目的:系统评价培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证的疗效以及证据质量,为临床决策及疾病指南制订提供循证依据。方法:检索中国知网(CNKI)、万方数据库(Wangfang)、Pubmed、Web of Science等8大中英文数据库,由...目的:系统评价培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证的疗效以及证据质量,为临床决策及疾病指南制订提供循证依据。方法:检索中国知网(CNKI)、万方数据库(Wangfang)、Pubmed、Web of Science等8大中英文数据库,由2名研究者独立进行文献筛选、信息提取、偏倚风险评估及方法学质量评价,并对纳入研究的总有效率、中医证候积分、第一秒用力呼气容积(FEV1)、第一秒用力呼气容积/用力肺活量(FEV1/FVC)、哮喘控制测试(ACT)评分等结局指标进行Meta分析,最终依照GRADE评估证据质量。结果:共纳入14项研究,合计1263例患者。结果显示:(1)培土生金中药联合常规西医疗法可有效改善患者总有效率,降低患者中医证候积分,改善患者FEV1水平、FEV1/FVC及ACT评分。(2)总有效率证据质量较优,可信度高,其余指标证据质量较低,尚待更多高质量的研究支持以提升证据级别。结论:培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证优于单用西医常规治疗,且在总有效率上证据质量较高,具有一定的循证学意义。展开更多
The good combination of mechanical and wear properties for cemented carbides is crucial.In this work,the wear behavior of functionally graded cemented carbide(FGCC)and non-graded cemented carbide(CC),with CoNiFeCr mul...The good combination of mechanical and wear properties for cemented carbides is crucial.In this work,the wear behavior of functionally graded cemented carbide(FGCC)and non-graded cemented carbide(CC),with CoNiFeCr multi-principal-element alloy(MPEA)binder,has been investigated by performing sliding wear tests and composition characterization.The results showed that compared with CC,FGCC had higher hardness,stronger fracture toughness,better wear performance,and similar TRS.FGCCs exhibited lower wear rates(3.44×10^(−7)–6.95×10^(−6)mm^(3)/(N m))and coefficients of friction(COFs)(0.27–0.39)than CCs from RT to 600℃due to mitigation of multiple risks caused by binder removal,fragmentation and pull-out of WC grains,high-temperature oxidation and softening.In the low-temperature wear stage,the MPEA binder underwent dynamic recrystallization(DRX)and twinning deformation before removing from the surface.The binder removal caused dislocation pile-ups and stacking faults(SFs)to form under high stress,resulting in fragmentation and pull-out of WC grains.The low-temperature wear was dominated by abrasive wear and adhesive wear,with a low wear rate and a high and unstable COF.In the high-temperature wear stage,initial pitting oxidation of WC grains generated many subgrain boundaries,reducing heat transfer and exacerbating oxidation,resulting in an oxide layer enriched with WO3,Mx Oy,and MWO4.High-temperature wear was dominated by oxidation wear and high-temperature softening,with a high wear rate and a low and smooth COF.The results from the present study do not only provide theoretical guidance for an understanding of the antiwear mechanism of WC-CoNiFeCr,but also a new approach for the preparation of cemented carbides with high wear resistance.展开更多
A sustainable approach for recovering battery grade FePO_(4) and Li_(2)CO_(3) from Al/F-bearing spent LiFePO_(4)/C powder was proposed,including acid leaching,fluorinated coordination precipitation,homogeneous precipi...A sustainable approach for recovering battery grade FePO_(4) and Li_(2)CO_(3) from Al/F-bearing spent LiFePO_(4)/C powder was proposed,including acid leaching,fluorinated coordination precipitation,homogeneous precipitation,and high-temperature precipitation.Under the optimal conditions,the leaching efficiencies of Li,Fe,P,Al,and F were 97.6%,97.1%,97.1%,72.5%,and 63.3%,respectively.The effects of different parameters on the removal of Al/F impurities were systematically evaluated,indicating about 99.4%Al and 96.4%F in the leachate were precipitated in the form of Na_(3)Li_(3)Al_(2)F_(12),and their residual concentrations were only 0.0124 and 0.328 g/L,respectively,which could be directly used to prepare battery grade FePO_(4)(99.68%in purity).Lithium in the Al/F-bearing residue could be extracted through CaCO_(3)−CaSO_(4) roasting followed by acid leaching,ultimately obtaining 99.87%purity of Li_(2)CO_(3).The recovery rates of Li and Fe were 96.88%and 92.85%,respectively.An economic evaluation demonstrated that the process was profitable.展开更多
In the category of general monoid graded rings, we propose a new graded radical, i.e. the graded P radical, obtain the structure theorem of corresponding semisimple graded rings, show that it is a graded special ...In the category of general monoid graded rings, we propose a new graded radical, i.e. the graded P radical, obtain the structure theorem of corresponding semisimple graded rings, show that it is a graded special radical and present the graded module characterization of it. Moreover, we investigate the relations between it and reflect P radical.展开更多
The graded density impactor(GDI)dynamic loading technique is crucial for acquiring the dynamic physical property parameters of materials used in weapons.The accuracy and timeliness of GDI structural design are key to ...The graded density impactor(GDI)dynamic loading technique is crucial for acquiring the dynamic physical property parameters of materials used in weapons.The accuracy and timeliness of GDI structural design are key to achieving controllable stress-strain rate loading.In this study,we have,for the first time,combined one-dimensional fluid computational software with machine learning methods.We first elucidated the mechanisms by which GDI structures control stress and strain rates.Subsequently,we constructed a machine learning model to create a structure-property response surface.The results show that altering the loading velocity and interlayer thickness has a pronounced regulatory effect on stress and strain rates.In contrast,the impedance distribution index and target thickness have less significant effects on stress regulation,although there is a matching relationship between target thickness and interlayer thickness.Compared with traditional design methods,the machine learning approach offers a10^(4)—10^(5)times increase in efficiency and the potential to achieve a global optimum,holding promise for guiding the design of GDI.展开更多
