西方职业高原现象研究进展

职业高原是员工在当前组织中处于职业生涯顶峰、难以得到继续发展的状态。对职业高原的研究,能够合理地解释员工对组织的情感承诺、职业心理和工作投入等各方面的变化,有利于提高组织的人力资源管理水平。文章运用理论述评的方法,对西方职业高原现象的研究进行了系统的梳理,简要评述了当前研究中存在的不足,认为将来的研究趋势应该注重职业高原的形成过程和量化研究。

摔跤高原训练初探

高原训练的特点是:在缺氧情况下进行训练。使机体血乳酸达到平原训练不能达到的水平,以提高机体无氧酵解和耐酸能力。同时,缺氧刺激骨髓血液有形成份再生及肾脏分泌红细胞生成素使血液红细胞和血红蛋白增加,机体携氧能力增强。因此,下山后在高原效应期间有助于提高运动能力。

英语学习者的“高原心理”

文章通过对英语学习中的高原效应与语言焦虑情绪的分析 ,对英语学习者的“高原心理”进行研究。结果表明导致焦虑的因素既可能是学习者的个人经历 ,也可能是教师的行为。因此 ,为了帮助学生克服高原效应 ,教师要充分考虑语言学习中的情感因素。

数学总复习“高原现象”成因及对策

数学总复习“高原现象”成因及对策□江苏省海安县明道小学马贞在学生技能形成中期往往出现进步暂时停顿甚至倒退的现象，这就是所谓的学习“高原期”现象。小学生在数学总复习期间常会出现这种学习上的“高原现象”。其主要表现是：精神疲倦，上课无精打采，思想开小差；...

长白山高原训练原理、训练方法及其应用

国内外众多周期性耐力性项目,利用合理的高原训练手段,在平原上获得佳绩,数见不鲜。该文“长白山高原训练原理、训练方法及其应用”是吉林省通化市科研课题的研究报告,本刊发表时,略有删节。他们的课题历时九个月,两次到长白山高原训练基地,对通化市体工队越野滑雪队、冬季两项队的运动员的血红蛋白、尿蛋白、血压、晨脉曲线、体重,测验比赛成绩及运动员自我感觉等指标进行了跟踪研究、综合分析,“从中优化筛选出长白山高原训练的有关规律”——其学术价值,方家自有公论。他们对于雪上项目如何科学的利用长白山高原训练的问题,作出了自己的回答;他们为提高雪上项目运动成绩的努力和探索的精神,弥足珍贵!其课题成果,对我国各雪队的训练工作,当不无裨益。本刊期待有披露更多的科研课题文章的荣幸机会!

从等温线的变化看中国大陆对全球升温的时空响应

利用中国气象中心160站点的实际观察资料,对中国半个世纪的气温变化进行了分析。通过利用插值法对各个站点的数据进行处理,分别做出50年代和90年代多年平均的冬夏季节以及年等温线。通过对比每个季节不同年代的等温线,发现中国的年等温线分布态势由夏季气温分布主宰。在这半个世纪中中国冬季和夏季等温线的分布以及变化存在很大的不同:冬季等温线基本上向高纬度方向移动,而夏季以高温和低温中心为基点,向高温或低温方向移动。夏季等温线变动幅度相对小,但夏季存在区域性的降温现象。在幅度上,等温线移动基本上是由南向北普遍增大,西北地区最大。最后对等温线的变化所揭示的气温变化规律以及气温变化的时空差异进行了机理上的分析和讨论。

白银盆地中新世末沙丘岩及其古沙漠与古环流重建

野外调查、室内样品分析及区域地层对比表明 ,广布于甘肃白银盆地的巨厚层发育大型交错斜层理的浅黄色固结砂岩是典型的沙丘岩 ,主要沉积于中新世末至上新世初 ,代表弱固定性沙漠 ,风系属行星西风 ,但盛行古风向分为SW至WNW两支 ,既不同于早白垩世鄂尔多斯盆地盛行NE向信风及W向行星西风 ,也不同于现代本区在东亚季风环流影响下盛行N、NNE及NE向冬季风的情况。这可能指示当时青藏高原已经隆升到海拔 1 0 0 0～3 0 0 0m ,引起西风环流在高原南北两侧发生季节性摆动绕流 。

