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Atomic regulations of single atom from metal-organic framework derived carbon for advanced water treatment

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Nano Research 2023年第7期16卷 10326-10341页

作者： Xiang Li Bo wang Key Laboratory of Cluster Science Ministry of Education Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsAdvanced Technologies Research Institute(Jinan)Advanced Research Institute of Multidisciplinary ScienceSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyNo.5South StreetZhongguancunHaidian DistrictBeijing 100081China

Single atom(SA)-embedded nitrogen-doped carbon has shown great potential in environmental remediation.Nowadays,engineered nanomaterials(ENMs)have attracted great research interests in recent years.Metal-organic framework(MOF)derived SAs show the advantages of tunable topology and averaged separated active sites.SAs bridge the gap between homogeneous and heterogeneous catalysts.The reaction efficiency can be significantly improved by designing the MOFs derived from carbon and SAs.In this review,the research advanced in MOFs-derived carbon and SAs in advanced oxidation process(AOP)in water were summarized.Major strategies to fabricate the SAs derived from MOFs were discussed,including the mixed/single metal strategy,metal-containing linker strategy,pore confinement strategy,thermal diffusion strategy,and pyrolysis MOFs with bulk metals.Advanced characterization technologies have been introduced,including electron microscopy and spectroscopic methods.To explain the catalytic mechanism for various applications,the relationship between the performance and the atomic configuration was systematically discussed.Recent applications of the MOFs derived from carbon and SAs have been summarized.A series of the latest work on effectively removing pollutants by SAs are also listed.Based on the fundamental knowledge and recent practical application of MOFs-derived carbon and SAs,some perspectives on the further directions were presented.This review offers guidance for applying novel engineered nanomaterials in the water treatment field.

关键词： single-atom catalysts(SACs) engineered nanomaterials(ENMs) metal-organic framework(MOF) MOFs derived carbon water treatment

Development and Challenges of Electrode Ionomers Used in the Catalyst Layer of Proton-Exchange Membrane Fuel Cells:A Review

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Transactions of Tianjin University 2023年第5期29卷 360-386页

作者： Qingnuan Zhang Bo wang School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100081China

The electrode ionomer plays a crucial role in the catalyst layer(CL) of a proton-exchange membrane fuel cell(PEMFC) and is closely associated with the proton conduction and gas transport properties,structural stability,and water management capability.In this review,we discuss the CL structural characteristics and highlight the latest advancements in ionomer material research.Additionally,we comprehensively introduce the design concepts and exceptional performances of porous electrode ionomers,elaborate on their structural properties and functions within the fuel cell CL,and investigate their effect on the CL microstructure and performance.Finally,we present a prospective evaluation of the developments in the electrode ionomer for fabricating CL,offering valuable insights for designing and synthesizing more efficient electrode ionomer materials.By addressing these facets,this review contributes to a comprehensive understanding of the role and potential of electrode ionomers for enhancing PEMFC performance.

关键词： Electrode ionomer Proton conduction Oxygen transport resistance Catalyst layer Proton-exchange membrane fuel cell

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Seed density affects post-dispersal seed predation:evidence from a seed removal experiment of 62 species

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Integrative Zoology 2020年第2期15卷 135-143页

作者： Bo wang School of Resources and Environmental Engineering Anhui UniversityHefeiAnhui ProvinceChina Center for Integrative Conservation Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan ProvinceChina

Post-dispersal seed predation plays an important role in plant demography and biodiversity maintenance.However,the effects of seed density on seed predation from previous studies have been inconsistent.We dissected the effects of density on the 2-step processes of seed predation using 101520 seeds from 62 plant species in an alpine pine forest for 3 consecutive years.In this study we explained the current controversy surrounding the effects of density on seed predation.Seed encounter frequency(at least 1 seed being predated from an experiment depot)showed positive density dependence,while seed exploitation(the proportion of seeds being predated of the encountered depots)showed negative density dependence.both density effects showed a consistent trend but with different magnitudes of effect across years.Final seed predation is the combination of seed encounter and seed exploitation.Final seed predation could be either positively or negatively density-dependent and was contingent on the magnitude of the difference between positive density-dependent seed encounter and negative density-dependent seed exploitation.Our results also indicated that studies including only a few species would produce biased results,because the density effect on seed predation differed greatly among plant species.Future studies should include a large number of plant species that possess a wide range of diverse seed traits to avoid potential bias and produce more comprehensive and accurate results.

