1. |
- Kristanl, Matej, et al.
(author)
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The Seventh Visual Object Tracking VOT2019 Challenge Results
- 2019
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In: 2019 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW). - : IEEE COMPUTER SOC. - 9781728150239 ; , s. 2206-2241
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Conference paper (peer-reviewed)abstract
- The Visual Object Tracking challenge VOT2019 is the seventh annual tracker benchmarking activity organized by the VOT initiative. Results of 81 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The evaluation included the standard VOT and other popular methodologies for short-term tracking analysis as well as the standard VOT methodology for long-term tracking analysis. The VOT2019 challenge was composed of five challenges focusing on different tracking domains: (i) VOT-ST2019 challenge focused on short-term tracking in RGB, (ii) VOT-RT2019 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2019 focused on long-term tracking namely coping with target disappearance and reappearance. Two new challenges have been introduced: (iv) VOT-RGBT2019 challenge focused on short-term tracking in RGB and thermal imagery and (v) VOT-RGBD2019 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2019, VOT-RT2019 and VOT-LT2019 datasets were refreshed while new datasets were introduced for VOT-RGBT2019 and VOT-RGBD2019. The VOT toolkit has been updated to support both standard short-term, long-term tracking and tracking with multi-channel imagery. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website(1).
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2. |
- Zhu, Zhifeng, et al.
(author)
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Effect of gas temperature on composition concentration measurements by laser-induced breakdown spectroscopy
- 2023
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In: Journal of Analytical Atomic Spectrometry. - : Royal Society of Chemistry (RSC). - 0267-9477 .- 1364-5544. ; 38:2, s. 382-390
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Journal article (peer-reviewed)abstract
- Laser-induced Breakdown Spectroscopy (LIBS) is widely applied to the quantitative measurement of gas composition concentrations. However, studies on the effect of gas temperature on LIBS are still lacking. Here, we investigated the effect of gas temperature on LIBS in terms of composition measurements in an air flow field. The air flow field was heated using a resistance wire to different gas temperatures ranging from 300-930 K in a heating tube. We evaluated the effect of gas temperature on the ratio of spectral line pairs, which is typically used for the calibrations of LIBS measurements. The variations in gas temperature change the ratio of spectral line pairs, which ultimately affects the accuracy of LIBS measurements. Further, the effect of gas temperature on the accuracy of LIBS measurements with different acquisition strategies was compared. The effects of gate width and delay time were investigated. An optimized acquisition strategy was proposed to reduce the effect of gas temperature on LIBS measurements. For LIBS measurements in gas flow fields, the effect of gas temperature on LIBS measurements can be reduced by using a large gate width and a suitable long delay time. The optimized acquisition strategy uses long-time averaging after an appropriate delay time to reduce the effect of gas temperature on plasma parameters. Finally, higher laser energy also helps to reduce the effect of gas temperature on LIBS measurements. In this paper, the LIBS measurement error caused by increasing the gas temperature from 300 K to 930 K is about 5%, roughly 0.8% per 100 K, with the optimized acquisition strategy. This paper can provide some help for LIBS measurements in gas samples with temperature variations.
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3. |
- Cai, Yunhao, et al.
(author)
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Effect of the Energy Offset on the Charge Dynamics in Nonfullerene Organic Solar Cells
- 2020
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In: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 12:39, s. 43984-43991
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Journal article (peer-reviewed)abstract
- The energy offset, considered as the driving force for charge transfer between organic molecules, has significant effects on both charge separation and charge recombination in organic solar cells. Herein, we designed material systems with gradually shifting energy offsets, including both positive and negative values. Time-resolved spectroscopy was used to monitor the charge dynamics within the bulk heterojunction. It is striking to find that there is still charge transfer and charge generation when the energy offset reached -0.10 eV (ultraviolet photoelectron spectroscopy data). This work not only indicates the feasibility of the free carrier generation and the following charge separation under the condition of a negative offset but also elucidates the relationship between the charge transfer and the energy offset in the case of polymer chlorination.
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4. |
- Li, Pin, et al.
