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Solubility determination and comparison ofβ-HMX and RDX in two binary mixed solvents(acetonitrile+water,nitric acid+water)

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Chinese Journal of Chemical Engineering 2024年第5期69卷 238-249页

作者： Yuehua Yao Fan Wang Yinguang Xu Zishuai Xu Lizhen Chen Jianlong wang School of Chemistry and Chemical Engineering North University of ChinaTaiyuan 030051China Gansu Yinguang Chemical Industry Group Co.Ltd. Baiyin 730900China

In order to remove hexahydro-1,3,5-trinitro-1,3,5-triazine(RDX),the main impurity,in process of polymorphic transformation of octrahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX),the solubility ofβ-HMX and RDX in acetonitrile(ACN)+water in the temperature range of 288.15-333.15 K and in nitric acid(HNO_(3))+water in the temperature range of 298.15-333.15 K were measured by laser dynamic method.The results showed that the solubility of bothβ-HMX and RDX in binary mixed solvents increased monotonously as the temperature increase at a given solvent composition or with increasing of mole fraction of solvent(ACN and nitric acid).Solubility data were well correlated by the modified Apelblat equation,Jouyban-Acree model,Yaws equation and van't Hoff equation,and the Yaws equation achieved the best fitting results according to the relative error and the mean square error root.Furthermore,the solubility ofβ-HMX and RDX in binary mixed solvent was compared,based on the solubility difference and the solvent's own properties,the best separation degree ofβ-HMX and RDX was found when the mole fraction of nitric acid was 0.22 at room temperature,which provided data support for HMX crystallization in mixed solvent.The solubility differences between RDX andβ-HMX in mixed solvents were explained from the formation of intermolecular and intramolecular hydrogen bonds.

关键词： Solubility Octrahydro-1 3 5 7-tetranitro-1 3 5 7-tetrazocine Hexahydro-1 3 5-trinitro-1 3 5-triazine Separation Model Hydrogen bond

Persistent mixing bursts in the equatorial Pacific thermocline induced by persistent equatorial waves

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Journal of Oceanology and Limnology 2024年第2期42卷 492-510页

作者： Jingjing ZHANG Chuanyu LIU Xiang GONG Fan Wang School of Mathematics and Physics Qingdao University of Science and TechnologyQingdao 266100China Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laoshan Laboratory Qingdao 266237China

A recent study by Liu et al.(2020)suggested that due to the saturation of equatorially trapped planetary waves with different dynamical types,temporal periods,meridional and baroclinic modes,complex layer structures of vertical velocity shear and hence turbulent mixing could frequently occur in the thermocline of the eastern equatorial Pacific.We investigated the occurrence of the interior turbulent mixing as indicated by shear instabilities,above the Equatorial Undercurrent(EUC)core at three equatorial sites along 140°W,170°W,and 165°E,respectively,based mainly on data from the Tropical Atmosphere and Ocean(TAO)mooring array.We found that turbulent mixing bursts persisted in the thermocline of all three sites.Specifically,the interior turbulent mixing layers(ITMLs)could occur in probability of approximately 68%,53%,and 48%at the three sites,respectively.The overall occurrence probability shows obvious and similar biannual variations at 140°W and 170°W,which is higher in boreal from late summer to winter and lower in spring.Vertically,the ITMLs are primarily located above the EUC core and prevail in deeper(shallower)layers from late summer to winter(spring).Most ITMLs(70%)lasted for hours to 3 days,and a few of them(15%)for more than 7 days.The thicknesses of ITMLs were concentrated between 15 and 55 m.At 165°E,the vertical distribution of ITML occurrence probability was different from that at 140°W and 170°W,as it did not show a preference for depths;the durations of ITMLs are short(also from hours to several days)and their thicknesses were between 5 and 25 m.These properties,particularly the high occurrence probability,and short durations demonstrated the persistence of thermocline mixing in the western to eastern equatorial Pacific thermocline and confirmed the generation mechanism by persistent equatorial waves as well.

