目的系统评价补肾方剂改善高龄女性自然妊娠结局的临床疗效和安全性。方法检索中国知网、万方数据库、维普数据库、SinoMed、PubMed、Web of Science、Cochrane Library、Embase等数据库建库至2022年6月收录的补肾方剂改善高龄女性自然...目的系统评价补肾方剂改善高龄女性自然妊娠结局的临床疗效和安全性。方法检索中国知网、万方数据库、维普数据库、SinoMed、PubMed、Web of Science、Cochrane Library、Embase等数据库建库至2022年6月收录的补肾方剂改善高龄女性自然妊娠结局的随机对照研究(RCT)。运用偏倚风险工具进行质量评估,使用RevMan软件进行Meta分析。结果共纳入14篇RCT。Meta分析结果显示:补肾方剂联合西药治疗在提高妊娠率[RR=1.71,95%CI(1.45,2.01),P<0.00001]、降低卵泡刺激素(FSH)水平[SMD=-1.63,95%CI(-2.84,-0.43),P=0.008]、提高雌二醇(E_(2))水平[SMD=3.97,95%CI(1.76,6.17),P=0.0004]、增加排卵期子宫内膜厚度[SMD=2.12,95%CI(1.07,3.18),P<0.0001]方面均优于西药组;且补肾方剂单独使用在提高妊娠率[RR=1.94,95%CI(1.31,2.88),P=0.001]、降低FSH水平[SMD=-0.48,95%CI(-0.74,-0.22),P=0.0003]方面也具有显著疗效。结论与西医治疗比较,补肾方剂可以显著改善高龄女性自然妊娠结局,且不良反应较少,但仍需更多高质量、大样本、多中心的RCT予以验证。展开更多
目的运用循证医学方法对腕踝针干预术后疼痛的疗效和安全性进行系统评价和Grade评价。方法计算机检索中国知网、万方、维普、中国生物医学文献数据库、PubMed、Embase、Web of Science、Cochrane Library中关于腕踝针干预术后疼痛的随...目的运用循证医学方法对腕踝针干预术后疼痛的疗效和安全性进行系统评价和Grade评价。方法计算机检索中国知网、万方、维普、中国生物医学文献数据库、PubMed、Embase、Web of Science、Cochrane Library中关于腕踝针干预术后疼痛的随机对照试验,检索时限为建库至2023年10月。采用RevMan 5.4软件进行Meta分析。结果纳入23篇文献,共计1968例患者,Meta分析结果显示,与常规治疗相比,腕踝针能够提高术后疼痛患者的总有效率[OR=4.42,95%CI(2.60,7.50),P<0.001],术后镇痛泵药量使用减少[MD=-9.03,95%CI(-12.09,-5.98),P<0.001],术后疼痛评分降低[MD=-1.39,95%CI(-1.68,-1.09),P<0.001],可减少不良反应发生率[RR=0.40,95%CI(0.32,0.48),P<0.001]以及临床满意度[OR=3.94,95%CI(2.40,6.48),P<0.001]。Grade证据分级结果显示:总有效率、不良反应发生率和临床满意度3项结局指标为中等质量证据,VAS评分指标为低质量证据,镇痛泵药量使用指标为极低质量证据。结论腕踝针可提高总有效率,减少术后镇痛药用量,不良反应少,安全性高,为患者提供了一种安全有效的镇痛方式。展开更多
Through equilibrium and non-equilibrium molecular dynamics simulations,we have demonstrated the inhibitory effect of composition graded interface on thermal transport behavior in lateral heterostructures.Specifically,...Through equilibrium and non-equilibrium molecular dynamics simulations,we have demonstrated the inhibitory effect of composition graded interface on thermal transport behavior in lateral heterostructures.Specifically,we investigated the influence of composition gradient length and heterogeneous particles at the silicene/germanene(SIL/GER)heterostructure interface on heat conduction.Our results indicate that composition graded interface at the interface diminishes the thermal conductivity of the heterostructure,with a further reduction observed as the length increases,while the effect of the heterogeneous particles can be considered negligible.To unveil the influence of composition graded interface on thermal transport,we conducted phonon analysis and identified the presence of phonon localization within the interface composition graded region.Through these analyses,we have determined that the decrease in thermal conductivity is correlated with phonon localization within the heterostructure,where a stronger degree of phonon localization signifies poorer thermal conductivity in the material.Our research findings not only contribute to understanding the impact of interface gradient-induced phonon localization on thermal transport but also offer insights into the modulation of thermal conductivity in heterostructures.展开更多
Based on the generalized Hamilton's principle,the nonlinear governing equation of an axially functionally graded(AFG)pipe is established.The non-trivial equilibrium configuration is superposed by the modal functio...Based on the generalized Hamilton's principle,the nonlinear governing equation of an axially functionally graded(AFG)pipe is established.The non-trivial equilibrium configuration is superposed by the modal functions of a simply supported beam.Via the direct multi-scale method,the response and stability boundary to the pulsating fluid velocity are solved analytically and verified by the differential quadrature element method(DQEM).The influence of Young's modulus gradient on the parametric resonance is investigated in the