检索结果-南通市图书馆

nano Research 2024年第9期17卷 8250-8260页

作者： Yun han Di Lan Mengjun han Zihao Xia Jiaxiao Zou Zirui Jia College of Chemistry and Chemical Engineering Qingdao UniversityQingdao 266071China School of Materials Science and Engineering Hubei University of Automotive TechnologyShiyan 442002China

The rational design of composition nanostructures and morphologies of the carbon-based composites materials has a significant potential for tuning electromagnetic parameters and thereby improving their performance as electromagnetic wave(EMW)*** this work,the flower-like Cu/Co-nC/MoS_(2)(nC=n-doped carbon skeleton)composites were successfully prepared by employing CuCoZn-ZIF(ZIF=zeolitic imidazolate framework)as precursor with subsequent annealing and hydrothermal *** unique flower-like morphology and electromagnetic synergy strategy between components enable the as-obtained Cu/Co-nC/MoS_(2)composites to exhibit outstanding microwave absorption ***,the minimum reflection loss of Cu/Co-nC/MoS_(2)reaches-54.36 dB at 2.7 *** the thickness reduces to 2.2 mm,the maximum effective absorption bandwidth can be achieved as large as 6.72 *** research develops useful ideas for optimizing multicomponent microwave absorbing materials.

关键词： ternary metal-organic frameworks(MOFs) MoS_(2) flower-like morphology microwave absorption

Geochemistry and origins of hydrogen-containing natural gases in deep Songliao Basin,China:Insights from continental scientific drilling

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2024年第2期21卷 741-751页

作者： Shuang-Biao han Chao-han Xiang Xin Du Lin-Feng Xie Jie Huang Cheng-Shan Wang College of Geoscience and Surveying Engineering China University of Mining and TechnologyBeijing100083China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing100083China

The different reservoirs in deep Songliao Basin have non-homogeneous lithologies and include multiple layers with a high content of hydrogen *** gas composition and stable isotope characteristics vary significantly,but the origin analysis of different gas types has previously been *** on the geochemical parameters of gas samples from different depths and the analysis of geological settings,this research covers the diverse origins of natural gas in different *** gas components are mainly methane with a small amount of C_(2+),and non-hydrocarbon gases,including nitrogen(n_(2)),hydrogen(H_(2)),carbon dioxide(CO_(2)),and helium(He).At greater depth,the carbon isotope of methane becomes heavier,and the hydrogen isotope points to a lacustrine sedimentary *** increasing depth,the origins of n_(2)and CO_(2)change gradually from a mixture of organic and inorganic to *** origins of hydrogen gas are complex and include organic sources,water radiolysis,water-rock(Fe^(2+)-containing minerals)reactions,and *** shales of Denglouku and Shahezi Formations,as source rocks,provide the premise for generation and occurrence of organic ***,the deep faults and fluid activities in Basement Formation control the generation and migration of mantle-derived *** discovery of a high content of H_(2)in study area not only reveals the organic and inorganic association of natural-gas generation,but also provides a scientific basis for the exploration of deep hydrogen-rich gas.

关键词： Gas compositions Stable isotopes Gas origins Hydrogen gas Songliao Basin

Sobolev Mapping of the Bergman Projections on Generalized Hartogs Triangles

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第2期40卷 451-466页

作者： Hong Yan LIU Zhen han TU School of Mathematics and Statistics Wuhan UniversityWuhan 430072P.R.China

In this paper,we investigate Sobolev mapping properties of the Bergman *** domain we focus on is defined byΩm/n:={(z,w)∈C^(1+n):|w1|<|z|m1/n1<1,…|wn|<|z|/m_(n)/n_(n)<1},where m=(m1,…mn)∈(Z^(+))^(n),n=(n1,…nn)∈(... 详细信息

In this paper,we investigate Sobolev mapping properties of the Bergman *** domain we focus on is defined byΩm/n:={(z,w)∈C^(1+n):|w1|n1n|n)/n_(n)n)∈(Z^(+))^(n),n=(n1,…nn)∈(Z^(+))n,n∈Z^(+).Sobolev irregularity of the Bergman projections on 2 is *** also prove some Sobolev regularity results of the Bergman projections onΩm/n for m=(1,…1).

