初始质量为七个太阳质量的AGB星的氢燃烧壳层的特性和物质抛射机理     

蒋苏云  黄润乾 《紫金山天文台台刊》1994,13(1):59-59

The property of the H-burning shell and the mecanism of the mass ejection of the AGB star are investigated by means of detailed computations carried out for the evolution of a star with its initial mass of 7. The energe generation rate εH of the H-burning shell changes periodically and has a phase-shifting with respect to that of the He-burning shell which undergoes thermonuclear runaway. For the most time of a period the value of εH is about one to three order of magnitude larger than that of the He-burning shell εHe . So the dominative energy supply of the star in the AGB phase comes from the H-burning shell. The luminosity of the star changes periodically and cynchronizes with the variation of εH . The upper limit of the luminosity of an AGB star can be obtained by the condition that the inward gravitational acceleration is balanced by the outward acceleration owing to the radiations, rotation and turbulent forces. Comparing the luminosity of the star with its upper limit, we can find that the lu  相似文献   

卫星遥感技术在秸秆焚烧监测业务中的应用   总被引：8，自引：0，他引：8  

邹春辉赵学斌  刘忠阳薛龙琴 郭其乐 《河南气象》2005,(3):24-26

农村秸秆焚烧常造成灰烬飞扬，烟雾迷漫，形成空气污染。常规的秸秆焚烧监测难度较大。本文介绍了河南省利用卫星遥感技术开展秸秆焚烧监测业务、服务的方法，包括卫星遥感技术监测秸秆焚烧火点的基本原理，以及秸秆焚烧火点遥感监测业务服务的流程、相关业务服务系统的组成及服务方式等。  相似文献   

Votalization of selenium in selenium-rich black rock series in Yutangba     

Shujuan SHI Yuegang TANG 《中国地球化学学报》2006,25(B08):48-48

Votalization of selenium in selenium-rich black rock series in Yutangba is discussed at 400, 500, 600, 700, 800 and 900℃.Votalization of selenium tends to increase when the temperature is high. So environmental influence of selenium-rich black rock series combustion needs to be considered.  相似文献   

Study on the distribution of PAHs in fly ash from coal and residual char combustion in a pressurized fluidized bed     

Hongcang ZHOU 《中国地球化学学报》2006,25(B08):54-55

Direct coal combustion not only has a low utilizing efficiency, but also produces a large amount of pollutants such as particulate, CO2, SO2, NOx, polycyclic aromatic hydrocarbons （PAHs）, PCDD/PCDFs, and so on. Coal gasification is a clean coal technology that presents good prospects for coal use, mainly for producing electricity with a high coal conversion efficiency and low environmental impact. However, there is a problem about the minimization of PAHs in coal gasification or direct coal combustion. PAHs are harmful to the environment and human health due to their high degree of mutagenicity and carcinogenicity when they enter human bodies through breathing, eating, and drinking. It is said that about 75%-90% cancers of human beings are mainly caused by PAHs. So the US EPA has prioritized 16 PAH compounds as hazardous air pollutants; these compounds are naphthalene （NAP）, acenaphthylene （AcPy）, acenaphthene （AcP）, fluorene （Flu）, phenanthrene （PhA）, anthracene （ANT）, fluoranthene （FluA）, pyrene （Pyr）, benzo （a） anthracene （BaA）, chrysene （Chr）, benzo （b） fluoranthene （BbF）, benzo （k） fluoranthene （BkF）, benzo （a） pyrene （BaP）, indeno（1,2,3,-cd） pyrene [In（1,2,3-cd） P], dibenzo （a,h） anthracene （DbA）, and benzo （ghi） perylene （BghiP）. The residual char is one of the main products during coal gasification, and then it is brought into the combustion chamber to combust. To investigate the distribution of PAHs in fly ash, the combustion of coal and residual char was tested in a pressurized spouted fluidized bed. After Soxhlet extraction and K-D concentration, the contents of 16 PAHs recommended by US EPA in coal, residual char, and fly ash, were analyzed by a HPLC coupled with fluorescence and diode-array detection.  相似文献   