学术交流在继续教育中的重要作用

学术交流是知识更新最经济,最有效的途径。学术交流是由两方面体现继续教育的,一是论文撰写中的提高,二是听取学术报告中的提高。如我台一位年轻的女预报员,为了参加华东地区暴雨预报会议,她除进行日常总结外,查阅了国内外文献资料后,终于寄出丁一篇优秀论文,得到专家高度评价。

试论运动训练科学化

运动训练科学化是科技兴体方针在竞技体育中的具体体现,也是发展竞技体育、提高运动水平的一项具有战略意义的根本大计。为加速我国运动训练科学化的进程,首先必须对运动训练科学化的含义、特征、意义、内容和途径等基本概念和理论问题有一个比较全面、正确的理解,以便确立我国运动训练科学化的正确方向,提高运动训练科学化的效益和效率。近年来国内已有不少学者、专家对此发表了不少很有见地的论述。笔者也不揣冒睐地谨以此文来参与这一问题的讨论。一、运动训练科学化的含义和特征运动训练科学化这一概念是由运动训练、科学和化这三个分概念组成的。

Regional Summer Temperature Decrease against Global Warming in China, Landform Effect?

The data of 16o national meteorological observatory （NMO） stations with long-term monthly temperature data for China were analyzed in this study to show the basin-centered summer temperature decrease against global warming in the past half century. The summer and winter isotherm structures of 1950s and 1990s worked out by interpolation show the isotherm structure variations： the isotherm structure generally moves northward in winter, but in summer it is characterized with separate high-temperature and low-temperature centers and the isotherm structure moves inward the centers with global warming, indicating that the temperature in the highland areas increases but that in the lowland areas decreases in the summer of the duration. The possible mechanism of the basin-centered temperature decrease in summer is discussed in this paper.

Modeling Regional and Local-scale Permafrost Distribution in Qinghai-Tibet Plateau Using Equivalent-elevation Method

This study proposes an equivalent-elevation method to evaluate the integrated effects of latitude and elevation on regional and local-scale permafrost distribution in the Qinghai-Tibet Plateau,and to model the general permafrost-distribution patterns in regional and local-scale area.It is found that the Gaussian curve―an empirical model describing the relation between variations of altitudinal permafrost lower limit (PLL) and latitude in the Northern Hemisphere―could be applied in regional-and local-scale areas in the Qinghai-Tibet Plateau in a latitude-sensitive interval of 30°-50°N.The curve was then used to evaluate the latitudinal effect on permafrost distribution through transforming the latitudinal effect into a kind of altitudinal difference of PLL.This study then calculated the local equivalent-elevation value by overlaying the altitudinal difference of PLL onto real elevation at a certain location.The equivalent-elevation method was verified in an experimental subwatershed of the Qinghai-Tibet Plateau.However,feasibility of the method should be further tested in order to extend for future studies.The use of equivalent-elevation values can build a platform for comparing the regional general permafrost distribution in the plateau,and for basing further evaluations of local factors' effects on regional permafrost distribution.

The Relationship between Normalized Difference Vegetation Index(NDVI) and Climate Factors in the Semiarid Region:A Case Study in Yalu Tsangpo River Basin of Qinghai-Tibet Plateau

The Yalu Tsangpo River basin is a typical semi-arid and cold region in the Qinghai-Tibet Plateau, where significant climate change has been detected in the past decades. The objective of this paper is to demonstrate how the regional vegetation, especially the typical plant types, responds to the climate changes. In this study, the model of gravity center has been firstly introduced to analyze the spatial-temporal relationship between NDVI and climate factors considering the time-lag effect. The results show that the vegetation grown has been positively influenced by the rainfall and precipitation both in moving tracks of gravity center and time-lag effect especially for the growing season during the past thirteen years. The herbs and shrubs are inclined to be influenced by the change of rainfall and temperature, which is indicated by larger positive correlation coefficients at the 0.05 confidence level and shorter lagging time. For the soil moisture, the significantly negative relationship of NDV-PDI indicates that the growth and productivity of the vegetation are closely related to the short-term soil water, with the correlation coefficients reaching the maximum value of o.81 at Lag 0-1. Among the typicalvegetation types of plateau, the shrubs of low mountain, steppe and meadow are more sensitive to the change of soil moisture with coefficients of -0.95, -0.93, -0.92, respectively. These findings reveal that the spatial and temporal heterogeneity between NDVI and climatic factors are of great ecological significance and practical value for the protection of eco-environment in Qinghai-Tibet Plateau.

