CONVERSION RATES OF SURFACE HOX RADICALS IN BEIJING CITY     

REN Xin-rong    WANG Li-xin  WANG Hui-xiang  MIAO Guo-fang 《中国地理科学(英文版)》2004,14(1):34-38

1INTRODUCTIONThe hydroxyl radicals play a central role in atmospher-ic photochemistry, reacting with a lot of compounds, often initiating their oxidation and subsequent loss and resulting in the formation of ozone and other deleteri-ous oxidants, acids, and fine particles in polluted ar-eas. A thorough understanding of this role is necessary for efficient, cost-effective pollution control. There-fore, the measurement of OH is very significant (E-HHAT etal., 1991). Nevertheless, most me…  相似文献   

THE CONSTRUCTION OF SIMULTANEOUS OPTIMAL EXPERIMENTAL DESIGNS FOR SEVERAL POLYNOMIALS IN THE CALIBRATION OF ANALYTICAL METHODS     

R.WOLTERS  G.KATEMAN 《地理学报(英文版)》1990,(2)

In this paper a criterion is described for the construction of experimental designs for the evaluation ofcalibration models in analytical chemistry.The proposed criterion seeks a compromise between theD-optimal designs for estimating the parameters of different polynomial models.A computer algorithmis presented for a sequential construction of experimental designs using the optimality criterion.Theperformance of the optimality criterion and the computer algorithm is elaborated for the problem ofdiscrimination between a first-to a third-degree polynomial for the calibration of analytical methods.Anexperimental design consisting of replicate measurements at five distinct levels equally spaced over thecalibration range proved a good solution.  相似文献   

新人文地理学     

M.S.劳  J.R.萧特  肖建成 《地理科学进展》1991,10(4):44-48

引言《地理学进展》的创刊号于1969年出版,在刊物创刊21周年之际,有必要对其宗旨和目的再作一次评析。本文将考察进步的概念,让我们先从定义入手。地理科学的进步,常常被定义为地理学家使他们的研究领域变得更具可知性的能力。像所有社会学科一样,这里存在着下定义的问题。更具知识性和可知性是什么意思?另一个更重要的问题是谁来决定这种进步是什么?学术研究来源于商界和政府在安排研究项目方面起至关重要且举足轻重作用的大千世界中,有时用一般的方式,有时则用特殊的方式。  相似文献   

ANALYSIS OF THE ENVIRONMENT FEATURE OF BREEDING AREA AND ENDANGERED FACTORS OF RED-CROWNED CRANE IN CHINA   总被引：1，自引：0，他引：1  

YU Jun-bao  LIU Jing-shuang  WANG Jin-da 《中国地理科学(英文版)》2001,11(2):186-191

1 POPULATION STATUS AND DISTRIBUTION OF RED-CROWNED CRANE IN CHINAAccording to aerial survey, the number of Red-crowned Crane(Grus japonensis) is about 700 in breeding areas of China in 1981－1984, accounting for 65％of total numbers in the world (LI et al., 1987; MAet al., 1987; MA, 1987; FENG et al., 1985). In August 1992, the international symposium of crane in the world was convened in Calgary, Canada. The number of the crane was estimated accurately. There w…  相似文献   

Directional Spectrum of Wind Waves: Part Ⅰ- Model and Derivation     

LIU Yuguang )  *  YAN Xiao-Hai )  SU Ming-Yang ) ) Physical Oceanography Laboratory  College of Marine Environment  Ocean University of China  Qingdao  P..R.China) Center for Remote Sensing  Graduate College of Marine Studies  University of Delaware  Newark  DE  USA) Oceanography Division  Naval Research Laboratory  Stennis Space Center  MS  USA 《中国海洋大学学报(英文版)》2003,2(1)

1　Introduction　Numerousinvestigationsondeepwaterwindwavespectrumhavebeen performed (Phillips ,195 8;Bretschneider,195 9;PiersonandMoscowitz ,196 4;Hasselmannetal.,1973;Donelanetal.,1985 ;Ban ner ,1990 ;Wenetal.,1999) .Ondimensionalground ,Phillips (195 8)suggestedthattheequilibriumfre quencyspectrumofwindwavesfordeepwatershouldbe proportionaltoω- 5,andthecorrespondingwavenumberspectrumshouldbe proportionaltok- 4,whereωistheangularfrequencyandkisthewavenumber.Forfully developedwindwaves…  相似文献   

