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44篇 您的检索式:作者名="Zhang Chengfeng"
    题名 作者 年代 出处 被引量
1Numerical Study of Flow and Heat Transfer Characteristics of Impingement/Effusion Cooling显示文摘Three-dimensional numerical simulation is carried out to investigate the flow and heat transfer characteristics of impingement/effusion cooling systems. The impingement/effusion holes are arranged on two parallel perforated plates respectively in a staggered manner. Every effusion hole has an inclined angle of 30° with respect to the surface. The two parallel plates are spaced three times the diameter of the effusion hole. The ratio of center-to-center spacing of adjacent holes to the diameter of the effusion hole is set to be 3.0,4.0 and 5.0 respectively. The flow field,temperature field and wall film cooling effectiveness are calculated for different blowing ratios ranging from 0.5 to 1.5. In general,the wall cooling effectiveness increases as the center-to-center spacing of adjacent holes decreases or the blowing ratio increases.Zhang Jingzhou Xie Hao Yang Chengfeng 2009Chinese Journal of Aeronautics2009,22,4:16
2Humoral immune response to circulating SARS-CoV-2 variants elicited by inactivated and RBD-subunit vaccines显示文摘SARS-CoV-2 variants could induce immune escape by mutations on the receptor-binding domain(RBD)and N-terminal domain(NTD).Here we report the humoral immune response to circulating SARS-CoV-2 variants,such as 501Y.V2(B.1.351),of the plasma and neutralizing antibodies(NAbs)elicited by CoronaVac(inactivated vaccine),ZF2001(RBD-subunit vaccine)and natural infection.Among 86 potent NAbs identified by high-throughput single-cell VDJ sequencing of peripheral blood mononuclear cells from vaccinees and convalescents,near half anti-RBD NAbs showed major neutralization reductions against the K417N/E484K/N501Y mutation combination,with E484K being the dominant cause.VH3-53/VH3-66 recurrent antibodies respond differently to RBD variants,and K417N compromises the majority of neutralizing activity through reduced polar contacts with complementarity determining regions.In contrast,the 242–244 deletion(242–244Δ)would abolish most neutralization activity of anti-NTD NAbs by interrupting the conformation of NTD antigenic supersite,indicating a much less diversity of anti-NTD NAbs than anti-RBD NAbs.Plasma of convalescents and CoronaVac vaccinees displayed comparable neutralization reductions against pseudo-and authentic 501Y.V2 variants,mainly caused by E484K/N501Y and 242–244Δ,with the effects being additive.Importantly,RBD-subunit vaccinees exhibit markedly higher tolerance to 501Y.V2 than convalescents,since the elicited anti-RBD NAbs display a high diversity and are unaffected by NTD mutations.Moreover,an extended gap between the third and second doses of ZF2001 leads to better neutralizing activity and tolerance to 501Y.V2 than the standard three-dose administration.Together,these results suggest that the deployment of RBD-vaccines,through a third-dose boost,may be ideal for combating SARS-CoV-2 variants when necessary,especially for those carrying mutations that disrupt the NTD supersite.Yunlong Cao Ayijiang Yisimayi Yali Bai Weijin Huang Xiaofeng Li Zhiying Zhang Tianjiao Yuan Ran An Jing Wang Tianhe Xiao Shuo Du Wenping Ma Liyang Song Yongzheng Li Xiang Li Weiliang Song Jiajing Wu Shuo Liu Xuemei Li Yonghong Zhang Bin Su Xianghua Guo Yangyang Wei Chuanping Gao Nana Zhang Yifei Zhang Yang Dou Xiaoyu Xu Rui Shi Bai Lu Ronghua Jin Yingmin Ma Chengfeng Qin Youchun Wang Yingmei Feng Junyu Xiao Xiaoliang Sunney Xie 2021Cell Research2021,31,7:12
3Influence of Multi-hole Arrangement on Cooling Film Development显示文摘A series of computations is conducted for many multi-hole arrangements at several blowing ratios to further investigate the evolution of the film from multi-holes. The influence of multi-hole arrangement on effusion film cooling is analyzed and a preliminary relationship evaluating the film development from developing state to developed state is brought forward. Results show that the coolant jets from front rows of multi-holes merge rapidly and the strength of the kidney vortices due to mainstream-coolant jet interaction in the downstream region are mitigated under super-long-diamond arrangement where the streamwise hole-to-hole pitch is bigger than spanwise hole-to-hole pitch. The holes array arranged in super-long-diamond mode is not only in favor of obtaining developed film layer, but also improving averaged adiabatic film cooling effectiveness.YANG Chengfeng ZHANG Jingzhou 2012Chinese Journal of Aeronautics2012,25,2:10
