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偶然中的必然:“回超”现象的发生学解析 被引量:19
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作者 汪流 郝亮 《武汉体育学院学报》 CSSCI 北大核心 2010年第5期33-37,共5页
作为业余足球联赛,"回超"堪称一个"草根"的奇迹。自下而上自发形成是其基本生成路径,草根性、群众性、自治性、公益性是其典型特征,丰富和满足基层群众业余文化生活需求是其存在的根本理由。研究认为,"回超&qu... 作为业余足球联赛,"回超"堪称一个"草根"的奇迹。自下而上自发形成是其基本生成路径,草根性、群众性、自治性、公益性是其典型特征,丰富和满足基层群众业余文化生活需求是其存在的根本理由。研究认为,"回超"现象不是单纯的社会活动,不是简单的体育赛事,也不是纯粹的足球比赛,其生成和发展的偶然因素背后,是中国公民社会的发展壮大、社会活动自组织能力的提升和公共体育服务社会化改革实践的必然。 展开更多
关键词 社会体育 足球联赛 发生学 回超现象” 体育赛事
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当前我国城市社区体育草根组织的运行机制研究——以回龙观地区足球协会为案例 被引量:11
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作者 郝亮 胡旭忠 +1 位作者 栗晓燕 马锦宗 《体育科技》 2011年第1期91-95,共5页
以回龙观地区足球协会为案例,对其人员配置、资源配置、筹资机制、信息联络机制、回超赛事运行机制、规章制度、管理评估机制等方面进行田野调查,分析回龙观地区足球协会面临的困境及原因,为其可持续发展提供对策。
关键词 回龙观业主足球协会 回超 社区体育草根组织 运行机制
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Cryogenic springback of 2219-W aluminum alloy sheet through V-shaped bending
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作者 Xiao-bo FAN Qi-liang WANG +1 位作者 Fang-xing WU Xu-gang WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第10期3185-3193,共9页
A V-shaped bending device was established to evaluate the effects of temperature and bending fillet radius on springback behavior of 2219-W aluminum alloy at cryogenic temperatures.The cryogenic springback mechanism w... A V-shaped bending device was established to evaluate the effects of temperature and bending fillet radius on springback behavior of 2219-W aluminum alloy at cryogenic temperatures.The cryogenic springback mechanism was elucidated through mechanical analyses and numerical simulations.The results indicated that the springback angle at cryogenic temperatures was greater than that at room temperature.The springback angle increased further as the temperature returned to ambient conditions,attributed to the combined effects of the “dual enhancement effect” and thermal expansion.Notably,a critical fillet radius made the springback angle zero for 90° V-shaped bending.The critical fillet radius at cryogenic temperatures was smaller than that at room temperature,owing to the influence of temperature variations on the bending moment ratio between the forward bending section at the fillet and the reverse bending section of the straight arm. 展开更多
关键词 2219-W aluminum alloy cryogenic forming V-shape bending SPRINGBACK critical fillet radius
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Two Results on Binary Matroids
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作者 孙良 赵军 杨刚 《Journal of Beijing Institute of Technology》 EI CAS 1998年第1期1-5,共5页
Aim To research new characterization and circuit property of binary matroid. Methods Constract the modular pairs of hyperplanes of a a matroid. Results and Conclusion It is proved that a matroid M on finite set S is b... Aim To research new characterization and circuit property of binary matroid. Methods Constract the modular pairs of hyperplanes of a a matroid. Results and Conclusion It is proved that a matroid M on finite set S is binary if and only if for any two distinct hyper-planes H1 and H2, if H1H2S ,and H1 and H2 are modular pair, then S-(H1H2) is a hyperplande .And a necessary and sufficient condition for a binary matroid to have a k-circuit is obtained. 展开更多
关键词 MATROID HYPERPLANE CIRCUIT cocircuit
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Effect of infliximab on small bowel stenoses in patients with Crohn's disease 被引量:7
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作者 Nadia Pallotta Fausto Barberani +3 位作者 Naima Abdulkadir Hassan Danila Guagnozzi Giuseppina Vincoli Enrico Corazziari 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第12期1885-1890,共6页
AIM: To assess prospectively small bowel stenoses in Crohn's disease (CD) patients treated with infliximab using Small Intestine Contrast Ultrasonography (SICUS). METHODS: Twenty patients (M 12, age, 42.7 ± 1... AIM: To assess prospectively small bowel stenoses in Crohn's disease (CD) patients treated with infliximab using Small Intestine Contrast Ultrasonography (SICUS). METHODS: Twenty patients (M 12, age, 42.7 ± 11.8 years), 15 of whom showed obstructive symptoms indicating the presence of small bowel stenosis, and 5 without stenosis, were treated with infliximab (5 mg/kg at wk 0, 2, 6 and 5 mg/kg every 8 wk thereafter) for steroid refractoriness, fistulizing disease, or to avoid high-risk