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Design， Synthesis and Fungicidal Activity of Pyrazinamide Analogs WANG Gang, LIANG Shuang, SHAN Zhonggang, YING Junwu, LYU Liang, LI Bin, YANG Huibin Chem. J. Chinese Universities    2024, 45 (10): 20240369-.   DOI: 10.7503/cjcu20240369 Abstract （314）   HTML （14）    PDF（pc） （4355KB）（5467）       Knowledge map    Save Pyraziflumid was a novel pyrazinamide analog fungicide developed by Nihon Nohyaku Co. In this work， 16 pyrazinamide analogs were synthesized using substituted pyrazine acid and 2-methyl-3-nitrophenol as initial materials through 4 steps. The structures of the target compounds were confirmed by nuclear magnetic resonance （1H NMR， 13C NMR） and high resolution mass spectrometer（HRMS）. The results of fungicidal activity at greenhouse showed that pyrazinamide analogs had excellent fungicidal activities against corn rust at 6.25 mg/L. Among them， the fungicidal activities of compounds 4， 5， 7， 8， 15 and 16 against corn rust at 6.25 mg/L were 100%. Molecular docking simulations revealed that compound 16 interacted with TRP-173 of succinate dehydrogenase（SDH） through hydrogen bonding， which could explain the probable mechanism of action between compound 16 and the target protein. These results indicated that compound 16 might be a promising fungicide candidate and provide valuable reference for further investigation. Table and Figures | Reference | Related Articles | Metrics

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Advances of Multifunctional Deoxyribozyme in Biomedical Analysis WANG Qing, HE Yuqiu, WANG Fuan Chem. J. Chinese Universities    2021, 42 (11): 3334-3356.   DOI: 10.7503/cjcu20210449 Abstract （1014）   HTML （32）    PDF（pc） （4427KB）（2874）       Knowledge map    Save Deoxyribozymes（DNAzymes） are synthetic deoxynucleotide oligomers with enzyme-like activities identified through in vitro SELEX selection technology. DNAzymes have been widely explored in a broad range of applications， notably in biosensing and biomedical devices， owing to their easy synthesis and modification， stable chemical structure and excellent catalytic activity. Regulating the activity of DNAzymes is the key for exploring its potential utilization in many fields， and the flexible control will dramatically promote the application of DNAzymes. In this review， we summarize some methods for the regulation of DNAzymes activity and introduce their main applications in biomedical analysis. It is believed that DNAzymes will play a critical role in chemistry and medicine in the future. Table and Figures | Reference | Related Articles | Metrics

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Fabrication and Properties of Epoxy Vitrimer Based on Multiply Dynamic Covalent Bonds YANG Weiming, XI Aoqian, YANG Bin, ZENG Yanning Chem. J. Chinese Universities    2022, 43 (11): 20220308-.   DOI: 10.7503/cjcu20220308 Abstract （561）   HTML （25）    PDF（pc） （8349KB）（2407）       Knowledge map    Save Traditional epoxy networks were wildly applied in composites， adhesives， coatings， electronic packaging and insulating materials， due to their excellent properties and stable network structure. However， once epoxy networks are formed， they cannot be reprocessed. When epoxy networks are damaged during the serving time， they cannot be self-healed. Epoxy vitrimers networks with dynamic reversible covalent bonds can reorganized their network typology under external stimuli， contributing to network reprocessing and self-healing. Currently， most epoxy vitrimers show a high temperature for reprocessing and self-healing， consuming high energy. Herein， the epoxy vitrimers with tri-dynamic covalent bonds（boronic ester bond， disulfide bond and ester bond） were fabricated by epoxy-thiol “click” reaction and epoxy-carboxylic acid reaction. The structures of the prepared epoxy vitrimers were characterized by Fourier transform Infrared spectrometer（FTIR） and Raman spectroscopy， and hydrogen bonds were found in the prepared epoxy vitrimers contributing to improvement of crosslink density. Meanwhile， the thermal stability， thermo-mechanical properties and mechanical properties of the prepared epoxy vitrimers were investigated by thermogravimetry（TG）， dynamic mechanical analysis（DMA） and tensile testing. Furthermore， self-healing， welding， shape memory and reprocessing capabilities of the prepared epoxy vitrimers were researched. The results display that at 80 ℃ the scratches on the prepared epoxy vitrimers can be fully recovered and the welding recovery of tensile strength of the prepared epoxy vitrimers is >80%， indicating excellent functionality. Table and Figures | Reference | Related Articles | Metrics

