地铁临时支援供电中压环网方案研究

因征地拆迁等原因,地铁主变电所及电缆通道常因工期滞后而需临时支援供电。针对临时支援供电问题研究其中压环网方案,提出了系统运行方式及可靠性、压降要求、倒接可行性和经济性4方面评价标准。以武汉地铁2号线南延线为例,提出3种临时支援供电方案。分别阐述了每种方案的运行方式,计算了环网压降,研究倒接方案的可行性和经济性。通过综合比较,总结出各方案的优缺点,提出注意事项,为后续工程提供思路。     

基于车辆自动定位数据的有轨电车运行效率分析与应用

结合有轨电车线路的现有车辆自动定位数据,分析有轨电车运行效率及其相关影响因素。其中,影响因素从站台、路段、交叉口3个方面进行考虑。定性分析了不同站台型式、站台位置、交叉口类型的属性特征,并量化不同路段的路段长度、所包含的交叉口个数,同时考虑了交叉口控制策略对有轨电车运行时间的影响。以某已运营的有轨电车线路为例,通过建立多元线性回归模型,从不同层面探究不同因素对已运营有轨电车线路运行效率的影响。最后用模型对有轨电车新建线路的运行效率进行预测,并提出建议。     

基于WSEIAC模型的主要部件可靠性和维修性对舰艇动力装置效能的影响分析

舰艇动力装置的复杂化、自动化程度的提高使得其可靠性和维修性等指标越来越成为制约其效能发挥的重要因素,而动力装置效能的发挥将直接影响作为作战武器平台的舰艇的战斗力的发挥,因此分析影响动力装置效能发挥的因素具有十分重要的意义。文章通过分析确立了动力装置的系统边界和系统状态,运用WSEIAC模型确定了动力装置系统效能与其主要组成系统的可靠性和维修性之间的关系,通过灵敏度分析给出了其关系曲线并进行了分析,得出了动力装置主要组成系统的最佳可靠性和维修性参数值,拓展了WSEIAC模型的应用范围,对于开展舰艇动力装置效费分析也具有重要的参考价值。     

Fluxes of dissolved inorganic carbon in three estuarine systems of the Cantabrian Sea (north of Spain)

The diffusive and in situ fluxes of dissolved inorganic carbon (DIC) and total alkalinity (TA) have been measured and an estimation has been made of the water–atmosphere fluxes of CO₂ in three estuarine systems of the Cantabrian Sea during the spring of 1998. Each of these systems undergoes a different anthropogenic influence. The diffusive fluxes of dissolved inorganic carbon and total alkalinity obtained present values ranging between 0.54–2.65 and 0.0–2.4 mmol m⁻² day⁻¹, respectively. These ranges are in agreement with those of other coastal systems. The in situ fluxes are high and extremely variable (35–284 mmol TA m⁻² day⁻¹, 43–554 mmol DIC m⁻² day⁻¹ and 22–261 mmol dissolved oxygen (DO) m⁻² day⁻¹), because the systems studied are very heterogeneous. The values of the ratio of the in situ fluxes of TA and DIC show on average that the rate of dissolution of CaCO₃ is 0.37 times that of organic carbon oxidation. Equally, the interval of variation of the relationship between the benthic fluxes of inorganic carbon and oxygen (F_DIC/F_DO) is very wide (0.3–13.9), which demonstrates the different contributions made by the processes of aerobic and anaerobic degradation of the organic matter, as well as by the dissolution–precipitation of CaCO₃. The water–atmosphere fluxes of CO₂ present a clear dependence on the salinity. The brackish water of these systems (salinity<20), where maximum fluxes of 989 mmol m⁻² day⁻¹ have been estimated, act as a source of CO₂ to the atmosphere. The more saline zones of the estuary (salinity>30) act as a sink of CO₂, with fluxes between −5 and −10 mmol m⁻² day⁻¹.     

生活小区管道直饮水的工艺及经济分析

分析了生活小区管道直饮水的净水工艺,对工艺流程各单元的原理和作用进行了阐述,并进行了经济分析,和桶装直饮水比较,管道直饮水的价格较低,表明生活小区管道直饮水系统有较大的发展空间。     

MARPOL73/78附则Ⅵ大气污染物排放控制的进展

文章以IMO大气污染通信工作组在2006年底召开的工作会议为背景,介绍了针对船用柴油发动机和燃料控制排放标准的讨论情况。     

Organic carbon budget for the Gulf of Bothnia

We calculated input of organic carbon to the unproductive, brackish water basin of the Gulf of Bothnia from rivers, point sources and the atmosphere. We also calculated the net exchange of organic carbon between the Gulf of Bothnia and the adjacent marine system, the Baltic Proper. We compared the input with sinks for organic carbon; permanent incorporation in sediments and mineralization and subsequent evasion of CO₂ to the atmosphere. The major fluxes were riverine input (1500 Gg C year^− 1), exchange with the Baltic Proper (depending on which of several possible DOC concentration differences between the basins that was used in the calculation, the flux varied between an outflow of 466 and an input of 950 Gg C year^− 1), sediment burial (1100 Gg C year^− 1) and evasion to the atmosphere (3610 Gg C year^− 1). The largest single net flux was the emission of CO₂ to the atmosphere, mainly caused by bacterial mineralization of organic carbon. Input and output did not match in our budget which we ascribe uncertainties in the calculation of the exchange of organic carbon between the Gulf of Bothnia and the Baltic Proper, and the fact that CO₂ emission, which in our calculation represented 1 year (2002) may have been overestimated in comparison with long-term means. We conclude that net heterotrophy of the Gulf of Bothnia was due to input of organic carbon from both the catchment and from the Baltic Proper and that the future degree of net heterotrophy will be sensible to both catchment export of organic carbon and to the ongoing eutrophication of the Baltic Proper.     

基于广义回归神经网络的瓦斯涌出量预测

简要介绍了瓦斯涌出量预测问题和广义回归神经网络（GRNN）的特点,指出与常用的BP神经网络相比,使用广义回归神经网络（GRNN）具有收敛迅速、人为干扰小等优点,适宜用于瓦斯涌出量的预测。并对一个案例进行预测,证明了广义回归神经网络（GRNN）可以满足实际生产的精度要求,较好解决瓦斯涌出量预测的问题。     

混合动力牵引调车机车的研发

阐述了混合动力牵引调车机车的概念和样车的结构性能,重点论述了样车主要研制内容及技术措施、节油减排效果、节油试验情况,从评估计算和试验验证两方面论证了混合动力技术能实现能量高效利用和循环利用的双重目标,总结了样车的研制成果。     

船舶柴油机颗粒物排放控制技术研究进展

颗粒物是船舶柴油机排气中的主要污染物,严重危害人体健康和大气环境,如何降低船机颗粒物排放已成为环境保护及柴油机领域的一个重点研究方向。本文对船机排放颗粒物的组分及来源进行分析,梳理论述目前主流的颗粒物排放控制技术及DPF再生技术。认为后处理技术是今后颗粒物排放控制技术研究的重点,其中,最有效、应用最广泛的是DPF技术,复合再生技术是DPF再生过程的发展方向,提出了船机颗粒物排放控制未来需重点研究的关键技术及长远发展目标。