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| 2. |
- Zeng, Xiao, et al.
(author)
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A scoping study on remelting process of a debris bed in the lower head of reactor pressure vessel
- 2023
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In: Annals of Nuclear Energy. - : Elsevier BV. - 0306-4549 .- 1873-2100. ; 189
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Journal article (peer-reviewed)abstract
- Coolability and retention of core melt (corium) in the lower head of reactor pressure vessel (RPV) has been accepted as a severe accident management strategy to maintain the reactor pressure vessel (RPV) integrity of a light water reactor. To qualify the in-vessel melt retention strategy, lots of studies have been performed to investigate the natural convection heat transfer of a melt pool in the lower head. However, little work has been attributed to the precursory phase of the melt pool, i.e., the remelting process of a debris bed which is formed in the lower head at the very beginning of corium relocation from the core the lower head. The present study is motivated to conduct an experimental study on the debris remelting process. For this purpose, a dedicated test facility named COREM (COrium REMelting) is conceived and constructed, which features internal heating of electromagnetic induction and visualization of debris remelting dynamics. The test section is a semicircular vessel representing a slice of scaled-down RPV lower head, whose front and back walls are made of transparent tempered glass which facilitate visualization and induction heating of the debris bed. Fiber probes with multiple optical temperature sensors are mounted in the semicircular wall of the test section to measure its temperature distribution. In the scoping test, n-octanol and Wood's metal are selected as the simulant materials of metallic and oxidic components of corium, respectively, and their particles ware loaded in the test section to form a debris bed. This paper presents the first two scoping tests which have been performed with the COREM facility so far, under different mixing ratios of two debris materials. The measured data include the photography of debris remelting processes and the temperatures in the debris bed and the semicircular wall. Based on the temperature distributions, heat flux profile along the semicircular vessel wall is also estimated. The scoping tests well reproduce the dynamic process of debris remelting, with two distinct stages of fusion of n-octanol and Wood's metal, i.e., melting successively from low to high melting-point debris particles. During the remelting process, the vessel wall temperatures increase with the polar angle firstly and then decrease gradually, leading to the highest temperature appearing in the middle of the lower layer of the stratified molten pool which is finally formed.
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| 3. |
- Chen, Guanying, et al.
(author)
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(alpha-NaYbF4:Tm3+)/CaF2 Core/Shell Nanoparticles with Efficient Near-Infrared to Near-Infrared Upconversion for High-Contrast Deep Tissue Bioimaging
- 2012
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In: ACS Nano. - : American Chemical Society (ACS). - 1936-0851 .- 1936-086X. ; 6:9, s. 8280-8287
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Journal article (peer-reviewed)abstract
- We describe the development of novel and biocompatible core/shell (alpha-NaYbF4:Tm3+)/CaF2 nanoparticles that exhibit highly efficient NIRin-NIROut upconversion (UC) for high contrast and deep bioimaging. When excited at similar to 980 nm, these nanoparticles emit photoluminescence (PL) peaked at similar to 800 nm. The quantum yield of this UC PL under low power density excitation (similar to 0.3 W/cm(2)) is 0.6 +/- 0.1%. This high UC PL efficiency is realized by suppressing surface quenching effects via heteroepitaxial growth of a biocompatible CaF2 shell, which results in a 35-fold increase in the intensity of UC PL from the core. Small-animal whole-body UC PL imaging with exceptional contrast (signal-to-background ratio of 310) is shown using BALB/c mice intravenously injected with aqueously dispersed nanoparticles (700 pmol/kg). High-contrast UC PL imaging of deep tissues is also demonstrated, using a nanoparticle-loaded synthetic fibrous mesh wrapped around rat femoral bone and a cuvette with nanoparticle aqueous dispersion covered with a 3.2 cm thick animal tissue (pork).
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| 4. |
- Huang, He, et al.