(author)
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CFD modeling of dynamic airflow and particle transmission in an aircraft lavatory
- 2023
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In: Building Simulation. - : Springer Nature. - 1996-3599 .- 1996-8744. ; 16:8, s. 1375-1390
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Journal article (peer-reviewed)abstract
- Lavatories are frequently used facilities, especially on long-haul flights. Flushing a vacuum toilet in a lavatory can induce strong airflow, produce aerosols in the toilet bowl, and resuspend deposited particles from the floor. However, the exact particle transport routes and the fates of particle after toilet flushing are unclear so far. This investigation used computational fluid dynamics (CFD) to model the transient airflow and pollutant transport after a toilet flushing process in a lavatory of a commercial aircraft. The time-varying pressure profile measured in a laboratory was assigned to the drainage valve as boundary conditions. The aerosols generated inside the toilet bowl during flushing and the particles resuspended from the lavatory floor were used as particle sources. Lagrangian tracking of airborne particles in the lavatory was conducted. In addition, ammonia gas was used to examine odor perception. The multi-physics software program COMSOL 5.4 was employed for numerical solution after being validated. The results revealed that more than 70% of the generated particles in the toilet bowl are drained into sewage. A few particles may leak out of the toilet bowl and remain suspended in the air for more than five minutes when the toilet lid is open during flushing. Flushing the toilet with a closed lid can effectively reduce the particle leakage and the spread of odor gas, but it leads to greater deposition of particles on both the lid and seat. There is a slight inhalation exposure risk in the initial three minutes after flushing with a closed lid.
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5. |
- Wang, Tengfei, et al.
(author)
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Dual-ionic imidazolium salts to promote synthesis of cyclic carbonates at atmospheric pressure
- 2022
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In: Green Energy and Environment. - : Elsevier BV. - 2096-2797 .- 2468-0257. ; 7:6, s. 1327-1339
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Journal article (peer-reviewed)abstract
- Novel dual-ionic imidazolium salts are shown to display excellent catalytic activity for cycloaddition of carbon dioxide and epoxides under room temperature and atmospheric pressure (0.1 MPa) without any solvent and co-catalyst leading to 96.1% product yield. It can be reused five times to keep the product yield over 90%. These intriguing results are attributed to a new reaction mechanism, which is supported by theoretical calculations along with the measurements of 13C NMR spectrum and Fourier transform infrared spectroscopy (FT-IR). The excellent catalytic activity can be traced to a CO2-philic group along with an electrophilic hydrogen atom. Our work shows that incorporation of CO2-philic group is an feasible pathway to develop the new efficient ionic liquids.
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6. |
- Zhang, Tengfei, et al.
(author)
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A fault reconfiguration strategy based on adjustable space operator discrete state transition algorithm for ship microgrid system
- 2022
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In: Electric power systems research. - : Elsevier. - 0378-7796 .- 1873-2046. ; 205
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Journal article (peer-reviewed)abstract
- As an independent power supply network, when the ship ring microgrid system (SRMS) fails or is damaged, the power-loss load can be reasonably distributed to other power sources through the control switch, thereby improving the reliability of the power grid. We consider the maximum power load, minimum switching action and generator efficiency as the reconfiguration goals. In order to complete the reconfiguration quickly, we present an optimization strategy based on an adjustable space operator (ASO) and the discrete state transition algorithm (DSTA), the ASODSTA. The main idea of DSTA is to use four spatial geometric operators to find the optimal solution. The optimization is completed by combining the operators with the sigmoid function, and an ASO is proposed as the variable of the sigmoid function. The spatial distribution of the candidate solutions is more widespread through the unification of the four operators. The introduction of the sigmoid function and the ASO improves the quality of the global optimal solution and shortens the running time of the algorithm. The simulation results show that the proposed method can solve the SRMS reconfiguration problem faster and more effectively by comparing with the algorithms EO, WOA, GWO and BPSO in the references.
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7. |
- Zhang, Xing, et al.
(author)
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Diagnosing NB plasmas on the EAST tokamak with new time-of-flight neutron spectrometer
- 2014
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In: Nuclear Fusion. - : IOP Publishing. - 0029-5515 .- 1741-4326. ; 54:10, s. 104008-
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Journal article (peer-reviewed)abstract
- The new neutron spectrometer time-of-flight enhanced diagnostics (TOFED) for the EAST tokamak is presented and its characteristics are described in terms of simulation results, as well as the interface in the torus hall along with new neutral beam (NB) injectors. The use of TOFED for studies of the slowing down of NB-injected deuterons is illustrated. The implications of measuring the neutron emission on a long pulse machine are discussed together with the experimental challenges and diagnostic possibilities approaching those to be encountered in continuous operation.
