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上海长江隧桥长重索施工技术 被引量:1
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作者 黄伟 《中国港湾建设》 2012年第6期53-56,75,共5页
随着我国桥梁事业的发展,斜拉索桥的跨度要求越来越大,施工技术难度也越来越大,其中必须首先解决斜拉索的施工难题。结合上海长江大桥的施工特点使用门机吊来吊装长重索至桥面,采用软硬结合的方式对长重索进行牵引;在施工中通过对长重... 随着我国桥梁事业的发展,斜拉索桥的跨度要求越来越大,施工技术难度也越来越大,其中必须首先解决斜拉索的施工难题。结合上海长江大桥的施工特点使用门机吊来吊装长重索至桥面,采用软硬结合的方式对长重索进行牵引;在施工中通过对长重索扭转方向的分析,采取了一个防扭措施。使斜拉索施工的安全和质量有了较大提高,为其它桥梁建设提供参考经验。 展开更多
关键词 重索吊装 重索牵引 重索防扭
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自由悬挂重索微振固有频率渐近解
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作者 龚道荣 《武陵学刊》 1995年第3期55-56,共2页
本文采用一种快速收剑的渐近法,给出了自由悬挂重索微振时固有频率的公式。
关键词 重索 固有频率 渐近解
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吊重索的负荷试验
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作者 Dengl.,K 冯自强 《湘钢译丛》 1993年第4期45-46,19,共3页
关键词 重索 负荷试验
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可变频幅相一体化测量系统研究 被引量:4
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作者 王剑 《工业控制计算机》 2011年第11期96-97,共2页
阐述一种基于重索采样的可变频幅相一体化自适应测量系统。首先介绍了重索采样算法的理论根据,并且进行了算法仿真实验和误差分析,然后在此基础上提出了针对可变频信号的自适应测量原理,并设计了幅相一体化测量系统方案。该方案经实验... 阐述一种基于重索采样的可变频幅相一体化自适应测量系统。首先介绍了重索采样算法的理论根据,并且进行了算法仿真实验和误差分析,然后在此基础上提出了针对可变频信号的自适应测量原理,并设计了幅相一体化测量系统方案。该方案经实验验证具有较高的测量精度和高实时性。 展开更多
关键词 幅相一体化测量 重索采样法 自适应测量 可变频
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Suppression strategy for parametrically excited lateral vibration of mass-loaded string
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作者 张长友 朱昌明 林忠钦 《Journal of Southeast University(English Edition)》 EI CAS 2004年第2期165-169,共5页
This paper discusses a simple way to suppress the parametrically excited lateral vibration of a mass-loaded string. Supposing that the mass at the lower end of the string is subjected to a vertical harmonic excitation... This paper discusses a simple way to suppress the parametrically excited lateral vibration of a mass-loaded string. Supposing that the mass at the lower end of the string is subjected to a vertical harmonic excitation and neglecting the higher order vibration modes, the equation of motion for the mass-loaded string can be represented by a Mathieus equation with cubic nonlinearity. According to the theory of the Mathieus equation, in the mass-loaded string system, when the vertical vibration frequency of the mass approaches twice the natural frequency of the string lateral vibration, once the vertical vibration amplitude of the mass exceeds a critical value, the parametric resonance will occur in the string. To avoid the parametric resonance, a vibration absorber, composed of a thin beam and two mass blocks attached at both sides of the beam symmetrically, is proposed to install with the mass to reduce its vertical vibration, and ultimately suppress the lateral vibration of the string. Such a suppression strategy is finally validated by experiments. 展开更多
关键词 mass-loaded string parametric resonance vibration absorber
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The cicada genus Pomponia St?l,1866(Hemiptera:Cicadidae) from China
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作者 王旭 魏琮 《Entomotaxonomia》 CSCD 2015年第3期201-206,共6页
Pomponia orientalis (Distant, 1912) is reported for the first time from China based on specimens collected from Yunnan Province. The morphological redescription and male genitalia of this species are provided. A key... Pomponia orientalis (Distant, 1912) is reported for the first time from China based on specimens collected from Yunnan Province. The morphological redescription and male genitalia of this species are provided. A key to the species of Pomponia from China is given. Geographical distribution of Chinese species of Pompon ia is discussed. 展开更多
关键词 Cicadomorpha CICADOIDEA REDESCRIPTION taxonomy geographical distribution key
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Three new species of Parandrexis(Coleoptera:Parandrexidae) from the Middle Jurassic Jiulongshan Formation of Inner Mongolia,China
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作者 陆塘梅 赵云云 +1 位作者 史宗冈 任东 《Entomotaxonomia》 CSCD 2015年第2期111-122,共12页
