检索结果-南通市图书馆

Experimental Study on Geometry Characteristics of Turbulent Premixed Flames for Natural Gas/Air Mixtures

Journal of Thermal Science 2025年第1期34卷 268-282页

作者： ZHENG Weilin WANG Qijiao XIAO Huahua CHEN Xiaoxiao XIE Fan ZENG Wen Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace University State Key Laboratory of Fire Science University of science and Technology of China AVIC Shenyang aircraft Design and research institute

In this study,focusing on the geometry characteristics of spherical expanding flame,the turbulent premixed flames of natural gas/air mixtures were investigated in a fan-stirred turbulent *** effects of initial temperature（T=300-400 K）,initial pressure（P=0.1-0.3 MPa）,turbulence intensity（u'=1.0-2.7 m/s）,oxygen volumetric percentage(φ（O2）=15%-21%) and carbon dioxide volumetric percentage(φ（CO2）=0-20%)were delved *** flame profile under the Cartesian coordinate system was derived from the schlieren images taken by the high-speed ***,from both macroscopic and microscopic perspectives,the influence of experimental conditions on the flame geometry characteristics was explored through flame front extraction,wavelet decomposition and network *** results demonstrate that for significant flame wrinkling,changes in species concentrations and turbulence intensity have more pronounced effects on the flame wrinkling *** wrinkling of the flame front maintains a certain degree of similarity,as evidenced by the locally concentrated distribution of the angles of the maximum fluctuation *** disturbance energy under large-scale（D6-D8） disturbances exhibits relatively high values with a similar trend,exerting a significant impact on the geometry characteristics of the flame *** peaks of correlation degree are scattered either with the decomposition scale or the development of flame radius,indicating no linear correlation between different detail ***,the probability distribution of node degrees in key wrinkled regions exhibits different trends with that of large-scale wrinkling and disturbance energy,especially with changes in initial *** occurs because the number of key wrinkles varies based on the perturbation's strength or the region's ***,an increase in the fluctuation frequency of the flame's local radius may not necessarily lead to an increase in the number of key folded regions.

关键词： fan-stirred turbulent combustor geometry characteristics large-scale wrinkling network topology wavelet decomposition

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Experimental study of effect of post processing on fracture toughness and fatigue crack growth performance of selective laser melting Ti-6Al-4V

引用

Chinese Journal of Aeronautics 2019年第10期32卷 2383-2393页

作者： Haiying ZHANG Dengke DONG Shaopu SU An CHEN aircraft strength research institute

For Ti-6Al-4V,a titanium alloy increasingly used in aerospace structure,selective laser melting(SLM)is an attractive additive manufacturing technology,which is attributed to its complex construction capability with high accuracy and good surface *** order to obtain qualified mechanical properties,SLM parameters and post processing should be tailored for diverse service *** toughness and fatigue crack growth(FCG)behavior are critical characteristics for damage tolerance evaluation of such metallic structures,and they are affected by post processing technologies *** objective of this study is to obtain the fracture toughness and fatigue crack growth behavior of Ti-6Al-4V manufactured by SLM,and to evaluate the influence of post-SLM thermomechanical treatment and surface *** toughness and FCG tests were performed for SLM Ti-6Al-4V in three types of post processing status:as-built,heat treated and hot isostatically pressed(HIPed),*** with as-built and machined surface were *** microstructure and fractography were analyzed as well in order to investigate the relevance among manufacture process,microstructure and mechanical *** results demonstrate that as-built SLM Ti-6Al-4V presents poor ductility and FCG behavior due to martensitic microstructure and residual *** heat treatment and hot isostatic pressing improve the plane-stress fracture toughness and FCG performance considerably,while surface machining shows slight effect.