surgery. SICUS was performed at the induction phase and at regular time intervals during the follow-up period of 34.7 ± 16.1 mo (range 7-58). Small bowel stenoses were detected by SICUS, endoscopy and MRI. RESULTS: In no case was progression of stenoses or the appearance of new ones seen. Of the 15 patients with stenosis, 5 stopped treatment after the induction phase (2 for no response, 3 for drug intolerance, one of whom showed complete regression of one stenosis). Among the remaining 10 patients, a complete regression of 8 stenoses (1 stenosis in 5 patients and 3 stenoses in one patient) was observed after 6-22 infliximab infusions. CONCLUSION: In patients with CD treated with infliximab we observed: (a) No progression of small bowel stenosis and no appearance of new ones, (b) Complete regression of 1/22 stenosis after the induction phase and of 8/15 (53.3%) stenosis after 6-22 infusionsduring maintenance therapy. 展开更多
关键词 Crohn's disease INFLIXIMAB Intestinalstenosis
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Prevalence of overweightedness in patients with gastro-esophageal reflux 被引量:7
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作者 Luca Piretta Federico Alghisi +1 位作者 Fiorella Anzini Enrico Corazziari 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第34期4602-4605,共4页
AIM: To evaluate whether the prevalence of overweight and obese conditions is increased in gastro-esophageal reflux disease (GERD) patients (with 24-h pathological pH recordings) in comparison to general population. M... AIM: To evaluate whether the prevalence of overweight and obese conditions is increased in gastro-esophageal reflux disease (GERD) patients (with 24-h pathological pH recordings) in comparison to general population. METHODS: A total of 196 consecutive patients (103 females, age range 18-83 years) with symptoms of gastro-esophageal reflux (GER) and 24-h pathological esophageal pH-metry. Body mass index (BMI) of the patients was calculated and its distribution (%) was compared with that of the Italian general population as assessed by National Bureau of Census (ISTAT). To evaluate the association of GERD with weight categories, the binomial test was employed. P < 0.05 was considered statistically significant. RESULTS: In males, overweightedness (BMI 25-25.9) was present in 43% of GERD patients vs 41.8% of Italian population (IP) (ns), obesity (BMI ≥ 30) in 10.9% vs 9.1% (ns). In females overweight was present in 34.9% of GERD patients vs 25.7% of IP (P < 0.01), obesity in 13.6% of GERD patients vs 9.1% of IP (P < 0.01). No statistically significant differences were noted in different age classes. CONCLUSION: In comparison to the Italian general population, the prevalence of overweightedness and obesity is increased in female but not in male patients with ascertained gastro-esophageal reflux disease. 展开更多
关键词 Gastro-esophageal reflux OBESITY OVERWEIGHT 24-h pH-metry Body mass index
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A RESEARCH OF UWB RAKE RECEIVER BASED ON NOVEL RLS ADAPTIVE ALGORITHM 被引量:2
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作者 Yin Yong Yu Nenghai Dong Weijie 《Journal of Electronics(China)》 2006年第3期341-345,共5页
A modified RAKE receiver based on novel Recursive Least Squares (RLS) adaptive algorithm is proposed. The receiver uses L-fingered correlators, which are composed of RLS adaptive filters, to enhance the performance ... A modified RAKE receiver based on novel Recursive Least Squares (RLS) adaptive algorithm is proposed. The receiver uses L-fingered correlators, which are composed of RLS adaptive filters, to enhance the performance of multipath receiving. It can also track the amplitude of the received signal to form a real-time amplitude estimation which is correlated with the power of excess delay bin. The simulation results based on the IEEE UltraWide Band (UWB) channel models (CMI to CM4) show that the novel RLS algorithm can alter the attenuation estimation with the finger's power delay profile, and RAKE receiver with few fingers can be employed to get high performance. 展开更多
关键词 UltraWide Band (UWB) RAKE receiver Recursive Least Squares (RLS)
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FPGA-based High-precision Measurement Algorithm for the Ultrasonic Echo Time of Flight 被引量:3
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作者 王伯雄 张金 《Journal of Measurement Science and Instrumentation》 CAS 2010年第2期103-107,共5页
