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16篇 您的检索式:作者名="WU Kefu"
    题名 作者 年代 出处 被引量
1Enhanced orange emission by doping CeB_6 in CaAlSiN_3:Ce^(3+) phosphor for application in white LEDs显示文摘A series of CeB6-doped and CeO_2-doped Ca_(1-x)SiAlN_3:xCe3+(denoted as CASN:Ce3+@CeB6 and CASN:Ce3+@CeO_2, respectively) were synthesized by alloy-nitridation method under high-purity nitrogen atmosphere. The morphologies, crystal phases, and luminescence properties were investigated in detail.With an increase in the concentration of CeB_6, the unit cell volume of CASN:Ce3+@CeB_6 slightly increases due to the substitution between ions, which leads to a change of micro structure around Ce3+. CASN:Ce3+@CeB6 efficiently emits yellow-orange light with a maximum emission intensity at around 550 nm for the content x of 0.01(being in comparable situation, CASN:Ce3+@CeO_2 is x = 0.04) when excited at460 nm. Compared with CASN:Ce3+@CeO_2, the red emission component of Ce3+ in CASN:Ce3+@CeB6 is much stronger. This is ascribed to energy transfer of intra-Ce3+(within one Ce3+ ion) and inter-Ce3+(between Ce3+ and Ce3+ ions). In addition, the replacements of N3-(0.132 nm for CN = 4) and O^(2-)(0.124 nm for CN = 4) by B^(2-)(0.140 nm for CN = 4), which can lead to a marked expansion of the host lattice and a decrease of the oxidation of samples, are also responsible for the increase of red emission component. Furthermore, CASN:Ce3+@CeB_6 phosphor has an excellent thermal stability because of the partial substitution of Ce-O(Ce-N) bonds by more covalent Ce-B. As a result, the outstanding luminescent properties of CASN:Ce3+@CeB6 phosphor make it practical to use in the single phosphor-coated high-color-rendering power white LED.Wenjie Wu Kefu Chao Wenquan Liu Lesi Wei Dahai Hu Taiyang Wang O. Tegus 2018Journal of Rare Earths2018,36,12:6
2Receptor role of membrane bound macrophage colony-stimulating factor显示文摘According to the definition of cytokine, the direction of signaling should be from cytokine to receptor. The counter receptor was presented. Membrane bound macrophage colony-stimulating factor (m-M-CSF) and its receptor (M-CSF-R) were shown in human leukemic cell line J6-1 as autojuxtacrine mechanism. Soluble M-CSF receptor (sM-CSF-R), which was isolated from J6-1 cells membrane, was added into J6-1 cell culture. It was observed inhibition of J6-1 cell proliferation, decreasing of mitosis index and ratio of multinuclear cells, enlargement of cell diameter and volume, down regulation of numerous surface antigens. Dramatic change of intracellular pH was shown between several min to 20 min after treatment of sM-CSF-R. It suggested that some information was transmitted via m-M-CSF from sM-CSF-R. This counter signaling was not influenced by saccharification of m-M-CSF.Wu Kefu He Zhihong Zheng Guoguang Rao Qing Wang Xin 1998Chinese Science Bulletin1998,43,12:5
3Vacancy manipulating of molybdenum carbide MXenes to enhance Faraday reaction for high performance lithium-ion batteries显示文摘“Intrinsic”strategies for manipulating the local electronic structure and coordination environment of defect-regulated materials can optimize electrochemical storage performance.Nevertheless,the structure–activity relationship between defects and charge storage is ambiguous,which may be revealed by constructing highly ordered vacancy structures.Herein,we demonstrate molybdenum carbide MXene nanosheets with customized in-plane chemical ordered vacancies(Mo_(1.33)CT_(x)),by utilizing selective etching strategies.Synchrotron-based X-ray characterizations reveal that Mo atoms in Mo1.33CTx show increased average valence of+4.44 compared with the control Mo_(2)CT_(x).Benefited from the introduced atomic active sites and high valence of Mo,Mo_(1.33)CT_(x)achieves an outstanding capacity of 603 mAh·g^(−1)at 0.2 A·g^(−1),superior to most original MXenes.Li+storage kinetics analysis and density functional theory(DFT)simulations show that this optimized performance ensues from the more charge compensation during charge–discharge process,which enhances Faraday reaction compared with pure Mo_(2)CT_(x).This vacancy manipulation provides an efficient way to realize MXene’s potential as promising electrodes.Xin Guo Changda Wang Wenjie Wang Quan Zhou Wenjie Xu Pengjun Zhang Shiqiang Wei Yuyang Cao Kefu Zhu Zhanfeng Liu Xiya Yang Yixiu Wang Xiaojun Wu Li Song Shuangming Chen Xiaosong Liu 2022Nano Research Energy2022,1,3:2
