基于模糊神经网络的学生科学素养影响机制研究

科学素养的影响机制对教育策略优化、人才培养质量提升,以及社会科技创新与可持续发展具有深远影响。然而,传统的经典教育统计学方法难以全面揭示这一复杂过程。为突破这一局限,采用先进的模糊神经网络技术,对包含53个国家共计113,314个有效样本的PISA2015数据库进行深度的数据挖掘分析。在特征选择后,识别出十项对学生科学素养提升具有积极影响的因素和一项消极影响因素。结果显示,社会经济发展水平是决定学生科学素养水平的关键因素;家庭教育投入与科学素养水平之间存在最强关联性;学习品质、高阶思维能力及科学本质理解在科学素养发展中起到核心推动作用;而信息技术的应用在影响学生科学学业表现上呈双刃剑效应。基于以上发现,建议教育领域顺应智能时代趋势,利用机器学习进行数据挖掘,推动计算教育学研究范式的转型;优化教育资源分配结构以促进科学素养教育公平;并革新学生培养策略,以实现学生科学素养的高质量发展。

Hydrodynamic Cavitation Enhanced SR-Aops Degradation of Organic Pollutants in Water:A Review

SR-AOP(sulfate radical advanced oxidation process)is a novel water treatment method able to eliminate refractory organic pollutants.Hydrodynamic cavitation(HC)is a novel green technology,that can effectively produce strong oxidizing sulfate radicals.This paper presents a comprehensive review of the research advancements in these fields and a critical discussion of the principal factors influencing HC-enhanced SR-AOP and the mechanisms of synergistic degradation.Furthermore,some insights into the industrial application of HC/PS are also provided.Current research shows that this technology is feasible at the laboratory stage,but its application on larger scales requires further understanding and exploration.In this review,some attention is also paid to the design of the hydrodynamic cavitation reactor and the related operating parameters.

我国小学科学教师课堂教学的信息技术使用广度与影响因素研究——基于31个省(自治区、直辖市)的大规模调查

小学科学教师的信息技术使用关系到数字化创新及科技后备人才的培养,作为职业素养的组成部分,必然受到多因素影响。基于全国31个省(自治区、直辖市)的13.1万份问卷调查数据,系统探讨我国小学科学教师信息技术的使用广度及其影响因素。研究发现,我国小学科学教师的信息技术使用广度较弱,显著受个体特征(性别、年龄、学历、专业)、从教经历(科学课专兼任、教龄、科学课教龄)、从教资本(教资拥有、教资获得、聘用方式、职称级别)和学校区域(地理分布、学校类型)的影响,而教师知识信念、教学实践和专业发展支持影响不明显,且国家教育信息化政策显著改善乡村教师的使用广度。建议开展核心素养导向的信息技术能力培训、探索信息技术服务学科教学的有效策略和构建技术驱动教学创新的协同发展机制,以此提升教师信息技术素养。

我国科学学科概念转变研究图景:阶段、主题与展望

概念转变研究始终是国际科学教育领域热点研究主题,也是我国科学教育领域的核心问题。为描绘我国概念转变的研究图景,基于检索、梳理知网中相关文献,分析我国概念转变研究的发展历程和研究主题。从研究结果来看,我国概念转变的研究主要包括前概念的内涵与概念转变教学策略阶段、前概念的探查与概念转变理论的引介阶段、前概念与概念转变理论系统研究阶段、概念转变跨学科整合与实证研究阶段、概念转变认知神经机制与科学化阶段。从研究主题来看,我国概念转变的研究主要包括前概念和概念转变的理论基础、前概念的诊断与探查的实证研究、概念转变的教学策略研究、教学实验研究、心理学与脑科学研究。最后,提出概念转变未来研究的建议,即深化现有研究和概念转变的脑科学研究。

Numerical Study of High-Temperature Nonequilibrium Flow around Reentry Vehicle Coupled with Thermal Radiation

