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611 results on '"Li, Junfang"'

112. Remarkable surface-enhanced Raman scattering of highly crystalline monolayer Ti3C2nanosheets

Author

Ye, Yuting, Yi, Wencai, Liu, Wei, Zhou, Yun, Bai, Hua, Li, Junfang, and Xi, Guangcheng

Abstract

As a powerful non-destructive and label-free detection technology, surface-enhanced Raman scattering (SERS) has been widely used in environmental-pollutant detection, biological-tissue sensing, molecular fingerprint analysis and so on. Different from the traditional SERS substrates represented by noble metals and semiconductors, herein, we report a new highly sensitive SERS substrate material with high stability, biocompatibility, and low cost, namely nucleusfree two-dimensional electron gas (2DEG) Ti3C2monolayer nanosheets. The highly crystalline monolayer Ti3C2nanosheets with clean surface are synthesized by an improved chemical exfoliation and microwave heating method. The unique structure of nucleus-free-2DEG in Ti3C2monolayer provides an ideal transport channel without nuclear scattering, which makes the highly crystalline monolayer Ti3C2nanosheets achieve a Raman enhanced factor of 3.82×108and a 10−11level detection limit for typical environmental pollutants such as azo dyes, trichlorophenol, and bisphenol A. Single-molecule imaging is also realized on the surface of the Ti3C2monolayers, which may be the first time that approximate single-molecule imaging has been achieved on a non-noblemetal SERS substrates. Preliminary toxicological experiments show that the cytotoxicity of this material is very low. Considering the facile synthesis, high biocompatibility, low cost and high chemical stability of carbide nanosheets, these Ti3C2monolayer nanosheets show significant promise for the design and fabrication of flexible SERS substrates for the sensing of trace substances with ultrahigh sensitivity.

Published
2024
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113. Multi-Node Motion Estimation Method Based on B-Spline of Array Position and Orientation System

Author

Li, Junfang Bao, Jianli Li, Chunyu Qu, and Yunzhu

Subjects
array position and orientation system (array POS), sub-inertial measurement units (sub-IMU), B-spline, global estimation
Abstract

The array position and orientation system (array POS), composed of one main POS and multiple sub-inertial measurement units (sub-IMUs), is key equipment in the aerial remote-sensing system, especially the multi-load system, which can provide motion compensation for the multi-load remote-sensing system to improve imaging quality. Nevertheless, the measurement information of each sub-IMU can only realize the motion information of the corresponding remote-sensing load. Ideally, each remote-sensing load should be equipped with a sub-IMU for motion compensation, which is impossible in actual engineering considering the volume, weight and cost. To solve this problem, a multi-node motion estimation method based on the B-spline of the array POS is proposed to realize the motion compensation of remote-sensing loads without sub-IMUs. Firstly, the transfer alignment method based on fiber-grating multi-dimensional deformation measurement was adopted. Motion parameters of the remote-sensing payload equipped with sub-IMUs at different times can be obtained by observing and correcting the errors between the main POS and sub-IMUs. In this way, the space-time characteristics of each interpolation point are fully utilized. Additionally, the motion information of the main POS and all sub-IMUs is fitted through the estimation method based on the B-spline, during which wing deformation is considered to obtain the motion parameters of the remote-sensing payload equipped without a sub-IMU. In this way, the spatial correlation between the information of each node is fully utilized. Due to the full utilization of the spatiotemporal correlation of the motion information of each sub node, high-precision and highly reliable motion information of the remote-sensing loads not equipped with sub-IMUs is obtained. Furthermore, the proposed method can be modified locally without affecting other nodes, and has the advantages of a simple algorithm and easy engineering implementation. Finally, a semi-physical simulation based on ground-loading test was conducted. The results show that the baseline in the X-axis, Y-axis and Z-axis direction is improved by 0.484 mm, 0.137 mm and 1.225 mm, respectively, and that the measurement accuracy of roll angle is improved by 0.011°.

