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| 1 | Machining of SiC ceramic matrix composites:A review显示文摘Continuous fiber reinforced SiC ceramic matrix composites(FRCMCs-SiC)are currently the preferred material for hot section components,safety–critical components and braking components(in the aerospace,energy,transportation)with high value,and have triggered the demand for machining.However,the high brittleness,anisotropy,and heterogeneity of materials bring great challenges to machining,due to high mechanical and thermal loads,severe tool wear,and poor machining quality.With the increasing demand of FRCMCs-SiC parts,high-quality and high-efficient machining has become a hot issue.This review paper provides a detailed literature survey on the machining of FRCMCs-SiC.The material removal mechanism,defect form,and interfacial mechanical properties of FRCMCs-SiC were summarized.The machining processes of FRCMCs-SiC were introduced,and their respective advantages and disadvantages were compared.Given the low machinability(high hardness,high brittleness,anisotropy,and heterogeneity)of FRCMCs-SiC,preliminary experiments have proved that ultrasonic-assisted machining and laser-assisted machining have shown unique advantages in reducing force and tool wear,improving machining quality and machining efficiency.The machined surface integrity was discussed,the influence of process parameters on the machined surface quality was analyzed,and the machining defects of FRCMCs-SiC were summarized.But for FRCMCs-SiC,the existing quantitative evaluation of the machined surface integrity was weak and unsystematic. | Qinglong AN Jie CHEN Weiwei MING Ming CHEN | 2021 | Chinese Journal of Aeronautics2021，34，4： | 21 |
| 2 | Allele-defined genome reveals biallelic differentiation during cassava evolution显示文摘Dear Editor,Generation of heterozygous genomes by hybridization between or within species can help maintain plant diversity and serve as a potential source of new species(Baek et al.,2018).Moreover,genomic heterozygosity is associated with genomic coadaptation,developmental stability,and heterosis.Accurate definition of alleles in haplotypes is necessary to precisely characterize allelic variation controlling agriculturally important traits(Shi et al.,2019).Currently,most released genomes have mosaic assembly of haplotypes due to random selection or collapse of alleles during genome assembly(Shi et al.,2019),which masked allelic variation and functional differentiation of divergent alleles in heterozygous species. | Wei Hu Changmian Ji Haitao shi Zhe Liang Zehong Ding Jianqiu Ye Wenjun Ou Gang Zhou Weiwei Tie Yan Yan Jinghao Yang Xiaoying Yang Yunxie Wei Zhiqiang Jin Jianghui Xie Ming Peng Wenquan Wang Anping Guo Biyu Xu Jianchun Guo Songbi Chen Liming Ma Mingcheng Wang Yang Zhou Xiaolong Li Ruoxi Li Siyi Guo Xinhui Xiao Zhongqing Wan Feifei An Jie Zhang Qingyun Leng Yin Li Ray Ming Kaimian Li | 2021 | Molecular Plant2021，14，6： | 8 |
| 3 | Building a sequence map of the pig pan-genome from multiple de novo assemblies and Hi-C data显示文摘Pigs were domesticated independently in the Near East and China,indicating that a single reference genome from one individual is unable to represent the full spectrum of divergent sequences in pigs worldwide.Therefore,12 de novo pig assemblies from Eurasia were compared in this study to identify the missing sequences from the reference genome.As a result,72.5 Mb of nonredundant sequences(~3% of the genome)were found to be absent from the reference genome(Sscrofa11.1)and were defined as pan-sequences.Of the pan-sequences,9.0 Mb were dominant in Chinese pigs,in contrast with their low frequency in European pigs.One sequence dominant in Chinese pigs contained the complete genic region of the tazarotene-induced gene 3(TIG3)gene which is involved in fatty acid metabolism.Using flanking sequences and Hi-C based methods,27.7% of the sequences could be anchored to the reference genome.The supplementation of these sequences could contribute to the accurate interpretation of the 3D chromatin structure.A web-based pan-genome database was further provided to serve as a primary resource for exploration of genetic diversity and promote pig breeding and biomedical research. | Xiaomeng Tian Ran Li Weiwei Fu Yan Li Xihong Wang Ming Li Duo Du Qianzi Tang Yudong Cai Yiming Long Yue Zhao Mingzhou Li Yu Jiang | 2020 | Science China(Life Sciences)2020，63，5： | 7 |
