[en] Upper and lower graphite divertor in EAST tokamak have been updated to tungsten divertors in 2014 and 2021 respectively to investigate the tungsten divertor operation and to realize high-performance long pulse discharge. Therefore, studies on the tungsten behavior are crucially important for improving the plasma performance. For the purpose four fast-time-response and four space-resolved extreme ultraviolet (EUV) spectrometers have been installed on EAST to observe line emissions from tungsten ions and their intensity radial profiles in wavelength ranges of 5 − 520 Å.

[en] An analytical model for the drain—source breakdown voltage of an RF LDMOS power transistor with a Faraday shield is derived on the basis of the solution of the 2D Poisson equation in a p-type epitaxial layer, as well as an n-type drift region by means of parabolic approximation of electrostatic potential. The model captures the influence of the p-type epitaxial layer doping concentration on the breakdown voltage, compared with the previously reported model, as well as the effect of the other device parameters. The analytical model is validated by comparing with a numerical device simulation and the measured characteristics of LDMOS transistors. Based on the model, optimization of LDMOS device parameters to achieve proper trade-off between the breakdown voltage and other characteristic parameters such as on-resistance and feedback capacitance is analyzed. (semiconductor devices)

[en] Highlights: • The energy transfer from Ce³⁺ to Tb³⁺ in NaCaGaSi₂O₇ host is the dipole-dipole interaction, and the efficiency is 83.5%. • The energy transfer critical distance was calculated to be 8 Å. • PL thermal quenching properties of phosphors have been investigated in detail. • The emission colour is tuned from deep blue (0.174, 0.048) to green (0.289, 0.439) by increasing the contents of Tb³⁺ions. - Abstract: The NaCaGaSi₂O₇:Ce³⁺,NaCaGaSi₂O₇:Tb³⁺ and NaCaGaSi₂O₇:Ce³⁺/Tb³⁺ phosphors were synthesized under a weak reducing atmosphere by the traditional high temperature solid state reaction method. The synthesized phosphors were characterized by X-ray diffraction (XRD), fluorescent decay times, photoluminescence (PL) emission and excitation spectra including temperature-dependent PL properties. The effects of Ce³⁺ singly doped and Ce³⁺/Tb³⁺ co-doped concentrations on the structure, luminescence properties and energy transfer of NaCaGaSi₂O₇ phosphors were studied in detail. The results indicated that the energy transfers between Ce³⁺ and Tb³⁺ in the host occurred mainly via a dipole-dipole mechanism, and the critical distances of the ion pairs (R_c) were calculated by the quenching concentration method and spectral overlap method. The Ce³⁺ emission intensity and decay lifetimes decrease with the raise of Tb³⁺ concentration in NaCaGaSi₂O₇:Ce³⁺/Tb³⁺ samples. The above results indicate that NaCaGaSi₂O₇:Ce³⁺/Tb³⁺ can be a candidate as a host material for solid-state lighting and display fields.

[en] Highlights: • Mg²⁺-Ge⁴⁺ ion pairs can partially substitute the Al³⁺ ions of YAG successfully. With the substitution, the garnet crystal structure remains unchanged. • With increasing Mg²⁺-Ge⁴⁺ ions concentrations, the emission spectra show a progressive red-shift, from 528 to 552 nm (about 24 nm). • In white LEDs, with increasing Mg²⁺-Ge⁴⁺ ions concentrations, the CCT decreased gradually from 6798 to 3261 K and the CRI increased from 76.5 to 89.3. - Abstract: Mg²⁺-Ge⁴⁺ ions substituted YAG: Ce³⁺ phosphors (Y₃Al_5-2xMg_xGe_xO₁₂: Ce³⁺) were prepared by high temperature solid state reaction method. X-ray diffraction (XRD), Scanning election microscope (SEM), Photoluminescence (PL) spectra and so on were used to characterize the samples. The effects of Mg²⁺-Ge⁴⁺ concentrations on the morphology, structure, luminescence properties, fluorescence lifetime and white LED performance of YAG: Ce³⁺ phosphors were studied in detail. The results indicate that Mg²⁺-Ge⁴⁺ ion pairs can partially substitute the Al³⁺ ions of YAG successfully. With the substitution, the garnet crystal structure remains unchanged. However the emission spectra show a progressive red-shift, from 528 to 552 nm (about 24 nm). The lifetime decreased rapidly from 84 to 26 ns. In particular, the correlated color temperature (CCT) decreases gradually from 6798 to 3261 K and the color rendering index (CRI) increases from 76.5 to 89.3 with the increasing of the incorporation content of Mg²⁺-Ge⁴⁺ ion pairs.

