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Formation of Face‑Centered Cubic Phase in Ti35 Alloy Under In Situ Heating Transmission Electron Microscopy

Acta Metallurgica Sinica(English Letters) 2023年第3期36卷 486-494页

作者： Jianan Hu Mengmeng Yang Wenlong Xiao Hao Wang Dehai Ping Chengze liu Shewei Xin Songquan Wu kai Zhang Yi Yang Lai‑Chang Zhang Aijun Huang School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education School of Materials Science and EngineeringBeihang UniversityBeijing 100191China School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China Xi’an Rare Metal Materials Institute Co.Ltd Xi’an 710016China Northwest Institute for Non-Ferrous Metal Research Xi’an 710016China School of Engineering Edith Cowan University270 Joondalup DriveJoondalupPerthWA 6027Australia Department of Materials Science and Engineering Monash UniversityClaytonVIC 3800Australia

A thermally induced hexagonal close-packed(HCP)to face-centered cubic(FCC)phase transition was investigated in anα-type Ti35 alloy with twinned structure by in situ heating transmission electron microscopy(TEM)and ab initio *** observations indicated that the HCP to FCC phase transition occurred both within matrix/twin and at the twin boundaries in the thinner region of the TEM film,and the FCC-Ti precipitated as plates within the matrix/twin,while as equiaxed cells at twin *** crystallographic orientation relationship between HCP-Ti and FCC-Ti can be described as:{111}FCC//{0002}HCP andFCC//*** HCP to FCC phase transition was accomplished by forming an intermediate state with a BB stacking sequence through the slip of partial *** formation of such FCC-Ti may be related to the thermal stress and *** initio calculations showed that the formation of FCC-Ti may also be related to the contamination of interstitial atoms such as oxygen.

关键词： In situ heating TEM FCC titanium Phase transition Ab initio calculation

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Strong Convergence Theorems for Strictly Asymptotically Pseudocontractive Mappings in Hilbert Spaces

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Acta Mathematica Sinica,English Series 2011年第7期27卷 1367-1378页

作者： shi Sheng ZHANG Department of Mathematics Yibin University Yibin 644007 P. R. China

The purpose of this paper is by using CSQ method to study the strong convergence problem of iterative sequences for a pair of strictly asymptotically pseudocontractive mappings to approximate a common fixed point in a Hilbert space. Under suitable conditions some strong convergence theorems are proved. The results presented in the paper are new which extend and improve some recent results of Acedo and Xu [Iterative methods for strict pseudo-contractions in Hilbert spaces. Nonlinear Anal., 67（7）, 2258-2271 （2007）], Kim and Xu [Strong convergence of modified Mann iterations for asymptoti- cally nonexpansive mappings and semigroups. Nonlinear Anal., 64, 1140-1152 （2006）], Martinez-Yanes and Xu [Strong convergence of the CQ method for fixed point iteration processes. Nonlinear Anal., 64, 2400-2411 （2006）], Nakajo and Takahashi pings and nonexpansive semigroups. J. Math [Strong convergence theorems for nonexpansive map- Anal. Appl., 279, 372-379 （2003）], Marino and Xu [Weak and strong convergence theorems for strict pseudocontractions in Hilbert spaces. J. Math. Anal. Appl., 329（1）, 336-346 （2007）], Osilike et al. [Demiclosedness principle and convergence theorems for k-strictly asymptotically pseudocontractive maps. J. Math. Anal. Appl., 326, 1334-1345 （2007）], liu [Convergence theorems of the sequence of iterates for asymptotically demicontractive and hemicontractive mappings. Nonlinear Anal., 26（11）, 1835-1842 （1996）], Osilike et al. [Fixed points of demi-contractive mappings in arbitrary Banach spaces. Panamer Math. J., 12（2）, 77-88 （2002）], Gu [The new composite implicit iteration process strictly pseudocontractive mappings. J. Math with errors for common fixed points of a finite family of Anal. Appl., 329, 766-776 （2007）].

