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Science China Earth Sciences 2015年第8期58卷 1305-1319,1-5页

作者： WANG LiNing ji jianQing SUN DongXia XU QinQin HAN BaoFu Research Institute of Petroleum Exploration and Development Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space Sciences Peking University

The extreme modern elevation of the Tianshan Mountains reflects the Cenozoic deformation. Apatite Fission Track （AFI） chronometry is widely used to study the latest cooling stages caused by tectonic process or by exhumation in the uppermost crust. However, uncertainties remain over timing constraints on thermal history of the Tianshan Mountains since the Cenozoic though a great mount of dating work had been done in this area. To address this issue, modern river sands from the drainage basin on the piedmont of the Tianshan Mountains were sampled to integrate regional information. Single grains were dated with the AFT method, and then different grain-age components were identified to provide thermochronological constraints of their sources. Combined with discussion of previous dataset, our results show the multi-staged rapid cooling cluster at 46-32, 25-24, 19-13, 8-6, and -3 Ma, respectively. We interpreted these cooling events as a result of interplays between the Cenozo- ic tectonic uplift of the mountains and regional climate change.

关键词： Tianshan Mountains detrital apatite fission track cooling stages exhumation thermal history

Rational design of biodegradable thermoplastic polyurethanes for tissue repair

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Bioactive Materials 2022年第9期7卷 250-271页

作者： Cancan Xu Yi hong Department of Bioengineering University of Texas at ArlingtonArlingtonTX76019USA

As a type of elastomeric polymers,non-degradable polyurethanes(PUs)have a long history of being used in clinics,whereas biodegradable PUs have been developed in recent decades,primarily for tissue repair and *** thermoplastic(linear)PUs are soft and elastic polymeric biomaterials with high mechanical strength,which mimics the mechanical properties of soft and elastic ***,biodegradable thermoplastic polyurethanes are promising scaffolding materials for soft and elastic tissue repair and ***,PUs are synthesized by linking three types of changeable blocks:diisocyanates,diols,and chain *** the combination of these three blocks can finely tailor the physio-chemical properties and generate new functional *** PUs have excellent processing flexibilities and can be fabricated into three-dimensional(3D)constructs using conventional and/or advanced technologies,which is a great advantage compared with cross-linked thermoset ***,they can be combined with biomolecules to incorporate desired bioactivities to broaden their biomedical *** this review,we comprehensively summarized the synthesis,structures,and properties of biodegradable thermoplastic PUs,and introduced their multiple applications in tissue repair and regeneration.A whole picture of their design and applications along with discussions and perspectives of future directions would provide theoretical and technical supports to inspire new PU development and novel applications.

关键词： Biodegradable polyurethane Thermoplastic Elastic Synthesis Tissue repair

Relationship between equilibrium potential and radius of lanthanides electrolyzed on the zinc cathode

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Chinese Journal of Chemical Engineering 2019年第12期27卷 3027-3035页

作者： Peng Li Milin Zhang Debin ji Min Qiu Li Liu Key Laboratory of Superlight Materials and Surface Technology Ministry of EducationCollege of Materials Science and Chemical EngineeringHarbin Engineering UniversityHarbin 150001China College of Science Heihe UniversityHeihe 164300China

The electrochemical behavior of lanthanide elements deposited on liquid zinc cathodes was studied using cyclic voltammetry(CV)and open circuit chronopotentiometry(OCP).We observed a"bimodal effect"in the equilibrium deposition potentials of zinc with lanthanides.A mathematic equation is derived to illustrate the relationship between the equilibrium potential of the intermetallic compounds formed by lanthanide elements and zinc and their atomic *** equation is not only applicable to lanthanide elements but also hold for other elements such as alkali metal lithium,alkaline earth metal magnesium,calcium and transition metal niobium,which have crucial theoretical significance for the electrolysis of intermetallic compounds,the separation,and extraction of metals.

关键词： Equilibrium Potential Electrolysis Molten salts Mathematical Grading rule Reduction

Aminated Copolymers as Flow Improvers for Super-viscous Crude Oils

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China Petroleum Processing & Petrochemical Technology 2007年第3期9卷 43-49页

作者： Zhang hong Shen Benxian Petroleum Processing Research Institute East China University of Science and Technology Shanghai 200237

The new flow improvers for super-viscous crude oils were developed via esterification of polybasic high carbon alcohol with methacrylate and copolymerizafion of monomers followed by amination of copolymers. The structure of the synthesized polymer flow improver additive was confirmed by IR spectroscopy and the crystal structure of the flow improver additives were determined by X-ray diffrac- tion analysis. The structure of wax crystals was also studied at the same time. The results showed that the wax crystal structure was closely related with the crystal structure of the flow improver, which could change the pour point depression and viscosity reduction behavior of the crude oil. When the wax crystal structure matched well with that of the additive, the wax crystals were dispersed satisfactorily, resulting in favorable effects in terms of pour point depression and viscosity reduction. The new synthe- sized aminated polymer flow improver additive was most efficient for treating super-viscous crude oils. The super-viscous crude oil had a high content of resins and asphaltenes, which might aggregate onto the surface of wax crystals to form blocks to limit the crude oil fluidity. However, amination of copolymers having similar structure with the resins and asphaltenes contained in crude oil could dissolve the huge polar groups to make the deposit formation difficult.

