检索结果-南通市图书馆

Strategies to achieve effective nitrogen activation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Carbon Energy 2024年第5期6卷 137-163页

作者： Bin Chang Huabin zhang Shuhui Sun Gaixia zhang KAUST Catalysis Center(KCC) King Abdullah University of Science and Technology(KAUST)ThuwalKingdom of Saudi Arabia Institut National de la Recherche Scientifique(INRS) CentreÉnergie Matériaux TélécommunicationsVarennesQuébecCanada Department of Electrical Engineering École de Technologie Supérieure(ÉTS)MontréalQuébecCanada

Ammonia serves as a crucial chemical raw material and hydrogen energy *** electrocatalytic nitrogen reduction reaction(NRR),powered by renewable energy,has attracted tremendous interest during the past few *** some achievements have been revealed in aqueous NRR,significant challenges have also been *** activity and selectivity are fundamentally limited by nitrogen activation and competitive hydrogen *** review focuses on the hurdles of nitrogen activation and delves into complementary strategies,including materials design and system optimization(reactor,electrolyte,and mediator).Then,it introduces advanced interdisciplinary technologies that have recently emerged for nitrogen activation using high-energy physics such as plasma and *** a better understanding of the corresponding reaction mechanisms in the coming years,these technologies have the potential to be extended in further *** review provides further insight into the reaction mechanisms of selectivity and stability of different reaction *** then recommend a rigorous and detailed protocol for investigating NRR performance and also highlight several potential research directions in this exciting field,coupling with advanced interdisciplinary applications,in situ/operando characterizations,and theoretical calculations.

关键词： activation via mediators catalyst optimization electrochemical nitrogen fixation high-energy activation of nitrogen nitrogen

Multicolor upconversion reversible modulations in YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) photochromic materials

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第2期42卷 270-277,I0002页

作者： Zhen zhang Peng Li Ziyi Xu Zhihao zhang Qiwei zhang Haiqin Sun Xihong Hao Inner Mongolia Key Laboratory of Ferroelectric-related New Energy Materials and Devices Schoolof Materials and MetallurgyInner Mongolia University of Science and TechnologyBaotou014010China College of Physics and Technology Guangxi Normal UniversityGuilin541004China

Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching ***,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism and multicolor upconversion properties from green,red to near infrared(NIR) emissions with increasing Yb *** multiband upconversion modulations are achieved by alternating light(365 and 405 nm) or thermal *** 365 nm irradiation,the luminescence color changes from yellow to red,the luminescent photoswitching contrast reaches up to 86.21%(green),82.12%(red) and 77.38%(NIR) in the Y_(0.83)Er_(0.01)Tm_(0.01)NbO_(4):0.15 Yb ***,the upconversion emission intensity before and after photochromic reaction shows remarkable change in a wide temperature range of 298-718 *** results indicate that the Er^(3+)/Tm^(3+)/Yb^(3+) tri-doped YNbO_(4) materials can be a good candidate in optical switching and data storage applications.

关键词： Photochromic materials Luminescence modulation Multicolor emission Photoswitching contrast Rare earths

Interface Engineering of Titanium Nitride Nanotube Composites for Excellent Microwave Absorption at Elevated Temperature

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第9期16卷 147-160页

作者： Cuiping Li Dan Li Shuai zhang Long Ma Lei zhang Jingwei zhang Chunhong Gong College of Chemistry and Molecular Sciences Henan UniversityKaifeng 475004People’s Republic of China National and Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004People’s Republic of China

Currently,the microwave absorbers usually suffer dreadful electromagnetic wave absorption(EMWA)performance damping at elevated temperature due to impedance mismatching induced by increased conduction ***,the development of high-performance EMWA materials with good impedance matching and strong loss ability in wide temperature spectrum has emerged as a top ***,due to the high melting point,good electrical conductivity,excellent environmental stability,EM coupling effect,and abundant interfaces of titanium nitride(TiN)nanotubes,they were designed based on the controlling kinetic diffusion procedure and Ostwald ripening *** from boosted heterogeneous interfaces between TiN nanotubes and polydimethylsiloxane(PDMS),enhanced polarization loss relaxations were created,which could not only improve the depletion efficiency of EMWA,but also contribute to the optimized impedance matching at elevated ***,the TiN nanotubes/PDMS composite showed excellent EMWA performances at varied temperature(298-573 K),while achieved an effective absorption bandwidth(EAB)value of 3.23 GHz and a minimum reflection loss(RLmin)value of−44.15 dB at 423 *** study not only clarifies the relationship between dielectric loss capacity(conduction loss and polarization loss)and temperature,but also breaks new ground for EM absorbers in wide temperature spectrum based on interface engineering.