4Viewpoints on the proinflammation state of leukemia显示文摘Proinflammation represents a pathophysiological state on the early stage of a number of diseases, especially the infectious and immunological ones. In recent years, proinflammation has attracted much attention, and the term 損roinflammation factors?appears frequently in the literature. While investigating leukemia and leukemic cells from the angle of 損roinflammation state? we got some intriguing findings, e.g. we detected the significantly elevated expression of proinflammation factor IL-18 in patients with acute myeloid leukemia (AML), which could up-regulate matrix metalloproteinases (MMP) and specific tissue inhibitors (TIMPs). The increased MMP may play a role in the aggressiveness of myeloid leukemic cells, and be associated with a poor prognosis. This phenomenon reflects an ignored aspect of leukemia. Investigations from the angle of 損roinflammation state?have broaden the fields of tumor and leukemia study.WU Kefu & MA Xiaotong National Laboratory of Experimental Hematology, Institute of Hematology, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin 300020, China Correspondence should be addressed to Wu Kefu (e-mail: kfwu@ public.tpt.tj.cn) 2003Chinese Science Bulletin2003,48,22:1
5A pulsed power supply based on power semiconductor switches and transmission line transformer显示文摘Qiu Jian Liu Kefu Wu Yifan 0,,04:1
6Repetitive and high voltage Marx generator using solid-state devices显示文摘Wu Yifan Liu Kefu Qiu Jian 2007IEEE Trans on Dielectrics and Electrical Insulation2007,14,4:1
7Analysis of the ligand-binding domain of macrophage colony-stimulating receptor显示文摘RNAs have been extracted from human placenta. Extracellular regions of M-CSFR, D1-3, D2-3 and D3 motifs have been amplified with RT-PCR. The proteins have been expressed in E.coli. Enzyme-linked immusorbent assay (EIA) shows that recombinant D1-3 possesses binding ability 3 times that of D2-3. Kd, the dissociation constant of the former is 11 nmol/L, and that of latter is 39 nmol/L. D3 lacks binding ability. These data suggest that D2-3 is the main site for M-CSF binding, D1 is an assistant site and also contributes to the conformation of site for ligand binding.LUO Shouqing ZHENG Dexian LIU Yanxin RAO Qing WU Kefu 2000Chinese Science Bulletin2000,45,13:1
8A pulsed power supply based on power semiconductor switches and transmission line transformer显示文摘Qiu Jian Liu Kefu Wu Yifan 2007IEEE Transactions on Dielectrics and Electrical Insulation2007,14,4:1
9Repetitive and high voltage Marx generator using solid-state devices显示文摘Wu Yifan Liu Kefu Qiu Jian 2007IEEE Trans on Dielectrics and Electrical Insulation2007,14,4:1
10Quantitative assessment of fibrosis-4 score and adverse clinical outcomes in patients with COVID-19显示文摘Dear editor,Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-Co V-2) is a global pandemic leading to a broad spectrum of clinical manifestations, from asymptomatic or mild-to-moderate symptoms, to severe illness, and even death. Accumulating evidence suggests that old age and underlying comorbidities。Kefu Tang Lu Wang Lu Shen Lin He Xi Wu 2022Science China(Life Sciences)2022,65,12:0
