检索结果-内蒙古大学图书馆

Moving policy and regulation forward for single-use plastic alternatives

Frontiers of Environmental Science & Engineering 2021年第3期15卷 191-194页

作者： Wenbing Tan Dongyu Cui Beidou Xi State Key Laboratory of Environmental Criteria and Risk Assessment and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater PollutionChinese Research Academy of Environmental SciencesBeijing 100012China School of Environment Tsinghua UniversityBeijing 100084China

Single-use plastics are often used once or cannot be reused for extended *** are widely consumed with the rapid development of social *** waste generated by single-use plastics threatens ecosystem health by entering the environment and ultimately restricts sustainable human *** innovation of sustainable and environmentally friendly single-use plastic alternative materials and the joint participation of governments,enterprises and the public are promising technologies and management approaches that can solve the problem of single-use plastics *** development of single-use plastic alternative products can be promoted fundamentally only by improving relevant legislation and standards,providing differentiated industrial policies,encouraging scientific and technological innovation and expanding public participation.

关键词： Single-use plastic alternatives Policy Regulation Sustainable development

来源：评论

学校读者我要写书评

暂无评论

Energy Minimization Oriented Resource Allocation for Relay Assisted NOMA-MEC Networks

Energy Minimization Oriented Resource Allocation for Relay A...

引用

2024 IEEE Global Communications Conference, GLOBECOM 2024

作者： Wang, Qianru Qian, Liping Wu, Yuan Yang, Xiaoniu Zhejiang University of Technology College of Information Engineering Hangzhou China University of Macau State Key Laboratory of Internet of Things for Smart City China Science and Technology on Communication Information Security Control Laboratory Jiaxing China Zhejiang University of Technology Institute of Cyberspace Security Hangzhou310023 China

ISBN: (纸本)9798350351255

With the growing demand for image transmission, there is a need for solutions that offer low energy consumption and low latency. In this paper, we present a novel relay-assisted system based on non-orthogonal multiple access (NOMA) and mobile edge computing (MEC). Our proposed system compresses images at the device end, decompresses them at either a relay or a cloud server (CS). The primary objective is to minimize system energy consumption under given task delay constraints. Considering that this is a non-convex optimization problem, we solve it by decomposing it into a continuous subproblem and a discrete subproblem. To solve the continuous subproblem, we convexify it by introducing new parameters and change variables to get the optimal the computing power of devices, relay and CS, sampling rate of devices, transmission power of devices and relay. To solve the discrete subproblem, we propose a cross-entropy (CE) algorithm to obtain the optimal decompression decision and subcarrier allocation decision. Simulation results demonstrate the accuracy and effectiveness of our algorithm in optimizing total energy consumption compared to the Linear Interactive and General Optimizer (LINGO) and frequency division multiple access (FDMA) methods. © 2024 IEEE.

关键词： Convex optimization

来源：评论

学校读者我要写书评

暂无评论

Forest Mercury Deposition Observation in Chongqing: Evaluating Effectiveness of Mercury Pollution control over the Past Decade in Southwestern China

ACS ES&T Air

引用

ACS ES&T Air 2025年第2期2卷 286-294页

作者： Ziyi Zhan Dongwei Lv Huang Zhou Qingru Wu Yuying Cui Lei Duan State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Tsinghua University 100084 Beijing China School of the Environment Nanjing University 210023 Nanjing China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Tsinghua University 100084 Beijing China；State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Tsinghua University 100084 Beijing China

As the largest Hg reservoir in terrestrial ecosystems, forests provide valuable insights into atmospheric Hg levels through observations of mercury deposition. In this study, we conducted a one-year observation of Hg deposition, by both throughfall and litterfall, in a forest located in Chongqing, an industrial hub in southwestern China, in 2021. We compared the results with observations made at the same sampling site in 2010–2011. The results showed that there were significant decreases in both Hg concentrations (from 115 μg·kg–1to 80.2 μg·kg–1for litterfall and from 68.4 ng·L–1to 4.01 ± 2.09 ng·L–1for throughfall) and Hg deposition fluxes (from 89.8 μg·m–2·yr–1to 19.9 μg·m–2·yr–1for total deposition, decreasing by 77.8%) in the forest from 2010 to 2021. The decrease in deposition might result from the synergistic effect of reduction in both anthropogenic (inventory-listed or nonquantitative) and re-emission sources. Over the decade since the initiation of theMinamata Convention on Mercury, atmospheric Hg levels have decreased significantly, mainly due to the co-benefits of conventional air pollutant control, indicating the effectiveness of China’s Hg pollution control policies.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Cu/Cr co-stabilization mechanisms in a simulated Al_(2)O_(3)-Fe_(2)O_(3)-Cr_(2)O_(3)-CuO waste system

