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Influence of PEG 6000 on gallium oxide(Ga_2O_3) polymorphs and photocatalytic properties

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Science China Chemistry 2015年第3期58卷 532-538页

作者： Xiaohui Chai zhihong liu Yingping Huang Key Laboratory of Analytical Chemistry for Biology and Medicine Ministry of Education College of Chemistry and Molecular Sciences Wuhan University Engineering Research Center of Eco-Environment in Three Gorges Reservoir Region Ministry of Education China Three Gorges University Collaborative Innovation Center for Geo-Hazards and Eco-Environment in Three Gorges Area Hubei Province China Three Gorges University

Three different nanorod-like gallium oxides with mono/poly-crystalline nature(α, β, and α/β-Ga2O3) were prepared by regulating the amount of polyethylene glycol(PEG) 6000 in the range of 0.2–0.8 g proportionally via a hydrothermal method combined with further calcination. The bandgap of the products, given by UV-Vis diffuse reflectance spectra(UV-Vis DRS), was in the order of α-Ga2O3 > α/β-Ga2O3 > β-Ga2O3. To further investigate the photocatalysis performance of the catalysts, the decomposition of rhodamine B(Rh B) by Ga2O3 under UV light illumination(λ < 387 nm) was presented and complete degradation could be achieved within 30 min, a result that showed the highest efficiency. The photocatalytic oxidation mechanism is further discussed and prominently related to the active species: hydroxyl radical(·OH) and superoxide radical(O·-2), which were confirmed by electron paramagnetic resonance(EPR).

关键词： gallium oxides photocatalysis UV light hydroxyl radical superoxide radical

Step-Directed Deposition of Au Nanostructures By Electron Beam Evaporation

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Journal of Rare Earths 2004年第Z2期22卷 141-144页

作者： Xu Xiangdong liu zhihong Wang Yinchuan liu Zhongfan Institute of Microelectronics Tsinghua UniversityBeijing 100084China Institute of MicroelectronicsTsinghua UniversityBeijing 100084China Center for Nanoscale Science & TechnologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Center for Nanoscale Science & TechnologyCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

Au atoms were vaporized by electron beam evaporation, and their subsequent growths on Si (111 ) and highly ordered pyrolytic graphite (HOPG) substrates were studied using atomic force microscopy. Results show that Au nanoparticles tend to nucleate and grow regularly along the step edges of HOPG, however, nanoparticles are distributed homogeneously over the whole Si substrate. The possibility of controlled growth of Au in ultrahigh vacuum with peculiar surface structures was preseuted.

关键词： electron beam evaporation HOPG Au controlled growth ultrahigh vacuum

Improving multi-target cooperative tracking guidance for UAV swarms using multi-agent reinforcement learning

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Chinese Journal of Aeronautics 2022年第7期35卷 100-112页

作者： Wenhong ZHOU Jie LI zhihong liu Lincheng SHEN College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China

Multi-Target Tracking Guidance(MTTG)in unknown environments has great potential values in applications for Unmanned Aerial Vehicle(UAV)*** Multi-Agent Deep Reinforcement Learning(MADRL)is a promising technique for learning cooperation,most of the existing methods cannot scale well to decentralized UAV swarms due to their computational complexity or global information *** paper proposes a decentralized MADRL method using the maximum reciprocal reward to learn cooperative tracking policies for UAV *** method reshapes each UAV’s reward with a regularization term that is defined as the dot product of the reward vector of all neighbor UAVs and the corresponding dependency vector between the UAV and the *** the dependence between UAVs can be directly captured by the Pointwise Mutual Information(PMI)neural network without complicated aggregation ***,the experience sharing Reciprocal Reward Multi-Agent Actor-Critic(MAAC-R)algorithm is proposed to learn the cooperative sharing policy for all homogeneous *** demonstrate that the proposed algorithm can improve the UAVs’cooperation more effectively than the baseline algorithms,and can stimulate a rich form of cooperative tracking behaviors of UAV ***,the learned policy can better scale to other scenarios with more UAVs and targets.

