对我国2000-2004年发表的“RS”论文的统计分析

本文对近年来国内主要科技期刊上有关“RS”论文进行统计与分析,叙述了近年来我国RS科学研究的现状和水平,揭示了这一学科的应用范围、研究者现状、分布的特点和规律,明确了RS在国民经济建设中的重要地位。对RS的发展阶段给予了评价。     

Interpretation of a two-point flux stencil for skew parallelogram grids

Control-volume formulations for elliptic equations often use two-point flux stencils, even for skew grids. Any two-point flux stencil may be interpreted as a multipoint flux stencil. This yields a definition of the permeability (or conductivity) tensor. Formulas for calculating the permeability tensor, based on the user-specified quantities in the two-point flux stencil, are given. Numerical test examples demonstrate the validity of the derivation.      

南方集约农区农牧结合对农业可持续发展的作用

为寻求该区农业可持续发展的途径,作者在分析其农业可持续发展的主要制约因素基础上,对农牧结合在实现农业可持续发展中的功能作了全面论述。结果表明,农牧结合是实现该区农业可持续发展的一条有效途径。最后还提出了该农区农牧结合的可行途径及有效措施     

Near-field probabilistic seismic hazard analysis with characteristic earthquake effects

In conventional seismic hazard analysis, uniform distribution over area and magnitude range is assumed for the evaluation of source seismicity which is not able to capture peculiar characteristic of near-fault ground motion well. For near-field hazard analysis, two important factors need to be considered: (1) rupture directivity effects and (2) occurrence of scenario characteristic ruptures in the nearby sources. This study proposed a simple framework to consider these two effects by modifying the predictions from the conventional ground motion model based on pulse occurrence probability and adjustment of the magnitude frequency distribution to account for the rupture characteristic of the fault. The results of proposed approach are compared with those of deterministic and probabilistic seismic hazard analyses. The results indicate that characteristic earthquake and directivity consideration both have significant effects on seismic hazard analysis estimates. The implemented approach leads to results close to deterministic seismic hazard analysis in the short period ranges (T < 1.0 s) and follows probabilistic seismic hazard analysis results in the long period ranges (T > 1.0 s). Finally, seismic hazard maps based on the proposed method could be developed and compared with other methods.     

Comment on “Is there a paleolimnological explanation for ‘walking on water’ in the Sea of Galilee?”

In a recent paper, Nof et al. (J Paleolimnol 35:417–439, 2006) suggest a physical mechanism which could account for the formation of ice on Lake Kinneret (Sea of Galilee) in northern Israel. Based on the sea surface temperature record of sediment cores from the Mediterranean Sea the authors argue that centennial-scale cold events had the potential to trigger local ‘springs ice’ formation on the lake in the past. Here, we demonstrate that a closer inspection of the paleoceanographic record in combination with correlation and regression analyses of meteorological data provides no evidence for such cold events in the lake region during the last 10,000 years. Thus, the formation of ‘springs ice’ on Lake Kinneret was unlikely at least since the beginning of the Neolithic.     

Managing Depleting Gold Revenues in Mali: An Assessment of Policy Options

This paper analyzes the impact of medium-term policy options in the context of gold resources depletion in Mali. Using a recursive-dynamic computable general equilibrium model calibrated to a 2006 Malian Social Accounting Matrix, we assess the impact of gold resources depletion in Mali and two policy options: the adoption of the permanent income hypothesis (PIH) and a “borrow and invest” scenario consisting at boosting public investment by 5% points of GDP. The depletion of gold resources in Mali would cause a substantial fall in GDP growth, and lead to unsustainable fiscal path if the government were to keep its current pattern of spending. Adopting either the “borrow and invest” fiscal approach or the PIH is likely to generate higher growth and a more sustainable fiscal framework compared to the status quo.