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Prediction of Thermal Coupled Thermometric Performance of Er <sup>3+</sup>
摘要： Predicting thermometric performance for diverse materials will facilitate the selection and design of nanothermometers to meet complex environment and specific signal output with saving a lot of time and expense. Herein we explore and unveil the thermal coupled thermometric performance of Er3+/Yb3+ co-doped a set of host lattices via the chemical bond theory of complex crystals. The unknown B and ΔE values of the thermometry are accurately estimated by the chemical bond parameters, further deepening our cognition of the correlation between luminescence properties of Er3+ ions and microscopic crystal structure. This allows us to precisely forecast the thermal coupled thermometric performance of Er3+ for varying host lattices in advance.
关键词： nanothermometers,chemical bond theory of complex crystals,thermally coupled levels,rare earth,luminescence intensity ratio thermometry
更新于2025-09-11 14:15:04
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Surface state-controlled C-dot/C-dot based dual-emission fluorescent nanothermometers for intra-cellular thermometry
摘要： Fluorescence-based nanothermometers have potential to offer accuracy in the measurement of temperature using non-contact approaches. Herein, a C-dot/C-dot based dual-emission temperature sensing platform is fabricated through the electrostatic self-assembly of two kinds of fluorescent CDs with opposite charges. This dual-emission platform consists of several nearly-spherical CDs with two emission centers in blue (440 nm) and orange (590 nm) regions. The orange fluorescence exhibits discernible response to external temperatures in the range of ～15 to 85 °C; on the other hand, the blue fluorescence remains nearly constant. A continuous fluorescence color change in response to temperature from orange to blue can be clearly observed by the naked eye. Thus, the as-prepared C-dot based dual-emission nanospheres can be used for optical thermometry with high reproducibility and sensitivity (0.93%/°C). Detailed characterization shows that temperature (in the 15–85 °C window) impacts the surface states of orange emissive CDs, leaving the blue emissive CDs unaffected. A model is proposed to explain the observations. Finally, by taking advantage of the excellent biocompatibility and stability, the CD based fluorescent nanothermometer is successfully used for the visual measurement of intracellular temperature variations.
关键词： intracellular thermometry,temperature sensing,nanothermometers,dual-emission,fluorescence,carbon dots
更新于2025-09-11 14:15:04
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Understanding the Relationship Between Real-Time Thermal Imaging and Thermal Damage Estimate During Magnetic Resonance–Guided Laser Interstitial Thermal Therapy
摘要： Objectives: Magnetic Resonance-guided Laser Interstitial Thermal Therapy (MRgLITT) is a minimally invasive procedure that utilizes intraoperative magnetic resonance thermometry (MRT) to generate a thermal damage estimate (TDE) of the ablative area. This study compared areas produced by the MRT heat map to the system-generated TDE produced by the Visualase software. Methods: All ablations were performed using the Visualase MRI-Guided Laser Ablation System. MRT heat-map and TDE were quantified using MATLAB version R2014a. The TDE was compared to the summed area of the green, yellow, and red areas (HM63.9) and the summed area of the light blue, green, yellow, and red areas (HM50.4) produced by the MRT heat map. Results: 56 patients undergoing MRgLITT were examined. The mean TDE produced was 236 mm2 (SEM = 9.5). The mean HM63.9 was 231 mm2 (SEM = 8.7), and the mean HM50.4 was 370 mm2 (SEM = 12.8). There was no significant difference between the TDE and HM63.9 (p = 0.51) . There was a significant difference between TDE and HM50.4 (p < 0.001) and between HM63.9 and HM50.4 (p < 0.001). Conclusions: The system-generated TDE consistently remains contained within the boundaries of the MRT heat map. At standard factory settings, the TDE and the area produced within the periphery of the HM63.9 are similar in magnitude. The light blue portion of the MRT heat map may serve as an additional means of predicting when critical structures may be at risk during laser ablation if exposed to further thermal stress.
