MICROWAVE-WAVE SPECTROSCOPY OF 5-METHYL HYDANTOIN

Hydantoin (Imidazolidine-2,4-dione, \chem{C_3H_4N_2O_2} is a five-membered heterocyclic compound, and has been regarded as a direct precursor of glycine, the simplest amino acid. The molecule was detected in carbonaceous chondrites together with several kinds of amino acids.\footnote{A. Shimomiya, and R. Ogasawara, Orig. Life Evol. Biosph. 32, 165 (2002)} We have measured pure rotational spectrum of the molecule in its ground and vibrationally excited states, and have provided the molecular line frequency list in the millimeter-wave region for astronomical search.\footnote{H. Ozeki, R. Miyahara, H. Ihara, S. Todaka, K. Kobayashi, and M. Ohishi, Astron. Astrophys. 600 A44 (2017).} 5-methyl hydantoin is the simplest chiral molecule among hydantoins, because either of the hydrogen atoms bonded to the C5 position of the five-membered ring is asymmetrically substituted. The molecule becomes a direct precursor of alanine, the simplest chiral amino acid. We have tried to observe pure rotational spectrum of 5-methyl hydantoin in the millimeter-wave to sub-millimeter-wave region. Guided with quantum chemical calculation, several spectral lines can be assigned to b-type transitions

FAR-INFRARED SPECTROSCOPY OF SHORT-LIVED SPECIES

Detection and characterization of short-lived species, or radicals, have been one of the main targets of high-resolution molecular spectroscopy. These kinetically unstable substances can be produced only in a very small amount under ordinary laboratory measurement conditions, it is essential to increase the sensitivity of the spectrometer and/or to improve the production efficiency of the molecules to be studied. Conventional microwave spectroscopy has taken an approach to raise the operating frequency to far-infrared region, expecting that effective absorption coefficient will increase. Sensitivity of the spectrometer in far-infrared region, or THz frequency region, has greatly improved thanks to succesful development of frequency multiplication techinques. Along with searching for an efficient production method of the short-lived species, many kinds of short-lived species can be possible to observe. Based on this situation, I would like to show several examples of far-infrared spectrosocpy of reactive species such as CH$_{2}$, NH$_{2}$, and CHF$_{2}$

How to evaluate science problem solving in a computerized learning environment? Construction of an analyzing scheme

Περιέχει το πλήρες κείμενοThis paper describes the construction of a ‘computerized science problem solving’ scheme, which enables analysis and evaluation of the effectiveness of science problem-solving by junior high-school students working in a computerized learning environment. The scheme was based on observations of 187 students as they solved qualitative science problems taken from a specific computerized learning environment. Students were also interviewed before and after the problem solving. The scheme is presented on two levels. The large-scale comprises 11 main categories, each sub-divided into sub-categories to yield the detailed-level. The sub-categories were based on a repertoire of activities found in the observation protocols, and were approved by external judgement and a validation process. The detailed-level scheme enables evaluation and statistical analysis of the participants' problem-solving effectiveness, providing substantial evidence for the construct validity of the scheme, and demonstrating its potential as a valid analyzing and evaluative tool for computerized science problem solving

Label-free observation of tissues by high-speed stimulated Raman spectral microscopy and independent component analysis

SPIE BiOS, 2013, San Francisco, California, United StatesYasuyuki Ozeki, Yoichi Otsuka, Shuya Sato, Hiroyuki Hashimoto, Wataru Umemura, Kazuhiko Sumimura, Norihiko Nishizawa, Kiichi Fukui, Kazuyoshi Itoh, "Label-free observation of tissues by high-speed stimulated Raman spectral microscopy and independent component analysis," Proc. SPIE 8588, Multiphoton Microscopy in the Biomedical Sciences XIII, 858806 (22 February 2013); https://doi.org/10.1117/12.200277

Large-scale mapping observations of the CI(3P1-3P0) and CO(J=3-2) lines toward the Orion A molecular cloud

Large scale mapping observations of the 3P1-3P0 fine structure transition of atomic carbon (CI, 492 GHz) and the J=3-2 transition of CO (346 GHz) toward the Orion A molecular cloud have been carried out with the Mt. Fuji submillimeter-wave telescope. The observations cover 9 square degrees, and include the Orion nebula M42 and the L1641 dark cloud complex. The CI emission extends over almost the entire region of the Orion A cloud and is surprisingly similar to that of 13CO(J=1-0).The CO(J=3-2) emission shows a more featureless and extended distribution than CI.The CI/CO(J=3-2) integrated intensity ratio shows a spatial gradient running from the north (0.10) to the south (1.2) of the Orion A cloud, which we interpret as a consequence of the temperature gradient. On the other hand, the CI/13CO(J=1-0) intensity ratio shows no systematic gradient. We have found a good correlation between the CI and 13CO(J=1-0) intensities over the Orion A cloud. This result is discussed on the basis of photodissociation region models.Comment: Text file is 13 pages long, and 3 figure files (pdf format). NRO Report No. 508 (1999). University of Tokyo, Resceu 41/9