BACKGROUND Endoscopic submucosal dissection(ESD)has become a widely accepted,minimally invasive treatment for gastrointestinal submucosal tumors.It has been reported that humanistic nursing care with graded psychologi...BACKGROUND Endoscopic submucosal dissection(ESD)has become a widely accepted,minimally invasive treatment for gastrointestinal submucosal tumors.It has been reported that humanistic nursing care with graded psychological interventions can effectively enhance patients’physical activity in patients,reduce postoperative complications,and improve their postoperative quality of life.AIM To investigate the effects of combining humanistic care with graded psychological support on nursing satisfaction and quality of life in patients undergoing ESD for gastrointestinal submucosal tumors.METHODS A retrospective analysis was conducted on the clinical data of 180 patients who underwent ESD surgery for gastrointestinal submucosal tumors at our hospital between March 2021 and February 2023.Patients were allocated into groups based on the nursing care they received:The control group,which received routine care(n=90),and the observation group,which was subjected to humanistic nursing care in combination with graded psychological support(n=90).Patient anxiety and depression were assessed using the self-rating anxiety scale(SAS)and self-rating depression scale(SDS).Quality of life was evaluated using the shortform 36 health survey,and additional indications such as time to first food intake,surgery duration,length of hospital stay,nursing satisfaction,and adverse reactions were also recorded.Data was analyzed using SPSS22.0,with t-tests employed for continuous variables andχ2 tests for categorical data.RESULTS Patients in the observation group experienced significantly shorter times to first postoperative meal,surgery,and hospital stay compared to the control group.After the intervention,the SAS score of the observation group was 43.17±5.68,and the SDS score was 41.57±6.52,both significantly lower than those of the control group,with SAS score of 52.38±5.21 and SDS score of 51.23±8.25.In addition,the observation group scored significantly higher in daily living,physical function,psychological well-being,and social functioning(80.01±6.39,83.59±6.89,81.69±5.34,and 85.23±6.05,respectively).Moreover,the observation group also exhibited higher satisfaction and selfefficacy scores and a lower incidence of adverse reactions compared to the control group(P<0.05).CONCLUSION For patients undergoing ESD for gastrointestinal submucosal tumors,humanistic nursing care in combination with graded psychological nursing care significantly shorten the times to first postoperative meal,surgery,and hospital stay,effectively alleviates anxiety and depression,improves quality of life and nursing satisfaction,and mitigate the incidence of adverse reactions.展开更多
Current modifications of Ti-based materials with porous scaffolds for achieving biological fixation often decrease corrosion fatigue strength(σ_(cf))of the resultant implants,thereby shortening their service lifes-pa...Current modifications of Ti-based materials with porous scaffolds for achieving biological fixation often decrease corrosion fatigue strength(σ_(cf))of the resultant implants,thereby shortening their service lifes-pan.To resolve this issue,in the present,a step-wise graded porous Ti-6Al-7Nb scaffold was additively manufactured on optimally surface mechanical attrition treated(SMATed)Ti-6Al-7Nb(specifically de-noted as S-Ti6Al7Nb)using laser powder bed fusion(PBF)technology.The microstructure,bond strength,residual stress distribution,and corrosion fatigue behavior of porous scaffolds modified S-Ti6Al7Nb were investigated and compared with those of mechanically polished Ti-6Al-7Nb(P-Ti6Al7Nb),S-Ti6Al7Nb,and porous scaffolds modified P-Ti6Al7Nb.Results showed that corrosion fatigue of porous scaffolds modi-fied Ti-6Al-7Nb was propagation controlled.Moreover,the crack propagation behavior in the PBF scaf-fold’s fusion zone(FZ)and heat-affected zone(HAZ),exhibiting insensitivity to the microstructural con-figurations characterized by columnar prior-βgrain(PBG)boundaries and acicularα''martensites,cou-pled with the PBF-induced residual tensile stresses in these regions,resulted in a considerable decrease inσ_(cf) for porous scaffolds modified P-Ti6Al7Nb compared to P-Ti6Al7Nb.In contrast,step-wise graded porous scaffold-modified S-Ti6Al7Nb demonstrated an improvedσ_(cf) which was even higher than that of P-Ti6Al7Nb.Such an advancement in corrosion fatigue strength is primarily attributed to the presence of residual compressive stresses within the underlying S-Ti6Al7Nb substrate,extending beyond FZ and HAZ.These stresses increased the crack propagation threshold,leading to crack deflection/branching and increased crack-path tortuosity,thereby synergistically markedly enhancing the crack propagation resis-tance of porous scaffolds modified S-Ti6Al7Nb.展开更多