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Structural Characteristics, Syntheses and Applications of Hyperbranched Polymers WEI Huan-Yu, SHI Wen-Fang Chem. J. Chinese Universities    2001, 22 (2): 338-344.   Abstract （1911）      PDF（pc） （737KB）（3538）       Knowledge map    Save Hyperbranched polymers have received more and more research interest from polymer scientists because of the unique strutural characteristics, synthetic methods as well as application fileds. The present paper reviews the most recent advances in hyperbranched polymer, with emphasis being laid on the above-mentioned three related aspects in an attempt to make this field to be further understood, and to accelerate it to develop more quickly. Fifty references were cited in this work. Related Articles | Metrics

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Charge Transfer in Organic Semiconductive Materials ZHOU Xue-Qin, WANG Mang, YANG Shi-Lin Chem. J. Chinese Universities    2000, 21 (8): 1312-1317.   Abstract （1912）      PDF（pc） （698KB）（2956）       Knowledge map    Save In this paper, the basic theory of charge transfer in organic semiconductive materials was introduced, and the recent progress in studies of the conductive, photoconductive and luminescent properties for organic semiconductors was reviewed with 50 references. It was believed that charge transfer was a dominant factor to understand these characteristics of organic semiconductive materials. Studying on charge transfer was very important to explore physical origins of some new phenomena and some new effects, as well as to find effective methods to predict the properties of organic semiconductive materials. Related Articles | Metrics

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Green Electrosynthesis Reaction of Potassium Azotetrazolium Salt Coupled by Hydrogen Production from Water Electrolysis by WS2 Nano Sheets YAO Tianhao, MA Yuhe, LIU Bolong, MA Yuqiang, ZHANG Cong, LI Jiachen, MA Haixia Chem. J. Chinese Universities    2023, 44 (12): 20230347-.   DOI: 10.7503/cjcu20230347 Abstract （459）   HTML （9）    PDF（pc） （5908KB）（1916）       Knowledge map    Save As a four-electron multi-step reaction process with sluggish kinetics， oxygen evolution reaction（OER） limits the reaction rate and reduces the overall efficiency of overall water splitting. Replacing OER with the oxidation reaction of thermodynamically more favorable organic energetic materials and coupling with hydrogen evolution reaction（HER）， so that the high value-added chemical products can be obtained while reducing the overall cell voltage to generate hydrogen. In this paper， a novel coupling system was proposed， in which the energy-containing ionic salt， potassium azotetrazolium salt（K2AZT）， was prepared on the anode side， and carbon cloth-supported tungsten disulfide nanosheets（CC@WS2 NSs） were used as HER catalyst to promote the HER on the cathode side. The system only requires a cell voltage of 1.65 V to achieve a current density of 10 mA/cm 2， which is 220 mV lower than that of conventional electrolyzed water（1.87 V）. In addition， the coupled system maintained smooth operation for at least 15 h， showing excellent stability. At the same time， the preparation of energetic compounds by green and safe electrochemical method avoids the problems of high energy consumption， high risk and high cost of traditional organic synthesis method， and provides a new synthesis strategy for the safe production of energetic materials. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics

