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Gradient maturation experiment on hairs implies taphonomic changes in fossil hairs

science China earth sciences 2025年第1期68卷 62-73页

作者： Xin LI Yibo ZHOU Tao ZHAO Xingjian HE Yanhong PAN State Key Laboratory for Mineral Deposits research Center for Critical Earth Material CyclingCentre for Research and Education on Biological Evolution and Environment and Frontiers ScienceSchool of Earth Sciences and EngineeringNanjing UniversityNanjing210023China Institute of Palaeontology Yunnan Key Laboratory of Earth System ScienceYunnan Key Laboratory for PalaeobiologyYunnan UniversityKunming650500China

Mammalian hair,as a key feature related to endothermy,physical protection,and camouflage,has a long geohistorical record that dates back even to the ***,the limited information on the taphonomy of hair hinders the understanding of its evolutionary significance in deep *** address this,we conducted taphonomic experiments to simulate the transformation process of black *** changes in the morphological structure,microscopic characteristics,and chemical composition of hair during the simulated fossilization process were documented by scanning electron microscopy,Fourier transform infrared(FTIR)spectroscopy,and Raman *** results revealed that damage to the morphology of hair began at a mild temperature(150–175℃),and hair transformed into a fluid-like mass at a relatively high temperature(200℃).In addition,the morphological structure of melanosomes had relatively greater preservation potential than keratins did,and the microscopic features of melanosomes were persistently *** Raman and FTIR spectra indicated that the characteristic melanin and keratin peaks changed as the temperature *** the chemical signals were not lost completely,the variations in the characteristic amide bands in the FTIR spectra indicate that the keratins severely degraded at high temperatures(>200℃),whereas the characteristic melanin bands in the Raman spectra suggested that melanin signals were still recognizable,even at high temperatures(>200℃).These results were confirmed by principal component analysis(PCA)and principal component analysis linear discriminant analysis(PCA–LDA).In addition,the Raman signals of all the samples in the simulated experiments were distinguished from the signals of common geological carbonaceous materials(humic acid),which suggested that Raman spectroscopy can be used to detect melanin in fossils.

关键词： Mammalian hair Melanin Keratin Fossilization Experimental taphonomy

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Constraints on what controls millennial-scale basin-wide denudation across mountain belts,Asia

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science China earth sciences 2025年第1期68卷 74-93页

作者： Ye YANG Steven A.BINNIE Sheng XU Cong-Qiang LIU Tibor J.DUNAI Institute of Surface-earth System science School of Earth System ScienceTianjin UniversityTianjin300072China Institute of Geology and Mineralogy University of CologneCologne50674Germany

The terrestrial cosmogenic nuclide dataset consisting of 1233^(10)Be measurements of fluvial sediment samples across the Asian mountain belts is used to constrain the influence of climate,tectonics and topography on earth-surface denudation processes.^(10)Be-derived basin-wide denudation rates were recalculated using a Monte Carlo simulation approach that relied on pixel-by-pixel production *** rates derived span four orders of magnitude,from 7.4±0.7 mm kyr^(-1)(1σ;Central Tibetan Plateau)to 9,646_(-744)^(+777)mm kyr^(-1)(1σ;Southern Tibetan Plateau),with a median of 186 mm kyr^(-1).Comparing our results with the traditional basin-wide production rate scaling model using a centroid coordinate and mean elevation,suggests that 96.6%of production rates will be underestimated using the latter method,especially for basins with a large *** bias between both methods reaches as large as 40%,caused by basin hypsometry and the nonlinear scaling of production rate with elevation and *** of the correlations between uniformly recalculated denudation rates and tectonics,climate,topography and rock lithology will facilitate the extrapolation of denudation rates in unknown basins using available *** the perspective of local scales,precipitation coupled with neotectonics-driven landslides is likely the most influential factor in subtropical Taiwan Island,while topography primarily constrains surface denudation rates in the eastern Tibetan Plateau within a narrow range of *** highland regions with glacier coverage,such as the Pamir,central and southern Tibetan Plateau high denudation rates are affected by glaciation,whereas lower precipitation and high erosion base level may limit river incision and evolving relief in the Central Tibetan *** contrast to local-scale findings highlighting a dominant factor constraining denudation rate,our large-scale quantitative analyses across the Asian mountain belts finds that(1)topographic

