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Effect of Uncertainty of the Pre-Exponential Factor on Kinetic Parameters of Hydrocarbon Generation from Organic Matter and its Geological Applications 被引量:1
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作者 WANG Min LU Shuangfang +1 位作者 XUE Haitao YU Zhanqing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第1期211-218,共8页
The source rock sample of the Shahejie Formation (upper Es4) in Jiyang Sag was pyrolyzed under open system with the Rock-Eval-lI apparatus, and then kinetic model parameters were calibrated for investigating the eff... The source rock sample of the Shahejie Formation (upper Es4) in Jiyang Sag was pyrolyzed under open system with the Rock-Eval-lI apparatus, and then kinetic model parameters were calibrated for investigating the effect of uncertainty of pre-exponential factors on kinetic parameters and geological applications, where the parallel first-order reaction rate model with an average pre- exponential factor and discrete distribution activity energies was used. The results indicate that when the pre-exponential factor changes from low to high, an extreme value for residual errors occurs. And with the increasing pre-exponential factor, the distribution shape of activation energies are nearly the same, but the values of activation energies move higher integrally, and the average activation energy increases about 12 kJ/mol for every 10-fold of the pre-exponential factors. Extrapolating the geological heating rate of 3.3 ~C/Ma, the results show that with the increases in pre-exponential factor, the geological temperature corresponding to TRo.5 (transforming ratio of hydrocarbon generation is 50%) increases gradually, and the additional temperature gradually decreases. Combined with geochemical data of source rock, the kinetic parameters with different pre-exponentia[ factors are used to calculate the transformation ratio of hydrocarbon generation, and the result indicates that kinetic parameters corresponding to the better optimized pre-exponential factor are more suitable. It is suggested that the risk assessment of hydrocarbon generation kinetic parameters should be enhanced when using the kinetic method to appraise the oil-gas resources. Meantime, the application result of different kinetic parameters should be verified with geological and geochemical data of source rock in the target area; therefore, the most suitable kinetic parameters for target can be obtained. 展开更多
关键词 pre-exponential factor activation energy UNCERTAINTY hydrocarbon generation kinetics geological application
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Compensation Effect in Heterogeneous Catalysis: Correlation between Observed Pre-exponential Factor (AoBs) and Observed Activation Energies (EoBs) of Isoamylalcohol Hydrogenolysis on Platinum Catalysts
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作者 Triyono, Wega Trisunaryanti Sri Sudiono 《材料科学与工程(中英文版)》 2010年第1期57-63,共7页
关键词 铂催化剂 指前因子 多相催化 活化能 异戊醇 补偿效应 Pt/γ-Al2O3 ARRHENIUS
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Paleodose evaluation of porcelain: a practical regressionmethod of saturation exponential in pre-dose technique 被引量:7
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作者 WANGWei-Da LEUNGPL 《Nuclear Science and Techniques》 SCIE CAS CSCD 2001年第2期154-160,共7页
