Shallow marine sand waves are formed on the seabed and are widely distributed within tidal environments.However,the use of multibeam echo sounding(MBES)is costly to obtain the bathymetric mapping of large complex sand...Shallow marine sand waves are formed on the seabed and are widely distributed within tidal environments.However,the use of multibeam echo sounding(MBES)is costly to obtain the bathymetric mapping of large complex sand waves.Therefore,we propose a new method that employs a combination of multiangle sun glint images and sparse MBES data to achieve comprehensive bathymetric mapping of large and complex sand waves.This method involves estimating sea surface roughness,automatically extracting sand-wave crests,conducting adaptive subregion partitioning,estimating the water depth at auxiliary points,and generating digital bathymetric models.The method was employed in a case study of sand waves on the Taiwan Bank.Bathymetric mapping was implemented for large complex sand waves over an area spanning approximately 350 km~2 using multiangle sun glint images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer and MBE S data.The results show that mapped and measured water depths were well-matched;the root-mean-square error of water depths was 1.77 m,and the relative error was 5.03%.These findings show that bathymetric mapping of large complex sand waves can be effectively conducted using the new method,and as such,the workload of MBES is reduced and efficiency is improved.展开更多
A multi-group cross-section library is fundamental for deterministic lattice physics calculations.Most existing multi-group cross-section libraries are customized for particular computer codes,as well as for particula...A multi-group cross-section library is fundamental for deterministic lattice physics calculations.Most existing multi-group cross-section libraries are customized for particular computer codes,as well as for particular types of nuclear reactors.This paper presents an HDF5-format multi-group cross-section library named XPZLIB.XPZLIB was produced using a selfdeveloped XPZR module integrated into the NJOY2016 code,and an in-house PyNjoy2022 system was developed for autoprocessing.XPZLIB contains detailed data content and well-organized data structures that are user-and developer-friendly.Three typical XPZLIBs with different numbers of energy groups,nuclides,and depletion reaction types were released via the Tsinghua cloud website.Furthermore,the applicability of the released XPZLIBs was investigated using HTGR and PWR lattice calculations,which can provide guidance for applying XPZLIB under different scenarios.展开更多
EVI2A has emerged as a significant biomarker in various diseases;however,its biological role and mechanism in kidney renal clear cell carcinoma(KIRC)remains unexplored.We used TCGA and GEO databases to analyze EVI2A g...EVI2A has emerged as a significant biomarker in various diseases;however,its biological role and mechanism in kidney renal clear cell carcinoma(KIRC)remains unexplored.We used TCGA and GEO databases to analyze EVI2A gene expression comprehensively and performed pan-cancer assessments.Clinical relevance was evaluated through Kaplan-Meier analysis and ROC curves.The gene’s immune relevance was explored through analyses of the tumor microenvironment(TME),Tumor Immune Single-cell Hub(TISCH),immune checkpoints,and immunotherapy sensitivity.Our results indicate that EVI2A expression is upregulated in KIRC,showing correlations with tumor grade and T/N/M stage.EVI2A demonstrates high diagnostic accuracy(AUC=0.906)and predicts poor overall and progression-free survival in KIRC patients.Furthermore,EVI2A expression exhibits significant associations with immunity,including TME scores and specific immune cell types such as Tfh cells,CD4 memory T cells,and CD8+T cells.Elevated EVI2A expression suggests increased sensitivity to PD-1/CTLA-4 and tyrosine kinase inhibitors.In vitro assays confirmed the impact of EVI2A on KIRC behavior,with its knockdown resulting in reduced cell proliferation and migration.In conclusion,our comprehensive analysis identifies EVI2A as a promising biomarker and a novel therapeutic target for intervening in KIRC.These findings hold significant implications for further research and potential clinical applications.展开更多
Background:Serum chitinase-3-like protein 1(CHI3L1)is a potential biomarker for fibrosis assessment.We aimed to evaluate serum CHI3L1 as a noninvasive diagnostic marker for chronic hepatitis B virusrelated fibrosis.Me...Background:Serum chitinase-3-like protein 1(CHI3L1)is a potential biomarker for fibrosis assessment.We aimed to evaluate serum CHI3L1 as a noninvasive diagnostic marker for chronic hepatitis B virusrelated fibrosis.Methods:Serum CHI3L1 levels were measured by ELISA in 134 chronic hepatitis B(CHB)patients.Significant fibrosis was defined as a liver stiffness>9.7 kPa.The performance of CHI3L1 was assessed and compared to that of other noninvasive tests by receiver operating characteristic(ROC)analysis.Results:Serum CHI3L1 levels were significantly higher in CHB patients with significant hepatic fibrosis(≥F2)than in those without significant hepatic fibrosis(<F2)(56.5 ng/mL vs.81.9 ng/mL,P<0.001).In CHB patients,the specificity and sensitivity of CHI3L1 for predicting significant fibrosis were 75.6%and 59.1%,respectively,with a cut-off of 76.0 ng/mL and an area under the ROC curve of 0.728(95%CI:0.637–0.820).Conclusions:Serum CHI3L1 levels could be an effective new serological biomarker for the diagnosis of liver fibrosis.Moreover,CHI3L1 is feasible in monitoring disease progression.展开更多
Objective: The purposes of this study were to assess the efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) for acute leukemia (AL) and analyze the factors affecting the prognosis of these pati...Objective: The purposes of this study were to assess the efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) for acute leukemia (AL) and analyze the factors affecting the prognosis of these patients. Methods: The clinical and follow-up data of 93 AL patients (median age, 30 years) undergoing allogeneic HSCT in Xiangya Hospital over the past 12 years were collected, and the potential factors affecting the efficacy and prognosis of allogeneic HSCT patients were determined. Results: Hematopoietic reconstitution was achieved in 90 patients. At the last follow-up, the incidences of severe acute graft versus host disease (aGvHD) and extensive chronic GvHD (cGvHD) were 14.0% and 20.0%, the 3-year cumulative incidence of transplantation related mortality (TRM) and relapse rate were 16.8%±6.1% and 21.3%±6.7%, and the estimated 3-year overall survival (OS) and disease-free survival (DFS) of the patients were 64.6%±5.4% and 56.5%±5.5%, respectively. Univariate analysis indicated that age older than 40 years, HLA mismatch, and severe lung infection within the first 100 days after transplantation were risk factors for severe aGvHD, age older than 40 years, HLA mismatch, severe lung infection within the first 100 days after transplantation, and severe aGvHD were risk factors for TRM, high-risk AL and lack of cGvHD were risk factors for relapse (all P〈0.05). Survival estimation showed that HLA mismatch, severe lung infection occurring within the first 100 days post-transplantation, high-risk AL severe aGvHD and lack of cGvHD were risk factors associated with poor prognosis (all P〈0.05). Further multivariate analyses revealed that severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD were independent risk factors for unfavorable outcomes (all P〈0.05). Conclusions: Allogeneic HSCT can improve the DFS of AL patients, and severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD are independent risk factors affecting the prognosis.展开更多
