Environmental impact factors

  • 文章类型: Journal Article
    我们提出了一个增强的地板场模型(FFM)来分析疏散过程中具有不同属性比例的人群的行为特征。此模型通过动态地板场(DFF)和静态地板场(SFF)控制行人的移动。DFF考虑了个人因素,如性别,熟悉环境,以及疏散人员的社会关系,影响安全疏散。同时,SFF包含了环境因素的影响,如障碍,退出,和指导作用。随后,采用体育中心疏散方案应用和验证了这种改进的FFM.结果表明,增强的FFM准确地复制了疏散人员的非对称行为和排队,当疏散人数随时间波动时,与其他模型很好地保持一致。在没有指导的情况下,熟悉环境和性别都是影响部分疏散的主要因素。此外,行人的性别显著影响整体疏散。值得注意的是,与撤离人员可获得的现有环境信息相比,实施指导以增强行人对环境的熟悉程度,从而提高了疏散效率。FFM模型和这些发现可能有助于模拟人员疏散和制定拥挤地区的应急管理策略。
    We propose an enhanced floor field model (FFM) to analyze the behavioral characteristics of crowds with varying attributes proportions during evacuation. This model governs pedestrian movement through the Dynamic Floor Field (DFF) and the Static Floor Field (SFF). The DFF takes into account individual factors such as the gender, familiarity with the environment, and social relationships of evacuees, which influence safe evacuation. Concurrently, the SFF encapsulates the impact of environmental factors like obstacles, exits, and guidance effects. Subsequently, this refined FFM was applied and validated using a sports center evacuation scenario. The results demonstrated that the enhanced FFM accurately replicated evacuees\' asymmetric behavior and queuing, and aligned well with other models when the number of evacuees fluctuated over time. In the absence of guidance, both environmental familiarity and gender emerged as primary factors influencing partial evacuation. Additionally, the gender of pedestrians significantly affected the overall evacuation. Notably, compared to pre-existing environmental information available to evacuees, the implementation of guidance to augment pedestrians\' environmental familiarity resulted in a more efficient evacuation. The FFM model and these findings could be instrumental in simulating personnel evacuation and formulating emergency management strategies in crowded areas.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

       PDF(Pubmed)