关键词： Strictly asymptotically pseudocontractive mapping strictly pseudocontractive mapping of Browder Petryshyn type CSQ methods common fixed point

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Attention mechanisms in computer vision:A survey

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Computational Visual Media 2022年第3期8卷 331-368页

作者： Meng-Hao Guo Tian-Xing Xu Jiang-Jiang liu Zheng-Ning liu Peng-Tao Jiang Tai-Jiang Mu Song-Hai Zhang Ralph R.Martin Ming-Ming Cheng shi-Min Hu BNRist Department of Computer Science and TechnologyTsinghua UniversityBeijing 100084China TKLNDST College of Computer ScienceNankai UniversityTianjin 300350China School of Computer Science and Informatics Cardiff UniversityCardiffUK

Humans can naturally and effectively find salient regions in complex *** by this observation,attention mechanisms were introduced into computer vision with the aim of imitating this aspect of the human visual *** an attention mechanism can be regarded as a dynamic weight adjustment process based on features of the input *** mechanisms have achieved great success in many visual tasks,including image classification,object detection,semantic segmentation,video understanding,image generation,3D vision,multimodal tasks,and self-supervised *** this survey,we provide a comprehensive review of various attention mechanisms in computer vision and categorize them according to approach,such as channel attention,spatial attention,temporal attention,and branch attention;a related repository https://***/MenghaoG uo/Awesome-Vision-Attentions is dedicated to collecting related *** also suggest future directions for attention mechanism research.

关键词： attention transformer computer vision deep learning salience

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Directed Self-assembly of Vertical PS-b-PMMA Nanodomains Grown on Multilayered Polyelectrolyte Films

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Chinese Journal of Polymer Science 2020年第1期38卷 92-99,I0008页

作者： kai liu Chun-Ming Yang Bo-Ming Yang Lan Zhang Wen-Chao Huang Xiao-Ping Ouyang Fu-Gang Qi Nie Zhao Feng-Gang Bian College of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201204China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai201204China

Layer-by-layer polyelectrolyte self-assembly, a common method for preparing high-quality ultra-thin films, was employed to direct the self-assembly behavior of polystyrene-block-poly(methyl methacrylate)(PS-b-PMMA) block copolymer for the first time. Differing from the previous neutral polymer brushes anchored to silicon substrates via chemical modification, polyelectrolyte multilayers(PEMs) were anchored by electrostatic interaction and provided a stable, smooth, and neutral interface. In the present study, PS-b-PMMA was deposited on poly(acrylamide hydrochloride)/poly(acrylic acid)(PAH/PAA) PEMs prepared by layer-by-layer self-assembly to successfully yield vertical nanodomains after thermal annealing. Seven layered PEMs revealed an excellent, smooth surface, with a low roughness of 0.6 nm. The periodic structure with interlamellar spacing of 47 nm was determined by grazing-incidence small-angle X-ray scattering(GISAXS). The morphology of the PS-b-PMMA nanodomains depended on the polyanion-to-polycation concentration ratio, which is related to the interaction between the block copolymer and the substrate. Our results demonstrate that layer-by-layer self-assembly is a helpful method for the phase separation of block polymers and the fabrication of vertical, ordered nanodomains.

关键词： Block copolymer Polyelectrolyte Self-assembly GISAXS

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Low-dose spectral insufflation computed tomography protocol preoperatively optimized for T stage esophageal cancer-preliminary research experience

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World Journal of Gastroenterology 2018年第36期24卷 4197-4207页

作者： Yue Zhou Dan liu Ping Hou kai-Ji Zha Feng Wang Kun Zhou Wei He Jian-Bo Gao Department of Radiology The First Affiliated Hospital of Zhengzhou University Department of Gastroenterology The First Affiliated Hospital of Zhengzhou University Department of Oncology The First Affiliated Hospital of Zhengzhou University Department of Thoracic Surgery The First Affiliated Hospital of Zhengzhou University

AIM To evaluate the T stage of esophageal squamous cell carcinoma(ESCC) using preoperative low-dose esophageal insufflation computed tomography(EICT).METHODS One hundred and twenty ESCC patients confirmed by surgery or esophagoscopy were divided into three groups. Groups B and C were injected with 300 mgI/kg contrast medium for automatic spectral imaging assist(GSI assist), while group A underwent a conventional 120 kVp computed tomography(CT) scan with a 450 mg I/kg contrast medium injection. EICT was performed in group C. Group A was reconstructed with filtered back projection, and groups B and C were reconstructed with 50% adaptive statistical iterative reconstruction. The contrast-to-noise ratio of lesion-to-mediastinal adipose tissue and the radiation dose were measured. Specific imaging features were observed, and T stage ESCCs were *** The sensitivity and accuracy of the T1/2 stage were higher in group C than in groups A and B(sensitivity: 43.75% vs 31.82% and 33.33%; accuracy: 54.29% vs 46.67% and 52.50%, respectively). With regard to the T3 stage, the sensitivity and specificity in group C were higher than those in groups A and B(sensitivity: 56.25% vs 41.17% and 44.44%; specificity: 73.68% vs 67.86% and 63.64%, respectively). The diagnostic sensitivity, specificity and accuracy of the T4 stage were similar among all groups. There were no significant differences in volume CT dose index [(5.91 ± 2.57) mGy vs(3.24 ± 1.20) vs(3.65 ± 1.77) mGy], doselength product [(167.10 ± 99.08) mGy·cm vs(113.24 ± 54.46) mGy·cm vs(117.98 ± 32.32) mGy·cm] and effective dose [(2.52 ± 1.39) vs(1.63 ± 0.76) vs(1.73 ± 0.44) mSv] among the groups(P > 0.05). However, groups B and C received similar effective doses but lower iodine loads than group A [(300 vs 450) mgI/kg].CONCLUSION EICT combined with GSI assist allows differential diagnosis between the T1/2 and T3 stages. The ability to differentially diagnose the T3 and T4 stages of medullary ESCC can be improved by

