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Using Roy’s Model to Evaluate the Care Given to Postpartum Women Following Caesarean Delivery 被引量:3
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作者 Serap Ejder Apay Türkan Pasinlioglu 《Open Journal of Nursing》 2014年第11期784-796,共13页
Background: To evaluate the care given using Roy’s Adaptation Model. Materials and Methods: A pretest-posttest experimental model with a control group. Study population comprised postpartum women (N = 134;65 in the e... Background: To evaluate the care given using Roy’s Adaptation Model. Materials and Methods: A pretest-posttest experimental model with a control group. Study population comprised postpartum women (N = 134;65 in the experimental group, 69 in the control group) who had caesarean full-term delivery in a Turkish maternity hospital between September 2009 and February 2011. Data were collected from the experimental group during seven home visits and from the control group at the end of the 6th week postpartum. Results: Percentage, chi-square, arithmetic mean, standard deviation, and the McNamer test were used to evaluate data establishing 36 nursing diagnoses: Physiological requirements (22), Self requirements (7), Role Function requirements (4), and Interdependence Mode requirements (3). It was determined that the care given during the postpartum period using Roy’s Adaptation Model resolved or prevented the majority of postpartum problems. The difference between most diagnoses was found to be statistically significant (p p < 0.001) during the last week of data collection. Conclusion: The care given in the postpartum period using Roy’s Adaptation Model resolved or prevented postpartum problems. 展开更多
关键词 POsTPARTUM PERIOD roy’s Adaptation model NURsING CARE
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Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of Parkinson's disease:a systematic review and meta-analysis 被引量:4
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作者 Jong Mi Park Masoud Rahmati +2 位作者 Sang Chul Lee Jae Il Shin Yong Wook Kim 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1584-1592,共9页
Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse ... Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols. 展开更多
关键词 ANIMAL animal experimentation mesenchymal stem cells models Parkinson’s disease stem cell transplantation
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A Model of Grand Unified Theory: Suggested Solution for CP-Violation Using Ideas of Phase Paths
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作者 Hung-Te Henry Su Po-Han Lee 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1878-1902,共25页
This study demonstrates that beyond standard model (BSM) cosmic fundamental interactions—weak, strong, and electromagnetic forces—can be unified through a common basis of representation. This unification allows for ... This study demonstrates that beyond standard model (BSM) cosmic fundamental interactions—weak, strong, and electromagnetic forces—can be unified through a common basis of representation. This unification allows for the derivation of the fine structure constant with running points of α(t) ≈ 1/(136.9038) at high energy scales, based on electroweak interactions. Through the application of the Ising model, the running point of the elementary charge e at high energy scales is determined, and Coulomb’s law is actually derived from the Yukawa potential. Theoretically, based on S. Weinberg’s electroweak interaction theory, this study unifies the strong and electromagnetic forces by representing them with rYuka, and further advances the reconstruction of the SU(3)C×SU(1)L×U(1)EMframework on the basis of electroweak interaction concepts. In fact, the cosmic fundamental forces can interchange at the mass gap, defined as the Yukawa turning phase at rYuka ≃1.9404 fm, with the SU(3)Diag structural constant fijk on glueballs calculated, estimating a spectrum mass gap of ∆0 > 0. 展开更多
关键词 BsM ELECTROWEAK GLUEBALLs Ising model Mass Gap s. Weinberg
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Evaluating the role of large language models in inflammatory bowel disease patient information
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作者 Eun Jeong Gong Chang Seok Bang 《World Journal of Gastroenterology》 SCIE CAS 2024年第29期3538-3540,共3页
This letter evaluates the article by Gravina et al on ChatGPT’s potential in providing medical information for inflammatory bowel disease patients.While promising,it highlights the need for advanced techniques like r... This letter evaluates the article by Gravina et al on ChatGPT’s potential in providing medical information for inflammatory bowel disease patients.While promising,it highlights the need for advanced techniques like reasoning+action and retrieval-augmented generation to improve accuracy and reliability.Emphasizing that simple question and answer testing is insufficient,it calls for more nuanced evaluation methods to truly gauge large language models’capabilities in clinical applications. 展开更多