  • 文章类型: Journal Article
    随着全球人口增长和气候变化,粮食安全和全球变暖已成为农业发展的两大挑战。地膜覆盖(PM)长期以来一直用于提高雨养农业系统的产量,但很少有研究关注长期和区域尺度上覆盖雨养马铃薯的土壤气体排放。本研究将田间数据与反硝化分解(DNDC)模型相结合,以评估PM对马铃薯产量的影响,中国雨养农业系统中的温室气体(GHG)和氨(NH3)排放。我们发现PM使马铃薯产量增加了39.7%(1505kgha-1),二氧化碳(CO2)排放量减少15.4%(123kgCO2eqha-1),一氧化二氮(N2O)排放量减少47.8%(1016千克二氧化碳当量ha-1),全球变暖潜能值(GWP)增加38.9%(1030千克二氧化碳当量ha-1),而NH3挥发减少了33.9%(8.4千克NH3ha-1),甲烷(CH4)排放量与CK相比变化不大。具体来说,华南(SC)PM后的产量显着增加,华北(NC),和中国西北地区(NWC),增加66.1%(2429千克公顷-1),44.1%(1173千克公顷-1),与CK相比,占43.6%(956千克公顷-1),分别。PM下GWP和温室气体排放强度(GHGI)的增加在中国东北地区(NEC)和NWC地区更为明显,GWP分别增加了57.1%和60.2%,GHGI的16.9%和10.3%。而在长江中下游(MLYR)和SC,PM使GHGI下降了10.2%和31.1%,分别。PM显著减少了所有地区的NH3排放,这些减少在中国西南地区(SWC)最为显著,SCandMLYR,占41%,38.0%,比CK低38.0%,分别。此外,气候和大气变量是温室气体和NH3排放的主要贡献者。总之,在MLYR和SC地区推广PM的使用是适当的,因为能够增加产量,同时减少环境影响(降低GHGI和NH3排放)。研究结果为PM马铃薯的可持续农业生产提供了理论依据。
    With global population growth and climate change, food security and global warming have emerged as two major challenges to agricultural development. Plastic film mulching (PM) has long been used to improve yields in rain-fed agricultural systems, but few studies have focused on soil gas emissions from mulched rainfed potatoes on a long-term and regional scale. This study integrated field data with the Denitrification-Decomposition (DNDC) model to evaluate the impacts of PM on potato yields, greenhouse gas (GHG) and ammonia (NH3) emissions in rainfed agricultural systems in China. We found that PM increased potato yield by 39.7 % (1505 kg ha-1), carbon dioxide (CO2) emissions by 15.4 % (123 kg CO2 eq ha-1), nitrous oxide (N2O) emissions by 47.8 % (1016 kg CO2 eq ha-1), and global warming potential (GWP) by 38.9 % (1030 kg CO2 eq ha-1), while NH3 volatilization decreased by 33.9 % (8.4 kg NH3 ha-1), and methane (CH4) emissions were little changed compared to CK. Specifically, the yield after PM significantly increased in South China (SC), North China (NC), and Northwest China (NWC), with increases of 66.1 % (2429 kg ha-1), 44.1 % (1173 kg ha-1), and 43.6 % (956 kg ha-1) compared to CK, respectively. The increase in GWP and greenhouse gas emission intensity (GHGI) under PM was more pronounced in the Northeast China (NEC) and NWC regions, with respective increases of 57.1 % and 60.2 % in GWP, 16.9 % and 10.3 % in GHGI. While in the Middle and Lower reaches of the Yangtze River (MLYR) and SC, PM decreased GHGI with 10.2 % and 31.1 %, respectively. PM significantly reduced NH3 emissions in all regions and these reductions were most significant in Southwest China (SWC), SCand MLYR, which were 41 %, 38.0 %, and 38.0 % lower than CK, respectively. In addition, climatic and edaphic variables were the main contributors to GHG and NH3 emissions. In conclusion, it is appropriate to promote the use of PM in the MLYR and SC regions, because of the ability to increase yields while reducing environmental impacts (lower GHGI and NH3 emissions). The findings provide a theoretical basis for sustainable agricultural production of PM potatoes.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    在这项研究中,海南岛三大河流49个抗生素抗性基因(ARGs)和两个整合酶基因(intl1、intl2)的发生与分布,中国,于2021年7月进行了调查,并探讨了目标基因在三条河流中的空间分布以及区域特征和环境因子等潜在影响因素。结果表明,在水体和沉积物中共检测到46个ARGs和2个整合酶基因,ARGs的绝对丰度范围为1.16×103至2.97×107拷贝/L和3.34×103-1.55×107拷贝/g。大环内酯类的ARGs,氨基糖苷类,磺胺类药物是本研究的主要ARGs类型。aadA2,tete,ermF,tetX,aac(6\')-Ib,tetW,qnrS基因是三条河流水体和沉积物中的主要ARGs。ARGs的相对丰度在中游和下游显示较高的丰度,在上游和河口显示较低的丰度。在进行相关分析后,发现在三个主要河流的水中检测到的ARGs之间存在显着正相关。然而,在沉积物中,tetC与tetQ呈负相关,macB与ermF和ereA呈负相关(p<0.05),其余ARGs呈正相关。具体来说,tetQ与tetC之间无显著正相关,macB和ereA,和沉积物中的ermF。在研究的九个环境因素中,发现pH是与水生环境中ARGs发生相关的主要因素,但它也仅与9种ARGs显著相关。在检测到的重金属中,在三条主要河流的水体中,只有Cd和Zn与两种ARGs表现出显著的相关性。结果表明,三大河流的ARGs污染处于起步阶段,检测丰度低,环境因素的影响很小,ARG之间的相互作用似乎是主要的驱动力。本研究为进一步了解热带海岛环境中ARGs的发生及其影响因素提供了科学依据。为后续管理奠定基础。
    In this study, the occurrence and distribution of 49 antibiotic resistance genes (ARGs) and two integrase genes (intl1, intl2) in three major rivers of Hainan Island, China, were investigated in July 2021, and to explore the spatial distribution of the target genes in the three rivers with the potential influencing factors such as regional characteristics and environmental factors. The results showed that a total of 46 ARGs and two integrase genes were detected in water and sediment, and the absolute abundance of ARGs ranged from 1.16 × 103 to 2.97 × 107 copies/L and 3.34 × 103-1.55 × 107 copies/g. ARGs of macrolides, aminoglycosides, and sulfonamides were this study\'s main types of ARGs. The aadA2, tetE, ermF, tetX, aac(6\')-Ib, tetW, and qnrS genes are predominant ARGs in the water and sediment of the three rivers. The relative abundance of ARGs shows higher abundance in the midstream and downstream and lower abundance in the upstream and estuarine. After conducting a correlation analysis, it was found that there was a significant positive correlation between the ARGs detected in the water of the three main rivers. However, in sediment, tetC was negatively correlated with tetQ, macB was negatively correlated with ermF and ereA (p < 0.05), while the remaining ARGs showed positive correlations. Specifically, there was no significant positive correlation between tetQ and tetC, macB and ereA, and ermF in the sediments. Among the nine environmental factors studied, pH was found to be the main factor associated with the occurrence of ARGs in the aquatic environment, but it was also significantly associated with only nine ARGs. Among the detected heavy metals, only Cd and Zn showed significant correlations with the two ARGs in the water bodies of the three main rivers. It indicated that the pollution of ARGs in the three major rivers was in the initial stage, the detection abundance was low, the influence of environmental factors was small, and the interaction between ARGs seemed to be the main driving force. This study provides a scientific basis for further understanding the occurrence of ARGs and their influencing factors in a tropical island environment, and lays a foundation for subsequent management.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    当微悬臂的自由端被遗传探针修饰时,该传感器可用于更广泛的应用,例如化学分析,生物测试,药物筛选,和环境监测。在本文中,为了阐明具有遗传探针修饰的微悬臂梁传感器的制备和检测过程,核心程序,如探针固定,互补杂交,以及信号提取和处理,进行组合和比较。然后,揭示微悬臂梁的检测机理和分析,检测结果的影响因素,理论研究,包括偏转原理,检测模型的建立和验证,以及环境影响因素进行了总结。接下来,为了展示基因探针修饰传感器的应用结果,基于检测目标的分类,核酸以外的其他物质的应用情况,病毒,细菌和细胞不被引入。最后,通过列举遗传探针修饰的微悬臂梁与微流控芯片结合的应用结果,展望了该技术未来的发展方向。希望这篇综述将有助于遗传探针修饰的微悬臂梁的未来设计,随着对敏感机制的进一步探索,优化设计和加工方法,扩大应用领域,并促进实际应用。
    When the free end of a microcantilever is modified by a genetic probe, this sensor can be used for a wider range of applications, such as for chemical analysis, biological testing, pharmaceutical screening, and environmental monitoring. In this paper, to clarify the preparation and detection process of a microcantilever sensor with genetic probe modification, the core procedures, such as probe immobilization, complementary hybridization, and signal extraction and processing, are combined and compared. Then, to reveal the microcantilever\'s detection mechanism and analysis, the influencing factors of testing results, the theoretical research, including the deflection principle, the establishment and verification of a detection model, as well as environmental influencing factors are summarized. Next, to demonstrate the application results of the genetic-probe-modified sensors, based on the classification of detection targets, the application status of other substances except nucleic acid, virus, bacteria and cells is not introduced. Finally, by enumerating the application results of a genetic-probe-modified microcantilever combined with a microfluidic chip, the future development direction of this technology is surveyed. It is hoped that this review will contribute to the future design of a genetic-probe-modified microcantilever, with further exploration of the sensitive mechanism, optimization of the design and processing methods, expansion of the application fields, and promotion of practical application.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