subcritical and supercritical regions.In general,the pipe in the supercritical region is more sensitive to the pulsating excitation.The nonlinearity changes from hard to soft,and the non-trivial equilibrium configuration introduces more frequency components to the vibration.Besides,the increasing Young's modulus gradient improves the critical pulsating flow velocity of the parametric resonance,and further enhances the stability of the system.In addition,when the temperature increases along the axial direction,reducing the gradient parameter can enhance the response asymmetry.This work further complements the theoretical analysis of pipes conveying pulsating fluid.展开更多
With the continuous advancement in topology optimization and additive manufacturing(AM)technology,the capability to fabricate functionally graded materials and intricate cellular structures with spatially varying micr...With the continuous advancement in topology optimization and additive manufacturing(AM)technology,the capability to fabricate functionally graded materials and intricate cellular structures with spatially varying microstructures has grown significantly.However,a critical challenge is encountered in the design of these structures–the absence of robust interface connections between adjacent microstructures,potentially resulting in diminished efficiency or macroscopic failure.A Hybrid Level Set Method(HLSM)is proposed,specifically designed to enhance connectivity among non-uniform microstructures,contributing to the design of functionally graded cellular structures.The HLSM introduces a pioneering algorithm for effectively blending heterogeneous microstructure interfaces.Initially,an interpolation algorithm is presented to construct transition microstructures seamlessly connected on both sides.Subsequently,the algorithm enables the morphing of non-uniform unit cells to seamlessly adapt to interconnected adjacent microstructures.The method,seamlessly integrated into a multi-scale topology optimization framework using the level set method,exhibits its efficacy through numerical examples,showcasing its prowess in optimizing 2D and 3D functionally graded materials(FGM)and multi-scale topology optimization.In essence,the pressing issue of interface connections in complex structure design is not only addressed but also a robust methodology is introduced,substantiated by numerical evidence,advancing optimization capabilities in the realm of functionally graded materials and cellular structures.展开更多
The most difficult and delicate part of the learning process is assessment.Assessment is difficult because during his/her accomplishment the teacher has to consider not only the acquisition of knowledge from students,...The most difficult and delicate part of the learning process is assessment.Assessment is difficult because during his/her accomplishment the teacher has to consider not only the acquisition of knowledge from students,but also the overall degree of development of their competencies.It is delicate,because through assessment we can influence the emotional side of students and their“willingness”to learn.Despite these facts,teachers need to evaluate students during the learning process.The purpose of the research is to find out what is the perception of teachers about the level of evaluation of students with final grade.The overall results showed that 89%of teachers agree,9%of them have a neutral attitude,and 2%do not agree that the evaluation of students with a final grade is done taking into account many aspects and using many methods,the overall average of the results,M=4.36.Based on the empirical results,it was found that teachers who have completed assessment training have a more positive approach to student assessment,as the average score is higher than teachers who have not completed assessment training.From the qualitative results it was understood that the Teachers did not encounter any difficulties during the assessment of the students.展开更多
Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers ar...Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers are renowned for their good mechanical properties,abundance,and short cycle growth.As beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic foundation.Three different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the thickness.The elastic properties of the composite are determined with the law of mixture.Employing Hamilton’s principle,the governing equations of motion are obtained.The generalized differential quadrature method(GDQM)is then applied to the equations to obtain the results.The achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam change.Furthermore,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber distribution.Eventually,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.展开更多
The ex-situ incorporation of the secondary SiC reinforcement,along with the in-situ incorporation of the tertiary and quaternary Mg_(3)N_(2) and Si_(3)N_(4) phases,in the primary matrix of Mg_(2)Si is employed in orde...The ex-situ incorporation of the secondary SiC reinforcement,along with the in-situ incorporation of the tertiary and quaternary Mg_(3)N_(2) and Si_(3)N_(4) phases,in the primary matrix of Mg_(2)Si is employed in order to provide ultimate wear resistance based on the laser-irradiation-induced inclusion of N_(2) gas during laser powder bed fusion.This is substantialized based on both the thermal diffusion-and chemical reactionbased metallurgy of the Mg_(2)Si–SiC/nitride hybrid composite.This study also proposes a functional platform for systematically modulating a functionally graded structure and modeling build-direction-dependent architectonics during additive manufacturing.This strategy enables the development of a compositional gradient from the center to the edge of each melt pool of the Mg_(2)Si–SiC/nitride hybrid composite.Consequently,the coefficient of friction of the hybrid composite exhibits a 309.3%decrease to–1.67 compared to–0.54 for the conventional nonreinforced Mg_(2)Si structure,while the tensile strength exhibits a 171.3%increase to 831.5 MPa compared to 485.3 MPa for the conventional structure.This outstanding mechanical behavior is due to the(1)the complementary and synergistic reinforcement effects of the SiC and nitride compounds,each of which possesses an intrinsically high hardness,and(2)the strong adhesion of these compounds to the Mg_(2)Si matrix despite their small sizes and low concentrations.展开更多
By analyzing the correlation between courses in students’grades,we can provide a decision-making basis for the revision of courses and syllabi,rationally optimize courses,and further improve teaching effects.With the...By analyzing the correlation between courses in students’grades,we can provide a decision-making basis for the revision of courses and syllabi,rationally optimize courses,and further improve teaching effects.With the help of IBM SPSS Modeler data mining software,this paper uses Apriori algorithm for association rule mining to conduct an in-depth analysis of the grades of nursing students in Shandong College of Traditional Chinese Medicine,and to explore the correlation between professional basic courses and professional core courses.Lastly,according to the detailed analysis of the mining results,valuable curriculum information will be found from the actual teaching data.展开更多
