期刊文献+
共找到330,995篇文章
< 1 2 250 >
每页显示 20 50 100
The Soft X-ray Imager(SXI)on the SMILE Mission 被引量:4
1
作者 S.Sembay A.L.Alme +83 位作者 D.Agnolon T.Arnold A.Beardmore A.Belén Balado Margeli C.Bicknell C.Bouldin G.Branduardi-Raymont T.Crawford J.P.Breuer T.Buggey G.Butcher R.Canchal J.A.Carter A.Cheney Y.Collado-Vega H.Connor T.Crawford N.Eaton C.Feldman C.Forsyth T.Frantzen G.Galgóczi J.Garcia G.Y.Genov C.Gordillo H-P.Gröbelbauer M.Guedel Y.Guo M.Hailey D.Hall R.Hampson J.Hasiba O.Hetherington A.Holland S-Y.Hsieh M.W.J.Hubbard H.Jeszenszky M.Jones T.Kennedy K.Koch-Mehrin S.Kögl S.Krucker K.D.Kuntz C.Lakin G.Laky O.Lylund A.Martindale J.Miguel Mas Hesse R.Nakamura K.Oksavik N.Østgaard H.Ottacher R.Ottensamer C.Pagani S.Parsons P.Patel J.Pearson G.Peikert F.S.Porter T.Pouliantis B.H.Qureshi W.Raab G.Randal A.M.Read N.M.M.Roque M.E.Rostad C.Runciman S.Sachdev A.Samsonov M.Soman D.Sibeck S.Smit J.Søndergaard R.Speight S.Stavland M.Steller TianRan Sun J.Thornhill W.Thomas K.Ullaland B.Walsh D.Walton C.Wang S.Yang 《Earth and Planetary Physics》 EI CSCD 2024年第1期5-14,共10页
The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese... The Soft X-ray Imager(SXI)is part of the scientific payload of the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission.SMILE is a joint science mission between the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS)and is due for launch in 2025.SXI is a compact X-ray telescope with a wide field-of-view(FOV)capable of encompassing large portions of Earth’s magnetosphere from the vantage point of the SMILE orbit.SXI is sensitive to the soft X-rays produced by the Solar Wind Charge eXchange(SWCX)process produced when heavy ions of solar wind origin interact with neutral particles in Earth’s exosphere.SWCX provides a mechanism for boundary detection within the magnetosphere,such as the position of Earth’s magnetopause,because the solar wind heavy ions have a very low density in regions of closed magnetic field lines.The sensitivity of the SXI is such that it can potentially track movements of the magnetopause on timescales of a few minutes and the orbit of SMILE will enable such movements to be tracked for segments lasting many hours.SXI is led by the University of Leicester in the United Kingdom(UK)with collaborating organisations on hardware,software and science support within the UK,Europe,China and the United States. 展开更多
关键词 Soft X-ray imaging micropore optics large area CCD
下载PDF
SMILE soft X-ray Imager flight model CCD370 pre-flight device characterisation 被引量:1
2
作者 S.Parsons D.J.Hall +4 位作者 O.Hetherington T.W.Buggey T.Arnold M.W.J.Hubbard A.Holland 《Earth and Planetary Physics》 EI CSCD 2024年第1期25-38,共14页
Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the sof... Throughout the SMILE mission the satellite will be bombarded by radiation which gradually damages the focal plane devices and degrades their performance.In order to understand the changes of the CCD370s within the soft X-ray Imager,an initial characterisation of the devices has been carried out to give a baseline performance level.Three CCDs have been characterised,the two flight devices and the flight spa re.This has been carried out at the Open University in a bespo ke cleanroom measure ment facility.The results show that there is a cluster of bright pixels in the flight spa re which increases in size with tempe rature.However at the nominal ope rating tempe rature(-120℃) it is within the procure ment specifications.Overall,the devices meet the specifications when ope rating at -120℃ in 6 × 6 binned frame transfer science mode.The se rial charge transfer inefficiency degrades with temperature in full frame mode.However any charge losses are recovered when binning/frame transfer is implemented. 展开更多
关键词 CCD soft X-ray imager characterisation SMILE
下载PDF
Design and performance evaluation of a large field-of-view dual-particle time-encoded imager based on a depth-of-interaction detector
3
作者 Dong Zhao Xu-Wen Liang +6 位作者 Ping-Kun Cai Wei Cheng Wen-Bao Jia Da-Qian Hei Qing Shan Yong-Sheng Ling Chao Shi 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第4期1-14,共14页
