Synthesis,energy transfer mechanism,and tunable emissions of novel Na3La(VO4)2:Re3+ (Re3+ = Dy3+, Eu3+, and Sm3+) vanadate phosphors for near-UV-excited white LEDs

In this study, novel Eu³⁺-, Dy³⁺-, and Sm³⁺-activated Na₃La(VO₄)₂ phosphors were synthesized using a solid state reaction method. X-ray diffraction analysis results indicated that the Na₃La(VO₄)₂ phosphors had an orthorhombic crystal structure with the Pbc21 space group. There were two different La(1)O₈ and La(2)O₈ polyhedra with high asymmetry in the crystal structure. Scanning electron microscopy revealed that the product had a sheet morphology with an irregular particle size. Further, the luminescence properties, including the excitation and emission spectra, and luminescence decay curve, were investigated using a fluorescence spectrometer. The results showed that the Na₃La(VO₄)₂ compound was an excellent host for activating the luminescence of Eu³⁺ (614 nm), Dy³⁺ (575 nm), and Sm³⁺ (647 nm) ions. Further, Dy³⁺/Eu³⁺ co-doped Na₃La(VO₄)₂ phosphors were exploited, and the energy transfer from Dy³⁺ to Eu³⁺ was demonstrated in detail by the photoluminescence excitation, photoluminescence spectra, and luminescent decay curves. The results showed that the energy transfer efficiency from Dy³⁺ to Eu³⁺ was highly efficient, and the energy transfer mechanism was dipole–dipole interactions. Finally, tunable emissions from the yellow region of CIE (0.3925, 0.4243) to the red region of CIE (0.6345, 0.3354) could be realized by rationally controlling the Dy³⁺/Eu³⁺ concentration ratio. These phosphors may be promising materials for the development of solid-state lighting and display systems.     

PLC与SEW多轴伺服驱动总线集成在玻璃生产线控中的应用

本文介绍了一种将西门子PLC与SEW多轴伺服驱动通过PROFINET总线组合集成的一套玻璃生产线线控系统的应用方案。     

摩擦变形量对异种金属摩擦焊组织和性能影响研究

针对摩擦变形量对异种金属的焊接质量影响情况认识不充分这一问题,开展了摩擦变形量对焊缝组织及力学性能影响规律的研究。基于微观组织、显微硬度和力学性能的对比分析,对调质态42CrMo与正火态36Mn2V管材不同摩擦变形量的连续驱动摩擦焊进行了研究,为其在工程应用提供理论依据。     

激光焦点磁力驱动平台的波动特性分析

针对现有驱动平台在传统PID参数控制下Y方向平动实验中出现的波动情况进行分析,猜测波动的原因是由于平台结构分布不均匀造成的。针对波动情况,建立在环形永磁铁和柱形永磁铁结构分布不均匀情况下驱动平台的数学模型。并对结构不均匀情况下数学模型进行Y方向的仿真分析。仿真结果表明,分布不均匀情况下的数学模型在仿真过程中会出现波动。仿真结果与猜测结果相同。实验过程中的波形情况是由于驱动平台的结构分布不均匀造成的。     

多点驱动带式输送机功率平衡机制研究

针对多点驱动带式输送机功率不平衡降低输送效率及生产寿命问题,对多电机间的协调控制进行研究。对传统偏差耦合多电机协调控制结构进行了改进,增加了基于转速功率控制的同步误差补偿器,通过求取所有电机的平均转速和单台电机的转速差,利用PI控制器,同时结合每台电机的系统转速跟踪误差,反馈补偿到每台电机的控制回路进行多电机协调控制。仿真结果表明,系统可以在负载变化扰动的情况下有效降低各电机的同步误差,特别是对系统刚启动时负载不均衡导致的电机功率不平衡问题,改进结构可以有效实现多电机间的功率平衡分配。     

东峡煤矿主煤流运输系统智能化集控设计

通过对东峡煤矿主煤流运输系统的改造,设计了一套智能化集控系统,采用变频驱动,并结合料流传感器,增设无线基站、本安网络摄像仪和语音扩播终端等设备,实现了带式输送机载荷分布的自动调节,提高了系统的可靠性和运行效率,实现了减员、节能、增效的目的。     

An orange-emitting phosphor BaSrGa4O8:Bi3+,K+ with unique one-dimensional chain structure for high index color WLEDs

