The NCEP data were applied to analyze causes of 'late spring coldness' occurring twice in Dalian in late April and mid May of 2008.The results showed that the 500 hPa Baikal ridge of high pressure maintained o...The NCEP data were applied to analyze causes of 'late spring coldness' occurring twice in Dalian in late April and mid May of 2008.The results showed that the 500 hPa Baikal ridge of high pressure maintained or strengthened in a stable manner.The delivery of accumulated cold air toward southeast was along the northwest airstream before the ridge.Therefore,the ridge of high pressure over Lake Baikal provided access for the cold air southward so that the cold air could continue to decline,resulting in the appearance of low temperature in late April and formation of 'late spring coldness'.The Northeast cold vortex(NECV) occurred frequently in mid May.There was a high possibility for low temperature and pluvial damages over Dalian.Thus the phenomenon of 'late spring coldness' appeared again.展开更多
Purpose: NKCP®, a natto-derived dietary food supplement whose main component is bacillopeptidase F produced by Bacillus subtilis var. natto, has antithrombotic, fibrinolytic, and pressure-lowering effects, an...Purpose: NKCP®, a natto-derived dietary food supplement whose main component is bacillopeptidase F produced by Bacillus subtilis var. natto, has antithrombotic, fibrinolytic, and pressure-lowering effects, and also is suggested to improve peripheral coldness. However, existing data are based on subjective evaluations with no scientific basis about the effects on peripheral coldness. Therefore, we aimed to investigate the effectiveness of NKCP®for peripheral coldness by measuring changes in blood flow using a laser doppler rheometer and biochemical indices. Patients and Methods: This was a double-blind, randomized, controlled study of individuals aged 30 - 70 years who complained of subjective symptoms of cold hands and feet. They were randomly divided into the NKCP®group and the placebo group to receive NKCP®250 mg once daily and dextrin 250 mg as placebo once daily, respectively. The experiment lasted 8 weeks, with an intervention period of 4 weeks and a washout period of 4 weeks. Results: One-month intake of NKCP®significantly increased blood flow rate for 1 min between 4 and 5 minutes after the end of cold loading compared to that before feeding (p = 0.038). Also, analysis of the 5-minute blood flow rate before and after 4 weeks of feeding showed a significant improvement in the NKCP®group (p = 0.007), although there was no significant difference in the placebo group (p = 0.215). Furthermore, the 5-minute blood flow at 4 weeks after the end of feeding was significantly improved compared to that before feeding in the NKCP®group (p = 0.049). Therefore, the effect continued for at least 1 month after discontinuation of administration. Conclusions: It is possible that NKCP®intake effectively improves blood flow in subjects with peripheral coldness. Therefore, continuous intake of NKCP®is expected to reduce the symptoms of peripheral coldness. In the future, it needs to investigate whether the effect of increasing blood flow after ingestion of NKCP®is effective in improving the symptoms of peripheral coldness.展开更多
`Since the outbreak of COVID-19,various regions have introduced their own TCM prevention and treatment methods.However,there are two opposing views on the nature of cold and temperature.Since modern times,the thought ...`Since the outbreak of COVID-19,various regions have introduced their own TCM prevention and treatment methods.However,there are two opposing views on the nature of cold and temperature.Since modern times,the thought of the unification of cold and temperature has developed rapidly,and many doctors gradually realized the importance and practicability of the unification of cold and temperature,and began to advocate the unification of cold and temperature syndrome.The prevention and treatment of COVID-19 in Jiangxi was developed by Professor Wu Bingcai,a master of Chinese medicine,based on the unified idea of cold and temperature,according to the characteristics of humid climate in Jiangxi,and in combination with the characteristics of COVID-19,the anti-toxin prescription for dispelling cold and desiccating dampness and the anti-toxin prescription for clearing heat and dehumidifying,which achieved exact and satisfactory results in clinical application.展开更多
Tumor is defined as a kind of chronic diseases by the World Health Organization.The integrative traditional Chinese and western medicine works well on the treatment of tumors,even in advanced patients or patients with...Tumor is defined as a kind of chronic diseases by the World Health Organization.The integrative traditional Chinese and western medicine works well on the treatment of tumors,even in advanced patients or patients with recurring and metastatic tumor.However,the pathogenic mechanism of tumors is still unclear.Therefore,based on the 19 th pathogenesis in Yellow Emperor's Internal Class that"Diseases producing the liquid that is clear and chill all result from coldness",the paper explore s the etiology pathogenesis of malignant tumors,and the correlation between which and tumor recurrence and metastasis,and also discusses the rules for the treatment of tumors at various stages with great method of warming yang for dispelling cold.展开更多
In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires...In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires.Microstructure and property analyses in both the cold-drawn and annealed states show that the incorporation of graphene significantly improves the ductility and electrical conductivity of the copper wire.After annealing at 350℃ for 30 minutes,the composite wire demonstrates a tensile strength of 270 MPa and an electrical conductivity of 102.74%IACS,both superior to those of pure copper wire under identical conditions.At 150℃,the electrical conductivity of the annealed composite wire reaches 72.60%IACS,notably higher than the 68.19%IACS of pure copper.The results suggest that graphene is uniformly distributed within the composite wire,with minimal impact on conductivity,while effectively refining the copper grain structure to enhance ductility.Moreover,graphene suppresses copper lattice vibrations at elevated temperatures,reducing the rate of conductivity degradation.展开更多
This study presents a comprehensive analysis of 132 tornadic events in northeastern China from 2004 to 2023,utilizing radar and ERA5 reanalysis data to investigate the climatology,environmental drivers,and synoptic li...This study presents a comprehensive analysis of 132 tornadic events in northeastern China from 2004 to 2023,utilizing radar and ERA5 reanalysis data to investigate the climatology,environmental drivers,and synoptic linkages with Northeast China cold vortices(NCCVs)of tornadic storms under different convective modes.Results reveal that discrete storms account for 70%of events,with clustered cells(CC)being the most frequent mode,while significant tornadoes(EF2+)are primarily associated with isolated cells(IC)and broken lines(BL).The storm mode distribution in northeastern China resembles that of the central United States but with a higher proportion of CC and lower IC.In contrast,southern China exhibits a higher frequency of quasi-linear(QL)modes(>50%),similar to European patterns.Although no single parameter clearly differentiates between all tornado modes,distinct morphological characteristics emerge through specific parameter combinations:NL modes are characterized by high 0-1 km storm-relative helicity(SRH1)and humidity but low 0-6 km shear(SR6),whereas IC modes display contrasting features with low SRH1 and high CAPE.Notably,83%of tornadoes are associated with NCCVs,preferentially forming in southeastern/southwestern quadrants.Strong tornadoes favor southeastern quadrants,while NCCV intensity correlates with tornadic distance from vortex centers.Three characteristic synoptic configurations emerge:(T1)strong deep vortices with vertically aligned cold troughs,generating southeast-dominant tornado clusters characterized by a high proportion of BL and QL modes;(T2)weaker vortices featuring sub-synoptic troughs,with southern-distributed events dominated by a predominance of the CC mode;(T3)transverse-trough systems exhibiting CAPE-SRH decoupling and reduced tornadic activity.This study enhances our understanding of tornadoes in northeastern China,informing future research on formation mechanisms,prediction methods,and disaster prevention strategies.展开更多
Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycli...Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycling,and reuse in different industries.Currently,a large portion of tailings are managed through the tailing storage facilities(TSF)where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood.This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles,freeze-thaw(F-T)and wet-dry(W-D)conditions,representing the seasonal variability in the cold and arid regions.The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope(SEM),volumetric strain(εvT,wet density(r),moisture content loss,and unconfined compressive strength(UCS)tests.The results indicated the vulnerability of Copper MT to 67%and 75%strength loss reaching residual states with 12 F-T and 8 W-D cycles,respectively.Whereas the stabilized MT retained 39%-55%and 16%-34%strength with F-T and W-D cycles,demonstrating increased durability.This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.展开更多
Phase Change Material(PCM)-based cold energy storage system(CESS)can effectively utilize the peak and valley power resources to reduce the excessive dependence on the power grid.In this study,a PCM-based CESS was desi...Phase Change Material(PCM)-based cold energy storage system(CESS)can effectively utilize the peak and valley power resources to reduce the excessive dependence on the power grid.In this study,a PCM-based CESS was designed for cold storage applications.The optimal number of PCM plates was determined through numerical simulations to meet the required cold storage temperature and control time.Additionally,the air temperature field,flow field,and melting characteristics of the PCMplates during the cooling release process were analyzed.The effects of plate positioning and thickness on the cooling release performance were further investigated.The results indicated that when 64PCMplateswere used,the duration formaintaining temperatures below−18℃increased from0.6 h to approximately 16.94 h.During the cooling release process,the temperature field in the cold storage exhibited stratification,and the melting of the PCM plates was non-uniform.Placing the PCM plates at the top or within the interlayers without cargo above proved more effective,with their cooling release power being approximately twice that of the PCM plates placed in the interlayers with cargo above.Furthermore,reducing the thickness of the PCMplates from15 to 7.5mmresulted in a 3.6-h increase in the time below−18℃and a 4.5-h reduction in the time required to reach 80%liquid phase fraction.展开更多
The common cold is caused by a large range of respiratory viruses and is the most common disease of mankind. There is a great need for a prophylactic treatment for colds. Specific antiviral treatments are only effecti...The common cold is caused by a large range of respiratory viruses and is the most common disease of mankind. There is a great need for a prophylactic treatment for colds. Specific antiviral treatments are only effective against one group of viruses and there is a need for a non-specific treatment that can be used against all respiratory viruses. Carrageenan is a general term used to describe a range of sulfated polysaccharides extracted from edible seaweeds. Large polyanionic molecules such as carrageenan have been shown to have antiviral activity against a wide range of viruses in vitro. The strong anionic charge of carrageenan attracts and traps viruses that have positively charged areas on their surface. The trapped viruses are then unable to infect epithelial cells. Iota-carrageenan exerts its’ antiviral activity by physical means due to its high anionic charge and it does not have any pharmacological properties and therefore does not have any toxicology or known side effects from treatment. Iota-carrageenan does not have any taste or smell and, when used as a nasal spray, does not have any adverse effects. Iota-carrageenan is an ideal prophylactic treatment for the common cold and is safe for use in children. Treatment of common cold with iota-carrageenan has to date been studied in five placebo-controlled clinical trials and these trials support both efficacy as a prophylactic treatment for colds and the safety and tolerability of iota-carrageenan.展开更多
Although magnesium-aluminum alloys,such as AZ80 and AZ91 have promising application potential in automotive,high-speed train and aerospace fields,their age-hardening response is generally not very appreciable.In this ...Although magnesium-aluminum alloys,such as AZ80 and AZ91 have promising application potential in automotive,high-speed train and aerospace fields,their age-hardening response is generally not very appreciable.In this work,the aging-hardening response of AZ80 alloy was effectively enhanced by applying cold-rolling deformation before conducting conventional aging treatment at 200°C.Compared to the directly aged sample,the yield strength of the pre-rolling and aged sample was increased by 35 MPa.Electron microscope examination confirmed that profuse{10¯11}and{10¯11}-{10¯12}twins,consisting of high density of dislocations and stacking faults,were generated by cold rolling.Blocky or ellipsoidal Mg_(17)Al_(12)precipitates formed at the twin boundaries(TBs)during subsequent aging treatment.Crystallographic analysis indicated that the precipitates at{10¯11}TBs always held an identical Potter OR with both the matrix and twin,while the precipitates at{10¯11}-{10¯12}TBs exhibited three different ORs:Burgers OR,Potter OR and P-S OR with either the matrix or the twin.Moreover,recrystallized grains were found inside{10¯11}-{10¯12}double twins after peak-aging at 200°C,implying that precipitation and recrystallization might occur concurrently along TBs at a relatively low temperature.It was speculated that the highly stored energy inside twins and the high elastic energy between the precipitates and twins were driving factors for the occurrence of recrystallization.展开更多
1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-...1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-sized particles(5-50μm)to fabricate coatings[1-3].CS has been extensively used in a variety of coating applications,such as aerospace,automotive,energy,medical,marine,and others,to provide protection against high temperatures,corrosion,erosion,oxidation,and chemicals[4,5].Nowadays,the technical interest in CS is twofold:(i)as a repair process for damaged components,and(ii)as a solid-state additive manufacturing process.Compared to other fusion-based additive manufacturing(AM)technologies,Cold Spray Additive Manufacturing(CSAM)is a new member of the AM family that can enable the fabrication of deposits without undergoing melting.The chemical composition has been largely preserved from the powder to the deposit due to the minimal oxidation.The significant advantages of CSAM over other additive manufacturing processes include a high production rate,unlimited deposition size,high flexibility,and suitability for repairing damaged parts.展开更多
