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Effects of lanthanum and gadolinium on proliferation and differentiation of primary osteoblasts

Progress in Natural Science:Materials International 2007年第5期17卷 618-623页

作者： Zhang Dawei , Zhang Jinchao , Chen Yao , Yang Mengsu and Yao Xinsheng (Department of Natural Products Chemistry, Shenyang Pharmaceutical university, Shenyang 110016, china shenzhen research institute of city university of hong kong, shenzhen 518057, china Department of Biology and Chemistry, city university of hong kong, china Department of Chemistry, College of Chemistry & Environmental Science, Hebei university, Baoding 071002, china Key Laboratory for research and Development of Traditional Chinese Medicine and Natural Medicine at shenzhen, shenzhen 518057, china) [a]Department of Natural Products Chemistry Shenyang Pharmaceutical University Shenyang China [b]shenzhen research institute of city university of hong kong Shenzhen China [c]Department of Biology and Chemistry City University of Hong Kong China [d]Department of Chemistry College of Chemistry & Environmental Science Hebei University Baoding China [e]Key Laboratory for research and Development of Traditional Chinese Medicine and Natural Medicine at shenzhen Shenzhen China

The effects of La3+ and Gd3+ on the proliferation, differentiation and adipogenic transdifferentiation of rat calvarial osteoblast-like cells (ROB cells) were evaluated by MTT method, measuring the activity of alkaline phosphatase (ALP) and Oil red O measurement. Both of La3+ and Gd3+ inhibited the proliferation of ROB cells at all concentrations (1×10-5, 1×10-6, 1×10-7, 1×10-8, 1×10-9 mol·L-1). La3+ at concentration of 1×10-5mol·L-1 significantly increased the alkaline phosphatase activity of ROB cells up to 3 folds (P<0.01). However, the effects reversed to inhibit at other concentrations. Gd played a negative role in the alkaline phosphatase activity. La3+ inhibited the adipogenic transdifferentiation of ROB cells at all concentrations in a dose-dependent way. However, Gd promoted the adipogenic transdifferentiation of ROB cells at 1×10 and 1×10 mol·L . These findings suggested that the effects of rare earth elements on the proliferation, differentiation and adipogenic transdifferentiation of ROB cells were dependent on their concentrations and species.

关键词： lanthanum gadolinium osteoblast-like cells proliferation differentiation transdifferentiation.

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Prominent removal of trace lead(Ⅱ)ions from polluted water by terephthalic acid reformed Al/Zn metal organic nanoflakes

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Particuology 2024年第1期84卷 81-88页

作者： Junhua Li Lingshu Gao Junmao hong Xiaofeng Shi Sifang kong Jingyu Wang Hassan Algadi Benbin Xu Zhanhu Guo School of Chemistry and Chemical Engineering North University of ChinaTaiyuan030051China School of Traffic&Environment Shenzhen Institute of Information TechnologyShenzhen518172China Department of Electrical Engineering Faculty of EngineeringNajran UniversityNajran11001Saudi Arabia Mechanical and Construction Engineering Faculty of Engineering and EnvironmentNorthumbria UniversityNewcastle Upon TyneNE18STUK

Terephthalic acid reformed Al/Zn metal organic nanoflake was prepared and functionalized with trie-thylamine(T-AlZn).Without adding terephthalic acid,there was no product of metal organic nanoflake.T-AlZn has a remarkable performance in removing trace lead(Ⅱ)ions(Pb^(2+)).The adsorption equipoise with the removal rate≥97%was reached within 35 *** removal rates of T-AlZn for Pb^(2+)declined by only 16.73%after four *** adsorption of T-AlZn for Pb^(2+)follows the Langmuir isotherms model and pseudo-second-order dynamics *** utmost adsorption competence was calculated as 215.27 mg g^(-1).The T-AlZn adsorbent exhibits a bright prospect in the adsorption for Pb^(2+)and is a considerable candidate in the disposal of industrial sewage.

