China's Total Emission Control Policy:a Critical Review

As part of a comprehensive environmental management system, many countries establish emission control targets for mass emissions of a pollutant. Such targets are often the key objective of an environmental policy, such as an emission trading program. In China, however, it is more than just an objective of one particular policy; it has become a concept that has influenced many national environmental policies and activities. The objective of this article is to review the implementation of the total emission c...     

电网发展、清洁电源接入与地区能源效率

鉴于我国已经建成全球规模最大的超高压和特高压电网,彻底弥补了电力跨区配置的电网基础设施短板,并且为清洁电源并入电网和跨区消纳提供了完善的基础设施,不仅克服我国电力负荷中心和能源基地的区域布局不协调,而且有益于缓解日益严峻的能源利用率低下和环境污染问题。本文利用1991—2012年全国29个省市面板数据实证研究了清洁电源并网对地区全要素能源效率的影响。为保证实证结果稳健性分别在线性和非线性实证框架下采用系统广义矩估计(SYS-GMM)和面板平滑转换模型(PSTR)两种方法估计了清洁电源接入高压、超高压和特高压电网的地区全要素能源效率异质性效应。实证结果显示:(1)我国电网基础设施对地区全要素能源效率具有明显的增进效应,特别是超高压电网在促进全要素能源效率提升上表现的最为突出,在特高压骨干网架尚未形成的情况下起到了支柱性作用。(2)高压、超高压、特高压与清洁电源交互项的估计系数始终位于负数区间,反映清洁电源并网的能源效率绩效并不明显,受限于并网规模和机制缺陷,还没有发挥出全要素能源效率提升作用。(3)随着人均GDP的不断提高,各等级电网对地区能源效率的益处越来越明显,并且存在着门槛效应。(4)特高压电网对地区能源效率的积极作用主要表现在东部沿海高收入省份,这些省份作为电力消费负荷中心,大规模接入清洁电源对能源效率改善裨益明显。接下来,需要根据地区的能源禀赋结构选择清洁电源的并网模式,完善的电网基础设施、合理的电源结构还需要配置以高效的清洁电源并网机制才能不断增进地区全要素能源效率。     

强“波特假说”存在产业异质性吗?——基于产业碳密集程度细分的视角

强"波特假说"认为严格而恰当的环境规制政策将使企业的生产效率呈现先降后升的趋势,为验证强"波特假说"及其产业异质性,首先建立产业碳密集指数,将工业部门36个细分行业划分为高碳密集产业、中碳密集产业和低碳密集产业;接着运用方向性距离函数测算2003—2014年细分行业的绿色全要素生产率,基于系统"GMM"估计方法验证三个细分行业的环境规制强度对绿色全要素生产率的影响。研究结果显示:第一,样本期间内,高碳密集产业的环境规制强度远远高于中低碳密集产业,这表明高碳密集产业一直是产业节能减排的重点对象,而碳排放情况较为严重的中碳密集产业则为"被遗忘的角落";第二,强"波特假说"在工业部门内存在产业异质性,高碳密集产业和中碳密集产业的环境规制强度与绿色全要素生产率呈"U"型关系,而在低碳密集产业中两者则呈倒"U"型关系;第三,相对于高碳密集产业,中碳密集产业因环境规制强度较容易跨越"U"型拐点而具有较大的减排空间,低碳密集产业在达到"U"型拐点之前,环境规制为其绿色全要素生产率提升的动力。本文研究结论蕴含如下的政策建议:根据产业的碳密集程度实施针对性的环境规制政策,持续加强中碳密集产业的环境规制力度,适度加强低碳密集产业的环境规制强度,高碳密集产业需根据不同阶段的经济水平设计具有针对性的环境规制政策,逐渐将三类产业的"遵循成本"效应转化为"创新补偿"效应,实现经济增长和环境保护的双赢。     

Impact of long‐term pesticide applications on some soil biological parameters

Abstract

The soil oxidative and anaerobic processes, as well as, the microbial biomass were followed during three years in a cotton farm (Tatuí) where the recommended pesticides have been used for several years, and in an experimental field (São Paulo) treated first time with the same pesticides. The oxidative process was monitored by the dehydrogenase (DHA)‐activity using triphenyltetrazolium chloride (TTC) as substrate. The anaerobic process was followed by the iron‐oxide reduction, and the microbial biomass was estimated by the substrate (glucose)‐indiced respiration. Increases in DHA‐activity and in the microbial biomass occurred only in the farm soil, with concomitant decreases in iron‐reduction. In the experimental field soil, the increases in DHA‐activity were followed only by decreases in iron‐reduction. Soil characteristics were the determining factor for different biological parameters after pesticide inputs. All the pesticides produced at least one clear but transient effect.     