Accurate aerodynamic heating prediction is of great significance to current manned space flight and deep space exploration missions.The temperature in the shock layer surrounding the reentry vehicle can reach up to 10,000 K and result in remarkable thermochemical nonequilibrium,as well as considerable radiative heat transfer.In general,high-temperature flow simulations coupled with thermal radiation require appropriate numerical schemes and physical models.In this paper,the equations governing hypersonic nonequilibrium flow,based on a three-temperature model combined with a thermal radiation solving approach,are used to investigate the radiation effects in the reentry shock layer.An axisymmetric spherical case shows that coupling the flow-field simulation with radiation has a scarce influence on the convective heating prediction,but has some impact on the radiative heating calculation.In particular,for the Apollo capsule reentry,both the absorption coefficient and incident radiation are remarkable inside the shock layer.The radiative heating maximum reaches nearly 38%of that of the convective heating making a considerable contribution to the total aerodynamic heating.These results indicate that in the hypersonic regime,in order to account for the total heating,it is necessary to simulate the high-temperature thermochemical nonequilibrium flows coupled with thermal radiation.

改革开放以来中国教育信息化政策育人历程研究——基于政策工具的文本分析

改革开放以来,中国教育信息化得到长足发展,政策体系不断完善,亦成为当前实现中国教育现代化发展的根基与保障。为理清政策视域下中国教育信息化发展之路,基于政策工具、教育领域和培养目标的三维分析框架,对1978—2021年期间38项国家层面的教育信息化政策进行分析。结果显示,改革开放至今的中国教育信息化政策以环境型政策工具使用最为频繁;校内教育一直是主流使用领域,家庭教育政策工具使用较少;领域素养的培养目标被较多提及。据此建议,相关部门需结合教育信息化发展需求,加强需求型政策工具和供给型政策工具的使用;平衡校内外领域的政策工具使用,特别是对家庭教育和校外教育给予一定的政策支持,调动多方力量协同参与;有效调控各教育环境中信息化政策工具的使用,培养目标综合关切学生高阶素养和通用素养。

Effects of Jasmonic Acid on the Expression of Capsaicin Biosynthesis Related Genes in Chili Pepper(Capsicum annuum)

To explore the regulatory effects of jasmonic acid （JA） on the expression of the genes involved in capsaicin biosynthesis pathway, the mRNA expression of the genes was determined by fluorescence-based quantitative PCR 0, 4, 12, 24 and 48 h after chili peppers （Capsicum annuum var. conoides） were treated with 100 μmol/L JA, and the content of capsaicin was measured by high performance liquid chromatography （HPLC） 0, 1, 3, 6, 10 and 15 d after JA treatment. The results showed that JA upregulated the mRNA levels of pal, C4h, Comt, 4Cl, Hct, Paint, Bcat, FatA and pun1 in chili pepper, thus promoting the synthesis of capsaicin to different extents.

世界慕课研究热点、趋势与启示

慕课诞生至今历经14年的发展,世界各国都在慕课建设中贡献智慧。基于文献计量学方法,采用CiteSpace对科学网核心数据合集中的社会科学引文索引文献进行可视化分析,探索世界慕课研究领域的现状、热点和趋势。结果表明,美国、中国和西班牙为世界慕课研究的核心地区;美国麻省理工学院是发文量最多的机构;慕课学习者学业表现的影响因素和评估是慕课研究的热点;慕课学习策略、基于机器学习的慕课学习分析和慕课学习持续性是未来研究的趋势。分析结果对中国慕课发展的启示包括以慕课发展推进教育公平、实现慕课学习的个性化支持、注重慕课质量及其评估、构建基于慕课的共同体。

TNFSF15 facilitates the differentiation of CD11b^(+) myeloid cells into vascular pericytes in tumors

