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Will polycentric cities cause more CO2 emissions? A case study of 232 Chinese cities

Journal of Environmental Sciences 2020年第10期32卷 33-43页

作者： Wei sha Ying Chen Jiansheng Wu Zhenyu Wang Key Laboratory for Urban Habitat Environmental Science and Technology School of Urban Planning and DesignPeking UniversityShenzhen 518055China Laboratory for Earth Surface Processes Ministry of EducationCollege of Urban and Environmental SciencesPeking UniversityBeijing 100871China

From 2000 to 2010 China experienced rapid economic development and *** cities in economically developed areas have developed from a single-center status to *** this study,we used exploratory spatial data analysis (ESDA) to identify the population centers,which identified 232 cities in China as having urban *** was used to represent urban agglomeration,and POLYD (representing how far is the city’s sub-centers to the main center),POLYC (representing the number of a city’s centers),and POLYP (representing the population distributed between the main center and the sub-centers) were used to indicate urban *** light data were used to determine the CO2 emissions from various cities in China.A mixed model was used to study the impact of urban aggregation and polycentric data on the CO2 emission efficiency in 2000 and *** study found that cities with higher compactness were distributed in coastal areas,and the cities with higher multicentricity were distributed in the Yangtze River Delta and shandong *** more compact the city was,the less conducive it was to improving CO2 emission *** development of the city was conducive to improving the CO2 emission efficiency,but the number of urban centers had no significant relationship with the CO2 emission *** research showed that the compactness and multicentricity of the city had an impact on the CO2 emission efficiency and provided some planning suggestions for the low carbon development of the city.

关键词： CO_2 emission efficiency polycentricity compactness Chinese cities

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Design,synthesis and applications of functional zirconium-based metal-organic frameworks

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Science China Chemistry 2023年第12期66卷 3383-3397页

作者： Le Shi Zhenning Yang Fanrui sha Zhijie Chen Stoddart Institute of Molecular Science Department of ChemistryZhejiang UniversityHangzhou 310058China Zhejiang-Israel Joint Laboratory of Self-Assembling Functional Materials ZJU-Hangzhou Global Scientific and Technological Innovation CenterZhejiang UniversityHangzhou 311215China Department of Chemistry and International Institute for Nanotechnology Northwestern UniversityEvanstonIllinois 60208United States

Zirconium-based metal-organic frameworks(Zr-MOFs)have been explored for applications including but not limited to water adsorption,gas storage and separation,heterogeneous catalysis,and chemical ***-MOFs serve as a major class of functional MOFs thanks to their high thermal,chemical and hydrolytic stability,large surface area,and tunable structures with the versatile *** this work,we highlight the design and synthesis of zirconium-based MOFs as well as their ***,we demonstrate how reticular chemistry can direct the rational design and synthesis of functional ZrMOFs and describe their structure–property *** addition,we feature synthetic strategies,including isoreticular expansion,linker functionalization,node functionalization,and defect engineering,as toolkits to construct tailored material for specific applications.

关键词： metal-organic frameworks Zr-MOFs reticular chemistry structure–property relationship

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A Study on Quasi-orthogonal M-ary Chirp Modulation

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Chinese Journal of Electronics 2019年第5期28卷 1053-1058页

作者： YANG Liu ZHANG Fangqi ZHENG Guoxin sha Jiajun Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication Shanghai Institute for Advanced Communication and Data ScienceShanghai University School of Electronic and Information Shanghai Dianji University Maglev Transportation Engineering R&D Center The Key Laboratory of Road and Traffic Engineering Ministry of Education Tongji University

This paper proposes and studies a novel M-ary chirp modulation scheme adopting quasi-orthogonal waveforms. The Symbol error probability(SEP) of M-ary modulation over Additive white Gaussian noise(AWGN)channel is derived based on coherent detection, which is a function of modulation factor and waveform ***, the SEP is investigated over a channel limited by a nominal bandwidth. Both theoretical analysis and simulations prove that the SEP performance of the proposed 8-ary chirp modulation outperforms that of conventional 8 Phase shift keying(8PSK) with the same bandwidth efficiency.