Based on the evaluation of advantages and disadvantages of high-precision digital time interval measuring algorithms, and combined with the principle of the typical time-difference ultrasonic flow measurement, the req... Based on the evaluation of advantages and disadvantages of high-precision digital time interval measuring algorithms, and combined with the principle of the typical time-difference ultrasonic flow measurement, the requirements for the measurement of echo time of flight put forward by the ultrasonic flow measurement are analyzed. A new high-precision time interval measurement algorithm is presented, which combines the pulse counting method with the phase delay interpolation. The pulse counting method is used to ensure a large dynamic measuring range, and a double-edge triggering counter is designed to improve the accuracy and reduce the counting quantization error. The phase delay interpolation is used to reduce the quantization error of pulse counting for further improving the time measurement resolution. Test data show that the systexn for the measurement of the ultrasonic echo time of flight based on this algorithm and implemented on an Field Programmable Gate Army(FleA) needs a relatively short time for measurement, and has a measurement error of less than 105 ps. 展开更多
关键词 ultrasonic flow measurement time of flight phase delay interpolation
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Anisotropic tensile behavior and related yield point phenomena in annealed ultrafine-grained pure aluminum 被引量:2
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作者 Xia HONG Andrew William GODFREY Wei LIU 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第4期585-591,共7页
It is found that tensile flow curves of samples of annealed ultrafine-grained aluminum AA1090 show the development of a yield point and a significant mechanical anisotropy.To rationalize the anisotropic tensile behavi... It is found that tensile flow curves of samples of annealed ultrafine-grained aluminum AA1090 show the development of a yield point and a significant mechanical anisotropy.To rationalize the anisotropic tensile behavior,the orientation data of the annealed material were measured using electron backscatter microscopy.It is found that the inferior mechanical properties of samples tested at 45°to the rolling direction may be attributed to a strong rolling texture effect and that the anisotropic magnitude of the yield drop may be related to the proportion of grains with soft orientations(defined as those with Schmid factor greater than 0.45)in the sample.Additionally,it is found that the anisotropy in tensile ductility is in general agreement with a Considère criterion analysis and that the mechanical anisotropy in the samples is only partly explained by the crystallographic texture,where microstructural anisotropy may also play a role. 展开更多
关键词 ultrafine-grained aluminum recovery annealing mechanical anisotropy yield drop DUCTILITY
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Time for a paradigm shift in the classification of muscle injuries
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作者 Bruce Hamilton Juan-Manuel Alonso Thomas M.Best 《Journal of Sport and Health Science》 SCIE 2017年第3期255-261,共7页
Muscle injuries remain one of the most common injuries in sport,yet despite this,there is little consensus on how to either effectively describe or determine the prognosis of a specific muscle injury.Numerous approach... Muscle injuries remain one of the most common injuries in sport,yet despite this,there is little consensus on how to either effectively describe or determine the prognosis of a specific muscle injury.Numerous approaches to muscle classification and grading of medicine have been applied over the last century,but over the last decade the limitations of historic approaches have been recognized.As a consequence,in the past 10 years,clinical research groups have begun to question the historic approaches and reconsider the way muscle injuries are classified and described.Using a narrative approach,this manuscript describes several of the most recent attempts to classify and grade muscle injuries and highlights the relative strengths and weaknesses of each system.While each of the new classification and grading systems have strengths,there remains little consensus on a system that is both comprehensive and evidence based.Few of the currently identified features within the grading systems have relevance to accurately determining prognosis. 展开更多