关键词： aminated copolymers flow improver super-viscous crude oil

Linguistic dynamic systems based on computing with words and their stabilities

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Science in China(Series F) 2009年第5期52卷 780-796页

作者： MO hong WANG FeiYue College of Electric and Information Engineering Changsha University of Science and Technology Changsha 410004 China Key Laboratory of Complex Systems and Intelligent Science Institute of Automation Chinese Academy of Science Beijing 100080 China

Linguistic dynamic systems （LDS） are the systems based on computing with words （CW） instead of computing with numbers or symbols. In this paper, LDS are divided into two types： type-I LDS being converted from conventional dynamical systems （CDS） by using extension principle and type-II LDS by using fuzzy logic rules. For type-I LDS, the method of endograph is provided to discuss the stabilities of type-I LDS and two cases of stabilities of logistic mappings： one is the states being abstracted and the other is parameters also being abstracted. For type-Ⅱ LDS, the method of degree of match is used to discuss the dynamical behavior of arbitrary initial words under fuzzy rule.

关键词： computing with words (CW) extension principle stability fuzzy rule degree of match

Reconstruction of sub cross-correlation cancellation technique for unambiguous acquisition of BOC(kn, n) signals

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Journal of Systems Engineering and Electronics 2019年第5期30卷 852-860页

作者： ji Yuanfa CHEN Xiaoqian FU Qiang SUN Xiyan ZHEN Weimin Guangxi Key Laboratory of Precision Navigation Technology and Application Guilin University of Electronic TechnologyGuilin 541004China National&Local Joint Engineering Research Center of Satellite Navigation Positioning and Location Service Guilin 541004China Key Laboratory of Radio Wave Environment and Modeling Technology Qingdao 266000China

In order to solve the problem of ambiguous acquisition of BOC signals caused by its property of multiple peaks,an unambiguous acquisition algorithm named reconstruction of sub cross-correlation cancellation technique(RSCCT)for BOC(kn,n)signals is *** this paper,the principle of signal decomposition is combined with the traditional acquisition algorithm structure,and then based on the method of reconstructing the correlation *** method firstly gets the sub-pseudorandom noise(PRN)code by decomposing the local PRN code,then uses BOC(kn,n)and the sub-PRN code cross-correlation to get the sub cross-correlation ***,the correlation peak with a single peak is obtained by reconstructing the sub cross-correlation function so that the ambiguities of BOC acquisition are *** simulation shows that RSCCT can completely eliminate the side peaks of BOC(kn,n)group signals while maintaining the narrow correlation of BOC,and its computational complexity is equivalent to sub carrier phase cancellation(SCPC)and autocorrelation side-peak cancellation technique(ASPeCT),and it reduces the computational complexity relative to *** BOC(n,n),the acquisition sensitivity of RSCCT is 3.25 dB,0.81 dB and 0.25 dB higher than binary phase shift keying(BPSK)-like,SCPC and ASPeCT at the acquisition probability of 90%,*** peak to average power ratio is 1.91,3.0 and 3.7 times higher than ASPeCT,SCPC and BPSK-like at SNR=–20 dB,*** BOC(2n,n),the acquisition sensitivity of RSCCT is 5.5 dB,1.25 dB and 2.69 dB higher than BPSK-like,SCPC and ASPeCT at the acquisition probability of 90%,*** peak to average power ratio is 1.02,1.68 and 2.12 times higher than ASPeCT,SCPC and BPSK-like at SNR=–20 dB,respectively.

关键词： signal decomposition sub cross-correlation reconstructingcorrelation function acquisition performance

A tensor model for liquid crystals on a spherical surface

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Science China Mathematics 2013年第12期56卷 2549-2559页

作者： CHENG hong ZHANG PingWen School of Mathematical Sciences Peking University

Rod-like molecules confined on a spherical surface can organize themselves into nematic liquid crystal phases. This can give rise to novel textures displayed on the surface, which has been observed in experiments. An important theoretical question is how to find and predict these textures. Mathematically, a stable configuration of the nematic fluid corresponds to a local minimum in the free energy landscape. By applying Taylor expansion and Bingham approximation to a general molecular model, we obtain a closed-form tensor model, which gives a free energy form that is different from the classic Landau-de Gennes model. Based on the tensor model, we implement an efficient numerical algorithm to locate the local minimum of the free energy. Our model successfully predicts the splay, tennis-ball and rectangle textures. Among them, the tennis-ball configuration has the lowest free energy.

