China Oil&Gas,as a prominent academic journal in the energy industry,has been dedicated to advancing academic research and industrial development in the oil and gas energy field.As one of the authoritative media o...China Oil&Gas,as a prominent academic journal in the energy industry,has been dedicated to advancing academic research and industrial development in the oil and gas energy field.As one of the authoritative media outlets in the international energy sector,the magazine has long focused on the evolution of the global energy landscape and has organized and participated in several influential academic activities and research projects.展开更多
Background:The aim was to explore the effect of macrophage polarization and macrophage-to-myofibroblast transition(MMT)in silicosis.Methods:Male Wistar rats were divided into a control group and a silicosis group deve...Background:The aim was to explore the effect of macrophage polarization and macrophage-to-myofibroblast transition(MMT)in silicosis.Methods:Male Wistar rats were divided into a control group and a silicosis group developed using a HOPE MED 8050 dynamic automatic dusting system.Murine mac-rophage MH-S cells were randomly divided into a control group and an SiO_(2) group.The pathological changes in lung tissue were observed using hematoxylin and eosin(HE)and Van Gieson(VG)staining.The distribution and location of macrophage marker(F4/80),M1 macrophage marker(iNOS),M2 macrophage marker(CD206),and myofibroblast marker(α-smooth muscle actin[α-SMA])were detected using immu-nohistochemical and immunofluorescent staining.The expression changes in iNOS,Arg,α-SMA,vimentin,and type I collagen(Col I)were measured using Western blot.Results:The results of HE and VG staining showed obvious silicon nodule formation and the distribution of thick collagen fibers in the lung tissue of the silicosis group.Macrophage marker F4/80 increased gradually from 8 to 32 weeks after exposure to silica.Immunohistochemical and immunofluorescent staining results revealed that there were more iNOS-positive cells and some CD206-positive cells in the lung tissue of the silicosis group at 8 weeks.More CD206-positive cells were found in the silicon nodules of the lung tissues in the silicosis group at 32 weeks.Western blot analysis showed that the expressions of Inducible nitric oxide synthase and Arg protein in the lung tissues of the silicosis group were upregulated compared with those of the con-trol group.The results of immunofluorescence staining showed the co-expression of F4/80,α-SMA,and Col I,and CD206 andα-SMA were co-expressed in the lung tissue of the silicosis group.The extracted rat alveolar lavage fluid revealed F4/80+α-SMA+,CD206+α-SMA+,and F4/80+α-SMA+Col I+cells using immunofluorescence staining.Similar results were also found in MH-S cells induced by SiO_(2).Conclusions:The development of silicosis is accompanied by macrophage polarization and MMT.展开更多
In the present study,we aimed to investigate whether anlotinib reverses osimertinib resistance by inhibiting the formation of epithelial-mesenchymal transition(EMT)and angiogenesis.In a clinical case,anlotinib reverse...In the present study,we aimed to investigate whether anlotinib reverses osimertinib resistance by inhibiting the formation of epithelial-mesenchymal transition(EMT)and angiogenesis.In a clinical case,anlotinib reversed osimertinib resistance in non-small cell lung cancer(NSCLC).Therefore,we performed immunohistochemical analyses on tumor tissues from three NSCLC patients with osimertinib resistance to analyze alterations in the expression levels of EMT markers and vascular endothelial growth factor A(VEGFA)before and after the development of osimertinib resistance.The results revealed the downregulation of E-cadherin,coupled with the upregulation of vimentin and VEGFA in tumor tissues of patients exhibiting osimertinib resistance,compared with those in tissues from patients before receiving osimertinib.Subsequently,we established osimertinib-resistant(Osi-R)cell lines and found that the Osi-R cells acquired EMT features.Next,we analyzed the synergistic effects of the combination therapy to verify whether anlotinib could reverse osimertinib resistance by inhibiting EMT.The expression levels of VEGFA and tube formation were analyzed in the combination group in vitro.Finally,we determined the reversal of osimertinib resistance by the combination of osimertinib and anlotinib in vivo using 20 nude mice.The combined treatment of osimertinib and anlotinib effectively prevented the metastasis of Osi-R cells,inhibited tumor growth,exerted antitumor activity,and ultimately reversed osimertinib resistance in mice.The co-administration of osimertinib and anlotinib demonstrated synergistic efficacy in inhibiting EMT and angiogenesis in three NSCLC patients,ultimately reversing osimertinib resistance.展开更多
The plastic deformation of semiconductors,a process critical to their mechanical and electronic properties,involves various mechanisms such as dislocation motion and phase transition.Here,we systematically examined th...The plastic deformation of semiconductors,a process critical to their mechanical and electronic properties,involves various mechanisms such as dislocation motion and phase transition.Here,we systematically examined the temperature-dependent Peierls stress for 30°and 90°partial dislocations in cadmium telluride(CdTe),using a combination of molecular statics and molecular dynamics simulations with a machine-learning force field,as well as density functional theory simulations.Our findings reveal that the 0 K Peierls stresses for these partial dislocations in CdTe are relatively low,ranging from 0.52 GPa to 1.46 GPa,due to its significant ionic bonding characteristics.Notably,in the CdTe system containing either a 30°Cd-core or 90°Te-core partial dislocation,a phase transition from the zinc-blende phase to theβ-Sn-like phase is favored over dislocation motion.This suggests a competitive relationship between these two mechanisms,driven by the bonding characteristics within the dislocation core and the relatively low phase transition stress of∼1.00 GPa.Furthermore,we observed a general trend wherein the Peierls stress for partial dislocations in CdTe exhibits a temperature dependence,which decreases with increasing temperature,becoming lower than the phase transition stress at elevated temperatures.Consequently,the dominant deformation mechanism in CdTe shifts from solid-state phase transition at low temperatures to dislocation motion at high temperatures.This investigation uncovers a compelling interplay between dislocation motion and phase transition in the plastic deformation of CdTe,offering profound insights into the mechanical behavior and electronic performance of CdTe and other II-VI semiconductors.展开更多
A novel substrate integrated microstrip to ultra-thin cavity filter transition operating in the W-band is proposed in this letter.The structure is a new method of connecting microstrip circuits and waveguide filters,a...A novel substrate integrated microstrip to ultra-thin cavity filter transition operating in the W-band is proposed in this letter.The structure is a new method of connecting microstrip circuits and waveguide filters,and this new structure enables a planar integrated transition from microstrip lines to ultra-thin cavity filters,thereby reducing the size of the transition structure and achieving miniaturization.The structure includes a conventional tapered microstrip transition structure,which guides the electromagnetic field from the microstrip line to the reduced-height dielectric-filled waveguide,and an air-filled matching cavity which is placed between the dielectric-filled waveguide and the ultra-thin cavity filter.The heights of the microstrip line,the dielectric-filled waveguide and the ultra-thin cavity filter are the same,enabling seamless integration within a planar radio-frequency(RF)circuit.To facilitate testing,mature finline transition structures are integrated at both ends of the microstrip line during fabrications.The simulation results of the fabricated microstrip to ultra-thin cavity filter transition with the finline transition structure,with a passband of 91.5-96.5 GHz,has an insertion loss of less than 1.9 dB and a return loss lower than-20 dB.And the whole structure has also been measured which achieves an insertion loss less than 2.6 dB and a return loss lower than-15 dB within the filter's passband,including the additional insertion loss introduced by the finline transitions.Finally,a W-band compact up-conversion module is designed,and the test results show that after using the proposed structure,the module achieves 95 dBc suppression of the 84 GHz local oscillator.It is also demonstrated that the structure proposed in this letter achieves miniaturization of the system integration without compromising the filter performance.展开更多
