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The Relationship between Magnetic Gradient and Magnetic Shear in Five Super Active Regions Producing Great Flares

Chinese Journal of Astronomy and Astrophysics 2006年第4期6卷 477-488页

作者： Hai-Min Wang hui song Ju jing Vasyl Yurchyshyn Yuan-Yong Deng Hong-Qi Zhang David Falconer jing Li National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Big Bear Solar Observatory New Jersey Institute of Technology Big Bear City CA 92314 USA Marshall Space Flight Center SD50 Huntsville AL 35812 USA Institute for Astronomy University of Hawaii 2680 Woodlawn Drive Honolulu HI 96822 USA

We study the magnetic structure of five well-known active regions that produced great flares （X5 or larger）. The six flares under investigation are the X12 flare on 1991 June 9 in AR 6659, the X5.7 flare on 2000 July 14 in AR 9077, the X5.6 flare on 2001 April 6 in AR 9415, the X5.3 flare on 2001 August 25 in AR 9591, the X17 flare on 2003 October 28 and the X10 flare on 2003 October 29, both in AR 10486. The last five events had corresponding LASCO observations and were all associated with Halo CMEs. We analyzed vector magnetograms from Big Bear Solar Observatory, Huairou Solar Observing Station, Marshall Space Flight Center and Mees Solar Observatory. In particular, we studied the magnetic gradient derived from line-of-sight magnetograms and magnetic shear derived from vector magnetograms, and found an apparent correlation between these two parameters at a level of about 90%. We found that the magnetic gradient could be a better proxy than the shear for predicting where a major flare might occur： all six flares occurred in neutral lines with maximum gradient. The mean gradient of the flaring neutral lines ranges from 0.14 to 0.50 G km^-1, 2.3 to 8 times the average value for all the neutral lines in the active regions. If we use magnetic shear as the proxy, the flaring neutral line in at least one, possibly two, of the six events would be mis-identified.

关键词： Sun: activity -- Sun: flares -- Sun: magnetic fields -- Sun: coronal mass ejections (CMEs)

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Mesenchymal stem cells-derived exosomes ameliorate blue light stimulation in retinal pigment epithelium cells and retinal laser injury by VEGF-dependent mechanism

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International Journal of Ophthalmology(English edition) 2018年第4期11卷 559-566页

作者： Guang-hui He Wei Zhang Ying-Xue Ma jing Yang Li Chen Jian song song Chen Tianjin Eye Hospital Tianjin Key Lab of Ophthalmologyand Visual ScienceTianjin Eye InstituteClinical College of OphthalmologyTianjin Medical UniversityTianjin 300020China

AIM： To observe the effect of exosomes derived from human umbilical cord blood mesenchymal stem cells（h UCMSCs） on the expression of vascular endothelial growth factor-A（VEGF-A） in blue light injured human retinal pigment epithelial（RPE） cells and laser-induced choroidal neovascularization（CNV） in ***： Exosomes were isolated from h UCMSCs and characterized by transmission electron microscope and Western blot. MSCs-derived exosomes were cultured with RPE cells exposed to blue light. The m RNA and protein expression of VEGF-A were determined by real time-polymerase chain reaction（PCR） and Western blot, respectively. Immunofluorescence assay was used for the detection of the expression level of VEGF-A. We injected different doses of MSCs-derived exosomes intravitreally to observe and compare their effects in a mouse model of laserinduced retinal injury. The histological structure of CNV in rats was inspected by hematoxylin-eosin（HE） staining and fundus fluorescein angiography. The expression of VEGF-A was detected by ***： Exosomes exhibited the typical characteristic morphology（cup-shaped） and size（diameter between 50 and 150 nm）. The exosomes marker, CD63, and h UCMSCs marker, CD90, showed a robust presence. In vitro, MSCsderived exosomes downregulated the m RNA（Exo-L： t=6.485, 7.959, 9.286; Exo-M： t=7.517, 10.170, 13.413; Exo-H： t=10.317, 12.234, 14.592, P〈0.05） and protein（Exo-L： t=2.945, 4.477, 6.657; Exo-M： t=4.713, 6.421, 8.836; Exo-H：t=6.539, 12.194, 12.783; P〈0.05） expression of VEGF-A in RPE cells after blue light stimulation. In vivo, we found that the MSCs-derived exosomes reduced damage, distinctly downregulated VEGF-A（Exo-H： t=0.957, 1.382; P〈0.05）, and gradually improved the histological structures of CNV for a better visual function（Exo-L： 0.346, Exo-M： 3.382, Exo-H： 8.571; P〈0.05）. CONCLUSION： MSCs-derived exosomes ameliorate blue light stimulation in RPE cells and laser-induced retinal injury via downregulation of VEGF

