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48篇 您的检索式:作者名="Qingfeng LU"
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1Effect of sintering temperature in argon atmosphere on microstructure and properties of 3D printed alumina ceramic cores显示文摘Alumina ceramics with different sintering temperatures in argon atmosphere were obtained using stereolithography-based 3D printing.The effects of sintering temperature on microstructure and physical and mechanical properties were investigated.The results show that the average particle size,shrinkage,bulk density,crystallite size,flexural strength,Vickers hardness,and nanoindentation hardness increased with the increase in sintering temperature,whereas the open porosity decreased with increasing sintering temperature.No change was observed in phase composition,chemical bond,atomic ratio,and surface roughness.For the sintered samples,the shrinkage in Z direction is much greater than that in X or Y direction.The optimum sintering temperature in argon atmosphere is 1350℃with a shrinkage of 3.0%,3.2%,and 5.5%in X,Y,and Z directions,respectively,flexural strength of 26.7 MPa,Vickers hardness of 198.5 HV,nanoindentation hardness of 33.1 GPa,bulk density of 2.5 g/cm^3,and open porosity of 33.8%.The optimum sintering temperature was 70℃higher than that sintering in air atmosphere when achieved the similar properties.He LI Yongsheng LIU Yansong LIU Qingfeng ZENG Kehui HU Zhigang LU Jingjing LIANG 2020Journal of Advanced Ceramics2020,9,2:13
2Molecular characteristics of the omp A gene of serotype B Chlamydia trachomatis in Qinghai Tibetan primary school students显示文摘To study the molecular characteristics of Chlamydia trachomatis, the major outer membrane protein gene(omp A) of C. trachomatis from primary school students with trachoma residing in the Qinghai Tibetan area was sequenced and compared with the same serotype in Gen Bank. In Jianshetang Primary School and Galeng Central Primary School in the Galeng Tibetan Township of Qinghai Haidong Sala Autonomous County, scraped samples were collected from the upper tarsal conjunctiva and lower conjunctival sac of both eyes of 45 students with trachoma, stored at 4°C, and transported to Beijing Tongren Hospital by air within 24 h. The samples were screened for C. trachomatis by real-time PCR. The omp A gene from the C. trachomatis-positive samples was amplified by nested PCR. The serotype was confirmed by National Center for Biotechnology Information(NCBI) BLAST search and homology analysis. The entire omp A gene sequence was compared with the corresponding gene sequences of serotype B strains available in Gen Bank. Of the 45 students aged 6–13 years with trachoma, 26 C. trachomatis-positive students were identified by the initial real-time PCR screening(average age,(9.09±1.63) years; sex ratio, 1.0), accounting for 57.78%(26/45). The cycle threshold values for real-time PCR were 16.79–37.77. Half(13/26) of C. trachomatis-positive students had a bacterial copy number of >105. The compliance rate of the omp A gene sequences with the C. trachomatis serotype B strains in Gen Bank was up to 99%. Two novel genetic mutations were found when the omp A gene was compared with those of the 11 serotype B strains in Gen Bank. The two non-synonymous mutations were located at(i) position 271 in the second constant domain, an adenine(A) to guanine(G) substitution(ACT?GCT), changing the amino acid at position 91 from threonine to alanine(Thr?Ala) in all 26 strains; and(ii) position 887 in the fourth variable domain, a cytosine(C) to thymine(T) substitution(GCA?GTA), changing the amino acid at residue 296 from alanine to valine(Ala?Val) in four of the 26 strains. Six mutations were identified relative to ATCC VR-573. The strains could be divided into two gene clusters according to the mutation at nucleotide position 887: CQZ-1(China Qinghai Tibetan-1) and CQZ-2(China Qinghai Tibetan-2). We thus detected two novel serotype B mutant strains of C. trachomatis among study subjects with trachoma.Xue Li Shaoya Zhang Qingfeng Liang Mei Wang Ailian Hu Xiuyuan Li Benshan Yang Mingxin Zhang Ningli Wang Xinxin Lu 2016Science China(Life Sciences)2016,59,6:6
