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Microstructure and mechanical properties of 3D printed ceramics with different vinyl acetate contents

rare Metals 2021年第11期40卷 3241-3250页

作者： He Li Yong-Sheng Liu Yan-Song Liu Qing-Feng Zeng Jing-Jing Liang Science and Technology on Thermostructural Composite materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China NPU-SAS Joint Research center of Advanced Ceramics Northwestern Polytechnical UniversityXi’an 710072China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

Stereolithography(SL)-based three-dimensional(3D) printing technique is an efficient method for the fabrication of alumina *** alumina slurry is difficult to obtain due to the barrier between hydrophilic alumina and oleophilic *** not only requires that the ceramic slurry possessed low viscosity and uniformity,but also requires that the slurry could complete the photocuring *** this study,vinyl acetate was added in the ceramic slurry as a bridge to connect alumina and resin,and the effects of vinyl acetate content on the microstructure and mechanical properties of the alumina ceramics were systematically *** results showed that the alumina ceramics were composed of three types of particles which included large aggregates,individual particles,and long-columnshaped *** shrinkage,bulk density,and crystallite size of the ceramics increased with the increase in vinyl acetate *** open porosity decreased with the increase in vinyl acetate *** flexural strength of the ceramics first increased and subsequently decreased with the increase in vinyl acetate *** shrinkage in Z direction was much greater than that in X or Y *** on the above results,the optimum vinyl acetate content for alumina slurry was 10 wt%,which resulted in sintered ceramic with the shrinkage of 15.6% in X direction,13.5% in Ydirection,21.9% in Z direction,bulk density of 1.9 g·cm^(-3),open porosity of 50.1%,and flexural strength of 24.4 *** sintered ceramics satisfy the requirement of alumina ceramic cores.

关键词： Stereolithography Alumina ceramics Vinyl acetate Microstructure Mechanical properties

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SHARAD study on the structures and permittivity of a buried impact crater in Martian Central Elysium Planitia

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Science China earth Sciences 2023年第11期66卷 2452-2462页

作者： Peng FANG Wenzhe FA Jinhai ZHANG Yangting LIN Key Laboratory of earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100029China Institute of Remote Sensing and Geographical Information System School of Earth and Space SciencesPeking UniversityBeijing 100871China

The Elysium Planitia,located in the transition zone between the northern and southern hemispheres,is one of the key areas for studying the stratigraphic structure and geological history of *** studies have shown that this plain has undergone complex surface modification processes including fluvial and volcanic processes,and systematic progress has been made in the study of macro-geological ***,there are relatively few studies on the regional structure of the plain,which restricts our understanding of the regional geological processes.A buried impact crater in the central part of the Elysium Planitia could have recorded the surface modification process since the formation of the impact crater,however,it is difficult to distinguish the subsurface stratigraphy due to the weak orbital radar reflection *** this study,we denoised Shallow Radar data and obtained a radargram with clear subsurface *** estimated the permittivity of subsurface materials via a multilayer reflection *** results show that two subsurface reflectors divide the structure of the buried impact crater into three layers(overlying layer,underlying layer,and bottom layer).The shallow subsurface reflector covers almost the whole impact crater,while the deep subsurface reflector covers only the southwest part of the impact *** the permittivity inversion results with the geological background of lava activity in the Elysium Planitia area,we argue that the overlying layer may be a mixture of regolith and lava flow with low density,while the underlying layer and bottom layer are dense lava *** reflector between the underlying layer and bottom layer is probably a thin deposit derived from weathering between two lava activities,and its possible formation mechanism is as follows:the crater rim and peripheral ejecta has undergone relatively strong wind erosion and the eroded material was transport to the southwestern part of the impact crater,forming

关键词： Mars Elysium Planitia SHARAD Buried crater Permittivity inversion

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Spatiotemporal patterns of the daily relative risk of COVID-19 in China

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Journal of Geographical Sciences 2021年第7期31卷 1039-1058页

作者： CHENG Changxiu JIANG Yifan SONG Changqing SHEN Shi WU Yunfeng ZHANG Tianyuan State Key Laboratory of earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Key Laboratory of Environmental Change and Natural Disaster Beijing Normal UniversityBeijing 100875China center for Geodata and Analysis Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China National Tibetan Plateau Data center Beijing 100101China

The coronavirus disease 2019(COVID-19)pandemic continues to threaten lives and the economy around the *** the risk of COVID-19 can help in predicting spreading trends,identifying risk areas,and making public health *** this study,we proposed a comparative risk assessment method to estimate comprehensive and dynamic COVID-19 risks by considering the pandemic severity and the healthcare system pressure and then employing the z-order curve and fractal *** took the COVID-19 cases from January 19-March 10,2020 in China as our research *** results and analysis revealed that(1)the proposed method demonstrated its feasibility to assess and illustrate pandemic risk;(2)the temporal patterns of the daily relative risk indices of 31 provinces were clustered into four groups(high-value,fluctuating-increase,inverted U-shaped,and low-stable);(3)the spatial distribution of the relative pandemic risk indicated a significant circular pattern centered on Hubei Province;and(4)healthcare system capacity is the key to reducing relative pandemic risk,and cases imported from abroad should be given more *** methods and results of this study will provide a methodological basis and practical guidance for regional pandemic risk assessment and public health decision-making.

