、发展的预报水平与实际需求仍有很大距离。推荐了美国为弥补热带气旋的发生、发展预报的不足而采取的对热带气旋的胚胎——热带扰动和热带低压进行监测的编号情况和方法。同时,根据几年来对上述情况的跟踪和分析,提供了几个较为实用的,可以及时了解全球热带扰动和热带低压最新发展动态的网站。所提供的理论动态和信息,可使船舶驾驶员和船舶安全管理人员了解目前国内外热带气旋发生、发展的研究和预报现状,在日常工作中及时了解热带气旋初生和发展的动态,最大程度地降低新生热带气旋对在热带气旋活动海区航行船舶的威胁,以达到保障航运企业安全生产的目的。     

Tropical cyclone genesis over the south China sea

The South China Sea (SCS) is among areas in the Northwest Pacific most frequented by tropical cyclones (TCs) with intensity reaching a tropical storm or stronger. It is also an area of significant TC genesis. In this study, TC genesis in SCS and its monsoonal variability for 1948–2003 are analyzed. Altogether, in May–September (southwest monsoon period) 157 TC geneses have occurred north of 12°N in SCS, while in October–December (northeast monsoon period) 64 out of 65 TC geneses have happened south of 18°N. It is found that the monsoonal characteristics of the SCS basically determine the region of TC genesis in each monsoon season. Winter TC genesis in the SCS happens over the region where the marine environment satisfies the four criterions on, respectively, the sea surface temperature (SST), mid-troposphere relative humidity, vertical shear of the horizontal winds and low-level atmospheric vorticity. During the summer, as the two criterions on SST and the mid-troposphere relative humidity are satisfied for the whole SCS, TC genesis occurs in the region where both the low-level vorticity and the vertical shear satisfy the criterion. In addition, there is likely more TC genesis in the winter during the onset of La Nina, and more TC genesis in the summer following the onset of El Nino.     

台山核电取水隧洞工程泥水处理技术的应用

为解决地层条件复杂、黏土含量极大的地质特点下泥水盾构施工中的泥和水能得到有效分离的问题,通过台山核电站取水隧洞工程泥水处理技术的设计实例,分析泥浆指标的管理和泥水处理的布局及流程,重点研究泥水处理系统的分离过程、浓缩过程及压滤过程的设计方案,总结出以下几个结论：泥水处理技术达到弃浆“零排放”标准的设计流程;浓缩机在泥水处理从分离过程到压滤过程中的作用;泥水处理技术在黏土地层中的成功应用,对类似工程施工有一定的参考价值。     

Global warming and severe weather activity

The concentration of atmospheric CO₂ has been significantly increasing mainly due to human consumption of fossil fuels since the middle of the 18th century. Although the recent increases of CO₂ could possibly give rise to some warming, serious problems remain unresolved in relation to the concept of global warming. The focus of this paper is directed at two areas: the first is the credibility of the global warming prediction, and the second is the long-term trend in severe weather activity associated with global warming. The global warming during the last century has been confirmed by observational data. The magnitude of the warming averaged globally is about 0.6°C during the last century, and is consistent with the computed increase in CO₂ concentration. The observational data indicate a large degree of hemispheric asymmetry; the warming of the Northern Hemisphere is slower and sometimes temporarily interrupted comparing with that of Southern Hemisphere. It is an open question why this hemispherical asymmetry is of opposite sense to the results of numerical simulations for the increases in CO₂ concentration. This question may possibly be resolved by consideration of the climatic effects of increases in anthropogenic aerosol levels in the troposphere in addition to greenhouse gas effects. One question raised by global warming is whether the frequency and intensity of extreme weather events have shown a long-term increased in association with global warming. Since extreme weather such as torrential rainfall and tropical cyclones are relatively small-scale, short-lived phenomena, they cannot be successfully simulated using general circulation models (GCM) at the present time. Furthermore, the limited period of the available observational data makes it difficult to produce any meaningful results with conventional statistical methods. A new statistical method, which was proposed by the present author and a colleague, is applied to the maximum daily precipitation data, and significant evidence is found for an interdecadal increasing trend in the intensity of extremely heavy rainfall. It is argued that the most likely cause of this trend is global warming. With regard to the relation between global warming and tropical cyclone activity, no significant results have yet been obtained either by numerical simulation or statistical analysis of historical data. Recent research analyzing historical data on the relation between tropical cyclone intensity and sea surface temperature has emphasized that the warmer sea surface accompanied by global warming could increase the maximum possible intensity of cyclones, although no appreciable change would be seen in the average intensity of regular storms. Presented at the International Conference on Technologies for Marine Environment Preservation (MARIENV’95), Tokyo, Japan, September 24–29, 1995.     

北部湾热带气旋增减水实例分析

本文对8007号热带气旋与8221号热带气旋引起的北部湾增减水情况进行了计算,初步探讨了北部湾风暴潮特征与形成原因。研究表明,由于北部湾水深较浅,受地形影响,当热带气旋来临时,增减水现象较显著。广西外海受热带气旋外围影响时,水位呈现增减水振动,当距离热带气旋中心较近时,出现风暴潮。     

HX_D1型交流传动机车辅助变压器通风冷却系统过滤分析与改进

介绍了HXD1机车辅助变压器柜及机械间通风冷却系统的构成,分析了通风冷却系统的过滤原理.通过试验数据说明了通风冷却系统的过滤效率.详细介绍了改进型通风冷却过滤系统的过滤原理及效果.     

基于多源预报的热带气旋危险区域的确定方法

为了提高热带气旋信息的完整性与准确性,分析了目前确定热带气旋中心周围危险区域的方法,提出了基于多源预报的热带气旋中心周围危险区域的确定方法。根据中、日、美三国对热带气旋中心位置的预报结果,求出预报的离散度,由预报位置与平均误差的关系,得出热带气旋90%落入概率的概率圆范围,然后将大风浪半径套在此概率圆的外面,可得到充分考虑多家热带气旋预报结果的热带气旋中心周围大风浪危险区域。可见,此方法提高了热带气旋预报圆的落入概率,有力保障了船舶绕避热带气旋的安全性。