The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK...The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.展开更多
The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of...The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.展开更多
In addition to their canonical roles in biosynthetic pathways,metabolites can be active participants in oncogenic signal-ling,but our understanding of these signalling mechanisms is incomplete.In a recent article publ...In addition to their canonical roles in biosynthetic pathways,metabolites can be active participants in oncogenic signal-ling,but our understanding of these signalling mechanisms is incomplete.In a recent article published in Cell,Mossmann et al.find a novel signalling role for accumulated arginine in hepato-cellular carcinoma(HCC)mediated by the RNA splicing factor and transcriptional modifier RNA-binding protein 39(RBM39).展开更多
Resistive random-access memory(RRAM),also known as memristors,having a very simple device structure with two terminals,fulfill almost all of the fundamental requirements of volatile memory,nonvolatile memory,and neuro...Resistive random-access memory(RRAM),also known as memristors,having a very simple device structure with two terminals,fulfill almost all of the fundamental requirements of volatile memory,nonvolatile memory,and neuromorphic characteristics.Its memory and neuromorphic behaviors are currently being explored in relation to a range of materials,such as biological materials,perovskites,2D materials,and transition metal oxides.In this review,we discuss the different electrical behaviors exhibited by RRAM devices based on these materials by briefly explaining their corresponding switching mechanisms.We then discuss emergent memory technologies using memristors,together with its potential neuromorphic applications,by elucidating the different material engineering techniques used during device fabrication to improve the memory and neuromorphic performance of devices,in areas such as ION/IOFF ratio,endurance,spike time-dependent plasticity(STDP),and paired-pulse facilitation(PPF),among others.The emulation of essential biological synaptic functions realized in various switching materials,including inorganic metal oxides and new organic materials,as well as diverse device structures such as single-layer and multilayer hetero-structured devices,and crossbar arrays,is analyzed in detail.Finally,we discuss current challenges and future prospects for the development of inorganic and new materials-based memristors.展开更多
The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing m...The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing minerals of the bauxites were found to comprise alumogoethite(α-Fe_(1−x)Al_(x)OOH),alumohematite(α-(Fe_(1−x)Al_(x))_(2)O_(3)),alumoakaganeite(β-Fe_(1−x)Al_(x)O(OH,Cl)),and chromite(FeCr_(2)O_(4)).The efficiency of Fe extraction from the bauxite by HCl leaching was 82.5%at 100℃,HCl concentration of 10%,solid/liquid ratio of 1:10,and the process duration of 60 min,with aluminum loss from the bauxites below 4.5%of the total Al contents in the bauxite.Analysis of the kinetics of the iron leaching process proved diffusion to be the limiting stage of the process at 90−100℃.Bauxite residue after leaching presented traces of α-Fe_(1−x)Al_(x)OOH and β-Fe_(1−x)Al_(x)O(OH,Cl),and most of the iron content was in the FeCr_(2)O_(4).In bauxite residue after HCl leaching,in addition to iron oxide,the contents of chromium and calcium oxides significantly decreased.The iron chloride liquor after leaching contained the rare earth elements(REE)of 6.8 mg/L Sc,4.1 mg/L Ce and 2.3 mg/L Ga.展开更多
Design of materials with particular functional properties is indispensable albeit very challenging.Chemical and structural analogies can be helpful in this endeavor,especially when a particular combination of properti...Design of materials with particular functional properties is indispensable albeit very challenging.Chemical and structural analogies can be helpful in this endeavor,especially when a particular combination of properties is sought after.Our aim is to bundle together 3 characteristics:high carrier mobility,magnetism,and scalability to nanomaterials in the form of a film–such a combination is particularly advantageous for spintronics.Here,inspired by recent studies of MAl_(2)Si_(2)and related compounds,we develop magnetic EuAl_(2)Ge_(2)and non-magnetic SrAl_(2)Ge_(2)nanomaterials with high carrier mobility.Topotactic syntheses employing sacrificial 2D templates result in epitaxial films of MAl_(2)Ge_(2)seamlessly integrated with germanium.The syntheses are followed by a study of the atomic structure,magnetic and electron transport properties.In particular,the films demonstrate high carrier mobility,exceeding 10,000 cm^(2)V^(-1)s^(-1)in the case of EuAl_(2)Ge_(2),making the materials appealing for applications.Taken together,MAl_(2)Ge_(2)and MAl_(2)Si_(2)form a class of high-mobility layered nanomaterials.展开更多