Fabricating high-loading Fe-N4 single-atom catalysts for oxygen reduction reaction by carbon-assisted pyrolysis of metal complexes

Iron-based single-atom catalysts with nitrogen-doped carbon as support(Fe-SA/NPC)are considered effective alternatives to replace Pt-group metals for scalable application in fuel cells.However,synthesizing high-loading Fe-SA catalysts by a simple procedure remains challenging.Herein,we report a high-loading(7.5 wt%)Fe-SA/NPC catalyst prepared by carbon-assisted pyrolysis of metal complexes.Both the nitrogen-doped porous carbon(NPC)support with high specific surface area and ο-phenylenediamine(o-PD)play key roles role in the preparation of high-loading Fe-SA/NPC catalysts.The results of X-ray photoelectron spectroscopy,high-angle annular dark-field scanning transmission electron microscopy,and X-ray absorption fine structure spectroscopy experiments show that the Fe atoms are anchored on the carbon carriers in a single-atom site configuration and coordinated with four of the doped nitrogen atoms of the carbon substrates(Fe-N_(4)).The activities of the Fe-SA/NPC catalysts in the oxygen reduction reaction increased with increasing iron loading.The optimized 250Fe-SA/NPC-800 catalyst exhibited an onset potential 0.97 V of and a half-wave potential of 0.85 V.Our study provides a simple approach for the large-scale synthesis of high-loading single-atom catalysts.

Effect of Altitude and Latitude on Surface Air Temperature across the Qinghai-Tibet Plateau

The correlation between mean surface air temperature and altitude is analyzed in this paper based on the annual and monthly mean surface air temperature data from 106 weather stations over the period 1961-2003 across the Qinghai-Tibet Plateau. The results show that temperature variations not only depend on altitude but also latitude, and there is a gradual decrease in temperature with the increasing altitude and latitude. The overall trend for the vertical temperature lapse rate for the whole plateau is approximately linear. Three methods, namely multivariate composite analysis, simple correlation and traditional stepwise regression, were applied to analyze these three correlations. The results assessed with the first method are well matched to those with the latter two methods. The apparent mean annual near-surface lapse rate is -4.8 ℃ /km and the latitudinal effect is -0.87 ℃ /°latitude. In summer, the altitude influences the temperature variations more significantly with a July lapse rate of -4.3℃/km and the effect of latitude is only -0.28℃ /°latitude. In winter, the reverse happens. The temperature decrease is mainly due to the increase in latitude. The mean January lapse rate is -5.0℃/km, while the effect of latitude is -1.51℃ /°latitude. Comparative analysis for pairs of adjacent stations shows that at a small spatial scale the difference in altitude is the dominant factor affecting differences in mean annual near-surface air temperature, aided to some extent bydifferences of latitude. In contrast, the lapse rate in a small area is greater than the overall mean value for the Qinghai-Tibet Plateau （5 to 13℃ /km）. An increasing trend has been detected for the surface lapse rate with increases in altitude. The temperature difference has obvious seasonal variations, and the trends for the southern group of stations （south of 33 o latitude） and for the more northerly group are opposite, mainly because of the differences in seasonal variation at low altitudes. For yearly changes, the temperature for high-altitude stations occurs earlier clearly. Temperature datasets at high altitude stations are well-correlated, and those in Nanjing were lagged for 1 year but less for contemporaneous correlations. The slope of linear trendline of temperature change for available years is clearly related to altitude, and the amplitude of temperature variation is enlarged by high altitude. The change effect in near-surface lapse rate at the varying altitude is approximately 1.0℃ /km on the rate of warming over a hundred-year period.

