Boosting oxygen reduction catalysis with abundant copper single atom active sites

Li, Feng,Han, Gao-Feng,Noh, Hyuk-Jun,Kim, Seok-Jin,Lu, Yalin,Jeong, Hu Young,Fu, Zhengping,Baek, Jong-Beom The Royal Society of Chemistry 2018 Energy & environmental science Vol.11 No.8

<P>With their high catalytic activity, stability, selectivity, and 100% atom utilization, single atomic non-noble metal based materials are valuable alternatives to efficient but expensive Pt based catalysts. For efficient catalysis, single-atom catalysts must expose abundant single atomic metal active centers. Here, we report the rational design and synthesis of a Cu single-atom catalyst with high Cu content of over 20.9 wt%, made of single atomic Cu anchored into an ultrathin nitrogenated two-dimensional carbon matrix (Cu-N-C). The high Cu content was achieved by the introduction of additional N species, which can securely trap and protect the Cu atoms. During oxygen reduction, the single atomic Cu exhibited over 54 times higher mass activity than metallic Cu nanoparticles at a potential of 0.85 V <I>versus</I> a reversible hydrogen electrode (RHE). Furthermore, the Cu-N-C exhibited 3.2 times higher kinetic current at 0.85 V (<I>vs.</I> RHE), and a much lower Tafel slope (37 mV dec<SUP>−1</SUP>), as well as better methanol/carbon monoxide tolerance and long-term stability than commercial Pt/C. Density functional theory (DFT) calculations reveal that the Cu active sites exhibit improved O-O bond stretching and favorable adsorption energies of O2 and OOH for four-electron oxygen reduction.</P>

Acoustic emission characterization and cracking characteristics of reinforced concrete pipe

Jianfeng Li,Linbing Wang,Dongcan Chen,Yalin Liu,Zhifei Gao,Wentao Wang,Hailu Yang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.9

Acoustic emission (AE) and digital image correlation (DIC) technology were used in this study to monitor the behavior of reinforced concrete pipe (RCP) in the optimized three-edge bearing test (TEBT). At the same time, the AE source location of different pipe sections was simulated. The results show that the whole compressive loading process for RCP could be divided into 3 to 4 stages. Both the AE counts and AE energy could well characterize the cracking of concrete, and AE energy was more sensitive to the breaking of steel bar. The amplitude and duration of AE signal produced by the breaking of steel bar were larger than those produced by the cracking of concrete. The AE frequency for concrete cracking was relatively scattered. The AE frequency for steel bar breaking was small and concentrated, and this frequency distribution showed an exponential decreasing trend. The results of optimized AE source location showed that the generation and development of cracks occur in the initial loading stage. The results of multi-index analysis showed that the cracks in the top (loading position) and the bottom (bearing position) of the RCP show that the cracks extend from the inner wall to the outer wall, while the cracks on the left and right sides perpendicular to the loading direction show that the cracks extend from the outer wall to the inner wall.

Preventive Effect of Polysaccharide of Larimichthys crocea Swim Bladder on Reserpine Induced Gastric Ulcer in ICR Mice

Gui-Jie Li,Peng Sun,Rui Wang,Yalin Zhou,Yu Qian,Xin Zhao 대한약리학회 2014 The Korean Journal of Physiology & Pharmacology Vol.18 No.2

