The effects of sodium sulfate on the emissions characteristics of an emulsified marine diesel oil-fired furnace     

Cherng-Yuan Lin  Jenq-Yih Pan 《Ocean Engineering》2001,28(4)

Degraded diesel oils are commonly used in marine power plants to conform to the demands of shipowners for fuel economy. The burning of these marine fuel oils, which frequently contain various extents of oxides of iron, silicon, calcium, vanadium and potassium, such as Na₂SO₄, Fe₂O₃, SiO₂, CaO, V₂O₅, etc., are susceptible to form much more complex compounds of either gaseous or solid phases. The release of these emissions to the environment may cause atmospheric pollution and a health hazard to human beings. Emulsification of a fuel oil with water to produce a micro-water-particles-dispersed-in-oil (W/O) emulsion has been considered as one of the promising techniques to improve combustion characteristics of low-grade marine oils and in turn effectively help to reduce the release of air pollutants. Marine fuel oil A, which approximates ASTM No. 2D oil was used as the test oil and the surfactant Span 80 was used to promote the affinity and integrating force between the components of the emulsion. An emulsifying/homogenizing machine was employed to stir the emulsion mixture of the marine oil, distilled water, surfactant Span 80 and sodium sulfate (Na₂SO₄) powder of 300 ppm. The mechanically blended emulsion mixture was injected, atomized and burned in an oil-fired furnace using an automatic burner. Burning gas composition, burning efficiency and gas temperature were measured and analyzed. Compared to neat marine diesel oil, W/O emulsions had higher combustion efficiencies, higher concentrations of O₂ and SO₂, while gas temperatures were lowered and CO and NO_x production was reduced. The addition of sodium sulfate decreased combustion efficiency and NO_x concentration and increased O₂, CO, and SO₂ concentrations.  相似文献   

河南禹州早二叠世山西组二1煤组植物化石     

张明达  郭晓宇  史骁 《世界地质》2022,(1)

报道了河南省禹州市神垕镇马垌剖面山西组二₁煤组的植物化石21属42种。该植物群以真蕨纲和种子蕨纲繁盛为特征,楔叶纲、瓢叶目、科达纲、苏铁纲及石松纲植物亦有一定的数量,属于华夏植物群中期组合特征,地质时代为早二叠世亚丁斯克期。结合国内同期植物群的对比,首次将该植物群的发育与全球气候变化及海平面升降相联系:当气候由冰室气候转变为暖室气候、海平面上升时,植物群演替加快,光合效率增加引起O₂剧增及CO₂剧降。  相似文献   

Discussion of the genetic relations between W and Sb-Au mineralization of Xiangzhong ore district: Constraints from Sr-Nd-H-O isotopic compositions of the Caojiaba W and Longshan Sb-Au depositsSCIEI北大核心CSCD     

张志远  谢桂青  袁亮 《岩石学报》2023,(6):1847-1860

湘中是全球最大的锑金矿集区,近年来又陆续探明了一批钨矿床,但这些钨矿和锑金矿之间的关系目前尚不明确。曹家坝钨矿床是目前该矿集区内规模最大的钨矿床(19.03Mt@0.37%WO3),矿体与矽卡岩密切共生,成矿作用划分为矽卡岩阶段、退化蚀变阶段和石英-白钨矿-硫化物阶段。不同阶段白钨矿δ18OV-SMOW变化范围为6.0‰-7.9‰,δDV-SMOW变化范围为-79.1‰--68.9‰,对应的δ18OH2O变化范围为3.3‰-5.2‰。白钨矿(87Sr/86Sr)t变化范围为0.72215-0.73049,εNd(t)变化范围为-12.8--10.6。龙山锑金矿床是矿集区内发育的大型脉状锑金矿床(4.2Mt@3.4%Sb和3.7g/t Au),矿体赋存在震旦系江口组板岩中,发育两个世代的白钨矿与辉锑矿共生。白钨矿δ18OV-SMOW变化范围为5.4‰-9.0‰,δDV-SMOW变化范围为-72.9‰--60.2‰,对应的δ18OH2O变化范围为3.1‰-6.7‰。Sr-Nd-H-O多元同位素特征显示,曹家坝钨矿床的成矿物质和成矿流体以岩浆来源为主,龙山锑金矿床有岩浆流体参与成矿,两者均有少量板溪群基底地层和大气降水的加入。综合本次及前人研究成果,曹家坝钨矿床和龙山锑金矿床具有成因联系,二者均是湘中矿集区晚三叠世岩浆热液W-Sb-Au成矿系统的重要组成部分。  相似文献   

高精度海洋重力测量中AIRSEA SystemⅡ的水平加速度改正     

谢清陆  高建尽  刘铭顺 《北京测绘》2012,(5):6-9

AIRSEA SystemⅡ已应用于我国的海洋重力测量,它主要由高精度的垂直加速度计和稳定平台组成。前者用于测量总加速度,后者使加速度计保持精确的垂直指向。海洋重力测量时,由于测量船水平加速度的存在,稳定平台难以精确维持水平从而使加速度计偏离正确指向,由此产生了水平加速度改正。为了提高测量精度,给出水平加速度改正计算的两种方法,即两步法和一步法。为有效地减弱因水平加速度改正不完善产生的系统性误差,提出了水平加速度改正的预滤波方法。最后利用中沙大环礁实测数据对此改正方法进行了验证和分析。  相似文献   