Since the concept of active suspensions appeared,its large possible benefits has attracted continuous exploration in the field of railway engineering.With new demands of higher speed,better ride comfort and lower main...Since the concept of active suspensions appeared,its large possible benefits has attracted continuous exploration in the field of railway engineering.With new demands of higher speed,better ride comfort and lower maintenance cost for railway vehicles,active suspensions are very promising technologies.Being the starting point of commercial application of active suspensions in rail vehicles,tilting trains have become a great success in some countries.With increased technical maturity of sensors and actuators,active suspension has unprecedented development opportunities.In this work,the basic concepts are summarized with new theories and solutions that have appeared over the last decade.Experimental studies and the implementation status of different active suspension technologies are described as well.Firstly,tilting trains are briefly described.Thereafter,an indepth study for active secondary and primary suspensions is performed.For both topics,after an introductory section an explanation of possible solutions existing in the literature is given.The implementation status is reported.Active secondary suspensions are categorized into active and semi-active suspensions.Primary suspensions are instead divided between acting on solid-axle wheelsets and independently rotating wheels.Lastly,a brief summary and outlook is presented in terms of benefits,research status and challenges.The potential for active suspensions in railway applications is outlined.展开更多
At peak granulite-facies metamorphic conditions, lower continental crust is arguably fluxed by large amounts of two key low water activity fluids: (i) high-density CO2 and/or (ii) concentrated saline so- lutions....At peak granulite-facies metamorphic conditions, lower continental crust is arguably fluxed by large amounts of two key low water activity fluids: (i) high-density CO2 and/or (ii) concentrated saline so- lutions. These fluids are either internally-derived, generated by mineral reactions or dehydration melting or, notably for CO2, externally-derived, issued from the underlying mantle. Postmetamorphic evolution results in complete disappearance of these fluids, except for minute remnants preserved in minerals as fluid inclusions. Two major processes are involved: (i) at peak conditions, granitoid magmas form, migrate upward, and crystallize as shallow intrusions in the upper crust (mineralized porphyry types or reduced intrusions); (ii) during the rapid decompression which almost systematically follows a period of post-peak isobaric cooling, especially for ultrahigh-temperature granulites (anticlockwise P-T paths), quartz-carbonate megashear zones are formed by repeated periods of seismic activity. Seismic activity may continue until all free fluids have disappeared, resulting in the ultramylonites and pseudotachylites that are found in many granulite domes. A great majority of vein-type Au deposits worldwide occur in the above-mentioned settings or nearby. We suggest that the Au has been scavenged by the granulite fluids, then redistributed and concentrated during the formation of veins and related phenomena.展开更多
BACKGROUND A vascular tumor is a benign tumor with unique clinical and pathological features.Perirenal vascular tumor is extremely rare and has not yet been reported.Clinically,it manifests as soreness and swelling.Co...BACKGROUND A vascular tumor is a benign tumor with unique clinical and pathological features.Perirenal vascular tumor is extremely rare and has not yet been reported.Clinically,it manifests as soreness and swelling.Color ultrasound and renal angiography illustrated the perirenal mass,which was closely connected with the kidney and the surrounding tissues and organs.Histology showed extensive embedded perirenal fat,and thin-walled vascular tissue displayed a pink stain due to red blood cells.CASE SUMMARY Herein,a case of robot-assisted retroperitoneal laparoscopic excision of a perirenal vascular tumor is reported.Analysis of the clinical,biological,and histological features of the perirenal vascular tumor can provide an in-depth understanding of the disease,which provides a theoretical and practical basis for better diagnosis and treatment.CONCLUSION This study contributes to a practical basis for the diagnosis and treatment of perirenal hemangiom.展开更多
Rudder is an important part for the glider aircraft. In order to satisfy the long-time high-velocity for the near-space vehicle in the atmosphere, the light- weight, high-stiffness and high-strength all-composites rud...Rudder is an important part for the glider aircraft. In order to satisfy the long-time high-velocity for the near-space vehicle in the atmosphere, the light- weight, high-stiffness and high-strength all-composites rudderpost is required urgently to be prepared. The all-composites rudderpost can keep high rudder efficiency in the high temperature environment. Based on the technique require-ment of high-performance composites rudder, a 3D C/SiC rudderpost was manufactured by the CVI-CMC-SiC [1] processes. It was found during rudderpost testing that the high-temperature mechanical properties decreased and had large discretization. The analysis of the failure mechanisms was conducted by FTA method to recognize the failure modes and main reasons for rudderpost abnormal fracture and to reproduce the fracture phenomenon, which could guide production company to modify their preparation process control. Then the modified processes were proved to be validated. And the stability and reliability of the production performances were improved.展开更多
Two dimensions (2D) C/SiC laminated composites is the material with isotropic properties in laminated sheets, which is considered as a promising thermal skin for aircrafts. There are intense thermal flux and thermal i...Two dimensions (2D) C/SiC laminated composites is the material with isotropic properties in laminated sheets, which is considered as a promising thermal skin for aircrafts. There are intense thermal flux and thermal impact at the local interference region during the flight of the aircrafts. Therefore, mastering ablation and mechanical properties of 2D C/SiC laminated composite under extreme environments become the guild lines for the designs of the flight corridor and the aircraft security. This paper presents the experimental results of the ablation and thermal impact of C/SiC composites under different thermal environments (thermal flux ~5 MW/m2), which were carried out with the equipments of free-jets and conduct pipes. The effects on the ablation and mechanical properties of the C/SiC composites are studied, including gas pressure, thermal temperature, and the rates of temperature increasing and decreasing. The results show that the active oxidation and ablation behaviors of 2D C/SiC laminated composites under the thermal flux 5 MW/m2 consist with that of theoretical simulations. The critical failure conditions of 2D C/SiC laminated composite is also provided for the enveloping designs of the whole composites lightweight aircrafts.展开更多