In this work,a novel surface strengthening strategy for Mg-Li alloys was proposed,called cold spraying assisted high-speed laser cladding.CuAl9 aluminum bronze coating was firstly deposited on Mg-Li alloy by cold spra...In this work,a novel surface strengthening strategy for Mg-Li alloys was proposed,called cold spraying assisted high-speed laser cladding.CuAl9 aluminum bronze coating was firstly deposited on Mg-Li alloy by cold spraying,and then CoCrFe_(0.5)Ni_(1.5)Mo_(0.1)Nb_(0.68)eutectic highentropy alloy(EHEA)coating was prepared on the CuAl9 coating utilizing high-speed laser cladding.A gradient coating consisted of in-situ transition region and EHEA layer formed by bidirectional diffusion.The in-situ transition region was composed ofβ-Li,Cu_(2)Mg and Cu_(3)Al_(2)phases.TEM analysis indicated that Cu_(2)Mg and Cu_(3)Al_(2)phases were well matched with theβ-Li matrix phase.The EHEA coating had a nano-lamellar eutectic microstructure with relatively small lamellar-spacing(<100 nm).Metallurgical bonding interfaces formed between the EHEA coating,transition region and Mg-Li substrate.The evolution mechanism of the coating was revealed from the perspectives of mixing enthalpy,atomic radius difference and laser energy distribution.In 3.5 wt.%NaCl solution,the corrosion potential of the EHEA coating(-24 m VSHE)was 1345 m VSHEhigher than that of Mg-Li alloy(-1369 m VSHE),while the corrosion current density of the EHEA coating(3.13×10^(-7)A·cm^(-2))was almost three orders of magnitude lower than that of Mg-Li alloy(1.25×10^(-4)A·cm^(-2)).The wear rate of Mg-Li alloy(1.11×10^(-3)mm^(3)/N·m)was about 36 times higher than that of the EHEA coating(3.05×10^(-5)mm^(3)/N·m).展开更多
Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties...Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties were investigated.The results showed that the cold arc process reduced splashing at the moment of liquid bridge breakage and effectively shortened the droplet transfer period.The microstructures of the deposited samples exhibited layered characteristics with alternating distributions of coarse and fine grains.During layer-by-layer deposition,the β-phase precipitated and grew preferentially along grain boundaries,while the fineη-Al_(8)Mn_(5)phase was dispersed in the α-Mg matrix.The mechanical properties of the CA-WAAM deposited sample showed isotropic characteristics.The ultimate tensile strength and elongation in the building direction(BD)were 282.7 MPa and 14.2%,respectively.The microhardness values of the deposited parts were relatively uniform,with an average value of HV 69.6.展开更多
Additive manufacturing (AM) of high-strength metallic alloys frequently encounters detrimental distortion and cracking, attributed to the accumulation of thermal stresses. These issues significantly impede the practic...Additive manufacturing (AM) of high-strength metallic alloys frequently encounters detrimental distortion and cracking, attributed to the accumulation of thermal stresses. These issues significantly impede the practical application of as-printed components. This study examines the Mg-15Gd-1Zn-0.4Zr (GZ151K, wt.%) alloy, a prototypical high-strength casting Mg-RE alloy, fabricated through laser powder bed fusion (LPBF). Despite achieving ultra-high strength, the GZ151K alloy concurrently exhibits a pronounced cold-cracking susceptibility. The as-printed GZ151K alloy consists of almost fully fine equiaxed grains with an average grain size of merely 2.87 µm. Subsequent direct aging (T5) heat treatment induces the formation of dense prismatic β' precipitates. Consequently, the LPBF-T5 GZ151K alloy manifests an ultra-high yield strength of 405 MPa, surpassing all previously reported yield strengths for Mg alloys fabricated via LPBF and even exceeding that of its extrusion-T5 counterpart. Interestingly, as-printed GZ151K samples with a build height of 2 mm exhibit no cracking, whereas samples with build heights ranging from 4 to 18 mm demonstrate severe cold cracking. Thermal stress simulation also suggests that the cold cracking susceptibility increases significantly with increasing build height. The combination of high thermal stress and low ductility in the as-printed GZ151K alloy culminates in a high cold cracking susceptibility. This study offers novel insights into the intricate issue of cold cracking in the LPBF process of high-strength Mg alloys, highlighting the critical balance between achieving high strength and mitigating cold cracking susceptibility.展开更多
The characteristics of summertime raindrop size distribution(DSD) and associated relations in the semi-arid region over the Inner Mongolian Plateau(IMP) were investigated,utilizing five-year continuous observations by...The characteristics of summertime raindrop size distribution(DSD) and associated relations in the semi-arid region over the Inner Mongolian Plateau(IMP) were investigated,utilizing five-year continuous observations by a PARSIVEL2disdrometer in East Ujimqin County(EUC),China.It is found that only 7.94% of the 15 664 one-min precipitation samples meet classification criteria as convective rain(CR),but its contribution to the total rainfall amount is 63.87%.Notably,40.72% of the rainfall comes from large-sized raindrops(D> 3 mm),despite the fact that large-sized raindrops account for only 1.73% of the CR total number concentration.Further results show that the mean value of mass-weighted mean diameters(Dm) is larger(2.43 mm) and generalized intercepts(lgN_(W)) is lower(3.19) in CR,aligning with a "continentallike" cluster,which is mainly influenced by the joint impact of in-cloud ice-based processes and the below-cloud environmental background.Also,the empirical relationships of shape-slope(μ-Λ),radar reflectivity-rain rate(Z-R),and rainfall kinetic energy(KE_(time)-Rand KE_(time)-Z) are localized.To quantitatively analyze the impact of DSD parameters on kinetic energy estimation,power-law KE_(time)-R and KE_(time)-Z relationships are derived based on the normalized gamma distribution.N_(W)takes precedence over μ in affecting variabilities of multiplicative coefficients,especially for KE_(time)-R relationship where the multiplicative coefficient is proportional to N_(W)^(-0.287).It should be noted that although the proportion of CR occurring throughout the summer is small,raindrops with lower N_(W) and larger Dmwill generate higher KE_(time),which will bring a higher potential risk of soil erosion in semi-arid regions over IMP.展开更多
This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the pre...This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the prepared surfaces are placed on top of each other and by rolling with reduction more than 50%,the bonding between layers is established.In this research,the roll bonding process was done at room temperature,without the use of lubricants and with a 70%thickness reduction.Then,the final thickness of the Ag/Al bilayer sheet reached 350μm by several stages of cold rolling.Before cold rolling,it should be noted that to decrease the hardness created due to plastic deformation,the roll-bonded samples were subjected to annealing heat treatment at 400℃for 90 min.Thus,the final samples were annealed at 200,300 and 400℃for 90 min and cooled in a furnace to examine the annealing temperature effects.The uniaxial tensile and microhardness tests measured mechanical properties.Also,to investigate the fracture mechanism,the fractography of the cross-section was examined by scanning electron microscope(SEM).To evaluate the formability of Ag/Al bilayer sheets,forming limit curves were obtained experimentally through the Nakazima test.The resistance of composites to failure due to cracking was also investigated by fracture toughness.The results showed that annealing increases the elongation and formability of the Ag/Al bilayer sheet while reduces the ultimate tensile strength and fracture toughness.However,the changing trend is not the same at different temperatures,and according to the results,the most significant effect is obtained at 300℃and aluminum layers.It was also determined that by increasing annealing temperature,the fracture mechanism from shear ductile with small and shallow dimples becomes ductile with deep cavities.展开更多
