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Fe Promotion Effect in Mn/USY for Low-temperature Selective Catalytic Reduction of NO with NH_(3)

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Chinese Chemical Letters 2006年第7期17卷 991-994页

作者： Qi Chun lin Ji Ming hao Jun Hua LI Department of Environmental Science and Engineering Tsinghua University Beijing 100084

A series of catalysts of Mn/USY and Mn-Fe/USY prepared by impregnation were studied for low-temperature selective catalytic reduction （SCR） of NO with NH3 in the presence of excess of oxygen. It was found that the addition of Fe enhanced the catalytic performance at low-temperature. Mn-Fe/USY catalyst yielded nearly 100% NO conversion in a range of temperature from 423 to 573 K at a space velocity of 36 000 cm3g^-1·h^-1. Coexistence of manganese and iron oxides enhanced the dispersion of the supported oxides, no visible phase of the oxides can be observed on catalyst. The addition of Fe enhanced the number and strength of the Bronsted and Lewis acid sites on the surface of the catalyst, which might promote the absorption of NH3 to form active intermediate and enhance the catalytic performance at low-temperature.

关键词： Low-temperature SCR Mn/USY Mn-Fe/USY SCR of NO with NH3.

Performance comparison of single-carrier and multi-carrier waveforms over terahertz wireless channels

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Digital Communications and Networks 2024年第5期10卷 1297-1304页

作者： Dongxuan He Zhi Zhang hao lin Zuomin Wu Yingpei Huang Zhaocheng Wang Department of Electronic Engineering Tsinghua University OPPO Research Institute Tsinghua Shenzhen International Graduate School

Terahertz(THz) wireless communication has been recognized as a powerful technology to meet the everincreasing demand of ultra-high rate *** order to achieve efficient and reliable wireless communications over THz bands,it is extremely necessary to find an appropriate waveform for THz *** this paper,performance comparison of various single-carrier and multi-carrier waveforms over THz channels will be ***,first,a system model for terahertz communication is briefly described,which includes amplifier nonlinearity,propagation characteristic,phase noise,***,the transceiver architectures related to both single-carrier and multi-carrier waveforms are presented,as well as their corresponding signal processing *** evaluate the suitability of the waveforms,key performance metrics concerning power efficiency,transmission performance,and computational complexity are *** results are provided to compare and validate the performance of different waveforms,which demonstrate the outstanding performance of Discrete-Fourier-Transform spread Orthogonal Frequency Division Multiplexing(DFT-s-OFDM) to THz communications when compared to Cyclic Prefix-OFDM(CP-OFDM) and other single-carrier waveforms.

关键词： Terahertz communication RF imperfection Single-carrier waveform Multi-carrier waveform

Defect-induced Surface and Interface Reconstruction in Novel Two-dimensional Materials Revealed by Low Voltage Scanning Transmission Electron Microscopy

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Chinese Journal of Structural Chemistry 2020年第3期39卷 401-414,375页

作者： WANG Gang GUO Zeng-Long NIU Kang-Di lin Jun-hao Department of Physics Southern University of Science and TechnologyShenzhen 518055China

Two-dimensional(2 D) materials attracted substantial attention due to their extraordinary physical properties resulting from the unique atomic thickness. 2 D materials could be considered as material systems with flat surfaces at both sides, while the van der Waals gap is a natural out-of-plane interface between two monolayers. However, defects are inevitably presented and often cause significant surface and interface reconstruction, which modify the physical properties of the materials being investigated. In this review article, we reviewed the effort achieved in probing the defect structures and the reconstruction of surface and interface in novel 2 D materials through aberration corrected low voltage scanning transmission electron microscopy(LVSTEM). The LVSTEM technique enables us to unveil the intrinsic atomic structure of defects atom-by-atom, and even directly visualize the dynamical reconstruction process with single atom precision. The effort in understanding the defect structures and their contributions in the surface and interface reconstructions in 2 D materials shed light on the origin of their novel physical phenomenon, and also pave the way for defect engineering in future potential applications.