  • 文章类型: Journal Article
    微生物的应用是一种有效的,经济,和生态修复黑臭河流的方法。在这项研究中,在修复过程中,通过典型黑臭溪流的驯化复杂微生物监测了田间处理效果和微生物群落变化。治疗后,总磷和氨含量分别下降了74.0%和76.3%,溶解氧浓度从1.65mg/L增加到4.90mg/L,表明适应的复合微生物的有效性。拟杆菌比例显著下降48.1%,厚壁菌比例平均上升2.23%,微生物多样性指数先增加后趋于均匀。冗余分析表明,pH值,溶解氧,和氧化还原电位共同决定了微生物群落的组成(p<0.05)。这些发现表明,驯化的复合微生物可以有效地修复黑色气味。
    Microbial application is an efficient, economical, and ecofriendly method for remediating black-odorous rivers. In this study, the field treatment effect and microbial community changes were monitored during remediation by the acclimated complex microorganisms of a typical black-odorous stream. After the treatment, the total phosphorus and ammonia contents decreased by 74.0% and 76.3% and the concentrations of dissolved oxygen increased from 1.65 to 4.90 mg/L, indicating the effectiveness of the acclimated composite microorganisms. The proportion of Bacteroidetes decreased significantly by 48.1% and that of Firmicutes increased by 2.23% on average, and the microbial diversity index first increased and then tended to be uniform. Redundancy analysis demonstrated that the pH, dissolved oxygen, and oxidation-reduction potential together determined the composition of the microbial communities (p < 0.05). These findings showed that the acclimated composite microorganisms can effectively remediate the black odor.
    导出

    更多引用

    收藏

    翻译标题摘要

    我要上传

    求助全文

公众号