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基于R-L分数阶定义的CCM Flyback变换器建模与分析
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作者 王硕禾 符屹男 +2 位作者 常宇健 杨鹏 李倩 《太阳能学报》 EI CAS CSCD 北大核心 2024年第6期217-225,共9页
针对电容电感都为分数阶这一事实,利用分数阶微积分R-L定义和状态空间平均法,对工作在电感电流连续模式(CCM)下的分数阶Flyback变换器进行建模与分析。推导CCM分数阶Flyback变换器的静态工作点和小信号传递函数以及变换器工作在CCM模式... 针对电容电感都为分数阶这一事实,利用分数阶微积分R-L定义和状态空间平均法,对工作在电感电流连续模式(CCM)下的分数阶Flyback变换器进行建模与分析。推导CCM分数阶Flyback变换器的静态工作点和小信号传递函数以及变换器工作在CCM模式下的条件。其次,讨论Caputo模型与R-L导数模型的区别,得出在R-L分数阶定义下直流静态工作点不仅与占空比相关,而且还与电感和电容的阶数以及负载有关。最后,在PSIM中搭建R-L分数阶CCM Flyback变换器电路模型,得到不同分数阶电感电容阶数下分数阶Flyback变换器输出电压和电感电流的仿真波形,通过仿真结果与理论计算结果对比,验证所建模型的正确性,得出分数阶电感电容的阶数会影响闭环控制器的设计和分数阶模型能更加精确地描述Flyback变换器的工作特性。 展开更多
关键词 DC-DC变换器 电力电子 仿真平台 r-l定义 分数阶建模
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基于Maxwell方程和R-L分数阶导数的高频激励条件下纳米晶材料磁滞特性预测模型
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作者 姬俊安 赵志刚 +3 位作者 张时 杜振斌 翟志强 贾慧杰 《中国电机工程学报》 EI CSCD 北大核心 2024年第13期5431-5440,I0035,共11页
准确预测高频激励条件下纳米晶材料的磁滞特性,对电力电子变压器等高频电力设备磁性元件的优化设计具有重要意义。该文基于Maxwell方程和Riemann-Liouville(R-L)分数阶导数,建立高频激励下纳米晶材料磁滞特性预测模型。首先,根据Maxwel... 准确预测高频激励条件下纳米晶材料的磁滞特性,对电力电子变压器等高频电力设备磁性元件的优化设计具有重要意义。该文基于Maxwell方程和Riemann-Liouville(R-L)分数阶导数,建立高频激励下纳米晶材料磁滞特性预测模型。首先,根据Maxwell方程,首次推导出计及趋肤效应影响的涡流磁场强度解析式;其次,针对现有静态磁滞特性和异常效应建模方法未考虑趋肤效应影响的问题,依据R-L型分数阶导数理论,建立有效描述带材内部磁通密度分布不均时纳米晶静态磁滞特性与异常效应综合预测模型,并提出一种考虑频率效应的阻尼系数ρ和非整数阶n的解析计算方法;最后,基于磁场分离理论,建立高频激励下纳米晶材料磁滞特性预测模型。通过与纳米晶材料1K107B在高频激励下实测磁滞回线进行对比,验证该文所建预测模型的有效性。相较于经典模型,该文所建模型对磁滞回线的预测精度提升了35.8%。 展开更多
关键词 MAXWEll方程 riemann-liouville(r-l)分数阶导数 趋肤效应 磁滞回线
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阿帕替尼联合埃克替尼治疗EGFR基因21号外显子L858R突变型NSCLC的临床观察
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作者 罗娜 马慧丽 杨启 《实用癌症杂志》 2024年第4期594-597,共4页
目的探究对表皮生长因子受体(EGFR)基因21号外显子L858R突变型非小细胞肺癌(NSCLC)采用阿帕替尼联合埃克替尼治疗的临床效果。方法将EGFR基因21号外显子L858R突变型NSCLC患者101例按随机数表法分为观察组(n=51)与对照组(n=50)。观察组... 目的探究对表皮生长因子受体(EGFR)基因21号外显子L858R突变型非小细胞肺癌(NSCLC)采用阿帕替尼联合埃克替尼治疗的临床效果。方法将EGFR基因21号外显子L858R突变型NSCLC患者101例按随机数表法分为观察组(n=51)与对照组(n=50)。观察组采用阿帕替尼联合埃克替尼治疗,对照组仅采用埃克替尼治疗,治疗时间为56 d,2个周期。比较2组近期疗效、不良反应,并采用K-M生存分析曲线图分析2组远期疗效。结果观察组与对照组的客观缓解率(ORR)(74.51%vs 74.00%)与疾病控制率(DCR)(92.16%vs 94.00%)差异均无统计学意义(P>0.05);治疗期间2组未出现2级以上不良反应,观察组高血压和蛋白尿发生率分别为52.94%、50.98%,分别高于对照组的16.00%、10.00%,差异有统计学意义(P<0.05)。观察组生存率显著高于对照组(69.3%vs 43.1%),差异有统计学意义(P<0.05)。结论EGFR基因21号外显子L858R突变型NSCLC采用阿帕替尼联合埃克替尼治疗,可延长患者的无进展生存时间,不良反应的发生可接受。 展开更多
关键词 非小细胞肺癌 阿帕替尼 埃克替尼 表皮生长因子受体 21号外显子l858r突变型
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Hardy-Littlewood截断极大算子的L^(p)范数的连续性
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作者 武嘉 魏明权 燕敦验 《中国科学院大学学报(中英文)》 CSCD 北大核心 2024年第1期28-34,共7页
研究截断极大算子M^(b)_(a)的L_(p)(R^(n))→L_(p)(R^(n))范数的连续性。首先,分别给出‖M^(b)_(a)‖L_(p)(R^(n))→L_(p)(R^(n))关于参数θ=b/a的左右连续性,然后证明‖M^(b)_(a)‖L_(p)(R^(n))→L_(p)(R^(n))在无穷远处的连续性。
关键词 截断极大算子 连续性 l_(p)(r^(n))→l_(p)(r^(n))范数
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安罗替尼联合埃克替尼治疗EGFR21外显子L858R突变肺腺癌合并脑转移患者的临床疗效及安全性
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作者 闫绍辉 付晏 +1 位作者 王栋 徐凯 《山东医药》 CAS 2024年第22期83-85,共3页
目的探讨安罗替尼联合埃克替尼治疗表皮生长因子受体(EGFR)21外显子L858R突变的肺腺癌合并脑转移的临床疗效及安全性。方法选取EGFR21外显子L858R突变的肺腺癌合并脑转移患者102例,随机分成观察组和对照组各51例。对照组行单药埃克替尼... 目的探讨安罗替尼联合埃克替尼治疗表皮生长因子受体(EGFR)21外显子L858R突变的肺腺癌合并脑转移的临床疗效及安全性。方法选取EGFR21外显子L858R突变的肺腺癌合并脑转移患者102例,随机分成观察组和对照组各51例。对照组行单药埃克替尼治疗,观察组行安罗替尼+埃克替尼治疗,疗程2个月。疗程结束后观察两组治疗总有效率及不良反应发生情况。治疗前及治疗2个月,采用全自动电化学发光仪检测两组血清糖类抗原125(CA125)、癌胚抗原(CEA)、组织多肽抗原(TPA)、细胞质胸苷激酶(TK1),采用生活质量量表(QLQ-C30)评估患者生活质量(包括躯体功能、角色功能、认知功能、心理功能和社会功能)。结果治疗2个月,观察组完全缓解、部分缓解、疾病稳定、疾病进展分别为16、27、5、3例,总有效率为84.31%;对照组分别为13、20、12、6例,总有效率64.71%;观察组治疗总有效率高于对照组(P<0.05)。治疗过程中不良反应主要为骨髓抑制、胃肠道反应、皮疹,观察组不良反应发生率为13.72%,对照组为11.76%,两组不良反应发生率比较差异无统计学意义(P>0.05)。治疗2个月,观察组血清CA125、CEA、TPA、TK1水平低于对照组,生活质量评分(包括躯体功能、角色功能、认知功能、心理功能和社会功能5项内容)高于对照组,两组比较差异均有统计学意义(P均<0.05)。结论与单药埃克替尼治疗比较,安罗替尼联合埃克替尼治疗EGFR21外显子L858R突变的肺腺癌合并脑转移患者有良好临床效果且用药较为安全。 展开更多
