Nitrogen-enriched micro-mesoporous carbon derived from polymers organic frameworks for high-performance capacitive deionization

Nitrogenization is an effective method for improving the capacitive deionization（CDI） performance of porous carbon materials. In particular, polymer organic frameworks with heteroatom doping, containing an ordered pore structure and excellent electrochemical stability, are ideal precursors for carbon materials for high-performance CDI. In this study, a nitrogen-enriched micro-mesoporous carbon（NMC） electrode was fabricated by carbonizing a Schiff base network-1 at 500, 600, and 700 °C. Scanning ...     

Temporal distribution and potential sources of atmospheric mercury measured at a high-elevation background station in Taiwan

Measurements of gaseous elemental mercury (GEM), reactive gaseous mercury (RGM), and particulate mercury (PHg) have been conducted at Lulin Atmospheric Background Station (LABS) in Taiwan since April 2006. This was the first long-term free tropospheric atmospheric Hg monitoring program in the downwind region of East Asia, which is a major Hg emission source region. Between April 13, 2006 and December 31, 2007, the mean concentrations of GEM, RGM, and PHg were 1.73 ng m^?3, 12.1 pg m^?3, and 2.3 pg m^?3, respectively. A diurnal pattern was observed for GEM with afternoon peaks and nighttime lows, whereas the diurnal pattern of RGM was opposite to that of GEM. Spikes of RGM were frequently observed between midnight and early morning with concurrent decreases in GEM and relative humidity and increases in O₃, suggesting the oxidation of GEM and formation of RGM in free troposphere (FT). Upslope movement of boundary layer (BL) air in daytime and subsidence of FT air at night resulted in these diurnal patterns. Considering only the nighttime data, which were more representative of FT air, the composite monthly mean GEM concentrations ranged between 1.06 and 2.06 ng m^?3. Seasonal variation in nighttime GEM was evident, with lower concentrations usually occurring in summer when clean marine air masses prevailed. Between fall and spring, air masses passed the East Asian continent prior to reaching LABS, contributing to the elevated GEM concentrations. Analysis of GEM/CO correlation tends to support the argument. Good GEM/CO correlations were observed in fall, winter, and spring, suggesting influence of anthropogenic emission sources. Our results demonstrate the significance of East Asian Hg emissions, including both anthropogenic and biomass burning emissions, and their long-range transport in the FT. Because of the pronounced seasonal monsoon activity and the seasonal variation in regional wind field, export of the Asian Hg emissions to Taiwan occurs mainly during fall, winter, and spring.     

地表水中溶解氧监测及变化规律

采用碘-淀粉光度法对连云港大浦河水域中溶解氧进行测定,并对其日变化、季节变化和垂直分布及变化规律进行了分析。     

Carbofuran degradation in soil profiles

Abstract

Two soils, Puyallup fine sandy loam from Puyallup, WA, and Ellzey fine sand from Hastings, FL, each with a prior history of carbofiiran exposure but with different pedological and climatological characteristics, were found to exhibit enhanced degradation toward carbofiiran in surface and subsurface soil layers. The treated Puyallup and Ellzey soils exhibited higher mineralization rates for both the carbonyl and the aromatic ring of carbofiiran when compared to untreated soils. Disappearance rates of [¹⁴C‐URL (uniformly ring labeled)] carbofiiran in the treated Ellzey soil was faster than in untreated soil, and also faster in surface soil than in subsurface soil. Initial degradation patterns in the treated Ellzey soil were also different from those in the untreated soil. The treated Ellzey soil degraded carbofuran mainly through biological hydrolysis, while untreated soil degraded carbofuran through both oxidative and hydrolytic processes.     

Comparison of surface emissions and subsurface distribution of cis- and trans-1,3-dichloropropne and chloropicrin in sandy field beds covered with four different plastic films

The purpose of this study was to conduct a field study at a Florida field site on surface emissions and subsurface distribution of cis-and trans-1,3-dichloropropene (1,3-D) and chloropicrin (CP) in raised beds injected with Telone C35 with four replications. A total of 16 beds were applied with Telone C35 by chisel injection and covered with four different plastic films, 4 beds for each film. Each bed was installed with five 20-cm long soil pore air probes and a surface air collection pan at arbitrarily locations along the length of each bed for sampling soil pore air and surface air, respectively, for analysis of the three biologically active compounds, cis- and trans-1,3-D and CP. We found that average concentrations of the three compounds at 20-cm depth among the beds covered with four different plastic films generally were not statistically different. Among the four beds covered with the same plastic film, average concentrations of the three compounds were statistically different only in the four metallic PE covered beds at 5 and 24 hours after injection. Volatilization rates of the three compounds among the beds covered with four different plastic films, with the exception of CP at 48 hours after injection, were not statistically different. It appeared that initial upward diffusion and volatilization flux were influenced by solar radiation. Initial subsurface concentrations of the three compounds and volatilization flux, especially cis-1,3-D, were greater in the beds on the east side of the field than that in the beds on the west side of the field. Whether or not difference in initial subsurface concentrations of the compounds between east side beds and west side beds may influence fumigant efficacy remains to be determined.     

