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Este artículo presenta un retrato holístico de Lesson Study Chinese (LS). Incluye las tradiciones históricas y culturales del LS chino, los mecanismos del LS chino, las características principales del LS chino en comparación con el LS japonés y su desarrollo reciente, y otras direcciones. Se discuten las implicaciones del SL chino para el desarrollo del SL a nivel internacional.

PurposeThis study aimed to explore how an adapted theoretical framework by networking two theories could help document teachers' collective learning through lesson study.Design/methodology/approachInterconnected Model of Teacher Professional Growth (IMPG) and Documentational Approach to Didactics (DAD) has been used individually to document teachers' professional learning from different aspects. The IMPG captures teachers’ growth through the iterative process and dynamics (i.e. enactment and reflection) among four domains (personal domain, external domain, practice domain and consequence domain). At the same time, the DAD primarily focuses on teacher learning through the interactions between resources and teachers. To deepen understanding of teachers' learning through lesson study, in this study, a networked theoretical framework through which the DAD model is enriched by incorporating some ideas from IMPG is proposed. A lesson study, including five stages of study, plan, enact, reflect and refine, facilitated by a researcher was conducted in Shanghai China. The data sets including all videotaped meetings and research lessons and lesson plans of the lesson study are analyzed based on the adapted framework qualitatively.FindingsThe results show that the teachers' document evolved from adopting the traditional teaching materials to adapting both traditional ones and e-resources with careful consideration of student learning through the lesson study process.Research limitations/implicationsThis study advances our understanding of networking strategies and their usefulness for deepening teacher professional learning as document development through lesson study. However, the sustainability of this type of professional learning needs to be further explored.Originality/valueThis study expands teacher learning through lesson study as the document development and enriches the DAD theory by illuminating the process of the documentational genesis.

Due to the COVID-19 pandemic in Shanghai, China, all school classes were delivered through an online environment from February 24 to May 22, 2020. To support this transition, the Shanghai Education Commission led expert teachers and specialists to develop a series of online video lessons based on the Shanghai unified curriculum, and suggested students watch the online video lessons individually from home, followed by an online synchronous lesson supported by class teachers. This study investigated what primary mathematics teachers learned from addressing these challenges through a case study. By following two purposefully selected teachers over 2 weeks during the transition, multiple data sets including online video lessons, online synchronous lessons, daily reflections, and post-online teacher interviews were collected. A fine-grained analysis of the data from the lens of the documentational approach to didactics found that teachers adaptively used online video lessons as important resources for their online synchronous lessons and virtual Teaching Research Groups as a teachers' collaboration mechanism supported them to develop online video lessons and address various technological constraints. Finally, implications of this case study for mathematics education globally are discussed.The online version contains supplementary material available at 10.1007/s10649-022-10172-2.

The linear positive magnetoresistance (LPMR) is a widely observed phenomenon in topological materials, which is promising for potential applications on topological spintronics. However, its mechanism remains ambiguous yet, and the effect is thus uncontrollable. Here, we report a quantitative scaling model that correlates the LPMR with the Berry curvature, based on a ferromagnetic Weyl semimetal CoS 2 that bears the largest LPMR of over 500% at 2 K and 9 T, among known magnetic topological semimetals. In this system, masses of Weyl nodes existing near the Fermi level, revealed by theoretical calculations, serve as Berry-curvature monopoles and low-effective-mass carriers. Based on the Weyl picture, we propose a relation MR = e ℏ B Ω F , with B being the applied magnetic field and Ω F the average Berry curvature near the Fermi surface, and further introduce temperature factor to both MR/ B slope (MR per unit field) and anomalous Hall conductivity, which establishes the connection between the model and experimental measurements. A clear picture of the linearly slowing down of carriers, i.e., the LPMR effect, is demonstrated under the cooperation of the k -space Berry curvature and real-space magnetic field. Our study not only provides experimental evidence of Berry curvature–induced LPMR but also promotes the common understanding and functional designing of the large Berry-curvature MR in topological Dirac/Weyl systems for magnetic sensing or information storage.