应用推荐分级的评估、制订和评价(grading of recommendations assessment,development and evaluation,GRADE)系统与中药有效性评价整合证据链法(integrated evidence chain-based effectiveness evaluation of traditional Chinese me...应用推荐分级的评估、制订和评价(grading of recommendations assessment,development and evaluation,GRADE)系统与中药有效性评价整合证据链法(integrated evidence chain-based effectiveness evaluation of traditional Chinese medicine,Eff-iEC)对指南或专家共识推荐频次较高的12种治疗骨质疏松症的常用中成药进行了证据评价。结果显示,仙灵骨葆胶囊/片根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为BA+B^(+)(中级证据);金天格胶囊根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为AA+B(高级证据);骨疏康颗粒/胶囊根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为BA+B^(+)(中级证据);左归丸根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为AA^(++)B^(+)(高级证据);强骨胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AA+B^(+)(高级证据);壮骨止痛胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为BA+B(中级证据);金匮肾气丸根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AA+B(高级证据);全杜仲胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AD+B^(+)(低级证据);淫羊藿总黄酮胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AAB^(+)(高级证据);右归丸根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AA^(++)B^(+)(高级证据);芪骨胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为BB^(+)B(中级证据);六味地黄丸根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为AA^(++)B^(+)(高级证据)。整体而言,Eff-iEC评价体系较GRADE系统能更全面地评价中医药的有效性证据,但仍有不够完善之处,制约其推广应用。在临床证据评价方面,Eff-iEC评价体系与GRADE系统均反映出当前中成药治疗骨质疏松症的临床研究质量普遍较低,未来尚需开展高质量临床试验,进一步验证临床疗效。展开更多
Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy depositio...Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy deposition(EB-DED)technique,including three samples with composition mutation of 100%,composition change rate of 10%and 30%.Results show that the composition-change rate significantly affects the microstructure and mechanical properties of the samples.In the sample with abrupt change of composition,the sharp shift in composition between 304 stainless steel and Mo leads to a great difference in the microstructure and hardness near the interface between the two materials.With the increase in the number of gradient layers,the composition changes continuously along the direction of deposition height,and the microstructure morphology shows a smooth transition from 304 stainless steel to Mo,which is gradually transformed from columnar crystal to dendritic crystal.Elements Fe,Mo,and other major elements transform linearly along the gradient direction,with sufficient interlayer diffusion between the deposited layers,leading to good metallurgical bonding.The smaller the change in composition gradient,the greater the microhardness value along the deposition direction.When the composition gradient is 10%,the gradient layer exhibits higher hardness(940 HV)and excellent resistance to surface abrasion,and the overall compressive properties of the samples are better,with the compressive fracture stress in the top region reaching 750.05±14 MPa.展开更多
Based on simplified calculations of one-dimensional wave systems,loading pressure platform curves of Al-Cu gradient materials(GMs)impactor were designed.The Al-Cu GMs were prepared using tape-pressing sintering,and th...Based on simplified calculations of one-dimensional wave systems,loading pressure platform curves of Al-Cu gradient materials(GMs)impactor were designed.The Al-Cu GMs were prepared using tape-pressing sintering,and their acoustic properties were characterized to match the design path.The parallelism of the Al-Cu GM was confirmed using a three-dimensional surface profilometry machine.A one-stage light-gas gun was used to launch the Al-Cu GM,impacting an Al-LiF target at a velocity of 400 m/s.The results of the experimental strain rate demonstrate that the Al-Cu GMs can realize the precise control of the strain rate within the range of 10^(4)‒10^(5)/s in the high-speed impact experiments.展开更多
SS316L alloy coupled with Inconel625 alloy were combined with Ti6Al4V or Inconel718 alloy through wire arc additive manufacturing technique to manufacture functionally graded materials(FGMs).Two FGMs,namely 60%SS316L+...SS316L alloy coupled with Inconel625 alloy were combined with Ti6Al4V or Inconel718 alloy through wire arc additive manufacturing technique to manufacture functionally graded materials(FGMs).Two FGMs,namely 60%SS316L+20%Inconel625+20%Ti6Al4V composite and 60%SS316L+20%Inconel625+20%Inconel718 composite,were prepared.The tensile strength,elongation,yield strength,hardness,cross section area of the parent material,and composition were analysed.Results illustrate that the 60%SS316L+20%Inconel625+20%Inconel718 composite has better mechanical properties than 60%SS316L+20%Inconel625+20%Ti6Al4V composite,and the comprehensive properties of 60%SS316L+20%Inconel 625+20%Ti6Al4V composite are better than those of the parent material SS316L.Hence,the composite of 60%SS316L+20%Inconel625+20%Inconel718 is optimal.Due to its high strength,the 60%SS316L+20%Inconel625+20%Inconel718 composite has great application potential in the field of high pressure pneumatic tool and defence tool.展开更多
