Graphene Based Electrochemical Sensor for the Detection of Volatile Organic Compounds

Many household consumables contain volatile organic compounds(VOCs)as the active ingredient.Long term exposure to VOCs could cause various health problems,especially to the respiratory system.Graphene has attracted a lot of attention recently for its potential to be used as sensing material for VOCs.In this project we have constructed graphene/PVA composite based gas sensors for VOC detection.It was perceived that the polymer could introduce better selectivity to the sensor.Results suggest that the proposed sensor is highly sensitive to low molecular weight VOCs and that the manner in which the sensor respond to the vapour depends on the polarity or hydrophobicity of the vapour.     

Molecules to materials

Molecular materials represent an area of fruitful interaction between synthetic chemistry, solid state physics and materials science. This article discusses the development of magnetic materials based on metal complexes, organometallic compounds and organic radicals.     

镧系β-二酮配合物低加热温度固相反应合成

１ＩｎｔｒｏｄｕｃｔｉｏｎＳｉｎｃｅｔｈｅ１９５０ｓ,ｌａｎｔｈａｎｉｄｅβｄｉｋｅｔｏｎａｔｅｓｈａｖｅｂｅｅｎｅｘｔｅｎｓｉｖｅｌｙｓｔｕｄｉｅｄａｎｄｗｉｄｅｌｙａｐｐｌｉｅｄ［１－３］．Ｂｅｃａｕｓｅｏｆｅｘｃｅｌｅｎｔｌａｓｅｒｐｒｏｐｅ...     

饱和蒸汽压测量及汽化潜热推算系统的开发

根据静态法测量液体饱和蒸汽压的实验原理,设计、建立了饱和蒸汽压测量实验系统,同时,开发了推算水溶液汽化潜热的计算机软件。以去离子水为工质对实验系统的准确性、可靠性、稳定性以及推算软件的适用性进行了验证。这套实验测量及推算系统已经应用于实际当中。     

城市生活垃圾好氧堆肥性质变化的研究

以生活垃圾为堆肥原料进行好氧堆肥,对其堆肥过程中C／N、温度、有机质等因素的变化规律进行研究。堆肥的温度明显地呈现出三个阶段,且温度在55℃以上的时间为8天;pH值总趋势为下降-上升-下降;有机质总趋势是逐渐减少,最大降幅为23％;全氮含量呈逐渐下降的趋势,堆肥后期逐渐稳定;氨氮含量呈下降的趋势,硝态氮含量呈上升的趋势;C／N比下降趋势不显著。     

“液体饱和蒸气压的测定”实验的改进

本文对“液体饱和蒸气压的测定”实验的改进进行了全面的研究。研究结果发现通过对该实验各部分的装置进行改进后,不但使整个实验过程的操作变得简单,易于学生掌握,而且还提高了实验结果的准确度,从而提高实验结果效果。     

《有机化学》教学规律初探

有机化学的学习要遵循其内在的规律性,而有机化合物的结构、性质及其制备方法是学习的重点.结合生产实践,设计有机化合物的合成工艺路线, 可巩固所学基础理论知识,并通过实验操作以培养学生较强的动手能力和分析问题、解决问题的能力.     

用简易动态法测定液体饱和蒸气压

介绍了简易动态法替代平衡法测定液体饱和蒸气压的实验装置,它具有操作简便,现象明显易观察等特点,数据重现性好。可大大缩短实验时间,提高实验效率。     

Synthesis of lanthanide β-diketonates by solid state reaction at low heating temperature

Solid state reactions between β-diketones (HPMBP, HDBM) and LnAc₃ · xH₂O(La,Nd:x=3/2; Tb:x=4) have been investigated at low heating temperature. Pure compounds of Ln(PMBP)₃ and Ln(DBM)₃ are obtained by solid state reaction, and characterized by elemental analysis, infrared radiation (IR), X-ray diffraction (XRD) and photoacoustic spectra. The solid state reaction properties of β-diketones and their influences on the structures of products are discussed. Project supported by the National Natural Science Foundation of China (29475209)     

纯液体饱和蒸气压测量的实验方法

运用静态升温法与静态降温法平行测定了纯液体(水)的饱和蒸气压,详细描述及讨论了两种方法的特性与异同,获得的实验结果令人满意,均与文献值吻合。     

Effects of polyurethane matrices on fungal tannase and gallic acid production under solid state culture

The influence of the physical structure of polyurethane matrix as a support in a solid state culture in tannase production and gallic acid accumulation by Aspergillus niger Aa-20 was evaluated. Three different polyurethane matrices were used as the support: continuous, semi-discontinuous and discontinuous. The highest tannase production at 2479.59 U/L during the first 12 h of culture was obtained using the discontinuous matrix. The gallic acid was accumulated at 7.64 g/L at the discontinuous matrix. The results show that the discontinuous matrix of polyurethane is better for tannase production and gallic acid accumulation in a solid state culture bioprocess than the continuous and semi-discontinuous matrices. Project supported by the Agricultural, Livestock and Fishing Department (SAGARPA, No. 12385) and the National Forest Commission (CONAFOR, No. 2004-C01-13), and the Council of Science and Technology, Mexico     