Published
2023
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114. A geometric characterization of a sharp Hardy inequality

Author

Lewis, Roger T., Li, Junfang, and Li, Yanyan

Subjects
Mathematics - Analysis of PDEs, Mathematics - Functional Analysis, Mathematics - Spectral Theory, 35R45, 35J20
Abstract

In this paper, we prove that the distance function of an open connected set in $\mathbb R^{n+1}$ with a $C^{2}$ boundary is superharmonic in the distribution sense if and only if the boundary is {\em weakly mean convex}. We then prove that Hardy inequalities with a sharp constant hold on {weakly mean convex} $C^{2}$ domains. Moreover, we show that the {weakly mean convexity} condition cannot be weakened. We also prove various improved Hardy inequalities on mean convex domains along the line of Brezis-Marcus \cite{BM}., Comment: The results were improved to $C^2$ domains

Published
2011

115. Hypersurfaces of Prescribed Curvature Measure

Author

Guan, Pengfei, Li, Junfang, and Li, YanYan

Subjects
Mathematics - Differential Geometry, Mathematics - Analysis of PDEs, 53C23, 35J60, 53C42
Abstract

We consider the corresponding Christoffel-Minkowski problem for curvature measures. The existence of star-shaped $(n-k)$-convex bodies with prescribed $k$-th curvature measures ($k>0$) has been a longstanding problem. This is settled in this paper through the establishment of a crucial $C^2$ a priori estimate for the corresponding curvature equation on $\mathbb S^n$.

Published
2011
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117. Differential Harnack inequalities on Riemannian manifolds I : linear heat equation

Author

Li, Junfang and Xu, Xiangjin

Subjects
Mathematics - Differential Geometry, 58G11
Abstract

In the first part of this paper, we get new Li-Yau type gradient estimates for positive solutions of heat equation on Riemmannian manifolds with $Ricci(M)\ge -k$, $k\in \mathbb R$. As applications, several parabolic Harnack inequalities are obtained and they lead to new estimates on heat kernels of manifolds with Ricci curvature bounded from below. In the second part, we establish a Perelman type Li-Yau-Hamilton differential Harnack inequality for heat kernels on manifolds with $Ricci(M)\ge -k$, which generalizes a result of L. Ni \cite{NL1,NL4}. As applications, we obtain new Harnack inequalities and heat kernel estimates on general manifolds. We also obtain various entropy monotonicity formulas for all compact Riemannian manifolds.

Published
2009

118. Rapid on‐site detection of persistent organic pollutants using multiwalled carbon nanotube–modified paper spray ionization and a miniature mass spectrometer.

Author

Guo, Xiangyu, Li, Junfang, Bai, Hua, and Ma, Qiang

Subjects
*PERSISTENT pollutants, *CARBON paper, *POLYCYCLIC aromatic hydrocarbons, *CARBON nanotubes, *MASS spectrometers, *ION traps, *ENVIRONMENTAL protection
Abstract

Rationale: Rapid on‐site detection of persistent organic pollutants (POP) is highly desirable for environmental protection. Methods: Herein, a rapid on‐site analytical workflow was developed for the investigation of polycyclic aromatic hydrocarbons and perfluorinated compounds using multiwalled carbon nanotube–modified paper spray ionization (PSI) coupled with a miniature ion trap mass spectrometer. Critical parameters regarding PSI and miniature mass spectrometry analysis were optimized. Results: The analytical performance of the developed method was evaluated under optimized conditions, obtaining a short analysis duration of less than 1 min, sufficient linearity with correlation coefficients greater than 0.99, acceptable recovery rates of 93.1%–105.8% with relative standard deviations of between 3.5% and 10.3%, and reasonable sensitivity with limits of detection and quantitation of 2–200 and 5–500 μg/L, respectively. Conclusions: Considering these aspects, it was concluded that the present approach demonstrated a promising solution for rapid on‐site detection of emerging POPs. [ABSTRACT FROM AUTHOR]

