京津冀地区水-经济-生态系统耦合协调发展模拟

针对京津冀地区水资源、经济社会和生态环境系统未来可能面临的失衡失稳问题,构建水-经济-生态系统动力学模拟模型,设置开源节流、发展经济、保护环境等5种情景方案,预测京津冀地区水资源、经济社会和生态环境系统指标发展趋势,运用耦合协调度模型模拟京津冀地区2020—2035年不同情景下耦合协调发展趋势。结果表明:2020—2035年5种情景下北京、天津和河北水-经济-生态系统耦合协调度均呈上升趋势,其中延续现状型耦合协调度均最低,开源节流型、发展经济型和保护环境型次之,综合协调型均最高。说明在维持现状发展条件下,京津冀水-经济-生态系统耦合协调发展程度略有增加但变化较小,只有在节约用水和发展经济的同时充分考虑环境保护才能促进区域协调发展;2035年延续现状情景下北京、天津和河北耦合协调发展水平均属于中级耦合协调型,综合协调情景下北京和天津耦合协调发展属于良好耦合协调型,河北省经济发展相对滞后导致耦合协调发展缓慢,仍属于中级耦合协调型,未来应注重京津冀一体化发展。研究可为京津冀地区协调可持续发展提供参考依据。

细胞自动机模型用于城市发展模拟的方法初探——以海口市为例

在简要阐述了细胞自动机模型的基本概念及其在地理学中的应用历史后 ,以海南省海口市的城市发展为例 ,初步探讨了应用该模型 ,对蔓延生长、中心生长、沿交通线生长和农村居民点城市化等四种城市扩展类型进行模拟 ,并将模拟成果与 1996及 2 0 0 0年城市实际发展状况作对比分析 ,模拟精度达到 82 %以上。我们认为 ,基于遥感和地理信息系统的细胞自动机模型应用是城市发展预测研究的一个有效工具。

基于时间动画的城市建筑建设发展模拟研究

针对城市建设建筑发展模拟存在的问题,总结出一种基于时间动画的模拟方法来反映出其动态发展变化过程。该模型能根据模拟过程的动态变化与相应的定性、定量、定位等因素指标,提出相应的规划规则用于模拟城市建设过程中的某个时间点的建设情况。同时通过与地图动画显示技术的结合,该模型可以较好展现建筑建设发展的动态情况。

基于生态发展动态模拟的河南省城镇化发展生态安全研究

采取生态足迹和生态赤字/盈余的生态安全评价模型,计算2018年郑州及其周边部分城市的生态足迹,分析生态现状并与其他城市和地区的生态足迹进行比对,得知河南省生态环境目前状态是相对优良的,河南省西部和南部拥有不低的植被覆盖率,且省内水质条件优良,该地区优势资源明确。计算2011-2018的生态足迹和生态承载力,并分别进行系统动力学和神经网络模拟预测,分析未来几十年可能出现长期的赤字局面,对未来生态环境有出现严重且不可逆转影响的可能性。要实现永续发展,需要逐步降低直至消除生态赤字,并抓住其中的重要限制因素——水资源。在河南省生态安全局势如严峻的情况下,解决水资源空间和时间分布不均,改变发展模式和消费方式势在必行,人与自然必须和谐发展。

网络攻防技术的特点及模拟方法的发展研究

随着科学技术不断发展,计算机网络技术得到了广泛的应用,例如在政府机关、企事业单位以及人们日常生活中随处可以看到的网络应用,因此计算机网络安全问题已成为众多计算机网络用户与企业关心的话题。本文从计算机网络攻防技术的相关理论知识与网络攻防技术的特点进行分析,探讨出网络攻防模拟方法的发展。

基于GIS的地理元胞自动机模拟框架及其应用

提出了一种基于GIS的地理元胞自动机模型框架:SimUrban,用于城市发展和演化的模拟与预测。该框架基于面向对象技术,在GIS环境下利用VS.NET开发而成,可以集成遥感和GIS数据以及新的转换规则和地理CA模型,从而模拟城市演化并进行精度评定。以上海市嘉定区为例,在SimUrban环境下利用基于主成分分析(PCA)的地理CA模型模拟了该区域1989-2006年城市发展和演化过程。

模拟仿真技术在智能网联汽车开发中的作用

本文介绍了智能网联汽车的发展现状,阐述了模拟仿真的重要性,并围绕当前热门模拟仿真技术趋势进行了对比分析,基于公司产品规划角度,分析了模拟仿真技术在智能网联汽车开发中的作用,提出了智能网联汽车开发建议,为智能网联技术的发展规划提供了一定指导。

基于最近发展区理论的初中科学课堂探索体会

"最近发展区"理论要求教师教学必须重视学习者的已有知识经验,并把它作为新知识的生长点,引导学习者从原有的知识经验中,生长出新的知识经验.本文在基层教学实践和研究的基础上,从"情境概念发展,模拟逻辑发展,比喻思维发展,顿悟质变发展"等几个发展类型讨论了如何构建最近发展区.