引用

Frontiers of Environmental Science & Engineering 2021年第6期15卷 259-270页

作者： Fanling Meng Yunxue Xia Jianshuai Zhang Dong Qiu Yaozhu Chu Yuanyuan Tang State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China

Chromium slag usually contains various heavy metals,making its safe treatment *** sintering has been applied to resolve this issue and emerged as an effective method for metal immobilization by incorporating heavy metals into stable crystal ***,there is limited knowledge about the reaction pathways adopted by multiple heavy metals and the co-stabilization functions of the crystal *** study the Cu/Cr co-stabilization mechanisms during thermal treatment,a simulated system was prepared using a mixture with a molar ratio of Al_(2)O_(3):Fe_(2)O_(3):Cr_(2)O_(3):CuO=1:1:1:*** samples were sintered at temperatures 600–1300℃ followed by intensive analysis of phase constitutions and microstructure development.A spinel phase(CuFe_(x)Al_(y)Cr_(2–x–y)O_(4))started to generate at 700℃ and the incorporation of Cu/Cr into the spinel largely complete at 900℃,although the spinel peak intensity continued increasing slightly at temperatures above 900℃.Fe_(2)O_(3)/Cr_(2)O_(3) was more easily incorporated into the spinel at lower temperatures,while more Al_(2)O_(3) was gradually incorporated into the spinel at higher ***,sintered sample microstructures became more condensed and smoother with increased sintering ***/Cr leachability substantially decreased after Cu/Cr incorporation into the spinel phase at elevated *** 600℃,the leached ratios for Cu and Cr were 6.28%and 0.65%,*** sintering temperature was increased to 1300℃,the leached ratios for all metal components in the system were below 0.2%.This study proposes a sustainable method for managing Cu/Cr co-exist slag at reasonable temperatures.

关键词： Spinel structure Copper Chromium Co-stabilization Thermal treatment

来源：评论

学校读者我要写书评

暂无评论

Resource utilization of typical biomass wastes as biochars in removing plasticizer diethyl phthalate from water: characterization and adsorption mechanisms

引用

Frontiers of Environmental Science & Engineering 2023年第1期17卷 49-61页

作者： Mei Shi Xiao Wang Mengying Shao Lun Lu Habib Ullah Hao Zheng Fengmin Li Institute of Coastal Environmental Pollution Control College of Environmental Science and EngineeringKey Laboratory of Marine Environment and Ecology(Ministry of Education)Ocean University of ChinaQingdao 266100China State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment South China Institute of Environmental SciencesMinistry of Ecology and EnvironmentGuangzhou 510655China Department of Environmental Science Zhejiang UniversityHangzhou 310058China Marine Ecology and Environmental Science Laboratory Pilot National Laboratory for Marine Science and TechnologyQingdao 266071China Sanya Oceanographic Institution Ocean University of ChinaSanya 572000China

Plastic pollution as a global environmental issue has become a research hotspot,among which the removal of inherent plasticizer(e.g.,phthalic acid esters,PAEs)received increasing ***,the effects of biochars derived from different feedstocks on the adsorption of PAEs are poorly ***,the characteristics of biochars derived from six largely produced biomass wastes in China at 400°C,as well as their performance in adsorption of diethyl phthalate(DEP),one of frequently detected PAEs in aqueous environment,were *** results indicated that the variation in feedstock type showed significant changes in the properties(e.g.,porosity,specific surface area,surface functional groups)of biochars,which affected DEP adsorption and *** order and Freundlich models fitted the adsorption data well,and adsorption mechanisms mainly included hydrophobic effect,followed by micropore filling,hydrogen bonding,andπ-πEDA *** thermodynamics revealed that the adsorption was a spontaneous and exothermic the adsorption capacities of DEP on these biochars slightly decreased with the increasing pH but increased with the increasing ionic *** these biochars,the giant reed biochar with relatively higher DEP adsorption and low desorption exhibited the great efficiency for DEP removal as an environment-friendly *** results highlighted the significant roles of micropore filling and hydrogen bond in determining adsorption capacity of designed biochars prepared from selecting suitable agricultural straws and wetland plant waste to typical *** findings are useful for producing designed biochars from different biomass wastes for plasticizer pollution control.