关键词： Metal organic complex Nanoflake Trace level Pb^(2+) Adsorption

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ZrO2 strengthened NiAl/Cr(Mo,Hf) composite fabricated by powder metallurgy

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Progress in Natural Science:Materials International 2012年第3期22卷 231-236页

作者： L.Y. Sheng a,b, J.T. Guo c, T.F. Xi a,b, B.C. Zhang c, H.Q. Ye c a PKU-HKUST shenzhen-hong kong Institution, shenzhen 518057, china b College of Engineering, Peking university, Beijing 100871, china c institute of Metal research, Chinese Academy of Sciences, Shenyang 110016, china [a] PKU-HKUST shenzhen-hong kong Institution Shenzhen 518057 China [b] College of Engineering Peking University Beijing 100871 China [c] institute of Metal research Chinese Academy of Sciences Shenyang 110016 China

The ZrO2 ceramic particles strengthened NiAl/Cr(Mo,Hf) composite was fabricated from the rapidly solidified NiAl/Cr(Mo,Hf) pre-alloyed powder and the ZrO2 powder by powder metallurgy technique. Microstructure examination revealed that in the prepared composite NiAl and Cr(Mo) phases distributed at the eutectic cell boundary become coarse but many Cr(Mo) platelets inside the eutectic cell were broken, which was different from the original powder. Moreover, fine Ni2AlHf and Hf solid solution particles distributed uniformly in the composite, and the ZrO2 particles mainly segregated along eutectic cell boundary. In addition, twin crystal and stacking faults were observed inside of ZrO2 grains. The experimental results showed that the ZrO2 ceramic particles strengthened NiAl/Cr(Mo,Hf) composite exhibited better room temperature and high temperature mechanical properties than the NiAl/Cr(Mo,Hf) alloy, which may be attributed to the fine structure and the strengthening effect of ZrO2 particles.

关键词： NiAl intermetallics NiAl/Cr(Mo) composite Powder metallurgy ZrO2 strengthening

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Three-Dimensional Sound Source Location Algorithm for Subsea Leakage Using Hydrophone

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china Ocean Engineering 2024年第2期38卷 326-337页

作者： LI Hao-jie CAI Bao-ping YUAN Xiao-bing kong Xiang-di LIU Yong-hong Javed Akbar KHAN CHU Zheng-de YANG Chao TANG An-bang College of Mechanical and Electronic Engineering China University of PetroleumQingdao 266580China shenzhen Urban Public Safety Technology institute Shenzhen 518000China institute of Hydrocarbon Recovery Universiti Teknologi PETRONASBandar Seri IskandarPerak Darul Ridzuan 32610Malaysia

Leakages from subsea oil and gas equipment cause substantial economic losses and damage to marine ecosystem,so it is essential to locate the source of the ***,due to the complexity and variability of the marine environment,the signals collected by hydrophone contain a variety of noises,which makes it challenging to extract useful signals for *** solve this problem,a hydrophone denoising algorithm is proposed based on variational modal decomposition(VMD)with grey wolf ***,the average envelope entropy is used as the fitness function of the grey wolf optimizer to find the optimal solution for the parameters K andα.Afterward,the VMD algorithm decomposes the original signal parameters to obtain the intrinsic mode functions(IMFs).Subsequently,the number of interrelationships between each IMF and the original signal was calculated,the threshold value was set,and the noise signal was removed to calculate the time difference using the valid signal obtained by ***,the arrival time difference is used to locate the origin of the *** localization accuracy of the method in finding leaks is investigated experimentally by constructing a simulated leak test rig,and the effectiveness and feasibility of the method are verified.

关键词： grey wolf optimizer variational modal decomposition mean envelope entropy correlation coefficient time difference of arrival

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Size Effect of Electromagnetic Constitutive Characteristics of Ultrathin Al Films

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Journal of Materials Science & Technology 2000年第5期16卷 540-542页

作者： Xuedong BAI+, Meng CHEN and Lishi WEN (institute of Metal research, Chinese Academy of Sciences, Shenyang 110015, china) R.F.Huang (Department of Physics & Materials Science, city university of hong kong, Kowloon, hong kong, china) institute of Metal research Chinese Academy of Sciences Shenyang 110015 China Department of Physics and Materials Science City University of Hong Kong Kowloon Hong Kong

The ultrathin aluminum films with thickness in the range of 2～60 nm have been deposited by dc magnetron sputtering apparatus. Reflectance and transmittance of the obtained samples were measured with a WFZ-900-D4 UV/VIS spectrophotometer. The optical constant (n, k) and permittivity (ε', ε') were determined by applying Newton-Simpson recurrent substitution method. The results indicate that the electromagnetic constitutive characteristic of ultrathin aluminum films is a function of thickness and has obvious size effect.