关键词： Decentralized cooperation Maximum reciprocal reward Multi-agent actor-critic Pointwise mutual information Reinforcement learning

Activity coefficient of NiO in SiO_(2)-saturated MnO–SiO_(2)slag and Al_(2)O_(3)-saturated MnO–SiO_(2)–Al_(2)O_(3)slag at 1623 K

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International Journal of Minerals,Metallurgy and Materials 2022年第2期29卷 248-255页

作者： Guoxing Ren Songwen Xiao Caibin Liao zhihong liu School of Metallurgy and Environment Central South UniversityChangsha 410083China Changsha Research Institute of Mining&Metallurgy Co. LtdChangsha 410012China

As a part of the fundamental study related to the reduction smelting of spent lithium-ion batteries and ocean polymetallic nodules based on MnO–SiO_(2)slags,this work investigated the activity coefficient of NiO in SiO_(2)-saturated Mn O–Si O_(2)slag and Al_(2)O_(3)-saturated Mn O–SiO_(2)–Al_(2)O_(3)slag at 1623 K with controlled oxygen partial pressure levels of 10^(-7),10^(-6),and 10^(-5)*** showed that the solubility of nickel oxide in the slags increased with increasing oxygen partial *** nickel in the Mn O–Si O_(2)slag and Mn O–Si O_(2)–Al_(2)O_(3)slag existed as Ni O under experimental *** addition of Al_(2)O_(3)in the Mn O–Si O_(2)slag decreased the dissolution of nickel in the slag and increased the activity coefficient of Ni ***,the activity coefficient of Ni O(γN_(i O)),which is solid Ni O,in the Si O_(2)saturated Mn O–Si O_(2)slag and Al_(2)O_(3)saturated Mn O–Si O_(2)–Al_(2)O_(3)slag at 1623 K can be respectively calculated asγN_(i O)=8.58w(Ni O)+3.18 andγN_(i O)=11.06w(Ni O)+4.07,respectively,where w(Ni O)is the Ni O mass fraction in the slag.

关键词： nickel equilibrium MnO–SiO_(2)slag MnO–SiO_(2)–Al_(2)O_(3)slag activity coefficient spent lithium-ion batteries recovery polymetallic nodules

Recovery Behavior of the Propagating Buckle on Elastic Structures

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China Ocean Engineering 1993年第3期8卷 313-322页

作者： liu, zhihong Huang, Yuying liu, Qikai Hubei China

Based on the beam system model used by Chater, Hutchinson and Neale (1982), the recovery behavior of propagating buckle on elastic structures is first found out from the computational results. As the representative of some elastic structures, the Chater-Hutchinson-Neale model indicates that once the buckle meets arrestors, unlike the case in submarine pipelines, it will be reflected back to continue its propagation in a negative phase or a negative direction. The pressure which maintains the negative propagation, however, is as same as that required for the positive propagation. This fact has been examined in the experiment of the bulge propagation on a long elastic latex tube. The present discovery greatly supports the hypothesis that the buckle propagation corresponds to the coexisting phase of structures.

关键词： Finite element method Mathematical models Ocean engineering Offshore structures Pressure effects

Preparation of M_(2)B_(5)O_(9)Cl:Eu^(2+)(M=Sr,Ca)blue phosphors by a facile low-temperature self-reduction method and their enhanced luminescent properties

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Journal of Rare Earths 2023年第3期41卷 349-357,I0001页

作者： Pan Liang Lianqing Li Tong Shen Wenli Lian zhihong liu Key Laboratory for Macromolecular Science of Shaanxi Province School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi'an 710062China School of Chemistry&Chemical Engineering Shaanxi Xueqian Normal UniversityXi'an 710100China

In this work,through a facile method of low-temperature(only 350℃)self-reduction,1D nano-sized M_(2)B_(5)O_(9)CI:Eu^(2+)(M=Sr,Ca)blue phosphors with highly efficient performance can be *** crystal structure,morphology and photoluminescence(PL)properties including thermal stability of M_(2)B_(5)O_(9)CI:Eu^(2+)(M=Sr,Ca)phosphors were *** M_(2)B_(5)O_(9)CI:Eu^(2+)(M=Sr,Ca)phosphors show broad band excitation spectra and narrow band emission *** photoluminescence quantum yields(PLQY)of M_(2)B_(5)O_(9)CI:Eu^(2+)(M=Sr,Ca)are as high as 98%and 87.2%,***,the color purities of M_(2)B_(5)O_(9)CI:Eu^(2+)(M=Sr,Ca)can reach 99.1%and 93.2%,respectively,When heated up to 150℃,the emission intensities of M_(2)B_(5)O_(9)CI:Eu^(2+)(M=Sr,Ca)phosphors can still keep 72.7%and80.0%,***,the above-mentioned phosphors exhibit outstanding performance when manufacturing WLEDs.

