Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation en...Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.展开更多
To achieve the loading of the stress path of hard rock,the spherical discrete element model(DEM)and the new flexible membrane technology were utilized to realize the transient loading of three principal stresses with ...To achieve the loading of the stress path of hard rock,the spherical discrete element model(DEM)and the new flexible membrane technology were utilized to realize the transient loading of three principal stresses with arbitrary magnitudes and orientations.Furthermore,based on the deep tunnel of China Jinping Underground Laboratory II(CJPL-II),the deformation and fracture evolution characteristics of deep hard rock induced by excavation stress path were analyzed,and the mechanisms of transient loading-unloading and stress rotation-induced fractures were revealed from a mesoscopic perspective.The results indicated that the stressestrain curve exhibits different trends and degrees of sudden changes when subjected to transient changes in principal stress,accompanied by sudden changes in strain rate.Stress rotation induces spatially directional deformation,resulting in fractures of different degrees and orientations,and increasing the degree of deformation anisotropy.The correlation between the degree of induced fracture and the unloading magnitude of minimum principal stress,as well as its initial level is significant and positive.The process of mechanical response during transient unloading exhibits clear nonlinearity and directivity.After transient unloading,both the minimum principal stress and minimum principal strain rate decrease sharply and then tend to stabilize.This occurs from the edge to the interior and from the direction of the minimum principal stress to the direction of the maximum principal stress on theε1-ε3 plane.Transient unloading will induce a tensile stress wave.The ability to induce fractures due to changes in principal stress magnitude,orientation and rotation paths gradually increases.The analysis indicates a positive correlation between the abrupt change amplitude of strain rate and the maximum unloading magnitude,which is determined by the magnitude and rotation of principal stress.A high tensile strain rate is more likely to induce fractures under low minimum principal stress.展开更多
In this editorial we comment on the article titled“Establishment and validation of an adherence prediction system for lifestyle interventions in non-alcoholic fatty liver disease”by Zeng et al published in a recent ...In this editorial we comment on the article titled“Establishment and validation of an adherence prediction system for lifestyle interventions in non-alcoholic fatty liver disease”by Zeng et al published in a recent issue of the World Journal of Gastroenterology.Non-alcoholic fatty liver disease(NAFLD)represents one of the current challenges in hepatology and public health,due to its continuous growing prevalence and the rising incidence of NAFLD-related fibrosis,non-alcoholic steatohepatitis and cirrhosis.The only effective therapeutic strategy for this dis-ease is represented by encouraging patients to improve their lifestyle through the modification of dietary intake and increased physical exercise,but the effective application of such modifications is often limited by various factors such as lack of information,psychological barriers or poor social support.While poor adherence to a healthy lifestyle can be decisive in determining the clinical outcome,in daily practice there is a lack of quantitative instruments aimed at identifying patients with the lowest adherence to lifestyle changes and higher risk of disease progre-ssion in the course of follow-up.In this article,Zeng et al propose a quantitative scale to assess the grade of adherence of patients with NAFLD to hea-lthy lifestyle intervention,called the Exercise and Diet Adherence Scale(EDAS).This scale,consisting of 33 items divided into 6 dimensions which relates to six subjective aspects in the self-management of NAFLD,has shown a good correlation with the identification of the sub-cohort of patients with the highest reduction in caloric intake,increase in physical exercise,probability of a reduction in liver stiffness measurement and alanine aminotransferase levels.The cor-relation among clinical outcomes and specific dimensions of this scale also highlights the pivotal role of a good and confidential doctor-patient relationship and of an effective communication.There is an urgent need for practical and effective instruments to assess the grade of self-management of NAFLD patients,together with the development of multidisciplinary teams with the aim of applying structured behavioral interventions.展开更多
AIM:To investigate the current situation and influencing factors of self-management ability in dry eye patients in west China.METHODS:A total of 265 patients clinically diagnosed with dry eye received a convenience su...AIM:To investigate the current situation and influencing factors of self-management ability in dry eye patients in west China.METHODS:A total of 265 patients clinically diagnosed with dry eye received a convenience survey questionnaire at West China Hospital of Sichuan University.All participants completed the rating scale of health self-management skill for adults(AHSMSRS),Huaxi Emotional-Distress Index(HEI),e-health literacy scale(e-HEALS)and Brief Illness Perception Questionnaire(Brief-IPQ).A generalized linear model was employed to establish a multivariate linear model with demographic data,psychological state,e-HEALS,and illness perception as independent variables and health selfmanagement skill score as the dependent variable.RESULTS:The mean score for health self-management skill was 165.58±15.79.Multivariate analysis revealed that advanced age,better illness perception and improved psychological state were associated with better health selfmanagement ability among dry eye patients.Furthermore,the health self-management ability of patients with a disease duration less than 1y was found to be higher compared to those with a disease duration exceeding 1y.CONCLUSION:The health self-management ability of dry eye patients in west China is relatively high.Age,duration of disease,illness perception and psychological state are the influencing factors on the health selfmanagement ability of dry eye patients.展开更多
Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium alloys.To investigate the influences of specimen orientation,the corrosion tes...Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium alloys.To investigate the influences of specimen orientation,the corrosion tests and(corrosion)fatigue crack growth tests were conducted.The rolled and transverse surfaces of the materials show distinct corrosion rate differences in the stable corrosion stage,but the truth is the opposite for the initial stage of corrosion.In air,specimen orientations have a significant influence on the plastic deformation mechanisms near the crack tip,which results in different fatigue fracture surfaces and cracking paths.Compared with R-T specimens,N-T specimens show a slower fatigue crack growth(FCG)rate in air,which can be attributed to crack closure effects and deformation twinning near the crack tip.The corrosion environment will not significantly change the main plastic deformation mechanisms for the same type of specimen.However,the FCG rate in phosphate buffer saline(PBS)is one order of magnitude higher than that in air,which is caused by the combined effects of hydrogen-induced cracking and anodic dissolution.Owing to the similar corrosion rates at crack tips,the specimens with different orientations display close FCG rates in PBS.展开更多
