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Going straight for the gut:gut-brain axis pathology and treatment of Parkinson's disease
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作者 Dominique Ebedes Cesar V.Borlongan 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第10期2111-2112,共2页
This perspective focuses on the recent literature regarding the role of the gut-brain axis(GBA) in fecal microbiota transplantation(FMT) and stem cell therapy(SCT) in Parkinson's disease(PD).PD is the second most ... This perspective focuses on the recent literature regarding the role of the gut-brain axis(GBA) in fecal microbiota transplantation(FMT) and stem cell therapy(SCT) in Parkinson's disease(PD).PD is the second most common neurodegenerative disease in the United States,yet therapies remain limited.Current research suggests that the GBA may play a role in the pathogenesis of PD.GBAbased FMT as well as SCT offer promising new avenues for PD treatment.Pro bing the interactions between FMT and SCT with the GBA may reveal novel therapeutics for PD. 展开更多
关键词 straight PATHOLOGY PATHOGENESIS
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Measuring tree stem diameters and straightness with depth-image computer vision
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作者 Hoang Tran Keith Woeste +2 位作者 Bowen Li Akshat Verma Guofan Shao 《Journal of Forestry Research》 SCIE CAS CSCD 2023年第5期1395-1405,共11页
Current techniques of forest inventory rely on manual measurements and are slow and labor intensive.Recent developments in computer vision and depth sensing can produce accurate measurement data at significantly reduc... Current techniques of forest inventory rely on manual measurements and are slow and labor intensive.Recent developments in computer vision and depth sensing can produce accurate measurement data at significantly reduced time and labor costs.We developed the ForSense system to measure the diameters of trees at various points along the stem as well as stem straightness.Time use,mean absolute error(MAE),and root mean squared error(RMSE)metrics were used to compare the system against manual methods,and to compare the system against itself(reproducibility).Depth-derived diameter measurements of the stems at the heights of 0.3,1.4,and 2.7 m achieved RMSE of 1.7,1.5,and 2.7 cm,respectively.The ForSense system produced straightness measurement data that was highly correlated with straightness ratings by trained foresters.The ForSense system was also consistent,achieving sub-centimeter diameter difference with subsequent measures and less than 4%difference in straightness value between runs.This method of forest inventory,which is based on depth-image computer vision,is time efficient compared to manual methods and less computationally and technologically intensive compared to Structure-from-Motion(SFM)photogrammetry and ground-based LiDAR or terrestrial laser scanning(TLS). 展开更多
关键词 Forest inventory Depth sensing Computer vision Tree diameter Stem straightness Trunk volume
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Straight and twisted Weyl nodal line phonons in Ho2CF2 material
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作者 康鑫越 李金洋 李思 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期77-81,共5页
Based on first-principles calculations, symmetry analysis and model construction, we predict that Ho2CF2hosts both straight and twisted Weyl nodal lines in its bulk phonon spectrum. We identify that the top two phonon... Based on first-principles calculations, symmetry analysis and model construction, we predict that Ho2CF2hosts both straight and twisted Weyl nodal lines in its bulk phonon spectrum. We identify that the top two phonon bands entangle with each other, forming two straight Weyl nodal lines on the K–H and K′–H′paths at the Brillouin zone(BZ) boundary,and six twisted Weyl nodal lines within the BZ. All the Weyl nodal lines along the kz direction and across the entire BZ.The symmetry analysis indicates that these Weyl nodal lines are protected by the PT symmetry and crystal symmetry. The Berry phase and drumhead-like nontrivial surface states are calculated. We also construct a tight-binding model to describe these nodal lines. Our work provides an excellent material platform for exploring the fascinating physics associated with straight and twisted Weyl nodal line phonons. 展开更多
