Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Opt Lett ; 48(19): 4981-4984, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37773365

RESUMO

In this Letter, inspired by the ghost imaging technique, we propose a wavefront shaping technique based on the third-order correlation of light fields (TCLF). Theoretically, we prove that if the light field fluctuation can be modeled by a complex Gaussian random process with a non-zero mean, the conjugate complex amplitude of the object and a focusing phase factor can be obtained by TCLF when using a single-point detector, which can support wavefront shaping. Experiments demonstrate that TCLF can achieve high-resolution wavefront shaping for scattered fields and scattering-assisted holography without additional operations such as optimization and phase shifting.

2.
Nanoscale ; 15(34): 13965-13970, 2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37565589

RESUMO

Metasurface has attracted massive interest owing to its ability to control light arbitrarily in a wide range of applications, such as high-speed imaging, optical interconnection, and spectroscopy. Here we propose a free space light modulator combined with a gold grating metasurface based on lithium niobate (LiNbO3). The quasi-bound states in the continuum (quasi-BIC) are achieved in the metasurface. In addition, the plasmonic quasi-BIC and the guided-mode resonance (GMR) can be modulated by controlling the polarization of the incident light without any geometric adjustment. Thus, the working wavelength range from 1480 nm to 1620 nm was achieved, and the maximum resonance depth reached about 51% at the resonant wavelength. In addition, the insertion loss of the device was -2.8 dB at a wavelength of 1510 nm. Furthermore, the dynamic modulation speed reached up to 190 MHz and the highest signal-to-noise ratio (SNR) could reach about 49 dB at a frequency of 65 MHz. The data showed potential for the material for applications such as near-infrared imaging, beam steering, and free-space optical communication links.

3.
Opt Lett ; 47(22): 5905-5908, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37219133

RESUMO

Electrically tunable metasurfaces can realize two-dimensional pixelated spatial light modulation and have a wide range of applications in optical switching, free-space communication, high-speed imaging, and so on, arousing the interest of researchers. Here, a gold nanodisk metasurface on a lithium-niobate-on-insulator (LNOI) substrate is fabricated and experimentally demonstrated as an electrically tunable optical metasurface for transmissive free-space light modulation. Using the hybrid resonance formed by the localized surface plasmon resonance (LSPR) of gold nanodisks and the Fabry-Perot (FP) resonance, the incident light is trapped in the gold nanodisk edges and a thin lithium niobate layer to realize field enhancement. In this way, an extinction ratio of 40% is achieved at the resonance wavelength. In addition, the proportion of hybrid resonance components can be adjusted by the size of the gold nanodisks. By applying a driving voltage of ± 2.8 V, a dynamic modulation of 135 MHz is achieved at resonant wavelength. The highest signal-to-noise ratio (SNR) is up to 48 dB at 75 MHz. This work paves the way for the realization of spatial light modulators based on CMOS-compatible LiNbO3 planar optics, which can be used in lidar, tunable displays, and so on.

4.
Opt Express ; 26(24): 31889-31897, 2018 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-30650768

RESUMO

We propose and demonstrate a novel flexible and elastic vibration-displacement fiber sensor with a doped polydimethylsiloxane (PDMS) micro-fiber based on model interference. High resolution three-dimensional displacement measurement is achieved through monitoring the output pattern and variation of power. The sensor with a length of about 200 µm reveals frequency range from 50 Hz to 14 kHz, covering all the human voice frequency, with greatly enhanced high signal to noise ratio (SNR) reaching up to 66 dB. This work suggests a simple structure, small size and low cost fiber-based convenient way to achieve a multifunctional sensing applications including human motion detection.

5.
Carbohydr Polym ; 124: 201-7, 2015 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-25839812

RESUMO

An evaluation system including colorimetric assay with iodine and potassium iodide, HPSEC-MALLS-RID analysis, GC-MS analysis, and saccharide mapping based on PACE analysis was proposed for the identification and discrimination of commercial product of Hericium erinaceus based on the chemical characters of polysaccharides in H. erinaceus fruiting body collected from different regions of China. The results showed that the molecular weights, the compositional monosaccharides and the glycosidic linkages of polysaccharides in H. erinaceus collected from different regions of China were similar, respectively. However, polysaccharides in the widely consumed product of H. erinaceus in China were significantly different from those of H. erinaceus fruiting body. The implications from these results were found to be beneficial to improve the quality control of polysaccharides from the H. erinaceus fruiting body, and suggest that the proposed evaluation system could be used as a routine approach for the quality control of polysaccharides in other edible and medicinal mushrooms.