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Statistical Mechanics and Reaction Dynamics Theory for Polycondensations WANG Hai-Jun, HONG Xiao-Zhong, BA Xin-Wu Chem. J. Chinese Universities    2005, 26 (11): 2077-2081.   Abstract （1887）      PDF（pc） （1363KB）（2290）       Knowledge map    Save By the investigations of two types of representative polycondensations from statistical theory and dynamics,the relationship between the dynamics and statistics of the system under consideration is pointed out.Based on this,we obtain the explicit relationship between the conversions and equilibrium dynamical constant and reaction free energy,by which the characterization of the average polymer physical quantities can further be simplified.Moreover,the influences of temperature and pressure on the polymerization process are discussed. Related Articles | Metrics

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Preparation and Characterization of Monodisperse Polystyrene Microspheres ZHANG Qiong-Gang, BAO De-Cai, MA Xiao-Jun Chem. J. Chinese Universities    2004, 25 (12): 2375-2378.   Abstract （2353）      PDF（pc） （1057KB）（2078）       Knowledge map    Save Monodisperse polystyrene(PS) microspheres with the size range of 2-20 μm were prepared by membrane emulsification and subsequent drying in liquid technique using the shirasu porous glass(SPG) membrane. The PS microspheres size was about twice of the membrane pore size and was slightly affected by the PS concentration. The distribution of the PS microspheres was strongly dependent on the emulsification pressure, and in a certain pressure range, monodispersed microspheres were obtained. Furthermore, PS microspheres with pores on the surface were prepared by adding toluene into the dispersion phase. The hollow PS microspheres were obtained by drying in liquid technique based on the formation of multiple W/O/W emulsions. Reference | Related Articles | Metrics

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Chem. J. Chinese Universities    2021, 42 (1): 0-.   Abstract （467）      PDF（pc） （323KB）（1979）       Knowledge map    Save Related Articles | Metrics

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Progress in the Study on Synthetic Method of Cyclopeptide TANG Yan-Chun, TIAN Gui-Ling, YE Yun-Hua Chem. J. Chinese Universities    2000, 21 (7): 1056-1063.   Abstract （1821）      PDF（pc） （819KB）（2233）       Knowledge map    Save The synthetic method and strategy of cyclopeptide were presented, some efficient coupling reagents were introduced, and different influence factors such as the concentration of reaction solution, structure of linear peptide precursor, conformation etc, were discussed. Related Articles | Metrics

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Studies on Amide Ⅲ Infrared Bands for the Secondary Structure Determination of Proteins XIE Meng-Xia, LIU Yuan Chem. J. Chinese Universities    2003, 24 (2): 226-231.   Abstract （3857）      PDF（pc） （1101KB）（2803）       Knowledge map    Save Fourier transform infrared spectroscopy is increasingly becoming an important method for quantitatively determining the secondary structure of proteins. Amide Ⅰ band(1 600-1 700cm-1) and amide Ⅲ (1 220-1 330cm-1) are two main bands for this purposes. Amide Ⅲ was neglected because of its relatively weak in signals, but there is not interference from water and water vapor vibration bands and it is more sensitive to the changes of protein secondary structure. In this paper, proteins BSA and RNase A were denatured by methanol. The component bands of secondary structure in amide Ⅲ were assigned by combining the quantitative results of amide Ⅰ band. α-Helix 1 330-1 290cm-1; β-turn 1 295-1 265cm-1; Random coil 1 270-1 245cm-1 and β-sheet 1 250-1 220cm-1. The overlapping area between the neighboring bands of different structures, such as 1 290-1 295cm-1, 1 265-1 270cm-1, 1 245-1 250cm-1, can be determined according to quantitative results of amide Ⅰ band. By using above assignments, the quantitative analysis results of the proteins in which the secondary structures have been known were consistent with that of X-ray data and amide Ⅰ band. Related Articles | Metrics