关键词 topological quasiparticles topological phonons straight nodal lines twisted nodal lines
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Related mechanisms and research progress in straight back syndrome
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作者 Mo-Wei Kong Zhen-Ying Pei +4 位作者 Xiong Zhang Qiu-Juan Du Qiang Tang Jun Li Guo-Xiang He 《World Journal of Cardiology》 2023年第10期479-486,共8页
Despite the high prevalence of straight back syndrome(SBS),there is still limited research on this condition,posing challenges for effective diagnosis and treatment.The disease has been known for a long time,but there... Despite the high prevalence of straight back syndrome(SBS),there is still limited research on this condition,posing challenges for effective diagnosis and treatment.The disease has been known for a long time,but there have been few related studies,which mostly consist of case reports.These studies have not been systematically summarized,making it difficult to meet the current needs of diagnosis and treatment.This article summarized the existing literature and comprehensively reviewed the diagnosis,pathogenesis,treatment,and research status of mitral valve prolapse related to SBS.We specifically emphasized the mechanisms and prognosis of SBS combined with mitral valve prolapse and discussed the latest research progress in this disease. 展开更多
关键词 straight back syndrome Mitral valve prolapse ARRHYTHMIA Review DIAGNOSIS Treatment
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Development and Performance Evaluation of Catalyst for Productive Ethylene Cracking Feedstock in Selective Hydrocracking of Straight Run Diesel Oil
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作者 Tiezhen Zhang Xin Zhang +5 位作者 Yungang Jia Haiyan Li Fangming Xie Zijin Yan Hongyu Tian Hongyu Zhang 《Open Journal of Applied Sciences》 CAS 2023年第3期414-423,共10页
The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable f... The upgrading of diesel oil to produce ethylene rich cracking feedstock is an important and promising technical route to reduce the ratio of diesel to gasoline. In the present work, a hydrocracking catalyst suitable for selective hydrocracking of straight run diesel oil to produce high-quality ethylene cracking feedstock at low cost was developed, by optimizing the composition of catalyst support materials, using amorphous silicon aluminum and aluminum oxide with high mesopore content as the main support, and modified Y zeolite with excellent aromatic ring opening selectivity as the acidic component. The catalyst has in-depth characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, N<sub>2</sub>-low temperature adsorption-desorption, NH<sub>3</sub>-temperature-programmed desorption, and IR techniques. And its catalytic cracking straight run diesel oil performance was evaluated. The results show that the prepared catalyst has high polycyclic aromatic hydrocarbon ring opening cracking selectivity. However, alkanes retained in diesel distillates can achieve the goal of producing more ethylene cracking feedstocks with low BMCI value under low and moderate pressure conditions. This work may shed significant technical insight for oil refining transformation. 展开更多
关键词 straight Run Diesel Mild Hydrocracking CATALYST Ethylene Cracking Feedstock Process Research
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Crossing Limit Cycles of Planar Piecewise Hamiltonian Systems with Linear Centers Separated by Two Parallel Straight Lines
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作者 Zhou Jin 《Journal of Applied Mathematics and Physics》 2023年第5期1429-1447,共19页
In this paper, we have studied several classes of planar piecewise Hamiltonian systems with three zones separated by two parallel straight lines. Firstly, we give the maximal number of limit cycles in these classes of... In this paper, we have studied several classes of planar piecewise Hamiltonian systems with three zones separated by two parallel straight lines. Firstly, we give the maximal number of limit cycles in these classes of systems with a center in two zones and without equilibrium points in the other zone (or with a center in one zone and without equilibrium points in the other zones). In addition, we also give examples to illustrate that it can reach the maximal number. 展开更多