The study site is a holistic patient-centered organization that has developed a 16-week long orientation program for new graduate nurses entering the hospital setting. The purpose of the program is for new graduate nu...The study site is a holistic patient-centered organization that has developed a 16-week long orientation program for new graduate nurses entering the hospital setting. The purpose of the program is for new graduate nurses to gain the confidence, competence, and critical thinking skills for providing safe patient care. The issue occurring within the organization is that there is an increasing rise in the number of turnover rates of new graduates leaving the hospital, thus making evaluating the program a necessity to problem-solving. There has been no evaluation of the program in the past five years to reveal why the increase in the recent turnover rates. The data collected during the interview process was coded and categorized into three main sections: organizational, substantive, and theoretical. The evaluator used an organizational category to investigate for board areas or issues within the problem attempting to be solved. The evaluator concluded from the results and findings that the issue, a poor preceptor-preceptee relationship was seen by all stakeholders involved. The literature presented concludes that continuous evaluation of orientation programs is crucial for the professional and personal growth of new graduate nurses in the hospital.展开更多
Research Background: The high prevalence of diabetes in Sudan, estimated at 16%, highlights the importance of effective health education in diabetes management. Diabetes self-management education has been identified a...Research Background: The high prevalence of diabetes in Sudan, estimated at 16%, highlights the importance of effective health education in diabetes management. Diabetes self-management education has been identified as a crucial tool in enhancing the knowledge, attitudes, and abilities necessary for self-management among individuals with diabetes. Aim: To assess the impact of diabetes self-management education on medication adherence and glycemic control in Sudanese adults with type 2 diabetes before and 3 months after the DSME intervention. Method: The study was conducted in Sudan between September 2022 and March 2023, it was an interventional, one-group, pre- and post-test study that aimed to assess the impact of diabetes self-management education (DSME) on medication adherence and diabetes control in Sudanese adults with type 2 diabetes. The research was conducted in primary health care centers in six cities in Sudan and involved 244 participants. The data entry and statistical analysis were conducted using the Statistical Package for Social Sciences version 27.0. A paired t test was used for analysis. Results: The study included 244 participants, 67% of whom were males. The age mean ± SD was 48.6 ± 9.3 years, and 85.3% of participants were married. Age at onset of diabetes mean ± SD was 40.60 ± 7.81 years;44.6% had diabetes for less than 5 years;and 84.1% had a positive family history of diabetes mellitus. The levels of poor, low, and partial adherence to medication decreased by 8.2%, 4%, and 20.6%, respectively, after the intervention. The levels of good and high medication regime adherence increased by 13% and 19.8%, respectively;BMI decreased by 1.1 ± 0.73 kg/m<sup>2</sup> (p = 0.005). The fasting blood sugar decreased by 69 ± 32.9 mg/dl (p = 0.049), and the glycated hemoglobin decreased by 1.21 ± 0.28% (p = 0.001). Conclusions: The findings of this study reinforce the importance of patient education in improving glycemic control and enhancing self-management behaviors. Patient education plays a critical role in enhancing glycemic control and self-management behaviors. It is essential for healthcare providers to adopt a patient-centered approach, taking into account the individual's beliefs, attitudes, and knowledge about their illness and treatment. Overcoming these challenges necessitates a comprehensive approach, including enhancing healthcare professionals’ knowledge and communication skills, offering accessible and culturally sensitive diabetes education programs, and addressing barriers to resources and support for self-management.展开更多
Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with ...Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with this challenge.Stable,high-quality wine grape production may be achieved by synchronizing the meso-and microclimate.To clarify the role of high altitude and row orientation in meso-and microclimate and the response of berries to it,we evaluated seven years(2012-2018)of climate data,two years of basic grape(Cabernet Sauvignon,Vitis vinifera L.)quality,and one-year microclimate from veraison to harvest.By comparing two locations(Sidon 2047 m,Sinon 2208 m)in Yunnan Province,China,we found that the average temperature has been stable at approximately 15℃ for seven years,with no extreme weather or,noticeable global warming.The light intensity(LI)in the north-south(NS)was more balanced than the east-west(EW)direction,and the east-west to the south(EW-S)canopy side was almost higher than the other sides.High LI was associated with high photosynthetically active radiation(PAR),ultraviolet(UV),and infrared(IR)light and vice versa.The north-south to the east(NS-E)and east-west to the north(EWN)sides were characterized by lower LI and higher UV and IR light,and higher total anthocyanin content.Most anthocyanin synthesis-related genes,for example,VvF3'H and VvF3'5'H,were highly expressed in NS-E from veraison to maturity.Perhaps UV and IR light induced their expression.This study provides new insights on the role of differently orientated rows in controlling grape quality due to varied light quality.The findings are globally significant,particularly in the context of climate change,and offer fresh insights into berry physiological responses and decision-making for the management of existing vineyards.展开更多
Generally,layered Ni-rich cathode materials exhibit the morphology of polycrystalline secondary sphere composed of numerous primary particles.While the arrangement of primary particles plays a very important role in t...Generally,layered Ni-rich cathode materials exhibit the morphology of polycrystalline secondary sphere composed of numerous primary particles.While the arrangement of primary particles plays a very important role in the properties of Ni-rich cathodes.The disordered particle arrangement is harmful to the cyclic performance and structural stability,yet the fundamental understanding of disordered structure on the structural degradation behavior is unclarified.Herein,we have designed three kinds of LiNi_(0.83)Co_(0.06)Mn_(0.11)O_(2) cathode materials with different primary particle orientations by regulating the precursor coprecipitation process.Combining finite element simulation and in-situ characterization,the Li^(+)transport and structure evolution behaviors of different materials are unraveled.Specifically,the smooth Li^(+)diffusion minimizes the reaction heterogeneity,homogenizes the phase transition within grains,and mitigates the anisotropic microstructural change,thereby modulating the crack evolution behavior.Meanwhile,the optimized structure evolution ensures radial tight junctions of the primary particles,enabling enhanced Li^(+)diffusion during dynamic processes.Closed-loop bidirectional enhancement mechanism becomes critical for grain orientation regulation to stabilize the cyclic performance.This precursor engineering with particle orientation regulation provides the useful guidance for the structural design and feature enhancement of Ni-rich layered cathodes.展开更多
The practical application of lithium(Li)metal anodes in high-capacity batteries is impeded by the formation of hazardous Li dendrites.To address this challenge,this research presents a novel methodology that combines ...The practical application of lithium(Li)metal anodes in high-capacity batteries is impeded by the formation of hazardous Li dendrites.To address this challenge,this research presents a novel methodology that combines laser ablation and heat treatment to precisely induce controlled grain growth within laser-structured grooves on copper(Cu)current collectors.Specifically,this approach enhances the prevalence of Cu(100)facets within the grooves,effectively lowering the overpotential for Li nucleation and promoting preferential Li deposition.Unlike approaches that modify the entire surface of collectors,our work focuses on selectively enhancing lithiophilicity within the grooves to mitigate the formation of Li dendrites and exhibit exceptional performance metrics.The half-cell with these collectors maintains a remarkable Coulombic efficiency of 97.42%over 350 cycles at 1 mA cm^(−2).The symmetric cell can cycle stably for 1600 h at 0.5 mA cm^(−2).Furthermore,when integrated with LiFePO4 cathodes,the full-cell configuration demonstrates outstanding capacity retention of 92.39%after 400 cycles at a 1C discharge rate.This study introduces a novel technique for fabricating selective lithiophilic three-dimensional(3D)Cu current collectors,thereby enhancing the performance of Li metal batteries.The insights gained from this approach hold promise for enhancing the performance of all laser-processed 3D Cu current collectors by enabling precise lithiophilic modifications within complex structures.展开更多