Antioxidants in Capsicum chinense: Variation among countries of origin

The main objective of this investigation was to evaluate fruits of C. chinense accessions for their concentration of β -carotene, ascorbic acid, and phenols for use as parents in breeding for these phytochemicals. Mature fruits of 63 accessions of C. chinense originally acquired from Belize, Brazil, Colombia, Ecuador, Mexico, Peru, Puerto Rico, and the United States were analyzed for their chemical composition. Fruits of C. chinense accessions PI-152452 (Brazil) and PI-360726 (Ecuador) contained the greatest concentrations of ascorbic acid (1.2 and 1.1 mg g^?1 fresh fruit, respectively), while PI-438648 (Mexico) contained the greatest concentration of total phenols content (349 μ g g^?1 fresh fruit) among the other 63 accessions tested. Accession PI-355817 from Ecuador contained the greatest concentrations of β -carotene (8 mg g^?1fresh fruit). These accessions were identified as potential candidates for mass production of antioxidants with health-promoting properties.     

膜生物反应器中生物膜的生长特性

实验采用经甲苯培养驯化而成的单一假单胞菌菌种,通过分析平板式生物膜反应器内,不同阶段假单胞细菌生物膜干重、厚度、活性生物量和生物种群分布的变化,研究生物膜特性与降解效率之间的关系。实验结果表明,在挂膜初期生物膜迅速生长,生物量以及生物膜干重增长很快,有利于甲苯及营养物质的传输,降解效率也快速提升。随着生物膜的生长,生物量及干重也逐步增加,厚度逐渐增加使传质阻力不断增大,生物膜上层微生物的有机底物供应不足,使生物膜上层结构稀疏,最终维持一个甲苯的总传输量与生化降解量的平衡,生物量的生长与衰亡也达到动态平衡,形成了一个较高且稳定的降解效率。     

微型测定法测定白醋中的总酸度

利用微型滴定法测定白醋中的总酸度,并对常量实验和微型实验的测定结果进行了比较分析。结果两种方法无显著性差异,F检验、t检验均在允许范围内,微型实验的准确度和精密度均达到常量实验的测定水平,完全满足化学分析要求,并且有效地节省了实验试剂,大大降低了实验成本。     

Modeled Summer Background Concentration of Nutrients and Suspended Sediment in the Mid‐Continent (USA) Great Rivers1

Angradi, Ted R., David W. Bolgrien, Matt A. Starry, and Brian H. Hill, 2012. Modeled Summer Background Concentration of Nutrients and Suspended Sediment in the Mid‐Continent (USA) Great Rivers. Journal of the American Water Resources Association (JAWRA) 48(5): 1054‐1070. DOI: 10.1111/j.1752‐1688.2012.00669.x Abstract: We used regression models to predict summer background concentration of total nitrogen (N), total phosphorus (P), and total suspended solids (TSS), in the mid‐continent great rivers: the Upper Mississippi, the Lower Missouri, and the Ohio. From multiple linear regressions of water quality indicators with land use and other stressor variables, we determined the concentration of the indicators when the predictor variables were all set to zero — the y‐intercept. Except for total P on the Upper Mississippi River, we could predict background concentration using regression models. Predicted background concentration of total N was about the same on the Upper Mississippi and Lower Missouri Rivers (430 μg l^?1), which was lower than percentile‐based values, but was similar to concentrations derived from the response of sestonic chlorophyll a to great river total N concentration. Background concentration of total P on the Lower Missouri (65 μg l^?1) was also lower than published and percentile‐based concentrations. Background TSS concentration was higher on the Lower Missouri (40 mg l^?1) than the other rivers. Background TSS concentration on the Upper Mississippi (16 mg l^?1) was below a threshold (30 mg l^?1) designed to protect aquatic vegetation. Our model‐predicted concentrations for the great rivers are an attempt to estimate background concentrations for water quality indicators independent from thresholds based on percentiles or derived from stressor‐response relationships.     

湘江株洲段丰水期镉污染负荷总量测算及分配

以2010年8月湘江干流株洲段代表性断面水质与底泥监测资料以及其他资料为基础,采用WASP7模型模拟该江段丰水期镉浓度,并进行镉污染负荷测算与分配。研究结果表明,WASP7模型较好地重现了镉浓度的变化规律,8月份该河段上游镉入流量2 446.33 kg,下游出流量3 076.44 kg,区间增量630.12 kg,其中点源负荷量241.67 kg,占38.4%,面源负荷量304.49 kg,占48.3%,内源负荷量为83.96 kg,占13.3%。     

微囊藻毒素-LR的全内反射荧光免疫传感器研究

在开发全内反射荧光免疫传感器的基础上,研究水中微囊藻毒素-LR(MC-LR)的检测方法。建立了基于MC-LR平面波导免疫芯片的制备方法,并结合流动分析和荧光检测开发检测系统,针对MC-LR的免疫检测条件进行优化。结果表明,全内反射荧光免疫传感器对MC-LR抗体的检测限为0.001μg/mL;在间接竞争免疫检测模式下,最优检测条件是预反应时间5min、预反应温度37℃、进样停留时间500s;在最优检测条件下,对MC-LR的检测限为0.100μg/L,线性区间为0.200~4.000μg/L;全内反射荧光免疫传感器检测MC-LR的加标回收率均在100.0%±20.0%,平行测定的相对标准偏差小于5%。