A practical regression method of saturation exponential in pre-dose technique is proposed. The method is mainly applied for porcelain datillg. To test the method, some simulated paleodoses of the imitations of ancient... A practical regression method of saturation exponential in pre-dose technique is proposed. The method is mainly applied for porcelain datillg. To test the method, some simulated paleodoses of the imitations of ancient porcelain were used. The measured results are in good agreement with the simulated values of the paleodoses, and the average ratios of the two values by using the two ways are 1.05 and 0.99 with standard deviations (±lσ) of 19% and 15% respectively. Such errors can be accepted in porcelain dating. 展开更多
关键词 瓷器 预辐照技术 饱和指数回归 年代断定
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Predictive Factors for Pre-Eclampsia: A Case-Control Study in Two Hospitals in Yaounde
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作者 Junie Annick Metogo Ntsama Ines Winnie Gouanfo +5 位作者 Claude Hector Mbia Wilfried Loic Tatsipie Pascal Mpono Madye Ngo Dingom Felix Essiben Claude Cyrille Noa Ndoua 《Open Journal of Obstetrics and Gynecology》 2024年第4期565-574,共10页
Introduction: Pre-eclampsia is a major cause of maternal and prenatal morbidity and mortality, that complicates 2% to 8% of pregnancies worldwide. The aim of this study was to determine the predictive factors for pre-... Introduction: Pre-eclampsia is a major cause of maternal and prenatal morbidity and mortality, that complicates 2% to 8% of pregnancies worldwide. The aim of this study was to determine the predictive factors for pre-eclampsia in two hospitals in the city of Yaoundé. Methods: A case-control study was conducted at the Gynaecology & Obstetrics department of the Yaoundé Gynaeco-Obstetric and Paediatric Hospital (YGOPH) and the Main Maternity of the Yaoundé Central Hospital (MM-YCH) from February 1 to July 30, 2022. The cases were all pregnant women presenting with pre-eclampsia. The control group included pregnant women without pre-eclampsia. Descriptive statistics followed by logistic regression analyses were conducted with level of significance set at p-value Results: Included in the study were 33 cases and 132 controls, giving a total of 165 participants. The predictive factors for pre-eclampsia after multivariate analysis were: primiparity (aOR = 51.86, 95% CI: 3.01 - 1230.96, p = 0.045), duration of exposure to partner’s sperm Conclusion: The odds of pre-eclampsia increased with primiparity, duration of exposure to partner’s sperm < 3 months, personal history of pre-eclampsia and maternal history of pre-eclampsia. Recognition of these predictor factors would improve the ability to diagnose and monitor women likely to develop pre-eclampsia before the onset of disease for timely interventions. 展开更多
关键词 pre-ECLAMPSIA predictive factors Yaoundé
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Fast-scale border collision bifurcation in SEPIC power factor pre-regulators 被引量:3
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作者 刘芳 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第7期2394-2404,共11页
In this paper we report a kind of fast-scale instability occurring in the single-ended primary inductance converter (SEPIC) power factor pre-regulator, which is designed to operate in discontinuous conduction mode. ... In this paper we report a kind of fast-scale instability occurring in the single-ended primary inductance converter (SEPIC) power factor pre-regulator, which is designed to operate in discontinuous conduction mode. Main results are given by exact cycle-by-cycle computer simulations as well as theoretical analysis. It is found that the instability phenomenon manifests itself as a fast-scale bifurcation at the switching period, which implies the occurrence of border collision bifurcation, or is related to the transition