低NOx燃烧技术综述

简述各种煤粉锅炉在满足环保要求的前提下,采用经济有效的技术措施,组织良好的燃烧,控制煤在燃烧过程中NOx的生成,低NOx燃烧技术及在实际工程中的应用。     

三峡工程蓄水运用后水库泥沙淤积及坝下游河道冲刷分析

根据三峡工程蓄水运用后的实测资料,简述三峡库区泥沙淤积、坝下游河道冲刷,并与论证阶段的研究成果进行对比。分析认为三峡工程蓄水运用8年,水库泥沙淤积及坝下游河道冲刷等出现的情况尚在原预测范围之内,表明原预测的研究成果可行;本次实测与预测对比,在时间上略显短促,仍需今后观测并作进一步对比;今后应加强原型观测及有关研究工作。     

分级燃烧对层燃炉NOx减排的效果研究

将分级燃烧低NOx技术应用于层燃炉,在实验炉中测试了其对NOx排放的控制效果.实验表明,空气分级在不对燃烧构成很大影响的前提下可以达到28%的NOx减排效果,而燃料分级则可降低NOx55%,可见分级燃烧对层燃炉中NOx控制也是有效的.     

Consequences of stream impoundment on fish communities in a small North American drainage

We examined impoundment associated fish community changes in the Kinkaid Creek drainage of southern Illinois by comparing collections made in 1998 and 1999 with a pre‐impoundment survey conducted in 1958. We also analyzed other historical pre‐ and post‐impoundment collections made during the past 60+ years. A dramatic change in fish community structure occurred with the pre‐impoundment community dominated by cyprinids and the post‐impoundment community now dominated by centrarchids. In addition, a 50% increase in the number of fish species known from the Kinkaid Creek drainage has occurred, with 35% of all species known from Illinois now present in the drainage. This increase in species richness coincides with the extirpation of six native species. Possible explanations for the changes in the species assemblage and increased species richness include the introduction and dispersal of non‐native fish species and habitat alteration. Finally, we contend that processes, such as habitat alteration, must be considered when analyzing the pattern of increased species richness caused by non‐native species seen in North American drainages. Copyright © 2001 John Wiley & Sons, Ltd.     

三峡水库2007年运行调度分析

2007年是三峡工程初期运行期的第一年,也是工程综合效益全面发挥的第一年。枯水期,三峡水库实施流量补偿调节,满足了通航要求;汛期,根据防总防洪调度指令实施调节,保护长江中下游的安全。     

Detection of colorectal liver metastases: prospective comparison of unenhanced and ferumoxides-enhanced magnetic resonance imaging at 1.5 T, dual-phase spiral CT, and spiral CT during arterial portography

The purpose of this study was to compare the efficacy of unenhanced and ferumoxides-enhanced magnetic resonance imaging with that of dual-phase spiral CT and spiral CT during arterial portography (CTAP) for the detection of colorectal liver metastases. Fourteen patients with liver metastases candidates for partial hepatectomy were examined with dual-phase spiral CT, unenhanced and ferumoxides-enhanced MR imaging at 1.5 T, and spiral CTAP. Imaging tests were read blinded, prospectively, quantitating number of lesions excepting CTAP which used US to exclude cysts. Subsequent intraoperative US and pathologic findings were correlated with preoperative imaging results. At surgery, 36 lesions 0.5–13 cm in diameter (mean ±standard deviation, 2.9±2.1 cm) were identified. Dual-phase spiral CT depicted 21/36 (58%); precontrast MR imaging, 19/36 (53%); ferumoxides-enhanced MR imaging, 30/36 (83%); and spiral CTAP, 34/36 (94%) lesions. Ferumoxides-enhanced MR imaging was significantly more sensitive than spiral CT and unenhanced MR imaging (P<0.01). The difference in sensitivity between ferumoxides-enhanced MR imaging and spiral CTAP was not statistically significant (P>0.1). Spiral CTAP, however, depicted nine false-positive lesions (2 hemangiomas, 7 perfusion defects). The positive predictive value was 79% for spiral CTAP and 100% for combined pre- and postcontrast MR imaging. We conclude that ferumoxides-enhanced MR imaging is superior to unenhanced MR imaging and biphasic spiral CT for depiction of colorectal liver metastases. Further investigation is needed to clarify whether MR imaging with use of ferumoxides might replace spiral CTAP for preoperative evaluation of liver resection candidates. Recipient of a Cum Laude award for a scientific exhibit at the 1997 ESMRMB annual meeting.     

陕西卤泊滩盐碱地综合治理的“改排为蓄 水地共处 和谐生态”模式研究

盐碱地作为一种重要的土地资源，其治理和改良意义重大。本研究以生态环境改善为目标，将盐碱地治理以“排”为核心改为以“蓄”为核心，提出并应用了“改排为蓄、水地共处、和谐生态”的综合治理模式。揭示了在蓄水条件下，水与土壤之间的动态循环压盐机理。通过科学掌握水盐运移规律,合理规划布置工程体系，采用“人工—自然”二元措施，逐步恢复区域生态，实现系统自我调节，水地资源动态平衡。通过近十年实践已取得了“经济—社会—生态”综合效益，并保证了区域“水土—生物—环境”生态系统和谐发展。     

百色水利枢纽下闸蓄水方案研究

针对百色水利枢纽由于移民搬迁滞后推迟到汛末下闸的问题,从各个方面对下闸蓄水方案进行分析研究后,决定于2005年8月26日下闸蓄水,使得2006年6月26日水库能蓄水到195 m,7月15日第一台机组顺利发电,达到了预定目标.     

Hydrogen as burner fuel: modelling of hydrogen–hydrocarbon composite fuel combustion and NOx formation in a small burner

The objective of this work is to investigate numerically the turbulent non‐premixed hydrogen (H₂) and hydrogen–hydrocarbon flames in a small burner. Numerical studies using Fluent code were carried out for air‐staged and non‐staged cases. The effects of fuel composition from pure hydrogen to natural gas (100%H₂, 70%H₂+30%CH₄, 10%H₂+90%CH₄, and 100%CH₄) were also investigated. The predictions are validated and compared against the experimental results previously obtained and results from the literature. Turbulent diffusion flames are investigated numerically using a finite volume method for the solution of the conservation equations and reaction equations governing the problem. Although, three different turbulence models were tested, the standard k–ε model was used for the modelling of the turbulence phenomena in the burner. The temperature and major pollutant concentrations (CO and NO_x) distributions are in good agreement with the existing experimental results. Air staging causes rich and lean combustion regions thus lower NO_x emissions through the combustor exit. Blending hydrogen with methane causes considerable reduction in temperature levels and thus NO emissions. Increasing the mixture ratio from stoichiometric to leaner mixtures also decreases the temperature and thus NO emissions. Hydrogen may be considered a good alternative fuel for burners, as its use reduces the emission of pollutants, and as it is a renewable synthetic fuel. Copyright © 2005 John Wiley & Sons, Ltd.