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Influence of Freezing Layer on the Crystallization Kinetics of PCL on Oriented PE Film

Chinese Journal of Polymer science 2023年第5期41卷 778-786,I0010页

作者： Hao Zhang Ying-Xiao Song Na Li Shao-Juan Wang Jian Hu Rui Xin Jie Zhang Chun-Feng Song Shou-Ke Yan Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber-PlasticsQingdao University of Science&TechnologyQingdao 266042China State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China

The effect of freezing layer on the crystallization kinetics of poly(ε-caprolactone)(PCL)thin and ultrathin films was investigated by monitor the growth process of it on oriented polyethylene(PE)and CaF_(2)with and without freezing layer,*** was found that the PCL films with similar thicknesses crystallize much faster on oriented PE than on CaF_(2)*** example,the crystallization rate constant of a 102 nm thick PCL film decreases tremendously by 3 orders of magnitude from 1.1×10^(-1) on PE substrate at 50℃to 7×10^(-4)on CaF_(2)surface at 40℃.Moreover,the crystallization of PCL accelerates on CaF_(2)surface while slows down at PE surface with increasing film *** ultrathin films of PCL with thickness less than 14 nm exhibits the fastest crystallization rate on oriented PE with a rate constant of about 3.5×10^(-1),which is 3 times higher than that of a ca.50 nm thick *** illustrates the great influence of freezing layer on the crystallization process of *** freezing layer thickness of PCL on PE is estimated to be in the range of 14-17 *** the radius of gyration(R_(g)~15.6 nm)of the used PCL material into account,the obtained results may imply the existence of a correlation between the R_(g)of PCL and its freezing layer thickness at PE substrate.

关键词： Poly(ε-caprolactone) Polyethylene Interface Freezing layer Crystallization kinetics

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Interdecadal Variations of ENSO Impacts over the Indo-Northwest Pacific Region and the Related Mechanisms

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Journal of Meteorological Research 2024年第2期38卷 235-248页

作者： Hongxia LAN Jing MA Haiming XU Jingjia LUO Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change(KLME/ILCEC)Nanjing University of Information Science&TechnologyNanjing 210044 School of Atmospheric Sciences Nanjing University of Information Science&TechnologyNanjing 210044

Owing to limited observations,it remains unknown whether the impact of El Niño-Southern Oscillation(ENSO)on the Indian Ocean-Northwest Pacific(IO-NWP)climate showed decadal changes in the early 20th *** multi-source reanalysis and hindcast datasets from the ECMWF and NOAA extending back to 1901,this study investigates interdecadal variations of the impact of ENSO on the IO-NWP climate from 1901 to *** is found that the influence of ENSO on the IO-NWP climate shows“strong-weak-strong”interdecadal change during *** is characterized by much weaker Indian Ocean sea surface temperature(SST)warming and a weaker NWP subtropical anticyclone(NWPSA)in the following summer of El Ni?o during 1946-1967,compared with those in the other two periods(1901-1945 and 1968-2009).Analyses of the datasets indicate that the interdecadal variation is mainly associated with the change in ENSO *** contrast to the period of 1946-1967,a greater SST variance occurred in the central-eastern equatorial Pacific during 1901-1945 and 1968-2009.A stronger El Ni?o tends to generate more significant anticyclonic anomalies over the southeast Indian Ocean through *** northwesterly anomalies to the south of the anticyclone weaken the southeast trade winds and warm the south Indian Ocean SST via wind-evaporation-SST feedback,and the positive south Indian Ocean SST anomalies trigger westward-propagating oceanic Rossby waves to induce stronger warming of the southwest Indian Ocean,leading to a significant asymmetric wind pattern across the equator in *** profound northeastward winds on the north side weaken the southwest monsoon,leading to a“second warming”over the north Indian Ocean in summer,which anchors the eastward-propagating warm Kelvin waves and results in a stronger NWPSA by inducing surface divergence and suppressing deep convection.

