促学性评价对中国大学英语学习者学习动机及写作能力的影响研究

本研究以4个英语写作班的97名英语专业本科生为研究对象,采用定量和定性相结合的方法,针对促学性评价对学生学习动机及写作能力的影响,学生对课堂促学性评价实践的感知,以及语言水平对学生促学性评价感知的影响进行了研究。研究结果表明:促学性评价通过强化学生的内在动因、任务价值感、学习掌控感、自我效能感等因素对学生的学习动机产生积极的影响。促学性评价能够显著提高学生的写作能力,尤其能提高写作流畅度。相比低水平学生,高水平学生能够更容易地感知、更好地接受促学性评价。

大学英语教材的非致学性研究

提出大学英语课程教学的致学性与非致学性,并从非致学性这一角度,分析当前大学英语教材中出现种种问题,其中包括课文没有实质性的内容即为空心课文;教材产生的负面价值取向;教材的非交际化。

大学英语教材的非致学性剖析

提出大学英语课程教学的致学性与非致学性,并从非致学性这一角度,分析当前大学英语教材中出现的种种问题,其中包括课文没有实质性的内容即为空心课文;教材产生的负面价值取向;教材的非交际化。

简论中国电影的文学性与全球性

本文简要阐述了中国电影的文学性,并在此基础上论述了中国电影在面对全球性的背景下如何保持其文学性。

黄宾虹笔墨精神中的不可学性

笔墨不是以模仿物象为创作目的,而是作为艺术形式表演语言,表达中国文化、中国哲学中独有的幽远意境.能将“笔墨”发挥到如此高超境界的,当中国绘画史上黄宾虹莫属,在艺术上坚守本土文化立场,坚持从山水画中寻找超越的动力,发掘笔墨语言的超长渗透力.笔墨对于心理情感因素的依赖,使他的艺术风格执着走上一条表现道路.笔墨点线勾擦、情感交织,形成高低起伏音乐性.他以独有笔墨节奏和韵律,充分表现对客观社会生活的主观能动反映,营造出崇高、浑厚又不失细腻的山水境界.黄宾虹在晚年的山水画中,笔墨已经是无迹可寻,所表现的物象也是超乎于自然,这就决定了他的可学性与不可学性、可取性与不可取性.

不同焊接工艺下Strenx700钢焊接接头力学性能研究

文中分别采用熔化极气体保护焊(GMAW)和焊条电弧焊(SMAW)对Strenx700低合金高强钢进行焊接试验,制订合理的焊接工艺参数以及焊接保障技术措施,确保焊接接头满足要求,采用硬度计、万能试验机对焊接接头的组织及力学性能进行了分析及测试。

论薛季宣、陈傅良对理学性理的兼容

南宋孝宗隆兴、乾道间至光宗绍熙时,理学主流派的性理之学与永嘉事功之学同时昌盛,后者在发展过程中能够兼容前者的合理因素,具体表现在薛季宣"问阵而称俎豆"和陈傅良兼重"勇猛"与"详密"。他们对理学性理的兼容,其核心旨趣是传统儒家的"中道"思想,为叶适创建事功"治统"体系奠定了思维基础。

A novel immiscible high entropy alloy strengthened via L1_(2)-nanoprecipitate

The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3) immiscible high-entropy alloy(HEA)was developed.After vacuum arc melting and copper mold suction casting,this HEA exhibits a unique phase separation microstructure,which consists of striped Cu-rich regions and Fe-rich region.Further magnification of the striped Cu-rich region reveals that it is composed of a Cu-rich dot-like phase and a Fe-rich region.The aging alloy is further strengthened by a L1_(2)-Ni_(3)(AlTi)nanoprecipitates,achieving excellent yield strength(1185 MPa)and uniform ductility(~8.8%).The differential distribution of the L1_(2) nanoprecipitate in the striped Cu-rich region and the external Fe-rich region increased the strength difference between these two regions,which increased the strain gradient and thus improved hetero-deformation induced(HDI)hardening.This work provides a new route to improve the HDI hardening of Fe-Cu alloys.