This study focuses on the analysis of the Chinese composition writing performance of fourth,fifth,and sixth grade students in 16 selected schools in Longhua District,Shenzhen during the spring semester of 2023.Using L...This study focuses on the analysis of the Chinese composition writing performance of fourth,fifth,and sixth grade students in 16 selected schools in Longhua District,Shenzhen during the spring semester of 2023.Using LIWC(Linguistic Inquiry and Word Count)as a text analysis tool,the study explores the impact of LIWC categories on writing performance which is scaled by score.The results show that the simple LIWC word categories have a significant positive influence on the composition scores of lower-grade students;while complex LIWC word categories have a significant negative influence on the composition scores of lower-grade students but a significant positive influence on the composition scores of higher-grade students.Process word categories have a positive influence on the composition scores of all three grades,but the impact of complex process word categories increases as the grade level rises.展开更多
The COVID-19 pandemic caused significant disruptions in the field of education worldwide,including in the United Arab Emirates.Teachers and students had to adapt to remote learning and virtual classrooms,leading to va...The COVID-19 pandemic caused significant disruptions in the field of education worldwide,including in the United Arab Emirates.Teachers and students had to adapt to remote learning and virtual classrooms,leading to various challenges in maintaining educational standards.The sudden transition to remote teaching could have a negative impact on students’reading abilities,especially in the Arabic language.To gain insight into the unique challenges encountered by Arabic language teachers in the UAE,a survey was conducted to explore their assessment of teaching quality,student-teacher interaction,and learning outcomes amidst the COVID-19 pandemic.The results of the survey revealed a significant decline of student reading abilities and identified several major issues in online Arabic language teaching.These issues included limited interaction between students and teachers,challenges in monitoring students’class participation and performance,and challenges in effectively assessing students’reading skills.The results also demonstrated some other challenges faced by Arabic language teachers,including a lack of preparedness,a lack of subscription to relevant platforms,and a lack of resources for online learning.Several solutions to these challenges are proposed,including reevaluating the balance between depth and breadth in the curriculum,integrating language skills into the curriculum more effectively,providing more comprehensive teacher professional development,implementing student grouping strategies,utilizing retired and expert teachers in specific content areas,allocating time for interventions,and improving support from both teachers and parents to ensure the quality of online learning.展开更多
目的系统评价前列舒通胶囊联合坦索罗辛治疗慢性前列腺炎(Chronic prostatitis,CP)的临床疗效。方法在线检索中国知识资源总库(CNKI)、万方数据、维普网、Sinomed、PubMed、Web of Science、Cochrane Library、Embase数据库建库至2023年...目的系统评价前列舒通胶囊联合坦索罗辛治疗慢性前列腺炎(Chronic prostatitis,CP)的临床疗效。方法在线检索中国知识资源总库(CNKI)、万方数据、维普网、Sinomed、PubMed、Web of Science、Cochrane Library、Embase数据库建库至2023年4月1日期间前列舒通胶囊联合坦索罗辛治疗CP的随机对照研究,采用Cochrane风险偏倚评估工具对文献进行质量评价,运用RevMan 5.3软件进行Meta分析,并对结局指标进行GRADE质量分级。结果共纳入10篇RCT,涉及1013例受试者。Meta分析结果显示:相较于单用坦索罗辛,前列舒通胶囊联合坦索罗辛治疗CP能够显著提高临床有效率[RR=1.23,95%CI(1.16~1.30),P<0.00001],降低NIH-CPSI评分[MD=-5.09,95%CI(-6.84~-3.34),P<0.00001],降低NIH-CPSI疼痛症状评分[MD=-3.17,95%CI(-4.12~-2.23),P<0.00001]、NIH-CPSI排尿症状评分[MD=-2.11,95%CI(-2.55~-1.67),P<0.00001]、NIH-CPSI生活质量评分[MD=-1.79,95%CI(-1.87~-1.71),P<0.00001]、前列腺液白细胞计数[MD=-2.73,95%CI(-4.13~-1.34),P<0.00001],且联合用药不会增加不良反应发生。GRADE证据分级显示:前列舒通胶囊联合坦索罗辛质量在有效率和NIH-CPSI生活质量评分指标为中级,NIH-CPSI评分、NIH-CPSI疼痛症状评分、NIH-CPSI排尿症状评分和前列腺液白细胞计数指标为低级。结论与单用坦索罗辛治疗比较,前列舒通胶囊联合坦索罗辛可以显著改善CP患者临床疼痛、排尿不适等临床症状,且不增加不良反应的发生,但仍需更多高质量、大样本、多中心的RCT予以验证。展开更多
