Obtaining high magnetic properties in high Ce-content magnets is essential to expand the widespread application of low-cost magnets.In this study,high Ce-content magnets with up to 45%Ce substitution for Nd were prepa...Obtaining high magnetic properties in high Ce-content magnets is essential to expand the widespread application of low-cost magnets.In this study,high Ce-content magnets with up to 45%Ce substitution for Nd were prepared by combining the single/dual/multi-main-phase processes with the Dy-containing grain boundary diffusion process(GBDP).The effects of base magnets with different Ce distributions on GBDP were systematically investigated.Magnetic properties and micro structure analysis reveal that high-performance multi-main-phase(MMP)diffused magnets with remanence(Br)up to 12.52 kGs,coercivity up to 16.08 kOe,and maximum magnetic energy product up to 36.44 MGOe are obtained,which is attributed to the regulation of Ce by the MMP process,and the optimization of microstructure by Gd-Cu alloy.Meanwhile,the diffusion efficiency is significantly improved because of Ce being restricted to the grain core,which promotes the formation of a continuous structure at the grain boundaries,and the formation of a continuous multilayer shell grain structure with high anisotropy field,while the Br of the diffused magnet is maintained.Besides,magnetic domain analysis shows that the MMP diffused magnet effectively suppresses the nucleation of demagnetized domains and enhances the pinning effect of domain walls.The study establishes an experimental foundation for the development of sintered high Ce-content magnets showcasing superior performance.展开更多
Laser cladding deposited Ti-6Al-4V titanium alloy universally shows more complex microstructures,each of which has significant effect on mechanical properties. Of particular α/β interface phase has been observed in ...Laser cladding deposited Ti-6Al-4V titanium alloy universally shows more complex microstructures,each of which has significant effect on mechanical properties. Of particular α/β interface phase has been observed in this paper under certain conditions. It demonstrates that the influence of the α/β interface phase on the tensile properties is closely associated with dislocations and twin substructure through comparison experiments. The results show that the α/β interface phase hinders dislocation motion and decreases effective slip length. In addition, the twin substructure has been activated in the α/β interface phase during tensile process and has acted somehow like grain boundaries. Therefore, the strength and the work-hardening rate of the laser cladding deposited Ti-6Al-4V titanium alloy have been significantly improved due to the dynamic Hall-Petch effect. Besides, the α/β interface phase leads to more uniform dislocations distribution, which implies that relative lower local concentrated stress will be produced along the α/β interface phase or colony boundary after the same amount of plastic deformation. Moreover,the twinning-induced plasticity effects in the α/β interface phase further increase the plastic deformation capacity. These results in higher elongation for the laser cladding deposited Ti-6Al-4V titanium alloy.It can be concluded that the current work suggests an effective method to simultaneously improve the strength and plasticity of laser cladding deposited Ti-6Al-4V titanium alloy based on the α/β interface phase.展开更多
Matrix-assisted laser desorption/ionization(MALDI)mass spectrometry imaging(MSI)is an attractive technology for the visualization of metabolite distributions in tissues.However,detection and identification of low-abun...Matrix-assisted laser desorption/ionization(MALDI)mass spectrometry imaging(MSI)is an attractive technology for the visualization of metabolite distributions in tissues.However,detection and identification of low-abundance or poorly ionized metabolites remains challenging.Although on-tissue chemical derivatization(OTCD)holds great promise for improving MALDI MS detection sensitivity and selectivity by modification of specific chemical groups,the available methods for subsequent metabolite annotation are limited.Herein,a laser-assisted chemical transfer(LACT)-based parallel OTCD strategy was established for visualizing and annotating carbonyl metabolites in murine brain tissues.Girard's T and Girard's P reagents were applied for parallel OTCD to generate the characteristic m/z pairs with a 19.969 Da mass shift(±0.020 Da tolerance)for rapid recognition of derivatized metabolites.The similarity of spatial distribution patterns of each m/z pair was further statistically evaluated to remove the ambiguous annotations due to the occurrence of interference compounds.As a result,90 ion pairs were annotated as candidate carbonyl metabolites,66 were previously known and 24 were potential unreported carbonyls.Furthermore,the spatial alterations of carbonyl metabolites in the ischemic rat brain were successfully visualized and characterized,including small molecule aldehydes and ketones,long-chain fatty aldehydes,and monosaccharides.This further emphasizes great potential of parallel OTCD strategy for efficient and confident molecular annotation of spatial submetabolomics data associated with brain diseases.展开更多
Background Based on the China-VHD database,this study sought to develop and validate a Valvular Heart Disease-specific Age-adjusted Comorbidity Index(VHD-ACI)for predicting mortality risk in patients with VHD.Methods&...Background Based on the China-VHD database,this study sought to develop and validate a Valvular Heart Disease-specific Age-adjusted Comorbidity Index(VHD-ACI)for predicting mortality risk in patients with VHD.Methods&Results The China-VHD study was a nationwide,multi-centre multi-centre cohort study enrolling 13,917 patients with moderate or severe VHD across 46 medical centres in China between April-June 2018.After excluding cases with missing key variables,11,459 patients were retained for final analysis.The primary endpoint was 2-year all-cause mortality,with 941 deaths(10.0%)observed during follow-up.The VHD-ACI was derived after identifying 13 independent mortality predictors:cardiomyopathy,myocardial infarction,chronic obstructive pulmonary disease,pulmonary artery hypertension,low body weight,anaemia,hypoalbuminaemia,renal insufficiency,moderate/severe hepatic dysfunction,heart failure,cancer,NYHA functional class and age.The index exhibited good discrimination(AUC,0.79)and calibration(Brier score,0.062)in the total cohort,outperforming both EuroSCORE II and ACCI(P<0.001 for comparison).Internal validation through 100 bootstrap iterations yielded a C statistic of 0.694(95%CI:0.665−0.723)for 2-year mortality prediction.VHD-ACI scores,as a continuous variable(VHD-ACI score:adjusted HR(95%CI):1.263(1.245-1.282),P<0.001)or categorized using thresholds determined by the Yoden index(VHDACI≥9 vs.<9,adjusted HR(95%CI):6.216(5.378-7.184),P<0.001),were independently associated with mortality.The prognostic performance remained consistent across all VHD subtypes(aortic stenosis,aortic regurgitation,mitral stenosis,mitral regurgitation,tricuspid valve disease,mixed aortic/mitral valve disease and multiple VHD),and clinical subgroups stratified by therapeutic strategy,LVEF status(preserved vs.reduced),disease severity and etiology.Conclusion The VHD-ACI is a simple 13-comorbidity algorithm for the prediction of mortality in VHD patients and providing a simple and rapid tool for risk stratification.展开更多
Commercial N52 sintered NdFeB magnets were processed by grain boundary diffusion(GBD)with Dy-Co-M(M=Cu,AI)alloys.The coercivity of magnets greatly increase to 17.62 and 18.83 kOe respectively when diffusing Dy_(58)Co_...Commercial N52 sintered NdFeB magnets were processed by grain boundary diffusion(GBD)with Dy-Co-M(M=Cu,AI)alloys.The coercivity of magnets greatly increase to 17.62 and 18.83 kOe respectively when diffusing Dy_(58)Co_(25)Cu_(17)and Dy_(58)Co_(25)Al_(17)alloys,which are obviously higher than that of Dy58Co42GBD-treated magnet with 16.64 kOe,Further thermal stability studies indicate that the thermal stability of Dy_(58)Co_(25)Cu_(17)and Dy_(58)Co_(25)Al_(17)GBD-treated magnets is further improved compared to the Dy58Co42GBD-treated magnet The results show that th e temperature coefficients of remanence(20-120℃)are reduced from-0.148%/℃to-0.134%/℃and-0.132%/℃by Dy_(58)Co_(25)Cu_(17)and Dy_(58)Co_(25)Al_(17)GBD-treatment,respectively.Besides,the irreversible magnetic flux losses(120℃)for Dy_(58)Co_(25)Cu_(17)and Dy_(58)Co_(25)Al_(17)diffusion magnets are 4.76%and 2.79%,respectively.Microstructural analyses demonstrate that the presence of Cu and Al elements reduces the excessive accumulation of Dy and Co on the surface in the diffusion magnets an d improves the diffusion depth and utilization of Dy and Co.Furthermore,the flow of Co from the triple junction phase to the thin grain boundary phase is promoted,which contributes to the uniform distribution of Co.In addition,the dynamic evolution of the magnetic domain structure during the temperature rise process was studied.This work provides insight into the preparation of high-performance and high-thermal stability magnets.展开更多