The optimization of deposited metal properties through the addition of rare earth elements to welding materials was explored.Utilizing optical microscope,scanning electron microscope,energy dispersive spectroscope,and...The optimization of deposited metal properties through the addition of rare earth elements to welding materials was explored.Utilizing optical microscope,scanning electron microscope,energy dispersive spectroscope,and X-ray diffractometer,combined with software tools like Matlab,Image-Pro Plus,and CHANNEL5,the influence mechanism of rare earth element addition on the strength,toughness,and inclusions of deposited metal in 1000 MPa grade high-strength steel was investigated.The results indicate that the incorporation of rare earth elements enhances the weldability of the welding materials.With the addition of rare earth elements,the tensile strength of the deposited metal increases from 935 MPa to 960 MPa.However,further addition leads to a decrease in tensile strength,while the yield strength continuously increases by 8.5%-17.2%.The addition of appropriate amounts of rare earth elements results in an increase in acicular ferrite and retained austenite content,as well as grain refinement in the deposited metal,leading to 8.5%-24.3% and 15.6%-42.2% enhancement in impact energy at−40℃ and−60℃,respectively.Additionally,the proper addition of rare earth elements modifies the inclusions and generates fine and dispersed composite inclusions that bond better with the matrix,thereby optimizing the properties of the deposited metal through various mechanisms.Adding an appropriate amount of rare earth elements can significantly enhance the properties of the deposited metal in 1000 MPa grade high-strength steel,and improve the match between high strength and toughness,meeting the demands for high-strength steel used in hydropower applications.展开更多
This review explores multi-directional functionally graded(MDFG)nanostructures,focusing on their material characteristics,modeling approaches,and mechanical behavior.It starts by classifying different types of functio...This review explores multi-directional functionally graded(MDFG)nanostructures,focusing on their material characteristics,modeling approaches,and mechanical behavior.It starts by classifying different types of functionally graded(FG)materials such as conventional,axial,bi-directional,and tri-directional,and the material distribution models like power-law,exponential,trigonometric,polynomial functions,etc.It also discusses the application of advanced size-dependent theories like Eringen’s nonlocal elasticity,nonlocal strain gradient,modified couple stress,and consistent couple stress theories,which are essential to predict the behavior of structures at small scales.The review covers the mechanical analysis of MDFG nanostructures in nanobeams,nanopipes,nanoplates,and nanoshells and their dynamic and static responses under different loading conditions.The effect of multi-directional material gradation on stiffness,stability and vibration is discussed.Moreover,the review highlights the need for more advanced analytical,semi-analytical,and numerical methods to solve the complex vibration problems ofMDFG nanostructures.It is evident that the continued development of these methods is crucial for the design,optimization,and real-world application of MDFG nanostructures in advanced engineering fields like aerospace,biomedicine,and micro/nanoelectromechanical systems(MEMS/NEMS).This study is a reference for researchers and engineers working in the domain of MDFG nanostructures.展开更多
Objective:To assess whether there is a correlation between CT scan severity score and pulmonary function in Interstitial Lung Disease,and provide a more reliable basis for clinical diagnosis and treatment.Materials an...Objective:To assess whether there is a correlation between CT scan severity score and pulmonary function in Interstitial Lung Disease,and provide a more reliable basis for clinical diagnosis and treatment.Materials and Methods:Sixty patients with clinical diagnosis of Interstitial Lung Disease(ILD)were collected,and chest CT and pulmonary function tests were performed at the same time.Here DLCO%and FEV1%were used as the pulmonary function indexes.The severity of the patients was assessed by CT scores as mild(range,1~10),moderate(range 11~20),and severe(range 21~30).Correlation analysis was carried out between CT score and pulmonary function index,and the lung function parameters of patients at three grades were compared between groups and pairwise among the means.Results:As per the CT severity classification,there were 13 mild cases,31 moderate cases,and 16 severe cases.CT score was negatively correlated with DLCO%and FEV1%.R value was-0.814 and-0.797,respectively;The comparison of the mean value of DLCO%and FEV1%among the three groups and the pairings of the mean value of DLCO%and FEV1%were statistically significant.Conclusion:There was good correlation between CT score of ILD and the pulmonary function index.The pulmonary function index of patients with different CT severity grading was statistically significant,which can provide a new basis for the clinical evaluation and diagnosis of the disease.展开更多
