Agricultural Structure in Western China by Comparing with before and after CFFG Based on Shift-share Method

Based on shift-share method, this article employs re- gional share, structural shift and competitive shift to analyze the structural benefit and competitive position of agricultural structure in western China by comparing with agriculture, foresting, stockbreeding and fishing before and after Conversion of Farmland to Forest and Grassland （CFFG）. Then authors draw following conclusion： while CFFG program has been put in practice, the agricultural structure in western China has some typical characteristics, such as growth faster, structural predominance obvious and more competitive. But the contributiveness from the competition is not too much yet, and the structural benefit of forest estate and stockbreeding are restrained.     

混凝-超滤短流程工艺处理北方水库原水简

采用混凝-超滤膜短流程工艺对大伙房水库原水进行处理，考察其除污染性能和膜污染情况，并对该短流程工艺参数进行优化。结果表明，当利用超滤膜直接过滤原水时，膜污染较重，并且对污染物质的去除率较低；而采用混凝-超滤短流程工艺时，膜污染得到一定程度上的缓解；当絮凝剂投加量为7 mg/L、膜清洗周期为30 min时，对浊度、COD_Mn和UV₂₅₄的去除率分别为95.61%、40.42%和37.12%，出水水质能够满足生活饮用水卫生标准。     

废弃印刷线路板碘化法浸金研究

针对碘化法从废弃印刷线路板中提取金的工艺设计，分别考察了碘的质量分数、n(I₂)/n(I^-)比值、固液比、双氧水的质量分数、pH值、浸出时间和浸出温度对金浸出率的影响。结合正交设计优化实验方法,提出了从废弃印刷线路板中碘化法浸取金的最佳工艺条件：碘的质量分数为1.1％，n(I₂)∶n(I^-)=1∶10，双氧水的质量分数为1.5％，浸出时间4 h，固液比为1∶10，浸出温度为常温（25℃），溶液pH值为中性，此时金浸出率可达97.5％。     

环丁砜-哌嗪溶液吸收烟道气中二氧化碳

采用搅拌实验装置,研究环丁砜溶液及不同配比的环丁砜-PZ复合溶液对烟道气中二氧化碳的吸收和解吸性能,揭示了吸收容量与酸碱度、时间之间的内在联系,并对CO2初始逸出温度、试液再生温度、试液再生率、再生pH下降率进行了细致记录分析。实验结果表明,环丁砜-PZ复合溶液配比为0.4∶0.6时:吸收效果最佳,吸收量约为0.126 mol;再生温度最高,为105℃;再生率最高,为90.34%。同时与相同配比的MEA、DEA相比具有较大再生优势。实验结果还表明,环丁砜-PZ复合体系之间存在负交互作用。     

Quantitative and qualitative characteristics of dissolved organic matter from eight dominant aquatic macrophytes in Lake Dianchi, China

The aim of this research was to determine and compare the quantitative and qualitative characteristics of dissolved organic matters (DOM) from eight aquatic macrophytes in a eutrophic lake. C, H, N, and P in ground dry leaves and C, N, and P in DOM of the species were determined, and C/N, C/P, C/H, DOC/C, TDN/N, TDP/P, DOC/TDN, and DOC/TDP were calculated. Chemical structures of the DOM were characterized by the use of multiple techniques including UV-visible, FT-IR, and ¹³C CP/MAS spectra. The results showed subtle differences in quantity and quality of DOM among species and life-forms. Except oriental pepper which had a C/H of 0.7, C/H of all the other species was 0.6. C/N and C/P of ground leaves was 10.5–17.3 and 79.4–225.3, respectively, which were greater in floating and submerged species than in the others. Parrot feather also had a small C/P (102.8). DOC/C, TDN/N, and TDP/P were 7.6–16.8, 5.5–22.6, and 22.9–45.6 %, respectively. Except C/N in emergent and riparian species, C/N in the other species and C/P in all the species were lower in their DOM than in the ground leaves. DOM of the macrophytes had a SUVA₂₅₄ value of 0.83–1.80. The FT-IR and ¹³C NMR spectra indicated that the DOM mainly contained polysaccharides and/or amino acids/proteins. Percent of carbohydrates in the DOM was 37.3–66.5 % and was highest in parrot feather (66.5 %) and crofton weed (61.5 %). DOM of water hyacinth, water lettuce, and sago pondweed may have the greatest content of proteins. Aromaticity of the DOM was from 6.9 % in water lettuce to 17.8 % in oriental pepper. DOM of the macrophytes was also different in polarity and percent of Ar–OH. Distinguished characteristics in quantity and quality of the macrophyte-derived DOM may induce unique environmental consequences in the lake systems.     