Despite emerging contemporary biotechnological methods such as gene-and stem cell-based therapy,there are no clinically established therapeutic strategies for neural regeneration after spinal cord injury.Our previous ...Despite emerging contemporary biotechnological methods such as gene-and stem cell-based therapy,there are no clinically established therapeutic strategies for neural regeneration after spinal cord injury.Our previous studies have demonstrated that transplantation of genetically engineered human umbilical cord blood mononuclear cells producing three recombinant therapeutic molecules,including vascular endothelial growth factor(VEGF),glial cell-line derived neurotrophic factor(GDNF),and neural cell adhesion molecule(NCAM)can improve morpho-functional recovery of injured spinal cord in rats and mini-pigs.To investigate the efficacy of human umbilical cord blood mononuclear cells-mediated triple-gene therapy combined with epidural electrical stimulation in the treatment of spinal cord injury,in this study,rats with moderate spinal cord contusion injury were intrathecally infused with human umbilical cord blood mononuclear cells expressing recombinant genes VEGF165,GDNF,NCAM1 at 4 hours after spinal cord injury.Three days after injury,epidural stimulations were given simultaneously above the lesion site at C5(to stimulate the cervical network related to forelimb functions)and below the lesion site at L2(to activate the central pattern generators)every other day for 4 weeks.Rats subjected to the combined treatment showed a limited functional improvement of the knee joint,high preservation of muscle fiber area in tibialis anterior muscle and increased H/M ratio in gastrocnemius muscle 30 days after spinal cord injury.However,beneficial cellular outcomes such as reduced apoptosis and increased sparing of the gray and white matters,and enhanced expression of heat shock and synaptic proteins were found in rats with spinal cord injury subjected to the combined epidural electrical stimulation with gene therapy.This study presents the first proof of principle study of combination of the multisite epidural electrical stimulation with ex vivo triple gene therapy(VEGF,GDNF and NCAM)for treatment of spinal cord injury in rat mode展开更多
当太阳直射点在北回归线上,北半球各地昼逐渐变成长,夜越来越短,宣告炎炎夏日的到来,许多人对夏季有着无比狂热的喜爱,莎士比亚在《Sonnet18》中写过一句流传经典的“Shall I compare thee to a summer's day?(我能否将你比作夏天?)...当太阳直射点在北回归线上,北半球各地昼逐渐变成长,夜越来越短,宣告炎炎夏日的到来,许多人对夏季有着无比狂热的喜爱,莎士比亚在《Sonnet18》中写过一句流传经典的“Shall I compare thee to a summer's day?(我能否将你比作夏天?)”,不难看出莎翁对夏季的赞许和偏爱,盛夏之时,人也容易感到疲劳,本期的设计物料馆以“热情仲夏夜”为主题,选取一系列适合夏季单品,无论放置于户内或是户外。展开更多
Three atmospheric boundary layer （ABL） schemes and two land surface models that are used in the Weather Research and Forecasting （WRF） model, version 3.4.1, were evaluated with numerical simulations by using data ...Three atmospheric boundary layer （ABL） schemes and two land surface models that are used in the Weather Research and Forecasting （WRF） model, version 3.4.1, were evaluated with numerical simulations by using data from the north coast of France （Dunkerque）. The ABL schemes YSU （Yonsei University）, ACM2 （Asymmetric Convective Model version 2）, and MYJ （Mellor-Yamada-Janjic） were combined with two land surface models, Noah and RUC （Rapid Update Cycle）, in order to determine the performances under sea-breeze conditions. Particular attention is given in the determination of the thermal internal boundary layer （TIBL）, which is very important in air pollution scenarios. The other physics parameterizations used in the model were consistent for all simulations. The predictions of the sea-breeze dynamics output from the WRF model were compared with observations taken from sonic detection and ranging, light detection and ranging systems and a meteorological surface station to verify that the model had reasonable accuracy in predicting the behavior of local circulations. The temporal comparisons of the vertical and horizontal wind speeds and wind directions predicted by the WRF model showed that all runs detected the passage of the sea-breeze front. However, except for the combination of MYJ and Noah, all runs had a time delay compared with the frontal passage measured by the instruments. The proposed study shows that the synoptic wind attenuated the intensity and penetration of the sea breeze. This provided changes in the vertical mixing in a short period of time and on soil temperature that could not be detected by the WRF model simulations with the computational grid used. Additionally, among the tested schemes, the combination of the local- closure MYJ scheme with the land surface Noah scheme was able to produce the most accurate ABL height compared with observations, and it was also able to capture the TIBL.展开更多
