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Interfacial Chain Entanglements Induced Melt Memory Effect in Poly(ε-caprolactone)/Silica Nanocomposites

Chinese Journal of Polymer Science 2022年第11期40卷 1451-1465页

作者： Xiang liu wen-Zhi Cui Wei Yu Advanced Rheology Institute Department of Polymer Science and EngineeringShanghai Key Laboratory of Electrical Insulation and Thermal AgeingState Key Laboratory for Metal Matrix Composite MaterialsShanghai Jiao Tong UniversityShanghai200240China

It is known that the enhanced melt memory effect is strongly correlated with the retarded chain ***,previous studies using differential scanning calorimetry(DSC)showed a weakened or even vanished melt memory in polymer nanocomposites,although adding nanoparticles in polymers often reduces chain *** this work,we added two kinds of silica nanoparticles,O15 and W22 nanoparticles(with low and high surface silanol density,respectively),to poly(ε-caprolactone)(PCL),where the degree of chain entanglements near nanoparticles increases,and chain dynamics is gradually retarded with increasing silica *** strongly aggregated W22 nanoparticles show significant heterogeneous nucleation,while well-dispersed O15 nanoparticles exhibit very weak heterogeneous *** contrast to the restrained self-nucleation effects during the rapid non-isothermal crystallization of two nanocomposites,we found evident melt memory effects during the slow isothermal crystallization in PCL/O15 nanocomposites as indicated by DSC and polarized light microscopy(PLM)*** melt memory becomes stronger with more O15 nanoparticles,but depends non-monotonically on the loadings of W22 *** lifetime of the melt memory effects matches the chain re-entanglement time of the SN melts of nanocomposites,which is consistent with our previous work on PCL miscible *** complicated influence of silica on nucleation and crystal growth is induced by the spatial inhomogeneity of chain entanglements in the silica-filled PCL *** decrease in the entanglement density of the interfacial chains in the SN melts of nanocomposites is conducive to nucleate under slow isothermal crystallization,but the chain mobility is still greatly restrained by the nanoparticles,causing the slow growth rate of spherulites and the difficulty to form nuclei under fast non-isothermal crystallization.

关键词： PCL Silica nanocomposite Self-nucleation crystallization

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Enhancing Li-ion conduction and mechanical properties via addition of fluorine-containing metal–organic frameworks in allsolid-state cross-linked hyperbranched polymer electrolytes

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Nano Research 2022年第10期15卷 8946-8954页

作者： wen wen Qinghui Zeng Pingping Chen Xin wen Zhenfeng Li Yu liu Jiazhu Guan Anqi Chen Wei liu Liaoyun Zhang School of chemical sciences University of Chinese Academy of SciencesBeijing 100049China Research Institute of Petroleum Exploration&Development(RIPED) PetroChinaBeijing 100083China

Poly(ethylene oxide)(PEO)-based solid polymer electrolytes(SPEs)are commonly used in lithium metal batteries(LMBs)for their good Li-salt solvating ability and easy ***,the relatively low Li-ion conduction ability hinders their further *** this work,a novel hyperbranched-polyether-type composite solid polymer electrolyte(CSPE)is prepared via a quick cross-linking reaction between aldehyde-terminated polyethylene glycol(PEG)and hyperbranched poly(ethylene imine)(HPEI)in the presence of lithium salt and fluorine-containing Zr-based metal–organic framework(MOF)UiO-66-(F)_(4).The hydrogen bonds between the fluorine atoms and amino groups in the electrolyte help to the better dispersion of UiO-66-(F)_(4) in the polymer matrix,which is beneficial to solving the problem of aggregation of ***,the CSPEs with the functional MOF fillers show improvements in both electrochemical and mechanical ***,the Li-ion transference number(t)is considerably enhanced from 0.23 to ***-solid-state LMBs based on the CSPE also present good cycling performances.A high specific discharge capacity of 141.4 mAh·g^(−1) is remained after 200 cycles at 0.2 *** study not only provides an effective synthesis method of the cross-linked hyperbranched polymer electrolyte,but also puts forward a new strategy for uniform dispersion of inorganic fillers in CSPEs.