Time-encoded imaging is useful for identifying potential special nuclear materials and other radioactive sources at a distance.In this study,a large field-of-view time-encoded imager was developed for gamma-ray and ne... Time-encoded imaging is useful for identifying potential special nuclear materials and other radioactive sources at a distance.In this study,a large field-of-view time-encoded imager was developed for gamma-ray and neutron source hotspot imaging based on a depth-of-interaction(DOI)detector.The imager primarily consists of a DOI detector system and a rotary dual-layer cylindrical coded mask.An EJ276 plastic scintillator coupled with two SiPMs was designed as the DOI detector to increase the field of view and improve the imager performance.The difference in signal time at both ends and the log of the signal amplitude ratio were used to calculate the interaction position resolution.The position resolution of the DOI detector was calibrated using a collimated Cs-137 source,and the full width at half maximum of the reconstruction position of the Gaussian fitting curve was approximately 4.4 cm.The DOI detector can be arbitrarily divided into several units to independently reconstruct the source distribution images.The unit length was optimized via Am-Be source-location experiments.A multidetector filtering method is proposed for image denoising.This method can effectively reduce image noise caused by poor DOI detector position resolution.The vertical field of view of the imager was(-55°,55°)when the detector was placed in the center of the coded mask.A DT neutron source at 20 m standoff could be located within 2400 s with an angular resolution of 3.5°. 展开更多
关键词 Time-encoded imager Depth-of-interaction detector Dual-particle imaging Hotspot imaging
下载PDF
Simulation of the SMILE Soft X-ray Imager response to a southward interplanetary magnetic field turning 被引量:1
4
作者 Andrey Samsonov Graziella Branduardi-Raymont +3 位作者 Steven Sembay Andrew Read David Sibeck Lutz Rastaetter 《Earth and Planetary Physics》 EI CSCD 2024年第1期39-46,共8页
The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)Soft X-ray Imager(SXI)will shine a spotlight on magnetopause dynamics during magnetic reconnection.We simulate an event with a southward interplanetary magne... The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)Soft X-ray Imager(SXI)will shine a spotlight on magnetopause dynamics during magnetic reconnection.We simulate an event with a southward interplanetary magnetic field turning and produce SXI count maps with a 5-minute integration time.By making assumptions about the magnetopause shape,we find the magnetopause standoff distance from the count maps and compare it with the one obtained directly from the magnetohydrodynamic(MHD)simulation.The root mean square deviations between the reconstructed and MHD standoff distances do not exceed 0.2 RE(Earth radius)and the maximal difference equals 0.24 RE during the 25-minute interval around the southward turning. 展开更多
关键词 MAGNETOPAUSE magnetic reconnection solar wind charge exchange southward interplanetary magnetic field numerical modeling Solar wind Magnetosphere Ionosphere Link Explorer(SMILE) Soft X-ray imager
下载PDF
End-to-end computational design for an EUV solar corona multispectral imager with stray light suppression
5
作者 Jinming Gao Yue Sun +6 位作者 Yinxu Bian Jilong Peng Qian Yu Cuifang Kuang Xiangzhao Wang Xu Liu Xiangqun Cui 《Astronomical Techniques and Instruments》 CSCD 2024年第1期31-41,共11页
An extreme ultraviolet solar corona multispectral imager can allow direct observation of high temperature coronal plasma,which is related to solar flares,coronal mass ejections and other significant coronal activities... An extreme ultraviolet solar corona multispectral imager can allow direct observation of high temperature coronal plasma,which is related to solar flares,coronal mass ejections and other significant coronal activities.This manuscript proposes a novel end-to-end computational design method for an extreme ultraviolet(EUV)solar corona multispectral imager operating at wavelengths near 100 nm,including a stray light suppression design and computational image recovery.To suppress the strong stray light from the solar disk,an outer opto-mechanical structure is designed to protect the imaging component of the system.Considering the low reflectivity(less than 70%)and strong-scattering(roughness)of existing extreme ultraviolet optical elements,the imaging component comprises only a primary mirror and a curved grating.A Lyot aperture is used to further suppress any residual stray light.Finally,a deep learning computational imaging method is used to correct the individual multi-wavelength images from the original recorded multi-slit data.In results and data,this can achieve a far-field angular resolution below 7",and spectral resolution below 0.05 nm.The field of view is±3 R_(☉)along the multi-slit moving direction,where R☉represents the radius of the solar disk.The ratio of the corona's stray light intensity to the solar center's irradiation intensity is less than 10-6 at the circle of 1.3 R_(☉). 展开更多
关键词 EUV solar corona imager Curved grating Stray light suppression Computational multispectral imaging
下载PDF
Transformer-Based Cloud Detection Method for High-Resolution Remote Sensing Imagery
6
