论岩溶地下水系统中的快速流与慢速流

<正> 由于岩溶区多重含水介质(大型岩溶洞穴管道与网络状溶蚀裂隙)受到不同强度降水入渗补给,各类含水介质对岩溶地下水的调节具有明显差异,导致岩溶地下水出现快速流与慢速流这两种不同流态流速的水源成份。研究这两种水源的形成过程,与含水介质结构相互关系以及如何划分这两种水源,不仅有助于岩溶水基本理论的研究,而且在水资源评价与规划中也具有重要意义。通过水源划分,可了解评价区域有多少快速地下径流需经工程措施调节,有多少慢速地下径流可直接作为供水水源。     

An enhanced supervised spatial decision support system of image classification: consideration on the ancillary information of paddy rice area

The analysis, measurement, and computation of remote sensing images often require an enhanced supervised classification technique to develop an efficient spatial decision support system. Rice is a crop of global importance, which has drawn a great interest in using remote sensing techniques for evaluating its production. Ancillary information is widely used to improve the classification accuracy of satellite images. However, few of these studies questioned the importance and strategies of using this ancillary information. The enhanced decision support system in our study has two stages. In the first stage, the images are obtained from the remote sensing technique and the ancillary information is employed to increase the accuracy of classification. In the second stage, it is decided to construct an efficiently supervised classifier, which is used to evaluate the ancillary information. Back-propagation neural network (BPN) with extended delta bar delta (EDBD) algorithm is incorporated into our decision support classifier system. This classifier renders two crucial contributions: (1) the EDBD algorithm accelerates the convergence speed of the learning process and (2) the relative importance (RI) on each band of ancillary information is evaluated rationally.     

Spatial form of urbanization,sustainability and fragmented landownership: the example of Ilan in Taiwan’s urbanization

As a part of the inevitable process of industrialization, urbanization and its associated spatial forms generally have a substantial effect on sustainability. This paper considers the spatial form and sustainability of urbanization by evaluating the interaction between land-use planning, urban regimes and the fragmented structure of land ownership. This paper conceptualizes the structure of landownership as an institution that affects the form of spatial development and thereby determines the spatial implications of urban sprawl on sustainability. With reference to the Ilan experience of urbanizing Taiwan, it shows that the development of spatial form and sustainability is the product of planning institution and urban regime mobilization, and it reflects the institutional impact of a fragmented landownership structure. The conclusion also discusses policy implications.     

Raman spectroscopic measurements of CO2 density: Experimental calibration with high-pressure optical cell (HPOC) and fused silica capillary capsule (FSCC) with application to fluid inclusion observations

Raman spectroscopy is a powerful method for the determination of CO₂ densities in fluid inclusions, especially for those with small size and/or low fluid density. The relationship between CO₂ Fermi diad split (Δ, cm⁻¹) and CO₂ density (ρ, g/cm³) has been documented by several previous studies. However, significant discrepancies exist among these studies mainly because of inconsistent calibration procedures and lack of measurements for CO₂ fluids having densities between 0.21 and 0.75 g/cm³, where liquid and vapor phases coexist near room temperature.In this study, a high-pressure optical cell and fused silica capillary capsules were used to prepare pure CO₂ samples with densities between 0.0472 and 1.0060 g/cm³. The measured CO₂ Fermi diad splits were calibrated with two well established Raman bands of benzonitrile at 1192.6 and 1598.9 cm⁻¹. The relationship between the CO₂ Fermi diad split and density can be represented by: ρ = 47513.64243 − 1374.824414 × Δ + 13.25586152 × Δ² − 0.04258891551 × Δ³ (r² = 0.99835, σ = 0.0253 g/cm³), and this relationship was tested by synthetic fluid inclusions and natural CO₂-rich fluid inclusions. The effects of temperature and the presence of H₂O and CH₄ on this relationship were also examined.     

Effects of increased CO2 on land water balance from 1850 to 1989

Numerous studies have shown that increased atmospheric CO₂ concentration is one of the most important factors altering land water balance. In this study, we investigated the effects of increased CO₂ on global land water balance using the dataset released by the Coupled Model Intercomparison Project Phase 5 derived from the Canadian Centre for Climate Modelling and Analysis second-generation Earth System Model. The results suggested that the radiative effect of CO₂ was much greater than the physiological effect on the water balance. At the model experiment only integrating CO₂ radiative effect, the precipitation, evapotranspiration (ET) and runoff had significantly increased by 0.37, 0.12 and 0.31 mm year^?2, respectively. Increases of ET and runoff caused a significant decrease of soil water storage by 0.05 mm year^?2. However, the results showed increases of runoff and decreases of precipitation and ET in response to the CO₂ fertilisation effect, which resulted into a small, non-significant decrease in the land water budget. In the Northern Hemisphere, especially on the coasts of Greenland, Northern Asia and Alaska, there were obvious decreases of soil water responding to the CO₂ radiative effect. This trend could result from increased ice–snow melting as a consequence of warmer surface temperature. Although the evidence suggested that variations in soil moisture and snow cover and vegetation feedback made an important contribution to the variations in the land water budget, the effect of other factors, such as aerosols, should not be ignored, implying that more efforts are needed to investigate the effects of these factors on the hydrological cycle and land water balance.     