The complex of calcineurin B-like protein(CBL)and CBL-interacting protein kinase(CIPK)serves as key components in calcium-sensing,orchestrating various signals crucial for plant growth,development,and responses to bio...The complex of calcineurin B-like protein(CBL)and CBL-interacting protein kinase(CIPK)serves as key components in calcium-sensing,orchestrating various signals crucial for plant growth,development,and responses to biotic and abiotic stresses.However,the mechanism underlying the response of this module to cold stress and its role in flower development in wintersweet(Chimonanthus praecox)remains unclear.Through expression pattern analysis,calcium ion(Ca^(2+))concentration assays,correlation analysis,and linear regression analysis,we found that the[Ca^(2+)],along with CpCBL8 and CpCIPK9 expression levels in wintersweet flower buds(FBs),significantly decreased during the initial flowering stage when the chilling requirement reached 570 chill units(CU).Notably,there was a significant positive correlation between[Ca^(2+)]and CpCBL8 expression.Ca^(2+)increased the expression of Cp CBL8 and CpCIPK9 in FBs,causing a significant delay in the flowering of wintersweet.Furthermore,the function of CpCBL8 was studied using heterologous transformation.Overexpression of CpCBL8 significantly delayed flowering time and significantly reduced cold tolerance and altered the expression pattern of endogenous genes related to low-temperature stress and flower development in transgenic Arabidopsis thaliana.Additionally,transcriptome analysis of chilling-induced dormancy breaking and flower bud enlargement revealed that CpCBL8 and CpCIPK9 were negatively regulated by cold,and the expression pattern of endogenous genes related to flower development and cold stress in wintersweet were similar to that of in A.thaliana.Moreover,protein-protein interaction(PPI)analysis revealed that CpCBL8 and CpCIPK9 interacted in the plasma membrane and nucleus.On the basis of these findings,we speculated that the CpCBL8-CpCIPK9 module plays a crucial role in regulating responses to cold stress and flower development in wintersweet.This study elucidated molecular mechanisms through which the downregulation of the Ca^(2+)-induced CpCBL8-CpCIPK9 module results in dormancy breaking and enhances cold tolerance.This study provides valuable insights for the cultivation of new varieties of wintersweet with increased ornamental value and enhanced cold stress tolerance.展开更多
Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous ...Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous quantitative analyses often simplified the chorus dispersion relation by using the cold plasma assumption.However,the applicability of the cold plasma assumption is doubtful,especially during geomagnetic disturbances.We here present a systematic statistical analysis on the validity of the cold plasma dispersion relation of chorus waves based on observations from the Van Allen Probes over the period from 2012 to 2018.The statistical results show that the observed magnetic field intensities deviate substantially from those calculated from the cold plasma dispersion relation and that they become more pronounced with an increase in geomagnetic activity or a decrease in background plasma density.The region with large deviations is mainly concentrated in the nightside and expands in both the radial and azimuthal directions as the geomagnetic activity increases or the background plasma density decreases.In addition,the bounce-averaged electron scattering rates are computed by using the observed and cold plasma dispersion relation of chorus waves.Compared with usage of the cold plasma dispersion relation,usage of the observed dispersion relation considerably lowers the minimum resonant energy of electrons and lowers the scattering rates of electrons above tens of kiloelectronvolts but enhances those below.Furthermore,these differences are more pronounced with the enhancement of geomagnetic activity or the decrease in background plasma density.展开更多
Liver transplantation(LT)has made significant progress in the treatment of end stage liver disease(ESLD).However,many patients still die from disease progression while awaiting transplantation.As the number of patient...Liver transplantation(LT)has made significant progress in the treatment of end stage liver disease(ESLD).However,many patients still die from disease progression while awaiting transplantation.As the number of patients on LT waiting lists is increasing,and the organ shortage crisis is obvious,various efforts have been made to increase the pool of available liver grafts[1].In addition to living donor liver transplantation(LDLT),improving the utilization rate of extended criteria donor(ECD)livers is an important way.However,under traditional cold storage,ECD livers are usually associated with a higher risk of ischemic biliary disease,early allograft dysfunction(EAD)or even primary nonfunction(PNF).The frequently described definition in the literature for ECD grafts generally includes elderly,steatotic,long cold ischemia time(CIT),grafts obtained from donation after circulatory death(DCD),split liver grafts,donors with increased risk of infectious disease transmission and prolonged donor intensive care unit stay[2].展开更多
Large interfacial strains in particles are crucial for promoting bonding in cold spraying(CS),initiated either by adiabatic shear instability(ASI)due to softening prevailing over strain hardening or by hydrostatic pla...Large interfacial strains in particles are crucial for promoting bonding in cold spraying(CS),initiated either by adiabatic shear instability(ASI)due to softening prevailing over strain hardening or by hydrostatic plasticity,which is claimed to promote bonding even without ASI.A thorough microstructural analysis is vital to fully understand the bonding mechanisms at play during microparticle impacts and throughout the CS process.In this study,the HEA CoCrFeMnNi,known for its relatively high strain hardening and resistance to softening,was selected to investigate the microstructure characteristics and bonding mech-anisms in CS.This study used characterization techniques covering a range of length scales,including electron channeling contrast imaging(ECCI),electron backscatter diffraction(EBSD),and high-resolution transmission microscopy(HR-TEM),to explore the microstructure characteristics of bonding and overall structure development of CoCrFeMnNi microparticles after impact in CS.HR-TEM lamellae were prepared using focused ion beam milling.Additionally,the effects of deformation field variables on microstructure development were determined through finite element modeling(FEM)of microparticle impacts.The ECCI,EBSD,and HR-TEM analyses revealed an interplay between dislocation-driven processes and twinning,leading to the development of four distinct deformation microstructures.Significant grain refinement occurs at the interface through continuous dynamic recrystallization(CDRX)due to high strain and temperature rise from adiabatic deformation,signs of softening,and ASI.Near the interface,a necklace-like structure of refined grains forms around grain boundaries,along with elongated grains,resulting from the coexistence of dynamic recovery and discontinuous dynamic recrystallization(DDRX)due to lower temperature rise and strain.Towards the particle or substrate interior,concurrent twinning and dislocation-mediated mechanisms refine the structure,forming straight,curved,and intersected twins.At the top of the particles,only deformed grains with a low dislocation density are observed.Our results showed that DRX induces microstructure softening in highly strained interface areas,facilitating atomic bonding in CoCrFeMnNi.HR-TEM investigation confirms the formation of atomic bonds between particles and substrate,with a gradual change in crystal lattice orientation from the particle to the substrate and the occurrence of some misfit dislocations and vacancies at the interface.Finally,the findings of this research suggest that softening and ASI,even in materials resistant to softening,are required to establish bonding in CS.展开更多
文摘The NCEP data were applied to analyze causes of 'late spring coldness' occurring twice in Dalian in late April and mid May of 2008.The results showed that the 500 hPa Baikal ridge of high pressure maintained or strengthened in a stable manner.The delivery of accumulated cold air toward southeast was along the northwest airstream before the ridge.Therefore,the ridge of high pressure over Lake Baikal provided access for the cold air southward so that the cold air could continue to decline,resulting in the appearance of low temperature in late April and formation of 'late spring coldness'.The Northeast cold vortex(NECV) occurred frequently in mid May.There was a high possibility for low temperature and pluvial damages over Dalian.Thus the phenomenon of 'late spring coldness' appeared again.