关键词 CLASSIFICATION GRADING Magnetic resonance imaging Muscle injury Return to play ULTRASOUND
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1.3μm high-power superluminescent diode
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作者 LIU Mingda SHI Jiawei +2 位作者 MA Dongge JIN Enshun LI Shuwen(Dept.of Elec.Eng.,Jilin University,Changchun 130023,CHN) 《Semiconductor Photonics and Technology》 CAS 1995年第1期67-70,共4页
The result of the evaporation of Sio/SiO2 two layer antireflection coatings monitored by the MODEL IL 400 DEPOSITION CONTROLLER is reported.A superluminescent diode with high output power is fabricated by evaporating ... The result of the evaporation of Sio/SiO2 two layer antireflection coatings monitored by the MODEL IL 400 DEPOSITION CONTROLLER is reported.A superluminescent diode with high output power is fabricated by evaporating antireflection coating on the front facet of 1.3μm buried heterostructure laser. 展开更多
关键词 Light Sources Antireflection Coating Vacuum Deposition Gyroscopes1 Introduction
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Resistin might not be a risk factor for carotid artery atherosclerosis in elderly Chinese males 被引量:2
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作者 Hao WANG Yu-Tang WANG Li FAN Yu-Tao GUO Yang SHI Tao TAO Yue-Xiang ZHAO 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2014年第3期222-228,共7页
Objective To investigate the correlation between the serum resistin level and carotid artery atherosclerosis in elderly Chinese males. Methods The study enrolled 235 elderly Chinese males [median age 76 (range 60-97... Objective To investigate the correlation between the serum resistin level and carotid artery atherosclerosis in elderly Chinese males. Methods The study enrolled 235 elderly Chinese males [median age 76 (range 60-97) years] scheduled for ultrasound examination of carotid artery plaque and determination of carotid artery intima-media thickness (CIMT). They were divided into carotid atherosclerotic plaque (CAP) and carotid atherosclerotic plaque-free (CAP-free) groups according to the ultrasound results. Their clinical profiles were col-lected, and the serum resistin and other blood biochemistry levels were determined.Results The CAP group was older and had a thicker mean CIMT than the CAP-free group. However, there was no difference in the serum resistin level between the groups. CIMT was positively correlated with age (r = 0.299,P〈 0.001). The serum resistin level was not correlated with CIMT, even after controlling for age. Multiple linear regression analysis revealed that age (β = 0.001,P〈 0.001) and body mass index (β = 0.002,P= 0.015) were significantly and posi-tively correlated with the mean CIMT. Only age [odds ratio (OR): 1.159; 95% confidence interval (CI): 1.078-1.183,P〈 0.001] was associ-ated with the presence of carotid artery atherosclerotic plaque. The serum resistin level was not correlated with the mean CIMT or associated with the presence of carotid artery atherosclerotic plaque.Conclusion The results suggest that resistin might not be a risk factor for atherosclerosis in elderly Chinese males. 展开更多
关键词 Resistin Intima-media thickness Atherosclerosis The elderly
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Ultrasonic echo denoising in liquid density measurement based on improved variational mode decomposition
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作者 WANG Xiao-peng ZHAO Jun ZHU Tian-liang 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2020年第4期326-334,共9页
The ultrasonic echo in liquid density measurement often suffers noise,which makes it difficult to obtain the useful echo waveform,resulting in low accuracy of density measurement.A denoising method based on improved v... The ultrasonic echo in liquid density measurement often suffers noise,which makes it difficult to obtain the useful echo waveform,resulting in low accuracy of density measurement.A denoising method based on improved variational mode decomposition(VMD)for noise echo signals is proposed.The number of decomposition layers of the traditional VMD is hard to determine,therefore,the center frequency similarity factor is firstly constructed and used as the judgment criterion to select the number of VMD decomposition layers adaptively;Secondly,VMD algorithm