Objective:To explore the role of specialized group management in the quality control of perioperative nursing.Methods:45 surgical nurses from our hospital were selected as the research subjects.Traditional operating r...Objective:To explore the role of specialized group management in the quality control of perioperative nursing.Methods:45 surgical nurses from our hospital were selected as the research subjects.Traditional operating room management was adopted from July 2019 to June 2020,and specialized group management was adopted from July 2020 to June 2021.The surgeon’s satisfaction,surgical nurses’core professional competence,and surgical patients’satisfaction were obtained through surveys and the results were analyzed.Results:Surgeon satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Besides,surgical nurses’core professional competency scores before the implementation of specialized group management were significantly lower than after its implementation(P<0.05).Lastly,surgical patients’satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Conclusion:Specialized group management helps to improve the quality of perioperative care and should be applied in clinical practice.展开更多
Through the use of purification and recirculation superheating techniques on molten glass,the Ni65Cu33Co2 alloy was successfully undercooled to a maximum temperature of 292 K.High-speed photography was employed to cap...Through the use of purification and recirculation superheating techniques on molten glass,the Ni65Cu33Co2 alloy was successfully undercooled to a maximum temperature of 292 K.High-speed photography was employed to capture the process of interface migration of the alloy liquid,allowing for an analysis of the relationship between the morphological characteristics of the alloy liquid solidification front and the degree of undercooling.Additionally,the microstructure of the alloy was examined using metallographic microscopy,leading to a systematic study of the microscopic morphological characteristics and evolution laws of the refined structure during rapid solidification.The research reveals that the grain refining mechanism of the Ni-Cu-Co ternary alloy is consistent with that of the binary alloy(Ni-Cu).Specifically,under low undercooling conditions,intense dendritic remelting was found to cause grain refinement,while under high undercooling conditions,recrystallization driven by accumulated stress and plastic strain resulting from the interaction between the liquid flow and the primary dendrites caused by rapid solidification was identified as the main factor contributing to grain refinement.Furthermore,the study highlights the significant role of the Co element in influencing the solidification rate and reheat effect of the alloy.The addition of Co was also found to facilitate the formation of non-segregated solidification structure,indicating its importance in the overall solidification process.展开更多
In order to enhance the mechanical properties of the selective laser-melted(SLM) high-Mg content AlSiMg1.4 alloy,the Zr element was introduced.The influence of Zr alloying on the processability,microstructure,and mech...In order to enhance the mechanical properties of the selective laser-melted(SLM) high-Mg content AlSiMg1.4 alloy,the Zr element was introduced.The influence of Zr alloying on the processability,microstructure,and mechanical properties of the alloy was systematically investigated through performing microstructure analysis and tensile testing.It was demonstrated that the SLM-fabricated AlSiMg1.4-Zr alloy exhibited high process stability with a relative density of over 99.5% at various process parameters.Besides,the strong grain refinement induced by the primary Al3Zr particle during the melt solidification process simultaneously enhanced both the strength and plasticity of the alloy.The values for the yield strength,ultimate tensile strength,and elongation of the SLM-fabricated AlSiMg1.4-Zr were(343±3) MPa,(485±4) MPa,and(10.2±0.2)%,respectively,demonstrating good strengthplasticity synergy in comparison to the AlSiMg1.4 and other Al-Si-based alloys fabricated by SLM.展开更多
In Mg-Ca alloys the grain refining mechanism,in particular regarding the role of nucleant substrates,remains the object of debates.Although native MgO is being recognised as a nucleating substrate accounting for grain...In Mg-Ca alloys the grain refining mechanism,in particular regarding the role of nucleant substrates,remains the object of debates.Although native MgO is being recognised as a nucleating substrate accounting for grain refinement of Mg alloys,the possible interactions of MgO with alloying elements that may alter the nucleation potency have not been elucidated yet.Herein,we design casting experiments of Mg-xCa alloys varied qualitatively in number density of native MgO,which are then comprehensively studied by advanced electron microscopy.The results show that grain refinement is enhanced as the particle number density of MgO increases.The native MgO particles are modified by interfacial layers due to the co-segregation of Ca and N solute atoms at the MgO/Mg interface.Using aberration-corrected scanning transmission electron microscopy and electron energy loss spectroscopy,we reveal the nature of these Ca/N interfacial layers at the atomic scale.Irrespective of the crystallographic termination of MgO,Ca and N co-segregate at the MgO/Mg interface and occupy Mg and O sites,respectively,forming an interfacial structure of a few atomic layers.The interfacial structure is slightly expanded,less ordered and defective compared to the MgO matrix due to compositional deviations,whereby the MgO substrate is altered as a poorer template to nucleate Mg solid.Upon solidification in a TP-1 mould,the impotent MgO particles account for the grain refining mechanism,where they are suggested to participate into nucleation and grain initiation processes in an explosive manner.This work not only reveals the atomic engineering of a substrate through interfacial segregation but also demonstrates the effectiveness of a strategy whereby native MgO particles can be harnessed for grain refinement in Mg-Ca alloys.展开更多
Specialized households serve as the primary units within specialized villages in China,and their capacity to withstand risks and external influences significantly shapes the future trajectory of specialized villages a...Specialized households serve as the primary units within specialized villages in China,and their capacity to withstand risks and external influences significantly shapes the future trajectory of specialized villages and the overall vitality of the rural economy.In this study,we established a measurement indicator system based on the definition of specialized households’resilience,elucidating the logical connection between specialized households’resilience and rural industrial development in China.The musical instrument industry in Lankao County,Henan Province of China,was employed as a case;survey data,the entropy method,and an obstacle diagnosis model were used to examine how instrument production specialized households responded to the challenges posed by Corona Virus Disease 2019(COVID-19)and the tightening of national environmental protection policies,yielding the following key findings:1)there exists substantial variation in the comprehensive resilience levels among different specialized households;2)the ability to learn and adapt is the most significant contributor to the overall resilience level of specialized households;3)technological proficiency and access to skilled talent emerge as pivotal factors influencing specialized households’resilience;4)the positioning of specialized households within the industrial supply chain and the stability of their income have a direct bearing on their resilience level.The influence of specialized households’resilience on industrial development primarily manifests in the following ways:stronger resilience correlates with increased stability in production and sales,fostering a more proactive approach to future actions.However,heightened exposure to the external macroeconomic environment can lead to a higher rate of export reduction.To enhance the development resilience of entities like specialized households and family farms,and to invigorate rural economic development,escalating investments in rural science and technology and prioritizing the training of technical talent become imperative.展开更多