关键词： ENSO Indo-Northwest Pacific Northwest Pacific subtropical anticyclone decadal changes

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Ballistic performance of spaced multi-ply soft fabrics: Experimental and numerical investigation

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Defence technology（防务技术） 2024年第4期34卷 143-155页

作者： Zhongwei Zhang Xiaoning Yang Yuan Lin Ziming Xiong Yuhang Xiang Yi Zhou Mingyang Wang State Key Laboratory of Explosion&Impact and Disaster Prevention&Mitigation Army Engineering University of PLANanjing 210007China School of Mechanical Engineering Nanjing University of Science&TechnologyNanjing 210007China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan 430200China Postdoctoral Station of Civil Engineering Army Engineering University of PLANanjing 210007China

It has been reported that the ply gap influences the ballistic resistance of spaced multi-ply fabric systems,but its working mechanism was not well-understood. This paper reports the experimental and numerical approaches and results of an investigation on the mechanisms that enable the improved ballistic performance of spaced multi-ply systems. Penetration tests were performed over a range of impact velocities ranging from 200 m/s to 400 m/s. The results confirmed that the ply gap is beneficial to the energy absorption capability of the systems. This is because the front plies tend to absorb more energy when they are not immediately constrained by the rear plies. During a ballistic event, the gap relieves the reflection of the compressive pulse, prolonging the projectile engagement time with the front plies;on the other hand, the rear plies become increasingly less active in dissipating energy as the gap *** the gap is sufficiently widened to avoid any interference between the plies before the failure of the front ply, the responses of the whole system no longer vary. It was also found that the ballistic performance of the spaced systems is influenced by ply thickness, impact velocity, and the stacking order of the ply gap.

关键词： Energy absorption capability Ply gap Ballistic performance The front ply The rear ply

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Plasma-assisted fabrication of multiscale materials for electrochemical energy conversion and storage

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Carbon Energy 2025年第2期7卷 144-171页

作者： Chen Li Tengfei Zhang Zhong Qiu Beirong Ye Xinqi Liang Xin Liu Minghua Chen Xinhui Xia Chen Wang Wangjun Wan Yongqi Zhang Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengduChina Key Laboratory of Engineering Dielectric and Applications(Ministry of Education) School of Electrical and Electronic EngineeringHarbin University of Science and TechnologyHarbinChina State Key Laboratory of New Textile Materials and Advanced Processing Technology Wuhan Textile UniversityWuhanChina College of Materials Science and Engineering Zhejiang University of TechnologyHangzhouChina School of Materials Science and Engineering Zhejiang UniversityHangzhouChina Zhejiang Academy of Science and Technology for Inspection and Quarantine HangzhouChina

Plasma,the fourth state of matter,is characterized by the presence of charged particles,including ions and *** has been shown to induce unique physical and chemical ***,there have been increased applications of plasma technology in the field of multiscale functional materials'preparation,with a number of interesting *** review will begin by introducing the basic knowledge of plasma,including the definition,typical parameters,and classification of plasma *** this,we will provide a comprehensive review and summary of the applications(phase conversion,doping,deposition,etching,exfoliation,and surface treatment)of plasma in common energy conversion and storage systems,such as electrocatalytic conversion of small molecules,batteries,fuel cells,and *** article summarizes the structure-performance relationships of electrochemical energy conversion and storage materials(ECSMs)that have been prepared or modified by *** also provides an overview of the challenges and perspectives of plasma technology,which could lead to a new approach for designing and modifying electrode materials in ECSMs.