3Zeolitic Imidazolate Framework 8-Derived Au@ZnO for Efficient and Robust Photocatalytic Degradation of Tetracycline显示文摘Summary of main observation and conclusion Tetracycline (TC) and other antibiotics accumulated in groundwater and soil pollute ecological environment and threaten human health. Gold nan oparticles doped on photocatalysts are able to enhance the photodegradation efficiency during removing these antibiotics, but preparation of Au nanoparticles of well-dispersion on photocatalysts remains challenging. In this work, zeolite imidazolate (ZIF-8) was employed as the precursor to prepare Au@ZnO photocatalyst via impregnation and in-situ reduction method to efficiently degrade the tetracycline in the aqueous solution. Au nanoparticles are of 10 nm in size and uniformly dispersed on the surfaces of ZnO microstructures. The as-prepared Au@ZnO is able to remove 85.5% of TC of 0.010 mg/mL within 2h, presenting higher photocatalytic activity than pure ZnO catalyst. Most importantly, the catalyst shows its superior stability after five cycles without structure and activity changing. The mechanism of the photocatalytic degradation was discussed in detail.Bijun Gao Jin Zhou Hongliang Wang Guping Zhang Jinghui He Qingfeng Xu Najun Li Dongyun Chen Hua Li Jianmei Lu 2019Chinese Journal of Chemistry2019,37,2:6
4Advancement toward Polymer Electrolyte Membrane Fuel Cells at Elevated Temperatures显示文摘Elevation of operational temperatures of polymer electrolyte membrane fuel cells(PEMFCs)has been demonstrated with phosphoric acid-doped polybenzimidazole(PA/PBI)membranes.The technical perspective of the technology is simplified construction and operation with possible integration with,e.g.,methanol reformers.Toward this target,significant efforts have been made to develop acid-base polymer membranes,inorganic proton conductors,and organic-inorganic composite materials.This report is devoted to updating the recent progress of the development particularly of acid-doped PBI,phosphate-based solid inorganic proton conductors,and their composite electrolytes.Long-term stability of PBI membranes has been well documented,however,at typical temperatures of 160℃.Inorganic proton-conducting materials,e.g.,alkali metal dihydrogen phosphates,heteropolyacids,tetravalent metal pyrophosphates,and phosphosilicates,exhibit significant proton conductivity at temperatures of up to 300℃ but have so far found limited applications in the form of thin films.Composite membranes of PBI and phosphates,particularly in situ formed phosphosilicates in the polymer matrix,showed exceptionally stable conductivity at temperatures well above 200℃.Fuel cell tests at up to 260℃ are reported operational with good tolerance of up to 16%CO in hydrogen,fast kinetics for direct methanol oxidation,and feasibility of nonprecious metal catalysts.The prospect and future exploration of new proton conductors based on phosphate immobilization and fuel cell technologies at temperatures above 200℃ are discussed.Jin Zhang David Aili Shanfu Lu Qingfeng Li and San Ping Jiang 2020Research2020,,1:6
5Pseudo-noise preamble based joint frame and frequency synchronization algorithm in OFDM communication systems显示文摘Frame and frequency synchronization are essential for orthogonal frequency division multiplexing(OFDM) systems. The frame offset owing to incorrect start point position of the fast Fourier transform(FFT) window, and the carrier frequency offset(CFO) due to Doppler frequency shift or the frequency mismatch between the transmitter and receiver oscillators, can bring severe intersymbol interference(ISI) and intercarrier interference(ICI) for the OFDM system. Relying on the relatively good correlation characteristic of the pseudonoise(PN) sequence, a joint frame offset and normalized CFO estimation algorithm based on PN preamble in time domain is developed to realize the frame and frequency synchronization in the OFDM system. By comparison, the performances of the traditional algorithm and the improved algorithm are simulated under different conditions. The results indicate that the PN preamble based algorithm both in frame offset estimation and CFO estimation is more accurate, resourcesaving and robust even under poor channel condition, such as low signaltonoise ratio(SNR) and large normalized CFO.Qingfeng Jing Ming Cheng Yuping Lu Weizhi Zhong Hongwei Yao 2014Journal of Systems Engineering and Electronics2014,25,1:4