of the regular operating mode of the SEPIC. According to the theoretical analysis and simulation results, the effects of parameters on system stability, and the locations of the bifurcation points are confirmed. Moreover, the effects of such an instability on power factor and switching stress are also discussed. Finally, the occurrence of the asymmetric bifurcation locations is investigated. The results show that this work provides a convenient means of predicting stability boundaries which can facilitate the selection of the practical parameters. 展开更多
关键词 fast-scale instability border collision bifurcation SEPIC power factor pre-regulator discontinuous current mode
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Interaction between the Wilms tumour factor-1 element in the promoter of Amh and a downstream enhancer is required for a strong expression of the gene in pre-pubertal sertoli cells 被引量:1
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作者 David W. Dresser 《American Journal of Molecular Biology》 2013年第3期165-172,共8页
Amh (anti-Müllerian hormone) is a single copy gene which is expressed strongly in Sertoli cells in the foetal testis and participates in the onset of sexual differentiation. Its promoter driving the expression of... Amh (anti-Müllerian hormone) is a single copy gene which is expressed strongly in Sertoli cells in the foetal testis and participates in the onset of sexual differentiation. Its promoter driving the expression of a reporter gene (d2EGFP) has been used to analyse the role of certain defined putative elements and a downstream enhancer element in gene expression. These experiments were carried out in vitro using a line of pre-pubertal mouse Sertoli cells, transienly transfected with circular DNA constructs with variously mutated promoter elements. A downstream enhancer element, situated immediately 3’ of the polyadenylation (PA) signal for Amh, has been inserted in an equivalent position in the d2EGFP construct. When the Amh promoter is unmodified, the downstream enhancer (DE) is positively associated with a large increase in EGFP expression. This is at least partly the consequence of an increased rate of expression by individual cells. Experiments using variously truncated Amh promoters indicate that an upstream region (-214 to -336) may play a minor role in facilitating enhancement. However mutation of the Wilms tumour factor-1 element, situated between the tata box and the start of translation, results in an almost complete suppression of enhancement. 展开更多
关键词 Mouse Cell Lines In Vitro AMH PROMOTER SMAT pre-Pubertal Sertoli DOWNSTREAM ENHANCER Wilms Tumour factor ELEMENT
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The Transcription Factors GATA-1 and GATA-4 Have Opposite Effects on DNA Expression Driven by an Amh Promoter
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作者 David W. Dresser 《American Journal of Molecular Biology》 2014年第3期150-158,共9页
An Amh promoter driving expression of a reporter gene (d2EGFP) has been used to analyze the role of two specific promoter transcription factor binding elements. In addition a downstream (3’) enhancer (DE) was also in... An Amh promoter driving expression of a reporter gene (d2EGFP) has been used to analyze the role of two specific promoter transcription factor binding elements. In addition a downstream (3’) enhancer (DE) was also investigated. The transcription factors GATA-1 and GATA-4 had opposite effects, the former being incremental and the latter decremental. The quantitative balance between these two factors may provide a degree of control over the level of gene expression. 展开更多
