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China Foundry 2024年第4期21卷 352-359页

作者： Zhen Zhang lin-na Feng Jin-he Wang zheng-kun li.hua-meng fu Hong li zheng-wang Zhu Hai-feng Zhang School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Metallurgy Northeastern UniversityShenyang 110004China

The infiltration casting method is widely employed for the preparation of ex-situ composite ***,the production of composite materials using this method must necessitates a comprehensive understanding of the wettability and interface characteristics between the reinforcing phase and the bulk metallic glasses(BMGs).This work optimized the composition of Zr-based BMGs through microalloying methods,resulting in a new set of Zr-based BMGs with excellent glass-forming *** experiments between the Zr-based BMGs melts and W substrates were conducted using the traditional sessile drop method,and the interfaces were characterized utilizing a scanning electron microscope(SEM)equipped with energy dispersive X-ray spectroscopy(EDS).The work demonstrates that the microalloying method substantially enhances the wettability of the Zr-based BMGs ***,the incorporation of Nb element impedes the formation of W-Zr phases,but the introduction of Nb element does not alter the extent of interdiffusion between the constituent elements of the amorphous matrix and W element,indicating that the influence of Nb element on the diffusion of individual elements is minute.

关键词： Zr-based BMGs infiltration casting method wettability interface characteristics W-Zr phases

Impact of Local Climate Zones on the Urban Heat and Dry Islands in Beijing:Spatial Heterogeneity and Relative Contributions

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Journal of Meteorological Research 2024年第1期38卷 126-137页

作者： Zuofang zheng fu LUO Nana li.hua GAO Yuanjian YANG Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089 School of Atmospheric Physics Nanjing University of Information Science&TechnologyNanjing 210044 Key Laboratory of Urban Meteorology China Meteorological AdministrationBeijing 100089

Based on the building height and density data on a 100-m resolution,hourly 2-m temperature and humidity data at83 automatic weather stations,and gridded local climate zone(LCZ)data on a 120-m resolution in urban Beijing in2020,this study first employs the semivariogram combined with building parameters to calculate spatial correlations and has identified an LCZ grid resolution of 500 m suitable for best usage of the available observation ***,how the spatially heterogeneous LCZs affect and contribute to the canopy urban heat island intensity(UHII)and urban dry island intensity(UDII)are quantitatively *** is found that UHII is high in winter and low in summer with a unimodal diurnal variation while UDI is low in winter but high in summer with a bimodal diurnal *** LCZ with compact mid-rise(open high-rise)buildings exhibits the highest UHII(UDII),followed by the compact high-rise(compact low-rise),while the LCZ of scattered trees presents both the lowest UHII and the lowest *** most significant difference in the UHII(UDII)among the nine LCZ types in the urban area of Beijing is2.62℃(1.1 g kg^(-1)).Area-weighted averaging analysis reveals that the open mid-rise LCZ is the most significant contributor to the UHII(UDII),immediately followed by compact mid-rise(open low-rise),with the least contribution from bare rock or paved(scattered trees).The results also indicate that beyond the intrinsic physical properties of the LCZs of a city,their area proportions cannot be overlooked in evaluating their impact on the UHI and *** quantitatively findings could help urban planners to create a livable urban climate and environment by adjusting the relevant land use.

关键词： local climate zone(LCZ) urban heat island(UHI) urban dry island(UDI) distribution pattern contribution rate Beijing

A tectono-thermal perspective on the petroleum generation,accumulation and preservation in the southern Ordos Basin, North China

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Petroleum Science 2024年第3期21卷 1459-1473页

作者： Peng Yang Zhan-li Ren Jin-hua fu Hong-Ping Bao Hui Xiao zheng Shi kun Wang Yuan-Yuan Zhang Wen-Hui liu Wen-Hou li State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an710069ShanxiChina National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Fields Exploration and Development Research Institute of PetroChina Changqing Oilfield CompanyXi'an710018ShaanxiChina Shaanxi Key Lab of Petroleum Accumulation Geology School of Earth Science and EngineeringXi'an Shiyou UniversityXian710065ShaanxiChina Wuxi Research Institute of Petroleum Geology Petroleum Exploration and Production Research InstituteSINOPECWuxi214126JiangsuChina