关键词： Fracture toughness Fatigue crack growth Heat treatment Selective laser melting Surface roughness

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Record-breaking bifunctional oxygen electrocatalyst accomplished by a data-driven approach for zinc-air batteries

引用

Journal of Energy Chemistry 2025年第1期100卷 144-145页

作者： Deviprasath Chinnadurai Zhi Wei Seh institute of Materials research and Engineering (IMRE) Agency for Science Technology and Research (A*STAR)

Rechargeable zinc-air batteries(ZABs) have recently drawn great attention in energy research due to their high theoretical capacity,low costs, and inherently safe nature [1–3]. However, the sluggish cathode reactions necessitate the development of bifunctional oxygen electrocatalysts with lower ΔE indicator values. The ΔE indicator is commonly employed to quantitatively evaluate the electrocatalytic activity of a bifunctional oxygen electrocatalyst,representing the overall overpotential from oxygen reduction reaction(ORR) to oxygen evolution reaction(OER).

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Design and Application of Turbine Cascade Partitioned Endwall Profiling

引用

Journal of Thermal Science 2025年第1期34卷 110-128页

作者： ZENG Fei JIANG Ruiqi XUE Xingxu DU Wei LUO Lei ZHOU Xun AECC Hunan Aviation Powerplant research institute School of Energy Science and Technology Harbin Institute of Technology Science and Technology on Diesel Engine Turbocharging Laboratory China North Engine Research Institute

The influence of partitioned profiling design based on a large-pitch highly loaded cascade is studied by numerical *** partitioned profile is mainly composed of a pressure-side convex structure near the leading edge and a suction-side convex structure at the midstream and downstream sides of the *** influence of the change in the vertex axial position and peak value of the B-line on the secondary flow control is *** this paper,air(ideal gas) is selected as the flow *** average static pressure at the outlet and the average total temperature at the inlet are kept *** γ-θ is used as the turbulence *** results show that the pressure-side convex structure suppresses the spanwise and pitchwise migration of the inlet flow by adjusting the static pressure distribution of the flow field,so the development of the pressure-side leg of the horseshoe vortex is effectively *** suction-side convex structure adjusts the static pressure distribution of the flow field and increases the included angle between the cross-flow and suction surface,so the accumulation of low-momentum fluid,the development of a corner vortex and the flow separation at the trailing edge of the suction-side surface are all suppressed near the endwall-suction ***,the energy loss coefficient of the large-pitch highly loaded cascade is decreased from 0.0564 to 0.0485,representing a 25% reduction in secondary flow losses.

关键词： Vortex flow

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Tackling the microlensing wave effects of strong lensing gravitational waves with TAAH

引用

Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 257-258页

作者： Zuhui Fan South-Western institute for Astronomy research Yunnan University

The rapid development of gravitational wave（GW） observations since their first detection in 2015 [1] has opened a completely new window for exploring the Universe. Consequently, astronomical research has entered the multimessenger era, allowing us to use different tracers to view the cosmos from various perspectives. Among others, the appealing application of gravitational wave events from compact binary mergers is that they can act as standard sirens to determine absolute cosmic distances entirely independent of standard candles. This approach is one of the most promising means to solve the current H0tension problem.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Comparative study of two lay-up sequence dispositions for flexible skin design of morphing leading edge

引用

Chinese Journal of Aeronautics 2021年第7期34卷 271-278页

作者： Yu YANG Zhigang WANG Shuaishuai LYU aircraft strength research institute Xi’an 710065China

Morphing leading edge has great potential for noise abatement and aerodynamic efficiency *** drooping effect is realized by bending of the flexible skin which encloses to form the leading *** the flexible skin is often made of composite laminates of Glass Fiber Reinforced Plastics(GFRP),the lay-up sequences have become the determinant,which affects not only the morphing quality but also the manufacturing *** optimizing methods of layup sequences are comparatively *** the first method,the laminal quantities in 0,±45and 90vary independently,while in the second one,the concept of isotropic laminate unit[0/45/45/90]s is employed and the unit quantity is the unique *** evaluation demonstrates that for both methods there is insignificant impact to the overall morphing quality;however,specific concern is equally necessary for these two methods to the tip of the leading edge where the skin is at its minimum thickness and bears the most severe bending *** terms of computational efficiency and post-processing labor,the second method has better performance.