关键词： density rodent seed encounter seed predation seed removal

Enrichment of anammox biomass during mainstream wastewater treatment driven by achievement of partial denitrification through the addition of bio-carriers

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Journal of Environmental Sciences 2024年第3期137卷 181-194页

作者： Yuqing Ma Bo wang Xiaodi Li Shuo wang Wen wang Yongzhen Peng National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology Engineering Research Center of BeijingBeijing University of TechnologyBeijing 100124China

Anammox is widely considered as the most cost-effective and sustainable process for nitrogen removal.However,how to achieve the enrichment of anammox biomass remains a challenge for its large-scale application,especially in mainstream wastewater treatment.In this study,the feasibility of enrichment of anammox biomass was explored through the realization of partial denitrification and the addition of bio-carriers.By using ordinary activated sludge,a sequencing batch reactor(SBR)followed by an up-fow anaerobic sludge bed(UASB)was operated at 25±2℃ for 214 days.The long-term operation was divided into five phases,in which SBR and UASB were started-up in Phases I and II,respectively.By eliminating oxygen and adjusting the infow ratios in Phases III-V,advanced nitrogen removal was achieved with the effuent total nitrogen being 4.7 mg/L and the nitrogen removal efficiency being 90.5%in Phase V.both in-situ and ex-situ activity tests demonstrated the occurrence of partial denitrification and anammox.Moreover,16S rRNA high-throughput sequencing analysis revealed that Candidatus Brocadia was enriched from below the detection limit to in biofilms(0.4%in SBR,2.2%in UASB)and the foc sludge(0.2%in SBR,1.3%in UASB),while Thauera was mainly detected in the foc sludge(8.1%in SBR,8.8%in UASB),which might play a key role in partial denitrification.Overall,this study provides a novel strategy to enrich anammox biomass driven by rapid achievement of partial denitrification through the addition of bio-carriers,which will improve large-scale application of anammox processes in mainstream wastewater treatment.

关键词： Enrichment Anammox biomass Bio-carriers Partial denitrification Mainstream wastewater

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Shallow Feature-driven Dual-edges Localization Network for Weakly Supervised Localization

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Machine Intelligence Research 2023年第6期20卷 923-936页

作者： Wenjun Hui Guanghua Gu Bo wang School of Information Science and Engineering Yanshan UniversityQinhuangdao066000China Hebei Key Laboratory of Information Transmission and Signal Processing Qinhuangdao066000China

Weakly supervised object localization mines the pixel-level location information based on image-level annotations.The traditional weakly supervised object localization approaches exploit the last convolutional feature map to locate the discriminative regions with abundant semantics.Although it shows the localization ability of classification network,the process lacks the use of shallow edge and texture features,which cannot meet the requirement of object integrity in the localization task.Thus,we propose a novel shallow feature-driven dual-edges localization(DEL)network,in which dual kinds of shallow edges are utilized to mine entire target object regions.Specifically,we design an edge feature mining(EFM)module to extract the shallow edge details through the similarity measurement between the original class activation map and shallow features.We exploit the EFM module to extract two kinds of edges,named the edge of the shallow feature map and the edge of shallow gradients,for enhancing the edge details of the target object in the last convolutional feature map.The total process is proposed during the inference stage,which does not bring extra training costs.Extensive experiments on both the ILSVRC and CUB-200-2011 datasets show that the DEL method obtains consistency and substantial performance improvements compared with the existing methods.

关键词： Weakly supervised object localization edge feature mining edge of shallow feature map edge of shallow gradients similarity measurement

采用动态禁止角的动力定位系统推力分配策略(英文)

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船舶力学 2014年第9期18卷 1024-1034页

作者：李博王磊上海交通大学海洋工程国家重点实验室上海200030

动力定位系统利用推力分配策略将总推力需求分配到多个推进器上。为了避免由推进器尾流造成的推进器之间的水动力干扰,通常会在推力分配策略中设置推进器回转方向的禁止角。全回转推进器水动力干扰试验的结果显示,推进器之间水动力干扰... 详细信息

动力定位系统利用推力分配策略将总推力需求分配到多个推进器上。为了避免由推进器尾流造成的推进器之间的水动力干扰,通常会在推力分配策略中设置推进器回转方向的禁止角。全回转推进器水动力干扰试验的结果显示,推进器之间水动力干扰的程度前后随推进器的相对转速而变化。以模型试验的数据为基础,文章首次提出了动态禁止角的概念和数学模型。通过在推力分配策略中设置动态禁止角,回转方向的禁止角将随推进器的相对转速变化而进行调整,从而完全避免推进器之间的水动力干扰问题。动力定位系统的数值模拟结果显示新的推力分配策略可以给出更合理的分配结果。

关键词：动态禁止角动力定位系统推进器水动力干扰

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A low-fabrication-temperature, high-gain chip-scale waveguide amplifier

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Science China(Information Sciences) 2022年第6期65卷 247-255页

作者： Bo wang Peiqi ZHOU Xingjun wang Yandong HE State Key Laboratory of Advanced Optical Communication Systems and Networks Department of ElectronicsSchool of Electronics Engineering and Computer Science Peking University Institute of Microelectronics School of Electronics Engineering and Computer Science Peking University Frontier Science Center for Nano-optoelectronics Peking University Peking University Yangtze Delta Institute of Optoelectronics Peng Cheng Laboratory