关键词 肺肿瘤 脑转移 EGFr21外显子l858r突变 安罗替尼 埃克替尼 临床疗效 用药安全
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Immunogenetic basis of chicken’s heterophil to lymphocyte ratio revealed by genome-wide indel variants analysis
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作者 ZHANG Jin WANG Jie +6 位作者 WANG Qiao CUI Huan-xian DING Ji-qiang WANG Zi-xuan Mamadou Thiam LI Qing-he ZHAO Gui-ping 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2023年第9期2810-2823,共14页
Enhancing host immunity is an effective way to reduce morbidity in chickens.Heterophil to lymphocyte ratio(H/L)is associated with host disease resistance in birds.Chickens with different H/L levels show different dise... Enhancing host immunity is an effective way to reduce morbidity in chickens.Heterophil to lymphocyte ratio(H/L)is associated with host disease resistance in birds.Chickens with different H/L levels show different disease resistances.However,the utility of the H/L as an indicator of immune function needs to be further analyzed.In this study,a H/L directional breeding chicken line(Jingxing yellow chicken)was constructed,which has been bred for 12 generations.We compared the function of heterophils,and combined statistical analysis to explore the candidate genes and pathways related to H/L.The oxidative burst function of the heterophils isolated from the H/L selection line(G12)was increased(P=0.044)compared to the non-selection line(NS).The 22.44 Mb genomic regions which annotated 300 protein-coding genes were selected in the genome of G9(n=92)compared to NS(n=92)based on a genome-wide selective sweep.Several selective regions were identified containing genes like interferon induced with helicase C domain 1(IFIH1)and moesin(MSN)associated with the intracellular receptor signaling pathway,C–C motif chemokine receptor 6(CCR6),dipeptidyl peptidase 4(DPP4)and hemolytic complement(HC)associated with the negative regulation of leukocyte chemotaxis and tight junction protein 1(TJP1)associated with actin cytoskeleton organization.In addition,45 genome-wide significant indels containing 29 protein-coding genes were also identified as associated with the H/L based on genome-wide association study(GWAS).The expression of protein tyrosine phosphatase non-receptor type 5(PTPN5)(r=0.75,P=0.033)and oxysterol binding protein like 5(OSBPL5)(r=0.89,P=0.0027)were positively correlated with H/L.Compared to the high H/L group,the expressions of PTPN5 and OSBPL5 were decreased(P<0.05)in the low H/L group of Beijing you chicken.The A/A allelic frequency of indel 5_13108985(P=3.85E–06)within OSBPL5 gradually increased from the NS to G5 and G9,and the individuals with A/A exhibited lower H/L than individuals with heterozygote A/ATCT(P=4.28E–04)and homozygous ATCT/ATCT(P=3.40E–05).Above results indicated oxidative burst function of heterophils were enhanced,and 22.44 Mb genomic regions were selected with the directional selection of H/L.In addition,PTPN5 and OSBPL5 genes were identified as H/L-related candidate genes.These findings revealed the complex genetic mechanism of H/L related to immunity and will allow selection for improving chicken immunity based on the H/L. 展开更多
关键词 H/l ratio heterophil INDEl selective sweep GWAS
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Effects of Different Protein Energy Ratios on Fattening Performance,Slaughter Performance and Meat Quality of Pigs
