快乐课堂快乐学——创设问题情境,引导学生喜学、乐学、会学、善学

丰富的课堂信息的生成要求教师有开放的心态、容纳百川的气量,并积极巧妙地为学生创设问题情境,激发学生参与的热情,放飞思想,营造轻松愉悦的学习氛围,引导学生喜学、乐学、会学、善学,力求做到快乐课堂快乐学,使我们的数学课堂成为学生发表真情实感的舞台。

沁园春·喜学“六中”公报

回望百年,恢宏史诗,壮丽篇章。善以史为鉴,可知兴替;看清过去,自信自强。历史决议,经验总结,决不忘苦难辉煌。主心骨,崎岖奋斗路,荡气回肠历史长河不息,新时代考卷更周详。咱千秋伟业,风华正茂;环球一同,人心所向。咬定青山,勇毅前行,新百年只争朝阳。定盘星,任乱云飞渡,指引方向。

浅析新课程改革后的体育课教学

新课程改革要求体育课教学不再仅仅是对学生身体素质的训练,更注重对学生体育情趣的培养、陶冶学生的情操,这就要求体育教师不断提高自身素质、更新知识结构,在课堂上能充分调动学生的能动性,让学生乐于学、喜于学、善于学,从而培养学生终身体育的习惯。

Changes in Agricultural Biodiversity: Implications for Sustainable Livelihood in the Himalaya

Himalayan mountain system is distinguished globally for a rich biodiversity and for its role in regulating the climate of the South Asia. Traditional crop-livestock mixed farming in the Himalaya is highly dependent on forests for fodder and manure prepared from forest leaf litter and livestock excreta. Apart from sustaining farm production, forests provide a variety of other tangible and intangible benefits, which are critical for sustainable livelihood of not only 115 million mountain people, but also many more people living in the adjoining plains. Extension of agricultural land- use coupled with replacement of traditional staple food crops by cash crops and of multipurpose agroforestry trees by fruit trees are widespread changes. Cultivation of Fagopyrum esculentum, Fagopyrum tataricum, Panicum miliaceum, Setaria italica and Pisum arvense has been almost abandoned. Increasing stress on cash crops is driven by a socio-cultural change from subsistence to market economy facilitated by improvement in accessibility andsupplyofstaplefoodgrainsatsubsidizedpriceby the government. Farmers have gained substantial economic benefits from cash crops. However, loss of agrobiodiversity implies more risks to local livelihood in the events of downfall in market price/demand of cashcrops,terminationofsupplyofstaplefoodgrains at subsidized price, pest outbreaks in a cash crop dominated homogeneous landscape and abnormal climate years. Indigenous innovations enabling improvement in farm economy by conserving and/enhancing agrobiodiversity do exist, but are highly localized. The changes in agrobiodiversity are such that soil loss and run-off from the croplands have dramatically increased together with increase in local pressure on forests. As farm productivity is maintained with forest-based inputs, continued depletion of forest resources will result in poor economic returns from agriculture to local people, apart from loss of global benefits from Himalayan forests. Interventions including improvement in traditionalmanureandmanagementofon-farm trees, participatorydevelopmentofagroforestryindegraded forestlandsandpoliciesfavoringeconomicbenefitsto local people from non-timber forest products could reduce the risks of decline in agricultural biodiversity and associated threats to livelihoods and Himalayan ecosystems.

The global diversification of songbirds (Oscines) and the build-up of the Sino-Himalayan diversity hotspot

Over the last decade, molecular phylogenetic studies have provided the foundation for a comprehensive analysis of the global diversification of songbirds (Oscines), which comprise nearly half of all the birds of the world. By comparing the spatial distribution of species representing basal and terminal root-path groups, this paper provides graphical illustrations of the global pattern of diversification for the major songbird clades. The worldwide expansion of songbirds started as an island radiation in the area where New Guinea is now located, but the mountains of southern China represent a principal center for more recent diversification. The paper suggests priorities and perspectives for further research aiming to understand what determines the variation in biodiversity on different spatial scales.

