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Isotope constraints on seasonal dynamics of nitrogen in Zhanjiang Bay, a typical mariculture bay in South China

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Acta Oceanologica Sinica 2024年第6期43卷 60-70页

作者： Chunqing chen Qibin Lao Fajin chen Guangzhe Jin Jiacheng Li Qingmei zhu College of Ocean and Meteorology Guangdong Ocean UniversityZhanjiang 524088China School of Chemistry and Environment Guangdong Ocean UniversityZhanjiang 524088China Key Laboratory for Coastal Ocean Variation and Disaster Prediction Guangdong Ocean UniversityZhanjiang 524088China Key Laboratory of Climate Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong ProvinceGuangdong Ocean UniversityZhanjiang 524088China

Eutrophication in coastal waters has been increasing remarkably,severely impacting the water quality in mariculture *** this study,we conducted multiple isotopic measurements on suspended particulate nitrogen(δ^(15)N-PN) and dissolved nitrate(δ^(15)N-NO_(3)^(-)and δ^(18)O-NO_(3)^(-)) in Zhanjiang Bay,a typical mariculture bay with a high level of eutrophication in South China,to investigate the changes in nitrogen sources and their cycling between the rainy and dry *** the rainy season,the study found no significant relation between δ^(15)NPN and δ^(15)N-NO_(3)^(-)due to the impact of heavy rainfall and terrestrial *** the upper bay,a slight nitrate loss and slightly higher δ_(15)N-NO_(3)^(-)and δ^(18)O-NO_(3)^(-)values were observed,attributed to intense physical sedimentwater *** some fluctuations,nitrate concentrations in the lower bay mainly aligned with the theoretical mixing line during the rainy season,suggesting that nitrate was primarily influenced by terrestrial erosion and that nitrate isotopes resembled the ***,the isotopic values of nitrate can be used for source apportionment in the rainy *** results indicated that soil nitrogen(36%) and manure and sewage(33%) were the predominant nitrogen sources contributing to nitrogen loads during this *** contrast,the dry season saw a deficient ammonium concentration(<0.2 μmol/L) in the bay,due to nearly complete consumption by phytoplankton during the red tide ***,the significant loss of nitrate and simultaneous increase in the stable isotopes of dissolved and particulate nitrogen suggest a strong coupling of assimilation and mineralization during the dry *** active biogeochemical processes during the dry season may be related to decreased runoff and increased water retention ***,our study illustrated the major seasonal nitrogen sources and their dynamics in Zhanjiang B ay,providing valuable insights for formulati

关键词： nitrogen stable nitrogen isotopes biogeochemical processes eutrophication Zhanjiang Bay

Transient synthesis of carbon-supported high-entropy alloy sulfide nanoparticles via flash Joule heating for efficient electrocatalytic hydrogen evolution

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Nano Research 2024年第4期17卷 3379-3389页

作者： Yuntian Liao Rongtao zhu Wenjun Zhang Haiyang zhu Yang Sun Jiale chen Zhenhua Dong Ronghuan Lv School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou 221116China

High entropy alloys(HEA)are frequently employed as catalysts in electrocatalytic hydrogen ***,the traditional high entropy alloy synthesis methods are time-consuming,energy-intensive,and environmentally polluting,which limits their application in the hydrogen evolution reaction(HER).This study leveraged the capabilities of flash Joule heating(FJH)to synthesize carbon-supported high-entropy alloy sulfide nanoparticles(CC-S-HEA)on carbon cloth(CC)with good self-standing properties within 300 *** carbon thermal shock generated by the Joule heating could pyrolyze the sulfur source into gas,resulting in numerous pore structures and defects on CC,forming an S-doped carbon substrate(CC-S).Then the S atoms were used to stably anchor the metal atoms on CC-S to form high-density uniformly dispersed HEA *** electrochemical test results demonstrated that CC-S-HEA prepared at 60 V flash voltage had HER performance comparable to Pt/*** density functional theory(DFT)calculation indicated that the S atoms on CC-S accelerated the electron transfer between the carbon substrate and HEA ***,the unique electronic structure of CC-S-HEA was beneficial to H*adsorption and promoted catalytic *** simplicity and versatility of FJH synthesis are of great significance for optimizing the synthesis of HEA and improving the quality of HEA products,which provides a broad application prospect for the synthesis of nanocatalysts with efficient HER performance.

