缙云山银木荷(Schima argentea Pritz.ex Diels)林物种组成与多样性变化

定位研究了25a来缙云山银木荷林物种组成及多样性在自然演替过程中的动态变化。结果表明,银木荷林维管植物物种由57种(隶属于24科,46属)减少到38种(隶属于19科,26属)。林下草本和层间植物逐渐消失,胸径大于7.5cm的乔木层树总胸断面积有所减少。尽管群落物种组成以及多样性发生改变,但是银木荷依然是优势树种,处于林冠层,而林冠亚层的白毛新木姜子、四川山矾、长蕊杜鹃逐渐增多,短刺米槠逐渐减少。群落乔木层4个α多样性指数都呈下降趋势,丰富度指数由2.98下降为1.99,Shannon-Wiener指数25a间减小了0.34,Simpson指数和Pielou指数变化都很小;β多样性分析结果显示,银木荷群落的物种差异很大。研究表明,25a间群落物种差异显著。揭示缙云山银木荷林自然演替过程中的物种组成和多样性变化规律,可为缙云山保护区及长江流域中上游亚热带常绿阔叶林的银木荷群落的管理提供一定的参考价值。     

1960年以来山西秋季连阴雨的气候特征分析

利用山西省66个测站1960-2009年秋季(9-11)月的逐日降水量,采用线性倾向估计、累积距平法、EOF及Morlct小波分析方法,系统地分析了山西秋季连阴雨的变化趋势和时空结构特征,建立了秋季连阴雨强度指数模型。结果表明:山西秋季年际区域性连阴雨次数和阴雨日数呈明显的线性减少趋势,过程雨量呈波动上升趋势,连阴雨次数的累积距平表现为"三升两降"型变化;山西秋季连阴雨的年际和年代际变化特征明显,1960-1970年代中期,有5~6年的周期变化,1990年代后期有2年的周期变化特征,年代际变化呈"波动状"变化规律;全省秋季连阴雨从南到北呈递减分布,除北部的天镇、山阴、繁峙等呈增加趋势外,各代表站表现为一致的减少趋势,南部、东南部及五台山为连阴雨多发区,大同盆地、忻州盆地、太原盆地为少发区;山西秋季连阴雨存在2~3年、8年左右的显著振荡周期。1970年代中期到1980年代中期,8年左右振荡周期的振幅最大,能量最强,是周期振荡最强的阶段。     

Winter survival of microbial contaminants in soil:An in situ verification

The aim of the research was to evaluate, at site scale, the influence of freezing and freeze/thaw cycles on the survival of faecal coliforms and faecal enterococci in soil, in a climate change perspective. Before the winter period and during grazing, viable cells of faecal coliforms and faecal enterococci were detected only in the first 10 cm below ground, while,after the winter period and before the new seasonal grazing, a lower number of viable cells of both faecal indicators was detected only in some of the investigated soil profiles, and within the first 5 cm. Taking into consideration the results of specific investigations, we hypothesise that the non-uniform spatial distribution of grass roots within the studied soil can play an important role in influencing this phenomenon, while several abiotic factors do not play any significant role. Taking into account the local trend in the increase of air temperature, a different distribution of microbial pollution over time is expected in spring waters, in future climate scenarios. The progressive increase in air temperature will cause a progressive decrease in freeze/thaw cycles at higher altitudes, minimising cold shocks on microbial cells, and causing spring water pollution also during winter.     