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作者 Cui YANG Rongsheng JIANG +8 位作者 Yongshao WU Xiying YANG Haihong LIAO Qian QIN Shishan QIN Ying ZHANG Jiahuang YANG Limei QIN Fulin WANG 《Agricultural Biotechnology》 CAS 2023年第2期59-62,75,共5页
[Objectives]Protein energy ratio refers to the proportional relationship between protein and energy levels in animal diets,i.e.,the grams of crude protein corresponding to every megacalorie of energy,which is generall... [Objectives]Protein energy ratio refers to the proportional relationship between protein and energy levels in animal diets,i.e.,the grams of crude protein corresponding to every megacalorie of energy,which is generally expressed as CP:ME or CP:DE.This study was conducted to investigate the effects of different diets on fattening and slaughter performance and meat quality traits for"L(Large Yorkshire)×L(Landrace)"crossbred pigs.[Methods]Eighteen piglets of L×L crossbred with similar body weights about 51 kg were selected.The piglets were divided into 3 groups randomly and each group was assigned to 3 replicates with 2 piglets in a replicate.Group A was fed diet Ⅰ (control diet),group B was fed the same diet of group A in the first month of the trial but fed diet Ⅱ in second month,and group C consumed diet Ⅲ.All the pigs were fed in the same feeding condition for two months except the different diets during the trial.One pig in similar body weight from each replicate was slaughtered for the determination of slaughter performance and meat quality traits in the end of the trial.[Results]The average daily feed intake(ADFI)of pigs from group B was only(2.32±0.52)kg and significantly lower than those from group A and group C(P<0.05),but no difference was found in average daily gain(ADG) and feed/gain(P>0.05).Also,no differences occurred in the carcass length,back fat thickness,longissimus muscle (LM) area and dressing percentage(P>0.05).In addition,no differences were found in the meat quality traits of shear force,meat color,pH_(45 min),pH_(24 h) and cooking loss(P>0.05).However,the water-holding capacity of meat from group C was(2.58±0.02)ms and significantly lower than that of(2.80±0.20)ms from group A(P<0.05).Although the contents of glutamic acid and cystine in LM from group B was significantly lower than those from group A and group C(P<0.05),no differences occurred in the contents of other amino acids,the total amino acid and total flavor amino acid among the three groups(P>0.05).However,the inosine monophosphate content of LM from group C was only(331.80±11.53)mg/100 g and significantly lower than those of(361.00±6.36)and(366.37±4.80)mg/100 g from group A and B(P<0.05).Even though no differences were found in the contents of DM and CP in LM among the three groups of pigs,the content of intramuscular fat(IMF)in LM from group B and group C was increased by 45.6%and 46.58%respectively from that of group A(P<0.05),but no difference occurred between group B and C(P>0.05).[Conclusions]DietsⅡ and Ⅲ in this study caused no differences in fattening and slaughter performance of L×L crossbred pigs,but the effects on some meat traits were still significant,especially on the improvement of intramuscular fat in experimental pigs.Therefore,they could improve the meat quality of crossbred pigs to a certain extent. 展开更多
关键词 Protein energy ratio l×l crossbred FATTENING Slaughter performance Meat quality IMF
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非洲猪瘟病毒B646L和F778R双基因PCR检测方法的构建
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作者 王慧 钟菊花 +3 位作者 杨俊 杜丽飞 王红兵 刘俊琦 《激光生物学报》 CAS 2023年第6期554-560,共7页
