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REVERSE ATOM TRANSFER RADICAL POLYMERIZATION OF STYRENE WITH COPPER-BASED CATALYST

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Chinese Journal of Polymer Science 2001年第1期19卷 59-64页

作者： Dong-qi qin Shu-hui qin kun-yuan Qiu Department of Polymer Science and Engineering College of Chemistry and Molecular EngineeringPeking University Beijing 100871 China Department of Polymer Science and Engineering College of Chemistry and Molecular EngineeringPeking University Beijing 100871 China Department of Polymer Science and Engineering College of Chemistry and Molecular EngineeringPeking University Beijing 100871 China

'Living'/controlled radical polymerization of styrene was carried out with diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS)/CuCl2/bipyridine (bipy) initiation system at 120 degreesC. The molecular weights of resultant PSt increased with the monomer conversion and the polydispersities were in the range of 1.37 similar to1.52. A linear ln([M](o)/[M]) versus time plot was also obtained indicating the constant concentration of growing radicals during the polymerization with this initiation system. End group analysis by H-1-NMR spectroscopic studies showed that the end groups of the polymer obtained is omega -functionalized by a chlorine group from the catalyst and alpha -functionalized by a (carbethoxy-cyano-phenyl)methyl group from the fragments of the initiator. Having CI atom at the chain end, the PSt obtained can be used as a macroinitiator to promote a chain-extension reaction with fresh St and block copolymerization reaction with a second monomer, such as methyl methacrylate, in the presence of CuCl/bipy catalyst via a conventional ATRP process.

关键词： 'living'/controlled radical polymerization reverse ATRP styrene DCDPS/CuCl2/bipy initiation system

Compression techniques of mechanical vibration signals based on optimal sparse representations

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High Technology Letters 2012年第3期18卷 256-262页

作者： Feng kun qin Qiang Jiang Zhinong Diagnosis and Self-Recovery Engineering Research Center Beijing University of Chemical Technology Beijing 100029 P. R. China

This paper presents the result of an experimental study on the compression of mechanical vibration signals. The signals are collected from both rotating and reciprocating machineries by the accelerometers and a data acquisition （DAQ） system. Four optimal sparse representation methods for compression have been considered including the method of frames （ MOF）, best orthogonal basis （ BOB）, matching pursuit （MP） and basis pursuit （BP）. Furthermore, several indicators including compression ratio （CR）, mean square error （MSE）, energy retained （ER） and Kurtosis are taken to evaluate the performance of the above methods. Experimental results show that MP outperforms other three methods.

关键词： signal compression mechanical vibration signals sparse representation matchingpursuit (MP) basis pursuit (BP)

Geographically varying relationships between population flows from Wuhan and COVID-19 cases in Chinese cities

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Geo-Spatial Information Science 2022年第2期25卷 121-131页

作者： Gang Xu Wenwu Wang Dandan Lu Binbin Lu kun qin Limin Jiao School of Remote Sensing and Information Engineering Wuhan UniversityWuhanChina Wuhan Geomatics Institute WuhanChina School of Resource and Environmental Sciences Wuhan UniversityWuhanChina

The COVID-19 epidemic widely spread across China from Wuhan,Hubei Province,because of huge migration before 2020 Chinese New *** studies demonstrated that population outflows from Wuhan determined COVID-19 cases in other cities but neglected spatial hetero-geneities of their ***,we use Geographically Weighted Regression(GWR)model to investigate the spatially varying influences of outflows from ***,the GWR model increases explanatory ability of outflows from Wuhan by 20%,with the adjusted R2 increasing from~0.6 of Ordinary Least Squares(OLS)models to~0.8 of GWR *** coefficient between logarithmic of outflows from Wuhan and COVID-19 cases in other cities is generally less than *** sub-linear scaling relationship indicates the increasing returns of outflows was restrained,proving the epidemic was efficiently controlled outside Hubei at the beginning without obvious local *** in GWR models vary in *** only cities around Wuhan but also cities having close connections with Wuhan experienced higher coefficients,showing a higher vulnerability of these *** secondary or multi-level trans-mission networks deserve to be further explored to fully uncover influences of migrations on the COVID-19 pandemic.

