Search

China initiated a new round of science curriculum reform in 2017. Using the tripartite curriculum framework (including policy, programmatic, and classroom curriculum), we introduce and analyse China’s policy curriculum and programmatic curriculum for science in primary school and senior high school, and describe the potential problems hindering the translation of these curricula into the classroom curriculum. We first identify the multiple aims of different stakeholders in science education, some of which influence the science policy curriculum. Then, we present the major changes in how the programmatic curriculum meets the policy curriculum. However, due to extracurricular factors, the current science curriculum reform may not unfold as expected. We end with a discussion of the three major characteristics of the revision process of science curriculum standards in China, some of which might inform the global community of science education. [ABSTRACT FROM AUTHOR]

This paper presents a revised learning progression for the energy concept and initial findings on diverse progressions among subgroups of sample students. The revised learning progression describes how students progress towards an understanding of the energy concept along two progress variables identified from previous studies – key ideas about energy and levels of conceptual development. To assess students understanding with respect to the revised learning progression, we created a specific instrument, the Energy Concept Progression Assessment (ECPA) based on previous work on assessing students’ understanding of energy. After iteratively refining the instrument in two pilot studies, the ECPA was administered to a total of 4550 students (Grades 8–12) from schools in two districts in a major city in Mainland China. Rasch analysis was used to examine the validity of the revised learning progression and explore factors explaining different progressions. Our results confirm the validity of the four conceptual development levels. In addition, we found that although following a similar progression pattern, students’ progression rate was significantly influenced by environmental factors such as school type. In the discussion of our findings, we address the non-linear and complex nature of students’ progression in understanding energy. We conclude with illuminating our research's implication for curriculum design and energy teaching. [ABSTRACT FROM PUBLISHER]

Late Devonian Minostrobus chaohuensis is one of the earliest monosporangiate-strobilate isoetaleans. Based on new material of this plant, the vegetative axis and microsporangiate strobilus are studied in detail, and the whole plant knowledge is summarized. The vegetative axis is isotomously branched. The stem is up to 55 mm in diameter with helically arranged leaf cushions. Stems and thick branches bear long fusiform leaf cushions and interareas with vertical linear ornamentations. A ligule pit, oblanceolate leaf scar, and vascular bundle scar appear on the leaf cushion. Distal axes have persistent lanceolate leaves and rhombic leaf bases. The microsporangiate strobilus is cylindrical in shape, possesses sporophyll with alate pedicel and long triangular lamina, uniseriate sporangial wall, subarchesporial pad inside the sporangium, and microspore with cingulum. Based on comparisons with other isoetaleans, the usage of the terms “leaf cushion” and “leaf base” is discussed, and Minostrobus chaohuensis is considered as a tree-like lycopsid. It suggests that arborescent isoetaleans with monosporangiate strobili had appeared and diversified in the Late Devonian. The multi-dichotomous branching system of Minostrobus provides new data on the evolution of growth architecture in rhizomorphic lycopsids. [ABSTRACT FROM AUTHOR]

Pleistocene cave deposits usually provide ideal materials for the study of mammals. Karst caves in Chongzuo, Guangxi Zhuang Autonomous Region of south China are famous for numerous studies on their abundant mammalian fossils and most importantly, Homo sapiens. Unfortunately, the environmental backgrounds, e.g. vegetation and climate, that governed these faunas, are usually lacking because there is no appropriate proxy. In this work, we analysed the palynological assemblages from seven well-dated karst caves in Chongzuo. The ages of these seven caves (2.0–0.11 Ma) cover almost the entire Pleistocene. Though the number of pollen and spores is comparatively low, as expected, we managed to reconstruct the principle vegetation types. The results show that the individual vegetations were mainly warm temperate to subtropical evergreen and deciduous broad-leaved mixed forests. The present study provides important background environmental information on the Pleistocene faunas and Homo sapiens in Guangxi, south China. [ABSTRACT FROM AUTHOR]