Introduction and Background: Registered nurses’ transit to the clinical placement areas after completing a three-year Bachelor of Nursing training. They should be supported by nurse leaders and nurse educators;to gai...Introduction and Background: Registered nurses’ transit to the clinical placement areas after completing a three-year Bachelor of Nursing training. They should be supported by nurse leaders and nurse educators;to gain confidence and the ability to perform critical care nursing, deal with high patient numbers, the ability to work independently and manage relationships with providers, families and the interprofessional team. Methods: A qualitative research design was employed to explore two important aspects of nursing professionalism. Firstly, the sentiments of senior registered nurses about professional mentorship of newly graduated nurses NGNs. Secondly the strategies employed by senior nurses to assist the transition of NGNs to professional nursing. Two nurse unit managers (NUM) participated as key informants. Results: Two themes will be discussed from the pilot study: Responsibilities and challenges faced by senior nurses while they supervise (NGNs) in their wards. Senior nurses’ workload and responsibilities fully occupy them during the days’ work, leaving very little time to spend supervising the NGNs. The challenges faced by senior nurses are those of restricted time, no proper resources, and mentoring manuals to guide the senior nurses. Discussion: The results of the pilot study present the challenges of senior nurses in supervising and training NGNs during transition, as they must complete the administrative tasks, finalizing rosters, and have direct patient contact. They usually face challenges while supervising the NGNs, sometimes leaving them to work on their own where the NGN is prone to make mistakes during patient care. Conclusion: Support and supervision are key to a successful transition, but senior nurses face difficulties, and challenges in many forms, there are no mentors available for the NGNs in any ward at the CWM Hospital while they train and supervise them during transitions. SNs take up a lot of responsibilities and provide support and supervision to NGNs. Some NGNs have undesirable attitudes that hinder the learning and teaching process. They also acknowledge that NGNs also need to play their role in learning to adapt to the new clinical environment with various challenges they face themselves.展开更多
Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+d...Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.展开更多
BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progr...BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progression of gastric cancer(GC)is not yet clear.AIM To explore the role and underlying mechanisms of action of RGS4 in GC develop-ment.METHODS The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC.Function assays were employed to assess the carcinogenic impact of RGS4,and the mechanism of its possible influence was detected by western blot analysis.A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.RESULTS RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues.Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage,increased tumor grade as well as poorer overall survival in patients with GC.Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation,migration and invasion.Similarly,xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth.Moreover,RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase,phosphatidyl-inositol-3-kinase,and protein kinase B,decreased vimentin and N-cadherin,and elevated E-cadherin.CONCLUSION High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker.RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.展开更多
Background: Since it was theorised by Abdel Omran in 1971, the epidemiological transition has been well documented in Latin America, Asia and even increasingly in Africa south of the Sahara. According to this theory, ...Background: Since it was theorised by Abdel Omran in 1971, the epidemiological transition has been well documented in Latin America, Asia and even increasingly in Africa south of the Sahara. According to this theory, sub-Saharan Africa is in the first phase of development corresponding to the “age of plague and famine”. Given the health statistics currently available, more and more low- and middle-income countries, including those in sub-Saharan Africa, are experiencing an increase in mortality and the economic impact associated with non-communicable diseases. Côte d’Ivoire is one of the countries in sub-Saharan Africa where non-communicable diseases are currently on the rise. Despite the significant changes observed over the last decades, few studies have been carried out on the epidemiological transition in Côte d’Ivoire. It therefore seemed necessary to examine the changes in patterns of disease occurrence and causes of death in Côte d’Ivoire. Objectives: This work aimed to determine the reality of the epidemiological transition in Côte d’Ivoire and characterize its facies from 1990 to 2020. Methods: A literature review was carried out using PubMed, Medline, Google Scholar, Google, institutional websites (WHO, World Bank), university library websites and institutional reports from Côte d’Ivoire. The indicators sought were mortality, morbidity, life expectancy and fertility. Results: Mortality fell overall from 13.88‰ to 9.70‰, with variations linked to cyclical situations. Life expectancy rose by 52.6 to 59.03 years, although it is still below 60. Fertility has fallen from 6.3 to 4.5 children. There is a general downward trend in morbidity due to communicable diseases between 2009 and 2019, followed by an increase in non-communicable diseases. Conclusion: Côte d’Ivoire is undergoing an original and complex epidemiological transition that needs to be taken into account in health policies and strategies.展开更多
A bearing fault diagnosis method based on the Markov transitionfield(MTF)and SEnet(SE)-IShufflenetV2 model is proposed in this paper due to the problems of complex working conditions,low fault diagnosis accuracy,and poo...A bearing fault diagnosis method based on the Markov transitionfield(MTF)and SEnet(SE)-IShufflenetV2 model is proposed in this paper due to the problems of complex working conditions,low fault diagnosis accuracy,and poor generalization of rolling bearing.Firstly,MTF is used to encode one-dimensional time series vibration sig-nals and convert them into time-dependent and unique two-dimensional feature images.Then,the generated two-dimensional dataset is fed into the SE-IShufflenetV2 model for training to achieve fault feature extraction and classification.This paper selects the bearing fault datasets from Case Western Reserve University and Paderborn University to experimentally verify the effectiveness and superiority of the proposed method.The generalization performance of the proposed method is tested under the variable load condition and different signal-to-noise ratios(SNRs).The experimental results show that the average accuracy of the proposed method under different working conditions is 99.2%without adding noise.The accuracy under different working conditions from 0 to 1 HP is 100%.When the SNR is 0 dB,the average accuracy of the proposed method can still reach 98.7%under varying working conditions.Therefore,the bearing fault diagnosis method proposed in this paper is characterized by high accuracy,strong anti-noise ability,and generalization.Moreover,the proposed method can also overcome the influence of variable working conditions on diagnosis accuracy,providing method support for the accurate diagnosis of bearing faults under strong noise and variable working conditions.展开更多