关键词： MRTI,Thermal ablation parameters,LITT,Laser interstitial thermal therapy,Magnetic resonance thermometry
更新于2025-09-11 14:15:04
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Measurement and Evaluation of Local Surface Temperature Induced by Irradiation of Nanoscaled or Microscaled Electron Beams
摘要： Electron beams (e-beams) have been applied as detecting probes and clean energy sources in many applications. In this work, we investigated several approaches for measurement and estimation of the range and distribution of local temperatures on a subject surface under irradiation of nano-microscale e-beams. We showed that a high-intensity e-beam with current density of 105-6 A/cm2 could result in vaporization of solid Si and Au materials in seconds, with a local surface temperature higher than 3000 K. With a lower beam intensity to 103-4 A/cm2, e-beams could introduce local surface temperature in the range of 1000–2000 K shortly, causing local melting in metallic nanowires and Cr, Pt, and Pd thin films, and phase transition in metallic Mg-B films. We demonstrated that thin film thermocouples on a freestanding Si3N4 window were capable of detecting peaked local surface temperatures up to 2000 K and stable, and temperatures in a lower range with a high precision. We discussed the distribution of surface temperatures under e-beams, thermal dissipation of thick substrate, and a small converting ratio from the high kinetic energy of e-beam to the surface heat. The results may offer some clues for novel applications of e-beams.
关键词： Vaporization,Local temperature,Nanoscale thermometry,Transmission electron microscopy,Thin film thermocouple,Energy converting,Electron beam,Scanning electron microscopy,Melting point
更新于2025-09-11 14:15:04
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Quantum dot thermometry at ultra-low temperature in a dilution refrigerator with a <sup>4</sup> He immersion cell
摘要： Experiments performed at a temperature of a few millikelvins require effective thermalization schemes, low-pass filtering of the measurement lines, and low-noise electronics. Here, we report on the modifications to a commercial dilution refrigerator with a base temperature of 3.5 mK that enable us to lower the electron temperature to 6.7 mK measured from the Coulomb peak width of a quantum dot gate-defined in an [Al]GaAs heteostructure. We present the design and implementation of a liquid 4He immersion cell tight against superleaks, implement an innovative wiring technology, and develop optimized transport measurement procedures.
关键词： quantum dot thermometry,ultra-low temperature,dilution refrigerator,4He immersion cell
更新于2025-09-11 14:15:04
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Yb3+/Tb3+/Ho3+: phosphate nanophase embedded glass ceramics: enhanced upconversion emission and temperature sensing behavior
摘要： Yb3+/Tb3+/Ho3+ tri-doped transparent phosphate glass–ceramics (GCs) were successfully synthetized by a conventional melt-quenching technique with subsequent glass crystallization. The formation of phosphate nanocrystals (NCs) with leucite structure was confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), selected-area electron diffraction (SAED). The variation of the decay curves confirms the accumulation of active centers into the NCs lattice. Hence, the UC emission intensity of Yb3+/Tb3+/Ho3+ doped GC610 sample is greatly enhanced relative to that in precursor glass (PG). And the UC energy transfers processes were systematically analysis. The result shows that the energy transfer of Ho3+→Tb3+ exists while Yb3+ as a sensitizer ion. Furthermore, the temperature-dependent UC luminescence and temperature sensing behaviors of the prepared materials based on the thermally coupled levels of Tb3+: 5D4 and Ho3+: 5F5 in the temperature range of 298–648 K were systematically investigated, to explore its possible application as optical thermometric medium, by utilizing the fluorescence intensity ratio (FIR) technique. The relative sensitivity (Sr) of 7.5 × 10?3 K?1 and absolute sensitivity (Sa) of 22 × 10?3 K?1 are achieved in the Yb3+/Tb3+/Ho3+ tri-doped GC. This GC materials is a very promising candidate for optical temperature sensors.