Open burning of wastes as the source of environmental contamination by POPs     

Sergey V. Kakareka Tamar I. Kukharchyk 《中国地球化学学报》2006,25(B08):177-178

In the paper the procedure for and results of a test study of a few persistent organic pollutants - polycyclic aromatic hydrocarbon （PAH）, polychlorinated biphenyls （PCB） and hexachlorobenzene （HCB） emission from the open burning of different types of wastes （domestic wastes, agricultural debris, landscape cleating debris, etc.） are discussed. The open burning of agricultural debris and landscape-clearing debris is widely applied in rural areas and small towns and in allotment gardens for the recovery of that part of wastes that can not be utilized for compost preparation. This process is most typical during the autumn season and to a lesser degree during spring. Burning occurs usually in bon fires. Burning modes differ depending on the volume of material burnt, the waste moisture content, the weather conditions, etc. During this process part of domestic wastes （polluted wood, paper, chipboard, films, plastics, etc.） are burned also. Investigations included the collection and preparation of combustible material, the simulation of open burning processes, particulate and gas emission sampling, chemical analysis of sample and data processing. Sampling procedures and sample preparation were agreeable to the emission sampling standards. The aerosol and vapour phases of POPs were collected by ordinary sampling train with pumping of waste gases through filter and solid sorbent （polyurethane foam）. For the measurements of PAH in emission, gas chromatography and mass spectrometry were used which make it possible to identify and determine 16 PAH compounds in the samples; this method was used for HCB determination also. Gas chromatography with ECD detector was used for PCB measurement. It was detected that the levels of PAH emission from wastes uncontrolled burning of wastes vary greatly. Influencing factors are composition and properties of refuse, temperature and mode of burning, level air supply. Generally, the increase of content of wood leads to the increase of PAH in emission. PAH emission also increased with increasing temperature of burning. The highest PAH values are characteristic of emissions from domestic refuse burning. Practically, all naphthalene, acenaphthylene, acenaphthene （from 60% to 100% of their total mass） and fluorene （14%-99%） were emitted in gaseous form.  相似文献   

Chemical characteristics of fine particles during spring dust storm dominant period in two Chinese cities, Baotou and Wuwei     

Min HU Fan YANG Dingli YUE Song GUO Mengting WEN Wenting ZHANG Feng TIAN 《中国地球化学学报》2006,25(B08):221-221

Mineral dust, including dust storm, fugitive and floating dust are the most important components of ambient aerosol in northern China during spring. Meanwhile, it goes through heating period when fossil fuel combustion acts as a dominant source. In order to understand the chemical characteristics of fine particles in North China, two sampling sites was established in Baotou City in the west of Inner Mongolia Autonomous Region and Wuwei City near the edge of Gobi to collect fine particles （PM 2.5） samples in the spring of 2004 and 2005, and analyze mass concentrations, ionic species and some element components of PM 2.5. The results indicated that dust events elevated the mass concentrations of particulate matter significantly, not only for coarse particles, but also for fine particles. Crustal components, organic matter and sulfates are three major compositions in fine particles, their mass concentrations and relative abundances are closely related with the frequency of dust events and coal combustion. The characteristics of fine particles are obviously diverse under different atmospheric conditions. （1） When the dust storms take place, the wind speeds are often higher than 10 m/s. A plenty of mineral aerosol is input from long distance, and also local soil dust is blown up to suspend in the air as particles. Therefore, the concentrations of PM 2.5 are enhanced dramatically. Mass concentrations and relative percentages of crustal components in PM 2.5 increased significantly during dust events. The mineral dust may help gas to particle conversation by heterogeneous reactions. Increases in mass concentrations of SO4^2-, NO3^- and NH4^＋ and organic matter in PM 2.5 were observed evidently. But their fractions in PM 2.5 do not increase simultaneously due to dilution of storing wind. （2） When wind velocity is lower （〈3 m/s）, air pollutants are accumulated, both mass concentrations of SO4^2-, NO3^- and NH4^＋ and organic matter, and their fractions in PM 2.5 increase, indicating severe anthropogenic pollution. The chemical characteristics of PM 2.5 in Baotou and Wuwei are also influenced by their industrial structure, topography and meteorological conditions.  相似文献   