Thermodynamic reassessment of Ga-Hg and Mg-Hg systems

The Ga-Hg binary system was thermodynamically assessed by the CALPHAD method, but only configuration contributions were considered to the entropy of the liquid. The Mg-Hg binary system has not been assessed yet. In the assessments of the Ga-Hg and Mg-Hg binary systems, solutions including liquid and hcp (Mg) were treated as substitution solutions, of which the excess Gibbs energies were formulated with the Relich-Kister polynomial. The intermetallic phases in the Mg-Hg binary system, Mg3Hg, Mg5Hg2, Mg2Hg, Mg5Hg3, MgHg, and MgHg2, were described as stoichiometric compounds. Based on the reported experimental data and thermodynamic properties of the phase diagram, sets of self-consistent parameters describing all phases in the Ga-Hg and the Mg-Hg binary systems were obtained.

Ethnobotanical Study towards Conservation of Medicinal and Aromatic Plants in Upper Catchments of Dhauli Ganga in the Central Himalaya

The present study broadly focused on medicinal plant species collected from wild by the villagers for different purposes in the upper catchment of Dhauli Ganga in Nanda Devi Biosphere Reserve(NDBR),in the central Himalaya.A schedule based survey was conducted during the years 2003-2005 in 15 villages of Chamoli district part of the NDBR.Information was collected from collectors, vaidya(medicine man)and those dealing with domestication and marketing of the medicinal plants. The aim of the study was to understand the prioritiesed medicinal plants,their mode of collection and document their ethnobotanical uses by the Bhotiya tribal communities,in this world heritage site. During the survey,50 medicinal plants belonging to 31 families and 44 genera were documented.Out of these,70% were harvested from the wild,22% were cultivated and 8% were cultivated as well as wild harvested.Of the cultivated species,8% were found growing in the kitchen gardens and 14%in the agricultural fields.However,42%of the plants had their roots and rhizomes used followed by leaves (26%),seeds(10%),seed and leaf(8%),bark and whole plant(6%)and flower(1%).Most plants were reported to be used for rheumatism(16),followed by stomach disorder(14),cold and cough(11),and jaundice(9).Thirty three plants species were reported to have more than one therapeutic uses,while 17 species were reported to be used against single ailment.The distance of villages from road head was one of the factors contributing to the decline in the medicinal plant population in their natural habitats. The availability of medicinal plants increased with increase in distance from road head and also the peoples'dependence on them.Documentation of the traditional knowledge will help in conservation of knowledge and also opportunity for using it for future training and use.The result of this study will help in promoting sustainable cultivation and implementation in conservation protocol of those species,which are in the verge of extinction in this region.

Glacier Fluctuations between 1975 and 2008 in the Greater Himalaya Range of Zanskar,Southern Ladakh

Glaciers in the Himalaya are often heavily covered with supraglacial debris,making them difficult to study with remotely-sensed imagery alone.Various methods such as band ratios can be used effectively to map clean-ice glaciers;however,a thicker layer of debris often makes it impossible to distinguish between supraglacial debris and the surrounding terrain.Previously,a morphometric mapping approach employing an ASTER-derived digital elevation model has been used to map glaciers in the Khumbu Himal and the Tien Shan.This study on glaciers in the Greater Himalaya Range in Zanskar,southern Ladakh,aims (i) to use the morphometric approach to map large debris-covered glaciers;and (ii) to use Landsat and ASTER data and GPS and field measurements to document glacier change over the past four decades.Field work was carried out in the summers of 2008.For clean ice,band ratios from the ASTER dataset were used to distinguish glacial features.For debris-covered glaciers,topographic features such as slope were combined with thermal imagery and supervised classifiers to map glacial margins.The method is promising for large glaciers,although problems occurred in the distal and lateral parts and in the fore field of the glaciers.A multi-temporal analysis of glaciers in Zanskar showed that in general they have receded since at least the mid-to late-1970s.However,some few glaciers that advanced or oscillated - probably because of specific local environmental conditions - do exist.