Structural mapping is an important method for studying algebraic structures.Hom-algebra and monoidal Hom-group are new structures produced by algebra and group structural mappings,respectively.These structures are imp...Structural mapping is an important method for studying algebraic structures.Hom-algebra and monoidal Hom-group are new structures produced by algebra and group structural mappings,respectively.These structures are important algebra and group generalizations and are closely related to them.Let(A,β)be a Hom-algebra and(G,α)a monoidal Hom-group.A structure of(A,β)graded by(G,α)is introduced;this structure is called Hom-group graded algebra.This study presents the definition of Hom group graded algebra,provides some examples,and dis-cusses its basic properties.Furthermore,a sufficient and necessary condition that makes(A,β)a strongly(G,α)-graded algebra is explored using a structure mapβand unit 1A.Finally,by using different maps,two sufficient and necessary conditions for a Hom-algebra to be a(G,α)-graded algebra are expressed in different ways.展开更多
文摘目的:系统评价培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证的疗效以及证据质量,为临床决策及疾病指南制订提供循证依据。方法:检索中国知网(CNKI)、万方数据库(Wangfang)、Pubmed、Web of Science等8大中英文数据库,由2名研究者独立进行文献筛选、信息提取、偏倚风险评估及方法学质量评价,并对纳入研究的总有效率、中医证候积分、第一秒用力呼气容积(FEV1)、第一秒用力呼气容积/用力肺活量(FEV1/FVC)、哮喘控制测试(ACT)评分等结局指标进行Meta分析,最终依照GRADE评估证据质量。结果:共纳入14项研究,合计1263例患者。结果显示:(1)培土生金中药联合常规西医疗法可有效改善患者总有效率,降低患者中医证候积分,改善患者FEV1水平、FEV1/FVC及ACT评分。(2)总有效率证据质量较优,可信度高,其余指标证据质量较低,尚待更多高质量的研究支持以提升证据级别。结论:培土生金中药联合西医常规疗法治疗支气管哮喘缓解期肺脾两虚证优于单用西医常规治疗,且在总有效率上证据质量较高,具有一定的循证学意义。
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3701800)Special funding support for the Yuelu Mountain National University Science and Technology City“Ranking the Top of the List”Research Project:(Tunnel Boring Machine High-performance Long-life Cutting Tools)the State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China.
文摘The good combination of mechanical and wear properties for cemented carbides is crucial.In this work,the wear behavior of functionally graded cemented carbide(FGCC)and non-graded cemented carbide(CC),with CoNiFeCr multi-principal-element alloy(MPEA)binder,has been investigated by performing sliding wear tests and composition characterization.The results showed that compared with CC,FGCC had higher hardness,stronger fracture toughness,better wear performance,and similar TRS.FGCCs exhibited lower wear rates(3.44×10^(−7)–6.95×10^(−6)mm^(3)/(N m))and coefficients of friction(COFs)(0.27–0.39)than CCs from RT to 600℃due to mitigation of multiple risks caused by binder removal,fragmentation and pull-out of WC grains,high-temperature oxidation and softening.In the low-temperature wear stage,the MPEA binder underwent dynamic recrystallization(DRX)and twinning deformation before removing from the surface.The binder removal caused dislocation pile-ups and stacking faults(SFs)to form under high stress,resulting in fragmentation and pull-out of WC grains.The low-temperature wear was dominated by abrasive wear and adhesive wear,with a low wear rate and a high and unstable COF.In the high-temperature wear stage,initial pitting oxidation of WC grains generated many subgrain boundaries,reducing heat transfer and exacerbating oxidation,resulting in an oxide layer enriched with WO3,Mx Oy,and MWO4.High-temperature wear was dominated by oxidation wear and high-temperature softening,with a high wear rate and a low and smooth COF.The results from the present study do not only provide theoretical guidance for an understanding of the antiwear mechanism of WC-CoNiFeCr,but also a new approach for the preparation of cemented carbides with high wear resistance.
基金financially supported by the Key Research and Development Program of Guangxi,China(No.GUIKE AB23026051)the Science and Technology Innovation Program of Hunan Province,China(No.2023RC3039)the Fundamental Research Funds for the Central Universities of Central South University,China.
文摘A sustainable approach for recovering battery grade FePO_(4) and Li_(2)CO_(3) from Al/F-bearing spent LiFePO_(4)/C powder was proposed,including acid leaching,fluorinated coordination precipitation,homogeneous precipitation,and high-temperature precipitation.Under the optimal conditions,the leaching efficiencies of Li,Fe,P,Al,and F were 97.6%,97.1%,97.1%,72.5%,and 63.3%,respectively.The effects of different parameters on the removal of Al/F impurities were systematically evaluated,indicating about 99.4%Al and 96.4%F in the leachate were precipitated in the form of Na_(3)Li_(3)Al_(2)F_(12),and their residual concentrations were only 0.0124 and 0.328 g/L,respectively,which could be directly used to prepare battery grade FePO_(4)(99.68%in purity).Lithium in the Al/F-bearing residue could be extracted through CaCO_(3)−CaSO_(4) roasting followed by acid leaching,ultimately obtaining 99.87%purity of Li_(2)CO_(3).The recovery rates of Li and Fe were 96.88%and 92.85%,respectively.An economic evaluation demonstrated that the process was profitable.