关键词 Crohn’s disease Ulcerative colitis Inflammatory bowel disease Chat generative pre-trained transformer Large language model Artificial intelligence
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Solving the Olbers’s Paradox, Explaining the “Red-Shift”, and Challenging the Relativities by “Sun Matters Theory” and “Sun Model of Universe”, an Evolution of the Einstein’s Static Universe Model
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作者 Wanpeng Sun 《Natural Science》 2024年第2期7-18,共12页
Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used ... Olbers’s paradox, known as the dark night paradox, is an argument in astrophysics that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. Big-Bang theory was used to partially explain this paradox, while introducing new problems. Hereby, we propose a better theory, named Sun Matters Theory, to explain this paradox. Moreover, this unique theory supports and extended the Einstein’s static universe model proposed by Albert Einstein in 1917. Further, we proposed our new universe model, “Sun Model of Universe”. Based on the new model and novel theory, we generated innovative field equation by upgrading Einstein’s Field Equation through adding back the cosmological constant, introducing a new variable and modifying the gravitationally-related concepts. According to the Sun Model of Universe, the dark matter and dark energy comprise the so-called “Sun Matters”. The observed phenomenon like the red shift is explained as due to the interaction of ordinary light with Sun Matters leading to its energy and frequency decrease. In Sun Model, our big universe consists of many universes with ordinary matter at the core mixed and surrounded with the Sun Matters. In those universes, the laws of physics may be completely or partially different from that of our ordinary universe with parallel civilizations. The darkness of night can be easily explained as resulting from the interaction of light with the Sun Matters leading to the sharp decrease in the light intensity. Sun Matters also scatter the light from a star, which makes it shining as observed by Hubble. Further, there is a kind of Sun Matters named “Sun Waters”, surrounding every starts. When lights pass by the sun, the Sun Waters deflect the lights to bend the light path. According to the Sun Model, it is the light bent not the space bent that was proposed in the theory of relativities. 展开更多
关键词 Olbers’s Paradox sun Matters Theory sun model of Universe Einstein’s Universe Dark Mass
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Hubble Tension Explanation from This Cosmological Model AΛΩ (Slow Bang Model, SB)
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作者 Jean Perron 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第1期106-125,共20页
In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of t... In this article we present a model of Hubble-Lemaître law using the notions of a transmitter (galaxy) and a receiver (MW) coupled to a model of the universe (Slow Bang Model, SB), based on a quantum approach of the evolution of space-time as well as an equation of state that retains all the infinitesimal terms. We find an explanation of the Hubble tension H<sub>0</sub>. Indeed, we have seen that this constant depends on the transceiver pair which can vary from the lowest observable value, from photons of the CMB (theoretical [km/s/Mpc]) to increasingly higher values depending on the earlier origin of the formation of the observed galaxy or cluster (ETG ~0.3 [Gy], ~74 [km/s/Mpc]). We have produced a theoretical table of the values of the constant according to the possible pairs of transmitter/receiver in the case where these galaxies follow the Hubble flow without large disturbance. The calculated theoretical values of the constant are in the order of magnitude of all values mentioned in past studies. Subsequently, we applied the models to 9 galaxies and COMA cluster and found that the models predict acceptable values of their distances and Hubble constant since these galaxies mainly follow the Hubble flow rather than the effects of a galaxy cluster or a group of clusters. In conclusion, we affirm that this Hubble tension does not really exist and it is rather the understanding of the meaning of this constant that is questioned. 展开更多
关键词 model of the Universe Cosmological Constant Hubble Constant Hubble’s Tension Hubble-Lemaître Law Hubble’s Flow