关键词： ^(10)Be-derived denudation rate Climate change Tectonic uplift Topographic gradient Asian mountains

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A deeper and hotter Martian core-mantle differentiation inferred from FeO partitioning

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science Bulletin 2025年第3期70卷 429-436页

作者： Yunguo Li Chunhui Li You Zhou Yun Liu Huaiwei Ni State Key Laboratory of Lithospheric and Environmental Coevolution University of Science and Technology of ChinaHefei 230026China Deep Space Exploration Laboratory/School of earth and Space sciences University of Science and Technology of ChinaHefei 230026China research centre for Planetary science College of Earth and Planetary SciencesChengdu University of TechnologyChengdu 610059China State Key Laboratory of Ore Deposit Geochemistry Chinese Academy of SciencesGuiyang 550081China

The core-mantle differentiation process plays a pivotal role in redistributing material on a massive scale,shaping the long-term evolution of rocky *** this process is crucial for gaining insights into the accretion and evolution of planets like ***,the details of Mars’s core-mantle differentiation remain poorly understood due to limited compositional data for its core and *** this study,we aim to constrain the Martian core-mantle differentiation by examining FeO partitioning between core and mantle materials,incorporating improved Martian compositional data from the InSight *** ab initio thermodynamic techniques,we calculated the FeO partition coefficient between liquid iron and silicate *** results align with previous studies while also clarifying the factors affecting partitioning *** on these findings and estimates of oxygen concentration in the core,we infer that Mars’s core and mantle likely differentiated at temperatures above 2440 K and pressures ranging from 14 to 22 *** these estimates are higher than previously reported,they are consistent with observed abundances of moderately siderophile elements and Mars’s accretion models.

关键词： Mars Core-mantle differentiation Volatile Partitioning

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The potential of Ca isotopes to trace subducted marine carbonates in deep mantle

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Journal of Oceanology and Limnology 2025年第1期43卷 29-40页

作者： Hongli ZHU Renqiang LIAO Long DU Zhaofeng ZHANG Key Laboratory of Ocean Observation and Forecasting Center of Deep Sea ResearchInstitute of OceanographyChinese Academy of SciencesQingdao 266071China Laboratory for Marine Geology Qingdao Marine Science and Technology CenterQingdao 266237China College of earth science and Engineering Shandong University of Science and TechnologyQingdao 266590China research Center for Planetary science College of Earth SciencesChengdu University of TechnologyChengdu 610059China

Marine carbonates,the major carrier of carbon upon the upper crust,can be subducted into the earth’s interior along with oceanic crust,and then returned to the surface through magmatism,which constitute the deep carbon *** process plays an important role in modulating the CO_(2) concentrations in the atmosphere over geologic time,and thus the forming of the habitable ***,identifying recycled marine carbonates in the mantle is critical to well understand the global deep carbon *** is one of the major constituent cations in marine carbonates and its isotopes may be a potential tracer for recycled marine carbonates in the *** further evaluate the capability and challenges of Ca isotopes as such a geochemical tracer,we reviewed the Ca isotopic compositions in important reservoirs and the behavior of Ca isotopes during high-temperature geological processes that are related to the deep carbon cycle,including plate subduction,mantle metasomatism,mantle partial melting,magma differentiation,*** studies show that carbonate-rich marine sediments have significantly lowerδ^(44/40) Ca than the earth mantle,and metasomatism by such recycled materials can cause lighter Ca isotopic compositions in deep mantle-derived rocks than those of the depleted mantle and mid ocean ridge ***,the Ca isotopic fractionation during partial melting of mantle peridotites is small(~0.10‰)and the Ca isotopic fractionation during plate subduction and intermediate-mafic magma evolution is *** investigations suggest that Ca isotopes have great advances in tracing such recycled materials in the ***,other processes(such as the influence by partial melts of eclogites)may induce similar effects on mantle-derived rocks as subducted marine carbonates but still remains debated,and thus further investigations are strongly needed in the future.