关键词： electrocatalysts energy conversion and storage nanomaterials plasma

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Core-shell-structured Composite ZSM-5@MCM-41 Catalysts:Fabrication,Characterization,and Enhanced Performance in Hexane Catalytic Cracking

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China Petroleum Processing & Petrochemical technology 2023年第4期25卷 41-51页

作者： Zhu Jiale Zhu Xuedong Yang Fan State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science&TechnologyShanghai 200237China

A series of core-shell zeolites with a ZSM-5 zeolite core and a MCM-41 shell with varying shell thicknesses were successfully fabricated via a cetyltrimethylammonium bromide(CTAB)-directed sol-gel coating method in an ultradilute solution. Extensive characterization techniques, including XRD, TEM, N_(2) adsorption-desorption, NH_(3)-TPD, and IR measurements, confirmed the successful coating of a microporous ZSM-5 core with a mesoporous MCM-41 shell layer and were further employed to explore the textural properties and acidic properties of the samples. The hexane cracking results revealed a significant enhancement in olefin yields after introducing the MCM-41 shell to ZSM-5. Interestingly, a volcanic trend in olefin yields was observed with the increase in the shell thickness. In particular, the highest olefin yield of 51.5%, exceeding that of the core catalyst by 17.1%, was achieved when the shell thickness was controlled at 40 ***, the catalyst lifetime investigation revealed that the core-shell composite catalyst exhibited a minimal reduction in hexane conversion of merely 3.8% over a 120 h reaction period, significantly outperforming the 11.3% reduction exhibited by the core catalyst. This remarkable catalytic performance was attributed to the passivation of external acid sites and the introduction of more developed pore channels by the shell, which effectively mitigated unwanted side reactions. The successful synthesis of these core-shell structured catalysts presents a novel strategy for improving catalytic performance in hexane cracking, in addition to serving as a solid foundation for the design of industrial catalysts for light naphtha cracking.

关键词： catalytic cracking light olefin core-shell ZSM-5 zeolite

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Engineering the thermostability of D-lyxose isomerase from Caldanaerobius polysaccharolyticus via multiple computer-aided rational design for efficient synthesis of D-mannose

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Synthetic and Systems Biotechnology 2023年第2期8卷 323-330页

作者： Hao Wu Ming Yi Xiaoyi Wu Yating Ding Minghui Pu Li Wen Yunhui Cheng Wenli Zhang Wanmeng Mu School of Food Science and Bioengineering Changsha University of Science&TechnologyChangsha410114China State Key Laboratory of Food Science and Technology Jiangnan UniversityWuxi214122China

D-Mannose is an attractive functional sugar that exhibits many physiological benefits on human *** demand for low-calorie sugars and sweeteners in foods are increasingly available on the *** sugar isomerases,such as D-lyxose isomerase(D-LIase),can achieve an isomerization reaction between D-mannose and ***,the weak thermostability of D-LIase limits its efficient conversion from D-fructose to ***,few studies are available that have investigated the molecular modification of D-LIase to improve its thermal *** this study,computer-aided tools including FireProt,PROSS,and Consensus Finder were employed to jointly design D-LIase mutants with improved thermostability for the first ***,the obtained five-point mutant M5(N21G/E78P/V58Y/C119Y/K170P)showed high thermal stability and cat-alytic *** half-life of M5 at 65◦C was 10.22 fold,and the catalytic efficiency towards 600 g/L of D-fructose was 2.6 times to that of the wild type enzyme,*** dynamics simulation and intramolecular forces analysis revealed a thermostability mechanism of highly rigidity conformation,newly formed hydrogen bonds andπ-cation interaction between and within protein domains,and redistributed surface electrostatic charges for the mutant *** research provided a promising D-LIase mutant for the industrial production of D-mannose from D-fructose.

关键词： D-lyxose isomerase Thermostability D-mannose Molecular modification

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Enhanced gas production and CO_(2) storage in hydrate-bearing sediments via pre-depressurization and rapid CO_(2) injection

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Chinese Journal of Chemical Engineering 2024年第3期67卷 126-134页

作者： Hongnan Chen Yifei Sun Bojian Cao Minglong Wang Ming Wang Jinrong Zhong Changyu Sun Guangjin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China School of Chemistry and Chemical Engineering Changsha University of Science&TechnologyChangsha 410114China

