昆明市东川区农业旱灾风险区识别研究

昆明市东川区是云南省农业旱灾危害较为严重的区域之一。利用2000-2007年东川区各乡镇历史灾情等数据资料,应用风险分析理论、效用理论、因子-成份分析方法等理论方法,在分别研究致灾风险度、承灾体易损性及地域人群对农业旱灾心理反响等基础上,构建了东川区农业旱灾风险评价模型。初步揭示出东川区农业旱灾风险度呈现出自南向北、自西向东逐渐增强的空间态势;识别出极高风险区、高风险区、中风险区和低风险区等4个农业旱灾风险区;发现东川区各地农业旱灾综合风险度、致灾风险度、承灾体易损度以及地域人群对旱灾的心理响应值等指数之间普遍存在着明显的正相关。     

Research on Methods of Ecological Security Assessment of the Middle and Lower Reaches of Liaohe River Based on GIS

Abstract

Ecological security assessment and early warning research possess the attributes of spatiality, non-linearity and randomicity, so we must process much spatial information. Spatial analysis and data management are the advantages of GIS, which can define distribution trend and spatial relations of environmental factors, and show ecological security pattern graphically. Spatial differences of ecological security assessment based on GIS are discussed in this paper, of which the middle and lower reaches of the Liaohe River is taken as a study case. First, to work out pressure-state-response (P-S-R) assessment indicators system, and investigate in person and gather information; second, to digitize the watershed; third, to quantize and calculate by the fuzzy method; last, to construct GIS grid database, and expound spatial differences of ecological security by GIS interpolation and assembly analysis.     

Interval association of remote sensing ecological index in China based on concept lattice

Environmental Science and Pollution Research - The correlation coefficient can calculate paired correlations among different ecological indicators as a whole, but it cannot calculate the specific...     

Flow cytometric assessment of the effects of chlorine,chloramine, and UV on bacteria by using nucleic acid stains and 5-cyano-2,3-ditolyltetrazolium chloride

Flow cytometry (FCM) has been widely used in multi-parametric assessment of cells in various research fields, especially in environmental sciences. This study detected the metabolic activity of Escherichia coli and Staphylococcus aureus by using an FCM method based on 5-cyano-2,3-ditolyltetrazolium chloride (CTC); the accuracy of this method was enhanced by adding SYTO 9 and 10%R2A broth. The disinfection effects of chlorine, chloramine, and UV were subsequently evaluated by FCM methods. Chlorine demonstrated stronger and faster destructive effects on cytomembrane than chloramine, and nucleic acids decomposed afterwards. The metabolic activity of the bacteria persisted after the cytomembranewas damaged as detected using CTC. Low-pressure (LP) UV or medium-pressure (MP) UV treatments exerted no significant effects on membrane permeability. The metabolic activity of the bacteria decreased with increasing UV dosage, and MP-UV was a stronger inhibitor of metabolic activity than LP-UV. Furthermore, the membrane of Gram-positive S. aureus was more resistant to chlorine/chloramine than that of Gram-negative E. coli. In addition, S. aureus showed higher resistance to UV irradiation than E. coli.

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Experimental research on displacing coal bed methane with supercritical CO2

The high-gas and low-permeability are the common problems of China coal mine, which restrain the mining of coal-seam gas resources safely and efficiently. Hence, to solve the problem of low permeability of coal seam, an experimental system was set up and experimental research was conducted to investigate the effect of the displacement of methane by injecting supercritical CO₂ into coal samples. The experimental results indicated that, the extraction effect of supercritical CO₂ changes the coal’s porosity, and broadens the seepage channel for methane. Thus, the methane could be desorbed effectively from the coal matrix, and flow through more cracks at higher speed.     

层次分析法在生活垃圾处置方案优选中的应用

对于如城市生活垃圾处置技术方案优选这类多目标、多方案决策问题,特别是在决策缺乏充分的信息支持前提时,AHP分析法的若干特点,显示其作为一种系统工程的理论工具具有一定的客观性、准确性和有效性,是一种简易而且可行的理论方法和手段。通过以某经济开发区生活垃圾处置方案的优选为例进行了探讨。     

生物铁-复合菌处理牛仔布印染废水

针对生化池1种或几种菌种启动慢、抗冲击负荷能力差和污泥处理效率低的问题,提出用生物铁法结合生物强化技术、投加复合优势菌的处理方法,应用于牛仔布染整废水处理,COD去除率、脱色率分别达到96%、99%,产泥量可减少80%以上,每吨水节约成本60%,吨水处理费用1.6~1.9元,无二次污染,可推广应用。     