文摘Purpose: NKCP®, a natto-derived dietary food supplement whose main component is bacillopeptidase F produced by Bacillus subtilis var. natto, has antithrombotic, fibrinolytic, and pressure-lowering effects, and also is suggested to improve peripheral coldness. However, existing data are based on subjective evaluations with no scientific basis about the effects on peripheral coldness. Therefore, we aimed to investigate the effectiveness of NKCP®for peripheral coldness by measuring changes in blood flow using a laser doppler rheometer and biochemical indices. Patients and Methods: This was a double-blind, randomized, controlled study of individuals aged 30 - 70 years who complained of subjective symptoms of cold hands and feet. They were randomly divided into the NKCP®group and the placebo group to receive NKCP®250 mg once daily and dextrin 250 mg as placebo once daily, respectively. The experiment lasted 8 weeks, with an intervention period of 4 weeks and a washout period of 4 weeks. Results: One-month intake of NKCP®significantly increased blood flow rate for 1 min between 4 and 5 minutes after the end of cold loading compared to that before feeding (p = 0.038). Also, analysis of the 5-minute blood flow rate before and after 4 weeks of feeding showed a significant improvement in the NKCP®group (p = 0.007), although there was no significant difference in the placebo group (p = 0.215). Furthermore, the 5-minute blood flow at 4 weeks after the end of feeding was significantly improved compared to that before feeding in the NKCP®group (p = 0.049). Therefore, the effect continued for at least 1 month after discontinuation of administration. Conclusions: It is possible that NKCP®intake effectively improves blood flow in subjects with peripheral coldness. Therefore, continuous intake of NKCP®is expected to reduce the symptoms of peripheral coldness. In the future, it needs to investigate whether the effect of increasing blood flow after ingestion of NKCP®is effective in improving the symptoms of peripheral coldness.
基金Science and Technology Research Project of Jiangxi Provincial Department of Science and Technology(No.S2020ZPYFG0006)"National Innovative Backbone Talents of Traditional Chinese Medicine"Training Program(National Letter of Education of Traditional Chinese Medicine Personnel[2019]No.128)
文摘`Since the outbreak of COVID-19,various regions have introduced their own TCM prevention and treatment methods.However,there are two opposing views on the nature of cold and temperature.Since modern times,the thought of the unification of cold and temperature has developed rapidly,and many doctors gradually realized the importance and practicability of the unification of cold and temperature,and began to advocate the unification of cold and temperature syndrome.The prevention and treatment of COVID-19 in Jiangxi was developed by Professor Wu Bingcai,a master of Chinese medicine,based on the unified idea of cold and temperature,according to the characteristics of humid climate in Jiangxi,and in combination with the characteristics of COVID-19,the anti-toxin prescription for dispelling cold and desiccating dampness and the anti-toxin prescription for clearing heat and dehumidifying,which achieved exact and satisfactory results in clinical application.
文摘Tumor is defined as a kind of chronic diseases by the World Health Organization.The integrative traditional Chinese and western medicine works well on the treatment of tumors,even in advanced patients or patients with recurring and metastatic tumor.However,the pathogenic mechanism of tumors is still unclear.Therefore,based on the 19 th pathogenesis in Yellow Emperor's Internal Class that"Diseases producing the liquid that is clear and chill all result from coldness",the paper explore s the etiology pathogenesis of malignant tumors,and the correlation between which and tumor recurrence and metastasis,and also discusses the rules for the treatment of tumors at various stages with great method of warming yang for dispelling cold.
基金Funded by Hunan Provincial Natural Science Foundation(No.2023JJ40074)Hunan Provincial Education Department Excellent Youth Project(No.21B0757)Hunan Provincial Engineering Technology Center(No.2022TP2036)。
文摘In this study,multilayer lamination welding was employed to prepare graphene/copper(Gr/Cu)composite billets from graphene-coated copper foils,followed by multi-pass cold drawing to produce Φ1 mm Gr/Cu composite wires.Microstructure and property analyses in both the cold-drawn and annealed states show that the incorporation of graphene significantly improves the ductility and electrical conductivity of the copper wire.After annealing at 350℃ for 30 minutes,the composite wire demonstrates a tensile strength of 270 MPa and an electrical conductivity of 102.74%IACS,both superior to those of pure copper wire under identical conditions.At 150℃,the electrical conductivity of the annealed composite wire reaches 72.60%IACS,notably higher than the 68.19%IACS of pure copper.The results suggest that graphene is uniformly distributed within the composite wire,with minimal impact on conductivity,while effectively refining the copper grain structure to enhance ductility.Moreover,graphene suppresses copper lattice vibrations at elevated temperatures,reducing the rate of conductivity degradation.
基金supported by the National Natural Science Foundation of China(Grant No.42305013)Joint Research Project for Meteorological Capacity Improvement(Grant Nos.23NLTSQ002 and 24NLTSQ001)+2 种基金China Meteorological Administration Tornado Key Laboratory(Grant No.TKL202307)the China Meteorological Administration Youth Innovation Team Fund(Grant No.CMA2024QN05)a research project of the Chinese Academy of Meteorological Science(Grant No.2023Z019)。
文摘This study presents a comprehensive analysis of 132 tornadic events in northeastern China from 2004 to 2023,utilizing radar and ERA5 reanalysis data to investigate the climatology,environmental drivers,and synoptic linkages with Northeast China cold vortices(NCCVs)of tornadic storms under different convective modes.Results reveal that discrete storms account for 70%of events,with clustered cells(CC)being the most frequent mode,while significant tornadoes(EF2+)are primarily associated with isolated cells(IC)and broken lines(BL).The storm mode distribution in northeastern China resembles that of the central United States but with a higher proportion of CC and lower IC.In contrast,southern China exhibits a higher frequency of quasi-linear(QL)modes(>50%),similar to European patterns.Although no single parameter clearly differentiates between all tornado modes,distinct morphological characteristics emerge through specific parameter combinations:NL modes are characterized by high 0-1 km storm-relative helicity(SRH1)and humidity but low 0-6 km shear(SR6),whereas IC modes display contrasting features with low SRH1 and high CAPE.Notably,83%of tornadoes are associated with NCCVs,preferentially forming in southeastern/southwestern quadrants.Strong tornadoes favor southeastern quadrants,while NCCV intensity correlates with tornadic distance from vortex centers.Three characteristic synoptic configurations emerge:(T1)strong deep vortices with vertically aligned cold troughs,generating southeast-dominant tornado clusters characterized by a high proportion of BL and QL modes;(T2)weaker vortices featuring sub-synoptic troughs,with southern-distributed events dominated by a predominance of the CC mode;(T3)transverse-trough systems exhibiting CAPE-SRH decoupling and reduced tornadic activity.This study enhances our understanding of tornadoes in northeastern China,informing future research on formation mechanisms,prediction methods,and disaster prevention strategies.
基金the W.M.Keck Center for Nano-Scale Imaging in the Department of Chemistry and Biochemistry at the University of Arizona(Grant No.RRID:SCR_022884),with funding from the W.M.Keck Foundation Grant.
