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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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Fano Effect in T-Shaped Double Quantum Dot Structure with Decoherence Effect

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Communications in Theoretical Physics 2008年第3期49卷 771-776页

作者： GAO wen-Zhu GONG wei-jiang ZHENG Yi-Song LIU Yu LU Tian-Quan Department of Physics Jilin University Changchun 130023 China

By introducing a floating lead to mimic the decoherence mechanism, the Fano effect in the linear conductance spectrum of a T-shaped double quantum dot structure is studied. We find that even in the case that the self-energy arising from the decoherence mechanism is much smaller than the coupling strength between the connected quantum dot and the conducting lead, the Fano lineshape can be largely destroyed. In addition, the decoherence renders the high-order electron transmission paths unimportant to contributing to the Fano lineshape.

关键词： quantum dot conductance Pkno effect

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Effect of chip rate on the ranging accuracy in a regenerative pseudo-noise ranging system

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Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第2期12卷 132-139页

作者： Jian-wen jiang wei-jun YANG Chao-jie ZHANG Xiao-jun JIN Zhong-he JIN Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China

The ranging accuracy of a pseudo-noise ranging system is mainly decided by range jitter and time delay discrimination. Many factors can affect the ranging accuracy, one of which is the chip rate. In digital signal processing, the time delay discrimination and autocorrelation function of sampled ranging sequences of different chip rates are very different. An approximation simulation model is established according to an in-phase quadrature (I/Q) correlator which is used to evaluate the time delay. Simulation results of the range jitter and time delay discrimination show that the chip rate which provides a non-integer sample-to-chip rate ratio can achieve a higher ranging accuracy, and some test results validate the simulation model. In some design missions, the simulation results may help to select an optimum sample-to-chip rate ratio to satisfy the design requirement on the ranging accuracy.

关键词： Ranging accuracy Range jitter Time delay discrimination Sample-to-chip rate ratio Integration time Autocorrelation function Fractional chip period delay

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A novel method for modeling the phase change of iron ore particles in the cohesive zone of a blast furnace

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Particuology 2024年第3期86卷 252-261页

作者： Dianyu E Yingming wen Jiayun Dan Youyuan jiang Guangchao wei Jiaxin Cui jiangxi Provincial Key Laboratory for Simulation and Modelling of Particulate Systems Jiangxi University of Science and TechnologyNanchang330013China International Institute for Innovation Jiangxi University of Science and TechnologyNanchang330013China Ironmaking Plant Xiangtan Iron and Steel Corporation of Hunan HualingXiangtan411101China Schoolof Transportation and Vehicle Enginering Shandong University of TechnologyZibo255000China

Cohesive zone plays a vital role in the stable operation of a blast furnace(BF),yet the complex phase change process of iron ore particles in this zone is still not well *** this study,a novel one-dimensional(1D)unsteady phase change model was developed to elucidate the heat transfer and melting mechanisms of iron ore *** model validation,the effects of several key operating parameters(e.g.,particle diameter,gas velocity,initial temperature)on the phase change behavior of iron ore particles were analyzed,and the joint effect of multiple parameters was *** results show that larger-sized iron ore particles possess lower specific surface areas,which in turn reduces their convective heat absorption ***,the distance from the solid-liquid phase interface to the particle surface increases,thereby slowing down the movement of the phase interface and pro-longing the melting duration of the *** the gas velocity and the initial temperature does not have a significant impact on reducing the duration of the complete melting *** the specified conditions,it is observed that increasing the gas velocity by 3-fold and 9-fold results in a reduction of the melting duration by 2.4%and 8.3%,*** the initial temperature of iron ore particles results in a decrease in the core-to-surface temperature difference,a slower heating rate,and a shorter duration to achieve *** the factors affecting the melting process,the particle diameter is found to be the most significant in terms of the liquid phase precipitation,mushy zone thickness,and core-to-surface temperature difference of iron ore particles.