关键词 Limit Cycles Planar Piecewise Hamiltonian Systems straight Lines CENTERS Equilibrium Points
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Effect of Specific Verbal Instructions on the Identification of Pain Location during a Passive Straight Leg Raise Test
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作者 Masae Ikeya Takumi Jiroumaru +2 位作者 Hitomi Bunki Noriyuki Kida Teruo Nomura 《Open Journal of Therapy and Rehabilitation》 2023年第2期45-53,共9页
Musculoskeletal pain is common. Because pain is subjective, objectively describing it is crucial. However, pain assessment may cause distress in patients;therefore, physical therapists (PTs) should conduct these tests... Musculoskeletal pain is common. Because pain is subjective, objectively describing it is crucial. However, pain assessment may cause distress in patients;therefore, physical therapists (PTs) should conduct these tests quickly and accurately. Simple and clear instructions are recommended for pain assessment. However, few studies have provided evidence to support this hypothesis. Correspondingly, this study aimed to confirm the effectiveness of specific verbal instructions for pain location during five consecutive Passive Straight Leg Raise (PSLR) tests. The 28 asymptomatic participants (age 27.4 ± 9.6 years) who provided informed consent received five consecutive PSLR tests: three without and two with specific verbal instructions to ascertain pain intensity, quality, and location. The participants drew pain locations on a body chart and described the pain intensity and quality after each test. All participants were interviewed regarding the differences they noted in the presence and absence of specific verbal instructions. Each pain location was classified into one of ten areas for statistical analysis. The proportion of participants who changed the pain location was compared between the tests using McNemar’s test, and the kappa coefficient was confirmed for consistency of pain location. There was a significant difference in the proportion of participants who changed their pain location between the second and third tests and from the third to the fourth test (McNemar’s test: p = 0.003). Kappa coefficients had low consistency (κ = 0.28) just after receiving the specific verbal instructions in the fourth test compared to the third test. Consistency improved in the fifth test (κ = 0.57);93% of the participants answered that the pain location had become clearer. This study revealed the effects of specific verbal instructions in identifying pain locations. This detailed information may help PTs provide appropriate treatment and contribute to reducing pain in clinical settings. 展开更多
关键词 Specific Verbal Instructions Pain Location Pain Assessment Passive straight Leg Raise Test
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采用STRAIGHT模型和深度信念网络的语音转换方法 被引量:4
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作者 王民 苏利博 +1 位作者 王稚慧 要趁红 《计算机工程与科学》 CSCD 北大核心 2016年第9期1950-1954,共5页
提出一种将STRAIGHT模型和深度信念网络DBN相结合实现语音转换的方式。首先,通过STRAIGHT模型提取出源说话人和目标说话人的语音频谱参数,用提取的频谱参数分别训练两个DBN得到语音高阶空间的个性特征信息;然后,用人工神经网络ANN将两... 提出一种将STRAIGHT模型和深度信念网络DBN相结合实现语音转换的方式。首先,通过STRAIGHT模型提取出源说话人和目标说话人的语音频谱参数,用提取的频谱参数分别训练两个DBN得到语音高阶空间的个性特征信息;然后,用人工神经网络ANN将两个具有高阶特征的空间连接并进行特征转换;最后,用基于目标说话人数据训练出的DBN来对转换后的特征信息进行逆处理得到语音频谱参数,并用STRAIGHT模型合成具有目标说话人个性化特征的语音。实验结果表明,采用此种方式获得的语音转换效果要比传统的采用GMM实现语音转换更好,转换后的语音音质和相似度与目标语音更接近。 展开更多
关键词 语音转换 straight模型 深度信念网络 高阶空间
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基于STRAIGHT算法的汉语语音morphing方法
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作者 甘振业 杨鸿武 蔡莲红 《西北师范大学学报(自然科学版)》 CAS 2008年第5期34-37,42,共5页
提出了一种新的基于STRAIGHT算法的汉语语音morphing方法.通过标注源和目标STRAIGHT频谱上的特征点,并利用线性和对数叠加的方法实现对频谱的morphing;通过插值的方法对基频进行morphing.实验结果表明,morphing后的语音在语义特征不变... 提出了一种新的基于STRAIGHT算法的汉语语音morphing方法.通过标注源和目标STRAIGHT频谱上的特征点,并利用线性和对数叠加的方法实现对频谱的morphing;通过插值的方法对基频进行morphing.实验结果表明,morphing后的语音在语义特征不变的情况下,保持了源和目标语音的特征,morphing的结果获得了高质量的合成语音,MOS得分为3.87分. 展开更多
关键词 straight算法 汉语语音 MORPHING 语音修改 基频
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基于STRAIGHT算法的个性化语音生成方法 被引量:1
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作者 甘振业 杨鸿武 《甘肃科技》 2010年第4期34-35,86,共3页
介绍了一种基于STRAIGHT语音修改算法的个性化语音的方法。对输入的语音提取基本信息,并进行频谱分析;利用STRAIGHT算法对相关参数进行修改;通过STRAIGHT合成器生成新的个性化的语音。实验结果表明,该方法可以得到高质量的个性化合成语... 介绍了一种基于STRAIGHT语音修改算法的个性化语音的方法。对输入的语音提取基本信息,并进行频谱分析;利用STRAIGHT算法对相关参数进行修改;通过STRAIGHT合成器生成新的个性化的语音。实验结果表明,该方法可以得到高质量的个性化合成语音,MOS得分为4.18分。 展开更多