为建立一种能够快速检测非洲猪瘟病毒(ASFV)的普通PCR方法,本研究分别以ASFV B646L和F778R基因为靶序列设计了两对特异性引物,建立ASFV B646L和F778R双基因普通PCR方法,并对其特异性、灵敏性及重复性进行检测。结果显示:该PCR体系(25.0... 为建立一种能够快速检测非洲猪瘟病毒(ASFV)的普通PCR方法,本研究分别以ASFV B646L和F778R基因为靶序列设计了两对特异性引物,建立ASFV B646L和F778R双基因普通PCR方法,并对其特异性、灵敏性及重复性进行检测。结果显示:该PCR体系(25.0μL体系)的最优组合为Pfu酶0.2μL、10×Reaction Buffer 2.5μL、2.5 mmol/L d NTP Mixture 2.5μL、B646L上下游引物各1.5μL、F778R上下游引物各0.5μL、DNA模板1.0μL;退火温度为57℃、退火时间为30 s、72℃延伸2.5 min,30个循环。该方法仅针对ASFV B646L和F778R基因进行特异性扩增,无交叉反应。同时对B646L和F778R阳性质粒的最低检测下限分别为7.2×10^(7)copies/μL、1.5×10^(6)copies/μL,试验重复性良好。本研究对于提高ASFV临床诊断的准确性、特异性和高效性具有重要价值,为其快速检测提供了可靠的技术支撑。 展开更多
关键词 非洲猪瘟病毒 多重PCr B646l基因 F778r基因 快速检测
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细菌种群增生中具L-R模型的迁移算子的占优本征值
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作者 吴红星 凌军 程国飞 《上饶师范学院学报》 2023年第6期13-19,共7页
近年来,关于迁移方程解的渐近性态和迁移算子的谱分析研究已取得一定的研究成果,然而迁移算子的占优本征值的存在性研究较少,尤其是对细菌种群模型相应迁移算子的占优本征值研究成果更是少之又少。在L2空间中,运用线性算子理论,研究以... 近年来,关于迁移方程解的渐近性态和迁移算子的谱分析研究已取得一定的研究成果,然而迁移算子的占优本征值的存在性研究较少,尤其是对细菌种群模型相应迁移算子的占优本征值研究成果更是少之又少。在L2空间中,运用线性算子理论,研究以细菌种群的年龄和遗传周长为特征的带初边值的L-R模型,采用构造算子、豫解算子等方法证明了该迁移算子AH的谱仅由至多可数个具有限代数重数的离散本征值组成以及该迁移算子存在占优本征值。 展开更多
关键词 细菌种群 l-r模型 迁移算子 占优本征值
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盐湖大气环境下316 L仪表管点蚀深度预测研究
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作者 骆正山 刘月 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第6期105-110,共6页
为提高316 L仪表管在盐湖大气环境下点蚀深度的预测精度,采用变阶平均弱化缓冲算子、积分背景值和新陈代谢对分数阶累加灰色模型FGM(1,1,r)进行改进,首先通过改进Tent混沌映射、莱维飞行和区间自适应反向学习策略提高黏菌算法(SMA)的寻... 为提高316 L仪表管在盐湖大气环境下点蚀深度的预测精度,采用变阶平均弱化缓冲算子、积分背景值和新陈代谢对分数阶累加灰色模型FGM(1,1,r)进行改进,首先通过改进Tent混沌映射、莱维飞行和区间自适应反向学习策略提高黏菌算法(SMA)的寻优能力和收敛速度,随后利用改进黏菌算法(ISMA)对FGM(1,1,r,ρ)中的参数r和ρ进行寻优,最后构建仪表管ISMA-FGM(1,1,r,ρ)点蚀深度预测模型。研究结果表明:经优化的新模型比原模型误差更小、拟合度更高,在仪表管点蚀深度预测方面具有更好的性能。研究结果可为仪表管道系统的完整性评价和风险预警提供参考。 展开更多
关键词 盐湖大气环境 316 l仪表管 点蚀深度 改进黏菌算法(ISMA) FGM(1 1 r)模型
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Q345R/316L蛇形轧制复合应变及曲率研究 被引量:4
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作者 宋佳宇 刘贵文 +5 位作者 魏鹏洋 杨树国 吕彦兵 乔福振 杨超 江连运 《太原科技大学学报》 2023年第6期560-566,570,共8页
为解决同步轧制工艺制备复合板时出现的结合强度低和板材弯曲等问题,提出了同径异速蛇形轧制复合工艺。采用Deform-2D平台对碳钢Q345R/不锈钢316L蛇形轧制复合过程进行模拟,获得了变形及微观组织,对结合面等效塑性应变、弯曲曲率和晶粒... 为解决同步轧制工艺制备复合板时出现的结合强度低和板材弯曲等问题,提出了同径异速蛇形轧制复合工艺。采用Deform-2D平台对碳钢Q345R/不锈钢316L蛇形轧制复合过程进行模拟,获得了变形及微观组织,对结合面等效塑性应变、弯曲曲率和晶粒大小进行了对比分析与研究。研究结果表明,与同步轧制相比,蛇形轧制能够显著提高复合板结合强度、降低弯曲程度并细化晶粒;在一定工艺参数范围内,结合面等效塑性应变随着初始层厚比、辊速比及工作辊直径的减小,压下率的增大而显著提高;在相同的工况下,当辊速比为1.20时,复合板接近平直状态;这为工业生产中制备性能优异且板形平直的复合板材提供技术支撑。 展开更多
关键词 Q345r/316l 蛇形轧制 等效塑性应变 弯曲曲率 晶粒大小
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单纯靶向或靶向联合治疗晚期EGFR 21 L858R突变肺腺癌患者的生存分析
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作者 何姣 韩志刚 俞婷婷 《现代肿瘤医学》 CAS 北大核心 2023年第23期4362-4366,共5页
目的:评价真实世界晚期EGFR 21 L858R突变肺腺癌患者单纯靶向或靶向联合治疗的疗效及安全性差异,分析影响无进展生存期(PFS)及总生存期(OS)的因素。方法:回顾性分析2015年01月至2019年12月在我院确诊的109例晚期EGFR 21 L858R突变肺腺... 目的:评价真实世界晚期EGFR 21 L858R突变肺腺癌患者单纯靶向或靶向联合治疗的疗效及安全性差异,分析影响无进展生存期(PFS)及总生存期(OS)的因素。方法:回顾性分析2015年01月至2019年12月在我院确诊的109例晚期EGFR 21 L858R突变肺腺癌患者的临床特征、治疗疗效、安全性及生存数据,采用SPSS 26.0软件进行统计分析。结果:靶向联合治疗组的中位PFS及中位OS明显优于单纯靶向治疗组(mPFS:14.5个月vs 10.3个月,P<0.05;mOS:31.9个月vs 24.6个月,P<0.05),两组患者ORR(54.4%vs 38.5%)及DCR(96.5%vs 94.2%)无统计学差异,但靶向联合治疗在一定程度提高了患者ORR,显示出较好的客观缓解率。对患者基线资料分析发现,初治时肿瘤大小、治疗方式、治疗前癌胚抗原(CEA)及细胞角质素19(CYFRA21-1)水平是疾病进展的独立预后因素,而年龄、初治时有无脑转移、治疗方式、糖类抗原125(CA125)及细胞角质素19(CYFRA21-1)水平均可影响患者的OS。安全性比较中发现,单纯靶向治疗最常见的不良反应为皮疹,其次是消化道反应;靶向联合治疗最常见不良反应为消化道反应,其次是骨髓抑制。总体而言,两组患者耐受性良好,但靶向联合治疗组不良反应发生率(68.4%)明显高于单纯靶向治疗组(38.5%),差异有统计学意义(P<0.001)。结论:晚期肺腺癌EGFR 21 L858R突变患者使用靶向联合治疗的疗效要优于单纯靶向治疗,且耐受性良好。初治时肿瘤大小、治疗前肿瘤相关抗原(CEA及CYFRA21-1)水平是PFS的独立预后因素,年龄、初治时有无脑转移、肿瘤相关抗原(CYFRA21-1、CA125)水平均可影响患者的OS。 展开更多
关键词 真实世界研究 肺腺癌 l858r突变 靶向治疗 预后