Published
2023
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119. First variation of the Log Entropy functional along the Ricci flow

Author

Li, Junfang

Subjects
Mathematics - Differential Geometry, Mathematics - Analysis of PDEs, 53C20, 53C21
Abstract

In this note, we establish the first variation formula of the adjusted log entropy functional $\mathcal Y_a$ introduced by Ye in \cite{Y2}. As a direct consequence, we also obtain the monotonicity of $\mathcal Y_a$ along the Ricci flow., Comment: 4 pages. One remark improved

Published
2007

120. The quermassintegral inequalities for starshaped domains

Author

Guan, Pengfei and Li, Junfang

Subjects
Mathematics - Differential Geometry, Mathematics - Analysis of PDEs, 52A40, 35J60
Abstract

We give a simple proof of the insoperimetric inequality for quermassintegrals of non-convex starshaped domains, using a reslut of Gerhardt \cite{G} and Urbas \cite{U} on an expanding geometric curvature flow., Comment: 7 pages

Published
2007

121. Eigenvalues and energy functionals with monotonicity formulae under Ricci flow

Author

Li, Junfang

Subjects
Mathematics - Differential Geometry, Mathematics - Analysis of PDEs, 53C44, 35K55
Abstract

In this note, we construct families of functionals of the type of $\mathcal{F}$-functional and $\mathcal{W}$-functional of Perelman. We prove that these new functionals are nondecreasing under the Ricci flow. As applications, we give a proof of the theorem that compact steady Ricci breathers must be Ricci-flat. Using these new functionals, we also give a new proof of Perelman's no non-trivial expanding breather theorem. Furthermore, we prove that compact expanding Ricci breathers must be Einstein by a direct method. In this note, we also extend X. Cao's methods of eigenvalues\cite{C} and improve their results., Comment: 19 pages, one reference added, to appear in Mathematische Annalen

Published
2007

122. Chaotic Optimization of Tethered Kites for Wind Energy Generator

Author

Li, Junfang, Sun, Mingwei, Wang, Zenghui, Chen, Zengqiang, Hutchison, David, Series editor, Kanade, Takeo, Series editor, Kittler, Josef, Series editor, Kleinberg, Jon M., Series editor, Mattern, Friedemann, Series editor, Mitchell, John C., Series editor, Naor, Moni, Series editor, Pandu Rangan, C., Series editor, Steffen, Bernhard, Series editor, Terzopoulos, Demetri, Series editor, Tygar, Doug, Series editor, Weikum, Gerhard, Series editor, Huang, De-Shuang, editor, Bevilacqua, Vitoantonio, editor, Premaratne, Prashan, editor, and Gupta, Phalguni, editor

Published
2017
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127. Clec7a is a Potential Target to Relieve Neuropathic Pain via Inhibiting Neuroinflammation Activation Through Regulating TLR4 Expression

Author

Li, Qiuyue, primary, Zhang, Yanqiong, additional, Li, Junfang, additional, Ma, Yan, additional, Liu, Xiuying, additional, Zhang, Fangbo, additional, Su, Jin, additional, Wang, Xiujie, additional, Zhang, Yi, additional, Li, Defeng, additional, Guo, Feifei, additional, Wang, Ping, additional, Xu, Haiyu, additional, and Yang, Hongjun, additional

Published
2019
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136. Disability and health-related quality of life in Chinese patients with rheumatoid arthritis: A cross-sectional study