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Effects of low molecular heparin combined with Roy adaptation model on hypercoagulable state, endothelial function and placental blood perfusion in patients with preeclampsia 被引量:1
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作者 Liang-Ying Yao Xiu-Qiong Zhang 《Journal of Hainan Medical University》 2017年第23期62-66,共5页
Objective: To investigate the effects of low molecular heparin combined with Roy adaptation model on hypercoagulable state, endothelial function and placental blood perfusion in patients with preeclampsia. Methods: A ... Objective: To investigate the effects of low molecular heparin combined with Roy adaptation model on hypercoagulable state, endothelial function and placental blood perfusion in patients with preeclampsia. Methods: A total of 71 patients with preeclampsia who were treated in Zigong Third People's Hospital between December 2014 and February 2017 were retrospectively analyzed and divided into the control group (n=38) who accepted conventional low molecular heparin therapy and the study group (n=33) who accepted low molecular heparin combined with Roy adaptation model therapy. The differences in hypercoagulable state, endothelial function and placental blood perfusion were compared between the two groups before intervention and after 8 weeks of intervention. Results: Before intervention, there was no statistically significant difference in the hypercoagulable state, endothelial function and placental blood perfusion between the two groups of patients. After 8 weeks of intervention, peripheral blood coagulation indexes TT and AT-Ⅲ levels of study group were higher than those of control group while D-D level was lower than that of control group;serum endothelial function index NO content was higher than that of control group while ET-1 content was lower than that of control group;ultrasonic placental blood perfusion parameters FI, VI and VFI levels were higher than those of control group. Conclusion: Low molecular heparin combined with Roy adaptation model intervention could further reduce the hypercoagulable state, decrease the vascular endothelial injury, and eventually increase the placental blood perfusion in patients with preeclampsia. 展开更多
关键词 PREECLAMPsIA roy adaptation model HYPERCOAGULABLE state ENDOTHELIAL function PLACENTAL blood PERFUsION
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Randomized controlled trials on Roy adaptation model nursing in patients with acute myocardial infarction in china: a systematic review 被引量:1
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作者 Guang-Hong Han Xiao-Li Pang Wei-Jie Gao 《Aging Communications》 2021年第4期1-5,共5页
Objective:This study was to evaluate the quality of the randomized controlled trials on Roy adaptation model nursing in individuals suffering from acute myocardial infarction in China.Methods:We systematically searche... Objective:This study was to evaluate the quality of the randomized controlled trials on Roy adaptation model nursing in individuals suffering from acute myocardial infarction in China.Methods:We systematically searched the Cnki,Wanfang and Vipdatabases,to get randomized controlled trials on Roy adaptation model nursing in individuals suffering from acute myocardial infarction.The search period was from inception to October 2020.According to the Cochrane risk bias assessment tool,the quality of the studies included was appraised.Results:A total of 55 studies were retrieved,and 11 were eventually included in the study.Among the studies included,the first study was published in 2008.The overall quality of the 11 studies included was relatively low.Conclusions:The overall quality of the randomized controlled trials on Roy adaptation model nursing in individuals suffering from acute myocardial infarction was not high,which would hinder the evidence transformation as well as clinical practice. 展开更多
关键词 Acute myocardial infarction roy adaptation model systematic review Randomize controlled trial NURsING
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Analysis of Porter’s Five Forces Competitive Model in China’s Property Rights Trading Market
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作者 Weinong Wang 《Proceedings of Business and Economic Studies》 2024年第3期206-211,共6页
In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of th... In recent years,China’s property rights trading market has been extremely competitive,but there are also new contradictions and challenges.This paper aims to analyze the external and internal competitive market of the property rights market through Porter’s five forces competition model,then find out the problems and defects in the development,thereby promoting the better development and progress of China’s property rights trading market. 展开更多
关键词 Porter’s five forces competitive model Market optimization Innovative development