关键词： Composite laminates Flexible skin Glass fiber reinforced plastics Lay-up sequence Leading edge Morphing wing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Reconstructing forest and grassland cover changes in China over the past millennium

引用

Science China Earth Sciences 2025年第1期68卷 94-110页

作者： Fanneng HE Fan YANG Yafei WANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Key research institute of Yellow River Civilization and Sustainable Development Henan University University of Chinese Academy of Sciences

Historical forest and grassland cover changes not only are critical indicators for quantifying ecological and environmental change processes but also serve as fundamental data for long-term climate change simulations and terrestrial ecosystem carbon emission assessments. However, because of limitations in historical data, quantitative estimations and spatially gridded reconstructions of these changes remain challenging, necessitating further methodological exploration. This study focused on China's present-day land area over the past millennium, objectively capturing the characteristics and drivers of forest and grassland cover changes. On this basis, using the forest transition theory and the space-for-time substitution method, we depicted the historical deforestation process as an inverted “S” curve and developed a model to reconstruct historical forest area changes based on the functional relationship between the forest area and population size dynamics. Subsequently, a gridded forest allocation model was established on the basis of deforestation tendencies. For the grassland cover, we implemented regionspecific methods, such as the cropland area deduction method and the habitat constraint method, to quantitatively reconstruct historical changes. Consequently, we obtained provincial forest and grassland area changes over the past millennium and mapped 10-km-resolution gridded data of forest and grassland cover. The results indicated the following.(1) The methods developed using population data as a proxy objectively reproduced the spatiotemporal evolution of forest and grassland cover in China over the past millennium. These feasible methods offer a novel pathway for the quantitative reconstruction of historical forest and grassland cover changes.(2) The data indicated that China's forest area generally decreased over the past millennium, characterized by a “decrease-then-increase” pattern. The forest area experienced three distinct phases: a slow decline(AD 1000

关键词： Land use and land cover change Forest Grassland Quantitative reconstruction Gridded reconstruction China historical period

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano-Enhanced Dairy Scum Biodiesel Blends:Unleashing the Power of Aluminium Oxide for Sustainable and Efficient Engine Performance

引用

Journal of Thermal Science 2025年第1期34卷 283-302页

作者： Veeranna MODI Prasad B.RAMPURE Sunil Kumar SHETTY Madeva NAGARAL Channa Keshava NAIK N Johar MGM Muhammad Irsyad ABDULLAH Abdullah I.AL-MANSOUR Shamshad ALAM KLE College of Engineering and Technology ChikodiVisvesvaraya Technological University Nitte (Deemed to be University) NMAM Institute of Technology (NMAMIT)Department of Mechanical Engineering aircraft research and Design Centre HAL Department of Mechanical Engineering BGS College of Engineering and TechnologyBengaluruAffiliated to Visvesvaraya Technological University Management and Science University Department of Civil Engineering College of EngineeringKing Saud University

This study investigates the effect of aluminium oxide nanoparticlesaddition to biodiesel blends made from dairy milk scum on performance and combustion characteristics of the diesel *** dispersion of Al2O3nanoparticles in B20 blends at different concentrations was done with the help of *** number of blends were prepared for the *** Machine learning algorithms(Random Forest（RF）and CatBoost) was used for the *** results show that in comparison to biodiesel blends without nanoparticles,the kinematic viscosity and density is higher for fuel blends with *** these Fuel blends have higher calorific *** blends exhibited reduced Brake Specific Fuel Consumption（BSFC） of2.85% than the blends without nano particles(Dairy Scum Methyl Ester Biodiesel 20%+Neat Diesel 80%（in volume）,DSMEB20),57.14% less CO,40.8% less hydrocarbon,and increased NOxemissions compared to conventional diesel,contributing to the development of environmentally friendly and renewable biofuel blends with *** B20NP30 is the optimal blend for performance and emission *** study concludes with findings on enhanced Brake Thermal Efficiency（BTE） of 26.29% in 3×10-5（in volume） Al2O3nanoparticle-blended DSME B20 and other DSME B20 fuel blends,emphasizing the importance of optimal nanoparticle *** correlation matrix shows how engine load,efficiency measures（BTE,BSFC）,and emissions（CO,CO2,NOx,Smoke） are connected in complex *** results help us understand the complicated dynamics of engine performance and emission characteristics ***'s diagram for BTE and BSFC shows that CatBoost-based BTE models perform superior to RF-based models during the training as well as testing *** results were obtained for CO and CO2emission results.

