DCLR Modifi ed Petroleum Asphalt Optimization and Mixture Road Performance

In recent decades,modified asphalt materials have been used in enhancing the traffic load on the roads.The main objective of this paper is to explore the modifi cation effect of direct coal liquefaction residue(DCLR)on as-phalt binders and investigate the effectiveness of DCLR in improving the performance of asphalt road.This paper prepared modifi ed petroleum as-phalt under diff erent process conditions and tested its penetration,softening point and ductility index.Based on the experimental data,according to gray correlation degree,the performance for the asphalt was compared.The performance for the modified asphalt is simulated and predicted using poly-nomial functions.The modifi ed asphalt was analyzed by FT-IR,TGA,SEM and HPLC.The results show that the optimal process conditions for DCLR modifi ed asphalt are shear mixing time of 45 min,shear mixing tempera-ture of 150℃ and shear mixing rate of 4000 r/min.The predicted fit with the experimental data of 0.993 further demonstrates the effectiveness of the method.The characterization results show no significant chemical change between the DCLR and the asphalt.DCLR can significantly improve the high temperature performance and water stability of the asphalt,but it has little impact on its low temperature performance.

Solvothermal-assisted assembly of MoS2 nanocages on graphene sheets to enhance the electrochemical performance of lithium-ion battery

An ordered hollow M0S2 nanocages/RGO nanocomposite is constructed by a simple solvothermal-assisted assembly method combined with freeze-drying and annealing.In this novel nanostructure,hollow M0S2 nanocages are homogeneously distributed on graphene sheets with a tight bond of C-O-Mo.The nanosized and hollow MoS2 nanocages can effectively accommodate the huge volume change during charge/discharge process and increase the number of electrochemical reaction active sites,accelerating the kinetics of lithiation/delithiation.The tight C-O-Mo bond between graphene and MoS2 further reinforces the structural stability,thus improve the electrical conductivity and substantially enhance the lithium storage performance of M0S2 anode material.As a result,this novel nanocomposite shows a long-cycle stability of 717.4 mAh·g^-1 after 800 cycles at a high current density of 3 A·g^-1,exhibiting great potential as an anode nanocomposite for advanced lithium-ion batteries.

Metabolic engineering of Escherichia coli for the production of Lacto-N-neotetraose(LNnT)

Lacto-N-neotetraose(LNnT),one of the most important human milk oligosaccharides,can be used as infants’food addi-tives.Nowadays,extraction,chemical and biological synthesis were utilized to obtain LNnT,while these methods still face some problems such as low yield and high cost.The aim of current work is to construct a de novo biosynthesis pathway of LNnT in E.coli K12 MG1655.The lgtA and lgtB were first expressed by a plasmid,resulting in a LNnT titer of 0.04 g/L.To improve the yield of LNnT on substrate lactose,lacZ and lacI were knocked out,and lacY was over-expressed.As a result,the yield of LNnT on lactose increased from 0.01 to 0.09 mol/mol,and the titer of LNnT elevated to 0.41 g/L.In addition,the pathway was regulated using the titer of Lacto-N-triose II(LNTII)as a measure,and obtained a high titer strain of LNnT for 1.04 g/L.Finally,the gene expressions were fine-tuned,the titer of LNnT reached 1.2 g/L,which was 93%higher than the control strain,and the yield on lactose reached 0.28 mol/mol.The engineering strategy of pathway construction and modulation used in this study is applicable to facilitate the microbial production of other metabolites in E.coli.