The southern Ordos Basin has excellent petroleum exploration ***,the tectono-thermal history and the controls on petroleum generation,accumulation and preservation conditions in southern basin are *** this study,we analyzed the present geothermal field,paleo-geothermal gradient,maturity of the hydrocarbon source rocks,uplift and cooling process and tectono-thermal evolution *** the study area,for the Ordovician,Permain and the Triassic strata,the present temperature is low(3070℃)in the southeastern area but high(80140℃)in the northwestern *** paleogeothermal gradient varied from 24℃/km to 30℃/km with a heat flow of 58—69 m W/m^(2)(i.e.,a medium-temperature basin).The paleo-temperatures are higher than the present temperatures and the maximum paleo-temperatures controlled the thermal maturity of the source *** vitrinite reflectance(Ro)values of the Triassic strata are>0.7%and the thermal maturity reached the middlemature oil generation *** Rovalues of the Permian-Ordovician strata are>1.8%and the thermal maturity reached the over-mature gas generation *** southern Ordos Basin has experienced the multiple tectonic events at the Late Ordovician Caledonian(452 Ma),Late Triassic(215 Ma),Late Jurassic(165160 Ma),End-Early Cretaceous(110100 Ma)and Cenozoic(since 40 Ma).A large-scale tectonothermal event occurred at the End-Early Cretaceous(110100 Ma),which was controlled by lithospheric extension,destruction and *** event led to the highest paleo-temperatures and thermal maturities and coeval with the peak period of petroleum generation and *** southern Ordos Basin has undergone rapid and large-scale uplift since the Late Cretaceous due to expansion of the northeastern margin of the Tibetan Plateau,uplift of the Qinling orogenic belt and thrust faulting in the liupanshan tectonic *** southern Ordos Basin experienced tectonic overprinting that was strong in the south and weak in the *** str

关键词： Fission-track dating Vitrinitereflectance Geothermal field Tectono-thermal evolution Petroleum geology Ordos Basin

An Example of Embedded Singular Continuous Spectrum for Discrete Schrödinger Operators

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1837-1849页

作者： zheng Qi fu Xiong li Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

We present an example of a potential such that the corresponding discrete Schrödinger operator has singular continuous spectrum embedded in the absolutely continuous spectrum.

关键词： Sparse potentials singular continuous spectrum Prüfer variables

Exploring Trade-offs in Thermal Interface Materials:The Impact of Polymer-Filler Interfaces on Thermal Conductivity and Thixotropy

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Chinese Journal of Polymer Science 2024年第7期42卷 916-925,I0006页

作者： Bin Zhang zheng-li Dou Yong-zheng Zhang Qiang fu Kai Wu College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu610065China

Effective thermal transport across solid-solid interfaces which is essential in thermal interface materials(TIMs),necessitates both optimal thixotropy and high thermal *** role of filler surface modification,a fundamental aspect of TIM fabrication,in the influence of these properties is not fully *** study employs the use of a silane coupling agent(SCA)to modify alumina,integrating experimental approaches with molecular dynamics simulations,to elucidate the interface effects on thixotropy and thermal conductivity in polydimethylsiloxane(PDMS)-based *** findings reveal that the variations of SCAs modify both interface binding energy and transition layer *** interface binding energy restricts macromolecular segmental relaxation near the interface,hindering desirable thixotropy and bond line *** the contrary,the thickness of the transition layer at the interface positively influences thermal conductivity,facilitating the transport of phonons between the polymer and ***,selecting an optimal SCA allows a balance between traditionally conflicting goals of high thermal conductivity and minimal bond line thickness,achieving an impressively low interface thermal resistance of just 2.45-4.29 K·mm^(2)·W^(-1)at275.8 kPa.

