基层环境保护行政执法现状分析及对策研究

经过二十多年的努力,中国已基本形成较完善地环境保护法体系,但是,基层环境保护行政执法仍面临立法有空白、体制不顺、能力弱、手段落后等诸多问题。结合实际对基层环境保护行政执法工作中存在的问题进行分析,提高领导对环境保护工作的认识,规范环境保护行政执法行为,提高环境保护行政执法水平,抓好环境保护机构及能力建设,提高广大公众的环境意识和环境法制观念仍是目前解决基层环境保护行政执法工作中存在的问题的有效手段。     

短柱气相色谱法研究焚烧炉飞灰上萘的氯化反应及其产物

本文用0.3mBenton-34/OV-1短填充柱气相色谱法研究了萘在焚烧炉飞灰上的氯化反直产物,实验表明,飞灰表面性质对氯化有促进作用,这种促进作用与飞灰的来源或表面性质有强烈关系,文中对有关分析方法和萘在焚烧炉飞灰上氯化反应的结果作了讨论。     

Small sample estimation for Taylor's power law

An analysis of counts of sample size N=2 arising from a survey of the grass Bromus commutatus identified several factors which might seriously affect the estimation of parameters of Taylor's power law for such small sample sizes. The small sample estimation of Taylor's power law was studied by simulation. For each of five small sample sizes, N=2, 3, 5, 15 and 30, samples were simulated from populations for which the underlying known relationship between variance and mean was given by ² = c^d. One thousand samples generated from the negative binomial distribution were simulated for each of the six combinations of c=1,2 and 11, and d=1, 2, at each of four mean densities, =0.5, 1, 10 and 100, giving 4000 samples for each combination. Estimates of Taylor's power law parameters were obtained for each combination by regressing log₁₀ s ² on log₁₀ m, where s ² and m are the sample variance and mean, respectively. Bias in the parameter estimates, b and log₁₀ a, reduced as N increased and increased with c for both values of d and these relationships were described well by quadratic response surfaces. The factors which affect small-sample estimation are: (i) exclusion of samples for which m = s ² = 0; (ii) exclusion of samples for which s ² = 0, but m > 0; (iii) correlation between log₁₀ s ² and log₁₀ m; (iv) restriction on the maximum variance expressible in a sample; (v) restriction on the minimum variance expressible in a sample; (vi) underestimation of log₁₀ s ² for skew distributions; and (vii) the limited set of possible values of m and s ². These factors and their effect on the parameter estimates are discussed in relation to the simulated samples. The effects of maximum variance restriction and underestimation of log₁₀ s ² were found to be the most severe. We conclude that Taylor's power law should be used with caution if the majority of samples from which s ² and m are calculated have size, N, less than 15. An example is given of the estimated effect of bias when Taylor's power law is used to derive an efficient sampling scheme.     

贵州省原煤中微量元素的组成特征

研究了贵州省各主要煤田中主要采煤层的Ａｓ,Ｂ,Ｂａ,Ｂｅ,Ｃｄ,Ｃｏ,Ｃｒ,Ｃ,Ｈｇ,Ｌｉ,Ｎｉ,Ｐｂ,Ｓｂ,Ｓｅ,Ｓｒ,Ｔｌ,Ｖ,Ｚｎ等微量元素的组成特征,贵州省原煤中微量元素的含量总体上的世界范围内的一致,但Ｓｂ,Ａｓ,Ｈｇ等有害元素则明显富集,由于煤炭成因上的特殊性,其微量元素的组成除受煤植物的影响外,后期在煤作用对其有决定性的影响。     

Simulating correlated count data

In this study we compare two techniques for simulating count-valued random n-vectors Y with specified mean and correlation structure. The first technique is to use a lognormal-Poisson hierarchy (L-P method). A vector of correlated normals Z is generated and transformed to a vector of lognormals X. Then, Y is generated as conditionally independent Poissons with means X _i . The L-P method is simple, fast, and familiar to many researchers. However, the method requires each Y _i to be overdispersed (i.e., σ² > μ), and only low correlations are possible with this method when the variables have small means. We develop a second technique to generate the elements of Y as overlapping sums (OS) of independent X _j ’s (OS method). For example, suppose X, X ₁, and X ₂ are independent. If Y ₁ = X + X ₁ and Y ₂ = X + X ₂, then Y ₁ and Y ₂ are correlated because they share the common component X. A generalized version of the OS method for simulating n-vectors of two-parameter count-valued distributions is presented. The OS method is shown to address some of the shortcomings of the L-P method. In particular, underdispersed random variables can be simulated, and high correlations are feasible even when the means are small. However, negative correlations cannot be simulated with the OS method, and when n > 3, the OS method is more complicated to implement than the L-P method.     

