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Significantly Enhanced Melt Memory Effect of Metallocene-made Isotactic Polypropylene Containing Talc

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Chinese Journal of Polymer Science 2024年第2期42卷 213-222,I0008页

作者： Hong-wen Sun fu-Shan Wang Yan Gao fu-Qing Wei Jia-Chun Feng State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai200433China Lanzhou Petrochemical Corporation of PetroChina Lanzhou730060China Lanzhou Petrochemical Research Center Petrochemical Research Institute of PetroChinaLanzhou730060China

The melt memory effect is a widely observed phenomenon in semi-crystalline polymers. In practical applications, various additives are usually introduced into polymers, which may affect their melt memory behavior. In this work, the effect of talc on the melt memory effect of metallocene-made isotactic polypropylene(M-PP) was investigated in detail by using the differential scanning calorimetry. The results indicated that the introduction of talc significantly strengthened the melt memory effect of M-PP. Specifically, the upper limit temperature of Domain II increased from 161 ℃ to 174 ℃, resulting in a substantial widening of the temperature range of Domain IIa from 1 ℃ to 14 ℃. Analysis of the crystal orientation of the M-PP containing talc cooled from various Ts suggested that the remarkably enhanced melt memory effect could be ascribed to the stabilization of oriented nuclei facilitated by talc. This stabilizing effect was likely attributable to the prefreezing effect or the sorption interaction between talc and the M-PP chains.

关键词： Metallocene-made isotactic polypropylene Talc Melt memory effect Crystal orientation

Investigation of Maxima Assumptions in Modelling Tropical Cyclone- Induced Hazards in the South China Sea

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China Ocean Engineering 2024年第3期38卷 491-504页

作者： wen Ze-guo WANG fu-ming WAN Jing YANG Fan School of Civil Engineering Sun Yat-sen University&Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Academy of Safety Science and Technology Guangzhou 510060China Guangdong Key Laboratory of Oceanic Civil Engineering Guangzhou 510275China Advanced Energy Science and Technology Guangdong Laboratory(Yangjiang Offshore Wind Energy Laboratory) Yangjiang 529500China

The present study aims to examine the suitability of two commonly used assumptions that simplify modelling metoceanconditions for designing offshore wind turbines in the South China Sea (SCS). The first assumption assumes thatjoint N-year extreme wind and wave events can be independently estimated and subsequently combined. The secondone assumes peak wind and waves can be modelled as occurring simultaneously during a tropical cyclone (TC) *** better understand the potential TC activity, a set of 10000 years synthetic TC events are generated. The wind fieldmodel and the Mike 2. spectral wave model are employed to model the TC-induced hazards. Subsequently, theeffect of the assumptions is evaluated by analyzing the peak structural response of both monopile and semisubmersibleoffshore wind turbines during TC events. The results demonstrate that the examined assumptions are generally *** assessing the implications of these assumptions, valuable insights are obtained, which can inform andimprove the modelling of TC-induced hazards in the SCS region.

关键词： tropical cyclone numerical wave modelling hazards offshore wind turbines structural response

A new interacting capillary bundle model on the multiphase flow in micropores of tight rocks

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Petroleum Science 2024年第2期21卷 1099-1112页

作者： wen-Quan Deng Tian-Bo Liang wen-Zhong Wang Hao Liu Jun-Lin Wu {2.-Jian Zhou National Key Laboratory of Petroleum Resources and Engineering China University of Petroleum(Beijing)Beijing102249China

Surfactants are widely used in the fracturing fluid to enhance the imbibition and thus the oil recovery rate. However, current numerical models cannot capture the physics behind capillary imbibition during the wettability alteration by surfactants. Although the interacting capillary bundle(ICB) model shows potential in characterizing imbibition rates in different pores during wettability alteration, the existing ICB models neglect the influence of wettability and viscosity ratio on the imbibition behavior, making it difficult to accurately describe the oil-water imbibition behavior within the porous media. In this work,a new ICB mathematical model is established by introducing pressure balance without assuming the position of the leading front to comprehensively describe the imbibition behavior in a porous medium under different conditions, including gas-liquid spontaneous imbibition and oil-water *** the pore size distribution of a tight rock is known, this new model can predict the changes of water saturation during the displacement process in the tight rock, and also determine the imbibition rate in pores of different sizes. The water saturation profiles obtained from the new model are validated against the waterflooding simulation results from the CMG, while the imbibition rates calculated by the model are validated against the experimental observations of gas-liquid spontaneous imbibition. The good match above indicates the newly proposed model can show the water saturation profile at a macroscopic scale while capture the underlying physics of the multiphase flow in a porous medium at a microscopic scale. Simulation results obtained from this model indicate that both wettability and viscosity ratio can affect the sequence of fluid imbibition into pores of different sizes during the multiphase flow, where less-viscous wetting fluid is preferentially imbibed into larger pores while more-viscous wetting fluid tends to be imbibed into smaller pores. fur