Objective:Immature vasculature lacking pericyte coverage substantially contributes to tumor growth,drug resistance,and cancer cell dissemination.We previously demonstrated that tumor necrosis factor superfamily 15(TNFSF15)is a cytokine with important roles in modulating hematopoiesis and vascular homeostasis.The main purpose of this study was to explore whether TNFSF15 might promote freshly isolated myeloid cells to differentiate into CD11b^(+) cells and further into pericytes.Methods:A model of Lewis lung cancer was established in mice with red fluorescent bone marrow.After TNFSF15 treatment,CD11b^(+) myeloid cells and vascular pericytes in the tumors,and the co-localization of pericytes and vascular endothelial cells,were assessed.Additionally,CD11b^(+) cells were isolated from wild-type mice and treated with TNFSF15 to determine the effects on the differentiation of these cells.Results:We observed elevated percentages of bone marrow-derived CD11b^(+)myeloid cells and vascular pericytes in TNFSF15-treated tumors,and the latter cells co-localized with vascular endothelial cells.TNFSF15 protected against CD11b^(+)cell apoptosis and facilitated the differentiation of these cells into pericytes by down-regulating Wnt3a-VEGFR1 and up-regulating CD49e-FN signaling pathways.Conclusions:TNFSF15 facilitates the production of CD11b^(+) cells in the bone marrow and promotes the differentiation of these cells into pericytes,which may stabilize the tumor neovasculature.

Numerical Investigation into the Transient Behavior of the Spike-Type Rotating Stall for a Transonic Compressor Rotor

In this paper,a numerical investigation into a spike-type rotating stall process is carried out considering a transonic compressor rotor(the NASA Rotor 37).Through solution of the Unsteady Reynolds-Averaged Navier-Stokes(URANS)equations,the evolution process from an initially circumferentially-symmetric near-stall flow field to a stable stall condition is simulated without adding any artificial disturbance.At the near-stall operating point,periodic fluctuations are present in the overall flow of the rotor.Moreover,the blockage region in the channel periodically shifts from middle span to the tip.This fluctuating condition does not directly lead to stall,while the full-annulus calculation eventually evolves to stall.Interestingly,a kind of“early disturbance”feature appears in the dynamic signals,which propagates forward ahead of the rotor.

Bioinformatics and Expression Analysis of CaERF Gene in Capsicum

AP2/ERF transcription factor is a kind of plant-specific transcription factor,which is widely involved in the whole process of plant growth and development,and has important regulatory effects in plant secondary metabolism.In this study,the CaERF gene was cloned from Capsicum annuum by RT-PCR.The bioinformatics and expression analysis revealed that the CDS region of this gene is 795 bp in length,encoding 264 amino acids,and the molecular weight and isoelectric point of the protein are 30.1 KD and 5.74,respectively;the gene encodes a 58-amino acid DNA-binding domain AP2 at 533-706,which is closest to Capsicum chinense in genetics;and the gene is expressed early in the fruit development from 16 to 20 d after flowering,and related to the level of pun 1 gene expression.The cloning and expression analysis of CaERF transcription factor gene laid a foundation for further study on the regulation of capsaicin synthesis.

Numerical Application of the Flamelet Model to Supersonic Turbulent Combustion

In this study,the flow field structure inside a scramjet combustor is numerically simulated using the flamelet/progress variable model.Slope injection is considered,with fuel mixing enhanced by means of a streamwise vortex.The flow field structure and combustion characteristics are analyzed under different conditions.Attention is also paid to the identification of the mechanisms that keep combustion stable and support enhanced mixing.The overall performances of the combustion chamber are discussed.

Review of Research Advances in CFD Techniques for the Simulation of Urban Wind Environments

Computational fluid dynamics(CFD)has become the main method for the prediction of the properties of the external wind environment in cities and other urban contexts.A review is presented of the existing literature in terms of boundary conditions,building models,computational domains,computational grids,and turbulence models.Some specific issues,such as the accuracy/computational cost ratio and the exploitation of existing empirical correlations,are also examined.