| 4 | Effects of in-situ TiB_(2)particles on machinability and surface integrity in milling of TiB_(2)/2024 and TiB_(2)/7075 Al composites显示文摘In-situ ceramics particle reinforced aluminum matrix composites are favored in the aerospace industry due to excellent properties.However,the hard ceramic particles as the reinforcement phase bring challenges to machining.To study the effect of in-situ TiB_(2)particles on machinability and surface integrity of TiB_(2)/2024 composite and TiB_(2)/7075 composite,milling experiments were performed,and compared with conventional 2024 and 7075 aluminum alloys.In-situ TiB_(2)particles clustered at the grain boundaries and dispersed inside the matrix alloy grains hinder the dislocation movement of the matrix alloy.Therefore,the milling force and temperature of the composites are higher than those of the aluminum alloys due to the increase of the strength and the decrease of the plasticity.In the milling of composites,abrasive wear is the main wear form of carbide tools,due to the scratching of hard nano-TiB_(2)particles.The composites containing in-situ TiB_(2)particles have machining defects such as smearing,micro-scratches,micro-pits and tail on the machined surface.However,in-situ TiB_(2)particles impede the plastic deformation of the composites,which greatly reduces cutting edge marks on the machined surface.Therefore,under the same milling parameters,the surface roughness of TiB_(2)/2024 composite and TiB_(2)/7075 composite is much less than that of2024 and 7075 aluminum alloy respectively.Under the milling conditions of this experiment,the machined subsurface has no metamorphic layer,and the microhardness of the machined surface is almost the same as that of the material.Besides,compared with 2024 and 7075 aluminum alloy,machined surfaces of TiB_(2)/2024 composite and TiB_(2)/7075 composite both show tensile residual stress or low magnitude of compressive residual stress. | Jie CHEN Weiwei YU Zhenyu ZUO Yugang LI Dong CHEN Qinglong AN Jiwei GENG Ming CHEN Haowei WANG | 2021 | Chinese Journal of Aeronautics2021，34，6： | 5 |
| 5 | A simple Fourier transform spectrometer for terahertz applications显示文摘A simple Fourier transform spectrometer was designed and constructed for the measurement of detectors,sources,passive devices and materials in the terahertz(THz) range.It can be operated at frequencies between 0.3 and 1.5 THz,using a 50-μm-thick Mylar-film beam splitter.The spectral range can be changed by altering the thickness of the beam splitter.The highest frequency resolution is 750 MHz.We studied the properties of heterodyne detectors including superconductor mixers and semiconductor harmonic mixers,direct detectors including an InSb semiconductor bolometer,superconducting tunnel junctions and the Golay cell,and sources including Gunn oscillators and a microwave source with its multipliers,as well as various materials and passive devices including Si wafers and metal mesh filters. | JIANG Yi LIANG Ming JIN BiaoBing KANG Lin XU WeiWei CHEN Jian WU PeiHeng | 2012 | Chinese Science Bulletin2012，57，6： | 4 |
| 6 | Modes of genetic adaptations underlying functional innovations in the rumen显示文摘The rumen is the hallmark organ of ruminants and hosts a diverse ecosystem of microorganisms that facilitates efficient digestion of plant fibers.We analyzed 897 transcriptomes from three Cetartiodactyla lineages:ruminants,camels and cetaceans,as well as data from ruminant comparative genomics and functional assays to explore the genetic basis of rumen functional innovations.We identified genes with relatively high expression in the rumen,of which many appeared to be recruited from other tissues.These genes show functional enrichment in ketone body metabolism,regulation of microbial community,and epithelium absorption,which are the most prominent biological processes involved in rumen innovations.Several modes of genetic change underlying rumen functional innovations were uncovered,including coding mutations,genes newly evolved,and changes of regulatory elements.We validated that the key ketogenesis rate-limiting gene(HMGCS2)with five ruminant-specific mutations was under positive selection and exhibits higher synthesis activity than those of other mammals.Two newly evolved genes(LYZ1 and DEFB1)are resistant to Gram-positive bacteria and thereby may regulate microbial community equilibrium.Furthermore,we confirmed that the changes of regulatory elements accounted for the majority of rumen gene recruitment.These results greatly improve our understanding of rumen evolution and organ evo-devo in general. | Xiangyu Pan Yudong Cai Zongjun Li Xianqing Chen Rasmus Heller Nini Wang Yu Wang Chen Zhao Yong Wang Han Xu Songhai Li Ming Li Cunyuan Li Shengwei Hu Hui Li Kun Wang Lei Chen Bin Wei Zhuqing Zheng Weiwei Fu Yue Yang Tingting Zhang Zhuoting Hou Yueyang Yan Xiaoyang Lv Wei Sun Xinyu Li Shisheng Huang Lixiang Liu Shengyong Mao Wenqing Liu Jinlian Hua Zhipeng Li Guojie Zhang Yulin Chen Xihong Wang Qiang Qiu Brian PDalrymple Wen Wang Yu Jiang | 2021 | Science China(Life Sciences)2021，64，1： | 3 |