6Microstructure and composition engineering Yb single-filled CoSb_(3) for high thermoelectric and mechanical performances显示文摘A broad tunability of the thermoelectric and mechanical properties of CoSb_(3) has been demonstrated by adjusting the composition with the addition of an increasing number of elements.However,such a strategy may negatively impact processing repeatability and composition control.In this work,singleelement-filled skutterudite is engineered to have high thermoelectric and mechanical performances.Increased Yb filling fraction is found to increase phonon scattering,whereas cryogenic grinding contributes additional microstructural scattering.A peak zT of 1.55 and an average zT of about 1.09,which is comparable to the reported results of multiple-filled SKDs,are realized by the combination of simple composition and microstructure engineering.Furthermore,the mechanical properties of Yb single-filled CoSb_(3) skutterudite are improved by manipulation of the microstructure through cryogenic grinding.These findings highlight the realistic prospect of producing high-performance thermoelectric materials with reduced compositional complexity.Zhenxing Zhou Matthias T.Agne Qihao Zhang Shun Wan Qingfeng Song Qing Xu Xiaofang Lu Shijia Gu Yuchi Fan Wan Jiang Gerald Jeffrey Snyder Lianjun Wang 2019Journal of Materiomics2019,5,4:4
7Study of infectious conjunctivitis among children in rural areas of Qinghai province显示文摘Infectious conjunctivitis is no longer a common eye disease in cities and developed areas, but in remote mountainous regions of China where living conditions are relatively under-developed, the occurrence of infectious conjunctivitis remains a public health issue. Here, we evaluate the ratio of infectious conjunctivitis among primary school students in the rural areas of Xunhua, Huangyuan, and Huzhu Counties in the Qinghai province of China, and report the microorganisms involved in causing infection. Of the 765 eligible primary school students, 694 participated to this study(a response rateof 90.7%), 381 boys and 313 girls, with a mean age of 7.52 years(range 7–9 years). A clinical diagnosis of infectious conjunctivitis was returned for 238 of the 694 children examined. The ratio of infectious conjunctivitis in Xunhua County(46.64%) was higher compared to that in Huangyuan(26.67%; P=0.03) and Huzhu Counties(23.61%; P=0.02). The leading cause of conjunctivitis was bacterial, followed by chlamydial and viral. Our results show that there is a high ratio of infectious conjunctivitis among rural primary school students in Qinghai province.Qingfeng Liang Xinxin Lu Mei Wang Lei Tian Antoine Labbé Ailian Hu 2016Science China(Life Sciences)2016,59,6:3
8Numerical modeling of SiC by low-pressure chemical vapor deposition from methyltrichlorosilane显示文摘The development of functional relationships between the observed deposition rate and the experimental conditions is an important step toward understanding and optimizing low-pressure chemical vapor deposition(LPCVD)or low-pressure chemical vapor infiltration(LPCVI).In the field of ceramic matrix composites(CMCs),methyltrichlorosilane(CH3 SiCl3,MTS)is the most widely used source gas system for SiC,because stoichiometric SiC deposit can be facilitated at 900°C–1300°C.However,the reliability and accuracy of existing numerical models for these processing conditions are rarely reported.In this study,a comprehensive transport model was coupled with gas-phase and surface kinetics.The resulting gas-phase kinetics was confirmed via the measured concentration of gaseous species.The relationship between deposition rate and 24 gaseous species has been effectively evaluated by combining the special superiority of the novel extreme machine learning method and the conventional sticking coefficient method.Surface kinetics were then proposed and shown to reproduce the experimental results.The proposed simulation strategy can be used for different material systems.Kang Guan Yong Gao Qingfeng Zeng Xingang Luan Yi Zhang Laifei Cheng Jianqing Wu Zhenya Lu 2020Chinese Journal of Chemical Engineering2020,28,6:3
