ISSN 0253-2778

CN 34-1054/N

2019 Vol. 49, No. 6

Display Method:
Combined toxicity of Fe3O4 nanoparticles and cadmium chloride in the liver of mice by oral route
GONG Jiachun, ZHANG Yan, GUI Zongxiang, HU Tingting, WANG Xiaoqin, WANG Ziyi, XU Xiaolong
2019, 49(6): 431-438. doi: 10.3969/j.issn.0253-2778.2019.06.001
The combined toxicity of Fe3O4 nanoparticles (nano-Fe3O4) and CdCl2 in the liver of mice was reported. The organ coefficient, histopathological changes, serum biochemical parameters and oxidative stress responses were determined in the liver of mice after oral administration of nano-Fe3O4 and/or CdCl2 for 7 d. The results show that nano-Fe3O4 and CdCl2 mutually competitively inhibit Fe and Cd uptake in the liver. Oral nano-Fe3O4 (50 mg/kg BW) does not induce obvious injury in mice. In contrast, oral CdCl2 (2.0 mg/kg BW) causes signigicant oxidative damage in the liver. Co-administration of nano-Fe3O4 with CdCl2 significantly attenuates CdCl2-induced damage in the liver through reduction of oxidative stress. The inhibition of Cd-induced deprivation of tissue Fe and decrease in Cd accumulation after co-administration of nano-Fe3O4 with CdCl2 might play two key roles in the protective effect of nano-Fe3O4 on CdCl2-induced oxidative damage. Nano-Fe3O4 may be used as a perfect MRI contrast agent and drug carrier for patients with Cd poisoning, since it not only acts as an MRI contrast agent or drug carrier, but also simultaneously attenuates Cd-induced toxicity.
Alkali-metal Li and 1,3-diaminopropane intercalated superconductor Lix(C3H10N2)yFe2Se2 with Tc~39 K
XU Wentao, XU Hanshu, ZENG Suyuan, LUO Jingjing, TANG Kaibin
2019, 49(6): 439-444. doi: 10.3969/j.issn.0253-2778.2019.06.002
A new FeSe-based superconductor Lix(C3H10N2)yFe2Se2 (C3H10N2 refers to 1,3-diaminopropane) was successfully synthesized via the two-step method. This new material belongs to a tetragonal system and has a superconducting transition temperature (Tc) of 35 K. After annealing at 125 °C for 12 h, the crystal structure of this sample remained constant, but the Tc suddenly moved to 39 K, as confirmed by the powder X-ray diffraction and the magnetic susceptibility, respectively. Before and after annealing, the lattice constants a and b changed within 0.3 %, and the changes in c were slightly larger than 1 %. Therefore, it can be inferred that the evident change in Tc between as-synthesized and annealed samples should be attributed to a rearrangement and more homogeneous distribution of the intercalated guests.
Selective reduction etherification of HMF to 2,5-bis (methoxymethyl) furan over Cu-Co catalyst
YANG Yanjun, LI Xinglong, FU Yao, ZHANG Yucang
2019, 49(6): 445-451. doi: 10.3969/j.issn.0253-2778.2019.06.003
The conversion and utilization of biomass platform molecule 5-hydroxymethyl furfural (5-HMF) with high added value has always been a research hotspot. Bifunctional catalyst Cu-Co catalyst prepared by sol-gel method was used to catalyze the hydroetherification of 5-HMF to 2,5- bis (methoxy methyl) furan (BMMF) under mild conditions. The highest yield of BMMF is 85.9% at 130 ℃, 2 MPa H2 and 2 h. Co3O4 species in the bifunctional catalyst provide the Lewis acid site, while Cu2O and Co0 species provide the hydrogenation atmosphere, ultimately achieving one-step reduction etherification of HMF to BMMF.
An optical spectrum study of interlayer interaction in WS2/WSe2 heterostructure
HUANG Jiaxin, XIE Shiyu, CHENG Xuerui, LI Yuanyuan, HU Chuansheng, QI Zeming
2019, 49(6): 452-457. doi: 10.3969/j.issn.0253-2778.2019.06.004
Atomic-scale two-dimentional transition metal dichalcogenides possess novel electronic and optical properties. Stacking them into van der Waals heterostructures generates new optical properties because of interlayer coupling and charge transfer at the interface, which has important potential applications in photoelectric devices. WS2/WSe2 heterostructure was fabricated successfully by mechanical exfoliation and the interlayer interaction was studied by temperature-dpendent Raman spectra and photoluminescence (PL) spectra. Interlayer phonon mode and exciton were observed from Raman spectra and PL spectra respectively indicating that WS2/WSe2 heterostructure had obvious interaction between layers. Because of type II band alignment at the interface of WS2/WSe2 heterostructure, electrons were transferred from WSe2 to WS2 thus significantly affecting the PL intenstiy of trions and excitons.
Cu(I) binds to the C-terminal domain of copper transport protein hCtr1 and transfers to copper chaperone Atox1
WEI Hao, XU Dechen, CUI Yang, WEI Kaiju, YUAN Siming, LIU Yangzhong
2019, 49(6): 458-464. doi: 10.3969/j.issn.0253-2778.2019.06.005
The intracellular C-terminal domain of human copper transporter hCtr1 is crucial for copper transport and delivery in cells. However, the mechanism of copper acquisition and distribution is not fully understood. The copper binding to hCtr1 was studiedusing a C-terminal peptide (C8) through the methods of UV-vis, NMR and MS spectroscopies. The results show that cuprous ions exhibit high binding affinity to C8 (log K=16.6). C8 can bind with multiple copper ions, and the His and Cys residues in the HCH motif are the key binding sites, while an aspartate residue could also be involved in the copper coordination. Further investigation reveals that copper ions can transfer from C8 to the copper chaperone Atox1. These data provide detailed information on the copper binding to hCtr1 and help understand the copperdistributions in cells.
An analysis of nonlinear response of free circular jets to acoustic excitation
GUO Peng, ZHAO Majie, ZHU Minming, YE Taohong
2019, 49(6): 465-475. doi: 10.3969/j.issn.0253-2778.2019.06.006