Although 316L stainless steel(SS316L)exhibits favorable ductility and toughness,its limited strength restricts its applicability.This study addressed this limitation by preparing a series of SS316L-xTC4 alloys(where x...Although 316L stainless steel(SS316L)exhibits favorable ductility and toughness,its limited strength restricts its applicability.This study addressed this limitation by preparing a series of SS316L-xTC4 alloys(where x indicates Ti6Al4V(TC4)contents of 0.5 wt%,1 wt%,2 wt%,and 4 wt%)with equiaxed grains,ultrafine grains,and heterogeneous structures using in-situ alloying via laser powder bed fusion.The Ti,Al,and V in the TC4 alloy were shown to stabilize and promote the formation of theαphase,which is stronger than theγphase in typical SS316L.Furthermore,these solute elements readily formed nanoparticles with impurities,such as C and O,to increase the nucleation rate and thereby achieve grain refinement.This resulted in the formation of ultrafine grains predominantly within theαphase,where the solute elements were primarily distributed.The formation of theαphase also impeded the growth of theγphase;coupled with the effects of the nanoparticles,this also significantly reduced the grain size in theγphase.Notably,the SS316L-2TC4 alloy exhibited fully equiaxed grains,and the coexistence of theαandγphases as well as ultrafine and coarse grains formed heterogeneous grain and dual-phase structures within.The synergistic effects of equiaxed grains,ultrafine grains,and heterostructures produced an SS316L alloy that exhibited both excellent strength and elongation.展开更多
By developing high comprehensive performance((BH)_(max)+H_(cj)),Nd-Fe-B magnets can operate stably in high-temperature applications,greatly expanding the application scenarios of them.Unfortunately,there is a constrai...By developing high comprehensive performance((BH)_(max)+H_(cj)),Nd-Fe-B magnets can operate stably in high-temperature applications,greatly expanding the application scenarios of them.Unfortunately,there is a constraint relationship between coercivity(H_(cj))and maximum magnetic energy product((BH)_(max)),and an increase in H_(cj) always accompanies a decrease in(BH)_(max).Here,the excellent comprehensive magnetic performance of up to 86.54,namely(BH)_(max) of 42.33 MGOe and H_(cj) of 44.21 kOe,is unprecedented in the sintered Nd-Fe-B magnets.This magnet is obtained by designing a unique grain structure through micrometallurgical reactions to prepare a matrix with excellent comprehensive performance,and then by stepwise diffusion,the(BH)_(max) and H_(cj) of the magnet are simultaneously enhanced.The magnet prepared in this way has a“double-shell core”structure and Tb segregation distribution inside the core.The working temperature of the magnet in this work reached 280℃,providing a new approach for the development of high-performance Nd-Fe-B magnets.展开更多
This paper studies a mirror-assisted rehabilitation training method based on a dual-arm robot,which aims to provide an effective rehabilitation training program for patients with upper limb dysfunction due to stroke o...This paper studies a mirror-assisted rehabilitation training method based on a dual-arm robot,which aims to provide an effective rehabilitation training program for patients with upper limb dysfunction due to stroke or other causes.During the mirror training task scenario,the subjects are visually guided to perform the mirror movement of both arms,and the dual-arm robot is used to facilitate the mirror-assisted rehabilitation from the healthy side to the affected side.Adaptive imped-ance control and force field channel design ensure the stability and safety of the rehabilitation process.In the rehabilitation training,appropriate assistance forces are provided within the channel to correct trajectory deviations,ensuring that the subjects'movement path aligns with the predetermined trajectory.Outside the channel,the superposition of stiffness and correction force fields prevents the subjects from deviating from the predetermined trajectory,thus avoiding injuries.In addition,the adaptive impedance control is capable of dynamically adjusting the impedance parameters according to the real-time state of the subjects,providing a personalized rehabilitation training program.This method significantly enhances both the safety and effectiveness of the rehabilitation training.The experimental results showed that the subjects'motion flexibility and safety were significantly improved during the mirror-assisted rehabilitation training.This study offers a new approach for the future development of rehabilitation robotics with broad application potential.展开更多
AIM To investigate the relationship between hypoxia-inducible factor-1α(HIF-1α), prolyl 4-hydroxylase beta(P4 HB) expression, and clinicopathologic parameters, as well as the prognostic value of these genes for pati...AIM To investigate the relationship between hypoxia-inducible factor-1α(HIF-1α), prolyl 4-hydroxylase beta(P4 HB) expression, and clinicopathologic parameters, as well as the prognostic value of these genes for patients with gastric cancer(Gc).METHODS Hypoxia is a critical factor that shapes the Gc microenvironment. In previous reports, we have demonstrated that P4 HB is a potential target of HIF-1α. In the present study, gene expression profiling interactive analysis(GEPIA) was used to analyze the relationship between P4 HB and hypoxia-associated genes. To this end, 428 Gc tissue samples were used to analyze the expression of HIF-1α and P4 HB via immunohistochemical staining. Patient samples were classified as having weak-expression or over-expression both in terms of HIF-1α and P4 HB. Correlations between biomarkers and clinicopathological factors were analyzed to predict survival. RESULTS P4 HB demonstrated a positive correlation with hypoxiaassociated genes(P < 0.05). HIF-1α and P4 HB overexpression have a significant correlation with TNM staging(χ2 = 23.32, P = 0.00; χ2 = 65.64, P = 0.00) and peritoneum cavity metastasis(χ2 = 12.67, P = 0.00; χ2 = 39.29, P = 0.00). In univariate analysis, patients with a high HIF-1α expression trend had a shorter disease-free survival(DFS: 44.80 mo vs 22.06 mo) and overall survival(OS: 49.58 mo vs 39.92 mo). P4 HB overexpression reflected similar results: patients with over-expression of P4 HB had a shorter survival time than those with weak-expression(DFS: 48.03 mo vs 29.64 mo, OS: 52.48 mo vs 36.87 mo). Furthermore, HIF-1α is also a clinicopathological predictor of dismal prognosis according to multivariate analysis(DFS, 95%c I: 0.52-0.88, P < 0.00; OS, 95%c I: 0.50-0.85, P < 0.00). However, P4 HB was meaningful in DFS(95%c I: 0.58-1.00, P < 0.05) but not in OS(95%c I: 0.72-1.23, P > 0.05).CONCLUSION Overexpression of HIF-1α and P4 HB is associated with poor prognosis in patients with Gc. Thus, these genes may be potential prognostic biomarker candidates in GC.展开更多
Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.A...Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.Around the beginning of this century,China Academy of Engineering Physics(CAEP)began to build some experimental facilities for HEDP investigations,among which the Primary Test Stand(PTS),a multi-module pulsed power facility with a nominal current of 10 MA and a current rising time~90 ns,is an important achievement on the roadmap of the electro-magnetically driven inertial confinement fusion(ICF)researches.PTS is the first pulsed power facility beyond 10 TW in China.Therefore,all the technologies have to be demonstrated,and all the engineering issues have to be overcome.In this article,the research outline,key technologies and the preliminary HEDP experiments are reviewed.Prospects on HEDP research on PTS and pulsed power development for the next step are also discussed.展开更多