CDK4/6 inhibitor acts on cell cycle.It can be used alone or in combination to treat lung cancer,liver cancer,pancreatic cancer and other cancers by restoring normal cell cycle,triggering anti-tumor immunity and changi...CDK4/6 inhibitor acts on cell cycle.It can be used alone or in combination to treat lung cancer,liver cancer,pancreatic cancer and other cancers by restoring normal cell cycle,triggering anti-tumor immunity and changing the microenvironment of tumors.It has a certain therapeutic effect,and has a certain inhibitory effect on the proliferation and development of malignant tumors.The combination of other antineoplastic drugs can effectively reduce the emergence of drug resistance and synergistically enhance the clinical efficacy.This article reviews the related research results of CDK4/6 inhibitors,as well as the literature,and summarizes the mechanism and clinical application of CDK4/6 inhibitors.Cyclin dependent kinase(CDK)is a group of serine/threonine protein kinases.The chemical action of CDK on serine/threonine protein is the key to driving cell cycle.The typical biological feature of cancer is cell cycle disorder.As the engine of cell cycle,CDK and its regulators play an important role in tumorigenesis and development.In modern times,cancer has gained a deeper understanding at the level of biomolecule.For cell receptors,more and more drugs are used for key genes.The new generation of CDK4/6 inhibitors cut into the cell cycle to treat malignant tumors,prevent cells from G1 phase to S phase.They have good clinical efficacy for ER+breast cancer patients.They are also used in clinical trials of lung cancer,melanoma and other malignant tumors to treat malignant tumors.Therapy provides a new way.展开更多
Catalytic Michael addition reaction represents a fundamental importance in organic synthetic chemistry.Whereas corresponding conversions toward intrinsically low reactive enamide remains an ongoing challenging.We here...Catalytic Michael addition reaction represents a fundamental importance in organic synthetic chemistry.Whereas corresponding conversions toward intrinsically low reactive enamide remains an ongoing challenging.We herein report a copper-catalyzed conjugate addition of allenes toβ-substituted alkenyl amides,one of the most challenging Michael acceptors.The present method utilizes readily available allenes as the latent carbon-based nucleophiles and simple,commonβ-substituted alkenyl amides as starting materials,unlike previous methods that usually preinstall an activating group to improve the reactivity of amide or uses highly reactive stoichiometric quantities of organometallics.Hence,this approach shows good functional group compatibility and can be implemented under mild reaction conditions with excellent level of chemo-and regioselectivities.展开更多
Dear Editor,Haploidentical allogeneic hematopoietic stem cell transplantation(haplo-HSCT),a curative therapy for severe aplastic anemia(SAA)patients,has been used clinically for decades.Two models,not involving ex vit...Dear Editor,Haploidentical allogeneic hematopoietic stem cell transplantation(haplo-HSCT),a curative therapy for severe aplastic anemia(SAA)patients,has been used clinically for decades.Two models,not involving ex vitro T-cell depletion,have been adopted for haplo-HSCT in patients with SAA.The first is referred to as the"Beijing protocol"(Xu et al.,2017),and comprises a conditioning regimen using busulfex(BU),cyclophosphamide(CY).展开更多
The southeastern Tibetan Plateau,which profoundly affects East Asia by helping to maintain the stability of climate systems,biological diversity and clean water,is one of the regions most vulnerable to water erosion,w...The southeastern Tibetan Plateau,which profoundly affects East Asia by helping to maintain the stability of climate systems,biological diversity and clean water,is one of the regions most vulnerable to water erosion,wind erosion,tillage erosion,freeze-thaw erosion and overgrazing under global climate changes and intensive human activities.Spatial variations in soil erosion in terraced farmland(TL),sloping farmland(SL)and grassland(GL)were determined by the^(137)Cs tracing method and compared with spatial variations in soil organic carbon(SOC)and total nitrogen(total N).The^(137)Cs concentration in the GL was higher in the 0-0.03 m soil layer than in the other soil layers due to weak migration and diffusion under low precipitation and temperature conditions,while the^(137)Cs concentration in the soil layer of the SL was generally uniform in the 0-0.18 m soil layer due to tillage-induced mixing.Low^(137)Cs inventories appeared at the summit and toe slope positions in the SL due to soil loss by tillage erosion and water erosion,respectively,while the highest^(137)Cs inventories appeared at the middle slope posi-tions due to soil accumulation under relatively flat landform conditions.In the GL,the^(137)Cs data showed that higher soil erosion rates appeared at the summit due to freeze-thaw erosion and steep slope gradients and at the toe slope position due to wind erosion,gully erosion,freeze-thaw erosion and overgrazing.The^(137)Cs inventory generally increased from upper to lower slope positions within each terrace(except the lowest terrace).The^(137)Cs data along the terrace toposequence showed abrupt changes in soil erosion rates between the lower part of the upper terrace and the upper part of the immediate terrace over a short distance and net deposition on the lower and toe terraces.Hence,tillage erosion played an important role in the soil loss at the summit slope positions of each terrace,while water erosion dominantly transported soil from the upper terrace to the lower terrace and resulted in net soil deposition on the flat lower terrace.The SOC inventories showed similar spatial patterns to the^(137)Cs inventories in the SL,TL and GL,and significant correlations were found between the SOC and^(137)Cs inventories in these slope landscapes.The total N inventories showed similar spatial patterns to the inventories of,37Cs and SOC,and significant correlations were also found between the total N and^(137)Cs inventories in the SL,TL and GL Therefore,^(137)Cs can successfully be used for tracing soil,SOC and total N dynamics within slope landscapes in the southeastern Tibetan Plateau.展开更多
Based on oceanic internal wave SAR imaging mechanism and the microwave scattering imaging model for oceanic surface features, we developed a new method to extract internal wave parameters from SAR imagery. Firstly, th...Based on oceanic internal wave SAR imaging mechanism and the microwave scattering imaging model for oceanic surface features, we developed a new method to extract internal wave parameters from SAR imagery. Firstly, the initial wind fields are derived from NCEP reanalysis data, the sea water density and oceanic internal wave pycnocline depth are estimated from the Levites data, the surface currents induced by the internal wave are calculated according to the KDV equation. The NRCS profile is then simulated by solving the action balance equation and using the sea surface radar backscatter model. Both the winds and internal wave pycnocline depth are adjusted by using the dichotomy method step by step to make the simulated data approach the SAR image. Then, the wind speed, pycnocline depth, the phase speed, the group velocity and the amplitude of internal wave can be retrieved from SAR imagery when a best fit between simulated signals and the SAR image appears. The method is tested on one scene SAR image near Dongsha Island, in the South China Sea, results show that the simulated oceanic internal wave NRCS profile is in good agreement with that on the SAR image with the correlation coefficient as high as 90%, and the amplitude of oceanic internal wave retrieved from the SAR imagery is comparable with the SODA data. Besides, the phase speeds retrieved from other 16 scene SAR images in the South China Sea are in good agreement with the empirical formula which describes the relations between internal wave phase speed and water depths, both the root mean square and relative error are less than O. 11 m.s 1 and 7%, respectively, indicating that SAR images are useful for internal wave parameters retrieval and the method developed in this paper is convergent and applicable.展开更多