11Highly Prevalent SARS-CoV-2 Antigenemia in COVID-19 Patients显示文摘Background:Many issues,such as severity assessment and antibody responses,remain to be answered eagerly for evaluation and understanding of COVID-19.Immune lesion is one of key pathogenesis of the disease.It would be helpful to understand the disease if an investigation on antigenemia and association was conducted in the patients with SARS-CoV-2 infection.Methods:A total of 156 patients admitted to the First People’s Hospital of Hefei or Anhui Provincial Hospital on January to February 2020 were involved in this study.SARS-CoV-2 nucleocapsid(NP)antigen,specific IgM/IgG antibodies,and RNA were detected in sequential sera from three COVID-19 patients,and additional 153 COVID-19 patients by means of NP-antigen capture enzyme-linked immunosorbent assay,colloidal gold quick diagnosis,and real-time RT-PCR,respectively.The clinical types of COVID-19 patients were classified into asymptomatic,mild,moderate,severe,and critical,following on the Chinese guideline of COVID-19 diagnosis and treatment.The demographic and clinical data of patients were obtained for comparable analysis.Results:NP antigen was detected in 5 of 20 sequential sera collected from three COVID-19 patients with typically clinical symptoms,and 60.13%(92/153)expanded samples collected within 17days after illness onset.No SARS-CoV-2 RNA segment was detected in these sera.The NP positive proportion reached a peak(84.85%,28/33)on 6 to 8days after illness onset.Both NP concentration and positive proportion were increased with the increase of clinical severity of COVID-19.Compared to NP negativepatients,NP positive patients had older age[years,medians(interquartileranges(IQR)),49(6)vs.31(11)],lowerpositive proportion of NP specific IgM[27.17%(25/92)vs.59.02%(36/61)],and IgG[21.74%(20/92)vs.59.02%(36/61)]antibodies,and longer duration[days,medians(IQR),24(10)vs.21(13)]from illness to recovery.Conclusions:SARS-CoV-2 NP antigenemia occurred in COVID-19,and presented highly prevalent at early stage of the disease.The antigenemia was related to clinical severity of the disease,and may beresponsible for the delay of detectable SARS-Cov-2IgM.Wenyan Zhang Wei Liu Jiawang Lin Jing Jin Kefu Zhao Liwei Zhu Xiuzhen Wang Lijie Wang Renshu Tang Yindi Zhu Wei Zhou Enqing You Lei Zhang Xuxiang Liu Jinju Wu Lili Chen Wenjing Wang Qiang Zhang Rongbao Gao 2022Infectious Diseases & Immunity2022,2,3:0
12Impacts of tropical cyclones and anthropogenic activities on marine vanadium: A unique perspective from high resolution Porites coral record显示文摘As a typical contaminant in fossil fuels,vanadium has undergone dramatically increase due to the impacts from human activities.The excessive anthropogenic vanadium emissions have altered natural geochemical processes.However,research on vanadium geochemistry in the ocean,which is the major sink for vanadium mobilized on land,has lagged much behind relative to those of other contaminants.Here we reconstruct historical patterns of vanadium in surface seawater utilizing a high-resolution temporal record(1984–2015 CE)of geochemical proxies(vanadium/calcium(V/Ca),δ^(18)O,δ^(13)C,etc.)in a Porites coral colony from an offshore non-estuarine island in the northern South China Sea(SCS).We find a close association between the surface winds and the temporal patterns of coral V/Ca ratios,revealing great potential for documenting prehistoric changes in tropical cyclones.Moreover,the coral V/Ca record remarkably captured the temporal patterns of anthropogenic activities,offering a valuable and novel tool for testing the efficacy of specific legislation on pollution prevention.Combined with the other reported coral vanadium data,we recovered the historical changes in vanadium emissions in the northern SCS and identified that changing industrial practices should be responsible for the differences in anthropogenic vanadium emissions at each stage.Our results demonstrated that the coral V/Ca ratio at a high temporal resolution has great potential as a new and direct geochemical proxy for tropical cyclones after removing artificial disturbances in the ocean.Wei JIANG Xingyuan WU Kefu YU Haodan YANG Shendong XU Ning WANG Yangyang YONG Yinan SUN Chaoshuai WEI Yinghui WANG 2022Science China Earth Sciences2022,65,12:0
13On Catastrophe and Cavitation for SphericalCavity显示文摘IntroductionInrecelltyears,theresearchesoncavitationandcatastropheofacavitysuppliedanewInethodforinvestigatingtheInechanicsofmaterialfailure.Oneofthemostilnporta.ntmethodstoinvestigatethemechanicsisbynonlineaxelasticitytogetherwithbifllrcationtheory...Ming JIN Kefu HUANG Jike WU(Department of Mechanics and Engineering Science, Peking University, Beijing 100871,China) 1999Communications in Nonlinear Science and Numerical Simulation1999,4,4:0
