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西藏当雄县日音拿锌铜矿床成因浅析
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作者 张炜 刘宏伟 《西部资源》 2012年第6期129-131,共3页
从矿床地质、稳定同位素、稀土元素、微量元素地球化学特征等方面进行分析,西藏当雄县日音拿锌铜矿床为岩浆矽卡岩型矿床,其成因机制是深部熔浆在上侵过程中经分异作用,以K、Na硅酸盐为主的熔浆浮于上部.以Cu、Mg、Fe为主的熔浆(矽卡岩... 从矿床地质、稳定同位素、稀土元素、微量元素地球化学特征等方面进行分析,西藏当雄县日音拿锌铜矿床为岩浆矽卡岩型矿床,其成因机制是深部熔浆在上侵过程中经分异作用,以K、Na硅酸盐为主的熔浆浮于上部.以Cu、Mg、Fe为主的熔浆(矽卡岩岩浆)沉于下部,从而形成含矿矽卡岩岩浆,进而形成岩浆型矽卡岩矿床。 展开更多
关键词 拿锌铜矿 岩浆矽卡岩 西藏
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全新的3D声音体验——Dolby Atmos与Auro-3D 被引量:3
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作者 周天纵 《演艺科技》 2015年第2期19-22,65,共5页
声音重放的理念及技术不断进步,Dolby和Barco两家公司分别发布了Dolby Atmos和Auro-3D技术,围绕声音对象(Object)及音床(Bed)这两个概念展开论述。
关键词 3D声 环绕声 杜比全景声 Auro-3D 对象 音床
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纪录片《美丽中国说》之《沙洲奇缘》声音创作谈
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作者 刘晓惠 《现代电视技术》 2022年第2期108-111,共4页
本文介绍了总台第一部8K超高清系列纪录片《美丽中国说》的声音制作全流程,对前期录音、后期声音设计、音响制作、三维声混音进行了阐述。
关键词 环境 三维声 声道 音床 对象
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杜比全景声实践解析 被引量:2
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作者 周立 《现代电视技术》 2017年第8期124-128,共5页
当今电视制播技术高速发展,在这场技术变革中,声音格式的迭代更替也在迅速展开,从单声道到立体声,从环绕声到三维声,声音工作者们在电视节目创作方面不断实验新的音频格式,本文为杜比全景声的实践解析,旨在摸索录音工艺流程中存在的普... 当今电视制播技术高速发展,在这场技术变革中,声音格式的迭代更替也在迅速展开,从单声道到立体声,从环绕声到三维声,声音工作者们在电视节目创作方面不断实验新的音频格式,本文为杜比全景声的实践解析,旨在摸索录音工艺流程中存在的普遍创作规律及独特的创意理念,发挥不同音频系统的各自优势,以更好地创作出精品节目。 展开更多
关键词 杜比全景声(Dolby Atmos) 音床(Bed) 对象(Object)
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Intraluminal versus infiltrating gallbladder carcinoma:Clinical presentation,ultrasound and computed tomography 被引量:7
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作者 Tze-Yu Lee Sheung-Fat Ko +5 位作者 Chung-Cheng Huang Shu-Hang Ng Jiun-Lung Liang Hsuan-Ying Huang Min-Chi Chen Shyr-Ming Sheen-Chen 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第45期5662-5668,共7页
AIM: To compare clinical presentation and ultrasound (US) and computed tomography (CT) sensitivity between intraluminal and infiltrating gallbladder carcinoma (GBCA). METHODS: This retrospective study evaluate... AIM: To compare clinical presentation and ultrasound (US) and computed tomography (CT) sensitivity between intraluminal and infiltrating gallbladder carcinoma (GBCA). METHODS: This retrospective study evaluated 65 cases of GBCA that were categorized morphologically into the intraluminaI-GBCA (n = 37) and infiltrating-GBCA (n = 28) groups. The clinical and laboratory findings, presence of gallstones, gallbladder size, T-staging, nodal status, sensitivity of preoperative US and CT studies, and outcome were compared between the two groups. RESULTS: There were no significant differences between the two groups with respect to female predominance, presence of abdominal pain, serum aminotransferases level, T2-T4 staging, and regional metastatic nodes. Compared with the patients with intraluminaI-GBCA, those with infiltrating-GBCA were significantly older (65.49 ± 1.51 years vs 73.07 ± 1.90 years), had a higher frequency of jaundice (3/37 patients vs 13/28 patients) and fever (3/37 patients vs 10/28 patients), higher alkaline phosphatase (119.36 ± 87.80 IU/L vs 220.68 ± 164.84 IU/L) and total bilirubin (1.74 ± 2.87 mg/L vs 3.50 ± 3.51 mg/L) levels, higher frequency of gallstones (12/37 patients vs 22/28 patients), smaller gallbladder size (length, 7.47± 1.70 cm vs 6.47 ± 1.83 cm; width, 4.21 ± 1.43 cm vs 2.67 ± 0.93 cm), and greater proportion of patients with 〈 12 mo survival (16/37 patients vs 18/28 patients). The sensitivity for diagnosing intraluminal- GBCA with and without gallstones was 63.6% and 91.3% by US, and 80% and 100% by CT, respectively. The sensitivity for diagnosing infiltrating-GBCA with and without gallstones was 12.5% and 25% by US, and 71.4% and 75% by c-r, respectively. CONCLUSION: In elderly women exhibiting small gallbladder and gallstones on US, especially those with jaundice, fever, high alkaline phosphatase and bilirubin levels, CT may reveal concurrent infiltrating-GBCA. 展开更多
关键词 Gallbladder neoplasms CARCINOMA ULTRASOUND Computed tomography
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Spectral analysis of bowel sounds in intestinal obstruction using an electronic stethoscope 被引量:14
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作者 Siok Siong Ching Yih Kai Tan 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第33期4585-4592,共8页