作者 Haotang Tan Song Sun +1 位作者 Tian Cheng Xiyuan Shu 《Computers, Materials & Continua》 SCIE EI 2024年第7期661-678,共18页
Cloud detection from satellite and drone imagery is crucial for applications such as weather forecasting and environmentalmonitoring.Addressing the limitations of conventional convolutional neural networks,we propose ... Cloud detection from satellite and drone imagery is crucial for applications such as weather forecasting and environmentalmonitoring.Addressing the limitations of conventional convolutional neural networks,we propose an innovative transformer-based method.This method leverages transformers,which are adept at processing data sequences,to enhance cloud detection accuracy.Additionally,we introduce a Cyclic Refinement Architecture that improves the resolution and quality of feature extraction,thereby aiding in the retention of critical details often lost during cloud detection.Our extensive experimental validation shows that our approach significantly outperforms established models,excelling in high-resolution feature extraction and precise cloud segmentation.By integrating Positional Visual Transformers(PVT)with this architecture,our method advances high-resolution feature delineation and segmentation accuracy.Ultimately,our research offers a novel perspective for surmounting traditional challenges in cloud detection and contributes to the advancement of precise and dependable image analysis across various domains. 展开更多
关键词 CLOUD TRANSFORMER image segmentation remotely sensed imagery pyramid vision transformer
下载PDF
Contribution of Imagery in the Diagnosis of Multisystemic Sarcoidosis in the Service Radiology Department of the Mother and Child Hospital “Le Luxembourg” in Bamako: A Case Report
7
作者 Mariko Mahamane Camara Mamoudou +7 位作者 Keita Aboubacar Sidiki N’Diaye Mahamadou Camara Mody Abdoulaye Fofana Youssouf Traoré Mohamed Maba Sidibé Siaka Sanogo Souleymane Keita Adama Diaman 《Open Journal of Medical Imaging》 2024年第3期79-85,共7页
The aim of this study was to report a case of multi-visceral sarcoidosis at the Mother-Child Hospital Center (CHME) “Le Luxembourg” in Bamako, Mali. Observation: This is a patient aged 62 at the time of consultation... The aim of this study was to report a case of multi-visceral sarcoidosis at the Mother-Child Hospital Center (CHME) “Le Luxembourg” in Bamako, Mali. Observation: This is a patient aged 62 at the time of consultation, a housewife, residing in the Banconi district, who was referred to us for thoracic-abdominopelvic imaging for chronic liver disease. After several diagnostic errors, the thoracic-abdominopelvic CT scan and liver MRI performed in our center showed, at the thoracoabdominal level, bilateral diffuse pulmonary micronodules and bilateral mediastinal-hilar lymphadenopathy;on the abdominal level, a dysmorphic liver with plaques of steatosis and a granular appearance of the liver parenchyma without periportal fibrosis. These imaging data combined with those from the liver nodule biopsy and biology confirmed the diagnosis of sarcoidosis type II. Treatment with corticosteroids gave satisfactory results and the patient recovered after 18 months. Clinical and CT monitoring 2 years from the start of the disease and 2 months from the end of treatment showed complete resolution of the lesions. Conclusion: The multi-visceral location of sarcoidosis is an entity whose diagnosis remains difficult;diagnostic and interventional imaging has an important place in its management. 展开更多
关键词 SARCOIDOSIS Multi VISCERAL imaging CHME Luxembourg
下载PDF
Lossless Compression Method for the Magnetic and Helioseismic Imager(MHI)Payload
8
作者 Li-Yue Tong Jia-Ben Lin +4 位作者 Yuan-Yong Deng Kai-Fan Ji Jun-Feng Hou Quan Wang Xiao Yang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第4期214-221,共8页
The Solar Polar-orbit Observatory(SPO),proposed by Chinese scientists,is designed to observe the solar polar regions in an unprecedented way with a spacecraft traveling in a large solar inclination angle and a small e... The Solar Polar-orbit Observatory(SPO),proposed by Chinese scientists,is designed to observe the solar polar regions in an unprecedented way with a spacecraft traveling in a large solar inclination angle and a small ellipticity.However,one of the most significant challenges lies in ultra-long-distance data transmission,particularly for the Magnetic and Helioseismic Imager(MHI),which is the most important payload and generates the largest volume of data in SPO.In this paper,we propose a tailored lossless data compression method based on the measurement mode and characteristics of MHI data.The background out of the solar disk is removed to decrease the pixel number of an image under compression.Multiple predictive coding methods are combined to eliminate the redundancy utilizing the correlation(space,spectrum,and polarization)in data set,improving the compression ratio.Experimental results demonstrate that our method achieves an average compression ratio of 3.67.The compression time is also less than the general observation period.The method exhibits strong feasibility and can be easily adapted to MHI. 展开更多