Prior to their extinction at the Triassic-Jurassic boundary, conodonts were relatively diverse and abundant during Norian time. The great faunal turnovers at the base of the Norian and the base of the Alaunian (Middle Norian) confirm that the end-Triassic mass extinction was protracted through Late Triassic time rather than a single event. Norian conodonts also display obvious geographic distribution. Thus, investigation of Norian conodonts is not only of biostratigraphic significance, but it will elucidate the end Triassic mass extinction event as well as Late Triassic palaeobiogeography. Lacian (Early Norian) and Alaunian faunas appear to have spread extensively through Tibetan terranes of the Eastern Tethys, yet evidence of a continuous Lacian to Alaunian conodont succession as well as faunal turnover at the base of the Alaunian is sparse. Our biostratigraphic investigation of carbonate deposits of the Mopanshan area of the South Qiangtang Terrane has yielded abundant Norian conodonts. The Lacian Ancyrogondolella uniformis-Norigondolella hallstattensis Fauna and the Alaunian Mockina postera-Norigondolella steinbergensis Fauna are well-represented in the study region. The Norian conodont succession of the Eastern Tethys may be correlative with that of the Western Tethys and Eastern Pacific. The obvious geographic distribution provides evidence that the Indus-YarluZangbo Suture Zone (IYZSZ) separated Eastern Tethys into northern Tethys and southern Tethys realms. Norian conodonts are less abundant and diverse in the southern Tethys realm relative to the northern (or peri-Gondwana) Tethys. The Himalaya Terrane in the south belonged to southern Tethys whereas the Lhasa and the South Qiangtang terranes were part of the northern Tethys. Moreover, the absence of Norigondolella steinbergensis from the southern Tethys seemed to differentiate this realm from the northern Tethys. • Early-Middle Norian conodonts aredescribedfor the first time from Qiangtang, Tibet 2) the recovered Norian conodonts necessitate reassessment of the age of the deposits 3) the Norian conodont succession is correlative with well-established successions from Western Tethys and Eastern Pacific • Norian conodonts help elucidate the palaeobiogeography of Northern Tethysand peri-Gondwana Tethys realms [ABSTRACT FROM AUTHOR]

Fossil blister pearls attached to the shells of an Anodonta mollusk from China, early Early Pleistocene, are reported here for the first time. The pearls were investigated in detail using a variety of methods. Micro-CT scanning of the fossil pearls was carried out to discover the inner structure and the pearl nucleus. Using CTAn software, changes in the gray levels of the biggest pearl, which reflect the changing density of the material, were investigated. The results provide us with some clues on how these pearls were formed. Sand grains, shell debris or material with a similar density could have stimulated the development of these pearls. X-ray diffraction analysis of one fossil pearl and the shell to which it was attached reveals that only aragonite exists in both samples. The internal structures of our fossil shells and pearls were investigated using a Scanning Electron Microscope. These investigations throw some light on pearl development in the past. [ABSTRACT FROM AUTHOR]

The arborescent lycopsid Sublepidodendron grabaui was widely distributed in the Late Devonian of South China. Its morphology and anatomy have been described, but the microsporangiate strobilus remains unclear. New material collected from the Guanshan Member of the Wutong Formation in Zhejiang Province allowed us to provide more details of this plant. The pseudomonopodial axis without secondary xylem bears medullated stele and branch traces arranged in irregular helices. The lateral branch possesses solid exarch primary xylem. This pseudomonopodial branching system possibly represents the crown or cauline lateral branch. The microsporangiate strobilus contains microspores belonging to the Lycospora granulata Group. The monosporangiate nature of S. grabaui is confirmed, and the classification of Sublepidodendraceae into the suborder Dichostrobiles is supported. The L. granulata Group microspores are suggested to occur not only in bisporangiate strobili but also in monosporangiate strobili. [ABSTRACT FROM AUTHOR]

