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The influence of proxy selection on global annual mean temperature reconstructions during the Common Era

Science China Earth Sciences 2024年第8期67卷 2522-2534页

作者： Bao YANG Xia Li Minhui hE Feng wang Yesi ZhAO Peng ZhANG Jianglin wang Frontiers Science Center for Critical Earth Material Cycling School of Geography and Ocean ScienceNanjing UniversityNanjing 210023China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Centre Eau Terre Environnement Institut National de la Recherche ScientifiqueQuébecQCG1K 9A9Canada GEOTOP Research Centre in the Dynamics of the Earth System MontréalQC H2X 3Y7Canada

The reconstruction of global annual mean temperatures made by the PAGES 2k Consortium in 2019 represents one of the most influential sequences of global climate variability over the Common ***,it is still not clear how the reconstruction can be influenced by the selection of reconstruction methods and the selection of proxy records with different temporal resolutions over different *** adopt a widely used Composite-Plus-Scale method to elucidate the effects of the selection of the proxy records on temperature *** ensure the uniformity of data,different types of proxy records spanning the past~2000 years from the PAGES 2k proxy network were used to investigate the potential effects of proxy selection in hemispheric and global temperature reconstructions during the past two *** long-term trends,spectral characteristics,and volcanic responses of the annual temperatures were studied based on the *** results reveal a significant cooling trend in the global annual mean temperature using both tree-ring and non-tree-ring records during the 1–1850CE period,and show that the cooling exhibits a stronger trend in the Southern hemisphere(sh)than that in the Northern hemisphere(Nh).Yet,the long-term trends vary according to different combinations of proxy *** reconstructions based on different types of proxies also exhibit different features in terms of volcanic responses and spectral ***-ring-based temperature reconstructions show stronger cooling responses to tropical volcanic eruptions,while non-tree-ring-based reconstructions suggest less robust volcanic responses,which may be related to dating uncertainties and low temporal resolution of the ***-ring width records tend to preserve a substantial proportion of high-frequency(iability,whereas non-tree-ring proxies tend to capture a larger fraction of low-frequency(>200 years)*** are needed to reduce uncertainti

关键词： Millennial cooling trend Global climate change Proxy records Volcanic eruptions Spectral properties Common Era

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Sulfhydryl-functionalized COF-based electrolyte strengthens chemical affinity toward polysulfides in quasi-solid-state Li-S batteries

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Carbon Energy 2024年第9期6卷 221-234页

作者： Linnan Bi Jie Xiao Yaochen Song Tianrui Sun Mingkai Luo Yi wang Peng Dong Yingjie Zhang Yao Yao Jiaxuan Liao Sizhe wang shulei Chou Yangtze Delta Region institute(Quzhou) University of Electronic Science and Technology of ChinaQuzhouChina National and Local Joint Engineering Research Center of Lithium-ion Batteries and Materials Preparation Technology Key Laboratory of Advanced Battery Materials of Yunnan ProvinceFaculty of Metallurgical and Energy EngineeringKunming University of Science and TechnologyKunmingChina institute for Carbon Neutralization College of Chemistry and Materials EngineeringWenzhou UniversityWenzhouChina School of Materials and Energy University of Electronic Science and Technology of ChinaChengduChina School of Materials Science and Engineering Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic MaterialsShaanxi University of Science&TechnologyXi'anChina

