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13篇 您的检索式:作者名="XU Xifeng"
    题名 作者 年代 出处 被引量
1Cocrystallization of N-donor type compounds with 5-sulfosalicylic acid:The effect of hydrogen-bonding supramolecular architectures显示文摘Benzotriazole,N,N'-dimethylpiperazine and N-methylpiperazine were applied to crystallize with 5-sulfosalicylic acid(5-H2SSA),affording three new binary molecular cocrystals [(C6H6N3+).(C7H5O6S-)].H2O(1),[(C6H16N22+)1/2.(C7H5O6S-)].H2O(2) and [(C5H14N22+).(C7H5O6S-)2].3H2O(3) under general conditions.Proton-transferring occurs from acid to nitrogen of N-donor compounds in all compounds 1,2 and 3.Analysis of the hydrogen-bonding synthons and their effects on crystal packing were also presented in the context of crystal engineering and host-guest chemistry.In compound 1,1-D infinite chains are extended to a 2-D layered architecture via strong O-H...O hydrogen bonds and then to a 3-D network by N-H...O interactions.Compound 2 and 3 both have the 1-D chain which is formed by O-H...O bonds and weak C-H...O hydrogen bonds.A common intramolecular S(6) [synthon I] ring is formed by the hydroxyl with the carboxyl group in all three compounds.WANG Lei XU LingYan XUE RuiFeng LU XiFeng CHEN RuiXin TAO XuTang 2012Science China Chemistry2012,55,1:8
2Establishment of a transgenic mouse model with liver-specific expression of secretory immunoglobulin D显示文摘Mutation of mevalonate kinase(MVK) is thought to account for most cases of hyperimmunoglobulinemia D syndrome(HIDS) with recurrent fever.However,its mechanism and the relationship between elevated serum immunoglobulin D(IgD) and the clinical features of HIDS are unclear.In this study,we generated by fusion PCR a vector to express high levels of chimeric secretory IgD(csIgD) specifically in the liver.We then generated seven founder lines of transgenic mice by co-microinjection,and verified them using genomic PCR and Southern blotting.We detected the expression of csIgD by reverse transcription PCR,quantitative PCR,western blotting,and enzyme-linked immunosorbent assays.We demonstrated that csIgD could be specifically and stably expressed in the liver.We used flow cytometry to show that overexpression of csIgD in the bone marrow and spleen cells had no effect on B cell development.Morphologic and anatomical observation of the transgenic mice revealed skin damage,hepatosplenomegaly,and nephromegaly in some transgenic mice;in these mice,pathological sections showed high levels of cell necrosis and protein-like sediments in the liver,spleen,and kidney.We demonstrated that the genomic insertion sites of the transgenes did not disrupt the MVK gene on mouse chromosome 5.This transgenic mouse will be useful to explore the pathogenesis of HIDS.WANG Ping WEI ZhiGuo YAN BoWen HUANG Tan GOU KeMian DAI YunPing ZHENG Min WANG MeiLi CHENG XueQian WANG XiFeng XU Chen SUN Yi 2012Science China(Life Sciences)2012,55,3:6
3Enhancing electrocatalytic N_(2)-to-NH_(3) fixation by suppressing hydrogen evolution with alkylthiols modified Fe_(3)P nanoarrays显示文摘Electrocatalytic N_(2) reduction provides an attractive alternative to Haber-Bosch process for artificial NH_(3) synthesis.The difficulty of suppressing competing proton reduction,however,largely impedes its practical use.Herein,we design a hydrophobic octadecanethiol-modified Fe_(3)P nanoarrays supported on carbon paper(C18@Fe_(3)P/CP)to effectively repel water,concentrate N_(2),and enhance N_(2)-to-NH_(3) conversion.Such catalyst achieves an NH_(3) yield of 1.80×10^(-10) mol s^(-1)·cm^(-2) and a high Faradaic efficiency of 11.22%in 0.1 M Na_(2)SO_(4),outperforming the non-modified Fe_(3)P/CP(2.16×10^(-11) mol s^(-1)·cm^(-2),0.9%)counterpart.Significantly,C18@Fe_(3)P/CP renders steady Nrfixing activlty/selectivity in cycling test and exhibits durability for at least 25 h.First-principles calculations suggest that the surface electronic structure and chemical activity of Fe_(3)P can be well tuned by the thiol modification,which facilitates N_(2) electroreduction activity and catalytic formation of NH_(3).Tong Xu Jie Liang Yuanyuan Wang Shaoxiong Li Zhaobai Du Tingshuai Li Qian Liu Yonglan Luo Fang Zhang Xifeng Shi Bo Tang Qingquan Kong Abdullah M.Asiri Chun Yang Dongwei Ma Xuping Sun 2022Nano Research2022,15,2:4
4Artful Application of Garden Plants in Classical Suzhou Gardens显示文摘Defi nition of plant landscaping and features of plant landscaping in classical Suzhou gardens were introduced, the forms of combining plants and buildings, rockeries and waterscapes were analyzed by elaborating selection of plant species and plant furnishings. In addition, manifestation of artistic beauty of the classical Suzhou gardens was explored, and protective measures were given.XU Xifeng HE Guomin 2014Journal of Landscape Research2014,6,1:2