BACKGROUNDLong noncoding RNAs (lncRNAs) are aberrant and play critical roles in gastriccancer (GC) progression and metastasis. Searching for coexpressed lncRNAclusters or representative biomarkers related to malignant...BACKGROUNDLong noncoding RNAs (lncRNAs) are aberrant and play critical roles in gastriccancer (GC) progression and metastasis. Searching for coexpressed lncRNAclusters or representative biomarkers related to malignant phenotypes of GC mayhelp to elucidate the mechanism of tumor development and predict the prognosisof GC.AIMTo investigate the prognostic value of NOTCH1 associated with lncRNA in T cellacute lymphoblastic leukemia 1 (NALT1) in GC and the mechanism of itsinvolvement in GC invasion and metastasis.METHODSRNA sequencing and corresponding clinical data were downloaded from TheCancer Genome Atlas database. The significance module was studied byweighted gene coexpression network analysis. A total of 336 clinical sampleswere included in the study. Gene silencing, reverse transcription polymerasechain reaction, western blotting, scrape motility assay, and Transwell migrationassay were used to assess the function of hub-lncRNAs.RESULTSAt the transcriptome level, 3339 differentially expressed lncRNAs were obtained.weighted gene coexpression network analysis was used to obtain 15 lncRNAclusters and observe their coexpression. Pearson’s correlation showed that blue module was correlated with tumor grade and survival. NALT1 was the hublncRNAof blue module and was an independent risk factor for GC prognosis.NALT1 was overexpressed in GC and its expression was closely related toinvasion and metastasis. The mechanism may involve NALT1 regulation ofNOTCH1, which is associated with lncRNA in T cell acute lymphoblasticleukemia, through cis regulation, thereby affecting the expression of the NOTCHsignaling pathway.CONCLUSIONNALT1 is overexpressed and promotes invasion and metastasis of GC. Themechanism may be related to regulation of NOTCH1 by NALT1 and its effect onNOTCH signaling pathway expression.展开更多
Some studies have suggested that early surgical treatment can effectively improve the prognosis of cervical spinal cord injury without radiological abnormality, but no research has focused on the development of a prog...Some studies have suggested that early surgical treatment can effectively improve the prognosis of cervical spinal cord injury without radiological abnormality, but no research has focused on the development of a prognostic model of cervical spinal cord injury without radiological abnormality. This retrospective analysis included 43 patients with cervical spinal cord injury without radiological abnormality. Seven potential factors were assessed: age, sex, external force strength causing damage, duration of disease, degree of cervical spinal stenosis, Japanese Orthopaedic Association score, and physiological cervical curvature. A model was established using multiple binary logistic regression analysis. The model was evaluated by concordant profiling and the area under the receiver operating characteristic curve. Bootstrapping was used for internal validation. The prognostic model was as follows: logit(P) =-25.4545 + 21.2576 VALUE + 1.2160SCORE-3.4224 TIME, where VALUE refers to the Pavlov ratio indicating the extent of cervical spinal stenosis, SCORE refers to the Japanese Orthopaedic Association score(0–17) after the operation, and TIME refers to the disease duration(from injury to operation). The area under the receiver operating characteristic curve for all patients was 0.8941(95% confidence interval, 0.7930–0.9952). Three factors assessed in the predictive model were associated with patient outcomes: a great extent of cervical stenosis, a poor preoperative neurological status, and a long disease duration. These three factors could worsen patient outcomes. Moreover, the disease prognosis was considered good when logit(P) ≥-2.5105. Overall, the model displayed a certain clinical value. This study was approved by the Biomedical Ethics Committee of the Second Affiliated Hospital of Xi'an Jiaotong University, China(approval number: 2018063) on May 8, 2018.展开更多
The effects of Ho substitution for Nd on the microstructure, corrosion resistance and thermal stability of the Nd-Fe-B magnets were investigated. The（Nd,Ho）-O phase was formed with increasing Ho substitution. The re...The effects of Ho substitution for Nd on the microstructure, corrosion resistance and thermal stability of the Nd-Fe-B magnets were investigated. The（Nd,Ho）-O phase was formed with increasing Ho substitution. The results of potentiodynamic polarization and highly accelerated stress test show improved corrosion resistance with increasing Ho substitution. The optimum mass loss 0.29 mg/cm^2 is achieved.Moreover, the average temperature coefficients for remanence and coercivity in the range of 25-150℃are both closer to zero, indicating improved thermal stability. The mechanisms for the improved corrosion resistance and thermal stability are discussed in relation to the microstructure featuring the（Nd,Ho）-O phase.展开更多
Magnesium and its alloys,as a promising class of materials,is popular in lightweight application and biomedical implants due to their low density and good biocompatibility.Additive manufacturing(AM)of Mg and its alloy...Magnesium and its alloys,as a promising class of materials,is popular in lightweight application and biomedical implants due to their low density and good biocompatibility.Additive manufacturing(AM)of Mg and its alloys is of growing interest in academia and industry.The domain-by-domain localized forming characteristics of AM leads to unique microstructures and performances of AM-process Mg and its alloys,which are different from those of traditionally manufactured counterparts.However,the intrinsic mechanisms still remain unclear and need to be in-depth explored.Therefore,this work aims to discuss and analyze the possible underlying mechanisms regarding defect appearance and elimination,microstructure formation and evolution,and performance improvement,based on presenting a comprehensive and systematic review on the relationship between process parameters,forming quality,microstructure characteristics and resultant performances.Lastly,some key perspectives requiring focus for further progression are highlighted to promote development of AM-processed Mg and its alloys and accelerate their industrialization.展开更多
Herbgenomics is an emerging field of traditional Chinese medicine(TCM)research and development.By combining TCM research with genomics,herbgenomics can help to establish the scientific validity of TCM and bring it int...Herbgenomics is an emerging field of traditional Chinese medicine(TCM)research and development.By combining TCM research with genomics,herbgenomics can help to establish the scientific validity of TCM and bring it into wider usage within the field of medicine.Salvia Linn.(S.Linn.)is a large genus of Labiatae that includes important medicinal plants.In this herbgenomics study,the complete chloroplast(cp)genomes of two Salvia spp.—namely,S.przewalskii and S.bulleyana,which are used as a surrogate for S.miltiorrhiza—were sequenced and compared with those of two other reported Salvia spp.—namely,S.miltiorrhiza and S.japonica.The genome organization,gene number,type,and repeat sequences were compared.The annotation results showed that both Salvia plants contain 114 unique genes,including 80 protein-coding,30 transfer RNA(tRNA),and four ribosomal RNA(rRNA)genes.Repeat sequence analysis revealed 21 forward and 22 palindromic sequences in both Salvia cp genomes,and 17 and 21 tandem repeats in S.przewalskii and S.bulleyana,respectively.A synteny comparison of the Salvia spp.cp genomes showed a high degree of sequence similarity in the coding regions and a relatively high divergence of the intergenic spacers.Pairwise alignment and single-nucleotide polymorphism(SNP)analyses found some candidate fragments to identify Salvia spp.,such as the intergenic region of the trnV–ndhC,trnQ–rps16,atpI–atpH,psbA–ycf3,ycf1,rpoC2,ndhF,matK,rpoB,rpoA,and accD genes.All of the results—including the repeat sequences and SNP sites,the inverted repeat(IR)region border,and the phylogenetic analysis—showed that S.przewalskii and S.bulleyana are extremely similar from a genetic standpoint.The cp genome sequences of the two Salvia spp.reported here will pave the way for breeding,species identification,phylogenetic evolution,and cp genetic engineering studies of Salvia medicinal plants.展开更多
Oxygen electrocatalysis,exemplified by the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is central to energy storage and conversion technologies such as fuel cells,metal-air batteries,and water ele...Oxygen electrocatalysis,exemplified by the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is central to energy storage and conversion technologies such as fuel cells,metal-air batteries,and water electrolysis.However,highly effective and inexpensive earth-abundant materials are sought after to replace the noble metal-based electrocatalysts currently in use.Recently,metal-organic frameworks(MOFs)and carbon-based MOF derivatives have attracted considerable attention as efficient catalysts due to their exceedingly tunable morphologies,structures,compositions,and functionalization.Here,we report two-dimensional(2D)MOF/MOF derivative coupled arrays on nickel foam as binder-free bifunctional ORR/OER catalysts with enhanced electrocatalytic activity and stability.Their remarkable electrochemical properties are primarily attributed to fully exposed active sites and facilitated charge-transfer kinetics.The coupled and hierarchical nanosheet arrays produced via our growth-pyrolysis-regrowth strategy offer promise in the development of highly active electrodes for energy-related electrochemical devices.展开更多
