检索结果-内蒙古大学图书馆

SSRN 2023年

作者： Guo, Jiaxun Wang, Xu Cao, Xiaofeng Qi, Weixiao Peng, Jianfeng Liu, Huijuan Qu, Jiuhui Center for Water and Ecology State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China

In lake environments, seasonal changes or extreme droughts can cause exposure of the lake sediment, leading to soil formation. Although previous studies have explored how environmental changes influence microbial functioning in the water-level-fluctuating zone, few studies have investigated how wholescale habitat changes affect microbial composition, community stability and ecological functions in lake environments. To address this, our study therefore investigated the effects of sediment-to-soil conversion on microbial composition, community stability and subsequent ecological functioning in Poyang Lake, China. Our results revealed that, during sediment-to-soil conversion, the number of total and unique operational taxonomic units (OTUs) decreased by 40% and 55%, respectively. Moreover, sediment-to-soil conversion decreased the microbial network’s connection and robustness but significantly increased its stability, through increased negative cohesion and modularity. In sediment and soil, the abundance of dominant bacteria, and bacterial diversity strongly affected microbial community stability, although this was not true in water. Furthermore, the specific microbial phyla and genes involved in the nitrogen cycle changed significantly after sediment-to-soil conversion, with the major nitrogen-cycling processes changing from denitrification and dissimilatory nitrate reduction to ammonium (DNRA) to nitrification and assimilatory nitrate reduction to ammonia (ANRA). Moreover, we observed a compensation mechanism in the functional genes related to the nitrogen cycle, such that all the nitrogen cycle’s processes were maintained after sediment-to-soil conversion. The oxidation-reduction potential strongly affected network complexity, microbial stability, and nitrogen cycling in the sediment and soil. These results are important for understanding the responses of microorganisms to climate change and extreme drought. © 2023, The Authors. All rights reserved.

关键词： Soils

来源：评论

学校读者我要写书评

暂无评论

Distribution, Sources, And Potential Health Risks of Fluoride, Total Iodine, and Nitrate In Rural Drinking Water Sources of North and East China

SSRN

引用

SSRN 2023年

作者： Huang, Shier Guo, Jiaxun Xie, Yu Bian, Rui Wang, Nan Qi, Weixiao Liu, Huijuan Center for Water and Ecology State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China

Small-scale water sources serving villages and towns are the main source of drinking water in rural areas. Compared to centralized water sources, rural water sources are less frequently monitored for water quality and have poor follow-up treatment facilities, making them vulnerable to drinking health risks. To reveal the hydrochemistry characteristics, contaminants sources, and health risks in rural water sources, 189 water samples were collected from lakes and reservoirs, rivers, and groundwater in North and East China for major ions, nutrient salts, microelements, and stable isotope analysis. Statistical analysis and isotopic tracing were performed, as well as an assessment of the risk to human health. The exceeding threshold rates for fluoride (F-) and nitrate (NO3-) in surface water were 1.8% and 9.1% respectively. For groundwater, the exceeding threshold rates were 20.9% for F-, 15.7% for total iodine (TI), and 4.5% for NO3-. F- and TI were mainly derived from the leaching of fluoride- and iodine-containing minerals by cationic exchange, and NO3- is mainly derived from nitrogen in the soil (31.7-43.9%), the use of ammonia fertilizers, and the discharge of manure and sewage. Nitrogen in the soil can be an important source of nitrate in the aquatic environment, and soils with higher clay content have a greater retention effect on the migration of nitrogen pollutants from the surface to the groundwater. F- in water sources contributes most to human health risks for drinking, followed by NO3- and TI, and a higher proportion of groundwater sources has health risks for drinking than that surface water sources. The authorities should give high priority to optimizing the choice of water sources and technology for water treatment, and rational measures should be taken to protect water sources from the threats of anthropogenic pollution. © 2023, The Authors. All rights reserved.

关键词： Risk assessment

来源：评论

学校读者我要写书评

暂无评论

Dissecting the contributions of organic nitrogen aerosols to global atmospheric nitrogen deposition and implications for ecosystems

引用

National Science Review 2023年第12期10卷 124-136页

作者： Yumin Li Tzung-May Fu Jian Zhen Yu Xu Yu Qi Chen Ruqian Miao Yang Zhou Aoxing Zhang Jianhuai Ye Xin Yang Shu Tao Hongbin Liu Weiqi Yao Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks School of Environmental Science and Engineering Southern University of Science and Technology Guangdong Provincial Observation and Research Station for Coastal Atmosphere and Climate of the Greater Bay Area Southern University of Science and Technology Division of Environment and Sustainability Hong Kong University of Science and Technology National Center for Applied Mathematics Shenzhen Department of Chemistry Hong Kong University of Science and Technology State Key Joint Laboratory of Environmental Simulation and Pollution Control International Joint Laboratory for Regional Pollution Control College of Environmental Sciences and Engineering Peking University Frontier Science Center for Deep Ocean Multispheres and Earth System and Physical Oceanography Laboratory Ocean University of China College of Oceanic and Atmospheric Sciences Ocean University of China Department of Ocean Science Hong Kong University of Science and Technology Department of Ocean Science and Engineering Southern University of Science and Technology