The slip behavior and precipitation behavior of four Al−Cu−Li single crystals with varying orientations at different temperatures were investigated using electron backscattering diffraction(EBSD)and transmission elect...The slip behavior and precipitation behavior of four Al−Cu−Li single crystals with varying orientations at different temperatures were investigated using electron backscattering diffraction(EBSD)and transmission electron microscopy(TEM).The maximum differences in yield strength and ductility of the single crystals at room temperature are 41.6%and 14.7%,respectively.This indicates that the mechanical properties are strongly influenced by the crystal orientation.Moreover,grains with varying orientations exhibit distinct slip characteristics,including slip homogenization,slip localization,and multiple slip.In single crystal SC1,slip localization primarily contributes to its inferior ductility compared to other grains.Nevertheless,during deformation at 250℃,the distinct morphology and distribution of precipitates in the crystals are also correlated with orientation,which causes the increase in the maximum elongation difference to 20.8%in all selected single crystals.Notably,SC1,with a precipitate volume fraction of 2.65%,exhibits more severe slip localization compared to room temperature conditions,while SC2,with a precipitate volume fraction of 4.79%,demonstrates cross-slip characteristics,significantly enhancing the plastic deformation capacity of the Al−Cu−Li alloy.展开更多
Hypertension(HTN)is one of the most common chronic diseases affecting over 30%of the adult population globally,with a growing incidence rate.This review assesses the relationship between health literacy(HL)interventio...Hypertension(HTN)is one of the most common chronic diseases affecting over 30%of the adult population globally,with a growing incidence rate.This review assesses the relationship between health literacy(HL)intervention and hypertension(HTN)self-management among people with HTN.The study design was a systematic review of empirical research articles using a well-defined strategy.Online journals were accessed through databases such as PubMed,CINAHL,Google Scholar,ProQuest,Global Health,WHOLIS,Embase,and EbscoHost,spanning from January 2016 to December 2022 as the scope of the study.Articles selected for inclusion were those published in English during the specified time frame and adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Sample,Phenomenon of Interest,Design,Evaluation,Research Type framework for systematic review,focusing on criteria related to the sample,the phenomenon of interest,study design,evaluation,and research type.Out of 180 studies initially identified in the database search,20 studies were ultimately included in the review.The findings were reported based on these five emerging themes:Relationship between HL and HTN self-management;Effect of HL intervention on HTN self-management;Factors predicting self-care behaviors among HTN patients with low HL;Effect of HL and self-management efficacy on health-related quality of life(HRQoL);and level of self-care practices.This review highlights a relationship between HL,self-efficacy,self-care,and HRQoL,underscoring the necessity for further well-designed intervention studies focused on enhancing HL in individuals with HTN in Nigeria to enhance their quality of life.展开更多
Objective:This paper presents an analysis of the concept of patient outcomes.Methods:The present study conducted searches on various databases,including Wanfang,Sinomed,CNKI,Pub Med,Cochrane Library,Embase,Web of Scie...Objective:This paper presents an analysis of the concept of patient outcomes.Methods:The present study conducted searches on various databases,including Wanfang,Sinomed,CNKI,Pub Med,Cochrane Library,Embase,Web of Science,and Ovid.The paper followed the Walker and Avant concept-analysis approach.Results:Initially,899 pieces of literature were identified through the search process,and after screening,41 of them were ultimately included in the analysis.The identified attributes of the concept included(1)capability,(2)decision making,and(3)action.These antecedents were shaped by factors such as illness perception,self-efficacy,and family and social.The consequences included(1)physiological effects,(2)psychological effects,and(3)social influence.Conclusions:The concept analysis of self-management in patients with diabetic foot ulcers(DFUs)not only aids in clinical practice and suppor ts interventions,but also contributes to the development of self-management theory.The common goal of clinical medical staff is to assist DFU patients in improving cognitive ability,making correct self-management decisions,and enhancing self-management behavior.展开更多
Objective: To explore the impact of the WeChat platform continuity of care model based on the KAP (knowledge, attitudes, and practices) theory on the self-management of stroke patients with hypertension after discharg...Objective: To explore the impact of the WeChat platform continuity of care model based on the KAP (knowledge, attitudes, and practices) theory on the self-management of stroke patients with hypertension after discharge from the hospital. Methods: 62 stroke patients with hypertension discharged from the rehabilitation department of a tertiary A hospital in Nanning City, Guangxi Zhuang Autonomous Region, from October 2022 to April 2023 were sampled by convenience sampling method. Patients discharged from Rehabilitation I were included in the control group, and conventional nursing care was used;while patients discharged from Rehabilitation II were included in the observation group, and WeChat platform continuity of nursing care model based on the KAP theory was implemented. The intervention effect of the two groups was compared. Results: After 4 and 12 weeks of intervention, the diastolic and systolic blood pressure of the patients in the observation group were lower than those in the control group (P < 0.05);after 12 weeks of intervention, the rate of medication adherence and the score of adherence to hypertension treatment in the observation group were significantly higher than those in the control group (P < 0.05). Conclusion: The application of the WeChat platform continuity of care model based on KAP theory to stroke patients with hypertension can improve blood pressure, medication adherence rate, hypertension treatment adherence, and overall enhance the self-management level of these patients.展开更多
Objective:To clarify the concept of self-management in hypertensive patients by analyzing the definition,attributes,and measurement tools through a literature review.Methods:An Internet-based search of the databases w...Objective:To clarify the concept of self-management in hypertensive patients by analyzing the definition,attributes,and measurement tools through a literature review.Methods:An Internet-based search of the databases was conducted using Academic Search Complete,Medical Line,CINAHL,Health Source:Nursing/Scholarly Edition,and Google Scholar.In the search process,keywords or free text were combined by using Boolean operators,with the search terms“self of management”or“self-management,”“concept*analysis”or“concept*definition,”and Walker and Avant’s concept analysis method was used.Results:Analysis of relevant literature summarized the conceptual attributes of self-management in hypertensive patients as the active participation of patients in the treatment process;the presence of interaction provided by patients and health care providers;the use of certain health management tools;and the aim of maintaining and improving the health status and living capacity of hypertensive patients.Conclusion:The concept of self-management for hypertensive patients was clarified,which helps to promote the application of hypertensive self-management in clinical work and improve outcomes and quality of life for patients with hypertension.展开更多
