检索结果-内蒙古大学图书馆

Water Research 2023年第1期236卷 119928页

作者： Luo, Tianyi Wei, Wei Ni, Bing-Jie State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China Centre for Technology in Water and Wastewater School of Civil and Environmental Engineering University of Technology Sydney SydneyNSW2007 Australia

Atomization Law of Swirl Nozzles Based on Cfd Technology and Development of a Novel Spray Dust Removal Nozzle for Mines

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Peng, Huitian Peng, Yifei Guo, Lidian Liu, Fei Xu, Changwei College of Safety and Environmental Engineering Shandong University of Science and Technology Qingdao266590 China State Key Laboratory of Mining Disaster Prevention and Control Co-found by Shandong Province The Ministry of Science and Technology Shandong University of Science and Technology Qingdao266590 China

The increase in highly mechanized coal mining has not only improved production efficiency but also brought serious dust pollution problems. Currently, spraying is the most commonly used dust removal technique in coal mines. However, the effect of spraying in coal mines is not ideal and the levels of dust pollution are more severe, so there is an urgent need to develop new and more efficient nozzles for dust removal spraying devices. Therefore, we used theoretical analysis, numerical simulation, and experimental measurement to study the influence of nozzle structure on dust removal ***, we constructed a VOF to DPM (volume of fluid to discrete phase model) model that could accurately simulate the nozzle atomization process. The VOF method is used to calculate the initial liquid atomization, and the DPM method is used to calculate the secondary droplet atomization. The model was used to study the atomization law of a nozzle’s internal and external spray fields. We analyzed the influence of a nozzle’s internal structure, such as whether there is a swirl core, the characteristics of the water surface of the swirl core (including the water passage area and the shape of the water surface), and the angle of the swirl core on the dust removal effect of the spray produced by the nozzle. Through our simulation, we determined that the optimal internal structure parameters of the nozzle were as follows. The water passage area of the swirl core Sl=4.5mm2, the swirl core through the water passage baffle is optimized for flat mouth, and the swirl core angle αl=70°. We used 3D printing technology to create this novel optimized nozzle and analyzed it experimentally. The data from experiments simulating the dust suppression effect on a coal mine site through spray showed that when the spray pressure was 6MPa, the dust removal rate when using the new nozzle was 87.4%, thus the spray dust removal effect had been improved. © 2024, The Authors. All rights reserved.

关键词： Computational fluid dynamics

Spatiotemporal Dynamics of Phytoplankton Biomass and Community Succession for Driving Factors in a Meso-Eutrophic Lake

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Cao, Jing Hou, Ze-Ying Li, Ze-Kun Zheng, Bing-Hui Chu, Zhao-Sheng National Engineering Laboratory for Lake Pollution Control and Ecological Restoration State Environment Protection Key Laboratory for Lake Pollution Control Chinese Research Academy of Environmental Sciences Beijing100012 China School of Environment Tsinghua University Beijing100084 China Environmental Monitoring Station of Dali Prefecture Dali671000 China

The dual effects of climate change and nutrient load on lake phytoplankton blooms, both caused by human activities, have attracted much attention. However, their roles and synergistic effects on phytoplankton biomass and community historical succession are not well understood, especially for meso-eutrophic plateau lakes. In this study, a multi-year (1997-2022) monthly dataset including hydro-chemical and meteorological indicators of the meso-eutrophic plateau lake Erhai in China, was used to explore the contributions of climate change and nutrient load on phytoplankton biomass variation and community succession. Phytoplankton biomass increased from 1997 to 2006, slowly decreased from 2006 to 2015, then increased again from 2015 to 2022, according to a generalised additive model (GAM). Alongside warming, carbon, nitrogen and phosphorus nutrients are key drivers of long-term interannual variation in phytoplankton biomass and historical succession of the phytoplankton community. The extensive blooms in recent years were strongly associated with both organic matter accumulation and global warming. Phytoplankton biomass in northern and southern districts was greater than in central areas, with Cyanophyta and Pyrrophyta dominating in the north and Chlorophyta prevalent in the south. Since 2015, phytoplankton diversity has increased significantly, and biomass has declined in the southern district but increased markedly in the northern district. Spatial heterogeneity was caused by the spatial distribution of nutrients and the buoyancy regulation capacity of cyanobacteria. The results demonstrate that bloom mitigation responds strongly to nitrogen and phosphorus control in meso-eutrophic lakes. Given the accumulation of organic matter in recent years, synergistic control of organic matter and total nitrogen and phosphorus could effectively reduce the risk of cyanobacterial and dinoflagellate blooms. © 2023, The Authors. All rights reserved.