9Fifty years of Quaternary palynology in the Tibetan Plateau显示文摘Quaternary palynology in the Tibetan Plateau(TP)was initiated in the 1960s to meet the needs of economic development in western China.Pollen analysis was conducted for the first time on a 200-m long core of Quaternary lacustrine sediments taken from the main body of the TP in order to study pollen assemblages as well as vegetation and climate changes of glacial(cold)/interglacial(warm)periods.Pollen analysis of alpine snow and ice began at the first scientific expedition to the TP in the 1970s.After the 1980s,a series of international collaborative programs were carried out under Sino-French,Sino-German,Sino-Australian,and Sino-American cooperation,marking the integration of Chinese Quaternary palynology society with the international community.New methods for Quaternary palynology were gradually promoted and applied,changing the vegetational and climatic interpretation of Quaternary palynology from qualitative to quantitative.Since the 1990s,many palynologists have carried out extensive Quaternary palynological studies on fossil pollen sites of more than 60 lakes/sections and alpine glaciers in the TP to discuss the spatiotemporal vegetation changes and climatic and environmental evolution of the TP since the Pleistocene.Over the past half-century,Quaternary palynology in the TP has contributed to the establishment of the Chinese Quaternary pollen database and the study of vegetation and climate evolution since the Last Glacial Maximum(LGM)in the TP.Currently available pollen records revealed the spatial and temporal distribution of vegetation in the TP since the LGM,exhibiting expansions and shrinkages of forest,meadow,grassland and desert in different periods such as the LGM,the last deglaciation,and Holocene optimum period.The paleomonsoon reflected by paleovegetation since the LGM has undergone the changes of weak-strengthening-strong-weakening but still active-shrinking,which is mainly affected by solar insolation.Lingyu TANG Caiming SHEN Houyuan LU Chuanhai LI Qingfeng MA 2021Science China Earth Sciences2021,64,11:3
10A mini-review on ZnIn_(2)S_(4)-Based photocatalysts for energy and environmental application显示文摘As one of the most attractive and eco-friendly technologies,semiconductor photocatalysis is demonstrated as a potential strategy to solve global energy shortage environmental pollution problems.Regarding semiconductor-based photocatalysts,Zinc indium sulfide(ZnIn_(2)S_(4)) with various morphological structures has become research hotspots owing to its superior visible light absorption,high chemical durability and low cost.Nevertheless,the photocatalytic activity of pristine ZnIn_(2)S_(4) is unsatisfactory due to limited range of visible light absorption and fast recombination rate of light-induced electrons and holes.Different modification strategies,such as metal deposition,element doping,vacancy engineering and semiconductor combination,have been systematically developed for enhancing the photocatalytic performance of ZnIn_(2)S_(4) materials.In order to promote further developments of ZnIn_(2)S_(4) in photocatalytic applications,this mini-review summarizes the progress of recent research works for the construction of highly activity ZnIn_(2)S_(4)-based photocatalysts for the first time.In addition,the typical applications of ZnIn_(2)S_(4)-based photocatalytic materials have been critically reviewed and described such as in hydrogen evolution from photocatalytic water splitting,carbon dioxide photoreduction,and treatment of water pollution.The current challenges and further prospects for the development of ZnIn_(2)S_(4) semiconductor photocatalysts are finally pointed out.Guping Zhang Hao Wu Dongyun Chen Najun Li Qingfeng Xu Hua Li Jinghui He Jianmei Lu 2022Green Energy & Environment2022,7,2:2