The significant impact of earthquakes on human lives and the built environment underscores the extensive human and economic losses caused by structural collapses. Over the years, researchers have focused on improving ...The significant impact of earthquakes on human lives and the built environment underscores the extensive human and economic losses caused by structural collapses. Over the years, researchers have focused on improving seismic design to mitigate earthquake-induced damages and enhance structural performance. In this study, a specific reinforced concrete (RC) frame structure at Kyungpook National University, designed for educational purposes, is analyzed as a representative case. Utilizing SAP 2000, the research conducts a nonlinear time history analysis to assess the structural performance under seismic conditions. The primary objective is to evaluate the influence of different column section designs, while maintaining identical column section areas, on structural behavior. The study employs two distinct seismic waves from Abeno (ABN) and Takatori (TKT) for the analysis, comparing the structural performance under varying seismic conditions. Key aspects examined include displacement, base shear force, base moment, joint radians, and layer displacement angle. This research is anticipated to serve as a valuable reference for seismic restraint reinforcement work on RC buildings, enriching the methods used for evaluating structures through nonlinear time history analysis based on the synthetic seismic wave approach.展开更多
This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approxi...This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approximately 30% of total energy consumed worldwide. The greatest contributors to energy expenditure in buildings are internal artificial lighting and heating and cooling systems. The WWR, determined by the proportion of the building’s glazed area to its wall area, is a significant factor influencing energy efficiency and minimizing energy load. This study introduces the development of a semi-automated computer model designed to offer a real-time, interactive simulation environment, fostering improving communication and engagement between designers and owners. The said model serves to optimize both the WWR and building orientation to align with occupants’ needs and expectations, subsequently reducing annual energy consumption and enhancing the overall building energy performance. The integrated model incorporates Building Information Modeling (BIM), Virtual Reality (VR), and Energy Analysis tools deployed at the conceptual design stage, allowing for the amalgamation of owners’ inputs in the design process and facilitating the creation of more realistic and effective design strategies.展开更多
The precipitation behaviors of 2124 aluminum alloy under the conditions of artificial aging (AA), creep aging (CA) and creep aging with pre-deformation (PCA) were investigated by means of mechanical property and...The precipitation behaviors of 2124 aluminum alloy under the conditions of artificial aging (AA), creep aging (CA) and creep aging with pre-deformation (PCA) were investigated by means of mechanical property and microstructure. The results show that the mechanical properties of CA treated sample decrease significantly compared with AA treated sample. The yield strength of the CA treated sample falls by 14%, the tensile strength falls by 6.2%, and the elongation falls by 21%. Nevertheless, the mechanical properties of PCA sample are improved obviously, close to the AA treated sample. Moreover, the generation and control mechanisms of the precipitation orientation effect in 2124 aluminum alloy were studied. It is deduced that the key mechanism lies in the effect of dislocation.展开更多
To increase efficiency and improve performance, reducing cost and emissions, advanced single crystal Ni-based superalloys are required in aerospace propulsion and power generating gas turbines. With the development of...To increase efficiency and improve performance, reducing cost and emissions, advanced single crystal Ni-based superalloys are required in aerospace propulsion and power generating gas turbines. With the development of alloy, significant improvements in casting techniques have been achieved by introducing the directionally solidified (DS) casting process followed by single crystal (SX) technique. The deviation of preferred orientation of single crystal superalloys is one of the most important defects in casting. In directional solidification equipment with high temperature gradient, single crystal specimens of DZ417G alloy were prepared successfully by the modified Bridgeman method with spiral grain selector. The orientation was investigated by means of X-ray diffraction (XRD) and electron backscattered diffraction (EBSD).The results show that the crystal selector with a smaller angle can effectively reduce the deviation of preferred orientation.展开更多
Based on the high-purity single-crystal tungsten nanowire firstly prepared by the metal-catalyzed vapor-phase reaction method, molecular dynamics method was used to calculate tensile stress-strain curves and simulate ...Based on the high-purity single-crystal tungsten nanowire firstly prepared by the metal-catalyzed vapor-phase reaction method, molecular dynamics method was used to calculate tensile stress-strain curves and simulate microscopic deformation structures of the single-crystal tungsten nanowires with different crystal orientations of 〈100〉, 〈110〉and 〈111〉, in order to reveal the effect of crystal orientation on their tensile mechanical properties and failure mechanisms. Research results show that all of the stress-strain curves are classified into four stages: elastic stage, damage stage, yielding stage and failure stage, where 〈100〉orientation has a special hardening stage after yielding and two descending stages. The crystal orientation has little effect on elastic modulus but great effect on tensile strength, yielding strength and ductility, depending on different atomic surface energies and principal sliding planes. The calculated values of elastic modulus are in good agreement with the tested values of elastic modulus.展开更多
基金the financial support from the National Key R&D program of China(2021YFF0500501 and 2021YFF0500504)the Fundamental Research Funds for the Central Universities(YJS2213 and JB211408)+1 种基金the National Natural Science Foundation of China(61874083)the Joint Research Funds of Department of Science&Technology of Shaanxi Province and Northwestern Polytechnical University(No.2020GXLH-Z-014)
文摘Low-temperature,ambient processing of high-quality CsPbBr_(3)films is demanded for scalable production of efficient,low-cost carbon-electrode perovskite solar cells(PSCs).Herein,we demonstrate a crystal orientation engineering strategy of PbBr_(2)precursor film to accelerate its reaction with CsBr precursor during two-step sequential deposition of CsPbBr_(3)films.Such a novel strategy is proceeded by adding CsBr species into PbBr_(2)precursor,which can tailor the preferred crystal orientation of PbBr_(2)film from[020]into[031],with CsBr additive staying in the film as CsPb_(2)Br_(5)phase.Theoretical calculations show that the reaction energy barrier of(031)planes of PbBr_(2)with CsBr is lower about 2.28 eV than that of(O2O)planes.Therefore,CsPbBr_(3)films with full coverage,high purity,high crystallinity,micro-sized grains can be obtained at a low temperature of 150℃.Carbon-electrode PSCs with these desired CsPbBr_(3)films yield the record-high efficiency of 10.27%coupled with excellent operation stability.Meanwhile,the 1 cm^(2)area one with the superior efficiency of 8.00%as well as the flexible one with the champion efficiency of 8.27%and excellent mechanical bending characteristics are also achieved.