(author)
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Material informatics for uranium-bearing equiatomic disordered solid solution alloys
- 2021
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In: Materials Today Communications. - : Elsevier BV. - 2352-4928. ; 29
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Journal article (peer-reviewed)abstract
- Near-equiatomic, multi-component alloys with disordered solid solution phase (DSSP) are associated with outstanding performance in phase stability, mechanical properties and irradiation resistance, and may provide a feasible solution for developing novel uranium-based alloys with better fuel capacity. In this work, we build a machine learning (ML) model of disordered solid solution alloys (DSSAs) based on about 6000 known multicomponent alloys and several materials descriptors to efficiently predict the DSSAs formation ability. To fully optimize the ML model, we develop a multi-algorithm cross-verification approach in combination with the SHapley Additive exPlanations value (SHAP value). We find that the Delta S-C, Lambda, Phi(s), gamma and 1/Omega, corresponding to the former two Hume - Rothery (H - R) rules, are the most important materials descriptors affecting DSSAs formation ability. When the ML model is applied to the 375 uranium-bearing DSSAs, 190 of them are predicted to be the DSSAs never known before. 20 of these alloys were randomly synthesized and characterized. Our predictions are in-line with experiments with 3 inconsistent cases, suggesting that our strategy offers a fast and accurate way to predict novel multi-component alloys with high DSSAs formation ability. These findings shed considerable light on the mapping between the material descriptors and DSSAs formation ability.
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| 5. |
- Li, Bo, et al.
(author)
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Joint IT and Spectrum Resource Load Balancing for VNF Selection in Inter-Datacenter Elastic Optical Networks
- 2017
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In: 2017 16TH INTERNATIONAL CONFERENCE ON OPTICAL COMMUNICATIONS & NETWORKS (ICOCN 2017). - : IEEE. - 9781538632734
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Conference paper (peer-reviewed)abstract
- The selection of virtualized network functions (VNFs) in service provisioning is a critical issue in inter-datacenter elastic optical networks. In this paper, considering load balancing of IT and spectrum resources, we propose two joint balancing factors, i.e., Global Balancing factor (GB factor) and Local Balancing factor (LB-factor) for VNFs selection. Then a Joint-Optimization Selection (JOS) algorithm is designed based on the joint balancing factors. Simulation results show that GB-factor based JOS can achieve better performance compared with LB-factor based JOS and benchmark algorithm.
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| 6. |
- Li, Fang, et al.
(author)
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Lie Detection Using fNIRS Monitoring of Inhibition-Related Brain Regions Discriminates Infrequent but not Frequent Liars
- 2018
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In: Frontiers in Human Neuroscience. - : Frontiers Media S.A.. - 1662-5161. ; 12
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Journal article (peer-reviewed)abstract
- Functional near-infrared spectroscopy (fNIRS) was used to test whether monitoring inhibition-related brain regions is a feasible method for detecting both infrequent liars and frequent liars. Thirty-two participants were divided into two groups: the deceptive group (liars) and the non-deceptive group (ND group, innocents). All the participants were required to undergo a simulated interrogation by a computer. The participants from the deceptive group were instructed to tell a mix of lies and truths and those of the ND group were instructed always to tell the truth. Based on the number of deceptions, the participants of the deceptive group were further divided into a infrequently deceptive group (IFD group, infrequent liars) and a frequently deceptive group (FD group, frequent liars). The infrequent liars exhibited greater neural activities than the frequent liars and the innocents in the left middle frontal gyrus (MFG) when performing the deception detection tasks. While performing deception detection tasks, infrequent liars showed significantly greater neural activation in the left MFG than the baseline, but frequent liars and innocents did not exhibit this pattern of neural activation in any area of inhibition-related brain regions. The results of individual analysis showed an acceptable accuracy of detecting infrequent liars, but an unacceptable accuracy of detecting frequent liars. These results suggest that using fNIRS monitoring of inhibition-related brain regions is feasible for detecting infrequent liars, for whom deception may be more effortful and therefore more physiologically marked, but not frequent liars.
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| 7. |
- Tian, Yu-Peng, et al.