关键词： Ca isotope marine carbonate mantle metasomatism partial melting fractional crystallization

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Constructing 2D bismuth-based heterostructure for highly efficient photocatalytic CO2 reduction

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Tungsten 2025年第1期7卷 71-79页

作者： Ruo-Hang Xu Hao-Yu Jiang Dan-Dan Cui Kun-Rong Du Hong-Run Zhang Sheng-Jie Xu Ya-Qi Li Zhi-Zhen Ren Liang Wang Wei-Chang Hao Yi Du School of Physics and BUAA-UOW Joint research centre Beihang University Shenzhen Institute of Beihang University centre for Catalysis and Clean Energy School of Environment and Science Griffith University

Reforming carbon dioxide（CO2） into fuels and valuable chemicals using solar energy holds significant potential for emission reduction and addressing energy supply *** recombination of photocarriers remains a major obstacle,however,to enhancing solar energy conversion efficiency in the photocatalytic reaction *** two-dimensional materials,constructing heterogeneous structures has emerged as an effective strategy to enhance the separation of photoexcited carriers by leveraging the internal electric field at the heterogeneous ***,we present a facile strategy for preparing Bi4NbO8Br/Bi2WO6plate-on-plate Z-scheme junctions with a strong internal electric field by in situ *** unique heterostructure facilitates efficient separation and transport of photoexcited charges by harnessing the internal electric field induced by chemical bonding at the lateral ***,the Bi4NbO8Br/Bi2WO6heterostructure exhibits enhanced CO2photoreduction properties,along with a CO yield rate of approximately 35 μmol·g-1·h-1under full light *** work offers novel insights into the synthesis of unique hetero structures intended to enhance the efficiency of photocatalytic CO2reduction.

关键词： Bi4NbO8Br/Bi2WO6 CO2 reduction Heterostructures Photocatalysts

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Is dark energy necessary for the sustainability of traversable wormholes?

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Chinese Physics C 2025年第1期49卷 290-304页

作者： Ayan Banerjee Sudan Hansraj Anirudh Pradhan Abdelghani Errehymy Astrophysics research centre School of MathematicsStatistics and Computer ScienceUniversity of KwaZulu-NatalPrivate Bag X54001Durban 4000South Africa Atrophysics research centre School of MathematicsStatistics and Computer ScienceUniversity of KwaZulu-NatalPrivate Bag X54001Durban 4000South Africa centre for Cosmology Astrophysics and Space ScienceGLA UniversityMathura-281406Uttar PradeshIndia

Dark energy is typically the principal component needed for the traversability of wormholes(WH),as it provides the negative gravity effect required to keep the throat ***,can this be achieved without dark energy?It turns out that if we couple the trace of energy-momentum with the standard Einstein-Hilbert Lagrangian and utilize a specific equation of state(EoS),dark energy may be *** Casimir stress energy is known to result in the violation of the null energy condition(NEC)on the energy momentum *** phenomenon makes such an EoS an ideal candidate for generating traversable WH *** laboratory proven phenomenon provides a natural mechanism to sustain an open WH throat without relying on dark ***,we generate two classes of WH solutions using this in energy-momentum trace-coupling *** the specific choice of the Casimir EoS relating the energy-momentum tensor components[Kar and Sahdev:***.D 52,2030(1995)]and different choices of redshift functions,we determine the WH geometry *** obtained WH solutions violate the NECs,and all qualitative constraints demanded for physically realizable WHs are *** is demonstrated via graphical plots for a suitably chosen range of coupling parameter ***,our study investigates the repulsive effect of gravity,revealing that its presence leads to a negative deflection angle for photons traveling along null ***,we observe a consistent pattern of negative values for the deflection angle across all values of in the three scenarios considered,thus indicating the clear manifestation of the repulsive gravity *** of this is possible without invoking the existence of dark energy.