关键词： hyperbranched cross-linked polymer electrolyte all-solid-state metal-organic frameworks composite lithium metal batteries

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Expression of hepatic Wnt5a and its clinicopathological features in patients with hepatocellular carcinoma

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Hepatobiliary & Pancreatic Diseases International 2018年第3期17卷 227-232页

作者： Li Wang Min Yao miao Fang wen-Jie Zheng Zhi-Zhen Dong liu-Hong Pan Hai-Jian Zhang Deng-Fu Yao Department of Medical Informatics Medical College of Nantong University Research Center of Clinical Medicine Affiliated Hospital of Nantong University Department of Immunology Medical College of Nantong University

Backgroud： Wingless-type MMTV integration site family member 5a （Wnt5a） is involved in ***, little data are available in Wnt5a signaling with hepatocellular carcinoma （HCC）. In thepresent study, we investigated t... 详细信息

关键词： Wnt5a signaling Hepatocellular carcinoma Clinical staging Tissue microarray Wnt/β-catenin pathway Wnt3a signaling

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Robust Assignment of Airport Gates with Operational Safety Constraints

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International Journal of Automation and computing 2016年第1期13卷 31-41页

作者： Shuo liu wen-Hua Chen Jiyin liu Department of Aeronautical and Automotive Engineering Loughborough University School of Business and Economics Loughborough University

This paper reviews existing approaches to the airport gate assignment problem （AGAP） and presents an optimization model for the problem considering operational safety constraints. The main objective is to minimize the dispersion of gate idle time periods （to get robust optimization） while ensuring appropriate matching between the size of each aircraft and its assigned gate type and avoiding the potential hazard caused by gate apron operational conflict. Genetic algorithm is adopted to solve the problem, An illustrative example is given to show the effectiveness and efficiency of the algorithm. The algorithm performance is further demonstrated using data of a terminal from Beijing Capital International Airport （PEK）.

关键词： Gate assignment problem operational safety constraints robust optimization conflict avoidance genetic algorithm.

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Synthesis and luminescence properties of Eu^(3+),Sm^(3+) doped(Y_xGd_(1-x))_2O_3:Si^(4+),Mg^(2+) long-lasting phosphor

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International Journal of Minerals,Metallurgy and Materials 2010年第3期17卷 347-352页

作者： Yan liu Shi-xiang liu Ming-wen Wang wen-jun Li Ting Zhang Xia Zhang School of Applied Science University of Science and Technology Beijing Beijing 100083 China

A novel red long-lasting phosphor, （YxGd1-x）2O3：Eu3＋, Sm3＋, Si4＋, Mg2＋, was synthesized by the co-precipitation method using oxalate precipitation as the precursor. X-ray diffraction （XRD）, scanning electronic microscopy （SEM）, integrated thermal analyzer （TG）, and photoluminescence spectra （PL） as well as the ST-900PM weak light photometer were used to study the synthesis conditions, morphology, luminescence properties, and the decay time of the phosphor. The XRD results show that the products synthesized at 1400~C for 4 h have good crystallization without any detectable impurity phases. Based on the PL spectra, the optimal conditions are as the following. The molar ratios of Y3＋ to Gd3＋ and Eu3＋ to Sm3＋ are 2：8 and 3：1, respectively, and the contents of Mg2＋ and SiO2 are 5mol% and 3mol%, respectively. The decay time monitored by the ST-900PM weak light photometer is 7200 s, increasing 44% and 100%, respectively, compared with the Eu3＋ and Sm3＋ single-doped phosphors. The results indicate that the energy transfer is from Sm3＋ to Eu3＋ ion, and Sm3＋ is a good sensitizer to Eu3＋.

关键词： long lasting phosphor luminescence energy transfer

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Optimizing CMT performance by joint predictions of bandwidth and RTT

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The Journal of China Universities of Posts and Telecommunications 2015年第4期22卷 81-91页

作者： Li wen Wang wenbo Jing Xiaojun liu wen School of Information and Communication Engineering Beijing University of Posts and Telecommunications Institute of China Electronics System Engineering Company Key Laboratory of Universal Wireless Communication Beijing University of Posts and Telecommunications The Archives of the Ministry of Information Technology