The effect of addition temperature of MgO particles(MgOp)on their dispersion behavior and the efficiency of grain refinement in AZ31 Mg alloy was investigated.In addition,the grain refinement mechanism was systematica...The effect of addition temperature of MgO particles(MgOp)on their dispersion behavior and the efficiency of grain refinement in AZ31 Mg alloy was investigated.In addition,the grain refinement mechanism was systematically studied by microstructure characterization,thermodynamic calculation,and analysis of solidification curves.The results show that the grain size of AZ31 Mg alloy initially decreases and then increases as the MgOp addition temperature is increased from 720 to 810℃,exhibiting a minimum value of 136μm at 780℃.The improved grain refinement efficiency with increasing MgOp addition temperature can be attributed to the reduced Mg melt viscosity and enhanced wettability between MgOp and Mg melt.Furthermore,a corresponding physical model describing the solidification behavior and grain refinement mechanism was proposed.展开更多
Second-generation high-temperature superconducting(HTS)conductors,specifically rare earth-barium-copper-oxide(REBCO)coated conductor(CC)tapes,are promising candidates for high-energy and high-field superconducting app...Second-generation high-temperature superconducting(HTS)conductors,specifically rare earth-barium-copper-oxide(REBCO)coated conductor(CC)tapes,are promising candidates for high-energy and high-field superconducting applications.With respect to epoxy-impregnated REBCO composite magnets that comprise multilayer components,the thermomechanical characteristics of each component differ considerably under extremely low temperatures and strong electromagnetic fields.Traditional numerical models include homogenized orthotropic models,which simplify overall field calculation but miss detailed multi-physics aspects,and full refinement(FR)ones that are thorough but computationally demanding.Herein,we propose an extended multi-scale approach for analyzing the multi-field characteristics of an epoxy-impregnated composite magnet assembled by HTS pancake coils.This approach combines a global homogenization(GH)scheme based on the homogenized electromagnetic T-A model,a method for solving Maxwell's equations for superconducting materials based on the current vector potential T and the magnetic field vector potential A,and a homogenized orthotropic thermoelastic model to assess the electromagnetic and thermoelastic properties at the macroscopic scale.We then identify“dangerous regions”at the macroscopic scale and obtain finer details using a local refinement(LR)scheme to capture the responses of each component material in the HTS composite tapes at the mesoscopic scale.The results of the present GH-LR multi-scale approach agree well with those of the FR scheme and the experimental data in the literature,indicating that the present approach is accurate and efficient.The proposed GH-LR multi-scale approach can serve as a valuable tool for evaluating the risk of failure in large-scale HTS composite magnets.展开更多
BACKGROUND Some patients with coronary atherosclerotic heart disease experience major adverse cardiac events(MACE)and require readmission after Coronary Artery Bypass Grafting(CABG)surgery.This is often attributed to ...BACKGROUND Some patients with coronary atherosclerotic heart disease experience major adverse cardiac events(MACE)and require readmission after Coronary Artery Bypass Grafting(CABG)surgery.This is often attributed to patients'unhealthy lifestyles and dietary habits,inadequate understanding of the disease,and poor disease management compliance.Thus,searching for more targeted nursing intervention models that can enhance patients'self-management abilities and reduce the risk of readmission after CABG surgery is significant.AIM To observe the impact of specialized nursing outpatient case management on patients after CABG surgery.METHODS A total of 103 patients who underwent CABG surgery in our hospital between April 2021 and April 2022 comprised the study sample.The patients were divided into two groups using an odd-even number grouping method.The control group received routine nursing care,while the case management group received specialized nursing outpatient case management.The differences in psychological status,adherence to medical treatment,self-care ability,knowledge mastery,quality of life scores,and the occurrence rate of MACE were compared between the two groups.RESULTS After the intervention,the case management group had lower scores on the selfrating depression scale and self-rating anxiety scale and lower MACE rate,as well as higher scores for adherence to a healthy diet,medication adherence,good lifestyle habits,regular exercise,and timely follow-up,higher scores on the Coronary Heart Disease Self-Management Scale,higher scores for managing adverse habits,symptoms,emotional cognition,emergency response,disease knowledge,general lifestyle,and treatment adherence,higher scores for understanding coronary heart disease,recognizing the importance of medication adherence,understanding selfcare points after CABG surgery,and being aware of post-CABG precautions,higher scores for physical well-being,disease condition,general health,social-psychological well-being,and work-related aspects(P<0.05).CONCLUSION Specialized nursing outpatient case management can enhance patient adherence to medical treatment,knowledge mastery,psychological well-being,and overall quality of life in patients after CABG surgery.展开更多
With the release of China Education Modernization 2035,education modernization has become a national strategic goal.In this context,Chongqing Energy Vocational College is actively exploring the“four integration and f...With the release of China Education Modernization 2035,education modernization has become a national strategic goal.In this context,Chongqing Energy Vocational College is actively exploring the“four integration and four innovation”specialized and creative integration talent cultivation mode,aiming at cultivating high-quality talents with innovative spirit and practical skills.This paper analyzes the status quo and challenges of talent cultivation in higher vocational education,puts forward the main practices of innovation-driven,creation and research,cross-border integration,and innovative practice,and has achieved remarkable results.Additionally,it summarizes the experience revelation and provides a reference for other higher vocational colleges and universities.展开更多
In this article,we first establish an asymptotically sharp result on the higher order Fréchet derivatives for bounded holomorphic mappings f(x)=f(0)+∞∑s=1Dskf(0)(x^(sk))/(sk)!:B_(X)→B_(Y),where B_X is the unit...In this article,we first establish an asymptotically sharp result on the higher order Fréchet derivatives for bounded holomorphic mappings f(x)=f(0)+∞∑s=1Dskf(0)(x^(sk))/(sk)!:B_(X)→B_(Y),where B_X is the unit ball of X.We next give a sharp result on the first order Fréchet derivative for bounded holomorphic mappings F(X)=F(0+)∞∑s=KD^(s)f(0)(x^(8)/s!):B_(X)→B_(Y),where B_(X)is the unit ball of X.The results that we derive include some results in several complex variables,and extend the classical result in one complex variable to several complex variables.展开更多