The corrosion and magnetocaloric property of LaFe11.5 Si1.5 compound with excess La from 0 wt% to 15 wt% were investigated by a scanning electron microscope(SEM), electrochemical workstation and a vibrating sample mag...The corrosion and magnetocaloric property of LaFe11.5 Si1.5 compound with excess La from 0 wt% to 15 wt% were investigated by a scanning electron microscope(SEM), electrochemical workstation and a vibrating sample magnetometer(VSM). With the increase of excess La from 0 wt%, 5 wt% to 10 wt% and15 wt%, most of the La-rich phase changes from granular La2 O3 phase to grain boundary LaFeSi phase.The La2 O3 is more stable than the main 1:13 phase, while LaFeSi phase is easy to be corroded than the1:13 phase. The maximum entropy change-△Smaxis 18.60, 21.48, 19.66 and 16.28 J/(kg·K) for 0 wt%,5 wt%, 10 wt% and 15 wt% excess of La, respectively. As adding 5 wt% excess La in LaFe11.5 Si1.5 compound leads to nearly single 1:13 phase, the largest magnetic entropy change and better corrosion resistance are obtained.展开更多
A bulk nanostructured twinning-induced plasticity (TWIP) steel with high ductility and high strength was fabricated by cryogenic asymmetry-rolling (cryo-ASR) and subsequent recovery treatment. It was found that th...A bulk nanostructured twinning-induced plasticity (TWIP) steel with high ductility and high strength was fabricated by cryogenic asymmetry-rolling (cryo-ASR) and subsequent recovery treatment. It was found that the cryo-ASRed TWIP steels exhibit simultaneous improvements in the ductility, strength and work hardening. Typical microstructures of the cryo-ASR TWIP steel were characterized by shear bands and intensive mechanical nano-sized twins induced by cryogenic deformation. These mechanical nano-scale twins remain thermally stable during the subsequent recovery treatment. It is believed that the ductility enhancement and high work-hardening ability for the cryo-ASR TWIP steels should be mainly attributed to the high-densitv pre-existing nano-scale twins.展开更多
Background:Natural ecosystems,such as forests and grasslands,can mitigate heat waves,but research on heat wave mitigation in mountain ecosystems is lacking.Considering the upper reaches of the Yangtze River basin(URYB...Background:Natural ecosystems,such as forests and grasslands,can mitigate heat waves,but research on heat wave mitigation in mountain ecosystems is lacking.Considering the upper reaches of the Yangtze River basin(URYB)as the study area,we first divided the URYB into mountainous and non-mountainous areas based on a digital elevation model(DEM).Then,we used temperature to identify heat waves and used the temperature and humidity index to identify suitable days.Finally,the differences between mountainous and non-mountainous areas were compared,and regional development strategies are proposed.Result:(1)The frequency and duration of heat waves increased by 0.433/y(P<0.1),0.07/y(P<0.05),while the number of suitable days in June,July,and August gradually decreased slightly by 0.0096/y(P<0.1),0.0125/y(P<0.1),0.004/y(P<0.1),respectively from 1986 to 2015.(2)The average monthly number of suitable days was the highest in mountainous areas during the summer from 1986 to 2015.Mountainous areas have an advantage in mitigating heat waves owing to landform-based changes in the local climate.(3)In addition to the landform,altitude was the main factor responsible for mitigating heat waves in mountainous areas.Conclusion:Parts of the plateau and whole mountain areas were found to be best for avoiding extremely high temperatures based on the number of suitable summer days from 1986 to 2015.We suggest formulating tourism promotion strategies,and strengthening tourism infrastructure,considering landscape protection and creation to promote sustainable regional development.展开更多
Influence of composition and annealing temperature on structure and magnetic properties of amorphous and nanocrystalline Fe78.4-xCoxSi9B9Nb2.6Cu1 (x=27.4, 40.0, 51.0, 78.4) alloys was investigated by X-ray diffracti...Influence of composition and annealing temperature on structure and magnetic properties of amorphous and nanocrystalline Fe78.4-xCoxSi9B9Nb2.6Cu1 (x=27.4, 40.0, 51.0, 78.4) alloys was investigated by X-ray diffraction (XRD) and the temperature dependence of permeability. According to the initial crystallization temperature (Tx1) from differential scanning calorimetry (DSC) curves of as-quenched amorphous alloys, 490-700 ℃ isothermal annealing was carded out to obtain the characteristic nanocrystalline structure. Furthermore, the soft magnetic properties were measured by temperature evolution of magnetic permeability to obtain the correlation between Co content, annealing temperature and magnetic permeability. The results show that, on the one hand, the annealing temperature exerts a significant effect on phase structure and initial permeability (μi). The higher-temperature (from 550 to 610 ℃) annealed Co content nanocrystalline samples can remain higher μi at elevated temperature. On the other hand, partial substitution Fe by Co can improve the high-temperature magnetic stability;however, the room-temperature permeability of higher Co content alloys decreases obviously at the same time. This phenomenon was analyzed from the viewpoint of the saturation magnetic induction (Bs), magnetic anisotropy (〈K〉) and magnetostriction (λs).展开更多
The hydrogen absorption of the LaFe(10.9)-Co(0.8)Si(1.3) compound under constant 1.01 × 10-5 Pa H2 gas in a flow hydrogen atmosphere was studied. The effects of hydrogen absorption on structure, Curie tempe...The hydrogen absorption of the LaFe(10.9)-Co(0.8)Si(1.3) compound under constant 1.01 × 10-5 Pa H2 gas in a flow hydrogen atmosphere was studied. The effects of hydrogen absorption on structure, Curie temperature, phase transition and magnetic property were investigated by X-ray diffraction(XRD), differential scanning calorimeter(DSC) and superconducting quantum interference device,respectively. The hydrides of LaFe(10.9)Co(0.8)Si(1.3) crystallize into NaZn(13)-type structural phase after hydrogen absorption at temperature from 548 to 623 K. Lower hydrogen absorption temperature is of no advantage for pure 1:13 phase formation in a flow H2 atmosphere. The Curie temperature(TC) of LaFe(10.9)Co(0.8)Si(1.3) compound increases by70 K or more after hydrogen absorption. For LaFe(10.9)-Co(0.8)Si(1.3)H(1.8) compound, the maximum magnetic entropy change and the relative cooling power under a magnetic field change of 0-2 T are 6.1 J·kg^-1·K^-1 and 170 J·kg^-1,respectively. Large refrigerant capacity, low hysteresis loss and wide temperature span of magnetic entropy change peak make it a competitive practical candidate for magnetic refrigerant.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.41876208,41830540,41576174)。
文摘Shallow marine sand waves are formed on the seabed and are widely distributed within tidal environments.However,the use of multibeam echo sounding(MBES)is costly to obtain the bathymetric mapping of large complex sand waves.Therefore,we propose a new method that employs a combination of multiangle sun glint images and sparse MBES data to achieve comprehensive bathymetric mapping of large and complex sand waves.This method involves estimating sea surface roughness,automatically extracting sand-wave crests,conducting adaptive subregion partitioning,estimating the water depth at auxiliary points,and generating digital bathymetric models.The method was employed in a case study of sand waves on the Taiwan Bank.Bathymetric mapping was implemented for large complex sand waves over an area spanning approximately 350 km~2 using multiangle sun glint images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer and MBE S data.The results show that mapped and measured water depths were well-matched;the root-mean-square error of water depths was 1.77 m,and the relative error was 5.03%.These findings show that bathymetric mapping of large complex sand waves can be effectively conducted using the new method,and as such,the workload of MBES is reduced and efficiency is improved.