关键词 语音合成 straight算法 语音修改 个性化语音
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一种基于Straight的语音焦点合成方法 被引量:3
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作者 杨金辉 易中华 王煦法 《计算机工程》 CAS CSCD 北大核心 2005年第13期46-47,128,共3页
针对汉语焦点的特性,设计了接近自然语流风格的实验语料。通过对语料的分析,运用CART技术,建立了焦点的韵律模型。在语音合成阶段,使用韵律模型生成语音的韵律参数,结合Straight算法,实现了语音焦点的合成。对合成效果的评测表明,该方... 针对汉语焦点的特性,设计了接近自然语流风格的实验语料。通过对语料的分析,运用CART技术,建立了焦点的韵律模型。在语音合成阶段,使用韵律模型生成语音的韵律参数,结合Straight算法,实现了语音焦点的合成。对合成效果的评测表明,该方法能够合成自然度很高的语音焦点。 展开更多
关键词 焦点 分类回归树 straight 基频曲线 语音合成
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基于STRAIGHT模型和人工神经网络的语音转换 被引量:5
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作者 张正军 杨卫英 陈赞 《电声技术》 2010年第9期49-52,共4页
采用STRAIGHT语音分析-合成模型,提取源说话人和目标说话人的基频和光滑声道谱作为表征语音特征的参数。在频谱训练阶段,把声道谱转换成MFCC参数,采用人工神经网络算法对源-目标说话人的MFCC参数进行训练映射。主观和客观试验结果表明,... 采用STRAIGHT语音分析-合成模型,提取源说话人和目标说话人的基频和光滑声道谱作为表征语音特征的参数。在频谱训练阶段,把声道谱转换成MFCC参数,采用人工神经网络算法对源-目标说话人的MFCC参数进行训练映射。主观和客观试验结果表明,该方法能取得较好的转换效果,转换语音和目标语音较接近,易于理解。 展开更多
关键词 straight模型 人工神经网络:语音转换
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基于STRAIGHT模型和ANN的语音转换方法研究
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作者 王光艳 高丽萍 +1 位作者 黄奕婷 于宝雲 《新一代信息技术》 2020年第22期12-18,共7页
本文提出一种基于STRAIGHT模型的人工神经网络语音转换方法,该方法先利用STRAIGHT模型提取出语音的各特征参数后,再利用人工神经网络来进行模型特征参数的训练,经过不断的信号刺激,得到映射规则,最后再进行语音的特征参数的合成,完成整... 本文提出一种基于STRAIGHT模型的人工神经网络语音转换方法,该方法先利用STRAIGHT模型提取出语音的各特征参数后,再利用人工神经网络来进行模型特征参数的训练,经过不断的信号刺激,得到映射规则,最后再进行语音的特征参数的合成,完成整个语音转换系统。STRAIGHT模型能提高转换语音的自然度、清晰度和可懂度。采用ANN进行模型特征参数训练,可以自动迭代更新数据权重,得到的映射规则能更好地规范要转换的特征参数,使得语音转换质量更高。 展开更多
关键词 语音转换 straight模型 人工神经网络
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Monte Carlo Method for the Uncertainty Evaluation of Spatial Straightness Error Based on New Generation Geometrical Product Specification 被引量:10
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作者 WEN Xiulan XU Youxiong +2 位作者 LI Hongsheng WANG Fenglin SHENG Danghong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第5期875-881,共7页
Straightness error is an important parameter in measuring high-precision shafts. New generation geometrical product speeifieation(GPS) requires the measurement uncertainty characterizing the reliability of the resul... Straightness error is an important parameter in measuring high-precision shafts. New generation geometrical product speeifieation(GPS) requires the measurement uncertainty characterizing the reliability of the results should be given together when the measurement result is given. Nowadays most researches on straightness focus on error calculation and only several research projects evaluate the measurement uncertainty based on "The Guide to the Expression of Uncertainty in Measurement(GUM)". In order to compute spatial straightness error(SSE) accurately and rapidly and overcome the limitations of GUM, a quasi particle swarm optimization(QPSO) is proposed to solve the minimum zone SSE and Monte Carlo Method(MCM) is developed to estimate the measurement uncertainty. The mathematical model of minimum zone SSE is formulated. In QPSO quasi-random sequences are applied to the generation of the initial position and velocity of particles and their velocities are modified by the constriction factor approach. The flow of measurement uncertainty evaluation based on MCM is proposed, where the heart is repeatedly sampling from the probability density function(PDF) for every input quantity and evaluating the model in each case. The minimum zone SSE of a shaft measured on a Coordinate Measuring Machine(CMM) is calculated by QPSO and the measurement uncertainty is evaluated by MCM on the basis of analyzing the uncertainty contributors. The results show that the uncertainty directly influences the product judgment result. Therefore it is scientific and reasonable to consider the influence of the uncertainty in judging whether the parts are accepted or rejected, especially for those located in the uncertainty zone. The proposed method is especially suitable when the PDF of the measurand cannot adequately be approximated by a Gaussian distribution or a scaled and shifted t-distribution and the measurement model is non-linear. 展开更多
关键词 uncertainty evaluation Monte Carlo method spatial straightness error quasi particle swarm optimization minimum zone solution geometrical product specification
