基于多主体系统的区位建模

探讨了基于多主体系统（multi-agent system，MAS）的城市商业区位建模的新方法。模型由相互作用的环境层和多主体层组成，旨在探索商业区位过程中消费者、商业设施、政府等多主体之间以及多主体与环境之间的微观相互作用而导致的宏观商业布局过程。该模型可以方便地探索销售商在不同选址策略下商业设施的区位分布，为商业选址提供有用的决策依据，并在一个虚拟的城市空间中模拟了销售商在不同选址策略下的选址决策。     

车载飞艇智能扫描定位监控系统研究

阐述了突发公共安全事件现场监控的重要性，讨论了一种基于移动指挥车和飞艇的扫描定位监控系统，实现了系统的各种功能。     

Does the Environmental Supervision System Improve Air Quality in China? An Empirical Study using the Difference-in-Differences Model

To effectively solve the problem of environmental pollution, the Chinese government has implemented an environmental supervision system since 2002. The environmental supervision system mainly uses the four functions of supervision, investigation, coordination, and emergency response to strengthen environmental protection supervision and law enforcement, respond to environmental emergencies, and coordinate cross-regional pollution disputes. As an important system design for China to control environmental pollution and promote the ecological transformation of economic development, the policy effect of the environmental supervision system deserves attention. This paper uses the difference-in-differences method to investigate the impact of the top-down environmental supervision system on air quality based on the 2000-2016 data for 285 prefecture-level cities in China. The results indicate that the annual average concentration of PM_2.5 decreased significantly after the implementation of the environmental supervision system. The dynamic analysis shows that PM_2.5 decreased most markedly in the first year after the implementation of the policy, and then the effect gradually weakened. Mechanism analysis suggests that the environmental supervision system can break the collusion between government and enterprise, encourage enterprises to carry out technological innovation, change pollutant discharge behavior and push local governments to adjust the industrial structure, enhance environmental protection awareness to reduce the PM_2.5 concentration, and improve air quality. Comparing different regions, the PM_2.5 in East China, North China and Northeast China are relatively high, and the pressure for air pollution control is great. Meanwhile, we find that the environmental supervision system has a significant station effect. Compared with other cities, the cities where the environmental supervision centers are located are more deterred by the environmental supervision, and their air quality has improved to a significantly greater degree. In the future, we should further strengthen the environmental supervision of high-pollution areas and non-station cities, and pay more attention to improving the long-term effect of the environmental supervision system.     

考虑地形运动学边界条件的斜压大气发展倾向计算

本文讨论在大范围高空温压场的斜压发展短期数值预报中考虑地形运动学边界条件的具体方法,并用张弛法计算了二个实例的高度倾向.计算结果说明在天山阿尔泰山一带地形变高在700mb 上可以大到70—80米/24小时,下层更大,是需要考虑的.但是由于地面风决定的困难,还需要考虑改进模式,在高速电子数学计算机上大量试验,才能在日常预报中使用.     

摩擦层中湍流系数

摩擦层中湍流系数,利用风标的分布,可以测定之。1902年,爱克曼创立了摩擦层中风标螺线,利用风标螺线,可以测定摩擦层中的湍流系数。1953年,莱赫特曼考虑了气压场随高度的变化,即热成风的因素,获得了良好的结果。但是,莱赫特曼公式之应用,只限定于恒态吹流,或恒态均匀温压场的条件之下,方能准确使用。这样是在一般情况之下难以满足的。关于摩擦层非恒态问题,1947年赵九章、裘碧克曾经讨论过。本文仅就非恒态湍流系数测定问题予以进一步探讨。并得到了较有广泛意义之公式。而莱赫特曼公式,系属温压场恒态,温压场中温度、压力梯度在均匀情况之下,该公式之特解。爱克曼范式,系属气压场稳定,温度梯度恒态为零时,该公式之特解。这样,该公式的计算,使得湍流系数测定工作精确化和广泛化。 最后,本文作了一些实际资料的计算与分析,和讨论在自然环境中湍流系数的变化。     

地转气流中的重力惯性内波

本文用一个一维线性的二层模式,分析了地转气流中重力惯性内波的动力学性质。讨论了重力惯性内波的不稳定性、相速度和群速度后,指出: 1)当地转风速大于重力内波波速时,某些尺度的重力惯性内波可以产生不稳定性,这种不稳定性可以用来解释某些中系统的发展。 2)某些波长的重力惯性内波,它的群速度可以大于相速度;因此在某一地区有中系统发展时,它的能量可以很快地传到下游,而在某下游产生新的系统。     

对流发展局部气象条件的初步理论分析

分析了线性化后的小尺度动力学方程组出现不稳定解的条件,从而讨论了对流发展的局部天气条件,指出盛行风的垂直二次切变是一个稳定因子。同时指出,大范围对流云成排出现与风速垂直二次切变的存在有关。     

二维能量平衡模式对若干气候问题的研究

Based on a two-dimensional energy balance model, the studies on some climatic issues such as the re- lationship between ice cap latitude and solar constant, desertifieation, and the warming effect of carbon dioxide, have been reviewed and discussed. The phenomenon that a fixed solar constant might correspond to different equilibrium ice cap latitudes is determined by the continuity of albedo distribution. The disconti- nuity in albedo distribution increases the number of equilibrium ice cap latitudes. Desert would expand both northward and southward when desert surface albedo is increasing. This would deteriorate the ecological environment in border regions, and then threaten the existence of local inhabitants. Melting of the polar ice would not be accelerated, with increasing carbon dioxide concentration. The ice cap latitude would move northward slowly, with some “hiatus” periods, under the slowly increasing global average surface tempera- ture. According to the current research, future development of the two-dimensional energy balance model and possible progress are also forecasted.     

Characteristics of Gaseous Pollutants at a Regional Background Station in Southern China

Measurements of gaseous pollutants （03, NOx, SO2, and CO） were conducted at Dinghushan background station in southern China from January to December 2013. The levels and variations of O3, NOx, SO2, and CO were analyzed and their possible causes discussed. The annual average concentrations of 03, NOx, SO2, and CO were 24.6 ± 23.9, 12.8 ± 10.2, 4.0 ± 4.8, and 348 ± 185 ppbv, respectively. The observed levels of the gaseous pollutants are comparable to those at other background sites in China. The most obvious diurnal variation of 03 was observed in autumn, with minima in the early morning and maxima in the afternoon. The diurnal variations of SO2 showed high values during the day. The diurnal cycles of NOx showed higher values in the morning and lower values during the night. Higher CO concentrations were observed in spring followed by winter, autumn, and summer. Biomass burning, in combination with the transport of regional pollution, is an important source of CO, SO2, and NOx in spring and winter. Backward trajectories were calculated and analyzed together with corresponding pollutant concentrations. The results indicate that air masses passing over polluted areas are responsible for the high concentrations of gaseous pollutants at the Dinghushan background station.     

GIS专业人才培养的实践教学体系构建

实践教学是GIS专业人才培养不可缺少的重要环节.文章在分析国内外GIS实践教学现状的基础上,建立了GIS专业实践教学系统,确定了实践体系、实践模式与综合能力间的关系,系统阐述了GIS实践教学体系和模式的主要内容,提出多层次知识结构GIS人才培养的实践教学体系和模式.该GIS实践教学系统在高校GIS实践教学中得以广泛推广,为GIS教育和GIS创新人才的培养发挥重要的作用.