后危机时代我国产业升级的约束条件及对策研究

产业升级是一项系统工程,目前面临一些约束条件,制约了产业升级的成效。本文分析了三个方面的约束因素:有效需求约束、供给约束、制度约束,并提出新形势下的产业结构调整对策:调整需求结构、要素投入结构、分配结构,扩大内需;调整三次产业结构;构建有利于产业结构调整的体制机制。     

Efficient management of eutrophic coastal zones in theory and practice: an application on nitrogen reduction to the Stockholm archipelago

This study estimates efficient nitrogen load reductions to the Stockholm archipelago, a Swedish coastal zone in the Baltic Sea, and compares these with politically determined and implemented nitrogen abatement programs. The region is relatively well equipped with necessary data, and a simple programming model is constructed. The results show a large divergence in efficient nitrogen reductions, mainly due to the divergences in benefit estimates from water quality improvements in the archipelago. However, the results need to be interpreted with caution due to all uncertainties related to predicting net values from changes in nitrogen load to a coastal zone. In spite of this, it is still of policy relevance to infer results which show that the politically determined target coincides with an efficient nitrogen reduction at relatively low benefit estimate, but that actual net benefits could be increased from a reallocation of abatement measures towards more low cost measures.     

新疆某石化企业污水库周边土壤对钴的吸附行为研究

采用静态吸附法研究了新疆菜石化企业污水库周边土壤对重金属钴的吸附特征,考察了溶液pH值、钴离子平衡质量浓度、背景电解质浓度、吸附时间和环境温度等因素对钴吸附量的影响,并对吸附机理进行了初步探讨.结果表明:溶液pH值为1～4时,改变pH值对土壤吸附钴的影响显著;吸附时间在3h左右时钴吸附量趋于稳定;随溶液背景电解质浓度增大,土壤对钴的吸附量呈现先急剧后缓慢的下降趋势;土壤对钴的吸附量随温度升高而增加.拟合结果表明,Langmuir和Freundlich模型能较好地描述土壤对钴吸附的热力学过程;在3h内,土壤对钴吸附的动力学过程可以用一级反应动力学方程表示.方差分析结果表明,对土壤吸附钴量有显著性影响的因素有溶液pH值、钴离子平衡浓度、吸附时间和温度等.     

乌鲁木齐市民用住宅室内氡浓度水平调查研究

对乌鲁木齐市具有代表性的民用住宅室内氡浓度进行了连续一年的监测调查,调查结果显示室内氡浓度平均值55.4 Bq／m3,低于国标的“200 Bq／m3”,并据此估算出其所致居民的年均有效剂量为1.400 mSv,以及所致居民支气管上皮组织、肺、性腺、骨髓及骨表面细胞等关键组织的年吸收剂量分别为1886．49,378.96,2.80,3.20,3.20μGy／a,大于UNSCEAR2000年报告的世界平均值1.008 mSv,结合室内氡的主要来源,提出了对建筑材料进行放射性监测、控制装修、工程竣工后开展室内环境监测、加强室内通风以及开展室内氡污染治理等措施控制室内氡浓度水平。     

漓江上游植被覆盖度时空变化对地表热场影响

自20世纪80年代以来，桂林漓江由于上游森林遭受破坏出现水生态环境快速恶化的趋势。地表热场的时空变化直接影响森林蒸散及水文效应。因此，对漓江上游1989~2006年5景TM/ETM+卫星图像，利用归一化植被指数反演植被覆盖度，利用单窗算法反演地表温度，提出归一化温度使不同时相地表热场具有可比性，分析植被覆盖度时空变化对地表热场的影响。结果表明，在空间上，地表温度随植被覆盖度的增加而降低，在植被覆盖度很高或很低时，这种影响相对变弱；在时间上，漓江上游1989~2000年植被中、高度覆盖面积从96.1%逐年下降到65.9%，导致归一化地表温度数值较高的像元比例相应增加；2000~2006年植被中、高度覆盖面积逐渐恢复上升到90.8%，但仍略低于1989年，使得归一化地表温度数值较高的像元比例相应减少。植被覆盖可以有效地降低漓江上游地表温度     

Effect of Monitoring Technique on Quality of Conservation Science

Monitoring free‐ranging animals in their natural habitat is a keystone of ecosystem conservation and increasingly important in the context of current rates of loss of biological diversity. Data collected from individuals of endangered species inform conservation policies. Conservation professionals assume that these data are reliable—that the animals from whom data are collected are representative of the species in their physiology, ecology, and behavior and of the populations from which they are drawn. In the last few decades, there has been an enthusiastic adoption of invasive techniques for gathering ecological and conservation data. Although these can provide impressive quantities of data, and apparent insights into animal ranges and distributions, there is increasing evidence that these techniques can result in animal welfare problems, through the wide‐ranging physiological effects of acute and chronic stress and through direct or indirect injuries or compromised movement. Much less commonly, however, do conservation scientists consider the issue of how these effects may alter the behavior of individuals to the extent that the data they collect could be unreliable. The emerging literature on the immediate and longer‐term effects of capture and handling indicate it can no longer be assumed that a wild animal's survival of the process implies the safety of the procedure, that the procedure is ethical, or the scientific validity of the resulting data. I argue that conservation professionals should routinely assess study populations for negative effects of their monitoring techniques and adopt noninvasive approaches for best outcomes not only for the animals, but also for conservation science. Efecto de la Técnica de Monitoreo en la Calidad de la Ciencia de la Conservación     

