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pH-Sensitive nanoscale materials as robust drug delivery systems for cancer therapy

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Chinese Chemical Letters 2020年第6期31卷 1345-1356,F0003页

作者： Zhaoqing Shi Qianqian Li lin mei School of Pharmaceutical Sciences(Shenzhen) Sun Yat-sen UniversityShenzhen 518107China Tsinghua Shenzhen International Graduate School.Tsinghua University Shenzhen 518055China

Cancer is one of the diseases that have the highest mortality,which threatens the human *** functions as the most widely used strategy in clinic to treat cancer,still exists urgent problems,like lacking selectivity and causing severe side *** to detailed researches on the metabolism,functions and histology of cancer tissues,many different features of cancer are uncovered,like lower pH in microenvironment,abnormal redox level in intracellular compartments and elevated expression level of several enzymes and ***,the development of smart nanoparticles that response to tumor specific microenvironment has lighted up hope for selective cancer ***,this review mainly focuses on pH-sensitive nano scale materials for anti-cancer drug *** summarized the formation progress of acidic tumor microenvironment,the mechanism of pHresponsive drug delivery system and nanomaterials that responsive to acidic pH in tumor microenvironment.

关键词： Cancer therapy Drug delivery systems Nanoparticles pH-sensitive material

Guaranteeing Wireless Communication Secrecy via a WFRFT-Based Cooperative System

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China Communications 2015年第9期12卷 76-82页

作者： Fang Xiaojie Sha Xuejun mei lin Communication Research Center Harbin Institute of Technology

In this paper, a weighted fractional Fourier transform(WFRFT) based cooperative overlay system, aiming to guarantee physical layer(PHY) security, is proposed. The paper elaborates how WFRFT and physical layer properties of the wireless medium are collaborated to guarantee the secrecy of wireless transmissions. In the proposed system, WFRFT is first preform on the secret data, such that the transmitted signal is distorted and can only be neutralized by inverse-WFRFT with the same parameter. And then two streams of the transformed sequences that bearing different messages are cooperatively and simultaneously transmitted to two legitimate receivers via a beamforming-liked method, respectively. In general, both the rapid spatial decorrelation property and the inherent security features of WFRFT are leveraged, such that only the eavesdropper's is degraded, and hence, the wireless communication secrecy is reliably guaranteed. Numerical simulations are conducted to evaluate the performance of the proposed system in terms of the average bit error rate and the secrecy capacity.

关键词： weighted fractional Fourier trans-form(WFRFT) physical layer(PHY) security secrecy capacity

Liouville Type Results for a p-Laplace Equation with Negative Exponent

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Acta Mathematica Sinica,English Series 2016年第12期32卷 1515-1540页

作者： Zong Ming GUO lin Feng mei Department of Mathematics He'nan Normal University

Positive entire solutions of the equation where 1 〈 p ≤ N, q 〉 0, are classified via their Morse indices. It is seen that there is a critical power q = qc such that this equation has no positive radial entire solution that has finite Morse index when q 〉 qc but it admits a family of stable positive radial entire solutions when 0 〈 q ≤ qc- Proof of the stability of positive radial entire solutions of the equation when 1 〈 p 〈 2 and 0 〈 q ≤ qc relies on Caffarelli-Kohn Nirenberg＇s inequality. Similar Liouville type result still holds for general positive entire solutions when 2 〈 p ≤ N and q 〉 qc. The case of 1 〈 p 〈 2 is still open. Our main results imply that the structure of positive entire solutions of the equation is similar to that of the equation with p = 2 obtained previously. Some new ideas are introduced to overcome the technical difficulties arising from the p-Laplace operator.

关键词： Positive entire solutions p-Laplacian morse index negative exponent critical value,liouville type results

Theoretical analysis of the sound absorption characteristics of periodically stiffened micro-perforated plates

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Acta Mechanica Sinica 2014年第5期30卷 714-726页

作者： Hai-An Zhou Xiao-Ming Wang Yu-lin mei School of Mechanical Engineering Shandong University of Technology School of Mechanical Engineering Dalian University of Technology School of Automotive Engineering Dalian University of Technology

The vibro-acoustic responses and sound absorption characteristics of two kinds of periodically stiffened micro-perforated plates are analyzed theoretically. The connected periodical structures of the stiffened plates can be ribs or block-like structures. Based on fundamental acoustic formulas of the micro-perforated plate of Maa and Takahashi, semi-analytical models of the vibrating stiffened plates are developed in this paper. Approaches like the space harmonic method, Fourier transforms and finite element method （FEM） are adopted to investigate both kinds of the stiffened plates. In the present work, the vibro-acoustic responses of micro-perforated stiffened plates in the wavenumber space are expressed as functions of plate displacement amplitudes. After approximate numerical solutions of the amplitudes, the vibration equations and sound absorption coefficients of the two kinds of stiffened plates in the physical space are then derived by employing the Fourier inverse transform. In numerical examples, the effects of some physical parameters, such as the perforation ratio, incident angles and periodical distances etc., on the sound absorption performance are examined. The proposed approaches are also validated by comparing the present results with solutions of Takahashi and previous studies of stiffened plates. Numerical results indicate that the flexural vibration of the plate has a signif- icant effect on the sound absorption coefficient in the water but has little influence in the air.