For lithium-sulfur batteries(Li-S batteries),a high-content electrolyte typically can exacerbate the shuttle effect,while a lean electrolyte may lead to decreased Li-ion conductivity and reduced catalytic conversion efficiency,so achieving an appropriate electrolyte-to-sulfur ratio(E/S ratio)is essential for improving the battery cycling efficiency.A quasi-solid electrolyte(COF-sh@PVDF-hFP)with strong adsorption and high catalytic conversion was constructed for in situ covalent organic framework(COF)growth on highly polarized polyvinylidene fluoride-hexafluoropropylene(PVDF-hFP)***-sh@PVDF-hFP enables efficient Li-ion conductivity with low-content liquid electrolyte and effectively suppresses the shuttle *** results based on in situ Fourier-transform infrared,in situ Raman,UV–Vis,X-ray photoelectron,and density functional theory calculations confirmed the high catalytic conversion of COF-sh layer containing sulfhydryl and imine groups for the lithium *** plating/stripping tests based on Li/COF-sh@PVDF-hFP/Li show excellent lithium compatibility(5 mAh cm^(-2) for 1400 h).The assembled Li-S battery exhibits excellent rate(2 C 688.7 mAh g^(-1))and cycle performance(at 2 C of 568.8 mAh g^(-1) with a capacity retention of 77.3%after 800 cycles).This is the first report to improve the cycling stability of quasi-solid-state Li-S batteries by reducing both the E/S ratio and the designing strategy of sulfhydryl-functionalized COF for quasi-solid *** process opens up the possibility of the high performance of solid-state Li-S batteries.

关键词： lithium-sulfur batteries low electrolyte-to-sulfur ratio polysulfide shuttle PVDF-hFP/COF

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Photochemistry of phenothiazine in benzene and cyclohexane

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Chinese Science Bulletin 1997年第12期42卷 998-1000页

作者： wang, sh Chen, DW Gou, JX wang, h institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

iN the last few years phenothiazine(PTh)and its derivatives have captured much attention inthe fields of medicines,biology,and microelectronic materials due to their ability to ef-ficiently photosensitize acid production in the presence of vicinal dibromides and hence tochange the solubilization of polymer *** photophysical and photochemical properties re-lated to the processes have been *** Barra et *** that the triplet

关键词： photochemistry ESR nitroxyl radical cation radical.

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Study of Sintering Behaviour and Electrical Conductivity of Cr-Zn-Fe-O System

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Journal of Materials Science & Technology 1999年第1期15卷 79-82页

作者： hanna, A.A. Khalil, M.sh. Saleh, h.i. Ali, A.F. inorganic Chemistry Department National Research Centre Dokki Cairo Egypt

A series of chemical composition based on Cr, Fe and O with Zn as a partially substituting ion has been prepared in the general formula Zn//xCr//1// minus //xFe//2O by coprecipitation method using Nh//4Oh as the precipitating agent at ph equals 10.3. The prepared samples were identified by both thermal analysis (DTA and TGA) and X-ray diffraction. it was found that no single phase is obtained for any of the studied compositions but a mixture of different phases is observed, depending on the molar percentage of zinc ion substitution as well as on the sintering temperature. The temperature dependence of the electrical conductivity, sigma , of the prepared samples is plotted between 25 and 680 degree C. it was observed that the electrical conductivity increases with temperature for both samples with x equals 0.00 and 0.80 Zn ion content while it is nearly temperature independent for samples with intermediate Zn concentration x equals 0.2 and 0.5 mol fraction. The activation energy, E//a, calculated from the linear relation, lg sigma -1000/T for the final mixtures (sintered at 1300 degree C) was calculated. (Edited author abstract) 16 Refs.

关键词： Chromium compounds

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Enzymatic C1 reduction using hydrogen in cofactor regeneration

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Frontiers of Chemical Science and Engineering 2024年第7期18卷 33-40页

作者： Ruishuang Sun Chenqi Cao Qingyun wang hui Cao Ulrich Schwaneberg Yu Ji Luo Liu haijun Xu Beijing Bioprocess Key Laboratory Beijing University of Chemical TechnologyBeijing 100029China institute of Biotechnology Rheinisch-Westfälische Technische Hochschale(RWTH)AachenAachen 52074Germany