关键词： Chirp modulation Correlation coefficient Quasi-orthogonal waveform

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Energy-efficient node deployment strategy for wireless sensor networks

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The Journal of China Universities of Posts and Telecommunications 2013年第1期20卷 54-57页

作者： sha Chao WANG Ru-chuan College of Computer Science and Technology Nanjing University of Posts and Telecommunications Jiangsu Provincial Key Laboratory of Wireless Sensor Networks Institute of Computer Technology Nanjing University of Posts and Telecommunications

To balancing energy consumption in wireless sensor networks, we proposed a fixed time interval node broadcasting scheme under variational acceleration straight-line movement model. Simulation results show that the approach proposed in this paper has a superior performance on energy consumption balance compared to uniform broadcasting methods.

关键词： wireless sensor networks energy balance variational acceleration movement

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Microstructure and wear behavior of Mo–60Si–5B coating doped with 0.5 at% La by spark plasma sintering

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Progress in Natural Science:Materials International 2022年第6期32卷 752-757页

作者： Zilong Wu Kanglu Feng Jiangbo sha Chungen Zhou School of Materials Science and Engineering Beihang University

Mo-60Si-5B coating doped with 0.5 at% La was prepared on niobium silicon based alloy by spark plasma *** microstructure and wear behavior of the 0.5La-Mo-60Si-5B（0.5La-MSB） coating were *** results show that the mean grain sizes of the Mo-60Si-5B（0La-MSB） and 0.5La-MSB coatings are calculated to be 3.27 μm and 2.85 μm,*** addition of La plays a role of refining the grains of 0.5La-MSB *** specific wear rate of 0.5La-MSB coating is decreased by up to 26.8% at the oscillation frequency of 20 Hz and the sliding load of 11 N compared to 0La-MSB *** anti-friction performance of Mo-60Si-5B coating is modified by the addition of 0.5 at.% *** improvement of anti-friction performance of the Mo-60Si-5B coating is due to the increased hardness and the provided lubrication function by La2O3.

关键词： Metal coatings La 2 O 3 Nanoindentation Wear behavior

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Synthesis of A Novel Fulleroaziridine Carrying 4-Deoxy-4'-demethylepipodophyllotoxin

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Chinese Chemical Letters 2003年第11期14卷 1123-1126页

作者： Qian Rong LI sha YANG Structure Research Laboratory University of Science and Technology of ChinaHefei 230026

A novel fulleroaziridine 2 with a closed 6,6-ring junction was synthesized from [60]fullerene and 4-azido-4-deoxy- 4?demethylepipodophyllotoxin 1 in 1, 2-dichlorobenzene at 110℃ for 45 h, in a yield of 39.3 % based o... 详细信息

关键词： Podophyllotoxin derivative azide fullerene fulleroaziridine cycloaddition.

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Cellular automata simulation of grain growth of powder metallurgy Ni-based superalloy

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Journal of Iron and Steel Research International 2023年第4期30卷 838-848页

作者： Yi-ling Jiang sha-sha Liu Rong-gui Lu Xu Cheng Jia Li Yang Chen Gao-feng Tian School of Materials Science and Engineering Beihang UniversityBeijing 100191China National Engineering Laboratory of Additive Manufacturing for Large Metallic Components Beijing 100191China Beijing Institute of Aeronautical Materials Beijing 100095China

Primary γ'phase instead of carbides and borides plays an important role in suppressing grain growth during solution at 1433 K of Ni-based FGH98 *** illustrate that as-fabricated FGH98 superalloy has equiaxed grain structure,and after heat treatment,grains remain equiaxed but grow *** order to clarify the effects of the size and volume fraction of the primaryγ'phase on the grain growth during heat treatment,a 2D cellular automata(CA)model was established based on the thermal activation and the lowest energy *** CA results are compared with the experimental results and show a good fit with an error less than 10%.Grain growth kinetics are depicted,and simulations in real time for various sizes and volume fractions of primaryγ'particles work out well with the Zener *** coefficient n value which reflects the pinning ability in Zener relation is theoretically calculated,and its minimum value is 0.23 when the radius of primaryγ'phase is 2.8μm.

