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Riverine sulfate sources and behaviors in arid environment,Northwest China:Constraints from sulfur and oxygen isotopes

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Journal of Environmental Sciences 2024年第3期137卷 716-731页

作者： Yifu Xu Wenjing liu Bing Xu zhifang Xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by humans.To understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern China,were investigated.These rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global average.The δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,respectively.The end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate gradients.Multiple isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid environment.Based on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely exposed.While the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier environment.Besides,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern China

Hydrogen bond-bridged phosphorene flexible film for photodynamic inhibiting Staphylococcus aureus

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Nano Research 2024年第6期17卷 5461-5468页

作者： Ziyu Wei Wenting Li Zhifang Liu Yongfa Zhu Huaqiang Cao Department of Chemistry Engineering Research Center of Advanced Rare Earth MaterialsTsinghua UniversityBeijing 100084China

Antibiotics are a widely used and effective treatment for bacterial infections.However,bacteria can gradually evolve during infection,leading to developing resistance to antibiotics,which renders previously effective treatments ineffective.Finding a useful and convenient manner to treat bacterial infections is a great challenge.Here,we report a flexible hydrogen-bond-bridged phosphorene film with photodynamic antibacterial properties and excellent mechanical properties,fabricated from electrochemical exfoliation of black phosphorus(BP).When illuminated under 700 nm light,the hydrogen bond-bridged phosphorene flexible film is capable of converting ground-state triplet oxygen(O_(2))into excited-state singlet oxygen(^(1)O_(2)),destroying the structure of the membrane of Staphylococcus aureus,and eventually leading to bacterial death,via breaking the C=C of unsaturated fatty acids within the bacterial cell membrane after the reaction between^(1)O_(2)and unsaturated fatty acids,thus realizing a highly efficient antibacterial approach,which is supported by gas chromatography-mass spectrometry(GC-MS)technique.This work establishes an effective phototherapy platform for treating bacterial traumatic infections.

关键词： hydrogen bond-bridged phosphorene flexible film photodynamic Staphylococcus aureus

Hydrochemistry and carbon isotope characteristics of Nujiang River water:Implications for CO_(2) budgets of rock weathering in the Tibetan Plateau

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Science China Earth Sciences 2023年第12期66卷 2953-2970页

作者： Wenjing liu Huiguo SUN Yuanchuan LI zhifang XU Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The Tibetan Plateau is one of the most complicated geographical units worldwide in terms of its tectonic and environmental background.Although a hotspot for continental weathering and carbon cycling studies,accurate determination of the weathering carbon budget is challenging in this area,especially sink and source flux quantification and the controlling mechanisms.Compared with other major rivers on the plateau,the Nujiang River is characterized by less human disturbance and maintains a relatively pristine state.This study investigates the high spatiotemporal resolution hydrochemistry and dual-carbon isotope composition(δ~(13)C_(DIC)andΔ~(14)C_(DIC))of river water in the Nujiang River Basin.The results revealed that the solutes and dissolved inorganic carbon in the river water are predominantly derived from rock weathering by carbonic and sulfuric acids,mainly due to the carbonate weathering process,and significantly enhanced by deep carbon sourcing from hot springs in the fault zone.The average contributions of geological and modern carbon in the main stream of the Nujiang River are 35.2%and 64.8%,respectively,and sulfide oxidation contributes>90%of sulfate ions in the river water.After considering the involvement of sulfuric acid generated by sulfide oxidation during rock weathering,the calculated consumption fluxes of atmospheric CO_(2) by silicate and carbonate weathering in the watershed were decreased by approximately 52.0%and 37.4%,respectively,compared with those calculated ignoring this process.Rock weathering of the Nujiang River Basin is a“CO_(2) sink”on a short time scale,while the participation of sulfuric acid makes it a“CO_(2) source”on a geological time scale.The high-frequency observations of ion concentrations,elemental ratios,and calculated contributions of different rock weathering materials indicate that carbonate rock weathering is more sensitive to temperature and runoff variations than silicate rock weathering,with the solute contribution from carbonate weathering increasing significantly

关键词： Tibetan Plateau Nujiang River Basin CO_(2)budgets of rock weathering Hydrochemistry and carbon isotope composition High spatiotemporal resolution

A Boosting Procedure for Variational-Based Image Restoration

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Numerical Mathematics(Theory,Methods and Applications) 2018年第1期11卷 49-73页

作者： Samad Wali Zhifang Liu Chunlin Wu Huibin Chang School of Mathematical Sciences Nankai UniversityTianjinChina School of Mathematical Sciences Tianjin Normal UniversityTianjinChina