| 7 | Divergent synthesis of four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid,esters and evaluation for the antifungal activity显示文摘The four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid 2 were synthesized via the selective direct Sharpless asymmetry dihydroxylation of geraniol as the key step in 35.0%-48.0% overall yields with91.9%-97.7% ee values for esters 4 and 31,3%-36.4% overall yields with 90.3-97.5% ee values for acids 2 using cis-and trans-geraniol as raw materials. Their structures were characterized by ~1H, ^(13)C NMR and HR-ESI-MS data. The in vivo bioassay results showed that the chiral acid(Z, S)-2 was a good lead compound with 80%-100% inhibitory rates against P. cubensis, E. graminis, P. sorghi and C. gloeosporioides at the concentration of 400 μg/mL. | Weiwei Wang Xiaoteng Zhang Yu Zhao Xinlei Liu Zhenhua Zhang Ming'an Wang | 2018 | Chinese Chemical Letters2018，29，12： | 2 |
| 8 | Awareness intervention for Beijing neurologists regarding secondary prevention of cerebral infarction/transient ischemia Cross-sectional investigation显示文摘BACKGROUND: Stroke prevention guidelines should be made available to neurologists for clinical application to aid in uniformity, timing, preciseness, and acceptance of disease. OBJECTIVE: To investigate the awareness of neurologists in some Beijing hospitals of intervention in secondary prevention of cerebral infarction/transient ischemia. DESIGN: Cross-sectional study. SETTING: Beijing Tiantan Hospital, Beijing Anzhen Hospital, General Hospital of Beijing Military Area, Command of Chinese PLA, Beijing Chuiyangliu Hospital, Beijing 6th Hospital, Beijing Hepingli Hospital, and Beijing Daxing District Hospital. PARTICIPANTS: A total of 28 (associate) chief physicians, 58 attending physicians, and 54 resident physicians who engaged in clinical treatment of cerebrovascular diseases were selected from 8 hospitals in Beijing from March to April 2007. All physicians provided informed consent. METHODS: Self-made closed questionnaires were provided for data collection, consisting of 16 questions that were single choice or multiple choice. Specifically, questions 1-7 focused on awareness of blood pressure regulation in different patients and first choice of decompression drug; questions 8-12 focused on awareness of lipid regulation; and questions 13-16 focused on awareness of anti-blood platelet drugs applied in secondary prevention. The scores ranged from 0-100 points, and each question was worth 6.25 points. The scores positively correlated with the awareness rate. To test leveling real-time, the survey lasted for a maximum of 20 minutes. One questionnaire was independently finished by each subject in the survey. MAIN OUTCOME MEASURES: Awareness intervention among neurologists during secondary prevention of cerebral infarction/transient ischemia and questionnaire scores. RESULTS: 140 subjects were included in the final analysis. ① The awareness rate among neurologists for intervention during secondary prevention of cerebral infarction/transient ischemia ranged from 0.7-57.9%, the scores ranged between 0-56 points, and the mean score was 26 points. ② Scores of resident physicians were 0-56 points with a mean score of 26 points; attending physicians scored 6-50 points, with a mean score of 26 points; and chief physicians scored 6-50 points, with a mean score of 23 points. There were no significant differences among the various physicians (F = 0.771, t = 0.465, P > 0.05). CONCLUSION: Awareness among neurologists of intervention during secondary prevention of cerebral infarction/transient ischemia is not ideal. However, there was no significant difference between professional titles. | Ruihua Ma Chunxue Wang Xianwei Wang Yuhui Zhang Yongjun Wang Yilong Wang Xingquan Zhao Jingjing Li Ying Lu Mingjie Xu Zhuo Zhang Li Wang Weiwei Zhang Lang Lin Jiping Tan Yao Li Ming Wei Hongtao Li | 2008 | Neural Regeneration Research2008，3，3： | 2 |