关键词： COVID-19 population flow scaling law Geographically Weighted Regression(GWR) spatial heterogeneity

Spatial Analysis of the Aging Population and Socio-economic Factors of China:Global and Local Perspectives

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Journal of Geodesy and Geoinformation Science 2024年第2期7卷 37-51页

作者： LU Binbin DONG Zheyi YUE Peng qin kun School of Remote Sensing and Information Engineering Wuhan UniversityWuhan 430072China

Population aging has become an inevitable trend and exerted profound influences on socio-economic development in *** this study,we utilized data from national population census and statistical yearbooks in 2010 and 2020 to explore spatio-temporal patterns of aging population and its coupling correlations with socio-economic factors from both global and local *** results from Local Indicators of Spatial Association(LISA)uncover notable spatial disparities in aging population rates,with higher rates concentrated in the eastern regions and lower rates in the western areas of the Chinese *** results from the global correlation analysis with the changes in aging population rates show significant positive correlations with government interventions and industrial structures,but negatively correlated with economic development,social consumption,and medical *** a local perspective,a Geographically Weighted(GW)correlation analysis is employed to uncover local correlations between aging trends and socio-economic *** insights gained from this technique not only underscore the complexity and diversity of economic implications stemming from population aging,but also provide invaluable guidance for crafting region-specific economic policies tailored to various stages of population aging.

关键词： spatial heterogeneity local technique GWmodelS GW correlation analysis,spatial autocorrelation

Genetic and antigenic characterization of recombinant nucleocapsid proteins derived from canine coronavirus and canine respiratory coronavirus in China

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Science China(Life Sciences) 2016年第6期59卷 615-621页

作者： Shuai Lu Yingzhu Chen kun qin Jianfang Zhou Yongliang Lou Wenjie Tan Institute of Medical Virology Wenzhou Medical University National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention

To characterize the antigenicity of nucleocapsid proteins(NP) derived from canine coronavirus(CCo V) and canine respiratory coronavirus(CRCo V) in China, the N genes of CCo V(CCo V-BJ70) and CRCo V(CRCo V-BJ202) were cloned from swabs obtained from diseased pet dogs in Beijing and then sequenced. The recombinant NPs(r NPs) were expressed in Escherichia coli and purified by nickel-affinity column and size exclusion chromatography. Sequencing data indicated that the N genes of CCo V-BJ70 and CRCo V-BJ202 belonging to two distinctly different groups were relatively conserved within each subgroup. Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) results showed that r NPs of CCo V and CRCo V were expressed efficiently and isolated with a final purity of over 95%. Western blot analysis revealed the r NP from CRCo V could cross-react with mice antisera against human coronavirus(HCo V-229 E, NL63, OC43, HKU1), while r NP of CCo V had cross-reactivity with only anti-sera against viruses belonging to the same group(HCo V-229 E and NL63). In summary, CCo V and CRCo V r NPs were successfully expressed in E. coli and showed antigenic cross-reactivity with antisera raised against human coronaviruses. These findings indicate that further serologic studies on coronavirus infections at the animal-human interface are needed.

关键词： canine coronavirus canine respiratory coronavirus nucleocapsid protein expression cross-reactivity

Phase Equilibria in AI-Ca-Li System： a Thermodynamic Description

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Chemical Research in Chinese Universities 2013年第6期29卷 1167-1172页

作者： WANG kun YIN Hui-qin CHENG Jin-hui ZUO Yong XIE Lei-dong University of Chinese Academy of Sciences Beijing 100049 P.R.China

Relations of equilibrium phases in the Al-Ca-Li system were calculated by means of the CALPHAD （calculation of phase diagram） method. The reported thermodynamic model parameters for all the constituent binary systems were directly used in the present calculation. A novel thermodynamic description for the three ternary intermetallic compounds（τ1 τ2 and τ3） was made on the basis of experimental phase equilibria in the Al-Ca-Li system. Comparison between the calculated and experimental phase equilibria shows that we have successfully derived a set of self-consistent thermodynamic parameters for the Al-Ca-Li system. These parameters were then used for the prediction of the selected isothermal and isopleth sections and projected liquidus surface of this ternary system over the entire composition range.