关键词： Bergman projections generalized Hartogs triangles Sobolev spaces

Slip distribution inversion of seismic sub-fault dip iteration using gradient based optimizer algorithm

在线全文

学校读者我要写书评

暂无评论

Geodesy and Geodynamics 2024年第2期15卷 114-121页

作者： Leyang Wang han Li Ming Pang Key Laboratory of Mine Environmental Monitoring and Improving Around Poyang Lake of Ministry of natural Resources East China University of TechnologyNanchang 330013China School of Surveying and Geoinformation Engineering East China University of TechnologyNanchang 330013China College of Resources and Environment Shandong Agricultural UniversityTaian 271018China

This paper considers setting different dips for different sub-faults to fit the actual rupture situation based on the fault rupture of the 2013 Lushan M_(S)7.0 ***,combined with the coseismic GnSS data of the Lushan earthquake,the source parameters and sliding distribution of the Lushan earthquake fault are ***,we use the gradient based optimizer(GBO)in nonlinear inversion to obtain the source parameters of this seismic *** inversion results indicate that the strike of the fault is 206.52°,the dip is 44.10°,the length is 21.92 km,and the depth is 12.79 *** refine the sliding distribution of the seismic fault,the seismic fault is divided into 3×3 ***,we fix the central sub-fault dip of 44.10°;the dip of other sub-faults is obtained by *** that,the model is further divided into a fault layer model composed of 23×19 sub fault slices,and using the Matlab fitting function is used to fit the dip of the 23×19 sub ***,the Lushan seismic fault plane is established as a shovel structure with steep upper and gentle lower,steep south and gentle *** slip distribution inversion results indicate that the depth of the slip peak is 13 km,the corresponding maximum slip momentum is 0.67 m,the seismic moment is 1.10×10^(19)n·m and the corresponding moment magnitude is *** results above are consistent with the research results of seismology.

关键词： Gradient basedoptimizer(GBO) Lushan earthquake non-planefault model Slid distribution

Effects of nitrogen deposition on the carbon budget and water stress in Central Asia under climate change

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2024年第8期16卷 1118-1129页

作者： han Qifei XU Wei LI Chaofan School of Geographical Sciences Nanjing University of Information Science&TechnologyNanjing 210044China

Atmospheric deposition of nitrogen(n)plays a significant role in shaping the structure and functioning of various terrestrial ecosystems ***,the magnitude of n deposition on grassland ecosystems in Central Asia still remains highly *** this study,a multi-data approach was adopted to analyze the distribution and amplitude of n deposition effects in Central Asia from 1979 to 2014 using a process-based denitrification decomposition(DnDC)*** showed that total vegetation carbon(C)in Central Asia was 0.35(±0.09)Pg C/a and the averaged water stress index(WSI)was 0.20(±0.02)for the whole *** n deposition led to an increase in the vegetation C of 65.56(±83.03)Tg C and slightly decreased water stress in Central *** of this study will expand both our understanding and predictive capacity of C characteristics under future increases in n deposition,and also serve as a valuable reference for decision-making regarding water resources management and climate change mitigation in arid and semi-arid areas globally.

关键词： carbon dynamics climate change grassland ecosystems nitrogen deposition water stress index

Photoinduced superlubricity on TiO_(2) surfaces

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第3期12卷 428-438页

作者： Ke han Liran MA Yu TIAn Jianbin LUO State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China Received:16 September 2022/Revised:28 October 2022/Accepted:27 December 2022The author(s)2022.