Effect of quenching cooling rate on residual stress and microstructure evolution of 6061 aluminum alloy

In this study,the cooling rate was manipulated by quenching with water of different temperatures(30,60 and 100℃).Surface and internal residual stresses in the quenched 6061 aluminum alloy samples were measured using hole-drilling and crack compliance methods,respectively.Then,the processability of the quenched samples was evaluated at cryogenic temperatures.The mechanical properties of the as-aged samples were assessed,and microstructure evolution was analyzed.The surface residual stresses of samples W30℃,W60℃and W100℃is−178.7,−161.7 and−117.2 MPa,respectively along x-direction,respectively;and−191.2,−172.1 and−126.2 MPa,respectively along y-direction.The sample quenched in boiling water displaying the lowest residual stress(~34%and~60%reduction in the surface and core).The generation and distribution of quenching residual stress could be attributed to the lattice distortion gradient.Desirable plasticity was also exhibited in the samples with relatively low quenching cooling rates at cryogenic temperatures.The strengthes of the as-aged samples are 291.2 to 270.1 MPa as the quenching water temperature increase from 30℃to 100℃.Fine and homogeneous β"phases were observed in the as-aged sample quenched with boiling water due to the clusters and Guinier-Preston zones(GP zones)premature precipitated during quenching process.

Role of inclination angle on columnar-to-equiaxed transition in the eutectic Al-5Mg-2Si alloy fabricated by laser powder bed fusion

In this study,the effect of inclination angles relative to the building direction in the additively manufactured eutectic Al-5Mg-2Si alloy was investigated through the laser powder bed fusion(LPBF).The microstructures and mechanical properties of the Al-5Mg-2Si alloy manufactured with different inclination angles(0°,30°,45°,60°and 90°)were reported and discussed.It is found that the“semicircular”melt pool(MP)in the load bearing face of 0°sample was eventually transformed into“stripe-like”MP in the 90°sample,accompanied by an increased fraction of melt pool boundaries(MPBs).Moreover,the microstructural analysis revealed that the columnar-to-equiaxed transition(CET)of theα-Al grains and eutectic Mg2Si was completed in the 90°sample,which were significantly refined with the average size of 10.6μm and 0.44μm,respectively.It is also found that the 90°sample exhibited good combination of strength and elongation(i.e.yield strength of 393 MPa,ultimate tensile strength of 483 MPa and elongation of 8.1%).The anisotropic mechanical properties were highly associated with the refined microstructures,thermal stress,and density of MPBs.Additionally,the CET driven by inclination angles was attributed to the variation of thermal conditions inside the local MPs.

Effect of annealing temperature on microstructure and mechanical properties of Mg-Zn-Zr-Nd alloy with large final rolling deformation

In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was investigated.The rolled Mg-3Zn-0.5Zr-0.6Nd alloy exhibited an ultimate tensile strength of 386 MPa,a yield strength of 361 MPa,and an elongation of 7.1%.Annealing at different temperatures resulted in reduced strength and obviously increased elongation for both alloys.Optimal mechanical properties for the Mg-3Zn-0.5Zr-0.6Nd alloy were achieved after annealing at 200℃,with an ultimate tensile strength of 287 MPa,a yield strength of 235 MPa,and an elongation of 26.1%.The numerous deformed microstructures,twins,and precipitated phases in the rolled alloy could impede the deformation at room temperature and increase the work hardening rate.After annealing,a decrease in the work hardening effect and an increase in the dynamic recovery effect were obtained due to the formation of fine equiaxed grains,and the increased volume fraction of precipitated phases,which significantly improved the elongation of the alloy.Additionally,the addition of Nd element could enhance the annealing recrystallization rate,reduce the Schmid factor difference between basal and prismatic slip systems,facilitate multi-system slip initiation and improve the alloy plasticity.