文摘In the category of general monoid graded rings, we propose a new graded radical, i.e. the graded P radical, obtain the structure theorem of corresponding semisimple graded rings, show that it is a graded special radical and present the graded module characterization of it. Moreover, we investigate the relations between it and reflect P radical.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2021B0301030001)the National Key Research and Development Program of China(Grant No.2021YFB3802300)the Foundation of National Key Laboratory of Shock Wave and Detonation Physics(Grant No.JCKYS2022212004)。
文摘The graded density impactor(GDI)dynamic loading technique is crucial for acquiring the dynamic physical property parameters of materials used in weapons.The accuracy and timeliness of GDI structural design are key to achieving controllable stress-strain rate loading.In this study,we have,for the first time,combined one-dimensional fluid computational software with machine learning methods.We first elucidated the mechanisms by which GDI structures control stress and strain rates.Subsequently,we constructed a machine learning model to create a structure-property response surface.The results show that altering the loading velocity and interlayer thickness has a pronounced regulatory effect on stress and strain rates.In contrast,the impedance distribution index and target thickness have less significant effects on stress regulation,although there is a matching relationship between target thickness and interlayer thickness.Compared with traditional design methods,the machine learning approach offers a10^(4)—10^(5)times increase in efficiency and the potential to achieve a global optimum,holding promise for guiding the design of GDI.
文摘BACKGROUND Endoscopic submucosal dissection(ESD)has become a widely accepted,minimally invasive treatment for gastrointestinal submucosal tumors.It has been reported that humanistic nursing care with graded psychological interventions can effectively enhance patients’physical activity in patients,reduce postoperative complications,and improve their postoperative quality of life.AIM To investigate the effects of combining humanistic care with graded psychological support on nursing satisfaction and quality of life in patients undergoing ESD for gastrointestinal submucosal tumors.METHODS A retrospective analysis was conducted on the clinical data of 180 patients who underwent ESD surgery for gastrointestinal submucosal tumors at our hospital between March 2021 and February 2023.Patients were allocated into groups based on the nursing care they received:The control group,which received routine care(n=90),and the observation group,which was subjected to humanistic nursing care in combination with graded psychological support(n=90).Patient anxiety and depression were assessed using the self-rating anxiety scale(SAS)and self-rating depression scale(SDS).Quality of life was evaluated using the shortform 36 health survey,and additional indications such as time to first food intake,surgery duration,length of hospital stay,nursing satisfaction,and adverse reactions were also recorded.Data was analyzed using SPSS22.0,with t-tests employed for continuous variables andχ2 tests for categorical data.RESULTS Patients in the observation group experienced significantly shorter times to first postoperative meal,surgery,and hospital stay compared to the control group.After the intervention,the SAS score of the observation group was 43.17±5.68,and the SDS score was 41.57±6.52,both significantly lower than those of the control group,with SAS score of 52.38±5.21 and SDS score of 51.23±8.25.In addition,the observation group scored significantly higher in daily living,physical function,psychological well-being,and social functioning(80.01±6.39,83.59±6.89,81.69±5.34,and 85.23±6.05,respectively).Moreover,the observation group also exhibited higher satisfaction and selfefficacy scores and a lower incidence of adverse reactions compared to the control group(P<0.05).CONCLUSION For patients undergoing ESD for gastrointestinal submucosal tumors,humanistic nursing care in combination with graded psychological nursing care significantly shorten the times to first postoperative meal,surgery,and hospital stay,effectively alleviates anxiety and depression,improves quality of life and nursing satisfaction,and mitigate the incidence of adverse reactions.
基金the National Key Research and Development Program of China(Grant No.2023YFC2412600)the National Natural Science Foundation of China(Grant No.51971171)for financially supporting this work.
文摘Current modifications of Ti-based materials with porous scaffolds for achieving biological fixation often decrease corrosion fatigue strength(σ_(cf))of the resultant implants,thereby shortening their service lifes-pan.To resolve this issue,in the present,a step-wise graded porous Ti-6Al-7Nb scaffold was additively manufactured on optimally surface mechanical attrition treated(SMATed)Ti-6Al-7Nb(specifically de-noted as S-Ti6Al7Nb)using laser powder bed fusion(PBF)technology.The microstructure,bond strength,residual stress distribution,and corrosion fatigue behavior of porous scaffolds modified S-Ti6Al7Nb were investigated and compared with those of mechanically polished Ti-6Al-7Nb(P-Ti6Al7Nb),S-Ti6Al7Nb,and porous scaffolds modified P-Ti6Al7Nb.Results showed that corrosion fatigue of porous scaffolds modi-fied Ti-6Al-7Nb was propagation controlled.Moreover,the crack propagation behavior in the PBF scaf-fold’s fusion zone(FZ)and heat-affected zone(HAZ),exhibiting insensitivity to the microstructural con-figurations characterized by columnar prior-βgrain(PBG)boundaries and acicularα''martensites,cou-pled with the PBF-induced residual tensile stresses in these regions,resulted in a considerable decrease inσ_(cf) for porous scaffolds modified P-Ti6Al7Nb compared to P-Ti6Al7Nb.In contrast,step-wise graded porous scaffold-modified S-Ti6Al7Nb demonstrated an improvedσ_(cf) which was even higher than that of P-Ti6Al7Nb.Such an advancement in corrosion fatigue strength is primarily attributed to the presence of residual compressive stresses within the underlying S-Ti6Al7Nb substrate,extending beyond FZ and HAZ.These stresses increased the crack propagation threshold,leading to crack deflection/branching and increased crack-path tortuosity,thereby synergistically markedly enhancing the crack propagation resis-tance of porous scaffolds modified S-Ti6Al7Nb.