is used to decompose the echo signal into several modal components with a single modal component,and the useful echo components are extracted based on the features of the ultrasonic emission signal;Finally,the liquid density is calculated by extracting the amplitude and time of the echo from the modal components.The simulation results show that using the improved VMD to decompose the echo signal not only can improve the signal-to-noise ratio of the echo signal to 20.64 dB,but also can accurately obtain the echo information such as time and amplitude.Compared with the ensemble empirical mode decomposition(EEMD),this method effectively suppresses the modal aliasing,keeps the details of the signal to the maximum extent while suppressing noise,and improves the accuracy of the liquid density measurement.The density measurement accuracy can reach 0.21%of full scale. 展开更多
关键词 liquid density measurement ultrasonic echo signal variational mode decomposition(VMD) signal denoising signal-to-noise ratio
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Role of echo Doppler ultrasonography in the evaluation of postprandial hyperemia in cirrhotic patients
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作者 Ozdogan Osman Atalay Huseyin +8 位作者 Cimsit Cagatay Tahan Veysel Tokay Sena Giral Adnan Imeryuz Nese Baltac|oglu Feyyaz Tuney Davut Erzen Canan Tozun Nurdan 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第2期260-264,共5页
AIM: To assess the role of echo-Doppler ultrasonography in postprandial hyperemia in cirrhotic patients by comparing the results with the hepatic vein catheterization technique.METHODS: Patients with cirrhosis, admitt... AIM: To assess the role of echo-Doppler ultrasonography in postprandial hyperemia in cirrhotic patients by comparing the results with the hepatic vein catheterization technique.METHODS: Patients with cirrhosis, admitted to the portal hemodynamic laboratory were included into the study. After an overnight fast, echo-Doppler ultrasonography (basal and 30 min after a standard meal) and hemodynamic studies by hepatic vein catheterization (basal, 15 min and 30 min after a standard meal) were performed. Ensure Plus (Abbot Laboratories, North Chicago, IL) was used as the standard liquid meal. Correlation analysis of the echo-Doppler and hepatic vein catheterization measurements were done for the basal and postprandial periods.RESULTS: Eleven patients with cirrhosis (5 Child A, 4 Child B, 2 Child C) were enrolled into the study. After the standard meal, 8 of the 11 patients showed postprandial hyperemia with increase in portal blood flow, portal blood velocity and hepatic venous pressure gradient. Hepatic venous pressure gradient in the postprandial period correlated positively with postprandial portal blood velocity (r = 0.8, P < 0.05) and correlated inversely with postprandial superior mesenteric artery pulsatility index (r = -1, P < 0.01).CONCLUSION: Postprandial hyperemia can be efficiently measured by echo-Doppler ultrasonography and the results are comparable to those obtained with the hemodynamic studies. 展开更多
关键词 Postprandial hyperemia ECHO-DOPPLER Hemodynamic study CIRRHOSIS Portal hypertension Portal pressure
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Ultrasound diagnosis about branchial cyst in parotid
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作者 Shi Qiuling Hui Luo Yang Jiao Tao Liu Jun Lu 《International English Education Research》 2014年第2期97-100,共4页
Study the audiovideo picture characteristic of gill slit and cyst in the parotid gland, canvass the diagnosis value of the supersound in this disease. Carry on comprehensive analysis to the audiovideo picture material... Study the audiovideo picture characteristic of gill slit and cyst in the parotid gland, canvass the diagnosis value of the supersound in this disease. Carry on comprehensive analysis to the audiovideo picture materials of cyst patient of gill slit in 39 parotid glands as diagnosed definitely by operation pathology. Divide into 3 kinds of types based on different echoes within gill slit and cyst in the parotid gland: Bag echo type, mixs echo type, real low echo type. Among them the number of ultrasonic suggestion is correct 28, accounts for 71.8%; Misdiagnose 11, accounts for 28.2%.Check and play an important role in diagnosis of this disease in conclusion supersound. Meanwhile, should improve the understanding of gill slit and cyst in mixing echo type and real low echo type parotid gland, in order to improve the correct rate of suggestion to these 2 kinds of types of the supersound. 展开更多
