Synthesis and luminescent properties of Er³⁺-activated LaBMoO₆ green-emitting phosphors for optical thermometry

Hua, Yongbin,Du, Peng,Su Yu, Jae Elsevier 2018 Materials research bulletin Vol.107 No.-

<P><B>Abstract</B></P> <P>The Er<SUP>3+</SUP>-activated LaBMoO<SUB>6</SUB> phosphors were synthesized by a sol-gel method. The photoluminescence (PL) emission intensity was revealed to be dependent on the Er<SUP>3+</SUP> ion concentration and its maximum value was achieved when the doping concentration was 1 mol%. From theoretical analysis, one knows that the concentration quenching mechanism is dominated by the electric dipole-dipole interaction with a critical distance of 28.47 Å. On the basis of the temperature-dependent PL green emission spectra from the <SUP>2</SUP>H<SUB>11/2</SUB> and <SUP>4</SUP>S<SUB>3/2</SUB> thermally coupled levels by means of the fluorescence intensity ratio technique, the temperature sensing properties of the resultant compounds were studied. When the temperature was 483 K, the sensor sensitivity of the studied samples reached up to 0.017 K<SUP>−1</SUP>. It was found that the sensor sensitivity of the prepared phosphors was hardly varied by the doping concentration. These obtained characteristics suggest that the Er<SUP>3+</SUP>-activated LaBMoO<SUB>6</SUB> phosphors have potential applications in optical thermometry.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Under 380 nm excitation, all the samples emitted visible green emissions from the Er<SUP>3+</SUP> ions. </LI> <LI> The optimal doping concentration was 1 mol% and the critical distance was 28.47 Å. </LI> <LI> The maximum sensor sensitivity of the studied phosphors was found to be as high as 0.0179 K<SUP>−1</SUP> at 483 K. </LI> <LI> The sensor sensitivity of the obtained samples was independent of Er<SUP>3+</SUP> ion concentration. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Er<SUP>3+</SUP>-activated LaBMoO<SUB>6</SUB> green-emitting phosphors with high sensor sensitivity for optical thermometry.</P> <P>[DISPLAY OMISSION]</P>

Eu³⁺-activated double perovskite Sr₃MoO₆ phosphors with excellent color purity for high CRI WLEDs and flexible display film

Hua, Yongbin,Hussain, Sk. Khaja,Yu, Jae Su Elsevier 2019 CERAMICS INTERNATIONAL Vol.45 No.15

<P><B>Abstract</B></P> <P>A red-emitting Eu<SUP>3+</SUP>-activated double perovskite Sr<SUB>3</SUB>MoO<SUB>6</SUB> phosphor material was successfully synthesized by a high-temperature solid-state reaction. Upon 353 and 467 nm excitations, the prepared phosphors exhibited the feature emission properties of Eu<SUP>3+</SUP> ions with the corresponding characteristic electronic transitions. The concentration quenching of Eu<SUP>3+</SUP> ions was found at 30 mol% and the quadrupole-quadrupole interaction was dominant in quenching process. The chromaticity coordinates for the optimal doping concentration of Eu<SUP>3+</SUP> ions under the 353 and 467 nm excitations were in the pure red region, while the color purity was calculated to be about 94.536 and 94.780%, respectively. The superior luminescence properties of the red-emitting Sr<SUB>3</SUB>MoO<SUB>6</SUB>:0.3Eu<SUP>3+</SUP> phosphor were achieved and with further blending with commercial phosphors, the white light-emitting diode (WLED) devices were fabricated for practical application. The fabricated WLED device based on 385 nm near-ultraviolet (NUV) chip revealed the color-rendering index and color temperature values of 90.96 and 6381 K, respectively. And the soft polydimethylsiloxane film emitted the pure red region under NUV light. These results suggest that this kind of material could be a promising red-emitting phosphor for WLEDs and flexible display film.</P>

Energy transfer from VO₄ ³⁻ group to Sm³⁺ ions in Ba₃(VO₄)₂:3<i>x</i>Sm³⁺ microparticles: A bifunctional platform for simultaneous optical thermometer and safety sign

Du, Peng,Hua, Yongbin,Yu, Jae Su Elsevier 2018 Chemical engineering journal Vol.352 No.-