Epithelial-mesenchymal transition(EMT)plays an irreplaceable role in the development of silicosis.However,molecular mechanisms of EMT induced by silica exposure still remain to be addressed.Herein,metabolic profiles o...Epithelial-mesenchymal transition(EMT)plays an irreplaceable role in the development of silicosis.However,molecular mechanisms of EMT induced by silica exposure still remain to be addressed.Herein,metabolic profiles of human alveolar type II epithelial cells(A549 cells)exposed directly to silica were characterized using non-targeted metabolomic approaches.A total of 84 differential metabolites(DMs)were identified in silica-treated A549 cells undergoing EMT,which were mainly enriched in metabolisms of amino acids(e.g.,glutamate,alanine,aspartate),purine metabolism,glycolysis,etc.The number of DMs identified in the A549 cells obviously increased with the elevated exposure concentration of silica.Remarkably,glutamine catabolism was significantly promoted in the silica-treated A549 cells,and the levels of related metabolites(e.g.,succinate)and enzymes(e.g.,α-ketoglutarate(α-KG)dehydrogenase)were substantially up-regulated,with a preference toα-KG pathway.Supplementation of glutamine into the cell culture could substantially enhance the expression levels of both EMT-related markers and Snail(zinc finger transcription factor).Our results suggest that the EMT of human alveolar epithelial cells directly induced by silica can be essential to the development of silicosis.展开更多
The pressure-actuated metal seal with soft metal coating has been widely used in complex working conditions such as high temperature,low temperature and high pressure.The investigation of the characteristics and bindi...The pressure-actuated metal seal with soft metal coating has been widely used in complex working conditions such as high temperature,low temperature and high pressure.The investigation of the characteristics and binding strength of the transition layer between the soft metal coating and the superalloy substrate is important to improve the sealing performance and to model and simplify the working through-process of metal sealing.The distribution characteristics of elements at soft metal-substrate interface and the binding strength between coating and substrate under different thicknesses and material combinations of coating layer were studied by experimental methods.The results indicate that the thickness of soft metal coating has little influence on the interface morphology of GH4169-Cu,GH4169-Ag and Cu-Ag,but has an influence on the thickness of transition layer between different metals,while this influence is weakened with increasing the coating thickness,and the thickness of transition layer is about 2μm when the coating thickness is more than 30μm.The cross-cut test shows that the Cu,Ag and Cu-Ag coatings are all well combined with nickel-based superalloy GH4169 substrate.The materials of soft metal,i.e.the coating materials,have significant influence on the characteristic of transition layer and the surface characteristics of coating after cross-cut test.展开更多
Adolescence and the journey to adulthood involves exciting opportunities as well as psychosocial stress for young people growing up.These normal experiences are potentially magnified for teenagers living with chronic ...Adolescence and the journey to adulthood involves exciting opportunities as well as psychosocial stress for young people growing up.These normal experiences are potentially magnified for teenagers living with chronic illness or disability and their families.Advances in care have improved survival for children with a variety of serious chronic medical conditions such that many who may once have died in childhood now survive well into adulthood with ongoing morbidity.For those with highly complex needs,care is often provided at major paediatric hospitals with expertise,specially trained personnel,and resources to support young people and their families for the first decades of life.At the end of adolescence,however,it is generally appropriate and necessary for young adults and their caregivers to transition to the care of clinicians trained in the care of adults at general hospitals.While there are some well-managed models to support this journey of transition,these are often specific to certain conditions and usually do not involve intensive care.Many patients may encounter considerable challenges during this period.Difficulties may include the loss of established therapeutic relationships,a perception of austerity and reduced amenity in facilities oriented to caring for adult patients,and care by clinicians with less experience with more common paediatric conditions.In addition,there is a risk of potential conflict between clinicians and families regarding goals of care in the event of a critical illness when it occurs in a young adult with major disability and long-term health issues.These challenges present genuine opportunities to better understand the transition from paediatric to adult-based care and to improve processes that assist clinicians who support patients and families as they shift between healthcare settings.展开更多
Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopo...Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopolymers,swimming bacteria,artificial swimmers,and animal herds.In contrast to wet active matter,dry active matter is an active system characterized by the absence of significant hydrodynamic interactions and conserved momentum.In dry active matter,the role of surrounding fluids is providing viscous friction at low Reynolds numbers and can be neglected at high Reynolds numbers.This review offers a comprehensive overview of recent experimental,computational,and theoretical advances in understanding phase transitions and critical phenomena in dry aligning active matter,including polar particles,self-propelled rods,active nematics,and their chiral counterparts.Various ways of determining phase transition points as well as non-equilibrium phenomena,such as collective motion,cluster formation,and creation and annihilation of topological defects are reviewed.展开更多
Mn_(3)Si_(2)Te_(6) is a ferrimagnetic nodal-line semiconductor with colossal angular magnetoresistance at ambient pressure.In this work,we investigated the effect of hydrostatic pressure on its electrical transport pr...Mn_(3)Si_(2)Te_(6) is a ferrimagnetic nodal-line semiconductor with colossal angular magnetoresistance at ambient pressure.In this work,we investigated the effect of hydrostatic pressure on its electrical transport properties,magnetic transition,and crystal structure by measuring resistivity,DC and AC magnetic susceptibility,and XRD under various pressures up to~20 GPa.Our results confirmed the occurrence of pressure-induced structural transition at P_(c)≈10–12 GPa accompanied by a concurrent drop of room-temperature resistance in Mn_(3)Si_(2)Te_(6).In the low-pressure phase at PP_(c),the sample exhibits a metallic behavior in the whole temperature range and its resistivity exhibits a kink anomaly at T_(M),characteristic of critical scattering around a magnetic transition.Recovery of the Raman spectrum upon decompression indicated that pressure-induced structural transition is reversible without amorphization under hydrostatic pressure conditions.Our present work not only resolves some existing controversial issues but also provides new insights into pressure-driven diverse behaviors of Mn_(3)Si_(2)Te_(6).展开更多
A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of...A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of heavy transition metal mononitrides.Here,we systematically investigate the structural evolutionof LaN under high pressure using first-principles calculations combined with angle-dispersive synchrotron X-raydiffraction,identifying the phase transition sequence and corresponding phase boundaries.Analyses of energetics,kinetic barriers,and lattice dynamics reveal distinct mechanisms driving these transitions.These results clarifythe structural stability of LaN and offer guidance for studying other heavy transition metal mononitrides withcomplex electronic behavior under extreme conditions.展开更多
