Shi Wei Wu

Effect of Ca2+ on Structure and Corrosion Resistance of Conversion Coating Formed on Cast AZ91D Magnesium Alloys

Phosphate conversion coatings was investigated on the surface of AZ91D magnesium alloy in a manganese dihydro phosphate baths. The influence of Ca2+ on coating microstructure was evaluate by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) techniques, and the corrosion resistance of the coating was tested by polarization curve methods in 3.5%NaCl. Surface observation results show that the conversion coating presents in crystal feature, and the coating containning Ca was uneven with large grains and small grains. The adding of Ca2+ compound in the bath was found to be important for the attainment of good combination between the coating and Mg alloy substrate. Polarization curve results indicate that the phosphate conversion coating containing Ca could enhance the corrosion potential and improve corrosion resistance.

Application of ICP-AES to the Detection of Heavy Metals in Cordyceps militaris from Shenyang

The microwave digestion-ICP-AES was used to detect the Cr, Cd, Pb, As, Hg and Ni in cordycepsmilitaris from Shenyang. The method accuracy was proved by the national standard method. The result shows the sequence of heavy metals was Pb>Ni >As > Cd> Cr, and Hg was not detected, as was detected in few sample. All the data showed that cordycepsmilitaris accords with the national standards. The method average recovery is 94.07%-107.58%, and RSD is 0.84%-3.25%. It is a promising analysis method on detection of heavy metals in cordycepsmilitaris.

Advances in Research of Botanical Insecticide

Botanical insecticides have advantages of wide range of sources, easily made with local materials, low-cost, cost savings, useful and safe to people, animals and crops, etc. The compound of botanical insecticide is an effective way to improve the efficacy of such pesticides. With the development of green agriculture, it will gain more and more attention.

Environmental Friendly Conversion Coating Formed on Magnesium Alloys and its Anti-Corrosion Performance

Conversion coatings on cast AZ91D magnesium alloy were prepared in the manganese dihydro phosphate baths. The corrosion behavior of the coated and uncoated alloys has been investigated by polarization curve methods. The morphology and composition of coated surfaces were investigated by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX ) as well as X-ray photoelectron spectroscopy (XPS) techniques. It is found that the conversion coating surface characterized by crystal particle and was composed of Mn3(PO4)2. Electrochemical investigation results indicated that the phosphate conversion coating could enhance the corrosion potential in great extent of about 1300mV compared with Mg alloy substrate.

Detection and Evaluation of Heavy Metal in Edible Fungi of Liaoning Province

Adopting microwave digestion and ICP-AES method while detecting Ni, Cr, Pb, Cd, As and Hg in edible fungus of Liaoning province, results show that the acceptance rate of heavy metal in lentinus edodes, oyster mushrooms, pleurotus eryngium, agrocybe cylindracea, agaricus bisporus, black fungus, coprinus comatus, cordyceps militaris was above 90%, Hg was not checked out, only in exceptional sampals Pb, Cd, Cr have checked out but not exceed, Ni and As out of limits, but the superscale was very small, the lentinus edodes in Liaoning province in a great measrue was safty.

Characterization of Phthalate Plasticizer from Bottled Beverages by GC-MS

A GC/MS method was established for the determination of phthalates plasticizers in bottled beverages. The calibration curves are all linear in the range of 0.01 to 5μg/L with correlation coefficients greater than 0.997. The recoveries are in the range between 97.27% and 105.05% under two levels. The testing data of the samples showed that the five bottled beverages all contained DBP, DIBP and DEHP plasticizers, and DIBP content was obviously higher than the other two.

Corrosion Protection of Molybdenum-Phosphorus Compounds Based Coating Formed on Hot Dip Galvanized Steel in a Cl- Ione Environment

Molybdate-phosphate conversion coating was prepared by adding addition agent towards molybdenum-phosphorus compounds based bath on comercial hot dip galvanized steel. The anti-corrosion performance of the coating was evaluated by electrochemical technique in 3.5%NaCl. It is found that the anodic branch of polarization curves presented in passivation character. Electrochemical impedance spectroscopy (EIS) results indicate that the radius of the capacity impedance for molybdate-phosphate film increased distinctly with pH decrease, which validate the excellent anti-corrosion performance of the film. The surface morphologies were observed using scanning electron microscopy (SEM), and the results show that the surface of hot dip galvanized steel is covered by a spiculate and floccule shape conversion coating. The chemical composition of the surface coating was investigated by energy dispersive X-ray (EDX), which illustrate that the conversion coating is composed of zinc,oxygen, phosphor and molybdenum.

Treatment of Chlorobenzene Containing Wastewater by Titanium Oxide Photocatalyst

In this study, we choose TiO2 as photocatalysis, and to deal with low concentration chlorobenzene-containing wastewater under the shining of ultraviolet light. Temperature, pH and flux have be inspected. The following conclusion is according to the experiment result: When chlorobenzenes concentration deciding for 50mg/L and TiO2s concentration is 1.0g/L , it is better to get the optimum parameter: temperature is 60°C, flux is 100L/h and in acidic condition.

Effect of Prepareing Conditions on the Tensile Strength of Bamboo Carbon-Polyvinyl Formal Biological Carrier

In this experiment the tensile strength of bamboo carbon- polyvinyl formal biological carrier (BCPFBC) were tested. The optimal parameters are as follow: 6ml of sulfuric acid, 4ml of formaldehyde, 2g of bamboo carbon dosage, 40°C of reaction temperature, and 2.1N.mm-2 of BCPFBC tensile strength.

Methyl Violet Degradation by Bamboo Charcoal/Microwave Method

In the paper methyl violet degradation by bamboo charcoal-microwave irradiation method was researched. The main parameters which were studied including the amount of bamboo charcoal, H2O2 dosage, FeSO4·7H2O dosage and time of microwave irradiation were investigated. The UV-visible spectra of methyl violet were determined. The results show that: under bamboo charcoal, H2O2 and FeSO4·7H2O microwave condition the degeneration rate of methyl violet was almost 100%. The increase of bamboo charcoal dosage can accelerate the reaction process, speeding up the degradation of methyl violet. The increase of H2O2 may provide more ·OH and speed up the reaction process, but when up to a certain amount, the influence is weakened. The lengthening of microwave time may enhance the reaction temperature, and urge the methyl violet to degrade completely. For 0.2 g·L-1 methyl violet 4:9 diluted, by adding 0.5g bamboo charcoal, 1 mL 36% H2O2, 1 mL FeSO4·7H2O of 1mol·L-1 and under mesotherm microwave for 30s, the methyl violet can be all degradated.