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1.
为实现白洋淀芦苇的有效利用,以白洋淀淀区芦苇(白苇)为原料,以KOH、K2CO3为活化剂,综合考虑制备过程中的剂料比、浸渍时间、活化温度、活化时间等因素的影响,通过正交试验,以碘吸附值和亚甲蓝吸附值综合作为吸附性能高低的评价标准,进行活性炭制备方法研究。结果表明:在以KOH为活化剂、剂料比为4∶1、浸渍时间36 h、850℃下活化1 h的条件下,制备的芦苇基生物质活性炭碘吸附值最高,亚甲基蓝吸附值较高;以K2CO3为活化剂、剂料比为3∶1、浸渍时间12 h、900℃下活化2 h的条件下,制备的芦苇基生物质活性炭有最高的碘吸附值和对亚甲蓝具有良好的吸附性。制备的生物质活性炭碘吸附值均高于国家活性炭一级品标准(1 000 mg/g),具备一定的实用性。  相似文献   
2.
为从更微观角度分析人群疏散过程中疏散行为及路网设计对疏散效果的影响,基于腾龙芳烃(漳州)有限公司“4·6”爆炸着火重大事故,构建多智能体人群应急疏散模型,模拟人群中个体群组、惯性、就近、从众、信息传播的行为决策及相互交互影响。结果表明:群组行为会严重影响应急疏散效果,在疏散路网两端避难所附近会出现明显拥堵现象,在疏散路网设计和避难所选择时,应尽可能避免出现极端汇流路段或节点;在应急培训中,应告知群众减少群组行为。研究结果可为人群应急疏散提供借鉴。  相似文献   
3.
为研究工程项目系统中,操作者安全行为与管理者奖惩行为的相互博弈情况,确定操作者和管理者收益,提出博弈演化与收益分析方法。操作者代表系统实际使用者,行为包括安全和不安全行为;管理者代表系统管理者和所有者,行为包括奖励和惩罚行为。确定方法的基本参数;研究博弈演化过程的博弈逻辑关系,从悲观和乐观角度研究二者不同行为相互作用后的收益关系,给出操作者收益和管理者收益的逻辑表达式。结果表明:方法能得到博弈过程演化结果,同时能根据收益结果表达式判断博弈胜出方。  相似文献   
4.
•Bacterially-mediated coupled N and Fe processes examined in incubation experiments. •NO3 reduction was considerably inhibited as initial Fe/N ratio increased. •The maximum production of N2 occurred at an initial Fe/N molar ratio of 6. •Fe minerals produced at Fe/N ratios of 1–2 were mainly easily reducible oxides. The Fe/N ratio is an important control on nitrate-reducing Fe(II) oxidation processes that occur both in the aquatic environment and in wastewater treatment systems. The response of nitrate reduction, Fe oxidation, and mineral production to different initial Fe/N molar ratios in the presence of Paracoccus denitrificans was investigated in 132 h incubation experiments. A decrease in the nitrate reduction rate at 12 h occurred as the Fe/N ratio increased. Accumulated nitrite concentration at Fe/N ratios of 2–10 peaked at 12–84 h, and then decreased continuously to less than 0.1 mmol/L at the end of incubation. N2O emission was promoted by high Fe/N ratios. Maximum production of N2 occurred at a Fe/N ratio of 6, in parallel with the highest mole proportion of N2 resulting from the reduction of nitrate (81.2%). XRD analysis and sequential extraction demonstrated that the main Fe minerals obtained from Fe(II) oxidation were easily reducible oxides such as ferrihydrite (at Fe/N ratios of 1–2), and easily reducible oxides and reducible oxides (at Fe/N ratios of 3–10). The results suggest that Fe/N ratio potentially plays a critical role in regulating N2, N2O emissions and Fe mineral formation in nitrate-reducing Fe(II) oxidation processes.  相似文献   
5.
王自龙  蒋勇 《火灾科学》2021,30(1):54-62
化工园区中危险源众多,一旦发生事故很容易在整个园区内蔓延和发展。针对化工园区内储罐密集,容易引发连锁反应导致事故扩大的特点,利用FDS软件对储罐火灾场景进行数值模拟,根据储罐所受热辐射确定化工园区内储罐火灾最可能的事故发生序列,并引入基于设备失效前时间的机械设备故障概率模型对罐区内单个储罐的火灾风险进行研究,得到储罐区火灾多米诺效应的时空演变。以某储罐区火灾为例,对多米诺效应下的火灾场景进行推演,结果表明该方法可以准确地预测多米诺效应过程中储罐的火灾风险,为化工园区应急响应提供有效支持。  相似文献   
6.
为提高闸阀可靠度计算准确性,将模糊准则引入闸阀可靠性设计,将闸阀应力与阀体通径、内压之间隐式关系显式化,并基于神经网络构建地震工况下闸阀数学模型;利用蒙特卡洛法,计算闸阀在常规方法下的可靠度;利用正态型隶属函数描述闸阀强度的模糊性,计算闸阀在考虑模糊强度时的可靠度;对比强度的模糊性对可靠度计算结果的影响,分析不同隶属函数下的闸阀模糊可靠度。与传统随机可靠度计算方法相比,该方法对不确定性描述更合理,理论上对可靠度的计算更加准确。  相似文献   
7.