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XPS Valence Band of ZnO Films LI Wan-Cheng, DU Guo-Tong, YANG Xiao-Tian, LIU Bo-Yang, ZHANG Yuan-Tao, ZHAO Bai-Jun, JIANG Xiu-Ying Chem. J. Chinese Universities    2004, 25 (11): 2078-2081.   Abstract （4646）      PDF（pc） （573KB）（2640）       Knowledge map    Save ZnO films are grown by the plasma-assisted metal organic chemical vapor deposition(MOCVD) on c-sapphire and are measured by XPS. The results show that comparing with O1s and Zn2p, Zn3d has more obvious chemical displacement which can help us study the characteristics of ZnO film more effectively. The binding energy of Zn3d electron becomes larger along with the strengthening of coupling between Zn3d or Zn3d+Zn4s and O2p. The temperature of DEZn is an important factor which affects the formation of covalent bond between Zn and O atoms. Reference | Related Articles | Metrics

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Facile Synthesis and Properties of Robust and Anti-swelling Hydrogels LUO Chunhui, ZHAO Yufei Chem. J. Chinese Universities    2021, 42 (6): 2024-2033.   DOI: 10.7503/cjcu20200722 Abstract （1867）   HTML （47）    PDF（pc） （4476KB）（1928）       Knowledge map    Save Robust and anti-swelling hydrogels based on commercial available polyvinyl alcohol（PVA） and chitosan（CS） were prepared via freezing-thawing cycle to prepare the precursor PVA-CS hydrogel firstly， followed by soaking in sodium chloride aqueous solution and dialysis against water to obtain the resultant PVA-CS-6.16-30 hydrogel. The microstructures of the two hydrogels were characterized， and their mechanical pro-perties were evaluated. Due to the multiple interactions of hydrogen bonding， crystalline region and chain entanglement， the obtained PVA-CS-6.16-30 hydrogel dissipated external energy more effectively. Compared with the precursor PVA-CS hydrogel， the free water content and mesh size of the resultant hydrogel declined from 62.8% and 6.11 to 52.6% and 5.21 nm， respectively. In contrast， the gel fraction， cross-linking density and crystalline degree of PVA increased from 58.6%， 7.69×10-4 and 14.8% to 86.8%， 9.97×10-4 mol/cm3 and 17.2%， respectively. Benefited from the higher cross-linking density and more homogeneous gel framework， the tensile strength， elongation at break， toughness as well as compressive stress of the resultant hydrogel increased to 2.9 MPa， 229%， 3.3 MJ/m3 and 7.6 MPa， respectively. Furthermore， it exhibited excellent anti-swelling and creep-resistant abilities. The resultant hydrogel maintained its original shapes and mechanical properties（tensile and compressive strength were 2.8 and 7.5 MPa， respectively） even after soaking in PBS aqueous solution for 7 d at 37 ℃. We hope that the full-fledged starting material， easy-operated process and balanced properties of the resultant hydrogel will promote the development of tissue engineering and biomedical materials for commercial applications. Table and Figures | Reference | Supplementary Material | Related Articles | Metrics

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High Temperature Treatment and Characterization of Carbon Nanotubes WANG Yao, HUANG Wei, WEI Fei, LUO Guo-Hua, YU Hao, AIHEMAI Ti-Jiang Chem. J. Chinese Universities    2003, 24 (6): 953-957.   Abstract （2572）      PDF（pc） （506KB）（2993）       Knowledge map    Save Multi-walled carbon nanotubes(MWNTs) produced by the catalytic chemical vapor deposition(CCVD) method in a nano-agglomerated fluidized-bed reactor(NAFBR) have been treated in a vacuum furnace at the temperatures between 1 500 and 2 150 ℃. High resolution transmission electron microscopy(HRTEM), laser Raman spectroscopy, X-ray diffraction(XRD) and thermogravimetric analysis(TGA) were performed to characterize the annealed and purified MWNTs. The results reveal that the graphite layers of the tube-walls are more regular after the high temperature treatment, which can be characterized by Raman analysis. However, large defects in tube-walls can not be healed completely. Heating the nanotubes up to 1 800 ℃ essentially results in the removal of nanometer catalyst particles, and MWNTs with a purity of more than 99% can be obtained. Related Articles | Metrics