目的系统评价正念疗法对肠造口患者病耻感的干预效果。方法计算机检索中国知网、维普、万方、中国生物医学文献数据库、PubMed、Cochrane libarary、Web of Science、Embase、EBSCOhost和JAMA美国医学会等10个电子数据库,各中英文电子...目的系统评价正念疗法对肠造口患者病耻感的干预效果。方法计算机检索中国知网、维普、万方、中国生物医学文献数据库、PubMed、Cochrane libarary、Web of Science、Embase、EBSCOhost和JAMA美国医学会等10个电子数据库,各中英文电子数据库建库至2022年9月10日收录的正念疗法对肠造口患者病耻感的随机对照试验研究(RCTs),采用Cochrane偏倚风险评估表进行偏倚风险评估、Rev Man 5.4软件进行Meta分析和GRADE系统对结局指标进行质量等级评价。结果共纳入6项符合纳入标准的RCTs,共609例患者,纳入研究方法学整体质量较低,Meta分析结果显示,正念疗法都能有效降低肠造口患者社会影响量表评分[MD=-10.24,95%CI(-16.43,-4.05),P=0.001]、社会排斥评分[MD=-4.40,95%CI(-5.59,-3.21),P<0.00001]、社会隔离评分[MD=-2.92,95%CI(-4.06,-1.78),P<0.00001]、经济歧视评分[MD=-1.62,95%CI(-2.75,-0.50),P=0.005]、内在羞耻感评分[MD=-2.51,95%CI(-3.90,-1.12),P=0.0004];GRADE证据质量评级显示纳入研究结局指标均被评为极低级质量。结论正念疗法在减轻肠造口患者病耻感具有积极的作用效果,在提升患者生活质量方面未来的研究还需要大样本、多中心的高质量随机对照研究提供有力的证据支持。展开更多
为系统评价黄芪注射液联合西医常规治疗慢阻肺稳定期患者的疗效及证据质量,对中国知网、维普数据库、万方数据知识服务平台、PubMed、Web of science、Embase数据库进行检索,检索时间范围设定为:各数据库建库至2021年12月21日。两位研...为系统评价黄芪注射液联合西医常规治疗慢阻肺稳定期患者的疗效及证据质量,对中国知网、维普数据库、万方数据知识服务平台、PubMed、Web of science、Embase数据库进行检索,检索时间范围设定为:各数据库建库至2021年12月21日。两位研究员一组,分别独立检索、筛选文献,对纳入文献用Cochrane的偏倚风险评估工具评估,RevMan5.4软件和Sta-ta15.0软件进行统计和Meta分析,并按照GRADE标准对证据质量进行质量评价。共纳入15项研究,包括1236例病例。Meta分析结果显示:与对照组相比,黄芪注射液联合西医常规治疗能降低急性加重次数,提高临床有效率,改善肺功能,降低mMRC评分,降低IL-8和TNF-α水平。可见黄芪注射液联合西医常规治疗对稳定期慢阻肺患者提高生活质量、运动能力和降低炎症水平上优势明显,但值得注意的是本次研究的证据质量级别低,需要更多更高质量的研究来提升证据级别,临床医生做临床决策时还需谨慎。展开更多
文摘目的系统评价补肾方剂改善高龄女性自然妊娠结局的临床疗效和安全性。方法检索中国知网、万方数据库、维普数据库、SinoMed、PubMed、Web of Science、Cochrane Library、Embase等数据库建库至2022年6月收录的补肾方剂改善高龄女性自然妊娠结局的随机对照研究(RCT)。运用偏倚风险工具进行质量评估,使用RevMan软件进行Meta分析。结果共纳入14篇RCT。Meta分析结果显示:补肾方剂联合西药治疗在提高妊娠率[RR=1.71,95%CI(1.45,2.01),P<0.00001]、降低卵泡刺激素(FSH)水平[SMD=-1.63,95%CI(-2.84,-0.43),P=0.008]、提高雌二醇(E_(2))水平[SMD=3.97,95%CI(1.76,6.17),P=0.0004]、增加排卵期子宫内膜厚度[SMD=2.12,95%CI(1.07,3.18),P<0.0001]方面均优于西药组;且补肾方剂单独使用在提高妊娠率[RR=1.94,95%CI(1.31,2.88),P=0.001]、降低FSH水平[SMD=-0.48,95%CI(-0.74,-0.22),P=0.0003]方面也具有显著疗效。结论与西医治疗比较,补肾方剂可以显著改善高龄女性自然妊娠结局,且不良反应较少,但仍需更多高质量、大样本、多中心的RCT予以验证。
文摘目的运用循证医学方法对腕踝针干预术后疼痛的疗效和安全性进行系统评价和Grade评价。方法计算机检索中国知网、万方、维普、中国生物医学文献数据库、PubMed、Embase、Web of Science、Cochrane Library中关于腕踝针干预术后疼痛的随机对照试验,检索时限为建库至2023年10月。采用RevMan 5.4软件进行Meta分析。结果纳入23篇文献,共计1968例患者,Meta分析结果显示,与常规治疗相比,腕踝针能够提高术后疼痛患者的总有效率[OR=4.42,95%CI(2.60,7.50),P<0.001],术后镇痛泵药量使用减少[MD=-9.03,95%CI(-12.09,-5.98),P<0.001],术后疼痛评分降低[MD=-1.39,95%CI(-1.68,-1.09),P<0.001],可减少不良反应发生率[RR=0.40,95%CI(0.32,0.48),P<0.001]以及临床满意度[OR=3.94,95%CI(2.40,6.48),P<0.001]。Grade证据分级结果显示:总有效率、不良反应发生率和临床满意度3项结局指标为中等质量证据,VAS评分指标为低质量证据,镇痛泵药量使用指标为极低质量证据。结论腕踝针可提高总有效率,减少术后镇痛药用量,不良反应少,安全性高,为患者提供了一种安全有效的镇痛方式。
基金Project supported by the National Natural Science Foundation of China (Grant No.12104291)。
文摘Through equilibrium and non-equilibrium molecular dynamics simulations,we have demonstrated the inhibitory effect of composition graded interface on thermal transport behavior in lateral heterostructures.Specifically,we investigated the influence of composition gradient length and heterogeneous particles at the silicene/germanene(SIL/GER)heterostructure interface on heat conduction.Our results indicate that composition graded interface at the interface diminishes the thermal conductivity of the heterostructure,with a further reduction observed as the length increases,while the effect of the heterogeneous particles can be considered negligible.To unveil the influence of composition graded interface on thermal transport,we conducted phonon analysis and identified the presence of phonon localization within the interface composition graded region.Through these analyses,we have determined that the decrease in thermal conductivity is correlated with phonon localization within the heterostructure,where a stronger degree of phonon localization signifies poorer thermal conductivity in the material.Our research findings not only contribute to understanding the impact of interface gradient-induced phonon localization on thermal transport but also offer insights into the modulation of thermal conductivity in heterostructures.