Author

Zhou, Yunshan, primary, Wang, Xiuru, additional, An, Yuan, additional, Zhang, Xiaoying, additional, Han, Shuling, additional, Li, Xiaofeng, additional, Wang, Lizhi, additional, Wang, Caihong, additional, Wang, Yongfu, additional, Yang, Rong, additional, Wang, Guochun, additional, Lu, Xin, additional, Zhu, Ping, additional, Chen, Lina, additional, Liu, Jinting, additional, Jin, Hongtao, additional, Liu, Xiangyuan, additional, Sun, Lin, additional, Wei, Ping, additional, Wang, Junxiang, additional, Chen, Haiying, additional, Cui, Liufu, additional, Shu, Rong, additional, Zhang, Zhuoli, additional, Li, Guangtao, additional, Li, Zhenbin, additional, Yang, Jing, additional, Li, Junfang, additional, Jia, Bin, additional, Zhang, Fengxiao, additional, Tao, Jiemei, additional, Lin, Jinying, additional, Wei, Qiumei, additional, Liu, Xiaomin, additional, Ke, Dan, additional, Hu, Shaoxian, additional, Ye, Cong, additional, Yang, Xiuyan, additional, Li, Hao, additional, Huang, Cibo, additional, Gao, Ming, additional, Li, Xingfu, additional, Song, Lijun, additional, Wang, Yi, additional, Wang, Xiaoyuan, additional, Mu, Rong, additional, Su, Yin, additional, and Li, Zhanguo, additional

Published
2018
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142. The effect of unilateral Forsus appliance in the treatment of ClassⅡmalocclusion subdivision

Author

WU Feng, LI Junfang, LIN Heping, and WANG Zhen

Subjects
Forsus appliance, ClassⅡmalocclusion subdivision, Cephalometric analysis, Malocclusion, Medicine
Abstract

Objective To assess the result of treatment in ClassⅡmalocclusion subdivision with unilateral Forsus appliance. Methods 23 patients with ClassⅡmalocclusion subdivision were selected, who were treated with Straight wire fixed appliance in combination with unilateral Forsus appliances while another 27 patients were untreated as con⁃ trol group. Lateral cephalographs were taken before and after the comprehensive treatment, and the indicators of dental, skeletal, and soft tissue profile were measured. Results The Forsus appliance can correct ClassⅡmalocclusion subdi⁃ vision through distalizing the upper teeth and moving the lower teeth mesially. Midline can be corrected at the same time. There was a statistically significant difference in the amount of tooth movement (P < 0.05). Conclusion Forsus appliance is an effective device for treating ClassⅡmalocclusion subdivision, which can induce significant dental and soft tissue changes.

Published
2017
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144. Additional file 2 of Disruption of C/EBPβ-Clec7a axis exacerbates neuroinflammatory injury via NLRP3 inflammasome-mediated pyroptosis in experimental neuropathic pain

Author

Wu, Dan, Zhang, Yanqiong, Zhao, Chunhui, Li, Qiuyue, Zhang, Junhong, Han, Jiaxin, Xu, Zhijian, Li, Junfang, Ma, Yan, Wang, Ping, and Xu, Haiyu

Abstract

Additional file 2. Table S1. The information of siRNA and primer sequences used in this study. Table S2. The information of antibodies used in this study. Table S3. E xpression patterns of 100 di fferentially expressed genes in SC between the sham and CCI model groups by Microarray Profiling (mixed sample, n = 3). Table S4. Expression patterns of 100 differentially expressed genes in SC between the sham and CCI model groups by RNA-seq (n = 4).

Published
2023
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145. Additional file 1 of Disruption of C/EBPβ-Clec7a axis exacerbates neuroinflammatory injury via NLRP3 inflammasome-mediated pyroptosis in experimental neuropathic pain

Author

Wu, Dan, Zhang, Yanqiong, Zhao, Chunhui, Li, Qiuyue, Zhang, Junhong, Han, Jiaxin, Xu, Zhijian, Li, Junfang, Ma, Yan, Wang, Ping, and Xu, Haiyu

Abstract

Additional file 1. Figure S1. Clec7a knockdown alleviated LPS and ATP induced BV2 cells pyroptosis. Figure S2. C/EBP β knockdown alleviated LPS and ATP induced BV2 cells pyroptosis.

Published
2023
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