Synthesis and Electrochemical Performance of Spheroid LiNi<Subscript>1/3</Subscript>Co<Subscript>1/3</Subscript>Mn<Subscript>1/3</Subscript>O<Subscript>2</Subscript> in the Electrolyte Modified by Ethylene Sulfate and Methylene Methanedisulfonate

In this study, spheroid LiNi_1/3Co_1/3Mn_1/3O₂ (NCM111) cathode material were synthesized using LiOH with Ni_0.5Co_0.2Mn_0.3(OH)₂ precursor by a simple solid-state reaction, and characterized by X-ray diffraction and scanning electron microscopy. Electrochemical behavior of NCM111 was investigated by electrochemical impedance spectroscopy (EIS) combining with cyclic voltammogram (CV) and charge/discharge test in the 1 M LiPF₆-EC:EMC electrolyte with ethylene sulfate (DTD) and methylene methanedisulfonate (MMDS) additives either singly or in combination with high cutoff voltage of 3.0–4.5 V at room temperature of 25 °C or elevated temperature of 55 °C. It was found that DTD additive can increase the initial coulombic efficiency of NCM111, and the spheroid NCM111 can obtain the maximum initial discharge capacity of 177.81 mAh/g with the 2 wt% DTD, and keep 92.29% capacity retention after 80 cycles. The MMDS additives would decrease the initial discharge capacity of the NCM111, and enhance significantly long cycle life of the NCM111 with the capacity retention of 99.23% over 80 cycles at high voltage of 4.5 V. The additive combination 2 wt% DTD?+?1 wt% MMDS was an optimal additive combination, demonstrating the 102.2% capacity retention over 80 cycles at room temperature and the 94.2% capacity retention over 70 cycles at elevated temperature of 55 °C. EIS results revealed that the additive blend of 2 wt% DTD?+?1 wt% MMDS can drastically lower the kinetics impedance and suppress the growth rate of R _ct for the NCM111 electrode.     

Pheromone-Based Pest Management in China: <Emphasis Type="Italic">Past,Present, and Future Prospects</Emphasis>

Semiochemical-based pest management technology has been widely used to monitor and control insect pests in agricultural, forestry, and public health sectors in the western world. It became a popular tool in the early 1970s with tremendous efforts in developing environment-friendly control technologies for the integrated pest management. However, in China, similar research lagged 15 to 20 years and was not initiated until the late 1980s. In this review, we present the early history of pheromone research that has led to the current practical applications in China, particularly in the development of pheromone-based pest management products. We also provide information regarding the current status of pheromone-based product manufacturing, marketing, and regulatory issues related to local semiochemical industries, which may be useful to other international companies interested in pursuing business in China. In addition, we share some research topics that represent new directions of the present pheromone research to explore novel tools for advancing semiochemical-based pest management in China.     

Giant dielectric phenomenon of Ba0.5Sr0.5TiO3/CaCu3Ti4O12 multilayers due to interfacial polarization for capacitor applications

Ba_0.5Sr_0.5TiO₃/CaCu₃Ti₄O₁₂ (BST/CCTO) multilayers with different stack sequences were deposited on LaNiO₃(LNO)/SiO₂/Si substrates by a sol-gel process. The dielectric properties of BST/CCTO multilayers are significantly affected by the deposition sequence, the layer thickness and the impurities, effects that are interpreted using the Maxwell-Wagner interfacial polarization model. Impurities are generated by elemental interdiffusion at the interfaces of BST/CCTO, and less at the interfaces of BST/LNO and CCTO/LNO. The dielectric permittivity of the CCTO/BST/LNO/SiO₂/Si sample reaches 352,200 at 10 kHz, and stabilizes above 20,000 in the range of 100 kHz to 1 MHz. This work demonstrates an effective approach to enhance dielectric properties for film capacitor applications by constructing multilayers with specific deposition sequences and layer thicknesses.     

生物慢滤工艺不同深度净化景观水效果研究

生物慢滤工艺对COD、SCOD和浊度去除率分别可达到49%、46%和77%;对COD、SCOD和浊度,系统表层填料对COD、SCOD和浊度的去除贡献较大;在填料5 cm以下装置对有机物和浊度的去除曲线斜率基本一致。生物慢滤池对于TP和溶解性磷酸盐可达到70%以上;系统对总氮去除率一般只有18.0%~30.0%,对氨氮去除率可达33%~67%。沿不同深度,磷和总氮的去除率基本呈不断增大的趋势;而氨氮的去除率呈现先增大后减小的规律。     

Syntheses,Crystal Structures and Properties of Two Supramolecular Coordination Polymers with 2,6-Pyridinedicarboxylic Acids and 4,4′-Bis(imidazolyl)biphenyl

Two supramolecular coordination polymers, [Cu(PDA)(4,4′-bibp)]_n (1) and [Zn(PDA)(4,4′-bibp)]_n (2) (PDA = 2,6-pyridinedicarboxylic acid and 4,4′-bibp = 4,4′-bis(imidazolyl)biphenyl), have been obtained under hydrothermal conditions. The two polymers were characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis. The X-ray single crystal analysis revealed that two complexes exhibit different supramolecular architectures. The photocatalytic studies indicate complex 1 is a good candidate for the photocatalytic degradation of methylene blue, rhodamine B and methylene violet. The photoluminescence behaviour of complex 2 was also discussed.     