关键词： interior turbulent mixing layer(ITML) weakly sheared layer(WSL) Equatorial Undercurrent(EUC)core occurrence probability seasonality

Contrasts of bimodal tropical instability waves(TIWs)-induced wind stress perturbations in the Pacific Ocean among observations,ocean models,and coupled climate models

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Journal of Oceanology and Limnology 2024年第1期42卷 1-23页

作者： Kai MA Chuanyu LIU Junli XU Fan Wang School of Mathematics and Physics Research Institute for Mathematics and Interdisciplinary SciencesQingdao University of Science and TechnologyQingdao 266100China Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Pilot National Laboratory for Marine Science and Technology(Qingdao) Qingdao 266237China

The coupling between wind stress perturbations and sea surface temperature(SST)perturbations induced by tropical instability waves(TIWs)in the Pacific Ocean has been revealed previously and proven crucial to both the atmosphere and ocean.However,an overlooked fact by previous studies is that the loosely defined“TIWs”actually consist of two modes,including the Yanai wave-based TIW on the equator(hereafter eTIW)and the Rossby wave-based TIW off the equator(hereafter vTIW).Hence,the individual feedbacks of the wind stress to the bimodal TIWs remain unexplored.In this study,individual coupling relationships are established for both eTIW and v TIW,including the relationship between the TIW-induced SST perturbations and two components of wind stress perturbations,and the relationship between the TIW-induced wind stress perturbation divergence(curl)and the downwind(crosswind)TIW-induced SST gradients.Results show that,due to different distributions of eTIW and vTIW,the coupling strength induced by the eTIW is stronger on the equator,and that by the vTIW is stronger off the equator.The results of any of eTIW and vTIW are higher than those of the loosely defined TIWs.We further investigated how well the coupling relationships remained in several widely recognized oceanic general circulation models and fully coupled climate models.However,the coupling relationships cannot be well represented in most numerical models.Finally,we confirmed that higher resolution usually corresponds to more accurate simulation.Therefore,the coupling models established in this study are complementary to previous research and can be used to refine the oceanic and coupled climate models.

关键词： bimodal tropical instability waves mesoscale air-sea interaction coupled models Yanai wave

Micro/nanoelectrode-based electrochemical methodology for single cell and organelle analysis

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Nano Research 2024年第1期17卷 196-206页

作者： Chuchu Xu De Yang Yuchan wang Ruolin Liu Fan Wang Zhongqun Tian Keke Hu Department of Chemistry College of Chemistry&Chemical EngineeringXiamen UniversityXiamen 361005China

Cells are the basic unit of life.Electrochemical analysis of single cells/organelles is essential for uncovering the molecular mechanisms of physiological and pathological processes that are difficult to elucidate on a larger scale.This paper provides an overview of the commonly used fabrication methods for micro/nanoelectrodes applied in the investigations of single cells/organelles as well as the corresponding electrochemical measurements over the last four years including extracellular measurement,combination of extra and intracellular measurement,intracellular reactive oxygen species and reactive nitrogen species(ROS/RNS)measurement,and isolated organelles measurement.

关键词： single cell/organelle micro/nanoelectrode electrochemical measurement chemical transmitters

Computational and dark-field ghost imaging with ultraviolet light

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Photonics Research 2024年第2期12卷 226-234页

作者： JIAQI SONG BAOLEI LIU YAO wang CHAOHAO CHEN XUCHEN SHAN XIAOLAN ZHONG LING-AN WU Fan Wang School of Physics Beihang UniversityBeijing 102206China Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems Department of Electronic Materials EngineeringResearch School of PhysicsThe Australian National UniversityCanberraACT 2600Australia Institute of Physics Chinese Academy of SciencesBeijing 100190China