Variational methods are an important class of methods for general image restoration.Boosting technique has been shown capable of improving many image denoising algorithms.This paper discusses a boosting technique for general variation-al image restoration methods.It broadens the applications of boosting techniques to a wide range of image restoration problems,including not only denoising but also deblur-ring and inpainting.In particular,we combine the recent SOS technique with dynamic parameter to variational methods.The dynamic regularization parameter is motivated by Meyer’s analysis on the ROF model.In each iteration of the boosting scheme,the variational model is solved by augmented Lagrangian method.The convergence analy-sis of the boosting process is shown in a special case of total variation image denoising with a“disk”input data.We have implemented our boosting technique for several im-age restoration problems such as denoising,inpainting and deblurring.The numerical results demonstrate promising improvement over standard variational restoration mod-els such as total variation based models and higher order variational model as total generalized variation.

关键词： Variational method image restoration total variation boosting augmented Lagrangian method

Safer Lithium-Ion Batteries from the Separator Aspect:Development and Future Perspectives

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Energy & Environmental Materials 2021年第3期4卷 336-362页

作者： Zhifang Liu Yingjun Jiang Qiaomei Hu Songtao Guo Le Yu Qi Li Qing liu Xianluo Hu State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

With the rapid development of lithium-ion batteries(LIBs),safety problems are the great obstacles that restrict large-scale applications of LIBs,especially for the high-energy-density electric vehicle industry.Developing component materials(e.g.,cathode,anode,electrolyte,and separator)with high thermal stability and intrinsic safety is the ultimate solution to improve the safety of LIBs.Separators are crucial components that do not directly participate in electrochemical reactions during charging/discharging processes,but play a vital role in determining the electrochemical performance and safety of LIBs.In this review,the recent advances on traditional separators modified with ceramic materials and multifunctional separators ranging from the prevention of the thermal runaway to the flame retardant are summarized.The component–structure–performance relationship of separators and their effect on the comprehensive performance of LIBs are discussed in detail.Furthermore,the research challenges and future directions toward the advancement in separators for high-safety LIBs are also proposed.

关键词： energy storage high safety lithium-ion batteries separators thermal stability

Metal surface wettability modification by nanosecond laser surface texturing:A review

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Biosurface and Biotribology 2022年第2期8卷 95-120页

作者： Zhifang Liu Tong Niu Yaxi Lei Yuanxin Luo Chongqing University of Technology ChongqingChina Chongqing University College of Mechanical and Vehicle EngineeringChongqingChina China Academy of Engineering Physics MianyangSichuanChina Chongqing University ChongqingChina Correspondence

Laser surface texturing(LST)is a non-contact manufacturing process for fabricating functional surfaces in a manner that improves the corresponding wettability,and is widely used in biomedicine and industry.Laser surface texturing is a facile approach that is compatible with various materials,can result in a hierarchical texture,and enables a high degree of surface wetting(i.e.,extreme wetting).In addition to surface structures,surface chemical modification is a primary factor in producing extreme wetting surfaces.This review discusses the effects of various surface textures and surface chemistries on wettability.Optimal laser parameters for the desired surface texture are based on the fundamental wettability and laser mechanism.In particular,bumps in the morphology are conducive to obtaining extreme wetting.Diverse surface chemical strategies result in extreme wetting by different mechanisms.This paper makes a rigorous evaluation of the laser parameters and optimal surface chemical modifications by elucidating the relationships between the surface structure,surface chemical modification,and wettability,and in so doing,determines the final wettability.The unresolved problems of LST are presented in the conclusion.This review provides guidance,development directions,and an integrated framework for LST,which will be useful for fabricating extreme wetting surfaces on various metals.

关键词： extreme wetting surface laser surface texturing nanosecond laser wettability

Genome-wide alternative splicing variation and its potential contribution to maize immature-ear heterosis

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The Crop Journal 2021年第2期9卷 476-486页

作者： Xiaojiao Hu Hongwu Wang Kun Li Xiaogang liu Zhifang Liu Yujin Wu Shuqiang Li Changling Huang National Engineer Laboratory of Crop Molecular Breeding Institute of Crop SciencesChinese Academy of Agricultural SciencesBeijing 100081China

