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Solar evaporation for simultaneous oil-water separation and electricity generation with Janus wood-based absorbers

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Frontiers of Environmental Science & Engineering 2024年第2期18卷 13-23页

作者： Yue yang Ze Fu Qi zhang Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse School of Environmental and Biological EngineeringNanjing University of Science&TechnologyNanjing 210094China Key Laboratory of Industrial Ecology and Environmental Engineering(Ministry of Education) School of Environmental Science and TechnologyDalian University of TechnologyDalian 116024China National Laboratory of Solid State Microstructures Collaborative Innovation Center of Advanced MicrostructuresCollege of Engineering and Applied SciencesKey Laboratory of Intelligent Optical Sensing and Manipulation(Ministry of Education)Jiangsu Key Laboratory of Artificial Functional MaterialsNanjing UniversityNanjing 210093China

Oily wastewater from ocean oil spills endangers marine ecosystems and human health. Therefore, developing an effective and sustainable solution for separating oil-water mixtures is urgent. Interfacial solar photothermal evaporation is a promising approach for the complete separation of two-phase mixtures using only solar energy. Herein, we report a carbonized wood-based absorber with Janus structure of comprising a hydrophobic top-layer and an oleophobic bottom-layer for simultaneous solar-driven oil-water separation and electricity generation. Under sunlight irradiation, the rapid evaporation of seawater will induce a separation of oil-water mixtures, and cause a high salt concentration region underlying the interface, while the bottom “bulk water” maintains in a low salt concentration, thus forming a salinity gradient. Electricity can be generated by salinity gradient power. Therefore, oil-water separation efficiency of > 99% and derived extra electricity power of ~0.1 W/m2 is achieved under solar radiation, demonstrating the feasibility of oil-water separation and electricity production synchronously directly using solar energy. This work provides a green and cost-effective path for the separation of oil-water mixtures.

关键词： Oily wastewater Carbonized wood Salinity gradient Electricity generation Solar irradiation

Conduction-convection coupled heat transfer around a hollow cylinder under different buoyancy forces

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Chinese Journal of Aeronautics 2024年第4期37卷 216-228页

作者： Wanyu zhang Jingyi WU Guang yang Institute of Refrigeration and Cryogenics Shanghai Jiao Tong UniversityShanghai 200240China

In order to clarify the effect of a buoyancy force on conduction–convection coupled heat transfer in a hollow cylinder, the flow and thermal characteristics were analyzed using an RNG k-ε turbulence model. The Reynolds number was fixed at 1.014 × 10^(6), and the Rayleigh number varied from 1.122 × 10^(10)to 1.088 × 10^(11). Results have shown that, when considering the effect of an opposed buoyancy force, increasing the Rayleigh number has a positive impact on the rate of change and uniformity of the cylinder temperature. The temperature distributions along the axial and circumferential directions are similar for different Rayleigh numbers, but extreme values *** the axial direction, the maximum temperature is obtained at the interface between the variable-diameter part and the constant-diameter part. The maximum dimensionless temperature value decreases to 0.12 when the Rayleigh number increases to 1.088 × 10^(11). Along the circumferential direction, the temperature distribution is affected by the buoyancy force, which results in the temperature of the upper part being higher than that of the lower part. After nondimensionalization of the temperature and time, a correlation was proposed to illustrate the transient heat transfer process quantitatively. The standard deviation of the maximum relative temperature, representing the temperature uniformity, was also calculated. It was found that the difference in the direction of the buoyancy force made a huge difference. Compared with the opposed buoyancy force, the maximum dimensionless temperature is almost two times higher with an assisted buoyancy force. Similarly, the heat transfer coefficient with an assisted buoyancy force is half of that with an opposed buoyancy force. Overall, an assisted buoyancy force plays a negative role in terms of thermal characteristics. The flow field around the hollow cylinder was also illustrated to reveal the mechanism of the buoyancy force on magnitude and direction aspects