<P><B>Abstract</B></P> <P>The Sm<SUP>3+</SUP>-doped Ba<SUB>3</SUB>(VO<SUB>4</SUB>)<SUB>2</SUB> microparticles were successfully synthesized via a simple sol-gel method. Both the recorded three-dimensional photoluminescence (PL) emission spectra and counter lines revealed that the near-ultraviolet light was a proper excitation lighting source for the studied samples. Under 352 nm of irradiation, the effect of Sm<SUP>3+</SUP> ion concentration on the PL emission properties of the microparticles was investigated and the optimum doping concentration was demonstrated to be 4 mol%. Based on the diversity in the thermal quenching performance of VO<SUB>4</SUB> <SUP>3−</SUP> group and Sm<SUP>3+</SUP> ions, a novel self-referencing non-invasion optical thermometer with high sensitivity and superior signal discriminability was designed. By taking the advantage of the temperature-dependent fluorescence intensity ratio between the VO<SUB>4</SUB> <SUP>3−</SUP> group and Sm<SUP>3+</SUP> ions, the optical thermometric properties of the Sm<SUP>3+</SUP>-doped Ba<SUB>3</SUB>(VO<SUB>4</SUB>)<SUB>2</SUB> microparticles in the temperature range of 303–463 K were analyzed. The maximum absolute and relative sensor sensitivities, which were hardly influenced by the PL emission intensity, were obtained to be 0.039 K<SUP>−1</SUP> and 2.24% K<SUP>−1</SUP>, respectively. Furthermore, the emitting color of the resultant compounds was found to be significantly dependent on the external temperature. These results suggest that the Sm<SUP>3+</SUP>-doped Ba<SUB>3</SUB>(VO<SUB>4</SUB>)<SUB>2</SUB> microparticles are a potential candidate for high-performance self-referencing optical thermometer and safety sign applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> All the samples can be excited by NUV light and the optimal doping content was 4 mol%. </LI> <LI> The energy transfer efficiency from VO<SUB>4</SUB> <SUP>3−</SUP> group to Sm<SUP>3+</SUP> ions reached up to 82.3% when <I>x</I> = 0.2. </LI> <LI> The FIR value of PL emission intensities of Sm<SUP>3+</SUP> to VO<SUB>4</SUB> <SUP>3−</SUP> was dependent on the temperature. </LI> <LI> The maximum absolution and relative sensor sensitivities were 0.039 K<SUP>−1</SUP> and 2.24% K<SUP>−1</SUP>, respectively. </LI> <LI> The emitting color relied on the temperature, which makes it suitable for safety sign. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Critic acid-assisted sol-gel synthesis of bifunctional Ba<SUB>3</SUB>(VO<SUB>4</SUB>)<SUB>2</SUB>:3<I>x</I>Sm<SUP>3+</SUP> microparticles for non-contact optical temperature sensor and safety sign.</P> <P>[DISPLAY OMISSION]</P>

Case Study On The Seismic Design Strategy For Post-Quake Functional Buildings In China

Peng Liu,Xue Li,Yu Cheng,Xiaoyu Gao,Jinai Zhang,Yongbin Liu Council on Tall Building and Urban Habitat Korea 2023 International journal of high-rise buildings Vol.12 No.3

In response to China's "Regulations on the Management of Earthquake Resistance of Building Constructions" on the provision of eight types of important buildings to maintain functional after fortified earthquakes occur, "Guidelines for Seismic Design of post-quake functional buildings (Draft for Review)" distinguishes Class I and Class II buildings, and gives the performance objectives and seismic verification requirements for design earthquakes and severe earthquakes respectively. In this paper, a hospital and a school building are selected as examples to design according to the requirements of fortification of Intensity 8 and 7 respectively. Two design strategies, the seismic isolation scheme and energy dissipation scheme, are considered which are evaluated through elastic-plastic dynamic time-history analysis to meet the requirement of post-quake functional buildings. The results show that the seismic isolation design can meet the requirements in the above cases, and the energy dissipation scheme is difficult to meet the requirements of the "Guidelines" on floor acceleration in some cases, for which the scheme shall be made valid through the seismic resilience assessment. The research in this paper can provide a reference for designers to choose schemes for post-quake functional buildings.