Two-dimensional(2D)magnetic materials promise unconventional properties and quantum phases as well as advances in ultracompact spintronics.Miniaturization of 2D magnets often reaches a single monolayer but in general ...Two-dimensional(2D)magnetic materials promise unconventional properties and quantum phases as well as advances in ultracompact spintronics.Miniaturization of 2D magnets often reaches a single monolayer but in general can go beyond this limit,as demonstrated by 2D magnetism of submonolayer Eu superstructures coupled with Si.The question is whether the submonolayer magnetism constitutes a general phenomenon.Herein,we demonstrate that regular Eu lattices form a class of 2D magnets displaying various structures,stoichiometries,and chemical bonding.We synthesized and studied a set of Eu superstructures on Ge(001).Their magnetic properties are consistent with the emergence of a magnetic order such as ferro-or ferrimagnetism.In particular,control over the magnetic transition temperature by weak magnetic fields indicates the 2D nature of the magnetism.Taken together,Eu/Ge and Eu/Si superstructures seed a nucleus of the research area addressing the emergence of magnetism in submonolayer chemical species.展开更多
JUNO is a multi-purpose neutrino observatory under construction in the south of China.This publication presents new sensitivity estimates for the measurement of the △m_(31)^(2),△m_(21)^(2),sin^(2)θ_(12),and sin^(2)...JUNO is a multi-purpose neutrino observatory under construction in the south of China.This publication presents new sensitivity estimates for the measurement of the △m_(31)^(2),△m_(21)^(2),sin^(2)θ_(12),and sin^(2)θ_(13) oscillation parameters using reactor antineutrinos,which is one of the primary physics goals of the experiment.The sensitivities are obtained using the best knowledge available to date on the location and overburden of the experimental site,the nuclear reactors in the surrounding area and beyond,the detector response uncertainties,and the reactor antineutrino spectral shape constraints expected from the TAO satellite detector.It is found that the △m_(21)^(2) and sin^(2)θ_(12) oscillation parameters will be determined to 0.5%precision or better in six years of data collection.In the same period,the △m_(31)^(2) parameter will be determined to about 0.2%precision for each mass ordering hypothesis.The new precision represents approximately an order of magnitude improvement over existing constraints for these three parameters.展开更多
Recent discoveries of intrinsic two-dimensional(2D)magnets open up vast opportunities to address fundamental problems in condensed matter physics,giving rise to applications from ultra-compact spintronics to quantum c...Recent discoveries of intrinsic two-dimensional(2D)magnets open up vast opportunities to address fundamental problems in condensed matter physics,giving rise to applications from ultra-compact spintronics to quantum computing.The ever-growing material landscape of 2D magnets lacks,however,carbon-based systems,prominent in other areas of 2D research.Magnetization measurements of the Eu/graphene compound-a monolayer of the EuC_(6) stoichiometry-reveal the emergence of 2D ferromagnetism but detailed studies of competing magnetic states are still missing.Here,we employ element-selective X-ray absorption spectroscopy(XAS)and magnetic circular dichroism(XMCD)to establish the magnetic structure of monolayer EuC6.The system exhibits the anomalous Hall effect,negative magnetoresistance,and magnetization consistent with a ferromagnetic state but the saturation magnetic moment(about 2.5/%/Eu)is way too low for the half-filled f-shells of Eu^(2+)ions.Combined XAS/XMCD studies at the Eu L3 absorption edge probe the EuC6 magnetism in high fields and reveal the nature of the missing magnetic moments.The results are set against XMCD studies in Eu/silicene and Eu/germanene to establish monolayer EuC6 as a prominent member of the family of Eu-based 2D magnets combining the celebrated graphene properties with a strong magnetism of europium.展开更多
From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ exper...From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.展开更多
Human pluripotent stem cells(h PSCs) represent heterogeneous populations, including induced pluripotent stem cells(i PSCs), endogenous plastic somatic cells, and embryonic stem cells(ESCs). Human ESCs are derived from...Human pluripotent stem cells(h PSCs) represent heterogeneous populations, including induced pluripotent stem cells(i PSCs), endogenous plastic somatic cells, and embryonic stem cells(ESCs). Human ESCs are derived from the inner cell mass of the blastocyst, and they are characterized by the abilities to self-renew indefinitely, and to give rise to all cell types of embryonic lineage(pluripotency) under the guidance of the appropriate chemical, mechanical and environmental cues. The combination of these critical features is unique to h ESCs, and set them apart from other human cells. The expectations are high to utilize h ESCs for treating injuries and degenerative diseases; for modeling of complex illnesses and development; for screening and testing of pharmacological products; and for examining toxicity, mutagenicity, teratogenicity, and potential carcinogenic effects of a variety of environmental factors, including ionizing radiation(IR). Exposures to genotoxic stresses, such as background IR, are unavoidable; moreover, IR is widely used in diagnostic and therapeutic procedures in medicine on a routine basis. One of the key outcomes of cell exposures to IR is the change in gene expression, which may underlie the ultimate h ESCs fate after such a stress. However, gaps in our knowledge about basic biology of h ESCs impose a serious limitation to fully realize the potential of h ESCs in practice. The purpose of this review is to examine the available evidence of alterations in gene expression in human pluripotent stem cells after genotoxic stress, and to discuss strategies for future research in this important area.展开更多