Additive manufacturing(AM)of Mg alloys has become a promising strategy for producing complex structures,but the corrosion performance of AM Mg components remains unexploited.In this study,wire and arc additive manufac...Additive manufacturing(AM)of Mg alloys has become a promising strategy for producing complex structures,but the corrosion performance of AM Mg components remains unexploited.In this study,wire and arc additive manufacturing(WAAM)was employed to produce single AZ31 layer.The results revealed that the WAAM AZ31 was characterized by significant grain refinement with non-textured crystallographic orientation,similar phase composition and stabilized corrosion performance comparing to the cast AZ31.These varied corrosion behaviors were principally ascribed to the size of grain,where cast AZ31 and WAAM AZ31 were featured by micro galvanic corrosion and intergranular corrosion,respectively.展开更多
High-performance cast magnesium rare-earth(Mg-RE) alloys are one of the most important materials among all developed Mg alloy families, and have shown great potential in military and weapons, aerospace and aviation, o...High-performance cast magnesium rare-earth(Mg-RE) alloys are one of the most important materials among all developed Mg alloy families, and have shown great potential in military and weapons, aerospace and aviation, orthopedic implants, etc. Controlling grain size and distribution of it is key to the promising mechanical performance of Mg-RE alloy casting components. During the casting of a real component, nearly every procedure in the fabrication process will influence the grain refinement effect. The procedure may include and may not be limited to the chemical inoculations, possibly applied physical fields, the interfere between grain refiner and purifications, and the casting techniques with different processing parameters. This paper reviews the recent advances and proposed future developments in these categories on grain refinement of cast Mg-RE alloys. The review will provide insights for the future design of grain refinement techniques,the choosing of processing parameters, and coping strategies for the failure of coarsening for cast Mg-RE components with high quality and good performance.展开更多
Vocational colleges attach great importance to labor education.Specialized courses are an effective way to cultivate students labor quality,and the integration of labor education in specialized courses plays an import...Vocational colleges attach great importance to labor education.Specialized courses are an effective way to cultivate students labor quality,and the integration of labor education in specialized courses plays an important role in the overall cultivation of students moral quality and practical ability.Combined with the teaching practice of landscape technology specialty,labor education is integrated into the teaching of Plant Cultivation and Maintenance,and certain results have been achieved.In this paper,the course content"grafting propagation"was analyzed from the aspects of overall teaching design,teaching implementation process,teaching effect and reflection improvement,so as to provide reference for other contents of this major or other majors to carry out integrated teaching.展开更多
Due to the significant differences in the formation temperature and crystal structure between the primaryα-Mg and eutecticβ-Mg_(17)Al_(12),it is a great challenge to achieve simultaneous refinement of the primary an...Due to the significant differences in the formation temperature and crystal structure between the primaryα-Mg and eutecticβ-Mg_(17)Al_(12),it is a great challenge to achieve simultaneous refinement of the primary and eutectic phases in Mg-Al based alloys via heterogeneous nucleation.Surprisingly,we found that theα-Mg andβ-Mg_(17)Al_(12) in the AZ80 alloy can be simultaneously refined after 0.2 wt.%Sm addition,with the grain size decreasing from∼217±15μm to∼170±10μm and theβ-Mg_(17)Al_(12) morphology changing from a typical continuous network to a nod-like or spherical structure.The simultaneous refinement mechanism is investigated through solidification simulation,transmission electron microscopy(TEM),and differential thermal analysis(DTA).In the AZ80-0.2Sm alloy,many Al8Mn4Sm particles can be observed near the center of theα-Mg grains or inside theβ-Mg_(17)Al_(12).Crystallographic calculations further reveal that the Al8Mn4Sm has good crystallographic matching with both theα-Mg andβ-Mg_(17)Al_(12),so it possesses the potency to serve as heterogeneous nucleation sites for both phases.The promoted heterogeneous nucleation on the Al8Mn4Sm decreases the undercooling required by the nucleation of the primary and eutectic phases,which enhances the heterogeneous nucleation rate,thus causing the simultaneous refinement of theα-Mg andβ-Mg_(17)Al_(12).The orientation relationships between the Al8Mn4Sm and Mg/Mg_(17)Al_(12) are identified,which are[1210]_(Mg)//[010]_(Al8Mn4Sm),(1010)_(Mg)//(301)_(Al8Mn4Sm) and[112]_(Mg_(17)Al_(12))//[010]_(Al8Mn4Sm),(110)_(Mg_(17)Al_(12))//(301)_(Al8Mn4Sm),respectively.Furthermore,the refinement of theβ-Mg_(17)Al_(12) accelerates its dissolution during the solution treatment,which is beneficial for cost saving in industrial applications.Other Al8Mn4RE compounds such as Al8Mn4Y might have the same positive effect on the simultaneous refinement due to the similar physicochemical properties of rare earth elements.This work not only proves the possibility of simultaneously refining the primary and eutectic phases in Mg-Al based alloys via heterogeneous nucleation,but also provides new insights into the development of refiners for cast Mg alloys.展开更多
Erratum to:International Journal of Minerals, Metallurgy and MaterialsVolume 28, Number 7, July 2021, Page 1112 The original version of this article unfortunately contained mistakes. Symbols in Table 2 are used incorr...Erratum to:International Journal of Minerals, Metallurgy and MaterialsVolume 28, Number 7, July 2021, Page 1112 The original version of this article unfortunately contained mistakes. Symbols in Table 2 are used incorrectly.展开更多
The molten Cu60Ni35Co5 ternary alloy was undercooled by fluxing method and solidified by natural cooling method.The microstructure of all undercooled samples were analyzed.It is found that the rapidly solidified Cu60N...The molten Cu60Ni35Co5 ternary alloy was undercooled by fluxing method and solidified by natural cooling method.The microstructure of all undercooled samples were analyzed.It is found that the rapidly solidified Cu60Ni35Co5 alloy has undergone two grain refinement phenomena within the undercooling range,and its microstructure and morphology change with the undercooling through the transformation process of“coarse dendrite-equiaxed dendrite-oriented fine dendrite-equiaxed crystal”.The refined structure with the maximum undercooling?T of 253 K was selected for electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM)tests.EBSD results show that the refined structure contains a high proportion of large angle grain boundaries(LAGBs),a large number of randomly oriented grains,and high proportion of twins,while TEM results show that the dislocation density in most areas is relatively low.The above characteristics confirm that the solidification structure is refined due to recrystallization behavior under high undercooling.展开更多