发展医学模拟教育提高急诊住院医生临床实践能力分析

分析发展医学模拟教育提高急诊住院医生临床实践能力。方法 以40例急诊科住院医生为对象,分为两组,分别应用常规教学、发展医学模拟教育,对比应用效果。结果 对比考核成绩、综合能力,研究组更优(P<0.05)。研究组学生教学后人文素养总分、伦理学基本问题评分、尊重原则是、医患沟通原理和技能、华森关怀原理评分均高于参照组,差异P<0.05。研究组教学满意度高于参照组,差异有统计学意义(P<0.05)。结论 急诊科教学中采用发展医学模拟教育,提高学生的学习成绩与综合能力,同时还能提高医生的人文素养,应用效果显著。

基于GIS的电子病例管理系统研究

病例是医院档案管理中的一项重要内容,也是资料最多、最繁杂的一项内容,使用电子病例可以更有效的管理这些资料。病例中的部分数据具有一定的空间特征,本系统旨在对GIS特有的空间分析功能应用于病例管理中的初步探讨,同时,通过登陆注册功能提高病例管理中数据的安全性,为病例数据的科学研究提供更方便、更直观、更可靠的依据。

果树剪枝机械化及自动化研究进展

整枝修剪是果园生产中最为耗时耗力的作业环节,整枝修剪对水果生产具有重要意义。随着现代果园种植规模扩大,技术工短缺、成本增加等问题突出。果树枝干复杂性、剪枝技术性和不可逆性等问题导致剪枝机械发展缓慢,成为限制水果生产重要因素之一。文章阐述目前国内外果园剪枝机械分类,相关机械结构、工作原理和剪枝效果,重点介绍新兴虚拟剪枝技术,论述其发展现状和相关技术,对剪枝机械发展趋势提出展望。

中国科学院区域可持续发展分析与模拟重点实验室2016年学术年会暨首届青年学者论坛综述——兼论青年地理学者的责任与担当

2016年6月28日,"中国科学院区域可持续发展分析与模拟重点实验室2016年学术年会暨首届青年学者论坛"在北京召开。重点实验室学术委员会成员、北京大学贺灿飞教授以及重点实验室全体成员参加了这次会议,樊杰研究员作重点实验室第一届学术委员会的工作报告,与会专家充分肯定了过去五年实验室建设所取得的成绩,也指出了提升的方向。9位青年学者围绕各自研究方向作了学术报告,重点围绕空间结构、企业区位、演化经济地理、知识流动、旅游乡村聚落、传统工业区转型、城镇化、土地非农化、大数据与城市发展模拟等展开。中国人文与经济地理学蓬勃发展,当前面临着重要机遇,青年地理学者应充满感恩和激情,脚踏实地,认识国情,夯实基础,增强国际化视野,探索前沿技术方法,加强不同单位间的学术交流,主动承接历史责任、敢于担当,在前辈地理学家所创立的学科基础上,进一步推动人文与经济地理学实现新的发展。

基于事实推理的开发区信息系统

本文研究了基于知识的决策支持系统，事实推理和推理作为两种范型在该知识支持系统中得到了应用，这种综合技术通过改进后用于对开发区进行监控和对居住区发展进行模拟。

Development of Liquid Slug Length in Gas-Liquid Slug Flow along Horizontal Pipeline: Experiment and Simulation

The liquid slug length distribution is crucial for designing the downstream processing system with mul-tiphase pipeline. Experiments were conducted in a 133m long horizontal test loop. The measurements were per-formed by conductivity probes to determine the liquid slug length distribution. The data covered both the slug and plug flow regimes. From experimental results, the mean liquid slug lengths were relatively insensitive to gas and liquid flow rates in the higher mixture velocity range. But in the lower mixture velocity range, the mean liquid slug length decreased and then increased with mixture velocity. It shows that the development length of slug flow was longer than x/D=1157. A slug tracking model was adapted to study the evolution of liquid slug length distribution in a horizontal pipeline. In the present model, the wake effect of elongated bubble and the pressure drop due to accel-eration are taken into account and random slug lengths are introduced at the entrance. The results of the model are compared with the measured slug length distributions of slug flow regime. It shows that the predicted mean and maximum slug lengths are in agreement with the experimental data at x/D=1157 and the form of the slug length distributions is also predicted well by the model.