关键词 SMAT-1 Mouse pre-Pubertal SERTOLI In Vitro AMH PROMOTER d2EGFP Transcription factors GATA-1 GATA-4
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Rationale of a Cross Sectional Analytic Study on Determinants of Recurrent Preeclampsia at University Clinics of Kinshasa (Democratic Republic of Congo) and at Victor Dupouy Hospital Center (France)
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作者 Mushengezi Amani Dieudonné Sengeyi Muela Andy Mbangama +4 位作者 Mokambanda Cynthia Awena Goy Sambwa Christian Kelele Nkongolo Freddy Muamba Banza Jésual Lotoy Otem Christian Ndesanzim 《Open Journal of Obstetrics and Gynecology》 2024年第5期824-831,共8页
Research Background: Pre-eclampsia is one of main causes of materno-foetal mortality and morbidity worldwide, with a prevalence of 3% - 7%. Although considered a primiparous condition, it can nevertheless recur. Sever... Research Background: Pre-eclampsia is one of main causes of materno-foetal mortality and morbidity worldwide, with a prevalence of 3% - 7%. Although considered a primiparous condition, it can nevertheless recur. Several factors appear to be associated with risk of recurrence of pre-eclampsia, such as the term of delivery of previous pregnancy, severity of disease, the existence of co-morbidities and the inter-genital space. Purpose: The aim of our study will be to analyse and identify in a population of pregnant women with a history of preeclampsia risk factors associated with occurrence of recurrent preeclampsia at University clinics of Kinshasa (Democratic Republic of Congo) and at Victor Dupouy Hospital Center (France). Methods: In this study, pregnant women with an history of preeclampsia who will give birth between November 2018 and October 2024 at University Clinics of Kinshasa (UCK) and Victor Dupouy Hospital Center (VDHC) will be included. This will be a cross-sectional analytical study, data from previous and subsequent pregnancies will be studied. Expected Result: The prevalence of recurrent preeclampsia in the study population will be determined. And we will highlight the factors that will determine the recurrence of preeclampsia by analysing the risk factors. Conclusion: Knowledge of the factors associated with recurrent preeclampsia could be an excellent tool for predicting and preventing the disease. 展开更多
关键词 Recurrent pre-Eclampsia Risk factor Determinants
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Prevalence and Demographic Distributions of Pre-Eclampsia among Pregnant Women at Ho Teaching Hospital
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作者 Adwoa Nyarko Joshua A. Kunfah +3 位作者 David Z. Kolbilla Collins Adombire Akayuure Jamilatu B. Kappiah Sylvanus Kampo 《Open Journal of Obstetrics and Gynecology》 2024年第4期621-636,共16页
Background: In Sub-Saharan Africa, pre-eclampsia remains a major health problem contributing to high rates of maternal mortality. Despite this condition having adverse effects on maternal and child health, its prevale... Background: In Sub-Saharan Africa, pre-eclampsia remains a major health problem contributing to high rates of maternal mortality. Despite this condition having adverse effects on maternal and child health, its prevalence and associated risk factors are still significant, especially in developing countries including Ghana. This study aimed to assess the prevalence and demographic distributions associated with pre-eclampsia among pregnant women at the Ho Teaching Hospital. Methods: A facility-based retrospective study was conducted by reviewing available data or hospital records of pregnant mothers