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塑性磨料气射流仿真与试验研究
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作者 易茜 赵洋洋 王燕萍 《塑料工业》 CAS CSCD 北大核心 2024年第5期169-174,共6页
塑性磨料气射流加工(PAJM)是一种先进的减材加工技术,是采用热固性塑性磨料代替传统硬磨料而发展的新型技术,该技术可有效去除表面涂层,且不损伤基材。基材无损主要是通过控制塑性磨料对基材的冲蚀应力,使得塑性磨料的冲蚀应力小于基材... 塑性磨料气射流加工(PAJM)是一种先进的减材加工技术,是采用热固性塑性磨料代替传统硬磨料而发展的新型技术,该技术可有效去除表面涂层,且不损伤基材。基材无损主要是通过控制塑性磨料对基材的冲蚀应力,使得塑性磨料的冲蚀应力小于基材纤维的极限强度或纤维与树脂的结合强度。本研究采用有限元仿真和试验相结合的方法,对颗粒速度进行理论分析、计算流体动力学仿真模拟和试验研究,研究不同气体压力下的颗粒速度,计算结果与试验数据吻合较好。结果表明,随着磨料颗粒离开喷嘴,在距离喷嘴出口6.2 dN内(dN为喷嘴内径),颗粒速度增加;相反,距离喷嘴出口6.2 dN外,颗粒速度逐渐减小。当磨料粒径由20~30目变为40~50目时,最大颗粒速度由164.365 m/s增加到228.402 m/s。随着磨料粒径的减小,颗粒速度增加,且发散角增加。相比而言,数值模型能更好的预测塑性磨料的颗粒速度和分布。该研究突出了控制颗粒粒径和支座距离对射流场颗粒速度和发散角的影响。为控制颗粒对基材的冲蚀应力,避免基材损伤提供理论参考。 展开更多
关键词 气射流加工 塑性磨料 颗粒速度 有限元仿真 数值模拟
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改进DenseNet模型在工件表面粗糙度视觉检测中的应用
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作者 周友行 易倩 +1 位作者 杨文佳 赵文杰 《机械科学与技术》 CSCD 北大核心 2024年第6期1042-1047,共6页
针对原始DenseNet模型检测工件表面粗糙度时间长、准确率较低的问题,结合卷积层滤波器注意力机制和批归一化层缩放系数提出一种工件表面粗糙度检测的深度学习模型。首先,利用注意力重要性值判定模块内的冗余通道。其次,在Dense Block模... 针对原始DenseNet模型检测工件表面粗糙度时间长、准确率较低的问题,结合卷积层滤波器注意力机制和批归一化层缩放系数提出一种工件表面粗糙度检测的深度学习模型。首先,利用注意力重要性值判定模块内的冗余通道。其次,在Dense Block模块内引入批归一化层缩放系数判别特征通道的重要程度。最后联合卷积层滤波器的注意力重要性值和批归一化层缩放系数裁剪冗余通道,实现模型剪枝。实验结果表明,原始DenseNet模型检测工件表面粗糙度的准确率为91.875%,检测时间为483 s。当剪枝率为20%时,其检测效果最好,检测准确率为96.875%,检测时间为255 s。相比于原始DenseNet模型,改进后的DenseNet模型检测效果更好,在质量检测领域方面具有一定的应用前景。 展开更多
关键词 粗糙度检测 深度学习 DenseNet 模型剪枝
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价值回归背景下国际碳交易制度的完善
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作者 徐军华 易倩 《中国地质大学学报(社会科学版)》 CSSCI 北大核心 2024年第6期37-50,共14页
《巴黎协定》国际碳交易制度体现了环境价值、经济价值和社会价值相统一的多维价值目标,这是对《京都议定书》时期碳交易实践的价值纠偏,也是对制度初衷的价值回归。然而,价值实现的关键在于制度规范与价值目标的契合度。以“价值——... 《巴黎协定》国际碳交易制度体现了环境价值、经济价值和社会价值相统一的多维价值目标,这是对《京都议定书》时期碳交易实践的价值纠偏,也是对制度初衷的价值回归。然而,价值实现的关键在于制度规范与价值目标的契合度。以“价值——原则——规则”作为分析框架,解析国际碳交易制度的功能价值,可知公平、环境完整性、人权保障和可持续发展应作为其核心原则。通过对国际碳交易规则与原则的匹配度检视,发现存在“国家自主贡献”的充分性和公平性评估机制缺失、资金和技术以及能力建设缺乏履约执行机制、人权保障和可持续发展原则存在“建设性模糊”、ITMOs实现核心原则具有不确定性等问题。故此,完善“国家自主贡献”的自证和跟踪机制、落实资金和能力建设支持机制、构建国际碳交易原则评估体系以及加强ITMOs规则的指导性是制度完善的有效路径。 展开更多
关键词 国际碳交易制度 公平原则 环境完整性 可持续发展 人权保障
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菟丝子治疗骨关节炎:网络药理学分析及实验验证 被引量:8
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作者 张天栋 彭青平 +3 位作者 刘欢 冯建国 易茜 黄文华 《中国组织工程研究》 CAS 北大核心 2024年第28期4516-4521,共6页
背景:菟丝子具有补肝肾、益精髓的功效,而骨关节炎的主要病机为肝肾亏虚,推测菟丝子与骨关节炎之间有一定的联系。目的:基于网络药理学和分子对接的分析手段挖掘骨关节炎和菟丝子之间的潜在联系,对中药本草菟丝子的作用机制进行合理的... 背景:菟丝子具有补肝肾、益精髓的功效,而骨关节炎的主要病机为肝肾亏虚,推测菟丝子与骨关节炎之间有一定的联系。目的:基于网络药理学和分子对接的分析手段挖掘骨关节炎和菟丝子之间的潜在联系,对中药本草菟丝子的作用机制进行合理的推测与验证。方法:先在中草药数据库TCMSP中筛选菟丝子的有效活性成分和作用靶点,另在疾病数据库GeneCards、OMIM、TTD中收集骨关节炎的相关基因;取交集后进行一系列分析,并筛选出核心基因;通过对核心基因的富集分析选择菟丝子作用于骨关节炎的通路,通过分子对接验证核心基因的作用,并依此选择合适的有效活性成分进行实验验证。结果与结论:①筛选出11种菟丝子的有效活性成分,菟丝子和骨关节炎有66个交集靶点基因,后续筛选出12个核心基因,包括肿瘤坏死因子、白细胞介素1B、TP53、RACα丝氨酸/苏氨酸蛋白激酶(AKT1)、血管内皮生长因子A、基质金属蛋白酶9、前列腺素过氧合酶2、胱天蛋白酶3、表皮生长因子、过氧化物酶体增生激活受体γ、白细胞介素10、血管细胞黏附因子1;②对核心基因进行富集分析后,选择经典炎症通路核因子κB信号通路进行后续菟丝子缓解骨关节炎炎症的分析验证;根据各活性成分和通路核心基因前列腺素过氧合酶2进行分子对接后得到的结果,选择亲和力最高的芝麻素进行后续细胞实验验证,结果证实了菟丝子的有效成分芝麻素可以通过抑制白细胞介素1β诱导的核因子κB信号通路降低环氧合酶2的表达;③结果表明,菟丝子的活性有效成分芝麻素通过抑制白细胞介素1β诱导的核因子κB信号通路降低环氧合酶2的表达,达到改善骨关节炎炎症的作用,证实了菟丝子在骨关节炎方面的治疗效果。 展开更多