CMT uses the stream control transmission protocol＇s（SCTPs） multihoming feature to distribute data across multiple end-to-end paths in a multihomed SCTP association. As the disparity of multipaths, it is facing a great challenge to solve the disorder of the received data packets. To lighten the reordering degree and then to improve the throughput performance, we need to estimate the real-time paths＇ bandwidth and round trip time（RTT） as exactly as possible. In this paper, we use the extended vector（ext-vec） Kalman filter（KF） to predict the available bandwidth and RTT of each path simultaneously. Based on this, we propose a predictive path selection algorithm for CMT in SCTP. To simulate and compare the algorithms＇ performance, two kinds of scenarios, bandwidth sensitive scenario and time and bandwidth sensitive scenario, are built and NS-2 is used. The simulation results show that the path selection algorithm can lessen the data packets disordering by correctly predicting each path＇s bandwidth and RTT in real time. Comparing the existing algorithms, the algorithm can converge more quickly and can improve the system total throughput in a certain extent in bandwidth sensitive scenario. To time and bandwidth sensitive scenario, it can greatly improve the convergence speed and total throughput.

关键词： CMT SCTP extended vector Kalman filter RTT throughput

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CALD1 facilitates epithelial-mesenchymal transition progression in gastric cancer cells by modulating the PI3K-Akt pathway

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World Journal of Gastrointestinal Oncology 2024年第3期16卷 1029-1045页

作者： wen-Qian Ma Ming-Chang miao Ping-An Ding Bi-Bo Tan wen-Bo liu Shuo Guo Li-Mian Er Zhi-Dong Zhang Qun Zhao Department of Endoscopy The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hebei ProvinceChina Hebei Key Laboratory of Precision Diagnosis and Comprehensive Treatment of Gastric Cancer Shijiazhuang 050011Hebei ProvinceChina Department of Radiotherapy The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hebei ProvinceChina The Third Department of Surgery The Fourth Hospital of Hebei Medical UniversityShijiazhuang 050011Hebei ProvinceChina

BACKGROUND CALD1 has been discovered to be abnormally expressed in a variety of malignant tumors,including gastric cancer(GC),and is associated with tumor progression and immune infiltration;however,the roles and mechanisms of CALD1 in epithe-lial-mesenchymal transition(EMT)in GC are *** To investigate the role and mechanism of CALD1 in GC progression,invasion,and *** In this study,the relationship between CALD1 and GC,as well as the possible network regulatory mechanisms of CALD1,was investigated by bioinformatics and validated by ***1-siRNA was synthesized and used to trans-fect GC *** activity was measured using the CCK-8 method,cell migration and invasive ability were measured using wound healing assay and Transwell assay,and the expression levels of relevant genes and proteins in each group of cells were measured using qRT-PCR and Western blot.A GC cell xenograft model RESULTS Bioinformatics results showed that CALD1 was highly expressed in GC tissues,and CALD1 was significantly higher in EMT-type GC tissues than in tissues of other types of *** prognosis of patients with high expression of CALD1 was worse than that of patients with low expression,and a prognostic model was constructed and *** experimental results were consistent with the results of the bioinformatics *** expression level of CALD1 in GC cell lines was all higher than that in gastric epithelial cell line GES-1,with the strongest expression found in AGS and MKN45 *** activity was significantly reduced after CALD1-siRNA trans-fection of AGS and MKN45 *** ability of AGS and MKN45 cells to migrate and invade was reduced after CALD1-siRNA transfection,and the related mRNA and protein expression was *** to bioinfor-matics findings in GC samples,the CALD1 gene was significantly associated with the expression of members of the PI3K-AKT-mTOR signaling pathway as well as the EMT signaling pathway,and was closely rel

关键词： Gastric tumor CALD1 Epithelial-mesenchymal transition Gene disruption Invasion Migration Bioinformatics

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Study on buffering performance of thin-walled metal tube with different angles

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Defence Technology（防务技术） 2018年第6期14卷 702-708页

作者： Qun liu wen-tao Wang wen-feng Zhang Beijing Institute of Space Mechanics and Electricity BeijingChina