Atmospheric deposition of particulate organic nitrogen（ONp） is a significant process in the global nitrogen cycle and may be pivotally important for N-limited ***,past models largely overlo oked the spatial and chemical inhomogeneity of atmospheric ONpand were thus deficient in assessing global *** constructed a comprehensive global model of atmospheric gaseous and particulate organic nitrogen（ON）,including the latest knowledge on emissions and secondary *** this model,we simulated global atmospheric ONpabundances consistent with *** estimated global atmospheric ON deposition was 26 Tg N yr-1,predominantly in the form of ONp(23 Tg N yr-1)and mostly from wildfires（37%）,oceans（22%） and aqueous productions（17%）.Globally,ONpcontributed as much as 40% to 80% of the total N deposition downwind of biomass-burning *** ONpdeposition thus constituted the dominant external N supply to the N-limited boreal forests,tundras and the Arctic Ocean,and its importance maybe amplified in a future warming climate.

关键词： organic nitrogen aerosol secondary organic nitrogen biomass burning

来源：评论

学校读者我要写书评

暂无评论

A Crystal-Embedded Hygroscopic Strategy for Making Transparent Anti-Frost Films

SSRN

引用

SSRN 2022年

作者： Zhao, Xinxin Xu, Zhengzheng Liu, Yan Zhou, Wengting Yang, Chuncheng Wang, Guoyong Key Laboratory of Automobile Materials Department of Materials Science and Engineering Jilin University Changchun130025 China State Key Laboratory of Automotive Simulation and Control Jilin University 5988 Renmin Street Changchun130025 China

Classical passive anti-frost surfaces represented by superhydrophobic surfaces can delay frost formation, but the rough structure of their surfaces may instead lead to frost pinning. It has recently been shown that by using hygroscopic droplets to locally reduce the water vapor pressure on a surface can create a region of inhibited condensation and frosting (RIC) on the surface. In this work, we combined this "humidity sink" effect with the superhydrophobic anti-frost mechanism, and prepared a porous superhydrophobic anti-frost surface with high light transmittance by replacing the hygroscopic droplets with KBr single crystal sheets. The most suitable pore size and spacing for frost inhibition were further investigated, and it was confirmed that a reasonable arrangement of hygroscopic pores could inhibit frosting on the whole surface. Compared with hygroscopic droplets, KBr single crystal sheet is more stable in moisture absorption, and there is no need to consider the volume and concentration changes during the process of moisture absorption, and no worries about leakage, which greatly reduces the cost and the impact on the environment. © 2022, The Authors. All rights reserved.

关键词： Drops

来源：评论

学校读者我要写书评

暂无评论

The Response of Microbial Compositions and Functions to Chronic Single and Multiple Antibiotic Exposure by Batch Experiment

SSRN

引用

SSRN 2023年

作者： Li, Siling Chen, Junwen Zhao, Jian Qi, Weixiao Liu, Huijuan Center for Water and Ecology State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China

Understanding the response of the microbial community to external disturbances such as micropollutants is vital for ecological risk evaluation. In this study, the effect of chronic antibiotic exposure on community compositions and functions was investigated by two batch experiments. The first experiment investigated the effect of chronic sulfamethoxazole (SMX) exposure, while the second investigated the combined effect of dissolved organic matter (DOM) sources and multi-antibiotic exposure. The results showed that the community responses to chronic antibiotic exposure depended on the dynamic balance among community resistance, adaptation, recovery, and selection, leading to nonlinear composition diversity variations. The disturbance strength of chronic SMX exposure increased with concentration (0.5–50 μg/L). However, complex sources and structures of coexisting organic matter might delay the disturbance by elevating metabolic activity and generating functional redundancy. Especially, when nutrient was a limiting factor, the disturbance strength by DOM source was greater than that by chronic antibiotic exposure. The resistance of abundant taxa to external distributions resulted in a low explanation of community diversity, while rare taxa played key roles in response to community variation and thereby affected community assembly. Long-term SMX exposure reduced the number of key species and favored the deterministic assembly process by 21%. However, elevated community adaptability might weaken the influence of antibiotic selection. Chronic SMX exposure elevated the relative abundance of sulfonamide resistance genes (sul1, sul2) by a factor of 1.2–4.3, while that of nitrogen-fixing genes (nifH, nifK) and the metabolic pathways related to the toluene, ethylbenzene, and dioxin degradation decreased. However, the combined influence of DOM sources and multi-antibiotic exposure barely caused the difference in the genes linking to element metabolism and drug resistance of mic