The transition metal trichalcogenides(TMTs)with quasi-one-dimensional(quasi-1D)layered crystal structure represent a unique platform to explore intriguing physical properties.Herein,we report the successful growth of ...The transition metal trichalcogenides(TMTs)with quasi-one-dimensional(quasi-1D)layered crystal structure represent a unique platform to explore intriguing physical properties.Herein,we report the successful growth of a new TMT TiSe_(3)single crystal by using a high-pressure and high-temperature technique.The crystal structure of TiSe_(3)was determined by measuring the single-crystal x-ray diffraction and selected area electron diffraction.The 1D chain-like structure along the b-axis is formed by the TiSe_(6)prisms which share their tops and bottoms with each other.TiSe_(3)is a narrow band gap semiconductor with electron-type carriers under ambient conditions identified by the electrical and Hall effect measurements.It exhibits a pressure-induced semiconductor-to-metal transition around 4 GPa.As the pressure further increases to~6 GPa,a pressure-induced Lifshitz transition occurs,as indicated by the electrical transport measurements,high-pressure crystal structure characterizations,and electronic band structure calculations.展开更多
Understanding the occurrence and characteristics of dry and wet events is crucial for effective disaster prevention,resource management,and risk reduction in vulnerable regions.This study analyzed the spatiotemporal p...Understanding the occurrence and characteristics of dry and wet events is crucial for effective disaster prevention,resource management,and risk reduction in vulnerable regions.This study analyzed the spatiotemporal patterns of dry-wet events and their transition characteristics in Uttar Pradesh,India.The standardized precipitation evapotranspiration index(SPEI)at a monthly timescale was utilized to identify hotspot regions vulnerable to concurrent and frequent dry and wet events and their transitions.The severity,duration,and intensity of dry and wet events were characterized with the run theory over SPEI time series data from 18 synoptic stations in Uttar Pradesh over 48 years(1971-2018),sourced from the Indian Institute of Tropical Meteorology and the India Meteorological Department.Multiple assessment methods were utilized to examine the interaction of these extreme events,considering characteristics such as wet-dry ratio,average transition time,and rapid transition times from wet to dry events and from dry to wet events.Average wet durations ranged from 1.27 to 1.58 months,and average dry durations ranged from 1.29 to 1.82 months.Rapid transition times from dry to wet events ranged from 2.5 to 4.1 months,and those for wet-to-dry events ranged from 2.1 to 5.3 months.The eastern region experienced a significantly high number of dry events,while the western and Bundelkhand regions experienced more intense dry events.In contrast,the eastern region had intense wet events.This research on the occurrence of dry-wet events and their transitions can provide valuable insights for government decision-making and disaster prevention and reduction efforts.展开更多
In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mit...In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mitigation.Abrupt transitions between drought and flood refer to a phenomenon in which an extreme drought event quickly shifts to an extreme flood event,or vice versa,within a relatively short time span.This phenomenon disrupts the traditional spatiotemporal distribution patterns of water-related disasters,reflecting not only the extreme unevenness in the distribution of water resources but also the rapid alternation of the water cycle's evolution(He et al.,2016).Moreover,due to its suddenness,extremity,and complexity,it poses severe threats to human societies and ecosystems.Scientifically addressing abrupt transitions between drought and flood has thus become a new challenge in flood and drought disaster prevention.展开更多
Motivated by recent studies of the cluster Mott insulator candidate compound Nb_(3)Cl_(8),this study performs^(93)Nb and^(35)Cl nuclear magnetic resonance(NMR)measurements to investigate the electron correlations.Belo...Motivated by recent studies of the cluster Mott insulator candidate compound Nb_(3)Cl_(8),this study performs^(93)Nb and^(35)Cl nuclear magnetic resonance(NMR)measurements to investigate the electron correlations.Below the structural transition temperature T_(s)∼97 K,all satellites of the^(93)Nb NMR spectra split into three distinct peaks,which suggests symmetry lowering due to the structural transition and could be attributed to the change in the Nb-Nb bond-lengths of the Nb3 clusters.The spin-lattice relaxation rate 1/T_(1)divided by the temperature T,1/T_(1)T,increases upon cooling to T_(s)for all Cl sites,whereas only the Knight shift K of Cl located at the center of the Nb_(3) clusters exhibits a temperature dependence similar to that observed in magnetic susceptibility.These findings collectively demonstrate the existence of strong spin correlations between the Nb atoms in Nb_(3)Cl_(8),which are closely associated with Mottness.展开更多
文摘China Oil&Gas,as a prominent academic journal in the energy industry,has been dedicated to advancing academic research and industrial development in the oil and gas energy field.As one of the authoritative media outlets in the international energy sector,the magazine has long focused on the evolution of the global energy landscape and has organized and participated in several influential academic activities and research projects.
基金The National Natural Science Foundation of China(no.82204006)the Science and Technology of Project of Hebei Education Department(QN2022009)+1 种基金the Provincial Graduate Student Innovation Funding Project of Hebei Province(CXZZBS2022104)the National Natural Science Foundation of Hebei Province(H2020209292).
文摘Background:The aim was to explore the effect of macrophage polarization and macrophage-to-myofibroblast transition(MMT)in silicosis.Methods:Male Wistar rats were divided into a control group and a silicosis group developed using a HOPE MED 8050 dynamic automatic dusting system.Murine mac-rophage MH-S cells were randomly divided into a control group and an SiO_(2) group.The pathological changes in lung tissue were observed using hematoxylin and eosin(HE)and Van Gieson(VG)staining.The distribution and location of macrophage marker(F4/80),M1 macrophage marker(iNOS),M2 macrophage marker(CD206),and myofibroblast marker(α-smooth muscle actin[α-SMA])were detected using immu-nohistochemical and immunofluorescent staining.The expression changes in iNOS,Arg,α-SMA,vimentin,and type I collagen(Col I)were measured using Western blot.Results:The results of HE and VG staining showed obvious silicon nodule formation and the distribution of thick collagen fibers in the lung tissue of the silicosis group.Macrophage marker F4/80 increased gradually from 8 to 32 weeks after exposure to silica.Immunohistochemical and immunofluorescent staining results revealed that there were more iNOS-positive cells and some CD206-positive cells in the lung tissue of the silicosis group at 8 weeks.More CD206-positive cells were found in the silicon nodules of the lung tissues in the silicosis group at 32 weeks.Western blot analysis showed that the expressions of Inducible nitric oxide synthase and Arg protein in the lung tissues of the silicosis group were upregulated compared with those of the con-trol group.The results of immunofluorescence staining showed the co-expression of F4/80,α-SMA,and Col I,and CD206 andα-SMA were co-expressed in the lung tissue of the silicosis group.The extracted rat alveolar lavage fluid revealed F4/80+α-SMA+,CD206+α-SMA+,and F4/80+α-SMA+Col I+cells using immunofluorescence staining.Similar results were also found in MH-S cells induced by SiO_(2).Conclusions:The development of silicosis is accompanied by macrophage polarization and MMT.