关键词： Buoyancy Conduction-convection heat transfer Transient analysis Hollow cylinder Non-dimensionalization

Deflagration and detonation induced by shock wave focusing at different Mach numbers

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Chinese Journal of Aeronautics 2024年第2期37卷 249-258页

作者： Zezhong yang Jun CHENG Bo zhang School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

Shock wave focusing is an effective way to create a hot spot or a high-pressure and hightemperature region at a certain place,showing its unique usage in detonation initiation,which is beneficial for the development of detonation-based *** flame propagation behavior after the autoignition induced by shock wave focusing is crucial to the formation and self-sustaining of the detonation *** this study,wedge reflectors with two different angles(60°and 90°)and a planar reflector are employed,and the Mach number of incident shock waves ranging from 2.0 to 2.8 is utilized to trigger different flame propagation *** pressure transducers and the high-speed schlieren imaging system are both employed to investigate the shock-shock collision and ignition *** results reveal a total of four flame propagation modes:deflagration,DDT(Deflagration-to-Detonation Transition),unsteady detonation,and direct *** detonation wave formed in the DDT and unsteady detonation mode is only approximately 75%-85%of the Chapman-Jouguet(C-J)speed;meanwhile,the directly induced detonation wave speed is close to the C-J *** waves,which are strong evidence for the existence of detonation waves,are discovered in *** usage of wedge reflectors significantly reduces the initial pressure difference ratio needed for direct detonation *** also provide a practical method for differentiating between detonation and deflagration modes,which involves contrasting the speed of the reflected shock wave with the speed of the theoretically nonreactive reflected shock *** findings should serve as a reference for the detonation initiation technique in advanced detonation propulsion engines.

关键词： Deflagration Detonation Hydrogen Ignition Shock wave focusing

Stabilization/solidification mechanisms of tin tailings and fuming slag-based geopolymers for different heavy metals

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Frontiers of Environmental Science & Engineering 2024年第5期18卷 43-55页

作者： Xian Zhou Zhengfu zhang Hui yang School of Materials Science and Engineering Kunming University of Science and TechnologyKunming650093China Kunming Metallurgical Research Institute Co. Ltd.Kunming650031China

Tin mine tailings(TMT)and fuming slag(FS)contain many heavy metals(As,Cr,Cu,Zn and Mn)that cause severe pollution to the ***,geopolymers were prepared using TMT,FS and flue gas desulfurization gypsum(FGDG)to immobilize heavy metals,and their compressive strength and heavy metal leaching toxicity were *** was first determined that T4F5(TMT:FS=4:5)sample exhibited the highest compressive strength(7.83 MPa).T4F5 achieved 95%immobilization efficiency for As and Cr,and nearly 100%for Cu,Zn and Mn,showing good immobilization performance.A series of characterization analyses showed that heavy metal cations can balance the charge in the geopolymer and replace Al in the geopolymer structure to form covalent *** addition,about 2%–20%of heavy metal Fe was immobilized in hydration products,heavy metal hydroxides and non-bridging Si–O and Al–O coordination with silica-aluminate ***_(3)^(3−) was oxidized into AsO_(4)^(3−),which may form Ca–As or Fe–As ***_(2)O_(7)^(2−)was converted to CrO_(4)^(2−)under alkaline environment and then combined with OH−to form Cr(OH)3 ***^(2+)may react directly with dissolved silicate to form Mn_(2)SiO_(4) and also form Mn(OH)_(2) *** unstable Mn(OH)_(2) can be further oxidized to MnO_(2).The heavy metal cations were immobilized in the silicoaluminate lattice,while the anions tended to form insoluble *** results may benefit the industry and government for better handling of TMT,FS and solid wastes containing the abovementioned five heavy metals.

