Li Li Feng

Influence of organic carboxylic acids on self-assembly of silver(I) complexes containing 1,2-bis(4-pyridyl)ethane ligands

Four silver(I) complexes, namely [Ag2(bpe)2](bdc)·8H2O (1), [Ag2(bpe)2(da)]·4H2O (2), [Ag4(bpe)3(bptc)]·9H2O (3), and Ag(bpe)2(bpdc)2 (4), have been successfully synthesized by the reactions between AgNO3, 1,2-bis(4-pyridyl)ethane (bpe) and different carboxylic acids, including 1,3-benzenedicarboxylic acid (H2bdc), diphenic acid (H2da), 3,3′,4,4′-biphenyltetracarboxylic acid (H4bptc), and 2,2′-bipyridine-3,3′-dicarboxylic acid (H2bpdc). All four compounds were characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. In (1), the Ag(I) atoms, in linear geometry, are joined into 1-D infinite cationic bpe-silver chains, and discrete bdc2− anions compensate the charge of the crystal structure. In (2), the Ag(I) atoms, adopting tetrahedral and trigonal geometries, are linked by bpe and da2− ligands into neutral double chains. In (3), the Ag(I) atoms, in T-shaped and linear environments, are coordinated by bpe and multidentate bptc4− ligands to construct a 2-D network. And in (4), the Ag(I) atoms, with trigonal and T-shaped coordination geometries, are coordinated by bpe and bpdc2− ligands to build up a 3-D framework. The different anions play different and important roles in directing the final crystal structures.

The Influences of Main Ingredients of the Reclaimed Water on Calcium Carbonate Scale in Recycling Cooling System

The main risk of reclaimed water reused in industry is to control fouling. The main ingredients in reclaimed water form the chemical scale which is one of the main components of the fouling in the recycling cooling system. The main chemical scale of reclaimed water is carbonate scale (calcite). In this paper, by using the actual reclaimed water which reused as make-up water in Beijing Thermal Power Plant to simulate the 4 times concentrate ratio recycling water to study the influence of main ingredients of reclaimed water such as pH，soluble silica, the most content of anions and cations on carbonate scale. The experimental results show that pH, soluble silica, calcium ion and alkalinity have greater influence on scale inhibition, but magnesium ion, chloride ion and sulfate ion have smaller influence on scale inhibition.

Preparation and Thermal Propertites of Polyethylene Glycol/ Silica Hollow Nanospheres Composite as Shape-Stabilized Phase Change Materials

Shape-stabilized phase change material (PCM) composed of polyethylene glycol and silica hollow nanospheres was prepared by a vacuum impregnating method. Thermal properties of the composite PCM were investigated by various techniques. Lower phase change temperature and enthalpy of the composite PCM were observed. It is concluded that the phase change properties of the composite PCM are influenced by the adsorption confinement of the PEG segments from the porous structure of the silica hollow nanospheres.

Investigation of Lead and Cadmium Content of Plant Leaves along a Ring Road in Beijing

The contents of lead and cadmium in the leaves of Chinese Rose along 4th ring roads in Beijing were determined respectively, and index of air environment pollution of plants was introduced to study the relationship between the content of lead and cadmium in leaves and air pollution. The results revealed that the air quality based from lead content in leaves at many locations belong to strongly polluted status, while the air quality based on cadmium content of Chinese Rose leaves at many location belonged to extremely polluted status. It is practical to evaluate air pollution conditions using content of heavy metal (such as lead and cadmium) in leaves of plant.

Preparation and Characterization of Hollow Silica Nanospheres

Monodisperse hollow silica nanospheres were prepared using functionalized polystyrene (PS) as a template and characterized by transmission electron microscopy (TEM), nitrogen adsorption and thermo gravimetry (TG) techniques. The effect of ammonia amount on hollow silica spheres was explored. It is found that the ammonia amount is important to the fabrication of hollow silica nanospheres. The roughness and thickness of the silica shell increased with the increase of ammonia amount. When ammonia amount reached 20 ml, the product hadn’t been hollow structural. The TGA curves and the BET results of the samples supplied a proof for the formation mechanism of the hollow silica spheres.

Oxidation of Formaldehyde over Birnessite-Type Manganese Oxides at Room-Temperature

A series of manganese oxides (Me-OL-1s, Me: Mg, Fe, Ni and Cu) were synthesized by static hydrothermal and ion-exchange method. The as-prepared samples were characterized by means of X-ray diffraction (XRD), Raman spectroscopy (Raman) and Scanning electron microscope (SEM). The catalytic activity of the Me-OL-1 samples for the formaldehyde degradation was investigated at room temperature. The synthetic Me-OL-1s belong to birnessite-type manganese oxides. All the Me-OL-1 catalysts show the activity for the catalytic oxidation of formaldehyde at room temperature and exhibit the activity order of Fe-OL-1 > Ni-OL-1 > Cu-OL-1 > Mg-OL-1. The removal rates of formaldehyde are increased with increasing contact time.

Preparation and catalytic performance of the CeO2/TiO2 composites

Abstract TiO2 nanoparticles were prepared via the sol–gel method using titanium sulphate as precursor. And the CeO2/TiO2 composites with various CeO2 content were obtained by impregnating TiO2 nanoparticles into the solution containing Ce4+ ions, drying and calcination, successively. It is found that the crystalline phase of TiO2 in the composites was anatase. Catalytic performances of the composites were investigated by the photocatalytic degradation of methyl orange and the removal of Chemical Oxygen Demand (COD) in wastewater. The composites showed higher catalytic activities than pure TiO2. The composites with 2% CeO2 content beared the highest photocatalytic activity. The degradation of methyl orange followed first-order reaction kinetics.

Study on Environment Engineering with the First Long-Term Agreement on Energy Efficiency of Netherlands and its Enlightenments

mproving energy efficiency is an important way of energy saving and emission reduction. Great achievements have been obtained by the First Long-term Agreements on Energy Efficiency (short for LTA1) of Netherlands in this regard. Whats more, it deserves to learn. The history, structure, operation process, achievements and deficiencies of LTA1 are analyzed systematically, and the enlightenments about how to improve energy efficiency in China will also be provided in this paper.

Preparation, Characterization and Catalytic Formaldehyde Oxidation at Room Temperature of MnOx

MnOx (Na-OL-1, Ni-OL-1 and Ni-OMS-1) were synthesized and characterized by various techniques. The performance of formaldehyde oxidation catalyzed by the as-synthesized MnOx at room temperature was investigated. It is found that the catalytic activity of formaldehyde oxidation over MnOx had the order as follows: Ni-OL-1 >> Na-OL-1> Ni-OMS-1. Both microstructure and interlayer spacing of MnOx combined affected the activity of catalytic formaldehyde oxidation.

Dielectrophoresis Response and Manipulation of Silica and its Application to Micro/Nanosensors

In this paper, silica microspheres and several novel μm scale DEP (dielectrophoresis) micro electrode array chips were prepared. A DEP experimental system was assembled to investigate the the DEP response of silica microspheres and micrometer particles. The effects of pattern of electrodes and frequency of AC field on the manipulation of silica microspheres were analyzed. The results showed that silica microspheres were manipulated by negative DEP (nDEP) in all types of electrodes, the position of silica microspheres in the electrodes changed when the frequency was changed and the phenomenon of nDEP was more obvious at higher frequency. A gas sensor was fabricated by dielectrophoretically assembling SiO2 micrometer particles. The sensor showed good response to SO2 and NH3 gas. The measurement results confirmed DEP could be a quicker method for constructing gas sensor.