基金the financial support from the National Natural Science Foundation of China(Grant No.51839003)Liaoning Revitalization Talents Program(Grant No.XLYCYSZX 1902)Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources(Grant No.2023zy002).
文摘To achieve the loading of the stress path of hard rock,the spherical discrete element model(DEM)and the new flexible membrane technology were utilized to realize the transient loading of three principal stresses with arbitrary magnitudes and orientations.Furthermore,based on the deep tunnel of China Jinping Underground Laboratory II(CJPL-II),the deformation and fracture evolution characteristics of deep hard rock induced by excavation stress path were analyzed,and the mechanisms of transient loading-unloading and stress rotation-induced fractures were revealed from a mesoscopic perspective.The results indicated that the stressestrain curve exhibits different trends and degrees of sudden changes when subjected to transient changes in principal stress,accompanied by sudden changes in strain rate.Stress rotation induces spatially directional deformation,resulting in fractures of different degrees and orientations,and increasing the degree of deformation anisotropy.The correlation between the degree of induced fracture and the unloading magnitude of minimum principal stress,as well as its initial level is significant and positive.The process of mechanical response during transient unloading exhibits clear nonlinearity and directivity.After transient unloading,both the minimum principal stress and minimum principal strain rate decrease sharply and then tend to stabilize.This occurs from the edge to the interior and from the direction of the minimum principal stress to the direction of the maximum principal stress on theε1-ε3 plane.Transient unloading will induce a tensile stress wave.The ability to induce fractures due to changes in principal stress magnitude,orientation and rotation paths gradually increases.The analysis indicates a positive correlation between the abrupt change amplitude of strain rate and the maximum unloading magnitude,which is determined by the magnitude and rotation of principal stress.A high tensile strain rate is more likely to induce fractures under low minimum principal stress.
文摘In this editorial we comment on the article titled“Establishment and validation of an adherence prediction system for lifestyle interventions in non-alcoholic fatty liver disease”by Zeng et al published in a recent issue of the World Journal of Gastroenterology.Non-alcoholic fatty liver disease(NAFLD)represents one of the current challenges in hepatology and public health,due to its continuous growing prevalence and the rising incidence of NAFLD-related fibrosis,non-alcoholic steatohepatitis and cirrhosis.The only effective therapeutic strategy for this dis-ease is represented by encouraging patients to improve their lifestyle through the modification of dietary intake and increased physical exercise,but the effective application of such modifications is often limited by various factors such as lack of information,psychological barriers or poor social support.While poor adherence to a healthy lifestyle can be decisive in determining the clinical outcome,in daily practice there is a lack of quantitative instruments aimed at identifying patients with the lowest adherence to lifestyle changes and higher risk of disease progre-ssion in the course of follow-up.In this article,Zeng et al propose a quantitative scale to assess the grade of adherence of patients with NAFLD to hea-lthy lifestyle intervention,called the Exercise and Diet Adherence Scale(EDAS).This scale,consisting of 33 items divided into 6 dimensions which relates to six subjective aspects in the self-management of NAFLD,has shown a good correlation with the identification of the sub-cohort of patients with the highest reduction in caloric intake,increase in physical exercise,probability of a reduction in liver stiffness measurement and alanine aminotransferase levels.The cor-relation among clinical outcomes and specific dimensions of this scale also highlights the pivotal role of a good and confidential doctor-patient relationship and of an effective communication.There is an urgent need for practical and effective instruments to assess the grade of self-management of NAFLD patients,together with the development of multidisciplinary teams with the aim of applying structured behavioral interventions.
文摘AIM:To investigate the current situation and influencing factors of self-management ability in dry eye patients in west China.METHODS:A total of 265 patients clinically diagnosed with dry eye received a convenience survey questionnaire at West China Hospital of Sichuan University.All participants completed the rating scale of health self-management skill for adults(AHSMSRS),Huaxi Emotional-Distress Index(HEI),e-health literacy scale(e-HEALS)and Brief Illness Perception Questionnaire(Brief-IPQ).A generalized linear model was employed to establish a multivariate linear model with demographic data,psychological state,e-HEALS,and illness perception as independent variables and health selfmanagement skill score as the dependent variable.RESULTS:The mean score for health self-management skill was 165.58±15.79.Multivariate analysis revealed that advanced age,better illness perception and improved psychological state were associated with better health selfmanagement ability among dry eye patients.Furthermore,the health self-management ability of patients with a disease duration less than 1y was found to be higher compared to those with a disease duration exceeding 1y.CONCLUSION:The health self-management ability of dry eye patients in west China is relatively high.Age,duration of disease,illness perception and psychological state are the influencing factors on the health selfmanagement ability of dry eye patients.
基金the National Natural Science Foundation of China(Nos.52175143 and 51571150)。
文摘Strong anisotropic corrosion and mechanical properties caused by specimen orientations greatly limit the applications of wrought magnesium alloys.To investigate the influences of specimen orientation,the corrosion tests and(corrosion)fatigue crack growth tests were conducted.The rolled and transverse surfaces of the materials show distinct corrosion rate differences in the stable corrosion stage,but the truth is the opposite for the initial stage of corrosion.In air,specimen orientations have a significant influence on the plastic deformation mechanisms near the crack tip,which results in different fatigue fracture surfaces and cracking paths.Compared with R-T specimens,N-T specimens show a slower fatigue crack growth(FCG)rate in air,which can be attributed to crack closure effects and deformation twinning near the crack tip.The corrosion environment will not significantly change the main plastic deformation mechanisms for the same type of specimen.However,the FCG rate in phosphate buffer saline(PBS)is one order of magnitude higher than that in air,which is caused by the combined effects of hydrogen-induced cracking and anodic dissolution.Owing to the similar corrosion rates at crack tips,the specimens with different orientations display close FCG rates in PBS.