关键词： exosome human umbilical cord mesenchymal stem cell retinal pigment epithelial cell choroidal neovascularization vascular endothelial growth factor

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Inducing Macrophages M2 Polarization by Dexamethasone Laden Mesoporous Silica Nanoparticles from Titanium Implant Surface for Enhanced Osteogenesis

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Acta Metallurgica Sinica(English Letters) 2019年第10期32卷 1253-1260页

作者： jing Luo Xin Ding Wen song Jian-Ying Bai jing Liu Zhe Li Fan-hui Meng Fang-Hao Chen Yu-Mei Zhang State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases Department of Prosthodontics School of Stomatology The Fourth Military Medical University Xi'an 710032 China Department of Stomatology General Hospital of Southern Theater Command of the Chinese People's Liberation Army Guangzhou 510010 China Huaian Stomatological Hospital Huaian 223001 China State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Oral Diseases Department of Dental Materials School of Stomatology The Fourth Military Medical University Xi'an 710032 China

The study conveys an idea to enhance the osseointegration of titanium implant (Ti) through modulating macrophages M2 polarization. The ?100 nm spherical mesoporous silica nanoparticles (MSN) that compromised of ~4-nm-diameter nano? tunnels were synthesized by the conventional "sol-gel" method, into which the dexamethasone (DEX) was loaded (DEX@ MSN). The DEX@MSN could consistently release DEX and showed favorable cytocompatibility in RAW264.7 cells. The arginase-1 expression, a specific marker for macrophages M2 polarization, was also enhanced by DEX @ MSN treatment. Then, the Ti was pre-treated with anodization under 5 V to generate the titania nanotubes with ?30 nm diameter (NT-30) and the DEX @ MSN was introduced onto NT-30 surface via electrophoretic deposition, with the aid of chitosan. After optimizing the deposition parameters, the supernatants of RAW264.7 from the decorated implant surface could significantly promote the osteogenic differentiation of murine primary bone marrow mesenchymal stem cells. These findings demonstrate that delivery of DEX from implant surface can modulate the macrophages M2 polarization and result in favorable osteogenesis.

关键词： Macrophages polarization Titanium implant Osteogenesis Dexamethasone Mesoporous silica nanoparticles Electrophoretic deposition

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Compressed sensing method for human activity recognition using tri-axis accelerometer on mobile phone

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The Journal of China Universities of Posts and Telecommunications 2017年第2期24卷 31-37,71页

作者： song hui Wang Zhongmin School of Computer Science and Technology Xi'an University of Posts and Telecommunications

The diversity in the phone placements of different mobile users＇ dailylife increases the difficulty of recognizing human activities by using mobile phone accelerometer data. To solve this problem, a compressed sensing method to recognize human activities that is based on compressed sensing theory and utilizes both raw mobile phone accelerometer data and phone placement information is proposed. First, an over-complete dictionary matrix is constructed using sufficient raw tri-axis acceleration data labeled with phone placement information. Then, the sparse coefficient is evaluated for the samples that need to be tested by resolving L1 minimization. Finally, residual values are calculated and the minimum value is selected as the indicator to obtain the recognition results. Experimental results show that this method can achieve a recognition accuracy reaching 89.86%, which is higher than that of a recognition method that does not adopt the phone placement information for the recognition process. The recognition accuracy of the proposed method is effective and satisfactory.