Expression of Sirt1 and Sirt2 in the Injured Optic Retina of Calorie-Restricted Rats

Purpose:To investigate retinal ganglion cell (RGC) survival after optic nerve injury in calorie-restricted (CR) rats,and analyze the potential role of Sirtuins.Methods:Ten-month old male Sprague-Dawley rats (n=14) were divided into calorie restricted (CR) and ad libitum (AL) groups.In the CR group (n=7),the rats were denied access to food every other day.Animals in the AL group (n=7) had had free access to food.PN-ON grafting was carried out on the right eye of all subjects after 5 months of feeding.Three weeks postoperatively,retina samples were collected,half of which were fixed in 4% paraformaldehyde (PFA) and subjected to standard immunofluorescence staining for TUJ-1.The remaining samples were subjected to total RNA analysis and RT-PCR for Sirt1 and 2 expression.Results:Comparing the amount of TUJ-1 staining between the groups,the mean density and the total number of RGCs showed no significant difference.RT-PCR results indicated that mRNA expression of Sirtuin2 in the CR group was significantly lower than that in the AL group,whereas no statistically significant difference was observed between the two groups regarding the mRNA expression of Sirt1.Conclusion:Calorie restriction had no impact on the survival of injured RGCs.The down-regulated mRNA expression of Sirt2 in the CR group may indicate an improved capacity for regeneration among these animals,but more work is needed to explore this possibility.

Analysis of Cloning and Expression Characteristics of Capsicum chinense Jacq. CcMYB Gene

In order to discuss the role of MYB gene in capsaicine synthesis process, one CcMYB gene was cloned from Capsicum chinense Jacq. by RT-PCR. Its cDNA has a total length of 1 038 bp, and was speculated to code 345 amino acids, comprising an complete open reading frame. The isoelectric point is 8.57, and the molecular weight is 38.2 KD. The protein is a neutral hydrophobin without transmentbrane structure. There are two MYBDNA domains at the N terminal. The fluorescence quantitative PCR results showed that CcMYB gene was expressed in all the root, stem, leaf, flower, placenta and fruit tissue of pepper, and the expression level was the highest in fruit ; and CcMYB was expressed in fruit at the highest level at turning stage, and at the second highest level at expansion stage, which accords with the expression profile of punl gene in fruit development period. It is speculated that CcMYB gene plays an important role in the regulation of capsaicine synthesis in C. chinense fruit.

补肾益精方对外周血干细胞在RCS大鼠视网膜上的募集及睫状神经营养因子表达的影响

目的:观察补肾益精方对外周血骨髓间充质干细胞在视网膜变性模型(RCS)大鼠视网膜募集及睫状神经营养因子(CNTF)分泌的影响,探讨补肾益精方治疗视网膜退行性病变的作用机制。方法:实验研究。采用尾静脉注射方式将1×107个GFP标记的骨髓间充质干细胞(GFP-MSCs)注射至3周龄RCS大鼠外周血,然后按随机数字表法分为蒸馏水组及补肾益精方(BSYJ)组,每组39只。注射后第1天开始分别采用蒸馏水及补肾益精方药液灌胃,正常SD大鼠作为对照组常规饲养。给药7d、14d及28d时分别采用视网膜铺片、免疫荧光显微镜观察GFP-MSCs在视网膜的募集情况;实时荧光定量PCR及免疫荧光双染技术检测视网膜表达CNTF的情况;TUNEL法检测视网膜细胞凋亡情况;采用单因素方差进行数据分析。结果:给药7d、14d和28d时,蒸馏水组GFP-MSCs的数目少于BSYJ组,其中给药28d时,2组差异有统计学意义(t=2.71,P=0.001)。给药7d、14d和28d时,BSYJ组CNTF表达较蒸馏水组均明显增加,3组差异有统计学意义(F=5.763,P=0.003;F=3.165,P=0.042;F=4.839,P=0.004)。给药7d和28d时,BSYJ组视网膜细胞凋亡率明显少于蒸馏水组,3组差异有统计学意义(F=0.002,P=0.001;F=0.307,P=0.004)。结论:补肾益精方能够促进外周血干细胞在视网膜上的募集以及促进CNTF的表达,这可能是补肾益精方延缓RCS大鼠视网膜细胞凋亡和病变进程的作用机制之一。