基金supported by the National Natural Science Foundation of China(Grant Nos.82172728,82370096).
文摘In the present study,we aimed to investigate whether anlotinib reverses osimertinib resistance by inhibiting the formation of epithelial-mesenchymal transition(EMT)and angiogenesis.In a clinical case,anlotinib reversed osimertinib resistance in non-small cell lung cancer(NSCLC).Therefore,we performed immunohistochemical analyses on tumor tissues from three NSCLC patients with osimertinib resistance to analyze alterations in the expression levels of EMT markers and vascular endothelial growth factor A(VEGFA)before and after the development of osimertinib resistance.The results revealed the downregulation of E-cadherin,coupled with the upregulation of vimentin and VEGFA in tumor tissues of patients exhibiting osimertinib resistance,compared with those in tissues from patients before receiving osimertinib.Subsequently,we established osimertinib-resistant(Osi-R)cell lines and found that the Osi-R cells acquired EMT features.Next,we analyzed the synergistic effects of the combination therapy to verify whether anlotinib could reverse osimertinib resistance by inhibiting EMT.The expression levels of VEGFA and tube formation were analyzed in the combination group in vitro.Finally,we determined the reversal of osimertinib resistance by the combination of osimertinib and anlotinib in vivo using 20 nude mice.The combined treatment of osimertinib and anlotinib effectively prevented the metastasis of Osi-R cells,inhibited tumor growth,exerted antitumor activity,and ultimately reversed osimertinib resistance in mice.The co-administration of osimertinib and anlotinib demonstrated synergistic efficacy in inhibiting EMT and angiogenesis in three NSCLC patients,ultimately reversing osimertinib resistance.
基金supported by the National Science Foundation(No.CMMI-2019459).
文摘The plastic deformation of semiconductors,a process critical to their mechanical and electronic properties,involves various mechanisms such as dislocation motion and phase transition.Here,we systematically examined the temperature-dependent Peierls stress for 30°and 90°partial dislocations in cadmium telluride(CdTe),using a combination of molecular statics and molecular dynamics simulations with a machine-learning force field,as well as density functional theory simulations.Our findings reveal that the 0 K Peierls stresses for these partial dislocations in CdTe are relatively low,ranging from 0.52 GPa to 1.46 GPa,due to its significant ionic bonding characteristics.Notably,in the CdTe system containing either a 30°Cd-core or 90°Te-core partial dislocation,a phase transition from the zinc-blende phase to theβ-Sn-like phase is favored over dislocation motion.This suggests a competitive relationship between these two mechanisms,driven by the bonding characteristics within the dislocation core and the relatively low phase transition stress of∼1.00 GPa.Furthermore,we observed a general trend wherein the Peierls stress for partial dislocations in CdTe exhibits a temperature dependence,which decreases with increasing temperature,becoming lower than the phase transition stress at elevated temperatures.Consequently,the dominant deformation mechanism in CdTe shifts from solid-state phase transition at low temperatures to dislocation motion at high temperatures.This investigation uncovers a compelling interplay between dislocation motion and phase transition in the plastic deformation of CdTe,offering profound insights into the mechanical behavior and electronic performance of CdTe and other II-VI semiconductors.
基金Supported by the Fundamental Research Funds for the Central Universities(ZYGX2021J008)。
文摘A novel substrate integrated microstrip to ultra-thin cavity filter transition operating in the W-band is proposed in this letter.The structure is a new method of connecting microstrip circuits and waveguide filters,and this new structure enables a planar integrated transition from microstrip lines to ultra-thin cavity filters,thereby reducing the size of the transition structure and achieving miniaturization.The structure includes a conventional tapered microstrip transition structure,which guides the electromagnetic field from the microstrip line to the reduced-height dielectric-filled waveguide,and an air-filled matching cavity which is placed between the dielectric-filled waveguide and the ultra-thin cavity filter.The heights of the microstrip line,the dielectric-filled waveguide and the ultra-thin cavity filter are the same,enabling seamless integration within a planar radio-frequency(RF)circuit.To facilitate testing,mature finline transition structures are integrated at both ends of the microstrip line during fabrications.The simulation results of the fabricated microstrip to ultra-thin cavity filter transition with the finline transition structure,with a passband of 91.5-96.5 GHz,has an insertion loss of less than 1.9 dB and a return loss lower than-20 dB.And the whole structure has also been measured which achieves an insertion loss less than 2.6 dB and a return loss lower than-15 dB within the filter's passband,including the additional insertion loss introduced by the finline transitions.Finally,a W-band compact up-conversion module is designed,and the test results show that after using the proposed structure,the module achieves 95 dBc suppression of the 84 GHz local oscillator.It is also demonstrated that the structure proposed in this letter achieves miniaturization of the system integration without compromising the filter performance.
文摘Introduction and Background: Registered nurses’ transit to the clinical placement areas after completing a three-year Bachelor of Nursing training. They should be supported by nurse leaders and nurse educators;to gain confidence and the ability to perform critical care nursing, deal with high patient numbers, the ability to work independently and manage relationships with providers, families and the interprofessional team. Methods: A qualitative research design was employed to explore two important aspects of nursing professionalism. Firstly, the sentiments of senior registered nurses about professional mentorship of newly graduated nurses NGNs. Secondly the strategies employed by senior nurses to assist the transition of NGNs to professional nursing. Two nurse unit managers (NUM) participated as key informants. Results: Two themes will be discussed from the pilot study: Responsibilities and challenges faced by senior nurses while they supervise (NGNs) in their wards. Senior nurses’ workload and responsibilities fully occupy them during the days’ work, leaving very little time to spend supervising the NGNs. The challenges faced by senior nurses are those of restricted time, no proper resources, and mentoring manuals to guide the senior nurses. Discussion: The results of the pilot study present the challenges of senior nurses in supervising and training NGNs during transition, as they must complete the administrative tasks, finalizing rosters, and have direct patient contact. They usually face challenges while supervising the NGNs, sometimes leaving them to work on their own where the NGN is prone to make mistakes during patient care. Conclusion: Support and supervision are key to a successful transition, but senior nurses face difficulties, and challenges in many forms, there are no mentors available for the NGNs in any ward at the CWM Hospital while they train and supervise them during transitions. SNs take up a lot of responsibilities and provide support and supervision to NGNs. Some NGNs have undesirable attitudes that hinder the learning and teaching process. They also acknowledge that NGNs also need to play their role in learning to adapt to the new clinical environment with various challenges they face themselves.