11Material Properties of Marine Hydrogenous Ferromanganese Crust and Its Performance in Desulfurization显示文摘海洋的氢的铁锰合金外壳,一个重要金属资源以后,作为自然 nano-structuredmaterial 的一种类型在各种各样的应用有重要潜力。由采用扫描电子显微镜学,氮吸附解吸附作用等温线测量, X 光检查荧光分光计和 X 光检查衍射方法,微观结构,表面性质和几个像板的铁锰合金外壳的化学成分从西北的太平洋取样了包括地被调查。尽管明显的差别从不同的层被观察,外壳是有高比面积区域,唯一的毛孔结构和丰富的过渡元素的典型多孔的材料。而且,在 desulfurization 过程的自然外壳的性能 preliminarily 在实验室实验被测试。外壳的 Thesulfur 能力分别地在房间温度和 350 deg C 是 13.1% 和 18.1% 。外壳能一个金属资源被用作不仅,而且作为环境材料。LU Xiancai HOU Qingfeng LIU Xiandong YANG Kan WANG Rucheng LING Hongfei XU Shijin 2006Acta Geologica Sinica(English Edition)2006,80,3:2
12An Improved Unsupervised Image Segmentation Method Based on Multi-Objective Particle Swarm Optimization Clustering Algorithm显示文摘Most image segmentation methods based on clustering algorithms use singleobjective function to implement image segmentation.To avoid the defect,this paper proposes a new image segmentation method based on a multi-objective particle swarm optimization(PSO)clustering algorithm.This unsupervised algorithm not only offers a new similarity computing approach based on electromagnetic forces,but also obtains the proper number of clusters which is determined by scale-space theory.It is experimentally demonstrated that the applicability and effectiveness of the proposed multi-objective PSO clustering algorithm.Zhe Liu Bao Xiang Yuqing Song Hu Lu Qingfeng Liu 2019Computers, Materials & Continua2019,,2:2
13Hierarchically ordered arrays based on solvent vapor annealed colloidal monolayers for antireflective coating显示文摘Lu Zheng Chong Geng Qingfeng Yan 2013Thin Solid Fihns2013,544,:1
14The surface fractal investigation on the carbon nanotubes modified by the adsorption of PAA显示文摘Hou Qingfeng Lu Xiancai Liu Xiandong Hu Baixing Shen Jian 2005Surface and Coating Technology2005,190,23:1
15miR-199-5p regulates spermiogenesis at the posttranscriptional level via targeting Tekt1 in allotriploid crucian carp显示文摘Background:Sperm abnormalities are one of the primary factors leading to male sterility,but their pathogenesis is still unclear.Although miRNAs are suggested to exert important roles in the regulation of spermatogenesis at both transcriptional and posttranscriptional levels,little is currently known regarding the regulation of sperm flagella assembly by microRNAs(miRNAs).The role of miRNAs in the development of sperm abnormalities in sterile triploid fish has not been studied.Results:In this study,we found that miR-199-5p was widely expressed in all detected tissues of different-ploidy crucian carp.As one of the testis-specific candidate markers,Tekt1 was predominantly expressed in the testis.Quantitative real-time PCR(qRT-PCR)analyses showed that the expression trend of miR-199-5p was exactly opposite to that of Tekt1.Through bioinformatics analysis,we identified a putative miR-199-5p binding site in the Tekt1 mRNA.We further identified Tekt1 as a target of miR-199-5p using luciferase reporter assay.Finally,we confirmed that miR-199-5p was necessary for sperm flagellar assembly and spermatogenesis in vivo via intraperitoneal injection of miR-199-5p antagomir or agomir in diploid red crucian carp.Moreover,miR-199-5p gainof-function could lead to spermatids apoptosis and abnormal spermatozoa structure,which is similar to that of allotriploid crucian carp.Conclusions:Our studies suggested that abnormally elevated miR-199-5p inhibited the sperm flagella formation in spermiogenesis by negatively regulating the expression of Tekt1,thereby causing sperm abnormalities of male allotriploid crucian carp.Shengnan Li Qiubei Wang Lu Huang Siyu Fan Ting Li Yuqing Shu Chun Zhang Yi Zhou Qingfeng Liu Kaikun Luo Min Tao Shaojun Liu 2022Journal of Animal Science and Biotechnology2022,13,5:1
