35,449 research outputs found
Metamaterial-based Toraldo pupils for super-resolution at millimetre wavelengths
No full textUsing the long-established Cardiff metal-mesh filter technology, we have exploited our ability to artificially manipulate the phase of a wavefront across a device in order to produce a dielectric-based Toraldo pupil working at millimeter wavelengths. The use of a Toraldo pupil to push the angular resolution of an optical imaging system beyond the classical diffraction limit is yet to be realized in the millimeter regime, but is an exciting prospect. Here we present the design and measured performance of a prototype Toraldo pupil, based on a 5 annuli design
Chen wai xia ju jian
No full text[v.1]. 總目 -- [v.2- 3]. 卷一至二. 清修妙論牋 : [二卷] -- [v.4-7 ]. 卷三至六. 四時調攝牋 : [四卷] -- [v.8-9 ]. 卷七至八. 起居安樂牋 : [二卷] -- [v.10-11 ]. 卷九至十. 延年却病牋 : [二卷] -- [v.12- 14]. 卷十一至十三. 飲饌服食牋 : [三卷] -- [v.15-17]. 卷十四至十六. 燕閑清賞牋 : [三卷] -- [v.18-19]. 卷十七至十八. 靈秘丹藥牋 : [二卷] -- [v.20]. 卷十九. 塵外遐舉牋.[v.1]. Zong mu -- [v.2- 3]. juan yi zhi er. Qing xiu miao lun jian : [er juan] -- [v.4-7 ]. juan san zhi liu. Si shi diao she jian : [si juan] -- [v.8-9 ]. juan qi zhi ba. Qi ju an yue jian : [er juan] -- [v.10-11 ]. juan jiu zhi shi. Yan nian que bing jian : [er juan] -- [v.12- 14]. juan shi yi zhi shi san. Yin zhuan fu shi jian : [san juan] -- [v.15-17]. juan shi si zhi shi liu. Yan xian qing shang jian : [san juan] -- [v.18-19]. juan shi qi zhi shi ba. Ling mi dan yao jian : [er juan] -- [v.20]. juan shi jiu. Chen wai xia ju jian.[高濂編] ; 鍾惺較閱.綫裝, 2函.框20.3x12.2公分, 9行18字. 白口, 四周黑邊, 單黑魚尾. 版心上鐫"遵生八牋", 中鐫卷次及子目題, 下鐫葉次.内封頁題"增補遵生八牋, 鍾伯敬先生重訂, 課花書屋藏板"前有高濓原序.《燕閑清賞牋》卷端題下鐫"古杭高濂深甫氏編次"《清修妙論牋》, 《起居安樂牋》, 《延年却病牋》, 《靈秘丹藥牋》分上, 下卷 ; 《飲饌服食牋》, 《燕閑清賞牋》分上, 中, 下卷 ; 《四時調攝牋》分春, 下[即"夏"], 秋, 冬卷.見《香港中文大學圖書館古籍善本書錄》(2001, p. 139)Xian zhuang, 2 han.Kuang 20.3 x 12.2 gong fen, 9 hang 18 zi. Bai kou, si zhou hei bian, dan hei yu wei. Ban xin shang juan "Zun sheng ba jian", zhong juan juan ci ji zi mu ti, xia juan ye ci.Nei feng ye ti "Zeng bu zun sheng ba jian, Zhong Bojing xian sheng chong ding, Ke hua shu wu cang ban"Qian you Gao Lian yuan xu."Yan xian qing shang jian" juan duan ti xia juan "Guhang Gao Lian shen fu shi bian ci""Qing xiu miao lun jian", "Qi ju an yue jian", "Yan nian que bing jian", "Ling mi dan yao jian" fen shang, xia juan ; "Yin zhuan fu shi jian", "Yan xian qing shang jian" fen shang, zhong, xia juan ; "Si shi diao she jian" fen Chun, xia [ji "Xia"], Qiu, Dong juan.Jian "Xianggang Zhong wen da xue tu shu guan gu ji shan ben shu lu" (2001, p. 139)[Gao Lian bian] ; Zhong Xing jiao yue
Supplementary_Material-revised – Supplemental material for Acid-induced intermolecular [3+2] cycloaddition/oxidation to synthesize polysubstituted benzo[f]isoindole-4,9-diones
No full textSupplemental material, Supplementary_Material-revised for Acid-induced intermolecular [3+2] cycloaddition/oxidation to synthesize polysubstituted benzo[f]isoindole-4,9-diones by Zhang-qi Lin, Chao-dong Li, Yu-jin Li, Yong-jian Zhang, Zi-chun Zhou, Qing Ye and Jian-rong Gao in Journal of Chemical Research</p
Gal/Xgal U/LDB Spectroscopic/Stratospheric THz Observatory:: GUSTO
No full textGal/Xgal U/LDB Spectroscopic/ Stratospheric THz Observatory (GUSTO) is a NASA Explorers Mission of Opportunity that will make large scale maps of the Milky Way and Large Magellanic Cloud in three important interstellar lines: [CII], [OI], and [NII] at 158, 63, and 205 μm, respectively. During its ~75 day stratospheric (~36 km) flight, GUSTO’s 0.9-meter balloon-borne telescope and THz heterodyne array receivers will provide the spectral and spatial resolution needed to untangle the complexities of the interstellar medium by probing all phases of its Life Cycle. The GUSTO payload consists of (1) a telescope; (2) three 8-pixel heterodyne array receivers; (3) autocorrelator spectrometers; (4) instrument control electronics; and (5) a cryostat. The GUSTO gondola is derived from successful APL designs. Much of the GUSTO instrument architecture and hardware is based on the experience gained in developing and flying the Stratospheric Terahertz Observatory (STO). GUSTO is currently undergoing integration and test and will launch from the NASA Long Duration Balloon (LDB) Facility near McMurdo, Antarctica in December 2023.ImPhys/Optic
5.3 THz MgB2 hot electron bolometer mixer operated at 20 K
No full textHeterodyne receivers combining a NbN HEB mixer with a local oscillator (LO) are the work horse for high resolution (≥106) spectroscopic observations at supra-terahertz frequencies. We report an MgB2 HEB mixer working at 5.3 THz with20 K operation temperature based on a previously published paper [Y. Gan et al, Appl. Phys. Lett., 119, 202601 (2021)]. The HEB consists of a 7 nm thick MgB2 submicron-bridge contacted with a spiral antenna. It has a Tc of 38.4 K. By using hot/cold blackbody loads and a Mylar beam splitter all in vacuum, and applying a 5.25 THz FIR gas laser as the LO, we measured a minimal DSB receiver noise temperature of 3960 K. The latter gives a DSB mixer noise temperature of 1470 K. This sensitivity is 28 times better than a room temperature Schottky mixer at 4.7 THz, but about 2.5 times less sensitive than an NbN HEB mixer. The latter must be operated around 4 K. The IF noise bandwidth is about 10 GHz, which is 2.5-3 times larger than an NbN HEB. With further optimization, such MgB2 HEBs are expected to reach a better sensitivity. That the low noise, wide IF bandwidth MgB2 HEB mixers can be operated in a compact, low dissipation 20 K Stirling cooler can significantly reduce the cost and complexity of heterodyne instruments and therefore facilitate new space missions.ImPhys/Optic
