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121.
根据KR搅拌式铁水脱硫的工艺流程、设备及操作特点,对铁水脱硫自动控制系统软件进行编制,并对软件调试中出现的问题加以解决,确保系统安全、可靠、高效运行。  相似文献   
122.
介绍了应用挪威DNV船级社SESAM软件进行海上平台导管架结构的评估方法和程序,并得出评估结论.  相似文献   
123.
气溶胶采样头在无人机上安装位置的模拟   总被引:1,自引:0,他引:1       下载免费PDF全文
利用流体力学软件CFD对固定翼无人机在海拔1000m高处以30m/s速度飞行时采样头的最佳安装位置进行了模拟.首先利用ICEM CFD前处理软件对无人机模型进行了网格划分;然后利用FLUENT软件及其中的DPM模型先后对气相(连续相)和颗粒相(离散相)分别进行了数值模拟,最后用DPM模型模拟了从速度入口方向以30m/s速度释放粒径为1,2.5,10μm的颗粒物,由颗粒物的轨迹图得到了颗粒物在机身周围的阴影区和密集区厚度.得到主要结论如下:对于本研究中的无人机,在海拔1000m高处,采集PM1,PM2.5,PM10时的气溶胶采样头的最佳安装位置为机身下部距机头距离约42~75cm,采样头探头距机身下部壁面的距离分别应大于4,4,4.3cm,但不超过26cm(机身下部距地面距离).  相似文献   
124.
The prosperity and well-being of human societies relies on healthy ecosystems and the services they provide. However, the biodiversity crisis is undermining ecosystems services and functions. Vultures are among the most imperiled taxonomic groups on Earth, yet they have a fundamental ecosystem function. These obligate scavengers rapidly consume large amounts of carrion and human waste, a service that may aid in both disease prevention and control of mammalian scavengers, including feral dogs, which in turn threaten humans. We combined information about the distribution of all 15 vulture species found in Europe, Asia, and Africa with their threats and used detailed expert knowledge on threat intensity to prioritize critical areas for conserving vultures in Africa and Eurasia. Threats we identified included poisoning, mortality due to collision with wind energy infrastructures, and other anthropogenic activities related to human land use and influence. Areas important for vulture conservation were concentrated in southern and eastern Africa, South Asia, and the Iberian Peninsula, and over 80% of these areas were unprotected. Some vulture species required larger areas for protection than others. Finally, countries that had the largest share of all identified important priority areas for vulture conservation were those with the largest expenditures related to rabies burden (e.g., India, China, and Myanmar). Vulture populations have declined markedly in most of these countries. Restoring healthy vulture populations through targeted actions in the priority areas we identified may help restore the ecosystem services vultures provide, including sanitation and potentially prevention of diseases, such as rabies, a heavy burden afflicting fragile societies. Our findings may guide stakeholders to prioritize actions where they are needed most in order to achieve international goals for biodiversity conservation and sustainable development.  相似文献   
125.
The outcome of analyses that prioritize locations for conservation on the basis of distributions of species, land cover, or other elements is influenced by the spatial resolution of data used in the analyses. We explored the influence of data resolution on prioritization of Finnish forests with Zonation, a software program that ranks the priority of cells in a landscape for conservation. We used data on the distribution of different forest types that were aggregated to nine different resolutions ranging from 0.1 × 0.1 km to 25.6 × 25.6 km. We analyzed data at each resolution with two variants of Zonation that had different criteria for prioritization, with and without accounting for connectivity and with and without adjustment for the effect on the analysis of edges between areas at the project boundary and adjacent areas for which data do not exist. Spatial overlap of the 10% of cells ranked most highly when data were analyzed at different resolutions varied approximately from 15% to 60% and was greatest among analyses with similar resolutions. Inclusion of connectivity or edge adjustment changed the location of areas that were prioritized for conservation. Even though different locations received high priority for conservation in analyses with and without accounting for connectivity, accounting for connectivity did not reduce the representation of different forest types. Inclusion of connectivity influenced most the outcome of fine-resolution analyses because the connectivity extents that we based on dispersal distances of typical forest species were small. When we kept the area set aside for conservation constant, representation of the forest types increased as resolution increased. We do not think it is necessary to avoid use of high-resolution data in spatial conservation prioritization. Our results show that large extent, fine-resolution analyses are computationally feasible, and we suggest they can give more flexibility to implementation of well-connected reserve networks.  相似文献   
126.
本文系统地介绍了有关水环境主要的形态模型、表面络合模型、点源和非点源污染模型及其计算机模型软件,并着重阐述了生态模型的发展及应用等  相似文献   
127.
128.
基于大涡模拟的旋风分离器内流场数值模拟研究   总被引:1,自引:0,他引:1  
为了研究旋风分离器内流场的运动状况,借助Fluent软件,采用大涡模拟,基于曲线坐标系的SIMPLEC算法,对切向入口的Stairmand旋风分离器内流场进行了三维数值模拟研究。数值结果表明,大涡模拟适合于三维强旋流的流场模拟,分离器内部的流动空间可分为内、外2个流动区域,在不同的流动区域中,气体压力、速度场的分布有较大的差异。而且压力分布与速度分布不是绝对的轴对称分布。数值模拟结果对其设计优化研究有一定的应用价值。  相似文献   
129.
本文为基于GIS的公共安全应急体系中各灾害模拟和后果分析模块,研究并建立了一个从概念到实现的统一可扩展的接口,使公共安全灾害模拟和后果分析领域的研究成果能被广泛共享,并且更容易建立一个整合各类已有研究成果的软件体系.并且,本文结合"国家十五重点科技攻关(滚动)项目:合肥市公共安全应急示范试点研究"项目给出了原型实现.  相似文献   
130.
基于OpenFOAM的城市街区毒气扩散模拟   总被引:1,自引:0,他引:1       下载免费PDF全文
为了对毒气扩散过程进行及时、有效的模拟,将开源计算流体动力学软件OpenFOAM与PISO算法(pressure implicit with splitting of operators,压力隐式算子分割算法)相结合,进行城市街区毒气扩散模拟研究. 将SIMPLE(semi-implicit method for pressure linked equations,压力耦合方程组的半隐式算法)与PISO算法进行了对比,指出以PISO算法为基础的数值模拟在城市街区这类大范围毒气扩散模拟中具有容差性强、计算较为稳定等优点. 以福州大学怡山校区为扩散区虚拟地理环境,选用氯气为假定毒气,利用OpenFOAM对氯气的扩散传播过程进行了模拟, 并与商用软件FLUENT在相同条件下的ρ(Cl2)模拟结果进行了对比. 结果表明,结合PISO算法的OpenFOAM能够较好地完成复杂虚拟地理环境下的毒气扩散过程模拟,其ρ(Cl2)模拟结果与FLUENT模拟结果的平均偏差小于5%,但在计算效率上却提高了41.89%.   相似文献   
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