admitted to the labor and maternity wards from January 2018 to December 2020. All pregnant women who were diagnosed with pre-eclampsia within this period were included in the study. The data were collected using a structured checklist. Results: 5609 data on pregnant women from 2018 to 2020 were recorded. Out of the 5609 data recorded, 314 pre-eclampsia cases were recorded giving an overall prevalence of 5.6%. The yearly prevalence for 2018, 2019, and 2020 were 4.6%, 5.6%, and 6.6%, respectively. The most recorded pre-eclampsia cases were seen among women within the age group of 18 - 24 years. The data showed that 112 (35.7%) of the pregnant women who had pre-eclampsia were nulliparous. Pre-eclampsia-associated maternal and fetal complications were;preterm delivery 221 (70.4%), intrauterine fetal death 62 (19.7%), eclampsia 9 (2.9%), HELLP syndrome 5 (1.6%) and maternal death 17 (5.4%). Associated factors of pre-eclampsia were parity, level of education, and occupation (p ≤ 0.05). Conclusion: The findings of this study showed a rising trend in the incidence of pre-eclampsia over the years at the Ho Teaching Hospital. Parity, level of education, and occupation were found to be associated with developing pre-eclampsia. 展开更多
关键词 pre-ECLAMPSIA preVALENCE Demographic Distributions Risk factors ANTENATAL MATERNAL
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IPS e.max Press铸瓷嵌体治疗后牙牙体缺损的效果及对龈沟液中CXCL16及RANK水平的影响 被引量:9
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作者 邹晶 韩浩 《检验医学与临床》 CAS 2022年第13期1785-1790,共6页
目的探讨IPS e.max Press铸瓷嵌体治疗后牙牙体缺损的效果及对龈沟液中人CXC型趋化因子配体16(CXCL16)和核因子κB受体激活因子(RANK)水平的影响。方法选取安康市中医院口腔科2017年2-8月收治的124例(190颗)后牙牙体缺损患者作为研究对... 目的探讨IPS e.max Press铸瓷嵌体治疗后牙牙体缺损的效果及对龈沟液中人CXC型趋化因子配体16(CXCL16)和核因子κB受体激活因子(RANK)水平的影响。方法选取安康市中医院口腔科2017年2-8月收治的124例(190颗)后牙牙体缺损患者作为研究对象,采用随机数字表法分为观察组和对照组,每组62例(95颗)。对照组患者采用合金嵌体治疗修复法,观察组患者采用IPS e.max Press铸瓷嵌体治疗修复法。治疗3个月后,以美牙效果、后牙牙体缺损边缘密合度作为观察指标,治疗1个月和3个月后检测龈沟液中炎症因子水平,比较龈沟液和血清中CXCL16和RANK水平。分别在治疗6、12、24个月后对患者进行随访并记录结果。结果治疗3个月后,观察组患者美牙效果满意度(94.74%)明显高于对照组(74.74%),差异有统计学意义(χ^(2)=14.691,P<0.05)。治疗3个月后,观察组患者后牙牙体缺损边缘密合度明显高于对照组,差异有统计学意义(χ^(2)=12.429,P<0.05)。治疗1个月后,由于手术治疗的炎性反应,观察组患者龈沟液中CXCL-16、RANK、白细胞介素(IL)-6及IL-8水平均较治疗前有所升高,但观察组患者明显低于对照组,差异均有统计学意义(P<0.05);治疗3个月后,术后炎性反应基本恢复,两组患者龈沟液中CXCL-16、RANK、IL-6及IL-8水平均较治疗1个月后降低,差异均有统计学意义(P<0.05),但观察组患者与对照组比较,差异无统计学意义(P>0.05);观察组患者治疗前后血清CXCL-16和RANK水平与对照组比较,差异均无统计学意义(P>0.05)。随访24个月后,观察组患者修复完整性、继发龋、牙周反应、对颌牙牙合面磨损情况成功率与对照组比较,差异均无统计学意义(P>0.05);但修复体颜色成功率明显优于对照组,差异有统计学意义(P<0.05)。结论与合金嵌体比较,IPS e.max Press铸瓷嵌体治疗后牙牙体缺损不但改善了美牙效果,还提高了牙体缺损边缘密合度,降低了龈沟液中IL-6、IL-8、CXCL16、RANK水平,减轻了炎性反应,治疗效果较好。 展开更多
关键词 牙体缺损 IPS e.max pres铸瓷嵌体治疗 合金嵌体治疗 美牙效果 边缘密合度 炎症因子
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中国西南地区艾滋病病毒感染者治疗前和获得性抗逆转录病毒耐药性研究
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作者 孔令弘 谢小馨 +4 位作者 符燕华 甘霖 杨小燕 马淑静 龙海 《中国全科医学》 CAS 北大核心 2025年第2期242-249,共8页
背景中国不同地区人类免疫缺陷病毒(HIV)感染者的治疗前耐药(PDR)和获得性耐药(ADR)的患病率及流行情况差异较大。这两种耐药对患者的抗病毒治疗效果具有不良影响,可能会加剧患者不良预后的发生。目前针对中国西南地区的HIV感染者PDR和... 背景中国不同地区人类免疫缺陷病毒(HIV)感染者的治疗前耐药(PDR)和获得性耐药(ADR)的患病率及流行情况差异较大。这两种耐药对患者的抗病毒治疗效果具有不良影响,可能会加剧患者不良预后的发生。目前针对中国西南地区的HIV感染者PDR和ADR患病率及流行情况的研究较少。目的调查在中国西南地区HIV感染者PDR和ADR的患病率及流行情况。方法纳入2021-01-01—2023-06-30在贵阳市公共卫生救治中心就诊并进行耐药基因检测的HIV感染者。使用HIV-1 pol序列分析HIV-1基因型和耐药性。使用斯坦福大学HIV耐药性数据库分析逆转录酶和蛋白酶Sanger序列的主要耐药性突变。通过Logistic回归模型评估与PDR相关的风险因素。结果共1613例HIV感染者参与研究,其中824例初治,789例经治。初治患者最常见的基因型为B+C(47.0%),耐药率为18.7%(154/824),非核苷类逆转录酶抑制剂(NNRTIs)为14.9%(123/824),核苷类逆转录酶抑制剂(NRTIs)为1.7%(14/824),蛋白酶抑制剂(PIs)为2.7%(22/824),整合酶链转移抑制剂(INSTIs)为1.9%(16/824)。经治患者最常见的基因型为CRF01-AE(37.4%),耐药率为27.8%(219/789),NNRTIs、NRTIs、PIs和INSTIs的突变率分别为7.7%(61/789)、19.3%(152/789)、2.7%(21/789)和1.1%(9/789)。多因素Logistic回归分析结果显示,传播途径、CD_(4)^(+)T细胞计数、病毒载量和确诊与抗逆转录病毒疗法(ART)间隔时间是HIV感染者PDR的影响因素(P<0.05)。结论流行于中国西南地区的HIV感染者PDR和ADR发生率较高,分别为18.7%和27.8%。PDR的影响因素包括传播途径、CD_(4)^(+)T细胞计数、病毒载量和确诊与ART间隔时间。因此,为了避免耐药性发生,迫切需要常规基线基因型耐药性检测和足够的病毒载量监测间隔时间。 展开更多