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Exploring the role of N-acetyltransferases in diseases:a focus on N-acetyltransferase 9 in neurodegeneration
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作者 Prajakta Deshpande Anuradha Venkatakrishnan Chimata Amit Singh 《Neural Regeneration Research》 SCIE CAS 2025年第10期2862-2871,共10页
Acetyltransferases,required to transfer an acetyl group on protein are highly conserved proteins that play a crucial role in development and disease.Protein acetylation is a common post-translational modification pivo... Acetyltransferases,required to transfer an acetyl group on protein are highly conserved proteins that play a crucial role in development and disease.Protein acetylation is a common post-translational modification pivotal to basic cellular processes.Close to 80%-90%of proteins are acetylated during translation,which is an irreversible process that affects protein structure,function,life,and localization.In this review,we have discussed the various N-acetyltransferases present in humans,their function,and how they might play a role in diseases.Furthermore,we have focused on N-acetyltransferase 9 and its role in microtubule stability.We have shed light on how N-acetyltransferase 9 and acetylation of proteins can potentially play a role in neurodegenerative diseases.We have specifically discussed the N-acetyltransferase 9-acetylation independent function and regulation of c-Jun N-terminal kinase signaling and microtubule stability during development and neurodegeneration. 展开更多
关键词 acetyl-coenzyme A Alzheimer’s disease animal models cell death DROsOPHILA eye human disease c-Jun N-terminal kinase signaling N-Acetyltransferases N-acetyltransferase 9 NEURODEGENERATION
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Rock skeleton models and seismic porosity inversion 被引量:3
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作者 贺锡雷 贺振华 +2 位作者 王绪本 熊晓军 蒋炼 《Applied Geophysics》 SCIE CSCD 2012年第3期349-358,363,共11页
By substituting rock skeleton modulus expressions into Gassmann approximate fluid equation, we obtain a seismic porosity inversion equation. However, conventional rock skeleton models and their expressions are quite d... By substituting rock skeleton modulus expressions into Gassmann approximate fluid equation, we obtain a seismic porosity inversion equation. However, conventional rock skeleton models and their expressions are quite different from each other, resuling in different seismic porosity inversion equations, potentially leading to difficulties in correctly applying them and evaluating their results. In response to this, a uniform relation with two adjusting parameters suitable for all rock skeleton models is established from an analysis and comparison of various conventional rock skeleton models and their expressions including the Eshelby-Walsh, Pride, Geertsma, Nur, Keys-Xu, and Krief models. By giving the two adjusting parameters specific values, different rock skeleton models with specific physical characteristics can be generated. This allows us to select the most appropriate rock skeleton model based on geological and geophysical conditions, and to develop more wise seismic porosity inversion. As an example of using this method for hydrocarbon prediction and fluid identification, we apply this improved porosity inversion, associated with rock physical data and well log data, to the ZJ basin. Research shows that the existence of an abundant hydrocarbon reservoir is dependent on a moderate porosity range, which means we can use the results of seismic porosity inversion to identify oil reservoirs and dry or water-saturated reservoirs. The seismic inversion results are closely correspond to well log porosity curves in the ZJ area, indicating that the uniform relations and inversion methods proposed in this paper are reliable and effective. 展开更多
关键词 Rock physics rock skeleton models adjusting parameters seismic porosityinversion Gassmann's equation
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Modeling foraging habitats of Hume’s Pheasant (Syrmaticus humiae) in Dazhong Mountain, Yunnan, southwestern China 被引量:5
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作者 周伟 李宁 +3 位作者 邓忠坚 张庆 李明会 王学荣 《Chinese Birds》 2010年第4期236-243,共8页
