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An Improved Unsupervised Image Segmentation Method Based on Multi-Objective Particle Swarm Optimization Clustering Algorithm

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Computers, Materials & Continua 2019年第2期58卷 451-461页

作者： Zhe liu Bao Xiang Yuqing Song Hu Lu qingfeng liu School of Computer Science and Telecommunication Engineering Jiangsu UniversityZhenjiang212013China School of Computer Science Jilin Normal UniversitySiping136000China Institute of Science and Technology Information Jiangsu UniversityZhenjiang212013China

Most image segmentation methods based on clustering algorithms use singleobjective function to implement image *** avoid the defect,this paper proposes a new image segmentation method based on a multi-objective particle swarm optimization(PSO)clustering *** 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 *** is experimentally demonstrated that the applicability and effectiveness of the proposed multi-objective PSO clustering algorithm.

关键词： Multi-objective optimization particle swarm optimization electromagnetic forces scale-space theory

2,11-Dimethoxyldipyridopurinone as an efficientreducing visible-light photocatalyst for organic transformations

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Organic Chemistry Frontiers 2022年第6期9卷 1634-1641页

作者： Yameng Wan qingfeng liu Hao Wu Zhiguo Zhang Guisheng Zhang Key Laboratory of Green Chemical Media and Reactions Ministry of EducationCollaborative Innovation Center of Henan Province for Green Manufacturing of Fine ChemicalsHenan Key Laboratory of Organic Functional Molecules and Drug InnovationNMPA Key Laboratory for Research and Evaluation of Innovative DrugSchool of Chemistry and Chemical EngineeringHenan Normal University46 East of Construction RoadXinxiangHenan 453007China

We report for the first time 2,11-dimethoxyldipyridopurinone (DP4) as a potent reducing visible-lightphotocatalyst toward three prototypic organic transformations: redox-neutral intramolecular aryltrifluoromethylations of acrylamides and the direct C–H arylation of heteroarenes with aryl diazonium salts, netoxidative hydroxylations of arylboronic acids using molecular oxygen as a green oxidant, and the netreductive dehalogenation/deuteration of α-bromocarbonyl compounds. This work reveals a bright futurefor dipyridopurinone derivatives as a new class of metal-free visible-light photocatalysts for a wide rangeof organic transformations.

关键词： visible catalyst boron

Enhanced thermoelectric performance of n-type Bi_(2)Te_(2.7)Se_(0.3) via a simple liquid-assisted shear exfoliation

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Journal of Materials Science & Technology 2022年第22期117卷 251-258页

作者： Yifeng Wang Yilin Song Kaikai Song Lin Pan Changchun Chen Kunihito Koumoto qingfeng liu College of Materials Science and Engineering Nanjing Tech UniversityNanjing 210009China Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech UniversityNanjing 210009China Nagoya Industrial Science Research Institute Nagoya 464-0819Japan Center of Nanotechnology King Abdulaziz UniversityJeddah 21589Saudi Arabia State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech UniversityNanjing 210009China

A liquid-assisted shear exfoliation (LASE) as a new powder metallurgy method coupled with spark plasmasintering (SPS) was applied for n-type Bi_(2)Te_(2.7)Se_(0.3) and the effects on microstructure and anisotropictransport properties were investigated. Results revealed an effective reduction of average grain size dueto LASE and a high texturing in the bulks. Moreover, along the in-plane direction, electrical conductivitywas increased noticeably due to an enhanced carrier concentration, leading to a significantly improvedpower factor of 25 μW cm^(–1) K^(–2) at 303 K. Meanwhile, the total thermal conductivity was reduced effectively owing to reduction both in lattice component due to enhanced phonon scattering with the grainsize reduction, and in the bipolar component inhibited by the increased carrier concentration. Ultimately,a peak thermoelectric figure of merit (ZT) value of 0.83 was obtained at 448 K along the in-plane direction, increased by 95% compared with the pristine one. These results demonstrate the LASE process as auseful assistant method for enhancing the TE performance of layered materials.

关键词： Bi_(2)Te_(2.7)Se^(0.3) Liquid-assisted shear exfoliation Textured microstructure Thermoelectric

Copper（I）-Catalyzed Intramolecular N-N Coupling of Cyclopropyl O-Acyl Ketoximes： Synthesis of Spiro-fused Pyrazolin-5-ones

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Chinese Journal of Chemistry 2016年第12期34卷 1309-1320页

作者： Zhiguo Zhang Junlong Li Guoqing Huang Kai Sun Guisheng Zhang Nana Ma qingfeng liu Tongxin liu Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals Key Laboratory of Green Chemical Media and Reactions Ministry of Education School of Chemistry and Chemical Engineering Henan Normal University Xinxiang Henan 453007 China Jilin Province Key Laboratory of Organic Functional Molecular Design & Synthesis Northeast Normal University Changchun Jilin 130024 China Handan Purification Equipment Research Institute Handan Hebei 056027 China College of Chemistry and Chemical Engineering Anyang Normal University Anyang Henan 455000 China

