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Mesoscale Simulation for Polymer Migration in Confined Uniform Shear Flow

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Chemical Research in Chinese Universities 2010年第1期26卷 122-127页

作者： HE Yan-dong WANG yong-lei lu zhong-yuan LI Ze-sheng State Key Laboratory of Theretical and Computational Chemistry Institute of Theoretical Chemistry Jilin University Changehun 130021P. R. China

The structure and dynamics of confined single polymer chain in a dilute solution, either in equilibrium or at different shear rates in the uniform shear flow fields, were investigated by means of dissipative particle dynamics simulations. The no-slip boundary condition without density fluctuation near the wall was taken into account to mimic the environment of a nanochannel. The dependences of the radius of gyration, especially in three different di- rections, and the density profile of the chain mass center on the strength of the confinement and the Weissenberg number（Wn） was studied. The effect of the interaction between polymer and solvent on the density profile was also investigated in the cases of moderate and strong Wn. In the high shear flow, the polymer migrates to the center of the channel with increasing Wn. There is only one density profile peak in the channel center in the uniform shear flow, which is in agreement with the results of the experiments and theory.

关键词： Confined polymer Dissipative particle dynamics No-slip boundary condition Uniform shear flow

Analysis of photocatalytic degradation of polyamide microplastics in metal salt solution by high resolution mass spectrometry

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Journal of Environmental Sciences 2024年第5期139卷 473-482页

作者： Yunjin zhong Lebing Zhuo Wangyang lu National Engineering Lab for Textile Fiber Materials&Processing Technology(Zhejiang) School of Materials Science&EngineeringZhejiang Sci-Tech UniversityHangzhou 310018China

Microplastic pollution has become one of the most concerned focuses in the *** many treatment methods,photocatalysis is considered to be one of the most environmentally friendly *** this work,the photodegradation behavior of polyamide microplastics is studied by using polyamide 6(PA6)as model microplastics and FeCl_(3) as *** is hoped that the PA6 fiber can be effectively degraded by utilizing the strong oxidizing active species that can be produced after FeCl_(3) is irradiated in *** results shows that PA6 fiber can be almost completely degraded after 10 days of irradiation in FeCl_(3) aqueous solution,indicating that it is promising to use this new method to solve the problem of PA6type *** addition,the chain scission mechanism and degradation process of PA6 are analyzed in detail by ultra-high performance liquid chromatography-tandem mass spectrometry(UPLC-MS),which provides a new insight for the study of polymer degradation mechanism.

关键词： FeCl_(3) Photocatalysis Polyamide 6 Chain scission

Miniaturized power detection module operating in millimeter wave band

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Journal of Electronic Science and Technology 2024年第2期22卷 69-76页

作者： Xiang Zhou Zhi-yong zhong School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

The miniaturized broadband detection module can be embedded into the microwave application system such as the front end of the transmitter to detect the power or other parameters in real *** is highly prospective in military and scientific *** this paper,a broadband power detection module operating at 26.5 GHz-40.0 GHz is designed by using low-barrier Schottky diode as the detector and a comparator for threshold *** module can dynamically detect the power range between-10 dBm and 10 dBm with the detection accuracy of 0.1 ***,the temperature compensation circuit is also applied to improve the measurement *** a result,the resulted error low to±1 dB in the temperature range of -55℃ to +85℃ is *** designed module is encapsulated by a Kovar alloy with a small volume of 9 mm×6 mm×3 *** endows the designed module the advantages of small size,easy integration,and low cost,and even it is applicable to high-reliability environments such as satellites.

关键词： Diode Miniaturization Power detection Temperature compensation

Research on the influences of motion characteristics of jetting projectile charge under water

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Defence Technology（防务技术） 2024年第3期33卷 411-425页

作者： Xing Chen yong-gang lu Institute of Systems Engineering China Academy of Engineering PhysicsMianyang 621900SichuanChina

Shaped charge warhead is important for enhancing the damage performance of underwater *** paper used finite element analysis software and based on JPC water penetration experiments to examine the influence of liner parameters(wall thickness,material),charge aspect ratio,and stand-off distance on the movement characteristics of JPC in *** findings reveal that the head diameter of the JPC increases and experiences significant erosion after entering the water,the effective length of the JPC in water undergoes two distinct phases:a growth phase and a decrease phase,with the velocity of the JPC decaying *** the liner thickness,stand-off distance and the charge aspect ratio can improve the erosion resistance and the velocity retention capacity of the *** optimal ranges for liner thickness and stand-off distance are 0.0363D_(k) to 0.0545D_(k)(D_(k) is the charge diameter),the stand-off distance should be within 1.0D_(k).After the charge aspect ratio higher than 1.25,the charge structure exerts minimal influence the movement characteristics of the JPC in *** density plays a crucial role in the velocity decay pattern of the JPC during *** with higher densities exhibit superior velocity retention capabilities in water,with the velocity decay pattern converging if the densities are ***,copper,tantalum and tungsten liners are deemed appropriate for underwater shaped charge ***,the results will provide an important reference for the design of underwater shaped charge warhead.