关键词 methods:data analysis techniques:image processing Sun:magnetic fields Sun:photosphere
下载PDF
From text to image:challenges in integrating vision into ChatGPT for medical image interpretation
9
作者 Shunsuke Koga Wei Du 《Neural Regeneration Research》 SCIE CAS 2025年第2期487-488,共2页
Large language models(LLMs),such as ChatGPT developed by OpenAI,represent a significant advancement in artificial intelligence(AI),designed to understand,generate,and interpret human language by analyzing extensive te... Large language models(LLMs),such as ChatGPT developed by OpenAI,represent a significant advancement in artificial intelligence(AI),designed to understand,generate,and interpret human language by analyzing extensive text data.Their potential integration into clinical settings offers a promising avenue that could transform clinical diagnosis and decision-making processes in the future(Thirunavukarasu et al.,2023).This article aims to provide an in-depth analysis of LLMs’current and potential impact on clinical practices.Their ability to generate differential diagnosis lists underscores their potential as invaluable tools in medical practice and education(Hirosawa et al.,2023;Koga et al.,2023). 展开更多
关键词 imagE DIAGNOSIS TEXT
下载PDF
Power of SAR Imagery and Machine Learning in Monitoring Ulva prolifera:A Case Study of Sentinel-1 and Random Forest
10
作者 ZHENG Longxiao WU Mengquan +5 位作者 XUE Mingyue WU Hao LIANG Feng LI Xiangpeng HOU Shimin LIU Jiayan 《Chinese Geographical Science》 SCIE CSCD 2024年第6期1134-1143,共10页
Automatically detecting Ulva prolifera(U.prolifera)in rainy and cloudy weather using remote sensing imagery has been a long-standing problem.Here,we address this challenge by combining high-resolution Synthetic Apertu... Automatically detecting Ulva prolifera(U.prolifera)in rainy and cloudy weather using remote sensing imagery has been a long-standing problem.Here,we address this challenge by combining high-resolution Synthetic Aperture Radar(SAR)imagery with the machine learning,and detect the U.prolifera of the South Yellow Sea of China(SYS)in 2021.The findings indicate that the Random Forest model can accurately and robustly detect U.prolifera,even in the presence of complex ocean backgrounds and speckle noise.Visual inspection confirmed that the method successfully identified the majority of pixels containing U.prolifera without misidentify-ing noise pixels or seawater pixels as U.prolifera.Additionally,the method demonstrated consistent performance across different im-ages,with an average Area Under Curve(AUC)of 0.930(+0.028).The analysis yielded an overall accuracy of over 96%,with an aver-age Kappa coefficient of 0.941(+0.038).Compared to the traditional thresholding method,Random Forest model has a lower estima-tion error of 14.81%.Practical application indicates that this method can be used in the detection of unprecedented U.prolifera in 2021 to derive continuous spatiotemporal changes.This study provides a potential new method to detect U.prolifera and enhances our under-standing of macroalgal outbreaks in the marine environment. 展开更多
关键词 Ulva prolifera Random Forest Sentinel-1 Synthetic Aperture Radar(SAR)image machine learning remote sensing Google Earth Engine South Yellow Sea of China
下载PDF
Advancement in utilization of magnetic resonance imaging and biomarkers in the understanding of schizophrenia
11
作者 Aidan K Tirpack Danyaal G Buttar Mandeep Kaur 《World Journal of Clinical Cases》 SCIE 2025年第1期11-15,共5页
Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental disorders.The utilization of neuroimaging or biomarkers to... Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental disorders.The utilization of neuroimaging or biomarkers to make the diagnosis and manage psychiatric disorders remains a distant goal.There have been several studies that examine brain imaging in psychiatric disorders,but more work is needed to elucidate the complexities of the human brain.In this editorial,we examine two articles by Xu et al and Stoyanov et al,that show developments in the direction of using neuroimaging to examine the brains of people with schizo-phrenia and depression.Xu et al used magnetic resonance imaging to examine the brain structure of patients with schizophrenia,in addition to examining neurotransmitter levels as biomarkers.Stoyanov et al used functional magnetic resonance imaging to look at modulation of different neural circuits by diagnostic-specific scales in patients with schizophrenia and depression.These two studies provide crucial evidence in advancing our understanding of the brain in prevalent psychiatric disorders. 展开更多