文摘Approximately 3.44 billion tons of copper mine tailings(MT)were produced globally in 2018 with an increase of 45%from 2010.Significant efforts are being made to manage these tailings through storage facilities,recycling,and reuse in different industries.Currently,a large portion of tailings are managed through the tailing storage facilities(TSF)where these tailings undergo hydro-thermal-mechanical stresses with seasonal cycles which are not comprehensively understood.This study presents an investigative study to evaluate the performance of control and cement-stabilized copper MT under the influence of seasonal cycles,freeze-thaw(F-T)and wet-dry(W-D)conditions,representing the seasonal variability in the cold and arid regions.The control and cement-stabilized MT samples were subjected to a maximum of 12 F-T and 12 W-D cycles and corresponding micro-and-macro behavior was investigated through scanning electron microscope(SEM),volumetric strain(εvT,wet density(r),moisture content loss,and unconfined compressive strength(UCS)tests.The results indicated the vulnerability of Copper MT to 67%and 75%strength loss reaching residual states with 12 F-T and 8 W-D cycles,respectively.Whereas the stabilized MT retained 39%-55%and 16%-34%strength with F-T and W-D cycles,demonstrating increased durability.This research highlights the impact of seasonal cycles and corresponding strength-deformation characteristics of control and stabilized Copper MT in cold and arid regions.
基金supported by National Natural Science Foundation of China(Nos.51806092,52201410)Non-Carbon Energy Conversion and Utilization Institute under the Shanghai Class IV Peak Disciplinary Development Program,High-End Foreign Experts Recruitment Plan of China(G2022013028L).
文摘Phase Change Material(PCM)-based cold energy storage system(CESS)can effectively utilize the peak and valley power resources to reduce the excessive dependence on the power grid.In this study,a PCM-based CESS was designed for cold storage applications.The optimal number of PCM plates was determined through numerical simulations to meet the required cold storage temperature and control time.Additionally,the air temperature field,flow field,and melting characteristics of the PCMplates during the cooling release process were analyzed.The effects of plate positioning and thickness on the cooling release performance were further investigated.The results indicated that when 64PCMplateswere used,the duration formaintaining temperatures below−18℃increased from0.6 h to approximately 16.94 h.During the cooling release process,the temperature field in the cold storage exhibited stratification,and the melting of the PCM plates was non-uniform.Placing the PCM plates at the top or within the interlayers without cargo above proved more effective,with their cooling release power being approximately twice that of the PCM plates placed in the interlayers with cargo above.Furthermore,reducing the thickness of the PCMplates from15 to 7.5mmresulted in a 3.6-h increase in the time below−18℃and a 4.5-h reduction in the time required to reach 80%liquid phase fraction.
文摘The common cold is caused by a large range of respiratory viruses and is the most common disease of mankind. There is a great need for a prophylactic treatment for colds. Specific antiviral treatments are only effective against one group of viruses and there is a need for a non-specific treatment that can be used against all respiratory viruses. Carrageenan is a general term used to describe a range of sulfated polysaccharides extracted from edible seaweeds. Large polyanionic molecules such as carrageenan have been shown to have antiviral activity against a wide range of viruses in vitro. The strong anionic charge of carrageenan attracts and traps viruses that have positively charged areas on their surface. The trapped viruses are then unable to infect epithelial cells. Iota-carrageenan exerts its’ antiviral activity by physical means due to its high anionic charge and it does not have any pharmacological properties and therefore does not have any toxicology or known side effects from treatment. Iota-carrageenan does not have any taste or smell and, when used as a nasal spray, does not have any adverse effects. Iota-carrageenan is an ideal prophylactic treatment for the common cold and is safe for use in children. Treatment of common cold with iota-carrageenan has to date been studied in five placebo-controlled clinical trials and these trials support both efficacy as a prophylactic treatment for colds and the safety and tolerability of iota-carrageenan.
基金financially supported by the National Natural Science Foundation of China(No.52071040 and 51871036)Natural Science Foundation of Shandong Province,China(No.ZR2022QE008)China Postdoctoral Science Foundation(No.2022M712984)。
文摘Although magnesium-aluminum alloys,such as AZ80 and AZ91 have promising application potential in automotive,high-speed train and aerospace fields,their age-hardening response is generally not very appreciable.In this work,the aging-hardening response of AZ80 alloy was effectively enhanced by applying cold-rolling deformation before conducting conventional aging treatment at 200°C.Compared to the directly aged sample,the yield strength of the pre-rolling and aged sample was increased by 35 MPa.Electron microscope examination confirmed that profuse{10¯11}and{10¯11}-{10¯12}twins,consisting of high density of dislocations and stacking faults,were generated by cold rolling.Blocky or ellipsoidal Mg_(17)Al_(12)precipitates formed at the twin boundaries(TBs)during subsequent aging treatment.Crystallographic analysis indicated that the precipitates at{10¯11}TBs always held an identical Potter OR with both the matrix and twin,while the precipitates at{10¯11}-{10¯12}TBs exhibited three different ORs:Burgers OR,Potter OR and P-S OR with either the matrix or the twin.Moreover,recrystallized grains were found inside{10¯11}-{10¯12}double twins after peak-aging at 200°C,implying that precipitation and recrystallization might occur concurrently along TBs at a relatively low temperature.It was speculated that the highly stored energy inside twins and the high elastic energy between the precipitates and twins were driving factors for the occurrence of recrystallization.
基金supported by the National Natural Science Foundation of China(No.52061135101 and 52001078)the German Research Foundation(DFG,No.448318292)+3 种基金the Technology Innovation Guidance Special Foundation of Shaanxi Province(No.2023GXLH-085)the Fundamental Research Funds for the Central Universities(No.D5000240161)the Project of Key areas of innovation team in Shaanxi Province(No.2024RS-CXTD-20)The author Yingchun Xie thanks the support from the National Key R&D Program(No.2023YFE0108000).
文摘1.Introduction.Cold Spray(CS)is a highly advanced solid-state metal depo-sition process that was first developed in the 1980s.This innovative technique involves the high-speed(300-1200 m/s)impact deposition of micron-sized particles(5-50μm)to fabricate coatings[1-3].CS has been extensively used in a variety of coating applications,such as aerospace,automotive,energy,medical,marine,and others,to provide protection against high temperatures,corrosion,erosion,oxidation,and chemicals[4,5].Nowadays,the technical interest in CS is twofold:(i)as a repair process for damaged components,and(ii)as a solid-state additive manufacturing process.Compared to other fusion-based additive manufacturing(AM)technologies,Cold Spray Additive Manufacturing(CSAM)is a new member of the AM family that can enable the fabrication of deposits without undergoing melting.The chemical composition has been largely preserved from the powder to the deposit due to the minimal oxidation.The significant advantages of CSAM over other additive manufacturing processes include a high production rate,unlimited deposition size,high flexibility,and suitability for repairing damaged parts.