Assuntos
Basidiomycota/química , Polissacarídeos/química , Basidiomycota/metabolismo , Cromatografia Líquida de Alta Pressão , Colorimetria , Carpóforos/química , Carpóforos/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Peso Molecular , Monossacarídeos/análise , Monossacarídeos/química , Monossacarídeos/isolamento & purificação , Polissacarídeos/análise , Polissacarídeos/isolamento & purificação , Análise de Componente Principal
6.
Carbohydr Polym ; 103: 100-9, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24528706

RESUMO

Polysaccharides from seven species of natural and cultured Cordyceps were firstly investigated and compared using saccharide mapping, partially acidic/enzymatic (α-amylase, ß-glucanase and pectinase) digestion followed with polysaccharide analysis by using carbohydrate gel electrophoresis (PACE) and high performance thin layer chromatography (HPTLC) analysis, respectively, to obtain the comprehensive profiles of hydrolysates of the polysaccharides and their characters. The results showed that 1,4-α-D-glucosidic, 1,4-ß-D-glucosidic and 1,4-α-D-galactosidic linkages were existed in natural and cultured Cordyceps sinensis, cultured Cordyceps militaris, natural Cordyceps gracilis and Cordyceps ciecadae. The similarity of polysaccharides from cultured C. militaris to natural C. sinensis was relatively high, which might contribute to the rational use of C. militaris. Moreover, different species of natural and cultured Cordyceps can be differentiated based on the saccharide mapping, which is helpful to well understand the structural characters of polysaccharides from different species of Cordyceps and to improve the quality control of polysaccharides in natural and cultured Cordyceps.


Assuntos
Cordyceps/química , Polissacarídeos/química , Cromatografia Líquida de Alta Pressão , Cordyceps/classificação , Eletroforese em Gel de Poliacrilamida , Especificidade da Espécie
7.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-642771

RESUMO

Objective To establish a stable primary culture of rat cerebellar granule neurons in vitro for further study the toxic effects of chronic arsenic exposure on cerebellar cells.Methods Cerebellar cortices were taken from brain of Wistar rat 5-7 day old after born under stereoscopic microscope.Single cell suspension was acquired after digestion and washing with trypsin (0.25%) and DNase Ⅰ solution,respectively.Granule cells were purified from other cells by differential velocity adherence method for two times.Rat cerebellar granule neurons were seeded in culture plate pre-coated with poly-L-lysine.Neurons growth,development and synaptic connections were observed daily.The neurons were identified by neuron specific enolase (NSE) immunofluorescence technique.Results The neurons were affixed to the culture plate in 24 hours,in reticular arrangement observed under contrast microscope.Granule cells gradually turned round from oval and outlines became clearer in 2-3 days.In 4-6 days,there were a wide range of synaptic connections among the neurons and a mature nerve cell network formed.A large quantity of cerebellar granule neurons was seen by NSE identification.Few bigger cells such as purkinjes cells and glial cell outlines were also seen in the same visual field.Conclusions This is a successful primary culture method for acquirement of rat cerebellar granule neurons.The method can provide experimental basis for future studies the toxic effects of chronic arsenic exposure on cerebellar cells.

8.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 26(3): 253-5, 2006 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-16613275

RESUMO

OBJECTIVE: To compare the short-term curative effect of clozapine (CZ) and its combination with electroacupuncture (EA) in treating schizophrenia. METHODS: Ninety schizophrenia patients were randomly divided into two groups equally: the EA group treated with combination of CZ (200 - 300 mg/d in mean) and EA, and the CZ group treated with CZ alone. The effects of treatment were evaluated with PANSS, CGI and TESS before and at the 2th, 4th, 6th and 8th weekend of the treatment. RESULTS: The initiation of effect in the two groups was the same, the total effective rate was 75% in the EA group and 73% in the CZ group. However, somatic complaint was lower and compliance was higher in the EA group than that in the CZ group respectively. CONCLUSION: With the effect equal to CZ, combination of CZ and EA shows higher compliance in treating schizophrenia, which would be beneficial in the later stage treatment for consolidation.


Assuntos
Terapia por Acupuntura , Clozapina/uso terapêutico , Eletroacupuntura , Esquizofrenia/terapia , Adolescente , Adulto , Clozapina/efeitos adversos , Terapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...