文摘应用推荐分级的评估、制订和评价(grading of recommendations assessment,development and evaluation,GRADE)系统与中药有效性评价整合证据链法(integrated evidence chain-based effectiveness evaluation of traditional Chinese medicine,Eff-iEC)对指南或专家共识推荐频次较高的12种治疗骨质疏松症的常用中成药进行了证据评价。结果显示,仙灵骨葆胶囊/片根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为BA+B^(+)(中级证据);金天格胶囊根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为AA+B(高级证据);骨疏康颗粒/胶囊根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为BA+B^(+)(中级证据);左归丸根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为AA^(++)B^(+)(高级证据);强骨胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AA+B^(+)(高级证据);壮骨止痛胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为BA+B(中级证据);金匮肾气丸根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AA+B(高级证据);全杜仲胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AD+B^(+)(低级证据);淫羊藿总黄酮胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AAB^(+)(高级证据);右归丸根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为AA^(++)B^(+)(高级证据);芪骨胶囊根据GRADE系统评价为D级(极低级证据),根据Eff-iEC体系评价为BB^(+)B(中级证据);六味地黄丸根据GRADE系统评价为C级(低级证据),根据Eff-iEC体系评价为AA^(++)B^(+)(高级证据)。整体而言,Eff-iEC评价体系较GRADE系统能更全面地评价中医药的有效性证据,但仍有不够完善之处,制约其推广应用。在临床证据评价方面,Eff-iEC评价体系与GRADE系统均反映出当前中成药治疗骨质疏松症的临床研究质量普遍较低,未来尚需开展高质量临床试验,进一步验证临床疗效。
基金National Natural Science Foundation of China(51975286)。
文摘Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy deposition(EB-DED)technique,including three samples with composition mutation of 100%,composition change rate of 10%and 30%.Results show that the composition-change rate significantly affects the microstructure and mechanical properties of the samples.In the sample with abrupt change of composition,the sharp shift in composition between 304 stainless steel and Mo leads to a great difference in the microstructure and hardness near the interface between the two materials.With the increase in the number of gradient layers,the composition changes continuously along the direction of deposition height,and the microstructure morphology shows a smooth transition from 304 stainless steel to Mo,which is gradually transformed from columnar crystal to dendritic crystal.Elements Fe,Mo,and other major elements transform linearly along the gradient direction,with sufficient interlayer diffusion between the deposited layers,leading to good metallurgical bonding.The smaller the change in composition gradient,the greater the microhardness value along the deposition direction.When the composition gradient is 10%,the gradient layer exhibits higher hardness(940 HV)and excellent resistance to surface abrasion,and the overall compressive properties of the samples are better,with the compressive fracture stress in the top region reaching 750.05±14 MPa.
基金Natural Science Foundation of Hubei Province(2024AFB432)National Natural Science Foundation of China(52171045,12302436,52302095)Research Fund of Jianghan University(2023JCYJ05)。
文摘Based on simplified calculations of one-dimensional wave systems,loading pressure platform curves of Al-Cu gradient materials(GMs)impactor were designed.The Al-Cu GMs were prepared using tape-pressing sintering,and their acoustic properties were characterized to match the design path.The parallelism of the Al-Cu GM was confirmed using a three-dimensional surface profilometry machine.A one-stage light-gas gun was used to launch the Al-Cu GM,impacting an Al-LiF target at a velocity of 400 m/s.The results of the experimental strain rate demonstrate that the Al-Cu GMs can realize the precise control of the strain rate within the range of 10^(4)‒10^(5)/s in the high-speed impact experiments.
文摘SS316L alloy coupled with Inconel625 alloy were combined with Ti6Al4V or Inconel718 alloy through wire arc additive manufacturing technique to manufacture functionally graded materials(FGMs).Two FGMs,namely 60%SS316L+20%Inconel625+20%Ti6Al4V composite and 60%SS316L+20%Inconel625+20%Inconel718 composite,were prepared.The tensile strength,elongation,yield strength,hardness,cross section area of the parent material,and composition were analysed.Results illustrate that the 60%SS316L+20%Inconel625+20%Inconel718 composite has better mechanical properties than 60%SS316L+20%Inconel625+20%Ti6Al4V composite,and the comprehensive properties of 60%SS316L+20%Inconel 625+20%Ti6Al4V composite are better than those of the parent material SS316L.Hence,the composite of 60%SS316L+20%Inconel625+20%Inconel718 is optimal.Due to its high strength,the 60%SS316L+20%Inconel625+20%Inconel718 composite has great application potential in the field of high pressure pneumatic tool and defence tool.