Both Cu60Ni38Co2 and Cu60Ni40 alloy were naturally cooled after rapid solidification from the liquid phase.The transformation law of the microstructure characteristics of the rapidly solidified alloy with the change o...Both Cu60Ni38Co2 and Cu60Ni40 alloy were naturally cooled after rapid solidification from the liquid phase.The transformation law of the microstructure characteristics of the rapidly solidified alloy with the change of undercooling(DT)was systematically studied.It was found that the two alloys experienced the same transformation process.The refinement structures under different undercoolings were characterized by electron backscatter diffraction(EBSD).The experimental results show that the characteristics of the refinement structure of the two alloys with low undercooling are the same,whereas,the characteristics of the refinement structure with high undercooling are opposite.The transmission electron microscope(TEM)results of Cu60Ni38Co2 alloy show that the dislocation network density of low undercooled microstructure is lower than that of high undercooled microstructure.By combining EBSD and TEM,it can be confirmed that the dendrite remelting fracture is the reason for the refinement of the low undercooled structure,while the high undercooled structure is refined due to recrystallization.展开更多
Inhaled chemicals can harm the airways.Different effects can result in distinct changes in respiratory patterns;the type of change indicates where and how the respiratory system is affected.Furthermore,changes in resp...Inhaled chemicals can harm the airways.Different effects can result in distinct changes in respiratory patterns;the type of change indicates where and how the respiratory system is affected.Furthermore,changes in respiratory patterns may be detected at much lower substance concentrations than those that cause more serious effects,such as histopathological changes.Changes in respiratory patterns can be studied experimentally by monitoring the breathing of mice placed in plethysmographs and exposing head-out to the test substance.The method is well established;however,it is not known if training mice in being restrained in the plethysmograph could increase the quality of data collection.Here we report the results of training mice to be restrained in plethysmographs for 5 consecutive days,with respect to body weight,respiratory parameters,and time spent in the plethysmograph,before they are removed because of unstable breathing patterns.The mice tolerated the procedure better(measured by time in the plethysmograph)on the second day of training than the first day.Training did not change the breathing parameters between days.Breathing parameters stabilized within 5 min after the mice were placed in the plethysmographs on all days.There was an average of 3%weight loss between the first and last days of the training,indicating that the training procedure placed some strain on the animals.Training reduces the number of mice attempting to escape from the plethysmograph.展开更多
The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were investigated.With increasing strain rate,the average grain size of compression-shea...The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were investigated.With increasing strain rate,the average grain size of compression-shear(CS)and compression-torsion(CT)samples are decreased,and the grain size of dynamic recrystallization(DRX)grains is also decreased.This is because that the precipitation number ofβphases is increased,and the hindering effect on grain growth can be significantly enhanced.The DRX fractions of CS and CT samples are decreased with increased strain rate.The low DRX fraction at high strain rate is related to the insufficient time for grains to nucleate.The DRX process can be promoted by the PSN mechanism of second phases,and the grain growth can be restricted by the pinning effect.At the same time,the texture strength is enhanced as the strain rate increased.Besides,the kinking degree of lamellar long-period stacking ordered(LPSO)phases is increased.Under complex shear stress conditions,non-basal slip,especially pyramidal slip,is easily activated and the texture is deflected greatly.Compared with the CS samples,CT samples have smaller average grain size,higher DRX fraction,and lower texture strength for a certain strain rate.This is because that the equivalent stress of the CT sample is larger,the stress triaxiality is smaller,so more serious dislocations are piled up near grain boundaries and second phases.At the same time,since CT sample was sheared with torsion,the dislocation movement path can be called“rotational dislocation accumulation”,and the longer distribution path of the CT sample is generated,so more sub-grains and low-angle grain boundaries(LAGBs)are formed.Compared with the CS sample,more huge-angle grain boundaries(HAGBs)and DRX grains are formed from grain boundary to grain interior,so better grain refinement effect is achieved.展开更多
Low absolute strength becomes one major obstacle for the wider applications of low/no rare-earth(RE) containing Mg alloys. This review firstly demonstrates the importance of grain refinement in improving strength of M...Low absolute strength becomes one major obstacle for the wider applications of low/no rare-earth(RE) containing Mg alloys. This review firstly demonstrates the importance of grain refinement in improving strength of Mg alloys by comprehensively comparing with other strategy, e.g., precipitation strengthening. Dynamic recrystallization(DRX) plays a crucial role in refining grain size of Mg wrought alloys.Therefore, secondly, the DRX models, grain nucleation mechanisms and the related grain refinement abilities in Mg alloys are summarized,including phase boundary, twin boundary and general boundary induced recrystallization. Thirdly, the newly developed low-RE containing Mg alloy, e.g., Mg-Ce, Mg-Nd and Mg-Sm based alloys, and the RE-free Mg alloys, e.g., Mg-Al, Mg-Zn, Mg-Sn and Mg-Ca based alloy,are reviewed, with the focus on enhancing the mechanical properties mainly via the grain refinement strategy. At the last section, the perspectives and outstanding issues concerning high-performance Mg wrought alloys are also proposed. This review is meant to promote the deep understanding on the critical role of grain refinement in Mg alloys and provide reference for the development of other high strength and low-cost Mg alloys which are fabricated by the conventional extrusion/rolling processing.展开更多
基金Hebei University Affiliated Hospital Youth Fund Scientific Research Project Project Number:2019Q017。
文摘Objective:To explore the role of specialized group management in the quality control of perioperative nursing.Methods:45 surgical nurses from our hospital were selected as the research subjects.Traditional operating room management was adopted from July 2019 to June 2020,and specialized group management was adopted from July 2020 to June 2021.The surgeon’s satisfaction,surgical nurses’core professional competence,and surgical patients’satisfaction were obtained through surveys and the results were analyzed.Results:Surgeon satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Besides,surgical nurses’core professional competency scores before the implementation of specialized group management were significantly lower than after its implementation(P<0.05).Lastly,surgical patients’satisfaction before the implementation of specialized group management was significantly lower than after its implementation(P<0.05).Conclusion:Specialized group management helps to improve the quality of perioperative care and should be applied in clinical practice.