Three well-preserved fossil species ofParandrexis longicornis Lu, Shih & Ren sp. nov., P. agilis Lu, Shih & Ren sp. nov. and P. oblongis Lu, Shih & Ren sp. nov. are described and illustrated from the late Middle Ju... Three well-preserved fossil species ofParandrexis longicornis Lu, Shih & Ren sp. nov., P. agilis Lu, Shih & Ren sp. nov. and P. oblongis Lu, Shih & Ren sp. nov. are described and illustrated from the late Middle Jurassic Jiulongshan Formation of Daohugou in Inner Mongolia Autonomous Region, China. These new species are distinguished from other described species of Parandrexis by body size, head dimension (ratio of length to width), pronotum shape, and antennal characters. Based on new morphological data, we emend the generic diagnosis. These findings support the sexual size dimorphism of parandrexids and suggest a gymnosperm sap feeding habit by Parandrexis. 展开更多
关键词 fossil beetle DAOHUGOU sexual size dimorphism feeding habits taxonomy key
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Parameter optimization of gravity density inversion based on correlation searching and the golden section algorithm 被引量:1
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作者 孙鲁平 刘展 首皓 《Applied Geophysics》 SCIE CSCD 2012年第2期131-138,233,共9页
For density inversion of gravity anomaly data, once the inversion method is determined, the main factors affecting the inversion result are the inversion parameters and subdivision scheme. A set of reasonable inversio... For density inversion of gravity anomaly data, once the inversion method is determined, the main factors affecting the inversion result are the inversion parameters and subdivision scheme. A set of reasonable inversion parameters and subdivision scheme can, not only improve the inversion process efficiency, but also ensure inversion result accuracy. The gravity inversion method based on correlation searching and the golden section algorithm is an effective potential field inversion method. It can be used to invert 2D and 3D physical properties with potential data observed on flat or rough surfaces. In this paper, we introduce in detail the density inversion principles based on correlation searching and the golden section algorithm. Considering that the gold section algorithm is not globally optimized. we present a heuristic method to ensure the inversion result is globally optimized. With a series of model tests, we systematically compare and analyze the inversion result efficiency and accuracy with different parameters. Based on the model test results, we conclude the selection principles for each inversion parameter with which the inversion accuracy can be obviously improved. 展开更多
关键词 Density inversion correlation searching golden section algorithm inversion parameter optimization
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Crane flies(Diptera: Tipuloidea: Tipulidae) from Dayaoshan National Nature Reserve, China and analysis of DNA barcodes, with description of one new species in the genus Indotipula
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作者 门秋雷 薛国喜 +1 位作者 孙梦溦 孙卓 《Entomotaxonomia》 CSCD 2017年第4期251-264,共14页
This paper reports six species of crane flies from Dayaoshan National Nature Reserve, Guangxi Zhuang Autonomous Region, China, including one new species, Indotipula jinxiuensis sp. nov. The males of Pselliophora guang... This paper reports six species of crane flies from Dayaoshan National Nature Reserve, Guangxi Zhuang Autonomous Region, China, including one new species, Indotipula jinxiuensis sp. nov. The males of Pselliophora guangxiensis Yang Yang, 1988 and Holorusia basiflava Yang Yang, 1993 and female of Pselliophora xanthopimplina Enderlein, 1921 are redescribed and illustrated with new morphological characters. The females of P. guangxiensis and H. basiflava are described and illustrated for the first time. A key for separating known species of Indotipula Edwards, 1931 from China is provided. DNA barcodes of all species in this study are provided and analyzed. 展开更多
关键词 NEMATOCERA DNA barcodes REDESCRIPTION taxonomy key
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Body mass index does not affect the survival of pancreatic cancer patients 被引量:6
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作者 Qing-long Jiang Cheng-feng Wang +11 位作者 Yan-tao tian Huang Huang Shui-Sheng Zhang Dong-bing Zhao Jie Ma Wei Yuan Yue-Min Sun Xu Che Jian-Wei Zhang Yun-Mian Chu Ya-Wei Zhang Ying-tai Chen 《World Journal of Gastroenterology》 SCIE CAS 2017年第34期6287-6293,共7页