By intergranular addition of Pr-Cu-Ti alloy powders in the Nd-Fe-B sintered magnets with the normal B component,we propose an approach to the optimization of grain boundary and local Nd-Fe-B composition system.The coe...By intergranular addition of Pr-Cu-Ti alloy powders in the Nd-Fe-B sintered magnets with the normal B component,we propose an approach to the optimization of grain boundary and local Nd-Fe-B composition system.The coercivity is enhanced from 1.42 to 1.86 T,while further addition leads to a reduction in remanence and coercivity.The analyses of phase composition reveal that Ti mainly exists in the form of metallic Ti alloy,and part of Ti combines with B to form the TiB2 phase after the liquid phase sintering process.This process results in a consumption of B in the local Nd-Fe-B composition system and a change of the grain boundary component,which contributes to the formation process of the RE_(6)(Fe,M)_(14) phase after the annealing process.Therefore,with the modification of grain boundary and composition system,the intergranular addition of Pr-Cu-Ti induces the generation of continuous thin grain boundary phases.It promotes the intergrain exchange decoupling,increasing the coercivity in the annealed magnet.While the excess addition results in the segregation of TiB_(2),as well as the precipitation of TiB_(2) into the Nd-Fe-B phase,which leads to structural defects.Thus,the further effort for the addition alloy with Ti to reduce the deterioration of the microstructure will lead to further improvement in magnetic properties.展开更多
In order to solve the problem that current theory models cannot accurately describe thick-hard roof(THR)elastic energy and assess the mine tremor disasters,a theoretical method,a Timoshenko beam theory on Winkler foun...In order to solve the problem that current theory models cannot accurately describe thick-hard roof(THR)elastic energy and assess the mine tremor disasters,a theoretical method,a Timoshenko beam theory on Winkler foundation was adopted to establish the THR’s periodic breaking model.The superposition principle was used for this complex model to derive the calculation formulas of the elastic energy and impact load on hydraulic supports.Then,the influence of roof thickness h,cantilever length L_(1),and load q on THR’s elastic energy and impact load was analyzed.And,the effect of mine tremor disasters was assessed.Finally,it is revealed that:(1)The THR’s elastic energy U exhibits power-law variations,with the fitted relationships U=0.0096L_(1)^(3.5866^),U=5943.9h^(-1.935),and U=21.049q^(2).(2)The impact load on hydraulic supports F_(ZJ) increases linearly with an increase in the cantilever length,thickness,and applied load.The fitted relationships are F_(ZJ)=1067.3L_(1)+6361.1,F_(ZJ)=125.89h+15100,and F_(ZJ)=10420q+3912.6.(3)Ground hydraulic fracturing and liquid explosive deep-hole blasting techniques effectively reduce the THR’s cantilever length at periodic breakages,thus eliminating mine tremor disasters.展开更多
Low cost and high abundance rare earth elements Y and Ce have attracted tremendous interests of the industrial and scientific societies for fabricating the highly cost-performance efficient rare earth permanent magnet...Low cost and high abundance rare earth elements Y and Ce have attracted tremendous interests of the industrial and scientific societies for fabricating the highly cost-performance efficient rare earth permanent magnets.However,the effect of separate replacement of Nd by Y or Ce on the performances of NdFeB-type magnet under the same atomic ratio and preparation conditions is still unclear.In this work,we systematically investigated the magnetic properties,thermal stabilities and service performances of(Nd_(0.8)Y_(0.2))_(13.80)Fe_(bal)Al_(0.24)Cu_(0.1)B_(6.04)(atomic fraction,denoted as 20 Y)and(Nd_(0.8)Ce_(0.2))_(13.80)Fe_(bal)Al_(0.24)Cu_(0.1)B_(6.04)(atomic fraction,denoted as 20 Ce)magnets.The results demonstrate that theμ_(0)M_(r),μ_(0)H_(c)and(BH)_(max)of 20 Y magnet are respectively 1.325 T,1.173 T and 343.467 kJ/m^(3),which are comprehensively higher than those of 20 Ce magnet(μ_(0)M_(r)=1.310 T,μ_(0)H_(c)=0.948 T,(BH)_(max)=321.105 kJ/m^(3)).Moreover,the 20 Y magnet has higher thermal stability compared with 20 Ce magnet which is favorable for the magnetic performances at elevated temperatures.The investigation of micro structure and elemental distribution indicates that the excellent magnetic performance s of NdY-Fe-B magnet can be attributed not only to the preferable intrinsic properties4πM_(s),H_(s)and T_(c)of Y_(2)Fe_(14)B,but also to the in-situ co re-shell structure of the 2:14:1 matrix phase grain with Yrich core and Nd-rich shell,along with the thicker grain boundary layer between the adjacent matrix phase grains in NdY-Fe-B magnet.Furthermore,the 20 Y magnet exhibits better mechanical property and higher corrosion resistance than 20 Ce magnet,which are helpful for prolonging the service life of the magnet in practical application.展开更多
In this study,element geochemistry and zircon chronology are used to analyze the Oligocene sediments in the Baiyun Sag,Zhujiang River Mouth Basin.The experimental results are discussed with respect to weathering condi...In this study,element geochemistry and zircon chronology are used to analyze the Oligocene sediments in the Baiyun Sag,Zhujiang River Mouth Basin.The experimental results are discussed with respect to weathering conditions,parent rock lithologies,and provenances.The chemical index of alteration and the chemical index of weathering values of mudstone samples from the lower Oligocene Enping Formation indicate that clastic particles in the study area underwent moderate weathering.Mudstone samples exhibit relatively enriched light rare earth elements and depleted heavy rare earth elements,"V"-shaped negative Eu anomalies,and negligible Ce anomalies.The rare earth element distribution curves are obviously right-inclined,with shapes and contents similar to those of post-Archean Australian shale and upper continental crust,indicating that the samples originated from acid rocks in the upper crust.The Hf-La/Th and La/Sc-Co/Th diagrams show this same origin for the sediments in the study area.For the samples from the upper Enping deltas,the overall age spectrum shows four major age peaks ca.59–68 Ma,98–136 Ma,153–168 Ma and 239–260 Ma.For the Zhuhai Formation samples,the overall age spectrum shows three major age peaks ca.149 Ma,252 Ma and 380 Ma.The detrital zircon shapes and U-Pb ages reveal that during Oligocene sedimentation,the sediments on the northwestern margin of the Baiyun Sag were supplied jointly from two provenances:Precambrian-Paleozoic metamorphic rocks in the extrabasinal South China fold zone and Mesozoic volcanic rocks in the intrabasinal Panyu Low Uplift,and the former supply became stronger through time.Thus,the provenance of the Oligocene deltas experienced a transition from an early proximal intrabasinal source to a late distal extrabasinal source.展开更多
基金Project supported by the National Key Research and Development Program of China(2021YFB3502803)The"Pioneer"and"Leading Goose"R&D program of Zhejiang(2022C01020)+3 种基金Science and Technology Program of Zhejiang Province(2024C01145)The Key Research and Development Program of Ningbo City(2023Z093)Kunpeng Plan of Zhejiang ProvinceNingbo Top Talent Program。
文摘Obtaining high magnetic properties in high Ce-content magnets is essential to expand the widespread application of low-cost magnets.In this study,high Ce-content magnets with up to 45%Ce substitution for Nd were prepared by combining the single/dual/multi-main-phase processes with the Dy-containing grain boundary diffusion process(GBDP).The effects of base magnets with different Ce distributions on GBDP were systematically investigated.Magnetic properties and micro structure analysis reveal that high-performance multi-main-phase(MMP)diffused magnets with remanence(Br)up to 12.52 kGs,coercivity up to 16.08 kOe,and maximum magnetic energy product up to 36.44 MGOe are obtained,which is attributed to the regulation of Ce by the MMP process,and the optimization of microstructure by Gd-Cu alloy.Meanwhile,the diffusion efficiency is significantly improved because of Ce being restricted to the grain core,which promotes the formation of a continuous structure at the grain boundaries,and the formation of a continuous multilayer shell grain structure with high anisotropy field,while the Br of the diffused magnet is maintained.Besides,magnetic domain analysis shows that the MMP diffused magnet effectively suppresses the nucleation of demagnetized domains and enhances the pinning effect of domain walls.The study establishes an experimental foundation for the development of sintered high Ce-content magnets showcasing superior performance.