关键词： Thermal interface material Surface modification Thermal conductivity Thixotropy Interface thermal resistance

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 20%,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

Ectomycorrhizal fungi and dark septate endophyte inoculation improve growth and tolerance of Pinus tabulaeformis under cadmium stress

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Pedosphere 2024年第2期34卷 473-483页

作者： Yong ZHOU Yanyan zheng Pengwei li lingjie XU Qiang fu College of Landscape Architecture and Tourism Hebei Agricultural UniversityBaoding 071000China

Forest trees can establish symbiotic associations with dark septate endophytes(DSEs)and ectomycorrhizal fungi(ECMF)***,the combined effects of these two fungi on the growth and cadmium(Cd)tolerance of host plants remain largely *** address this knowledge gap,a pot experiment was conducted to examine the effects of the interaction between an ECMF strain(Suillus granulatus)and a DSE strain(Pseudopyrenochaeta sp.)on Pinus tabulaeformis under Cd stress,by assessing plant growth and physiological parameters,nutrient uptake,and soil ***,the colonization rates of both fungal strains were found to increase in response to Cd stress,with the extent of this increase being influenced by the specific fungal species and the Cd level in the *** to the non-inoculation treatment,single inoculation with fungal strain resulted in enhanced biomass,root development,and nutrient contents in *** seedlings under Cd ***,a synergistic effect was observed when these seedlings were co-inoculated with *** and Pseudopyrenochaeta sp.,as indicated by significantly greater measurements in various indicators compared to both the single and non-inoculation *** inoculation effectively regulated the antioxidant defense responses and photosynthesis of *** seedlings subjected to Cd stress,particularly in the co-inoculation *** addition,fungal inoculation facilitated the Cd accumulation in ***,suggesting a promising potential for the implementation of bioremediation strategies in the areas contaminated with heavy *** findings from this study indicate that the utilization of root symbiotic fungi obtained from stress environments could potentially enhance the growth performance and tolerance of *** towards heavy metals,and co-inoculation of both fungal groups may result in even more pronounced synergistic effects on the overall fitness of the plant.

关键词： antioxidant defense response colonization rate fungal inoculation heavy metal tolerance physiological parameter root symbiotic fungi soil property

3D printed grafts with gradient structures for organized vascular regeneration

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International Journal of Extreme Manufacturing 2024年第3期6卷 505-520页

作者： Yuewei Chen Zhongfei Zou Tao fu Zhuang li Zhaojie Zhang meng Zhu Qing Gao Shaofei Wu Guosheng fu Yong He Jiayin fu State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027People’s Republic of China School of Mechanical Engineering Guizhou UniversityGuiyang 550025People’s Republic of China Key Laboratory of Cardiovascular Intervention and Regenerative Medicine of Zhejiang Province Department of CardiologySir Run Run Shaw HospitalZhejiang UniversityHangzhou 310016People’s Republic of China School of Mechanical Engineering Guizhou Institute of TechnologyGuiyang 550003People’s Republic of China Department of Oral and Maxillofacial Surgery The Second Affiliated Hospital of Zhejiang University School of MedicineSchool of Stomatologyand Key Laboratory of Oral Biomedical Research of Zhejiang ProvinceHangzhouZhejiang 310006People’s Republic of China

Synthetic vascular grafts suitable for small-diameter arteries(<6 mm) are in great ***,there are still no commercially available small-diameter vascular grafts(SDVGs) in clinical practice due to thrombosis and stenosi... 详细信息

Synthetic vascular grafts suitable for small-diameter arteries(linical practice due to thrombosis and stenosis after in vivo *** designing SDVGs,many studies emphasized reendothelization but ignored the importance of reconstruction of the smooth muscle layer(SML).To facilitate rapid SML regeneration,a high-resolution 3D printing method was used to create a novel bilayer SDVG with structures and mechanical properties mimicking natural *** by the collagen alignment of SML,the inner layer of the grafts had larger pore sizes and high porosity to accelerate the infiltration of cells and their circumferential alignment,which could facilitate SML reconstruction for compliance restoration and spontaneous *** outer layer was designed to induce fibroblast recruitment by low porosity and minor pore size and provide SDVG with sufficient mechanical *** month after implantation,the arteries regenerated by 3D-printed grafts exhibited better pulsatility than electrospun grafts,with a compliance(8.9%) approaching that of natural arteries(11.36%) and significantly higher than that of electrospun ones(1.9%).The 3D-printed vascular demonstrated a three-layer structure more closely resembling natural arteries while electrospun grafts showed incomplete endothelium and immature *** study shows the importance of SML reconstruction during vascular graft regeneration and provides an effective strategy to reconstruct blood vessels through 3D-printed structures rapidly.