Ultraviolet(UV)imaging enables a diverse array of applications,such as material composition analysis,biological fluorescence imaging,and detecting defects in semiconductor manufacturing.However,scientific-grade UV cameras with high quantum efficiency are expensive and include complex thermoelectric cooling systems.Here,we demonstrate a UV computational ghost imaging(UV-CGI)method to provide a cost-effective UV imaging and detection strategy.By applying spatial–temporal illumination patterns and using a 325 nm laser source,a singlepixel detector is enough to reconstruct the images of objects.We use UV-CGI to distinguish four UV-sensitive sunscreen areas with different densities on a sample.Furthermore,we demonstrate dark-field UV-CGI in both transmission and reflection schemes.By only collecting the scattered light from objects,we can detect the edges of pure phase objects and small scratches on a compact disc.Our results showcase a feasible low-cost solution for nondestructive UV imaging and detection.By combining it with other imaging techniques,such as hyperspectral imaging or time-resolved imaging,a compact and versatile UV computational imaging platform may be realized for future applications.

关键词： ghost illumination versatile

The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation

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Advances in Atmospheric Sciences 2024年第1期41卷 173-187页

作者： Lei ZHU Chunsong LU Xiaoqi XU Xin HE Junjun LI Shi LUO Yuan wang Fan Wang Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)and Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration Nanjing University of Information Science and TechnologyNanjing 210044China Nanjing Joint Institute for Atmospheric Sciences Nanjing 210019China College of Aviation Meteorology Civil Aviation Flight University of ChinaGuanghan 618307China Collaborative Innovation Center for Western Ecological Safety Lanzhou UniversityLanzhou 730000China Department of Geography Hong Kong Baptist UniversityHong Kong SAR 999077China

The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus clouds.Accurately obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization scheme.In this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy simulation.The results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved variables.The probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous studies.Further analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the future.The results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization.

关键词： large-eddy simulation cumulus clouds entrainment rate probability density functions spatial and temporal distribution

An Ion-Pumping Interphase on Graphdiyne/Graphite Heterojunction for Fast-Charging Lithium-Ion Batteries

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CCS Chemistry 2024年第1期6卷 110-124页

作者： Juan An Fan Wang Jia-Yue Yang Guoxing Li Yuliang Li Shandong Provincial Key Laboratory for Science of Material Creation and Energy Conversion Science Center for Material Creation and Energy ConversionSchool of Chemistry and Chemical EngineeringInstitute of Frontier and Interdisciplinary ScienceShandong UniversityQingdao 266237 Optics&Thermal Radiation Research Center Institute of Frontier and Interdisciplinary ScienceShandong UniversityQingdao 266237 Institute of Chemistry The Chinese Academy of SciencesBeijing 100190 University of Chinese Academy of Sciences Beijing 100049

The sluggish lithium-ion(Li-ion)transport kinetics in graphite anode hinders its application in fast-charging Li-ion batteries(LIBs).Here,we develop an ionpumping interphase(IPI)on graphdiyne(GDY)/graphite heterojunction anodes to boost the ionic transport kinetics and enable high-performance,fast-charging LIBs.The IPI changed the ion solvation/desolvation environment by covalent/non-covalent interactions with Li ions or solvents to optimize solid-electrolyte interphase(SEI)and regulate Li-ion transport behavior.We studied the in situ growth of few-layer GDY on graphite surface(GDY/graphite)as the IPI and found that the strong interaction between GDY and Li ions enabled surface-induced modification of the ion solvation behavior and surface-assisted desolvation effect to accelerate the Li-ion desolvation process.A functional anion-derived SEI layer with improved Li-ion conductivity was created.Together with the generated built-in electric field at GDY/graphite hetero-interface self-pumping Li ions to intercalate into the graphite,the Li-ion transport kinetics was significantly enhanced to effectively eliminate Li plating and large voltage polarization of the graphite anodes.A fast Li intercalation in GDY/graphite without Li oversaturation at the edge of the graphite was directly observed.The superior performance with high capacity(139.2 mA h g^(-1))and long lifespan(1650 cycles)under extremely fast-charging conditions(20 C,1 C=372 mA g^(-1))was achieved on GDY/graphite anodes.Even at low temperatures(-20℃),a specific capacity of 128.4 mA h g^(-1) was achieved with a capacity retention of 80%after 500 cycles at a 2 C rate.