关键词 Gill slit and cyst in parotid gland supersound diagnosed Picture dividing type of the audiovideo
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Non-invasive determination of hepatic steatosis by acoustic structure quantification from ultrasound echo amplitude 被引量:15
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作者 Hidekatsu Kuroda Keisuke Kakisaka +7 位作者 Naohisa Kamiyama Takayoshi Oikawa Mio Onodera Kei Sawara Kanta Oikawa Ryujin Endo Yasuhiro Takikawa Kazuyuki Suzuki 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第29期3889-3895,共7页
AIM:To use leptin-deficient(ob/ob) mice with demonstrated differences in steatosis levels to test a new diagnostic method using the acoustical structure quantification(ASQ) mode and the associated analytical parameter... AIM:To use leptin-deficient(ob/ob) mice with demonstrated differences in steatosis levels to test a new diagnostic method using the acoustical structure quantification(ASQ) mode and the associated analytical parameter,"focal disturbance ratio"(FD-ratio).METHODS:Nine ob/ob mice,at 5,8,and 12 wk of age(n = 3 in each age group),were used as models for hepatic steatosis.Echo signals obtained from ultrasonography in the mice were analyzed by ASQ,which uses a statistical analysis of echo amplitude to estimate inhomogeneity in the diagnostic region.FD-ratio,as calculated from this analysis,was the focus of the present study.FD-ratio and fat droplet areas and sizes were compared between age groups.RESULTS:No fibrosis or inflammation was observed in any of the groups.The fat droplet area significantly(P < 0.01) increased with age from 1.25% ± 0.28% at 5 wk to 31.07% ± 0.48% at 8 wk to 51.69% ± 3.19% at 12 wk.The median fat droplet size also significantly(P < 0.01) increased with age,from 1.33(0.55-10.52) m at 5 wk,2.82(0.61-44.13) m at 8 wk and 6.34(0.66-81.83) m at 12 wk.The mean FD-ratio was 0.42 ± 0.11 at 5 wk,0.11 ± 0.05 at 8 wk,and 0.03 ± 0.02 at 12 wk.The FD-ratio was significantly lower at 12 wk than at 5 wk and 8 wk(P < 0.01).A significant negative correlation was observed between the FD-ratio and either the fat droplet area(r =-0.7211,P = 0.0017) or fat droplet size(r =-0.9811,P = 0.0052).CONCLUSION:This tool for statistical analysis of signals from ultrasonography using the FD-ratio can be used to accurately quantify fat in vivo in an animal model of hepatic steatosis,and may serve as a quantitative biomarker of hepatic steatosis. 展开更多
关键词 Non-alcoholic fatty liver disease Quantitation of hepatic steatosis Animal model Focal disturbance ratio Acoustic structure quantification Ultrasonography
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THE DETERMINATIVE ROLE OF INTRAOPERATIVEECHO IN TRICUSPID VALVULOPLASTY 被引量:2
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作者 王国干 刘永民 +4 位作者 孟宪强 樊朝美 刘汉英 朱晓东 蔡如升 《Chinese Medical Sciences Journal》 CAS CSCD 1997年第4期244-247,共4页
A transesophageal echocardiography (TEE) was used in monitoring the operation of tricuspid valvulo-plasty’ Nine Patients with rheumaTic heart disease were studiedThe results showed that intraoperative TEE was importa... A transesophageal echocardiography (TEE) was used in monitoring the operation of tricuspid valvulo-plasty’ Nine Patients with rheumaTic heart disease were studiedThe results showed that intraoperative TEE was important on the improvlng method of tricuspid an-nuloplasty, it help to determine surgical procedure, control annulus-reducing procedure and assess the re-sult lmmediately after operation. The results suggested that intraoperative TEE can be wideIy used invalvuloplasTy in future. 展开更多
关键词 transesophageal echocardiography intraoperative echocardiography
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Classification of Ultrasonic Signs Pre-processed by Fourier Transform through Artificial Neural Network Using the Echo Pulse Technique for the Identification of Defects in Welded Joints of Structural Steel
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作者 Renata Torres Melo Sotero Maria Clea S. de Albuquerque +2 位作者 Francisco G. de Paula Claudia T. T. Farias Eduardo F. de Simas Filho 《Journal of Mechanics Engineering and Automation》 2015年第5期286-290,共5页