关键词： Blast furnace Iron ore melting Cohesive zone Heat transfer Phase change

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Large eddy simulation of boundary layer combustion of hydrogen and hydrocarbon fuel films in a modeled scramjet combustor

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Chinese Journal of Aeronautics 2024年第7期37卷 109-133页

作者： Jianfei wei Silong ZHANG Jingying ZUO Xin LI jiang QIN wen BAO School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China

Supersonic fuel film cooling is a promising way to simultaneously reduce the severe wall heat and friction load of the internal passage in a scramjet engine when operating at hypersonic *** eddy simulations were performed to investigate the cooling and wall friction characteristics of hydrogen and hydrocarbon films under inert and reactive *** results show that the essential difference of the turbulent state in the mixing layer contributes to the totally different behaviors of the cooling and wall friction reduction performances of the two fuel *** turbulent transport processes between the hydrogen film and the mainstream are much weaker as compared to the case of hydrocarbon film,making inert hydrogen rather superior in cooling and friction reduction ***,the increase of wall temperature for hydrogen film under the inert case is mainly driven by the loss of hydrogen with high heat capacity instead of by direct heat ***,the film cooling performance severely deteriorates when the hydrogen film burns due to presence of severe heat release sources near the *** the other hand,combustion of hydrocarbon film in the boundary layer can remarkably improve its originally barely-satisfactory cooling and friction reduction performance to the level comparable to that of hydrogen film,due to the suppression of turbulent transport processes in the mixing layer and presence of heat absorption sources near the ***,the hydrogen film is more advantageous in friction reduction,while the hydrocarbon film is more suitable for cooling.

关键词： Supersonic film cooling Hydrogen Hydrocarbon Boundary layer combustion Large eddy simulation

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Potential therapeutic role of spermine via Rac1 in osteoporosis:Insights from zebrafish and mice

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Zoological Research 2024年第2期45卷 367-380页

作者： Rui-Xue jiang Nan Hu Yu-wei Deng Long-wei Hu Hao Gu Nan Luo Jin wen Xin-Quan jiang Department of Prosthodontics Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai 200011China College of Stomatology Shanghai Jiao Tong UniversityNational Center for StomatologyNational Clinical Research Center for Oral DiseasesShanghai Key Laboratory of StomatologyShanghai Research Institute of StomatologyShanghai Engineering Research Center of Advanced Dental Technology and MaterialsShanghai 200125China Department of Endodontics Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai Jiao Tong UniversityShanghai 200011China Department of Oral and Maxillofacial-Head and Neck Oncology Shanghai Ninth People’s HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200011China Department of Preventive Dentistry Shanghai Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai Jiao Tong UniversityShanghai 200011China

Osteoporosis(OP)is a prevalent metabolic bone *** drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the development of more effective and safer targeted *** a zebrafish(Danio rerio)larval model of osteoporosis,we explored the influence of the metabolite spermine on bone *** showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone *** not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and ***,spermine showcased protective attributes in the nervous systems of both zebrafish embryos and *** the molecular level,Rac1 was identified as playing a pivotal role in mediating the antiosteoporotic effects of spermine,with P53 potentially acting downstream of *** findings were confirmed using mouse(Mus musculus)models,in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions,suggesting strong potential as a bonestrengthening *** study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development,highlighting pivotal molecular *** their efficacy and safety,human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.

关键词： Osteoporosis Spermine Rac1 Zebrafish Mice

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General formalism for dirty extreme-mass-ratio inspirals

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 22-29页

作者： Ye jiang wen-Biao Han Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai Frontiers Science Center for Gravitational Wave Detection Shanghai 200240China

Detecting the environment around the supermassive black holes and tests of general relativity are important applications of extreme-mass-ratio inspirals(EMRIs).There is still a challenge to efficiently describe various“dirty”impacts on the inspirals,such as dark matter,gas,dipole radiation,and electromagnetic *** this study,we find the inherent linearity of the asymptotic solution of the inhomogeneous Teukolsky *** the basis of this property,we completely decouple the factors of the perturber and the background spacetime in the energy fluxes and *** the new decoupling form,the waveforms of EMRIs with non-geodesic motion in Kerr spacetime can be conveniently *** will help to resolve the environment(including gas,field,dark matter,electromagnetic interaction)around supermassive black holes and test general relativity.