基金supported by the National Key R&D Program of China(2020YFE0202500).
文摘A multi-group cross-section library is fundamental for deterministic lattice physics calculations.Most existing multi-group cross-section libraries are customized for particular computer codes,as well as for particular types of nuclear reactors.This paper presents an HDF5-format multi-group cross-section library named XPZLIB.XPZLIB was produced using a selfdeveloped XPZR module integrated into the NJOY2016 code,and an in-house PyNjoy2022 system was developed for autoprocessing.XPZLIB contains detailed data content and well-organized data structures that are user-and developer-friendly.Three typical XPZLIBs with different numbers of energy groups,nuclides,and depletion reaction types were released via the Tsinghua cloud website.Furthermore,the applicability of the released XPZLIBs was investigated using HTGR and PWR lattice calculations,which can provide guidance for applying XPZLIB under different scenarios.
基金the Ethics Committee of the First Affiliated Hospital of Nanchang University(Approval:(2023)CDYFYYLK(03-013)).
文摘EVI2A has emerged as a significant biomarker in various diseases;however,its biological role and mechanism in kidney renal clear cell carcinoma(KIRC)remains unexplored.We used TCGA and GEO databases to analyze EVI2A gene expression comprehensively and performed pan-cancer assessments.Clinical relevance was evaluated through Kaplan-Meier analysis and ROC curves.The gene’s immune relevance was explored through analyses of the tumor microenvironment(TME),Tumor Immune Single-cell Hub(TISCH),immune checkpoints,and immunotherapy sensitivity.Our results indicate that EVI2A expression is upregulated in KIRC,showing correlations with tumor grade and T/N/M stage.EVI2A demonstrates high diagnostic accuracy(AUC=0.906)and predicts poor overall and progression-free survival in KIRC patients.Furthermore,EVI2A expression exhibits significant associations with immunity,including TME scores and specific immune cell types such as Tfh cells,CD4 memory T cells,and CD8+T cells.Elevated EVI2A expression suggests increased sensitivity to PD-1/CTLA-4 and tyrosine kinase inhibitors.In vitro assays confirmed the impact of EVI2A on KIRC behavior,with its knockdown resulting in reduced cell proliferation and migration.In conclusion,our comprehensive analysis identifies EVI2A as a promising biomarker and a novel therapeutic target for intervening in KIRC.These findings hold significant implications for further research and potential clinical applications.
基金the Research Ethics Committee of The First Affiliated Hospital of Zhejiang University School of Medicine(No.2018-918).
文摘Background:Serum chitinase-3-like protein 1(CHI3L1)is a potential biomarker for fibrosis assessment.We aimed to evaluate serum CHI3L1 as a noninvasive diagnostic marker for chronic hepatitis B virusrelated fibrosis.Methods:Serum CHI3L1 levels were measured by ELISA in 134 chronic hepatitis B(CHB)patients.Significant fibrosis was defined as a liver stiffness>9.7 kPa.The performance of CHI3L1 was assessed and compared to that of other noninvasive tests by receiver operating characteristic(ROC)analysis.Results:Serum CHI3L1 levels were significantly higher in CHB patients with significant hepatic fibrosis(≥F2)than in those without significant hepatic fibrosis(<F2)(56.5 ng/mL vs.81.9 ng/mL,P<0.001).In CHB patients,the specificity and sensitivity of CHI3L1 for predicting significant fibrosis were 75.6%and 59.1%,respectively,with a cut-off of 76.0 ng/mL and an area under the ROC curve of 0.728(95%CI:0.637–0.820).Conclusions:Serum CHI3L1 levels could be an effective new serological biomarker for the diagnosis of liver fibrosis.Moreover,CHI3L1 is feasible in monitoring disease progression.
文摘Objective: The purposes of this study were to assess the efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) for acute leukemia (AL) and analyze the factors affecting the prognosis of these patients. Methods: The clinical and follow-up data of 93 AL patients (median age, 30 years) undergoing allogeneic HSCT in Xiangya Hospital over the past 12 years were collected, and the potential factors affecting the efficacy and prognosis of allogeneic HSCT patients were determined. Results: Hematopoietic reconstitution was achieved in 90 patients. At the last follow-up, the incidences of severe acute graft versus host disease (aGvHD) and extensive chronic GvHD (cGvHD) were 14.0% and 20.0%, the 3-year cumulative incidence of transplantation related mortality (TRM) and relapse rate were 16.8%±6.1% and 21.3%±6.7%, and the estimated 3-year overall survival (OS) and disease-free survival (DFS) of the patients were 64.6%±5.4% and 56.5%±5.5%, respectively. Univariate analysis indicated that age older than 40 years, HLA mismatch, and severe lung infection within the first 100 days after transplantation were risk factors for severe aGvHD, age older than 40 years, HLA mismatch, severe lung infection within the first 100 days after transplantation, and severe aGvHD were risk factors for TRM, high-risk AL and lack of cGvHD were risk factors for relapse (all P〈0.05). Survival estimation showed that HLA mismatch, severe lung infection occurring within the first 100 days post-transplantation, high-risk AL severe aGvHD and lack of cGvHD were risk factors associated with poor prognosis (all P〈0.05). Further multivariate analyses revealed that severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD were independent risk factors for unfavorable outcomes (all P〈0.05). Conclusions: Allogeneic HSCT can improve the DFS of AL patients, and severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD are independent risk factors affecting the prognosis.