关键词： Antibiotics

来源：评论

学校读者我要写书评

暂无评论

Room-temperature liquid metal synthesis of nanoporous copper-indium heterostructures for efficient carbon dioxide reduction to syngas

引用

Science China Materials 2022年第12期65卷 3504-3512页

作者： Xingcheng Ma Feng Wang Dongxu Jiao Dantong Zhang Xiao Zhao David JSingh Jingxiang Zhao Xiaoqiang Cui Weitao Zheng State Key Laboratory of Automotive Simulation and Control School of Materials Science and EngineeringKey Laboratory of Automobile Materials of MOEJilin UniversityChangchun 130012China Key Laboratory of Photonic and Electronic Bandgap Materials Ministry of Educationand College of Chemistry and Chemical EngineeringHarbin Normal UniversityHarbin 150025China Department of Physics and Astronomy and Department of Chemistry University of MissouriColumbiaMissouri 65211United States Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and TechnologyShenzhen 518055China

Nanoporous metals show promising performances in electrochemical *** this paper,we report a self-supporting bimetallic porous heterogeneous indium/copper structure synthesized with a eutectic gallium-indium(EGaIn)material on a copper *** nanoporous copper-indium heterostructure catalyst exhibits excellent performance in the reduction of carbon dioxide to *** ratio of H_(2)/CO is tunable from 0.47 to 2.0 by changing working *** catalyst is highly stable,showing 96%maintenance of the current density after a 70-h continuous *** functional theory calculations reveal that the indium/copper interface induces charge redistribution within the copper surface,leading to the formation of two distinct active sites,namely,Cu^(δ)and Cu0,and enabling a high-performance generation of CO and H_(2).This work provides a new strategy for obtaining self-supporting nanoporous metal electrode catalysts.

关键词： syngas liquid metal EGaIn heterostructure nanoporous metal

来源：评论

学校读者我要写书评

暂无评论

Vertical Tire Forces Estimation of Multi-Axle Trucks Based on an Adaptive Treble Extend Kalman Filter

引用

Chinese Journal of Mechanical Engineering 2021年第3期34卷 317-335页

作者： Buyang Zhang Ting Xu Hong Wang Yanjun Huang Guoying Chen Jihua Laboratory Foshan 528200GuangdongChina State Key Laboratory of Automotive Simulation and Control Jilin UniversityChangchun 130022China Tsinghua Intelligent Vehicle Design and Safety Research Institute Tsinghua UniversityBeijing 100084China Department of Mechanical and Mechatronics Engineering University of WaterlooWaterlooCanada.

Vertical tire forces are essential for vehicle modelling and dynamic ***,an evaluation of the vertical tire forces on a multi-axle truck is difficult to *** current methods require a large amount of experimental data and many sensors owing to the wide variation of the parameters and the *** simplify the design process and reduce the demand of the sensors,this paper presents a practical approach to estimating the vertical tire forces of a multi-axle truck for dynamic *** estimation system is based on a novel vertical force model and a proposed adaptive treble extend Kalman filter(ATEKF).To adapt to the widely varying parameters,a sliding mode update is designed to make the ATEKF adaptive,and together with the use of an initial setting update and a vertical tire force adjustment,the overall system becomes more *** particular,the model aims to eliminate the effects of the over-constraint and the uneven weight *** results show that the ATEKF method achieves an excellent performance in a vertical force evaluation,and its performance is better than that of the treble extend Kalman filter.

关键词： Estimation theory Adaptive treble extend Kalman filter Vehicle dynamics Multi-axle truck Vertical tire force estimation

来源：评论

学校读者我要写书评

暂无评论

Consumer perceptions and behaviors toward take-out food plastic packaging reduction: A case study of college students in China

Circular Economy

引用

Circular Economy 2023年第3期2卷

作者： Guan, Yusheng Wei, Fan Liu, Sijie Tan, Quanyin Li, Jinhui School of Environment Tsinghua University Beijing100084 China State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China