关键词： Plastic pollution Phthalic acid esters Designed biochar Wetland plant Adsorption

来源：评论

学校读者我要写书评

暂无评论

Very-Short-Term Wind Power Forecasting for New-Built Wind Farms Based on Online Sparse Vector Autoregressive Model 1

引用

17th Annual Conference of China Electrotechnical Society, CES 2022

作者： Xu, Yang Dong, Qi Li, Li Zhang, Qinglei Zhang, Yao Shaanxi Province Key Laboratory of Smart Grid Xi’an Jiaotong University Xi’an710049 China Power Dispatch and Control Center State Grid Shaanxi Electric Power Company Limited Xi’an710048 China

ISBN: (数字)9789819904082

ISBN: (纸本)9789819904075

Very-short-term wind power prediction is of great significance for the safe and stable operation of power system. As a well-known time series model, vector autoregressive (VAR) model is very suitable for very-short-term forecasting, and it can consider the temporal and spatial correlation among multiple wind farms to improve the forecasting accuracy. However, when there are a large number of wind farms, VAR model is prone to over-fitting. Slow calculation speed is also the problem of VAR model. This paper adds regularization terms in estimating coefficients to obtain a sparse coefficient matrix, which helps to avoid over-fitting. Online VAR model is used to improve the calculation speed, and a specific improved online VAR method is proposed for forecasting wind power output from new-built wind farms. This method is tested in a specific case, and the prediction accuracy and calculation speed are better than the traditional VAR model. In addition, the improved online VAR method can accurately predict wind power output of new-built wind farms with little historical data. © 2023, Beijing Paike Culture Commu. Co., Ltd.

关键词： Wind farm

来源：评论

学校读者我要写书评

暂无评论

Simulation and Verification of Sub-synchronous Oscillation from Impedance Perspective-Taking a Wind Power Base in China as an Example 6th

Simulation and Verification of Sub-synchronous Oscillation f...

引用

6th PURPLE MOUNTAIN FORUM on smart Grid protection and control, PMF2021

作者： Xu, Guang Zhu, Ling Li, Jianhua Huang, Zhiguang Li, Zhaowei Hou, Yuqiang NARI Technology Co. Ltd Jiangsu Nanjing211106 China East China Grid Co. Ltd Shanghai200120 China State Key Laboratory of Smart Grid Protection and Control Jiangsu Nanjing211106 China

ISBN: (纸本)9789811671555

Recently, numerous sub-synchronous oscillations (SSO) events have occurred in many wind farms in China, which seriously threatened the power system security and stability. It is generally believed that the LC resonance between the wind farm side and the grid side with series compensation (SC) devices is one of the conditions that cause the SSO. This paper takes a real power grid as an example, reappeared the SSO events through electromagnetic simulation, analyzed the key influence factors, and proposes a strategy from impedance perspective in the end based on reasonable assumptions, in order to suppress the SSO shortly after the oscillations happened. Firstly, make off-line impedance analysis based on the deterministic grid structure, and then give the sensitivity results of each wind farm to the SSO. Finally, cut off the wind farm based on the sensitivity orders during the SSO. The simulation results were performed to verify the validity. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Electromagnetic simulation

来源：评论

学校读者我要写书评

暂无评论

NILT - Based Transient Traveling Wave Calculation Method for Lightning Stroke on Coupled Transmission Lines in DC Systems

NILT - Based Transient Traveling Wave Calculation Method for...