基金Funded by the Basic Research Project in Shanxi Province(No.202103021224183)。
文摘Through the use of purification and recirculation superheating techniques on molten glass,the Ni65Cu33Co2 alloy was successfully undercooled to a maximum temperature of 292 K.High-speed photography was employed to capture the process of interface migration of the alloy liquid,allowing for an analysis of the relationship between the morphological characteristics of the alloy liquid solidification front and the degree of undercooling.Additionally,the microstructure of the alloy was examined using metallographic microscopy,leading to a systematic study of the microscopic morphological characteristics and evolution laws of the refined structure during rapid solidification.The research reveals that the grain refining mechanism of the Ni-Cu-Co ternary alloy is consistent with that of the binary alloy(Ni-Cu).Specifically,under low undercooling conditions,intense dendritic remelting was found to cause grain refinement,while under high undercooling conditions,recrystallization driven by accumulated stress and plastic strain resulting from the interaction between the liquid flow and the primary dendrites caused by rapid solidification was identified as the main factor contributing to grain refinement.Furthermore,the study highlights the significant role of the Co element in influencing the solidification rate and reheat effect of the alloy.The addition of Co was also found to facilitate the formation of non-segregated solidification structure,indicating its importance in the overall solidification process.
基金supported by the National Natural Science Foundation of China (Nos.51801079, 52001140)。
文摘In order to enhance the mechanical properties of the selective laser-melted(SLM) high-Mg content AlSiMg1.4 alloy,the Zr element was introduced.The influence of Zr alloying on the processability,microstructure,and mechanical properties of the alloy was systematically investigated through performing microstructure analysis and tensile testing.It was demonstrated that the SLM-fabricated AlSiMg1.4-Zr alloy exhibited high process stability with a relative density of over 99.5% at various process parameters.Besides,the strong grain refinement induced by the primary Al3Zr particle during the melt solidification process simultaneously enhanced both the strength and plasticity of the alloy.The values for the yield strength,ultimate tensile strength,and elongation of the SLM-fabricated AlSiMg1.4-Zr were(343±3) MPa,(485±4) MPa,and(10.2±0.2)%,respectively,demonstrating good strengthplasticity synergy in comparison to the AlSiMg1.4 and other Al-Si-based alloys fabricated by SLM.
基金financial support under grant number EP/N007638/1supported by EPSRC under grant number EP/W021080/1
文摘In Mg-Ca alloys the grain refining mechanism,in particular regarding the role of nucleant substrates,remains the object of debates.Although native MgO is being recognised as a nucleating substrate accounting for grain refinement of Mg alloys,the possible interactions of MgO with alloying elements that may alter the nucleation potency have not been elucidated yet.Herein,we design casting experiments of Mg-xCa alloys varied qualitatively in number density of native MgO,which are then comprehensively studied by advanced electron microscopy.The results show that grain refinement is enhanced as the particle number density of MgO increases.The native MgO particles are modified by interfacial layers due to the co-segregation of Ca and N solute atoms at the MgO/Mg interface.Using aberration-corrected scanning transmission electron microscopy and electron energy loss spectroscopy,we reveal the nature of these Ca/N interfacial layers at the atomic scale.Irrespective of the crystallographic termination of MgO,Ca and N co-segregate at the MgO/Mg interface and occupy Mg and O sites,respectively,forming an interfacial structure of a few atomic layers.The interfacial structure is slightly expanded,less ordered and defective compared to the MgO matrix due to compositional deviations,whereby the MgO substrate is altered as a poorer template to nucleate Mg solid.Upon solidification in a TP-1 mould,the impotent MgO particles account for the grain refining mechanism,where they are suggested to participate into nucleation and grain initiation processes in an explosive manner.This work not only reveals the atomic engineering of a substrate through interfacial segregation but also demonstrates the effectiveness of a strategy whereby native MgO particles can be harnessed for grain refinement in Mg-Ca alloys.
基金Under the auspices of the China Social Science(No.21BJY218)National Natural Science Foundation of China(No.41801113)Newcomer funding from Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences(No.E0V00100)。
文摘Specialized households serve as the primary units within specialized villages in China,and their capacity to withstand risks and external influences significantly shapes the future trajectory of specialized villages and the overall vitality of the rural economy.In this study,we established a measurement indicator system based on the definition of specialized households’resilience,elucidating the logical connection between specialized households’resilience and rural industrial development in China.The musical instrument industry in Lankao County,Henan Province of China,was employed as a case;survey data,the entropy method,and an obstacle diagnosis model were used to examine how instrument production specialized households responded to the challenges posed by Corona Virus Disease 2019(COVID-19)and the tightening of national environmental protection policies,yielding the following key findings:1)there exists substantial variation in the comprehensive resilience levels among different specialized households;2)the ability to learn and adapt is the most significant contributor to the overall resilience level of specialized households;3)technological proficiency and access to skilled talent emerge as pivotal factors influencing specialized households’resilience;4)the positioning of specialized households within the industrial supply chain and the stability of their income have a direct bearing on their resilience level.The influence of specialized households’resilience on industrial development primarily manifests in the following ways:stronger resilience correlates with increased stability in production and sales,fostering a more proactive approach to future actions.However,heightened exposure to the external macroeconomic environment can lead to a higher rate of export reduction.To enhance the development resilience of entities like specialized households and family farms,and to invigorate rural economic development,escalating investments in rural science and technology and prioritizing the training of technical talent become imperative.
基金the National Natural Science Foundation of China(No.51871155).