Characterization of low-loss hydrogenated amorphous silicon films for superconducting resonators
No full textSuperconducting resonators used in millimeter-submillimeter astronomy would greatly benefit from deposited dielectrics with a small dielectric loss. We deposited hydrogenated amorphous silicon films using plasma-enhanced chemical vapor deposition, at substrate temperatures of 100°C, 250°C and 350°C. The measured void volume fraction, hydrogen content, microstructure parameter, and bond-angle disorder are negatively correlated with the substrate temperature. All three films have a loss tangent below 10−5 for a resonator energy of 105 photons, at 120 mK and 4–7 GHz. This makes these films promising for microwave kinetic inductance detectors and on-chip millimeter-submilimeter filters.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Tera-Hertz SensingSanitary Engineerin
Multi-octave anti-reflection coating for polypropylene-based quasi-optical devices
No full textThe sensitivity requirements of modern CMB instruments place high demands on the use of low loss materials for filter, lens and window devices. Anti-reflection coating (ARC) designs are routinely used to effect minimal dielectric fringing over a limited waveband, however there is a need to maximize this bandwidth over the operating range of the instrument. Here we present the design, manufacture and testing of prototype polypropylene devices based on multiple layer ARCs, to effect high transmission over three octaves of frequency
Development of large-diameter flat mesh-lenses for millimetre wave instrumentation
No full textWe present novel optics solutions based on metal mesh flat lenses which can be used to mimic a refracting lens. This approach removes the bulk of the dielectric materials (polyethylene or silicon) required for fast optical refracting systems. Additional attractive property of these lenses is that they filter out unwanted higher frequency radiation, they are easy to anti-reflection coat and they are extremely light. Measurements from 300mm diameter prototypes of both a Fresnel-type graded-index lens and a phase-delay type mesh-lens are presented
Simulating the Radiation Loss of Superconducting Submillimeter Wave Filters and Transmission Lines Using Sonnet EM
No full textSuperconducting resonators and transmission lines are fundamental building blocks of integrated circuits for millimeter-submillimeter astronomy. Accurate simulation of radiation loss from the circuit is crucial for the design of these circuits because radiation loss increases with frequency, and can thereby deteriorate the system performance. Here we show a stratification for a 2.5-dimensional method-of-moment simulator Sonnet EM that enables accurate simulations of the radiative resonant behavior of submillimeter-wave coplanar resonators and straight coplanar waveguides (CPWs). The Sonnet simulation agrees well with the measurement of the transmission through a coplanar resonant filter at 374.6 GHz. Our Sonnet stratification utilizes artificial lossy layers below the lossless substrate to absorb the radiation, and we use co-calibrated internal ports for de-embedding. With this type of stratification, Sonnet can be used to model superconducting millimeter-submillimeter wave circuits even when radiation loss is a potential concern.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Tera-Hertz Sensin
Large format imaging spectrograph for the Large Submillimeter Telescope (LST)
No full textWe present a conceptual study of a large format imaging spectrograph for next-generation large (50-m class) single-dish telescopes, i.e., the Large Submillimeter Telescope (LST) and Atacama Large Aperture Submillimeter Telescope (AtLAST). Recent discoveries of high-redshift star-forming galaxies at z=8-9 and candidate quiescent galaxies at z~6 indicate the onset of earliest star formation just a few 100 million years after the Big Bang (i.e., z = 12 - 15), and LST/AtLAST will provide a unique pathway to uncover spectroscopically-identified ``first forming galaxies’’ in the pre-reionization era, once it will be equipped with a large format imaging spectrograph. We describe the preliminary of 3-band, medium resolution (R=2000) imaging spectrograph with ~1.5 M detectors in total based on the KATANA concept (Karatsu et al.~2019), which exploits technologies of the integrated superconducting spectrometer (ISS) and a large-format imaging array like A-MKID.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Tera-Hertz Sensin
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