关键词： COVID-19 risk assessment spatiotemporal patterns z-order curve fractal

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Assessing the vulnerability of a forest ecosystem to climate change and variability in the western Mediterranean sub-region of Turkey：future evaluation

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Journal of Forestry Research 2018年第5期29卷 1177-1186页

作者： Murat Türkes Nebiye Musaoglu Orkan Ozcan center for Climate Change and Policy Studies Bogazici University 34342 Bebek Istanbul Turkey Geomatics Engineering Department Civil EngineeringFaculty Istanbul Technical University34469 Maslak Istanbul Turkey Eurasia Institute of earth Sciences Istanbul TechnicalUniversity 34469 Maslak Istanbul Turkey

This study evaluates the multifactorial spatial modelling used to assess vulnerability of the Du¨ zlerc？am？（Antalya） forest ecosystem to climate *** was done to produce data,to develop tools to support decisionmaking and the management of vulnerable Mediterranean forest ecosystems affected by climate change,and to increase the ability of these forest ecosystems to adapt to global *** on regionally averaged future climate assessments and projected climate indicators,both the study site and the western Mediterranean sub-region of Turkey will probably become associated with a drier,hotter,more continental and more water-deficient *** analysis holds true for all future scenarios,with the exception of RCP4.5 for the period from 2015 to ***,the present dry-sub humid climate dominating this sub-region and the study area shows a potential for change towards more dry climatology and for it to become semiarid between 2031 and 2050 according to the RCP8.5 high emission *** the observed and estimated results and assessments summarized in this study show clearly that the densest forest ecosystem in the southern part of the study site,characterized by mainly Mediterranean coniferous and some mixed forest and maquis vegetation,will very likely be influenced by medium and high degrees of vulnerability to future environmental degradation,climate change and variability.

关键词： Forest ecosystem RCP scenarios Regional climate model Vulnerability

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Characterization of the molecular dysfunctions occurring in Aicardi-Goutieres syndrome patients with mutations in ADAR1

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Genes & Diseases 2024年第3期11卷 116-119页

作者： Sofan Al wardat Loredana Frasinlli Elisa Orecchini Federica Rey Silvia Anna Ciafre Silvia Galardi Jessica Garau Stella Gagliardi Simona Orcesi Davide Tonduti Stephana Carelli Cristina Cereda Ernesto Picardi Alessandro Michienzi Department of Biomedicine and Prevention University of Rome Tor VergataRome 00133Italy Pediatric Clinical Research center"Romeo ed Enrica Invernizzi" Department of Biomedical and Clinical SciencesUniversity of MilanoMilano 20157Italy center of functional Genomics and rare Diseases Department of PediatricsBuzzi Children's HospitalMilano20154Italy Department of Child Neurology and Psychiatry IRccs Mondino FoundationPavia 27100Italy Unit of Pediatric Neurology C.O.A.L.A(Center for Diagnosis and Treatment of Leukodystrophies)Buzzi Children's HospitalMilano 20154Italy Department of Biosciences Biotechnologies and EnvironmentUniversityof Bari"AldoMoro"Bari 70125Italy Institute of Biomembranes Bioenergetics and Molecular Biotechnologies(IBIOM)National Research Council(CNR)Bari 70126Italy Biostructures and Biosystems National Institute(INBB) Rome00136Italy Institute of Biochemistry and Cell Biology IBBC-CNRCampus Adriano Buzzati TraversoRome 00015Italy

Aicardi-Goutieres syndrome(AGS)is a systemic inflammatory disorder caused by mutations in any one of the nine different genes,whose deficiency provokes a type I(interferon)IFN response probably central to pathogenesis.^(1) ADAR1,one of the genes mutated in AGS(AGS6),encodes for an enzyme that belongs to the ADAR family(ADAR1,ADAR2,and ADAR3)that catalyzes the conversion of adenosine to inosine within double-stranded RNAs(dsRNAs)(RNA editing A-to-1).

