Fabrication of supported acid catalytic composite fibers by a simple and low-cost method and their application on the synthesis of liquid biofuel 5-ethoxymethylfurfural

In this paper, sulfonic groups functionalized annealed bio-based carbon microspheres loaded polytetrafluoroethylene (A-BCMSs-SO3H@PTFE) fibers with high activity, high stability, and easy regeneration were successfully fabricated by a simple method using low-cost raw materials. The characterization results showed that the annealed biomass carbon microspheres derived from waste Camellia oleifera shells were evenly distributed on the polytetrafluoroethylene fibers and the sulfonic groups can be successfully loaded on the surface of annealed biomass carbon microspheres by room temperature sulfonation. Subsequently, the as-prepared A-BCMSs-SO3H@PTFE fibers were applied to the acid-catalyzed synthesis of liquid biofuel 5-ethoxymethylfurfural. The catalytic experiment results indicated that the annealing temperature and time during catalyst preparation have a significant effect on the activity and selectivity of A-BCMSs-SO3H@PTFE fibers. The results of catalytic reaction kinetics showed that the yield of 5-ethoxymethylfurfural can reach more than 60％after 72 h of acid-catalyzed reaction. The stability test showed that the as-prepared A-BCMSs-SO3H@PTFE fibers still maintained a stable acid catalytic activity after four recycles.     

几种化学物质对番茄幼苗耐低温弱光能力的影响

以4叶期番茄为试材,对叶面喷施不同浓度的CaCl_2、甜菜碱和ALA(5-氨基乙酰丙酸),用人工霜箱进行低温弱光胁迫处理,通过观测、计算冷害指数,测定净光合速率、气孔导度等指标,结果表明,CaCl_2、甜菜碱和ALA等几种化学物质能够提高番茄幼苗的耐低温弱光能力,其中CaCl_2的适宜浓度为0．4～1 mmol/L,甜菜碱的适宜浓度为2．5 mmol/L,ALA的适宜浓度为30mg/L。     

BOD_5快速测定法

寻求BOD生化过程动力学方程,依据广泛性的、相关性很好的多组实验数据(X,Y),建立回归方程用于计算BOD5。本法仍以国标GB/T7488-1987为依据,仅以较少培养时间的BOD值推算得BOD5值。BOD5的计算值与其实测值间的相对误差<5%。     

H-ZSM-5分子筛吸附-氧化NOx的研究

针对湿法脱硫后船舶尾气特点,考察了3种不同硅铝比的H-ZSM-5分子筛对船舶脱硫后尾气中NO_x的吸附-氧化过程及其影响因素,并采用TPD研究了干气下不同硅铝比的分子筛吸附饱和后的脱附情况.结果表明:干气条件下,硅铝比低的分子筛具有较好的吸附效果;硅铝比高的分子筛具有较好的抗水性,但从干气到饱和湿度下,硅铝比为300的分子筛的NO氧化率从36%降至18%;干气下,低温有利于分子筛的吸附-氧化;分子筛用量增加能够增加其对NO_x的吸附效果和氧化效果.TPD结果表明:NO和NO2共吸附在分子筛上,3种分子筛中脱附出的NO_x中NO2均占脱附总量的80%以上,但在600℃时,NO_x在分子筛上脱附仍不完全.     

安全文化宣教机理研究

为明晰安全文化宣教机理,从而提升安全文化宣教效果,基于宣传与教育的定义,提出安全文化宣教的定义,并分析其内涵。基于此,构建并解析安全文化宣教的“5-13”模式和受众处理安全文化符号信息的过程模型。在此基础上,提炼驱动受众心理的猎奇心理、重情心理与审美需要等16条理论依据和与之对应的一些具体方法。结果表明,设计、筹划和实施安全文化宣教活动和行为应以安全文化宣教的“5-13”模式和受众处理安全文化符号信息的过程模型为依据,有效驱动受众心理是提高安全文化宣教效果的关键。     

桂林“5.9”山体滑坡的暴雨成因分析

对造成2011年5月9日广西桂林咸水乡山体滑坡的暴雨成因进行了分析,结果表明,滑坡是由于暴雨因素诱发的地质灾害,短时强暴雨是造成山体滑坡的直接原因.大量的水汽传送到滑坡点,同时低层辐合抬升,因而滑坡点是大暴雨的发生地.滑坡发生滞后强降雨结束2.5h.滑坡点位于暴雨中心带,暴雨区位于高空急流的右侧,200h Pa为强烈辐散区,高空辐散带的走向与山脉走向一致.西南低空急流与地形的相互作用是暴雨形成的直接原因,雷达回波显示在“湘桂走廊”存在强风速的出流与横向风速梯度,对应反射率有弓状回波,同时具有前侧V形人流缺口和后侧V形下沉缺口等对流单体特征.     