Carbon emission reduction and clean energy development are urgent demands for mankind in the coming *** an efficient CO_(2) storage method can significantly reduce CO_(2) emissions in the short *** this study,we attempted to construct sediment samples with different residual CH_(4) hydrate amounts and reservoir conditions,and then investigate the potentials of both CO_(2) storage and enhanced CH_(4) recovery in depleted gas hydrate deposits in the permafrost and ocean zones,*** results demonstrate that CO_(2) hydrate formation rate can be significantly improved due to the presence of residual hydrate seeds;However,excessive residual hydrates in turn lead to the decrease in CO_(2) storage *** by the T-P conditions of the reservoir,the storage amount of liquid CO_(2) can reach 8 times that of gaseous CO_(2),and CO_(2) stored in hydrate form reaches 2-4 ***,we noticed two other advantages of this *** is that CO_(2) injection can enhance CH_(4) recovery rate and increases CH_(4) recovery by 10%-20%.The second is that hydrate saturation in the reservoir can be restored to 20%-40%,which means that the solid volume of the reservoir avoids serious ***,this is crucial for protecting the goaf *** summary,this approach is greatly promising for high-efficient CO_(2) storage and safe exploitation of gas hydrate.

关键词： Hydrate Depressurization CO_(2) storage CH_(4) production Reservoir remediation

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Laser powder bed fusion of WE43 magnesium alloy with superior balance of strength and ductility

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Journal of Magnesium and Alloys 2025年第3期13卷 1275-1293页

作者： Wenhe Xu Jikang Li Zhenwu Zhang Hongwei Yuan Guojin An Hai Shi Chao Cai Wenming Jiang Wei Li Qingsong Wei State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Guizhou Aerospace Nanhai Science&Technology Co. Ltd.Zunyi 563000China Guizhou Aerospace Fenghua precision equipment Co. LtdGuiyang 550009China Key Laboratory of Metallurgical Equipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081China

WE43 is a high-strength magnesium alloy containing rare-earth elements such as Y,Gd and ***,how to further obtain the balance of strength and ductility,as well as the manufacture of complex structures is still a dilemma for its engineering *** this study,WE43 alloy samples withﬁne microstructures,high densiﬁcation and excellent mechanical properties were successfully prepared by laser powder bed fusion(LPBF)additive *** optimal process window was established,and the formation mechanisms of three types of porosity defects were revealed,namely lack-of-fusion pores,meltﬂuctuation-induced pores,and keyhole-induced *** the combined process of laser power of 200 W and scanning speed of 600 mm/s,samples with a high density of 99.89%were ***,periodic heterogeneous microstructure was prepared along the build direction,i.e.,ﬁne grains(∼4.1μm)at melt pool boundaries and coarse grain(∼23.6μm)inside melt *** was mainly due to the preferential precipitation of Zr and Mg_(3)(Gd,Nd)nano-precipitates at the melt pool boundaries providing nucleation sites for the *** special feature could provide an extra hetero-deformation induced(HDI)strengthening and retard *** optimal tensile yield strength,ultimate tensile strength and elongation at break were 276±1 MPa,292±1 MPa and 6.1±0.2%,*** obtained tensile properties were superior to those of other magnesium alloys and those fabricated by other *** solid solution strengthening(∼24.5%),grain boundary strengthening(∼14.4%)and HDI strengthening(∼32.2%)were the main sources of high yield *** work provides a guidance on studying the pore defect suppression and strengthening mechanisms of WE43 alloy and other magnesium alloys produced by LPBF.