关键词： ADAR1 interferon res

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Difference in calcium ion precipitation between free and immobilized Halovibrio mesolongii HMY2

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Journal of Environmental Sciences 2022年第12期34卷 184-200页

作者： Huaxiao Yan Meiyu Huang Jihan Wang Heding Geng Xiyu Zhang Ziyang Qiu Yongliang Dai Zuozhen Han Yudong Xu Long Meng Lanmei Zhao Maurice E.Tucker Hui Zhao College of Chemical and Biological Engineering College of Safety and Environmental EngineeringCollege of Earth Science and EngineeringShandong University of Science and TechnologyQingdao 266590China Laboratory for Marine Mineral Resources Center for Isotope Geochemistry and GeochronologyQingdao National Laboratory for Marine Science and TechnologyQingdao 266237China School of earth Sciences University of BristolBristol BS81RJUK Cabot Institute University of BristolCantock’s CloseBristol BS81UJUK

Biomineralization has become a research focus in wastewater treatment due to its much lower costs compared to traditional ***,the low sodium chloride(NaCl)-tolerance of bacteria limits applications to only water with low NaCl ***,calcium ions in hypersaline wastewater(10%NaCl)were precipitated by free and immobilized Halovibrio mesolongii HMY2 bacteria and the differences between them were *** results show that calcium ions can be transformed into several types of calcium carbonate with a range of morphologies,abundant organic functional groups(C-H,C-O-C,C=O,etc),protein secondary structures(β-sheet,α-helix,3_(10)helix,andβ-turn),P=O and S-H indicated by P2p and S2p,and more negativeδ^(13)C_(PDB)(‰)values(-16.8‰to-18.4‰).The optimal conditions for the immobilized bacteria were determined by doing experiments with six factors and five levels and using response surface *** the action of two groups of immobilized bacteria prepared under the optimal conditions,by the 10^(th)day,Ca^(2+)ion precipitation ratios had increased to 79%-89%and 80%-88%with changes in magnesium ion *** ions can significantly inhibit the calcium ion precipitation,and this inhibitory effect can be decreased under the action of immobilized *** induced by immobilized bacteria always aggregated together,had higher contents of Mg,P,and S,lower stable carbon isotope values and less well-developed protein secondary *** study demonstrates an economic and eco-friendly method for recycling calcium ions in hypersaline wastewater,providing an easy step in the process of desalination.

关键词： Biomineralization Halovibrio mesolongii Hypersaline wastewater Calcium ion removal Intracellular aragonite

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The longevity of subcontinental lithospheric mantle beneath Jiangsu-Anhui Region——The Os isotope model age of mantle-derived peridotite xenoliths

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Science China earth Sciences 2001年第12期44卷 1110-1118页

作者：支霞臣彭子成陈道公余春江孙卫东 LaurieReisberg 1. Department of earth and Space Sciences University of Science and Technology of China China 2. Laboratory of Chemical Geodynamics USTC China 3. Advance Research center for earth Science and Astronomy USTC Third World Academy of Sciences 230026 Hefei China 4. CRPG CNRS 15 Rue Notre-Dame des Pauvres B. P. 20 54501 Vandoeuvre-les-Nancy France

The basalt-borne peridotite xenoliths from Jiangsu-Anhui provinces were analyzed for whole rock Os isotopic compositions in two laboratories of USTC, China and CRPG, France, respectively. The ^(187)Os/^(188)Os ratio of the sample set ranges from 0.119 to 0.129 (25 samples, USTC) and from 0.117 to 0.131 (17 samples, CRPG). The Os isotopic compositions of most samples are less than 0.129 and depleted relatively to the primitive mantle, showing a good correlation with the major element compositions. With the ^(187)Os/^(188)Os-AI2O3 alumichron, the samples yield a model age of 2.5±0.1 Ga (data of USTC) and 1.9±0.1 Ga (data of CRPG), late Archean to early Pro-terozoic. The two samples with the lowest ^(187)Os/^(188)Os ratio (0.119 and 0.117) have the T_(RD) (Re depleted age) of 1.1 Ga (USTC) and 1.4 Ga (CRPG), mid-Proterozoic. The Os isotope model age shows that the peridotite xenoliths from Cenozoic alkali basalt in Jiangsu-Anhui provinces have an old formation age (early- to mid- Proterozoic). They are not newly produced mantle after the Phanerozoic replacement of the lithosphere mantle, but residual fractions of Proterozoic mantle.

关键词： peridotite xenoliths Os isotope model age subcontinental lithospheric mantle Jiangsu-Anhui provinces.