四川盆地秸秆还田与稻田新三熟制的农产品服务价值     

刘定辉朱钟麟  胡世忠陈永华 《山地学报》2006,24(B10):16-20

四川省传统稻田种植模式为稻麦（油）轮作，中稻收后到小麦、油菜播栽前尚有2个月左右的休闲期，该时段的温光时资源占全年的20％左右，利用潜力大。经多年研究集成了以秸秆覆盖还田提升土壤有机质、提高稻田综合生产能力的“水稻-蔬菜-小麦”、“水稻-秋马铃薯-油菜”、“水稻-蔬菜-春马铃薯”稻田新三熟种植模式，对三种新模式的农产品服务价值研究结果表明：秸秆覆盖稻田新三熟显著提高了稻田的综合生产能力，“稻-芋／油”三熟新模式比传统“稻-油”两熟模式的生产力提高115．2％，产值达到42218．4元/a；“稻-菜-麦”和“稻-菜-芋”三熟新模式分别比传统“稻-麦”两熟模式生产力提高92．3％、168．3％，周年公顷产值达到35798．9元、49952．2元；“稻-油”保护性耕作两熟模式与传统“稻-油”农作模式相比，虽然生产力相当，但由于降低了生产成本，年农产品服务价值每公顷增加904．0元，增加8．7％，“稻-麦”保护性耕作两熟模式与传统“稻-麦”农作模式相比，年农产品服务价值每公顷增加5341．5元，增加57．5％；“稻-芋／油”三熟新模式比传统“稻-油”和保护性耕作两熟模式年农产品服务价值每公顷分别增加18006．2元、17102．2元；“稻-菜-麦”和“稻-菜-芋”三熟新模式分别比传统“稻-麦”两熟模式农产品服务价值增加16835．5元、25063．8元，比保护性耕作模式分别增加11494．0元、19722．3元。  相似文献   

勘探六号首钻试油成功     

李俊杰 《海洋地质译丛》2011,(4):33-33

中国石化集团公司最先进的自升式海上钻井平台”勘探六号”首钻开门红。10月3日下午6时,由上海海洋石油局”勘探六号”承钻的东海”NB-13—4—2”井,一条巨大的火龙从平台燃烧臂喷涌而出,映红夜空,宣告该平台投入作业首钻试油成功。试油期间,该平台严格遵守上海局HSE石油作业操作规程,特别对环境保护和井控安全作了精心布置,反复对喷淋系统进行调试,放喷时严密监视喷淋装置,观察海面,确保对海洋环境零污染。  相似文献   

煤燃烧过程中微量元素的迁移和富集   总被引：5，自引：0，他引：5  

黄文辉  唐修义 《中国煤田地质》2002,14(Z1):75-87

煤中微量元素在燃烧过程中产生迁移与富集。大部分元素在煤的燃烧产物中得以富集,一些挥发性强的元素将扩散到大气中。在飞灰中,大部分环境有害元素的富集程度与其粒度成反比,即在细粒飞灰中更加富集,由此对人体健康的潜在危害也更大。在我国,大型燃煤电厂的环境问题值得重视,同时大量的民用炉灶产生的环境污染更加严重,值得进一步研究与治理。  相似文献   

锅炉微机智能控制系统在锅炉房设计中的应用     

邓丽娟 《中国勘察设计》2002,(4):56-57

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