Dispersive liquid–liquid microextraction of cadmium(II) for preconcentration prior to flame atomic absorption spectrometric detection in water

A dispersive liquid–liquid microextraction procedure for cadmium(II) as its 2-(5-bromo-2-pyridylazo)-5-diethylamino-phenol chelate is presented. Carbon tetrachloride and methanol were used as extraction and dispersive solvents, respectively. After phase separation, the preconcentrated-separated cadmium(II) is determined by flame atomic absorption spectrometry with a microinjection technique. The factors which affected the extraction efficiency, i.e. the pH of the sample solution and the volumes of reagent and sample were investigated. The effects of some alkali, alkali earth, and transition metal ions, and of some anions on the recovery of cadmium were also studied. A preconcentration factor of 250 was obtained for a sample volume of 50?mL under optimum conditions. The method was validated by analysis of certified reference materials and applied to some water samples from Turkey.     

Hepatoprotective activity of 1-(4-(Dimethylamino)Benzylidene)-5-(2-Oxoindolin-3-ylidene) Thiocarbohydrazone in rats

The aim of the present study was to evaluate the hepatoprotective activity of 1-(4-(dimethylamino)benzylidene)-5-(2-oxoindolin-3-ylidene) thiocarbohydrazone, a novel isatin derivative against carbon tetrachloride (CCl₄)-induced hepatotoxicity in rats. Hepatic damage was induced by administration of CCl₄ (1 ml/kg, b.w., p.o.) in combination with liquid paraffin (1:1) as a single dose. The hepatotoxic rats were treated with test compound at doses of 50 or 100 mg/kg for three days and liver damage biomarkers, including activities of serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), serum alkaline phosphatase (ALP), and levels of total serum bilirubin (TB) measured in blood samples. Results demonstrated that treatment with test compound at doses of 50 or 100 mg/kg to hepatotoxic rats produced a significant dose-dependent reduction of elevated SGOT, SGPT, ALP activities and TB levels indicating a hepatoprotective effect that was confirmed by histopathological examination of liver tissues. The study results confirmed the hepatoprotective activity of 1-(4-(dimethylamino)benzylidene)-5-(2-oxoindolin-3-ylidene) thiocarbohydrazone in rats.     

Methodological approach for metal pollution evaluation in sediments collected from the Taranto Gulf

The concentrations of Hg, Cd, Pb, Cu, Ni, V, and Sn were determined in marine sediments collected from Taranto Gulf (Ionian Sea, Southern Italy). The aim of this article is to study the methodological approach in order to evaluate total metal levels determined in marine sediments of a contaminated area (Taranto Gulf, Southern Italy), to identify contaminated areas and to predict adverse biological effects based on Sediment Quality Guidelines (SQGs). The results are discussed in relation to geological characteristics of sediments in order to define background levels and anthropogenic input. Experimental results were elaborated by multivariate statistical techniques and Geographical Information System (GIS) software. The geoaccumulation index I _geo and two sets of SQGs (in particular (a) the threshold effect level (TEL), the probable effect level (PEL) and (b) the effect range-low (ERL) and the effect range median (ERM)) have been used for environmental evaluation of metal concentrations. Results show that in Taranto coastal area, Mar Piccolo basin represents the most contaminated area. A comparison with results from other Mediterranean areas demonstrates that for some metals (such as Cd, Pb, and Hg) Taranto seas represent one of the most polluted areas in the Mediterranean Sea. A comparison of metal levels with SQGs also suggests an ecotoxicological risk for benthic organisms mainly in the first inlet of Mar Piccolo.     

长江三峡水库水污染控制若干问题

论述了三峡水库几个重要水环境问题,对近年来三峡水库水污染控制科学研究工作进行回顾,评述了一些重要研究成果,就三峡水库水质模拟、水体富营养化、水库泥沙截留淤积和重金属污染等问题进行了深入探讨。基于国际水协会最新推出的河流水质模型,提出了三峡水库水环境模拟研究的观点和方法;基于湖泊（水库）生态动力学模型原理,在对水体中磷元素预测的基础上,从营养盐含量、水深、流速、温度因素等与富营养化非线性映射关系出发,初步建立三峡水库水体富营养化人工神经网络模型,对三峡水库水体富营养化潜势进行研究,分析讨论了一些初步结果;论述了水库泥沙截留淤积及其与水体中污染物,特别是重金属污染的相互作用;建议三峡水库近期内应予以重视的一些重要水环境科学问题。