We modeled foraging habitats of Hume’s Pheasant (Syrmaticus humiae) on a macro-habitat level using ArcGIS in an attempt to provide scientific reference for management and restoration of habitats. Field work was condu... We modeled foraging habitats of Hume’s Pheasant (Syrmaticus humiae) on a macro-habitat level using ArcGIS in an attempt to provide scientific reference for management and restoration of habitats. Field work was conducted from March to April in 2006 and 2008, and from October to November in 2005 and 2008 in Dazhong Mountain, Yunnan Province, southwestern China. The selection of ecological factors was estimated by means of a resource selection index, distance analysis and the method of hierarchical habitat selection. The foraging habitat patches were modeled spatially by ArcGIS. The results show that actual and potential foraging patches overlapped considerably in spring and autumn. The number and total areas of patches in the autumn were smaller than those in the spring. The minimum and average areas of patches in the autumn were larger than those in the spring, while the maximum areas of actual and potential foraging patches in the autumn were equal to those in the spring. Similarity in the selection for survival and safety consideration in both seasons was the main strategy for landscape factors of habitats by Hume’s Pheasant, while seasonal difference in selecting a landscape matrix was their secondary strategy, affecting landscape factors in the habitat. Changes of foraging patches in both seasons reflect a difference of resources requirement by the bird. Fragmentation and miniaturization of foraging patches would result in the formation of a meta-population of Hume’s Pheasant. 展开更多
关键词 Hume’s Pheasant (syrmaticus humiae) foraging strategy habitat modeling habitat patch
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Leaf Area Calculation Model of E.urophylla and E.grandis×E.urophylla 被引量:1
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作者 朱宏光 赵金龙 +1 位作者 温远光 侯日华 《Agricultural Science & Technology》 CAS 2010年第8期4-6,9,共4页
[Objective] The aim was to build an optimal leaf area measurement model of E. urophylla and E. grandis×E.urophylla. [Method] The correlation between leaf area and leaf's eigenvalue of E. urophylla and E. grandis... [Objective] The aim was to build an optimal leaf area measurement model of E. urophylla and E. grandis×E.urophylla. [Method] The correlation between leaf area and leaf's eigenvalue of E. urophylla and E. grandis×E.urophylla were studied. [Result] There was certain difference in leaf characteristics values between the 2 species. The leaf areas of E. urophylla and E. grandis×E.urophylla both had significant correlation with leaf length,leaf width,leaf perimeter,leaf length × leaf width,the ratio of leaf length to leaf width,shape factor,etc.,so the factors could be constructed into a regression model with leaf area. Among them,the best 2 models for leaf area calculation which were built by leaf length × leaf width of E. urophylla and E. grandis×E.urophylla both had relatively high accuracy and practical applications. [Conclusion] The research provides a simple and effective leaf area measurement method for studies on the 2 tree species. 展开更多
关键词 E. urophylla E. grandis×E.urophylla Leaf's eigenvalue Leaf area Calculation model
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The Cultural Implication of Brick Carving Model Calligraphy in Shanxi Chang's Manor
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作者 潘冬梅 冯涛 《Journal of Landscape Research》 2009年第11期63-67,共5页
Focusing on the unique style of brick carving model calligraphy in Shanxi Chang's manor,this research analyses the content and feature of the different parts of brick carving,and discuses the presenting cultural d... Focusing on the unique style of brick carving model calligraphy in Shanxi Chang's manor,this research analyses the content and feature of the different parts of brick carving,and discuses the presenting cultural deposits.It reflects the deep Confucian culture of Shanxi Chang's manor,with the peculiar charming in culture and aesthetic value. 展开更多
关键词 The Chang’s MANOR model CALLIGRAPHY BRICK CARVING Chinese traditional culture
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高压管汇材料疲劳性能测试及P-S-N模型曲线的拟合 被引量:1
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作者 黄艳娟 周思柱 李宁 《长江大学学报(自然科学版)》 2024年第3期55-61,共7页
高压管汇作为压裂设备中的主要易损件之一,其失效危害较大。它的失效原因主要是疲劳、冲蚀、腐蚀或者材料缺陷引起的刺漏和爆裂,其中尤以疲劳失效最不可预估。目前,对于高压管汇材料的疲劳性能研究不够深入,为解决高压管汇材料疲劳寿命... 高压管汇作为压裂设备中的主要易损件之一,其失效危害较大。它的失效原因主要是疲劳、冲蚀、腐蚀或者材料缺陷引起的刺漏和爆裂,其中尤以疲劳失效最不可预估。目前,对于高压管汇材料的疲劳性能研究不够深入,为解决高压管汇材料疲劳寿命的准确描述问题,以某国产高压管汇材料为例,进行了一系列疲劳试验,并基于试验数据,采用多种分布模型和不同S-N模型进行拟合分析,得出综合评价拟合能力最强的P-S-N模型。结果表明,该材料在中长疲劳寿命区,Weibull三参数模型在7级应力水平下综合评价能力最好;在存活率分别为50%、90%、99%、99.9%时,指数S-N模型的拟合系数均大于0.98,拟合能力最好。得出的P-S-N模型曲线可以为高压管汇的疲劳寿命以及安全设计提供依据。 展开更多
关键词 高压管汇材料 正态分布模型 Weibull分布模型 P-s-N模型 幂函数s-N模型 指数s-N模型
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Analysis of the Self-correction Model——from the view of cognitive psychology
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作者 佘阿莉 《海外英语》 2015年第19期245-246,248,共3页
In view of the learners Chinglish,this paper puts forward a new teaching model-the Self-correction Model and makes an analysis of it from the view of cognitive psychology.