关键词： Imbibition Multiphase flow Tight rock Interacting capillary bundle model Wettability

PVP/PAN-derived porous carbon fiber for zinc-ion hybrid supercapacitors

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Rare Metals 2024年第7期43卷 3066-3073页

作者： Shu-Hua Yang wen-Qing fu Yan-Wei Cui Bing-Qiang Cao Materials Center for Energy and Photoelectrochemical Conversion School of Material Science and EngineeringUniversity of JinanJinan 250022China

Porous carbon fibers are promising cathodes for zinc-ion hybrid supercapacitors(ZHSs)owing to their abundant active sites,great conductivity,and stable physical and chemical ***,designing a proper preparation technique to regulate the microstructure of carbon fibers still remains a great ***,a poly vinylpyrrolidone/po-lyacry lonitrile(PVP/PAN)-derived porous carbon fiber is developed via the PVP/PAN blend electrospinning and hydrothermal selective PVP removal *** hydrothermal selective PVP removal strategy can effectively avoid a cross-linking between PVP and PAN during the traditional stabilization at air *** PVP/PAN-derived porous carbon fiber,the sufficient micropores provide abundant space for the Zn^(2.)storage,whereas the proper mesopores contribute to the fast ion *** hierarchical porous structures endow ZHSs with high specific capacity and high-rate *** ZHS assembled with the optimal PVP/PAN-derived porous carbon fiber(PVP-PANC-0.8)displays an outstanding specific capacity of 2.8 mAh·g^(-1),high rate capability(49.5%)from 0.5 to 5 A·g^(-1),and 72.2.%capacity retention after 10,000 cycles at 0.5 A·g^(-1).

关键词： Zinc-ion hybrid supercapacitors Porous carbon fibers Hierarchical porous structures Electrospinning

The Effect of Blending Ratio on the Structure and Properties of the PPR/PS In situ Fiber Reinforced System Prepared by Multi-Flow Vibration Injection Molding

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Chinese Journal of Polymer Science 2024年第6期42卷 851-863页

作者： Yan-Jiang Li Meng-Long Hu Jun-wen Zhang Qiang fu Jie Zhang College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China

To enhance the mechanical properties of polypropylene random copolymer(PPR),polystyrene(PS)with four different contents were added to the PPR matrix through melt ***,using the Multi-Flow Vibration Injection Molding(MFVIM)technology,PPR/PS in situ microfiber composites(MFC)with different blending ratios were *** results indicated that blending ratio had a great impact on the phase morphology and crystal structure of MFVIM samples,which was different from those of conventional injection molding(CIM)*** ultrafine fibers could be formed under the shear field and could absorb the PPR molecular chains to form hybrid shish-kebab ***,the PPR matrix could also form shish-kebab structures under the effect of strong *** the PS content reached 2.%,under the combined action of PS in situ microfibers and highly oriented crystal structure,the tensile strength and Young’s modulus of the sample were obviously improved and the impact strength remained at a relatively high *** a strong and tough balanced PPR based material was *** results provide valuable insights for expanding the industrial and daily-life applications of PPR and show promising development prospects.

关键词： PPR MFVIM In situ microfibers Shearfield Hybrid shish-kebab structures

Testing the first law of black hole mechanics with gravitational waves

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Science China(Physics,Mechanics & Astronomy) 2024年第10期67卷 76-82页

作者： Chao-Wan-Zhen Wang Jin-Bao Zhu Guo-Qing Huang fu-wen Shu Department of Physics Nanchang UniversityNanchang 330031China Center for Relativistic Astrophysics and High Energy Physics Nanchang UniversityNanchang 330031China GCAP-CASPER Physics DepartmentBaylor UniversityWaco 76798-7316USA

The successful observation of gravitational waves has provided humanity with an additional method to explore the universe,particularly black *** this study,we utilize data from LIGO and Virgo gravitational wave observations to test the first law of black hole mechanics,employing two different *** consider the secondary compact object as a perturbation to the primary black hole before the merger,and the remnant black hole as a stationary black hole after the *** the pre-merger and post-merger analysis,our results demonstrate consistency with the first law,with an error level of approximate 2.%at a68%credibility level for *** the full inspiral-merger-ringdown analysis,our results show consistency with the first law of black hole mechanics,with an error level of about 6%at a 68%credibility level and 10%at a 95%credibility level for ***,we observe that the higher the mass ratio of the gravitational wave source,the more consistent our results are with the first law of black hole ***,our study sheds light on the nature of compact binary coalescence and their implications for black hole mechanics.