关键词： wormholes traversability casimir f(R,T)gravity deflection angle

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Resilient satellite-based PNT system design and key technologies

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science China earth sciences 2025年第3期68卷 669-682页

作者： Yuanxi YANG Zheng YAO Yue MAO Tianhe XU Dixing WANG Key Laboratory of Smart earth Xi'an research Institute of Surveying and Mapping Department of Electronic Engineering Tsinghua University School of Space science and Technology Shandong University

Satellite-based positioning navigation and timing(PNT) system is the most fundamental and convenient application system in PNT fields now and in the future, thus the satellite-based PNT service system should be more and more robust, reliable and easy to be applied. Aiming at the weak service performance of the existing BeiDou constellation in the Antarctic and Arctic regions and the possible discontinuous problems in the autonomous orbit determination using BeiDou terminals on board of low earth orbit(LEO) satellites, we propose a scheme to optimize the BeiDou constellation configuration. A relatively optimized deep space PNT service constellation is designed in order to overcome the weak service capability of the BeiDou navigation constellation in deep space. We find that more satellites in the same orbital plane have better positioning geometry than increasing the number of constellation orbital planes. Furthermore, the idea of resilient satellite-based PNT service mode combining deep, high, medium, and low earth orbit navigation constellations is proposed, in order to improve the service capability of multi navigation constellations. To strengthen the satellite PNT service ability, the resilient strategies of on-board phased array antenna, on-board atomic clocks and satellite signal generator are proposed, in which the adaptively possible adjustment of signal power, signal frequency, signal modulation waveform and information format are discussed. Some examples to demonstrate the resilient satellite-based PNT application modes are given.

关键词： BeiDou navigation constellation Resilient navigation constellation Resilient PNT service Resilient signal modulation Adaptive signal power

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Acellular scaffold‑based approach for in situ genetic engineering of host T‑cells in solid tumor immunotherapy

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Military Medical research 2025年第1期12卷 16-35页

作者： Hiren Y.Dandia Mamatha M.Pillai Deepak Sharma Meghna Suvarna Neha Dalal Ayush Madhok Arvind Ingle Shubhada V.Chiplunkar Sanjeev Galande Prakriti Tayalia Department of Biosciences and Bioengineering Indian Institute of Technology BombayPowaiMumbai 400076India Radiation Biology and Health sciences Division Bhabha Atomic Research CentreMumbai 400085India centre of Excellence in Epigenetics Department of BiologyIndian Institute of Science Education and ResearchPune 411008India Advanced centre for Treatment Research and Education in Cancer(ACTREC)Tata Memorial CentreKhargharMumbai 410210India

Background:Targeted T-cell therapy has emerged as a promising strategy for the treatment of hematological ***,its application to solid tumors presents significant challenges due to the limited accessibility and *** delivery of tumor-specific T-cells using biomaterials has shown promise,however,procedures required for genetic modification and generation of a sufficient number of tumor-specific T-cells ex vivo remain major obstacles due to cost and time ***:Polyethylene glycol(PEG)-based three-dimensional(3D)scaffolds were developed and conjugated with positively charged poly-L-lysine(PLL)using carbamide chemistry for efficient loading of lentiviruses(LVs)carrying tumor antigen-specific T-cell receptors(TCRs).The physical and biological properties of the scaffold were extensively ***,the scaffold loaded with OVA-TCR LVs was implanted in B16F10 cells expressing ovalbumin(B16-OVA)tumor model to evaluate the anti-tumor response and the presence of transduced ***:Our findings demonstrate that the scaffolds do not induce any systemic inflammation upon subcutaneous implantation and effectively recruit T-cells to the *** B16-OVA melanoma tumor-bearing mice,the scaffolds efficiently transduce host T-cells with OVA-specific *** genetically modified T-cells exhibit homing capability towards the tumor and secondary lymphoid organs,resulting in a significant reduction of tumor size and systemic increase in anti-tumor *** cell profiling revealed a significantly high percentage of transduced T-cells and a notable reduction in suppressor immune cells within the tumors of mice implanted with these ***:Our scaffold-based T-cell therapy presents an innovative in situ localized approach for programming T-cells to target solid *** approach offers a viable alternative to in vitro manipulation of T-cells,circumventing the need for large-scale in vitro generat