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Rapid Grafting of Phenylboronic Acid with Hydroxypropyl Chitosan Mediated by HATU LI Aoqi, HU Chuanzhi, SHI Han, DENG Mingyu, XIAO Bo, JIANG Bo Chem. J. Chinese Universities    2023, 44 (6): 20220698-.   DOI: 10.7503/cjcu20220698 Abstract （810）   HTML （21）    PDF（pc） （1100KB）（1441）       Knowledge map    Save Phenylboronic acid（PBA） can form reversible covalent bonds with cis-1，2-diol or 1，3-diol in an aqueous solution， which makes it useful as the glucose-responsive units or dynamic cross-linking groups in nano/hydrogels. In this paper， PBA was efficiently grafted on hydroxypropyl chitosan（HPCS） by employing 2-（7-azabenzotriazol-1-yl）- N，N，N'，N'-tetramethyluronium hexafluorophosphate（HATU） as a coupling reagent in dimethyl sulfoxide（DMSO）. The resulting carboxyphenylboronic acid-grafted hydroxypropyl chitosan（CPBA-HPCS） was soluble when pH>8.5， and the structure was characterized and confirmed by Fourier-transform infrared spectroscopy（FTIR） and nuclear magnetic resonance（NMR）. In addition， the kinetics of the reaction were studied and a series of CPBA-HPCS with different substitution degrees（up to 0.78） was prepared. This novel chitosan derivative has good application prospects in the preparation of smart hydrogels and drug carriers. Table and Figures | Reference | Related Articles | Metrics

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Progress in Synthetic Peptide Vaccine XU Jia-Xi Chem. J. Chinese Universities    2000, 21 (11): 1688-1693.   Abstract （1829）      PDF（pc） （553KB）（1476）       Knowledge map    Save Research progress in synthetic peptide vaccine has been reviewed. Various methods seeking for epitopic peptides, including enzyme hydrolysis and chemical cleavage, deductive method aided by computer, chemically synthetic peptide method and X-ray crystal structure, were discussed. Preparation methods and applications of various synthetic peptide antigens such as peptide-carrier complex antigen, polymeric peptide antigen, etc, used in vaccination recently have been introduced systematically. Related Articles | Metrics

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Recent Advances in Amorphous FePO4 for Sodium-Ion Battery Cathodes SHENG Xinru, ZHANG Zhuangzhuang, DING Tangjing, LIAO Jiaying, ZHOU Xiaosi Chem. J. Chinese Universities    2023, 44 (5): 20220724-.   DOI: 10.7503/cjcu20220724 Abstract （678）   HTML （24）    PDF（pc） （1386KB）（1470）       Knowledge map    Save With the increasingly serious energy and environmental problems， the development of green energy storage and conversion technologies becomes more and more crucial. As an environmentally friendly energy storage device， the rapid development of the sodium-ion batteries（SIBs） has stimulated the demand for high-performance cathode materials. Among various kinds of cathode materials， amorphous iron phosphate（FePO4） has attracted enormous attention as a promising cathode material for sodium-ion batteries because of its high theoretical specific capacity and superior electrochemical reversibility. Herein， this review is focused on recent advances in amorphous FePO4 for sodium-ion battery cathodes. First， the common characteristics and applications of amorphous FePO4 are introduced. Next， the synthesis methods are summarized， including template synthesis， hydrothermal synthesis and some other methods. Subsequently， the research progress of strategies to improve sodium-ion storage properties is introduced in detail， with an emphasis on the relationship between structure and performance. Finally， the conclusion and prospects in this field are discussed. Table and Figures | Reference | Related Articles | Metrics