A convenient copper-catalyzed approach has been developed for the synthesis of substituted spiro-fused pyrazolin-5-ones from readily available cyclopropyl O-acyl ketoximes via an intramolecular N-N bond formation reac... 详细信息

关键词： copper-catalyzed N-Nbond formation O-acyl ketoximes pyrazolin-5-ones cyclopropyl oximes

Financing Alternatives for Chinese Small and Medium Enterprises: The Case for a Small and Medium Enterprise Stock Market

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China & World Economy 2007年第1期15卷 26-42页

作者： Hung-gay Fung qingfeng liu Jot Yau Dr Y. S. Tsiang Professor College of Business Administration and Center for International Studies University of Missouri St. Louis USA Assistant Professor College of Business James Madison University USA Professor Department of Finance Albers School of Business and Economics Seattle University USA

Financing alternatives for small and medium enterprises in China are discussed in the present study. In particular, we analyze the significant changes and developments m China＇s ＂second board＂ stock market. China ＇s extensive network of regional assets and equity exchanges, which were set up to facilitate private equity transfer, and non-performing loan transactions seem to partially fill the void for small and medium enterprises, which cannot easily obtain approval for listing on the stock exchanges. Foreign investors can identify investment opportunities in non-listed domestic state-owned and private businesses through these regional assets and equity exchanges. At the same time, foreign stock markets are now attracting the young Chinese enterprises to list their stocks on their exchanges.

关键词： Chinese small and medium enterprise financing stock exchange

The key role of myostatin b in somatic growth in fishes derived from distant hybridization

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Science China(Life Sciences) 2024年第7期67卷 1441-1454页

作者： qingfeng liu Lujiao Duan Bei Li Xuanyi Zhang Fanglei liu Jianming Yu Yuqin Shu Fangzhou Hu Jingjing Lin Xiaoxia Xiong Shaojun liu State Key Laboratory of Developmental Biology of Freshwater Fish Hunan Normal UniversityChangsha 410081China College of Life Sciences Hunan Normal UniversityChangsha 410081China

The basic mechanism of heterosis has not been systematically and completely *** previous studies,we obtained three economically important fishes that exhibit rapid growth,WR(WCC♀×RCC♂),WR-Ⅱ(WR♀×WCC♂),and WR-Ⅲ(WR-Ⅱ♀×4nAU♂),through distant ***,the mechanism underlying this rapid growth remains *** this study,we found that WR,WR-Ⅱ,and WR-Ⅲshowed muscle hypertrophy and higher muscle protein and fat contents compared with their parent species(RCC and WCC).Candidate genes responsible for this rapid growth were then obtained through an analysis of 12 muscle ***,the mRNA level of mstnb(myostatin b),which is a negative regulator of myogenesis,was significantly reduced in WR,WR-Ⅱ,and WR-Ⅲcompared with the parent *** verify the function of mstnb,a mstnb-deficient mutant RCC line was generated using the CRISPR-Cas9 *** average body weight of mstnb-deficient RCC at 12 months of age was significantly increased by 29.57%compared with that in wild-type ***,the area and number of muscle fibers were significantly increased in mstnb-deficient RCC,indicating hypertrophy and ***,the muscle protein and fat contents were significantly increased in mstnb-deficient *** molecular regulatory mechanism of mstnb was then revealed by transcription profiling,which showed that genes related to myogenesis(myod,myog,and myf5),protein synthesis(PI3K-AKT-mTOR),and lipogenesis(pparγand fabp3)were highly activated in hybrid fishes and mstnb-deficient *** study revealed that low expression or deficiency of mstnb regulates somatic growth by promoting myogenesis,protein synthesis,and lipogenesis in hybrid fishes and mstnb-deficient RCC,which provides evidence for the molecular mechanism of heterosis via distant hybridization.