Superlubricity control is of great interest in both industry and scientific research,and several methods have been proposed to achieve this *** this work,ultraviolet(UV)light was introduced into titanium dioxide(TiO_(2))and silicon nitride(Si_(3)n_(4))tribosystems to accomplish photoinduced *** friction coefficients(COFs)between Si_(3)n_(4) balls and TiO_(2) plates in the mixtures of sulfuric acid(H^(2)SO_(4))solution and glycerol solution were obviously reduced,and the system entered the superlubricity region(COFnation at a speed of 56 mm/***,the COF was much larger without UV treatment than that with UV *** formation of silica(SiO_(2))layers on the surfaces of Si_(3)n_(4) balls and the elastohydrodynamic effects were determined to be fundamental to the low friction in this experiment,and the enhancement of the combination between the TiO_(2) surface and the hydroxy group of glycerol by UV illumination was the key to the photoinduced superlubricity in this *** findings showed one method for achieving superlubricity by introducing a light field that could be further applied to special working conditions.

关键词： light control friction superlubricity glycerol titanium dioxide(TiO_(2))

Plasma-exfoliated g-C_(3)n_(4) with oxygen doping: tailoring photocatalytic properties

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2024年第2期18卷 27-39页

作者： Yuxin Li Junxin Guo Rui han Zhao Wang national Engineering Research Centre of Industry Crystallization Technology School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Heteroatom doping and defect engineering have been proposed as effective ways to modulate the energy band structure and improve the photocatalytic activity of g-C_(3)n_(4). In this work, ultrathin defective g-C_(3)n_(4) was successfully prepared using cold plasma. Plasma exfoliation reduces the thickness of g-C_(3)n_(4) from 10 nm to 3 nm, while simultaneously introducing a large number of nitrogen defects and oxygen atoms into g-C_(3)n_(4). The amount of doped O was regulated by varying the time and power of the plasma treatment. Due to n vacancies, O atoms formed strong bonds with C atoms, resulting in O doping in g-C_(3)n_(4). The mechanism of plasma treatment involves oxygen etching and gas expansion. Photocatalytic experiments demonstrated that appropriate amount of O doping improved the photocatalytic degradation of rhodamine B compared with pure g-C_(3)n_(4). The introduction of O optimized the energy band structure and photoelectric properties of g-C_(3)n_(4). Active species trapping experiments revealed ·O_(2)^(–) as the main active species during the degradation.

关键词： graphitic carbon nitride cold plasma oxygen doping nitrogen defect visible-light photocatalysis

nHC-derived carbon-centered luminescent radicals with shortwavelength emission via suppression of Kasha's rule

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第8期67卷 2679-2685页

作者： Can Chen Xin Li Xinhua Ouyang Ying-Feng han Key Laboratory of Synthetic and natural Functional Molecule Chemistry of the Ministry of Education Xi’an Key Laboratory of Functional Supramolecular Structure and MaterialsCollege of Chemistry and Materials ScienceNorthwest UniversityXi’an 710127China College of Material Engineering Fujian Agriculture and Forestry University Fuzhou 350108China

Luminescent organic radicals have garnered increasing attention owing to their versatile applications in sensing, imaging, and organic light-emitting diodes(OLEDs), attributed to their unique emission properties originating from the doublet spin ***, the natural narrow bandgap of organic free radicals typically limits their emission to the long-wavelength *** luminescent organic radicals with short-wavelength emission remains a significant challenge. Herein, a series of carbon-centered radicals with short-wavelength emission(383–476 nm) by combining n-heterocyclic carbenes with various polycyclic aromatic hydrocarbons(PAHs)(2-naphthyl, 2a~Ⅰ and 2b~Ⅰ;2-phenanthryl, 2a~Ⅱand 2b~Ⅱ;2-anthryl, 2a~Ⅲand 2b~Ⅲ;3-phenanthryl, 2a~Ⅳand 2b~Ⅳ). Theoretical calculations reveal that the introduction of PAHs significantly increases the ΔE_(D2-D1) in 2a^(Ⅰ–Ⅲ)and 2b^(Ⅰ–Ⅲ)compared to that in phenyl-derived radical congeners. Consequently, the internal transition from D2 to D1 is impeded, leading to a high yield of D2 emission and a suppressed Kasha's rule, thereby overcoming the limitations imposed by their narrow bandgap. For 2a~Ⅳ and 2b~Ⅳ, despite a moderately large ΔED2-D1value, the ΔED3-D1value exceeds 1 e V, indicating that their emission likely originates from the D3 state. Furthermore, we utilized 2a~Ⅲand 2b~Ⅲ as emissive materials in OLEDs,resulting in blue emissions with external quantum efficiencies of 7.5% and 6.5%, respectively.