Degradation mechanism of rock under impact loadings by integrated investigation on crack and damage development

Failure of rock under impact loadings involves complex micro-fracturing and progressive damage. Strength increase and splitting failure have been observed during dynamic tests of rock materials. However, the failure mechanism still remains unclear. In this work, based on laboratory tests, numerical simulations with the particle flow code(PFC) were carried out to reproduce the micro-fracturing process of granite specimens. Shear and tensile cracks were both recorded to investigate the failure mode of rocks under different loading conditions. At the same time, a dynamic damage model based on the Weibull distribution was established to predict the deformation and degradation behavior of specimens. It is found that micro-cracks play important roles in controlling the dynamic deformation and failure process of rock under impact loadings. The sharp increase in the number of cracks may be the reason for the strength increase of rock under high strain rates. Tensile cracks tend to be the key reason for splitting failure of specimens. Numerical simulation of crack propagation by PFC can give vivid description of the failure process. However, it is not enough for evaluation of material degradation. The dynamic damage model is able to predict the stress-strain relationship of specimens reasonably well, and can be used to explain the degradation of specimens under impact loadings at macro-scale. Crack and damage can describe material degradation at different scales and can be used together to reveal the failure mechanism of rocks.

Kinetic Energy Budget Equations of Rotational and Divergent Flow in Terrain-following Coordinates

In this study, kinetic energy budget equations of rotational and divergent flow in pressure coordinates are derived on terrain-following coordinates. The new formulation explicitly shows the terrain effects and can be applied directly to model-simulated dynamic and thermodynamic fields on the model's original vertical grid. Such application eliminates interpolation error and avoids errors in virtual weather systems in mountainous areas. These advantages and their significance are demonstrated by a numerical study in terrain-following coordinates of a developing vortex after it moves over the Tibetan Plateau in China.

Physical and Numerical Modelling Applied to a Major New Port Development and Impacts of Its Deep Navigational Channel

This paper describes the use of a numerical and physical modelling study in the design of large breakwaters for a new port and dry dock complex on the southern coast of Oman. The numerical modelling was carried out to optimise the entrance channel layout with respect to wave penetration into the port and to refine design conditions for the sizing of the primary armour on the breakwaters. Wave conditions inside and outside of the port have been assessed using the 2-dimensional numerical wave penetration model MIKE21 EMS （Elliptic Mild-Slope）. As part of the design process, 3D physical modelling studies were also undertaken at Delft Hydraulics in the Netherlands to confirm the stability of the armour on the trunk and roundhead of the breakwaters and to verify the influence of the deep approach channel on stability. The opportunity was taken to extend the physical model tests to assess the influence of the deep channel on wave penetration through the port entrance. The paper focuses on the influence of the deep channel on wave conditions in the entrance to the port and compares the results from the numerical and physical modelling.

Suggestion of global model for carob batch fermentation to produce bioethanol

Modelling of carob batch fermentation is established basing on mass transfer balances. The modelling treats the reaction kinetics of substrate （S）, the micro-organisms （X） and the ethanol （E）. Nine models are taken from the literature to describe specific organism growth rate and specific ethanol development rate. These models treat all types of fermentation. The Phisalapbong et al. model and the Ghose and Tyagi model show the best fit of the experimental data. This affirms that the batch fermentation of carob is conducted with substrate and/or ethanol inhibition. Some simulations and relationships （X = f（S）, E = f（S）） are obtained from the Phisalaphong et al. model. Those simulations show a lot of important and useful results of carob batch fermentation process.

Urban-Design Process with Snow and Wind Simulations： A Study on the Kitami City Hall

Regional climatic conditions should be considered while designing urban development plans, with special attention to the impact of snowfall on public spaces in cities with harsh winters. The Kitami-city-hall-renewal project in Hokkaido, Japan was studied as an environmental assessment of snow drifting. Assessments of the two site plans proposed during the architectural planning process （A-type and B-type） were conducted in terms of the following three items： （1） The two site plans indicate snow-drifting problems around the main entrance; （2） More number of local snowdrifts on the main-street sidewalks were suggested in the B-type design; （3） Less number of snowdrifts in the parking area beside the railroad were indicated in the A-type design. These results were reflected in the architectural planning process. On the basis of this study, a desirable design process incorporating environmental assessments has been identified for cities with harsh winters.

Influence of Internal and External Parameters in Temperature of Hybrid PV/T Water Collector

The combination of photovoltaic system with a thermal to form the hybrid PVT （photovoltaic thermal）, which together will generate electricity and heat. This energy depends on the input that is to say the energy of solar radiation, temperature and speed wind and output which is the operating temperature of the system. This production also depends on the mode of heat removal. The authors present in this article; a study by a numerical simulation of the thermal behavior of a prototype hybrid sensor through the development of an energy balance that involves heat exchange between the different components of the hybrid sensor, and it will allow us to study the influence of internal and external parameters on the temperature variation in the different layers of the prototype PV/T studied.