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Influence of Vertical Load on Lateral-Loaded Monopiles by Numerical Simulation 被引量:1
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作者 Qiang Li Pan Chen +2 位作者 Lihong Gao Dan Meng Jinjie Zou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第4期465-481,共17页
Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflect... Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflection of the pile.This paper investigated the influence of vertical load on the behaviour of monopiles installed in the sand under combined load using three-dimensional numerical methods.The commercial software PLAXIS was used for simulations in this paper.Monopiles were modelled as a structure incorporating linear elastic material behaviour and soil was modelled using the Hardening-Soil(HS)constitutive model.The monopiles under vertical load,lateral load and combined vertical and lateral loads were respectively studied taking into account the sequence of load application and pile slenderness ratio(L/D;L and D are the length and diameter of the pile).Results suggest that the sequence of load application plays a major role in how vertical load affects the deflection behaviour of the pile.Specifically,when L/D ratios obtained by lengthening the pile while keeping its diameter constant are 3,5 and 8,the relationships between lateral load and the deflection behaviour of the pile under the effect of vertical load demonstrate a similar trend.Furthermore,the cause of increased lateral capacity of the pile under the action of applied vertical load in the common practical application case and in the VPL case was analyzed by studying the variation law of soil stress along the pile embedment.Results confirm that the confining effect of vertical load increases means effective stress of the soil around the pile,thus increasing soil stiffness and pile capacity. 展开更多
关键词 PIlE lateral capacity combined load sequence of load application l/D ratio
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基于NPV Scheduler软件的露天转地下矿山开采境界研究 被引量:3
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作者 马宁 汪昌亮 丁鹏 《中国矿山工程》 2023年第2期21-25,共5页
基础的L-G图论法未考虑地下开采可能的成本优势,在露天转地下矿山开采境界圈定时存在一定的局限性。本文通过对价格法与储量盈利比较法计算的经济合理剥采比进行分析,结合NPV Scheduler软件研究了露天转地下开采境界圈定方法,并通过工... 基础的L-G图论法未考虑地下开采可能的成本优势,在露天转地下矿山开采境界圈定时存在一定的局限性。本文通过对价格法与储量盈利比较法计算的经济合理剥采比进行分析,结合NPV Scheduler软件研究了露天转地下开采境界圈定方法,并通过工程实例验证了该方法的合理性。研究成果对露天转地下矿山开采境界的确定具有一定的指导意义。 展开更多
关键词 露天转地下 NPV Scheduler 经济合理剥采比 l-G图论法
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Prognostic value of the preoperative fibrinogen-to-albumin ratio in pancreatic ductal adenocarcinoma patients undergoing R0 resection 被引量:5
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作者 Li-Peng Zhang Hu Ren +1 位作者 Yong-Xing Du Cheng-Feng Wang 《World Journal of Gastroenterology》 SCIE CAS 2020年第46期7382-7404,共23页
BACKGROUND Inflammation plays an important role in tumor progression,and growing evidence has confirmed that the fibrinogen-to-albumin ratio(FAR)is an important prognostic factor for overall survival in malignant tumo... BACKGROUND Inflammation plays an important role in tumor progression,and growing evidence has confirmed that the fibrinogen-to-albumin ratio(FAR)is an important prognostic factor for overall survival in malignant tumors.AIM To investigate the prognostic significance of FAR in patients undergoing radical R0 resection of pancreatic ductal adenocarcinoma(PDAC).METHODS We retrospectively analyzed the data of 282 patients with PDAC who underwent radical R0 resection at The Cancer Hospital of the Chinese Academy of Medical Sciences from January 2010 to December 