关键词： two-dimensional materials defects surface and interface reconstruction low voltage scanning transmission electron microscopy

A preliminary study on the theory and method of comprehensiveregionalization of cryospheric services

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Advances in Climate Change Research 2019年第2期10卷 115-123页

作者： lin hao-Xi HUANG Jin-Chuan FANG Chuang-lin QI Xiao-Xiao CHEN Yun-Qian Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Regional Sustainable Development Modeling Chinese Academy of Sciences Beijing 100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing 100049 China Beijing National Day School Beijing 100039 China

As one of the five most important spheres affecting climate systems globally, the cryosphere not only exerts crucial impacts on natural environment, but also plays a key role in guaranteeing the goods and services provision of the oasis in the cold and arid regions. However, there is a lack of synthesized knowledge about the contributions and profitability on socio-economic aspects of the cryospheric services (CSs). To cope with this key and urgent sustainable development issues, this study constructs a comprehensive regionalization research system that integrates the natural and socio-economic aspects for cryospheric characteristics with emphasis on interdisciplinary approaches. Guided by the supply- demand equilibrium model and the service maximization model, the research system consists of establishing a classification system for CSs, identifying the spatial distribution pattern of CSs, and constructing the comprehensive regionalization of CSs, which finally divides the research area into relatively independent, complete, and organically linked CS units of multiple spatial levels. By setting up a bridge between the CSs with socio-economic needs, it has profound and practical significance and implications for implementing the sustainable utilization strategies and macroeconomic policymaking for global environmental protection.

关键词： Principle Method Service Comprehensive regionalization Cryosphere

Effective field theory approach to lepton number violatingτdecays

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Chinese Physics C 2021年第7期45卷 31-42页

作者： Yi Liao Xiao-Dong Ma hao-lin Wang School of Physics Nankai UniversityTianjin 300071 Department of Physics National Taiwan UniversityTaipei 10617 Center for High Energy Physics Peking UniversityBeijing 100871

We continue our endeavor to investigate lepton number violating(LNV)processes at low energies in the framework of effective field theory(EFT).In this work we study the LNV tau decaysτ^(+)→lP_(i)^(+)P_(J)^(+),where L=e.μand P_(i,j)^(+)denote the lowest-lying charged pseudoscalarsπ^(+),K^(+).We analyze the dominant contributions in a series of EFTs from high to low energy scales,namely the standard model EFT(SMEFT),the low-energy EFT(LEFT),and the chiral perturbation theory(χPT).The decay branching ratios are expressed in terms of the Wilson coefficients of dimension-five and-seven operators in SMEFT and the hadronic low-energy *** Wilson coefficients involve the first and second generations of quarks and all generations of leptons;thus,they cannot be explored in low-energy processes such as nuclear neutrinoless double beta decay or LNV kaon ***,the current experimental upper bounds on the branching ratios are too weak to set useful constraints on these ***,if we assume the new physics scale is larger than 1 TeV,the branching ratios are well below the current experimental *** also estimate the hadronic uncertainties incurred in applyingχPT toτdecays by computing one-loop chiral logarithms and attempt to improve the convergence of chiral perturbation by employing dispersion relations in the short-distance part of the decay amplitudes.

关键词： lepton number violation tau lepton effective field theory chiral perturbation theory beyond standard model

A Novel Method to Fabricate Steel-Al Foam Sandwich Panel with Metallic Bonding

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Journal of Wuhan University of Technology(Materials Science) 2019年第6期34卷 1429-1432页

作者： LIANG Xiaolong LUO Hongjie lin hao LU Xiaotong WU linli School of Metallurgy Northeastern UniversityShenyang 110819China Engineering Technology Research Center of Ministry of Education for Materials Advanced Preparation Shenyang 110819China

Al foam sandwich panel(AFS) with metallic bonding was fabricated by foaming a hotpressed three-layer composite with two steel facesheets and a melt route precursor as core. The melt route precursor was fabricated by dispersing undecomposed blowing agent into molten Al, followed by solidification. Microstructures of the joints during fabrication process were analyzed by scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS). Static three-point bending was conducted to evaluate joint quality of the AFS. It was found that a primary bonding was achieved by hot-pressing and significant diffusion layer of Fe-Al intermetallic compounds was sustained between steel and Al foam core by foaming. Damage modes of the AFS under three-point bending were dominated by indentation, plastic hinges, core shear and crack. Delamination between steel and foam was absent, implying that reliable metallic bonding was achieved. This method allows for producing large-scale AFS with steel facesheets.