Acoustic excitation is an effective means of flow and combustion control.To investigate the modulation effects of acoustic excitation on the circular jet, large eddy simulation was adopted to calculate the circular jet (Re=2020) submitted to acoustic modulation with different frequencies. The nonlinear response of the flow field to acoustic excitation was studied. The analysis of vorticity field and Q criterion demonstrate that the response of the flow field structure is dependent on the excitation frequency. The analysis of transfer function and decomposition of fluctuating velocity reveal that the propagation of perturbation wave has three modes: convective mode, mixed acoustic-convective mode and acoustic mode, which agrees well with the experimental results. The spatial distributions of power spectrum density (PSD) of velocity display the redistribution of turbulent energy in the frequency space. It is shown that the response of jets to excitation reflects the flow structures and is closely related to the propagation mode of the perturbations. When the excitation frequency is near the preferred frequency of the jet, the perturbations propagate in a convective mode, while the flow structures and energy distribution in frequency space exhibit a significant change.
Numerical study of combustion in an HCCI fuelled with methane-hydrogen
DENG Quanwei, LIN Qizhao
2019, 49(6): 476-486. doi: 10.3969/j.issn.0253-2778.2019.06.007
To study the effect of initial parameters on homogeneous charge compression ignition(HCCI) combustion performance of CH4-H2 mixtures with different hydrogen ratios, numerical research was carried out through combustion software Chemkin, and the rate of production (ROP) analysis method was used to study the influence of hydrogen mixing ratio and excess air coefficient on the dominant mechanism of NO emission. The result shows that hydrogen ratio, compression ratio, inlet temperature and air excess coefficient affect NOx emission by affecting the temperature in the engine, and the NOx emission can be controlled by reducing the compression ratio and inlet temperature properly and increasing the air excess coefficient at high hydrogen ratios. The analysis shows that the contribution rate of thermodynamic mechanism increases with the increase of hydrogen ratios and decreases with the increase of the excess air coefficient, while the contribution rate of N2O intermediate mechanism increases with the increase of the excess air coefficient. When the excess air coefficient is 2.5, the dominant position of the two mechanisms is approximately the same.
Numerical simulation of heat transfer performance of CFRP plate adhesive structure
SONG Xiaoqian, HU Peng, LIU Yang
2019, 49(6): 487-493. doi: 10.3969/j.issn.0253-2778.2019.06.008
The steady-state heat transfer characteristics of typical bonding structures such as butting and splicing in carbon fiber reinforced composite (CFRP) grille reflector were analyzed by ANSYS finite element method. The effects of epoxy resin with high thermal conductivity materials such as alumina, silicon nitride and graphene on heat transfer were compared and analyzed. The results show that with the increase in thermal conductivity of epoxy resin adhesives, the thermal resistance of the bonding interface decreases, the temperature difference of bonding site decreases, and the temperature distribution uniformity is higher, thus providing a research basis for effectively predicting the temperature distribution and thermal deformation of solid reflectors in orbit.
Inventory control of fresh food supply chain and its differential game considering fresh-keeping effort
CHEN Wuyuan, ZHANG Shaofeng, HU Xiaoli, ZHANG Lipai
2019, 49(6): 494-505. doi: 10.3969/j.issn.0253-2778.2019.06.009
Due to the perishable, fresh, deteriorating characteristics of fresh food, the inventory control of the fresh food supply chain is a strain for management. The fundamental metamorphic inventory model was improved, considering the preservation efforts of supplier and retailer, and prices and freshness factors affecting time-varying demand rate was built. Revenue sharing parameters and cost sharing parameters were considered, and the variational method was used to set up differential game models including jointly managed inventory (JMI) and decentralized inventory management (DIM) under the background of continuous time. Nash equilibrium’s existence of constraint equations was proved and corresponding optimal inventory differential strategies were proposed. Finally, by numerical simulation, preservation efforts, inventory changes and total supply chain profits were explored under the two models and corresponding suggestions were given.
Information sharing mechanism of dairy supply chain under emergencies
HUAN Meili, CHEN Pengfei, ZHANG Li, HOU Yunxian
2019, 49(6): 506-516. doi: 10.3969/j.issn.0253-2778.2019.06.010
A game equilibrium was studied in which a secondary dairy supply chain system consisting of one manufacturer and one retailer experiences a random disturbance of the market demand information caused by emergencies, and dairy product retailers can accurately grasp the information due to their close touch with the market and decide whether to share it with the dairy manufacturer. The results show that demand information sharing can increase the benefits of the entire dairy supply chain under certain conditions. Based on the principle of the overall profit maximization of the dairy supply chain and the Pareto condition of dairy manufacturer and retailer, the incentive model of demand information sharing during emergencies was constructed. Simulation results show that the incentive model can maximize the overall benefits of the dairy supply chain.