海河流域河流氮污染特征及其演变趋势

收集海河流域重点水功能区主要监测站点2000—2011年总氮(TN)、氨氮(NH+4-N)、硝氮(NO-3-N)、亚硝氮(NO-2-N)指标的历史数据,并且实测2009年350个样点的氮素指标,以探明海河流域河流氮污染特征及其演变趋势.结果表明,海河流域氮污染现状严重,2011年TN、NH+4-N、NO-3-N和NO-2-N的平均浓度分别为7.92、4.25、1.28、0.013 mg·L-1,TN、NH+4-N超地表水V类水质标准现象严重(2.0 mg·L-1),其中海河干流水系、北三河(北运河、潮白河、蓟运河)水系和子牙河水系污染较重.在空间尺度上,海河流域氮污染沿山区-平原方向呈现出明显逐渐上升的变化特征.在时间尺度上,TN与NH+4-N浓度变化均在2005年与2011年出现峰值,TN浓度与NH+4-N、NO-3-N、NO-2-N浓度呈现极显著正相关(p0.01),NH+4-N是海河流域氮污染的主要污染因子.2000—2011年,NH+4-N劣V类(2.0 mg·L-1)站点比例整体上表现为减少趋势,由2000年的28.87%降为2011年的17.56%,劣V类站点NH+4-N浓度均值由2000年的7.91 mg·L-1降为2011年的6.50mg·L-1.在海河流域中,黑龙港运东水系、子牙河水系河流NH+4-N污染较重,各年平均浓度均超过地表水V类水质标准,NH+4-N平均浓度呈现随年份逐渐降低的趋势.在海河流域氮污染整体表现为好转的趋势下,氮污染的现状仍然严峻,需加强控制.     

中国东中西部经济带的水环境库兹涅茨假说实证及其影响因素研究

“八五”至“十二五”期间,中国取得巨大的经济成果的同时带来了严重的水环境污染问题.文章分析了东中西部三大经济带经济发展及COD和氨氮两种主要水污染排放的差异,及其与经济发展的关系进行了EKC假说的实证研究.研究结果表明,部分污染物的拟合曲线尚处于上升阶段,未能出现典型的倒U型曲线,可能导致水环境质量恶化.环境基础设施建设、人口分布和产业结构等因素与COD和氨氮的排放量密切相关,因此,中国必须采取各种环境管理和技术手段,促使区域水污染物排放量指标与经济发展的拟合曲线出现转折点,改善水环境质量.     

基于降低温室效应的航空器运行策略

以航空器运行对环境造成温室效应的两个主要因素—CO_2和凝结尾为研究对象,通过绝对全球温变潜势(AGTP)建立科学统一的衡量标准,将CO_2和凝结尾对环境的影响转换为全球地表温度的改变,为降低温室效应提供依据。最后结合典型高空的探空资料对实际增温进行计算,对比分析25、50、100年时间水平下CO_2和凝结尾对全球地表温度造成的影响,为航空器降低温室效应提供飞行高度指导。     

海南省麒麟菜自然保护区麒麟菜资源研究

2012年对海南省麒麟菜保护区内野生麒麟菜资源进行调查研究。结果表明,海南省麒麟菜自然保护区有琼枝和耳突卡帕藻2种麒麟菜,优势种为琼枝。保护区内麒麟菜分布面积约为19.40 km2,平均覆盖度为0.54%,平均生物量为7.30 g/m2。其中文昌海域约为14.35 km2,平均覆盖度为0.55%,平均生物量为7.85 g/m2;琼海海域约为5.05 km2,平均覆盖度为0.49%,平均生物量为5.78 g/m2。伴生生物有33科50种,其中多毛类有9科14种,软体动物有14科17种,甲壳类9科18种以及棘皮动物1科1种,平均生物量为6.38 g/m2,平均栖息密度为72.72个/m2。优势种为斑纹围沙蚕、地中海巨亮钩虾、雷氏藻钩虾和四肢舟钩虾。受草食性动物、渔业活动、陆源污染和海洋工程影响海南省麒麟菜保护区麒麟菜大面积减少。     

Determination of Commonly Used Herbicides in Surface Water Using Solid-Phase Extraction and Dual-Column HPLC-DAD

The present study describes the application of different solid-phase extraction techniques for the extraction, separation, and quantitative determination of 10 commonly used herbicides with different chemical structures (chlorsulfuron, diuron, bentazone, linuron, chlorpropham, fenoxoprop-ethyl, MCPA, diclofop-methyl, fluazifop-butyl, trifluraline) in water. Octadecyl (C₁₈) Empore extraction disks, octadecyl (C₁₈), and stryene divinylbenzene (SDB) Bond Elut Env cartridges were compared for solid-phase extraction efficiency. Herbicides were separated and quantified by reversed-phase high performance liquid chromatography with diode-array detection (HPLC-DAD) with simultaneous separation on two columns of differing polarity (C₁₈ and CN) to confirm identification. Analytical separation was performed simultaneously on C₁₈ and CN columns. Reanalysis of the sample extracts on a (cyano) CN column were used to confirm the identity of these compounds. Method optimization and validation parameters were presented in this work. Recoveries varied from 76.0% to 99.0% for C₁₈ disks, from 75.1% to 100.0% for C₁₈ cartridges, and from 54.0% to 98.0% for SDB cartridges over concentrations at 0.025–0.4 μg L^?1. The limits of detection were 0.012–0.035 μg L^?1.     