Speciation of Cu and Zn during composting of pig manure amended with rock phosphate

Pig manure usually contains a large amount of metals, especially Cu and Zn, which may limit its land application. Rock phosphate has been shown to be effective for immobilizing toxic metals in toxic metals contaminated soils. The aim of this study work was to investigate the effect of rock phosphate on the speciation of Cu and Zn during co-composting of pig manure with rice straw. The results showed that composting process and rock phosphate addition significantly affected the changes of metal species. During co-composting, the exchangeable and reducible fractions of Cu were transformed to organic and residue fractions, thus the bioavailable Cu fractions were decreased. The rock phosphate addition enhanced the metal transformation depending on the level of rock phosphate amendment. Zinc was found in the exchangeable and reducible fractions in the compost. The bioavailable Zn fraction changed a little during the composting process. The composting process converted the exchangeable Zn fraction into reducible fraction. Addition of an appropriate amount (5.0%) of rock phosphate could advance the conversion. Rock phosphate could reduce metal availability through adsorption and complexation of the metal ions on inorganic components. The increase in pH and organic matter degradation could be responsible for the reduction in exchangeable and bioavailable Cu fractions and exchangeable Zn fraction in rock phosphate amended compost.     

北京城市雨水、树冠水和地表径流中有机氯农药的污染特征

对北京降雨过程中雨水、树冠水、地表径流等介质中有机氯农药(OCPs)的污染特征进行了研究,研究的污染物包括六氯苯(HCB)、六六六(HCH)和滴滴涕(DDT)。结果显示,在雨水、树冠水和地表径流中,HCH含量最高(几何平均浓度分别为11.1、21.6和25.1 ng/L),其次是HCB(几何平均浓度分别为3.71、3.54和5.91 ng/L)和DDT(几何平均浓度分别为2.64、4.66和10.6 ng/L)。对地表径流样品中所测的OCPs组分浓度与径流水质参数和气象参数的相关分析显示,所测各OCPs组分浓度与pH呈显著负相关,与径流的溶解性有机碳含量呈显著正相关,降雨量和雨前晴天数对不同组分OCPs的影响并不完全相同。平均贡献率的计算表明,雨水是城市地表径流中OCPs的一个重要来源,树冠水的贡献也不可忽视。     

本质阻燃PA纤维及纤维（织物）阻燃技术最近进展

本文首先概论了纤维（织物）阻燃技术,其次重点讨论了两种含磷本质阻燃PA纤维,一种是由含磷羟基羧酸或含磷二元羧酸与己二胺及己二酸共缩聚而后纺丝制得．另一种是用螺环磷酰氯与PA66及PA6纤维反应制得,后者具膨胀性。最后是综述了纤维（织物）阻燃技术的最新进展,包括新型表面改性技术及纳米技术等。     

Microbial degradation of propoxur in turfgrass soil.

This study was conducted to determine the degradation rates in turfgrass soil over a 12-month period after a single field application of propoxur and to isolate microorganisms from the soil capable of degrading the insecticide. Soil samples were collected from a turfgrass experimental site near Fort Lauderdale, FL one week before the field application of propoxur, and over a 12-month period after the field application. Mineralization rates in surface (0-15 cm depth) and subsurface (15-30 cm depth) soil samples collected before the field application were low. Mineralization in surface and subsurface samples collected 1, 6 and 8 months after the field application was much higher than for corresponding samples collected before the field application. Mineralization in the subsurface samples collected 12 months after the field application had reverted back to the similar rate for the corresponding sample collected before field application. Half-life values (t1/2) for propoxur showed similar trends to the results of mineralization. After a single application of propoxur, degradation in turfgrass soil was enhanced. Such enhancement lasted less than 12 months for the subsurface, but more than 12 months for the surface. A strain of Arthrobacter sp. capable of degrading propoxur was isolated from the soil.     

东西方文化分别对汉、英语语言的影响

文化是一个社会全部物质文明和精神文明的总和，是具有较强民族性的东西。一方面，语言既是文化的一部分，又是文化的载体；另一方面，文化对语言的发展又起着重要的制约作用。东西方文化在哲学观念、历史背景、生活环境、生活习俗等方面的不同分别影响着汉语和英语的形成、发展及应用，并使得它们在长期的使用中逐渐形成自己的特色。