关键词 SCHIZOPHRENIA Magnetic resonance imaging Biomarkers NEUROTRANSMITTERS Psychiatric disorders
下载PDF
Magnetic resonance imaging evaluation and nuclear receptor binding SET domain protein 1 mutation in the Sotos syndrome with attention-deficit/hyperactivity disorder
12
作者 Wei Zhu 《World Journal of Clinical Cases》 SCIE 2025年第2期5-9,共5页
Sotos syndrome is characterized by overgrowth features and is caused by alterations in the nuclear receptor binding SET domain protein 1 gene.Attentiondeficit/hyperactivity disorder(ADHD)is considered a neurodevelopme... Sotos syndrome is characterized by overgrowth features and is caused by alterations in the nuclear receptor binding SET domain protein 1 gene.Attentiondeficit/hyperactivity disorder(ADHD)is considered a neurodevelopment and psychiatric disorder in childhood.Genetic characteristics and clinical presentation could play an important role in the diagnosis of Sotos syndrome and ADHD.Magnetic resonance imaging(MRI)has been used to assess medical images in Sotos syndrome and ADHD.The images process is considered to display in MRI while wavelet fusion has been used to integrate distinct images for achieving more complete information in single image in this editorial.In the future,genetic mechanisms and artificial intelligence related to medical images could be used in the clinical diagnosis of Sotos syndrome and ADHD. 展开更多
关键词 Sotos syndrome Attention-deficit/hyperactivity disorder Genetic mutation Magnetic resonance imaging Wavelet fusion
下载PDF
Recent progress in the applications of presynaptic dopaminergic positron emission tomography imaging in parkinsonism
13
作者 Yujie Yang Xinyi Li +7 位作者 Jiaying Lu Jingjie Ge Mingjia Chen Ruixin Yao Mei Tian Jian Wang Fengtao Liu Chuantao Zuo 《Neural Regeneration Research》 SCIE CAS 2025年第1期93-106,共14页
Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.... Nowadays,presynaptic dopaminergic positron emission tomography,which assesses deficiencies in dopamine synthesis,storage,and transport,is widely utilized for early diagnosis and differential diagnosis of parkinsonism.This review provides a comprehensive summary of the latest developments in the application of presynaptic dopaminergic positron emission tomography imaging in disorders that manifest parkinsonism.We conducted a thorough literature search using reputable databases such as PubMed and Web of Science.Selection criteria involved identifying peer-reviewed articles published within the last 5 years,with emphasis on their relevance to clinical applications.The findings from these studies highlight that presynaptic dopaminergic positron emission tomography has demonstrated potential not only in diagnosing and differentiating various Parkinsonian conditions but also in assessing disease severity and predicting prognosis.Moreover,when employed in conjunction with other imaging modalities and advanced analytical methods,presynaptic dopaminergic positron emission tomography has been validated as a reliable in vivo biomarker.This validation extends to screening and exploring potential neuropathological mechanisms associated with dopaminergic depletion.In summary,the insights gained from interpreting these studies are crucial for enhancing the effectiveness of preclinical investigations and clinical trials,ultimately advancing toward the goals of neuroregeneration in parkinsonian disorders. 展开更多
关键词 aromatic amino acid decarboxylase brain imaging dopamine transporter Parkinson’s disease PARKINSONISM positron emission tomography presynaptic dopaminergic function vesicle monoamine transporter type 2
下载PDF
Investigation on Physiological Status of Regional Vegetation Using Pushbroom Hyperspectral Imager Data 被引量:1
14
作者 甘甫平 王润生 +1 位作者 马蔼乃 杨苏明 《Acta Botanica Sinica》 CSCD 2002年第8期983-989,共7页
To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in Septemb... To extract vegetation pigment concentration and physiological status has been studied in two test areas covered with swamp and flourish vegetation using pushbroom hyperspectral imager (PHI) data which flied in September of 2000 at Daxing'anling district of Heilongjiang Province, China. The ratio analysis of reflectance spectra (RARS) indices, which were put forward by Chappelle et al (1992), are chosen in this paper owing to their effect and simpleness against both comparison with various methods and techniques for exploration of pigment concentration and characteristics of PHI data. The correlation coefficients between RARS indices and pigment