大学英语教师的素质要求(英文)

自北京成功申办 2 0 0 8年奥运会以后 ,中国掀起了一股学习外语的热潮。目前虽然有许多学习外语的方式 ,但大多数人还是选择了到高校参加各种类型的学习班。由于目前高校英语师资严重缺乏 ,这种情况不仅加重了现有高校英语教师肩上的担子 ,而且对他们的素质也提出了更高的要求。本文阐述了高校英语教师必须具备的各项素质 。

Livestock Dynamic Responses to Climate Change in Alpine Grasslands on the Northern Tibetan Plateau:Forage Consumption and Time-lag Effects

Climate change and forage-intake are important components of livestock population systems,but our knowledge about the effects of changes in these properties on livestock is limited,particularly on the Northern Tibetan Plateau.Based on corresponding independent models（CASA and TEM）,a human-induced NPP（NPPH） value and forage-intake threshold were obtained to determine their influences on livestock population fluctuation and regrowth on the plateau.The intake threshold value provided compatible results with livestock population performance.If the forage-intake was greater than the critical value of 1.9（kg DM d^（-1） sheep^（-1））,the livestock population increased;otherwise,the livestock population decreased.It takes four years to transfer a disturbance in primary productivity to the next trophic level.The relationships between livestock population and NPP_H value determined population dynamics via the forage-intake value threshold.Improved knowledge on lag effects will advance our understanding of drivers of climatic changes on livestock population dynamics.

Graphene-templated synthesis of sandwich-like porous carbon nanosheets for efficient oxygen reduction reaction in both alkaline and acidic media

Developing low-cost, high-performance elec- trocatalysts for the oxygen reduction reaction （ORR） is crucial for implementation of fuel cells and metal-air batteries into practical applications. Graphene-based catalysts have been extensively investigated for ORR in alkaline electrolytes. However, their performance in acidic electrolytes still requires further improvement compared to the Pt/C catalyst. Here we report a self-templating approach to prepare graphene-based sandwich-like porous carbon nanosheets for efficient ORR in both alkaline and acidic electrolytes. Graphene oxides were first used to adsorb m-phenylenediamine molecules which can form a nitrogen-rich polymer network after oxidative poly- merization. Then iron （Fe） salt was introduced into the polymer network and transformed into ORR active Fe-N-C sites along with Fe, FeS, and FEN0.05 nanopartides after pyr- olysis, generating ORR active sandwich-like carbon na- nosheets. Due to the presence of multiple ORR active sites. The as-obtained catalyst exhibited prominent ORR activity with a half-wave potential -30 mV more positive than Pt/C in 0.1 mol L-1 KOH, while the half-wave potential of the catalyst was only -40 mV lower than that of commercial Pt/C in 0.1 mol L-1 HClO4. The unique planar sandwich-like structure could expose abundant active sites for ORR. Meanwhile, the graphene layer and porous structure could simultaneously enhance electrical conductivity and facilitate mass transport. The prominent electrocatalytic activity and durability in both alkaline and acidic electrolytes indicate that these carbon na- nosheets hold great potential as alternatives to precious metal- based catalysts, as demonstrated in zinc-air batteries and proton exchange membrane fuel cells.

Large magnetocaloric effect in metamagnetic HoPdAl

Magnetic properties and magnetocaloric effects （MCEs） of the HoPdA1 compounds with the hexagonal ZrNiAl-type and the orthorhombic TiNiSi-type structures are investigated. Both the compounds are found to be antiferromagnet with the Nrel tem- perature TN=12 and 10 K, respectively. A field-induced metamagnetic transition from antiferromagnetic （AFM） state to ferro- magnetic （FM） state is observed below TN. For the hexagonal HoPdA1, a small magnetic field can induce an FM-like state due to a weak AFM coupling, which leads to a high saturation magnetization and gives rise to a large MCE around TN. The maxi- mal value of magnetic entropy change （ASM） is -20.6 J/kg K with a refrigerant capacity （RC） value of 386 J/kg for a field change of 0-5 T. For the orthorhombic HoPdA1, the critical field required for metamagnetic transition is estimated to be about 1.5 T, showing a strong AFM coupling. However, the maximal ASM value is still -13.7 J/kg K around TN for a field change of 0-5 T. The large reversible ASM and considerable RC suggest that HoPdA1 may be an appropriate candidate for magnetic re- frigerant in a low temperature range.