文摘The effect of addition temperature of MgO particles(MgOp)on their dispersion behavior and the efficiency of grain refinement in AZ31 Mg alloy was investigated.In addition,the grain refinement mechanism was systematically studied by microstructure characterization,thermodynamic calculation,and analysis of solidification curves.The results show that the grain size of AZ31 Mg alloy initially decreases and then increases as the MgOp addition temperature is increased from 720 to 810℃,exhibiting a minimum value of 136μm at 780℃.The improved grain refinement efficiency with increasing MgOp addition temperature can be attributed to the reduced Mg melt viscosity and enhanced wettability between MgOp and Mg melt.Furthermore,a corresponding physical model describing the solidification behavior and grain refinement mechanism was proposed.
基金Project supported by the National Natural Science Foundation of China(Nos.11932008 and 12272156)the Fundamental Research Funds for the Central Universities(No.lzujbky-2022-kb06)+1 种基金the Gansu Science and Technology ProgramLanzhou City’s Scientific Research Funding Subsidy to Lanzhou University of China。
文摘Second-generation high-temperature superconducting(HTS)conductors,specifically rare earth-barium-copper-oxide(REBCO)coated conductor(CC)tapes,are promising candidates for high-energy and high-field superconducting applications.With respect to epoxy-impregnated REBCO composite magnets that comprise multilayer components,the thermomechanical characteristics of each component differ considerably under extremely low temperatures and strong electromagnetic fields.Traditional numerical models include homogenized orthotropic models,which simplify overall field calculation but miss detailed multi-physics aspects,and full refinement(FR)ones that are thorough but computationally demanding.Herein,we propose an extended multi-scale approach for analyzing the multi-field characteristics of an epoxy-impregnated composite magnet assembled by HTS pancake coils.This approach combines a global homogenization(GH)scheme based on the homogenized electromagnetic T-A model,a method for solving Maxwell's equations for superconducting materials based on the current vector potential T and the magnetic field vector potential A,and a homogenized orthotropic thermoelastic model to assess the electromagnetic and thermoelastic properties at the macroscopic scale.We then identify“dangerous regions”at the macroscopic scale and obtain finer details using a local refinement(LR)scheme to capture the responses of each component material in the HTS composite tapes at the mesoscopic scale.The results of the present GH-LR multi-scale approach agree well with those of the FR scheme and the experimental data in the literature,indicating that the present approach is accurate and efficient.The proposed GH-LR multi-scale approach can serve as a valuable tool for evaluating the risk of failure in large-scale HTS composite magnets.
文摘BACKGROUND Some patients with coronary atherosclerotic heart disease experience major adverse cardiac events(MACE)and require readmission after Coronary Artery Bypass Grafting(CABG)surgery.This is often attributed to patients'unhealthy lifestyles and dietary habits,inadequate understanding of the disease,and poor disease management compliance.Thus,searching for more targeted nursing intervention models that can enhance patients'self-management abilities and reduce the risk of readmission after CABG surgery is significant.AIM To observe the impact of specialized nursing outpatient case management on patients after CABG surgery.METHODS A total of 103 patients who underwent CABG surgery in our hospital between April 2021 and April 2022 comprised the study sample.The patients were divided into two groups using an odd-even number grouping method.The control group received routine nursing care,while the case management group received specialized nursing outpatient case management.The differences in psychological status,adherence to medical treatment,self-care ability,knowledge mastery,quality of life scores,and the occurrence rate of MACE were compared between the two groups.RESULTS After the intervention,the case management group had lower scores on the selfrating depression scale and self-rating anxiety scale and lower MACE rate,as well as higher scores for adherence to a healthy diet,medication adherence,good lifestyle habits,regular exercise,and timely follow-up,higher scores on the Coronary Heart Disease Self-Management Scale,higher scores for managing adverse habits,symptoms,emotional cognition,emergency response,disease knowledge,general lifestyle,and treatment adherence,higher scores for understanding coronary heart disease,recognizing the importance of medication adherence,understanding selfcare points after CABG surgery,and being aware of post-CABG precautions,higher scores for physical well-being,disease condition,general health,social-psychological well-being,and work-related aspects(P<0.05).CONCLUSION Specialized nursing outpatient case management can enhance patient adherence to medical treatment,knowledge mastery,psychological well-being,and overall quality of life in patients after CABG surgery.
文摘With the release of China Education Modernization 2035,education modernization has become a national strategic goal.In this context,Chongqing Energy Vocational College is actively exploring the“four integration and four innovation”specialized and creative integration talent cultivation mode,aiming at cultivating high-quality talents with innovative spirit and practical skills.This paper analyzes the status quo and challenges of talent cultivation in higher vocational education,puts forward the main practices of innovation-driven,creation and research,cross-border integration,and innovative practice,and has achieved remarkable results.Additionally,it summarizes the experience revelation and provides a reference for other higher vocational colleges and universities.
基金supported by the NSFC(11871257,12071130)supported by the NSFC(11971165)。
文摘In this article,we first establish an asymptotically sharp result on the higher order Fréchet derivatives for bounded holomorphic mappings f(x)=f(0)+∞∑s=1Dskf(0)(x^(sk))/(sk)!:B_(X)→B_(Y),where B_X is the unit ball of X.We next give a sharp result on the first order Fréchet derivative for bounded holomorphic mappings F(X)=F(0+)∞∑s=KD^(s)f(0)(x^(8)/s!):B_(X)→B_(Y),where B_(X)is the unit ball of X.The results that we derive include some results in several complex variables,and extend the classical result in one complex variable to several complex variables.
基金the financial support by National Key Research and Development Project(Grand No.2020YFC1107202)Guangdong Basic and Applied Basic Research Foundation(Grand No.2020A1515110754)+3 种基金MOE Key Lab of Disaster Forest and Control in Engineering,Jinan University(Grand No.20200904008)Educational Commission of Guangdong Province(Grand No.2020KTSCX012)the Fundamental Research Funds for Central Universities(Grand No.21620342)the support from National Natural Science Foundation of China,NSFC(Grand No.51775556)。
文摘Additive manufacturing(AM)of Mg alloys has become a promising strategy for producing complex structures,but the corrosion performance of AM Mg components remains unexploited.In this study,wire and arc additive manufacturing(WAAM)was employed to produce single AZ31 layer.The results revealed that the WAAM AZ31 was characterized by significant grain refinement with non-textured crystallographic orientation,similar phase composition and stabilized corrosion performance comparing to the cast AZ31.These varied corrosion behaviors were principally ascribed to the size of grain,where cast AZ31 and WAAM AZ31 were featured by micro galvanic corrosion and intergranular corrosion,respectively.
