地下水与玄武财反应趋势分析   总被引：1，自引：0，他引：1  

艾瑶  高明 《高校地质学报》1998,4(2):220-228

通过建立水化学平衡反应模型,计算地下水组分的各种可能存在形式的浓度和活度,并求得各种矿的饱和指数,再用饱和指数分析水－岩相互作用过程中矿物的溶解与沉淀反应趋势。本文采用该方法对盱眙玄武岩土区水－岩间反应趋势进行了分析。  相似文献   

湘西南石英脉型金矿水-岩反应与锶、氢、氧同位素的关系     

吴湘滨  戴塔根  何绍勋 《矿物岩石地球化学通报》1998,(4)

同位素方法已广泛用于矿床成因研究：确定矿床的形成年代,研究含矿热液的来源和地质过程。但是针对具体矿床,这方面研究仍存在许多不确定性或多解性。湘西南石英脉型金矿的成矿流体来源,是一个颇有争议的问题,有人认为成矿流体主要有变质水,后期可能有大气降水加入［...  相似文献   

The Project for Intercomparison of Land-surface Parameterization Schemes (PILPS) phase 2(c) Red-Arkansas River basin experiment:: 2. Spatial and temporal analysis of energy fluxes   总被引：3，自引：0，他引：3  

Xu Liang  Eric F. Wood  Dennis P. Lettenmaier  Dag Lohmann  Aaron Boone  Sam Chang  Fei Chen  Yongjiu Dai  Carl Desborough  Robert E. Dickinson  Qingyun Duan  Michael Ek  Yeugeniy M. Gusev  Florence Habets  Parviz Irannejad  Randy Koster  Kenneth E. Mitchell  Olga N. Nasonova  Joel Noilhan  John Schaake  Adam Schlosser  Yaping Shao  Andrey B. Shmakin  Diana Verseghy  Kirsten Warrach  Peter Wetzel  Yongkang Xue  Zong-Liang Yang  Qing-cun Zeng 《Global and Planetary Change》1998,19(1-4)

The energy components of sixteen Soil-Vegetation Atmospheric Transfer (SVAT) schemes were analyzed and intercompared using 10 years of surface meteorological and radiative forcing data from the Red-Arkansas River basin in the Southern Great Plains of the United States. Comparisons of simulated surface energy fluxes among models showed that the net radiation and surface temperature generally had the best agreement among the schemes. On an average (annual and monthly) basis, the estimated latent heat fluxes agreed (to within approximate estimation errors) with the latent heat fluxes derived from a radiosonde-based atmospheric budget method for slightly more than half of the schemes. The sensible heat fluxes had larger differences among the schemes than did the latent heat fluxes, and the model-simulated ground heat fluxes had large variations among the schemes. The spatial patterns of the model-computed net radiation and surface temperature were generally similar among the schemes, and appear reasonable and consistent with observations of related variables, such as surface air temperature. The spatial mean patterns of latent and sensible heat fluxes were less similar than for net radiation, and the spatial patterns of the ground heat flux vary greatly among the 16 schemes. Generally, there is less similarity among the models in the temporal (interannual) variability of surface fluxes and temperature than there is in the mean fields, even for schemes with similar mean fields.  相似文献   

塑料大棚小气候开发利用及气象服务探讨     

代怀山  钱妙芬 《成都信息工程学院学报》1998,(2)

根据大量资料分析和实地考察,对我国塑料大棚小气候开发利用进行了综述,并对蔬菜大棚气象服务进行探讨,为塑料大棚应用于农业产业化,取得更好经济效益,提供参考。  相似文献   

滇西耿马盆地构造—沉积综合分析     

赵易奎  赵泽江 《矿物岩石》1998,18(1):54-59

滇西耿马盆地位于三江褶皱系保山褶皱带的耿马—澜沧复背斜,面积１９５ｋｍ２,接受广泛的河湖相沉积,为典型的第三系小型陆相盆地。盆地内沉积受构造控制明显,沿边界断层主要发育冲积扇、近岸水下扇沉积,远离断层发育深湖相或半深湖相沉积。耿马盆地的构造样式与沉积展布在滇西具有极好的代表性,故从构造－沉积相互作用角度对其分析,对于指导滇西其他第三系盆地的勘探有重要意义。  相似文献   