关键词： liquid crystal nematic texture Bingham closure approximation tennis-ball configuration

Inverse reliability analysis and design for tunnel face stability considering soil spatial variability

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1552-1564页

作者： Zheming Zhang jian ji Xiangfeng Guo Siang Huat Goh Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing210098China Department of Civil and Environmental Engineering National University of SingaporeSingapore

The traditional deterministic analysis for tunnel face stability neglects the uncertainties of geotechnical parameters,while the simplified reliability analysis which models the potential uncertainties by means of random variables usually fails to account for soil spatial *** overcome these limitations,this study proposes an efficient framework for conducting reliability analysis and reliability-based design(RBD)of tunnel face stability in spatially variable soil *** three-dimensional(3D)rotational failure mechanism of the tunnel face is extended to account for the soil spatial variability,and a probabilistic framework is established by coupling the extended mechanism with the improved Hasofer-Lind-Rackwits-Fiessler recursive algorithm(iHLRF)as well as its inverse analysis *** proposed framework allows for rapid and precise reliability analysis and RBD of tunnel face *** demonstrate the feasibility and efficacy of the proposed framework,an illustrative case of tunnelling in frictional soils is presented,where the soil's cohesion and friction angle are modelled as two anisotropic cross-correlated lognormal random *** results show that the proposed method can accurately estimate the failure probability(or reliability index)regarding the tunnel face stability and can efficiently determine the required supporting pressure for a target reliability index with soil spatial variability being taken into ***,this study reveals the impact of various factors on the support pressure,including coefficient of variation,cross-correlation between cohesion and friction angle,as well as autocorrelation distance of spatially variable soil *** results also demonstrate the feasibility of using the forward and/or inverse first-order reliability method(FORM)in high-dimensional stochastic *** is hoped that this study may provide a practical and reliable framework for determining the stability of tunnels in complex

关键词： Limit analysis Tunnel face stability Spatial variability HLRF algorithm Inverse reliability method

An automated pulmonary parenchyma segmentation method based on an improved region growing algorithm in PET-CT imaging

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Frontiers of Computer Science 2016年第1期10卷 189-200页

作者： Juanjuan ZHAO Guohua ji Xiaohong HAN Yan QIANG Xiaolei LIAO College of Computer Science and Technology Taiyuan University of Technology Taiyuan 030024 China Key Laboratory of Advanced Transducers and Intelligent Control Systems Taiyuan University of Technology Taiyuan 030024 China

To address the incomplete problem in pulmonary parenchyma segmentation based on the traditional methods, a novel automated segmentation method based on an eight- neighbor region growing algorithm with left-right scanning and four-corner rotating and scanning is proposed in this pa- per. The proposed method consists of four main stages： image binarization, rough segmentation of lung, image denoising and lung contour refining. First, the binarization of images is done and the regions of interest are extracted. After that, the rough segmentation of lung is performed through a general region growing method. Then the improved eight-neighbor region growing is used to remove noise for the upper, mid- dle, and bottom region of lung. Finally, corrosion and ex- pansion operations are utilized to smooth the lung boundary. The proposed method was validated on chest positron emis- sion tomography-computed tomography （PET-CT） data of 30 cases from a hospital in Shanxi, China. Experimental results show that our method can achieve an average volume overlap ratio of 96.21 ± 0.39% with the manual segmentation results. Compared with the existing methods, the proposed algorithm segments the lung in PET-CT images more efficiently and ac- curately.

关键词： pulmonary parenchyma segmentation bot-tom region of lung image binarization iterative threshold seeded region growing four-corner rotating and scanning,denoising contour refining PET-CT

Fabrication of Macroporous Protein-containing Films through the Reverse Emulsions Approach Featuringβ-Cyclodextrin-conjugated PEG-PLGA Copolymers

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Chinese Journal of Polymer Science 2016年第6期34卷 730-738页

作者： ji-jie wen 吕宏光 de-e liu 高辉 School of Chemistry and Chemical Engineering Tianjin Key Laboratory of Organic Solar Cells and Photochemical ConversionTianjin University of TechnologyTianjin 300384China

A series of β-cyclodextrin-conjugated 4-arm poly（ethylene glycol）-poly（lactide-co-glycolide）（4-arm PEG-PLGA） copolymers were synthesized by a ring-opening polymerization of D,L-lactide and glycolide using 4-arm PEG as initiator, and then conjugated with mono（6-ethylenediamine-6-deoxy）- β-cyclodextrin （CDen） or ethylenediamino-bridged bis- β-CD （BCDen）. The chemical structures of copolymers were confirmed by IH-NMR and FTIR spectroscopy. The , β-CD-conjugated PEG-PLGA formed stable reverse micelles due to the formation of fl-CD and bovine serum albumin （BSA） inclusion complexation, which could accommodate BSA in the organic solvent with improved encapsulation efficiency. Moreover, we demonstrated a one-step approach to construct macroporous protein-containing films using these reverse micelles. The films with ordered pore arrays were directly prepared from reverse micelles. Interestingly, the protein was totally located in the whole matrix except for the pores.

关键词： β-Cyclodextrin Copolymer Reverse micelles Ordered porous structures Proteins.