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raman spectroscopy | 量子荧光|微型光纤光谱仪-ag贵宾会

ion beam induced cubic to monoclinic phase transformation of nanocrystalline yttria

ion beam induced cubic to monoclinic phase transformation of nanocrystalline yttria

sol gel derived nanocrystalline yttria pellets are irradiated with 120 mev ag9 ions for fluence in the range 1 1012–3 1013 ions cm 2. pristine and irradiated samples are characterized by x-ray diffraction (xrd), transmission electron microscopy (tem) and raman spectroscopy. xrd pattern of pristine y2o3 nanocrystal reveal cubic structure. a new xrd peak at 30.36 is observed in pellet irradiated with 1 1013 ions cm 2. the peak at 30.36 is corresponding to ?40 2? plane of monoclinic phase. the diffraction intensity of ?40 2? plane increases with ag9 ion fluence. raman spectrum of pristine pellet show bands corresponding to cubic phase. and, ion irradiated sample show new peaks at 410, 514 and 641 cm 1 corresponding monoclinic phase. hr-tem and saed pattern of ion irradiated sample confirmed the presence of monoclinic phase. hence, it is confirmed that, 120 mev ag9 ions induce phase transformation in nanocrystalline y2o3.

recently nanocrystalline yttrium oxide (y2o3) attracted extensive research interest due to its unique optical, electrical, chemical and thermal properties. y2o3 finds wide usage in a many luminescent host materials, medical diagnostics as well as biological, industrial and research fields [1–3]. cubic phase of y2o3 exhibit wide transparent range from uv (220 nm) to infrared ( 8 lm) region, it is optically isotropic and hard, having high refractive index ( 1.92). it possess high corrosion resistivity, high radiation stability, high melting point ( 2723 k), large band gap (5.72 ev) and low phonon energy ( 380 cm 1) which leads to very narrow emission and enhanced quantum efficiency [4,5].

raman microspectrometer combined with scattering microscopy and lensless imaging for bacteria identification

raman microspectrometer combined with scattering microscopy and lensless imaging for bacteria identification

in this paper, we report on a compact prototype capable both of lensfree imaging, raman spectrometry and scattering microscopy from bacteria samples. this instrument allows high-throughput real-time characterization without the need of markers, making it potentially suitable to field label-free biomedical and environmental applications.

recent challenging tasks in many fields are the identification, analysis and characterization of single bacteria within heterogeneous mixture. raman spectroscopy and elastic scattering spectroscopy have shown success in application to biological problems. however, raman technique requires a careful positioning of the excitation source onto single bacteria dispersed in a liquid mixture and dried on a hard surface, such as microscope coverslip1-3. a new lensfree imaging technique that can serve numerous biological applications has been developed in the recent years4,5. with this technology we are able first to localize bacteria over a large fov, then to address investigation exactly over single microorganism pre-identified in order to follow with raman spectroscopy and diffracted pattern imaging6.

spectral fiber sensors for cancer diagnostics in vitro

spectral fiber sensors for cancer diagnostics in vitro

cancer is one of the leading causes for morbidity and mortality worldwide. therefore, efforts are concentrated on cancer detection in an early stage to enhance survival rates for cancer patients. a certain intraoperative navigation in the tumor border zone is also an essential task to lower the mortality rate after surgical treatment. molecular spectroscopy methods proved to be powerful tools to differentiate cancerous and healthy tissue. within our project comparison of different vibration spectroscopy methods were tested to select the better one or to reach synergy from their combination. one key aspect was in special fiber probe development for each technique. using fiber optic probes in raman, mir and nir spectroscopy is a very powerful method for non-invasive in vivo applications. miniaturization of raman probes was achieved by deposition of dielectric filters directly onto the silica fiber end surfaces. raman, nir and mir spectroscopy were used to analyze samples from kidney tumors. the differentiation between cancer and healthy samples was successfully obtained by multivariate data analysis.

according to the world cancer report in 20141 cancer is one of the leading causes for morbidity and mortality worldwide. around 14 million new cases and 8.2 million cancer related deaths were registered in 2012, and the number of new cancer patients diagnosed each year will rise by 20% between 2002 and 2020. reports in the literature show2 that up to 30% of surgical procedures result in an incomplete removal of the tumor. the task to define tumor margins in-vivo is a great challenge, and optical spectroscopy may solve this problem.

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