浅谈《防震减灾法》在河北省贯彻执行中的问题及对策

从贯彻实施防震减灾法律法规的实践入手,针对《防震减灾法》在河北省贯彻实施过程中存在的问题,进行分析探讨,提出了解决的对策,目的在于更进一步促进防震减灾工作的深入开展。     

Kinematic dynamo action in a sphere: Effects of periodic time-dependent flows on solutions with axial dipole symmetry

Choosing a simple class of flows, with characteristics that may be present in the Earth's core, we study the ability to generate a magnetic field when the flow is permitted to oscillate periodically in time. The flow characteristics are parameterised by D, representing a differential rotation, M, a meridional circulation, and C, a component characterising convective rolls. The dynamo action of all solutions with fixed parameters (steady flows) is known from earlier studies. Dynamo action is sensitive to these flow parameters and fails spectacularly for much of the parameter space where magnetic flux is concentrated into small regions, leading to high diffusion. In addition, steady flows generate only steady or regularly reversing oscillatory fields and cannot therefore reproduce irregular geomagnetic-type reversal behaviour. Oscillations of the flow are introduced by varying the flow parameters in time, defining a closed orbit in the space ( D,?M ). When the frequency of the oscillation is small, the net growth rate of the magnetic field over one period approaches the average of the growth rates for steady flows along the orbit. At increased frequency time-dependence appears to smooth out flux concentrations, often enhancing dynamo action. Dynamo action can be impaired, however, when flux concentrations of opposite signs occur close together as smoothing destroys the flux by cancellation. It is possible to produce geomagnetic-type reversals by making the orbit stray into a region where the steady flows generate oscillatory fields. In this case, however, dynamo action was not found to be enhanced by the time-dependence. A novel approach is being taken to solve the time-dependent eigenvalue problem where, by combining Floquet theory with a matrix-free Krylov-subspace method, we can avoid large memory requirements for storing the matrix required by the standard approach.     

A parallel evolutionary strategy based simulation–optimization approach for solving groundwater source identification problems

Groundwater characterization involves the resolution of unknown system characteristics from observation data, and is often classified as an inverse problem. Inverse problems are difficult to solve due to natural ill-posedness and computational intractability. Here we adopt the use of a simulation–optimization approach that couples a numerical pollutant-transport simulation model with evolutionary search algorithms for solution of the inverse problem. In this approach, the numerical transport model is solved iteratively during the evolutionary search. This process can be computationally intensive since several hundreds to thousands of forward model evaluations are typically required for solution. Given the potential computational intractability of such a simulation–optimization approach, parallel computation is employed to ease and enable the solution of such problems. In this paper, several variations of a groundwater source identification problem is examined in terms of solution quality and computational performance. The computational experiments were performed on the TeraGrid cluster available at the National Center for Supercomputing Applications. The results demonstrate the performance of the parallel simulation–optimization approach in terms of solution quality and computational performance.     

A New Strategy for Solving a Class of Constrained Nonlinear Optimization Problems Related to Weather and Climate Predictability

There are three common types of predictability problemsin weather and climate, which each involve different constrained nonlinearoptimization problems: the lower bound of maximum predictable time, theupper bound of maximum prediction error, and the lower bound of maximumallowable initial error and parameter error. Highly efficient algorithmshave been developed to solve the second optimization problem. And thisoptimization problem can be used in realistic models for weather and climateto study the upper bound of the maximum prediction error. Although afiltering strategy has been adopted to solve the other two problems, directsolutions are very time-consuming even for a very simple model, whichtherefore limits the applicability of these two predictability problems inrealistic models. In this paper, a new strategy is designed to solve theseproblems, involving the use of the existing highly efficient algorithms forthe second predictability problem in particular. Furthermore, a series ofcomparisons between the older filtering strategy and the new method areperformed. It is demonstrated that the new strategy not only outputs thesame results as the old one, but is also more computationally efficient.This would suggest that it is possible to study the predictability problemsassociated with these two nonlinear optimization problems in realisticforecast models of weather or climate.     