关键词： Laser powder bed fusion(LPBF) WE43 alloy Pore defect Microstructure Strengthening mechanisms

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Effect of lanthanum oxide on microstructure and mechanical properties of ZK60 magnesium alloy

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Journal of Rare Earths 2024年第12期42卷 2270-2278,I0003页

作者： Wei Qiu Zhaoyuan Lu Senmao Zhang Shuanglong Li Jian Chen Wei Chen Wei Li Yanjie Ren Jun Luo Maohai Yao Wen Xie School of Energy and Power Engineering Changsha University of Science&TechnologyChangsha410114China Key Laboratory of Energy Efficiency and Clean Utilization The Education Department of Hunan ProvinceChangsha University of Science&TechnologyChangsha410114China School of Mechanical&Energy Engineering Zhejiang University of Science&TechnologyHangzhou310023China Hunan Provincial Key Laboratory of Vehicle Power and Transmission System Hunan Institute of EngineeringXiangtan411104China Hunan Rare Earth Metal Material Research Institute Institute of Rare Earth Light AlloysChangsha410126China

Different amounts of La_(2)O_(3)were added to ZK60 alloy to observe the changes in microstructure and mechanical properties of ZK60-XLa_(2)O_(3)(X=0,0.2 wt%,0.5 wt%)*** findings reveal that within the as-cast ZK60 alloy,the Mg-Zn binary phase is manifested as rod-shaped precipitates,exhibiting a dispersed distribution predominantly along the grain boundary *** the increase of La_(2)O_(3)addition,the rod-like Mg-Zn binary phases are gradually replaced by Mg-Zn-La ternary phases,and these Mg-Zn-La ternary phases are semi-continuously distributed around the grain *** ZK602 and ZK605 alloys result in a corresponding improvement in ductility after *** is noteworthy that the ductility of the as-extruded ZK605 alloy is increased by 59.4%compared to ZK60 at the expense of a reduction of only 3.9%in yield *** together,the significant increase in ductility of ZK605 is mainly due to the weakening of the basal texture,which is weakened by the redox reaction of La_(2)O_(3)with the a-Mg matrix,generating the La *** decrease in yield strength of ZK605 in the extruded state is closely related to the observed grain coarsening phenomenon and the basal texture *** the same time,the ultimate tensile strength of ZK605 shows a slight increase,which is mainly due to the second phase *** Mg-Zn-La ternary phase exhibits a notably hard character,and it is evident that the distribution of this phase becomes progressively denser as the La_(2)O_(3)content increases.

关键词： ZK60 La_(2)O_(3) Microstructure Mechanical properties Basal texture Rare earths

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Secondary electron emission and photoemission from a negative electron affinity semiconductor with large mean escape depth of excited electrons

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Chinese Physics B 2023年第4期32卷 677-690页

作者：谢爱根董红杰刘亦凡 School of Physics and Optoelectronic Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Jiangsu Key Laboratory for Optoelectronic Detection of Atmosphere and Ocean Nanjing University of Information Science&TechnologyNanjing 210044China Jiangsu international Joint Laboratory on Meteorological Photonics and Optoelectronic Detection Nanjing University of Information Science&TechnologyNanjing 210044China

The formulae for parameters of a negative electron affinity semiconductor(NEAS)with large mean escape depth of secondary electrons A(NEASLD)are *** methods for obtaining parameters such asλ,B,E_(pom)and the maximumδandδat 100.0 keV≥E_(po)≥1.0 keV of a NEASLD with the deduced formulae are presented(B is the probability that an internal secondary electron escapes into the vacuum upon reaching the emission surface of the emitter,δis the secondary electron yield,E_(po)is the incident energy of primary electrons and E_(pom)is the E_(po)corresponding to the maximumδ).The parameters obtained here are analyzed,and it can be concluded that several parameters of NEASLDs obtained by the methods presented here agree with those obtained by other *** relation between the secondary electron emission and photoemission from a NEAS with large mean escape depth of excited electrons is investigated,and it is concluded that the presented method of obtaining A is more accurate than that of obtaining the corresponding parameter for a NEAS with largeλ_(ph)(λ_(ph)being the mean escape depth of photoelectrons),and that the presented method of calculating B at E_(po)>10.0 keV is more widely applicable for obtaining the corresponding parameters for a NEAS with largeλ_(ph).

关键词： negative electron affinity semiconductor secondary electron emission photoemission the probability secondary electron yield large mean escape depth of excited electrons

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