基金supported by the National Natural Science Foundation of China (Grant Nos.U2037601,51821001,and 52105348)the Natural Science Foundation for Young of Jiangsu Province (Grant No.BK20190863)the Research Program of Joint Research Center of Advanced Spaceflight Technologies (No.USCAST2020-31)。
文摘High-performance cast magnesium rare-earth(Mg-RE) alloys are one of the most important materials among all developed Mg alloy families, and have shown great potential in military and weapons, aerospace and aviation, orthopedic implants, etc. Controlling grain size and distribution of it is key to the promising mechanical performance of Mg-RE alloy casting components. During the casting of a real component, nearly every procedure in the fabrication process will influence the grain refinement effect. The procedure may include and may not be limited to the chemical inoculations, possibly applied physical fields, the interfere between grain refiner and purifications, and the casting techniques with different processing parameters. This paper reviews the recent advances and proposed future developments in these categories on grain refinement of cast Mg-RE alloys. The review will provide insights for the future design of grain refinement techniques,the choosing of processing parameters, and coping strategies for the failure of coarsening for cast Mg-RE components with high quality and good performance.
基金Supported by the Philosophy and Social Science Research Project of Colleges and Universities in Jiangsu Province(2021SJA0752)The Fifth Issue of Vocational Education Teaching Reform Research Topic of Jiangsu Province(ZYB581)Teaching Reform Research Project of Urban Vocational Colleges in Jiangsu(YB2021018).
文摘Vocational colleges attach great importance to labor education.Specialized courses are an effective way to cultivate students labor quality,and the integration of labor education in specialized courses plays an important role in the overall cultivation of students moral quality and practical ability.Combined with the teaching practice of landscape technology specialty,labor education is integrated into the teaching of Plant Cultivation and Maintenance,and certain results have been achieved.In this paper,the course content"grafting propagation"was analyzed from the aspects of overall teaching design,teaching implementation process,teaching effect and reflection improvement,so as to provide reference for other contents of this major or other majors to carry out integrated teaching.
基金Financial supports from The National Natural Science Foundation of China(Nos.52104376,U19A2084,52074132,and 52004100)China Postdoctoral Science Foundation(2021T140250 and 2021M701376)+1 种基金Partial financial support came from The Science and Technology Development Program of Jilin Province(Nos.20200401025GX and 20200201002JC)Program for JLU Science and Technology Innovative Research Team(JLUSTIRT,2017TD-09)。
文摘Due to the significant differences in the formation temperature and crystal structure between the primaryα-Mg and eutecticβ-Mg_(17)Al_(12),it is a great challenge to achieve simultaneous refinement of the primary and eutectic phases in Mg-Al based alloys via heterogeneous nucleation.Surprisingly,we found that theα-Mg andβ-Mg_(17)Al_(12) in the AZ80 alloy can be simultaneously refined after 0.2 wt.%Sm addition,with the grain size decreasing from∼217±15μm to∼170±10μm and theβ-Mg_(17)Al_(12) morphology changing from a typical continuous network to a nod-like or spherical structure.The simultaneous refinement mechanism is investigated through solidification simulation,transmission electron microscopy(TEM),and differential thermal analysis(DTA).In the AZ80-0.2Sm alloy,many Al8Mn4Sm particles can be observed near the center of theα-Mg grains or inside theβ-Mg_(17)Al_(12).Crystallographic calculations further reveal that the Al8Mn4Sm has good crystallographic matching with both theα-Mg andβ-Mg_(17)Al_(12),so it possesses the potency to serve as heterogeneous nucleation sites for both phases.The promoted heterogeneous nucleation on the Al8Mn4Sm decreases the undercooling required by the nucleation of the primary and eutectic phases,which enhances the heterogeneous nucleation rate,thus causing the simultaneous refinement of theα-Mg andβ-Mg_(17)Al_(12).The orientation relationships between the Al8Mn4Sm and Mg/Mg_(17)Al_(12) are identified,which are[1210]_(Mg)//[010]_(Al8Mn4Sm),(1010)_(Mg)//(301)_(Al8Mn4Sm) and[112]_(Mg_(17)Al_(12))//[010]_(Al8Mn4Sm),(110)_(Mg_(17)Al_(12))//(301)_(Al8Mn4Sm),respectively.Furthermore,the refinement of theβ-Mg_(17)Al_(12) accelerates its dissolution during the solution treatment,which is beneficial for cost saving in industrial applications.Other Al8Mn4RE compounds such as Al8Mn4Y might have the same positive effect on the simultaneous refinement due to the similar physicochemical properties of rare earth elements.This work not only proves the possibility of simultaneously refining the primary and eutectic phases in Mg-Al based alloys via heterogeneous nucleation,but also provides new insights into the development of refiners for cast Mg alloys.
文摘Erratum to:International Journal of Minerals, Metallurgy and MaterialsVolume 28, Number 7, July 2021, Page 1112 The original version of this article unfortunately contained mistakes. Symbols in Table 2 are used incorrectly.
基金Funded by the Basic Research Projects in Shanxi Province (202103021224183)。
文摘The molten Cu60Ni35Co5 ternary alloy was undercooled by fluxing method and solidified by natural cooling method.The microstructure of all undercooled samples were analyzed.It is found that the rapidly solidified Cu60Ni35Co5 alloy has undergone two grain refinement phenomena within the undercooling range,and its microstructure and morphology change with the undercooling through the transformation process of“coarse dendrite-equiaxed dendrite-oriented fine dendrite-equiaxed crystal”.The refined structure with the maximum undercooling?T of 253 K was selected for electron backscatter diffraction(EBSD)and transmission electron microscopy(TEM)tests.EBSD results show that the refined structure contains a high proportion of large angle grain boundaries(LAGBs),a large number of randomly oriented grains,and high proportion of twins,while TEM results show that the dislocation density in most areas is relatively low.The above characteristics confirm that the solidification structure is refined due to recrystallization behavior under high undercooling.