It is due to the need to ensure the security and integrity of equipment, that the non-destructive tests have been increasingly used in the industrial sector. Among these, the ultrasonic pulse echo technique is the mos... It is due to the need to ensure the security and integrity of equipment, that the non-destructive tests have been increasingly used in the industrial sector. Among these, the ultrasonic pulse echo technique is the most used in industry, mainly for its simplicity and efficiency. With one transducer only, it is possible to emit the ultrasonic and receive the echo pulse. The ANNs (artificial neural networks) are artificial intelligence techniques that, when properly trained, align themselves to inspection tests becoming a powerful tool in the detection and fault identification. In this work, the echo pulse technique was used to detect discontinuities in welds, where ANNs were fed from the information obtained by digital signal processing techniques (Fourier transform), to identify and classify three distinct classes of defects. Results showed that with the combination of feature extraction by Fourier transformation and classification with neural networks, it is possible to obtain an automatic defect detection system in welded joints with average efficiency. 展开更多
关键词 Non-destructive testing digital signal processing neural networks echo pulse ultrasound.
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A Comparative Study of Process Parameter Optimization and Process of Flavonoid in Planted Trollius Chinensis through Backflow Method, Ultrasonic Wave Method and MicrowaveMethod
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作者 Yongfeng Liang 《International Journal of Technology Management》 2014年第7期155-158,共4页
It takes flavonoid extraction rate as indicator and adopts the method of orthogonal experiment to study process of total flavonoid in Trollius chinensis through ultrasonic wave assisted extraction, microwave assisted ... It takes flavonoid extraction rate as indicator and adopts the method of orthogonal experiment to study process of total flavonoid in Trollius chinensis through ultrasonic wave assisted extraction, microwave assisted extraction and backflow extraction, as well as optimization of process parameter. The result indicates that in terms of extraction efficiency, microwave extraction method is better than ultrasonic radiation extraction method, which is better than backflow extraction method. Optimal process parameter through backflow extraction is: backflow temperature 60℃, fluid material ratio 1:20, ethanol density 65%, backflow time 60min; optimal process parameter through ultrasonic wave assisted extraction is: ultrasonic radiation temperature 70℃, fluid material ratio 1:20, ethanol density 65%, ultrasonic wave radiation time 45rain; optimal process parameter of microwave assisted extraction is: microwave radiation temperature 60℃, fluid material ratio 1:20, ethanol density 75%, microwave radiation time 45min. 展开更多
关键词 Trollius chinensis ultrasonic wave extraction backflow extraction microwave extraction
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Recent Progress on RF Superconductivity and ERL 被引量:1
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作者 郝建奎 赵夔 《Chinese Physics C》 SCIE CAS CSCD 北大核心 2008年第z1期200-203,共4页
RF superconducting cavities can work in CW mode or long pulse mode.RF superconducting technology is widely used in particle accelerators.The development of RF superconductivity is limited by the material,surface treat... RF superconducting cavities can work in CW mode or long pulse mode.RF superconducting technology is widely used in particle accelerators.The development of RF superconductivity is limited by the material,surface treatment and installation.SRF technology is improved greatly after dozens of years'researches.Lots of techniques and experiences have been accumulated by running superconducting accelerators.In recent years,researches and developments have been carried out for future large scientific project.New cavity shape and superconducting cavities made of large grain niobium are the hot frontiers in SRF field.Energy Recovery Linacs have been developed in recent years.ERLs has many advantages such as high efficiency,energy saving,good stability,low radiation level,etc.ERLs are more and more used in advanced light sources and free electron laser facilities. 展开更多
关键词 RF superconductivity ERL accelerating gradient
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