During the last century, as the area of wheat grown under advanced grain husbandry has increased worldwide, so too has the importance of Fusarium ear scab (FES) (synonym, Fusarium head blight) caused by several specie...During the last century, as the area of wheat grown under advanced grain husbandry has increased worldwide, so too has the importance of Fusarium ear scab (FES) (synonym, Fusarium head blight) caused by several species of the fungus Fusarium. Yield losses due to FES can total 20%-40% and more depending on climatic conditions. During the last twenty years epidemics of FES in cereals have become chronic all over the world, including the United States and Russia. The most destructive of these were observed in 1982, 1986, 1990-1996 in USA and in the south of Russia in 1982, 1984, 1988, 1992. The harmful effect of FES is manifested not only in reduced grain yields, but also in the contamination of grains and grain products with mycotoxins, such as deoxynivalenol (DON) and its derivatives (3-alfa acetyl-DON, 15-alfa acetyl-DON), T-2 toxin and zearalenone. Standard means to control FES (cultural control methodologies, chemical pesticides, and FES resistant varieties) have little effect or are not practical and rarely reduce the accumulation of mycotoxins in grain. We have developed a new technique to reduce FES using biological preparations. The technique utilizes wheat seed pretreatment with a biofungicide “Mycol” in combination with spraying wheat plants during flowering with a yeast preparation. Technology for production of Mycol on the basis of Trichoderma asperellum strain GJS 03-35 (systematics by Samuels) has been developed. This strain shows hyperparasitic activity against a wide spectrum of plant pathogens, including Fusarium graminearum, a causative agent of FES in wheat. Experiments conducted in the United States demonstrated that spraying wheat plants during flowering with the patented yeast Cryptococcus nodaensis OH 182.9 (NRRL Y-30216) reliably reduces FES development. Tests of the Mycol preparation and the yeast OH 182.9 (EOD) have been performed on the spring wheat “Ivolga” in greenhouse conditions (the Moscow region) and on the winter wheat “Kupava” in field trials in the North Caucasian reg展开更多
基金supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+22 种基金the CAS Center for Excellence in Particle PhysicsWuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules (IN2P3) in Francethe Istituto Nazionale di Fisica Nucleare (INFN) in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique (F.R.S-FNRS)FWO under the "Excellence of Science-EOS" in Belgiumthe Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo in Chilethe Charles University Research Centrethe Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft (DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+ in Germanythe Joint Institute of Nuclear Research (JINR)Lomonosov Moscow State University in Russiathe joint Russian Science Foundation (RSF)National Natural Science Foundation of China (NSFC) research programthe MOST and MOE in Taiwan,Chinathe Chulalongkorn UniversitySuranaree University of Technology in Thailandthe University of California at Irvine in USA
文摘The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.
基金supported by the National Key R&D Program of China under Contract No.2022YFA1602200the International Partnership Program of the Chineses Academy of Sciences under Grant No.211134KYSB20200057the STCF Key Technology Research and Development Project.
文摘The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.
基金support from the National Institute of General Medical Sciences,R35GM147118 to LS and PHS NRSA T32GM007270 to DS.
文摘In addition to their canonical roles in biosynthetic pathways,metabolites can be active participants in oncogenic signal-ling,but our understanding of these signalling mechanisms is incomplete.In a recent article published in Cell,Mossmann et al.find a novel signalling role for accumulated arginine in hepato-cellular carcinoma(HCC)mediated by the RNA splicing factor and transcriptional modifier RNA-binding protein 39(RBM39).
基金Basic Science Research Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Education(NRF-2019R1F1A1057243)together with the Future Semiconductor Device Technology Development Program(20003808,10080689,20004399)funded by MOTIE(Ministry of Trade,Industry&Energy)and KSRC(Korea Semiconductor Research Consortium).