| 9 | Feasibility study of creep feed grinding of 300M steel with zirconium corundum wheel显示文摘The ultrahigh strength 300M steel has been commonly used in the manufacture of aircraft landing gear and rotor shaft parts due to its excellent mechanical properties.Creep feed grinding is one of the essential operations during the whole component manufacturing processes.In this work,the feasibility of creep feed grinding of 300M steel by using the hard zirconium corundum wheel was theoretically and experimentally evaluated.A variety of responses including grinding forces,temperature fields,specific grinding energy,surface integrity and chip modes were carefully recorded.Besides,the mechanism of ground surface profile generation and the spatial frequency spectrum of the surface profile were tentatively analyzed.It was found that the wheel speed has a relative influence on the grinding forces and temperatures of which the work hardening effect dominates the material removal with lower wheel speed while the thermal softening becomes crucial as the wheel speed exceeds the critical value for the studied 300M steel.Furthermore,a scattered spatial frequency spectrum for the generated surface profile was noticed with lower wheel speed while the spectrum gathers towards the lower frequency values with higher amplitude as the wheel speed increases.The shearing chip and flowing chip dominates the main chip type,indicating the excellent abrasive sharpness during the grinding process.In general,the used zirconium corundum wheel presents feasibility for the creep feed grinding of 300M steel because of the high material removal rate,absence of surface burn,low wheel wear and higher compressive residual stresses. | Jiaqiang DANG Heng ZANG Qinglong AN Weiwei MING Ming CHEN | 2022 | Chinese Journal of Aeronautics2022，35，3： | 2 |
| 10 | Surface morphology characterization of unidirectional carbon fibre reinforced plastic machined by peripheral milling显示文摘This paper aims to characterise surface morphology and 3D roughness parameters of unidirectional carbon fibre reinforced plastic(UD-CFRP)milled at 0°,45°,90°,and 135°fibre orientation angles(FOAs).Side milling experiments are conducted on UD-CFRP laminates.Surface damage forms and texture direction of milled surface are analysed.Spatial frequency of defects on CFRP surface is quantitatively determined using radially averaged 2D PSD.The kinematicdynamic surface topography is reconstructed considering feed,runout and vibration,then the ideal roughness parameters,S_(a),S_(q),S_(sk),and S_(ku)are calculated and compared with the measured ones,finally the material factor-induced roughness components are quantified.Results show that CFRP surface has no regular feed marks.The frequency of fibre breakage or surface defects is greater than tooth passing frequency.FOAs sorted by their average S_(a)in descending order is135°>90°>45°>0°,where surface defects contribute 93.9%,77.1%,73.2%,72.2%of the total roughness respectively,which suggests that surface defects show a more important role than tool kinematics and vibration in formation of milled surface.The negative Skewness(Ssk<0)and high Kurtosis(S_(ku)=4.0–11.5)of milled surface signify porosity and the presence of many anomalous deep valleys in milled surface,respectively. | Chongyan CAI Jiaqiang DANG Qinglong AN Weiwei MING Ming CHEN | 2022 | Chinese Journal of Aeronautics2022，35，2： | 2 |
| 11 | Highly sensitive,sub-microsecond polymer photodetectors for blood oxygen saturation testing显示文摘Bottom surface of active layers and interface of indium tin oxide(ITO)electrodes and active layers play a crucial role in determining the performance of polymer photodetectors with photomultiplication(PM-PPDs).The interfacial trapped electron distribution closing to ITO electrodes will determine spectral response range and external quantum efficiency(EQE)of PMPPDs.The bottom interface is more sensitive than top interface when light is coming from the ITO side,and the larger density of generated charge on the bottom interfaces will induce interfacial band more bending for efficient charge tunneling injection.Highly sensitive and sub-microsecond PM-PPDs are achieved with PMBBDT:Y6(100:7,w/w)as active layers under forward bias,yielding EQE of 18,700%at 320 nm,21,700%at 600 nm and 16,400%at 810 nm under a bias of 7 V,respectively,as well as fast response time of 79μs.The high EQE of the PM-PPDs is attributed to efficient hole tunneling injection from ITO electrode under forward bias.The electron traps closing to ITO electrode will be quickly filled up when light is coming from ITO side,leading to interfacial band more bending for hole tunneling injection.Importantly,the PM-PPDs is performed to measure heart rate(HR)and blood oxygen saturation(SpO_(2)),and the measured data by the PM-PPDs are very similar with those obtained by commercial photodetectors. | Zijin Zhao Baiqiao Liu Changlin Xie Yao Ma Jian Wang Ming Liu Kaixuan Yang Yunhua Xu Jian Zhang Weiwei Li Liang Shen Fujun Zhang | 2021 | Science China Chemistry2021，64，8： | 2 |