14Internalization and half-life of membrane-bound macrophage colony-stimulating factor显示文摘The binding of recombinant human macrophage colony-stimulating factor (M-CSF) soluble receptor (rh-M-CSF-sR) to membrane-bound macrophage colony stimulating factor (m-M-CSF) and the internalization and recycling of rh-M-CSF-sR/m-M-CSF complexes mediated by m-M-CSF were studied with a model of J6-1 cell line. The results indicated that m-M-CSF bound rh-M-CSF-sR with high affinity (Kd= 1.78×10 12 mol/L) and mediated a temperature- and energy-dependent internalization of rh-M-CSF-sR, and that internalized rh-M-CSF-sR could return to the cell surface in an m-M-CSF-bound state, suggesting that m-M-CSF may have a capability to mediate the internalization and recycling of rh-M-CSF-sR/m-M-CSF complexes. In addition, the half-lives of cell-associated M-CSF and its receptor of stimulated normal human cord blood mononuclear cells (CBMCs) and 4 leukemic cell lines were measured by indirect immunoflu-orescence and flow cytometry. The results showed that the half-lives of the various kinds of M-CSF isoforms andTANG Shengsong LIU Hanzhi CHEN Guibin RAO Qing GENG Yiqi ZHENG Guoguang ZHENG Dexian WU Kefu 2000Chinese Science Bulletin2000,45,18:0
15Catalytic reduction of low-concentration CO_2 with water by Pt/Co@NC显示文摘The reduction of low-concentration carbon dioxide with water to organic fuels is still a huge challenge. In this study, we successfully designed the partially oxidized cobalt nanoparticles coated by the nitrogendoped carbon layer(Co@NC) of 2-8 nm via a facile method and then interspersed with different amount of Pt nanoparticles. The Co@NC decorated with 1 wt% Pt exhibits the best ability for CO_2 reduction to CH_4 and a CH_4 production rate of 14.4 μmol·g^(-1)·h^(-1) is achieved. It is worth noting that the system is carried out under low-concentration CO_2(400 ppm) circumstance without any sacrificial agent, which could be meaningful to the design of catalysts for atmospheric CO_2 reduction.Qianqian Wang Wenzhong Wang Ling Zhang Yang Su Kefu Wang Huixia Wu 2018Journal of Materials Science & Technology2018,34,12:0
16Interface regulation of Cu_(2)Se via Cu–Se–C bonding for superior lithium-ion batteries显示文摘Transition metal selenides have aroused great attention in recent years due to their high theoretical capacity.However,the huge volume fluctuation generated by conversion reaction during the charge/discharge process results in the significant electrochemical performance reduction.Herein,the carbon-regulated copper(I)selenide(Cu_(2)Se@C)is designed to significantly promote the interface stability and ion diffusion for selenide electrodes.The systematic X-ray spectroscopies characterizations and density functional theory(DFT)simulations reveal that the Cu–Se–C bonding forming on the surface of Cu2Se not only improves the electronic conductivity of Cu_(2)Se@C but also retards the volume change during electrochemical cycling,playing a pivotal role in interface regulation.Consequently,the storage kinetics of Cu_(2)Se@C is mainly controlled by the capacitance process diverting from the ion diffusion-controlled process of Cu2Se.When employed this distinctive Cu_(2)Se@C as anode active material in Li coin cell configuration,the ultrahigh specific capacity of 810.3 mA·h·g^(−1)at 0.1 A·g^(−1)and the capacity retention of 83%after 1,500 cycles at 5 A·g^(−1)is achieved,implying the best Cu-based Li^(+)-storage capacity reported so far.This strategy of heterojunction combined with chemical bonding regulation opens up a potential way for the development of advanced electrodes for battery storage systems.Kefu Zhu Shiqiang Wei Quan Zhou Shuangming Chen Yunxiang Lin Pengjun Zhang Yuyang Cao Changda Wang Yixiu Wang Yujian Xia Dengfeng Cao Zeinab Mohamed Xin Guo Xiya Yang Xiaojun Wu Li Song 2023Nano Research2023,16,2:0
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