关键词： Absorption- Stiffened- Micro-perforated Spaceharmonic - Finite element method

Video structural description technology for the new generation video surveillance systems

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Frontiers of Computer Science 2015年第6期9卷 980-989页

作者： Chuanping HU Zheng XU Yunhuai LIU lin mei The Third Research Institute of the Ministry of Public Security Shanghai 200031 China

The increasing need of video based applications issues the importance of parsing and organizing the content in videos. However, the accurate understanding and manag- ing video contents at the semantic level is still insufficient. The semantic gap between low level features and high level semantics cannot be bridged by manual or semi-automatic methods. In this paper, a semantic based model named video structural description （VSD） for representing and organizing the content in videos is proposed. Video structural descrip- tion aims at parsing video content into the text information, which uses spatiotemporal segmentation, feature selection, object recognition, and semantic web technology. The pro- posed model uses the predefined ontologies including con- cepts and their semantic relations to represent the contents in videos. The defined ontologies can be used to retrieve and organize videos unambiguously. In addition, besides the de- fined ontologies, the semantic relations between the videos are mined. The video resources are linked and organized by their related semantic relations.

关键词： video structural description video content ex- traction video resources management domain ontology

BER analysis of STBC hybrid carrier system based on WFRFT with frequency domain equalization

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Science China(Information Sciences) 2018年第8期61卷 147-159页

作者： Zhenduo WANG lin mei Xuejun SHA Naitong ZHANG Communication Research Center Harbin Institute of Technology Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory

The inherent characteristic of hybrid carrier(HC) scheme based on the weighted-type fractional Fourier transform(WFRFT) is revealed. The proposed linear combination of single carrier(SC) and multicarrier’s(MC) characteristics is helpful to balance the conflicting requirements and achieve the comparative analysis of SC/MC. As an example, analytical SER/BER expressions of HC system with zero forcing(ZF)and minimum mean square error(MMSE) equalization are derived. In addition, the derived BER expressions are extended to multi-input systems. A unified framework of space time block code(STBC) HC scheme is proposed with two WFRFT modules at the transmitter or receiver, where STBC-SC and STBC-MC systems are the special cases of the novel structure.

关键词： single carrier multi-carrier weighted-type fractional Fourier transform hybrid carrier zero forcing minimum mean square error space time block code

Regional Evolution Features and Coordinated Development Strategies for Northeast China

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Chinese Geographical Science 2006年第4期16卷 378-382页

作者： mei lin XU Xiaopo CHEN Mingxiu College of Urban and Environmental Sciences Northeast Normal University Changchun 130024 China College of Humanities and Sciences Northeast Normal University Changchun 130117 China

Northeast China, as the most important production base of agriculture, forestry, and livestock-breeding as well as the old industrial base in the whole country, has been playin a key role in the construction and development of China＇s economy. However, after the policy of reform and open-up was taken in China. the economic development speed and efficiency ofthis area have turned to be evidently lower than those of coastal area and the national average level as well, which is so-called ＇Northeast Phenomenon＇ and ＇Neo-Northeast Phenomenon＇. In terms of those phenomena, this paper firstly reviews the spatial and temporal features of the regional evolution of this area so as to unveil the profound forming causes of ＇Northeast Phenomena＇ and ＇Neo-Northeast Phenomena＇. And then the paper makes a further exploration into the status quo of this region and its forming causes by analyzing its economy gross, industrial structure, product structure, regional eco-categories, etc. At the end of the paper, the authors put forward the basic coordinated development strategies for Northeast China. namely we can revitalize this area by means of adjustment of economic structure, regional coordination, planning urban and rural areas as a whole, institutional innovation, etc.

关键词： regional evolution spatial-temporal feature coordinated development strategy Northeast China

Multiscale Characteristics and Connection Mechanisms of Attraction Networks:A Trajectory Data Mining Approach Leveraging Geotagged Data

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Chinese Geographical Science 2024年第3期34卷 533-547页

作者： JIANG Hongqiang WEI Ye mei lin WANG Zhaobo School of Resource and Environment Engineering Ludong UniversityYantai 264025China School of Geographical Sciences Northeast Normal UniversityChangchun 130024China Changchun University of Finance and Economics Changchun 130122China Jilin Jizhi City Architectural Design Co. LTDChangchun 130012China

Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination *** paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the *** results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism *** macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high *** mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of *** pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four diff

关键词： attraction network travel mobility polycentric structure network motif connectivity mechanism destination management organization(DMO) destination planning Beijing,China

Black phosphorus-based nano-drug delivery systems for cancer treatment:Opportunities and challenges

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Asian Journal of Pharmaceutical Sciences 2021年第1期16卷 1-3页

作者： Nansha Gao lin mei Institute of Pharmaceutics School of Pharmaceutical Sciences(Shenzhen)Sun Yat-sen UniversityShenzhen 518107China Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China

The numbers of research studies investigating black phosphorus(BP)-based nano-drug delivery systems and their potential applications are rapidly growing because of the unique properties of BP(such as a layer-dependent bandgap,moderate carrier mobility,high capacity of drug loading,intrinsic photothermal and photoacoustic properties,good biocompatibility,etc.).They are highly suitable for phototherapy(photothermal therapy and photodynamic therapy),drug delivery,bioimaging and theranostics[1].In the present report,the opportunities for BP nanomaterialbased drug delivery systems are highlighted.

关键词： therapy drug phosphorus