文摘The study site is a holistic patient-centered organization that has developed a 16-week long orientation program for new graduate nurses entering the hospital setting. The purpose of the program is for new graduate nurses to gain the confidence, competence, and critical thinking skills for providing safe patient care. The issue occurring within the organization is that there is an increasing rise in the number of turnover rates of new graduates leaving the hospital, thus making evaluating the program a necessity to problem-solving. There has been no evaluation of the program in the past five years to reveal why the increase in the recent turnover rates. The data collected during the interview process was coded and categorized into three main sections: organizational, substantive, and theoretical. The evaluator used an organizational category to investigate for board areas or issues within the problem attempting to be solved. The evaluator concluded from the results and findings that the issue, a poor preceptor-preceptee relationship was seen by all stakeholders involved. The literature presented concludes that continuous evaluation of orientation programs is crucial for the professional and personal growth of new graduate nurses in the hospital.
文摘Research Background: The high prevalence of diabetes in Sudan, estimated at 16%, highlights the importance of effective health education in diabetes management. Diabetes self-management education has been identified as a crucial tool in enhancing the knowledge, attitudes, and abilities necessary for self-management among individuals with diabetes. Aim: To assess the impact of diabetes self-management education on medication adherence and glycemic control in Sudanese adults with type 2 diabetes before and 3 months after the DSME intervention. Method: The study was conducted in Sudan between September 2022 and March 2023, it was an interventional, one-group, pre- and post-test study that aimed to assess the impact of diabetes self-management education (DSME) on medication adherence and diabetes control in Sudanese adults with type 2 diabetes. The research was conducted in primary health care centers in six cities in Sudan and involved 244 participants. The data entry and statistical analysis were conducted using the Statistical Package for Social Sciences version 27.0. A paired t test was used for analysis. Results: The study included 244 participants, 67% of whom were males. The age mean ± SD was 48.6 ± 9.3 years, and 85.3% of participants were married. Age at onset of diabetes mean ± SD was 40.60 ± 7.81 years;44.6% had diabetes for less than 5 years;and 84.1% had a positive family history of diabetes mellitus. The levels of poor, low, and partial adherence to medication decreased by 8.2%, 4%, and 20.6%, respectively, after the intervention. The levels of good and high medication regime adherence increased by 13% and 19.8%, respectively;BMI decreased by 1.1 ± 0.73 kg/m<sup>2</sup> (p = 0.005). The fasting blood sugar decreased by 69 ± 32.9 mg/dl (p = 0.049), and the glycated hemoglobin decreased by 1.21 ± 0.28% (p = 0.001). Conclusions: The findings of this study reinforce the importance of patient education in improving glycemic control and enhancing self-management behaviors. Patient education plays a critical role in enhancing glycemic control and self-management behaviors. It is essential for healthcare providers to adopt a patient-centered approach, taking into account the individual's beliefs, attitudes, and knowledge about their illness and treatment. Overcoming these challenges necessitates a comprehensive approach, including enhancing healthcare professionals’ knowledge and communication skills, offering accessible and culturally sensitive diabetes education programs, and addressing barriers to resources and support for self-management.
基金supported by the National Natural Science Foundation of China(Grant No.31772258)the National Key Research and Development Program(Grant No.2019YFD1000102-11)。
文摘Climate change and extreme weather pose significant challenges to the traditional viticulture regions.Emerging high-altitude grape-producing regions with diverse orientations have shown great potential in coping with this challenge.Stable,high-quality wine grape production may be achieved by synchronizing the meso-and microclimate.To clarify the role of high altitude and row orientation in meso-and microclimate and the response of berries to it,we evaluated seven years(2012-2018)of climate data,two years of basic grape(Cabernet Sauvignon,Vitis vinifera L.)quality,and one-year microclimate from veraison to harvest.By comparing two locations(Sidon 2047 m,Sinon 2208 m)in Yunnan Province,China,we found that the average temperature has been stable at approximately 15℃ for seven years,with no extreme weather or,noticeable global warming.The light intensity(LI)in the north-south(NS)was more balanced than the east-west(EW)direction,and the east-west to the south(EW-S)canopy side was almost higher than the other sides.High LI was associated with high photosynthetically active radiation(PAR),ultraviolet(UV),and infrared(IR)light and vice versa.The north-south to the east(NS-E)and east-west to the north(EWN)sides were characterized by lower LI and higher UV and IR light,and higher total anthocyanin content.Most anthocyanin synthesis-related genes,for example,VvF3'H and VvF3'5'H,were highly expressed in NS-E from veraison to maturity.Perhaps UV and IR light induced their expression.This study provides new insights on the role of differently orientated rows in controlling grape quality due to varied light quality.The findings are globally significant,particularly in the context of climate change,and offer fresh insights into berry physiological responses and decision-making for the management of existing vineyards.
基金supported by National Natural Science Foundation of China (52070194,52073309)Natural Science Foundation of Hunan Province (2022JJ20069)。
文摘Generally,layered Ni-rich cathode materials exhibit the morphology of polycrystalline secondary sphere composed of numerous primary particles.While the arrangement of primary particles plays a very important role in the properties of Ni-rich cathodes.The disordered particle arrangement is harmful to the cyclic performance and structural stability,yet the fundamental understanding of disordered structure on the structural degradation behavior is unclarified.Herein,we have designed three kinds of LiNi_(0.83)Co_(0.06)Mn_(0.11)O_(2) cathode materials with different primary particle orientations by regulating the precursor coprecipitation process.Combining finite element simulation and in-situ characterization,the Li^(+)transport and structure evolution behaviors of different materials are unraveled.Specifically,the smooth Li^(+)diffusion minimizes the reaction heterogeneity,homogenizes the phase transition within grains,and mitigates the anisotropic microstructural change,thereby modulating the crack evolution behavior.Meanwhile,the optimized structure evolution ensures radial tight junctions of the primary particles,enabling enhanced Li^(+)diffusion during dynamic processes.Closed-loop bidirectional enhancement mechanism becomes critical for grain orientation regulation to stabilize the cyclic performance.This precursor engineering with particle orientation regulation provides the useful guidance for the structural design and feature enhancement of Ni-rich layered cathodes.