关键词： Grain growth Cellular automata Ni-based FGH98 superalloy Primary γ'phase Microstructure

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Improvement of isothermal oxidation resistance of aγ'-strengthened Co-Al-W-Mo-Ta-B alloy at 800℃via doping Ce

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Rare Metals 2021年第8期40卷 2065-2075页

作者： Fei Zhong Zhuo-Lin Tao Jiang-Bo sha School of Materials Science and Engineering Beihang UniversityBeijing100191China College of Chemistry and Materials Science Hubei Engineering UniversityXiaogan432000China

Isothermal oxidation resistance,oxide scale evolution and failure mechanism of Ce-doped Co-Al-W-MoTa-B alloy(0.01 at%,0.05 at%,0.10 at%and 0.20 at%Ce)exposed at 800℃were *** 0.01 Ce and 0.05 Ce alloys were consisted ofγ/γ’coherent micro structure,while theκ-Co_(3)W compound precipitated at the grain boundary of the 0.1 OCe and 0.20 Ce alloys in addition to theγ/γ’*** oxidation kinetics curves of the Cedoped alloys exhibited a parabolic time dependence on the weight *** an increasing nominal Ce content,the weight gain of the Co-Al-W-Mo-Ta-B alloys monotonically *** oxide scale composed of a dense and uniform outer Co_(3)O_(4)+CoO layer,a middle CoAl2 O4 and CoWO4 compound layer and an inner Al_(2)O_(3)*** excellent oxidation resistance of 0.2 Ce alloy was mainly attributed to a shorter incubation stage for the formation of the continuous and protective Al_(2)O_(3)layer and the thickest Al_(2)O_(3)layer during entire oxidation process.

关键词： Co-Al alloy Intermetallics Ce doping Oxidation

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Guaranteeing Wireless Communication Secrecy via a WFRFT-Based Cooperative System

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China Communications 2015年第9期12卷 76-82页

作者： Fang Xiaojie sha Xuejun Mei Lin Communication Research Center Harbin Institute of Technology

In this paper, a weighted fractional Fourier transform(WFRFT) based cooperative overlay system, aiming to guarantee physical layer(PHY) security, is proposed. The paper elaborates how WFRFT and physical layer properties of the wireless medium are collaborated to guarantee the secrecy of wireless transmissions. In the proposed system, WFRFT is first preform on the secret data, such that the transmitted signal is distorted and can only be neutralized by inverse-WFRFT with the same parameter. And then two streams of the transformed sequences that bearing different messages are cooperatively and simultaneously transmitted to two legitimate receivers via a beamforming-liked method, respectively. In general, both the rapid spatial decorrelation property and the inherent security features of WFRFT are leveraged, such that only the eavesdropper's is degraded, and hence, the wireless communication secrecy is reliably guaranteed. Numerical simulations are conducted to evaluate the performance of the proposed system in terms of the average bit error rate and the secrecy capacity.

关键词： weighted fractional Fourier trans-form(WFRFT) physical layer(PHY) security secrecy capacity

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3D tumor model biofabrication

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Bio-Design and Manufacturing 2021年第3期4卷 526-540页

作者： Ming Li Xueer Song sha Jin Kaiming Ye Department of Biomedical Engineering Center of Biomanufacturing for Regenerative MedicineBinghamton UniversityState University of New York(SUNY)PO Box 6000BinghamtonNY 13902USA

Animal models have been extensively used in cancer pathology studies and drug *** models,however,fail to reflect the complex human tumor microenvironment and do not allow for high-throughput drug screening in more human-like physiological ***-dimensional(3D)cancer models present an alternative to automated high-throughput cancer drug discovery and *** this review,we highlight recent technology innovations in building 3D tumor models that simulate the complex human tumor microenvironment and responses of patients to *** discussed various biofabrication technologies,including 3D bioprinting techniques developed for characterizing tumor progression,metastasis,and response to treatment.

关键词： Tumor models Biofabrication Tumor spheroids Microfluidic devices 3D bioprinting

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