关键词： Esophageal neoplasms tomography tumor staging

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Chlorophyll-a concentrations in 82 large alpine lakes on the Tibetan Plateau during 2003–2017: temporal–spatial variations and influencing factors

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International Journal of Digital Earth 2021年第6期14卷 714-735页

作者： Xuehui Pi Lian Feng Weifeng Li Junguo liu Xingxing Kuang Kun shi Wei Qi Deliang Chen Jing Tang School of Environmental Science and Engineering Southern University of Science and TechnologyShenzhenPeople’s Republic of China Department of Urban Planning and Design The University of Hong KongPok Fu LamHong Kong State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjingPeople’s Republic of China Regional Climate Group Department of Earth SciencesUniversity of GothenburgGothenburgSweden Department of Biology University of CopenhagenCopenhagenDenmark

As essential parts of the unique ecosystem of Tibetan Plateau(TP),the sizes and associated physical properties of alpine lakes have long been ***,little is known about one of the most critical biogeochemical properties,*** Chlorophyll-a(Chl-a)***,for the first time,we presented a comprehensive investigation of the temporal–spatial variations in Chl-a in 82 lakes(>50 km^(2))across the entire TP region,based on MODIS observations in the period of 2003–*** results showed that the 82 lakes exhibited an average longterm mean Chl-a of 3.3±4.3 mg m^(−3),with high Chl-a lakes concentrated in the eastern and southern inner TP basin and northeastern parts of the *** interannual trend analysis revealed that lakes exhibiting(significantly)decreasing Chl-a trends and(significantly)increasing Chl-a trends were comparable in numbers but differed in distribution patterns.A correlation analysis indicated that at least 70%of the interannual variability in Chl-a values of lakes was significantly correlated with one of the four environmental factors(wind speed,ice cover duration,lake water surface temperature and surface runoff)and lake *** addition,glacier meltwater tended to reduce lake Chl-a while salinity levels showed minor influences.

关键词： Chlorophyll-a inland water Tibetan Plateau remote sensing alpine lake

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Benzodiazepines in complex biological matrices: Recent updates on pretreatment and detection methods

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Journal of Pharmaceutical Analysis 2023年第5期13卷 442-462页

作者： Yi-Xin Zhang Yuan Zhang Yu Bian Ya-jie liu Ai Ren Yu Zhou Du shi Xue-Song Feng School of Pharmacy China Medical UniversityShenyang110122China Department of Pharmacy National Cancer Center/National Clinical Research Centerfor Cancer/Cancer Hospital ChineseAcademy of Medical Sciences and Peking Union Medical CollegeBeijing100021China Department of Urology The First Hospital of China Medical UniversityShenyang110001China

Benzodiazepines(BDZs)are used in clinics for anxiolysis,anticonvulsants,sedative hypnosis,and muscle *** have high consumptions worldwide because of their easy availability and potential *** are often used for suicide or criminal practices such as abduction and drug-facilitated sexual *** pharmacological effects of using small doses of BDZs and their detections from complex biological matrices are *** pretreatment methods followed by accurate and sensitive detections are ***,pretreatment methods for the extraction,enrichment,and preconcentration of BDZs as well as the strategies for their screening,identification,and quantitation developed in the past five years have been ***,recent advances in various methods are *** and advantages of each method are *** directions of the pretreatment and detection methods for BDZs are also reviewed.