Howl variation across Himalayan, North African, Indian, and Holarctic wolf clades： tracing divergence in the world＇s oldest wolf lineages using acoustics

Vocal divergence within species often corresponds to morphological, environmental, and genetic differences between populations. Wolf howls are long-range signals that encode individual, group, and subspecies differences, yet the factors that may drive this variation are poorly understood. Furthermore, the taxonomic division within the Canis genus remains contended and additional data are required to clarify the position of the Himalayan, North African, and Indian wolves within Canis lupus. We recorded 451 howls from the 3 most basal wolf lineages-Himalayan C. lupus chanco-Himalayan haplotype, North African C. lupus lupaster, and Indian C. lupus pallipes wolves-and present a howl acoustic description within each clade. With an additional 619 howls from 7 Holarctic subspecies, we used a random forest classifier and principal component analysis on 9 acoustic parameters to assess whether Himalayan, North African, and Indian wolf howls ex- hibit acoustic differences compared to each other and Holarctic wolf howls. Generally, both the North African and Indian wolf howls exhibited high mean fundamental frequency （F0） and short duration compared to the Holarctic clade. In contrast, the Himalayan wolf howls typically had lower mean F0, unmodulated frequencies, and short howls compared to Holarctic wolf howls. The Himalayan and North African wolves had the most acoustically distinct howls and differed significantly from each other and to the Holarctic wolves. Along with the influence of body size and environmental differences, these results suggest that genetic divergence and/or geographic distance may play an important role in understanding howl variation across subspecies.

Genetic diversification in the East Himalayas as revealed by comparative phylogeography of the black-throated bushtit and Elliot＇s laughing thrush

The Southwest Mountainous region of the eastern Himalayas is a hotspot with extraordinarily high biodiversity and endemism, but the processes that have driven this unique diversity are largely unknown. We evaluated processes that have con- tributed to the current observed high genetic diversity in this region by integrating comparative phylogeography with ecological niche modeling in a study of two representative birds of the Southwest Mountains： the black-throated bushtit Aegithalos concinnus and the Elliot＇s laughing thrush Garrulax elliotii. Mitochondrial DNA analyses revealed multiple divergent genetic lineages, which are roughly congruent with the north, south and east eco-subregion division of the Southwest Mountains. This strong geo- graphical structure in these two species suggests that lineage diversification has proceeded in situ between the eco-subregions of the Southwest Mountains. During Pleistocene glaciations, the two species responded differently to climatic fluctuations. A. con- cinnus maintained rather stable habitats, mostly evergreen forests, during glacial cycles and thus kept a stable population size and further accumulated genetic diversity. In contrast, G. elliotii, which is mostly active in shrublands, has shifted its suitable habitats with glacial cycles. This species dispersed to low elevation areas during glacial periods, which provided multiple opportunities for gene admixture. The admixture causes the mixing of previously isolated genetic lineages and thus obscures the pattern of genetic variation [Current Zoology 61 （5）： 935-942, 2015].

Impact of forest fire on soil seed bank composition in Himalayan Chir pine forest

Aims To explain how plant community copes with a recurring anthropogenic forest fire in Himalayan Chir pine forest,it is important to understand their postfire regeneration strategies.The primary aim of the study was to know:(i)how fire impact soil seed bank composition and(ii)how much soil seed bank composition differs with standing vegetation after the forest fire.Methods Soil samples were collected from burned and adjoining unburned sites in blocks using three layers down to 9 cm depth immediately after a forest fire and incubated in the net-house for seedling emergence.Same sites were revisited during late monsoon/early autumn season to know the species composition of standing vegetation recovered after a forest fire.Important Findings Soil contained viable seeds of>70 species.The average seed bank density was 8417 and 14217 seeds/m^(2) in the burned and unburned site,respectively.In both sites,it decreased with increasing soil depth.Overall fire had no significant impact on seed density;however,taking individual layers into consideration,fire had a significant impact on seed density only in the uppermost soil layer.The species richness of soil seed bank and standing vegetation was 73 and 100,respectively(with 35 shared species),resulting in a similarity of about 40%.In contrast,>80%species in soil seed bank was found similar between burned and unburned sites.Further,there were no significant differences in species richness of standing vegetation in burned(87 spp.)and unburned(78 spp.)sites.Our results showed that fire had an insignificant impact on soil seed bank composition and restoration potential of a plant species from seeds.The understory herb and shrub plant community’s ability to form a fire-resistant viable soil seed bank and capable to recover in the postfire rainy season,explains how they reduce the risk of recurring fire damage in maintaining their population.