基金supported by the National Natural Science Foundation of China(No.21805018)by Sichuan Science and Technology Program(Nos.2022ZHCG0018,2023NSFSC0117 and 2023ZHCG0060)Yibin Science and Technology Program(No.2022JB005)and China Postdoctoral Science Foundation(No.2022M722704).
文摘Layered transition metal oxides have emerged as promising cathode materials for sodium ion batteries.However,irreversible phase transitions cause structural distortion and cation rearrangement,leading to sluggish Na+dynamics and rapid capacity decay.In this study,we propose a medium-entropy cathode by simultaneously introducing Fe,Mg,and Li dopants into a typical P2-type Na_(0.75)Ni_(0.25)Mn_(0.75)O_(2)cathode.The modified Na_(0.75)Ni_(0.2125)Mn_(0.6375)Fe_(0.05)Mg_(0.05)Li_(0.05)O_(2)cathode predominantly exhibits a main P2 phase(93.5%)with a minor O3 phase(6.5%).Through spectroscopy techniques and electrochemical investigations,we elucidate the redox mechanisms of Ni^(2+/3+/4+),Mn^(3+/4+),Fe^(3+/4+),and O_(2)-/O_(2)^(n-)during charging/discharging.The medium-entropy doping mitigates the detrimental P2-O_(2)phase transition at high-voltage,replacing it with a moderate and reversible structural evolution(P2-OP4),thereby enhancing structural stability.Consequently,the modified cathode exhibits a remarkable rate capacity of 108.4 mAh·g^(-1)at 10C,with a capacity retention of 99.0%after 200 cycles at 1C,82.5%after 500 cycles at 5C,and 76.7%after 600 cycles at 10C.Furthermore,it also demonstrates superior electrochemical performance at high cutoff voltage of 4.5 V and extreme temperature(55 and 0℃).This work offers solutions to critical challenges in sodium ion batteries cathode materials.
基金Supported by the Fundamental Research Program of Shanxi Province,No.202203021222418Research Program of Shanxi Provincial Health Commission,No.2023061+2 种基金Fundamental Research Cooperation Program of Beijing-Tianjin-Hebei Region of Natural Science Foundation of Tianjin,No.22JCZXJC00140Tianjin Major Science and Technology Project,No.21ZXJBSY00110Tianjin Health and Science and Technology Project,No.TJWJ2024ZK001.
文摘BACKGROUND Regulator of G protein signaling(RGS)proteins participate in tumor formation and metastasis by acting on theα-subunit of heterotrimeric G proteins.The speci-fic effect of RGS,particularly RGS4,on the progression of gastric cancer(GC)is not yet clear.AIM To explore the role and underlying mechanisms of action of RGS4 in GC develop-ment.METHODS The prognostic significance of RGS4 in GC was analyzed using bioinformatics based public databases and verified by immunohistochemistry and quantitative polymerase chain reaction in 90 patients with GC.Function assays were employed to assess the carcinogenic impact of RGS4,and the mechanism of its possible influence was detected by western blot analysis.A nude mouse xenograft model was established to study the effects of RGS4 on GC growth in vitro.RESULTS RGS4 was highly expressed in GC tissues compared with matched adjacent normal tissues.Elevated RGS4 expression was correlated with increased tumor-node-metastasis stage,increased tumor grade as well as poorer overall survival in patients with GC.Cell experiments demonstrated that RGS4 knockdown suppressed GC cell proliferation,migration and invasion.Similarly,xenograft experiments confirmed that RGS4 silencing significantly inhibited tumor growth.Moreover,RGS4 knockdown resulted in reduced phosphorylation levels of focal adhesion kinase,phosphatidyl-inositol-3-kinase,and protein kinase B,decreased vimentin and N-cadherin,and elevated E-cadherin.CONCLUSION High RGS4 expression in GC indicates a worse prognosis and RGS4 is a prognostic marker.RGS4 influences tumor progression via the focal adhesion kinase/phosphatidyl-inositol-3-kinase/protein kinase B pathway and epithelial-mesenchymal transition.
文摘Background: Since it was theorised by Abdel Omran in 1971, the epidemiological transition has been well documented in Latin America, Asia and even increasingly in Africa south of the Sahara. According to this theory, sub-Saharan Africa is in the first phase of development corresponding to the “age of plague and famine”. Given the health statistics currently available, more and more low- and middle-income countries, including those in sub-Saharan Africa, are experiencing an increase in mortality and the economic impact associated with non-communicable diseases. Côte d’Ivoire is one of the countries in sub-Saharan Africa where non-communicable diseases are currently on the rise. Despite the significant changes observed over the last decades, few studies have been carried out on the epidemiological transition in Côte d’Ivoire. It therefore seemed necessary to examine the changes in patterns of disease occurrence and causes of death in Côte d’Ivoire. Objectives: This work aimed to determine the reality of the epidemiological transition in Côte d’Ivoire and characterize its facies from 1990 to 2020. Methods: A literature review was carried out using PubMed, Medline, Google Scholar, Google, institutional websites (WHO, World Bank), university library websites and institutional reports from Côte d’Ivoire. The indicators sought were mortality, morbidity, life expectancy and fertility. Results: Mortality fell overall from 13.88‰ to 9.70‰, with variations linked to cyclical situations. Life expectancy rose by 52.6 to 59.03 years, although it is still below 60. Fertility has fallen from 6.3 to 4.5 children. There is a general downward trend in morbidity due to communicable diseases between 2009 and 2019, followed by an increase in non-communicable diseases. Conclusion: Côte d’Ivoire is undergoing an original and complex epidemiological transition that needs to be taken into account in health policies and strategies.
基金supported by Hebei Natural Science Foundation under Grant No.E2024402079Key Laboratory of Intelligent Industrial Equipment Technology of Hebei Province(Hebei University of Engineering)under Grant No.202206.
文摘A bearing fault diagnosis method based on the Markov transitionfield(MTF)and SEnet(SE)-IShufflenetV2 model is proposed in this paper due to the problems of complex working conditions,low fault diagnosis accuracy,and poor generalization of rolling bearing.Firstly,MTF is used to encode one-dimensional time series vibration sig-nals and convert them into time-dependent and unique two-dimensional feature images.Then,the generated two-dimensional dataset is fed into the SE-IShufflenetV2 model for training to achieve fault feature extraction and classification.This paper selects the bearing fault datasets from Case Western Reserve University and Paderborn University to experimentally verify the effectiveness and superiority of the proposed method.The generalization performance of the proposed method is tested under the variable load condition and different signal-to-noise ratios(SNRs).The experimental results show that the average accuracy of the proposed method under different working conditions is 99.2%without adding noise.The accuracy under different working conditions from 0 to 1 HP is 100%.When the SNR is 0 dB,the average accuracy of the proposed method can still reach 98.7%under varying working conditions.Therefore,the bearing fault diagnosis method proposed in this paper is characterized by high accuracy,strong anti-noise ability,and generalization.Moreover,the proposed method can also overcome the influence of variable working conditions on diagnosis accuracy,providing method support for the accurate diagnosis of bearing faults under strong noise and variable working conditions.