关键词： TiN nanotubes Interface engineering Polarization loss Impedance matching Electromagnetic wave absorption performance

A Detailed Thermal Resistance Network Analysis of FCBGA Package

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第1期33卷 18-28页

作者： DANG Hao LU Yang DU Yanzheng zhang Xiu zhang Qian MA Weigang zhang Xing Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Engineering MechanicsTsinghua UniversityBeijing 100084China Zhongxing Telecom Equipment Corporation Shanghai 201203China

Using thermal models to describe the heat dissipation process of FCBGA is a significant topic in the field of ***,the thermal resistance model considering the structure of each part of the chip is still ambiguous and rare,but it is quite desirable in *** this work,we propose a detailed thermal resistance network model,and describe it by using thermal conduction resistance and thermal spreading *** a striking FCBGA case,we calculated the thermal resistance of each part of the structure according to the temperature field simulated by *** thermal resistance network can be used to predict the temperatures in the chip under different *** example,when the power changes by 40%,the relative error of junction temperature prediction is only 0.24%.The function of the detailed thermal resistance network in evaluating the optimization space and determining the optimization direction is *** work illustrates a potential thermal resistance analysis method for electronic devices such as FCBGA.

关键词： FCBGA package thermal resistance network thermal spreading resistance junction temperature

Effect of Shape and Placement of Twisted Pin Fins in a Rectangular Channel on Thermo-Hydraulic Performance

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2024年第5期33卷 1773-1793页

作者： LI Yong zhang Jin zhang Yingchun zhang Jiajie MA Suxia SUNDEN Bengt XIE Gongnan College of Electrical and Power Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Cleaner Intelligent Control on Coal&Electricity Ministry of EducationTaiyuan 030024China Shanxi Provincial Key Laboratory of High Efficiency Heat Storage and Low Carbon Heat Supply Taiyuan 030008China School of Energy and Power Engineering North University of ChinaTaiyuan 030051China Department of Energy Sciences Lund UniversityP.O.Box 118Lund SE 22100Sweden School of Marine Science and Technology Northwestern Polytechnical UniversityXi'an 710072China

To enhance the thermo-hydraulic performance of cooling channels,this investigation examines the influence of distinct cross-sectional shapes(i.e.,triangular,rectangular,and hexagonal)of twisted pin fins and their arrangements in straight and cross *** ambient air cooling test platform was established to numerically and experimentally investigate the flow and heat transfer characteristics of 360°twisted pin fins at Re=*** findings reveal that straight rows exhibit higher Nu values than cross rows for triangular and rectangular twisted pin fins,and Nu increases with *** contrast,for hexagonal twisted pin fins,only straight rows at Re=19000 exhibit superior overall thermal performance compared to cross ***,the heat transfer performance of the cooling channel with hexagonal twisted fins surpasses both triangular and rectangular configurations,especially at high Reynolds numbers(Re=22800).Although the heat transfer coefficient of the cooling channel with hexagonal twisted fins is significantly enhanced by 132.71%compared to the flat channel,it also exhibits the highest thermal resistance and relative friction among the three types of twisted fins,the maximum of which are 2.14 and ***,the hydrothermal performance factor(HTPF)of the cooling channels with different types of twisted pin fins depends on the Reynolds number and arrangement *** Re=15200,the highest HTPF achieved for the cross-row hexagonal twisted pin fins is 0.99.

关键词： twisted pin fin cross arrangement heat transfer pressure drop HTPF

Thermal stable Pt clusters anchored by K/TiO_(2)—Al_(2)O_(3)for efficient cycloalkane dehydrogenation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第8期72卷 187-198页

作者： Zhendong Wang Bofeng zhang Guozhu Liu Xiangwen zhang Key Laboratory for Green Chemical Technology of the Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Zhejiang Institute of Tianjin University Ningbo 315201China

Catalytic dehydrogenation of cycloalkanes is considered a valuable endothermic process for alleviating the thermal barrier issue of hypersonic ***,conventional Pt-based catalysts often face the severe problem of metal sintering under high-temperature ***,we develop an efficient K_(2)CO_(3)-modified Pt/TiO_(2)—Al_(2)O_(3)(K—Pt/TA)for cycloalkane *** optimized K—Pt/TA showed a high specific activity above 27.9 mol·mol^(-1)·s^(-1)(H_(2)/Pt),with toluene selectivity above 90.0%at 600℃with a high weight hourly space velocity of 266.4 h^(-1).The introduction of alkali metal ions could generate titanate layers after high-temperature hydrogen reduction treatment,which promotes the generation of oxygen vacancy defects to anchored Pt *** addition,the titanate layers could weaken the surface acidity of catalysts and inhibit side reactions,including pyrolysis,polymerization,and isomerization ***,this work provides a modification method to develop efficient and stable dehydrogenation catalysts under high-temperature conditions.