关键词 HIV 耐药 基因型 治疗前耐药 获得性耐药 危险因素
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Relationship of Pre-Existing Maternal/Caregiver Acute Respiratory Infection in the Pattern and Risk of Acute Respiratory Infection among Infants in Rivers State, Nigeria 被引量:2
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作者 A. S. Ibama I. N. S. Dozie +4 位作者 O. C. Abanobi A. N. Amadi G. Iwuoha T. Jaja P. Dennis 《International Journal of Clinical Medicine》 2018年第10期787-798,共12页
History of upper respiratory tract infection in the mother or siblings was associated with higher risk of acute lower respiratory tract infection in cases. Most upper respiratory tract infections were caused by viral ... History of upper respiratory tract infection in the mother or siblings was associated with higher risk of acute lower respiratory tract infection in cases. Most upper respiratory tract infections were caused by viral pathogens and likely to occur in many members of the family. The study aimed to determine the existence and pattern of relationship between risk of acute respiratory infection (ARI) among infants and exposure to pre-existing maternal/caregiver acute respiratory tract infection. The study was designed as a community-based Nested case-control study of 1100 infants randomly selected from 12 communities out of 6 Local Government Areas of the 3 senatorial districts of Rivers State. A multistage random sampling technique was used in selecting the subjects up to the community level. Descriptive method was used to represent the characteristics of the subjects and the differences in ARI between exposed and unexposed infants were tested in a bivariate logistics regression at 5% level of significance. Odds ratio (OR) was used to interpret the size effect measures of ARI on exposure to pre-existing maternal/caregiver ARI differences. A total of 275 Cases of ARI and 825 controls were included in the study. Among exposed infants (N = 104), ARI cases were found to be higher n = 80 (76.9%) than in control n = 24 (23.1%). Whereas, among unexposed infants N = 991, ARI cases were found to be lower n = 195 (19.7%) than in control n = 796 (80.3%). For the exposed infants, the odds for ARI were 13.5 times significantly higher compared to those of their unexposed counterparts (OR-Unadjusted = 13.52, (p < 0.0001, 95% CI = 0.047 - 0.121)). The findings will widen the horizon in the etiological consideration of ARI among infants vis-à-vis exposure potential to pre-existing maternal/caregiver ARI via nursing care. Therefore, community-based sensitization programme on barrier nursing care techniques and personal hygiene practices should be on focus. 展开更多
关键词 Acute-Respiratory-Infection PATTERN RISK-factor Maternal/Caregiver pre-Existing Barrier-Nursing
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基于Lamb波和改进贝叶斯融合算法的CFRP边缘分层损伤分析 被引量:1
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作者 吕伟 文学 +1 位作者 付为刚 唐靖昆 《复合材料科学与工程》 CAS 北大核心 2024年第5期114-120,128,共8页
贝叶斯融合法在CFRP上的损伤定位分析结果比较好,但在传感器网络边缘区域会出现比较明显的定位误差。为解决原有算法对传感器网络边缘的分层损伤定位不精确的问题,分析了两种不同损伤因子构成的贝叶斯融合算法在CFRP上的损伤定位效果,... 贝叶斯融合法在CFRP上的损伤定位分析结果比较好,但在传感器网络边缘区域会出现比较明显的定位误差。为解决原有算法对传感器网络边缘的分层损伤定位不精确的问题,分析了两种不同损伤因子构成的贝叶斯融合算法在CFRP上的损伤定位效果,验证了以ToF损伤因子形成的贝叶斯融合算法对CFRP损伤定位的可行性,以及贝叶斯融合算法对边缘分层损伤的定位精度;在以损伤因子DI所形成概率成像算法的基础上,以衰减更快的指数权重代替线性权重,将改进的概率成像算法重新代入以贝叶斯为框架的算法中形成一种新的贝叶斯融合算法。结果表明,与现有的融合重构算法相比,改进的融合重构算法至少将损伤定位精度误差减少了58%,定位误差不大于5 mm。 展开更多