文摘Resistive random-access memory(RRAM),also known as memristors,having a very simple device structure with two terminals,fulfill almost all of the fundamental requirements of volatile memory,nonvolatile memory,and neuromorphic characteristics.Its memory and neuromorphic behaviors are currently being explored in relation to a range of materials,such as biological materials,perovskites,2D materials,and transition metal oxides.In this review,we discuss the different electrical behaviors exhibited by RRAM devices based on these materials by briefly explaining their corresponding switching mechanisms.We then discuss emergent memory technologies using memristors,together with its potential neuromorphic applications,by elucidating the different material engineering techniques used during device fabrication to improve the memory and neuromorphic performance of devices,in areas such as ION/IOFF ratio,endurance,spike time-dependent plasticity(STDP),and paired-pulse facilitation(PPF),among others.The emulation of essential biological synaptic functions realized in various switching materials,including inorganic metal oxides and new organic materials,as well as diverse device structures such as single-layer and multilayer hetero-structured devices,and crossbar arrays,is analyzed in detail.Finally,we discuss current challenges and future prospects for the development of inorganic and new materials-based memristors.
基金Ministry of Science and Higher Education of the Russian Federation(scientific topic No.0137-2019-0023).
文摘The chemical and mineral compositions of bauxite recovered from the Severoonezhsk Bauxite Mine(Arkhangelsk region,Russia)were studied by XRD,ICP-OES,TG/DSC,SEM,TEM,and Mössbauer spectroscopy.The iron-containing minerals of the bauxites were found to comprise alumogoethite(α-Fe_(1−x)Al_(x)OOH),alumohematite(α-(Fe_(1−x)Al_(x))_(2)O_(3)),alumoakaganeite(β-Fe_(1−x)Al_(x)O(OH,Cl)),and chromite(FeCr_(2)O_(4)).The efficiency of Fe extraction from the bauxite by HCl leaching was 82.5%at 100℃,HCl concentration of 10%,solid/liquid ratio of 1:10,and the process duration of 60 min,with aluminum loss from the bauxites below 4.5%of the total Al contents in the bauxite.Analysis of the kinetics of the iron leaching process proved diffusion to be the limiting stage of the process at 90−100℃.Bauxite residue after leaching presented traces of α-Fe_(1−x)Al_(x)OOH and β-Fe_(1−x)Al_(x)O(OH,Cl),and most of the iron content was in the FeCr_(2)O_(4).In bauxite residue after HCl leaching,in addition to iron oxide,the contents of chromium and calcium oxides significantly decreased.The iron chloride liquor after leaching contained the rare earth elements(REE)of 6.8 mg/L Sc,4.1 mg/L Ce and 2.3 mg/L Ga.
基金supported by NRC“Kurchatov Institute”and the Russian Science Foundation(grants No.22-13-00004(synthesis),No.19-19-00009(magnetism studies),and No.20-79-10028(electron transport studies))support from the President's scholarship(SP 3111.2022.5)。
文摘Design of materials with particular functional properties is indispensable albeit very challenging.Chemical and structural analogies can be helpful in this endeavor,especially when a particular combination of properties is sought after.Our aim is to bundle together 3 characteristics:high carrier mobility,magnetism,and scalability to nanomaterials in the form of a film–such a combination is particularly advantageous for spintronics.Here,inspired by recent studies of MAl_(2)Si_(2)and related compounds,we develop magnetic EuAl_(2)Ge_(2)and non-magnetic SrAl_(2)Ge_(2)nanomaterials with high carrier mobility.Topotactic syntheses employing sacrificial 2D templates result in epitaxial films of MAl_(2)Ge_(2)seamlessly integrated with germanium.The syntheses are followed by a study of the atomic structure,magnetic and electron transport properties.In particular,the films demonstrate high carrier mobility,exceeding 10,000 cm^(2)V^(-1)s^(-1)in the case of EuAl_(2)Ge_(2),making the materials appealing for applications.Taken together,MAl_(2)Ge_(2)and MAl_(2)Si_(2)form a class of high-mobility layered nanomaterials.