AIM to evaluate the association of body mass index(b MI) with the overall survival of pancreatic ductal adenocarcinoma(PDAC) patients.METHODS A retrospective analysis of PDAC patients diagnosed in the National Cancer ... AIM to evaluate the association of body mass index(b MI) with the overall survival of pancreatic ductal adenocarcinoma(PDAC) patients.METHODS A retrospective analysis of PDAC patients diagnosed in the National Cancer Center of China between January 1999 and December 2014 was performed. these patients were categorized into four b MI groups(< 18.5, 18.5-22.9, 23-27.4 and ≥ 27.5 kg/m2). χ2 tests for comparison of the proportions of categorical variables, and Student's t-test or Mann-Whitney test for continuous variables were employed. Survival analysis was performed with the Kaplan-Meyer method. their HRs of mortality and 95%CIs were estimated using the Cox proportional hazards model.RESULTS With a median age of 59.6 years(range: 22.5-84.6 years), in total 1783 PDAC patients were enrolled in this study. their mean usual b MI was 24.19 ± 3.53 for the whole cohort. More than half of the patients(59.3%) experienced weight loss during the disease onset and progression. Compared with healthy-weight individuals, newly diagnosed patients who were overweight or obese had more severe weight loss during their disease onset and progression(P < 0.001). Individuals who were overweight or obese were associated with positive smoking history(P < 0.001). A significant difference in comorbidity of diabetes(P = 0.044) and coronary artery disease(P < 0.001) was identified between high b MI and normal-weight patients. After a median follow-up of 8 mo, the survival analysis showed no association between b MI and the overall survival(P = 0.90, n = 1783). When we stratified the whole cohort by pancreatic cancer stage, no statistically significant association between b MI and overall survival was found for resectable(P = 0.99, n = 217), unresectable locally advanced(P = 0.90, n = 316) and metastatic patients(P = 0.88, n = 1250), respectively. the results did not change when we used the b MI at diagnosis.CONCLUSION Our results showed no significance of b MI for the overall survival of PDAC patients. 展开更多
关键词 body mass index Pancreatic cancer OVERWEIGHT Smoking history Survival analysis
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Effect of Timing of Tracheotomy on Clinical Outcomes: an Update Meta-analysis Including 11 Trials 被引量:10
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作者 Liang Shan Rui Zhang Lian-di Li 《Chinese Medical Sciences Journal》 CAS CSCD 2013年第3期159-166,共8页
Objective To estimate the relative effect of early vs. late tracheotomy on clinical end-points in unselected intensive care unit (ICU) patients undergoing mechanical ventilation. Methods We searched electronic data... Objective To estimate the relative effect of early vs. late tracheotomy on clinical end-points in unselected intensive care unit (ICU) patients undergoing mechanical ventilation. Methods We searched electronic databases (up to February 27, 2013) for both randomized control trials and observational studies satisfying the predefined inclusion criteria. 展开更多
关键词 intensive care unit artificial respiration TRACHEOTOMY META-ANALYSIS
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Long-term treatment with proton pump inhibitor is associated with undesired weight gain
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作者 Ichiro Yoshikawa Makiko Nagato +2 位作者 Masahiro Yamasaki Keiichiro Kume Makoto Otsuki 《World Journal of Gastroenterology》 SCIE CAS CSCD 2009年第38期4794-4798,共5页
AIM:To examine the effects of long-term proton pump inhibitor (PPI) therapy on body weight (BW) and body mass index (BMI) in patients with gastroesophageal reflux disease (GERD).METHODS: The subjects were 52 patients ... AIM:To examine the effects of long-term proton pump inhibitor (PPI) therapy on body weight (BW) and body mass index (BMI) in patients with gastroesophageal reflux disease (GERD).METHODS: The subjects were 52 patients with GERD and 58 sex-and age-matched healthy controls. GERD patients were treated with PPI for a mean of 2.2 years (range, 0.8-5.7 years), and also advised on lifestyle modifications (e.g. selective diet, weight management). BW, BMI and other parameters were measured at