关键词： activity recognition compressed sensing mobile phone accelerometer phone placements

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Investigations on methane hydrate formation,dissociation,and viscosity in gas-water-sand system

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Petroleum Science 2022年第5期19卷 2420-2430页

作者： Shang-Fei song Shun-Kang Fu Qing-Yun Liao Bo-hui Shi Hong-Ju Chen jing Gong State Key Laboratory of Natural Gas Hydrates/National Engineering Laboratory for Pipeline Safety China University of PetroleumBeijing102249China PipeChina West East Pipeline Company Shanghai200122China Key Lab of Deepwater Engineering CNOOC Research InstituteBeijing100028China

Understanding the kinetics and viscosity of hydrate slurry in gas-water-sand system is of great significance for the high-efficiency and high-safety development of natural gas *** effect of micronsized sands with various concentrations and particle sizes on the hydrate formation,dissociation,and viscosity in gas-water-sand system are investigated in this *** experimental results show that the hydrate induction time in the sandy system is slightly prolonged compared to the pure gas-water system,and the inhibition effect first strengthens and then weakens as the sand concentration increases from0 wt%to 5 wt%.Besides,the difference of hydrate formation amount in various cases is not *** concentration and particle size of sand have little effect on the kinetics of hydrate *** promoting and inhibiting effects on hydrate formation have been found in the sandy multiphase *** the viscosity characteristics,there are three variations of hydrate slurry viscosity during the formation process:Steep drop type,S-type and Fluctuation ***,appropriate sand size is helpful to reduce the randomness of slurry viscosity ***,even at the same hydrate volume fraction,the slurry viscosity in the formation process is significantly higher than that in dissociation process,which needs further *** work provides further insights of hydrate formation,dissociation,and viscosity in gas-water-sand system,which is of great significance for safe and economic development of natural gas hydrates.

关键词： Hydrate slurry Micron-sized sands Hydrate formation Hydrate dissociation Viscosity characteristics

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EFFECT OF DAMAGE EVOLUTION ON POISSON'S RATIO OF CONCRETE UNDER SULFATE ATTACK

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Acta Mechanica Solida Sinica 2011年第3期24卷 209-215页

作者： hui song Jiankang Chen The Faculty of Mechanical Engineering and Mechanics Ningbo University Ningbo 315211 China State Key Laboratory of Turbulence and Complex Systems Peking University Beijing 100871 China

Experimental results about concrete under sulfate attack are summarized, which include the variation of mass density of samples and velocity of ultrasonic wave propagating in samples. The evolution damage is analyzed in terms of the experimental results, and close attention is paid to the effect of damage evolution on Poisson＇s ratio. This study shows that Poisson＇s ratio is significantly affected by the concentration of solution and water-cement ratio. Poisson＇s ratio of concrete changes very little when the water-cement ratio is selected as 0.6 or 0.8, so that such change may be neglected. If water-cement is 0.4, however, the Poisson＇s ratio of the sample significantly changes. When the concrete sample of 0.4 water-cement ratio is immersed in sodium sulfate solution of 8% concentration for 285 days, Poisson＇s ratio increase 10.14% compared with its initial value. There exist a sensitive region and a non-sensitive region for the change rate of Poisson＇s ratio with respect to corrosion time. The change rate of Poisson＇s ratio monotonously decreases with corrosion time in the sensitive region; in the non-sensitive region, the change rate of Poisson＇s ratio is almost equal to zero.

关键词： concrete sulfate attack porosity Poisson's ratio damage evolution

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Efficient circularly polarized photoluminescence and electroluminescence of chiral spiro-skeleton-based thermally activated delayed fluorescence molecules

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Science China Chemistry 2022年第7期65卷 1347-1355页

作者： Yi-Pin Zhang Shi-Quan song Meng-Xi Mao Cheng-hui Li You-Xuan Zheng jing-Lin Zuo State Key Laboratory of Coordination Chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China MaAnShan High-Tech Research Institute of Nanjing University Maanshan 238200China

Chiral thermally activated delayed fluorescence(TADF) molecules showing circularly polarized luminescence(CPL) have great potential in 3D displays. However, the relationships among CPL property, device performance and molecule structure are still not clear. In this article, we develop a strategy to promote dissymmetry factors without sacrifice in device performance and study the impact of molecule structures towards CPL property. Three novel TADF enantiomers are synthesized and studied.(R/S)-SCN with diminutive cyano group as an acceptor shows dissymmetry factor |gPL| ≈ 1.4×10^(-3) and noticeable organic light-emitting diode(OLED) performances with a maximum external quantum efficiency(EQEmax) of 23.0%. For(R/S)-SPHCN, the prolonged electron withdrawing group benzonitrile enhances |gPL| up to 3.6×10^(-3) with decreased device EQEmaxof 15.4%. By further replacing benzonitrile with(trifluoromethyl)pyridine, the enantiomers of(R/S)-SCFPY show similar |gPL| factors of 3.5×10^(-3) and device EQE_(max)up to 23.3%, which represents the highest efficiency among sprio-type TADF materials based OLEDs. Furthermore, the OLEDs also show obvious circularly polarized electroluminescence with gELfactors of-1.4/1.8×10^(-3),-3.6/3.6×10^(-3) and-3.7/3.6×10^(-3), respectively. These results indecate by delicate functional group engineering, high g factor can be achieved while maintaining decent device performances. Besides,(R/S)-SCFPY represents an impressive TADF emitter, which shows promoted g factor and recorded high device EQE_(max)among similar molecules.