基金supported by the grant of Russian Science Foundation,No.16-15-00010(to RRI)supported by the Russian Government Program of Competitive Growth of Kazan Federal University。
文摘Despite emerging contemporary biotechnological methods such as gene-and stem cell-based therapy,there are no clinically established therapeutic strategies for neural regeneration after spinal cord injury.Our previous studies have demonstrated that transplantation of genetically engineered human umbilical cord blood mononuclear cells producing three recombinant therapeutic molecules,including vascular endothelial growth factor(VEGF),glial cell-line derived neurotrophic factor(GDNF),and neural cell adhesion molecule(NCAM)can improve morpho-functional recovery of injured spinal cord in rats and mini-pigs.To investigate the efficacy of human umbilical cord blood mononuclear cells-mediated triple-gene therapy combined with epidural electrical stimulation in the treatment of spinal cord injury,in this study,rats with moderate spinal cord contusion injury were intrathecally infused with human umbilical cord blood mononuclear cells expressing recombinant genes VEGF165,GDNF,NCAM1 at 4 hours after spinal cord injury.Three days after injury,epidural stimulations were given simultaneously above the lesion site at C5(to stimulate the cervical network related to forelimb functions)and below the lesion site at L2(to activate the central pattern generators)every other day for 4 weeks.Rats subjected to the combined treatment showed a limited functional improvement of the knee joint,high preservation of muscle fiber area in tibialis anterior muscle and increased H/M ratio in gastrocnemius muscle 30 days after spinal cord injury.However,beneficial cellular outcomes such as reduced apoptosis and increased sparing of the gray and white matters,and enhanced expression of heat shock and synaptic proteins were found in rats with spinal cord injury subjected to the combined epidural electrical stimulation with gene therapy.This study presents the first proof of principle study of combination of the multisite epidural electrical stimulation with ex vivo triple gene therapy(VEGF,GDNF and NCAM)for treatment of spinal cord injury in rat mode
文摘当太阳直射点在北回归线上,北半球各地昼逐渐变成长,夜越来越短,宣告炎炎夏日的到来,许多人对夏季有着无比狂热的喜爱,莎士比亚在《Sonnet18》中写过一句流传经典的“Shall I compare thee to a summer's day?(我能否将你比作夏天?)”,不难看出莎翁对夏季的赞许和偏爱,盛夏之时,人也容易感到疲劳,本期的设计物料馆以“热情仲夏夜”为主题,选取一系列适合夏季单品,无论放置于户内或是户外。
基金Supported by National Council for Scientific and Technological Development(301591/2009-1)
文摘Three atmospheric boundary layer （ABL） schemes and two land surface models that are used in the Weather Research and Forecasting （WRF） model, version 3.4.1, were evaluated with numerical simulations by using data from the north coast of France （Dunkerque）. The ABL schemes YSU （Yonsei University）, ACM2 （Asymmetric Convective Model version 2）, and MYJ （Mellor-Yamada-Janjic） were combined with two land surface models, Noah and RUC （Rapid Update Cycle）, in order to determine the performances under sea-breeze conditions. Particular attention is given in the determination of the thermal internal boundary layer （TIBL）, which is very important in air pollution scenarios. The other physics parameterizations used in the model were consistent for all simulations. The predictions of the sea-breeze dynamics output from the WRF model were compared with observations taken from sonic detection and ranging, light detection and ranging systems and a meteorological surface station to verify that the model had reasonable accuracy in predicting the behavior of local circulations. The temporal comparisons of the vertical and horizontal wind speeds and wind directions predicted by the WRF model showed that all runs detected the passage of the sea-breeze front. However, except for the combination of MYJ and Noah, all runs had a time delay compared with the frontal passage measured by the instruments. The proposed study shows that the synoptic wind attenuated the intensity and penetration of the sea breeze. This provided changes in the vertical mixing in a short period of time and on soil temperature that could not be detected by the WRF model simulations with the computational grid used. Additionally, among the tested schemes, the combination of the local- closure MYJ scheme with the land surface Noah scheme was able to produce the most accurate ABL height compared with observations, and it was also able to capture the TIBL.
基金This work is supported by NRC“Kurchatov Institute”,the Ministry of Science and Higher Education of Russia(Agreement No.075-15-2021-1351)the Russian Science Foundation(grants No.22-13-00004(synthesis)+1 种基金20-79-10028(structural characterization)19-19-00009(studies on magnetism)).
文摘Two-dimensional(2D)magnetic materials promise unconventional properties and quantum phases as well as advances in ultracompact spintronics.Miniaturization of 2D magnets often reaches a single monolayer but in general can go beyond this limit,as demonstrated by 2D magnetism of submonolayer Eu superstructures coupled with Si.The question is whether the submonolayer magnetism constitutes a general phenomenon.Herein,we demonstrate that regular Eu lattices form a class of 2D magnets displaying various structures,stoichiometries,and chemical bonding.We synthesized and studied a set of Eu superstructures on Ge(001).Their magnetic properties are consistent with the emergence of a magnetic order such as ferro-or ferrimagnetism.In particular,control over the magnetic transition temperature by weak magnetic fields indicates the 2D nature of the magnetism.Taken together,Eu/Ge and Eu/Si superstructures seed a nucleus of the research area addressing the emergence of magnetism in submonolayer chemical species.