2019.The surv_cutpoint function of the R package survminer via RStudio software(version 1.3.1073,http://www.rstudio.org)was used to determine the optimal cut-off values of biological markers,such as preoperative FAR.The Kaplan-Meier method and log-rank tests were used for univariate survival analysis,and a Cox regression model was used for multivariate survival analysis for PDAC patients who underwent radical R0 resection.RESULTS The optimal cut-off value of FAR was 0.08 by the surv_cutpoint function.Higher preoperative FAR was significantly correlated with clinical symptoms(P=0.001),tumor location(P<0.001),surgical approaches(P<0.001),preoperative plasma fibrinogen concentration(P<0.001),and preoperative plasma albumin level(P<0.001).Multivariate analysis showed that degree of tumor differentiation(P<0.001),number of metastatic lymph nodes[hazard ratio(HR):0.678,95%confidence interval(CI):0.509-0.904,P=0.008],adjuvant therapy(HR:1.604,95%CI:1.214-2.118,P=0.001),preoperative cancer antigen 19-9 level(HR:1.740,95%CI:1.288-2.352,P<0.001),and preoperative FAR(HR:2.258,95%CI:1.720-2.963,P<0.001)were independent risk factors for poor prognosis in patients with PDAC who underwent radical R0 resection.CONCLUSION The increase in preoperative FAR was significantly related to poor prognosis in patients undergoing radical R0 resection for PDAC.Preoperative FAR can be used clinically to predict the prognosis of PDAC patients undergoing radical R0 resection. 展开更多
关键词 Pancreatic ductal adenocarcinoma r0 resection Fibrinogen-to-albumin ratio Biomarker Prognosis Survival
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R/S ratio in lead Ⅱ, and the prognostic significance of red cell distribution width in acute coronary syndrome 被引量:1
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作者 Abuzer Coskun Sevki Hakan Eren 《World Journal of Clinical Cases》 SCIE 2019年第16期2217-2226,共10页
BACKGROUND In spite of developing medical technologies to discover the etiopathogenesis of diseases and developments in the treatment of coronary artery disease,acute coronary syndromes (ACS) continue to be the main c... BACKGROUND In spite of developing medical technologies to discover the etiopathogenesis of diseases and developments in the treatment of coronary artery disease,acute coronary syndromes (ACS) continue to be the main cause of mortality and morbidity worldwide.New cardiac biomarkers and techniques are needed to help provide rapid diagnosis in order to evaluate risk in coronary artery patients.AIM To evaluate the effects of R to S ratio (RSR) in the electrocardiograph of patients with ACS,from the point of the arising complication after myocardial infarction (MI),to three-vessel disease (TVD) and mortality.METHODS The data of 1,296 patients with ACS,who presented to the emergency department of our hospital with chest pain between January 2014 and December 2018 and were admitted to the cardiology clinic,were retrospectively included in this cross-sectional cohort study.Patients with an RSR value less than Ⅰ were assigned to group I,while those with an RSR value greater than Ⅰ were assigned to group Ⅱ.RESULTS In our study,466 (35.9%) of the 1,296 patients,357 (38.3%) in group 1 and 109 (29.9%) in group 2,were female,with a mean age of 61.56 ± 9.42.ST-elevation MI 573 (44.2%),unstable angina (UA) 502 (38.7%) and non ST-elevation MI 220 (17%) were more prevalent in group I.Acute anterior MI 263 (20.3) in group I,and acute inferior MI 184 (14.2) in group Ⅱ was higher.Ischemic heart failure was the most common complication.In group Ⅱ,the red cell distribution width (RDW) was 15.42 ± 1.82,the gensini score was 48.39 ± 36.44,the left ventricular ejection fraction was 41.17 ± 10.41,the TVD was 111 (8.5),and the mortality rate was 72 (5.6),which was significantly higher than group Ⅰ RDW;in MI with ST and non- ST-elevation,in TVD,mortality and complications were high and low in UA.In single and multivariate regression analyses,the variables were associated with ACS risk.CONCLUSION RSR levels may be an auxiliary predictive value in ACS in terms of complications developing after MI,TVD,and mortality. 展开更多