关键词： chiral spiro-skeleton thermally activated delayed fluorescence circularly polarized photoluminescence circularly polarized electroluminescence dissymmetry factor

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States of graphene oxide and surface functional groups amid adsorption of dyes and heavy metal ions

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Chinese Journal of Chemical Engineering 2023年第11期63卷 197-208页

作者： Zhaoyang Han Ling Sun Yingying Chu jing Wang Chenyu Wei Qianlei Jiang Changbao Han hui Yan Xuemei song Institute of Advanced Energy Materials and Devices Faculty of Materials and ManufacturingKey Laboratory of Advanced Functional Materials of Education Ministry of ChinaBeijing University of TechnologyBeijing 100124China Beijing Guyue New Materials Research Institute Beijing University of TechnologyBeijing 100124China

Water pollution regarding dyes and heavy metal ions is crucial facing the *** to effectively separate these contaminants from water has been a key *** oxide(GO)promises the greenwater world as a long-lasting spotlight adsorbent material and therefore,harnessing GO has been the research hotspot for over a *** state of GO as well as its surface functional groups plays an important role in *** the way of preparation and structural modification matters to the performance of *** this review,the significance of the state of existence of stock GO and surface functional groups is explored in terms of preparation,structural modification,and ***,various adsorbates for GO adsorption are also involved,the discussion of which is rarely established elsewhere.

关键词： Stock graphene oxide Surface functional groups Existence state Adsorbates Enhanced adsorption Dyes

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A NEW WELL TEST MODEL FOR A TWO-ZONE LINEAR COMPOSITE RESERVOIR WITH VARIED THICKNESSES

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Journal of Hydrodynamics 2010年第6期22卷 804-809页

作者： ZHANG Lie-hui GUO jing-jing LIU Qi-guo State Key Laboratory of Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500China

This article presents a new well test model for two-zone linear composite reservoirs, where the rock and fluid properties as well as the formation thicknesses on both sides of the discontinuity are distinctly different. An analytical solution of pressure-transient behavior for a line-source, constant-rate well in this type of reservoir configuration is obtained with Fourier space transformation and Laplace transformation. By applying Duhamel principle, the wellbore storage and skins effects can easily be included. A set of type curves are generated and the sensitivities of the relevant parameters are discussed. A new correlating parameter MhDl√ηD is proposed to identify the pressure response in the pressure derivative curve. The model as well as the corresponding type curves are quite general that they are useful in predicting the production performance or analyzing the production data from this type of well-reservoir systems.

关键词： non-uniform thickness linear composite well test model type curve

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Exploring User Influence for Topical Group Recommendation

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Chinese Journal of Electronics 2017年第1期26卷 106-111页

作者： WANG jing ZHAO hui LIU Zhijing Xidian University Xi'an Jiaotong University

With the development of social networks,many recommendation systems recommend items to a group of users, known as group recommendation. However, it will not be an appropriate recommendation without user topical influence analysis. We proposed a new group recommendation based on user topical influence *** firstly construct several topical sub-groups depending on topics. Then we analyze user topical influence in subgroup, including user influence on specific topic and the topical sub-group. Besides, four user-factors are introduced to calculate the user social influence on topical sub-groups more accurately. Based on user topical influence analysis,we present our topical group recommendation algorithm,which calculates the predicted rating value for sub-group by aggregating weighted ratings of all users in the subgroup. The experimental results show convincingly that our proposed method can improve the group recommendation quality.

关键词： Group recommendation Social networks Topical sub-groups User topical influence

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