16Effects of substituents on the third ordernoniinearopticalproperties of po显示文摘Dong Yanmao Lu Jianmei Xu Qingfeng 2010Synthetic Met- als2010,160,56:1
17A secure spectrum auction scheme without the trusted party based on the smart contract显示文摘With the development of communication 5G networks and technologies,spectrum resources are increasingly scarce.The scarcity of the spectrum resource makes market-driven spectrum auction become an important means of spectrum allocation,and due to the complexity of the network environment,the security of spectrum auctions can not be ignored.Most existing secure spectrum auction schemes introduce a semi-honest agent to complete spectrum auction.However,the hypothetical semi-honest model does not guarantee the security of spectnim auction in the actual application scenario,which may lead to potential security threats:the agent may reveal the privacy of bidders,agent or auctioneer may collude with the bidder to manipulate the spectrum auction,and so on.In this paper,a secure spectrum auction scheme without a trusted party is proposed based on the smart contract technology,and the smart contract written into the blockchain replaces the traditional semi-honest agent to cooperate with the auctioneer server to complete the auction.In order to ensure the security of our scheme,a secure spectrum auction protocol is designed,in which the Software Guard Extensions(SGX)technology and Paillier cryptosystem are used to protect the privacy of bidders.Public verification is provided in our protocol by using extensive Pedersen commitment,which prevents the auctioneer server and the bidder from colluding with each other and verifies group bid sum values.Finally,the security analysis is given to propose several types of attacks that can be defended.Besides,theoretical analysis and simulation experiments of our protocol are also provided.Jiaqi Wang Ning Lu Qingfeng Cheng Lu Zhou Wenbo Shi 2021Digital Communications and Networks2021,7,2:1
18A joint call for actions to advance taxonomy in China显示文摘Taxonomy plays an important role in understanding the origin, evolution, and ecological functionality of biodiversity. There are large number of unknown species yet to be described by taxonomists, which together with their ecosystem services cannot be effectively protected prior to description. Despite this, taxonomy has been increasingly underrated insufficient funds and permanent positions to retain young talents. Further, the impact factordriven evaluation systems in China exacerbate this downward trend, so alternative evaluation metrics are urgently necessary. When the current generation of outstanding taxonomists retires,there will be too few remaining taxonomists left to train the next generation. In light of these challenges, all co-authors worked together on this paper to analyze the current situation of taxonomy and put out a joint call for immediate actions to advance taxonomy in China.Chaodong Zhu Arong Luo Ming Bai Michael COrr Zhonge Hou Siqin Ge Jun Chen Yibo Hu Xuming Zhou Gexia Qiao Hongzhi Kong Limin Lu Xiaohua Jin Lei Cai Xinli Wei Ruilin Zhao Wei Miao Qingfeng Wang Zhongli Sha Qiang Lin Meng Qu Jianping Jiang Jiatang Li Jing Che Xuelong Jiang Xiaoyong Chen Lianming Gao Zongxin Ren Chunlei Xiang Shixiao Luo Donghui Wu Dong Liu Yanqiong Peng Tao Su Chenyang Cai Tianqi Zhu Wanzhi Cai Xingyue Liu Hu Li Huaijun Xue Zhen Ye Xuexin Chen Pu Tang Shujun Wei Hong Pang Qiang Xie Feng Zhang Feng Zhang Xianjin Peng Aibing Zhang Taiping Gao Changfa Zhou Chen Shao Libin Ma Zhaoming Wei Yunxia Luan Ziwei Yin Wu Dai Cong Wei Xiaolei Huang Jingxian Liu Xiangsheng Chen Tianci Yi Zhisheng Zhang Zhulidezi Aishan Qin Li Hongying Hu 2022Zoological Systematics2022,47,3:1
19Atom transfer radical polymerization of styrene initiated by triphenylrnethyl chloride 显示文摘XU Yuanqing LU Jianmei XU Qingfeng 2005Euro Polym J2005,41,24:1
20Reverse atom transfer radical polymerization of MMA initiated by triphenylmethane显示文摘XU Yuanqing XU Qingfeng LU Jianmei 2007PolymBull2007,58,80:1
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