Simulation of rainfall anomalies leading to the 2005 drought in Amazonia using the CLARIS LPB regional climate models

The meteorological characteristics of the drought of 2005 in Amazonia, one of the most severe in the last 100 years were assessed using a suite of seven regional models obtained from the CLARIS LPB project. The models were forced with the ERA-Interim reanalyses as boundary conditions. We used a combination of rainfall and temperature observations and the low-level circulation and evaporation fields from the reanalyses to determine the climatic and meteorological characteristics of this particular drought. The models reproduce in some degree the observed annual cycle of precipitation and the geographical distribution of negative rainfall anomalies during the summer months of 2005. With respect to the evolution of rainfall during 2004–2006, some of the models were able to simulate the negative rainfall departures during early summer of 2005 (December 2004 to February 2005). The interannual variability of rainfall anomalies for both austral summer and fall over northern and southern Amazonia show a large spread among models, with some of them capable of reproducing the 2005 observed negative rainfall departures (four out of seven models in southern Amazonia during DJF). In comparison, all models simulated the observed southern Amazonia negative rainfall and positive air temperature anomalies during the El Nino-related drought in 1998. The spatial structure of the simulated rainfall and temperature anomalies in DJF and MAM 2005 shows biases that are different among models. While some models simulated the observed negative rainfall anomalies over parts of western and southern Amazonia during DJF, others simulated positive rainfall departures over central Amazonia. The simulated circulation patterns indicate a weaker northeasterly flow from the tropical North Atlantic into Amazonia, and reduced flows from southern Amazonia into the La Plata basin in DJF, which is consistent with observations. In general, we can say that in some degree the regional models are able to capture the response to the forcing from the tropical Atlantic during the drought of 2005 in Amazonia. Moreover, extreme climatic conditions in response to anomalous low-level circulation features are also well captured, since the boundary conditions come from reanalysis and the models are largely constrained by the information provided at the boundaries. The analysis of the 2005 drought suggests that when the forcing leading to extreme anomalous conditions is associated with both local and non-local mechanisms (soil moisture feedbacks and remote SST anomalies, respectively) the models are not fully capable of representing these feedbacks and hence, the associated anomalies. The reason may be a deficient reproduction of the land–atmosphere interactions.     

Radiation Pressure in a Superdense Electron Plasma

An expression for the radiation pressure in high density plasma is derived on the basis of plasma waves and semiclassical theory of radiation. Comparison of our result with that of Planck, Sommerfeld and Landau and Lifshitz is briefly discussed. It is shown that the radiation pressure in a high density plasma is not just one third of the corresponding energy density because of the different dependence on the index of refraction n (ω). Possible applications to the thermal history of early universe and late stage stellar evolution are also stressed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Acoustic power mapping for active regions from MDI, HLH, and TON data

Based on the HLH and TON ground-based helioseismological projects and the SOHO/MDI spaceborne project, we obtained acoustic power maps of active regions averaged over 1 mHz intervals. These maps allowed the spatial and frequency distributions of acoustic power in an active region and its surroundings to be studied. The time step of the HLH data is 42 s, which makes it possible to investigate the acoustic power up to 11.9 mHz. Data in the Ca II K and Ni I lines, which originate in the middle chromosphere and the photosphere, respectively, give an idea of the height distribution of acoustic oscillation energy in the solar atmosphere. The acoustic halo produced by excess acoustic power around sunspots clearly shows up on acoustic maps in the Ca II K line and, to a lesser degree, in the Doppler Ni I line shifts. Ground-based observations also reveal a large enhancement of acoustic power inside sunspots. Our tests show that this effect results from the combination of a high intensity gradient in the data and atmospheric seeing. The latter was reduced by referencing each image to the sunspot. The spatial distribution of power inside the sunspot due to atmospheric seeing was found to depend on the exposure time of the data used. Excluding the nonsolar effects, a common property of all acoustic maps is the suppression of the solar-oscillation acoustic power in active regions.     

A Model of Quasars and AGNs with Magnetic Monopoles

An evolutionary model of quasars and AGNs with magnetic monopoles is proposed. Their energy source is due to nucleon decay induced by the monopoles. Both the mass and the luminosity of quasars and AGNs will gradually decrease in time because their constituent baryons are kept decaying and are transformed into radiation. The physical significance and theoretical predictions of our evolutionary model are stressed.