基金supported by the National Key Research And Development Plan, China (No. 2016YFB1100100)the Research Fund of the State Key Laboratory of Solidification Processing (NWPU), China (No. KP201611)the National Natural Science Foundation of China (No. 51475380)
文摘Laser cladding deposited Ti-6Al-4V titanium alloy universally shows more complex microstructures,each of which has significant effect on mechanical properties. Of particular α/β interface phase has been observed in this paper under certain conditions. It demonstrates that the influence of the α/β interface phase on the tensile properties is closely associated with dislocations and twin substructure through comparison experiments. The results show that the α/β interface phase hinders dislocation motion and decreases effective slip length. In addition, the twin substructure has been activated in the α/β interface phase during tensile process and has acted somehow like grain boundaries. Therefore, the strength and the work-hardening rate of the laser cladding deposited Ti-6Al-4V titanium alloy have been significantly improved due to the dynamic Hall-Petch effect. Besides, the α/β interface phase leads to more uniform dislocations distribution, which implies that relative lower local concentrated stress will be produced along the α/β interface phase or colony boundary after the same amount of plastic deformation. Moreover,the twinning-induced plasticity effects in the α/β interface phase further increase the plastic deformation capacity. These results in higher elongation for the laser cladding deposited Ti-6Al-4V titanium alloy.It can be concluded that the current work suggests an effective method to simultaneously improve the strength and plasticity of laser cladding deposited Ti-6Al-4V titanium alloy based on the α/β interface phase.
基金supported by the National Natural Science Foundation of China(Nos.82374028 and 81803957)。
文摘Matrix-assisted laser desorption/ionization(MALDI)mass spectrometry imaging(MSI)is an attractive technology for the visualization of metabolite distributions in tissues.However,detection and identification of low-abundance or poorly ionized metabolites remains challenging.Although on-tissue chemical derivatization(OTCD)holds great promise for improving MALDI MS detection sensitivity and selectivity by modification of specific chemical groups,the available methods for subsequent metabolite annotation are limited.Herein,a laser-assisted chemical transfer(LACT)-based parallel OTCD strategy was established for visualizing and annotating carbonyl metabolites in murine brain tissues.Girard's T and Girard's P reagents were applied for parallel OTCD to generate the characteristic m/z pairs with a 19.969 Da mass shift(±0.020 Da tolerance)for rapid recognition of derivatized metabolites.The similarity of spatial distribution patterns of each m/z pair was further statistically evaluated to remove the ambiguous annotations due to the occurrence of interference compounds.As a result,90 ion pairs were annotated as candidate carbonyl metabolites,66 were previously known and 24 were potential unreported carbonyls.Furthermore,the spatial alterations of carbonyl metabolites in the ischemic rat brain were successfully visualized and characterized,including small molecule aldehydes and ketones,long-chain fatty aldehydes,and monosaccharides.This further emphasizes great potential of parallel OTCD strategy for efficient and confident molecular annotation of spatial submetabolomics data associated with brain diseases.
基金supported by the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(No.2017-12M-3-002)the National Key R&D Program of China(No.2020YFC2008100).
文摘Background Based on the China-VHD database,this study sought to develop and validate a Valvular Heart Disease-specific Age-adjusted Comorbidity Index(VHD-ACI)for predicting mortality risk in patients with VHD.Methods&Results The China-VHD study was a nationwide,multi-centre multi-centre cohort study enrolling 13,917 patients with moderate or severe VHD across 46 medical centres in China between April-June 2018.After excluding cases with missing key variables,11,459 patients were retained for final analysis.The primary endpoint was 2-year all-cause mortality,with 941 deaths(10.0%)observed during follow-up.The VHD-ACI was derived after identifying 13 independent mortality predictors:cardiomyopathy,myocardial infarction,chronic obstructive pulmonary disease,pulmonary artery hypertension,low body weight,anaemia,hypoalbuminaemia,renal insufficiency,moderate/severe hepatic dysfunction,heart failure,cancer,NYHA functional class and age.The index exhibited good discrimination(AUC,0.79)and calibration(Brier score,0.062)in the total cohort,outperforming both EuroSCORE II and ACCI(P<0.001 for comparison).Internal validation through 100 bootstrap iterations yielded a C statistic of 0.694(95%CI:0.665−0.723)for 2-year mortality prediction.VHD-ACI scores,as a continuous variable(VHD-ACI score:adjusted HR(95%CI):1.263(1.245-1.282),P<0.001)or categorized using thresholds determined by the Yoden index(VHDACI≥9 vs.<9,adjusted HR(95%CI):6.216(5.378-7.184),P<0.001),were independently associated with mortality.The prognostic performance remained consistent across all VHD subtypes(aortic stenosis,aortic regurgitation,mitral stenosis,mitral regurgitation,tricuspid valve disease,mixed aortic/mitral valve disease and multiple VHD),and clinical subgroups stratified by therapeutic strategy,LVEF status(preserved vs.reduced),disease severity and etiology.Conclusion The VHD-ACI is a simple 13-comorbidity algorithm for the prediction of mortality in VHD patients and providing a simple and rapid tool for risk stratification.
基金Project supported by the National Key R&D Program of China(2022YFB3505003,2021YFB3502802)the Natural Science Foundation of Zhejiang Province(LQ23E010001)+3 种基金"Pioneer"and"Leading Goose"R&D program of Zhejiang(2022C01020)Key Research and Development Program of Ningbo City(2023Z093)Kunpeng Plan of Zhejiang ProvinceNingbo Top Talent Program。
文摘Commercial N52 sintered NdFeB magnets were processed by grain boundary diffusion(GBD)with Dy-Co-M(M=Cu,AI)alloys.The coercivity of magnets greatly increase to 17.62 and 18.83 kOe respectively when diffusing Dy_(58)Co_(25)Cu_(17)and Dy_(58)Co_(25)Al_(17)alloys,which are obviously higher than that of Dy58Co42GBD-treated magnet with 16.64 kOe,Further thermal stability studies indicate that the thermal stability of Dy_(58)Co_(25)Cu_(17)and Dy_(58)Co_(25)Al_(17)GBD-treated magnets is further improved compared to the Dy58Co42GBD-treated magnet The results show that th e temperature coefficients of remanence(20-120℃)are reduced from-0.148%/℃to-0.134%/℃and-0.132%/℃by Dy_(58)Co_(25)Cu_(17)and Dy_(58)Co_(25)Al_(17)GBD-treatment,respectively.Besides,the irreversible magnetic flux losses(120℃)for Dy_(58)Co_(25)Cu_(17)and Dy_(58)Co_(25)Al_(17)diffusion magnets are 4.76%and 2.79%,respectively.Microstructural analyses demonstrate that the presence of Cu and Al elements reduces the excessive accumulation of Dy and Co on the surface in the diffusion magnets an d improves the diffusion depth and utilization of Dy and Co.Furthermore,the flow of Co from the triple junction phase to the thin grain boundary phase is promoted,which contributes to the uniform distribution of Co.In addition,the dynamic evolution of the magnetic domain structure during the temperature rise process was studied.This work provides insight into the preparation of high-performance and high-thermal stability magnets.