基金Project supported by the National Natural Science Foundation of China (Nos.12002195 and 12372015)the National Science Fund for Distinguished Young Scholars of China (No.12025204)the Program of Shanghai Municipal Education Commission of China (No.2019-01-07-00-09-E00018)。
文摘Based on the generalized Hamilton's principle,the nonlinear governing equation of an axially functionally graded(AFG)pipe is established.The non-trivial equilibrium configuration is superposed by the modal functions of a simply supported beam.Via the direct multi-scale method,the response and stability boundary to the pulsating fluid velocity are solved analytically and verified by the differential quadrature element method(DQEM).The influence of Young's modulus gradient on the parametric resonance is investigated in the subcritical and supercritical regions.In general,the pipe in the supercritical region is more sensitive to the pulsating excitation.The nonlinearity changes from hard to soft,and the non-trivial equilibrium configuration introduces more frequency components to the vibration.Besides,the increasing Young's modulus gradient improves the critical pulsating flow velocity of the parametric resonance,and further enhances the stability of the system.In addition,when the temperature increases along the axial direction,reducing the gradient parameter can enhance the response asymmetry.This work further complements the theoretical analysis of pipes conveying pulsating fluid.
基金the National Key Research and Development Program of China(Grant Number 2021YFB1714600)the National Natural Science Foundation of China(Grant Number 52075195)the Fundamental Research Funds for the Central Universities,China through Program No.2172019kfyXJJS078.
文摘With the continuous advancement in topology optimization and additive manufacturing(AM)technology,the capability to fabricate functionally graded materials and intricate cellular structures with spatially varying microstructures has grown significantly.However,a critical challenge is encountered in the design of these structures–the absence of robust interface connections between adjacent microstructures,potentially resulting in diminished efficiency or macroscopic failure.A Hybrid Level Set Method(HLSM)is proposed,specifically designed to enhance connectivity among non-uniform microstructures,contributing to the design of functionally graded cellular structures.The HLSM introduces a pioneering algorithm for effectively blending heterogeneous microstructure interfaces.Initially,an interpolation algorithm is presented to construct transition microstructures seamlessly connected on both sides.Subsequently,the algorithm enables the morphing of non-uniform unit cells to seamlessly adapt to interconnected adjacent microstructures.The method,seamlessly integrated into a multi-scale topology optimization framework using the level set method,exhibits its efficacy through numerical examples,showcasing its prowess in optimizing 2D and 3D functionally graded materials(FGM)and multi-scale topology optimization.In essence,the pressing issue of interface connections in complex structure design is not only addressed but also a robust methodology is introduced,substantiated by numerical evidence,advancing optimization capabilities in the realm of functionally graded materials and cellular structures.