Anatomy of composition and nature of plate convergence： Insights for alternative thoughts for terminal India-Eurasia collision

The pattern and timing of collision between India and Eurasia have long been a major concern of the international community. However, no consensus has been reached hitherto. To explore and resolve the disagreements in the Himalayan study,in this paper we begin with the methodology and basic principles for the anatomy of composition and nature of convergent margins,then followed by an effort to conduct a similar anatomy for the India-Eurasia collision. One of the most common patterns of plate convergence involves a passive continental margin, an active continental margin and intra-oceanic basins together with accreted terranes in between. The ultimate configuration and location of the terminal suture zone are controlled by the basal surface of the accretionary wedge, which may show fairly complex morphology with Z-shape and fluctuant geometry. One plausible method to determine the terminal suture zone is to dissect the compositions and structures of active continental margins. It requires a focus on various tectonic elements belonging to the upper plate, such as accretionary wedges, high-pressure(HP)-ultra-high-pressure(UHP) metamorphic rocks, Barrovian-type metamorphic rocks and basement nappes, together with superimposed forearc basins.Such geological records can define the extreme limits and the intervening surface separating active margin from the passive one,thus offering a general sketch for the surface trace of the terminal suture zone often with a cryptic feature. Furthermore, the occurrence of the cryptic suture zone in depth may be constrained by geophysical data, which, in combination with outcrop studies of HP-UHP metamorphic rocks, enables us to outline the terminal suture zone. The southern part of the Himalayan orogen records complicated temporal and spatial features, which are hard to be fully explained by the classic "two-plate-one-ocean" template,therefore re-anatomy of the compositions and nature for this region is necessitated. Taking advantage of the methodology and basic principles of plate convergence anatomy and synthesizing previous studies together with our recent research, we may gain new insights into the evolution of the Himalayan orogeny.(1) The Yarlung-Zangbo ophiolite is composed of multiple tectonic units rather than a single terminal suture zone, and a group of different tectonic units were juxtaposed against each other in the backstop of the Gangdese forearc.(2) The Tethyan Himalayan Sequence(THS) contains mélanges with typical block-in-matrix structures, uniform southwards paleocurrents and age spectra of detrital zircons typical of Eurasia continent. All of these facts indicate that the THS belonged to Eurasia plate before the terminal collision, emplaced in the forearc of the Gangdese arc.(3) The Greater Himalayan Crystalline Complex(GHC) and Lesser Himalayan Sequence(LHS) comprise complex components including eclogites emplaced into the GHC and the upper part of the LHS. Judging from the fact that HP-UHP metamorphic rocks are exhumed and emplaced in the upper plate, the GHC and the upper part of the LHS where eclogite occur should be assigned to the upper plate, lying above the terminal subduction zone surface. It is the very surface along which the continuous subduction of the India subcontinent occurred, therefore acting as the terminal, cryptic suture. From the suture further southward, the bulk rock associations of the LHS and Sub-Himalayan Sequence(Siwalik) show little affinity of mélange, probably belonging to the foreland system of the India plate. By the anatomy of tectonic features of all the tectonic units in the Himalayan orogen as well as the ages of the subduction-accretion related deformation, we conclude that the terminal India-Eurasia collision occurred after 14 Ma, the timing of the metamorphism of the eclogites emplaced into the upper plate. The development of rifts stretching in N-S direction in Tibet and tectonic events with the transition from sinistral to dextral movements in shear zones, such as the Ailaoshan fault in East Tibet, can coordinately reflect the scale and geodynamic influence of the India-Eurasia convergence zone.By conducting a detailed anatomy of the southern Himalayas, we propose a new model for the final collision-accretion of the Himalayan orogeny. Our study indicates that the anatomy of structures, composition, and tectonic nature is the key to a better understanding of orogenic belts, which may apply to all the orogenic belts around the world. We also point out that several important issues regarding the detailed anatomy of the structures, compositions and tectonic nature of the Himalayan orogeny in future.