5All-optical modulation of quantum states by nonlinear metasurface显示文摘Metasurfaces have proven themselves an exotic ability to harness light at nano-scale,being important not only for classical but also for quantum optics.Dynamic manipulation of the quantum states is at the heart of quantum information processing;however,such function has been rarely realized with metasurfaces so far.Here,we report an all-optical dynamic modulation of the photonic quantum states using the nonlinear metasurface.The metasurface consists of a metallic nanostructure combined with a photoisomerizable azo layer.By tuning the plasmonic resonance through optically switching the azo molecules between their binary isomeric states,we have realized dynamic control of transmission efficiencies of orthogonally polarized photons and also the phase delay between them,thereby an entangled state was efficiently controlled.As an illustration,a quantum state distillation has been demonstrated to recover a Bell state from a non-maximally entangled one to that with fidelities higher than 98%.Our work would enrich the functions of the metasurface in the quantum world,from static to dynamic modulation,making the quantum metasurface going practical.Di Zhang Yang Chen Shengchao Gong Wei Wu Wei Cai Mengxin Ren Xifeng Ren Shuang Zhang Guangcan Guo Jingjun Xu 2022Light(Science & Applications)2022,11,3:1
6Hydrogen-bonding directed cocrystallization of flexible piperazine with hydroxybenzoic acid derivatives:Structural diversity and synthon prediction显示文摘Four hydroxybenzoic acid building blocks,m-hydroxybenzoic acid,2,4-dihydroxybenzoic acid,2,5-dihydroxyterephthalic acid,and 5-hydroxyisophthalic acid,have been synthesized as robust cocrystallizing agents and employed in reactions with piperazine,including [(C4H12N22+).(C7H5O3)2 ](1),[(C4H12N22+).(C 7H5O4)2 ](2),[(C4H12N22+).(C8H5O62)](3),and [(C4H12N22+)1/2.(C8H5O5)].2H2O(4).Hydrogen-bonded directed assemblies of four salts were validated by single-crystal X-ray diffraction analysis.In compounds 1-4,hydroxybenzoic acids are all deprotonated and piperazine molecules are all protonated to form piperazine dications and keep the chair conformation.Thermal stability of these compounds has been investigated.WANG Lei XUE RuiFeng XU LingYan LU XiFeng CHEN RuiXin TAO XuTang 2012Science China Chemistry2012,55,7:1
7Association of mitochondrial DNA copy number in peripheral blood leukocytes with risk of esophageal adenocarcinoma显示文摘Enping Xu Wenjie Sun Jian Gu Wong-Ho Chow Jaffer A. Ajani Xifeng Wu 2013Carcinogenesis2013,,11:1
8Characterization of the lubricity of bio-oil/diesel fuel blends by high frequency reciprocating test rig显示文摘Yufu Xu Qiongjie Wang Xianguo Hu Chuan Li Xifeng Zhu 2009Energy2009,,1:1
9Research on parametric modeling technology of marine propeller显示文摘ZHANG Shengwen XU Ling FANG Xifeng LIU Chuanlun 2011Advanced Material Research2011,,314316:1
10Production ofN-AcetylD-Neuraminic acid by use of an efficient spore surface display system显示文摘Xiaoman Xu Chao Gao Xifeng Zhang 2011Applied Env Microbio2011,77,10:1
11Radiometric system for measuring the spectrum below ocean surface显示文摘Xu Zhongmin Yu Bingxi Jin Xifeng 2004ISIST2004 Proceeding2004,,3:1
12Electroacupuncture upregulated platelet derived growth factor expression in spared dorsal root ganglion of cats显示文摘A bilateral spared dorsal root ganglion model was established in healthy adult cats by bilateral resection of L 1-5 and L 7 -S 2 dorsal root ganglia. L 6 dorsal root ganglia were spared. Zusanli (ST36) and Xuanzhong (BL39) or Futu (ST32) and Sanyinjiao (SP6) were alternatively electro-stimulated on the right leg. Immunohistochemical staining of anti-serum platelet-derived growth factor demonstrated that the number of total neurons and medium-small sized platelet-derived growth factor positive neurons was significantly decreased on the 7 th day following injury. After 7 days of acupuncture, the total number of positive and large neurons staining for platelet-derived growth factor on the acupuncture side significantly increased compared to the non-acupuncture side. After acupuncture for 14 days, the total positive and medium-small sized neurons significantly increased compared with the non-acupuncture side. Results indicate that acupuncture promoted the synthesis of platelet-derived growth factor in spared dorsal root ganglia.Xifeng Wang Lianshuang Zhang Xiaobo Xu Wei Zhao Guixiang Liu 2012Neural Regeneration Research2012,7,27:0
13Trend Analysis and Intervention Effect Starting Point Detection of COVID-19 Epidemics Using Recalibrated Time Series Models—Worldwide,2020显示文摘Objective:This study aimed to identify a model for short-term coronavirus disease 2019(COVID-19)trend prediction and intervention evaluation.Methods:We compared the autoregressive integrated moving average(ARIMA)model and Holt exponential smoothing(Holt)model on predicting the number of cumulative COVID-19 cases in China.Based on the mean absolute percentage error(MAPE)value,the optimal model was selected and further tested using data from the United States,Italy and Republic of Korea.The intervention effect starting time points and abnormal trend changes were detected by observing the pattern of differences between the predicted and real trends.Results:The recalibrated ARIMA model with a 5-day prediction time span has the best model performance with MAPEs ranged between 2%and 5%.The intervention effects started to show on February 7 in the mainland of China,March 5 in Republic of Korea and April 27 in Italy,but have not been detected in the US as of May 19.Temporary abnormal trends were detected in Korea and Italy,but the overall epidemic trends were stable since the effect starting points.Conclusion:The recalibrated ARIMA model can detect the intervention effects starting points and abnormal trend changes;thus to provide valuable information support for epidemic trend analysis and intervention evaluation.Shu Li Chen Chen Shuyin Cao Kejia Hu Hao Lei Xiaolin Xu Qinchuan Wang Changzheng Yuan Sicong Wang Sisi Wang Junlin Jia Yuanqing Ye Xifeng Wu 2021China CDC weekly2021,3,20:0
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