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Effect of Working Position on Vertical Motion Straightness of Open Hydrostatic Guideways in Grinding Machine 被引量:5
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作者 ZHA JUn WANG Zhiwei +1 位作者 XUE Fei CHEN Yaolong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第1期46-52,共7页
Hydrostatic guideways have various applications in precision machine tools due to their high motion accuracy. The analysis of motion straightness in hydrostatic guideways is generally ignoring the external load on the... Hydrostatic guideways have various applications in precision machine tools due to their high motion accuracy. The analysis of motion straightness in hydrostatic guideways is generally ignoring the external load on the slider. A variation force also exists, caused by the different working positions, together with the dead load of the slider and that of other auxiliary devices. The effect of working position on vertical motion straightness is investigated based on the equivalent static model, considering the error averaging effort of pressured oil film in open hydrostatic guideways. Open hydrostatic guideways in LGF1000 are analyzed with this approach. The theoretical results show that the slider has maximum vertical motion straightness when the working position is closer the guiderail of Y axis. The vertical motion straightness reaches a minimum value as the working position is located at the center of the two guiderails on the Y axis. The difference between the maximum and minimum vertical motion straightness is 34.7%. The smaller vertical motion straightness is attributed to the smaller spacing of the two pads centers, along the Y direction. The experimental results show that the vertical motion straightness is 4.15 μm/1200 mm, when the working position is located in the middle of the Xbeam, and 5.08 pro/1200 mm, when the working position is approaching the Y guiderails, denoting an increase of 18.3%. The changing trends of the measured results validate the correctness of the theoretical model. The research work can be used to reveal the variation law of accuracy of the open hydrostatic guideways, under different working positions, to predict the machining precision, and provides the basis for an error compensation strategy for gantry type grinding machines. 展开更多
关键词 open hydrostatic guideways error averaging vertical motion straightness working position
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On-Machine Measurement of the Straightness and Tilt Errors of a Linear Slideway Using a New Four-Sensor Method 被引量:3
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作者 Lei Zhao Kai Cheng +1 位作者 Hui Ding Liang Zhao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第2期122-132,共11页
Although there are some multi-sensor methods for measuring the straightness and tilt errors of a linear slideway, they need to be further improved in some aspects, such as suppressing measurement noise and reducing pr... Although there are some multi-sensor methods for measuring the straightness and tilt errors of a linear slideway, they need to be further improved in some aspects, such as suppressing measurement noise and reducing precondition.In this paper, a new four-sensor method with an improved measurement system is proposed to on-machine separate the straightness and tilt errors of a linear slideway from the sensor outputs, considering the influences of the reference surface profile and the zero-adjustment values. The improved system is achieved by adjusting a single sensor to di erent positions. Based on the system, a system of linear equations is built by fusing the sensor outputs to cancel out the e ects of the straightness and tilt errors. Three constraints are then derived and supplemented into the linear system to make the coe cient matrix full rank. To restrain the sensitivity of the solution of the linear system to the measurement noise in the sensor outputs, the Tikhonov regularization method is utilized. After the surface profile is obtained from the solution, the straightness and tilt errors are identified from the sensor outputs. To analyze the e ects of the measurement noise and the positioning errors of the sensor and the linear slideway, a series of computer simulations are carried out. An experiment is conducted for validation, showing good consistency. The new four-sensor method with the improved measurement system provides a new way to measure the straightness and tilt errors of a linear slideway, which can guarantee favorable propagations of the residuals induced by the noise and the positioning errors. 展开更多