基金supported by National Key Research and Development Program of China(Grant No.2022YFB4602301)the National Natural Science Foundation of China(Grant Nos.52405371,52275381,52174346)+1 种基金the Training Program of Innovation and Entrepreneurship for Undergraduates(Grant No.CXCY2024027)We thank Qian Wang(Northwestern Polytechnical University),Yida Feng(Liaocheng University),Jingdong Ma(Liaocheng University),and Keri Xiaoqiangshiyao(Liaocheng University)for their support of this research.
文摘Although 316L stainless steel(SS316L)exhibits favorable ductility and toughness,its limited strength restricts its applicability.This study addressed this limitation by preparing a series of SS316L-xTC4 alloys(where x indicates Ti6Al4V(TC4)contents of 0.5 wt%,1 wt%,2 wt%,and 4 wt%)with equiaxed grains,ultrafine grains,and heterogeneous structures using in-situ alloying via laser powder bed fusion.The Ti,Al,and V in the TC4 alloy were shown to stabilize and promote the formation of theαphase,which is stronger than theγphase in typical SS316L.Furthermore,these solute elements readily formed nanoparticles with impurities,such as C and O,to increase the nucleation rate and thereby achieve grain refinement.This resulted in the formation of ultrafine grains predominantly within theαphase,where the solute elements were primarily distributed.The formation of theαphase also impeded the growth of theγphase;coupled with the effects of the nanoparticles,this also significantly reduced the grain size in theγphase.Notably,the SS316L-2TC4 alloy exhibited fully equiaxed grains,and the coexistence of theαandγphases as well as ultrafine and coarse grains formed heterogeneous grain and dual-phase structures within.The synergistic effects of equiaxed grains,ultrafine grains,and heterostructures produced an SS316L alloy that exhibited both excellent strength and elongation.
基金supported by the National Key Research and Development Program of China(No.2021YFB3502802)Zhejiang Provincial Department of Science and Technology of China(No.2022C01020)+3 种基金the Key Research and Development Program of Ningbo City(No.2023Z093)Ningbo Natural Science Foundation(No.2023J344)the Natural Science Foundation of Zhejiang Province(No.LQ23E010001)Ningbo Young Science and Technology Innovation Leading Talents(No.2023QL040).
文摘By developing high comprehensive performance((BH)_(max)+H_(cj)),Nd-Fe-B magnets can operate stably in high-temperature applications,greatly expanding the application scenarios of them.Unfortunately,there is a constraint relationship between coercivity(H_(cj))and maximum magnetic energy product((BH)_(max)),and an increase in H_(cj) always accompanies a decrease in(BH)_(max).Here,the excellent comprehensive magnetic performance of up to 86.54,namely(BH)_(max) of 42.33 MGOe and H_(cj) of 44.21 kOe,is unprecedented in the sintered Nd-Fe-B magnets.This magnet is obtained by designing a unique grain structure through micrometallurgical reactions to prepare a matrix with excellent comprehensive performance,and then by stepwise diffusion,the(BH)_(max) and H_(cj) of the magnet are simultaneously enhanced.The magnet prepared in this way has a“double-shell core”structure and Tb segregation distribution inside the core.The working temperature of the magnet in this work reached 280℃,providing a new approach for the development of high-performance Nd-Fe-B magnets.
基金supported by the Shanghai Municipal Economic and Information Commission(Project No.240404).
文摘This paper studies a mirror-assisted rehabilitation training method based on a dual-arm robot,which aims to provide an effective rehabilitation training program for patients with upper limb dysfunction due to stroke or other causes.During the mirror training task scenario,the subjects are visually guided to perform the mirror movement of both arms,and the dual-arm robot is used to facilitate the mirror-assisted rehabilitation from the healthy side to the affected side.Adaptive imped-ance control and force field channel design ensure the stability and safety of the rehabilitation process.In the rehabilitation training,appropriate assistance forces are provided within the channel to correct trajectory deviations,ensuring that the subjects'movement path aligns with the predetermined trajectory.Outside the channel,the superposition of stiffness and correction force fields prevents the subjects from deviating from the predetermined trajectory,thus avoiding injuries.In addition,the adaptive impedance control is capable of dynamically adjusting the impedance parameters according to the real-time state of the subjects,providing a personalized rehabilitation training program.This method significantly enhances both the safety and effectiveness of the rehabilitation training.The experimental results showed that the subjects'motion flexibility and safety were significantly improved during the mirror-assisted rehabilitation training.This study offers a new approach for the future development of rehabilitation robotics with broad application potential.
基金Supported by Liaoning S and T Project,No.2015020269Doctor fund of Liaoning Province Cancer Hospital and Institute,No.Z1410
文摘AIM To investigate the relationship between hypoxia-inducible factor-1α(HIF-1α), prolyl 4-hydroxylase beta(P4 HB) expression, and clinicopathologic parameters, as well as the prognostic value of these genes for patients with gastric cancer(Gc).METHODS Hypoxia is a critical factor that shapes the Gc microenvironment. In previous reports, we have demonstrated that P4 HB is a potential target of HIF-1α. In the present study, gene expression profiling interactive analysis(GEPIA) was used to analyze the relationship between P4 HB and hypoxia-associated genes. To this end, 428 Gc tissue samples were used to analyze the expression of HIF-1α and P4 HB via immunohistochemical staining. Patient samples were classified as having weak-expression or over-expression both in terms of HIF-1α and P4 HB. Correlations between biomarkers and clinicopathological factors were analyzed to predict survival. RESULTS P4 HB demonstrated a positive correlation with hypoxiaassociated genes(P < 0.05). HIF-1α and P4 HB overexpression have a significant correlation with TNM staging(χ2 = 23.32, P = 0.00; χ2 = 65.64, P = 0.00) and peritoneum cavity metastasis(χ2 = 12.67, P = 0.00; χ2 = 39.29, P = 0.00). In univariate analysis, patients with a high HIF-1α expression trend had a shorter disease-free survival(DFS: 44.80 mo vs 22.06 mo) and overall survival(OS: 49.58 mo vs 39.92 mo). P4 HB overexpression reflected similar results: patients with over-expression of P4 HB had a shorter survival time than those with weak-expression(DFS: 48.03 mo vs 29.64 mo, OS: 52.48 mo vs 36.87 mo). Furthermore, HIF-1α is also a clinicopathological predictor of dismal prognosis according to multivariate analysis(DFS, 95%c I: 0.52-0.88, P < 0.00; OS, 95%c I: 0.50-0.85, P < 0.00). However, P4 HB was meaningful in DFS(95%c I: 0.58-1.00, P < 0.05) but not in OS(95%c I: 0.72-1.23, P > 0.05).CONCLUSION Overexpression of HIF-1α and P4 HB is associated with poor prognosis in patients with Gc. Thus, these genes may be potential prognostic biomarker candidates in GC.
文摘Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.Around the beginning of this century,China Academy of Engineering Physics(CAEP)began to build some experimental facilities for HEDP investigations,among which the Primary Test Stand(PTS),a multi-module pulsed power facility with a nominal current of 10 MA and a current rising time~90 ns,is an important achievement on the roadmap of the electro-magnetically driven inertial confinement fusion(ICF)researches.PTS is the first pulsed power facility beyond 10 TW in China.Therefore,all the technologies have to be demonstrated,and all the engineering issues have to be overcome.In this article,the research outline,key technologies and the preliminary HEDP experiments are reviewed.Prospects on HEDP research on PTS and pulsed power development for the next step are also discussed.