Effect of thermo-mechanical treatment on microstructure and mechanical properties of wire-arc additively manufactured Al-Cu alloy

Wire-arc additive manufacture(WAAM)has great potential for manufacturing of Al-Cu components.However,inferior mechanical properties of WAAM deposited material restrict its industrial application.Inter-layer cold rolling and thermo-mechanical heat treatment(T8)with pre-stretching deformation between solution and aging treatment were adopted in this study.Their effects on hardness,mechanical properties and microstructure were analyzed and compared to the conventional heat treatment(T6).The results show that cold rolling increases the hardness and strengths,which further increase with T8 treatment.The ultimate tensile strength(UTS)of 513 MPa and yield stress(YS)of 413 MPa can be obtained in the inter-layer cold-rolled sample with T8 treatment,which is much higher than that in the as-deposited samples.The cold-rolled samples show higher elongation than that of as-deposited ones due to significant elimination of porosity in cold rolling;while both the T6 and T8 treatments decrease the elongation.The cold rolling and pre-stretching deformation both contribute to the formation of dense and dispersive precipitatedθ′phases,which inhibits the dislocation movement and enhances the strengths;as a result,T8 treatment shows better strengthening effect than the T6 treatment.The strengthening mechanism was analyzed and it was mainly related to work hardening and precipitation strengthening.

Time-dependent effects in transient liquid phase bonding of 304L and Cp-Ti using an Ag-Cu interlayer

One of the challenges for bimetal manufacturing is the joining process.Hence,transient liquid phase(TLP)bonding was performed between 304L stainless steel and Cp-Ti using an Ag-Cu interlayer with a thickness of 75μm for bonding time of 20,40,60,and 90 min.The bonding temperature of 860℃ was considered,which is under the β transus temperature of Cp-Ti.During TLP bonding,various intermetallic compounds(IMCs),including Ti_(5)Cr_(7)Fe_(17),(Cr,Fe)_(2)Ti,Ti(Cu,Fe),Ti_(2)(Cu,Ag),and Ti_(2)Cu from 304L toward Cp-Ti formed in the joint.Also,on the one side,with the increase in time,further diffusion of elements decreases the blocky IMCs such as Ti_(5)Cr_(7)Fe_(17),(Cr,Fe)_(2)Ti,Ti(Cu,Fe)in the 304L diffusion-affected zone(DAZ)and reaction zone,and on the other side,Ti_(2)(Cu,Ag)IMC transformed into fine morphology toward Cp-Ti DAZ.The microhardness test also demonstrated that the(Cr,Fe)_(2)Ti+Ti_(5)Cr_(7)Fe_(17) IMCs in the DAZ on the side of 304L have a hardness value of HV 564,making it the hardest phase.The maximum and minimum shear strength values are equal to 78.84 and 29.0 MPa,respectively.The cleavage pattern dominated fracture surfaces due to the formation of brittle phases in dissimilar joints.

Evolution of mechanical properties,localized corrosion resistance and microstructure of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging

The evolution of mechanical properties,localized corrosion resistance of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging(NIA)was investigated by hardness test,electrical conductivity test,tensile test,intergranular corrosion test,exfoliation corrosion test,slow strain rate tensile test and electrochemical test,and the mechanism has been discussed based on microstructure examination by optical microscopy,electron back scattered diffraction,scanning electron microscopy and scanning transmission electron microscopy.The NIA treatment includes a heating stage from 40℃to 180℃with a rate of 20℃/h and a cooling stage from 180℃to 40℃with a rate of 10℃/h.The results show that the hardness and strength increase rapidly during the heating stage of NIA since the increasing temperature favors the nucleation and the growth of strengthening precipitates and promotes the transformation of Guinier-Preston(GPI)zones toη'phase.During the cooling stage,the sizes ofη'phase increase with a little change in the number density,leading to a further slight increase of the hardness and strength.As NIA proceeds,the corroded morphology in the alloy changes from a layering feature to a wavy feature,the maximum corrosion depth decreases,and the reason has been analyzed based on the microstructural and microchemical feature of precipitates at grain boundaries and subgrain boundaries.