PurposeThis special issue reveals how lesson study in China continues to serve as a powerful platform to support change in teaching. The papers included in this issue explore how university faculty members and researchers support teachers to cross boundaries resulting from the introduction of key competencies-based (hexin suyang 核心素养) curriculum reform (KCR).Design/methodology/approachThe theme of continuity and change is examined against the backdrop of Chinese lesson study's (CLS's) consistent supporting role in enabling curriculum reform. These analyses make use of concepts involved in understanding boundary crossing, such as using boundary objects and their roles, to help make sense of the new theories, tools, and resources as well as relationships engendered in responding to the reform's demand. While recognizing the continuity at play in Chinese LS, the authors use the lens of learning at the boundary of research-practice partnerships (RPPs) (Farrell et al., 2022) to contemplate the future of CLS.FindingsThe papers touch on three major themes: (1) the role of university-school partnerships in meeting the new demands of key competencies reform; (2) resourceful tools, strategies and structures to support boundary crossing for teachers; and (3) roles and relationships for mutual learning in university-school partnerships. Together these three themes, considered across the papers in this issue, point to the need to redefine CLS to engender versatility and hybridity and to enlist mutual learning relationships in future university-school partnerships. Such redefinition positions lesson study to both continue and change.Research limitations/implicationsThe papers in this issue are expected to promote mutualist learning in future CLS research-practice partnerships. To do so, research needs to move from focusing on change of a single case teacher to clarifying what experts and teachers each learn from the LS and from each other. Attention also needs to focus on the collaborative discourse and ways such discourse is able to promote mutual learning, emotional support in facing change as well as critical and constructive problem solving.Practical implicationsPractically, to better support boundary crossing, this special issue encourages academics and teachers to identify and work around boundary objects and their enabling features to enhance knowledge and identity of both university and teacher participants for more effective research-practice partnerships.Originality/valueThis special issue offers a pioneering set of studies that contributes to an in-depth understanding of how CLS is supporting the current competencies-based reform in China. It also provides concrete future directions for research and practice to enhance university-school partnerships' response to reform.

UNLABELLED: In the research reported in this paper we investigated teachers' changes when adopting and adapting to emergency online teaching during the COVID-19 pandemic, from the perspective of the Interconnected Model of Professional Growth (IMPG). By adapting complementary accounts methodology to research into teachers' changes when addressing the unexpected migration to online teaching, an integrated data set, including online teaching videos, teacher daily reflections, and teacher interviews from two purposefully selected teachers over two weeks of online teaching, was collected and analyzed qualitatively. Both teachers encountered different difficulties and thus had different knowledge changes displayed in different change routes. For the experienced teacher, students' mistakes in homework and her online teaching practice triggered her knowledge changes. For the young teacher, the online video lessons, relevant resources on the Internet and students' performance were her primary sources that triggered the changes of her knowledge for teaching. These differences between the experienced teacher and young teacher provide evidence of the complexity of teacher's professional growth, which is related to a variety of external and internal factors. This study demonstrates how the IMPG model helps uncover teachers' changes in such an unprecedented virtual-teaching environment. Finally, the implications of this study for teacher professional development in general are discussed. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11858-022-01378-y.

PurposeThis study aims to explore how a Chinese lesson study (LS) supports a teacher's learning of transforming curriculum reform ideas into classroom practices.Design/methodology/approachData analyzed in this study included lesson plans, three videotaped research lessons, three audio-taped group meetings, interviews, the teacher's reflection journals and other related materials. Clarke and Hollingsworth's interconnected model of professional growth (IMPG) was adopted as the theoretical and analytical framework for examining the teacher's learning process.FindingsThis study found that teachers can deepen their understanding of innovative curriculum ideas and implement them through an iterative cycle of planning, enactment and reflection in LS. Involving knowledgeable others in the process and reflecting on evidence-based evaluation of students' learning outcomes is crucial for changing the teacher's knowledge, beliefs, attitudes and teaching practices. Theoretical tools, such as learning trajectory, are useful for transforming curriculum reform ideas that teachers find abstract and overly broad into concrete and actionable lesson designs.Originality/valueTheoretically, this study can broaden our knowledge about how the under-studied mechanism of Chinese LS can contribute to helping teachers to transform reform ideas into classroom practices. Practically, this study provides suggestions for researchers and educators to reflect on and improve the effectiveness of teachers' professional development programs in a reform context.