关键词： Al2O3 concentration CI engine Dairy Scum Methyl Ester Biodiesel

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Emerging trends in the selective production of value-added aromatics

引用

Science China Chemistry 2025年第1期68卷 15-20页

作者： Yuchao Wu Houliang Dai Weisheng Yang Yaxing Li Lichen Liu Petrochemical research institute Company Limited China National Petroleum Corporation Engineering research Center of Advanced Rare Earth Materials Department of Chemistry Tsinghua University

1 Introduction Aromatics (mainly benzene, toluene, and xylenes, BTX) are essential intermediates in the chemical industry. They are employed in the synthesis of a broad spectrum of chemicals and materials, e.g., various polymers, plastics, resins, solvents, dyes, pharmaceuticals [1]. The manufacturing pathway of BTX mainly includes petroleum reforming of naphtha, coal-to-aromatics, methanol-to-aromatics [2].

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Distribution and mapping of temperate savanna in the sandy lands of eastern China

引用

Science China Earth Sciences 2025年第1期68卷 128-141页

作者： Xiaoya LI Feng WANG Tao DUAN Kaijie YANG Bin YANG Chunmei WANG Xin TIAN Qi LU institute of Ecological Conservation and Restoration Institute of Desertification Studies Chinese Academy of Forestry institute of Desertification Institute of Desertification Studies Chinese Academy of Forestry institute of Great Green Wall Satellite Application Centre for Ecology and Environment MEE institute of Microelectronics Chinese Academy of Sciences Aerospace Information research institute Chinese Academy of Sciences institute of Forest Resource Information Techniques Chinese Academy of Forestry

Savannas are distributed globally across various *** perform a significant socioeconomic role in regulating net primary productivity and the terrestrial carbon *** to the high spatial heterogeneity induced by the mixed distribution of trees and grasses,current global land-cover classification maps often classify savannas as forests or grasslands Temperate savannas in China cover a vast area,yet their spatial patterns and extent remain poorly *** study developed a novel remote sensing temperate savannas mapping method by integrating very high-resolution （VHR） unmanned aerial vehicle （UAV） and GF-6 satellite imagery based on the vegetation structure characteristics of temperate savannas using the FAO definition of *** and validation datasets were collected from VHR UAV imagery covering the main temperate savannah types with a ground area of 1818 *** fractional woody vegetation cover （FWVC） and fractional herbaceous vegetation cover （FHVC） in temperate savannas were estimated by integrating Classification and Regression Tree and Random Forest *** current distribution of temperate savannas in the Horqin and Otindag Sandy Lands of Eastern China was mapped to a unit area of 0.5 *** root-mean-square error （RMSE） values for the FWVC and FHVC models were 10.69% and 11.67%,and the R2values were 0.66 and 0.63,*** assessment indicated that the new temperate savanna map had high identification accuracy,with a Kappa coefficient of 0.70,overall accuracy of 0.88,and average accuracy of *** savannas in the sandy lands of eastern China were primarily distributed in the northern Horqin Sandy Land the central and eastern regions of the Otindag Sandy Land,and the transition zone from the southern slopes of the Greater Khingan Mountains to the plains,covering a total area of 3.27×10～6 *** main savannah types were elm,oak/maple,and shrub *** savannas were widely distributed in the Otindag Sandy

关键词： Temperate savanna UAV imagery GF-6 Fractional woody vegetation cover Fractional herbaceous vegetation cover Machine learning

来源：

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：