Carbon dioxide fixation presents a potential solution for mitigating the greenhouse gas *** carbon dioxide fixation,C1 compound reduction requires a high energy *** calculations suggest that the energy source for cofactor regeneration plays a vital role in the effective enzymatic C1 *** utilizes renewable hydrogen to achieve the regeneration and supply cofactor nicotinamide adenine dinucleotide(NADh),providing a driving force for the reduction reaction to reduce the thermodynamic barrier of the reaction cascade,and making the forward reduction pathway thermodynamically *** on the regeneration of cofactor NADh by hydrogenase,and coupled with formaldehyde dehydrogenase and formolase,a favorable thermodynamic mode of the C1 reduction pathway for reducing formate to dihydroxyacetone(DhA)was designed and *** resulted in accumulation of 373.19μmol·L^(-1) DhA after 2 h,and conversion reaching 7.47%.These results indicate that enzymatic utilization of hydrogen as the electron donor to regenerate NADh is of great significance to the sustainable and green development of bio-manufacturing because of its high economic efficiency,no by-products,and environment-friendly ***,formolase efficiently and selectively fixed the intermediate formaldehyde(FALD)to DhA,thermodynamically pulled formate to efficiently reduce to DhA,and finally stored the low-grade renewable energy into chemical energy with high energy density.

关键词： [NiFe]-hydrogenase sh formolase NADh regeneration C1 compound reduction thermodynamic calculation

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Effects of Charge inheritance on high Zn-Al Based Alloy

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Journal of Materials Science & Technology 1995年第2期11卷 153-156页

作者： GENG, h MA, JJ YANG, sh shandong Polytechnic Univ Jinan China

The effects of several kinds of charges on microstructure and mechanical properties of ZA27 zinc alloy have been studied. Experimental results show that a certain amount of the mechining charge, granular charge and remelting charge treated in suitable way can increase greatly the mechanical properties of ZA27 alloy. it is thought that the charges possess microstructure inheritance to ZA27 alloy, so cause the property changes according to the viewpoints of casting alloy inheritance.

关键词： Zinc alloys

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Sliding Wear Behavior of a Grey Cast iron Surface Remelted by TiG

引用

Journal of Materials Science & Technology 2009年第5期25卷 622-628页

作者： h.Mohamadzadeh h.Saghafian sh.Kheirandish Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyTehranIran

The sliding wear behavior of a grey cast iron surface remelted by tungsten inert gas （TiG） was studied and compared with the unremelted one in the current work. To evaluate the wear behavior a Pin-on-Disk wear test machine was used. Pins which were prepared from the samples with the remelted layers of different thicknesses of 1.2, 1.8, 2.5 and 3 turn were worn on an AiSiD3 steel counterface having a hardness of 63hRC under the applied loads of 54, 76 and gg N at a constant sliding velocity of 0.45 m/s. Scanning electron microscopy （SEM） equipped with energy dispersive X-ray analysis （EDS） and X-ray diffraction （XRD） techniques were used to characterize worn surface and subsurface and also wear debris obtained from the wear tests under different test conditions. Results showed that surface remelted grey cast iron have better wear properties for all applied normal loads in comparison with unremelted ones. Microscopic studies on the worn surfaces and subsurfaces of samples revealed that dominant wear mechanism for surface remelted samples was mild oxidative, while it was severe for unremelted samples. increasing remelted layer thickness and then forming grosser microstructure lead to a decline of wear properties, whereas lower thickness of remelted layer with finer microstructure due to having higher cooling rate through remelting process can withstand better against wear.

关键词： Grey cast iron Surface remelted Tungsten inert gas (TiG) Wear

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A near-infrared fluorescent probe for visualizing transformation pathway of Cys/hcy and h2S and its applications in living system

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Chinese Chemical Letters 2024年第5期35卷 296-301页

作者： Yudi Cheng Xiao wang Jiao Chen Zihan Zhang Jiadong Ou Mengyao she Fulin Chen Jianli Li Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education Xi’an Key Laboratory of Functional Supramolecular Structure and MaterialsCollege of Chemistry&Materials ScienceNorthwest UniversityXi’an 710127China Key Laboratory of Resource Biology and Biotechnology in Western China Ministry of EducationBiomedicine Key Laboratory of Shaanxi ProvinceLab of Tissue Engineeringthe College of Life SciencesFaculty of Life Science&MedicineNorthwest UniversityXi’an 710069China