关键词 Acute COrONArY SYNDrOME EMErGENCY DEPArTMENT r/S ratio red cell distribution WIDTH
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Investigation on the Folding Mode and Deployment Process of an Inflatable Boarding Platform for the Marine Emergency Evacuation System
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作者 Qiang Li Pan Chen +2 位作者 Lihong Gao Dan Meng Jinjie Zou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第4期483-510,共28页
Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflect... Monopiles are the most common foundation form of offshore wind turbines,which bear the vertical load,lateral load and bending moment.It remains uncertain whether the applied vertical load increases the lateral deflection of the pile.This paper investigated the influence of vertical load on the behaviour of monopiles installed in the sand under combined load using three-dimensional numerical methods.The commercial software PLAXIS was used for simulations in this paper.Monopiles were modelled as a structure incorporating linear elastic material behaviour and soil was modelled using the Hardening-Soil(HS)constitutive model.The monopiles under vertical load,lateral load and combined vertical and lateral loads were respectively studied taking into account the sequence of load application and pile slenderness ratio(L/D;L and D are the length and diameter of the pile).Results suggest that the sequence of load application plays a major role in how vertical load affects the deflection behaviour of the pile.Specifically,when L/D ratios obtained by lengthening the pile while keeping its diameter constant are 3,5 and 8,the relationships between lateral load and the deflection behaviour of the pile under the effect of vertical load demonstrate a similar trend.Furthermore,the cause of increased lateral capacity of the pile under the action of applied vertical load in the common practical application case and in the VPL case was analyzed by studying the variation law of soil stress along the pile embedment.Results confirm that the confining effect of vertical load increases means effective stress of the soil around the pile,thus increasing soil stiffness and pile capacity. 展开更多
关键词 PIlE lateral capacity combined load sequence of load application l/D ratio
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Comparing overall survival between first generation EGFR-TKIs and chemotherapy in lung cancer patients with Del19/L858R 被引量:3
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作者 Wei Deng Yuanyuan Lei +4 位作者 Siyang Liu Jinji Yang Haiyan Tu Honghong Yan Yilong Wu 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2016年第3期339-347,共9页