关键词 菟丝子 骨关节炎 芝麻素 核因子ΚB信号通路 环氧合酶2 网络药理学 分子对接 炎症反应
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UV-C与柠檬酸处理对采后香蕉贮藏品质的影响
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作者 易茜 吴宁 +2 位作者 李景原 王瀚博 张亮 《热带作物学报》 CSCD 北大核心 2024年第2期415-423,共9页
香蕉是富含营养物质且具有重要经济价值的热带水果,也是中国南方四大水果之一。香蕉是一种典型的呼吸跃变型果实,采后乙烯的大量释放使香蕉在贮藏过程中加快成熟和衰老,影响香蕉贮藏保鲜及经济价值。因此有必要研究提高香蕉采后贮藏品... 香蕉是富含营养物质且具有重要经济价值的热带水果,也是中国南方四大水果之一。香蕉是一种典型的呼吸跃变型果实,采后乙烯的大量释放使香蕉在贮藏过程中加快成熟和衰老,影响香蕉贮藏保鲜及经济价值。因此有必要研究提高香蕉采后贮藏品质的技术方法,为实践应用提供理论依据。本研究以采后香蕉为材料,分别通过UV-C辐照、柠檬酸浸泡以及二者的复合处理3种方法处理香蕉,在温度为(20±2)℃、湿度为60%~70%的条件下黑暗贮藏12 d,分别于贮藏期的第1、6、9、12天对各组进行随机取样,通过测定硬度、失重率、可滴定酸含量、可溶性固形物含量等生理和品质指标,研究不同处理方法对采后香蕉贮藏品质的影响。结果表明:3.96×10^(-2)KJ/m^(2)UV-C辐照和复合处理(3.96×10^(-2)KJ/m^(2)UV-C辐照+2.0%柠檬酸)对香蕉的保鲜效果明显优于柠檬酸处理,表现为显著抑制果实硬度的下降,延缓失重率的增加,抑制可溶性固形物含量的增加和可滴定酸含量的下降,维持果实糖酸比。在贮藏结束时,与CK相比,UV-C辐照和复合处理的香蕉硬度分别增加9.09%和13.63%,失重率分别减少22.00%和11.43%,糖酸比分别减少40.00%和42.30%。此外,UV-C辐照和复合处理有效抑制了香蕉黄酮类物质、酚类物质和维生素C含量的下降,提高了果实DPPH自由基清除率和抗氧化能力。在贮藏结束时,与CK相比,UV-C辐照和复合处理的维生素C含量分别增加了0.82%和1.27%,总多酚含量分别增加了25.92%和41.65%,总黄酮含量均增加了约30.00%,DPPH自由基清除率分别增加了13.98%和36.59%。综上所述,UV-C辐照和复合处理均可提高采后香蕉贮藏品质,延长其货架期。因此,可以选用该方法作为绿色、安全有效的香蕉采后保鲜技术。 展开更多
关键词 香蕉 UV-C 柠檬酸 贮藏品质
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基于氧化应激反应探讨慢性体表溃疡发病机理及象皮生肌膏联合托里消毒散的干预作用
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作者 林雅思 孙之中 +4 位作者 刘朝红 陈其华 易倩 赵姣 何欢 《世界中西医结合杂志》 2024年第4期699-704,共6页
目的 探讨慢性体表溃疡发病机理以及象皮生肌膏联合托里消毒散的干预作用。方法 将30只SPF级雄性SD大鼠按随机数字表法分为空白对照组、模型组、象皮生肌膏组、托里消毒散组、象皮生肌膏联合托里消毒散组,每组各6只。采用金黄色葡萄球... 目的 探讨慢性体表溃疡发病机理以及象皮生肌膏联合托里消毒散的干预作用。方法 将30只SPF级雄性SD大鼠按随机数字表法分为空白对照组、模型组、象皮生肌膏组、托里消毒散组、象皮生肌膏联合托里消毒散组,每组各6只。采用金黄色葡萄球菌造模,连续给药1周后,检测创面组织中血管内皮生长因子(Vascular endothelial growth factor,VEGF)、血管内皮细胞生长因子受体2(Vascular endothelial growth factor receptor 2,VEGFR-2)、核因子E2相关因子2(Nuclear factor erythroid 2-related factor 2,Nrf2)、NAD(P)H醌氧化还原酶1[NAD(P)H quinone oxidoreductase1,NQO1)、血红素加氧酶1(Heme oxygenase-1,HO-1)]表达水平。结果 与空白对照组比较,模型组创面组织中VEGF、VEGFR-2表达均明显降低,差异有统计学意义(P<0.01);与模型组比较,象皮生肌膏组、托里消毒散组、象皮生肌膏联合托里消毒散组VEGF、VEGFR-2表达均明显升高,差异有统计学意义(P<0.01)。与对照组比较,模型组中Nrf2、NQO1、HO-1表达水平升高,差异有统计学意义(P<0.01);与模型组比较,象皮生肌膏组、托里消毒散组、象皮生肌膏联合托里消毒散组Nrf2表达水平均明显升高,NQO1和HO-1表达降低,差异有统计学意义(P<0.01)。结论 大鼠慢性溃疡的形成可能与氧化应激反应抑制了VEGF通路及Nrf2通路有关,而象皮生肌膏联合托里消毒散可能通过调节上述通路促进溃疡处血管新生和抗氧化应激,进而提高创面愈合能力。 展开更多
关键词 慢性皮肤溃疡 托里消毒散 象皮生肌膏 血管新生 氧化应激
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麦冬多糖对破骨细胞分化的影响研究 被引量:1
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作者 易倩 张合富 +4 位作者 李官翔 樊丽莎 邓加加 张伶燕 张健 《现代医药卫生》 2024年第2期190-195,共6页
目的探讨麦冬多糖(OPS)对破骨细胞分化的影响。方法从C57BL/6j小鼠股骨中提取骨髓单核巨噬细胞(BMMs),在细胞培养液中分别添加2.5、10.0和40.0μg/mL OPS(A、B、C组),对照组未添加OPS。检测OPS对BMMs细胞活性、破骨细胞骨吸收能力及抗... 目的探讨麦冬多糖(OPS)对破骨细胞分化的影响。方法从C57BL/6j小鼠股骨中提取骨髓单核巨噬细胞(BMMs),在细胞培养液中分别添加2.5、10.0和40.0μg/mL OPS(A、B、C组),对照组未添加OPS。检测OPS对BMMs细胞活性、破骨细胞骨吸收能力及抗酒石酸酸性磷酸酶(TRAP)活性的影响,同时分析OPS对碳酸酐酶2(Car2)、组织蛋白酶K(CTSK)、基质金属蛋白酶9(MMP-9)、TRAP、液泡型H^(+)-ATP酶(V-ATPase)mRNA表达的影响。结果A、B、C组48、96 h时吸光度值比较,差异无统计学意义(P>0.05)。与对照组(1.00±0.15)比较,B组成熟破骨细胞数目降低至(0.61±0.06)(P<0.05),而C组成熟破骨细胞数目为(0.31±0.03)(P<0.05)。与对照组相比,B、C组5 d时破骨细胞TRAP活性显著降低(P<0.05)。A、B、C组7 d时破骨细胞TRAP活性显著低于对照组(P<0.05)。A、B、C组骨吸收面积仅为对照组的71%、40%和6%(P<0.05)。与对照组比较,B、C组Car2、CTSK、MMP-9、TRAP、V-ATPase mRNA表达水平显著降低(P<0.01)。结论OPS可显著抑制破骨细胞分化功能,是一种潜在的用于骨质疏松治疗的抗骨吸收药物。 展开更多