Sulfydryl-contained(-sh)substances including hydrogen sulfide(h_(2)S),cysteine(Cys),homocysteine(hcy)and glutathione(Gsh)play crucial roles in living systems,and their variations are closely associated with various ***,we developed a near-infrared intramolecular charge transfer(iCT)based fluorescent probe Y-NBD,achieving detection of Cys/hcy and h_(2)S with different fluorescent signals(green-red for Cys/hcy,red for h_(2)S),large Stokes shifts(∼100/105nm or 191 nm)and high signal-background-ratio,but not responding to Gsh.Y-NBD was successfully applied to image exogenous/endogenous Cys/hcy and h_(2)S in various living cancer cells(heLa,A549,and hepG2)and in *** not only visualized the transformation pathway of several thiols in hepG2 cells but also verified that the intestine is the main site for the activation and metabolism of Y-NBD in zebrafish,as well as realized to evaluate the degree of drug-induced liver *** work provides a promising tool for imaging Cys/hcy and h_(2)S in living systems and shows great potency in evaluating drug-induced liver injury and its treatment.

关键词： Fluorescent probe Near-infrared hydrogen sulfide Cysteine/homocysteine Large Stokes shift Dicyanoisophorone Drug-induced liver injury

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Acatulides A-G,neuroprotective macrolides from Acaulium album h-JQSF

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Chinese Chemical Letters 2024年第3期35卷 379-383页

作者： Zhi-Wu Tong Ting-Ting wang Pei Yang Jia-Lin Sun Chen-Peng Zhang Salman Khan Xin-Cun wang Rui-hua Jiao hui-Ming Ge Wen-Ying Zhuang Gang hu Ren Xiang Tan State Key Laboratory of Pharmaceutical Biotechnology Institute of Functional BiomoleculesNanjing UniversityNanjing 210023China State Key Laboratory Cultivation Base for TCM Quality and Efficacy Nanjing University of Chinese MedicineNanjing 210023China insitute of Microbiology Chinese Academy of SciencesBeijing 100101China

Fungal symbionts co-evolve with hosts and microbial co-inhabitants to acquire an unpredictable potential for producing novel bioactive metabolites,but the knowledge about the topic remains patchy and *** we present the chemical characterization of acatulides A-G(1-7)as architecturally unprecedented macrolides from the solid-state culture of Acaulium album h-JQSF,an arthropod-associated *** acatulide structures were elucidated by spectroscopic analysis,modified Mosher's method and single-crystal X-ray *** plausible biosynthetic pathways for compounds 1-4 are ***,acatulides B-D(2-4)and G(7)were demonstrated to be neuroprotective against the 1-methyl-4-phenylpyridinium(MPP+)-induced damage to sh-SY5Y cells and nematode Caenorhabditis elegans(***).

关键词： Acaulium album Macrolides Acatulides A–G Mosher’s method Neuroprotective

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Dry Sliding Oxidative Wear in Plain Carbon Dual Phase Steel

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Journal of iron and Steel Research international 2007年第4期14卷 43-48页

作者： V Abouei h Saghafian sh Kheirandish Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyNarmak 16844TehranIran

To investigate the tribological potential of the dual phase （DP） steel as a wear resistant material, the wear and the friction characteristics of this steel, which consists of hard martensite islands embedded in a ductile ferrite matrix, have been investigated and compared with those observed in plain carbon hardened （h） steel that has the same carbon content of 0.2%. Dry sliding wear tests have been carried out using a pin-on-disk wear testing machine at different normal loads of 21.3 N, 28. 5 N, 35.7 N, and 42.6 N and at a constant sliding velocity of 1.20 m/s. The analysis of surface and wear debris of samples showed that the wear mechanism was mainly mild oxidative. The friction and the wear rate of the h steel and the DP Steel have been explained with respect to the microstructure and the wear mechanism.

关键词： dual phase steel wear microstructure heat treatment

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