4Evolution of Jobs-housing Spatial Relationship in Beijing Metropolitan Area:A Job Accessibility Perspective显示文摘With the urban expansion and economic restructuring, the jobs-housing relationship has become an important issue in studies on urban spatial structure. This paper employed a job accessibility model, which is an evaluation instrument to measure the jobs-housing relationship in Beijing Metropolitan Area from a job accessibility perspective. The results indicate that the population in the central city is declining, whereas the population in the suburbs is consistently growing and forming new population centers. However, the distribution pattern of employment is still highly centralized. Job accessibility varies in different locations, but the inner-city areas(within the Third Ring road) have seen improved job accessibility over time while job accessibility in the suburbs(especially outside the Fourth Ring road) has decreased, and this has led it to become a primary area of residential and employment mismatch. At the same time, the new towns in the outer suburbs have not yet demonstrated great potential to attract more jobs. In addition we find that, to some extent, urban planning changes the jobs-housing relationship, but a polycentric urban spatial structure is not yet evident. The floating population and related housing policy also affect the jobs-housing relationship. We propose some measures to resolve the spatial mismatch as well as some future research directions.HAN Huiran YANG Chengfeng WANG Enru SONG Jinping ZHANG Meng 2015Chinese Geographical Science2015,25,3:9
5Phylogenetic and genetic characterization of a 2017 clinical isolate of H7N9 virus in Guangzhou,China during the fifth epidemic wave显示文摘Pathogenic H7N9 influenza viruses continue to pose a public health concern. The H7N9 virus has caused five outbreak waves of human infections in China since 2013. In the present study, a novel H7N9 strain(A/Guangdong/8 H324/2017) was isolated from a female patient with severe respiratory illness during the fifth wave of the 2017 H7N9 epidemic. Phylogenetic analysis showed that the H7N9 viruses collected during the fifth wave belong to two different lineages: the Pearl River Delta lineage and the Yangtze River Delta lineage. The novel isolate is closely related to the Pearl River Delta H7N9 viruses, which were isolated from patients in Guangdong Province. The novel H7N9 isolate has an insertion of three basic amino acids in the cleavage site of hemagglutinin(HA), which may enhance virulence in poultry. The 2017 isolate also possesses an R292 K substitution in the neuraminidase(NA)protein, which confers oseltamivir resistance. This study highlights the pandemic potential of the novel H7N9 virus in mammals;thus, future characterization and surveillance is warranted.Yongqiang Deng Chunlin Li Jianfeng Han Yingfen Wen Jian Wang Wenxing Hong Xiaofeng Li Zhongyu Liu Qing Ye Jing Li Changshuai Zhou Lei Yu Chengfeng Qin Fuchun Zhang Tao Jiang 2017Science China(Life Sciences)2017,60,12:9
6Influence of foraminifera on formation and occurrence characteristics of natural gas hydrates in fine-grained sediments from Shenhu area, South China Sea显示文摘Marine gas hydrates accumulate primarily in coarse-grained, high-permeability layers; however, highly saturated natural gas hydrates have been discovered in the fine-grained sediments of Shenhu area, South China Sea(SCS). This may be explained by key factors, such as the great abundance of foraminifera shells. In this paper, by analyzing the SCS foraminifera structure and performing hydrate formation experiments in the foraminifera shells, the contribution of foraminifera to hydrate accumulation in the SCS was investigated from a microscopic point of view. Simulations of hydrate formation were carried out in both pure SCS foraminifera shells and the host sediments. Pore structures in typical foraminifera were studied by use of micro-focus X-ray computed tomography(CT) and scanning electron microscopy(SEM). Hydrate growth and occurrence characteristics in the foraminifera shells were observed in-situ. The results showed that the presence of foraminifera significantly enhanced the effective porosity of the SCS sediments. Moreover, while the hydrates grew preferentially in the chambers of the coarse-grained foraminifera by adhering to the inner walls of the foraminifera shells, no apparent hydrate accumulation was observed in the fine-grained or argillaceous matrix. These findings provide a basis for further studies on the accumulation mechanism of hydrates and physical properties of hydrate reservoir in the South China Sea.LI ChengFeng HU GaoWei ZHANG Wei YE YuGuang LIU ChangLing LI Qing SUN JianYe 2016Science China Earth Sciences2016,59,11:7