| 12 | DTHMM based delay modeling and prediction for networked control systems显示文摘In the forward channel of a networked control system (NCS), by defining the network states as a hidden Markov chain and quantizing the network-induced delays to a discrete sequence distributing over a finite time interval, the relation between the network states and the network-induced delays is modelled as a discrete-time hidden Markov model (DTHMM). The expectation maximization (EM) algorithm is introduced to derive the maximumlikelihood estimation (MLE) of the parameters of the DTHMM. Based on the derived DTHMM, the Viterbi algorithm is introduced to predict the controller-to-actuator (C-A) delay during the current sampling period. The simulation experiments demonstrate the effectiveness of the modelling and predicting methods proposed. | Shuang Cong Yuan Ge Qigong Chen Ming Jiang Weiwei Shang | 2010 | Journal of Systems Engineering and Electronics2010，21，6： | 2 |
| 13 | The Morphology and Electrophysiology of the Cochlea of the Miniature Pig显示文摘 | Weiwei Guo Haijin Yi Lili Ren Lei Chen Lidong Zhao Wei Sun Shi‐Ming Yang | 2015 | Anat. Rec2015，，3： | 2 |
| 14 | Deactivation of Ni/TiO2catalyst in the hydrogenation of nitrobenzene in water and improvement in its stability by coating a layer of hydrophobic carbon显示文摘 | Lin Weiwei Cheng Haiyang Ming Jun | 2012 | Journal of Catalysis2012，291，： | 1 |
| 15 | Functional identification of gene cluster for the aniline metabolic pathway mediated by transposable element显示文摘A convenient and widely applicable method has been developed to clone aniline metabolic gene cluster in this study. Three positive recombinant plasmids pDA1, pDB2 and pDB11 were cloned from genomic library of aniline degradation strain AD9. The result of aniline dioxygenase (AD) activity and catechol 2,3-oxygenase (C23O) activity assay showed that pDA1 and pDB11 contain aniline dioxy-genase genes and catechol 2,3-dioxygenase genes, respectively. The sequence analysis of the total 24.7-kb region revealed that this region contains 25 ORFs, of which 17 genes involve metabolism of aniline. In the gene cluster, the first five genes (tadQTA1A2B) and the subsequent gene (tadR1) were pre-dicted to encode a multi-component aniline dioxygenase and a LysR-type regulator, respectively, while the others (tadD1C1D2C2EFGIJKL) were expected to encode meta- cleavage pathway enzymes for catechol degradation. The gene cluster was surrounded by two IS1071 sequences. | LIANG Quanfeng CHEN Ming xu Yuquan ZHANG Wei PING Shuzhen LU Wei SONG Xianlong WANG Weiwei GENG Lizhao Takeo Masahiro LIN Min | 2005 | Chinese Science Bulletin2005，50，15： | 1 |
| 16 | Harmful effect of ER β on BCRP ‐mediated drug resistance and cell proliferation in ER α/ PR ‐negative breast cancer显示文摘 | Weiwei Li Ming Jia Xiaomin Qin Jing Hu Xiaofang Zhang Gengyin Zhou | 2013 | FEBS J2013，，23： | 1 |
| 17 | Modelling the spindle-holder taper joint in machine tools: A tapered ze- ro-thickness finite element method显示文摘 | Xiao Weiwei Mao Kuanmin Zhu Ming | 2014 | Journal of Sound and Vibration2014，333，22： | 1 |
| 18 | Yin Yang 1 Plays an Essential Role in Breast Cancer and Negatively Regulates p27显示文摘 | Meimei Wan Weiwei Huang Timothy E. Kute Lance D. Miller Qiang Zhang Heather Hatcher Jingxuan Wang Daniel B. Stovall Gregory B. Russell Paul D. Cao Zhiyong Deng Wei Wang Qingyuan Zhang Ming Lei Suzy V. Torti Steven A. Akman Guangchao Sui | 2012 | The American Journal of Pathology2012，，： | 1 |
| 19 | Nutrition-related disease and death in Zhejiang province显示文摘 | Ding Gangqiang Yu Ming Gong Weiwei | 2004 | Asia Pacific J of Clin Nutr2004，13，12： | 1 |
| 20 | Identification of Markovian open system dynamics for qubit systems显示文摘We discuss the problem of identification of the dynamical generators for open two-level quantum systems in a Markovian environment.Based on Bloch sphere representation,the identification problem is converted to the estimation of a 3-dimensional real process matrix A and an inhomogeneous term c.The parameter identifiability and sufficient conditions for completely identification of A and c are obtained.Further discussion shows that the obtained sufficient conditions are not always necessary.The approach can be generalized to finite-level open quantum systems in an arbitary Markovian environment. | ZHOU WeiWei SCHIRMER Sophie GONG ErLing XIE HongWei ZHANG Ming | 2012 | Chinese Science Bulletin2012，57，18： | 1 |
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