Sustainable use of natural resources would entail ensuring that derived economic benefits today do not undermine the welfare of generations to come. On this basis, this study examines the nexus between natural resource rents and carbon dioxide (CO2) emissions disaggregated into production and consumption-based (i.e., trade-adjusted) CO2 emissions for a selected panel of 45 developing and transition economies over the period 1995–2017. The empirical model also incorporates the impacts of population, affluence, and energy intensity. The results show that affluence increases production-based CO2 emissions by 1.407%, with the EKC's predicted inverted U-shaped curve only explaining consumption-based CO2 emissions. Economic reliance on natural resource rents and energy intensification contribute 0.022% and 0.766%, respectively, to CO2 emissions embedded in territorial production inventories and 0.035% and 0.583%, respectively, to CO2 emissions embedded in consumption inventories. The bootstrap non-causality test shows that historical data on each variable has significant predictive power for future CO2 emissions from both sources. The historical information about natural resource rents has significant predictive power over the future levels of affluence and energy intensity. Clearly, the results show that the environmental impact of natural resource rents is stronger when CO2 emissions are adjusted for trade and varies among the countries, with Bangladesh, Guinea, India, Malaysia, Mexico, Nigeria, Pakistan, Saudi Arabia, Vietnam, and Zimbabwe among the most affected countries. Overall, this study provides motivation for policies to keep the use of natural resources within sustainable limits.  相似文献   
8.
The iron and steel industry is not only an important foundation of the national economy, but also the largest source of industrial air pollution. Due to the current status of emissions in the iron and steel industry, ultra-low pollutant emission control technology has been researched and developed. Liquid-phase proportion control technology has been developed for magnesian fluxed pellets, and a blast furnace smelting demonstration project has been established to use a high proportion of fluxed pellets (80%) for the first time in China to realize source emission reduction of SO2 and NOx. Based on the characteristics of high NOx concentrations and the coexistence of multiple pollutants in coke oven flue gas, low-NOx combustion coupled with multi-pollutant cooperative control technology with activated carbon was developed to achieve efficient removal of multiple pollutants and resource utilization of sulfur. Based on the characteristics of co-existing multiple pollutants in pellet flue gas, selective non-catalytic reduction (SNCR) coupled with ozone oxidation and spray drying adsorption (SDA) was developed, which significantly reduces the operating cost of the system. In the light of the high humidity and high alkalinity in flue gas, filter materials with high humidity resistance and corrosion resistance were manufactured, and an integrated pre-charged bag dust collector device was developed, which realized ultra-low emission of fine particles and reduced filtration resistance and energy consumption in the system. Through source emission reduction, process control and end-treatment technologies, five demonstration projects were built, providing a full set of technical solutions for ultra-low emissions of dust, SO2, NOx, SO3, mercury and other pollutants, and offering technical support for the green development of the iron and steel industry.  相似文献   
9.
刘欣宇  卢江  孟璇  刘铮  宋鹏  李季  田光明 《环境科学》2023,44(8):4647-4654
收集整理1992年1月至2022年5月长江经济带地区长期定位施肥试验文献,提取并整合了其中农田土壤有机碳的资料.采用归一化处理和变化速率的分析方法,研究长期不同施肥措施下长江经济带地区农田土壤有机碳含量的总体变化,并比较3种耕作模式及不同土壤类型下土壤有机碳含量的变化差异,判断分析试验持续年限长短对土壤有机碳动态的影响.结果表明,在长期不同施肥措施下,我国长江经济带地区农田土壤有机碳含量整体呈上升趋势,无机氮肥磷肥配施(NP)、无机氮磷钾肥配施(NPK)、单独施用有机肥(O)和有机无机肥配施(NPKO)处理均能增加农田土壤的有机碳含量,其中以NPKO处理为最大,而单独施用无机氮肥(N)则会降低土壤有机碳含量.旱田、水田和水旱轮作农田土壤有机碳含量变化速率分别为0.22、 0.24和0.16g·(kg·a)-1,3种耕作模式在土壤固碳效果方面并无显著性差异.O和NPKO处理下所带来的有机碳相对快速增加效应在旱田土壤中的持续年限最高不超过28 a,而在水田及水旱轮作土壤中依然可以持续到28 a以上.在不同的土壤类型下,土壤有机碳含量的变化速率存在着一定的差异,平均有机...  相似文献   
10.
The nirS-type denitrifying bacterial community is the main drivers of the nitrogen loss process in drinking water reservoir ecosystems.The temporal patterns in nirS gene abundance and nirS-type denitrifying bacterial community harbored in aerobic water layers of drinking water reservoirs have not been studied well.In this study,quantitative polymerase chain reaction (qPCR) and Illumina Miseq sequencing were employed to explore the nirS gene abundance and denitrifying bacterial community structur...  相似文献   
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