关键词 贝叶斯融合 碳纤维复合材料 损伤因子 指数权重 边缘分层损伤 定位精度
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Analysis of US Sector of Services with a New Fama-French 5-Factor Model
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作者 Quan Yang Liuling Li +1 位作者 Qingyu Zhu Bruce Mizrach 《Applied Mathematics》 2017年第9期1307-1319,共13页
In this paper, we empirically test a new model with the data of US services sector, which is an extension of the 5-factor model in Fama and French (2015) [1]. 3 types of 5 factors (Global, North American and US) are c... In this paper, we empirically test a new model with the data of US services sector, which is an extension of the 5-factor model in Fama and French (2015) [1]. 3 types of 5 factors (Global, North American and US) are compared. Empirical results show the Fama-French 5 factors are still alive! The new model has better in-sample fit than the 5-factor model in Fama and French (2015). 展开更多
关键词 FAMA-FRENCH 5-factor Model (FF5) Standardized Standard ASYMMETRIC exponential Power Distribution (SSAEPD) EGARCH
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Analysis of 48 US Industry Portfolios with a New Fama-French 5-Factor Model
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作者 Liuling Li Xiao Rao +1 位作者 Wentao Zhou Bruce Mizrach 《Applied Mathematics》 2017年第11期1684-1702,共19页
In this paper, we analyze US stock market with a new 5-factor model in Zhou and Li (2016) [1]. Data we use are 48 industry portfolios (Jul. 1963-Jan. 2017). Parameters are estimated by MLE. LR and KS are used for mode... In this paper, we analyze US stock market with a new 5-factor model in Zhou and Li (2016) [1]. Data we use are 48 industry portfolios (Jul. 1963-Jan. 2017). Parameters are estimated by MLE. LR and KS are used for model diagnostics. Model comparison is done with AIC. The results show Fama-French 5 factors are still alive. This new model in Zhou and Li (2016) [1] fits the data better than the one in Fama and French (2015) [2]. 展开更多
关键词 FAMA-FRENCH 5-factor Model (FF5) Standardized Standard ASYMMETRIC exponential Power Distribution (SSAEPD) GARCH
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基于热分解的舰用复合材料S2/430LV热工参数
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作者 陈国涛 梅志远 吕岩松 《海军工程大学学报》 CAS 北大核心 2024年第4期49-56,共8页
为了研究S2/430LV在热分解前后的热工参数,首先利用热重分析仪对氮气环境中S2/430LV复合材料和430LV树脂进行30~800℃环境下热重试验,分析了两种材料在不同升温速率下热分解响应特征;然后,基于阿伦尼乌斯方程,采用微分法与积分法相结合... 为了研究S2/430LV在热分解前后的热工参数,首先利用热重分析仪对氮气环境中S2/430LV复合材料和430LV树脂进行30~800℃环境下热重试验,分析了两种材料在不同升温速率下热分解响应特征;然后,基于阿伦尼乌斯方程,采用微分法与积分法相结合的方法,确定了S2/430LV热分解动力学参数。研究结果表明:430LV树脂和S2/430LV复合材料在氮气环境中均呈现单一热分解过程,纤维织物会促进430LV树脂基体热分解反应;采用Kissinger方程和Flynm-Wall-Ozawa方程确定S2/430LV活化能取值范围;利用Coats-Redfern方程确定S2/430LV最优热分解机理函数和指前因子,从而建立分解率和温度的函数关系式;采用混合定律,建立了考虑材料分解的热工参数模型。研究结果可为舰艇复合材料结构耐火传热性能研究提供有效数据支撑。 展开更多
关键词 热重试验 阿伦尼乌斯方程 活化能 机理函数 指前因子 混合定律 热工参数模型
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Role of Progesterone in TLR4-MyD88-dependent Signaling Pathway in Pre-eclampsia
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作者 朱颖 吴敏 +1 位作者 吴超英 夏革清 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2013年第5期730-734,共5页