关键词： Size Effect of Electromagnetic Constitutive Characteristics of Ultrathin Al Films Al

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Tribological characteristics of UHMWPE composite and relationship with its compressive behavior

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Science china(Physics,Mechanics & Astronomy) 2004年第z1期47卷 79-87页

作者： LI Jian, GUO Zhiguang, HUA Meng, QIN Xiangpei & WEN ShizhuWuhan research institute of Materials Protection, Wuhan 430030, china Department of Manufacturing Engineering and Engineering Management, city university of hong kong, hong kong, china State Key Laboratory of Tribology, Tsinghua university, Beijing 1000184, china 1. Wuhan research institute of Materials Protection 430030 Wuhan China2. State Key Laboratory of Tribology Tsinghua University 1000i84 Beijing China3. Department of Manufacturing Engineering and Engineering Management City University of Hong Kong Hong Kong China

The triboogical characteristics and the mechanics compress behaviors of pure and composite ultra high molecular weight polyethylene (UHMWPE) were investigated using tribological apparatus and universal materials testing apparatus *** show that there are direct relationships between the sliding friction, wear characteristics, and compression behaviors of UHMWPE composite. The composite of UHMWPE with added copper particles had great improvement in tribological characteristics and mechanics behaviors. Based on the experimental results, a microstructure model of UHMWPE-copper composite is preliminarily proposed.

关键词： UHMWPE, composite tribology, compressive behavior creep.

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Integral ear elimination and virtual point-based updating algorithms for constrained Delaunay TIN

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Science china(Technological Sciences) 2008年第S1期51卷 135-144页

作者： WU LiXin1,2,WANG YanBing2,3 & SHI WenZhong2,4 1 institute for Geo-informatics & Digital Mine research,Northeastern university,Shenyang 110004,china 2 institute for GIS/RS/GPS & Subsidence Engineering research,china university of Mining & Technology,Beijing 100085,china 3 Laboratory of 3D Information Acquisition & Application,Capital Normal university,Beijing 100037,china 4 Center for Advanced GIS research,LSGI,Polytechnic university hong kong,hong kong,china Northeastern Univ Inst Geoinformat & Digital Mine Res Shenyang 110004 Peoples R China china Univ Mining & Technol Inst GIS RS GPS & Subsidence Engn Res Beijing 100085 Peoples R China Capital Normal Univ Lab Informat Acquisit & Applicat Beijing 100037 Peoples R China hong kong Polytech Univ LSGI Ctr Adv GIS Res Hong Kong Hong Kong Peoples R China

Constrained Delaunay Triangular Irregular Networks (CD-TIN),a kind of special data structure,have many practical applications in Geoinformatics,especially in the representation of linear constrained triangulation for DTM and DSM,such as in digital city and digital mine. Past researches on D-TIN mainly focused on point in-sertion and deletion without consideration of constraint,and that on CD-TIN usu-ally paid more attention to the insertion algorithms for points and edges,but little to the deletion algorithms. The presented algorithms are far insufficient for the dy-namic updating of CD-TIN. In this paper,the constraint edge in CD-TIN is consid-ered to be any set of broken lines,i.e.,polygon edges,broken lines and simple segments. The constraint edge may be composed of one or more constraint seg-ments,and it is allowed to be in any form: Open or close,intersection or self-in-tersection. By improving to present insertion and deletion algorithms for D-TIN,two new algorithms for CD-TIN updating are presented. According to the polymorphism of the constraints in CD-TIN,virtual point is adopted to represent the crossing node between constraint edges when a constraint edge is inserted in CD-TIN. Two new algorithms named as Integral Ear Elimination (IEE) and Influence Domain Retrian-gulation for Virtual Point (IDRVP) are presented,the former is for constraint point deletion,while the later is for the insertion and deletion of constraint edge. The principle of IDRVP is that to divide the influence domain of a virtual point into some parts by the constraint-keeping edges,and to retriangulate each part of the influ-ence domain individually referring to the constraint visible property and constraint empty circle (CEC) criterion. Finally,a prototype system is developed with VC++,one case on the integration of 3D terrain and buildings is demonstrated to test the correctness of new algorithms. It shows that the new algorithms are effective for the updating of CD-TIN.