关键词： high entropy alloy flash Joule heating carbon thermal shock hydrogen evolution reaction density functional theory

Parameter selection for the hydroconversion of waste polyethylene plastic under mild conditions: A comprehensive evaluation

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Science China(Technological Sciences) 2024年第8期67卷 2413-2426页

作者： chenG LeiLei chen RuiZhe zhu WeiQiang TIAN ShaoNan GU Jing YUAN HaoRan chen Yong Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China School of Energy Science and Engineering University of Science and Technology of ChinaHefei 230026China Institute of Process Engineering Chinese Academy of SciencesBeijing 100190China

The hydrogenolysis/hydrocracking of waste polyethylene(PE) has recently been intensively studied, with the general pursuit of low-temperature reaction conditions, increased oil-phase yield, and narrower carbon chain distribution. Before this, we utilized a ball-milled ZSM-22 catalyst loaded with Ru nanoparticles(NPs), which exhibited excellent hydroconversion performance. It deconstructed PE into >80 wt.% oil products under low temperatures and short reaction times. Herein, we investigated the influence of varying temperature/pressure parameters on the degree of specific hydrocracking/internal hydrogenolysis/terminal hydrogenolysis reactions. From the comprehensive energy efficiency perspective, including stirring, reaction, and product separation, as well as taking into account the degree of product isomerization and catalyst lifespan, we analyzed the optimization of parameters. This research abandons the notion that lower temperatures are better and proposes a more comprehensive evaluation framework for low-consumption hydroconversion of PE to produce high-value products.

关键词： plastic upcycling polyethylene hydrocracking hydrogenolysis comprehensive energy efficiency

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Photocatalytic in situ H_(2)O_(2) production and activation for enhanced ciprofloxacin degradation over CeO_(2)-Co_(3)O_(4)/g-C_(3)N_(4):key role of CeO_(2)

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Rare Metals 2024年第6期43卷 2695-2707页

作者： Hong-Jie zhu Yi-Kai Yang ming-Hui Li Lu-Ning Zou Hai-Tao Zhao Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology School of Chemistry and Chemical Engin College of Ecology and Environment Anhui Normal UniversityWuhu241002China Liaocheng YiLu Advanced Materials Co. LtdLiaocheng 252000China

The abused ciprofloxacin antibiotics have caused significant environmental *** oxidative degradation of ciprofloxacin exhibits promising efficacy,it often entails excessive energy ***,it is necessary to explore an effective and ecologically sustainable degradation ***,we demonstrated that g-C_(3)N_(4) decorated with the coordinated CeO_(2)and Co_(3)O_(4)(CeO_(2)-Co_(3)O_(4)/CN)exhibited effective ciprofloxacin photodegradation via in situ H_(2)O_(2) production and activation *** indicate that the introduced CeO_(2) enhances the transference of photogenerated electrons to O_(2) by adjusting the oxygen vacancy of photocatalyst,thereby increasing the generation of superoxide radicals,which in turn generate H_(2)O_(2),resulting in a 22.4-fold increase in H_(2)O_(2) generation over g-C_(3)N_(4).Moreover,the in situ H_(2)O_(2)generation facilitated by CeO_(2) is confirmed to be essential for ciprofloxacin degradation via CeO_(2)-Co_(3)O_(4)/CN,as it provides enough oxidant for Co_(3)O_(4) to activate into hydroxyl radicals for the pollutants ***,CeO_(2)-Co_(3)O_(4)/CN achieves a ciprofloxacin degradation ratio of 97.7%within 80 *** study introduces a novel approach that combines H_(2)O_(2) generation and activation,offering an innovative perspective for achieving clean and efficient purification of antibiotic-contaminated water.

关键词： CeO_(2) In situ H_(2)O_(2)generation Ciprofloxacin degradation Photocatalyst

Nitrogen isotope stratigraphy of the Early Cambrian successions in the Tarim Basin:Spatial variability of nitrogen cycling and its implication for paleo-oceanic redox conditions

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Acta Geochimica 2024年第4期43卷 785-801页

作者： Bi zhu Xuefeng Li Lu Ge Yongquan chen Institute of Earth’s Critical Zone School of Earth Sciences and EngineeringHohai UniversityNanjing 210098China Research Institute of Exploration and Development Tarim Oil Field CompanyPetroChinaKorlaChina