稻草及稻草循环利用后的废弃物还田效益研究

本文针对中南丘陵水稻产区农田稻草经过稻草直接还田(鲜稻草)、稻草过腹还田(新鲜牛粪)、稻草栽培食用菌后还田(新鲜菌渣)、稻草产沼气后还田(新鲜沼渣)等几种主要的循环利用方式后的废弃物还田,结合化肥配施对水稻产量及土壤基本理化性状影响的研究,以期寻找一种既能达到有机废弃物的循环再利用,改善生态环境,又能够改良土壤理化性状并达到水稻丰产的目的.试验结果显示:相对于常规的化肥施用,几种有机废弃物还田加化肥配施均有利于土壤有机质(1.71%～6.98%),碱解氮(4.30%～15.05%),有效磷(11.22%～21.43%)等养分的提高;增加了土壤团聚体R0.25(干筛6.60%～8.74%,湿筛2.64%～45.06%)、平均质量直径(干筛26.91%～52.69%,湿筛4.55%～32.73%)及几何平均直径(干筛17.88%～35.56%,湿筛3.08%～6.15%);在产量方面,虽较常规施肥有所下降,但经济效益却是增加的,较常规施肥增收75.6元·hm2到1 057.0元·hm2,其中沼渣还田的增益率最高达8.59%.     

Mechanism of limestone corrosion by Gongronella butleri NL-15北大核心CSCD

The key to soil spray-sowing technology is the use of the highly-effective rock-corroding strains, and the mechanism of rock corrosion will provide theoretical references to screen the strains. To investigate the corrosion mechanism of limestone by microorganisms, the dominant and highly-effective limestone-corroding strain Gongronella butleri NL-15 was isolated and purified from the microorganisms on the rock surface. The concentration of calcium (Ca), magnesium (Mg), potassium, and phosphorus was analyzed by ICP. The pH of the fermentation broth of the strain at different intervals was measured using a precise pH instrument. The content of organic acids (critic, succinic, lactic, fumaric, acetic, and propanoic acids) and the scanning electron microscope feature of rock particles in the fermentation broth at different intervals were also analyzed by HPLC. The results showed that the concentration of Ca2+ and Mg2+ in the fermentation broth correlated negatively with the pH value (P < 0.01). The pH of control was 6.87, and that of the fermentation broth after 15 days dropped to 5.12. The concentration of Ca and Mg was 38.96 and 10.85 mg/L respectively, whereas that of the fermentation broth after 15 days increased to 367.56 and 76.16 mg/L respectively. The content of the total organic acids and lactic acid increased with increase in fermentation time. The content of the total organic acids on days 2, 5, 9, and 15 in the fermentation broth was 3.43, 5.40, 6.63, and 7.26 mg/mL, respectively, and the content of lactic acid was 1.79, 2.85, 5.16, and 5.04 mg/mL, respectively. The mycelium of the G. butleri NL-15 adhered to the surface of rock particles and threaded into unconsolidated rocks. Thus, the organic acids, especially lactic acid produced by the fungi G. butleri NL-15, caused unconsolidation of rock and improved the growth of fungi mycelium into the unconsolidated rock. This was the primary cause for limestone corrosion, and the release of Ca and Mg from the rock and its disintegration. © 2018 Science Press. All rights reserved.     

Pyrolysis behaviors of oil sludge based on TG/FTIR and PY-GC/MS

Pyrolysis is an alternative technology for oil sludge treatment. Thermogravimetric Analysis-Fourier Transform Infrared Spectroscopy and Pyrolysis-Gas Chromatography/Mass Spectrometry were employed to investigate the pyrolysis process and products of oil sludge. The pyrolysis process was divided into five stages: drying and gas desorption, oil volatilization, main pyrolysis, semi-coke charring, and mineral decomposition. The main reaction temperatures ranged from 497.6 K to 753.2 K. The products were mainly composed of pairs of alkane and alkene (carbon number ranges from 1 to 27). The mechanisms consisted of random chain scission followed by end chain scission at high temperatures with volatilization occurring during the whole process. This study is useful not only for the proper design of a pyrolysis system, but also for improving the utilization of liquid oil products.