关键词： Cycloalkane dehydrogenation Pt clusters Oxygen vacancy defects Coking Stability Deactivation

Investigation on crystallization behavior between(Sc_(x)Yb_(1−x))O_(1.5)and CMAS:A new insight in the effect of Sc substitution

在线全文

学校读者我要写书评

暂无评论

Journal of Advanced Ceramics 2024年第6期13卷 789-799页

作者： Guangheng zhang Jinyu Shi Jie zhang Jingyang Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Environmental barrier coatings(EBCs)with thermomechanical robustness against calcium–magnesium–aluminum–silicate(CMAS)deposits are in high *** aim of this work was to clarify the influence of Sc^(3+)on the crystallization behavior of Yb-based coatings against CMAS *** reaction products of solid solutions with compositions traversing the Sc_(2)O_(3)–Yb_(2)O_(3)system indicate that Sc^(3+)tends to form[BO_(6)]coordination polyhedra in the crystal structure to promote the formation of garnet and diopside,while Yb^(3+)occupies 7-,8-,and 9-coordinate sites to crystallize apatite and *** transformation of crystalline products from apatite/silicocarnotite to garnet/diopside greatly improves the efficiency of CMAS melt consumption and facilitates the prevention of its further penetration and *** on the commonality of cation occupancy in crystallography,an A(CaO+YbO_(1.5))–B(ScO_(1.5)+MgO+AlO_(1.5))–T(SiO_(2))pseudoternary phase diagram is established,which has great potential for describing phase equilibrium in coating-deposit systems and can provide guidance for the compositional design of corrosion-resistant coatings.

关键词： crystallization behavior cation partitioning scandium-ytterbium oxide(Sc_(x)Yb_(1−x))O_(1.5)solid solution calcium-magnesium-aluminum-silicate(CMAS)deposit pseudoternary phase diagram

Protective benefit of folded linear HDPE board sand fences along the Golmud-Korla Railway,China:Field observation and wind tunnel study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2024年第7期21卷 2206-2219页

作者： zhang Kai TIAN Jianjin WANG Zhenghui zhang Hailong zhang Xingxin College of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730000China Key Laboratory of Desert and Desertification Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Civil Engineering Chongqing UniversityChongqing 400045China

The Milan Gobi area of the Golmud-Korla Railway in northwest China is located in the lower dispersal area of the mountain pass and has strong winds with evident double wind direction *** study introduced a novel sand fence deployment technique,termed‘folded linear deployment',designed to position the sand fence orthogonally to the two predominant wind directions for optimal *** study used wind tunnel and field tests to evaluate the wind and sand flow characteristics,as well as the windproof and sandresistant performance of folded linear HDPE(Highdensity polyethylene)board sand *** results suggest that the airflow around the fence creates clear zoning *** deceleration area on the BSF(backwind side of the sand fence)is much larger than that on the DSF(downwind side of the sand fence).Thus,sand particles are primarily deposited on the *** different wind speeds,the airflow at 2 and 5 h on the DSF is not *** WSP(wind speed profile)presents a logarithmic *** airflow is disturbed at 1-20 h on the BSF,and the WSP gradually deviates from the logarithmic ***,as the airflow moves away from the fence,the WSP gradually approaches a logarithmic ***,the WPE(windproof efficiency)and SRE(sand-resistant efficiency)of the sand fence exceed 80%.In addition,the results of wind tunnel tests are compared with those of field *** overall dispersion is good,and the best dispersion is found at z/H=2.00,indicating good agreement between the two test *** study provides a scientific basis for the design of sand hazard control measures,similar to the railway project in the Gobi Gale area.

关键词： Folded linear HDPE board sand fence Double wind direction Gobi area Protection benefit

Neighbor Sum Distinguishing Total Choosability of Planar Graphs with Maximum Degree at Least 10

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第1期40卷 211-224页

作者： Dong-han zhang You Lu Sheng-gui zhang Li zhang School of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an710129China School of Mathematics and Computer Application Shangluo UniversityShangluo726000China

A neighbor sum distinguishing(NSD)total coloringφof G is a proper total coloring of G such thatΣz∈EG(u)U{u}φ(z)≠Σz∈EG(v)U{v}φ(z)for each edge uv∈E(G),where EG(u)is the set of edges incident with a vertex *** 2015,Pilśniak and Wozniak conjectured that every graph with maximum degreeΔhas an NSD total(Δ+3)-***,Yang et *** that the conjecture holds for planar graphs withΔ≥10,and Qu et *** that the list version of the conjecture also holds for planar graphs withΔ≥*** this paper,we improve their results and prove that the list version of the conjecture holds for planar graphs withΔ≥10.

关键词： planar graphs neighbor sum distinguishing total choosibility combinatorial nullstellensatz discharging method