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| 1 | Improvements of heat resistance and adhesive property of condensed poly-nuclear aromatic resin via epoxy resin modification显示文摘A bisphenol epoxy resin was used as modifier to increase the heat resistance of condensed poly-nuclear aromatic(COPNA) resin. The basic properties of COPNA resin and modified resin were characterized by Fourier transform infrared spectroscopy(FT-IR), nuclear magnetic resonance spectroscopy(1H-NMR), vapor pressure osmometry(VPO) and elemental analysis(EA). Average structural parameters of resins were calculated by the improved Brown-Ladner method, and heat resistance of resins was tested by thermogravimetric analysis(TGA). The chemical structure, mechanical properties and heat resistivity of the resin/graphite composites prepared with different resins were compared. The results show that the adhesive property and heat resistance of COPNA resin can be remarkably improved by addition of 5 wt.% epoxy resin. The reason is that the reactions between epoxy groups of epoxy resin and hydroxyl groups of COPNA resin improve the heat resistance and adhesive property of COPNA resin. Electric motor brushes with good mechanical properties and low electrical resistivity were successfully prepared by using the modified resin as binder. | Wu Mingbo Wang Yuwei Jiang Wei Li Shibin Sun Qiqian Zheng Jingtang Qiu Jieshan | 2014 | Petroleum Science2014，11，4： | 5 |
| 2 | Process and Kinetics of Pyrolysis of COPNA Resin Synthesized from FCC Slurry显示文摘The mechanism and kinetics of pyrolysis of condensed poly-nuclear aromatic(COPNA) resins were investigated by non-isothermal thermogravimetry/derivative thermogravimetry measurements at various heating rates(10, 20 and 30 K/min) in nitrogen atmosphere. The changes in the functional groups, microstructure, and elemental composition of COPNA resins heated to different temperatures(200, 400, and 600 ℃) were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, and elemental analysis, respectively. The results of the pyrolytic experiments indicated that the pyrolysis process could be divided into three stages: an initial weight loss stage ranging from 225—450 ℃, a second weight loss stage ranging from 450—560 ℃, and a thermally stable stage occurring above 560 ℃. The heating rate had little effect on the pyrolysis process, and thermogravimetric parameters of COPNA resin, such as temperature at initial weight loss stage(Ti), temperature at final weight loss stage(Tf) and temperature at maximum weight loss stage(Tmax), shifted towards higher temperatures when the heating rate was increased. At higher heating temperature, the number of aliphatic chains and substituted groups attached to aromatic rings of the resultant sample was reduced, whereas the C/H ratio and porosity rate increased. Pyrolysis kinetics studies showed that the activation energy(E) range for the first and second weight loss stages was 150—210 k J/mol and 210—275 k J/mol, respectively, which showed that the mechanism of thermal decomposition differed from that of the weight loss stages. The k0 value was in the orders of between 1011/s and 1018/s when the activation energy was less than 250 k J/mol. When the activation energiy was greater than 250 k J/mol, there was a linearly increasing relationship between k0 and E. | Li Shibin Sun Qiqian Jiang Wei Teng Chuanliang Wu Mingbo | 2016 | China Petroleum Processing & Petrochemical Technology2016，18，2： | 1 |
| 3 | Curing Mechanism of Condensed Polynuclear Aromatic Resin and Thermal Stability of Cured Resin显示文摘In order to improve the thermal stability of condensed polynuclear aromatic(COPNA) resin synthesized from vacuum residue, 1,4-benzenedimethanol was added to cure COPNA resin. The curing mechanism was investigated by proton nuclear magnetic resonance spectrometry, solid carbon-13 nuclear magnetic resonance spectrometry and Fourier transform infrared spectroscopy. Microstructures of the uncured and the cured COPNA resins were studied by scanning electron microscopy and X-ray diffractometry. The thermal stability of COPNA resins before and after curing was tested by thermogravimetric analysis. The element composition of the cured COPNA resin heated at different temperatures was analyzed by an element analyzer. The results showed that the uncured COPNA resin reacted with the cross-linking agent during the curing process, and the curing mechanism was confirmed to be the electrophilic substitution reaction. Compared with the uncured COPNA resin, the cured COPNA resin had a smooth surface, well-ordered and streamlined sheet structure with more crystalline solids, better molecular arrangement and orientation. The weight loss process of the uncured and cured COPNA resins was divided into three stages. Carbon residue of the cured COPNA resin was 41.65% at 600 ℃, which was much higher than 25.02% of the uncured COPNA resin, which indicated that the cured COPNA resin had higher thermal stability. | Li Shibin Sun Qiqian Wang Yuwei Wu Mingbo Zhang Zailong | 2015 | China Petroleum Processing & Petrochemical Technology2015，17，2： | 1 |