The application of generalized linear mixed models to multi-level sampling for insect population monitoring

Iwao's quadratic regression or Taylor's Power Law (TPL) are commonly used to model the variance as a function of the mean for sample counts of insect populations which exhibit spatial aggregation. The modeled variance and distribution of the mean are typically used in pest management programs to decide if the population is above the action threshold in any management unit (MU) (e.g., orchard, forest compartment). For nested or multi-level sampling the usual two-stage modeling procedure first obtains the sample variance for each MU and sampling level using ANOVA and then fits a regression of variance on the mean for each level using either Iwao or TPL variance models. Here this approach is compared to the single-stage procedure of fitting a generalized linear mixed model (GLMM) directly to the count data with both approaches demonstrated using 2-level sampling. GLMMs and additive GLMMs (AGLMMs) with conditional Poisson variance function as well as the extension to the negative binomial are described. Generalization to more than two sampling levels is outlined. Formulae for calculating optimal relative sample sizes (ORSS) and the operating characteristic curve for the control decision are given for each model. The ORSS are independent of the mean in the case of the AGLMMs. The application described is estimation of the variance of the mean number of leaves per shoot occupied by immature stages of a defoliator of eucalypts, the Tasmanian Eucalyptus leaf beetle, based on a sample of trees within plots from each forest compartment. Historical population monitoring data were fitted using the above approaches.     

云南临沧盆地土壤天然放射性测定及环境影响评价

临沧盆地受其基底花岗岩的影响,环境中存在天然放射性水平异常。本文测得其土壤中放射性核素226Ra、238U、232Th和40K的比活度分别为53.4(38.7-62.8)、161.2(127.3-211.7)、120.9(106.5-140.6)和632.2(521.7-707.5)Bq/kg,明显高于全国和世界平均值。花岗岩天然放射性水平较高,与土壤放射性有一定的相关性,为土壤伴生放射性提供了较好的来源。采用测得的土壤放射性核素226Ra、232Th和40K的比活度,计算了距地面1m高处空气中γ辐射吸收剂量率和年有效剂量率,并对γ辐射外照射水平进行了评价。评价结果表明,虽然该区的空气吸收剂量率较高,但是年有效剂量率在容许范围之内。因此该区属于外照射水平的安全区域,人居环境不受影响。     

中国城市化与能源强度关系的交互动态响应分析

基于1990-2009年的统计数据,建立城市化率和能源强度间的向量自回归模型,运用协整分析、脉冲响应函数和动态方差分解法,从不同视角对两组变量的交互动态响应关系进行分析和预测,旨在揭示我国城市化水平与能源利用效率的内在联系、互动机制与发展趋势。分析结果表明:尽管在短期内呈现波动态势,我国城市化水平与能源强度之间存在长期均衡关系;两组变量的动态脉冲响应为负,体现出城市化率和能源强度之间的反向变动走势;与城市化相比,能源强度的脉冲曲线波动剧烈,说明单纯依靠能源系统内部来改善能源效率缺乏可持续性;方差分解时序值显示,能源强度对城市化变动因素的累计贡献较低,而城市化水平对能源强度变动的影响显著且增长迅速,说明能源强度的降低并不是城市化率提高的主要动力,反之城市化水平的提高对能源强度的下降具有较强的促进作用。由此可见,通过城市的优化开发与系统建设,能够有效促进能源的可持续利用,实现能源消费与经济增长间的均衡发展。     

FRP加固钢筋混凝土梁的抗剪计算方法

随着利用FRP加固混凝土结构研究的深入和应用的拓展,FRP加固钢筋混凝土梁抗剪性能的研究已取得了丰硕的成果。以往对抗剪承载力的分析大多是基于有效应变即对极限应变进行有效折减的方法,而最近的研究则引入了裂缝处FRP应变分布不均匀系数。在此基础上,本文综合考虑了FRP发挥的最大应变、沿裂缝应变分布的不均性以及斜裂缝倾角对有效应变的影响,提出了等效有效应变的概念,使计算趋于简单和清晰。本文收集了128根FRP全包裹的、以FRP断裂破坏为主的钢筋混凝土梁的抗剪实验数据,通过对主要影响因素的统计分析,建立了等效有效应变简单可靠的计算公式和基于FRP断裂的抗剪承载力设计方法。128根实验梁的抗剪计算结果表明,本文提出的方法简单可行,意义明确,且精度要比已有的建议公式稍高。