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Preparation and Catalytic Performance of Surface-covered AuNPs@PNIPAM Composite Particles YAN Yutian, WU Si, CHANG Kangkang, XIA Yuzheng, CHEN Xiaonong, SHI Shuxian Chem. J. Chinese Universities    2023, 44 (4): 20220636-.   DOI: 10.7503/cjcu20220636 Abstract （352）   HTML （15）    PDF（pc） （5605KB）（1302）       Knowledge map    Save Gold nanoparticles（AuNPs） with high surface energy are easy to agglomerate in water， which restricts their applications. In this study， poly（N-isopropyl acrylamide）（PNIPAM） microgel and AuNPs were combined by electrostatic interaction through physical blending method inorder to cause negative citrate-stabilized AuNPs absorbed on the surface of positive PNIPAM microgels. The prepared surface-covered AuNPs@PNIPAM particles not only have excellent dispersion stability， but also exhibit a temperature-dependent colorimetric property， showing a reversible change of “red→purple→red” during the temperature change of 25 ℃→50 ℃→25 ℃. In addition， the p-nitrophenol（4-NP） reduction reaction was used as the simulated catalytic reaction to examine the catalytic performance of AuNPs@PNIPAM. The results showed that the catalytic performance of AuNPs@PNIPAM first decreased and then increased with temperature. Compared to similar materials reported in the literature， the AuNPs@PNIPAM showed both temperature-colorimetric properties and catalytic performance. Table and Figures | Reference | Related Articles | Metrics

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Advances in Alloy-based High-capacity Li-containing Anodes for Lithium-ion Batteries MAO Eryang, WANG Li, SUN Yongming Chem. J. Chinese Universities    2021, 42 (5): 1552-1568.   DOI: 10.7503/cjcu20200750 Abstract （1311）   HTML （66）    PDF（pc） （7469KB）（2131）       Knowledge map    Save The emergent Li-containing alloys（LixMy， M refers to metal or nonmetal element that can react with Li to form alloys） is a class of promising electrode materials for next-generation high energy lithium-ion batteries. They deliver high theoretical specific capacities that are several times that of current graphite and can act as active lithium suppliers that are different from traditional lithium-free alloy anodes（Si， Sn， P， etc.）. The LixMy anodes can pare with high-capacity Li-free cathodes（such as Sulfur， O2， FeF3， V2O5， etc.） to develop a new full battery system. In this paper， researches on Li-containing alloy-based high-capacity anodes LixMy（e.g.， Li4.4Si， Li4.4Sn， Li3P， Li2.25Al， etc.） were reviewed. Scientific challenges and technical difficulties of LixMy anodes were systematically analyzed and discussed. Various methods for materials synthesis and electrodes fabrication were summarized. Furthermore， various full-cell configurations based on LixMy anodes were introduced， including Li-ion batteries（LIBs）， Li-ion-sulfur batteries（LISBs）， and Li-ion-oxygen batte-ries（LIOBs）. Moreover， research strategies and achievements on addressing the challenges of LixMy anodes and improving their performance were discussed， including composition adjustment， surface coating， material composite， electrode treatment， and electrolyte engineering， etc. Also， perspectives and new insights for the future development of LixMy anodes are proposed. Table and Figures | Reference | Related Articles | Metrics

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Applications of Metal-organic Framework-based Material in Carbon Dioxide Photocatalytic Conversion ZHAO Yingzhe, ZHANG Jianling Chem. J. Chinese Universities    2022, 43 (7): 20220223-.   DOI: 10.7503/cjcu20220223 Abstract （803）   HTML （29）    PDF（pc） （4990KB）（1534）       Knowledge map    Save Converting carbon dioxide（CO2） into fuels or high-additional-valued chemicals is an efficient route to decrease atmospheric CO2 concentration and mitigate green-house effect. Particularly， the photocatalytic CO2 conversion is of importance due to its mild reaction condition and low energy consumption. Metal-organic framework-based（MOF-based） materials are a kind of efficient catalyst for CO2 photocatalytic conversion owing to their unique features such as large specific surface area， good photoelectric properties and various tunability. In this article， the applications of MOF-based materials in CO2 photocatalytic reduction， cycloaddition and carboxylation in recent two years were reviewed. The advantages， limitations and future development of MOF-based materials for photocatalytic CO2 conversion reactions were discussed. Table and Figures | Reference | Related Articles | Metrics