基金financially supported by the National Natural Science Foundation of China(No.51975137,52205189)。
文摘In this work,a novel surface strengthening strategy for Mg-Li alloys was proposed,called cold spraying assisted high-speed laser cladding.CuAl9 aluminum bronze coating was firstly deposited on Mg-Li alloy by cold spraying,and then CoCrFe_(0.5)Ni_(1.5)Mo_(0.1)Nb_(0.68)eutectic highentropy alloy(EHEA)coating was prepared on the CuAl9 coating utilizing high-speed laser cladding.A gradient coating consisted of in-situ transition region and EHEA layer formed by bidirectional diffusion.The in-situ transition region was composed ofβ-Li,Cu_(2)Mg and Cu_(3)Al_(2)phases.TEM analysis indicated that Cu_(2)Mg and Cu_(3)Al_(2)phases were well matched with theβ-Li matrix phase.The EHEA coating had a nano-lamellar eutectic microstructure with relatively small lamellar-spacing(<100 nm).Metallurgical bonding interfaces formed between the EHEA coating,transition region and Mg-Li substrate.The evolution mechanism of the coating was revealed from the perspectives of mixing enthalpy,atomic radius difference and laser energy distribution.In 3.5 wt.%NaCl solution,the corrosion potential of the EHEA coating(-24 m VSHE)was 1345 m VSHEhigher than that of Mg-Li alloy(-1369 m VSHE),while the corrosion current density of the EHEA coating(3.13×10^(-7)A·cm^(-2))was almost three orders of magnitude lower than that of Mg-Li alloy(1.25×10^(-4)A·cm^(-2)).The wear rate of Mg-Li alloy(1.11×10^(-3)mm^(3)/N·m)was about 36 times higher than that of the EHEA coating(3.05×10^(-5)mm^(3)/N·m).
基金supported by the National Natural Science Foundation of China(No.51805265)the Fundamental Research Funds for the Central Universities,China(No.30922010921).
文摘Thin walls of an AZ91 magnesium alloy with fine equiaxed grains were fabricated via cold arc-based wire arc additive manufacturing(CA-WAAM),and the droplet transfer behaviours,microstructures,and mechanical properties were investigated.The results showed that the cold arc process reduced splashing at the moment of liquid bridge breakage and effectively shortened the droplet transfer period.The microstructures of the deposited samples exhibited layered characteristics with alternating distributions of coarse and fine grains.During layer-by-layer deposition,the β-phase precipitated and grew preferentially along grain boundaries,while the fineη-Al_(8)Mn_(5)phase was dispersed in the α-Mg matrix.The mechanical properties of the CA-WAAM deposited sample showed isotropic characteristics.The ultimate tensile strength and elongation in the building direction(BD)were 282.7 MPa and 14.2%,respectively.The microhardness values of the deposited parts were relatively uniform,with an average value of HV 69.6.
基金supported by the National Key Research and Development Program of China(No.2021YFB3701000)the National Natural Science Foundation of China(Nos.51971130,52201129,U21A2047,51821001,U2037601)+2 种基金support by the China Postdoctoral Science Foun-dation(2023M742219)the Postdoctoral Fellowship Program of CPSF under Grant Number GZB20240419support by the Ministry of Education,Singapore,under its Academic Research Fund Tier 2(MOE-T2EP50221-0013).
文摘Additive manufacturing (AM) of high-strength metallic alloys frequently encounters detrimental distortion and cracking, attributed to the accumulation of thermal stresses. These issues significantly impede the practical application of as-printed components. This study examines the Mg-15Gd-1Zn-0.4Zr (GZ151K, wt.%) alloy, a prototypical high-strength casting Mg-RE alloy, fabricated through laser powder bed fusion (LPBF). Despite achieving ultra-high strength, the GZ151K alloy concurrently exhibits a pronounced cold-cracking susceptibility. The as-printed GZ151K alloy consists of almost fully fine equiaxed grains with an average grain size of merely 2.87 µm. Subsequent direct aging (T5) heat treatment induces the formation of dense prismatic β' precipitates. Consequently, the LPBF-T5 GZ151K alloy manifests an ultra-high yield strength of 405 MPa, surpassing all previously reported yield strengths for Mg alloys fabricated via LPBF and even exceeding that of its extrusion-T5 counterpart. Interestingly, as-printed GZ151K samples with a build height of 2 mm exhibit no cracking, whereas samples with build heights ranging from 4 to 18 mm demonstrate severe cold cracking. Thermal stress simulation also suggests that the cold cracking susceptibility increases significantly with increasing build height. The combination of high thermal stress and low ductility in the as-printed GZ151K alloy culminates in a high cold cracking susceptibility. This study offers novel insights into the intricate issue of cold cracking in the LPBF process of high-strength Mg alloys, highlighting the critical balance between achieving high strength and mitigating cold cracking susceptibility.
基金supported by the National Natural Science Foundation of China(Grant Nos.42325503,42075063,42075066,and 42021004)the Hubei Provincial Natural Science Foundation and the Meteorological Innovation and Development Project of China(Grant No.2023AFD096)the Beijige Foundation of NJIAS(Grant No.BJG202304).
文摘The characteristics of summertime raindrop size distribution(DSD) and associated relations in the semi-arid region over the Inner Mongolian Plateau(IMP) were investigated,utilizing five-year continuous observations by a PARSIVEL2disdrometer in East Ujimqin County(EUC),China.It is found that only 7.94% of the 15 664 one-min precipitation samples meet classification criteria as convective rain(CR),but its contribution to the total rainfall amount is 63.87%.Notably,40.72% of the rainfall comes from large-sized raindrops(D> 3 mm),despite the fact that large-sized raindrops account for only 1.73% of the CR total number concentration.Further results show that the mean value of mass-weighted mean diameters(Dm) is larger(2.43 mm) and generalized intercepts(lgN_(W)) is lower(3.19) in CR,aligning with a "continentallike" cluster,which is mainly influenced by the joint impact of in-cloud ice-based processes and the below-cloud environmental background.Also,the empirical relationships of shape-slope(μ-Λ),radar reflectivity-rain rate(Z-R),and rainfall kinetic energy(KE_(time)-Rand KE_(time)-Z) are localized.To quantitatively analyze the impact of DSD parameters on kinetic energy estimation,power-law KE_(time)-R and KE_(time)-Z relationships are derived based on the normalized gamma distribution.N_(W)takes precedence over μ in affecting variabilities of multiplicative coefficients,especially for KE_(time)-R relationship where the multiplicative coefficient is proportional to N_(W)^(-0.287).It should be noted that although the proportion of CR occurring throughout the summer is small,raindrops with lower N_(W) and larger Dmwill generate higher KE_(time),which will bring a higher potential risk of soil erosion in semi-arid regions over IMP.
基金Project(4013311)supported by the National Science Foundation of Iran(INSF)。
文摘This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the prepared surfaces are placed on top of each other and by rolling with reduction more than 50%,the bonding between layers is established.In this research,the roll bonding process was done at room temperature,without the use of lubricants and with a 70%thickness reduction.Then,the final thickness of the Ag/Al bilayer sheet reached 350μm by several stages of cold rolling.Before cold rolling,it should be noted that to decrease the hardness created due to plastic deformation,the roll-bonded samples were subjected to annealing heat treatment at 400℃for 90 min.Thus,the final samples were annealed at 200,300 and 400℃for 90 min and cooled in a furnace to examine the annealing temperature effects.The uniaxial tensile and microhardness tests measured mechanical properties.Also,to investigate the fracture mechanism,the fractography of the cross-section was examined by scanning electron microscope(SEM).To evaluate the formability of Ag/Al bilayer sheets,forming limit curves were obtained experimentally through the Nakazima test.The resistance of composites to failure due to cracking was also investigated by fracture toughness.The results showed that annealing increases the elongation and formability of the Ag/Al bilayer sheet while reduces the ultimate tensile strength and fracture toughness.However,the changing trend is not the same at different temperatures,and according to the results,the most significant effect is obtained at 300℃and aluminum layers.It was also determined that by increasing annealing temperature,the fracture mechanism from shear ductile with small and shallow dimples becomes ductile with deep cavities.
