1986—2015年青藏高原哈拉湖湖泊动态对气候变化的响应

湖泊是气候变化的敏感指示器,研究其动态变化对揭示全球气候变化具有重要意义。以哈拉湖流域为研究区,基于3S技术提取流域内湖泊面积、形状等信息,揭示近30年哈拉湖流域湖泊动态变化特征,并探讨其对气候变化的响应。结果表明：1986—2015年间,哈拉湖流域湖泊面积变化呈“V”型,其动态变化大致可分为两个阶段：波动下降阶段（1986—2001年）和波动上升阶段（2001—2015年）。其中1986—2001年湖泊面积由593.68 km²减少到584.83 km²（减少8.85 km²）;2001—2015年由584.83 km²增加到614.31 km²（增加29.48 km²）。对湖泊面积变化量与冰川面积变化量及同期遥感数据阶段各气候要素相关分析发现,湖泊面积变化量与阶段降水量呈正相关,且相关显著性水平在0.01以上,进而降水量是湖泊动态变化的主导因素。     

Recent application of Computational Fluid Dynamics (CFD) in process safety and loss prevention: A review

In recent years, significant progress has been made to ensure that process industries are among the safest workplaces in the world. However, with the increasing complexity of existing technologies and new problems brought about by emerging technologies, a strong need still exists to study the fundamentals of process safety and predict possible scenarios. This is attained by conducting the corresponding consequence modeling and risk assessments. As a result of the continuous advancement of Computational Fluid Dynamics (CFD) tools and exponentially increased computation capabilities along with better understandings of the underlying physics, CFD simulations have been applied widely in the areas of process safety and loss prevention to gain new insights, improve existing models, and assess new hazardous scenarios. In this review, 126 papers from 2010 to 2020 have been included in order to systematically categorize and summarize recent applications of CFD for fires, explosions, dispersions of flammable and toxic materials from accidental releases, incident investigations and reconstructions, and other areas of process safety. The advantages of CFD modeling are discussed and the future of CFD applications in this research area is outlined.     

Book reviews and notices

The aim of sustainable development is to balance social, economic, and environmental needs. In order to justify the decisions they make, stakeholders must quantify the different impacts found in the operations and developments of companies and/or projects throughout their life cycle. However, as some areas are subjective in nature, the quantification process of the different impacts and the assessment of sustainable development performance become arduous tasks of development, validation, and application of scientific and empirical methods with the intrinsic objective of finding an agreement among the involved parties (i.e., stakeholders). Several environmental and sustainability assessment tools, instruments, processes, and methodologies have been developed; rating systems stand out and have gained attention and credibility, as demonstrated by the vast number of certified projects around the world and the widely-known usefulness and advantages of their application. The Wa-Pa-Su project sustainability rating system presents an integrated approach to sustainability assessment by integrating three distinctive areas of knowledge: (1) sustainable development theory and fundamentals supports the ultimate goal of the rating system, which is to contribute to sustainability, with the aim of finding a path to balance social, economic, and environmental needs; (2) continual performance improvement becomes essential due to the duration of the projects, as it is critical to allow organizations or projects to improve performance over time; and (3) multi-criteria decision analysis assists with the assessment process through stakeholder engagement and participation, and the design and implementation of a criteria weighting system.     

建筑火灾烟气中CO迁移规律的FDS模拟

以T型"侧间-走廊"典型建筑火灾为模拟对象,分析烟气在走廊中的水平和垂直流动特征,并对火源房门高低、走廊端头启闭和多房门启闭等场景使用火灾模拟软件(FDS)进行了模拟和远距离房间CO浓度的迁移规律的分析。结果表明:烟气从火源房间经拱腹溢出在走廊中形成受限空间的顶棚射流;门檐高度决定了CO能够在走廊中的迁移量;烟气在走廊远距离封闭端头形成上部的热烟气层,中部回流层和下层的补气层;其中中部烟气回流层的高低、流速和CO浓度是影响临近非火源房间CO浓度的重要因素。走廊启闭和多房门火灾场景的模拟结果也进一步证明了CO的迁移规律。     

流域污染负荷水质响应的时空数值源解析方法研究

以目前广泛应用的环境流体动力学模型EFDC为平台,构建时空数值源解析方法,理论上可以得到任意时刻任意空间点位污染物的来源构成.其原理是考虑水质模型的微分方程,直接对每个污染负荷再微分,从而将原来1个微分方程变为关于每个污染源的微分方程组,然后联立以EFDC的水动力模型求解,得到每个源对每个时空点的贡献.概化的抚仙湖模型作为数值案例用以验证方法.时空数值源解析的结果与传统扰动方法的结果几乎重合,验证了时空数值源解析方法的正确性.另一方面,数值案例中存在34个独立的污染源,扰动法则需要35次模拟,而时空数值源解析方法的结果通过单次模拟就可得到,说明时空数值源解析方法具有明显的计算效率优势.而通过对结果的进一步分析可以发现,时空数值源解析方法可以提供更精确的源贡献的动态描述.     

Changes in the Carabid Fauna (Coleoptera, Carabidae) of Meadow Steppes during the Past Decades

Basic trends in the structural dynamics of the meadow-steppe carabid fauna over the period from 1970 to 1997 have been analyzed. Data on changes in the abundance and composition of dominant species are reported. Transformation of carabidocenoses is mainly accounted for by an increased humidity of the climate and the related mesophytization of forest–steppe ecosystems.     

旋转式滗水器设计的动力学计算

在对旋转式滗水器进行了水力学和运动学计算的基础上，对旋转式滗水器进行了动力学计算，给出了其动力学计算公式，与水力学和运动学计算公式一起，共同给出了旋转式滗水器完整的设计计算公式。     

Removal of congo red and basic violet 1 by chir pine (Pinus roxburghii) sawdust,a saw mill waste: batch and column studies

The efficiency of chir pine sawdust (CPS) for adsorptive removal of the dyes, congo red (CR) and basic violet 1 (BV), from aqueous solution was evaluated using batch and column studies. The equilibrium was attained in 60 min for CR and 45 min for BV. The adsorption of BV obeyed the Langmuir isotherm model while the Freundlich isotherm fitted the equilibrium data of CR adsorption. The Langmuir monolayer adsorption capacities (Q_o) of CPS for BV and CR were 11.3 and 5.8 g kg^?1, respectively. The kinetic data for CR were best fitted to the Lagergren pseudo-first-order model and for BV to the pseudo-second-order model. The intra-particle diffusion was found to be the rate-controlling step for CR adsorption, while the adsorption kinetics of BV were controlled by both intra-particle and liquid-film diffusion. The thermodynamic parameters indicated that the adsorption process was spontaneous and endothermic in nature. The adsorption activation energy (E_a) for CR (124 kJ mol^?1) implied chemical adsorption while that for BV (5.4 kJ mol^?1) indicated physical adsorption. An increase in the Thomas model constant (K_Th) with increasing flow indicated that for both dyes the mass transport resistance decreased during adsorption. Thus, CPS may be an efficient low-cost adsorbent for decolorization of dye-containing wastewaters.