基金supported by the National Natural Science Foundation of China(Nos.22206207,22127810,and 22276224)the Natural Science Foundation of Guangdong Province(Nos.2021A1515011546 and 2023A1515010085)the Science and Technology Planning Project of Guangzhou(No.202102080005)。
文摘Epithelial-mesenchymal transition(EMT)plays an irreplaceable role in the development of silicosis.However,molecular mechanisms of EMT induced by silica exposure still remain to be addressed.Herein,metabolic profiles of human alveolar type II epithelial cells(A549 cells)exposed directly to silica were characterized using non-targeted metabolomic approaches.A total of 84 differential metabolites(DMs)were identified in silica-treated A549 cells undergoing EMT,which were mainly enriched in metabolisms of amino acids(e.g.,glutamate,alanine,aspartate),purine metabolism,glycolysis,etc.The number of DMs identified in the A549 cells obviously increased with the elevated exposure concentration of silica.Remarkably,glutamine catabolism was significantly promoted in the silica-treated A549 cells,and the levels of related metabolites(e.g.,succinate)and enzymes(e.g.,α-ketoglutarate(α-KG)dehydrogenase)were substantially up-regulated,with a preference toα-KG pathway.Supplementation of glutamine into the cell culture could substantially enhance the expression levels of both EMT-related markers and Snail(zinc finger transcription factor).Our results suggest that the EMT of human alveolar epithelial cells directly induced by silica can be essential to the development of silicosis.
基金National Natural Science Foundation of China(52375378)National Key Laboratory of Metal Forming Technology and Heavy Equipment(S2308100.W12)Huxiang High-Level Talent Gathering Project of Hunan Province(2021RC5001)。
文摘The pressure-actuated metal seal with soft metal coating has been widely used in complex working conditions such as high temperature,low temperature and high pressure.The investigation of the characteristics and binding strength of the transition layer between the soft metal coating and the superalloy substrate is important to improve the sealing performance and to model and simplify the working through-process of metal sealing.The distribution characteristics of elements at soft metal-substrate interface and the binding strength between coating and substrate under different thicknesses and material combinations of coating layer were studied by experimental methods.The results indicate that the thickness of soft metal coating has little influence on the interface morphology of GH4169-Cu,GH4169-Ag and Cu-Ag,but has an influence on the thickness of transition layer between different metals,while this influence is weakened with increasing the coating thickness,and the thickness of transition layer is about 2μm when the coating thickness is more than 30μm.The cross-cut test shows that the Cu,Ag and Cu-Ag coatings are all well combined with nickel-based superalloy GH4169 substrate.The materials of soft metal,i.e.the coating materials,have significant influence on the characteristic of transition layer and the surface characteristics of coating after cross-cut test.
文摘Adolescence and the journey to adulthood involves exciting opportunities as well as psychosocial stress for young people growing up.These normal experiences are potentially magnified for teenagers living with chronic illness or disability and their families.Advances in care have improved survival for children with a variety of serious chronic medical conditions such that many who may once have died in childhood now survive well into adulthood with ongoing morbidity.For those with highly complex needs,care is often provided at major paediatric hospitals with expertise,specially trained personnel,and resources to support young people and their families for the first decades of life.At the end of adolescence,however,it is generally appropriate and necessary for young adults and their caregivers to transition to the care of clinicians trained in the care of adults at general hospitals.While there are some well-managed models to support this journey of transition,these are often specific to certain conditions and usually do not involve intensive care.Many patients may encounter considerable challenges during this period.Difficulties may include the loss of established therapeutic relationships,a perception of austerity and reduced amenity in facilities oriented to caring for adult patients,and care by clinicians with less experience with more common paediatric conditions.In addition,there is a risk of potential conflict between clinicians and families regarding goals of care in the event of a critical illness when it occurs in a young adult with major disability and long-term health issues.These challenges present genuine opportunities to better understand the transition from paediatric to adult-based care and to improve processes that assist clinicians who support patients and families as they shift between healthcare settings.
基金granted by the National Natural Science Foundation of China(No.12047503)Wenzhou Institute,University of Chinese Academy of Sciences(No.WIUCASQD2023009)。
文摘Active matter is a non-equilibrium condensed system consisting of self-propelled particles capable of converting stored or ambient energy into collective motion.Typical active matter systems include cytoskeleton biopolymers,swimming bacteria,artificial swimmers,and animal herds.In contrast to wet active matter,dry active matter is an active system characterized by the absence of significant hydrodynamic interactions and conserved momentum.In dry active matter,the role of surrounding fluids is providing viscous friction at low Reynolds numbers and can be neglected at high Reynolds numbers.This review offers a comprehensive overview of recent experimental,computational,and theoretical advances in understanding phase transitions and critical phenomena in dry aligning active matter,including polar particles,self-propelled rods,active nematics,and their chiral counterparts.Various ways of determining phase transition points as well as non-equilibrium phenomena,such as collective motion,cluster formation,and creation and annihilation of topological defects are reviewed.
基金supported by the National Key R&D Program of China (Grant Nos. 2023YFA1406100, 2022YFA1403900, 2024YFA1408400, 2021YFA1400200, 2022YFA1403800, and 2023YFA1406500)the National Natural Science Foundation of China (Grant Nos. 12174424, 12025408, 11921004, U22A6005, and 12274459)+1 种基金the Youth Innovation Promotion Association of Chinese Academy of Sciences (Grant No. 2023007)the Chinese Academy of Sciences President’s International Fellowship Initiative (Grant No. 2024PG0003)。
文摘Mn_(3)Si_(2)Te_(6) is a ferrimagnetic nodal-line semiconductor with colossal angular magnetoresistance at ambient pressure.In this work,we investigated the effect of hydrostatic pressure on its electrical transport properties,magnetic transition,and crystal structure by measuring resistivity,DC and AC magnetic susceptibility,and XRD under various pressures up to~20 GPa.Our results confirmed the occurrence of pressure-induced structural transition at P_(c)≈10–12 GPa accompanied by a concurrent drop of room-temperature resistance in Mn_(3)Si_(2)Te_(6).In the low-pressure phase at PP_(c),the sample exhibits a metallic behavior in the whole temperature range and its resistivity exhibits a kink anomaly at T_(M),characteristic of critical scattering around a magnetic transition.Recovery of the Raman spectrum upon decompression indicated that pressure-induced structural transition is reversible without amorphization under hydrostatic pressure conditions.Our present work not only resolves some existing controversial issues but also provides new insights into pressure-driven diverse behaviors of Mn_(3)Si_(2)Te_(6).