基金Funding was provided by Horizon 2020 Framework Programme(Grant No.777564).
文摘Since the concept of active suspensions appeared,its large possible benefits has attracted continuous exploration in the field of railway engineering.With new demands of higher speed,better ride comfort and lower maintenance cost for railway vehicles,active suspensions are very promising technologies.Being the starting point of commercial application of active suspensions in rail vehicles,tilting trains have become a great success in some countries.With increased technical maturity of sensors and actuators,active suspension has unprecedented development opportunities.In this work,the basic concepts are summarized with new theories and solutions that have appeared over the last decade.Experimental studies and the implementation status of different active suspension technologies are described as well.Firstly,tilting trains are briefly described.Thereafter,an indepth study for active secondary and primary suspensions is performed.For both topics,after an introductory section an explanation of possible solutions existing in the literature is given.The implementation status is reported.Active secondary suspensions are categorized into active and semi-active suspensions.Primary suspensions are instead divided between acting on solid-axle wheelsets and independently rotating wheels.Lastly,a brief summary and outlook is presented in terms of benefits,research status and challenges.The potential for active suspensions in railway applications is outlined.
文摘At peak granulite-facies metamorphic conditions, lower continental crust is arguably fluxed by large amounts of two key low water activity fluids: (i) high-density CO2 and/or (ii) concentrated saline so- lutions. These fluids are either internally-derived, generated by mineral reactions or dehydration melting or, notably for CO2, externally-derived, issued from the underlying mantle. Postmetamorphic evolution results in complete disappearance of these fluids, except for minute remnants preserved in minerals as fluid inclusions. Two major processes are involved: (i) at peak conditions, granitoid magmas form, migrate upward, and crystallize as shallow intrusions in the upper crust (mineralized porphyry types or reduced intrusions); (ii) during the rapid decompression which almost systematically follows a period of post-peak isobaric cooling, especially for ultrahigh-temperature granulites (anticlockwise P-T paths), quartz-carbonate megashear zones are formed by repeated periods of seismic activity. Seismic activity may continue until all free fluids have disappeared, resulting in the ultramylonites and pseudotachylites that are found in many granulite domes. A great majority of vein-type Au deposits worldwide occur in the above-mentioned settings or nearby. We suggest that the Au has been scavenged by the granulite fluids, then redistributed and concentrated during the formation of veins and related phenomena.
文摘BACKGROUND A vascular tumor is a benign tumor with unique clinical and pathological features.Perirenal vascular tumor is extremely rare and has not yet been reported.Clinically,it manifests as soreness and swelling.Color ultrasound and renal angiography illustrated the perirenal mass,which was closely connected with the kidney and the surrounding tissues and organs.Histology showed extensive embedded perirenal fat,and thin-walled vascular tissue displayed a pink stain due to red blood cells.CASE SUMMARY Herein,a case of robot-assisted retroperitoneal laparoscopic excision of a perirenal vascular tumor is reported.Analysis of the clinical,biological,and histological features of the perirenal vascular tumor can provide an in-depth understanding of the disease,which provides a theoretical and practical basis for better diagnosis and treatment.CONCLUSION This study contributes to a practical basis for the diagnosis and treatment of perirenal hemangiom.
文摘Rudder is an important part for the glider aircraft. In order to satisfy the long-time high-velocity for the near-space vehicle in the atmosphere, the light- weight, high-stiffness and high-strength all-composites rudderpost is required urgently to be prepared. The all-composites rudderpost can keep high rudder efficiency in the high temperature environment. Based on the technique require-ment of high-performance composites rudder, a 3D C/SiC rudderpost was manufactured by the CVI-CMC-SiC [1] processes. It was found during rudderpost testing that the high-temperature mechanical properties decreased and had large discretization. The analysis of the failure mechanisms was conducted by FTA method to recognize the failure modes and main reasons for rudderpost abnormal fracture and to reproduce the fracture phenomenon, which could guide production company to modify their preparation process control. Then the modified processes were proved to be validated. And the stability and reliability of the production performances were improved.
文摘Two dimensions (2D) C/SiC laminated composites is the material with isotropic properties in laminated sheets, which is considered as a promising thermal skin for aircrafts. There are intense thermal flux and thermal impact at the local interference region during the flight of the aircrafts. Therefore, mastering ablation and mechanical properties of 2D C/SiC laminated composite under extreme environments become the guild lines for the designs of the flight corridor and the aircraft security. This paper presents the experimental results of the ablation and thermal impact of C/SiC composites under different thermal environments (thermal flux ~5 MW/m2), which were carried out with the equipments of free-jets and conduct pipes. The effects on the ablation and mechanical properties of the C/SiC composites are studied, including gas pressure, thermal temperature, and the rates of temperature increasing and decreasing. The results show that the active oxidation and ablation behaviors of 2D C/SiC laminated composites under the thermal flux 5 MW/m2 consist with that of theoretical simulations. The critical failure conditions of 2D C/SiC laminated composite is also provided for the enveloping designs of the whole composites lightweight aircrafts.
基金National Natural Science Foundation of China(No.81660774,No.8176150139).
文摘CDK4/6 inhibitor acts on cell cycle.It can be used alone or in combination to treat lung cancer,liver cancer,pancreatic cancer and other cancers by restoring normal cell cycle,triggering anti-tumor immunity and changing the microenvironment of tumors.It has a certain therapeutic effect,and has a certain inhibitory effect on the proliferation and development of malignant tumors.The combination of other antineoplastic drugs can effectively reduce the emergence of drug resistance and synergistically enhance the clinical efficacy.This article reviews the related research results of CDK4/6 inhibitors,as well as the literature,and summarizes the mechanism and clinical application of CDK4/6 inhibitors.Cyclin dependent kinase(CDK)is a group of serine/threonine protein kinases.The chemical action of CDK on serine/threonine protein is the key to driving cell cycle.The typical biological feature of cancer is cell cycle disorder.As the engine of cell cycle,CDK and its regulators play an important role in tumorigenesis and development.In modern times,cancer has gained a deeper understanding at the level of biomolecule.For cell receptors,more and more drugs are used for key genes.The new generation of CDK4/6 inhibitors cut into the cell cycle to treat malignant tumors,prevent cells from G1 phase to S phase.They have good clinical efficacy for ER+breast cancer patients.They are also used in clinical trials of lung cancer,melanoma and other malignant tumors to treat malignant tumors.Therapy provides a new way.