关键词： small-diameter vascular graft smooth muscle layer 3D printing endothelialization

Numerical and experimental study of the effects of wind turbine operation on sand-dust transport characteristics

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 97-113页

作者： Gaosheng Ma Hong Han Ye li Deshun li Yan Wang Ning fu Quan zheng Rennian li School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou 730050China Gansu Provincial Technology Center for Wind Turbines Lanzhou 730050China Key Laboratory of Fluid Machinery and Systems Lanzhou 730050China Multiple function Towing Tank Laboratory State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Given factors such as reduced land availability for onshore wind farms,wind resource enrichment levels,and costs,there is a growing trend of establishing wind farms in deserts,the Gobi,and other arid ***,the relationship between sanddust weather environments and wind turbine operations has garnered significant *** investigate the impact of wind turbine wakes on sand-dust transportation,this study employs large eddy simulation to model flow fields,coupled with an actuator line model for simulating rotating blades and a multiphase particle in cell model for simulating sand *** research focuses on a horizontal axis wind turbine model and examines the motion and spatiotemporal distribution characteristics of four typical sizes of sand particles in the turbine *** findings reveal that sand particles of varying sizes exhibit a spiral settling pattern after traversing the rotating plane of wind turbine blades,influenced by blade shedding vortex and *** particles tend to cluster in the peripheries of the vortex cores of low vorticity in the wind turbine *** rotation of wind turbines generates a wake vortex structure that causes a significant clustering of sand particles at the tip *** the wake distance increases,the particles that cluster at the turbine's tip gradually spread outward to approximately twice the rotor diameter and then begin to mix with the incoming flow *** turbines have a noticeable impact on sand-dust transportation,hindering their movement to a significant *** average sand-blocking rate exhibits a trend of initially increasing and then decreasing as the wake distance *** its peak,the sand-blocking rate reaches an impressive 67.55%.The presence of wind turbines induces the advanced settling of sand particles,resulting in a“triangular”distribution of the deposition within the ground projection area of the wake.

关键词： wind turbine particle transportation actuator line model dry deposition particle clustering

Constructing hierarchical ZSM-5 coated with small ZSM-5 crystals via oriented-attachment and in situ assembly for methanol-to-aromatics reaction

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Frontiers of Chemical Science and Engineering 2024年第7期18卷 41-53页

作者： Ning Yang Tingjun fu Chuntao Cao Xueqing Wu Huiling zheng Zhong li State Key Laboratory of Clean and Efficient Coal Utilization College of Chemical Engineering and TechnologyTaiyuan University of TechnologyTaiyuan 030024China

Developing hierarchical and nanoscale ZSM-5 catalysts for diffusion-limited reactions has received ever-increasing attention. Here, ZSM-5 architecture integrated with hierarchical pores and nanoscale crystals was successfully prepared via in situ self-assembly of nanoparticles-coated silicalite-1. First, the oriented attachment of amorphous nanoparticles on external surface of silicalite-1 was achieved by controlling the alkalinity of Si-Al coating solution. The partial exposure of the external surface of silicalite-1 ensured the uniform removal of silicon in the bulk phase for the creation of hierarchical pores during the subsequent desilication-recrystallization. The uniform removal of silicon species in the bulk phase was mainly due to the synergistic effect of surface protection and alkaline etching, which could be balanced by regulating the relative amount of tetrapropylammonium cation and OH– in desilication-recrystallization solution. Importantly, the removed silicon from silicalite-1 recrystallized and in situ assembled into final ZSM-5 nanocrystals induced by surface Si-Al nanoparticles. The hierarchical pores and nanoscale crystals on this integrated architecture not only promoted the removal of coke precursors from micropores but also provided large external specific surface (91 m^(2)·g^(-1)) for coke deposition. Consequently, a much longer catalytic lifetime was achieved for methanol-to-aromatics reaction compared to conventional hollow structure ZSM-5 (84 h vs 46 h), with relatively high stability.

关键词： hierarchical ZSM-5 nanocrystal integrated architecture diffusion coke