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The development of an algorithm to enhance and match the resolution of satellite measurements from AMSR-E

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Science China earth Sciences 2011年第3期54卷 410-419页

作者： WANG YongQian SHI JianCheng JIANG LingMei DU JinYang TIAN BangSen State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications of Chinese Academy of Sciences Beijing 100101 China Graduate University of Chinese Academy of Sciences Beijing 100049 China College of Environmental andResource Science Chengdu University of Information Technology Chengdu 610225 China School of Geography Beijing Normal University Beijing 100875 China center for earth Observation and Digital earth Chinese Academy of Sciences Beijing 100101 China

Microwave radiometers have many applications because of their penetration ability. However, two major problems remain that obstruct the development of microwave research. One factor that limits their commercial application is the relatively low resolution of microwave radiometers. The other is the non-uniform spatial resolution for each frequency of the radiometer. The resolution mismatch becomes a critical consideration when observations at two or more frequencies must be combined. In this paper, we have used the Backus-Gilbert method to solve these two problems, while AMSR-E is chosen as the research object. First, we derived the Backus-Gilbert method in detail. The simulated data were then used to decide the optimum parameters in the Backus-Gilbert method. To enhance the resolution, the Backus-Gilbert method has been applied to the AMSR-E data, which covered the Mexico Gulf and the Amazon River. After resolution was enhanced, detailed information was obtained and compared with visible high resolution data. To match the resolution, the AMSR-E data from the Oklahoma Little Washed were used to compute the Microwave Vegetation Index (MVI), which was developed by J. C. Shi. Compared to the original MVIs, the information contained in the MVIs that were processed by the Backus-Gilbert method is more reliable.

关键词： AMSR-E resolution enhancement resolution match Backus-Gilbert

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Electrical and thermal conductivity of earth's core and its thermal evolution——A review

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Acta Geochimica 2022年第4期41卷 665-688页

作者： Yuan Yin Qingwen Zhang Youjun Zhang Shuangmeng Zhai Yun Liu State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang550081China International Research center for Planetary Science College of Earth SciencesChengdu University of TechnologyChengdu610059China Institute of Atomic and Molecular Physics Sichuan UniversityChengdu610065China Key Laboratory of High-Temperature and High-Pressure Study of the earth’s Interior Institute of GeochemistryChinese Academy of SciencesGuiyang550081China

The earth’s core is composed of iron,nickel,and a small amount of light elements(e.g.,Si,S,O,C,N,H and P).The thermal conductivities of these components dominate the adiabatic heat flow in the core,which is highly correlated to *** we review a large number of studies on the electrical and thermal conductivity of iron and iron alloys and discuss their implications on the thermal evolution of the earth’s *** summary,we suggest that the Wiedemann-Franz law,commonly used to convert the electrical resistivity to thermal conductivity for metals and alloys,should be cautiously applied under extremely high pressure-temperature(P-T)conditions(e.g.,earth’s core)because the Lorentz number may be P-T *** date,the discrepancy in the thermal conductivity of iron and iron alloys remains between those from the resistivity measurements and the thermal diffusivity modeling,where the former is systematically *** studies reconcile the electrical resistivity by first-principles calculation and direct measurements,and this is a good start in resolving this *** to an overall higher thermal conductivity than previously thought,the inner core age is presently constrained at~1.0 ***,light elements in the core would likely lower the thermal conductivity and prolong the crystallization of the inner ***,whether thermal convection can power the dynamo before the inner core formation depends on the amounts of the proper light elements in the *** works are needed to establish the thermal evolution model of the core.

关键词： earth’s core Electrical and thermal conductivity Iron and its alloys Thermal evolution Geodynamo

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Enhancement Mechanism of Cerium in 316LN Austenitic Stainless Steel During Creep at 700 ℃

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Acta Metallurgica Sinica(English Letters) 2023年第3期36卷 507-512页

作者： Renxian Yang Xin Cai Leigang Zheng Xiaoqiang Hu Dianzhong Li Shenyang National Laboratory for materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Effect of cerium(Ce)on creep strength and microstructure of 316LN austenitic stainless steel(316LN steel)at 700℃/150 MPa was investigated by scanning electron microscopy(SEM),scanning transmission electron microscopy(STEM)and thermodynamic *** of 0.032 wt%Ce to 316LN steel results in a prominent increase in creep life from 313 to 556 *** enriches in titanium nitride nanoparticles,increases slightly the activity and diffusion coefficient of Mo,and facilitates the formation of fine and dense intragranular Laves phase *** the creep strength is remarkably enhanced by Ce addition in 316LN steel through the intragranular Laves phase precipitation *** reveals a new insight into the improvement effect of rare earth(RE)elements such as Ce on creep strength of austenitic stainless steels,which inspired the design of RE-microalloying heat-resistant steels.

关键词： 316LN austenitic stainless steel rare earth Creep Laves phase Precipitation strengthening

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