关键词： Heavy metals Cementitious materials Tin tailings Stabilization/solidification Redox

An extended state observer with adjustable bandwidth for measurement noise

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Journal of Systems Engineering and Electronics 2024年第1期35卷 233-241页

作者： zhang Shihua QI Xiaohui yang Sen Shijiazhuang Campus Army Engineering University of PLAShijiazhuang 050053China

In this paper,a bandwidth-adjustable extended state observer(ABESO)is proposed for the systems with measurement *** is known that increasing the bandwidth of the observer improves the tracking speed but tolerates noise,which conflicts with observation ***,we introduce a bandwidth scaling factor such that ABESO is formulated to a 2-degree-of-freedom *** observer gain is determined and the bandwidth scaling factor adjusts the bandwidth according to the tracking *** the tracking error decreases,the bandwidth decreases to suppress the noise,otherwise the bandwidth does not *** is proven that the error dynamics are bounded and converge in finite *** relationship between the upper bound of the estimation error and the scaling factor is *** the scaling factor is less than 1,the ABESO has higher estimation accuracy than the linear extended state observer(LESO).Simulations of an uncertain nonlinear system with compound disturbances show that the proposed ABESO can successfully estimate the total disturbance in noisy *** mean error of total disturbance of ABESO is 15.28% lower than that of LESO.

关键词： extended state observer(ESO) boundedness and convergence adjustable bandwidth measurement noise

Prospects of sediment deposition at small watershed scale in the black soil region of Northeast China: A mini review

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Pedosphere 2024年第1期34卷 30-35页

作者： Guanghui zhang yang yang Yingna LIU Zhiqiang WANG State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China School of Geography Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

Sediment deposition is one of the most significant processes in small watersheds characterized by gentle long hillslopes in the black soil(Mollisol)region of Northeast China, as indicated by severe ephemeral gully and gully erosion on hillslopes and very low sediment concentrations in river *** reviews have been conducted to summarize the related research in this region. The objectives of this review were to identify the potential factors influencing sediment deposition, review related studies, and propose future research needs in the black soil region of Northeast China. Sediment deposition is controlled by the deficit between sediment transport capacity of flow and sediment load. Hence, all factors affecting flow transport capacity and sediment load directly affect sediment deposition. For a specific small watershed, the change in slope gradient along the flow path is the key factor affecting sediment deposition. Shelterbelts, ridge tillage systems, terraces, grass strips, road distribution, ponds and reservoirs, and land-use patterns also influence the spatial distribution and rate of deposition. The trace method has been widely used to quantify sediment deposition in this region. The results of cesium-137(^(137)Cs),lead-210(^(210)Pb), and magnetic susceptibility reveal that serious deposition occurs on the back and foot slopes. Distinct deposition occurs in front of contour shelterbelts. Future studies should focus on the methodology, spatial and temporal variations, dominant influencing factors and their mechanisms, and the potential effects on land productivity within specific small watersheds and across the black soil region. This review provides insights into the sediment deposition process in small watersheds characterized by gentle, long hillslopes.

关键词： Mollisol sedimentation soil and water conservation soil erosion soil redistribution

Untethered Micro/Nanorobots for Remote Sensing:Toward Intelligent Platform

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Nano-Micro Letters 2024年第2期16卷 450-483页

作者： Qianqian Wang Shihao yang Li zhang Jiangsu Key Laboratory for Design and Manufacture of Micro‑Nano Biomedical Instruments School of Mechanical EngineeringSoutheast UniversityNanjing 211189People’s Republic of China Department of Mechanical and Automation Engineering The Chinese University of Hong KongShatinHong Kong 999077People’s Republic of China Chow Yuk Ho Technology Centre for Innovative Medicine The Chinese University of Hong KongShatinHong Kong 999077People’s Republic of China T Stone Robotics Institute The Chinese University of Hong KongShatinHong Kong 999077People’s Republic of China Department of Surgery The Chinese University of Hong KongShatinHong Kong 999077People’s Republic of China