关键词： Delaunay TIN spatial constraint data updating spatial modeling polymorphism digital mine

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Chaos-based encryption for fractal image coding

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Chinese Physics B 2012年第1期21卷 115-126页

作者：袁正雄黄国和 Department of Electronic Engineering City University of Hong Kong

A chaos-based cryptosystem for fractal image coding is proposed. The Renyi chaotic map is employed to determine the order of processing the range blocks and to generate the keystream for masking the encoded sequence. Compared with the standard approach of fraetal image coding followed by the Advanced Encryption Standard, our scheme offers a higher sensitivity to both plaintext and ciphertext at a comparable operating efficiency. The keystream generated by the Renyi chaotic map passes the randomness tests set by the United States National institute of Standards and Technology, and so the proposed scheme is sensitive to the key.

关键词： chaos cryptography joint image compression and encryption fractal image coding

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Low-complexity distributed differential spacetime coding scheme for amplify-and-forward cooperative networks

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Science in china(Series F) 2009年第8期52卷 1418-1427页

作者： YU XiangBin1,2, BI GuangGuo3 & XU WeiYe4 1 College of Information Science and Technology, Nanjing university of Aeronautics and Astronautics, Nanjing 210016, china 2 Department of Electronic Engineering, city university of hong kong, hong kong, china 3 National Mobile Communications research Laboratory, Southeast university, Nanjing 210096, china 4 Department of Communication Engineering, Nanjing institute of Technology, Nanjing 211167, china College of Information Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Department of Electronic Engineering City University of Hong Kong Hong Kong China National Mobile Communications research Laboratory Southeast University Nanjing 210096 China Department of Communication Engineering Nanjing Institute of Technology Nanjing 211167 China

By introducing a space-time coding scheme based on amicable orthogonality, we develop a distributed differential space-time coding scheme with the amplify-and-forward （AF） method for wireless cooperative networks. The scheme requires no knowledge of the channel state information at both transmitters and receivers, and effectively decreases the realization complexity due to no channel estimation. Moreover, it has lower decoding complexity and higher coding advantage than the existing scheme, thus avoiding the shortcoming of exponential decoding complexity of some existing schemes. According to the pairwise error probability （PEP） analysis of the system, the power allocations of source and relay terminals are jointly optimized, and as a result, the PEP is minimized, which will provide a helpful guideline for system design. Numerical calculation and simulation results show that the developed scheme is superior to the existing scheme. Moreover, the scheme with optimal power allocation yields obvious performance improvement over that with equal power allocation.

关键词： differential space-time coding cooperative communication amplify-and-forward method power allocation

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TAX EVASION:MODELS WITH SELF-AUDIT

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Journal of Systems Science & Complexity 2008年第4期21卷 487-518页

作者： Kin Keung LAI Department of Management Sciences City University of Hong Kong College of Business Management Hunan University

Different from traditional tax audit, supervision with self-audit is a combination of audit by the taxpayer himself and audit by the tax authority. This paper mainly studies a taxpayer＇s optimal policy of tax evasion under supervision with self-audit and its related properties, in order to deduce some effective suggestions and theoretical bases to restrain tax evasion. Assuming that only a certain proportion of evaded tax can be discovered when the audit is executed, the authors first formulate a static model with self-audit. This model is divided into two stages. At the first stage, taxpayers declare their taxes, then the tax authority chooses audit objects, based on a known probability, and announces the result; if the taxpayer is chosen, he will enter the second stage, during which he has a chance to pay the evaded tax and the corresponding late fees and then is audited by the tax authority. The authors show the existence and uniqueness of the optimal amount of tax evasion at the first stage and the optimal proportion to self-expose at the second stage. The authors also discuss the related properties of the interior solution, and do elasticity analyses on some parameters. Besides, the authors extend the static model into the corresponding two-period model, and study the existence and uniqueness of the solution of the extended model. Finally, under the assumption that tax evasion can only be discovered with a certain probability when the audit is executed, the authors formulate another static model with self-audit and investigate its properties.

关键词： Existence and uniqueness of the solution self-audit static model tax evasion two-period model.

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