The Early Cambrian represents a critical time period characterized by extraordinary biological innovations and dynamic redox conditions in *** isotopic signatures of ancient sediments have the potential to elucidate the evolutionary path of marine redox states and the biogeochemical nitrogen cycle within the water column of the Early Cambrian *** existing research on this topic has predominantly focused on South China,the exploration of other continental margins has been limited,leaving contradictory hypotheses *** this study,pairedδ^(15)N andδ^(13)C org analyses were performed on the Lower Cambrian successions from the Shiairike section(inner ramp)and Well Tadong 2(deep shelf/basin)in the northwestern and eastern Tarim Basin,*** data from the Shiairike section reveal a discernible shift in the operation of different nitrogen cycles for the black chert-shale unit,also referred to as the black rock series in Chinese literature,of the Yurtus Formation(Fortunian stage to lower Stage 3).Oscillatingδ^(15)N values for its lower part are suggestive of alternating anaerobic assimilation of NH 4+and denitrification/*** is likely attributed to a shallow,unstable chemocline consistent with the upwelling and incursion of deep,anoxic waters during a major *** contrast,aerobic nitrogen cycling,indicated by positiveδ^(15)N values of>2‰,dominated the upper part alongside a reduction in upwelling *** the other hand,theδ^(15)N signatures of Xishanbulake and Xidashan Formations of Well Tadong 2,which encompass a time interval from the Cambrian Fortunian Age to Age 4,are indicative of N_(2)fixation by diazotrophs as the major nitrogen *** two studied intervals,although not time-equivalent,exhibit separated states of nitrogen cycling at least during the deposition of the Yurtus black rock *** spatially different nitrogen cycling of the studied sections is compatible with a redox-stratified ocean dur

关键词： Nitrogen isotopes Early Cambrian Tarim Black rock series

Copper Catalyzed Enantioconvergent Nucleophilic Substitutions

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Chinese Journal of Chemistry 2024年第10期42卷 1161-1174页

作者： Chunxi Huang Zilong Wan Aoping zhu Caiyou chen College of Chemistry and Molecular Sciences Wuhan UniversityWuhanHubei 430072China Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and College of Chemistry and Chemical Engineering Hubei UniversityWuhanHubei 430062China

As a versatile earth-abundant transition metal,Cu has long been widely applied in the C—C and C—X bond forming *** for now,low-valent Cu(Ⅰ)is known to reduce the redox active electrophiles via an SET pathway to give the corresponding radical and Cu(Ⅱ)*** resulting Cu(Ⅱ)species can interact with the radical via the out-sphere pathway,affording the coupling ***,Cu(Ⅱ)can trap the radical through the inner-sphere process to generate Cu(Ⅲ)species and then realize challenging bond formations due to the facile reductive elimination of Cu(Ⅲ)*** copper catalysis has been widely applied in arylations of various nucleophiles,copper-catalyzed enantioconvergent nucleophilic substitutions of racemic alkyl electrophiles have been less explored,likely due to the difficulties in overcoming the reduction potential of alkyl electrophiles,elimination of side reactions,and enantiomeric *** order to overcome the high reduction potential of alkyl electrophiles,the photo-induced strategy has been developed under mild *** alternative strategy with new anionic tridentate ligands has also been reported in this *** review summarizes recent developments in copper-catalyzed enantioconvergent nucleophilic substitutions of alkyl electrophiles by various nucleophiles to realize C—N,C—C,C—B,C—P and C—O bond formations and their brief mechanistic studies.

关键词： Enantioconvergent Nucleophilic substitution Copper Radical reactions Photocatalysis Asymmetric catalysis

Automatic Road Tunnel Crack Inspection Based on Crack Area Sensing and Multiscale Semantic Segmentation

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Computers, Materials & Continua 2024年第4期79卷 1679-1703页

作者： Dingping chen Zhiheng zhu Jinyang Fu Jilin He College of Mechanical and Electrical Engineering Central South UniversityChangsha410083China Department of Geotechnical Guangdong Hualu Transportation Technology Company LimitedGuangzhou510000China National Engineering Research Center of High-Speed Railway Construction Technology Changsha410075China