Objective: Combined overall survival (OS) analysis of Lux-Lung 3 and Lux-Lung 6 demonstrated that patients with epidermal growth factor receptor (EGFR) exon 19 deletions (Del19) would benefit from first-line se... Objective: Combined overall survival (OS) analysis of Lux-Lung 3 and Lux-Lung 6 demonstrated that patients with epidermal growth factor receptor (EGFR) exon 19 deletions (Del19) would benefit from first-line second generation EGFR tyrosine kinase inhibitors (TKIs) afatinib but not for those with L858R. This study was to investigate the survival difference between first-line first generation EGFR-TKIs and chemotherapy in patients with either Del19 or L858R, and to directly compare OS in these two mutation groups. Methods: Eligibles were all prospective and retrospective studies comparing EGFR-TKIs with conventional chemotherapy or receiving single agent EGFR-TKIs and demonstrating survival analysis based on mutation types. The primary outcome was OS measured as pooled hazard ratios (HRs). All measures were pooled using random- effects models and 95% confidential interval (95% CI) was calculated. Results: A total of 14 studies incorporating 1,706 patients with either Del19 or L858R were included. Enrolling patients with Del19 or L858R in randomized controlled trials (RCTs), first-line first generation EGFR-TKIs were associated with no OS benefit, compared with chemotherapy (pooled HR_TKI/Chemo for Del19: 0.82, 95% CI: 0.64- 1.06, P=0.14; pooled HR_TKI/Chemo for L858R: 1.15, 95% CI: 0.85-1.56, P=0.38). Direct comparison of Del19 with L858R receiving with first-line first generation EGFR-TKIs demonstrated no significant survival difference (pooled HR19/21: 0.88, 95% CI: 0.67-1.16, P=0.37). Conclusions: Among patients with advanced non-small cell hmg cancer (NSCLC) harboring Del19 and L858R, first-line first generation EGFR-TKIs demonstrated no survival benefit comparing with chemotherapy. Direct comparison between Del19 and L858R revealed no significant survival difference after first-line first generation EGFR-TKIs. 展开更多
关键词 NSClC EGFr Del19/l858r first generation EGFr-TKIs OS
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Preparation of Layered Potassium Titanate Whiskers with Large Length-diameter Ratio by KDC Method 被引量:4
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作者 吉晓莉 WU Shijiang +1 位作者 章嵩 ZHAO Xiujian 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第4期669-673,共5页
Pure K2Ti4O9 whiskers were prepared by KDC(Kneading-Drying-Calcination) method with TiO2 and K2CO3 as raw materials. The influences of TiO2/K2CO3 molar ratio(RT/K), calcination temperature(TC) and cooling proces... Pure K2Ti4O9 whiskers were prepared by KDC(Kneading-Drying-Calcination) method with TiO2 and K2CO3 as raw materials. The influences of TiO2/K2CO3 molar ratio(RT/K), calcination temperature(TC) and cooling process on phase composition and morphology of the whiskers were investigated by TG-DSC(thermo gravimetric-differential scanning calorimeter), XRD(X-ray diffraction), and SEM(scanning electron microscope). Pure K2Ti4O9 potassium titanate whiskers with large length-diameter ratio(r)(over 250) can be obtained at RT/K = 2.9 and TC = 950 ℃. 展开更多
关键词 KDC(kneading-drying-calcination) method potassium titanate whiskers TiO2/K2CO3 molar ratiorT/K) length-diameter ratior
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陶瓷超滤膜在5-羟基-L-色氨酸发酵产物提取中的应用
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作者 张怡君 田俊波 +3 位作者 杨志彬 郝晋博 胡江林 吕志堂 《河北大学学报(自然科学版)》 CAS 北大核心 2024年第1期77-83,共7页
为提高5-羟基-L-色氨酸(5-hydroxy-L-tryptophan,5-HTP)提取分离效率,降低能耗和污染排放,选择陶瓷超滤膜应用于从发酵液中提取5-HTP的工艺,对陶瓷超滤膜的过滤条件进行优化.首先优选出适合的膜孔径为10 nm,进一步优化得到陶瓷超滤膜分... 为提高5-羟基-L-色氨酸(5-hydroxy-L-tryptophan,5-HTP)提取分离效率,降低能耗和污染排放,选择陶瓷超滤膜应用于从发酵液中提取5-HTP的工艺,对陶瓷超滤膜的过滤条件进行优化.首先优选出适合的膜孔径为10 nm,进一步优化得到陶瓷超滤膜分离提取5-HTP的3个最优工艺参数:发酵液pH值3.5,跨膜压差0.75 MPa,料液过膜温度35℃.在此工艺条件下,5-HTP的透过率在92%以上,对游离蛋白质截留率达90%以上,满足进一步浓缩、结晶制备5-HTP的要求,达到了优化预期效果,为陶瓷超滤膜应用于从发酵液中工业化提取5-HTP提供了可靠依据. 展开更多
关键词 陶瓷超滤膜 5-羟基-l-色氨酸 过滤条件 透过率 截留率
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