关键词 MULTI-SENSOR method straightNESS ERROR TILT ERROR On-machine measurement LINEAR slideway ERROR separation technique
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Cemented Müller straight stem total hip replacement:18 year survival,clinical and radiological outcomes 被引量:4
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作者 Vasileios S Nikolaou Demetrios Korres +4 位作者 Stergios Lallos Andreas Mavrogenis Ioannis Lazarettos Ioannis Sourlas Nicolas Efstathopoulos 《World Journal of Orthopedics》 2013年第4期303-308,共6页
AIM: To present the 18 year survival and the clinical and radiological outcomes of the Müller straight stem, cemented, total hip arthroplasty(THA).METHODS: Between 1989 and 2007, 176 primary total hip arthroplast... AIM: To present the 18 year survival and the clinical and radiological outcomes of the Müller straight stem, cemented, total hip arthroplasty(THA).METHODS: Between 1989 and 2007, 176 primary total hip arthroplasties in 164 consecutive patients were performed in our institution by the senior author. All patients received a Müller cemented straight stem and a cemented polyethylene liner. The mean age of the patients was 62 years(45-78). The diagnosis was primary osteoarthritis in 151 hips, dysplasia of the hip in 12 and subcapital fracture of the femur in 13. Following discharge, serial follow-up consisted of clinical evaluation based on the Harris Hip Score and radiological assessment. The survival of the prosthesis using revision for any reason as an end-point was calculated by KaplanMeier analysis.RESULTS: Twenty-four(15%) patients died during the follow-up study, 6(4%) patients were lost, while the remaining 134 patients(141 hips) were followedup for a mean of 10 years(3-18 years). HSS score at the latest follow-up revealed that 84 hips(59.5%) had excellent results, 30(22.2%) good, 11(7.8%) fair and 9(6.3%) poor. There were 3 acetabular revisions due to aseptic loosening. Six(4.2%) stems were diagnosed as having radiographic definitive loosening; however, only 1 was revised. 30% of the surviving stems showed no radiological changes of radiolucency, while 70% showed some changes. Survival of the prosthesis for any reason was 96% at 10 years and 81% at 18 years. CONCLUSION: The 18 year survival of the Müller straight stem, cemented THA is comparable to those of other successful cemented systems. 展开更多
关键词 Total hip Replacement MULLER straight STEM CEMENTED SURVIVORSHIP
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Water-saving Potential in aeolian sand soil under straight tube and surface drip irrigation in Taklimakan Desert in Northwest China 被引量:6
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作者 ZhongWen Bao HuLin Du XiaoJun Jin 《Research in Cold and Arid Regions》 2011年第3期243-251,共9页
Evaporation loss from the saturated soil beneath drip irrigation emitters highly influences the irrigation efficiency of drip krigation (D1]. Subsurface drip irrigation (SDI) is one good approach to curb this ineff... Evaporation loss from the saturated soil beneath drip irrigation emitters highly influences the irrigation efficiency of drip krigation (D1]. Subsurface drip irrigation (SDI) is one good approach to curb this inefficiency, but in a new irrigation method, straight tube irrigation (STI), the irrigation tubes do not need to be buried and thus STI is recommended to increase the irrigation efficiency under normal surface-applied DI. STI consists of only connectors and water-transference tubes that can directly transfer irrigation water from the lateral emitters in the drip line to the root zone of plants. Five-month field experiments were carried out in aeolian sand soil in the forest-belts of the Taklimakan Desert, which have poor water storage capacity, to compare the potential water saving between STI and DI. The preliminary results showed that, compared with DI, STI (1) improved the soil water content in soil depths from 40 to 100 cm under the soil surface; (2) achieved the same irrigation effects in relatively shorter irrigation durations; (3) had very little water loss due to deep seepage; and (4) formed a layer of dry sand about 10 to 30 cm thick immediately below the soil surface, which lessened evaporation loss of soil water beneath the emitters on the soil surface. This demonstrates that STI can maximize the water-saving potential of DI through the reduction of wetted soil perimeters on the soil surface. This is valuable information for water-saving engineering applications and projects with STI in arid and semiarid regions. 展开更多