baseline and end of study.RESULTS: Twenty-four GERD patients were treated daily with 10 mg omeprazole, 12 with 20 mg omeprazole, 8 with 10 mg rabeprazole, 5 with 15 mg lansoprazole, and 3 patients with 30 mg lansoprazole. At baseline, there were no differences in BW and BMI between reflux patients and controls. Patients with GERD showed increases in BW (baseline: 56.4±10.4 kg, end: 58.6±10.8 kg, mean±SD, P<0.0001) and BMI (baseline: 23.1±3.1 kg/m2, end: 24.0±3.1 kg/m2, P<0.001), but no such changes were noted in the control group. Mean BW increased by 3.5 kg (6.2% of baseline) in 37 (71%) reflux patients but decreased in only 6 (12%) patients during treatment.CONCLUSION: Long-term PPI treatment was associated with BW gain in patients with GERD. Reflux patients receiving PPI should be encouraged to manage BW through lifestyle modifi cations. 展开更多
关键词 Gastroesophageal reflux disease Protonpump inhibitor Body weight
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HQ-Tree: A Distributed Spatial Index Based on Hadoop 被引量:5
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作者 FENG Jun TANG Zhixian WEI Mian XU Liming 《China Communications》 SCIE CSCD 2014年第7期128-141,共14页
In this paper,we propose a novel spatial data index based on Hadoop:HQ-Tree.In HQ-Tree,we use PR QuadTrec to solve the problem of poor efficiency in parallel processing,which is caused by data insertion order and spac... In this paper,we propose a novel spatial data index based on Hadoop:HQ-Tree.In HQ-Tree,we use PR QuadTrec to solve the problem of poor efficiency in parallel processing,which is caused by data insertion order and space overlapping.For the problem that HDFS cannot support random write,we propose an updating mechanism,called "Copy Write",to support the index update.Additionally,HQ-Tree employs a two-level index caching mechanism to reduce the cost of network transferring and I/O operations.Finally,we develop MapReduce-based algorithms,which are able to significantly enhance the efficiency of index creation and query.Experimental results demonstrate the effectiveness of our methods. 展开更多
关键词 spatial index QUADTREE HADOOP MAPREDUCE
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Power loss reduction of distribution systems using BFO based optimal reconfiguration along with DG and shunt capacitor placement simultaneously in fuzzy framework 被引量:1
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作者 M.Mohammadi A.Mohammadi Rozbahani S.Bahmanyar 《Journal of Central South University》 SCIE EI CAS CSCD 2017年第1期90-103,共14页
In distribution systems,network reconfiguration and capacitor placement are commonly used to diminish power losses and keep voltage profiles within acceptable limits.Moreover,the problem of DG allocation and sizing is... In distribution systems,network reconfiguration and capacitor placement are commonly used to diminish power losses and keep voltage profiles within acceptable limits.Moreover,the problem of DG allocation and sizing is great important.In this work,a combination of a fuzzy multi-objective approach and bacterial foraging optimization(BFO) as a meta-heuristic algorithm is used to solve the simultaneous reconfiguration and optimal sizing of DGs and shunt capacitors in a distribution system.Each objective is transferred into fuzzy domain using its membership function.Then,the overall fuzzy satisfaction function is formed and considered a fitness function inasmuch as the value of this function has to be maximized to gain the optimal solution.The numerical results show that the presented algorithm improves the performance much more than other meta-heuristic algorithms.Simulation results found that simultaneous reconfiguration with DG and shunt capacitors allocation(case 5) has 77.41%,42.15%,and 56.14%improvements in power loss reduction,load balancing,and voltage profile indices,respectively in 33-bus test system.This result found 87.27%,35.82%,and 54.34%improvements of mentioned indices respectively for 69-bus system. 展开更多
关键词 network reconfiguration distributed generation (DG) capacitor banks fuzzy framework bacterial foragingoptimization
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An Adaptive Spectral Conjugate Gradient Method with Restart Strategy
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作者 Zhou Jincheng Jiang Meixuan +2 位作者 Zhong Zining Wu Yanqiang Shao Hu 《数学理论与应用》 2024年第3期106-118,共13页