concentration of vegetation were up to 0.8. The new RARS indices modes are established in the two test areas using both PHI data and spectra of different vegetations measured in the field. The indices' parameter images of chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoids (Cars) of the test areas covered with swamp and flourish vegetation are acquired by the new RARS indices modes. Furthermore, the regional concentration of Chl a and Chl b are extracted and quantified using regression equations between RARS indices and pigment concentrations, which were built by Blackburn (1998). The results showed the physiological status and variety clearly, and are in good agreement with the distribution of vegetation in the field. 展开更多
关键词 pigment indices pigment concentration CHLOROPHYLL ratio analysis of reflectance spectra (RARS) indices pushbroom hyperspectral imager (PHI) Daxing'anling district
下载PDF
Principle and Analysis of Novel Gate-Induced Noise in Pixel MOSFET of CMOS Imagers
15
作者 金湘亮 陈杰 仇玉林 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第9期921-926,共6页
A detailed principle and a rigorous analysis of a new noise,the gate-induced noise,in pixel MOSFET of CMOS imagers are provided.The gate-induced noise of the MOSFET is more notable in the strong reversion region than... A detailed principle and a rigorous analysis of a new noise,the gate-induced noise,in pixel MOSFET of CMOS imagers are provided.The gate-induced noise of the MOSFET is more notable in the strong reversion region than that in the subthreshold region when the applied gate voltage is low.However,the applied gate voltage being up to 3V,the gate-induced noise is more notable with the ω/ω T increasing when the MOSFET operates in the subthreshold region than that in the strong reversion region.Between the photocurrent I D and the root mean square value of the gated-induced noise,current i 2 d presents the relation of i 2 d∝I D in the saturation region of the strong reversion and approximately i 2 d∝I D in the subthreshold region.A deta iled and rigorous study of the gate-induced noise in the reset MOSFET for the p hotodiode APS and improved photodiode APS are provided.The improvement of logari thmic response APS is analyzed and the simulation results show that the gate-in duced noise can be reduced. 展开更多
关键词 gate-induced noise pixel MOSFET improved photodiode APS CMOS imagers
下载PDF
Alpha Imager EP凝胶成像系统故障维修
16
作者 刘海燕 常玉梅 《医疗卫生装备》 CAS 2012年第3期145-145,共1页
凝胶成像系统是分子生物学常用仪器,在医院临床检验和科研开发中发挥着重要的辅助作用。其主要是对电泳后的琼脂糖凝胶中的核酸在紫外灯管下的影像进行采集,并进行图像保存与定性分析。我院于2008年购进1台Al-pha Imager EP凝胶成像系统... 凝胶成像系统是分子生物学常用仪器,在医院临床检验和科研开发中发挥着重要的辅助作用。其主要是对电泳后的琼脂糖凝胶中的核酸在紫外灯管下的影像进行采集,并进行图像保存与定性分析。我院于2008年购进1台Al-pha Imager EP凝胶成像系统,此机器操作简便、图像清晰,并可以进行核酸半定量分析。 展开更多
关键词 凝胶成像系统 imager 故障维修 ALPHA EP 图像清晰 分子生物学 琼脂糖凝胶
下载PDF
IMATION969 HQ Laser Imager故障检修
17
作者 张兵 《医疗设备信息》 2002年第9期59-59,共1页
关键词 IMATION 969 HQ LASER imager 故障 检修
下载PDF
Evaluation of Two Absolute Radiometric Normalization Algorithms for Pre-processing of Landsat Imagery 被引量:13
18
作者 徐涵秋 《Journal of China University of Geosciences》 SCIE CSCD 2006年第2期146-150,157,共6页
In order to evaluate radiometric normalization techniques, two image normalization algorithms for absolute radiometric correction of Landsat imagery were quantitatively compared in this paper, which are the Illuminati... In order to evaluate radiometric normalization techniques, two image normalization algorithms for absolute radiometric correction of Landsat imagery were quantitatively compared in this paper, which are the Illumination Correction Model proposed by Markham and Irish and the Illumination and Atmospheric Correction Model developed by the Remote Sensing and GIS Laboratory of the Utah State University. Relative noise, correlation coefficient and slope value were used as the criteria for the evaluation and comparison, which were derived from pseudo-invarlant features identified from multitemporal Landsat image pairs of Xiamen (厦门) and Fuzhou (福州) areas, both located in the eastern Fujian (福建) Province of China. Compared with the unnormalized image, the radiometric differences between the normalized multitemporal images were significantly reduced when the seasons of multitemporal images were different. However, there was no significant difference between the normalized and unnorrealized images with a similar seasonal condition. Furthermore, the correction results of two algorithms are similar when the images are relatively clear with a uniform atmospheric condition. Therefore, the radiometric normalization procedures should be carried out if the multitemporal images have a significant seasonal difference. 展开更多
关键词 LANDSAT radiometrie correction data normalization pseudo-invariant features image processing.