关键词 破骨细胞 麦冬多糖 分化 骨吸收 骨质疏松
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Studies of an event-building algorithm of the readout system for the twin TPCs in HFRS
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作者 Jing Tian Zhi-Peng Sun +4 位作者 Song-Bo Chang yi qian Hong-Yun Zhao Zheng-Guo Hu Xi-Meng Chen 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第4期82-95,共14页
The High-energy Fragment Separator(HFRS),which is currently under construction,is a leading international radioactive beam device.Multiple sets of position-sensitive twin time projection chamber(TPC)detectors are dist... The High-energy Fragment Separator(HFRS),which is currently under construction,is a leading international radioactive beam device.Multiple sets of position-sensitive twin time projection chamber(TPC)detectors are distributed on HFRS for particle identification and beam monitoring.The twin TPCs'readout electronics system operates in a trigger-less mode due to its high counting rate,leading to a challenge of handling large amounts of data.To address this problem,we introduced an event-building algorithm.This algorithm employs a hierarchical processing strategy to compress data during transmission and aggregation.In addition,it reconstructs twin TPCs'events online and stores only the reconstructed particle information,which significantly reduces the burden on data transmission and storage resources.Simulation studies demonstrated that the algorithm accurately matches twin TPCs'events and reduces more than 98%of the data volume at a counting rate of 500 kHz/channel. 展开更多
关键词 High counting rate Twin TPCs Trigger-less Readout electronics Event building Hierarchical data processing
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Predicting hepatocellular carcinoma: A new non-invasive model based on shear wave elastography
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作者 Dong Jiang yi qian +9 位作者 yi-Jun Gu Ru Wang Hua Yu Hui Dong Dong-Yu Chen Yan Chen Hao-Zheng Jiang Bi-Bo Tan Min Peng yi-Ran Li 《World Journal of Gastroenterology》 SCIE CAS 2024年第25期3166-3178,共13页
BACKGROUND Integrating conventional ultrasound features with 2D shear wave elastography(2D-SWE)can potentially enhance preoperative hepatocellular carcinoma(HCC)predictions.AIM To develop a 2D-SWE-based predictive mod... BACKGROUND Integrating conventional ultrasound features with 2D shear wave elastography(2D-SWE)can potentially enhance preoperative hepatocellular carcinoma(HCC)predictions.AIM To develop a 2D-SWE-based predictive model for preoperative identification of HCC.METHODS A retrospective analysis of 884 patients who underwent liver resection and pathology evaluation from February 2021 to August 2023 was conducted at the Oriental Hepatobiliary Surgery Hospital.The patients were divided into the modeling group(n=720)and the control group(n=164).The study included conventional ultrasound,2D-SWE,and preoperative laboratory tests.Multiple logistic regression was used to identify independent predictive factors for RESULTS In the modeling group