As a generalization of the two-term conjugate gradient method(CGM),the spectral CGM is one of the effective methods for solving unconstrained optimization.In this paper,we enhance the JJSL conjugate parameter,initiall... As a generalization of the two-term conjugate gradient method(CGM),the spectral CGM is one of the effective methods for solving unconstrained optimization.In this paper,we enhance the JJSL conjugate parameter,initially proposed by Jiang et al.(Computational and Applied Mathematics,2021,40:174),through the utilization of a convex combination technique.And this improvement allows for an adaptive search direction by integrating a newly constructed spectral gradient-type restart strategy.Then,we develop a new spectral CGM by employing an inexact line search to determine the step size.With the application of the weak Wolfe line search,we establish the sufficient descent property of the proposed search direction.Moreover,under general assumptions,including the employment of the strong Wolfe line search for step size calculation,we demonstrate the global convergence of our new algorithm.Finally,the given unconstrained optimization test results show that the new algorithm is effective. 展开更多
关键词 Unconstrained optimization Spectral conjugate gradient method Restart strategy Inexact line search Global convergence
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Iterated index formulae for closed geodesies with applications 被引量:8
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作者 刘春根 龙以明 《Science China Mathematics》 SCIE 2002年第1期9-28,共19页
In this paper, various precise iteration equalities and inequalities of Morse indices for the closed geodesics are established. As applications of these formulae, multiplicity results of closed geodesics on some Riema... In this paper, various precise iteration equalities and inequalities of Morse indices for the closed geodesics are established. As applications of these formulae, multiplicity results of closed geodesics on some Riemannian manifolds are proved. 展开更多
关键词 Riemannian manifold Morse index ITERATION
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Influences of olfactory ensheathing cells transplantation on axonal regeneration in spinal cord of adult rats 被引量:5
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作者 沈慧勇 唐勇 +2 位作者 吴燕峰 陈燕涛 程志安 《Chinese Journal of Traumatology》 CAS 2002年第3期136-141,共6页
Objective: To observe whether olfactory ensheathing cells could be used to promote axonal regeneration in a spontaneously nonregenerating system.Methods: After laminectomy at the lower thoracic level, the spinal cords... Objective: To observe whether olfactory ensheathing cells could be used to promote axonal regeneration in a spontaneously nonregenerating system.Methods: After laminectomy at the lower thoracic level, the spinal cords of adult rats were exposed and completely transected at T10. A suspension of ensheathing cells was injected into the lesion site in 12 adult rats, and control D/F 12 ( 1∶1 mixture of DMEM and Hams F 12) was injected in 12 adult rats. Six weeks and ten weeks after cell transplantation, the rats were evaluated by climbing test and motor evoked potentials (MEPs) monitoring. The samples were procured and studied with histologicl and immunohistochemical methods.Results: At the 6th week after cell transplantation, all the rats in both the transplanted and control groups were paraplegic and the MEPs could not be recorded. At the 10th week after cell transplantation, of 7 rats in the control group, 2 rats had muscles contraction of the lower extremities, 2 rats had hips and/or knees active movement; and 5 rats MEPs could be recorded in the hind limbs in the transplanted group (n=7). None of the rats in the control group had functional improvement and no MEPs recorded (n=7). Numerous regenerating axons were observed through the transplantation and continued to regenerate into the denervated host tract. Cell labelling using anti Myelin Basic Protein (MBP) and anti Nerve Growth Factor Receptor (anti NGFR) indicated that the regenerated axons were derived from the appropriate neuronal source and that donor cells migrated into the denervated host tract. But axonal degeneration existed and regenerating axons were not observed within the spinal cords of the adult rats with only D/F 12 injection. Conclusions: The axonal regeneration in the transected adult rat spinal cord is possible after ensheathing cells transplantation. 展开更多