关键词 potential water saving evaporation loss straight tube irrigation drip irrigation EFFICIENCY Taklimakan Desert
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Adaptive robust dissipative designs on straight path control for underactuated ships 被引量:3
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作者 Li Tieshan Yang Yansheng Hong Biguang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2006年第1期177-181,共5页
An adaptive robust control algorithm for ship straight path control system in the presence of both modeling uncertainties and the bounded disturbances is proposed. Motivated by the backstepping approach, the algorithm... An adaptive robust control algorithm for ship straight path control system in the presence of both modeling uncertainties and the bounded disturbances is proposed. Motivated by the backstepping approach, the algorithm is developed by using the dissipation theory, such that the resulting dosed-loop system is both strictly dissipative and asymptotically adaptively stable for all admissible uncertainties. Also, it is able to steer an underactuated ship along a prescribed straight path with ultimate bounds under external disturbances induced by wave, wind and ocean current. When there are no disturbances, the straight path control can be implemented in a locally asymptotically stable manner. Simulation results on an ocean-going training ship ‘YULONG' are presented to validate the effectiveness of the algorithm. 展开更多
关键词 underactuated ship straight path control nonlinear system adaptive backstepping design robust control.
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Virtual straightening of scraper conveyor based on the position and attitude solution of industrial robot model 被引量:2
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作者 Suhua Li Jiacheng Xie +3 位作者 Fang Ren Xin Zhang Xuewen Wang Binbin Wang 《International Journal of Coal Science & Technology》 EI CAS CSCD 2021年第5期1149-1170,共22页
The movement of the floating connecting mechanism between a hydraulic support and scraper conveyor is space movement;thus,when the hydraulic support pushes the scraper conveyor,there is an error between the actual dis... The movement of the floating connecting mechanism between a hydraulic support and scraper conveyor is space movement;thus,when the hydraulic support pushes the scraper conveyor,there is an error between the actual distance of the scraper conveyor and the theoretical moving distance.As a result,the scraper conveyor cannot obtain the straightness requirement.Therefore,the movement law of the floating connecting mechanism between the hydraulic support and scraper conveyor is analyzed and programmed into the Unity3D to realize accurate pushing of the scraper conveyor via hydraulic support.The Coal Seam?Equipment Joint Virtual Straightening System is established,and a straightening method based on the motion law of a floating connection is proposed as the default method of the system.In addition,a straightening simulation of the scraper conveyor was performed on a complex coal seam floor,the results demonstrate that the average straightening error of the scraper conveyor is within 2-8 mm,and is in direct proportion to the fluctuation of the coal seam floor in the strike of the seam with high accuracy,the straightness of scraper conveyor is more affected by the subsidence terrain during straightening than by the bulge terrain.And some conclusions are verified by experiment.Based on the verification of the relevant conclusions,a comparison and analysis of Longwall Automation Steering Committee(LASC)straightening technology and default straightening method in the simulation system shows that the straightness accuracy of LASC straightening technology under complex floor conditions is slightly less than that of the default straightening method in the proposed system. 展开更多
关键词 Virtual reality Scraper conveyor Hydraulic support Posture solution straightness control
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