7寨卡病毒引起小鼠睾丸损伤并导致雄性不育显示文摘虽然寨卡病毒与其他黄病毒属成员,如登革热病毒、乙型脑炎病毒和两尼罗病毒都是通过蚊媒传播,但是前人的研究发现寨卡病毒在精液中存在数月之久,暗示其性接触传播的可能性。本研究表明寨卡病毒影响雄性生殖系统,提示了其对男性健康的潜在危害。Wenqiang Ma Shihua Li Shuoqian Ma Lina Jia Fuchun Zhang Yong Zhang Jingyuan Zhang Gary Wong Shanshan Zhang Xuancheng Lu Mei Liu Jinghua Yan Wei Li Chuan Qin Daishu Han Chengfeng Qin Na Wang 李向东 高福 2017科学新闻2017,19,4:5
8Crystalline behaviors and phase transition during the manufacture of fine denier PA6 fibers显示文摘Recently we have successfully produced fine denier PA6 fibers by using additives containing lanthanide compounds.Meanwhile,crystallization and phase transition of PA6 fibers during spinning and drawing processes were investigated.During the spinning process,β phase crystal could be obtained in as-spun PA6 fibers which were produced with relatively high melt draw ratio,while γ phase crystal predominated when the melt draw ratio was relatively low.β phase crystal,whose behaviors are similar with those of γ phase by FT-IR and XRD characterization,could be transformed to α form easily when PA6 fibers are immersed in boiling water.However,γ phase crystal of PA6 remains unchanged in boiling water.Thus,β and γ phase crystals of PA6 can be differentiated by the crystalline behaviors of PA6 fibers after treatment in boiling water.Further experiments demonstrate that the β phase can also be produced during a drawing process where a phase transformation from γ to α occurs.In other words,β phase may act as an intermediate state during the phase transformation.ZHANG ChengFeng LIU YuHai LIU ShaoXuan LI HuiZhen HUANG Kun PAN QingHua HUA XiaoHui HAO ChaoWei MA QingFang LV ChangYou LI WeiHong YANG ZhanLan ZHAO Ying WANG DuJin LAI GuoQiao JIANG JianXiong XU YiZhuang WU JinGuang 2009Science China Chemistry2009,52,11:4
9In-situ emb e dding zeolitic imidazolate framework derived Co–N–C bifunctional catalysts in carbon nanotube networks for flexible Zn–air batteries显示文摘Recently, the development of high-performance bifunctional oxygen catalysts integrated with flexible conductive scaffolds f or rechargeable metal-air batteries has attracted considerable interest, driving by fastgrowing wearable electronics. Herein, we report a flexible bifunctional oxygen catalyst thin film consisting of Co–N–C bifunctional catalysts embedding in carbon nanotube(CNT) networks. The catalyst is readily prepared by pyrolysis of cobalt-based zeolitic imidazolate frameworks(ZIF-67) that are in-situ synthesized in CNT networks. Such catalyst film demonstrates very high catalytic activities for oxygen reduction(onset potential: 0.91 V, and half-wave potential: 0.87 V vs. RHE) and oxygen evolution(10 m Acm^-2 at 1.58 V) reactions, high methanol tolerance property, and long-term stability(97% current retention). Moreover, our integrated catalyst film shows very good structure flexibility and robustness. Based on the obtained film air electrodes, flexible Zn–air batteries demonstrate low charging and discharging overpotentials(0.82 V at 1 m A cm^-1) and excellent structure stability in the bending tests. These results indicate that presently reported catalyst films are potential air electrodes for flexible metal–air batteries.Bo Lv Sha Zeng Wei Yang Jian Qiao Chao Zhang Chengfeng Zhu Minghai Chen Jiangtao Di Qingwen Li 2019Journal of Energy Chemistry2019,28,11:2
10Targeting EZH1/2 induces cell cycle arrest and inhibits cell proliferation through reactivation of p57CDKN1C and TP53INP1 in mantle cell lymphoma显示文摘Objective: To explore the effect of dysregulation of epigenetic regulator EZH1 and EZH2 on the proliferation in MCL and the underlying mechanisms.Methods: In this study, we elucidated the role of EZH1 and EZH2 overexpression by immunohistochemistry and correlated them to clinical outcome in 41 MCL patients.Quantitative real-time PCR and Western blot were applied to confirm the level of EZH1 and EZH2 in well-characterized MCL cell lines which were compared to those of na?ve B cells.Then we manipulated the expression of EZH1 and EZH2 in MCL cells using CRISPR/Cas9 system to directly investigate their functional roles in MCL.We also evaluated the effect of two small molecule selective inhibitors, EPZ005687 and UNC1999, on MCL cell proliferation, cell cycle distribution and apoptosis in vitro.Finally, we performed RNA-sequencing(RNA-Seq) and Chromatin immunoprecipitation(ChIP) assay to further gain insight into the underlying molecular mechanisms.Results: We found that EZH2 protein is overexpressed