关键词 Spinal cord injuries Axonal regeneration Olfactory ensheathing cells
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An innovative method to evaluate the severe level of general Qi deficiency
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作者 Lu Yu Niu Tingli +6 位作者 Chen Tianyu Gao Lujiao Ma Liangxiao Li Haiyan Zhu Qingwen Yang Xuezhi Niu Xin 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2018年第4期585-592,共8页
OBJECTIVE:The study aim was to use existing relevant indexes to establish an index series for the quantitative measurement of Qi deficiency pattern(QDP) in Traditional Chinese Medicine(TCM).METHODS:Seventeen indexes o... OBJECTIVE:The study aim was to use existing relevant indexes to establish an index series for the quantitative measurement of Qi deficiency pattern(QDP) in Traditional Chinese Medicine(TCM).METHODS:Seventeen indexes of arterial oxygen saturation(SaO_2),TCM pulse diagnosis,heart rate,and blood pressure were integrated into an index series,and 94 selected subjects were divided into a healthy control group,a mild QDP group,and a typical QDP group.All three groups were then synchronously given a breath-holding(BH) test and index detections using TCM apparatus for auxiliary diagnosis and treatment and a photoplethysmograph.The detections were carried out repeatedly until there was no monotonic change in the value of the minimal SaO_(2d)uring a BH measurement(SaO_(2 min)) or in the duration of BH during a BH measurement(TBH).RESULTS:BH measurement and index detection data from 380 eligible cases were analyzed and a significant intergroup difference was found for 12 indexes.CONCLUSION:An index series for quantitative QDP measurement could comprise the 12 effective indexes:RSaO_(2d)(rate of decline of SaO_(2d)uring a BH measurement),RSaO_(2r)(recovery rate of SaO_2 after a BH measurement),SaO_(2 min),BFV(blood flow velocity),TSaO_(2d)(the time at which SaO_2 started declining during a BH measurement),TBH,TSa_(O2 min)(the time of occurrence of the minimal SaO_(2d)uring a BH measurement),TSa O_(2 max)(the time of occurrence of the maximal SaO_2 after a BH measurement),PTP(pulse-touching pressure),SBP(systolic blood pressure),PWV(pulse wave velocity),and DBP(diastolic blood pressure).Of the indexes,RSaO_(2d)could play akey role in quantitative QDP measurement;RSaO_(2r) and Sa O_2 mincould be used to differentiate the QDP symptom of shortness of breath and as early-warning indexes for chronic obstructive pulmonary disease.BFV,TSaO_(2d),and TBHcould be used to quantitatively assess the QDP symptoms of spontaneous perspiration and shortness of breath. 展开更多
关键词 Qi deficiency pattern Dynamic arterial oxygen saturation pulse diagnosis Breath-holding measurement TCM
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Searching Multiple Structural Changes of Chinese Stock Market via GMDH
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作者 Yixiang Tian Li Zhou 《Journal of Systems Science and Information》 2009年第3期193-200,共8页
This paper analyzes multiple structural changes by GMDH (Group Meth- ods of Data Handling), which have obvious advantages. Our method extends the model of Lumsdaine & Papell[1] (1997), and it could be applied to ... This paper analyzes multiple structural changes by GMDH (Group Meth- ods of Data Handling), which have obvious advantages. Our method extends the model of Lumsdaine & Papell[1] (1997), and it could be applied to the case of more than two structural changes. Because of simultaneously considering every structural change of the hypothesis, it is likely to be of particular relevance in practice. And it can decrease large investigation costs by MATLAB programming. What is more, we can select the criterion value of F incremental statistic to control the significance of the breaks, based on kinds of investigation intentions. And the empirical evidences on Shenzhen Composite Index are presented to illustrate the usefulness of our method. 展开更多
关键词 GMDH multiple structural changes F incremental statistic
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