基金Supported by Liaoning S&T Project,No.20180550971 and No.20170520447CSCO-MERCK SERNO oncology research fund,No.Y-MX2016-031
文摘BACKGROUNDLong noncoding RNAs (lncRNAs) are aberrant and play critical roles in gastriccancer (GC) progression and metastasis. Searching for coexpressed lncRNAclusters or representative biomarkers related to malignant phenotypes of GC mayhelp to elucidate the mechanism of tumor development and predict the prognosisof GC.AIMTo investigate the prognostic value of NOTCH1 associated with lncRNA in T cellacute lymphoblastic leukemia 1 (NALT1) in GC and the mechanism of itsinvolvement in GC invasion and metastasis.METHODSRNA sequencing and corresponding clinical data were downloaded from TheCancer Genome Atlas database. The significance module was studied byweighted gene coexpression network analysis. A total of 336 clinical sampleswere included in the study. Gene silencing, reverse transcription polymerasechain reaction, western blotting, scrape motility assay, and Transwell migrationassay were used to assess the function of hub-lncRNAs.RESULTSAt the transcriptome level, 3339 differentially expressed lncRNAs were obtained.weighted gene coexpression network analysis was used to obtain 15 lncRNAclusters and observe their coexpression. Pearson’s correlation showed that blue module was correlated with tumor grade and survival. NALT1 was the hublncRNAof blue module and was an independent risk factor for GC prognosis.NALT1 was overexpressed in GC and its expression was closely related toinvasion and metastasis. The mechanism may involve NALT1 regulation ofNOTCH1, which is associated with lncRNA in T cell acute lymphoblasticleukemia, through cis regulation, thereby affecting the expression of the NOTCHsignaling pathway.CONCLUSIONNALT1 is overexpressed and promotes invasion and metastasis of GC. Themechanism may be related to regulation of NOTCH1 by NALT1 and its effect onNOTCH signaling pathway expression.
基金supported by the National Natural Science Foundation of China,No.30672136(to HPL)
文摘Some studies have suggested that early surgical treatment can effectively improve the prognosis of cervical spinal cord injury without radiological abnormality, but no research has focused on the development of a prognostic model of cervical spinal cord injury without radiological abnormality. This retrospective analysis included 43 patients with cervical spinal cord injury without radiological abnormality. Seven potential factors were assessed: age, sex, external force strength causing damage, duration of disease, degree of cervical spinal stenosis, Japanese Orthopaedic Association score, and physiological cervical curvature. A model was established using multiple binary logistic regression analysis. The model was evaluated by concordant profiling and the area under the receiver operating characteristic curve. Bootstrapping was used for internal validation. The prognostic model was as follows: logit(P) =-25.4545 + 21.2576 VALUE + 1.2160SCORE-3.4224 TIME, where VALUE refers to the Pavlov ratio indicating the extent of cervical spinal stenosis, SCORE refers to the Japanese Orthopaedic Association score(0–17) after the operation, and TIME refers to the disease duration(from injury to operation). The area under the receiver operating characteristic curve for all patients was 0.8941(95% confidence interval, 0.7930–0.9952). Three factors assessed in the predictive model were associated with patient outcomes: a great extent of cervical stenosis, a poor preoperative neurological status, and a long disease duration. These three factors could worsen patient outcomes. Moreover, the disease prognosis was considered good when logit(P) ≥-2.5105. Overall, the model displayed a certain clinical value. This study was approved by the Biomedical Ethics Committee of the Second Affiliated Hospital of Xi'an Jiaotong University, China(approval number: 2018063) on May 8, 2018.
基金Project supported by the Ningbo Major Technology Innovation Projects(2017B10005)Ningbo Natural Science Foundation(2015A610011)Guangxi Science and Technology Project(2016AD05041)
文摘The effects of Ho substitution for Nd on the microstructure, corrosion resistance and thermal stability of the Nd-Fe-B magnets were investigated. The（Nd,Ho）-O phase was formed with increasing Ho substitution. The results of potentiodynamic polarization and highly accelerated stress test show improved corrosion resistance with increasing Ho substitution. The optimum mass loss 0.29 mg/cm^2 is achieved.Moreover, the average temperature coefficients for remanence and coercivity in the range of 25-150℃are both closer to zero, indicating improved thermal stability. The mechanisms for the improved corrosion resistance and thermal stability are discussed in relation to the microstructure featuring the（Nd,Ho）-O phase.
基金supported by Scientific Research Program Funded by Shaanxi Provincial Education Department(Program No.22JK0479)Research Start-up Project of Xi’an University of Technology(Grant No.101-256082204)+5 种基金International Science and Technology Cooperation Program of Shaanxi Province(No.2023-GHZD-50)Project of Science and Technology Shaanxi Province(No.2023-JC-YB-412)Project of Science and Technology Shaanxi Province(No.2023-JC-QN-0573)Projects of Major Innovation Platforms for Scientific and Technological and Local Transformation of Scientific and Technological Achievements of Xi’an(No.20GXSF0003)Projects of Major Scientific and Technological Achievements Local Transformation of Xi’an(No.2022JHZDZH-0039)Higher Education Institution Discipline Innovation and Intelligence Base of Shaanxi Provincial(No.S2021-ZC-GXYZ-0011).
文摘Magnesium and its alloys,as a promising class of materials,is popular in lightweight application and biomedical implants due to their low density and good biocompatibility.Additive manufacturing(AM)of Mg and its alloys is of growing interest in academia and industry.The domain-by-domain localized forming characteristics of AM leads to unique microstructures and performances of AM-process Mg and its alloys,which are different from those of traditionally manufactured counterparts.However,the intrinsic mechanisms still remain unclear and need to be in-depth explored.Therefore,this work aims to discuss and analyze the possible underlying mechanisms regarding defect appearance and elimination,microstructure formation and evolution,and performance improvement,based on presenting a comprehensive and systematic review on the relationship between process parameters,forming quality,microstructure characteristics and resultant performances.Lastly,some key perspectives requiring focus for further progression are highlighted to promote development of AM-processed Mg and its alloys and accelerate their industrialization.
基金This work is supported by the National Nature Science Foundation of China(QFSL2018004,2017YFC1702100,and 81741060)the Fundamental Research Funds for the Central Public Welfare Research Institutes(ZXKT17004).
文摘Herbgenomics is an emerging field of traditional Chinese medicine(TCM)research and development.By combining TCM research with genomics,herbgenomics can help to establish the scientific validity of TCM and bring it into wider usage within the field of medicine.Salvia Linn.(S.Linn.)is a large genus of Labiatae that includes important medicinal plants.In this herbgenomics study,the complete chloroplast(cp)genomes of two Salvia spp.—namely,S.przewalskii and S.bulleyana,which are used as a surrogate for S.miltiorrhiza—were sequenced and compared with those of two other reported Salvia spp.—namely,S.miltiorrhiza and S.japonica.The genome organization,gene number,type,and repeat sequences were compared.The annotation results showed that both Salvia plants contain 114 unique genes,including 80 protein-coding,30 transfer RNA(tRNA),and four ribosomal RNA(rRNA)genes.Repeat sequence analysis revealed 21 forward and 22 palindromic sequences in both Salvia cp genomes,and 17 and 21 tandem repeats in S.przewalskii and S.bulleyana,respectively.A synteny comparison of the Salvia spp.cp genomes showed a high degree of sequence similarity in the coding regions and a relatively high divergence of the intergenic spacers.Pairwise alignment and single-nucleotide polymorphism(SNP)analyses found some candidate fragments to identify Salvia spp.,such as the intergenic region of the trnV–ndhC,trnQ–rps16,atpI–atpH,psbA–ycf3,ycf1,rpoC2,ndhF,matK,rpoB,rpoA,and accD genes.All of the results—including the repeat sequences and SNP sites,the inverted repeat(IR)region border,and the phylogenetic analysis—showed that S.przewalskii and S.bulleyana are extremely similar from a genetic standpoint.The cp genome sequences of the two Salvia spp.reported here will pave the way for breeding,species identification,phylogenetic evolution,and cp genetic engineering studies of Salvia medicinal plants.