关键词： Phase diagram Thermodynamics Alloy

Development of liquiritigenin-phospholipid complex with the enhanced oral bioavailability

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Chinese Journal of Natural Medicines 2020年第12期18卷 916-921页

作者： SHI Chang-Can qin kun-Ming XU Ke CHEN An CAI Ting CAI Bao-Chang School of Pharmacy Nanjing University of Chinese MedicineNanjing 210046China School of Pharmacy China Pharmaceutical UniversityNanjing 210009China Nanjing Haichang Chinese Medicine Group Corporation Nanjing 210061China

In the present study,liquiritigenin-phospholipid complex(LPC)was developed and evaluated to increase the oral bioavailability of liquiritigenin.A single-factor test methodology was applied to optimize the formulation and process for preparing *** effects of solvent,drug concentration,reaction time,temperature and drug-to-phospholipid ratio on encapsulation efficiency were *** were characterized by UV-visible spectroscopy,differential scanning calorimetry(DSC),fourier transform infrared spectroscopy(FTIR),and powder X-ray diffractometry(PXRD).The apparent solubility and n-octanol/water partition coefficient were *** pharmacokinetic characteristics and bioavailability of the LPC were investigated after oral administration in rats in comparison with liquiritigenin *** LPC was successfully *** optimum level of various parameters for liquiritigeninphospholipid complex was obtained at the drug concentration of 8 mg·mL-1,reaction time for 15 min,reaction temperature of 30℃,a ratio of 1∶4.5(W/W)drug-to-phospholipid and anhydrous ethanol as reaction *** to liquiritigenin,the AUC0-t of the LPC was increased by 239%.The liquiritigenin-phospholipid complex significantly increase the lipid solubility and bioavailability of liquiritigenin,suggesting that it is an effective formulation for further development and clinical applications.

关键词： Liquiritigenin Liquiritigenin-phospholipid complex Solubility Characterization Cioavailability

Optimization of the processing technology of Fructus Arctii by response surface methodology

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Chinese Journal of Natural Medicines 2015年第3期13卷 222-231页

作者： LIU Qi-Di qin kun-Ming SHEN Bao-Jia CAI Hao CAI Bao-Chang Engineering Center of State Ministry of Education for Chinese Medicine Processing Nanjing University of Chinese Medicine Nanjing Haichang Chinese Medicine Group Co Ltd Key Laboratory of State Administration of TCM for Standardization of Chinese Medicine Processing

The present study was designed to optimize the processing of Fructus Arctii by response surface methodology （RSM）. Based on single factor studies, a three-variable, three-level Box-Behnken design （BBD） was used to monitor the effects of independent variables, including processing temperature and time, on the dependent variables. Response surfaces and contour plots of the contents of total lignans, chlorogenic acid, arctiin, and aretigenin were obtained through ultraviolet and visible （UV-Vis） monitoring and high performance liquid chromatography （HPLC）. Fructus Arctii should be processed under heating in a pot at 311℃, medicine at 119℃ for 123s with flipping frequently. The experimental values under the optimized processing technology were consistent with the predicted values. In conclusion, RSM is an effective method to optimize the processing of traditional Chinese medicine （TCM）.

关键词： Fructus Arctii Processing technology Response surface methodology (RSM)

The inferior frontal gyrus and familial risk for bipolar disorder

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Psychoradiology 2022年第4期2卷 171-179页

作者： kun qin John A.Sweeney Melissa P.DelBello Department of Psychiatry and Behavioral Neuroscience University of Cincinnati College of MedicineCincinnatiOH 45219USA Huaxi MR Research Center(HMRRC) Department of RadiologyWest China Hospital of Sichuan UniversityChengduSichuan 610041China

Bipolar disorder(BD)is a familial disorder with high *** factors have been linked to the pathogenesis of *** of probands with BD who are at familial risk can exhibit brain abnormalities prior to illness *** its involvement in prefrontal cognitive control and in frontolimbic circuitry that regulates emotional reactivity,the inferior frontal gyrus(IFG)has been a focus of research in studies of BD-related pathology and BD-risk *** this review,we discuss multimodal neuroimaging findings of the IFG based on studies comparing at-risk relatives and low-risk *** of these studies in at-risk cases suggests the presence of both risk and resilience markers related to the ***-risk individuals exhibited larger gray matter volume and increased functional activities in IFG compared with low-risk controls,which might result from an adaptive brain compensation to support emotion regulation as an aspect of psychological *** connectivity between IFG and downstream limbic or striatal areas was typically decreased in at-risk individuals relative to controls,which could contribute to risk-related problems of cognitive and emotional ***-scale and longitudinal investigations on at-risk individuals will further elucidate the role of IFG and other brain regions in relation to familial risk for BD,and together guide identification of at-risk individuals for primary prevention.

关键词： bipolar disorder prefrontal limbic familial risk resilience magnetic resonance imaging genetic risk