Ambient TSP concentration and dustfall in major cities of China: Spatial distribution and temporal variability

Based on environmental monitoring data in 93 major cities and meteorological records at 398 weather stations in China from 1981 to 2007, total suspended particle (TSP) concentration, the intensity of dustfall, and sand and dust storm frequency (F_d) were analysed. During the past 27 years, the annual average TSP concentration (C_TSP) in 93 cities was 402 μg m^?3. Annual average C_TSP decreased from the north to the south and from inland to the coast areas with a peak value of 628.8 μg m^?3 in Lanzhou. In the 1980s, 1990s and 2000s, annual average C_TSP was 628.7, 319.2, and 250.1 μg m^?3, respectively. Annual average intensity of dustfall (I_d) was 240.5 t km^?2 a^?1, decreased from northern to southern China and from inland to the coast areas with the maximum value of 717.2 t km^?2 a^?1 in Baotou. In the 1980s, 1990s and 2000s, annual average I_d was 334.8, 220.9, 146 t km^?2 a^?1 respectively. Annual average I_d in the Loess Plateau region was commonly higher than 200 t km^?2 a^?1. The annual average F_d decreased from arid regions in northwestern China to humid areas in southeastern China with two sand and sand storm centers existing in Xinjiang Taklamakan Desert and western Inner Mongolia. The annual average F_d in the 1980s, 1990s, 2000s was 16, 8, 6 days respectively, decreased steadily from 18 days in 1981–5 days in 2007. Annual average I_d had a positive linear relation to annual average C_TSP (R² = 0.96). Annual average F_d had a positive relation with annual average C_TSP (R² = 0.97) as well as annual average I_d (R² = 0.94). TSP was the chief pollutant influencing Air Pollution Index (API) in northern China in spring and winter seasons. Sand and dust storm might be a major factor affecting the temporal variability and spatial distribution of TSP and dustfall in China.     

利用CRT屏玻璃制备板状泡沫玻璃

以废旧阴极射线管(CRT屏)为主要原料,混合碳粉作为发泡剂,硼砂为助熔剂、稳泡剂,利用烧结法制备出的板状泡沫玻璃是一种高性能无机建筑保温材料。利用TG-DSC-MS研究分析了CRT屏玻璃的热性能与发泡剂协同作用的关系。配合料被预先压制成板块状,然后在发泡温度下进行烧成。研究了发泡剂碳粉的含量、发泡温度和发泡时间与其结构、性能的关系。研究分析表明,以废CRT屏玻璃为主要原料、碳粉为发泡剂,将混合料压制成块,烧制出板状泡沫玻璃。其较佳的发泡温度为850℃、碳粉的最佳用量范围为0.3%～0.5%,较好的发泡时间为30 min。烧制的板状泡沫玻璃的密度为0.292 g/cm3。在相同的制备条件下,随着发泡温度的升高,气泡孔径也呈现增大趋势,孔壁也逐渐变薄。随着发泡时间逐渐增加,气孔的直径迅速增大,并有形成连通孔。     

Synthesis of hybrid carbon nanotubes using Brassica juncea L. application to photodegradation of bisphenol A