关键词 the sELF-CORRECTION model the information PROCEssING model piaget’s THEORY HUMANIsM
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深水采油树Spring-Seal密封圈接触模型构建与实验测试
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作者 张红 龙圣均 +1 位作者 冯定 黄熠 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第8期112-119,共8页
为提高深水采油树在高压、高温、低温等工况下长时间工作的稳定性,对采油树密封圈进行重新设计,提出Spring-Seal密封圈(以下简称S密封圈);基于赫兹接触理论、填料密封接触理论,重新构建S密封圈接触力学模型;建立有限元仿真分析模型,分... 为提高深水采油树在高压、高温、低温等工况下长时间工作的稳定性,对采油树密封圈进行重新设计,提出Spring-Seal密封圈(以下简称S密封圈);基于赫兹接触理论、填料密封接触理论,重新构建S密封圈接触力学模型;建立有限元仿真分析模型,分析不同条件下S密封圈的密封性能,同时验证新建接触模型的合理性;利用实验测试S密封圈的实际密封效果。研究结果表明:S密封圈在高压、高温、低温等工况下能够长时间稳定工作且密封性能良好。研究结果可为S密封圈的接触研究及工程运用提供理论参考。 展开更多
关键词 s密封圈 接触模型 密封性能 实验
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Functions of Allusions from Leppihalme’s model
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作者 倪志莉 《魅力中国》 2009年第15期188-189,共2页
The general function of allusions is often thought to add clarity and significance to ideas and descriptions.However,it would be difficult to establish an exhaustive list of mutually exclusive category
关键词 Functions of Allusions from Leppihalme’s model
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DYNAMIC MODELING FOR AIRSHIP EQUIPPED WITH BALLONETS AND BALLAST 被引量:9
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作者 CAI Zi-li(蔡自立) Qu Wei-dong(屈卫东) XI Yu-geng(席裕庚) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第8期1072-1082,共11页
Total dynamics of an airship is modeled. The body of an airship is taken as a submerged rigid body with neutral buoyancy, i. e. , buoyancy with value equal to that of gravity, and the coupled dynamics between the body... Total dynamics of an airship is modeled. The body of an airship is taken as a submerged rigid body with neutral buoyancy, i. e. , buoyancy with value equal to that of gravity, and the coupled dynamics between the body with ballonets and ballast is considered. The total dynamics of the airship is firstly derived by Newton-Euler laws and Kirchhoff' s equations. Furthermore, by using Hamiltonian and Lagrangian semidirect product reduction theories, the dynamics is formulated as a Lie-Poisson system, or also an Euler-Poincare system. These two formulations can be exploited for the control design using energy-based methods for Hamiltonian or Lagrangian system. 展开更多
关键词 AIRsHIP dynamical modeling Kirchhoff' s equation semi-direct product reduction
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D-S理论和Markov链组合的桥梁性能退化预测研究
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作者 杨国俊 田里 +2 位作者 唐光武 毛建博 杜永峰 《应用数学和力学》 CSCD 北大核心 2024年第4期416-428,共13页
为准确预测桥梁性能退化,考虑到数据随机性和微小扰动发生状态跳跃,提出了一种D-S(Dempster-Shafer)证据理论和Markov链组合的桥梁性能退化组合预测模型和性能退化率的概念.该模型基于指数平滑(exponential smoothing,ES)方法获得新的... 为准确预测桥梁性能退化,考虑到数据随机性和微小扰动发生状态跳跃,提出了一种D-S(Dempster-Shafer)证据理论和Markov链组合的桥梁性能退化组合预测模型和性能退化率的概念.该模型基于指数平滑(exponential smoothing,ES)方法获得新的预测数据序列,并利用Markov链和D-S理论不断进行优化,从而实现桥梁性能退化的组合预测.实际工程的应用结果表明:性能退化率可以直观地表征在梁性能退化的速度.其次,该模型的平均相对误差为1.54%,较于回归、灰色和模糊加权Markov链模型,精度分别提高了1.11%,0.88%和2.8%,而后验差比值为0.242,小于0.35;模型的标准差为9.021,相比其他模型分别减小了3.978,3.405和7.500,而变异系数为0.109,均小于其他模型,验证了组合预测模型在精度和稳定性方面的优越性,可为在役桥梁结构性能退化预测与维护提供理论基础. 展开更多
关键词 桥梁工程 性能退化预测 D-s证据理论 MARKOV链 组合预测模型 桥梁性能退化率
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