Conversion of methanol into light olefins over ZSM-11 catalyst in a circulating fluidized-bed unit

Methanol conversion and the reaction pathway were investigated in a pilot-scale circulating fluidized-bed (CFB) unit over hierarchical ZSM-11 catalyst. Experimental results indicated that ZSM-11 catalyst was highly resistant to external coke due to the formation of mesopores. Elevated temperatures favored the production of propylene and butylene and decreased the yield of ethylene. Additionally, no direct relations were shown between the formation of ethylene and other products under different pressures, suggesting that ethylene was a primary product produced at the initial of the reaction. Methylation-cracking and oligomerization were verified as the main reaction pathway for the formation of C ₃ ⁺ alkenes., Methylation and oligomerization of olefins were dominated under high methanol partial pressure and consequently responsible for the production of higher olefins, while the b-scission of C ₇ ⁼ for propene and butylene, and C ₈ ⁼ for butylene were enhanced at low methanol partial pressure.     

生物分离工程课程教学改革的探索与实践

我们针对生物工程专业的特点,对生物分离工程课程教学的改革进行了探索,通过优化教学内容,改进教学手段,加强理论与实践的结合,激发学生学习的兴趣,提高学生的动手能力。教学实践取得了良好的效果,也为学生将来从事相关工作打下良好的基础。     

3-甲氧基-2-甲基苯甲酸的合成研究

介绍了以2,6-二氯甲苯为原料,经醚化、格氏反应、水解三步反应合成3-甲氧基-2-甲基苯甲酸的合成工艺.合成总收率达到72%,产品纯度达到99%.     

Preparation and characterization of dual-responsive spiropyran-based random copolymer brushes via surface-initiated atom transfer radical polymerization

Silica nanoparticles (SiO₂) were grafted with the precursor random copolymer of 1′-(2-acryloxyethyl)-3′,3′-dimethyl-6-nitrospiro-(2H-1-benzopyran-2,2′-indoline) (SPMA) and tert-butyl methacrylate (tBMA) by surface-initiated atom transfer radical polymerization (SI-ATRP), and SiO₂-g-P(SPMA-co-methacrylic acid (MAA)) was obtained via chemical hydrolysis of the resulting precursor random copolymer in acidic conditions. From transmission electron microscopy, we observed the spherical morphology of monodispersed silica nanoparticles and core-shell structure of SiO₂-g-P(SPMA-co-MAA). Energy dispersive spectroscopy, Fourier transform infrared spectra, X-ray photoelectron spectroscopy, and the thermogravimetric analysis indicated that the polymer had been successfully grafted onto the surface of silica nanoparticles. The dual-responsive properties were characterized by means of ultraviolet-visible spectrophotometer and dynamic light scattering. The average hydrodynamic diameter of SiO₂-g-P(SPMA-co-MAA) increased from 185.7 to 212.7 nm under ultraviolet light irradiation for 5 min. Also, the particle size of SiO₂-g-P(SPMA-co-MAA) increased with the rising pH value of surrounding condition.     

Effect of alumina on the structure and properties of polyimide matrix films

To improve the properties of polyimide (PI), different mass fractions of alumina (Al₂O₃) nanoparticles, unmodified or modified by KH550, were incorporated into PI matrix to form PI/Al₂O₃ hybrid films by in situ polymerisation. The effects of Al₂O₃ additives on the structure, dielectric and mechanical properties of the films were studied. Fourier transform infrared spectroscopy confirmed the successful preparation of PI/Al₂O₃ hybrid films, and the microstructures of the samples showed a more uniform dispersion of the modified Al₂O₃ nanoparticles than the unmodified ones in the matrix. The dielectric constant of the films increased with increasing filler content, and the maximum electrical breakdown strength of 311 MV m^?1 was obtained with a filler content of 8.0 wt-% modified Al₂O₃ in the matrix. Both unmodified and modified Al₂O₃-reinforced PI hybrids demonstrated improved mechanical properties compared with the PI matrix. Moreover, the properties of films with Al₂O₃ modified by KH550 were better.