Kinetic Determination of Urea in Milk Powder by Nonlinear Chemical Fingerprint Technique

To detect urea content in milk powder, a nonlinear chemical fingerprint technique was developed. In our study, Belousov-Zhabotinsky oscillatory chemical reaction (B-Z) was performed using milk powder and malonic acid as main dissipative substances. The same dosage of milk powder with or without artificially added urea was introduced to “H+ + Ce4+ + + malonic acid” oscillating system, respectively, and nonlinear chemical fingerprints of different milk powder were thus obtained. The proposed method was based on a linear relationship between inductive time of non-linear chemical fingerprints and urea content in milk powder, which held when urea content in milk powder was in the range of 0 - 40 mg/g. A detection limit of 7.8 × 10-3mg/g was also obtained. Our results showed that the method could be used to certify urea content in milk powder without pretreatment of samples, which was more simple and economical compared with traditional methods.

Molten salt-assisted synthesis of bulk CoOOH as a water oxidation catalyst

Different sizes of layered CoOOH were synthesized by the molten-salt-assisted method at different temperatures.X-ray diffraction and scanning electron microscope studies reveal that CoOOH grew at(003)with increasing temperature,and its size can reach dozens of microns.X-ray absorption near edge structure and XPS studies demonstrate that the Co valence state of CoOOH-750 is trivalent,and X-ray Absorption Fine Structure shows that it had a higher symmetry and lower disorder degree,indicating that CoOOH-750 has higher crystallinity and Co3+.The results of electrochemical tests show that CoOOH-750 exhibited the best oxygen-evolution-reaction(OER)catalytic activity.

Rational synthesis of CaCo_2O_4 nanoplate as an earth-abundant electrocatalyst for oxygen evolution reaction

To accelerate the kinetics of oxygen evolution reaction(OER)regarding the energy conversion and storage approaches,the discovery of desirable cost-effective and highly efficient electrocatalysts is of prime importance.This study demonstrates a layered CaCo_2O_4with a two-dimensional nanoplate structure,which possesses electrocatalytic activity for OER.The OER activity was achieved on CaCo_2O_4with a Tafel slope of 71 mV dec^(-1)and a current density of 10 mA cm^(-2)at an overpotential of 371 mV,which was more active than the similar structure LiCoO_2catalyst.Combined with X-ray absorption fine structure and density functional theory calculations,the enhanced OER activity and stability are mainly attributed to the unique electronic structure derived from the interaction of Ca and Co,and improved electrical conductivity.CaCo_2O_4can be developed as a highly active and earth-abundant catalyst for OER in energy conversion and storage technologies.

Technology of Eliminating White Smoke from Flue Gas

Based on the corresponding relationship chart of saturation humidity and temperature of wet flue gas,the formation mechanism of"white smoke plume"and the technology of eliminating white smoke from flue gas were analyzed.Besides,the energy balance of each elimination technology was calculated according to the theoretical formulas,and"energy saving"was compared.The technology of eliminating white smoke from flue gas needs to solve the problems of"emission reduction"and"energy conservation"in industrial enterprises.It brings new ideas and directions to enterprises for"energy conservation and emission reduction",eases the pressure on enterprises to protect the environment,improves enterprises'use efficiency of primary energy,and provides a reliable choice for enterprises to survive and enhance their competitiveness.In addition,it can effectively solve the dehumidification and elimination of wet flue gas,not only eliminate the pollution from white smoke plume,but also achieve environmental protection up-to-standard and ultra-low near zero emission at low cost,enhance the efficiency of coal combustion,in particular recover the moisture and residual heat in flue gas,and solve the contradiction between the environment and development.