考虑从众阈值和主体特征的人群疏散元胞自动机模型*

为研究从众行为对人群疏散效率的影响,建立考虑从众阈值和主体特征的人群疏散元胞自动机模型,通过引入从众阈值反映人群中不同个体的从众选择程度,耦合每个主体不同特征属性、不同人员认知能力导致的疏散从众选择差异,利用元胞自动机模拟人群运动状态及动态演化过程,探究从众行为对人群疏散过程的作用规律。结果表明:人群疏散中选择从众行为的人员比例与整体疏散效率存在对应关系,本模型原始工况下,当人群中约60%的人员做出从众选择时,疏散效率相对最优。     

Carbon dioxide emissions,urbanization level,and industrial structure: empirical evidence from North China

Environmental Science and Pollution Research - This paper aims to examine the nexus among carbon dioxide (CO2) emissions, urbanization level and industrial structure in North China over the period...     

絮团尺寸对全尾砂絮凝沉降效果的影响研究*

为研究絮团尺寸对全尾砂絮凝沉降效果的影响,采用正交实验和图像颗粒分析相结合的方法,进行多因素耦合条件下全尾砂絮凝沉降实验,基于Giddings函数的沉降速度模型,提出全尾砂絮团图像颗粒分析,探究各时段絮团尺寸的变化规律。研究结果表明:当尾砂浆浓度为15%、絮凝剂溶液浓度为0.25%、絮凝剂单耗为20 g/t,pH值为10时,絮凝沉降效果最佳,最大沉降速度达13.12 mm/s;随着沉降时间的增加,沉降速度随絮团直径、长径比减小而减小,随圆形度增大而减小。研究结果可为实际生产中控制全尾砂絮凝沉降参数、提高沉降速率提供参考。     

Effects of La,Ce on nitrogen removal in sequencing batch reactor

Batch experiments were conducted to study the short-term biological effects of rare earth ions (La³⁺, Ce³⁺) and their mixture on the nitrogen removal in a sequencing batch reactor (SBR). The data showed that higher NH⁺₄―N removal rate, total inorganic nitrogen removal efficiency, and denitrification efficiency were achieved at lower concentrations of rare earth elements (REEs) (<1mg/L). In the first hour of the aeration stage of SBR, the presence of REEs increased the total inorganic nitrogen removal efficiency and NH⁺₄―N removal efficiency by 15.7% and 10%―15%, respectively. When the concentrations of REEs were higher than 1mg/L, the total inorganic nitrogen removal efficiency decreased, and nitrate was found to accumulate in the effluent. When the concentrations of REEs was up to 50.0mg/L, the total inorganic nitrogen removal efficiency was less than 30% of the control efficiency with a high level of nitrate. Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.     

自适应综合型馈线自动化及其测试

针对配网线路开关类型、保护时限配合等不同的自动化应用条件,分析了自适应综合型馈线自动化在生产现场常用的4种配置方法和每种配置方法的优缺点。采用基于无线组网的二次信号混合注入法,解决了被测设备间距远、测试仪器数量有限等问题,对宁夏2条投用自适应综合型馈线自动化功能的10 kV配网线路开展馈线自动化测试,结果证明该方法可对线路故障处理逻辑进行验证,为该功能的进一步实用化提供了参考。     

Cost,environmental impact,and resilience of renewable energy under a changing climate: a review

Energy derived from fossil fuels contributes significantly to global climate change, accounting for more than 75% of global greenhouse gas emissions and approximately 90% of all carbon dioxide emissions. Alternative energy from renewable sources must be utilized to decarbonize the energy sector. However, the adverse effects of climate change, such as increasing temperatures, extreme winds, rising sea levels, and decreased precipitation, may impact renewable energies. Here we review renewable energies with a focus on costs, the impact of climate on renewable energies, the impact of renewable energies on the environment, economy, and on decarbonization in different countries. We focus on solar, wind, biomass, hydropower, and geothermal energy. We observe that the price of solar photovoltaic energy has declined from $0.417 in 2010 to $0.048/kilowatt-hour in 2021. Similarly, prices have declined by 68% for onshore wind, 60% for offshore wind, 68% for concentrated solar power, and 14% for biomass energy. Wind energy and hydropower production could decrease by as much as 40% in some regions due to climate change, whereas solar energy appears the least impacted energy source. Climate change can also modify biomass productivity, growth, chemical composition, and soil microbial communities. Hydroelectric power plants are the most damaging to the environment; and solar photovoltaics must be carefully installed to reduce their impact. Wind turbines and biomass power plants have a minimal environmental impact; therefore, they should be implemented extensively. Renewable energy sources could decarbonize 90% of the electricity industry by 2050, drastically reducing carbon emissions, and contributing to climate change mitigation. By establishing the zero carbon emission decarbonization concept, the future of renewable energy is promising, with the potential to replace fossil fuel-derived energy and limit global temperature rise to 1.5 °C by 2050.

     

水解-好氧生物法处理城市污水试验研究

采用水解 好氧工艺的原理 ,设计了将污水与污泥处理合二为一的高效组合水解池 三相生物流化床流程 ,在广州经济技术开发区进行了处理量为 1 0 0L/h的城市污水处理试验。试验结果表明 :在平均进水CODCr为 4 92 3mg/L ,BOD5为 2 4 0 9mg/L ,SS为 5 5 2 3mg/L ,NH4 N为 1 8 8mg/L ,TP为 2 0mg/L条件下 ,平均出水CODCr为 4 7 3mg/L ,BOD5为 2 2 lmg/L ,SS为 1 3 9mg/L ,NH4 N为 5 2mg/L ,TP为 1 4mg/L ,并进行了该工艺中污泥循环的初步分析 ,为该工艺处理城市污水工业化提供了技术参考。     

新型人工浮岛流场数值模拟与结构优化分析

近期提出的新型人工浮岛是通过两种不同透水能力基质材料的填充在系统内部形成2个不同水流与溶解氧浓度区域,两区域的过流能力及两者之间水流交换量对系统脱氮除磷效果具有较大的影响。为实现这一新型人工浮岛基质结构设计参数的优化,进一步提高净化能力,应用数值模拟方法对不同结构条件下流场进行了模拟。模拟结果发现,影响两区域水流交换量及其过流能力的主要因素包括：基质材料的填充形状、填充深度及透水能力,其中“钟乳状”形态较“层状”填充形态人工浮岛具有更好的两区域间水流交换能力及过流能力,理论上具有更好的净化效果。根据模拟结果确定的设计参数构建小试试验系统进行对比试验研究,试验结果与数值模拟结论吻合。可见,采用数值模拟方法对人工浮岛内部水流状态进行模拟分析,能够为人工浮岛结构优化设计提供依据。     

北京地区的流场分析

本文利用测风站的资料分析了北京地区的流场。分析结果表明,北京地区流场大致具有四种类型:1.平行线型流场;2.辐合环流型流场;3.辐合线型流场;4.波状辐合线型流场。     

海洋微生物降解石油的研究

从青岛近岩海水中分离、筛选到73株细菌和10株真菌，并对其降解石油的能力进行了研究，结果表明，多数菌具有明显的降解石油的能力，部分菌株对短链烷烃正已烷和芳香烃萘具有不同程度的降解能力，其中，有3个菌株对石油的生物降解率分别高达58.35％、62.75％、71.06％。