Provenances of atmospheric dust over Korea from Sr–Nd isotopes and rare earth elements in early 2006

Sr and Nd isotopic composition of pre- and syn-Asian dust (Hwangsa) particles collected from three different water depths at two different offshore sites, western Korea and rare earth elemental composition of syn-Asian dust particles collected from three islands around the Korean Peninsula in late April 2006 were analyzed to interpret their provenance. The dust Sr–Nd isotopic compositions vary spatiotemporally, but they show specific values when the Hwangsa event occurred. Satellite images, airmass backward trajectory modeling, and comparison with Sr–Nd isotopic ratios and rare earth elements compositions of soils and desert sands of northern China all suggest the major source of dust particles for the late April 2006 Hwangsa event to be the Mu Us Desert in northern China. Dust particles of the pre-Hwangsa period include both background dusts and the previous Hwangsa event dust particles, and they are interpreted to have been originated from various arid regions of China such as the Hobq Desert, the Mu Us Desert, and the Taklamakan Desert in different times. Different background dust sources during pre-Hwangsa period in early 2006 resulted from the changing route of the westerlies.     

电力安全工器具智能管理系统的研发及应用

电力安全工器具种类多、数量大，作为保障各类电工操作安全、有序作业必不可少的器具，高效率、专业化和智能型管理是电力企业安全质效提升的重要举措。针对现场电力安全工器具管理存在的诸多问题，基于“云平台”自动模式识别技术，研发电力安全工器具智能管理系统，集各个安全工器具身份标识、位置信息、出入库记录、损坏报废标记以及超过检测周期警报提示为一体。通过周期测试和现场应用，结果表明：该系统以安全工器具个体为管理单元，分层分类，构建大数据库，信息覆盖全面完整；分布式区块链技术有力支撑平台数据的实时更新和资源共享，提升管理效率；指纹登录，智能感应，出入库时间缩短了2/3，取用便捷，提高工作效率；智能扫描检测功能，及时警示反馈，有效避免现场违规使用事件的发生，助力安全生产，夯实安全质效。     

Experimental study on the discharge characteristics of viscous debris flow with grid-type dam

Environmental Fluid Mechanics - Experimental tests were conducted on a rectangular flume with different grid-type dam grid sizes, channel slopes and debris flow bulk density. We use the Bernoulli...     

Effects of sandy desertified land rehabilitation on soil carbon sequestration and aggregation in an arid region in China

The rehabilitation of sandy desertified land in semi-arid and arid regions has a great potential to increase carbon sequestration and improve soil quality. Our objective was to investigate the changes in the soil carbon pool and soil properties of surface soil (0–15 cm) under different types of rehabilitation management. Our study was done in the short-term (7 years) and long-term (32 years) desertification control sites in a marginal oasis of northwest China. The different management treatments were: (1) untreated shifting sand land as control; (2) sand-fixing shrubs with straw checkerboards; (3) poplar (Populus gansuensis) shelter forest; and (4) irrigated cropland after leveling sand dune. The results showed that the rehabilitation of severe sandy desertified land resulted in significant increases in soil organic C (SOC), inorganic C, and total N concentrations, as well as enhanced soil aggregation. Over a 7-year period of revegetation and cultivation, SOC concentration in the recovered shrub land, forest land and irrigated cropland increased by 4.1, 14.6 and 11.9 times compared to the control site (shifting sand land), and increased by 11.2, 17.0 and 23.0 times over the 32-year recovery period. Total N, labile C (KMnO₄–oxidation C), C management index (CMI) and inorganic C (CaCO₃–C) showed a similar increasing trend as SOC. The increased soil C and N was positively related to the accumulation of fine particle fractions. The accumulation of silt and clay, soil C and CaCO₃ enhanced the formation of aggregates, which was beneficial to mitigate wind erosion. The percentage of >0.25 mm dry aggregates increased from 18.0% in the control site to 20.0–87.2% in the recovery sites, and the mean weight diameter (MWD) of water-stable aggregates significantly increased, with a range of 0.09–0.30 mm at the recovery sites. Long-term irrigation and fertilization led to a greater soil C and N accumulation in cropland than in shrub and forest lands. The amount of soil C sequestration reached up to 1.8–9.4 and 7.5–17.3 Mg ha^?1 at the 0–15 cm layer over a 7- and 32-year rehabilitation period compared to the control site, suggesting that desertification control has a great potential for sequestering soil C and improving soil quality in northwest China.     

Emergy-based assessment on industrial symbiosis: a case of Shenyang Economic and Technological Development Zone

Industrial symbiosis is the sharing of services, utility, and by-product resources among industries. This is usually made in order to add value, reduce costs, and improve the environment, and therefore has been taken as an effective approach for developing an eco-industrial park, improving resource efficiency, and reducing pollutant emission. Most conventional evaluation approaches ignored the contribution of natural ecosystem to the development of industrial symbiosis and cannot reveal the interrelations between economic development and environmental protection, leading to a need of an innovative evaluation method. Under such a circumstance, we present an emergy analysis-based evaluation method by employing a case study at Shenyang Economic and Technological Development Zone (SETDZ). Specific emergy indicators on industrial symbiosis, including emergy savings and emdollar value of total emergy savings, were developed so that the holistic picture of industrial symbiosis can be presented. Research results show that nonrenewable inputs, imported resource inputs, and associated services could be saved by 89.3, 32.51, and 15.7 %, and the ratio of emergy savings to emergy of the total energy used would be about 25.58 %, and the ratio of the emdollar value of total emergy savings to the total gross regional product (GRP) of SETDZ would be 34.38 % through the implementation of industrial symbiosis. In general, research results indicate that industrial symbiosis could effectively reduce material and energy consumption and improve the overall eco-efficiency. Such a method can provide policy insights to industrial park managers so that they can raise appropriate strategies on developing eco-industrial parks. Useful strategies include identifying more potential industrial symbiosis opportunities, optimizing energy structure, increasing industrial efficiency, recovering local ecosystems, and improving public and industrial awareness of eco-industrial park policies.