AIM: To determine the value of bowel sounds analysis using an electronic stethoscope to support a clinical diagnosis of intestinal obstruction. METHODS: Subjects were patients who presented with a diagnosis of possibl... AIM: To determine the value of bowel sounds analysis using an electronic stethoscope to support a clinical diagnosis of intestinal obstruction. METHODS: Subjects were patients who presented with a diagnosis of possible intestinal obstruction based on symptoms, signs, and radiological findings. A 3MTH Littmann Model 4100 electronic stethoscope was used in this study. With the patients lying supine, six 8-second recordings of bowel sounds were taken from each patient from the lower abdomen. The recordings were analysed for sound duration, soundto-sound interval, dominant frequency, and peak frequency. Clinical and radiological data were reviewed and the patients were classified as having either acute, subacute, or no bowel obstruction. Comparison of bowel sound characteristics was made between these subgroups of patients. In the presence of an obstruction, the site of obstruction was identified and bowel calibre was also measured to correlate with bowel sounds. RESULTS: A total of 71 patients were studied during the period July 2009 to January 2011. Forty patientshad acute bowel obstruction (27 small bowel obstruction and 13 large bowel obstruction), 11 had subacute bowel obstruction (eight in the small bowel and three in large bowel) and 20 had no bowel obstruction (diagnoses of other conditions were made). Twenty-five patients received surgical intervention (35.2%) during the same admission for acute abdominal conditions. A total of 426 recordings were made and 420 recordings were used for analysis. There was no significant difference in sound-to-sound interval, dominant frequency, and peak frequency among patients with acute bowel obstruction, subacute bowel obstruction, and no bowel obstruction. In acute large bowel obstruction, the sound duration was significantly longer (median 0.81 s vs 0.55 s, P = 0.021) and the dominant frequency was significantly higher (median 440 Hz vs 288 Hz, P = 0.003) when compared to acute small bowel obstruction. No significant difference was seen between acute large bowel obstruction and large bowel pseudoobstruction. For patients with small bowel obstruction, the sound-to-sound interval was significantly longer in those who subsequently underwent surgery compared with those treated non-operatively (median 1.29 s vs 0.63 s, P < 0.001). There was no correlation between bowel calibre and bowel sound characteristics in both acute small bowel obstruction and acute large bowel obstruction. CONCLUSION: Auscultation of bowel sounds is nonspecific for diagnosing bowel obstruction. Differences in sound characteristics between large bowel and small bowel obstruction may help determine the likely site of obstruction. 展开更多
关键词 Bowel sounds Intestinal obstruction Spectral analysis Electronic stethoscope
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Implementation of a Novel Algorithm on Acoustic Doppler Current Profiler Signal Processing System
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作者 朱昊 刘文耀 《Transactions of Tianjin University》 EI CAS 2005年第4期299-302,共4页
Acoustic Doppler current profiler (ADCP) uses acoustic energy directed along narrow beams for current measurement. In conventional method, the quantity of sampling affects the precision of fast Fourier transform (... Acoustic Doppler current profiler (ADCP) uses acoustic energy directed along narrow beams for current measurement. In conventional method, the quantity of sampling affects the precision of fast Fourier transform (FFT) algorithm, and the algorithm needs a large amount of data to process. A novel frequency estimator.enhanced least mean square (ELMS) algorithm for a single complex sinusoid in complex white Gaussian noise, is proposed in ADCP system. As sampling frequency equals 120 krad/s and the sampling number equals 240. the minimum resolving is 0. 5 krad/s. All variances keep 11.11%. ELMS algorithm needs less data than FFT. And the robust algorithm can estimate the spectrum true value to 99.9% when the signal to noise ratio (SNR) is equal to 0 dB. Experiments prove that the estimation values will diverge much from the ideal when SNR is less than -6 dB. 展开更多
关键词 acoustic Doppler current profiler: fast Fourier transform Gaussian noise enhanced least mean square signal to noise ratio
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The Influence of an Acoustic Field on the Bed Expansion of Fine Particles
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作者 Akash M. Langde R.L.Sonolikar 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第4期649-655,共7页
Fine particles are difficult to fluidize due to strong interparticle attraction.An attempt has been made to study the bed expansion of silica gel(dp=25μm) powder in presence of an acoustic field.A 135 mm diameter flu... Fine particles are difficult to fluidize due to strong interparticle attraction.An attempt has been made to study the bed expansion of silica gel(dp=25μm) powder in presence of an acoustic field.A 135 mm diameter fluidized bed activated by an acoustic field with sound intensity up to 145 dB and frequency from 90 Hz to 170 Hz was studied.The effects of sound pressure level,sound frequency and particle loading on the bed expansion were investigated.Experimental results showed that,bed expansion was good in presence of acoustic field of particular frequency.In addition,it was observed that in presence of acoustic field the bed collapses slowly. 展开更多
关键词 acoustic field FREQUENCY VIBRATION fluidized bed fine powder EXPANSION
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