关键词： Lakes

Facile Fabrication of 2d Mof-Based Membrane with Hierarchical Structures for Ultrafast Oil-Water Separation

学校读者我要写书评

暂无评论

SSRN 2022年

作者： He, XuanTing Li, Boyu Liu, Jiaxiang Tao, Wenquan Li, Zhuo State Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science & Engineering Tongji University 1239 Siping Road Shanghai200092 China

The surface chemical composition and building unit structures of membrane are the key factors to realize highly-efficient oil-water separation. Here we report the synthesis of Cu-CAT-1 metal-organic frameworks (MOFs) with unique two-dimensional (2D) hierarchical structures grown directly on copper mesh (Cu-CAT-1@CM) for oil-water separation. The Cu-CAT-1@CM membrane with micro-/nano- architecture exhibits robust superhydrophilicity and underwater super-hydrophobicity characteristics, allowing gravity-driven oil-water separation by achieving ultrahigh flux up to 329 kL∙m-2∙h-1. The membrane shows excellent separation performances by testing various oils, particularly actual crude oil and xylene, which are considered as the notorious pollutants in the water. The residual oil contents of six samples are all less than 24.6 mg/L. The mechanism analysis demonstrated that the appropriate hierarchical structures of the membrane surface is the code for the extreme wettability that remarkably improved the separation efficiency. Moreover, such a membrane with high performance can be readily synthesized by electrochemical method at room temperature in only 20 minutes, which shows the advantages of facile and environmentally friendly fabrication process as well as low cost. This energy-saving of gravity-driven and ultra-high permeability allows the rapid separation of oil-water mixture, which shows the potential applications for resolving the problem of oil pollution. © 2022, The Authors. All rights reserved.

关键词： Membranes

Construction of Antimicrobial Peptides/Alginate Multilayers Modified Membrane: Antibiofouling Performance and Mechanisms

学校读者我要写书评

暂无评论

SSRN 2023年

作者： Chen, Yanrui Zhang, Xingran Li, Fang Ma, Jinxing Wang, Zhiwei College of Environmental Science and Engineering Textile Pollution Controlling Engineering Centre Ministry of Ecology and Environment Donghua University Shanghai201620 China Key Laboratory for City Cluster Environmental Safety and Green Development The Ministry of Education School of Ecology Environment and Resources Guangdong University of Technology Guangzhou510006 China State Key Laboratory of Pollution Control and Resource Reuse Shanghai Institute of Pollution Control and Ecological Security School of Environmental Science and Engineering Tongji University Shanghai200092 China

Biofouling remains to be one of major obstacles for membrane-based technology in water and wastewater treatment, calling for the development of antibiofouling membranes. For the traditional release-killing strategy, uncontrollable release of biocides and thus a short lifetime as well as the potentially environmental risk are thorny issues for the modified membranes. Herein, hydrophilic hydrogel multilayers with controllable thickness at nanometer scale on a poly(vinylidene fluoride) (PVDF) microfiltration membrane were constructed via layer-by-layer (LbL) self-assembly of non-drug-resistant antimicrobial peptides (AMPs) and alginate. The AMPs/alginate multilayers modified membranes exhibited enhanced hydrophilicity, well-controlled pore size distribution and prominent antimicrobial ability against Escherichia coli and Staphylococcus aureus. The strong interaction of AMPs and alginate imparted by the gel network enabled the slow release rate of AMPs in water phase (i.e., 1.79 ± 0.07 μg/cm2 d of initial release rate and 0.55 ± 0.03 μg/cm2 d of steady release rate). Long-term antibiofouling tests showed that the AMPs/alginate modified membranes with ten multilayers (MSA10) exhibited a significantly reduced transmembrane pressure increase rate of 0.81 ± 0.01 kPa/d which was much lower than that of the control membranes (1.80 ± 0.20 kPa/d). Furthermore, the AMPs/alginate multilayers modified membranes revealed high stability suffering from long-term operation and chemical cleaning cycles. The novel AMP/alginate-incorporated modifying method provides a new dimension to enhance antibiofouling performance of membranes for water and wastewater treatment. © 2023, The Authors. All rights reserved.