关键词： Polyethylene glycol diacrylate Poly-L-lysine Lentiviruses T-cell therapy B16F10-OVA melanoma

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An investigation on the wind profiles and gravity wave dynamics in MLT region based on the meteor radars from the Meridian Project

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earth and Planetary Physics 2025年第1期9卷 29-38页

作者： Tai Liu Zhe Wang MengXi Shi Willie Soon ShiCan Qiu Department of Geophysics College of the Geology Engineering and GeomaticsChang’an UniversityXi’an 710054China Center for Environmental research and earth sciences(CERES) SalemMA 01970USA Institute of earth Physics and Space science(ELKH EPSS) 9400SopronHungary

The meteor radar can detect the zenith angle,azimuth,radial velocity,and altitude of meteor trails so that one can invert the wind profiles in the mesosphere and low thermosphere(MLT)region,based on the Interferometric and Doppler *** this paper,the horizontal wind field,gravity wave(GW)disturbance variance,and GW fluxes are analyzed through the meteor radar observation from 2012−2022,at Mohe(53.5°N,122.4°E)and Zuoling(30.5°N,114.6°E)stations of the(Chinese)Meridian *** Lomb−Scargle periodogram method has been utilized to analyze the periodic variations for time series with observational data *** results show that the zonal winds at both stations are eastward dominated,while the meridional winds are southward *** variance of GW disturbances in the zonal and meridional directions increases gradually with height,and there is a strong pattern of annual *** zonal momentum flux of GW changes little with height,showing weak annual *** meridional GW flux varies gradually from northward to southward with height,and the annual periodicity is *** both stations,the maximum values of zonal and meridional wind occur close to the peak heights of GW flux,with opposite *** observational evidence is consistent with the filtering *** horizontal wind velocity,GW flux,and disturbance variance of the GW at Mohe are overall smaller than those at Zuoling,indicating weaker activities in the MLT at *** power spectral density(PSD)calculated by the Lomb−Scargle periodogram shows that there are 12-month period and 6-month period in horizontal wind field,GW disturbance variance and GW flux at both stations,and especially there is also a 4-month cycle in the disturbance *** PSD of the 12-month and 6-month cycles exhibits maximum values below 88 km and above 94 km.

关键词： meteor radar wind field gravity wave Lomb−Scargle method

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Structural and microwave absorption properties of CoFe_(2)O_(4)/residual carbon composites

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 221-232页

作者： Yuanchun Zhang Shengtao Gao Xingzhao Zhang Dacheng Ma Chuanlei Zhu Jun He Joint National-Local Engineering research centre for Safe and Precise Coal Mining Anhui University of Science and TechnologyHuainan 232001China School of Chemical and Blasting Engineering Anhui University of Science and TechnologyHuainan 232001China

Electromagnetic interference,which necessitates the rapid advancement of substances with exceptional capabilities for bsorbing electromagnetic waves,is of urgent concern in contemporary *** this work,CoFe_(2)O_(4)/residual carbon from coal gasification fine slag(CFO/RC)composites were created using a novel hydrothermal *** mechanisms for microwave absorption,including conductive loss,natural resonance,interfacial dipole polarization,and magnetic flux loss,are involved in these ***,compared with pure residual carbon materials,this composite offers superior capabilities in microwave *** 7.76GHz,the CFO/RC-2 composite achieves an impressive minimum reflection loss(RL_(min))of-43.99 dB with a thickness of 2.44 ***,CFO/RC-3 demonstrates an effective absorption bandwidth(EAB)of up to 4.16 GHz,accompanied by a thickness of *** study revealed the remarkable capability of the composite to diminish electromagnetic waves,providing a new generation method for microwave absorbing materials of superior quality.

关键词： coal gasification slag residual carbon hydrothermal method microwave absorption CoFe_(2)O_(4)

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