Lecturers’Efforts in Building Rapport in the English-Medium Instruction(EMI)Context:Focus on the Use of Communication Strategies

Past studies reveal the prevalence of anxiety,coupled with low motivation and disengagement among students in English-medium instruction(EMI)programs.Given the detrimental impact these negative emotions can have on learning outcomes,it is imperative that teachers establish positive emotional rapport with their students.This study explores how experienced and highly rated EMI lecturers at a Chinese university’s overseas campus use communication strategies to build rapport with their students during interactive academic activities.It identifies the strategies used by these lecturers and examines how the strategies facilitate the teaching-learning process.The data,consisting of 10 hours of tutorials and 10 hours of supervisor-student supervision meetings,is analyzed using an adapted Conversation Analysis(CA)approach.The analysis reveals three types of communication strategies(CSs)frequently used by lecturers:back-channeling,codeswitching,and co-creation of messages.By employing these strategies,the lecturers established a strong rapport with the students,which created an encouraging and supportive learning environment.Consequently,this positive atmosphere facilitated students’learning of content knowledge through English.The findings of this study have implications for the training of lecturers who encounter difficulties in establishing rapport with multilingual students in the EMI setting.

Bearing mechanism of roof and rib support structure in automatically formed roadway and its support design method

Non-pillar mining technology with automatically formed roadway is a new mining method without coal pillar reservation and roadway excavation.The stability control of automatically formed roadway is the key to the successful application of the new method.In order to realize the stability control of the roadway surrounding rock,the mechanical model of the roof and rib support structure is established,and the influence mechanism of the automatically formed roadway parameters on the compound force is revealed.On this basis,the roof and rib support structure technology of confined lightweight concrete is proposed,and its mechanical tests under different eccentricity are carried out.The results show that the bearing capacity of confined lightweight concrete specimens is basically the same as that of ordinary confined concrete specimens.The bearing capacity of confined lightweight concrete specimens under different eccentricities is 1.95 times higher than those of U-shaped steel specimens.By comparing the test results with the theoretical calculated results of the confined concrete,the calculation method of the bearing capacity for the confined lightweight concrete structure is selected.The design method of confined lightweight concrete support structure is established,and is successfully applied in the extra-large mine,Ningtiaota Coal Mine,China.

Temperature-Induced Unfolding Pathway of Staphylococcal Enterotoxin B:Insights from Circular Dichroism and Molecular Dynamics Simulation

In this study,circular dichroism(CD)and molecular dynamics(MD)simulation were used to investigate the thermal unfolding pathway of staphylococcal enterotoxin B(SEB)at temperatures of 298–371 and 298–500 K,and the relationship between the experimental and simulation results were explored.Our computational findings on the secondary structure of SEB showed that at room temperature,the CD spectroscopic results were highly consistent with the MD results.Moreover,under heating conditions,the changing trends of helix,sheet and random coil obtained by CD spectral fitting were highly consistent with those obtained by MD.In order to gain a deeper understanding of the thermal stability mechanism of SEB,the MD trajectories were analyzed in terms of root mean square deviation(RMSD),secondary structure assignment(SSA),radius of gyration(R_(g)),free energy surfaces(FES),solvent-accessible surface area(SASA),hydrogen bonds and salt bridges.The results showed that at low heating temperature,domain Ⅰ without loops(omitting the mobile loop region)mainly relied on hydrophobic interaction to maintain its thermal stability,whereas the thermal stability of domain Ⅱ was mainly controlled by salt bridges and hydrogen bonds.Under high heating temperature conditions,the hydrophobic interactions in domain Ⅰ without loops were destroyed and the secondary structure was almost completely lost,while domain Ⅱ could still rely on salt bridges as molecular staples to barely maintain the stability of the secondary structure.These results help us to understand the thermodynamic and kinetic mechanisms that maintain the thermal stability of SEB at the molecular level,and provide a direction for establishing safer and more effective food sterilization processes.