It has been an urgent need for developing a new bright long-wave emitting phosphor to improve the color rendering index (CRI) of white light-emitting diodes (WLEDs). Here, based on the concept of oxygen vacancy-induced long-wave emission by Bi³⁺ doping, we selected BaSrGa₄O₈ as the matrix, which has a low-dimensional chain structure that can produce enough oxygen vacancies. After the introduction of Bi³⁺, orange emission was successfully achieved. To further improve the luminescence efficiency, the system of BaSrGa₄O₈:Bi³⁺,K⁺ was designed. Interestingly, although significant emission enhancement was obtained, the material showed reduced absorption with increased oxygen vacancies. More detailed experimental evidences confirm that oxygen vacancies can activate Bi³⁺ to achieve long-wave emission. Our results provide a new way to design Bi³⁺-based long-wave emitting phosphors with low-dimensional crystal structure. Finally, a WLED device containing BaSrGa₄O₈:Bi³⁺,K⁺ was fabricated and exhibited an enhanced CRI, which shows a promising application in WLEDs.     

游戏机手柄热流道立式注塑4层叠层注塑模设计

设计了一种4层叠层模用于实现游戏机手柄的高效率注塑生产，解决了塑件成型时在保证塑件成型精度的基础上，单次注塑量产数量4倍倍增难题。4层叠层模的结构由4层结构相同的单层模具通过一定的空间组序排列组装后，应用立式注塑机来进行注射成型。单层模结构设计采用两板式2次开模热流道浇注两板模形式，第一次开模用于热流道嘴与塑件的冷流道部分分离，第二次开模用于塑件从型腔镶件中脱模脱出。为解决单层模做4层叠层组合后，顶出板无动力顶出的问题，在单层模的模架模板侧边对称设置了拉杆，将单层模在开模动力转化为单层模中顶出板的顶出拉力，巧妙地解决了单层模做4层叠层安装后各单层模的顶出元件顶出板无推动力的问题。模具结构布局及机构的驱动设置设计合理，有较好的工程设计参考意义。     

Facile synthesis of the desired red phosphor Li2Ca2Mg2Si2N6:Eu2+ for high CRI white LEDs and plant growth LED device

The red emission with suitable peak wavelength and narrow band is acutely required for high color rendering index (CRI) white LEDs without at the cost of the luminous efficacy. Herein, the Li₂Ca₂Mg₂Si₂N₆:Eu²⁺ red phosphor was prepared with facile solid-state method using Ca₃N₂, Mg₃N₂, Si₃N₄, Li₃N, and Eu₂O₃ as the safety raw materials under atmospheric pressure for the first time, which shows red emission peaking at 638 nm with full width at half maximum (FWHM) of 62 nm under blue light irradiation and becomes the desired red phosphor to realize the balance between luminous efficacy and high CRI in white LEDs. The morphology, structure, luminescence properties, thermal quenching behavior, and chromaticity stability of the Li₂Ca₂Mg₂Si₂N₆:Eu²⁺ phosphor are investigated in detail. Concentration quenching occurs when the Eu²⁺ content exceeds 1.0 mol%, whereas high-temperature photoluminescent measurements show a 32% drop from the room-temperature efficiency at 423 K. In view of the excellent luminescence performances of Li₂Ca₂Mg₂Si₂N₆:Eu²⁺ phosphor, a white LEDs with CRI of 91 as a proof-of-concept experiment was fabricated by coating the title phosphor with Y₃Al₅O₁₂:Ce³⁺ on a blue LED chip. In addition, the potential application of the title phosphor in plant growth LED device was also demonstrated. All the results indicate that Li₂Ca₂Mg₂Si₂N₆:Eu²⁺ is a promising red-emitting phosphor for blue LED-based high CRI white LEDs and plant growth lighting sources.     

基于压缩机-支架系统的异常噪声研究

针对某乘用车发动机转速在1 573 r/min，压缩机开启时车内噪声异常的问题，对样车进行试验分析与诊断，对压缩机-支架系统进行仿真分析，提出改进方案并验证改进效果。利用LMS声振信号采集系统采集振动噪声数据，采用频谱分析、阶次追踪等方法，并结合压缩机-支架系统模态仿真结果，确定车内异常噪声是压缩机轴频21阶与压缩机-支架系统3阶模态频率接近发生共振造成的。通过优化支架结构来提高压缩机-支架系统3阶模态频率以此来避免共振，并换装橡胶驱动盘缓和压缩机输入扭矩波动。将改进结构进行整车试验，结果表明：匀速工况空调开启时问题转速下，车内噪声降低了2.5 dB(A)；匀加速工况空调开启时发动机转速1 500~1 650 r/min区间，车内噪声无峰值，其余转速空调开启时改进前/后车内噪声基本不变，噪声波动趋势平缓。