垂直加速度对SⅡ型海洋重力仪的影响及消除     

谢清陆  李应超  位文强 《北京测绘》2012,(2):65-67

根据海洋重力测量的实际情况,结合SⅡ型海洋重力仪的结构特点,分析垂直加速度对SⅡ型海洋重力仪的影响,进而采取强阻尼的措施减弱这种影响,对于测量船实时航行状态操纵,提高作业效率具有很重要的作用。  相似文献   

SN 1994W: an interacting supernova or two interacting shells?     

Luc Dessart  D. John Hillier  Suvi Gezari  Stéphane Basa  Tom Matheson 《Monthly notices of the Royal Astronomical Society》2009,394(1):21-37

We present a multi-epoch quantitative spectroscopic analysis of the Type IIn supernova (Type IIn SN) 1994W, an event interpreted by Chugai et al. as stemming from the interaction between the ejecta of a SN and a  0.4 M_⊙  circumstellar shell ejected 1.5 yr before core collapse. During the brightening phase, our models suggest that the source of optical radiation is not unique, perhaps associated with an inner optically thick cold dense shell and outer optically thin shocked material. During the fading phase, our models support a single source of radiation, an hydrogen-rich optically thick layer with a near-constant temperature of ∼7000 K that recedes from a radius of  4.3 × 10¹⁵  at a peak to  2.3 × 10¹⁵ cm  40 d later. We reproduce the hybrid narrow-core broad-wing line profile shapes of SN 1994W at all times, invoking an optically thick photosphere exclusively (i.e. without any external optically thick shell). In SN 1994W, slow expansion makes scattering with thermal electrons a key escape mechanism for photons trapped in optically thick line cores, and allows the resulting broad incoherent electron-scattering wings to be seen around narrow-line cores. In SNe with larger expansion velocities, the thermal broadening due to incoherent scattering is masked by the broad profile and the dominant frequency redshift occasioned by bulk motions. Given the absence of broad lines at all times and the very low ⁵⁶Ni yields, we speculate whether SN 1994W could have resulted from an interaction between two ejected shells without core collapse. The high conversion efficiency of kinetic to thermal energy may not require a SN-like energy budget for SN1994W.  相似文献   

GasBenchⅡ顶空瓶内空气背景对<100μg碳酸盐中碳氧同位素在线测定的影响及校正方法初探   总被引：3，自引：2，他引：1  

杜广鹏  王旭  张福松 《岩矿测试》2010,29(6):631-638

较为系统地研究了在特定排空时间下GasBenchⅡ顶空瓶内背景CO2的量和同位素组成变化,并检查了该空白CO2组分对碳酸盐C、O同位素在线测定的影响。结果发现,由于排空时间较短所导致的顶空瓶内剩余的空气CO2或由于排空方法不当所导致的外部空气少量回流都会对小样品量(100μg)碳酸盐C、O同位素测定结果产生显著影响。其影响程度取决于空白CO2的量和空白CO2与碳酸盐样品之间C、O同位素的差别大小。由此,对小样品量碳酸盐C、O同位素的测定结果进行了空白校正。当碳酸盐样品质量在20~100μg,校正后δ13C和δ18O值的标准偏差分别小于0.12‰和0.13‰,这证明了该空白校正方法的可行性。由于顶空瓶中空白CO2的量很小,所以对痕量CO2的量、δ13C和δ18O测定值的测定会存在一定波动,这对碳酸盐δ13C和δ18O校正值产生小于0.2‰的不确定度。采用准确测定的实验室空气CO2的δ13C和δ18O值则会大大减少该不确定度的影响。  相似文献   

地面高精度磁测在印尼滨海型磁铁矿应用     

胡维竹  杨茂齐 《云南地质》2010,29(2):197-200

综合运用低纬度化极与建立模型正演等数据处理手段进行隐伏矿体预测,发现与成矿有关的磁异常,显示良好成矿前景。钻孔证实有工业矿体。  相似文献   

Deep optical observations of the interaction of the SS 433 microquasar jet with the W50 radio continuum shell     

P. Boumis  J. Meaburn  J. Alikakos  M. P. Redman  S. Akras  F. Mavromatakis  J. A. López  A. Caulet  C. D. Goudis 《Monthly notices of the Royal Astronomical Society》2007,381(1):308-318

  相似文献   

一个罕见的铀钨矿物组合     

罗兴章  闵茂中  李贤国  翟丽英  杨哲 《矿物学报》2001,21(2):129-132

本文首次报导钨锰矿和铀矿物在空间上叠生的现象。这种叠生现象出现在一种很特别类型的矿床中，与传统的铀钨伴生理论有悖，这种铀、钨叠生矿化不仅具有重要的经济价值，而且也会拓展铀、乌伴生理论的研究。  相似文献