基金supported by the National Natural Science Foundation of China(Grant No.52375438)Shenzhen Science and Technology Programs(Grant No.JCYJ20220818100408019,JSGG20220831101401003,JSGG20210802154007021,KQTD201708101102503570).
文摘The practical application of lithium(Li)metal anodes in high-capacity batteries is impeded by the formation of hazardous Li dendrites.To address this challenge,this research presents a novel methodology that combines laser ablation and heat treatment to precisely induce controlled grain growth within laser-structured grooves on copper(Cu)current collectors.Specifically,this approach enhances the prevalence of Cu(100)facets within the grooves,effectively lowering the overpotential for Li nucleation and promoting preferential Li deposition.Unlike approaches that modify the entire surface of collectors,our work focuses on selectively enhancing lithiophilicity within the grooves to mitigate the formation of Li dendrites and exhibit exceptional performance metrics.The half-cell with these collectors maintains a remarkable Coulombic efficiency of 97.42%over 350 cycles at 1 mA cm^(−2).The symmetric cell can cycle stably for 1600 h at 0.5 mA cm^(−2).Furthermore,when integrated with LiFePO4 cathodes,the full-cell configuration demonstrates outstanding capacity retention of 92.39%after 400 cycles at a 1C discharge rate.This study introduces a novel technique for fabricating selective lithiophilic three-dimensional(3D)Cu current collectors,thereby enhancing the performance of Li metal batteries.The insights gained from this approach hold promise for enhancing the performance of all laser-processed 3D Cu current collectors by enabling precise lithiophilic modifications within complex structures.
基金supported by the National Natural Science Foundation of China (No.U21B6004)Major Project of Scientific Innovation of Hunan Province,China (No.2021GK1040)National Key R&D Program of China (No.2020YFA0711104)。
文摘The slip behavior and precipitation behavior of four Al−Cu−Li single crystals with varying orientations at different temperatures were investigated using electron backscattering diffraction(EBSD)and transmission electron microscopy(TEM).The maximum differences in yield strength and ductility of the single crystals at room temperature are 41.6%and 14.7%,respectively.This indicates that the mechanical properties are strongly influenced by the crystal orientation.Moreover,grains with varying orientations exhibit distinct slip characteristics,including slip homogenization,slip localization,and multiple slip.In single crystal SC1,slip localization primarily contributes to its inferior ductility compared to other grains.Nevertheless,during deformation at 250℃,the distinct morphology and distribution of precipitates in the crystals are also correlated with orientation,which causes the increase in the maximum elongation difference to 20.8%in all selected single crystals.Notably,SC1,with a precipitate volume fraction of 2.65%,exhibits more severe slip localization compared to room temperature conditions,while SC2,with a precipitate volume fraction of 4.79%,demonstrates cross-slip characteristics,significantly enhancing the plastic deformation capacity of the Al−Cu−Li alloy.
文摘Hypertension(HTN)is one of the most common chronic diseases affecting over 30%of the adult population globally,with a growing incidence rate.This review assesses the relationship between health literacy(HL)intervention and hypertension(HTN)self-management among people with HTN.The study design was a systematic review of empirical research articles using a well-defined strategy.Online journals were accessed through databases such as PubMed,CINAHL,Google Scholar,ProQuest,Global Health,WHOLIS,Embase,and EbscoHost,spanning from January 2016 to December 2022 as the scope of the study.Articles selected for inclusion were those published in English during the specified time frame and adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and Sample,Phenomenon of Interest,Design,Evaluation,Research Type framework for systematic review,focusing on criteria related to the sample,the phenomenon of interest,study design,evaluation,and research type.Out of 180 studies initially identified in the database search,20 studies were ultimately included in the review.The findings were reported based on these five emerging themes:Relationship between HL and HTN self-management;Effect of HL intervention on HTN self-management;Factors predicting self-care behaviors among HTN patients with low HL;Effect of HL and self-management efficacy on health-related quality of life(HRQoL);and level of self-care practices.This review highlights a relationship between HL,self-efficacy,self-care,and HRQoL,underscoring the necessity for further well-designed intervention studies focused on enhancing HL in individuals with HTN in Nigeria to enhance their quality of life.
基金supported by the Health Science and Technology Project of Pudong New Area Health Commission(No.PW2023A-09)the Academic Leaders Training Program of Pudong Health Bureau of Shanghai(No.PWRd2022-16)+1 种基金Tongji University“Third Year Action Plan for Discipline Construction of School of Nursing”(No.JS2210328)Important Weak Subject Construction Project of Shanghai Pudong New Area Health Commission(No.PWZbr2022-04)。
文摘Objective:This paper presents an analysis of the concept of patient outcomes.Methods:The present study conducted searches on various databases,including Wanfang,Sinomed,CNKI,Pub Med,Cochrane Library,Embase,Web of Science,and Ovid.The paper followed the Walker and Avant concept-analysis approach.Results:Initially,899 pieces of literature were identified through the search process,and after screening,41 of them were ultimately included in the analysis.The identified attributes of the concept included(1)capability,(2)decision making,and(3)action.These antecedents were shaped by factors such as illness perception,self-efficacy,and family and social.The consequences included(1)physiological effects,(2)psychological effects,and(3)social influence.Conclusions:The concept analysis of self-management in patients with diabetic foot ulcers(DFUs)not only aids in clinical practice and suppor ts interventions,but also contributes to the development of self-management theory.The common goal of clinical medical staff is to assist DFU patients in improving cognitive ability,making correct self-management decisions,and enhancing self-management behavior.