基金Funded by the Basic Research Projects in Shanxi Province(No.202103021224183)。
文摘Both Cu60Ni38Co2 and Cu60Ni40 alloy were naturally cooled after rapid solidification from the liquid phase.The transformation law of the microstructure characteristics of the rapidly solidified alloy with the change of undercooling(DT)was systematically studied.It was found that the two alloys experienced the same transformation process.The refinement structures under different undercoolings were characterized by electron backscatter diffraction(EBSD).The experimental results show that the characteristics of the refinement structure of the two alloys with low undercooling are the same,whereas,the characteristics of the refinement structure with high undercooling are opposite.The transmission electron microscope(TEM)results of Cu60Ni38Co2 alloy show that the dislocation network density of low undercooled microstructure is lower than that of high undercooled microstructure.By combining EBSD and TEM,it can be confirmed that the dendrite remelting fracture is the reason for the refinement of the low undercooled structure,while the high undercooled structure is refined due to recrystallization.
基金FFIKA,Focused Research Effort on Chemicals in the Working Environment from the Danish Governmentthe Danish Working Environment Research Fund(project name:SikkerMotor),Grant/Award Number:29-2019-09。
文摘Inhaled chemicals can harm the airways.Different effects can result in distinct changes in respiratory patterns;the type of change indicates where and how the respiratory system is affected.Furthermore,changes in respiratory patterns may be detected at much lower substance concentrations than those that cause more serious effects,such as histopathological changes.Changes in respiratory patterns can be studied experimentally by monitoring the breathing of mice placed in plethysmographs and exposing head-out to the test substance.The method is well established;however,it is not known if training mice in being restrained in the plethysmograph could increase the quality of data collection.Here we report the results of training mice to be restrained in plethysmographs for 5 consecutive days,with respect to body weight,respiratory parameters,and time spent in the plethysmograph,before they are removed because of unstable breathing patterns.The mice tolerated the procedure better(measured by time in the plethysmograph)on the second day of training than the first day.Training did not change the breathing parameters between days.Breathing parameters stabilized within 5 min after the mice were placed in the plethysmographs on all days.There was an average of 3%weight loss between the first and last days of the training,indicating that the training procedure placed some strain on the animals.Training reduces the number of mice attempting to escape from the plethysmograph.
基金supported by Project supported by the Joint Funds of the National Natural Science Foundation of China(Grant No.U20A20230)Natural Science Foundation of Shanxi Province(No.201901D111176)+2 种基金Project supported by the Key R&D program of Shanxi Province(No.2020XXX015)Research Project Supported by Shanxi Scholarship Council of China(2021-127)Graduate Education Innovation Program of Shanxi Province(2022Y579).
文摘The effects of different complex shear stress conditions on grain refinement and texture evolution of Mg-13Gd-4Y-2Zn-0.5Zr alloy were investigated.With increasing strain rate,the average grain size of compression-shear(CS)and compression-torsion(CT)samples are decreased,and the grain size of dynamic recrystallization(DRX)grains is also decreased.This is because that the precipitation number ofβphases is increased,and the hindering effect on grain growth can be significantly enhanced.The DRX fractions of CS and CT samples are decreased with increased strain rate.The low DRX fraction at high strain rate is related to the insufficient time for grains to nucleate.The DRX process can be promoted by the PSN mechanism of second phases,and the grain growth can be restricted by the pinning effect.At the same time,the texture strength is enhanced as the strain rate increased.Besides,the kinking degree of lamellar long-period stacking ordered(LPSO)phases is increased.Under complex shear stress conditions,non-basal slip,especially pyramidal slip,is easily activated and the texture is deflected greatly.Compared with the CS samples,CT samples have smaller average grain size,higher DRX fraction,and lower texture strength for a certain strain rate.This is because that the equivalent stress of the CT sample is larger,the stress triaxiality is smaller,so more serious dislocations are piled up near grain boundaries and second phases.At the same time,since CT sample was sheared with torsion,the dislocation movement path can be called“rotational dislocation accumulation”,and the longer distribution path of the CT sample is generated,so more sub-grains and low-angle grain boundaries(LAGBs)are formed.Compared with the CS sample,more huge-angle grain boundaries(HAGBs)and DRX grains are formed from grain boundary to grain interior,so better grain refinement effect is achieved.
基金supported by National Key Research and Development Program of China (No.2023YFB3710900)National Natural Science Foundation of China (Nos.U2241235,U2167213,51971053)+2 种基金funded by the Project of Promoting Talents in Liaoning province (No.XLYC2203202)the financial assistance from Young Elite Scientists Sponsorship Program by CAST (2019-2021QNRC001,2019-2021QNRC002,2019-2021QNRC003)the fund from the Fundamental Research Funds for the Central Universities (N2202020)。
文摘Low absolute strength becomes one major obstacle for the wider applications of low/no rare-earth(RE) containing Mg alloys. This review firstly demonstrates the importance of grain refinement in improving strength of Mg alloys by comprehensively comparing with other strategy, e.g., precipitation strengthening. Dynamic recrystallization(DRX) plays a crucial role in refining grain size of Mg wrought alloys.Therefore, secondly, the DRX models, grain nucleation mechanisms and the related grain refinement abilities in Mg alloys are summarized,including phase boundary, twin boundary and general boundary induced recrystallization. Thirdly, the newly developed low-RE containing Mg alloy, e.g., Mg-Ce, Mg-Nd and Mg-Sm based alloys, and the RE-free Mg alloys, e.g., Mg-Al, Mg-Zn, Mg-Sn and Mg-Ca based alloy,are reviewed, with the focus on enhancing the mechanical properties mainly via the grain refinement strategy. At the last section, the perspectives and outstanding issues concerning high-performance Mg wrought alloys are also proposed. This review is meant to promote the deep understanding on the critical role of grain refinement in Mg alloys and provide reference for the development of other high strength and low-cost Mg alloys which are fabricated by the conventional extrusion/rolling processing.