关键词： gravitational wave Teukolsky equation extreme-mass-ratio inspirals

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Highly homogeneous zero-index metamaterials make devices more compact and perform better

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Light(Science & Applications) 2024年第5期13卷 806-807页

作者： wei-Xiang jiang State Key Laboratory of Millimeter Waves School of Information Science and EngineeringSoutheast University210096 NanjingChina

A highly homogeneous microwave zero-index metamaterial based on high-permittivity SrTiO3 ceramics is demonstrated to realize the small-aperture high-directivity *** a novel technique is a remarkable step forward to de... 详细信息

关键词： ceramics SrTiO3 Highly

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Mesenteric adipose tissue B lymphocytes promote intestinal injury in severe acute pancreatitis by mediating enteric pyroptosis

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Hepatobiliary & Pancreatic Diseases International 2024年第3期23卷 300-309页

作者： Qing Huang Jia-wen Liu Hai-Bin Dong Zheng-Jie wei Jin-Zhe Liu Yu-Tang Ren Xuan jiang Bo jiang Department of Gastroenterology Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China

Background:Visceral adipose tissue(VAT)has been linked to the severe acute pancreatitis(SAP)prognosis,although the underlying mechanism remains *** has been reported that pyroptosis worsens *** present study aimed to verify whether mesenteric adipose tissue(MAT,a component of VAT)can cause secondary intestinal injury through the pyroptotic ***:Thirty-six male Sprague Dawley(SD)rats were divided into six different *** rats were randomly divided into the SAP and control *** monitored the changes of MAT and B lymphocytes infiltration in MAT of SAP *** SAP rats were injected with MAT B lymphocytes or phosphate buffer solution(PBS).The remaining twelve SAP rats were first injected with MAT B lymphocytes,and then with MCC950(NLRP3 inhibitor)or *** collected blood and tissue samples from pancreas,gut and MAT for ***:Compared to the control rats,the SAP group showed inflammation in MAT,including higher expression of tumor necrosis factor(TNF-α)and interleukin-6(IL-6),lower expression of IL-10,and histological *** cytometry analysis revealed B lymphocytes infiltration in MAT but not T lymphocytes and *** SAP rats also exhibited intestinal injury,characterized by lower expression of zonula occludens-1(ZO-1)and occludin,higher levels of lipopolysaccharide and diamine oxidase,and pathological *** expression of NLRP3 and n-GSDMD,which are responsible for pyroptosis,was increased in the intestine of SAP *** injection of MAT B lymphocytes into SAP rats exacerbated the inflammation in *** upregulation of pyroptosis reduced tight junction in the intestine,which contributed to the SAP progression,including higher inflammatory indicators and worse histological *** administration of MCC950 to SAP+MAT B rats downregulated pyroptosis,which subsequently improved the intestinal barrier and ameliorated inflammatory response of ***:In SAP,MAT B lymphocytes aggravated local

关键词： Acute pancreatitis Mesenteric adipose tissue B lymphocyte Intestinal barrier Pyroptosis

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An extended numerical model of the first exothermic peak for three dimensional printed cement-based materials

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 80-88页

作者： wei jiang wenqian LI Xi CHEN School of Materials Science and Engineering Tongji UniversityShanghai 200092China School of Civil Engineering Tongji UniversityShanghai 200092China

The first exothermic peak of cement-based material occurs a few minutes after mixing,and the properties of three dimensional(3D)printed concrete,such as setting time,are very sensitive to *** this background,based on the classical Park cement exothermic model of hydration,we propose and construct a numerical model of the first exothermic peak,taking into account the proportions of C_(3)S,C_(3)A and quicklime in *** calculated parameters are calibrated by means of relevant published exothermic test *** is found that this developed model offers a good simulation of the first exothermic peak of hydration for C_(3)S and C_(3)A proportions from 0 to 100% of cement clinker and reflects the effect of quicklime content at 8%-10%.The unique value of this research is provision of an important computational tool for applications that are sensitive to the first exothermic peak of hydration,such as 3D printing.

关键词： 3D printed cement-based materials cement hydration the first exothermic peak liquid quick-setting agent numerical model

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