下载PDF
Mapping the bathymetry of shallow coastal water using singleframe fine-resolution optical remote sensing imagery 被引量:7
19
作者 LI Jiran ZHANG Huaguo +2 位作者 HOU Pengfei FU Bin ZHENG Gang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第1期60-66,共7页
This paper presents a bathymetry inversion method using single-frame fine-resolution optical remote sensing imagery based on ocean-wave refraction and shallow-water wave theory. First, the relationship among water dep... This paper presents a bathymetry inversion method using single-frame fine-resolution optical remote sensing imagery based on ocean-wave refraction and shallow-water wave theory. First, the relationship among water depth, wavelength and wave radian frequency in shallow water was deduced based on shallow-water wave theory. Considering the complex wave distribution in the optical remote sensing imagery, Fast Fourier Transform (FFT) and spatial profile measurements were applied for measuring the wavelengths. Then, the wave radian frequency was calculated by analyzing the long-distance fluctuation in the wavelength, which solved a key problem in obtaining the wave radian frequency in a single-frame image. A case study was conducted for Sanya Bay of Hainan Island, China. Single-flame fine-resolution optical remote sensing imagery from QuickBird satellite was used to invert the bathymetry without external input parameters. The result of the digital elevation model (DEM) was evaluated against a sea chart with a scale of 1:25 000. The root-mean-square error of the inverted bathymetry was 1.07 m, and the relative error was 16.2%. Therefore, the proposed method has the advantages including no requirement for true depths and environmental parameters, and is feasible for mapping the bathymetry of shallow coastal water. 展开更多
关键词 BATHYMETRY optical remote sensing image NEARSHORE QUICKBIRD
下载PDF
Sea ice thickness estimation in the Bohai Sea using geostationary ocean color imager data 被引量:7
20
作者 LIU Wensong SHENG Hui ZHANG Xi 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第7期105-112,共8页
A method to estimate the thickness of the sea ice of the Bohai Sea is proposed using geostationary ocean color imager (GOCI) data and then applied to the dynamic monitoring of the sea ice thickness in the Bohal Sea ... A method to estimate the thickness of the sea ice of the Bohai Sea is proposed using geostationary ocean color imager (GOCI) data and then applied to the dynamic monitoring of the sea ice thickness in the Bohal Sea during the winter of 2014 to 2015. First of all, a model is given between the GOCI shortwave broadband albedo and the reflectance of each band with high temporal resolution GOCI data. Then, the relationship model between the sea ice thickness and the GOCI shortwave broadband albedo is established and applied to the thickness extraction of the sea ice in the Bohai Sea. Finally, the sea ice thickness extraction method is tested by the results based on the MODIS data, thermodynamic empirical models (Lebedev and Zubov), and the in situ ice thickness data. The test results not only indicated that the sea ice thickness retrieval method based on the GOCI data was a good correlation (r2〉0.66) with the sea ice thickness retrieved by the MODIS and thermodynamic empirical models, but also that the RMS is only 6.82 cm different from the thickness of the sea ice based on the GOCI and in situ data. 展开更多
关键词 sea ice thickness geostationary ocean color imager Bohai Sea
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部