With the prevalence of online take-out food, the increasingly generated single-use plastic packaging waste has aroused public concern in the context of combating plastic pollution globally. The majority of present studies have focused on product design and policy design to influence the corporate behaviors in packaging waste management. Few attentions have been concentrated on consumer perceptions, a neglected vital factor in commercial practices, which determines whether the proposed measures can be effectively applied. This study takes college students, the main consumer group of take-out who are most likely to receive new environmental protection concepts, as a case study and employs the contingent valuation method to investigate their perceptions and behaviors toward emerging plastic packaging reduction approaches and taxation mechanisms. It was found that packaging circulation was preferred mostly with a proportion of 73.20% of the respondents, while taxation mechanism was more favored by those who have higher daily expenditure on meals. Gender, living costs and ordering frequency could significantly influence the acceptance levels. Therefore, a circulation mechanism using cabinet near take-out food hot spots and third-party cleaning services could target students and officers as pioneers. Regarding the taxation approach, it was suggested that the payment that most of the respondents could accept is 1.5 CNY. This study serves as a reference for the reduction of plastic waste from take-out packaging on campus, and provides a possible model that could reduce the environmental impacts of take-out food packaging through both taxation and circulation measures. The findings are expected to bring primary insights for take-out food plastic packaging reduction in China. For future studies, the methodology of this study was also well-prepared to investigate a larger scale of consumers and develop a more universal policy. © 2023 The Author(s)

关键词： Students

来源：评论

学校读者我要写书评

暂无评论

Optimal Auxiliary Frequency control of Wind Turbine Generators and Coordination with Synchronous Generators

引用

CSEE Journal of Power and Energy Systems 2021年第1期7卷 78-85页

作者： Ming Sun Yong Min Lei Chen Kaiyuan Hou Deming Xia Hangyin Mao State Key Laboratory of Control and Simulation of Power System and Generation Equipment Department of Electrical EngineeringTsinghua UniversityBeijing 100084China with Northeast Branch of State Grid Corporation of China Shenyang 110180Liaoning ProvinceChina with State Grid Zhejiang Electric Power Co.LTD. Hangzhou 310007Zhejiang ProvinceChina

Auxiliary frequency control of a wind turbine generator(WTG) has been widely used to enhance the frequencysecurity of power systems with high penetration of renewableenergy. Previous studies recommend two types of control schemes,including frequency droop control and emulated inertia control,which simulate the response characteristics of the synchronousgenerator (SG). This paper plans to further explore the optimalauxiliary frequency control of the wind turbine based on previousresearch. First, it is determined that the virtual inertia control haslittle effect on the maximum rate of change of frequency (MaxROCOF)if the time delay of the control link of WTG is taken intoconsideration. Secondly, if a WTG operates in maximum powerpoint tracking (MPPT) mode and uses the rotor deceleration forfrequency modulation, its optimal auxiliary frequency control willcontain only droop control. Furthermore, if the droop control isproperly delayed, better system frequency response (SFR) willbe obtained. The reason is that coordination between the WTGand SG is important for SFR when the frequency modulationcapability of the WTG is limited. The frequency modulationcapability of the WTG is required to be released more ***, when designing optimal auxiliary frequency controlfor the WTG, a better control scheme is worth further study.

关键词： Frequency droop control power system frequency security rate of change of frequency(ROCOF) virtual inertia control wind turbine generator auxiliary frequency control

来源：评论

学校读者我要写书评

暂无评论

A Prognostic-Based Energy Management Strategy for Vehicular Pemfc Systems Considering Performance Degradation Mitigation

SSRN

引用

SSRN 2023年

作者： Hu, Fuyuan Ma, Yan State Key Laboratory of Automotive Simulation and Control Jilin University Changchun China Department of Control Science and Engineering Jilin University Renmin Street 5988 Changchun130012 China

Proton exchange membrane fuel cell (FC) is a promising alternative for facilitating popularization of clean energy sources. In automotive industry, low durability has been a main obstacle hindering the commercialization of vehicular FC systems. Efficient energy management strategies (EMS) perform a crucial role in degradation mitigation of FC systems. Unlike other degradation-conscious EMSs based on current health status estimation, an EMS integrated with prognostic process is developed to realize energy-saving and degradation mitigation in this paper. Firstly, a virtual steady voltage-based health indicator (HI) is extracted by identifying a series of linear parameter varying autoregressive models with exogenous inputs (LPV-ARX) in sliding time segments. Furthermore, on the basis of HI data extracted, echo state network (ESN) is utilized for HI state prediction of FC stack in real time. With the help of LPV-ARX model combined with ESN, a data-driven surrogate model for stack degradation prediction is established. Finally, descent Bayesian optimization (DBO) algorithm is proposed to search the optimal operation parameters based on the data-driven surrogate model, thereby the fuel economy and degradation mitigation are achieved. The effectiveness of the proposed approach is validated via MATLAB simulation, and a baseline EMS without prognostic mechanism is used for demonstrating its advantages. © 2023, The Authors. All rights reserved.

关键词： Automotive industry

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：