文摘Objective: To explore the impact of the WeChat platform continuity of care model based on the KAP (knowledge, attitudes, and practices) theory on the self-management of stroke patients with hypertension after discharge from the hospital. Methods: 62 stroke patients with hypertension discharged from the rehabilitation department of a tertiary A hospital in Nanning City, Guangxi Zhuang Autonomous Region, from October 2022 to April 2023 were sampled by convenience sampling method. Patients discharged from Rehabilitation I were included in the control group, and conventional nursing care was used;while patients discharged from Rehabilitation II were included in the observation group, and WeChat platform continuity of nursing care model based on the KAP theory was implemented. The intervention effect of the two groups was compared. Results: After 4 and 12 weeks of intervention, the diastolic and systolic blood pressure of the patients in the observation group were lower than those in the control group (P < 0.05);after 12 weeks of intervention, the rate of medication adherence and the score of adherence to hypertension treatment in the observation group were significantly higher than those in the control group (P < 0.05). Conclusion: The application of the WeChat platform continuity of care model based on KAP theory to stroke patients with hypertension can improve blood pressure, medication adherence rate, hypertension treatment adherence, and overall enhance the self-management level of these patients.
文摘Objective:To clarify the concept of self-management in hypertensive patients by analyzing the definition,attributes,and measurement tools through a literature review.Methods:An Internet-based search of the databases was conducted using Academic Search Complete,Medical Line,CINAHL,Health Source:Nursing/Scholarly Edition,and Google Scholar.In the search process,keywords or free text were combined by using Boolean operators,with the search terms“self of management”or“self-management,”“concept*analysis”or“concept*definition,”and Walker and Avant’s concept analysis method was used.Results:Analysis of relevant literature summarized the conceptual attributes of self-management in hypertensive patients as the active participation of patients in the treatment process;the presence of interaction provided by patients and health care providers;the use of certain health management tools;and the aim of maintaining and improving the health status and living capacity of hypertensive patients.Conclusion:The concept of self-management for hypertensive patients was clarified,which helps to promote the application of hypertensive self-management in clinical work and improve outcomes and quality of life for patients with hypertension.
文摘The significant impact of earthquakes on human lives and the built environment underscores the extensive human and economic losses caused by structural collapses. Over the years, researchers have focused on improving seismic design to mitigate earthquake-induced damages and enhance structural performance. In this study, a specific reinforced concrete (RC) frame structure at Kyungpook National University, designed for educational purposes, is analyzed as a representative case. Utilizing SAP 2000, the research conducts a nonlinear time history analysis to assess the structural performance under seismic conditions. The primary objective is to evaluate the influence of different column section designs, while maintaining identical column section areas, on structural behavior. The study employs two distinct seismic waves from Abeno (ABN) and Takatori (TKT) for the analysis, comparing the structural performance under varying seismic conditions. Key aspects examined include displacement, base shear force, base moment, joint radians, and layer displacement angle. This research is anticipated to serve as a valuable reference for seismic restraint reinforcement work on RC buildings, enriching the methods used for evaluating structures through nonlinear time history analysis based on the synthetic seismic wave approach.
文摘This study unfolds an innovative approach aiming to address the critical role of building design in global energy consumption, focusing on optimizing the Window-to-Wall Ratio (WWR), since buildings account for approximately 30% of total energy consumed worldwide. The greatest contributors to energy expenditure in buildings are internal artificial lighting and heating and cooling systems. The WWR, determined by the proportion of the building’s glazed area to its wall area, is a significant factor influencing energy efficiency and minimizing energy load. This study introduces the development of a semi-automated computer model designed to offer a real-time, interactive simulation environment, fostering improving communication and engagement between designers and owners. The said model serves to optimize both the WWR and building orientation to align with occupants’ needs and expectations, subsequently reducing annual energy consumption and enhancing the overall building energy performance. The integrated model incorporates Building Information Modeling (BIM), Virtual Reality (VR), and Energy Analysis tools deployed at the conceptual design stage, allowing for the amalgamation of owners’ inputs in the design process and facilitating the creation of more realistic and effective design strategies.
基金Projects(2010CB731700,2012CB619500)supported by the National Basic Research Program of ChinaProject(51375503)supported by the National Natural Science Foundation of China
文摘The precipitation behaviors of 2124 aluminum alloy under the conditions of artificial aging (AA), creep aging (CA) and creep aging with pre-deformation (PCA) were investigated by means of mechanical property and microstructure. The results show that the mechanical properties of CA treated sample decrease significantly compared with AA treated sample. The yield strength of the CA treated sample falls by 14%, the tensile strength falls by 6.2%, and the elongation falls by 21%. Nevertheless, the mechanical properties of PCA sample are improved obviously, close to the AA treated sample. Moreover, the generation and control mechanisms of the precipitation orientation effect in 2124 aluminum alloy were studied. It is deduced that the key mechanism lies in the effect of dislocation.
基金Project (51074105) supported by the National Natural Science Foundation of ChinaProjects (08DZ1130100, 10520706400) supported by the Science and Technology Commission of Shanghai Municipality, ChinaProject (2007CB613606) supported by the National Basic Research Program of China
文摘To increase efficiency and improve performance, reducing cost and emissions, advanced single crystal Ni-based superalloys are required in aerospace propulsion and power generating gas turbines. With the development of alloy, significant improvements in casting techniques have been achieved by introducing the directionally solidified (DS) casting process followed by single crystal (SX) technique. The deviation of preferred orientation of single crystal superalloys is one of the most important defects in casting. In directional solidification equipment with high temperature gradient, single crystal specimens of DZ417G alloy were prepared successfully by the modified Bridgeman method with spiral grain selector. The orientation was investigated by means of X-ray diffraction (XRD) and electron backscattered diffraction (EBSD).The results show that the crystal selector with a smaller angle can effectively reduce the deviation of preferred orientation.
基金Projects(50374082,5071112018)supported by the National Natural Science Foundation of China
文摘Based on the high-purity single-crystal tungsten nanowire firstly prepared by the metal-catalyzed vapor-phase reaction method, molecular dynamics method was used to calculate tensile stress-strain curves and simulate microscopic deformation structures of the single-crystal tungsten nanowires with different crystal orientations of 〈100〉, 〈110〉and 〈111〉, in order to reveal the effect of crystal orientation on their tensile mechanical properties and failure mechanisms. Research results show that all of the stress-strain curves are classified into four stages: elastic stage, damage stage, yielding stage and failure stage, where 〈100〉orientation has a special hardening stage after yielding and two descending stages. The crystal orientation has little effect on elastic modulus but great effect on tensile strength, yielding strength and ductility, depending on different atomic surface energies and principal sliding planes. The calculated values of elastic modulus are in good agreement with the tested values of elastic modulus.