关键词： metallic composites melt route precursor hot-pressing diffusion delamination

Herscovici’s Conjecture on the Product of the Thorn Graphs of the Complete Graphs

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Journal of the Operations Research Society of China 2014年第2期2卷 263-269页

作者： Dong-lin hao Ze-Tu Gao Jian-Hua Yin Department of Mathematics College of Information Science and TechnologyHainan UniversityHaikou 570228China

Given a distribution of pebbles on the vertices of a connected graph G,a pebbling move on G consists of taking two pebbles off one vertex and placing one on an adjacent *** t-pebbling number f_(t)(G)of a simple connected graph G is the smallest positive integer such that for every distribution of fteGT pebbles on the vertices of G,we can move t pebbles to any target vertex by a sequence of pebbling *** conjectured that for any connected graphs G and H,f_(1)(G×H)≤f1(G)f1(H).Herscovici further conjectured that fst(G×H)≤6 fseGTfteHT for any positive integers s and *** et al.(Discret Math,309:3431–3435,2009)proved that Graham’s conjecture holds when G is a thorn graph of a complete graph and H is a graph having the 2-pebbling *** this paper,we further show that Herscovici’s conjecture is true when G is a thorn graph of a complete graph and H is a graph having the 2t-pebbling property.

关键词： Thorn graph t-Pebbling number Graham’s conjecture Herscovici’s conjecture

Thoracolumbar surgery for degenerative spine diseases complicated with tethered cord syndrome:A case report

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World Journal of Clinical Cases 2022年第28期10卷 10375-10383页

作者： Yue-Tian Wang Guan-Zhang Mu hao-lin Sun Department of Orthopedics Peking University First HospitalBeijing 100034China

BACKGROUND Tethered cord syndrome(TCS) secondary to split cord malformation(SCM) is rare in *** is as yet no consensus about the optimal treatment method for adult patients with SCMs and degenerative spine diseases such as lumbar stenosis,spondylolisthesis and ossification of the ligamentum flavum(OLF).The tethered cord poses a great challenge to the decompression and fusion procedures for the intraoperative stretching of the spinal cord,which might lead to deteriorated neural ***,we report on a case to add our treatment experience to the medical *** SUMMARY We treated a 67-year-old female patient with type II SCM suffering from lumbar disc herniation,degenerative lumbar spondylolisthesis and thoracic *** patient underwent thoracolumbar spinal fusion and decompression surgery for severe lower back pain,extensive left lower limb muscle weakness and intermittent *** the thoracolumbar surgery,without stretching the tethered cord,the patient achieved complete relief of pain and lower extremity weakness at final *** For adult patients with underlying TCS secondary to SCM coupled with thoracic OLF and lumbar spondylolisthesis,a thoracolumbar fusion surgery could be safe and effective with the tethered cord *** is critical to design individualized surgical protocols to reduce the stretch of the low-lying spinal cord.

关键词： Tethered cord syndrome Split cord malformations Ossification of ligamentum flavum Spondylolisthesis Thoracolumbar surgery Case report

Fieldwork Test Research of the Impact on Building Physical Environment on Six Types of Atrium Space in Cold Climates

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Journal of Harbin Institute of Technology(New Series) 2014年第4期21卷 84-90页

作者： Ye-hao Song Jun-Jie Li Ning Zhu Jia-Liang Wang Zheng-hao lin School of Architecture Tsinghua University Key Laboratory of Urban-Rural Eco Planning & Green Building Ministry of EducationTsinghua University

Since the research on verification to passive design strategies in sustainable building is at the initial stage,and its test method and verification conclusion are not scientific enough to validate,this paper proposes the necessity of building physical environmental monitoring to quantitative optimization of passive strategies efficiency from the perspective of architecture design and building environment. Adopting comparative research method,this research chooses six types of atrium space in cold climate in China as a prototype,focusing on building physical environmental performance difference in and between atrium and building main space. Spatial parameters of the atrium space will be divided into four factors: spatial geometry,interfacial properties,internal and external related categories. With subdividing these four factors into sub-factors,this paper makes crosscomparison among the sub-factors to clarify passive strategies effectiveness in atrium. Data comparison analysis shows that Winter atrium passive strategy in cold regions from traditional view is not obvious in practical application,and test data need to be stratified refined in atrium design in case of optimizing passive strategy from building prototype perspective.

关键词： atrium space building physical environment fieldwork test space effect