analysis,maximal elasticity(Emax)of tumors and their peripheries,platelet count,cirrhosis,and blood flow were independent risk indicators for malignancies.These factors yielded an area under the curve of 0.77(95%confidence interval:0.73-0.81)with 84%sensitivity and 61%specificity.The model demonstrated good calibration in both the construction and validation cohorts,as shown by the calibration graph and Hosmer-Lemeshow test(P=0.683 and P=0.658,respectively).Additionally,the mean elasticity(Emean)of the tumor periphery was identified as a risk factor for microvascular invasion(MVI)in malignant liver tumors(P=0.003).Patients receiving antiviral treatment differed significantly in platelet count(P=0.002),Emax of tumors(P=0.033),Emean of tumors(P=0.042),Emax at tumor periphery(P<0.001),and Emean at tumor periphery(P=0.003).CONCLUSION 2D-SWE’s hardness value serves as a valuable marker for enhancing the preoperative diagnosis of malignant liver lesions,correlating significantly with MVI and antiviral treatment efficacy. 展开更多
关键词 Shear wave elastography Predicting model Microvascular invasion Antiviral treatment Hepatocellular carcinoma
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A novel mouse model of calcific aortic valve stenosis
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作者 Ningjing qian Yaping Wang +12 位作者 Wangxing Hu Naifang Cao yi qian Jinyong Chen Juan Fang Dilin Xu Haochang Hu Shuangshuang Yang Dao Zhou Hanyi Dai Dongdong Wei Jian'an Wang Xianbao Liu 《Animal Models and Experimental Medicine》 CAS CSCD 2024年第4期523-532,共10页
Background:Calcific aortic valve stenosis(CAVS)is one of the most challenging heart diseases in clinical with rapidly increasing prevalence.However,study of the mecha-nism and treatment of CAVS is hampered by the lack... Background:Calcific aortic valve stenosis(CAVS)is one of the most challenging heart diseases in clinical with rapidly increasing prevalence.However,study of the mecha-nism and treatment of CAVS is hampered by the lack of suitable,robust and efficient models that develop hemodynamically significant stenosis and typical calcium deposi-tion.Here,we aim to establish a mouse model to mimic the development and features of CAVS.Methods:The model was established via aortic valve wire injury(AVWI)combined with vitamin D subcutaneous injected in wild type C57/BL6 mice.Serial transthoracic echocardiography was applied to evaluate aortic jet peak velocity and mean gradi-ent.Histopathological specimens were collected and examined in respect of valve thickening,calcium deposition,collagen accumulation,osteogenic differentiation and inflammation.Results:Serial transthoracic echocardiography revealed that aortic jet peak velocity and mean gradient increased from 7 days post model establishment in a time depend-ent manner and tended to be stable at 28 days.Compared with the sham group,sim-ple AVWI or the vitamin D group,the hybrid model group showed typical pathological features of CAVS,including hemodynamic alterations,increased aortic valve thicken-ing,calcium deposition,collagen accumulation at 28 days.In addition,osteogenic dif-ferentiation,fibrosis and inflammation,which play critical roles in the development of CAVS,were observed in the hybrid model.Conclusions:We established a novel mouse model of CAVS that could be induced efficiently,robustly and economically,and without genetic intervention.It provides a fast track to explore the underlying mechanisms of CAVS and to identify more effec-tive pharmacological targets. 展开更多