The role of progesterone in the Toll-like receptor 4 (TLR4)-MyD88-dependent signaling pathway in pre-eclampsia was studied. Peripheral blood mononuclear cells (PBMCs) from pre-eclampsia (PE) patients were subjec... The role of progesterone in the Toll-like receptor 4 (TLR4)-MyD88-dependent signaling pathway in pre-eclampsia was studied. Peripheral blood mononuclear cells (PBMCs) from pre-eclampsia (PE) patients were subjected to primary culture, and stimulated with different concentra- tions of progesterone (0, 10^-8, 10^-6, and 10^-4 mol/L). The mRNA expression of TLR4, MyD88 and nu- clear factor-kappaB (NF-κB) was detected by using real-time PCR. The Ikappa-B protein expression was detected by using Western blotting. The expression of tumor necrosis factor-or (TNF-α and inter- leukin-6 (IL-6) in the supernatant was determined by using ELISA. With the concentrations of proges- terone increasing, the mRNA expression levels of TLR4, MyD88 and NF-κB in 2^△△CT value were sig- nificantly decreased, and the IkappaB protein expression levels were significantly increased. The TNF-α and IL-6 expression showed a downward trend when the progesterone concentration increased, and there were significant differences among all of the groups (P〈0.05). It was suggested that progesterone can inhibit the TLR4-MyD88-dependent signaling pathway in PE significantly and benefit for the preg- nancy. 展开更多
关键词 PROGESTERONE pre-ECLAMPSIA Toll-like receptor 4 tumor necrosis factor nuclear tac-tor-B Ikappa-κB INTERLEUKIN-6
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中国省域交通碳排放空间关联格局的驱动特征
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作者 杨青 郭露 +1 位作者 刘星星 赵坤强 《中国环境科学》 EI CAS CSCD 北大核心 2024年第2期1171-1184,共14页
利用我国2003~2020年省级交通碳排放数据,基于模体结构分析和指数随机图模型对中国交通碳排放空间关联网络的宏观格局、微观连通和驱动特征进行研究.结果表明,中国交通碳排放空间关联网络呈现周期波动特征,等级均衡化发展和核心虹吸的... 利用我国2003~2020年省级交通碳排放数据,基于模体结构分析和指数随机图模型对中国交通碳排放空间关联网络的宏观格局、微观连通和驱动特征进行研究.结果表明,中国交通碳排放空间关联网络呈现周期波动特征,等级均衡化发展和核心虹吸的空间分布,演化出少核心—多半核心—边缘新格局,碳转移路径表现出明显的空间惰性与时间惯性以及区域集中性;经纪属性在推动跨区域交通协同减排的经济活动中发挥重要作用;内生网络的互惠性、连通性、集聚性对交通碳排放网络形成具有重要驱动作用,行为者属性中发出、接收、抑制、互惠的驱动关系明显,外部网络的影响具有明显的地理邻近效应,呈现出地理距离衰减规律特征.由此提出短期重大项目驱动,推动绿色交通转型联动;中期提升协同水平,加强跨区域交通碳减排协调机制;长期顶层零碳设计,工业化-产业化-市场化全面协同等政策建议. 展开更多
关键词 交通碳排放 模体结构分析 指数随机图模型 驱动要素
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PRPF31因子对视网膜色素变性影响的研究进展
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作者 李静 毕宏生 宋继科 《国际眼科杂志》 CAS 2024年第12期1932-1938,共7页
剪接因子(SFs)是一种蛋白质,是剪接体的动态复合体的一部分。剪接体就像“剪刀”一样,能够精确地加工真核生物中前mRNA(pre-mRNA),形成多种mRNA序列,该过程对于基因调控和蛋白质表达十分重要。前mRNA加工因子31(PRPF31)是在生物组织中... 剪接因子(SFs)是一种蛋白质,是剪接体的动态复合体的一部分。剪接体就像“剪刀”一样,能够精确地加工真核生物中前mRNA(pre-mRNA),形成多种mRNA序列,该过程对于基因调控和蛋白质表达十分重要。前mRNA加工因子31(PRPF31)是在生物组织中广泛表达的一种SFs, PRPF31突变会特异性地导致常染色体显性视网膜色素变性(adRP),称为PRPF31-RP。目前PRPF31-RP的发病机制尚不清晰。文章从PRPF31突变或缺失导致组织和生物学过程受损的角度对PRPF31在adRP发生发展分子机制及该病治疗的研究进展做一综述,以期为PRPF31-RP的发病机制与防治的研究提供新的思路。 展开更多
关键词 剪接因子 前mRNA加工因子31(PRPF31) 视网膜色素变性 机制 治疗
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子痫前期患者循环PLGF水平对预测病情及评估母婴结局的价值初探
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作者 盛红娜 范卓然 +1 位作者 华绍芳 张俊农 《天津医药》 CAS 2024年第6期630-634,共5页
目的探讨循环胎盘生长因子(PLGF)水平与子痫前期(PE)病情程度及母婴结局、胎盘病理学改变的相关性。方法选取PE患者159例为研究对象,根据终止妊娠孕周分为:PE_(1)组(62例,<34周终止妊娠的PE患者)和PE_(2)组(97例,≥34周终止妊娠的PE... 目的探讨循环胎盘生长因子(PLGF)水平与子痫前期(PE)病情程度及母婴结局、胎盘病理学改变的相关性。方法选取PE患者159例为研究对象,根据终止妊娠孕周分为:PE_(1)组(62例,<34周终止妊娠的PE患者)和PE_(2)组(97例,≥34周终止妊娠的PE患者);选取同期分娩的107例非PE患者作为对照,根据终止妊娠孕周分为:非PE_(1)组(41例,<34周终止妊娠的非PE患者),非PE_(2)组(66例,≥34周终止妊娠的非PE患者)。收集各组孕妇一般资料:年龄、体质量指数(BMI)、入院收缩压、舒张压,24 h尿蛋白定量、孕产次、是否存在胎儿生长受限(FGR)、胎儿宫内窘迫。新生儿一般资料:术中记录是否有羊水粪染、新生儿窒息,新生儿入住新生儿重症监护病房(NICU)天数;检测分娩当日孕妇静脉血PIGF;将患者胎盘行病理检测并评分;胎儿娩出后行脐动脉血气分析并记录酸碱度(p H)、碱剩余(BE)、乳酸(LAC)。结果PE_(1)组和PE_(2)组与相应孕周非PE_(1)和非PE_(2)组年龄、孕次、产次差异无统计学意义;PE_(1)组与PE_(2)组BMI分别高于非PE_(1)、非PE_(2)组,PLGF分别低于非PE_(1)、非PE_(2)组,且PE_(1)组PLGF低于PE_(2)组(P<0.05)。PE_(1)组患者24 h尿蛋白定量、收缩压、舒张压、胎盘异常病理改变评分高于PE_(2)组(P<0.05)。PE_(1)组与PE_(2)组产时羊水粪染、胎儿宫内窘迫情况、脐动脉血p H值差异无统计学意义,与PE_(2)组比较,PE_(1)组新生儿窒息及FGR比例、脐动脉血LAC升高,BE值降低,入住NICU时间延长(P<0.05)。结论PE患者循环PLGF水平降低,PLGF水平在PE病情评估、预测不良妊娠结局方面有一定价值。 展开更多
关键词 胎盘生长因子 妊娠结局 胎盘 先兆子痫
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