One-step fabrication of bulk SnTe thermoelectric material with excellent performance through self-propagating high-temperature synthesis under high-gravity field.

The conventional fabrication methods (for example, melting and powder metallurgy) of bulk thermoelectric materials are time- and energy-consuming, which restrict their large-scale application. In this work, ultra-fast self-propagating synthesis under a high-gravity field was used to prepare SnTe bulks, which shortened the synthesis time from several days to a few seconds. The grain growth was suppressed and some small pores were reserved in the matrix during the ultra-fast solidification process. The increased grain boundaries and pores (nanoscale to micron scale) enhanced phonon scattering, which greatly decreased the lattice thermal conductivity. The obtained minimum lattice thermal conductivity is 0.81 W m

Negative and zero thermal expansion (NTE and ZTE) materials are widely adopted to eliminate the harmful effect from the "heat expansion and cool contraction" effect and frequently embrace novel fundamental physicochemical mechanisms. To date, the manipulation of NTE and ZTE materials has mainly been realized by chemical component regulation. Here, we propose another method by making use of the anisotropy of thermal expansion in noncubic single crystals, with maximal tunability from the integration of linear NTE, ZTE and positive thermal expansion (PTE). We demonstrate this concept in borate optical crystals of AEB

PurposeThis paper presented the learning process of a group of primary mathematics teachers who participated in two iterations of lesson design, enactment and reflection in a Chinese Lesson Study.Design/methodology/approachAn expansive learning theory was employed to examine the teachers’ learning process in lesson study (LS) on representing fractions on a number line. The evolution of a germ cell was utilized to feature the transformation of the object of activity from abstract to concrete through resolving contradictions among LS members. The videos of lesson planning, research lessons (RLs) and debriefing meetings were collected and analyzed to reveal the expansive learning process.FindingsThe analysis showed that the teachers expanded their learning through transforming the object from diffuse to concrete and expanded through consciously articulating the germ cell. The outcomes of object-oriented activity include improving the enacted lesson which promoted students’ conceptual understanding.Originality/valueThis study made a unique contribution to understanding the learning process of teachers in Chinese LS from the perspective of expansive learning.

To resist large electromagnetic loads, the ITER correction coils (CCs) are protected by a 20-mm thickness 316LN austenitic stainless steel case. Due to the strict tolerance requirement of the case manufacture, tungsten inert gas (TIG) welding technology was used for subcase assembly welding, whereas laser beam welding (LBW) technology was applied to enclosure welding of the cases. The case shall be operated at 4.2 K and shall undergo considerably cyclic stress due to magnet electromagnetization as well as interaction with the toroidal field (TF) and poloidal field (PF). This article focuses on the assessment of the mechanical properties of the welding joints at cryogenic temperature. Results indicated that the values of the ultimate tensile strength of the TIG welding joint and the LBW welding joint were 1555 and 1522 MPa, respectively, which reach to 99.7 and 97.6% of that of the base material (BM). The elongation at the fracture of both the TIG and LBW weldments was larger than 35%. The plane strain fracture toughness K Ic( J ) of the TIG and the LBW weldments was 210 and 241 MPa·m1/2, respectively. The fractographic analysis indicated that the fracture surface was composed of fine equiaxed dimples, which indicated that both welding joints fractured in a ductile manner. The welding joints survived the minimum of 30 000 cycles fatigue test at stress level and load ratio specified by the ITER document. In addition, the fatigue crack growth rates of both welding joints were lower than that of the BM. All mechanical properties of both the welding joints satisfied the ITER specifications.

Teacher collaborative learning is key in teacher professional development. Yet, how teachers learn in cross-cultural professional development settings remains largely unexplored. This paper examines the case of a Chinese mathematics teacher who learned through addressing various challenges when teaching in an English school in a China-UK exchange program. A praxeological perspective was used to analyze the data, including lesson plans, classroom observation notes, and post-lesson meetings. Results showed that collaboration and adaptation helped the teacher address the obstacles generated by cultural differences. The analysis revealed the difficulties the teacher encountered and how the mathematical and didactic praxeologies implemented evolved and helped overcome these challenges, broadening her mathematics knowledge for teaching. Finally, the implications of the case study on teacher collaborative learning in cross-cultural settings are discussed.