Directional Spectrum of Wind Waves: Part Ⅱ- Comparison and Confirmation     

LIU Yuguang )  *  YAN Xiao-Hai )  SU Ming-Yang ) ) Physical Oceanography Laboratory  College of Marine Environment  Ocean University of China  Qingdao  P..R.China) Center for Remote Sensing  Graduate College of Marine Studies  University of Delaware  Newark  DE  USA ) Oceanography Division  Naval Research Laboratory  Stennis Space Center  MS  USA 《中国海洋大学学报(英文版)》2003,2(1)

1　Introduction1.1　Proposed ModelonDirectionalFrequencySpec trum　ThisisthePartⅡofthetwo papersetondirection alspectraofwindwaves.Anewmodelonthedirec tionalspectrumofwindwavesfordeepwaterispro posedbasedonthestatisticsofwindwavesinthePartⅠ .Substituting (4 5 )ofPartⅠinto (4 0 )andaddingapeak enhancementitemγΓ,weobtainS(ω ,) =0 .0 0 93αaαwD( ,k) ωpω2 ξ- 4g2ω5×exp - 2 ξ+14[bωp +(1-b)ωp]4ω4 γΓ. (1)Here ,αaisthewaveagefactorofspectralcoefficientdefinedbyαa = ω0 .55…  相似文献   

DEM FROM SAR:PRINCIPLE AND APPLICATION     

Li Deren  Yang Jie 《大地测量与地球动力学》2003,23(Z1)

1　IntroductionWiththetechnologicalimprovementsofradarimagerysystems,thescientificcommunitieshavebetteropportunitiestostudyapplicationsinvariousremotesensingfieldssuchasoceanography ,geolo gy ,atmosphere ,cartography ,environmentsurveil lance .Theseresearchstudieshaveacommonobjec tive:toknowmoreabouttheearth’senvironmentandtheinaccessiblecelestialobjectsmoreprecisely .Cartographicinformationisimportantformanyfields:theterritorydevelopmentanddefense ,theforestforecasts,theminingresources,etc.F…  相似文献   

PRIMARY STUDY OF SULFATE AND CARBONACEOUS AEROSOLS IN BEIJING     

Su Weihan  Zhang Qiupeng  Song Wenzhi  R. L. Do  R. D. Giauque  T. Novakov 《大气科学进展》1987,4(2):225-232

Results of our aerosol study, performed during 1983–1984 in Beijing, demonstrate that ambient carbonaceous aerosols are derived mainly from coal combustion. Different SO₂ oxidation processes have been observed in summer and winter. The winter sulfate appears to be produced locally and associated with products of incomplete combustion.  相似文献   

有关土壤系统内部临界阈的几个例子     

D.R.马斯  马建华 《地理科学进展》1987,6(3):13-17

一、石灰性母质中的粘粒移动碳酸盐淋溶是土壤粘粒以淋溶方式迁移的一个必要条件（搏尔等,1980）。像Ca⁺⁺和Mg⁺⁺等二价阳离子具有强烈的凝聚作用,可抑制粘粒的淋溶。在湿润环境中,碳酸盐最终要被淋洗掉,当活性碳酸盐和交换性Ca⁺⁺淋洗到一定程度时,粘粒就不再以凝聚状态存在而开始移动,此时,碳酸盐和Ca⁺⁺的含量即可看作一种临界阈值。  相似文献   

印度马德拉斯含水层系统水文地球化学对人类健康的影响     

S.Marikam  R.Sakthivadivel  束龙仓 《世界地质》1991,(1)

从1985年开始,安娜大学水资源中心在马德拉斯含水层系统(MAS)有规律地进行了水文地球化学研究,该含水层系统包括北-西北部多层含水层和南部半承压含水层。马德拉斯大城市居民的60～70~*％,供水来自马德拉斯含水层系统,在干旱年份,近  相似文献