关键词： JPC Movement characteristics Underwater penetration Numerical simulation

p-d Orbital Hybridization Engineered Single-Atom Catalyst for Electrocatalytic Ammonia Synthesis

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Energy & Environmental Materials 2024年第2期7卷 119-125页

作者： Jingkun Yu Xue yong Siyu lu Green Catalysis Center and College of ChemistryZhengzhou UniversityZhengzhou 450001China Department of Chemistry University of SheffieldSheffieldS37HFUK

The rational design of metal single-atom catalysts(SACs)for electrochemical nitrogen reduction reaction(NRR)is ***-dimensional metal-organic frameworks(2DMOFs)is a unique class of promising *** to now,the roles of individual metals,coordination atoms,and their synergy effect on the electroanalytic performance remain ***,in this work,a series of 2DMOFs with different metals and coordinating atoms are systematically investigated as electrocatalysts for ammonia synthesis using density functional theory *** a specific metal,a proper metal-intermediate atoms p-d orbital hybridization interaction strength is found to be a key indicator for their NRR catalytic *** hybridization interaction strength can be quantitatively described with the p-/d-band center energy difference(Δd-p),which is found to be a sufficient descriptor for both the p-d hybridization strength and the NRR *** maximum free energy change(ΔG_(max))andΔd-p have a volcanic relationship with OsC_(4)(Se)_(4)located at the apex of the volcanic curve,showing the best NRR *** asymmetrical coordination environment could regulate the band structure subtly in terms of band overlap and *** work may shed new light on the application of orbital engineering in electrocatalytic NRR activity and especially promotes the rational design for SACs.

关键词： first-principle calculations Nitrogen reduction p-d orbital hybridization single-atom catalysts

Comparison of Combustion Characteristics of Tars Produced with Tobacco Stem Biomass Gasification

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Journal of Renewable Materials 2024年第1期12卷 119-129页

作者： Bo Chen Mingjun Wang Bo Liu Chunping lu Guohai Jia yong Chao Chao zhong School of Mechanical Engineering Hunan Institute of EngineeringXiangtan411104China School of Automotive Engineering Xiangtan Institute of TechnologyXiangtan411100China School of Electrical and Information Engineering Hunan Institute of EngineeringXiangtan411104China China Metallurgic Jingcheng(Xiangtan)Heavy Industry Equipment Co. Ltd.Xiangtan411100China Hunan Shuanghuan Fiber Molding Machinery Co. Ltd.Xiangtan411100China

In order to study the combustion characteristics of tar in biomass gasifier inner wall and gasification gas,“tobacco stem semi-tar inside furnace”,“tobacco stem tar inside furnace”and“tobacco stem tar out-of-furnace”were subjected to thermogravimetric experiments,and the combustion characteristics and kinetic characteristics were *** result shows that“tobacco stem semi-tar inside furnace”has the highest value and“tobacco stem tar out-of-furnace”is has the lowest value on ignition characteristics,combustion characteristics and combustible stability;“tobacco stem semi-tar inside furnace”has the lowest value and“tobacco stem tar outside furnace”has the highest value on burnout characteristics;“tobacco stem tar outside furnace”has the highest value and“tobacco stem tar inside furnace”has the lowest value on integrated combustion characteristics.

关键词： Tobacco stem tar gasifier combustion characteristics

Study of the pressure transient behavior of directional wells considering the effect of non-uniform flux distribution

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Petroleum Science 2024年第3期21卷 1765-1779页

作者： Yan-zhong Liang Bai-lu Teng Wan-Jing luo School of Energy Resources China University of Geosciences(Beijing)Beijing100083China

During the production,the fluid in the vicinity of the directional well enters the wellbore with different rates,leading to non-uniform flux distribution along the directional ***,in all existing studies,it is oversimplified to a uniform flux distribution,which can result in inaccurate results for field ***,this paper proposes a semi-analytical model of a directional well based on the assumption of non-uniform flux ***,the direction well is discretized into a carefully chosen series of linear sources,such that the complex well trajectory can be captured and the nonuniform flux distribution along the wellbore can be considered to model the three-dimensional flow *** using the finite difference method,we can obtain the numerical solutions of the transient flow within the *** the aid of Green's function method,we can obtain the analytical solutions of the transient flow from the matrix to the *** complete flow behavior of a directional well is perfectly represented by coupling the above two types of transient ***,on the basis of the proposed model,we conduct a comprehensive analysis of the pressure transient behavior of a directional *** computation results show that the flux variation along the direction well has a significant effect on pressure *** addition,the directional well in an infinite reservoir may exhibit the following flow regimes:wellbore afterflow,transition flow,inclined radial flow,elliptical flow,horizontal linear flow,and horizontal radial *** horizontal linear flow can be observed only if the formation thickness is much smaller than the well ***,a dip region that appears on the pressure derivative curve indicates the three-dimensional flow behavior near the wellbore.

关键词： Directional well Pressure transient behavior Semi-analytical model Non-uniform flux

CATALYTIC SYNTHESIS OF α-CYANO-α,β-UNSATURATED SULPHONES IN THE PRESENCE OF ORGANOTELluRIUM OXIDE

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Chinese Chemical Letters 1991年第9期2卷 683-684页

作者： Qi zhong yong Jun lu Chang Qing LIU Wei Guo TAO yong Jun ZOU Chemistry Department,Yangzhou Teachers College,Yangzhou,225002

Using bis(p-methoxyphenyl)telluroxide(BMPTO)as the catalyst, phenylsulphonyl acetonitrile condensed easily with aromatic aldehydes at room temperature to give -cyano- ,β-unsaturated sulphones in high yields.

关键词： OC UNSATURATED SULPHONES IN THE PRESENCE OF ORGANOTELluRIUM OXIDE CATALYTIC SYNTHESIS OF CYANO De

Taxonomic and multi-gene phylogenetic studies of Tubeufiales

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Taxonomic and multi-gene phylogenetic studies of Tubeufiales