关键词： Yb3+/Tb3+/Ho3+ tri-doped,phosphate glass–ceramics,upconversion emission,temperature sensing,optical thermometry
更新于2025-09-10 09:29:36
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Alkaline-Earth Fluorohalide Nanocrystals for Upconversion Thermometry
摘要： The temperature-dependent luminescence response of SrFCl:Yb,Er and SrFBr:Yb,Er upconverting nanocrystals was investigated with an eye towards the expansion of the library of host materials for optical thermometry. Steady-state and luminescence decays of the 2H11/2 and 4S3/2 thermally coupled levels of the Er3+ activator were probed in the 100?450 K temperature range. Fluorescence intensity ratios and thermometric sensitivities were extracted in two temperature regimes. In the low-temperature regime, SrFCl:Yb,Er and SrFBr:Yb,Er displayed maximum sensitivities of 3.2 × 10?2 K?1 (125 K) and 2.1 × 10?2 K?1 (175 K), respectively. In the high-temperature regime, sensitivities were comparable to those observed in upconverting nanocrystals such as NaYF4:Yb,Er at room temperature, with values of 9.4 × 10?3 K?1 (325 K) for SrFCl:Yb,Er and 1.1 × 10?2 K?1 (300 K) for SrFBr:Yb,Er. The observed temperature-dependent responses resulted from long- and short-lived Er3+ emitters present in both fluorohalide hosts. For each type of emitter, radiative constants and activation energies for thermal quenching of the emission from the 4S3/2 level were estimated using a single-barrier quenching model. The local atomic environments of the long- and short-lived Er3+ emitters differed to a greater extent in SrFCl:Yb,Er than in SrFBr:Yb,Er.
关键词： SrFBr,Nanocrystals,Thermometry,SrFCl,Upconversion,Rare-earth
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Microwave Method for Closure of Quasi-Spherical Resonator
摘要： Quasi-spherical microwave cavity resonators are widely used in primary thermometry. To realize high-accuracy microwave resonant frequency measurement, it is essential to close the two quasi-hemispheres correctly. We show how to do this using microwave resonance signals to monitor shape and sealing as torques to equatorial bolts are increased. The present resonator was closed with torques up to 105 cNm. The method should be useful to monitor the closing of other quasi-spherical cavities.
关键词： Quasi-spherical cavity,Resonant frequency,Thermometry,Microwave measurement,Thermodynamic temperature
更新于2025-09-10 09:29:36
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Lanthanide-Based Thermometers: At the Cutting-Edge of Luminescence Thermometry
摘要： Present technological demands in disparate areas, such as microfluidics and nanofluidics, microelectronics and nanoelectronics, photonics and biomedicine, among others, have reached to a development such that conventional contact thermal probes are not accomplished anymore to perform accurate measurements with submicrometric spatial resolution. The development of novel noncontact thermal probes is, then, mandatory, contributing to an expansionary epoch of luminescence thermometry. Luminescence thermometry based on trivalent lanthanide ions has become very popular since 2010 due to the unique versatility, stability, and narrow emission band profiles of the ions that cover the entire electromagnetic spectrum with relatively high emission quantum yields. Here, a perspective overview on the field is given from the beginnings in the 1950s until the most recent cutting-edge examples. The current movement toward usage of the technique as a new tool for thermal imaging, early tumor detection, and as a tool for unveiling the properties of the thermometers themselves or of their local neighborhoods is also summarized.
关键词： Luminescent Nanothermometers,Early Tumor Detection,Luminescence Thermometry,Lanthanide-Based Thermometers,Thermal Imaging
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Methods for Electrical Cooling and Thermometry of a Suspended Silicon Chip
摘要： We suspend a heavily doped conducting silicon chip by tunnel junctions and aluminum leads, which permits the measurement and control of electrical and phonon heat ?uxes. Experiments and analysis on heat conduction and electrical cooling utilize techniques developed for electron pumps and primary thermometry, and the techniques developed for the cooler may also be useful for the development quantum phase slip based devices.
关键词： quantum standard,thermometry,electrical cooling,Cryogenics
更新于2025-09-10 09:29:36