This project’s aim was to determine the reserpine-induced gastric ulcer preventive effect of polysaccharideof Larimichthys crocea swim bladder (PLCSB) in ICR mice. The anti-gastric ulcer effectsof polysaccharide of Larimichthys crocea swim bladder was evaluated in mice model using morphologicaltest, serum levels assay, cytokine levels assay, tissue contents analysis, reverse transcription-polymerase chain reaction (RT-PCR) analysis and western bolt assay. High concentration (50mg/kg dose) of PLCSB reduced IFN-γ as compared to low concentration (25 mg/kg dose) and controlmice. SS and VIP serum levels of PLCSB treated mice were higher than those of control mice, andMOT and SP serum levels were lower than control mice. Gastric ulcer inhibitory index of PLCSBtreatment groups mice were much lower than control mice, and the high concentration treated micewere similar to the ranitidine treated mice. The SOD and GSH-Px activities of PLCSB treated micewere higher than control mice, close to normal mice and ranitidine treated mice. PLCSB treated micealso showed the similar contents of NO and MDA to normal group. By RT-PCR and western blot assay,PLCSB significantly induced inflammation in tissues of mice by downregulating NF-κ B, iNOS, andCOX-2, and upregulating IκB-α . These results suggest that PLCSB showed a good gastric ulcerpreventive effect as the gastric ulcer drug of ranitidine. Polysaccharide of Larimichthys crocea swimbladder may be used as a drug material from marine products.

Coverage Holes Compensation Algorithms Based on Event-Driven Strategy in Wireless Sensor Networks

Zeyu Sun,Yali Yun,Yalin Nie,Yuanbo Li 보안공학연구지원센터 2016 International Journal of Future Generation Communi Vol.9 No.9

The process of random deployments, Coverage holes’ phenomena were appeared in wireless sensor network system. This paper presents a probabilistic model by means of event-driven policy coverage holes’ compensation method (Coverage Holes Compensation Algorithms Based on Event-Driven Strategy, CHCAEDS). Firstly, the characteristics of random deployment verified, given the random deployment of representation, followed by the use of probabilistic knowledge within the surveillance area coverage desired and the number of nodes is solved using the minimum number of nodes in order to achieve maximum coverage area; and finally, simulation experiment show, CHCAEDS algorithm with other algorithms in the network life cycle and the algorithm running time increased by 12.59% and10.82%.

Thermal history of the Jurassic marine sequences in the Qiangtang Basin, northern Tibetan Plateau: implication for the hydrocarbon preservation

Mingming Fei,Licheng Wang,Yalin Li,Yushuai Wei 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.4

The Jurassic marine sequences of the Qiangtang Basin in the northern part of the Tibet Plateau have the best petroleum exploration prospect. The prototype basin has undergone multi-stage and complicated tectonic events since the Cretaceous, especially the mid-Cretaceous tectonic event and the Cenozoic uplift of Tibetan Plateau. However, little information about the impact of these tectonic events on petroleum preservation has been done. In this paper, the burial and thermal histories modeling using vitrinite reflectance (Ro) are used to characterize the impact. The results showed that there is a regional falling of palaeotemperature in the Qiangtang Basin during the mid-Cretaceous indicating a regional tectonic event caused by the collision between Lhasa and Qiangtang blocks. However, the Cenozoic tectonic event caused by the uplift of Tibetan Plateau since 30 Ma was only recorded in the Southern Qiangtang Depression and not obvious in the Northern Qiangtang Depression, which indicates that uplift-denudation caused by the mid-Cretaceous tectonic event was extensive in whole Qiangtang Basin and more significant to the hydrocarbon accumulation than those in the Cenozoic. The event could damage the previously formed hydrocarbon traps and caused the leaking of cap-rocks for the dramatically denudation especially in the Southern Qiangtang Depression. We speculated that the Northern Qiangtang Depression has the lower thickness of denudation and barely influenced by the Cenozoic tectonic events and thus is primary exploration target for gas or gas hydrate.