关键词： Benzodiazepine Biological matrices Detectionmethods Samplepreparation

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Tetra-,penta-,and hexa-nor-lanostane triterpenes from the medicinal fungus Ganoderma australe

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Natural Products and Bioprospecting 2022年第1期12卷 505-514页

作者： Lin Zhou Subiy Akbar Meng-Xi Wang He-Ping Chen Ji-kai liu School of Pharmaceutical Sciences South-Central Minzu University430074 WuhanChina

Chemical investigation on the medicinal fungus Ganoderma australe led to the identification of ten new nor-lanostane triterpenes,namely two hexa-nor ones,ganoaustratetraenones A(1)and B(2),five penta-nor ones,ganoaustraldehydes A-E(3-7),and three tetra-nor ones ganoaustrenoic acids A-C(8-10).The chemical structures along with the absolute configurations were determined by extensive spectroscopic analysis of 1D&2D NMR and HRESIMS *** postulated biosynthesis pathways of these compounds were *** A(3)and B(4)showed moderate inhibition against nitric oxide production in RAW264.7 macrophage cells with the respec-tive IC_(50) values of 32.5,34.2μM(the IC_(50) of positive control pyrrolidine dithiocarbamate was 20.0μM).

关键词： Basidiomycete Ganoderma australe Nor-lanostane Structural determination Anti-NO production

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A Critical Review on Superchilling Preservation Technology in Aquatic Product

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Journal of Integrative Agriculture 2014年第12期13卷 2788-2806页

作者： WU Chun-hua YUAN Chun-hong YE Xing-qian HU Ya-qin CHEN shi-guo liu Dong-hong Department of Food Science and Nutrition Zhejiang Key Laboratory for Agro-Food Processing Fuli Institute of Food Science Zhejiang University Faculty of Fisheries Kagoshima University

aquatic product, known as one of the good resources for white meat, has been widely accepted by the consumers due to its high protein, low fat, especially low cholesterol. With the fast development of living standards around the world, the consumer demands for high quality, nutrition, safety and freshness of ifshery food are increasing. Thus, high efifcient preservation technologies for aquatic products become particularly important. Superchilling is one of the controlled-temperature preservation technologies for seafood. Aquatic products can be kept in better quality under superchilling conditions. This review introduced the principle and development of superchilling process, mainly focusing on research progresses and technical dififculties of superchilling. The growth mechanism of ice crystals and the feasibility of application of computational lfuid dynamics in analyzing the temperatures variation and ice crystals during superchilling progress were also discussed, which will provide theoretical foundation for its improvement and application.

关键词： aquatic product superchilling freshness growth mechanism of ice crystals computational lfuid dynamics

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Combating the Coronavirus Pandemic:Early Detection,Medical Treatment,and a Concerted Effort by the Global Community

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Research 2020年第1期2020卷 1141-1175页

作者： Zichao Luo Melgious Jin Yan Ang Siew Yin Chan Zhigao Yi Yi Yiing Goh Shuangqian Yan Jun Tao kai liu Xiaosong Li Hongjie Zhang Wei Huang Xiaogang liu Department of Chemistry National University of SingaporeSingapore 117543Singapore NUS Graduate School for Integrative Sciences and Engineering Singapore 117456Singapore Frontiers Science Center for Flexible Electronics&Shaanxi Institute of Flexible Electronics Northwestern Polytechnical UniversityXi’an 710072China Sports Medical Centre The Second Affiliated Hospital of Nanchang UniversityNanchang 330000China State Key Laboratory of Rare Earth Resource Utilization Chang Chun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China Department of Oncology The Fourth Medical Center of Chinese People’s Liberation Army General HospitalBeijing 100048China Department of Chemistry Tsinghua UniversityBeijing 100084China Key Laboratory of Flexible Electronics&Institute of Advanced Materials Nanjing Tech UniversityNanjing 211816China The N.1 Institute for Health National University of SingaporeSingapore Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350807China

The World Health Organization(WHO)has declared the outbreak of 2019 novel coronavirus,known as 2019-nCoV,a pandemic,as the coronavirus has now infected over 2.6 million people globally and caused more than 185,000 fatalities as of April 23,*** disease 2019(COVID-19)causes a respiratory illness with symptoms such as dry cough,fever,sudden loss of smell,and,in more severe cases,difficulty *** date,there is no specific vaccine or treatment proven effective against this viral *** and accurate diagnosis of COVID-19 is thus critical to curbing its spread and improving health *** transcription-polymerase chain reaction(RT-PCR)is commonly used to detect the presence of *** techniques,such as recombinase polymerase amplification(RPA),loopmediated isothermal amplification(LAMP),clustered regularly interspaced short palindromic repeats(CRISPR),and microfluidics,have allowed better disease ***,as part of the effort to expand screening capacity,we review advances and challenges in the rapid detection of COVID-19 by targeting nucleic acids,antigens,or *** also summarize potential treatments and vaccines against COVID-19 and discuss ongoing clinical trials of interventions to reduce viral progression.

关键词： diagnosis Early Combat

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