Untethered micro/nanorobots that can wirelessly control their motion and deformation state have gained enormous interest in remote sensing applications due to their unique motion characteristics in various media and diverse *** are developing micro/nanorobots as innovative tools to improve sensing performance and miniaturize sensing systems,enabling in situ detection of substances that traditional sensing methods struggle to *** the past decade of development,significant research progress has been made in designing sensing strategies based on micro/nanorobots,employing various coordinated control and sensing *** review summarizes the latest developments on micro/nanorobots for remote sensing applications by utilizing the self-generated signals of the robots,robot behavior,microrobotic manipulation,and robot-environment *** recent studies and relevant applications in remote sensing,we also discuss the challenges and future perspectives facing micro/nanorobots-based intelligent sensing platforms to achieve sensing in complex environments,translating lab research achievements into widespread real applications.

关键词： Micro/nanorobot Remote sensing Wireless control Self-propulsion Actuation at small scales

Separate Neural Networks for Gains and Losses in Intertemporal Choice

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Neuroscience Bulletin 2018年第5期34卷 725-735页

作者： yang-yang zhang Lijuan Xu Zhu-Yuan Liang Kun Wang Bing Hou Yuan Zhou Shu Li Tianzi Jiang School of Psychology Shaanxi Normal University Brainnetome Center Institute of Automation University of Chinese Academy of Sciences National Laboratory of Pattern Recognition Institute of Automation University of Chinese Academy of Sciences CAS Key Laboratory of Behavioral Science Institute of Psychology Department of Psychology University of Chinese Academy of Sciences Department of Psychology and Behavioral Sciences Zhejiang University CAS Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of Sciences The Clinical Hospital of Chengdu Brain Science Institute MOE Key Lab for Neuroinformation University of Electronic Science and Technology of China

An important and unresolved question is how human brain regions process information and interact with each other in intertemporal choice related to gains and losses. Using psychophysiological interaction and dynamic causal modeling analyses, we investigated the functional interactions between regions involved in the decision- making process while participants performed temporal discounting tasks in both the gains and losses domains. We found two distinct intrinsic valuation systems underlying temporal discounting in the gains and losses domains： gains were specifically evaluated in the medial regions, including the medial prefrontal and orbitofrontal cortices, and losses were evaluated in the lateral dorsolateral prefrontal cortex. In addition, immediate reward or pun- ishment was found to modulate the functional interactions between the dorsolateral prefrontal cortex and distinct regions in both the gains and losses domains： in the gains domain, the mesolimbic regions; in the losses domain, the medial prefrontal cortex, anterior cingulate cortex, and insula. These findings suggest that intertemporal choice of gains and losses might involve distinct valuation systems, and more importantly, separate neural interactions may implement the intertemporal choices of gains and losses. These findings may provide a new biological perspective for understanding the neural mechanisms underlying intertemporal choice of gains and losses.

关键词： Intertemporal choice Discounting losses Effective connectivity Dynamic causal model Dorso-lateral prefrontal cortex Insula

Post lithium-sulfur battery era:challenges and opportunities towards practical application

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Science China Chemistry 2024年第1期67卷 106-121页

作者： Jiahang Chen yang zhang Jun yang Yanna Nuli Jiulin Wang State Key Laboratory of Chemistry and Utilization of Carbon-Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830046China Department of Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Lithium-sulfur(Li-S)batteries have been regarded as a promising next-generation energy storage system owing to the high theoretical energy density and natural abundance of *** fundamental researches have pushed the flourishing development on electrochemical behaviors in recent 20 *** is time to evolve into post-Li-S battery era with the pursuit towards practical *** the landmark leap,numerous new challenges appear under harsh conditions,such as high sulfur loading,low cathode density,lean electrolyte and limited lithium ***,we summarize the considerable parameters of pouch Li-S cells and review the pioneering studies focused on the cathode structure,conversion kinetics,electrode interphase and battery *** interwoven relationship of these key points is concluded and discussed,which provides guidance to future researches aiming to safe and long-lifespan Li-S batteries with high energy density.

关键词： lithium-sulfur batteries practical application harsh conditions energy density pouch cells