基金funded by the Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0236)Fundamental Research Funds for the Central Universities(SWU-XDJH202308)Earmarked Funds for the China Agriculture Research System(CARS-26)。
文摘The complex of calcineurin B-like protein(CBL)and CBL-interacting protein kinase(CIPK)serves as key components in calcium-sensing,orchestrating various signals crucial for plant growth,development,and responses to biotic and abiotic stresses.However,the mechanism underlying the response of this module to cold stress and its role in flower development in wintersweet(Chimonanthus praecox)remains unclear.Through expression pattern analysis,calcium ion(Ca^(2+))concentration assays,correlation analysis,and linear regression analysis,we found that the[Ca^(2+)],along with CpCBL8 and CpCIPK9 expression levels in wintersweet flower buds(FBs),significantly decreased during the initial flowering stage when the chilling requirement reached 570 chill units(CU).Notably,there was a significant positive correlation between[Ca^(2+)]and CpCBL8 expression.Ca^(2+)increased the expression of Cp CBL8 and CpCIPK9 in FBs,causing a significant delay in the flowering of wintersweet.Furthermore,the function of CpCBL8 was studied using heterologous transformation.Overexpression of CpCBL8 significantly delayed flowering time and significantly reduced cold tolerance and altered the expression pattern of endogenous genes related to low-temperature stress and flower development in transgenic Arabidopsis thaliana.Additionally,transcriptome analysis of chilling-induced dormancy breaking and flower bud enlargement revealed that CpCBL8 and CpCIPK9 were negatively regulated by cold,and the expression pattern of endogenous genes related to flower development and cold stress in wintersweet were similar to that of in A.thaliana.Moreover,protein-protein interaction(PPI)analysis revealed that CpCBL8 and CpCIPK9 interacted in the plasma membrane and nucleus.On the basis of these findings,we speculated that the CpCBL8-CpCIPK9 module plays a crucial role in regulating responses to cold stress and flower development in wintersweet.This study elucidated molecular mechanisms through which the downregulation of the Ca^(2+)-induced CpCBL8-CpCIPK9 module results in dormancy breaking and enhances cold tolerance.This study provides valuable insights for the cultivation of new varieties of wintersweet with increased ornamental value and enhanced cold stress tolerance.
基金supported by the National Natural Science Foundation of China (NSFC) through Grant Number 42074193
文摘Theoretical analysis has demonstrated that the dispersion relation of chorus waves plays an essential role in the resonant interaction and energy transformation between the waves and magnetospheric electrons.Previous quantitative analyses often simplified the chorus dispersion relation by using the cold plasma assumption.However,the applicability of the cold plasma assumption is doubtful,especially during geomagnetic disturbances.We here present a systematic statistical analysis on the validity of the cold plasma dispersion relation of chorus waves based on observations from the Van Allen Probes over the period from 2012 to 2018.The statistical results show that the observed magnetic field intensities deviate substantially from those calculated from the cold plasma dispersion relation and that they become more pronounced with an increase in geomagnetic activity or a decrease in background plasma density.The region with large deviations is mainly concentrated in the nightside and expands in both the radial and azimuthal directions as the geomagnetic activity increases or the background plasma density decreases.In addition,the bounce-averaged electron scattering rates are computed by using the observed and cold plasma dispersion relation of chorus waves.Compared with usage of the cold plasma dispersion relation,usage of the observed dispersion relation considerably lowers the minimum resonant energy of electrons and lowers the scattering rates of electrons above tens of kiloelectronvolts but enhances those below.Furthermore,these differences are more pronounced with the enhancement of geomagnetic activity or the decrease in background plasma density.
文摘Liver transplantation(LT)has made significant progress in the treatment of end stage liver disease(ESLD).However,many patients still die from disease progression while awaiting transplantation.As the number of patients on LT waiting lists is increasing,and the organ shortage crisis is obvious,various efforts have been made to increase the pool of available liver grafts[1].In addition to living donor liver transplantation(LDLT),improving the utilization rate of extended criteria donor(ECD)livers is an important way.However,under traditional cold storage,ECD livers are usually associated with a higher risk of ischemic biliary disease,early allograft dysfunction(EAD)or even primary nonfunction(PNF).The frequently described definition in the literature for ECD grafts generally includes elderly,steatotic,long cold ischemia time(CIT),grafts obtained from donation after circulatory death(DCD),split liver grafts,donors with increased risk of infectious disease transmission and prolonged donor intensive care unit stay[2].
文摘Large interfacial strains in particles are crucial for promoting bonding in cold spraying(CS),initiated either by adiabatic shear instability(ASI)due to softening prevailing over strain hardening or by hydrostatic plasticity,which is claimed to promote bonding even without ASI.A thorough microstructural analysis is vital to fully understand the bonding mechanisms at play during microparticle impacts and throughout the CS process.In this study,the HEA CoCrFeMnNi,known for its relatively high strain hardening and resistance to softening,was selected to investigate the microstructure characteristics and bonding mech-anisms in CS.This study used characterization techniques covering a range of length scales,including electron channeling contrast imaging(ECCI),electron backscatter diffraction(EBSD),and high-resolution transmission microscopy(HR-TEM),to explore the microstructure characteristics of bonding and overall structure development of CoCrFeMnNi microparticles after impact in CS.HR-TEM lamellae were prepared using focused ion beam milling.Additionally,the effects of deformation field variables on microstructure development were determined through finite element modeling(FEM)of microparticle impacts.The ECCI,EBSD,and HR-TEM analyses revealed an interplay between dislocation-driven processes and twinning,leading to the development of four distinct deformation microstructures.Significant grain refinement occurs at the interface through continuous dynamic recrystallization(CDRX)due to high strain and temperature rise from adiabatic deformation,signs of softening,and ASI.Near the interface,a necklace-like structure of refined grains forms around grain boundaries,along with elongated grains,resulting from the coexistence of dynamic recovery and discontinuous dynamic recrystallization(DDRX)due to lower temperature rise and strain.Towards the particle or substrate interior,concurrent twinning and dislocation-mediated mechanisms refine the structure,forming straight,curved,and intersected twins.At the top of the particles,only deformed grains with a low dislocation density are observed.Our results showed that DRX induces microstructure softening in highly strained interface areas,facilitating atomic bonding in CoCrFeMnNi.HR-TEM investigation confirms the formation of atomic bonds between particles and substrate,with a gradual change in crystal lattice orientation from the particle to the substrate and the occurrence of some misfit dislocations and vacancies at the interface.Finally,the findings of this research suggest that softening and ASI,even in materials resistant to softening,are required to establish bonding in CS.