[en] Particle-in-cell simulation and analytical modeling demonstrate that the reflection of a single-cycle light pulse from a thin target can produce an ultrashort ultraintense electromagnetic field.

[en] Large amplitude oscillations in the expansion of a cylindrical electron–positron plasma layer are investigated. The cold fluid equations and the Poisson's equation are solved non-perturbatively in order to allow for very large amplitude oscillations. It is found that oscillations are self-excited during the expansion and can grow to very large amplitudes as the expansion slows down with time and the plasma density decreases. The kinetic energy of the expansion is thereby converted into that of the oscillations. (paper)

[en] Highlights: • The Y_2.85Al₅O_11.55N_0.3: Ce³⁺_0.15 phosphors are prepared using AlN and SiO₂ as the sources of N³⁻ and Si⁴⁺. • The CFS and NE play a conflicting role in spectral tuning in the resultant phosphors. • The tendency to bond with N³⁻ for the cations changes from Y³⁺>Ce³⁺ to Ce³⁺>Y³⁺ when Si⁴⁺ were introduced. • Both red-shift and FWHM of emission spectra reach the maximum when N³⁻ and Si⁴⁺ have the same amount. Y_2.85Al_5-ySi_yO_12-(3x-y)/2N_x: Ce³⁺_0.15 phosphors were prepared using aluminum nitride (AlN) and silica (SiO₂) as the sources of N and Si by the high temperature solid state reaction method. XRD patterns of the phosphors present a pure phase but have a slight translation compared to the standard card of Y₃Al₅O₁₂(YAG). The Al³⁺-N^3- bonds and Y³⁺-N^3- bonds were detected by the analysis of X-ray photoelectron spectroscopy (XPS). The tendency to bond with N³⁻ ions for the cations changes from Y³⁺>Ce³⁺ to Ce³⁺>Y³⁺ for the samples introduced SiO₂. Photoluminescence spectra (PL & PLE) show that the crystal field splitting (CFS) and the nephelauxetic effect (NE) play a conflicting role in spectral shifting. When x = y, NE plays a major role and the emission red shift reaches the maximum. The thermoluminescence tests (TL) confirm that temperature quenching of the phosphors is caused by the thermally-activated crossover process.

[en] Precision medicine is a potential effective therapeutic for various human diseases. Currently, metal complex-based drugs are being successfully used in clinical applications owing to diverse properties such as multiple redox states, photo-induced ligand exchange, and preferential ligand and coordination numbers, which facilitate drug design and development. However, drawbacks such as toxicity, lack of specificity, and severe side effects have hampered their therapeutic outcome. Therefore, innovative strategies for improving the specificity and pharmacokinetics of conventional metal complex-based therapeutic agents are required. Recently, nanotechnology, which provides a unique toolbox for developing effective and safer medicine, has attracted considerable attention, mainly because of their ability to reduce side effects and enhance drug loading efficiency and pharmacokinetics. Considering the promising chemical and physical properties of diverse nanostructures, nanoformulation of metal complexes can be used to effectively address the problems associated with current metallodrug complexes, especially those based on stimuli-responsive therapeutic strategies, with excellent spatial, temporal, and dosage control. In this review, we have mainly focused on the specificity and environment-responsiveness of metallodrug nanoformulations as therapeutics, and summarized the recent strategies being used for developing metal complex-functionalized intelligent nanoplatforms, which respond to various types of stimuli, including endogenous signals (pH, redox conditions, and enzyme activities) or external triggers (light irradiation and magnetic field manipulations). In addition, we have also discussed the potential challenges associated with use of metallodrugs and their nanoformulations as effective precision therapy with improved specificity and minimal side effects.