关键词 animal model calcific aortic valve stenosis valve calcification
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建筑机器人标准化现状及需求分析
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作者 易谦 朱晓鹏 朱新龙 《建设科技》 2024年第2期81-85,共5页
近年来,建筑机器人快速发展,并在建筑施工、建材加工等多个环节进行推广应用,拥有巨大的市场潜力。机器人标准化建设是我国建筑机器人产业发展的关键因素之一,是保证我国建筑机器人产业在全球竞争中抢占先机,获得优势的重要手段。为进... 近年来,建筑机器人快速发展,并在建筑施工、建材加工等多个环节进行推广应用,拥有巨大的市场潜力。机器人标准化建设是我国建筑机器人产业发展的关键因素之一,是保证我国建筑机器人产业在全球竞争中抢占先机,获得优势的重要手段。为进一步加快推进我国建筑机器人领域标准化水平,实现产业的快速发展和竞争实力的提升,本文梳理了国内外建筑机器人相关标准化现状,深入分析建筑机器人技术和产业发展对标准化工作的需求,提出了我国建筑机器人标准化工作开展的建议。 展开更多
关键词 建筑机器人 标准化 标准体系 CR认证
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A Review of Interaction Between Neon Flying Squid(Ommastrephes bartramii) and Oceanographic Variability in the North Pacific Ocean 被引量:26
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作者 YU Wei CHEN Xinjun +1 位作者 yi qian TIAN Siquan 《Journal of Ocean University of China》 SCIE CAS 2015年第4期739-748,共10页
The neon flying squid (Ommastrephes bartramii) is a short-lived opporttmistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic... The neon flying squid (Ommastrephes bartramii) is a short-lived opporttmistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic eggs to nektonic adults is closely linked to oceanographic conditions. The fluctuations in O. bartramii abundance and distribution tend to increase and widen continu- ously due to the heavy influences of ocean-climate events on various spatio-temporal scales. In this study, we reviewed the interac- tion between O. bartramii and oceanography variability in the North Pacific with respect to large-scale climatic-oceanic phenomena including E1 Nifio, La Nifia, Kuroshio, Oyashio and Pacific Decadal Oscillation (PDO), as well as regional environmental variables such as sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS), chlorophyll-a (Chl-a) concentration, and plankton density. The population dynamics of O. bartramii is mediated mainly by meso- and large-scale climatic-oceanic events (e.g., Kuroshio and Oyashio Currents) rather than other local environmental conditions (e.g., SST and Chl-a concentration), because all of the oceanographic influences are imposed on the context of large-scale climate changes (e.g., PDO). An unstructured-grid finite- volume coastal ocean model coupled with an individual-based model is proposed to simulate relevant physical-biological oceano- graphic processes for identifying ocean-climate influence and predicting O. bartramii distribution and abundance in the North Pacific. Future research needs to be focused on improving the knowledge about early life history of O. bartramii and evaluating the relation- ship between marine physical environment and two separate passive drifting life stages of O. bartramii including free-floating eggs and planktonic paralarvae. 展开更多