| 4 | Prospective controlled study on mycophenolate mofetil and prednisolone in the treatment of membranous nephropathy with nephrotic syndrome显示文摘 | TAK MAOCHAN AI WULIN SYDNEY CWTANG JIA QIQIAN MAN FAILAM YIU WINGHO KAI CHUNGTSE KWOK WAHCHAN KAR NENGLAI COLIN SOTANG | 2007 | Nephrology2007，，6： | 1 |
| 5 | Prospective controlled study on mycophenolate mofetil and prednisolone in the treatment of membranous nephropathy with nephrotic syndrome显示文摘 | TAK MAOCHAN AI WULIN SYDNEY CWTANG JIA QIQIAN MAN FAILAM YIU WINGHO KAI CHUNGTSE KWOK WAHCHAN KAR NENGLAI COLIN SOTANG | 2007 | Nephrology2007，，6： | 1 |
| 6 | A range -free local- ization algorithm for wirelesssensor networks 显示文摘 | HUANG Qiqian SELVAKENNEDYR S | 2008 | Computer Aided Designed2008，13，5： | 1 |
| 7 | Impacts of fire severity and post-fire reforestation on carbon pools in boreal larch forests in Northeast China显示文摘Aims Boreal larch(Larix gmelinii)forests in Northeast China have been widely disturbed since the 1987 conflagration;however,its long-term effects on the forest carbon(C)cycling have not been explored.The objective of this study thus was to quantify the effects of fire severity and post-fire reforestation on C pools and the changes of these forests.Methods Sixteen permanent plots have been set in two types of larch stands(L.gmelinii-grass,LG;and L.gmelinii-Rhododendron dahurica,LR)with three levels of fire severity(unburned,low-severity and high-severity but replanted),at 1987 burned sites in Daxing’anling,northeastern China,to repeatedly measure ecosystem C pools in 1998 and 2014.C components were partitioned into vegetation(foliage,branch,stem and roots),soil and detritus(standing and fallen woody debris and litter).The fire effects on post-fire C dynamics were examined by comparing the differences of C pools and changes between the two field investigations caused by fire severity.Important Findings During the study period,unburned mature stands were C sinks(105 g C m^(−2) year^(−1) for LG,and 190 g C m^(−2) year^(−1) for LR),whereas the low-severity stands were C-neutral(−4 and 15 g C m^(−2) year^(−1) for LG and LR,respectively).The high-severity burned but reforested stands were C sinks,among which,however,magnitudes(88 and 16 g C m^(−2) year^(−1) for LG and LR,respectively)were smaller than those of the two unburned stands.Detritus C pools decreased significantly(with a loss ranging from 26 to 38 g C m^(−2) year^(−1))in the burned stands during recent restoration.Soil organic C pools increased slightly in the unmanaged stands(unburned and lowseverity,with accumulation rates ranging from 4 to 35 g C m^(−2) year^(−1)),but decreased for the high-severity replanted stands(loss rates of 28 and 36 g C m^(−2) year^(−1) for LG and LR,respectively).These results indicate that fire severity has a dynamic post-fire effect on both C pools and distributions of the boreal larch forests,and that effective reforestation practice accelerates forest C sequestration. | Xueyang Hu Jianxiao Zhu Chuankuan Wang Tianli Zheng Qiqian Wu Hui Yao Jingyun Fang | 2016 | Journal of Plant Ecology2016，9，1： | 1 |
| 8 | A Range-Free Localization Algorithm for Wireless Sensor Networks显示文摘 | Huang Qiqian Selvakennedyr S | 2008 | Computer Aided Designed2008，13，5： | 1 |
| 9 | Prospective controlled study on mycophenolate mofetil and prednisolone in the treatment of membranous nephropathy with nephrotic syndrome显示文摘 | TAK MAOCHAN AI WULIN SYDNEY CWTANG JIA QIQIAN MAN FAILAM YIU WINGHO KAI CHUNGTSE KWOK WAHCHAN KAR NENGLAI COLIN SOTANG | 2007 | Nephrology2007，，6： | 1 |
| 10 | Study on Leaching Conditions of Miao Medicine Xiange Zuyu Powder显示文摘[Objectives]This study was conducted to optimize the soaking conditions of Miao medicine Xiange Zuyu Powder.[Methods]With the water-soluble extract as an investigation index,an L_(9)(3^(4))orthogonal test was carried out to investigate the amount of water added,soaking temperature,soaking times and soaking time,and the best soaking conditions for Xiange Zuyu Powder were screened.[Results]The optimal soaking conditions were as follows:adding 1000 ml of boiling water at 100℃,soaking for 20 min each time,3 times in total.[Conclusions]The soaking scheme is reasonable and can provide a reasonable basis for clinical medication. | Yuanfeng YANG Yuchuan LI Renhui YANG Lida CHEN Qiqian CHEN | 2022 | Agricultural Biotechnology2022，11，3： | 0 |
| 11 | Physicochemical properties, molecular structure, antioxidant activity, and biological function of extracellular melanin from Ascosphaera apis显示文摘Ascosphaera apis spores containing a dark-colored pigment infect honeybee larvae,resulting in a large-scale collapse of the bee colony due to chalkbrood disease.However,little is known about the pigment or whether it plays a role in bee infection caused by A.apis.In this study,the pigment was isolated by alkali extraction,acid hydrolysis,and repeated precipitation.Ultraviolet(UV)analysis revealed that the pigment had a color value of 273,a maximum absorption peak at 195 nm,and a high alkaline solubility(7.67%)and acid precipitability.Further chemical structure analysis of the pigment,including elemental composition,Fourier transform infrared(FTIR)spectroscopy,Raman