High frequency shock load is often generated during pyrotechnic device working, which is detrimental to spacecraft structures and electric devices. Therefore, it is valuable to reduce the shock load in pyrotechnic device design. Actually, there are several ways to decrease pyroshock loads, such as reduction of powder,installation of buffering structure, insulation of damageable devices, and so on. Considered assuring the function of pyrotechnic device and minimum of structure modification, shock absorbing structure is more propitious to be introduced in pyrotechnic device. In this paper, based on the method of thinwalled metal tube diameter-expanding, a thin-walled tube shock buffering structure was designed on a separate bolt. Built on the simplified structure of a separate bolt, the model of cone piston impacting thin-walled tube absorber was established, and the thin-walled tube shock absorbing characteristics and the relation between cone angles and absorber performance were analyzed. The results showed that the change of buffering force of thin-walled tube could be divided into four phases, and each phase was correspondent to the cone piston structure. In addition, as the cone angle increases, the max shock acceleration changes in the style of decrease-increase-decrease-increase, which is the result of coupled effects of cone piston max enter depth, buffering force and energy loss. In short, these results could establish the relationships between thin-walled tube absorbing performance and its structure, which is of significance to develop low-shock pyrotechnic device.

关键词： Pyroshock Shock absorbing Thin-walled metal tube

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Impact of Carbon Chain Structures in the Backbone on the Flexibility of Modified Polyarylene Sulfide Resins: Molecular Dynamics Simulations and Mesoscopic Analysis

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Chinese Journal of Polymer Science 2024年第4期42卷 544-557页

作者： Chi Zhang Rong liu Jing-Yuan liu wen-Wei Jiang Key Laboratory of Fine Chemical Engineering and Functional Materials School of Chemical EngineeringSichuan UniversityChengdu610065China

In the domain of high-performance engineering polymers, the enhancement of mechanical flexibility in poly(phenylene sulfide) (PPS) resins has long posed a significant challenge. A novel molecular structure, designated as PP-He-IS, wherein imide rings and an aliphatic hexylene chain are covalently incorporated into the PPS backbone to enhance its flexibility, is introduced in this study. Molecular dynamics (MD) simulations are employed to systematically explore the effects of diversifying the backbone chain structures by substituting phenyl units with alkyl chains of varying lengths, referred to as PP-A-IS where “A” signifies the distinct intermediary alkyl chain configurations. Computational analyses reveal a discernable decrement in the glass transition temperature (Tg) and elastic modulus, counterbalanced by an increment in yield strength as the alkyl chain length is extended. Notably, the PP-He-IS variant is shown to exhibit superior yield strength while simultaneously maintaining reduced elastic modulus and Tg values, positioning it as an advantageous candidate for flexible PPS applications. Mesoscopic analyses further indicate that structures such as PP-He-IS, PP-Pe-IS, and PP-Bu-IS manifest remarkable flexibility, attributable to the presence of freely rotatable carbon-carbon single bonds. Experimental validation confirms that a melting temperature of 504 K which is lower than that of conventional PPS, and lower crystallinity are exhibited by PP-He-IS, thereby affording enhanced processability without compromising inherent thermal stability. Novel insights into the strategic modification of PPS for mechanical flexibility are thus furnished by this study, which also accentuates the pivotal role played by molecular dynamics simulations in spearheading high-throughput investigations in polymer material modifications.

关键词： Molecular dynamics simulations Polyarylene Sulfide Main-chain modifications Flexibility Aliphatic hexylene chain

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An Approximation Algorithm Based on Seeding Algorithm for Fuzzy k-Means Problem with Penalties

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Journal of the Operations Research Society of China 2024年第2期12卷 387-409页

作者： wen-Zhao liu Min Li School of Mathematics and Statistics Shandong Normal UniversityJinan 250014ShandongChina

As a classic NP-hard problem in machine learning and computational geometry,the k-means problem aims to partition the given dataset into k clusters according to the minimal squared Euclidean *** from k-means problem and most of its variants,fuzzy k-means problem belongs to the soft clustering problem,where each given data point has relationship to every center *** to fuzzy k-means problem,fuzzy k-means problem with penalties allows that some data points need not be clustered instead of being paid *** this paper,we propose an O(αk In k)-approximation algorithm based on seeding algorithm for fuzzy k-means problem with penalties,whereαinvolves the ratio of the maximal penalty value to the minimal ***,we implement numerical experiments to show the effectiveness of our algorithm.

关键词： Approximation algorithm Seeding algorithm Fuzzy k-means problem with penalties

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