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8. |
- Zheng, Danning, et al.
(author)
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Role of water in dual-ionic pyrazolium salt promoted conversion of CO2 at atmospheric pressure and room temperature
- 2023
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In: Catalysis Science & Technology. - : Royal Society of Chemistry. - 2044-4753 .- 2044-4761. ; 13:6, s. 1818-1829
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Journal article (peer-reviewed)abstract
- Dual-ionic pyrazolium salts have in this work been synthesized and shown to catalyze the coupling reaction of carbon dioxide (CO2) with epichlorohydrin achieving a 90% yield under 30 °C and 0.1 MPa CO2 pressure. With the aid of a small amount of water, the product yield is greatly improved up to 99.5% under the same reaction conditions, which corresponds to a rate enhancement of up to 1.4 times for the formation of the carbonate. We propose and explore a dual origin of the role of water, first by affecting the gas to liquid mass transfer of CO2, and second a mechanism where water triggers a proton transfer that in turn underlies efficient conversion of CO2. This theoretically derived mechanism is also confirmed by 13C NMR and FT-IR spectroscopy results. The catalyst was found to be reusable eight times without obvious reduction of catalytic activity. The finding presented that an already efficient reaction to attract CO2 is further greatly promoted only by the addition of water which can have important ramifications for green technology.
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9. |
- Zhivov, Alexander, et al.
(author)
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Principles of air and contaminant movement inside and around buildings
- 2020. - 2nd
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In: Industrial Ventilation Design Guidebook. - : Elsevier BV. ; , s. 245-370
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Book chapter (other academic/artistic)abstract
- Proper selection and sizing of ventilation systems require knowledge of emissions from internal contaminant and heat sources and an understanding of the characteristics of air and contaminant movement. In this chapter, the major factors affecting air and contaminant movement inside ventilated space are summarized and classified as: (1) transport mechanism of contaminant in ventilated space; (2) contaminant sources; (3) forced convection or supply air jets introduced into the room by mechanical or natural ventilation systems, or their combination; (4) free convection flows along heated and cooled vertical surfaces and above heat sources; (5) airflow created in the vicinity of local and general exhausts; (6) aerodynamic means of large opening protection; and (7) airflow through intended and unintended openings and cracks in the building envelope. This chapter provides some guidance on how to select predominant factors affecting air and contaminant movement, account for their joint effects, and predict airflow characteristics.
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10. |
- Zhou, Ping, et al.
(author)
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Molecular characterization of transcriptome-wide interactions between highly pathogenic porcine reproductive and respiratory syndrome virus and porcine alveolar macrophages in vivo
- 2011
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In: International Journal of Biological Sciences. - 1449-2288. ; 7:7, s. 947-959
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Journal article (peer-reviewed)abstract
- Porcine reproductive and respiratory syndrome virus (PRRSV) infects mainly the porcine alveolar macrophages (PAMs) and causes porcine reproductive and respiratory syndrome (PRRS). Previous studies have analyzed the global gene expression profiles of lung tissue in vivo and PAMs in vitro following infection with PRRSV, however, transcriptome-wide understanding of the interaction between highly pathogenic PRRSV (HP-PRRSV) and PAMs in vivo has not yet been established. In this study, we employed Affymetrix microarrays to investigate the gene expression patterns of PAMs isolated from Tongcheng piglets (a Chinese indigenous breed) after infection with HP-PRRSV. During the infection, Tongcheng piglets exhibited typical clinical signs, e.g. fever, asthma, coughing, anorexia, lethargy and convulsion, but displayed mild regional lung damage at 5 and 7 dpi. Microarray analysis revealed that HP-PRRSV infection has affected PAMs in expression of the important genes involved in cytoskeleton and exocytosis organization, protein degradation and folding, intracellular calcium and zinc homeostasis. Several potential antiviral strategies might be employed in PAMs, including upregulating IFN-induced genes and increasing intracellular zinc ion concentration. And inhibition of the complement system likely attenuated the lung damage during HP-PRRSV infection. Transcriptomic analysis of PAMs in vivo could lead to a better understanding of the HP-PRRSV-host interaction, and to the identification of novel antiviral therapies and genetic components of swine tolerance/susceptibility to HP-PRRS.
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