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Diffusion and sound absorption properties of the quadratic residue diffuser structure with perforated panel 被引量:3
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作者 CAI Jun BAO Fei +1 位作者 WANG Yachen WANG Yanqin 《Chinese Journal of Acoustics》 CSCD 2016年第3期255-264,共10页
Acoustic structure study always is the academic research interest. Diffusion ab?sorbing structure(DiflFsorber) has good research value because it has both diflFusion property and sound absorption property. Quadrati... Acoustic structure study always is the academic research interest. Diffusion ab?sorbing structure(DiflFsorber) has good research value because it has both diflFusion property and sound absorption property. Quadratic residue diffusers(QRD) structure which had good diffusion property was combined with the perforated panel which had good sound absorption property in this study. According to standard AES-4id-2001, the diffusion experiments were carried out to study QRD structure and ones composited with perforated-panels which had1 mm-thickness and perforated percentage of 3%, 5%, 8% respectively. The polar coordinate diagrams of different structure were analyzed to derive the diffusion coefficients. Results showed that the composite structure still had good diffusion performance in the frequency range from100 Hz to 800 Hz. The reflection sound energy of composite structure reduced obviously in the perforated panel resonance frequency range where there was about 2 dB reduction averagely.The study result can provide the reference for the design and development of diifsorber. 展开更多
关键词 RATE diffusion and sound absorption properties of the quadratic residue diffuser structure with perforated panel
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Recent development of transient electronics 被引量:2
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作者 Huanyu Cheng Vikas Vepachedu 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2016年第1期21-31,共11页
Transient electronics are an emerging class of electronics with the unique characteristic to completely dissolve within a programmed period of time. Since no harmful byproducts are released, these electronics can be u... Transient electronics are an emerging class of electronics with the unique characteristic to completely dissolve within a programmed period of time. Since no harmful byproducts are released, these electronics can be used in the human body as a diagnostic tool, for instance, or they can be used as environmentally friendly alternatives to existing electronics which disintegrate when exposed to water. Thus, the most crucial aspect of transient electronics is their ability to disintegrate in a practical manner and a review of the literature on this topic is essential for understanding the current capabilities of transient electronics and areas of future research. In the past, only partial dissolution of transient electronics was possible, however, total dissolution has been achieved with a recent discovery that silicon nanomembrane undergoes hydrolysis. The use of single- and multi-layered structures has also been explored as a way to extend the lifetime of the electronics. Analytical models have been developed to study the dissolution of various functional materials as well as the devices constructed from this set of functional materials and these models prove to be useful in the design of the transient electronics. 展开更多
关键词 Transient electronics Model of reactive diffusion Encapsulation strategy Multilayer structures
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Candidate Biomarkers in Children with Autism Spectrum Disorder: A Review of MRI Studies 被引量:7
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作者 Dongyun Li Hans-Otto Karnath Xiu Xu 《Neuroscience Bulletin》 SCIE CAS CSCD 2017年第2期219-237,共19页
Searching for effective biomarkers is one of the most challenging tasks in the research ?eld of Autism Spectrum Disorder(ASD). Magnetic resonance imaging(MRI) provides a non-invasive and powerful tool for investi... Searching for effective biomarkers is one of the most challenging tasks in the research ?eld of Autism Spectrum Disorder(ASD). Magnetic resonance imaging(MRI) provides a non-invasive and powerful tool for investigating changes in the structure, function, maturation,connectivity, and metabolism of the brain of children with ASD. Here, we review the more recent MRI studies in young children with ASD, aiming to provide candidate biomarkers for the diagnosis of childhood ASD. The review covers structural imaging methods, diffusion tensor imaging, resting-state functional MRI, and magnetic resonance spectroscopy. Future advances in neuroimaging techniques, as well as cross-disciplinary studies and largescale collaborations will be needed for an integrated approach linking neuroimaging, genetics, and phenotypic data to allow the discovery of new, effective biomarkers. 展开更多
关键词 Autism spectrum disorder Biomarker Neuroimaging Structural MRI diffusion tensor imaging Resting-state functional MRI Magnetic resonance spectroscopy Children Human
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Can multi-modal neuroimaging evidence from hippocampus provide biomarkers for the progression of amnestic mild cognitive impairment? 被引量:4
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作者 Jiu Chen Zhijun Zhang Shijiang Li 《Neuroscience Bulletin》 SCIE CAS CSCD 2015年第1期128-140,共13页
Impaired structure and function of the hippocampus is a valuable predictor of progression from amnestic mild cognitive impairment(a MCI) to Alzheimer's disease(AD). As a part of the medial temporal lobe memory sy... Impaired structure and function of the hippocampus is a valuable predictor of progression from amnestic mild cognitive impairment(a MCI) to Alzheimer's disease(AD). As a part of the medial temporal lobe memory system,the hippocampus is one of the brain regions affected earliest by AD neuropathology,and shows progressive degeneration as a MCI progresses to AD. Currently,no validated biomarkers can precisely predict the conversion from a MCI to AD. Therefore,there is a great need of sensitive tools for the early detection of AD progression. In this review,we summarize the specifi c structural and functional changes in the hippocampus from recent a MCI studies using neurophysiological and neuroimaging data. We suggest that a combination of advanced multi-modal neuroimaging measures in discovering biomarkers will provide more precise and sensitive measures of hippocampal changes than using only one of them. These will potentially affect early diagnosis and disease-modifying treatments. We propose a new sequential and progressive framework in which the impairment spreads from the integrity of fibers to volume and then to function in hippocampal subregions. Meanwhile,this is likely to be accompanied by progressive impairment of behavioral and neuropsychological performance in the progression of a MCI to AD. 展开更多
关键词 Alzheimer's disease amnestic mild cognitive impairment hippocampus episodic memory functional magnetic resonance imaging structural magnetic resonance imaging diffusion tensor imaging multi-modal MRI biomarker
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