基金the financial support from the National Natural Science Foundation of China(NSFC,Nos.22171042,21831002,and 22193012)the Jilin Province Natural Science Foundation(No.20160520140JH)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Ten Thousand Talents Program for generous financial support。
文摘Catalytic Michael addition reaction represents a fundamental importance in organic synthetic chemistry.Whereas corresponding conversions toward intrinsically low reactive enamide remains an ongoing challenging.We herein report a copper-catalyzed conjugate addition of allenes toβ-substituted alkenyl amides,one of the most challenging Michael acceptors.The present method utilizes readily available allenes as the latent carbon-based nucleophiles and simple,commonβ-substituted alkenyl amides as starting materials,unlike previous methods that usually preinstall an activating group to improve the reactivity of amide or uses highly reactive stoichiometric quantities of organometallics.Hence,this approach shows good functional group compatibility and can be implemented under mild reaction conditions with excellent level of chemo-and regioselectivities.
文摘Dear Editor,Haploidentical allogeneic hematopoietic stem cell transplantation(haplo-HSCT),a curative therapy for severe aplastic anemia(SAA)patients,has been used clinically for decades.Two models,not involving ex vitro T-cell depletion,have been adopted for haplo-HSCT in patients with SAA.The first is referred to as the"Beijing protocol"(Xu et al.,2017),and comprises a conditioning regimen using busulfex(BU),cyclophosphamide(CY).
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Program(STEP2019QZKK0307)+1 种基金the Sichuan Science and Technology Program(2022YFS0500)the National Natural Science Foundation of China(No.41401313).
文摘The southeastern Tibetan Plateau,which profoundly affects East Asia by helping to maintain the stability of climate systems,biological diversity and clean water,is one of the regions most vulnerable to water erosion,wind erosion,tillage erosion,freeze-thaw erosion and overgrazing under global climate changes and intensive human activities.Spatial variations in soil erosion in terraced farmland(TL),sloping farmland(SL)and grassland(GL)were determined by the^(137)Cs tracing method and compared with spatial variations in soil organic carbon(SOC)and total nitrogen(total N).The^(137)Cs concentration in the GL was higher in the 0-0.03 m soil layer than in the other soil layers due to weak migration and diffusion under low precipitation and temperature conditions,while the^(137)Cs concentration in the soil layer of the SL was generally uniform in the 0-0.18 m soil layer due to tillage-induced mixing.Low^(137)Cs inventories appeared at the summit and toe slope positions in the SL due to soil loss by tillage erosion and water erosion,respectively,while the highest^(137)Cs inventories appeared at the middle slope posi-tions due to soil accumulation under relatively flat landform conditions.In the GL,the^(137)Cs data showed that higher soil erosion rates appeared at the summit due to freeze-thaw erosion and steep slope gradients and at the toe slope position due to wind erosion,gully erosion,freeze-thaw erosion and overgrazing.The^(137)Cs inventory generally increased from upper to lower slope positions within each terrace(except the lowest terrace).The^(137)Cs data along the terrace toposequence showed abrupt changes in soil erosion rates between the lower part of the upper terrace and the upper part of the immediate terrace over a short distance and net deposition on the lower and toe terraces.Hence,tillage erosion played an important role in the soil loss at the summit slope positions of each terrace,while water erosion dominantly transported soil from the upper terrace to the lower terrace and resulted in net soil deposition on the flat lower terrace.The SOC inventories showed similar spatial patterns to the^(137)Cs inventories in the SL,TL and GL,and significant correlations were found between the SOC and^(137)Cs inventories in these slope landscapes.The total N inventories showed similar spatial patterns to the inventories of,37Cs and SOC,and significant correlations were also found between the total N and^(137)Cs inventories in the SL,TL and GL Therefore,^(137)Cs can successfully be used for tracing soil,SOC and total N dynamics within slope landscapes in the southeastern Tibetan Plateau.
基金We would like to thank Remote Sensing Ground Station of China, Chinese Academy of Sciences (CAS) and European Space Agency for providing the ERS-1/2 SAR, ENVISAT ASAR and Radarsat-1 SAR images, the CISL Research Data Archive (RDA) for providing the NCEP reanalysis wind data, both http://www.nodc.noaa.gov/and http://iridl. ldeo,columbia.edu for providing the Levitus98 data and SODA data, and Dr. R. Romeiser for sharing the radar microwave backscatter imaging model of M4S. This research is jointly supported by the National Natural Science Foundation of China (Grant Nos. 41106155 and 41471227) and under the Open Fund of State Key Laboratory of Satellite Ocean Environment Dynamics (No. SOEDI407). This work is also supported by General Research Fund of Hong Kong Research Grants Council (RGC) under grants CUHK 402912 and 403113. We also would like to thank the anonymous reviewers' comments to improve the original manuscript.
文摘Based on oceanic internal wave SAR imaging mechanism and the microwave scattering imaging model for oceanic surface features, we developed a new method to extract internal wave parameters from SAR imagery. Firstly, the initial wind fields are derived from NCEP reanalysis data, the sea water density and oceanic internal wave pycnocline depth are estimated from the Levites data, the surface currents induced by the internal wave are calculated according to the KDV equation. The NRCS profile is then simulated by solving the action balance equation and using the sea surface radar backscatter model. Both the winds and internal wave pycnocline depth are adjusted by using the dichotomy method step by step to make the simulated data approach the SAR image. Then, the wind speed, pycnocline depth, the phase speed, the group velocity and the amplitude of internal wave can be retrieved from SAR imagery when a best fit between simulated signals and the SAR image appears. The method is tested on one scene SAR image near Dongsha Island, in the South China Sea, results show that the simulated oceanic internal wave NRCS profile is in good agreement with that on the SAR image with the correlation coefficient as high as 90%, and the amplitude of oceanic internal wave retrieved from the SAR imagery is comparable with the SODA data. Besides, the phase speeds retrieved from other 16 scene SAR images in the South China Sea are in good agreement with the empirical formula which describes the relations between internal wave phase speed and water depths, both the root mean square and relative error are less than O. 11 m.s 1 and 7%, respectively, indicating that SAR images are useful for internal wave parameters retrieval and the method developed in this paper is convergent and applicable.