Palynomorphs extracted from the sediments in Queque Cave of the late Early Pleistocene in Chongzuo, Guangxi Zhuang Autonomous Region were investigated to reconstruct the paleoenvironment in the study area. While the sediments are pollen-poor, they are sufficiently productive to carry out a paleoenvironmental analysis. The source vegetation reflected by the palynomorphs from the unfossiliferous layer was temperate to warm temperate deciduous and evergreen broadleaved forest while it was warm temperate to subtropical deciduous and evergreen broadleaved forest from the mammalian horizons. Climatic parameters obtained using the Coexistence Approach indicate that the unfossiliferous layer (MAT = 11.3–15.4 °C, MAP = 601.1–1076.1 mm) was cooler and drier than that from the mammal-bearing layers (MAT = 12.6–18.6 °C, MAP = 784.7–1523.1 mm). [ABSTRACT FROM AUTHOR]

Palynological analysis of 24 samples from four types of natural pollen traps (Lugu Lake bottom sediments, surface soil, bark samples, and moss cushions) in four sites at different altitudes from the Lugu Lake area, southwest China, has been undertaken to investigate pollen dispersal and deposition in a mountainous area and assist with the interpretation of fossil pollen analysis. Detailed comparisons between the palynological assemblage and the modern vegetation in the Lugu Lake region have been carried out. Preliminary interpretations of the correlation between pollen assemblage and vegetation at the different vertical vegetational zones can be recognized by the percentages of the main taxa, and most of the pollen taxa except Pinus are expected to be underrepresented. Exotic pollen grains can be transported over mountains more than 70 km away by wind. Upslope or downslope transport of pollen grains is crucial when reconstructing palaeoclimate in mountainous areas. We summarize the altitudinal distributions of modern woody plants whose pollen grains are present at three sites, and reveal that pollen grains are more readily carried uphill than downhill. These findings have important implications regarding the reconstruction of vegetation in mountainous regions and the interpretion of palaeoelevations. [ABSTRACT FROM AUTHOR]

A new conifer, Austrohamia acanthobractea, sp. nov., is described from the Jurassic Daohugou flora, Inner Mongolia Autonomous Region, China. The material consists of impressions represented by well-preserved leafy twigs and branches as well as ovulate cones. Leafy shoots with at least two orders of branching; ultimate branchlets alternate or sub-opposite with helically arranged leaves, decurrent at base with distal rounded tip; dorsiventrally flattened and univeined. Ovuliferous cones elliptical, less than 1 cm long, terminally borne on ultimate and penultimate branches, composed of helically arranged bracts with ovules disposed on their adaxial surfaces. The presence of similar, if not identical taxa, on both sides of the Pacific indicates the cosmopolitan distribution of primitive Cupressaceae between East Asia (Eurasia) and South America in the Pangaea. [ABSTRACT FROM AUTHOR]

The Lhasa Terrane of Tibet is critical to understanding Early Triassic crustal convergence of Gondwana and Eurasia. However, its palaeo-position during this period remains obscure. This paper considers the disputed tectonic nature of the Lhasa Terrane during Triassic time. The debate has taken the form of two schools of thought regarding the Lhasa Terrane. One holds that the terrane was a stable carbonate platform during Triassic time. The opposing view maintains that the Lhasa Terrane occupied a compressional orogenic belt. These contrasting explanations stem mainly from the absence of a sedimentary record, especially in the southern part of the Lhasa Terrane of Tibet. We report on results of a biostratigraphic investigation of a dolomite unit considered to be of Guadalupian age in the Comai area, southern Lhasa Terrane. This work yielded the ellisonid conodont species Pachycladina rendona n. sp. Wu and Ji suggesting an Early Triassic age and a low latitude depositional setting of the dolomite. Further, these findings favor correlation of the dolomite with the upper member of the Upper Permian to Lower Triassic Mujiuco Formation. Results of the present study, especially the newly collected Pachycladina fauna, suggest that the Lhasa Terrane was an element of a low-latitude carbonate platform that had separated from Gondwana during the Early Triassic. It is hoped that our findings will promote further research of the Triassic sedimentary history and paleogeographic evolution of the Lhasa Terrane. • The ellisonid Pachycladina fauna has been recovered from the southern Lhasa Terrane. • The Pachycladina fauna places the Lhasa Terrane at low latitude during the Induan. • The western Lhasa Terrane was a carbonate platform setting during the Early Triassic. [ABSTRACT FROM AUTHOR]