(author)
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Investigations and facile synthesis of a series of novel multi-functional two-photon absorption materials
- 2007
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In: Journal of Materials Chemistry. - : Royal Society of Chemistry (RSC). - 0959-9428 .- 1364-5501. ; 17:34, s. 3646-3654
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Journal article (peer-reviewed)abstract
- Six centrosymmetric D-(pi-A)(3) structural triphenylamine derivatives that can be used as two- photon photopolymerization and optical data storage chromophores, tris[ 4-( 4- pyridylethenyl) phenyl] amine ( 1), tris[ 4-( 2- pyridylethenyl) phenyl] amine ( 2), tris( 4- cyanoethenylphenyl) amine ( 3), tris[ 4- butylacrylatephenyl] amine ( 4), tris[ 4- methylacrylatephenyl] amine ( 5) and tris[ 4- acrylicethenylphenyl] amine ( 6), have been successfully synthesized via a triple palladium-catalyzed Heck coupling reaction, and the novel chromophores were fully characterized by elemental analysis, IR, (1)H-NMR and ESIMS. The structure for 3 was determined by single crystal X-ray diffraction study. One- and two-photon absorption and fluorescence in various solvents were experimentally investigated. Two-photon initiated polymerization microfabrication and optical data recording experiments were carried out under 780 nm laser radiation, and the possible polymerization mechanism is discussed based on theoretical calculations. All the six chromophores have relatively large two-photon absorption crosssections, and exhibit optical memory and highly efficient two-photon initiated polymerization abilities.
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| 8. |
- Wang, Ke, et al.
(author)
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100 Gb/s RZ-OOK transmission through 212 km deployed SSMF using monolithically integrated ETDM receiver module
- 2011
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In: Optics Communications. - : Elsevier BV. - 0030-4018 .- 1873-0310. ; 284:3, s. 782-786
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Journal article (peer-reviewed)abstract
- 100 Gb/s on-off keying (OOK) transmission over 212 km installed standard single-mode fibers using an Indium Phosphide (InP)-based electrical clock-data-recovery (CDR) and demultiplexer module was demonstrated 5 5 x 10(-11) bit error rate (BER) performance was achieved and 11 dB optical signal-to-noise ratio (OSNR) penalty was required at 10(-9) BER after transmission
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| 9. |
- Wang, Yi-Tong, et al.
(author)
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Direct production of biodiesel via simultaneous esterification and transesterification of renewable oils using calcined blast furnace dust
- 2021
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In: Renewable energy. - : Elsevier BV. - 0960-1481 .- 1879-0682. ; 175, s. 1001-1011
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Journal article (peer-reviewed)abstract
- Direct production of biodiesel by both esterification and transesterification of renewable oils with acid value (AV) of 9.6-28.9 mg KOH/g using calcined blast furnace dust is studied. Blast furnace dust calcined at 600-700 degrees C obviously promotes efficient biodiesel production because of the crystal form transformation from lead sulfate particles in dust into active lead oxide, lead sulfide, and lead particles. It is found for the first time that lead oxide, lead sulfide and lead particles can resist saponification from fatty acids to catalyze raw renewable oils to biodiesel with catalytic activity order as follows: lead oxide > lead > lead sulfide > lead sulfate. Biodiesel production process is optimized according to an orthogonal design with biodiesel yield of 92 wt% obtained at AV of 9.6 mg KOH/g (82 wt% after 5 cycles). Biodiesel yield of 84 wt% is achieved at AV of 28.9 mg KOH/g with acidity of 0.18 mmol/g. Calcined blast furnace dust presents potential applications in the production of biodiesel from renewable oils with high AVs.
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| 10. |
- Zhao, Li-Chen, et al.
(author)
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Spin soliton with a negative-positive mass transition
- 2020
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In: Physical Review A: covering atomic, molecular, and optical physics and quantum information. - : AMER PHYSICAL SOC. - 2469-9926 .- 2469-9934. ; 101:4
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Journal article (peer-reviewed)abstract
- We obtain a striking spin soliton in a two-component Bose-Einstein condensate and investigate its motions in the presence of a constant force. The initially static spin soliton first moves in a direction opposite to the force and then changes direction, showing an extraordinary ac oscillation. The underlying mechanism is uncovered: the spin soliton can exhibit a periodic transition between negative and positive inertial mass because of a particular relation between its energy and moving velocity. We then develop a quasiparticle model that can account for this extraordinary oscillation. Important implications and possible applications are discussed.
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