关键词： Peptides

Integrated Optimization of Capacity Allocation and Timetable Design for Metro-Based Passenger and Freight Cotransportation

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Di, Zhen Luo, Jun Shi, Jungang Qi, Jianguo Zhang, Shenghu School of Transportation Engineering East China Jiaotong University Nanchang330013 China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing100044 China School of Mathematics and Statistics Jiangxi Normal University Nanchang330022 China

Multimodal integration is helpful for solving the problems of sustainable urban freight, and employing a metro-based cotransportation system during off-peak hours is a potential solution before an underground logistics system is built. Regarding metro-based passenger and freight cotransportation, this study investigates an integrated optimization problem for metro lines under the train-shared mode. The final decision includes the size of the train fleet, train timetable, carriage arrangement plan for trains, and freight flow assignment. Since the arrival rates of demands are viewed as continuous functions over time, this integrated problem is formulated as a nonlinear mixed integer model. To overcome the most complex part of the model, a gradient-based heuristic algorithm is proposed. Finally, some numerical examples in a real metro line are examined to test the applicability and effectiveness of the proposed model and algorithm, and the impact of metro-based freight on passengers is also analyzed. © 2024, The Authors. All rights reserved.

关键词： Heuristic algorithms

A Top-k QoS-Optimal Service Composition Approach Under Dynamic Environment 7th

学校读者我要写书评

暂无评论

A Top-k QoS-Optimal Service Composition Approach Under Dynam...

7th International Conference on Artificial Intelligence and Security, ICAIS 2021

作者： Tian, Cheng Zhang, Zhao Yang, Sha Huang, Shuxin Sun, Han Wang, Jing Zhang, Baili School of Computer Science and Engineering Southeast University Nanjing211189 China State Key Laboratory of Smart Grid Protection and Control Nanjing211106 China Nari Group Corporation Nanjing211106 China

ISBN: (纸本)9783030786083

To deal with low efficiency of existing Web service composition algorithms under dynamic environment, this paper proposes a Top-k QoS-optimal service composition algorithm based on QWSC-K static algorithm. The algorithm first considers the influence of dynamic environment on the existing service composition and service dependency graph, and classifies the changed services in dynamic environment. Moreover, different strategies are adopted to obtain the intermediate results of service composition for different categories of services. The influence of different service categories on the service dependency graph is analyzed to realize the updating of the service dependency graph. Finally, based on the updated service dependency graph and the intermediate results of the service composition, the adaptive incremental update can be applied to change the original service composition results, avoiding the time-consuming re-query process. Experiments show that the algorithm is efficient and accurate in dynamic environment. © 2021, Springer Nature Switzerland AG.

关键词： Quality of service

Experimental Study on Increasing the Permeability of Coal Body Based on Aeo-9 Compounding Solution

学校读者我要写书评

暂无评论

SSRN 2024年

作者： Xie, Jun Zhang, Jingyi Chen, Dawei Wang, Faquan College of Safety and Environmental Engineering Shandong University of Science and Technology Qingdao266590 China State Key Laboratory of Mining Disaster Prevention and Control Co-found by Shandong Province the Ministry of Science and Technology Shandong University of Science and Technology Qingdao266590 China