珠江三角洲小流域地下水化学特征及演化规律

珠江三角洲地下水环境日益恶化,已成为制约经济社会发展的重要因素。以珠海市具有典型特征的闭合小流域作为研究对象,分旱、雨两季采集地下水分析主要离子及D、18O同位素,全面系统地研究了地下水水化学的时空变异特征与演变规律。结果表明:研究区内地下水主要受大气降水及附近地表水体渗透补给,以蒸发及地下水径流排泄,季节变化对区域内水化学空间变异性影响较小。沿地下水流方向(补给区-径流区-排泄区),地下水化学类型主要从Ca-Na(Mg)-HCO3型向Na-Cl和Na-K-HCO3-CO3型演化,风化-溶滤、离子交换、海陆交互作用是控制当地地下水质演变的主要水文化学过程。     

Impact of Grazing Intensity during Drought in an Arizona Grassland

Abstract:  The ecological benefits of changing cattle grazing practices in the western United States remain controversial, due in part to a lack of experimentation. In 1997 we initiated an experimental study of two rangeland alternatives, cattle removal and high-impact grazing, and compared grassland community responses with those with more conventional, moderate grazing practices. The study was conducted in a high-elevation, semiarid grassland near Flagstaff, Arizona (U.S.A.). We conducted annual plant surveys of modified Whittaker plots for 8 years and examined plant composition shifts among treatments and years. High-impact grazing had strong directional effects that led to a decline in perennial forb cover and an increase in annual plants, particularly the exotic cheatgrass ( Bromus tectorum L.). A twofold increase in plant cover by exotic species followed a severe drought in the sixth year of the study, and this increase was greatest in the high-impact grazing plots, where native cover declined by one-half. Cattle removal resulted in little increase in native plant cover and reduced plant species richness relative to the moderate grazing control. Our results suggest that some intermediate level of cattle grazing may maintain greater levels of native plant diversity than the alternatives of cattle removal or high-density, short-duration grazing practices. Furthermore, episodic drought interacts with cattle grazing, leading to infrequent, but biologically important shifts in plant communities. Our results demonstrate the importance of climatic variation in determining ecological effects of grazing practices, and we recommend improving conservation efforts in arid rangelands by developing management plans that anticipate this variation.     

论环境的行政公益诉讼

中国尚未建立环境的行政公益诉讼,而传统诉讼制度的问题和缺陷日益显露,导致环境得不到很好地保护。根据环境法中关于环境权的理论、公众参与的原则以及公益诉讼的理论,中国应该尽快建立环境行政公益诉讼制度,赋予公众环境的行政公益诉讼资格,使作为公共利益的环境能得到切实的保护和改善。     

对我国生态补偿的立法构想

分析了以往生态补偿的定义,并从法律的角度给出了生态补偿应有的涵义,即是指为了恢复、维持和增强生态系统的生态功能,国家对导致生态功能减损的自然资源开发或利用者收费(税)以及国家或生态受益者对为改善、维持或增强生态服务功能为目的而作出特别牺牲者给予经济和非经济形式的补偿。回顾了我国有关生态补偿的政策与法律的规定,并探讨了其缺陷:我国有关生态补偿的政策与法律虽然较多,规定得较早,但这些规定很不规范和系统,而且过于原则、缺乏可操作性,对负外部性行为的生态补偿存在政策与法律的缺位,即使是对正外部性行为也并非真正意义上的补偿,而只是一种补助或补贴。对我国生态补偿的立法构建提出了初步设想:一要补偿政策应当法律化,使生态补偿成为一项名副其实的法律制度;二要要构建合理的生态补偿法律体系。     

对于环境执法监管中的几点建议

针对温总理在2006年全国环境保护大会上提到的现阶段环境执法存在的问题，提出了尽快完善环境法规体系，建立环境执法管理制度；建立完善的领导干部环保政绩考核制度。彻底消除地方保护主义；建立健全公众参与与环境行为公示制度；提高环境监管能力建设，切实加大环境执法力度；创新环境执法思路和手段，严打各种环境违法行为等建议。