Heterosis is a well-known phenomenon widely applied in agriculture.Recent studies have suggested that differential gene and protein expression between hybrids and their parents play important roles in heterosis.Alternative splicing(AS)is an essential posttranscriptional mechanism that can greatly affect the transcriptome and proteome diversity in plants.However,genome-wide AS divergence in hybrids compared to their parents and its potential contribution to heterosis have not been comprehensively investigated.We report the direct profiling of the AS landscape using RNA sequencing data from immature ears of the maize hybrid ZD808 and its parents NG5 and CL11.Our results revealed a large number of significant differential AS(DAS)events in ZD808 relative to its parents,which can be further classified into parental-dominant and novel DAS patterns.Parental-dominant,especially NG5-dominant,events were prevalent in the hybrid,accounting for 42%of all analyzed DAS events.Functional enrichment analysis revealed that the NG5-dominant AS events were involved mainly in regulating the expression of genes associated with carbon/nitrogen metabolism and cell division processes and contributed greatly to maize ear heterosis.Among ZD808,CL11,and NG5,32.5%of DAS contained or lacked binding sites of at least one annotated maize microRNA(miRNA)and may be involved in miRNA-mediated posttranscriptional regulation.Cis regulation was the predominant contributor to AS variation and participates in many important biological processes associated with immature ear development.This study provides a comprehensive view of genome-wide alternative splicing variation in a maize hybrid.

关键词： Maize Heterosis Dominant alternative splicing Cis-regulation

Anisotropic electrical properties of aligned PtSe_(2) nanoribbon arrays grown by a pre-patterned selective selenization process

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Nano Research 2022年第5期15卷 4668-4676页

作者： Huaipeng Wang Zhifang Liu Yilin Sun Xiaofan Ping Jianlong Xu Yingtao Ding Haowen Hu Dan Xie Tianling Ren School of Integrated Circuits Beijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijing 100084China Department of Chemistry Tsinghua UniversityBeijing 100084China School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China Institute of Functional Nano&Soft Materials(FUNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesSoochow UniversitySuzhou 215123China State Key Lab of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

This study proposes a feasible and scalable production strategy to naturally obtain aligned platinum diselenide(PtSe_(2))nanoribbon arrays with anisotropic conductivity.The anisotropic properties of two-dimensional(2D)materials,especially transition-metal dichalcogenides(TMDs),have attracted great interest in research.The dependence of physical properties on their lattice orientations is of particular interest because of its potential in diverse applications,such as nanoelectronics and optoelectronics.One-dimensional(1D)nanostructures facilitate many feasible production strategies for shaping 2D materials into unidirectional 1D nanostructures,providing methods to investigate the anisotropic properties of 2D materials based on their lattice orientations and dimensionality.The natural alignment of zigzag(ZZ)PtSe_(2) nanoribbons is experimentally demonstrated using angle-resolved polarized Raman spectroscopy(ARPRS),and the selective growth mechanism is further theoretically revealed by comparing edges and edge energies of different orientations using the density functional theory(DFT).Back-gate field-effect transistors(FETs)are also constructed of unidirectional PtSe_(2) nanoribbons to investigate their anisotropic electrical properties,which align with the results of the projected density of states(DOS)calculations.This work provides new insight into the anisotropic properties of 2D materials and a feasible investigation strategy from experimental and theoretical perspectives.

关键词： PtSe_(2) scalable production anisotropic properties nanoribbons density functional theory

Integrating surface and interface engineering to improve optoelectronic performance and environmental stability of MXenebased heterojunction towards broadband photodetection

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Nano Research 2023年第7期16卷 10148-10155页

作者： Zhifang Liu Mingjie Li Yilin Sun Huaipeng Wang Hongwu Chen Yulan Tian Han Wang Yingtao Ding Zhiming Chen School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China School of Integrated Circuits Beijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijing 100084China Research Institute of Petroleum Processing SinopecNo.18Xueyuan RoadHaidian DistrictBeijing 100083China Department of Chemistry Tsinghua UniversityBeijing 100084China

Two-/three-dimensional(2D/3D)heterojunction-based photodetectors have attracted much attention due to their highly efficient photoelectric conversion driven by the built-in electric field for high-speed photoresponse.However,a large dark current induced by unexpected surface states at the interface between 2D materials and 3D bulks is widely observed in such structures,greatly degrading their optoelectronic performance.Herein,a heterojunction of proton acid HCl treated MXene(H-MXene)/TiO_(2)/Si via integrating surface and interface engineering is fabricated,which exhibits decreased dark current and improved environmental stability.A feasible strategy to optimize the interface properties between MXene and Si is proposed by an in-situ oxidation process of MXene into TiO_(2),resulting in a suppressed dark current as well as high specific detectivity.Benefitting from the enhanced light absorption of MXene on the bulk Si substrate,the photoresponse of as-fabricated devices in the near-infrared region is also elevated.Moreover,the treatment of proton acid HCl on the surface of MXene brings better conductivity and environmental stability due to the decreased layer spacing of MXene,which is further confirmed by both experimental and theoretical methods.This work opens a unique way to comprehensively boost the optoelectronic performance of MXene-based photodetectors.

关键词： Ti_(3)C_(2)T_(x)MXene two-/three-dimensional(2D/3D)heterojunction photodetectors in-situ oxidation ion exchange