关键词： extreme fast-charging lithium-ion batteries lithium-ion transport kinetics ion-pumping interphase graphdiyne/graphite heterojunction

Co-aromatization of methane and hexane over Pt encapsulated in ZSM-5 zeolite and the electronic effect of K promoters

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Science China Chemistry 2024年第3期67卷 1017-1027页

作者： Bei Liu Fan Wang Xiaomeng Dou Pengfei Li Hongwei Xiang Yong Yang Peng He State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China Department of Chemistry Tsinghua UniversityBeijing 100084China National Energy R&D Center for Coal to Liquid Fuels Synfuels China Technology Co.Ltd.Beijing 101407China University of Chinese Academy of Sciences Beijing 101408China Leibniz-Institut für Katalyse e.V.an der Universitat Rostock Rostock 18059Germany

The co-aromatization of methane with higher hydrocarbons represents a promising route to valorize methane, an abundant but underexploited carbon resource. In this study, we elucidate a novel approach to enhance the catalytic co-aromatization of hexane and methane by confining Pt within zeolite catalysts and modulating its electron density. Our findings show that encapsulating Pt within MFI structure is pivotal for activating the feedstock and fostering the formation of aromatic products. Interaction between K atoms and the silanol nest forms siloxy groups which are critical for the stabilization of Pt species. Tuning the K content in PtSn@MFI catalysts adeptly alters the electronic configuration of Pt clusters. This modification is corroborated by infrared and X-ray photoelectron spectroscopy analysis, and density functional theory calculations. Remarkably, the catalyst with 0.8 wt% K exhibits an optimal Pt electron density, driving its superior efficacy in the co-aromatization reaction, converting 0.78 mol of methane for each mole of hexane processed. By employing ~(13)C isotopic labeling and solid-state NMR studies, we demonstrate the participation of methane in the adsorbed species inside the zeolite channel and its incorporation to the benzyl site of the substitute group and phenyl rings in aromatic compounds, underscoring the importance of Pt encapsulation.

关键词： Pt encapsulation MFI zeolite methane activation co-aromatization ^(13)C solid-state NMR

Modifiable risk factors for esophageal cancer in endoscopic screening population:A modeling study

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Chinese Medical Journal 2024年第3期137卷 350-352页

作者： Qian Zhang Fan Wang Hao Feng Jie Xing Shengtao Zhu Hao Zhang Yang Li Wenqiang Wei Shutian Zhang Department of Gastroenterology Beijing Friendship HospitalCapital Medical UniversityNational Clinical Research Center for Digestive DiseaseBeijing Digestive Disease CenterBeijing Key Laboratory for Precancerous Lesion of Digestive DiseaseBeijing 100050China Center for Applied Statistics and School of Statistics Renmin University of ChinaBeijing 100872China Statistical Consulting Center Renmin University of ChinaBeijing 100872China National Cancer Center National Clinical Research Center for CancerCancer InstituteChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China Peking Union Medical College Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China Department of Gastroenterology Jizhong Energy Fengfeng Group HospitalHandanHebei 056000China RSS and China-Re Life Joint Lab on Public Health and Risk Management Renmin University of ChinaBeijing 100872China

To the Editor:Esophageal cancer,one of the most common cancer types in China,with an estimated 346,633 new cases and 323,600 deaths in 2022,is becoming an increasingly serious clinical and public health problem.^([1])The successful promotion of the self-management strategy has indicated that lifestyle modifications can be valuable in the primary prevention of cancer development.Adopting a healthy lifestyle has become a novel strategy for primary prevention and risk reduction in high-risk areas.Previous epidemiological studies have identified several lifestyle-related risk factors for esophageal cancer,including smoking and diet.^([2])Each factor can typically explain a modest proportion of cancer risk.However,when combined,these known risk factors may substantially affect the risk of esophageal cancer.Nevertheless,some risk factors for esophageal cancer are non-modifiable,including age,low socioeconomic status,and family history.Whether and how these non-modifiable risk factors affect primary cancer prevention by intervening with modifiable risk factors remain unclear.

关键词： esophageal prevention promotion