[en] Highlights: • MCNTs@TpPa-1 composites were prepared simply and rapidly by mechanochemistry methods firstly. • Well water dispersibility and many adsorption sites endow MCNTs@TpPa-1 with excellent extraction effect for MCs in water. • A facile MSPE-HPLC-MS/MS analysis method for MCs in water samples was developed with high sensitivity. Easy-preparation magnetic solid-phase extraction (MSPE) adsorbents with excellent extraction performance are very indispensable for MSPE techniques. Herein, a magnetic carbon nanotube covalent organic framework composite (MCNTs@TpPa-1) was prepared simply and rapidly through mechanochemical synthesis as MSPE adsorbent for enriching microcystins (MCs). The synthesized MCNTs@TpPa-1 exhibited well water dispersibility, high affinity with MCs and large surface area, resulting in outstanding extraction performance for MCs. Subsequently, combined with high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS), an efficient, sensitive and convenient MSPE method was set up for the determination of trace MCs from aqueous sample, which exhibited acceptable repeatability (RSDs (relative standard deviations) ≤ 6.8%, n = 6), low limits of detection (LODs, 0.8–1.5 pg mL⁻¹), reliable linearity (R ≥ 0.9991) and broad range of linearity (2.0–1000 pg mL⁻¹). Furthermore, the developed method was applied to lake samples and trace MCs (9.6–24.6 pg mL⁻¹) were found with satisfactory recovery (85.0–106.0%). The results indicated powerfully MCNTs@TpPa-1 was of significant potential as an MSPE sorbent for detection of trace MCs in water. Moreover, considering the complexity of traditional preparation methods, novel prospects for preparing magnetic covalent organic frameworks (COFs) with excellent extraction properties were opened up.

[en] Highlights: • A new type of Y_2.94Al_4−xSi_xGaO₁₂: 0.06Ce³⁺ phosphors with weak thermal quenching and long afterglow were synthesized by the conventional solid-state reaction route. • 88% of the room-temperature emission intensity is still maintained at 453 K, indicating a good thermal stability and practicality. • It should be noted that the encoding process does not require a specific wavelength light source, but ordinary sunlight. -- Abstract: In order to prepare various Y_2.94Al_4−xSi_xGaO₁₂: 0.06Ce³⁺ phosphors, a traditional approach to solid-state reaction was adopted. XRD and Rietveld were refined to confirm the cubic garnet crystal structure of phosphors. Besides, the substance displayed a wide mission band varying between 475 nm and 650 nm due to the 5d→4f transitions of the Ce³⁺ ions as excited by a 450 nm wavelength. Furthermore, as the Si⁴⁺ concentration increases from 0 to 0.6, we can observe a blue shift in the emission spectrum from 510 nm to 502 nm. The emission intensity at 453 K is still 88% of that at room temperature. At the same time, through the auxiliary calculation of activation energy, the advantages of thermal stability and the weakness of thermal quenching are explained. Surprisingly, a demonstrational application confirmed the excellent capability of optical data retention in encoding/decoding the material, including a designed bar code and graphic patterns. It is suggested that phosphor is applicable for the development of white LEDs based on the blue LED-chip. In particular, when some unexpected circumstances occur and lighting conditions suddenly break down, LED with long afterglow performance can alleviate the discomfort caused by the change. It is also expected to move forward the study on Long-lasting phosphorescence (LLP) materials and their practical application in optical storage.