基金Supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+18 种基金the CAS Center for Excellence in Particle Physics,Wuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique(F.R.S-FNRS)FWO under the“Excellence of Science-EOS in Belgium”the Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo and ANID-Millennium Science Initiative Program-ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+in Germanythe Joint Institute of Nuclear Research(JINR)and Lomonosov Moscow State University in Russiathe joint Russian Science Foundation(RSF)National Natural Science Foundation of China(NSFC)research programthe MOST and MOE in Taiwanthe Chulalongkorn University and Suranaree University of Technology in Thailand,University of California at Irvinethe National Science Foundation in USA。
文摘JUNO is a multi-purpose neutrino observatory under construction in the south of China.This publication presents new sensitivity estimates for the measurement of the △m_(31)^(2),△m_(21)^(2),sin^(2)θ_(12),and sin^(2)θ_(13) oscillation parameters using reactor antineutrinos,which is one of the primary physics goals of the experiment.The sensitivities are obtained using the best knowledge available to date on the location and overburden of the experimental site,the nuclear reactors in the surrounding area and beyond,the detector response uncertainties,and the reactor antineutrino spectral shape constraints expected from the TAO satellite detector.It is found that the △m_(21)^(2) and sin^(2)θ_(12) oscillation parameters will be determined to 0.5%precision or better in six years of data collection.In the same period,the △m_(31)^(2) parameter will be determined to about 0.2%precision for each mass ordering hypothesis.The new precision represents approximately an order of magnitude improvement over existing constraints for these three parameters.
基金supported by NRC“Kurchatov Institute”(No.1055(characterization))the Russian Foundation for Basic Research(grant 19-07-00249(transport measurements)),and the Russian Science Foundation(grants 19-19-00009(synthesis)and 20-79-10028(magnetization measurements)).D.V.A.acknowledges support from the Presidents scholarship(SP 1398.2019.5).
文摘Recent discoveries of intrinsic two-dimensional(2D)magnets open up vast opportunities to address fundamental problems in condensed matter physics,giving rise to applications from ultra-compact spintronics to quantum computing.The ever-growing material landscape of 2D magnets lacks,however,carbon-based systems,prominent in other areas of 2D research.Magnetization measurements of the Eu/graphene compound-a monolayer of the EuC_(6) stoichiometry-reveal the emergence of 2D ferromagnetism but detailed studies of competing magnetic states are still missing.Here,we employ element-selective X-ray absorption spectroscopy(XAS)and magnetic circular dichroism(XMCD)to establish the magnetic structure of monolayer EuC6.The system exhibits the anomalous Hall effect,negative magnetoresistance,and magnetization consistent with a ferromagnetic state but the saturation magnetic moment(about 2.5/%/Eu)is way too low for the half-filled f-shells of Eu^(2+)ions.Combined XAS/XMCD studies at the Eu L3 absorption edge probe the EuC6 magnetism in high fields and reveal the nature of the missing magnetic moments.The results are set against XMCD studies in Eu/silicene and Eu/germanene to establish monolayer EuC6 as a prominent member of the family of Eu-based 2D magnets combining the celebrated graphene properties with a strong magnetism of europium.
基金supported by the following funding sources:Science Committee of the Republic of Armenia Grant No.18T-1C180Australian Research Council and research grant Nos.DP180102629,DP170102389,DP170102204,DP150103061,FT130100303,and FT130100018+22 种基金Austrian Federal Ministry of Education,Science and Research,and Austrian Science Fund No.P 31361-N36Natural Sciences and Engineering Research Council of Canada,Compute Canada and CANARIEChinese Academy of Sciences and research grant No.QYZDJ-SSW-SLH011National Natural Science Foundation of China and research grant Nos.11521505,11575017,11675166,11761141009,11705209,and 11975076LiaoNing Revitalization Talents Program under contract No.XLYC1807135Shanghai Municipal Science and Technology Committee under contract No.19ZR1403000Shanghai Pujiang Program under Grant No.18PJ1401000the CAS Center for Excellence in Particle Physics(CCEPP)the Ministry of Education,Youth and Sports of the Czech Republic under Contract No.LTT17020Charles University grants SVV260448 and GAUK 404316European Research Council,7th Framework PIEF-GA-2013-622527Horizon 2020 Marie Sklodowska-Curie grant agreement No.700525’NIOBE,’Horizon 2020 Marie Sklodowska-Curie RISE project JENNIFER grant agreement No.644294Horizon 2020 ERC-Advanced Grant No.267104NewAve No.638528(European grants)L’Institut National de Physique Nucléaire et de Physique des Particules(IN2P3)du CNRS(France),BMBF,DFG,HGF,MPG and AvH Foundation(Germany)Department of Atomic Energy and Department of Science and Technology(India)Israel Science Foundation grant No.2476/17United States-Israel Binational Science Foundation grant No.2016113Istituto Nazionale di Fisica Nucleare and the research grants BELLE2Japan Society for the Promotion of Science,Grant-in-Aid for Scientific Research grant Nos.16H03968,16H03993,16H06492,16K05323,17H01133,17H05405,18K03621,18H03710,18H05226,19H00682,26220706,and 26400255the National Institute of Informatics,and Science Information NETwork 5(SINET5)the Ministry of Education,Culture,Sports,Science,an
文摘From April to July 2018,a data sample at the peak energy of the T(4 S) resonance was collected with the Belle Ⅱ detector at the SuperKEKB electron-positron collider.This is the first data sample of the Belle Ⅱ experiment.Using Bhabha and digamma events,we measure the integrated luminosity of the data sample to be(496.3±0.3±3.0) pb-1,where the first uncertainty is statistical and the second is systematic.This work provides a basis for future luminosity measurements at Belle Ⅱ.