关键词： Low-temperature self-reduction Borate phosphor Ultra-high quantum yield High color purity Rare earths

Run-Time Dynamic Resource Adjustment for Mitigating Skew in MapReduce

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Computer Modeling in Engineering & Sciences 2021年第2期126卷 771-790页

作者： zhihong liu Shuo Zhang Yaping liu Xiangke Wang Dong Yin College of Intelligence and Technology National University of Defense TechnologyChangsha410073China Cyberspace Institute of Advanced Technology Guangzhou UniversityGuangzhou510006China

MapReduce is a widely used programming model for large-scale data ***,it still suffers from the skew problem,which refers to the case in which load is imbalanced among *** problem can cause a small number of tasks to consume much more time than other tasks,thereby prolonging the total job completion *** solutions to this problem commonly predict the loads of tasks and then rebalance the load among ***,solutions of this kind often incur high performance overhead due to the load prediction and ***,existing solutions target the partitioning skew for reduce tasks,but cannot mitigate the computational skew for map ***,in this paper,we present DynamicAdjust,a run-time dynamic resource adjustment technique for mitigating *** than rebalancing the load among tasks,DynamicAdjust monitors the run-time execution of tasks and dynamically increases resources for those tasks that require more *** so doing,DynamicAdjust can not only eliminate the overhead incurred by load prediction and rebalancing,but also culls both the partitioning skew and the computational *** are conducted based on a 21-node real cluster using real-world *** results show that DynamicAdjust can mitigate the negative impact of the skew and shorten the job completion time by up to 40.85%.

关键词： MapReduce task scheduling resource allocation data skew big data

Preparing 3D Perovskite Li_(0.33)La_(0.557)TiO_(3)Nanotubes Framework Via Facile Coaxial Electro-Spinning Towards Reinforced Solid Polymer Electrolyte

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Energy & Environmental Materials 2023年第4期6卷 273-279页

作者： Yichun Zhao Lin Fan Biao Xiao Shaojun Cai Jingchao Chai Xueqing liu Jiyan liu zhihong liu Department of Polymer Material and Engineering Jianghan UniversityWuhan 430056China Key Laboratory of Optoelectronic Chemical Materials and Devices Ministry of EducationJianghan UniversityWuhan 430056China Flexible Display Materials and Technology Co-innovation Centre of Hubei Province Jianghan UniversityWuhan 430056China

It is of significance to construct continuous multiphase percolation channels with fast lithium-ion pathway in hybrid solid electrolytes.3D ceramic nanostructure frameworks have attracted great attention in this ***,the three-dimensional perovskite Li_(0.33)La_(0.557)TiO_(3)nanotubes framework(3D-LLTO-NT)is fabricated via a facile coaxial electro-spinning process followed by a calcination process at 800°*** hybrid polymer electrolyte of 3DLLTO-NT framework and poly(ethylene carbonate)(3D-LLTO-NT@PEC)shows improved ionic conductivity of 1.73×10^(-4)S cm^(-1)at ambient temperature,higher lithium-ion transference number(t_(Li)^(+))of 0.78 and electrochemical stability window up to 5.0 V vs Li/Li^(+).The all-solid-state cell of LiFePO_(4)/3D-LLTO-NT@PEC/Li delivers a high specific capacity of 140.2 mAh g^(-1)at 0.1 C at ambient *** outstanding performance is attributed to the 3D ceramic nanotubes frameworks which provide fast lithium ion transfer pathway and stable interfaces.

关键词： coaxial electro-spinning ion conductivity Li_(0.33)La_(0.557)TiO_(3) nanotubes solid composite electrolyte

Preparation and properties of bacteriophage-borne enzyme degrading bacterial exopolysaccharide

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High Technology Letters 2008年第2期14卷 210-215页

作者：牟海津 Wang Jingxue Jiang Xiaolu liu zhihong Colege of Food Sciences and Engineering Ocean University of China Qingdao 266003 P.R.China＇ Yellow Sea Fisheries Research Institute Qingdao 265071 P. R. China

Bacteriophages infected different serotypes of Klebsiella were isolated from sewage. Among them, a heatstable polysaccharide depolymerase enzyme which could degrade bacterial exopolysaccharide effectively was prepared from the phage infecting Klebsiella K13. Treatment at 60℃ for 30 min could inactivate most of the K13 phage, with the titration decreasing from 6.4×10^8 PFU/mL to 1.6×10^6 PFU/mL. However, no obvious loss of phage enzyme activity was found after this treatment. The optimum hydrolytic temperature of phage enzyme was 60℃, with an activity 57 % higher than that at 30℃. The addition of phage enzyme could result in a rapid decrease of viscosity of exopolysaccharide （EPS） solution within minutes, indicating that K13 phage polysaccharide depolymerase acts as a kind of endo-glycanohydrolase. HPLC and reducing sugar analysis showed that the hydrolysis of EPS approached approximately the maxi-mum at 4h when the final concentration of phage was 6.0 x los PFU/mL. The results showed that K/eb-siella K13 phage depolymerase enzyme could be used as a good tool for the preparation of EPS oligosac- charide.

关键词： bacterial exopolysaccharide Klebsiella bacteriophage polysaccharide depolymerase