基金Provincial Key Research and Development Plan of Heilongjiang(2022ZX04A01)。
文摘The optimization of deposited metal properties through the addition of rare earth elements to welding materials was explored.Utilizing optical microscope,scanning electron microscope,energy dispersive spectroscope,and X-ray diffractometer,combined with software tools like Matlab,Image-Pro Plus,and CHANNEL5,the influence mechanism of rare earth element addition on the strength,toughness,and inclusions of deposited metal in 1000 MPa grade high-strength steel was investigated.The results indicate that the incorporation of rare earth elements enhances the weldability of the welding materials.With the addition of rare earth elements,the tensile strength of the deposited metal increases from 935 MPa to 960 MPa.However,further addition leads to a decrease in tensile strength,while the yield strength continuously increases by 8.5%-17.2%.The addition of appropriate amounts of rare earth elements results in an increase in acicular ferrite and retained austenite content,as well as grain refinement in the deposited metal,leading to 8.5%-24.3% and 15.6%-42.2% enhancement in impact energy at−40℃ and−60℃,respectively.Additionally,the proper addition of rare earth elements modifies the inclusions and generates fine and dispersed composite inclusions that bond better with the matrix,thereby optimizing the properties of the deposited metal through various mechanisms.Adding an appropriate amount of rare earth elements can significantly enhance the properties of the deposited metal in 1000 MPa grade high-strength steel,and improve the match between high strength and toughness,meeting the demands for high-strength steel used in hydropower applications.
文摘This review explores multi-directional functionally graded(MDFG)nanostructures,focusing on their material characteristics,modeling approaches,and mechanical behavior.It starts by classifying different types of functionally graded(FG)materials such as conventional,axial,bi-directional,and tri-directional,and the material distribution models like power-law,exponential,trigonometric,polynomial functions,etc.It also discusses the application of advanced size-dependent theories like Eringen’s nonlocal elasticity,nonlocal strain gradient,modified couple stress,and consistent couple stress theories,which are essential to predict the behavior of structures at small scales.The review covers the mechanical analysis of MDFG nanostructures in nanobeams,nanopipes,nanoplates,and nanoshells and their dynamic and static responses under different loading conditions.The effect of multi-directional material gradation on stiffness,stability and vibration is discussed.Moreover,the review highlights the need for more advanced analytical,semi-analytical,and numerical methods to solve the complex vibration problems ofMDFG nanostructures.It is evident that the continued development of these methods is crucial for the design,optimization,and real-world application of MDFG nanostructures in advanced engineering fields like aerospace,biomedicine,and micro/nanoelectromechanical systems(MEMS/NEMS).This study is a reference for researchers and engineers working in the domain of MDFG nanostructures.
基金providing by the Shenzhen City Nanshan District Science and Technology Plan Project(Medical and Health Category)(Grant No.2018073)。
文摘Objective:To assess whether there is a correlation between CT scan severity score and pulmonary function in Interstitial Lung Disease,and provide a more reliable basis for clinical diagnosis and treatment.Materials and Methods:Sixty patients with clinical diagnosis of Interstitial Lung Disease(ILD)were collected,and chest CT and pulmonary function tests were performed at the same time.Here DLCO%and FEV1%were used as the pulmonary function indexes.The severity of the patients was assessed by CT scores as mild(range,1~10),moderate(range 11~20),and severe(range 21~30).Correlation analysis was carried out between CT score and pulmonary function index,and the lung function parameters of patients at three grades were compared between groups and pairwise among the means.Results:As per the CT severity classification,there were 13 mild cases,31 moderate cases,and 16 severe cases.CT score was negatively correlated with DLCO%and FEV1%.R value was-0.814 and-0.797,respectively;The comparison of the mean value of DLCO%and FEV1%among the three groups and the pairings of the mean value of DLCO%and FEV1%were statistically significant.Conclusion:There was good correlation between CT score of ILD and the pulmonary function index.The pulmonary function index of patients with different CT severity grading was statistically significant,which can provide a new basis for the clinical evaluation and diagnosis of the disease.
基金The National Natural Science Foundation of China (No. 12271089, 12471033)。
文摘Structural mapping is an important method for studying algebraic structures.Hom-algebra and monoidal Hom-group are new structures produced by algebra and group structural mappings,respectively.These structures are important algebra and group generalizations and are closely related to them.Let(A,β)be a Hom-algebra and(G,α)a monoidal Hom-group.A structure of(A,β)graded by(G,α)is introduced;this structure is called Hom-group graded algebra.This study presents the definition of Hom group graded algebra,provides some examples,and dis-cusses its basic properties.Furthermore,a sufficient and necessary condition that makes(A,β)a strongly(G,α)-graded algebra is explored using a structure mapβand unit 1A.Finally,by using different maps,two sufficient and necessary conditions for a Hom-algebra to be a(G,α)-graded algebra are expressed in different ways.