关键词 Ommastrephes bartramii oceanographic influence early life history physical-biological model North Pacific Ocean
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Effects of environmental variations on the abundance of western winter-spring cohort of neon flying squid(Ommastrephes bartramii) in the Northwest Pacific Ocean 被引量:10
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作者 YU Wei CHEN Xinjun +2 位作者 CHEN Yong yi qian ZHANG Yang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第8期43-51,共9页
During 1995-2011, annual production of winter-spring cohort of Ommastrephes bartramii for Chinese squidjigging fishery has greatly fluctuated, which is closely related to the environmental conditions on the spawning a... During 1995-2011, annual production of winter-spring cohort of Ommastrephes bartramii for Chinese squidjigging fishery has greatly fluctuated, which is closely related to the environmental conditions on the spawning and fishing grounds. To better understand how squid recruitment and abundance were infuenced by ocean environmental conditions, biological and physical environmental variables including sea surface temperature (SST), SST anomaly (SSTA), chlorophyll a (Chl a) concentration and the Kuroshio Current were examined during years with the highest (1999), intermediate (2005), and lowest (2009) catches. Catch per unit effort (CPUE) of the squid-jigging vessels was used as an indicator of squid abundance. The results indicated that high SST and Chl a concentration on the spawning ground in 1999 resulted in favorable incubation and feeding conditions for squid recruitment. Whereas the suitable spawning zone (SSZ) in 2009 shifted southward and coincided with low SST and Chl a concentration, resulting in a reduction in the squid recruitment. The small difference of SSZ area in the three years suggested the SSZ provided limited influences on the variability in squid recruitment. Furthermore, high squid abundance in 1999 and 2005 was associated with warm SSTA on the fishing ground. While the cool SSTA on the fishing ground in 2009 contributed to adverse habitat for the squid, leading to extremely low abundance. It was inferred that strengthened intensity of the Kuroshio force generally yielded favorable environmental conditions for O. bartramii. Future research are suggested to focus on the fundamental research oil the early life stage of O. bartramii and mechanism of how the ocean-climate variability affects the squid abundance and spatial distribution by coupling physical model with squid biological process to explore transport path and abundance distribution. 展开更多
关键词 Ommastrephes bartramii environmental conditions RECRUITMENT ABUNDANCE Northwest Pacific Ocean
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Interannual and Seasonal Variability of Winter-Spring Cohort of Neon Flying Squid Abundance in the Northwest Pacific Ocean During 1995–2011 被引量:5
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作者 YU Wei CHEN Xinjun yi qian 《Journal of Ocean University of China》 SCIE CAS 2016年第3期480-488,共9页
