Search

Ionic liquids found a wide application in catalysis and extraction due to their unique properties. Herein, ethylene glycol dimethacrylate as the cross-linker and 1-vinyl-3- butylimidazolium tetrafluoroborate as functional monomer via thermally initiated free-radical polymerization was prepared as a novel copolymer solid phase micro-extraction (SPME) coating. A surface modified stainless-steel wire was implemented as the substrate. Factors affecting the extraction performances of the copolymer, including the molar ratio of monomers to cross-linkers, the amount of porogen agent, and polymerization time were evaluated and optimized. To evaluate the extraction performance, five commonly seen polycyclic aromatic hydrocarbons (PAHs) were taken as the analytical targets. The potential factors affecting extraction efficiency were optimized. The as-prepared SPME device, coupled with gas chromatography, was successfully applied for the determination of PAHs in water samples. The wide linear range, low detection limit, good reproducibility, selectivity, and excellent thermal stability indicate the promising application of the newly developed SPME fiber in environmental monitoring as well as in other samples having complex matrices.

C8-Alkyl-substituted purine analogues were synthesized through direct alkylation of 8-H purine with tetrahydrofuran in the presence of Co catalyst in one step. The reactions gave a series of novel C8-oxygen heterocyclic alkyl purine compounds in good yields under mild reaction conditions by the readily available alkylating reagents, providing a complementary route to the classical coupling reactions for the synthesis of C8-alkyl-substituted purine analogues.

A galvanic replacement strategy has been successfully adopted to design AgxAu1–x@CeO2 core@shell nanospheres derived from Ag@CeO2 ones., A galvanic replacement strategy has been successfully adopted to design AgxAu1–x@CeO2 core@shell nanospheres derived from Ag@CeO2 ones. After etching using HAuCl4, the Ag core was in situ replaced with AgxAu1–x alloy nanoframes, and void spaces were left under the CeO2 shell. Among the as-prepared AgxAu1–x@CeO2 catalysts, Ag0.64Au0.36@CeO2 shows the optimal catalytic performance, whose catalytic efficiency reaches even 2.5 times higher than our previously reported Pt@CeO2 nanospheres in the catalytic reduction of 4-nitrophenol (4-NP) by ammonia borane (AB). Besides, Ag0.64Au0.36@CeO2 also exhibits a much lower 100% conversion temperature of 120 °C for catalytic CO oxidation compared with the other samples.

An often real problem encountered in performance evaluations for aviation subcontract production (SP) enterprise of XAC was difficult to establish the quantificational targets and quantifiable performance indicators. Key performance indicators (KPI) is a target-type quantitative management indicators that measuring the process performance. The practical manufacturing enterprise in aviation subcontract production is expatiated, and the overall KPI analysis and design process from planning to final implementation and proceedings is put forward by using the KPI performance assessment. It is important to improve human resources management and to enhance the economic benefits for aviation SP enterprise of XAC.

A buyer-oriented electronic supply chain management (e-SCM) to the core issue of supply chain management (SCM) with coordination and stimulation approach by adopting the return contract was studied, and a practical explanation and operable plan with coordination and stimulation in e-SCM on the basis of return contract was propose. When the supplier in such supply chain gives the buyer a certain rebate rate to unsold products, the SCM can be coordinated. The buyer always has the motivation to join the e-SCM, but the supplier’s motivation depends on the rate of commission and coordination mechanism. When the rate of commission is lowered to a certain level, the supplier will join the e-SCM even without any extra incentive. However, when the rate of commission is increased to a certain higher level, the supplier will not join the e-SCM even if the buyer offers the highest subsidy. When the situation is between the above two cases, i.e., if the buyer gives a certain amount of subsidy to the supplier, the whole supply chain still can be coordinated.

Aviation subcontract production (SP), the particular manufacturing mode of aeronautical manufacturing enterprise (AME), is an important approach and instrumentality participated in international market competition. In this paper, a Web-based approach of remote cooperative production scheduling and control (CPSC) in distributed network manufacturing for subcontract production is proposed, and an implement framework on remote CPSC over Internet is accomplished. As a result, this study on the remote CPSC over Internet in distributed network manufacturing for SP is important for advancing the technical ability of aviation manufacturing, enhancing the manufacturing strength, and promoting the management level of the aeronautical SP, and a prospective and specific sample model with manufactures in decentralized network and integrated product development and manufacturing.