spectroscopy,mass spectrometry,and nuclear magnetic resonance(NMR),proved that it was a eumelanin with a typical indole structure.The molecular formula of melanin is C10H6O4N2,and its molecular weight is 409 Da.Melanin has hydroxyl,carboxyl,amino,and phenolic groups that can potentially chelate to metal ions.Antioxidant function analyses showed that A.apis melanin had a high scavenging activity against superoxide,hydroxyl,and 2,2-diphenyl-1-picrylhydrazyl(DPPH)radicals,and a high reducing ability to Fe3+.Indirect immunofluorescence assay(IFA),scanning electron microscopy(SEM),and transmission electron microscopy(TEM)analyses showed that A.apis melanin was located on the spore wall.The spore wall localization,antioxidant activity,and metal ion chelating properties of fungal melanin have been suggested to contribute to spore pathogenicity.However,further infection experiments showed that melanin-deficient spores did not reduce the mortality of bee larvae,indicating that melanin does not increase the virulence of A.apis spores.This study is the first report on melanin produced by A.apis,providing an important background reference for further study on its role in A.apis. | Zhi LI Hui HENG Qiqian QIN Lanchun CHEN Yuedi WANG Zeyang ZHOU | 2022 | Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2022，23，5： | 0 |
| 12 | Strain-enhanced polarization sensitivity inβ-Ga_(2)O_(3)photodetector显示文摘Polarization-sensitive photodetection and imaging have great application value in fields such as polarization division multiplexing optical communication,remote sensing,near-field imaging and military monitoring.Pursuing a high polarization ratio has always been the research hotspot in polarization-sensitive photodetectors.In this paper,we report a compression strain enhanced polarization ratio inβ-gallium oxide(β-Ga_(2)O_(3))single crystal flake.A rigorous crystallographic analysis confirmed its high crystalline quality and orientation.Angle-resolved polarization Raman spectroscopy(ARPRS)was adopted to study the anisotropy of its optical properties.Extensive ARPRS measurements and theoretical calculation consistently demonstrate the strong optical anisotropy in the high-qualityβ-Ga_(2)O_(3)flake.A polarization ratio of 0.96 was obtained in the flatβ-Ga_(2)O_(3)flake.Furthermore,mechanical strain of±0.7%was introduced intoβ-Ga_(2)O_(3).An increased polarization ratio of 0.98 was achieved in the case of 0.7%compression strain,which is,to the best of our knowledge,the highest value for UVC polarization-sensitive photodetectors.That corresponds to an improved polarization rejection ratio of 100.This work proposed a new path towards improving polarization sensitivity by applying strain engineering in the active material. | Yonghui Zhang Huili Liang Fei Xing Qiqian Gao Yu Feng Yuping Sun Zengxia Mei | 2024 | Science China(Physics,Mechanics & Astronomy)2024，67，4： | 0 |
| 13 | Acute Toxicity Test of Miantan Fuzheng Powder显示文摘[Objectives] An acute toxicity test of Miantan Fuzheng Powder was conducted on rabbits,which were given Miantan Fuzheng Powder at its maximum administration dosage and observed for 14 d,so as to provide reference for medicine development and clinical test.[Methods] New zealand rabbits were divided into four groups randomly,each of which included 4 rabbits,half male and half female.The Miantan Fuzheng Powder-intact skin and Miantan Fuzheng Powderdamaged skin groups were applied with Miantan Fuzheng Powder once at a dose of 5 g/kg body weight,and the blank control group-intact skin and blank controldamaged skin groups were given the auxiliary material( vaseline) once.The rabbits were observed continuously for 14 d after the administration,and variation in body weight was recorded during the observation and then statistically analyzed with SPSS.After the 14 d of observation,the animals were killed through pentobarbital anesthesia and anatomized to observe main visceral organs including heart,liver,spleen lung and kidney.If toxic effect or organ abnormality exists,pathological sections would be prepared and observed.[Results] Rabbits in the blank control and Miantan Fuzheng Powder groups all showed normal appearance,behavior,breath state,position and posture,response to stimulation and growth of body weight,and no irritative erythema and edema on the skin,and the damaged skin recovered naturally within 14 d.No obvious abnormality was observed on visceral organs in autopsy.The Miantan Fuzheng Powder-intact skin and Miantan Fuzheng Powder-damaged skin groups had no significant differences in body weight from the blank control group-intact skin and blank control-damaged skin groups before administration,and on the 7^(th) and 14^(th) day after administration.[Conclusions] In this acute toxicity test,the Miantan Fuzheng Powder-intact skin and Miantan Fuzheng Powder-damaged skin groups were given the drug at the maximum administration dosage of 5 g/kg body weight,which was about 119 times of the clinical dose for human,and no obvious toxic effect was observed. | Qiqian CHEN Xiangling QU Xianmei XU | 2018 | Agricultural Biotechnology2018，7，6： | 0 |
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