改进的模拟退火-变尺度优化方法在测井解释中的应用     

林海燕  戴云 《矿物岩石》1998,(Z1)

实际中的测井参数反演是一个多参数、非线性优化问题,所采用的目标函数,即度量由参数化的理论模型得出的预测值与观测值的吻合程度,往往存在多解的现象。针对这种状况我们提出了模拟退火与变尺度综合反演方法用于参数计算,经过实际试算证明该方法效果很好。  相似文献   

Gamma-ray burst afterglows: effects of radiative corrections and non-uniformity of the surrounding medium   总被引：2，自引：0，他引：2  

Z. G. Dai  & T. Lu 《Monthly notices of the Royal Astronomical Society》1998,298(1):87-92

The afterglow of a gamma-ray burst (GRB) is commonly thought to be the result of continuous deceleration of a relativistically expanding fireball in the surrounding medium. Assuming that the expansion of the fireball is adiabatic and that the density of the medium is a power-law function of shock radius, i.e. n _ext ∝  R ^{− k} , we study the effects of the first-order radiative correction and the non-uniformity of the medium on a GRB afterglow analytically. We first derive a new relation among the observed time, the shock radius and the Lorentz factor of the fireball: t _⊕ =  R /4(4− k ) γ²c, and also derive a new relation among the comoving time, the shock radius and the Lorentz factor of the fireball: t _co = 2 R /(5− k ) γc. We next study the evolution of the fireball by using the analytic solution of Blandford &38; McKee. The radiation losses may not significantly influence this evolution. We further derive new scaling laws both between the X-ray flux and observed time and between the optical flux and observed time. We use these scaling laws to discuss the afterglows of GRB 970228 and GRB 970616, and find that if the spectral index of the electron distribution is p  = 2.5, implied from the spectra of GRBs, the X-ray afterglow of GRB 970616 is well fitted by assuming k  = 2.  相似文献   

银川市主要污染物变化特征及其关系研究     

高睿娜  孙银川  左河疆  高娜  王岱 《气象与环境学报》2022,38(1):33-39

利用2013-2019年银川市主要污染物浓度数据,分析了近年来银川市主要污染物浓度变化特征,并运用主成分分析法对主要污染物之间的关系进行研究。结果表明：近年来银川市主要污染物浓度除O₃逐年呈上升趋势外,其他均呈下降趋势;市区站O₃浓度较郊区背景站低,其他污染物市区较郊区背景站高;市区站PM₁₀和PM_2.5浓度超国家二级标准;除O₃浓度夏季高,冬季低外,其他污染物冬季高,夏季低;CO、NO₂、PM₁₀、PM_2.5浓度呈"双峰型"日变化特征,O₃和SO₂呈"单峰型"日变化特征。银川市主要污染物NO₂浓度与CO和O₃相关性显著,PM₁₀和PM_2.5之间相关性显著;污染物第一主成分是NO₂、CO和O₃,方差贡献率达到50%以上,加之银川市O₃浓度逐年呈升高趋势,表明近年来银川市大气光化学污染增加。  相似文献   

Scientific objectives and payloads of Chang’E-1 lunar satellite   总被引：1，自引：0，他引：1  

Sun Huixian  Dai Shuwu  Yang Jianfeng  Wu Ji  Jiang Jingshan 《Journal of Earth System Science》2005,114(6):789-794

China plans to implement its first lunar exploration mission Chang’E-1 by 2007. The mission objectives are

–	• to obtain a three-dimensional stereo image of the lunar surface,
–	• to determine distribution of some useful elements and to estimate their abundance
–	• to survey the thickness of lunar soil and to evaluate resource of3He and
–	• to explore the environment between the Moon and Earth.

To achieve the above mission goals, five types of scientific instruments are selected as payloads of the lunar craft. These include stereo camera and spectrometer imager, laser altimeter, microwave radiometer, gamma and X-ray spectrometers and space environment monitor system. In order to collect, process, store and transmit the scientific data of various payloads a special payload data management system is also included. In this paper the goals of Chang’E-1 and its payloads are described  相似文献   

The basic features of zooplankton in the western waters of Taiwan Strait     

Cai Bingji  Lian fiuangshan  Lin Yuhui  Lin Mao  Dai Yanyu  Liu Jinghong  Chen Ruixiang 《海洋学报(英文版)》1996,15(1):139-144

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