基金Supported by The Intramural Research Program of the National Institutes of Health,Clinical Center
文摘Human pluripotent stem cells(h PSCs) represent heterogeneous populations, including induced pluripotent stem cells(i PSCs), endogenous plastic somatic cells, and embryonic stem cells(ESCs). Human ESCs are derived from the inner cell mass of the blastocyst, and they are characterized by the abilities to self-renew indefinitely, and to give rise to all cell types of embryonic lineage(pluripotency) under the guidance of the appropriate chemical, mechanical and environmental cues. The combination of these critical features is unique to h ESCs, and set them apart from other human cells. The expectations are high to utilize h ESCs for treating injuries and degenerative diseases; for modeling of complex illnesses and development; for screening and testing of pharmacological products; and for examining toxicity, mutagenicity, teratogenicity, and potential carcinogenic effects of a variety of environmental factors, including ionizing radiation(IR). Exposures to genotoxic stresses, such as background IR, are unavoidable; moreover, IR is widely used in diagnostic and therapeutic procedures in medicine on a routine basis. One of the key outcomes of cell exposures to IR is the change in gene expression, which may underlie the ultimate h ESCs fate after such a stress. However, gaps in our knowledge about basic biology of h ESCs impose a serious limitation to fully realize the potential of h ESCs in practice. The purpose of this review is to examine the available evidence of alterations in gene expression in human pluripotent stem cells after genotoxic stress, and to discuss strategies for future research in this important area.
文摘During the last century, as the area of wheat grown under advanced grain husbandry has increased worldwide, so too has the importance of Fusarium ear scab (FES) (synonym, Fusarium head blight) caused by several species of the fungus Fusarium. Yield losses due to FES can total 20%-40% and more depending on climatic conditions. During the last twenty years epidemics of FES in cereals have become chronic all over the world, including the United States and Russia. The most destructive of these were observed in 1982, 1986, 1990-1996 in USA and in the south of Russia in 1982, 1984, 1988, 1992. The harmful effect of FES is manifested not only in reduced grain yields, but also in the contamination of grains and grain products with mycotoxins, such as deoxynivalenol (DON) and its derivatives (3-alfa acetyl-DON, 15-alfa acetyl-DON), T-2 toxin and zearalenone. Standard means to control FES (cultural control methodologies, chemical pesticides, and FES resistant varieties) have little effect or are not practical and rarely reduce the accumulation of mycotoxins in grain. We have developed a new technique to reduce FES using biological preparations. The technique utilizes wheat seed pretreatment with a biofungicide “Mycol” in combination with spraying wheat plants during flowering with a yeast preparation. Technology for production of Mycol on the basis of Trichoderma asperellum strain GJS 03-35 (systematics by Samuels) has been developed. This strain shows hyperparasitic activity against a wide spectrum of plant pathogens, including Fusarium graminearum, a causative agent of FES in wheat. Experiments conducted in the United States demonstrated that spraying wheat plants during flowering with the patented yeast Cryptococcus nodaensis OH 182.9 (NRRL Y-30216) reliably reduces FES development. Tests of the Mycol preparation and the yeast OH 182.9 (EOD) have been performed on the spring wheat “Ivolga” in greenhouse conditions (the Moscow region) and on the winter wheat “Kupava” in field trials in the North Caucasian reg