in approximately half of this cohort of MCL cases.More importantly, the overexpression of EZH2 is associated with poor OS in the patients.Nevertheless, simple EZH2 depletion in vitro has little impact on the viability of MCL cells, predominantly because of the consequent up-regulation of EZH1.Consistently, UNC1999, a dual EZH1/2 inhibitor, unlike the EZH2 selective inhibitor EPZ005687, exerts a potent inhibitory effect on MCL cells.Furthermore, we discover CDKN1C and TP53 INP1 as the two important cell cycle regulators, the expression of which are repressed by EZH1/2 mediated epigenetic regulation and are restored by EZH1/2 dual inhibition.Conclusions: Our study suggests that EZH2 participates in the pathogenesis of MCL which may serve as a potential biomarker for prognosis prediction.The dual inhibition of EZH1/2 is a promising therapeutic strategy for MCL.Wei Li Chengfeng Bi Yating Han Tian Tian Xianhuo Wang Huijing Bao Xiaoying Xu Xuhan Zhang Lu Liu Weiwei Zhang Hai Gao Huaqing Wang Huilai Zhang Bin Meng Xi Wang Kai Fu 2019Cancer Biology & Medicine2019,16,3:2
11Caffeic acid phenethyl ester (CAPE) prevents transformation of human cells by arsenite (As) and suppresses growth of As-transformed cells 显示文摘Chengfeng Yang Jing Wu Ronghe Zhang 2005Toxicology2005,213,12:1
12Characteristics of particulate matter from emissions of four typical coal-fired power plants in China显示文摘Zhang Chengfeng Yao Qiang Sun Junming 2005Fuel Processing Technology2005,86,7:1
13Experimental investigation on film cooling characteristics from a row of holes with ridge-shaped tabs显示文摘Yang Chengfeng Zhang Jingzhou 2012Experimental Thermal and Fluid Science2012,37,:1
14Characteristics of particulate matter from emissions of four typical coal-fired power plants in China 显示文摘Zhang Chengfeng Yao Qiang Sun Junming 2005Fuel Processing Technology2005,86,7:1
15A novel synthesis of hexasubstituted cyclotri-phosphazenes显示文摘Chengfeng Ye Zefu Zhang Weimin Jiu 2002Synthetic Communications2002,32,2:1
16Spherical hydroxyapatite with colloidal stability prepared in aqueous solutions containing polymer/surfactant pair显示文摘Chengfeng Li Guochang Li Shuguang Liu Jiahai bai Aijuan zhang 2010Colloids and Surfaces A: Physicochemical and Engineering Aspects2010,,1:1
17Characteristics of particulate matter from emissions of four typical coal-fired power plants in China显示文摘Zhang Chengfeng Yao Qiang Sun Junming 2005Fuel Processing Tecnology2005,,86:1
18Method for detecting the pollution degree of naturally contaminated insulator based on hyperspectral characteristics显示文摘Insulator pollution degree detection is of great significance for preventing a flashover.Equivalent salt deposit density,leakage current,and surface pollution layer conductivity are commonly used to describe insulator pollution degree;however,all these parameters have limitations in field application and real‐time monitoring.Non‐contact detection methods,such as infrared thermal imaging and ultraviolet imaging,only image insulators in a specific band,which makes the extracted features limited.Hyperspectral technology is the new comprehensive image data technology based on imaging spectroscopy that has the advantages of multiband high resolution.Therefore,a method based on hyperspectral image and spectral characteristics is proposed to fully characterize natural pollution in-formation and accurately detect the pollution degree of insulators.The hyperspectral spectral line characteristics,image texture,and colour characteristic data of insulators were extracted and fused and then used to establish the pollution degree detection model on the basis of integrated learning classification algorithms.The results show that the model based on fusion data has an accuracy rate of 95.0%,which is more accurate than the model based on spectral line features only.Consequently,hyperspectral technology can realize the non‐contact detection of pollution degree and provide some guidance for cleaning the contamination of external insulation.Chengfeng Yin Zhang Xiao Yujun Guo Chaoqun Shi Xueqin Zhang Guangning Wu 2021High Voltage2021,6,6:1
19Bone Marrow Transplantation Combined with Mesenchymal Stem Cells Induces Immune Tolerance without Cytotoxic Conditioning显示文摘Yunchuan Wang Jiaqi Liu Chengfeng Xu Wanfu Zhang Li Bai Na Li Yang Liu Yaojun Wang Yingjun Su Dahai Hu 2011Journal of Surgical Research2011,,1:1
20Characteristics of Particulate Matter from Emissions of Four Typicalcoal-fired Power Plants in China显示文摘Zhang Chengfeng Yao Qiang Sun Junming 2005Fuel Processing Technology2005,86,7:1
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