The chelating agent can deconvolute the metal ions in the coal body into a free state and communicate with the pores of the coal body. However, as the mining depth increases, the chelating agent cannot effectively wet the coal body. Therefore, it is particularly important to select a solution that can both communicate the pores of the lignite and increase the permeability radius in the coal body. In this paper, a wetting agent is added on the basis of chelating agent to improve the wettability of aqueous solution to coal using compounding solution. The optimum quality concentration of the compounding solution was selected by ICP and contact angle experiments. The pore changes of the coal were analysed by SEM and BET results. The results showed that the Ca2+, Mg2+, and Fe2+/3+ leaching effect was significant under the AEO-9 compounding system. When the quality concentration of the wetting agent and the chelating agent was 0.05%, and the compounding ratio was 1:1, the contact angle between coal and solution surface was 24.47°. At this time, the average pore diameter was 4.8636 nm, the pore specific surface area was 0.8717 m²/g. The internal micropores expanded into mesopores or macropores. © 2024, The Authors. All rights reserved.

关键词： Lignite

Iterative Learning Based Train Stop control with Initial state Shifts for Urban Rail Transit 10

学校读者我要写书评

暂无评论

Iterative Learning Based Train Stop Control with Initial Sta...

10th IEEE Data Driven control and Learning Systems Conference, DDCLS 2021

作者： Yu, Ruochuan Tang, Tao Yin, Chenkun Xun, Jing Xi, Jiayi Zheng, Xiaobin State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing100044 China Advanced Control Systems Laboratory School of Electronic and Information Engineering Beijing Jiaotong University Beijing100044 China Traffic Control Technology Co. Ltd Beijing100070 China Beijing Transport Institute Beijing100073 China

ISBN: (纸本)9781665424233

In this paper, a partitioned terminal iterative learning control (TILC) strategy for urban rail transit with initial state shifts is proposed to solve the accurate stop problem. A supervised machine learning method is used to pre-processing the historical operation data (i.e. the initial speed and the position data pairs in the stopping stage). And for each category the TILC algorithm is applied, realizing the update of the control law in a small range. Simulation results show that the proposed algorithm can achieve the stop accuracy of ±15cm even though the initial state varies over a certain range during the iterations. This meets the general requirement of accurate train stop for urban rail transit (±30cm). © 2021 IEEE.

关键词： Iterative methods

Oscillation Suppression Method based on Power control Optimization of the Wind Farms 3

学校读者我要写书评

暂无评论

Oscillation Suppression Method based on Power Control Optimi...

3rd IEEE International Power Electronics and Application Conference and Exposition, PEAC 2022

作者： Yang, Jiaqi Wang, Shaojun Li, Zhen Tian, Xu Liu, Bin Liu, Xiangdong Beijing Institute of Technology School of Automation Beijing China Co.Ltd Bayannur Power Supply Bureau Inner Mongolia China State Key Laboratory for Intelligent Control and Decision of Complex Systems Beijing China Beijing University of Mining and Technology Beijing Electric Engineering and Automation Beijing China Tsinghua University Department of Electrical Engineering Beijing China

ISBN: (数字)9781665491419

ISBN: (纸本)9781665491419

Oscillation issues in the grid-connected wind farm system can severely deteriorate the power system security and lead to serious damage. Based on the impedance analysis method, many oscillation suppression methods have been proposed for reshaping the impedance characteristics of system to avoid the risk of oscillations. However, modifying converters' controllers to reshape the wind turbines (WTs) impedance and usage of additional damping devices for reshaping the grid impedance both are time-consuming and costly. Therefore, based on the sequence impedance model of the grid-connected wind farm system, this paper proposes a novel oscillation suppression method by optimizing the power control of wind farm. The system stability margin can be improved by modifying the number of online WTs and the output power of each WT to reshape the impedance of wind farm, under the precondition that the output power demand of wind farm is satisfied. Then, the intelligent particle swarm optimization (PSO) algorithm is used to solve the optimization approach to obtain the number of online WTs with optimal stability margin. Finally, the simulation confirms the effectiveness of the proposed oscillation suppression method. © 2022 IEEE.

关键词： System stability