PurposeFinding ways in which technology can be used to modify, strengthen, scale up and sustain lesson study (LS) is an emerging field of research. It has become even more important due to a pandemic leading to teacher and student learning being delivered online. The purpose of this paper is to present research findings about experiences of online LS and identify issues for further research.Design/methodology/approachA systematic search of articles from 2010 to 2020 identified 13 relevant papers, and through analysis, some major themes were identified. All papers in the special issue were synthesized from the lens of the identified themes; finally, further directions are discussed.FindingsIn general, various online LS models were found to have features that resulted in positive effects on teaching and learning, but, whilst several characteristics of effective online learning were identified, some studies also highlighted issues.Research limitations/implicationsThere is a need for larger scale projects over an extended period to assess the effectiveness of online LS. Future research focused on carrying out learning study online as well as consideration of equity issues associated with online LS are also suggested.Originality/valueThe studies presented in this issue address the opportunities and challenges of conducting online LS during a pandemic and beyond. Together, the literature review and contributory papers provide an international perspective of using online LS and identify important issues for further research.

PurposeThis study aimed to explore how a group of Chinese primary mathematics teachers learned through conducting an online cross-cultural lesson study between China and Australia.Design/methodology/approachAn expansive learning theory was adopted to examine teachers' learning through collective activities across different activity systems. Multiple data sets including videos of research lessons, debriefings and audios of interviews were collected. From the expansive learning perspective, based on a fine-grained qualitative data analysis, various contradictions (as driving forces of learning) were identified and the ways of resolving the contradictions (as enactment of learning) were located to feature teacher learning throughout the online lesson study process.FindingsTeachers' expansive learning includes enhancing teachers' MKT and Mathematics TPACK, developing instructional design skills and capabilities in addressing challenges occurring in the virtual environment were identified.Research limitations/implicationsTheoretically, the study illustrated how expansive learning theory could be utilized to examine teacher collaborative learning in the online cross-cultural lesson study. Practically, this study showed that reiterative cycles and experts' facilitation are crucial to expansive learning for linking research to classroom practice. However, this study did not focus on student learning in the virtual environment. Australian teachers' reciprocal learning through the online lesson study also requires further exploration.Originality/valueBoth online lesson study and cross-cultural collaboration are innovative. The expansive learning lens are creatively used to examine the complexity of teacher learning in such a novel environment.

As an efficient converter between electromagnetic and mechanical energies, magnetostriction is an intriguing property for not only fundamental studies but also technological applications. However, the understanding of its microscopic origin remains challenging, which is critical for the development of magnetostriction materials. Here, the critical role of spin rotation in the giant magnetostriction of La(Fe,Al)13 is first revealed by the in-situ magnetic and temperature field of neutron powder diffraction. The giant magnetostriction originates from magnetic-field-driven spin moment rotation of canting structure, in which the sharp increase of ferromagnetic component causes the elongation of icosahedron inside of lattice. Furthermore, it is the first time to reveal the accurate canting antiferromagnetic structure in La(Fe,Al)13. The present study provides a new strategy, i.e., the spin rotation, for exploring new magnetostriction functional materials.

Achieving high performances of ultra-low thermal expansion (ULTE) and high thermal conductivity remains challenging, due to the strong phonon/electron-lattice coupling in ULTE materials. In this study, the challenge has been solved via the construction of the core-shell structure in 0.5PbTiO3-0.5(Bi0.9La0.1)FeO3@Cu composites by the electroless plating, which can simultaneously combine the advantages of the negative thermal expansion material of 0.5PbTiO3-0.5(Bi0.9La0.1)FeO3 in controlling thermal expansion, and copper metal in high thermal conductivity. By changing the volume fraction of copper, the coefficient of thermal expansion of composites can be adjusted continuously from positive to negative. In particular, a ULTE (ΔT = 400 K) has been achieved in the composite of 35 vol % Cu. Intriguingly, a 3D thermal conductive network copper structure is formed for thermal conducting, which can double the thermal conductivity of the 35 vol % Cu composite from the methods by the traditional mixing (32 W·m-1·K-1) up to the core-shell structure (60 W·m-1·K-1). The present work not only provides a composite material with excellent comprehensive properties but also proposes a general chemical method to resolve the problem of low thermal conductivity in most ULTE materials.