室温固相反应在大学化学中的应用

文章讨论了室温固相反应的特点和表征方法，介绍了室温固相反应在大学无机化学和有机化学实验中的某些应用。     

海洋微藻对海水中有机物的净化作用研究

主要探讨了微藻(塔胞藻)对海水中有机物的净化作用．在其培养液中加入有机物(苯、苯酚和二甲苯),塔胞藻经过一定时间生长繁殖,观察培养液内有机物的含量．结果发现液体内塔胞藻细胞浓度达到104个／mL时,对有机物的净化作用最明显,同时还发现微藻对各种有机物吸附效率各不相同．     

两种光色性化合物的固相合成

通过室温固相反应制备了双硫腙金属配合物(锌、汞)。介绍了合成和光色性的教室演示方法;讨论了该类化合物的光色性机理。     

远红外丙纶针织面料的汽态湿舒适性能

本文对远红外丙纶针织面料的汽态湿舒适性能进行研究,采用国内最新研制的“织物汽相缓冲作用仪”进行试验测试,远红外丙纶针织面料在此仪器上的测试是国内首次进行的,对远红外丙纶针织面料的推广应用及深入研究具有实际参考价值．     

Science Letters:Effects of polyurethane matrices on fungal tannase and gallic acid production under solid state culture

The influence of the physical structure of polyurethane matrix as a support in a solid state culture in tannase production and gallic acid accumulation by Aspergillus niger Aa-20 was evaluated. Three different polyurethane matrices were used as the support: continuous, semi-discontinuous and discontinuous. The highest tannase production at 2479.59 U/L during the first 12 h of culture was obtained using the discontinuous matrix. The gallic acid was accumulated at 7.64 g/L at the discontinuous matrix. The results show that the discontinuous matrix of polyurethane is better for tannase production and gallic acid accumulation in a solid state culture bioprocess than the continuous and semi-discontinuous matrices.     

理想双液系T-X图的计算

导出了理想双液系T-X图液相线和气相线的计算公式,并以苯-甲苯双液系为例进行实际计算,结果令人满意.     

Steroids: A timeless fascination

Steroids are solid organic compounds derived from all life forms, including microorganisms, plants and animals. They obtain their generic name ‘steroids’ from Greek: stereos = solid. Steroids encompass a wide variety of compounds of vital importance to life such as sterols, bile acids, sex hormones, anti-inflammatory corticoid hormones, etc. This article highlights some of the important aspects of cholesterol, the principal sterol of higher animals.     

Catalytic ozonation-biological coupled processes for the treatment of industrial wastewater containing refractory chlorinated nitroaromatic compounds

A treatability study of industrial wastewater containing chlorinated nitroaromatic compounds (CNACs) by a catalytic ozonation process (COP) with a modified Mn/Co ceramic catalyst and an aerobic sequencing batch reactor (SBR) was investigated.A preliminary attempt to treat the diluted wastewater with a single SBR resulted in ineffective removal of the color,ammonia,total organic carbon (TOC) and chemical oxygen demand (COD).Next,COP was applied as a pretreatment in order to obtain a bio-compatible wastewater for SBR treatment in a second step.The effectiveness of the COP pretreatment was assessed by evaluating wastewater biodegradability enhancement (the ratio of biology oxygen demand after 5 d (BOD5) to COD),as well as monitoring the evolution of TOC,carbon oxidation state (COS),average oxidation state (AOS),color,and major pollutant concentrations with reaction time.In the COP,the catalyst preserved its catalytic properties even after 70 reuse cycles,exhibiting good durability and stability.The performance of SBR to treat COP effluent was also examined.At an organic loading rate of 2.0 kg COD/(m3·d),with hydraulic retention time (HRT)=10 h and temperature (30±2) °C,the average removal efficiencies of NH3-N,COD,BOD5,TOC,and color in a coupled COP/SBR process were about 80%,95.8%,93.8%,97.6% and 99.3%,respectively,with average effluent concentrations of 10 mg/L,128 mg/L,27.5 mg/L,25.0 mg/L,and 20 multiples,respectively,which were all consistent with the national standards for secondary discharge of industrial wastewater into a public sewerage system (GB 8978-1996).The results indicated that the coupling of COP with a biological process was proved to be a technically and economically effective method for treating industrial wastewater containing recalcitrant CNACs.     

孟加拉湾风暴影响楚雄雨季开始的分析研究

本文通过对比合成分析2000年以后因孟湾风暴影响造成楚雄州汛期第一场大雨的三次过程,发现此类系统影响时:500-700hPa上孟湾有深厚的低中心在90°E附近登陆,700hPa上高原东南侧有东东北—西西南向切变线与登陆的低中心连接。控制两广和云南东南部的副高较强、经向度较大,高原东部到四川的高压一般偏强,切变南压时,副高一般有强—减弱—维持的趋势。500hPa上高原东部出现高空槽,引导冷空气南下,冷空气路径为从高原东部经甘肃、四川中东部进入我省。水汽通量显示水汽输送带中心和登陆的风暴中心一致,北抬登陆后东移经过云南,为云南大范围强降水提供充足的水汽。