Pinning Impulsive Synchronization of Stochastic Memristor-based Neural Networks with Time-varying Delays

Qianhua Fu,Jingye Cai,Shouming Zhong,Yongbin Yu 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.1

This paper investigates the exponential and asymptotical synchronization of stochastic memristor-basedneural networks (SMNNs) with time-varying delays via pinning impulsive control. A novel type of pinning impulsivecontrollers is introduced to synchronize the master system and slave system. Based on the physical propertiesof memristor, the mathematical model of SMNNs is obtained by the theories of drive-response concept, set-valuedmaps and stochastic differential inclusions. Then some sufficient verifiable conditions are constructed for the synchronizationof SMNNs by applying the Lyapunov-Krasovskii functional (LKF) method. Furthermore, some improvementsabout the proposed control method are also discussed in this paper. Finally, numerical examples arepresented to demonstrate the effectiveness of the theoretical results.

景德镇陶瓷工业文化遗产景观的生成及其特征

涂彦珣(Yanxun Tu),李锦伟(Jinwei Li),郁永彬(Yongbin Yu),吴军明(Junming Wu) YIXIN 출판사 2024 Journal of Humanities and Social Sciences Vol.2 No.1

陶瓷工业文化遗产景观的保护更新是推动当代陶瓷文化创造性转化与创新性发展的重要实践。本文围绕技术变革与陶瓷工业化发展分析景德镇陶瓷工业文化遗产景观生成原因及特征,旨在重视并发挥陶瓷工业文化遗产景观在试验区建设中的相关作用,唤醒其陶瓷工业文化意识。不仅为研究陶瓷文化提供一种可行性视角,更赋予了陶瓷文化新的内涵价值;有助于实现陶瓷文化在后工业时代的转向与发展,为建设景德镇国家陶瓷文化传承创新试验区提供一定现实参考。 The protection and renewal of ceramic industry cultural heritage landscape is an important practice to promote the creative transformation and innovative development of contemporary ceramic culture. This paper analyzes the reasons and characteristics of the ceramic industry cultural heritage landscape in Jingdezhen based on the technological change and the development of ceramic industrialization, aiming to pay attention to and give play to the relevant role of ceramic industry cultural heritage landscape in the construction of the pilot area, and awaken their cultural awareness of ceramic industry. It not only provides a feasible perspective for the study of ceramic culture, but also gives new connotation value to ceramic culture. It will help realize the transformation and development of ceramic culture in the post-industrial era, and provide a certain practical reference for the construction of Jingdezhen National ceramic culture inheritance and innovation experimental zone.

Novel discontinuous control for exponential synchronization of memristive recurrent neural networks with heterogeneous time-varying delays

Zhang, Ruimei,Zeng, Deqiang,Park, Ju H.,Zhong, Shouming,Yu, Yongbin Elsevier 2018 Journal of the Franklin Institute Vol.355 No.5

<P><B>Abstract</B></P> <P>This paper investigates the exponential synchronization problem of memristive recurrent neural networks (MRNNs) with heterogeneous time-varying delays (HTVDs). First, a novel discontinuous feedback control is designed, in which a tunable scalar is introduced. The tunable scalar makes the controller more flexible in reducing the upper bound of the control gain. Based on this control scheme, the double integral term can be successfully used to construct the LKF. Second, New method for tackling memristive synaptic weights and new estimation technique are presented. Third, based on the LKF and estimation technique, synchronization criterion is derived. In comparison with existing results, the established criterion is less conservatism thanks to the double integral term of the LKF. Finally, numerical simulations are presented to validate the effectiveness and advantages of the proposed results.</P>

Improved Delay-dependent Stability Criteria for Networked Control System with Two Additive Input Delays

Daixi Liao,Shouming Zhong,Jinnan Luo,Xiaojun Zhang,Yongbin Yu,Qishui Zhong 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.9

This paper is concerned with stability criteria of networked control system with two additive time-varying delay components. Firstly, by separating the whole delay interval into subintervals and using a new inequality in combination with convex polyhedron method, a less conservative criterion is proposed and an approach of stabilization controller design is given based on the obtained criterion. Secondly, a congruent condition and an extended condition with the same allowable delay upper bound are respectively deduced by using two different inequalities. Finally, some numerical examples are presented to illustrate the effectiveness of the obtained method.