文摘The most difficult and delicate part of the learning process is assessment.Assessment is difficult because during his/her accomplishment the teacher has to consider not only the acquisition of knowledge from students,but also the overall degree of development of their competencies.It is delicate,because through assessment we can influence the emotional side of students and their“willingness”to learn.Despite these facts,teachers need to evaluate students during the learning process.The purpose of the research is to find out what is the perception of teachers about the level of evaluation of students with final grade.The overall results showed that 89%of teachers agree,9%of them have a neutral attitude,and 2%do not agree that the evaluation of students with a final grade is done taking into account many aspects and using many methods,the overall average of the results,M=4.36.Based on the empirical results,it was found that teachers who have completed assessment training have a more positive approach to student assessment,as the average score is higher than teachers who have not completed assessment training.From the qualitative results it was understood that the Teachers did not encounter any difficulties during the assessment of the students.
文摘Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent years.Bamboo fibers are renowned for their good mechanical properties,abundance,and short cycle growth.As beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic foundation.Three different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the thickness.The elastic properties of the composite are determined with the law of mixture.Employing Hamilton’s principle,the governing equations of motion are obtained.The generalized differential quadrature method(GDQM)is then applied to the equations to obtain the results.The achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam change.Furthermore,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber distribution.Eventually,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.
基金supported by the Learning & Academic Research Institution for Master’s and Ph.D. Students and Postdocs (LAMP) Program of the National Research Foundation of Korea (NRF) grant funded by the Ministry of Education (No. RS-2023-00285353)supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIP) (NRF-2021R1A2C3006662, NRF-2022R1A5A1030054, and 2021R1A2C1091301)+3 种基金the support from Natural Sciences and Engineering Research Council of Canada (NSERC)Canada Foundation for Innovation (CFI)Atlantic Canada Opportunities Agency (ACOA)the New Brunswick Innovation Foundation (NBIF)
文摘The ex-situ incorporation of the secondary SiC reinforcement,along with the in-situ incorporation of the tertiary and quaternary Mg_(3)N_(2) and Si_(3)N_(4) phases,in the primary matrix of Mg_(2)Si is employed in order to provide ultimate wear resistance based on the laser-irradiation-induced inclusion of N_(2) gas during laser powder bed fusion.This is substantialized based on both the thermal diffusion-and chemical reactionbased metallurgy of the Mg_(2)Si–SiC/nitride hybrid composite.This study also proposes a functional platform for systematically modulating a functionally graded structure and modeling build-direction-dependent architectonics during additive manufacturing.This strategy enables the development of a compositional gradient from the center to the edge of each melt pool of the Mg_(2)Si–SiC/nitride hybrid composite.Consequently,the coefficient of friction of the hybrid composite exhibits a 309.3%decrease to–1.67 compared to–0.54 for the conventional nonreinforced Mg_(2)Si structure,while the tensile strength exhibits a 171.3%increase to 831.5 MPa compared to 485.3 MPa for the conventional structure.This outstanding mechanical behavior is due to the(1)the complementary and synergistic reinforcement effects of the SiC and nitride compounds,each of which possesses an intrinsically high hardness,and(2)the strong adhesion of these compounds to the Mg_(2)Si matrix despite their small sizes and low concentrations.
文摘By analyzing the correlation between courses in students’grades,we can provide a decision-making basis for the revision of courses and syllabi,rationally optimize courses,and further improve teaching effects.With the help of IBM SPSS Modeler data mining software,this paper uses Apriori algorithm for association rule mining to conduct an in-depth analysis of the grades of nursing students in Shandong College of Traditional Chinese Medicine,and to explore the correlation between professional basic courses and professional core courses.Lastly,according to the detailed analysis of the mining results,valuable curriculum information will be found from the actual teaching data.