Towards a new climate economics:research areas and prospects

International cooperation to address climate change now stands at a crossroads.With a new international regime for emissions reduction established by the Durban Platform, "New Climate Economics(NCE)" has become a research hotspot.The need for urgent action to combat climate change has prompted discussion on reforms of economic growth patterns and the energy system.The industrial civilization,therefore,now faces a transition towards a new pathway for ecological sustainability.NCE explores new economic concepts,theories,and analytical methods to design a balanced pathway for sustainable growth and emission reduction.Instead of getting trapped in discussions on allocation of emission reduction responsibilities and obligations among countries,NCE pays more attention to developing win-win multilateral cooperation mechanisms that facilitate collaborative RD and knowledge sharing.In addition,NCE studies incentives for low-carbon transition,turning carbon emission reduction into a domestic need for countries to increase their international competitiveness.To achieve the 2°C target,most countries around the world face challenges of insufficient emission allowances to cover expected emissions associated with their projected economic growth.As carbon emissions rights becomes an increasingly scarce resource,increasing the carbon productivity of the economy turns to be the critical path to address the dilemma of green or growth.NCE studies the historical evolution of carbon productivity for countries at different development stages as well as ways to enhance such carbon productivity.This type of study provides invaluable lessons for emerging economies to reach their own emission peaks without losing the momentum of growth.Replacing fossil fuels with new and renewable energy has proven to be an inevitable choice for reshaping the energy system and addressing climate change- it has already become a global trend.NCE studies incentives for new energy technology innovation and deployment provided by carbon pricing,and sheds light on the co-benefits of climate change mitigation,such as resource conservation,environmental protection,and energy security.The role of carbon pricing in promoting intemational RD cooperation and technical transfer will also be studied.The shift in consumption patterns is another key factor enabling a low-carbon transformation.Therefore,NCE also explores the theoretical work on new values of wealth,welfare and consumption,new lifestyles in the context of ecological civilization,concepts and implementation of low-carbon urban planning in developing countries,and the impacts of consumption pattern changes on social development,material production,and urban infrastructure construction.     

泰来县庄园式治沙做法及效益浅析

黑龙江省西部泰来县在典型风沙干旱区,环境极其恶劣的沙带上,通过多年的探索和实践,已创建了庄园式生态经济型治沙的有效成功模式,明显地改善了当地生产、生存、生态环境,同时取得了显著的经济效益和社会效益.     

The Convergence Analysis on the Economic Growth and Energy Intensity Gap between Regional Sectors

In this paper,the authors have analyzed the relationship between energy intensity gap and GDP per worker gap of China’s western and eastern provinces over the period 1997-2006.Using panel data model with lag adjustment,taking the above provinces and six industrial sectors (agriculture,forestry,animal husbandry,and fisheries,industry,construction industry,transport,storage and post & telecommunications,wholesale and retail trades & catering industry,and other sectors of tertiary industry.) as the investigated subjects,the authors have conducted empirical study on the convergence of GDP per worker gap and the convergence of energy intensity gap with respect to the variation of GDP per worker gap,and have concluded that:First,the GDP per worker gap of the six industrial sectors and provinces are convergent,and of this,the convergence rate of GDP per worker gap of Construction Industry is the fastest,while that of Industry is the slowest.Second,the overall energy intensity gap between eastern and western provinces is convergent,that is,with the narrowing of GDP per worker gap between eastern and western provinces,the energy intensity gap converges,but its convergence rate is slower than that of GDP per worker gap.Third,energy intensity gap between various industrial sectors of the east and the west is either convergent or divergent,and there are differences.The energy intensity gap of agriculture,forestry,animal husbandry,and fisheries,industry,and construction industry is convergent,while that of the other three industrial sectors is divergent.Fourth,the convergence of the overall energy intensity of the western provinces is not in conformity with the convergence of the various industrial sectors,and there are significant differences,indicating that the western provinces and autonomous regions should take measures to more effectively improve their overall energy utilization efficiency at the industrial sector level.     

Global Trend of Low-carbon Economy and China's Responses

Based on the analysis on the global economic crisis,climate change crisis and their mutual underlying reasons,the authors believe that low-carbon economy has become an inevitable choice to break through the dual crises,coordinate the economic development,and protect the global climate.The global trend of low-carbon economy finds expression in Green Recovery currently,while,in a long run,it will give rise to a new pattern of world competition in politics,economy,technology,trade and finance.The impact of the...     

丁二烯过氧化物的生成、危害及安全性研究

综述了国内外丁二烯过氧化物研究进展，主要包括丁二烯过氧化物的危害性、成因、危险评价和热稳定性，并对今后的研究方向进行了展望。     

圆锥形零件冲压成形过程分析

通过分析圆锥形零件变形毛坯上不同部分在成形中的作用,揭示了该类零件的冲压成形特点,得出了悬空侧壁部分的变形状态是该类零件成形的关键,而径向拉应力是实现侧壁部分成形的必要条件,同时也是这部分冲压成形成败的关键。为此,经力学分析得出了侧壁部分径向拉应力的解析式和造成圆锥形零件破裂的最大径向拉应力的计算式,为进一步研究提供了理论基础。