| 1. |
- Fan, Jin, et al.
(författare)
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Development of wideband orthomode transducers for FAST cryogenic receiver system
- 2020
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Ingår i: Research in Astronomy and Astrophysics. - : IOP Publishing. - 1674-4527. ; 20:5
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the design, construction, and performance of the wideband orthomode transducers (OMTs) for the L- (1.2-1.8 GHz), the S- (2-3 GHz) and the P- (0.56-1.12 GHz) band receiver systems of the Five-hundred-meter Aperture Spherical radio Telescope (FAST). These OMTs operate at the cryogenic temperature of 70K to reduce their thermal noise contribution to the receiver chains. The development on the FAST L- and S-band quad-ridged waveguide (QRWG) OMTs is carried out based on the theoretical mode analysis. In view of the miniaturization of FAST cryogenic receiver system at P-band, a novel wideband compact bowtie dipole OMT is designed with an octave bandwidth as well as a length of only quarter wavelength. The proposed L-, S- and P-band OMTs are designed and optimized by using Ansys High Frequency Structure Simulator (HFSS), and then manufactured, tested at room temperature. Measurement of FAST cryogenic receiver system noise is also performed with the L-, S- and P-band OMTs installed. The measured results fully comply with the design specifications.
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| 2. |
- Gan, Wensheng, et al.
(författare)
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Utility-Driven Data Analytics on Uncertain Data
- 2020
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Ingår i: IEEE Systems Journal. - : IEEE. - 1932-8184 .- 1937-9234. ; 14:3, s. 4442-4453
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Tidskriftsartikel (refereegranskat)abstract
- Modern Internet of Things (IoT) applications generate massive amounts of data, much of them in the form of objects/items of readings, events, and log entries. Specifically, most of the objects in these IoT data contain rich embedded information (e.g., frequency and uncertainty) and different levels of importance (e.g., unit risk/utility of items, interestingness, cost, or weight). Many existing approaches in data mining and analytics have limitations, such as only the binary attribute is considered within a transaction, as well as all the objects/items having equal weights or importance. To solve these drawbacks, a novel utility-driven data analytics algorithm named HUPNU is presented in this article. As a general utility-driven uncertain data mining model, HUPNU can extract High-Utility patterns by considering both Positive and Negative unit utilities from Uncertain data. The qualified high-utility patterns can be effectively discovered for intrusion detection, risk prediction, manufacturing management, and decision-making, among others. By using the developed vertical Probability-Utility list with the positive and negative utilities structure, as well as several effective pruning strategies, experiments showed that the developed HUPNU approach with the pruning strategies performed great in mining the qualified patterns efficiently and effectively.
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| 3. |
- Liu, Junwen, et al.
(författare)
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Isotope constraints of the strong influence of biomass burning to climate-forcing Black Carbon aerosols over Southeast Asia
- 2020
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 744
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Tidskriftsartikel (refereegranskat)abstract
- Black Carbon (BC) deteriorates air quality and contributes to climate warming, yet its regionally- and seasonally-varying emission sources are poorly constrained. Here we employ natural abundance radiocarbon (C-14) measurements of BC intercepted at a northern Malaysia regional receptor site, Bachok, to quantify the relative biomass vs. fossil source contributions of atmospheric BC, in a first year-round study for SE Asia (December 2015-December 2016). The annual average C-14 signature suggests as large contributions from biomass burning as from fossil fuel combustion. This is similar to findings from analogous measurements at S Asian receptors sites (similar to 50% biomass burning), while E Asia sites are dominated by fossil emission (similar to 20% biomass burning). The C-14-based source fingerprinting of BC in the dry spring season in SE Asia signals an even more elevated biomass burning contribution (similar to 70% or even higher), presumably from forest, shrub and agricultural fires. This is consistent with this period showing also elevated ratio of organic carbon to BC (up from similar to 5 to 30) and estimates of BC emissions from satellite fire data. Hence, the present study emphasizes the importance of mitigating dry season vegetation fires in SE Asia.
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| 4. |
- Yang, Wen-Jing, et al.
(författare)
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Heparanase from triple-negative breast cancer and platelets acts as an enhancer of metastasis
- 2020
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Ingår i: International Journal of Oncology. - : SPANDIDOS PUBL LTD. - 1019-6439 .- 1791-2423. ; 57:4, s. 890-904
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Tidskriftsartikel (refereegranskat)abstract
- Triple-negative breast cancer (TNBC), which is characterized by inherently aggressive behavior and lack of recognized molecular targets for therapy, poses a serious threat to women's health worldwide. However, targeted treatments have yet to be made available. A crosstalk between tumor cells and platelets (PLT) contributing to growth, angiogenesis and metastasis has been reported in numerous cancers. Heparanase (Hpa), the only mammalian endoglycosidase that cleaves heparan sulfate, has been demonstrated to contribute to the growth, angiogenesis and metastasis of numerous cancers. Hypoxia affects the growth, angiogenesis and metastasis of nearly all solid tumors, and the ability of Hpa to promote invasion is enhanced in hypoxia. However, whether Hpa can strengthen the crosstalk between tumor cells and PLT, and whether enhancing the biological function of Hpa in TNBC promotes malignant progression, have yet to be fully elucidated. The present study, based on bioinformatics analysis and experimental studies in vivo and in vitro, demonstrated that Hpa enhanced the crosstalk between TNBC cells and PLT to increase the supply of oxygen and nutrients, while also conferring tolerance of TNBC cells to oxygen and nutrient shortage, both of which are important for overcoming the stress of hypoxia and nutritional deprivation in the tumor microenvironment, thereby promoting malignant progression, including growth, angiogenesis and metastasis in TNBC. In addition, the hypoxia-inducible factor-1a (HIF-1a)/vascular endothelial growth factor-a (VEGF- a)/phosphorylated protein kinase B (p-)Akt axis may be the key pathway involved in the effects of Hpa on the biological processes mentioned above. Therefore, improving local hypoxia, anti-Hpa treatment and inhibiting PLT activation may improve the prognosis of TNBC.
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