The increasing prevalence of integrated on-chip optoelectronic devices has identified serious issues regarding inter-device transmission and coupling losses, highlighting an urgent need for on-chip waveguide amplifiers to compensate for these losses. Compared with other Er-based optical materials, erbium silicate is ideally suited to high-efficiency on-chip amplifiers and lasers because of its extremely high Er3+concentration(1022cm-3). Nevertheless, erbium silicate must be annealed above 1000℃ to crystallize and activate the Er3+, which damages other on-chip optoelectronic components and is not conducive to device integration.Here, we report a low-fabrication-temperature, high-luminescence-efficiency gain material by adding Bi2O3to an erbium-ytterbium silicate mixed film. Our experiments demonstrate that the proposed film crystallizes at 600℃ while the activation of Er3+is also achieved, which is the lowest activation temperature of on-chip waveguide amplifier to our knowledge. This material forms the basis for a new chip-scale waveguide amplifier design, with a theoretical multi-energy-level model of Bi-Er-Yb in the mixed thin films used to analyze its signal enhancement properties. We achieve a peak on-chip gain of 23 dB in a 3.3-mm-long waveguide under the pump and signal powers of 300 mW and 1 μW, respectively. These results highlight the potential of the proposed material for realizing on-chip amplifiers and lasers for large-scale nanophotonic integrated circuits.

关键词： photonic circuit integration low fabrication temperature high gain rare earth material waveguide amplifier

Rotating Stomata Measurement Based on Anchor-Free Object Detection and Stomata Conductance Calculation

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Plant Phenomics 2023年第4期5卷 767-778页

作者： Fan Zhang Bo wang Fuhao Lu Xinhong Zhang Huaihe Hospital of Henan University Kaifeng 475004China Henan Key Laboratory of Big Data Analysis and Processing Henan UniversityKaifeng 475004China State Key Laboratory of Crop Stress Adaptation and Improvement Henan UniversityKaifeng 475004China School of Software Henan UniversityKaifeng 475004China

Stomata play an essential role in regulating water and carbon dioxide levels in plant leaves,which is important for photosynthesis.Previous deep learning-based plant stomata detection methods are based on horizontal detection.The detection anchor boxes of deep learning model are horizontal,while the angle of stomata is randomized,so it is not possible to calculate stomata traits directly from the detection anchor boxes.Additional processing of image(e.g.,rotating image)is required before detecting stomata and calculating stomata traits.This paper proposes a novel approach,named DeepRSD(deep learning-based rotating stomata detection),for detecting rotating stomata and calculating stomata basic traits at the same time.Simultaneously,the stomata conductance loss function is introduced in the DeepRSD model training,which improves the efficiency of stomata detection and conductance calculation.The experimental results demonstrate that the DeepRSD model reaches 94.3%recognition accuracy for stomata of maize leaf.The proposed method can help researchers conduct large-scale studies on stomata morphology,structure,and stomata conductance models.

关键词： calculation. Deep rotating

Seed size affects rodent–seed interaction consistently across plant species but not within species:evidence from a seed tracking experiment of 41 tree species

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Integrative Zoology 2022年第5期17卷 930-943页

作者： Si CHEN Li FENG Bo wang School of Resources and Environmental Engineering Anhui UniversityHefeiAnhui ProvinceChina Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnan ProvinceChina Ailaoshan Station of Subtropical Forest Ecosystem Studies Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesJingdongYunnan ProvinceChina Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration(Anhui University) HefeiAnhui ProvinceChina

Scatter-hoarding rodents play a crucial role in seed survival and seed dispersal.As one of the most important seed traits,seed size and its effect on rodent–seed interaction attract lots of attention.Current studies usually target one or a few species and show inconsistent patterns;however,few experiments include a large number of species although many plant species usually coexist in natural forest and overlap in fruiting time.Here,we tracked the dispersal and predation of 26100 seeds belonging to 41 tree species in a subtropical forest for 2 years.Most species showed no relationships between seed size and rodent foraging preference,while the remaining species displayed diverse of patterns:monotonic decrease and increase trends,and hump-shaped and U-shaped patterns,indicating that a one-off study with a few species might give misleading information.However,the seed size effect across species was consistent in both years,indicating that including a large number of species that hold a sufﬁcient range of seed size may avoid the aforementioned bias.Interestingly,seed size effect differed among rodent foraging processes:a negative effect on seed harvest,a hump-shaped effect on seed removal and removal distance,while a positive effect on overwinter survival of cached seeds,indicating that rodents may make trade-offs between large and small seeds both among foraging processes and within a single process,thus lead to a parabolic relationship between seed size and seed dispersal success,that is medium-sized seeds were more likely to be removed and cached,and transported with a further distance.

关键词： foraging preference plant–animal interaction scatter-hoarding seed dispersal seed predation