Hyperaccumulators contain tubular cellulose and heavy metals, which can be used as the sources of carbon and metals to synthesize nanomaterials. In this paper, carbon nanotubes (CNTs), Cu_0.05Zn_0.95O nanoparticles, and CNTs/Cu_0.05Zn_0.95O nanocomposites were synthesized using Brassica juncea L. plants, and the ultraviolet (UV)-light-driven photocatalytic degradations of bisphenol A (BPA) using them as photocatalysts were studied. It was found that the outer diameter of CNTs was around 50 nm and there were a few defects in the crystal lattice. The synthesized Cu_0.05Zn_0.95O nanocomposites had a diameter of around 40 nm. Cu_0.05Zn_0.95O nanocomposites have grown on the surface of the CNTs and the outer diameter of them was around 100 nm. The synthesized hybrid carbon nanotubes using B. juncea could enhance the efficiency of photocatalytic degradation on BPA. The complete equilibration time of adsorption/desorption of BPA onto the surface of CNTs, Cu_0.05Zn_0.95O nanoparticles, and CNTs/Cu_0.05Zn_0.95O nanocomposites was within 30, 20, and 30 min, and approximately 14.9, 8.7, and 17.4 % BPA was adsorbed by them, respectively. The combination of UV light irradiation (90 min) with CNTs, Cu_0.05Zn_0.95O nanoparticles, and CNTs/Cu_0.05Zn_0.95O nanocomposites could lead to 48.3, 75.7, and 92.6 % decomposition yields of BPA, respectively. These findings constitute a new insight for synthesizing nanocatalyst by reusing hyperaccumulators.     

Chromium exhibits adverse effects at environmental relevant concentrations in chronic toxicity assay system of nematode Caenorhabditis elegans

Here we investigated whether the assay system (10-d) in Caenorhabditis elegans can be used to evaluate chronic toxicity of chromium (Cr(VI)) at environmental relevant concentrations ranging from 5.2 μg L⁻¹ to 260 μg L⁻¹. The results indicated that lethality, locomotion behavior as revealed by head thrash, body bend, and forward turn, metabolism as revealed by pumping rate and mean defecation cycle length, intestinal autofluorescence, and ROS production were severely altered in Cr chronically exposed nematodes at environmental relevant concentrations. The most surprising observations were that head thrash, body bend, intestinal autofluorescence, and ROS production in 13 μg L⁻¹ Cr exposed nematodes were significantly influenced. The observed adverse effects of Cr on survival, locomotion behavior, and metabolism were largely due to forming severe intestinal autofluorescence and ROS production. Therefore, our findings demonstrate the usefulness of chronic toxicity assay system in C. elegans in evaluating the chronic toxicity of toxicants at environmental relevant concentrations.     

Anaerobic biodegradation of cellulosic material: Batch experiments and modelling based on isotopic data and focusing on aceticlastic and non-aceticlastic methanogenesis

Utilizing stable carbon isotope data to account for aceticlastic and non-aceticlastic pathways of methane generation, a model was created to describe laboratory batch anaerobic decomposition of cellulosic materials (office paper and cardboard). The total organic and inorganic carbon concentrations, methane production volume, and methane and CO₂ partial pressure values were used for the model calibration and validation. According to the fluorescent in situ hybridization observations, three groups of methanogens including strictly hydrogenotrophic methanogens, strictly aceticlastic methanogens (Methanosaeta sp.) and Methanosarcina sp., consuming both acetate and H₂/H₂CO₃ as well as acetate-oxidizing syntrophs, were considered. It was shown that temporary inhibition of aceticlastic methanogens by non-ionized volatile fatty acids or acidic pH was responsible for two-step methane production from office paper at 35 °C where during the first and second steps methane was generated mostly from H₂/H₂CO₃ and acetate, respectively. Water saturated and unsaturated cases were tested. According to the model, at the intermediate moisture (150%), much lower methane production occurred because of full-time inhibition of aceticlastic methanogens. At the lowest moisture, methane production was very low because most likely hydrolysis was seriously inhibited. Simulations showed that during cardboard and office paper biodegradation at 55 °C, non-aceticlastic syntrophic oxidation by acetate-oxidizing syntrophs and hydrogenotrophic methanogens were the dominant methanogenic pathways.