关键词： gravitational waves black hole mechanics data analysis ringdown

Elastohydrodynamic Lubrication Interface Stiffness and Damping Considering Asperity Lateral Contact

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Acta Mechanica Solida Sinica 2024年第1期37卷 109-123页

作者： Zhiqiang Gao Yu Zhang Xian Wei Yanfang Zhu Lixia Peng Weiping fu wen Wang School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048China School of Intelligent Manufacturing Panzhihua UniversityPanzhihua 617000China Material Corrosion and Protection Key Laboratory of Sichuan Province Sichuan University of Light Chemical TechnologyYibin 644002China School of Mechanical Engineering Anyang Institute of TechnologyAnyang 455099China

Elastohydrodynamic lubrication(EHL)point contact occurs between two rough surfaces at the mesoscopic level,while the interaction of rough surfaces involves contact between asperities at the microscale *** most cases,the contact between asperities within an interface takes the form of lateral contact rather than peak *** devoid of contact asperities are filled with lubricating ***,conventional models often oversimplify lateral contact forms as interactions between asperities and a smooth,rigid *** simplifications fail to accurately represent the true contact conditions and can lead to inaccuracies in the analysis of EHL’s contact *** address this issue,we have developed a novel EHL interface model comprising two rough *** model allows us to explore the influence of asperity height,contact angle,and contact azimuth angle on EHL interface performance.

关键词： EHL interface Asperity lateral contact Contact stiffness Damping

Improving Thermal-oxidative Aging Resistance of Styrene-butadiene Rubber by Antioxidant Loaded Silica Aerogel

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Chinese Journal of Polymer Science 2024年第8期42卷 1198-1209页

作者： Xue-Fei Ping Yu Wang Lu Liu fu-Yong Liu Hong-Wei He Pi Wang wen-wen Yu Qiang Zheng College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering Taiyuan 030032China Key Laboratory of Macromolecular Synthesis and functionalization Department of Polymer Science and EngineeringZhejiang UniversityHangzhou 310058China

The antioxidant N-isopropyl-N'-phenyl-p-phenylenediamine(4010NA)was dissolved in ethanol and impregnated into silica aerogel(SAG)via vacuum-pressure cycles,yielding composite particles(A-N)with enhanced sustained-release and reinforcing *** effect of A-N on the mechanical properties and thermal-oxidative aging resistance of styrene-butadiene rubber(SBR)vulcanizates was *** and BET assessments indicated that the loading efficiency of 4010NA in SAG reached 14.2.%within ethanol's solu bility *** A-N into SBR vulcanizates significantly elevated tensile strength by 17.5%and elongation at break by 41.9%over those with fumed silica and ***,A-N notably enhanced the thermal-oxidative aging resistance of *** aging for 96 h at 100℃,the tensile strength and elongation at break of SBR with A-N sustained 70.09%and 58.61%of their initial values,respectively,with the retention rate of elongation at break being 62.8%higher than that of SBR with fumed silica and free *** study revealed that A-N composite particles significantly inhibited the crosslinking in SBR's molecular chains,reducing hardening and embrittlement during later thermal-oxidative aging stages.

关键词： Styrene-butadiene rubber Silica aerogel Loading modification Thermal-oxidative aging

Study on the clogging mechanism of punching screen in sand control by the punching structure parameters

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Petroleum Science 2024年第1期21卷 609-620页

作者： fu-Cheng Deng fu-Lin Gui Bai-Tao Fan Lei {2. Sheng-Hong Chen Ning Gong Yun-Chen Xiao Zhi-Hui Xu Yangtze University Jingzhou434023HubeiChina CNOOC Research Institute Ltd. Beijing100028China CNOOC Ener Tech-Drilling&Production Co. Tianjin300457China Tianjin Branch of CNOOC Ltd. Tianjin300459China

As an independent sand control unit or a common protective shell of a high-quality screen,the punching screen is the outermost sand retaining unit of the sand control pipe which is used in geothermal well or oil and gas ***,most screens only consider the influence of the internal sand retaining medium parameters in the sand control performance design while ignoring the influence of the plugging of the punching screen on the overall sand retaining performance of the *** explore the clogging mechanism of the punching screen,this paper established the clogging mechanism calculation model of a single punching screen sand control unit by using the computational fluid mechanics-discrete element method(CFD-DEM)combined *** to the combined motion of particles and fluids,the influence of the internal flow state on particle motion and accumulation was *** results showed that(1)the clogging process of the punching sand control unit is divided into three stages:initial clogging,aggravation of clogging and stability of *** the initial stage of blockage,coarse particles form a loose bridge structure,and blockage often occurs preferentially at the streamline gathering place below chamfering inside the sand control *** the stage of blockage intensification,the particle mass develops into a relatively complete sand bridge,which develops from both ends of the opening to the center of the *** the stable plugging stage,the sand deposits show a“fan shape”and form a“V-shaped”gully inside the punching slot element.(2.Under a certain reservoir particle-size distribution,The slit length and opening height have a large influence on the permeability and blockage rate,while the slit width size has little influence on the permeability and blockage *** microscopic clogging mechanism and its law of the punching screen prevention unit are proposed in this study,which has some field guidance significance for the design of punching screen

关键词： Punching screen Plugging CFD-DEM Size parameter Sand control