基金supported by the Natural Science Foundation of China(Grant Nos.T2325013,12474004,and 52288102)the National Key Research and Development Program of China(Grant No.2021YFA1400503)the Program for Jilin University Science and Technology Innovative Research Team。
文摘A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of heavy transition metal mononitrides.Here,we systematically investigate the structural evolutionof LaN under high pressure using first-principles calculations combined with angle-dispersive synchrotron X-raydiffraction,identifying the phase transition sequence and corresponding phase boundaries.Analyses of energetics,kinetic barriers,and lattice dynamics reveal distinct mechanisms driving these transitions.These results clarifythe structural stability of LaN and offer guidance for studying other heavy transition metal mononitrides withcomplex electronic behavior under extreme conditions.
基金the National Key R&D Program of China(Grant Nos.2023YFA1406100 and 2024YFA1400066)the Open Research Fund of Beijing National Laboratory for Condensed Matter Physics(Grant No.2023BNLCMPKF002)+6 种基金supported by the National Natural Science Foundation of China(Grant Nos.52288102 and 52090020)the S&T Program of Hebei(Grant No.225A1102D)the Open Projects from the State Key Laboratory of Metastable Materials Science and Technology,Yanshan University(Grant No.202301)carried out at the Synergetic Extreme Condition User Facility(SE-CUF)of the Chinese Academy of Sciencessupport from the Analytical Instrumentation Center(Grant No.SPST-AIC10112914)School of Physical Science and Technology(SPST),ShanghaiTech Universitysupported by the Double First-Class Initiative Fund of ShanghaiTech University.
文摘The transition metal trichalcogenides(TMTs)with quasi-one-dimensional(quasi-1D)layered crystal structure represent a unique platform to explore intriguing physical properties.Herein,we report the successful growth of a new TMT TiSe_(3)single crystal by using a high-pressure and high-temperature technique.The crystal structure of TiSe_(3)was determined by measuring the single-crystal x-ray diffraction and selected area electron diffraction.The 1D chain-like structure along the b-axis is formed by the TiSe_(6)prisms which share their tops and bottoms with each other.TiSe_(3)is a narrow band gap semiconductor with electron-type carriers under ambient conditions identified by the electrical and Hall effect measurements.It exhibits a pressure-induced semiconductor-to-metal transition around 4 GPa.As the pressure further increases to~6 GPa,a pressure-induced Lifshitz transition occurs,as indicated by the electrical transport measurements,high-pressure crystal structure characterizations,and electronic band structure calculations.
文摘Understanding the occurrence and characteristics of dry and wet events is crucial for effective disaster prevention,resource management,and risk reduction in vulnerable regions.This study analyzed the spatiotemporal patterns of dry-wet events and their transition characteristics in Uttar Pradesh,India.The standardized precipitation evapotranspiration index(SPEI)at a monthly timescale was utilized to identify hotspot regions vulnerable to concurrent and frequent dry and wet events and their transitions.The severity,duration,and intensity of dry and wet events were characterized with the run theory over SPEI time series data from 18 synoptic stations in Uttar Pradesh over 48 years(1971-2018),sourced from the Indian Institute of Tropical Meteorology and the India Meteorological Department.Multiple assessment methods were utilized to examine the interaction of these extreme events,considering characteristics such as wet-dry ratio,average transition time,and rapid transition times from wet to dry events and from dry to wet events.Average wet durations ranged from 1.27 to 1.58 months,and average dry durations ranged from 1.29 to 1.82 months.Rapid transition times from dry to wet events ranged from 2.5 to 4.1 months,and those for wet-to-dry events ranged from 2.1 to 5.3 months.The eastern region experienced a significantly high number of dry events,while the western and Bundelkhand regions experienced more intense dry events.In contrast,the eastern region had intense wet events.This research on the occurrence of dry-wet events and their transitions can provide valuable insights for government decision-making and disaster prevention and reduction efforts.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3209800)the National Natural Science Foundation of China(Grant No.52279011).
文摘In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mitigation.Abrupt transitions between drought and flood refer to a phenomenon in which an extreme drought event quickly shifts to an extreme flood event,or vice versa,within a relatively short time span.This phenomenon disrupts the traditional spatiotemporal distribution patterns of water-related disasters,reflecting not only the extreme unevenness in the distribution of water resources but also the rapid alternation of the water cycle's evolution(He et al.,2016).Moreover,due to its suddenness,extremity,and complexity,it poses severe threats to human societies and ecosystems.Scientifically addressing abrupt transitions between drought and flood has thus become a new challenge in flood and drought disaster prevention.
基金supported by the National Key Research and Development Projects of China(Grant Nos.2022YFA1403402,2023YFA1406103,2024YFA1409200,2024YFA1611302,and 2023YFF0718400)the National Natural Science Foundation of China(Grant Nos.12374142,12304170,W2411004,and 12374197)+3 种基金the Beijing Natural Science Foundation(Grant No.JQ23001)the Beijing National Laboratory for Condensed Matter Physics(Grant No.2024BNLCMPKF005)the Guangdong Basic and Applied Basic Research Foundation(Grant No.2023B151520013)supported by the Synergetic Extreme Condition User Facility(SECUF,https://cstr.cn/31123.02.SECUF)。
文摘Motivated by recent studies of the cluster Mott insulator candidate compound Nb_(3)Cl_(8),this study performs^(93)Nb and^(35)Cl nuclear magnetic resonance(NMR)measurements to investigate the electron correlations.Below the structural transition temperature T_(s)∼97 K,all satellites of the^(93)Nb NMR spectra split into three distinct peaks,which suggests symmetry lowering due to the structural transition and could be attributed to the change in the Nb-Nb bond-lengths of the Nb3 clusters.The spin-lattice relaxation rate 1/T_(1)divided by the temperature T,1/T_(1)T,increases upon cooling to T_(s)for all Cl sites,whereas only the Knight shift K of Cl located at the center of the Nb_(3) clusters exhibits a temperature dependence similar to that observed in magnetic susceptibility.These findings collectively demonstrate the existence of strong spin correlations between the Nb atoms in Nb_(3)Cl_(8),which are closely associated with Mottness.