미디어 소비와 문화 가치관: 중국 관객들의 한국 드라마 선호연구

장위제(Zhang yujie),이아림(Li yalin) 한국콘텐츠학회 2024 한국콘텐츠학회 종합학술대회 논문집 Vol.2024 No.5

A Linear Recoding and Power Allocation Scheme with Complex Parameters Based on Block Diagonalization Algorithm

Zeyu Sun,Chuanfeng Li,Yalin Nie,Yangjie Cao,Yuanbo Li 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.9

MIMO system performance mainly by correlation of spatial interference presence and space, In order to overcome these effects, it is necessary by pre-coding technology to achieve, Here we mainly use block diagonalization algorithm both linear pre-coding for analysis and further integration of the average power allocation algorithm and power allocation algorithm MATLAB simulation. Through research and data analysis, system performance block diagonalization algorithm is better than under zero forcing algorithms. When the same number of transmit antennas, the number of receive antennas are the same, the average power and power calculation algorithm with SNR increases, can effectively channel capacity to achieve the desired optimum value.

A Nonlinear Multiple-target Coverage Protocol Based on Data Integration of Wireless Sensor Networks

Zeyu Sun,Yongsheng Zhang,Chuanfeng Li,Yangjie Cao,Yalin Nie,Yuanbo Li 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.10

In the process of coverage for multiple targets, due to the existence of a large number of redundant data make the effective monitoring area coverage decreased and force the network to consume more energy. Therefore, this paper proposes a multi-target k-coverage preservation protocol. First of all, establish the affiliation between the sensor nodes and target nodes through the network model, present a method to compute the coverage expected value of the monitoring area; secondly, in the network energy conversion, using scheduling mechanism in sensor nodes to attain the network energy balance, and achieve different network coverage quality through different nodes energy conversion. Finally, simulation results show that NMCP can effectively reduce the number of active nodes meeting certain coverage requirements and then improve the network lifetime.

Microstructure and Hydrogen Absorption Properties of a BCC Phase Accompanied Laves Alloy

Yunlong Zhang,Tiebang Zhang,Jinshan Li,Ruolin Li,Yun Yu,Yalin Lu 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.3

A non-stoichiometry Zr0.7Ti0.4V1.5Cr0.4alloy has been synthesized by arc melting following annealing treatment or meltspinningto obtain the bulk and ribbon samples, respectively. XRD investigation reveals the multiphase structure consistingof C15-Laves, V-BCC and a small amount of α-Zr or Zr3V3O. The alloy shows easy activation and fast hydrogenationkinetics. The annealed alloy absorbs 2.51 wt% H at room temperature, higher than the melt-spun ribbons. Refined grains bymelt-spinning accelerates the hydrogenation of bulk alloy. The absorption behavior in presence of 1 mol% air has been testedto evaluate the anti-poisoning ability. Pressure–composition–temperature characteristics and thermodynamics parametersindicate the low equilibrium pressure and high hydrides stability. Hydrides investigation reveals that the Laves phase dominantmultiphase structure contributes to the enhanced hydrogen capacity and multi-stage hydrogen release in DSC curve.

NiCoSe4@CFF with excellent properties prepared by microwave method for flexible supercapacitors and oxygen evolution reaction

Lijun Du,Ning Lv,Jiashuai Li,Jiayi Zhang,Yilan Chen,Yalin Zhang,Zhen Li,Xianqiang Huang,Jujie Luo 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.120 No.-

NiCoSe4 nanoflowers were synthesized on carbon fiber felt (CFF) by microwave method, and the effects ofmicrowave time and microwave power on the morphology, physical phase and performance ofNiCoSe4@CFF were explored. The results display that the nanostructured NiCoSe4 prepared under themicrowave irradiation of 1000 W for 120 s is uniformly loaded on the CFF. The NiCoSe4@CFF electrodeexhibits a superior specific capacity of 1653.6F g1 at 1A/g and maintains a superior cycling performanceof 87.05 % of the initial capacitance over 150,000 cycles. In addition, the flexible supercapacitor fabricatedwith NiCoSe4@CFF as the cathode exhibits excellent flexibility and flexural strength. As an effective catalystfor oxygen evolution reaction (OER), NiCoSe4@CFF demonstrates a low overpotential of 0.358 V, arelatively small Tafel slope of 115.93 mV dec1 and an excellent lifetime at 10 mA cm2.