Interactions of aquaculture and waste disposal in the coastal zone

Throughout the world, the coastal zones of many countries are used increasingly for aquaculture in addition to other activities such as waste disposal. These activities can cause environmental problems and health problems where they overlap. The interaction between aquaculture and waste disposal, and their relationship with eutrophication are the subjects of this paper. Sewage discharge without adequate dispersion can lead to nutrient elevation and hence eutrophication which has clearly negative effects on aquaculture with the potential for toxic blooms. Blooms may be either toxic or anoxia-causing through the decay process or simply clog the gills of filter-feeding animals in some cases. With the development of aquaculture, especially intensive aquaculture, many environmental problems appeared, and have resulted in eutrophication in some areas. Eutrophication may destroy the health of whole ecosystem which is important for sustainable aquaculture. Sewage discharge may also cause serious public health problems. Filter-feeding shellfish growing in sewage-polluted waters accumulate micro-organims, including human pathogenic bacteria and viruses, and heavy metal ion, presenting a significant health risk. Some farmed animals may also accumulate heavy metals from sewage. Bivalves growing in areas affected by toxic algae blooms may accumulate toxins (such as PSP, DSP) which can be harmful to human beings.     

阿克苏中心地震台数字化前兆仪器运行质量分析

通过对阿克苏中心地震台前兆仪器故障进行相关检查和分析处理,判断产生的各类干扰因素,并提出处理方法,为仪器运行、数据处理及使用奠定基础,保证观测资料的连续、完整和可靠.     

基于GIS成矿预测中几个关键问题的探讨

在前人研究结果和实践的基础上,提出了基于GIS成矿预测需要解决的几个关键问题,包括矿产地质数据处理、专家的知识经验、成矿预测数学方法的选取、数字化的成矿预测数据在不同GIS软件间的转换等,对其中一些关键问题提出相应的研究思路及解决办法。     

CHALLENGES AND PROBLEMS：CHINA‘S URBAN GOVERNANCE

Chinaˊs urban reforms have brought social progress and development,but a comprehensive national system of social welfare(for example,unemployment insurance,pensions,medical care and public housing)for new migrants from rural areas is lacking.One of the most remarkable changes in Chinese cities in the last decade was a change in so-cial“equality“,with the rise of new poverty both in individual communities and some social groups in urban society.Howev-er,there is little social assistance and public infrastructure for the migrants.Governments or communities or individual should pay attention to the control of new urban poverty and new slums.This paper consider that it is necessary to launch a successful policy,which include mainly:1)accommodating urban growth through low-cost investment projects;2)ur-ban economy depends heavily on successful macroeconomic policy;3)to broaden the three channels linking adjustment to the incidence of urban poverty;4)to restructure urban economic based on the high or new technology;5)to coordi-nate relationship between urban economic growth and environment management for sustainable development of Beijingˊs metropolitan fringe.     

东营市浅层卤水资源开发现状及开采潜力分析

采取环境地质调查、水位测量、水样分析、土样分析、抽水试验等多种工作手段,对东营市卤水开采现状进行了详细调查,分析总结了卤水资源开采对地质环境的影响,并结合开采现状,进行了浅层卤水资源开采潜力分析,为当地合理布局开发提供了依据。     

中非旅游合作的现状和未来

中非合作论坛北京峰会的成功召开表明,中国愿意与非洲国家共同努力,尽快摆脱贫困,共享发展成果,走向共同富裕.从非洲概况和非洲旅游资源的优势、特征及旅游市场的现状和未来着手,针对非洲旅游市场存在的问题,提出中非旅游合作的思路和对策.对当代非洲旅游开展全方位的研究,就是为开展全方位中非旅游合作作准备;为尽快摆脱贫困,共享发展成果,走向共同富裕献计献策.