The detection of crack defects on the walls of road tunnels is a crucial step in the process of ensuring travel safetyand performing routine tunnel maintenance. The automatic and accurate detection of cracks on the surface of roadtunnels is the key to improving the maintenance efficiency of road tunnels. Machine vision technology combinedwith a deep neural network model is an effective means to realize the localization and identification of crackdefects on the surface of road *** propose a complete set of automatic inspection methods for identifyingcracks on the walls of road tunnels as a solution to the problem of difficulty in identifying cracks during manualmaintenance. First, a set of equipment applied to the real-time acquisition of high-definition images of walls inroad tunnels is designed. Images of walls in road tunnels are acquired based on the designed equipment, whereimages containing crack defects are manually identified and selected. Subsequently, the training and validationsets used to construct the crack inspection model are obtained based on the acquired images, whereas the regionscontaining cracks and the pixels of the cracks are finely labeled. After that, a crack area sensing module is designedbased on the proposed you only look once version 7 model combined with coordinate attention mechanism (CAYOLOV7) network to locate the crack regions in the road tunnel surface images. Only subimages containingcracks are acquired and sent to the multiscale semantic segmentation module for extraction of the pixels to whichthe cracks belong based on the DeepLab V3+ network. The precision and recall of the crack region localizationon the surface of a road tunnel based on our proposed method are 82.4% and 93.8%, respectively. Moreover, themean intersection over union (MIoU) and pixel accuracy (PA) values for achieving pixel-level detection accuracyare 76.84% and 78.29%, respectively. The experimental results on the dataset show that our proposed two-staged

关键词： Road tunnel crack inspection crack area sensing multiscale semantic segmentation CA-YOLO V7 DeepLab V3+

Interfacial engineering of the layered oxide cathode materials for sodium-ion battery

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Nano Research 2024年第3期17卷 1441-1464页

作者： Quanqing Zhao Ruru Wang ming Gao Faheem KButt Jianfeng Jia Haishun Wu Youqi zhu Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of Education School of Chemistry and Materials ScienceShanxi Normal UniversityTaiyuan 030032China Metals and Chemistry Research Institute China Academy of Railway Sciences Corporation LimitedBeijing 100081China Department of Physics Division of Science and TechnologyUniversity of EducationLahore 54770Pakistan Research Center of Materials Science Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green ApplicationsBeijing Institute of TechnologyBeijing 100081China

The layered metal oxides are reviewed as the hopeful cathode materials for high-performance sodium-ion batteries(SIBs)due to their large theoretical capacity,favorable two-dimensional(2D)ion diffusion channel,and simple ***,their cycling stability,rate capability,and thermal stability are still significantly concerned and highlighted before further practical *** chemical,mechanical and electrochemical stability of the cathode–electrolyte interfaces upon cycling is of great ***,the unique structural and electrochemical properties of the layered oxide cathode materials for SIB are *** mechanism of bulk/surface degradation induced by oxygen evolution,phase transition,microcrack,and electrolyte decomposition is thoroughly ***,the interfacial engineering to construct stable interface through various effective methods is fully *** future outlook and challenges for interfacial engineering in this filed are also *** review should shed light on the rational design and construct of robust interface for applications of superior layered oxide cathodes in SIB and may suggest future research directions.

关键词： interfacial engineering sodium-ion battery layered oxide electrolyte interface

Nanomedicine-mediated immunogenic cell death and its combination with immune checkpoint blockade therapy

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Science China(Technological Sciences) 2024年第8期67卷 2350-2362页

作者： chen JunBin ZHANG YuXi SU Miao zhu YueQiang YANG Xianzhu School of Biomedical Sciences and Engineering South China University of TechnologyGuangzhou International CampusGuangzhou 511442China National Engineering Research Center for Tissue Restoration and Reconstruction Guangdong Provincial Key Laboratory of Biomedical EngineeringKey Laboratory of Biomedical Materials and Engineering of the Ministry of EducationSouth China University of TechnologyGuangzhou 510006China

Cancer immunotherapies, which train the natural immune system to specifically kill tumor cells while sparing the healthy cells,have helped revolutionize cancer treatments and demonstrated promising clinical therapeutic benefits for decades. However, the therapeutic outcome of immunotherapies, even for the most successful immune checkpoint blockade(ICB) therapy, remains unsatisfactory in the clinical practice, mainly due to the low immunogenicity of solid tumors and its immunosuppressive tumor microenvironment(TME). Notably, several cancer treatment modalities, including chemotherapy, radiotherapy, and phototherapy, have been revealed to evoke tumor immunogenicity and reverse immunosuppressive TME via inducing immunogenic cell death(ICD) of tumor cells, which synergistically sensitized tumors to ICB therapy. Nanomedicines have been extensively applied to augment ICD-inducing treatment modalities and potentiate ICB therapeutic efficacy therapy due to the opportune convergence of immunotherapy and nanotechnology. Here, we discuss the recent advances in nanomedicine-mediated ICD and its combination with ICB therapy.

关键词： cancer immunotherapy nanomedicine immunogenic cell death immune checkpoint blockade