文摘This study focuses on the analysis of the Chinese composition writing performance of fourth,fifth,and sixth grade students in 16 selected schools in Longhua District,Shenzhen during the spring semester of 2023.Using LIWC(Linguistic Inquiry and Word Count)as a text analysis tool,the study explores the impact of LIWC categories on writing performance which is scaled by score.The results show that the simple LIWC word categories have a significant positive influence on the composition scores of lower-grade students;while complex LIWC word categories have a significant negative influence on the composition scores of lower-grade students but a significant positive influence on the composition scores of higher-grade students.Process word categories have a positive influence on the composition scores of all three grades,but the impact of complex process word categories increases as the grade level rises.
文摘The COVID-19 pandemic caused significant disruptions in the field of education worldwide,including in the United Arab Emirates.Teachers and students had to adapt to remote learning and virtual classrooms,leading to various challenges in maintaining educational standards.The sudden transition to remote teaching could have a negative impact on students’reading abilities,especially in the Arabic language.To gain insight into the unique challenges encountered by Arabic language teachers in the UAE,a survey was conducted to explore their assessment of teaching quality,student-teacher interaction,and learning outcomes amidst the COVID-19 pandemic.The results of the survey revealed a significant decline of student reading abilities and identified several major issues in online Arabic language teaching.These issues included limited interaction between students and teachers,challenges in monitoring students’class participation and performance,and challenges in effectively assessing students’reading skills.The results also demonstrated some other challenges faced by Arabic language teachers,including a lack of preparedness,a lack of subscription to relevant platforms,and a lack of resources for online learning.Several solutions to these challenges are proposed,including reevaluating the balance between depth and breadth in the curriculum,integrating language skills into the curriculum more effectively,providing more comprehensive teacher professional development,implementing student grouping strategies,utilizing retired and expert teachers in specific content areas,allocating time for interventions,and improving support from both teachers and parents to ensure the quality of online learning.
文摘目的系统评价正念疗法对肠造口患者病耻感的干预效果。方法计算机检索中国知网、维普、万方、中国生物医学文献数据库、PubMed、Cochrane libarary、Web of Science、Embase、EBSCOhost和JAMA美国医学会等10个电子数据库,各中英文电子数据库建库至2022年9月10日收录的正念疗法对肠造口患者病耻感的随机对照试验研究(RCTs),采用Cochrane偏倚风险评估表进行偏倚风险评估、Rev Man 5.4软件进行Meta分析和GRADE系统对结局指标进行质量等级评价。结果共纳入6项符合纳入标准的RCTs,共609例患者,纳入研究方法学整体质量较低,Meta分析结果显示,正念疗法都能有效降低肠造口患者社会影响量表评分[MD=-10.24,95%CI(-16.43,-4.05),P=0.001]、社会排斥评分[MD=-4.40,95%CI(-5.59,-3.21),P<0.00001]、社会隔离评分[MD=-2.92,95%CI(-4.06,-1.78),P<0.00001]、经济歧视评分[MD=-1.62,95%CI(-2.75,-0.50),P=0.005]、内在羞耻感评分[MD=-2.51,95%CI(-3.90,-1.12),P=0.0004];GRADE证据质量评级显示纳入研究结局指标均被评为极低级质量。结论正念疗法在减轻肠造口患者病耻感具有积极的作用效果,在提升患者生活质量方面未来的研究还需要大样本、多中心的高质量随机对照研究提供有力的证据支持。
文摘为系统评价黄芪注射液联合西医常规治疗慢阻肺稳定期患者的疗效及证据质量,对中国知网、维普数据库、万方数据知识服务平台、PubMed、Web of science、Embase数据库进行检索,检索时间范围设定为:各数据库建库至2021年12月21日。两位研究员一组,分别独立检索、筛选文献,对纳入文献用Cochrane的偏倚风险评估工具评估,RevMan5.4软件和Sta-ta15.0软件进行统计和Meta分析,并按照GRADE标准对证据质量进行质量评价。共纳入15项研究,包括1236例病例。Meta分析结果显示:与对照组相比,黄芪注射液联合西医常规治疗能降低急性加重次数,提高临床有效率,改善肺功能,降低mMRC评分,降低IL-8和TNF-α水平。可见黄芪注射液联合西医常规治疗对稳定期慢阻肺患者提高生活质量、运动能力和降低炎症水平上优势明显,但值得注意的是本次研究的证据质量级别低,需要更多更高质量的研究来提升证据级别,临床医生做临床决策时还需谨慎。