关键词： distant hybridization heterosis somatic growth myostatin b genome editing

The construction of in vitro nasal cavity-mimic M-cell model,design of M cell-targeting nanoparticles and evaluation of mucosal vaccination by nasal administration

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Acta Pharmaceutica Sinica B 2020年第6期10卷 1094-1105页

作者： Xiaotong Yang Xianchun Chen Ting Lei Lin Qin Yang Zhou Chuan Hu qingfeng liu Huile Gao Key Laboratory of Drug Targeting and Drug Delivery System of the Education Ministry Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial TechnologyWest China School of Pharmacy Sichuan UniversityChengdu 610041China College of Materials Science and Engineering Sichuan UniversityChengdu 610064China Shanghai University of Medicine&Health Sciences Affiliated Sixth People's Hospital South Campus Shanghai 201499China

In order to better evaluate the transport effect of nanoparticles through the nasal mucosa,an in vitro nasal cavity-mimic model was designed based on M *** differentiation of M cells was induced by co-culture of Calu-3 and Raji cells in invert *** ZO-1 protein staining and the transport of fluorescein sodium and dexamethasone showed that the inverted co-culture model formed a dense monolayer and possessed the transport *** differentiation of M cells was observed by upregulated expression of Sialyl Lewis A antigen(SLAA)and integrinβ1,and down-regulated activity of alkaline *** targeting M cells with iRGD peptide(cRGDKGPDC),the transport of nanoparticles *** vivo,the co-administration of iRGD could result in the increase of nanoparticles transported to the brain through the nasal cavity after intranasal *** the evaluation of immune effect in vivo,the nasal administration of OVA-PLGA/iRGD led to more release of IgG,IFN-γ,IL-2 and secretory IgA(sIgA)compared with OVA@PLGA ***,the study constructed in vitro M cell model,and proved the enhanced effect of targeting towards M cell with iRGD on improving nasal immunity.

关键词： M cells In vitro Cell model iRGD peptide Nasal administration Mucosal vaccination

Material Properties of Marine Hydrogenous Ferromanganese Crust and Its Performance in Desulfurization

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Acta Geologica Sinica(English Edition) 2006年第3期80卷 441-450页

作者： LU Xiancai HOU qingfeng liu Xiandong YANG Kan WANG Rucheng LING Hongfei XU Shijin State Key Laboratory for Mineral Deposits Research Department of Earth Sciences Nanjing University Nanjing Jiangsu 210093

Marine hydrogenous ferromanganese crust, an important metal resource in the future, has significant potential in various applications as a type of natural nano-structured material. By employing scanning electronic microscopy, nitrogen adsorption-desorption isotherm measurement, Xray fluorescence spectrometer and X-ray diffraction methods, the micro-structure, surface properties and chemical composition of several plate-like ferromanganese crusts sampled from the northwestern Pacific were investigated comprehensively. Although obvious differences were observed from different layers, the crust is a typical porous material with high specific surface area, unique pore structure and abundant transition elements. Furthermore, the performance of natural crust in desulfurization process was preliminarily tested in laboratory experiments. The suffur capacities of the crust are 13.1% and 18.1% at room temperature and 350 ℃, respectively. The crust can be used not only as a metal resource, but also as an environmental material.

关键词： ferromanganese crust pore structure surface property desulfurization

Targeted disruption of tyrosinase causes melanin reduction in Carassius auratus cuvieri and its hybrid progeny

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Science China(Life Sciences) 2019年第9期62卷 1194-1202页

作者： qingfeng liu Yanhua Qi Qiuli Liang Jia Song Junmei liu Wuhui Li Yuqin Shu Min Tao Chun Zhang Qinbo Qin Jing Wang Shaojun liu State Key Laboratory of Developmental Biology of Freshwater Fish Hunan Normal UniversityChangsha 410081China College of Life Sciences Hunan Normal UniversityChangsha 410081China

The white crucian carp(Carassius auratus cuvieri,WCC) not only is one of the most economically important fish in Asia,characterized by strong reproductive ability and rapid growth rates,but also represents a good germplasm to produce hybrid progenies with *** knockout technique provides a safe and acceptant way for fish *** gene knockout in WCC and its hybrid progeny will be of great importance for both genetic studies and hybridization ***(TYR) is a key enzyme in melanin *** of tyr in zebrafish and mice results in mosaic pigmentation or total ***,we successfully used CRISPR-Cas9 to target tyr in WCC and its hybrid progeny(WR) derived from the cross of WCC(♀) and red crucian carp(Carassius auratus red var.,RCC,♂).The level of TYR protein was significantly reduced in mutant *** the mutant WCC and the mutant WR showed different degrees of melanin reduction compared with the wild-type sibling control fish,resulting from different mutation efficiency ranging from 60% to 90%.In addition,the transcriptional expression profiles of a series of pivotal pigment synthesis genes,***1,mitfa,mitfb,dct and sox10,were down-regulated in tyr-CRISPR WCC,which ultimately caused a reduction in melanin *** results demonstrated that tyr plays a key role in melanin synthesis in WCC and WR,and CRISPR-Cas9 is an effective tool for modifying the genome of economical ***,the tyr-CRISPR models could be valuable in understanding fundamental mechanisms of pigment formation in non-model fish.

关键词： white crucian carp hybridization CRISPR-Cas9 tyrosinase pigmentation