腹腔镜下子宫肌瘤剔除术与开腹手术治疗子宫肌瘤对性功能、性激素及复发率的影响

目的 探讨腹腔镜下子宫肌瘤剔除术(LM)与开腹手术治疗子宫肌瘤对性功能、性激素及复发率的影响。方法 选取2019年6月至2022年6月在安徽省宿州市泗县人民医院就诊的80例子宫肌瘤患者作为研究对象,根据手术方式分为腹腔镜组(n=26)和开腹组(n=54)。腹腔镜组行LM治疗,开腹组行开腹子宫肌瘤剔除术(TAM)治疗。比较两组围术期指标、手术前后女性性功能指数量表(FSFI)评分、性激素水平、术后并发症发生情况及随访6个月的结果。结果 与开腹组比较,腹腔镜组手术和住院时间更短,术中出血量更少(P<0.05);术后,腹腔镜组FSFI评分高于开腹组(P<0.05);腹腔镜组性激素水平优于开腹组(P<0.05);随访期间,两组肌瘤残留率和复发率无显著差异(P>0.05)。结论 与TAM治疗子宫肌瘤患者相比,LM治疗可以缩短手术和住院时间,减少术中出血量,降低对性功能和卵巢功能的影响,且并发症发生率更低。

基于产后出血高危因素评估表的前瞻性护理在妊娠期高血压产妇中的应用效果

目的 观察基于产后出血高危因素评估表的前瞻性护理在妊娠期高血压(PIH)产妇中的应用效果。方法 回顾性分析2020年1月至2022年12月于安庆市立医院分娩的92例PIH产妇的临床资料,根据护理方式不同分为研究组(n=48)与对照组(n=44),对照组给予常规护理,研究组则在对照组基础上予以基于产后出血高危因素评估表的前瞻性护理。比较两组产妇产后2 h及24 h的出血量、干预前后的焦虑自评量表(SDS)及抑郁自评量表(SAS)评分、血液动力学指标水平,并比较两组分娩结局。结果 研究组产妇产后2 h及24 h的出血量均低于对照组(P<0.05)。干预后两组产妇的SAS及SDS评分、收缩压(SBP)、舒张压(DBP)、心率(HR)较干预前低,且研究组低于对照组(P<0.05)。研究组产妇自然分娩比例及Apgar评分高于对照组(P<0.05)。结论 基于产后出血高危因素评估表的前瞻性护理可有效减少PIH产妇的产后出血量与出血率,同时能缓解产妇的负面情绪,并有助于改善血液动力学水平与分娩结局。

Th1/Th2免疫失衡与PCOS不孕症患者IUI治疗后临床结局的关系

目的 研究辅助性T淋巴细胞亚群比值(Th1/Th2)免疫失衡与多囊卵巢综合征(PCOS)不孕症患者宫腔内人工授精(IUI)治疗后临床结局的关系。方法 前瞻性选取2019年2月至2020年12月在咸宁市中心医院进行IUI治疗的120例PCOS不孕症患者作为研究对象,根据治疗效果分为成功组(n=29),失败组(n=91)。比较两组性激素及Th1/Th2,并分析Th1及Th2水平的相关性。结果 成功组Th1、Th2、Th1/Th2显著低于失败组(P<0.05),成功组补体C3、补体C4、免疫球蛋白A(IgA)、免疫球蛋白G(IgG)、免疫球蛋白M(IgM)水平显著高于失败组(P<0.05)。相关性分析结果显示,患者的IUI治疗不良结局与Th1、Th2、Th1/Th2呈正相关。结论 Th1/Th2免疫失衡与PCOS不孕症患者IUI治疗后临床结局有显著相关性。