文摘Oxygen electrocatalysis,exemplified by the oxygen reduction reaction(ORR)and oxygen evolution reaction(OER),is central to energy storage and conversion technologies such as fuel cells,metal-air batteries,and water electrolysis.However,highly effective and inexpensive earth-abundant materials are sought after to replace the noble metal-based electrocatalysts currently in use.Recently,metal-organic frameworks(MOFs)and carbon-based MOF derivatives have attracted considerable attention as efficient catalysts due to their exceedingly tunable morphologies,structures,compositions,and functionalization.Here,we report two-dimensional(2D)MOF/MOF derivative coupled arrays on nickel foam as binder-free bifunctional ORR/OER catalysts with enhanced electrocatalytic activity and stability.Their remarkable electrochemical properties are primarily attributed to fully exposed active sites and facilitated charge-transfer kinetics.The coupled and hierarchical nanosheet arrays produced via our growth-pyrolysis-regrowth strategy offer promise in the development of highly active electrodes for energy-related electrochemical devices.
基金Project supported by Major Project of"Science and Technology Innovation 2025"in Ningbo(2018B10086)Major project of"Inner Mongolia Science and Technology"(2019ZD020)+3 种基金Zhejiang Province Public Welfare Technology Application Research Project(LGG21E010007)Major Scientific and Technological Re search and Development Projects in Jiangxi Province(20203ABC28W006)Kunpeng Project in Zhejiang Province,National Natural Science Foundation of China(52101238)Ningbo Top Talent Program。
文摘By intergranular addition of Pr-Cu-Ti alloy powders in the Nd-Fe-B sintered magnets with the normal B component,we propose an approach to the optimization of grain boundary and local Nd-Fe-B composition system.The coercivity is enhanced from 1.42 to 1.86 T,while further addition leads to a reduction in remanence and coercivity.The analyses of phase composition reveal that Ti mainly exists in the form of metallic Ti alloy,and part of Ti combines with B to form the TiB2 phase after the liquid phase sintering process.This process results in a consumption of B in the local Nd-Fe-B composition system and a change of the grain boundary component,which contributes to the formation process of the RE_(6)(Fe,M)_(14) phase after the annealing process.Therefore,with the modification of grain boundary and composition system,the intergranular addition of Pr-Cu-Ti induces the generation of continuous thin grain boundary phases.It promotes the intergrain exchange decoupling,increasing the coercivity in the annealed magnet.While the excess addition results in the segregation of TiB_(2),as well as the precipitation of TiB_(2) into the Nd-Fe-B phase,which leads to structural defects.Thus,the further effort for the addition alloy with Ti to reduce the deterioration of the microstructure will lead to further improvement in magnetic properties.
基金supported by the Chongqing Postdoctoral Special Support(No.2022CQBSHTB1022)the Autonomous General Projects of State Key Laboratory of Coal Mine Disaster Dynamics and Control(No.2011DA105287-MS202209)the State Key Laboratory of Coal Mine Disaster Dynamics and Control Faces the 2030 project(No.2011DA105287-MX2030-202002).
文摘In order to solve the problem that current theory models cannot accurately describe thick-hard roof(THR)elastic energy and assess the mine tremor disasters,a theoretical method,a Timoshenko beam theory on Winkler foundation was adopted to establish the THR’s periodic breaking model.The superposition principle was used for this complex model to derive the calculation formulas of the elastic energy and impact load on hydraulic supports.Then,the influence of roof thickness h,cantilever length L_(1),and load q on THR’s elastic energy and impact load was analyzed.And,the effect of mine tremor disasters was assessed.Finally,it is revealed that:(1)The THR’s elastic energy U exhibits power-law variations,with the fitted relationships U=0.0096L_(1)^(3.5866^),U=5943.9h^(-1.935),and U=21.049q^(2).(2)The impact load on hydraulic supports F_(ZJ) increases linearly with an increase in the cantilever length,thickness,and applied load.The fitted relationships are F_(ZJ)=1067.3L_(1)+6361.1,F_(ZJ)=125.89h+15100,and F_(ZJ)=10420q+3912.6.(3)Ground hydraulic fracturing and liquid explosive deep-hole blasting techniques effectively reduce the THR’s cantilever length at periodic breakages,thus eliminating mine tremor disasters.
基金Project supported by the Key Research and Development Program of Shandong Province(2019JZZY010321)the Major Project of"Science and Technology Innovation 2025"in Ningbo City(2020Z050)+1 种基金Ningbo Natural Science Foundation(202003N4352)the Science and Technology Major Project of the Jiangbei District of Ningbo(202001A01)。
文摘Low cost and high abundance rare earth elements Y and Ce have attracted tremendous interests of the industrial and scientific societies for fabricating the highly cost-performance efficient rare earth permanent magnets.However,the effect of separate replacement of Nd by Y or Ce on the performances of NdFeB-type magnet under the same atomic ratio and preparation conditions is still unclear.In this work,we systematically investigated the magnetic properties,thermal stabilities and service performances of(Nd_(0.8)Y_(0.2))_(13.80)Fe_(bal)Al_(0.24)Cu_(0.1)B_(6.04)(atomic fraction,denoted as 20 Y)and(Nd_(0.8)Ce_(0.2))_(13.80)Fe_(bal)Al_(0.24)Cu_(0.1)B_(6.04)(atomic fraction,denoted as 20 Ce)magnets.The results demonstrate that theμ_(0)M_(r),μ_(0)H_(c)and(BH)_(max)of 20 Y magnet are respectively 1.325 T,1.173 T and 343.467 kJ/m^(3),which are comprehensively higher than those of 20 Ce magnet(μ_(0)M_(r)=1.310 T,μ_(0)H_(c)=0.948 T,(BH)_(max)=321.105 kJ/m^(3)).Moreover,the 20 Y magnet has higher thermal stability compared with 20 Ce magnet which is favorable for the magnetic performances at elevated temperatures.The investigation of micro structure and elemental distribution indicates that the excellent magnetic performance s of NdY-Fe-B magnet can be attributed not only to the preferable intrinsic properties4πM_(s),H_(s)and T_(c)of Y_(2)Fe_(14)B,but also to the in-situ co re-shell structure of the 2:14:1 matrix phase grain with Yrich core and Nd-rich shell,along with the thicker grain boundary layer between the adjacent matrix phase grains in NdY-Fe-B magnet.Furthermore,the 20 Y magnet exhibits better mechanical property and higher corrosion resistance than 20 Ce magnet,which are helpful for prolonging the service life of the magnet in practical application.
基金The National Natural Science Foundation of China under contract No.91528303the National Science and Technology Major Project under contract Nos 2016ZX05026,2011ZX05025 and 2008ZX05025+1 种基金the National Basic Research Program(973 Program)of China under contract No.2009CB219400the Foundation for Excellent Youth Scholars of NIEER,CAS
文摘In this study,element geochemistry and zircon chronology are used to analyze the Oligocene sediments in the Baiyun Sag,Zhujiang River Mouth Basin.The experimental results are discussed with respect to weathering conditions,parent rock lithologies,and provenances.The chemical index of alteration and the chemical index of weathering values of mudstone samples from the lower Oligocene Enping Formation indicate that clastic particles in the study area underwent moderate weathering.Mudstone samples exhibit relatively enriched light rare earth elements and depleted heavy rare earth elements,"V"-shaped negative Eu anomalies,and negligible Ce anomalies.The rare earth element distribution curves are obviously right-inclined,with shapes and contents similar to those of post-Archean Australian shale and upper continental crust,indicating that the samples originated from acid rocks in the upper crust.The Hf-La/Th and La/Sc-Co/Th diagrams show this same origin for the sediments in the study area.For the samples from the upper Enping deltas,the overall age spectrum shows four major age peaks ca.59–68 Ma,98–136 Ma,153–168 Ma and 239–260 Ma.For the Zhuhai Formation samples,the overall age spectrum shows three major age peaks ca.149 Ma,252 Ma and 380 Ma.The detrital zircon shapes and U-Pb ages reveal that during Oligocene sedimentation,the sediments on the northwestern margin of the Baiyun Sag were supplied jointly from two provenances:Precambrian-Paleozoic metamorphic rocks in the extrabasinal South China fold zone and Mesozoic volcanic rocks in the intrabasinal Panyu Low Uplift,and the former supply became stronger through time.Thus,the provenance of the Oligocene deltas experienced a transition from an early proximal intrabasinal source to a late distal extrabasinal source.