引用

IEEE International Conference on Power and Energy Systems (ICPES)

作者： Ziqiang Ouyang Zheng Yan Tonghua Wu Wei Dai Xindong Li Xiaofan Hou State Key Laboratory of Smart Grid Protection and Control (Nari Group Corporation) Laboratory of Control of Power Transmission and Conversion Ministry of Education Shanghai Jiao Tong University Shanghai China State Key Laboratory of Smart Grid Protection and Control (Nari Group Corporation) Nanjing China

Overhead lines are the main way of power transmission in HVDC system. The fault traveling wave propagates along the line after lightning stroke, which may cause accidents. Fault identification and protection design rely on traveling wave analysis and calculation. The time domain solution of transmission line telegraph equations is complicated. Analysis in the complex frequency domain can reduce the computational difficulty. Firstly, this paper decouples the DC transmission line through phase-mode transformation and establishes the model. Then, the post-lightning boundary conditions are introduced and the calculation network is established. On this basis, it solves the expression of traveling wave based on nodal analysis method. Finally, with the numerical inverse Laplace transform, calculation results in complex frequency domain are converted into time domain. The proposed method can reflect the transient process after lightning stroke, which has engineering value for protection design.

关键词： Fault diagnosis Power transmission lines Frequency-domain analysis Simulation Lightning Voltage Transmission line theory

来源：评论

学校读者我要写书评

暂无评论

Analytical and Numerical Investigation of Primary and Cross Waves in a Flume with Double Shoals

引用

China Ocean Engineering 2025年第2期39卷 290-302页

作者： WANG Gang XIN Song-gang LI Chuan-zhong FU Rui-li ZHANG Yao SHI Hua-bin Key Laboratory of Coastal Disaster and Protection(Hohai University) Ministry of EducationNanjing 210098China College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590China National Marine Hazard Mitigation Service Ministry of Natural ResourcesBeijing 100000China State Key Laboratory of Internet of Things for Smart City and Department of Ocean Science and Technology University of MacaoMacaoChina

Flume experiments play a pivotal role in studying wave propagation,with wave elements typically assumed to remain constant in the perpendicular ***,evident cross wave phenomena were observed within flumes under certain *** paper presents new analytical solutions for both primary and cross waves on double shoals in a flume via linear shallow-water equations,which may be used to idealize dynamic experimental configurations of coral *** primary waves on double shoals are described by the associated Legendre functions,whereas the ultimate solutions are derived by considering the incident and reflected waves in front of a bathymetry and the transmitted waves positioned behind *** effects of the angular frequency and topographic parameters on the primary waves are subsequently *** waves on double shoals constitute a type of topographically trapped wave whose solutions are formulated by combining the first and second types of the associated Legendre *** angular frequency is not only determined by the wavenumber but also influenced by the topographic *** experiments are conducted to investigate the generation mechanism of cross *** consistency between the numerical results and analytical solutions confirms the validity of the new analytical framework of cross waves on double shoals.

关键词： cross waves primary waves analytical solutions wave flume numerical experiments

来源：评论

学校读者我要写书评

暂无评论

CHEMICAL PRECIPITATION METHOD FOR THE REMOVAL OF BORON FROM AQUEOUS SOLUTION

引用

UPB Scientific Bulletin, Series B: Chemistry and Materials Science 2022年第2期84卷 31-44页

作者： Yu, T. He, R.R. Wang, F. Zhang, L. Zhang, X.F. Qu, C.T. College of Chemistry and Chemical Engineering Shaanxi Province Key Laboratory of Environmental Pollution Control and Reservoir Protection Technology of Oilfields Xi’an Shiyou University Xi’an710065 China State Key Laboratory of Petroleum Pollution Control CNPC Research Institute of Safety and Environmental Technology Beijing102206 China PCOC No. 1 Oil Production Plant Yanan716000 China

Boron removal is essential for the reuse of solutions after treatment. In this study, the effects of factors such as the type and amount of precipitant, pH, reaction temperature, and reaction time on the boron removal from solution by chemical precipitation were investigated. The orthogonal test results indicated that among the four precipitants, Ca(OH)2 had the highest boron removal rate, which was19.0%. When Ca(OH)2 was used as the precipitant, the best conditions for boron removal were obtained as Ca(OH)2=0.5 g, pH=10.5, reaction temperature=80 °C, reaction time = 120 mi and boron removal rate = 59.0%. © 2022, Politechnica University of Bucharest. All rights reserved.

关键词： Boron

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：