基于语音的抑郁症识别

抑郁症是世界范围内常见的精神疾病之一,抑郁症患者往往长期伴随情绪低落,如悲伤内疚、低自尊、兴趣丧失、功能减退等,对个人、家庭及社会造成了巨大损失.抑郁症的发病原因复杂,临床诊断存在一定的困难,有必要寻找一种更加便捷、客观、高效的方式来辅助抑郁症的快速识别.语音作为一个相对客观且容易获得的变量,具有其潜在的价值.本研究旨在构建基于语音的抑郁症识别模型,探究语音与抑郁症之间的关系.收集了103名被试(45名抑郁症患者,58名健康人)的语音数据,实验组为临床确诊的抑郁症患者,年龄在23.8~44.6岁之间,控制组为健康人,年龄为20.1~41.7岁.我们采用了3(情绪状态:正性、中性、负性)×3(任务类型:语言问答、文本朗读、图片描述)的实验设计,运用机器学习的分类算法——逻辑回归(LR)来构建抑郁识别模型.实验结果表明,语音的抑郁识别精度可以达到82.9%.本文采用机器学习方法,基于语音变量建立有效的抑郁症自动识别模型,为抑郁症的辅助识别提供客观的指标和依据.

我国小学科学教师教学实践现状及影响机制——基于31个省(自治区、直辖市)的调研

小学科学教师的教学实践直接关系创新后备人才的培养,探索其影响机制可以为教师专业发展提供循证依据。本研究依托2021年下半年教育部基础教育教学指导委员会科学教学专委会组织的全国31个省(自治区、直辖市)的小学科学教师队伍现状调研数据,深入分析小学科学教师的教学实践现状及其影响机制。研究发现:我国小学科学教师的一般教学法知识较好,学科教学法居中,实践型智慧最为薄弱,信息技术应用、跨学科与问题解决式教学以及探究教学等实践能力亟待提高;教学实践在背景因素影响下存在显著的差异表现,前五位依次为专兼任、科学课教龄、性别、地理地区和聘用方式;专业知识与信念对教学实践有显著正向影响,教师培训状况、学校氛围在教师专业知识对教学实践的正向影响中发挥调节作用。建议针对小学科学教师教学实践的薄弱环节实施精准培训,分段分级设置小学科学教师专业标准,健全小学科学教师专业发展保障机制,强化小学科学教师的学科身份认同,循证决策以激发教师实践的内生动力。

中国共产党领导下我国教育技术百年历程

中国共产党建党百年来,根植于中华民族伟大复兴的教育强国梦,我国教育技术在实践历程中先行担当起新民主主义革命宣传与教化的载体,随后与生产劳动相结合并服务于社会主义革命与建设事业,通过技术跃迁助力电化教育成熟与教育信息化普及,在智能教育融合创生发展中展现新时代育人本质。教育技术以教学实践应用为主线并融合学习理论不断演进,起始于学科知识普及,兴起于电化教育应用,发展于计算机辅助教学,创新于跨学科融合发展。现象学视域下,教育技术的百年发展呈现出解释学关系中的工具与手段说、具身关系中的目的与方法说、它异与背景关系的改造与塑造说的逻辑演进历程。开启新征程,中国共产党领导下教育技术事业始终坚持以人为本的育人本质,重视学科导向的技术指向与课程结构的深层耦合,实现技术作为教育创新内生动力的研究范式转向。