基金Project supported by the Natural Science Foundation of Hebei Education Department(Grant No.ZD2017066,2018101000441)Special Funding Projects for Scientific Research of Shijiazhuang Tiedao University(Grant No.Z661210729)Tianjin Research Program of Application Foundation and Advanced Technology(Grant No.14JCQNJC04000)
文摘The corrosion and magnetocaloric property of LaFe11.5 Si1.5 compound with excess La from 0 wt% to 15 wt% were investigated by a scanning electron microscope(SEM), electrochemical workstation and a vibrating sample magnetometer(VSM). With the increase of excess La from 0 wt%, 5 wt% to 10 wt% and15 wt%, most of the La-rich phase changes from granular La2 O3 phase to grain boundary LaFeSi phase.The La2 O3 is more stable than the main 1:13 phase, while LaFeSi phase is easy to be corroded than the1:13 phase. The maximum entropy change-△Smaxis 18.60, 21.48, 19.66 and 16.28 J/(kg·K) for 0 wt%,5 wt%, 10 wt% and 15 wt% excess of La, respectively. As adding 5 wt% excess La in LaFe11.5 Si1.5 compound leads to nearly single 1:13 phase, the largest magnetic entropy change and better corrosion resistance are obtained.
基金financially supported by the Jiangxi Provincial Science and Technology Department(No.20151BDH80082)the China National Major Science and Technology Project(No.2014ZX07214-002)the financial support from China Postdoctoral Science Foundation(No.2015M581608)
文摘A bulk nanostructured twinning-induced plasticity (TWIP) steel with high ductility and high strength was fabricated by cryogenic asymmetry-rolling (cryo-ASR) and subsequent recovery treatment. It was found that the cryo-ASRed TWIP steels exhibit simultaneous improvements in the ductility, strength and work hardening. Typical microstructures of the cryo-ASR TWIP steel were characterized by shear bands and intensive mechanical nano-sized twins induced by cryogenic deformation. These mechanical nano-scale twins remain thermally stable during the subsequent recovery treatment. It is believed that the ductility enhancement and high work-hardening ability for the cryo-ASR TWIP steels should be mainly attributed to the high-densitv pre-existing nano-scale twins.
基金This work was supported by the Ecosystem Services Flow based on the Cascade Process,[32071664]Second Tibetan Plateau Scientific Expedition and Research Program(STEP)[2019QZKK0307]+1 种基金Major Scientific and Technological Special Program of Sichuan Province,China[2018SZDZX0027]Technology Program of China Quality Certification Centre[2021CQC21-stzx].
文摘Background:Natural ecosystems,such as forests and grasslands,can mitigate heat waves,but research on heat wave mitigation in mountain ecosystems is lacking.Considering the upper reaches of the Yangtze River basin(URYB)as the study area,we first divided the URYB into mountainous and non-mountainous areas based on a digital elevation model(DEM).Then,we used temperature to identify heat waves and used the temperature and humidity index to identify suitable days.Finally,the differences between mountainous and non-mountainous areas were compared,and regional development strategies are proposed.Result:(1)The frequency and duration of heat waves increased by 0.433/y(P<0.1),0.07/y(P<0.05),while the number of suitable days in June,July,and August gradually decreased slightly by 0.0096/y(P<0.1),0.0125/y(P<0.1),0.004/y(P<0.1),respectively from 1986 to 2015.(2)The average monthly number of suitable days was the highest in mountainous areas during the summer from 1986 to 2015.Mountainous areas have an advantage in mitigating heat waves owing to landform-based changes in the local climate.(3)In addition to the landform,altitude was the main factor responsible for mitigating heat waves in mountainous areas.Conclusion:Parts of the plateau and whole mountain areas were found to be best for avoiding extremely high temperatures based on the number of suitable summer days from 1986 to 2015.We suggest formulating tourism promotion strategies,and strengthening tourism infrastructure,considering landscape protection and creation to promote sustainable regional development.
基金financially supported by the National Natural Science Foundation of China (No. 11604242)Tianjin Research Program of Application Foundation and Advanced Technology, China (No. 14JCQNJC04000)
文摘Influence of composition and annealing temperature on structure and magnetic properties of amorphous and nanocrystalline Fe78.4-xCoxSi9B9Nb2.6Cu1 (x=27.4, 40.0, 51.0, 78.4) alloys was investigated by X-ray diffraction (XRD) and the temperature dependence of permeability. According to the initial crystallization temperature (Tx1) from differential scanning calorimetry (DSC) curves of as-quenched amorphous alloys, 490-700 ℃ isothermal annealing was carded out to obtain the characteristic nanocrystalline structure. Furthermore, the soft magnetic properties were measured by temperature evolution of magnetic permeability to obtain the correlation between Co content, annealing temperature and magnetic permeability. The results show that, on the one hand, the annealing temperature exerts a significant effect on phase structure and initial permeability (μi). The higher-temperature (from 550 to 610 ℃) annealed Co content nanocrystalline samples can remain higher μi at elevated temperature. On the other hand, partial substitution Fe by Co can improve the high-temperature magnetic stability;however, the room-temperature permeability of higher Co content alloys decreases obviously at the same time. This phenomenon was analyzed from the viewpoint of the saturation magnetic induction (Bs), magnetic anisotropy (〈K〉) and magnetostriction (λs).
基金financially supported by the Tianjin Research Program of Application Foundation and Advanced Technology (No.14JCQNJC04000)the National Key Research and Development Program of China (No.2017YFB0702700)the Hebei Provincial Education Department Project (No.ZD2017066)
文摘The hydrogen absorption of the LaFe(10.9)-Co(0.8)Si(1.3) compound under constant 1.01 × 10-5 Pa H2 gas in a flow hydrogen atmosphere was studied. The effects of hydrogen absorption on structure, Curie temperature, phase transition and magnetic property were investigated by X-ray diffraction(XRD), differential scanning calorimeter(DSC) and superconducting quantum interference device,respectively. The hydrides of LaFe(10.9)Co(0.8)Si(1.3) crystallize into NaZn(13)-type structural phase after hydrogen absorption at temperature from 548 to 623 K. Lower hydrogen absorption temperature is of no advantage for pure 1:13 phase formation in a flow H2 atmosphere. The Curie temperature(TC) of LaFe(10.9)Co(0.8)Si(1.3) compound increases by70 K or more after hydrogen absorption. For LaFe(10.9)-Co(0.8)Si(1.3)H(1.8) compound, the maximum magnetic entropy change and the relative cooling power under a magnetic field change of 0-2 T are 6.1 J·kg^-1·K^-1 and 170 J·kg^-1,respectively. Large refrigerant capacity, low hysteresis loss and wide temperature span of magnetic entropy change peak make it a competitive practical candidate for magnetic refrigerant.