关键词： n-heterocyclic carbenes luminescent organic molecules carbon-centered radicals short-wavelength emission

Variability of the Pacific subtropical cells under global warming in CMIP6 models

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第1期42卷 24-40页

作者： Xue han Junqiao FEnG Yunlong LU Dunxin HU Key Laboratory of Ocean Circulation and Waves Chinese Academy of SciencesQingdao 266071China Institute of Oceanology Chinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China Laboratory for Ocean Dynamics and Climate Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China

The Pacific subtropical cells(STCs)are shallow meridional overturning circulations connecting the tropics and subtropics,and are assumed to be an important driver of the tropical Pacific decadal *** variability of STCs under global warming is investigated using multimodal outputs from the latest phase of the Coupled Model Inter-comparison Project(CMIP6)and ocean reanalysis ***,the volume transport diagnostic analysis is employed to evaluate how coupled models and ocean reanalysis products reproduce interior STC *** variation of heat transport by the interior STC under the high-emissions warming scenarios is also *** results show that the multimodal-mean linear trends of the interior STC transport along 9°S and 9°n are-0.02 Sv/a and 0.04 Sv/a under global warming,respectively,which is mainly due to the combined effect of the strengthened upper oceanic stratification and the weakening of wind *** is a compensation relationship between the interior STC and the western boundary transport in the future climate,and the compensation relationship of 9°S is more significant than that of 9°*** addition,compared with ocean reanalysis products,the coupled models tend to underestimate the variability of the interior STC transport convergence,and thus may lose some sea surface temperature(SST)driving force,which may be the reason for the low STC-SST correlation simulated by the *** future scenario simulation shows that the heat transport of interior STC is weakened under global warming,with a general agreement across models.

关键词： interior subtropical cell(STC) global warming Coupled Model Inter-comparison Project(CMIP6) western boundary transport

Mutations in the SARS-CoV-2 spike receptor binding domain and their delicate balance between ACE2 affinity and antibody evasion

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2024年第6期15卷 403-418页

作者： Song Xue Yuru han Fan Wu Qiao Wang Key Laboratory of Medical Molecular Virology (MOE/nHC/CAMS) Shanghai Institute of Infectious Disease and BiosecurityShanghai Frontiers Science Center of Pathogenic Microorganisms and InfectionSchool of Basic Medical SciencesShanghai Medical CollegeFudan UniversityShanghai 200032China

Intensive selection pressure constrains the evolutionary trajectory of SARS-CoV-2 genomes and results in various novel variants with distinct mutation *** mutations,particularly those within the receptor binding domain(RBD)of SARS-CoV-2 spike(S)protein,lead to the functional alteration in both receptor engagement and monoclonal antibody(mAb)***,we review the data of the RBD point mutations possessed by major SARS-CoV-2 variants and discuss their individual effects on ACE2 affinity and immune *** single amino acid substitutions within RBD epitopes crucial for the antibody evasion capacity may conversely weaken ACE2 binding ***,this weakened effect could be largely compensated by specific epistatic mutations,such as n501Y,thus maintaining the overall ACE2 affinity for the spike protein of all major *** predominant direction of SARS-CoV-2 evolution lies neither in promoting ACE2 affinity nor evading mAb neutralization but in maintaining a delicate balance between these two ***,this review interprets how RBD mutations efficiently resist antibody neutralization and meanwhile how the affinity between ACE2 and spike protein is maintained,emphasizing the significance of comprehensive assessment of spike mutations.

关键词： ACE2 affinity maintained