The neon flying squid, Ommastrephes bartramii, is a species of economically important cephalopod in the Northwest Pacific Ocean. Its short lifespan increases the susceptibility of the distribution and abundance to the... The neon flying squid, Ommastrephes bartramii, is a species of economically important cephalopod in the Northwest Pacific Ocean. Its short lifespan increases the susceptibility of the distribution and abundance to the direct impact of the environmental conditions. Based on the generalized linear model(GLM) and generalized additive model(GAM), the commercial fishery data from the Chinese squid-jigging fleets during 1995 to 2011 were used to examine the interannual and seasonal variability in the abundance of O. bartramii, and to evaluate the influences of variables on the abundance(catch per unit effort, CPUE). The results from GLM suggested that year, month, latitude, sea surface temperature(SST), mixed layer depth(MLD), and the interaction term(SST×MLD) were significant factors. The optimal model based on GAM included all the six significant variables and could explain 42.43% of the variance in nominal CPUE. The importance of the six variables was ranked by decreasing magnitude: year, month, latitude, SST, MLD and SST×MLD. The squid was mainly distributed in the waters between 40?N and 44?N in the Northwest Pacific Ocean. The optimal ranges of SST and MLD were from 14 to 20℃ and from 10 to 30 m, respectively. The squid abundance greatly fluctuated from 1995 to 2011. The CPUE was low during 1995–2002 and high during 2003–2008. Furthermore, the squid abundance was typically high in August. The interannual and seasonal variabilities in the squid abundance were associated with the variations of marine environmental conditions and the life history characteristics of squid. 展开更多
关键词 Ommastrephes bartramii abundance variability Chinese squid-jigging fishery generalized linear model generalizedadditive model
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共享制造下基于数据迁移的滚齿加工碳耗预测方法 被引量:1
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作者 易茜 罗雨松 +3 位作者 胡春晖 卓俊康 李聪波 易树平 《中国机械工程》 EI CAS CSCD 北大核心 2023年第15期1820-1831,共12页
针对一般制造企业生产智能化程度不高、单个企业难以收集足够加工数据的问题,提出了一种共享制造下企业间数据迁移的滚齿加工碳耗预测方法。分析滚齿加工数据特征,在共享制造环境下提出用改进TrAdaBoost算法的数据迁移方法融合企业间的... 针对一般制造企业生产智能化程度不高、单个企业难以收集足够加工数据的问题,提出了一种共享制造下企业间数据迁移的滚齿加工碳耗预测方法。分析滚齿加工数据特征,在共享制造环境下提出用改进TrAdaBoost算法的数据迁移方法融合企业间的滚齿加工碳耗数据,形成跨企业联合数据集;利用蜻蜓算法优化支持向量回归,构造了跨企业滚齿加工碳耗预测模型。通过案例分析验证了所提方法的有效性,其预测性能在数据量少、数据关联性差的情况下具有优势,平均相对误差和决定系数分别比传统算法平均提高59.23%和16.56%。 展开更多
关键词 共享制造 滚齿加工 迁移学习 碳耗预测
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Fishing Ground Distribution of Neon Flying Squid (Ommastrephes bartramii) in Relation to Oceanographic Conditions in the Northwest Pacific Ocean 被引量:2
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作者 YU Wei CHEN Xinjun yi qian 《Journal of Ocean University of China》 SCIE CAS CSCD 2017年第6期1157-1166,共10页
Neon flying squid, Ommastrephes bartramii, is a squid species of the North Pacific Ocean, which plays an important economical role in the international fishery. Logbook data for Chinese squid-jigging fishery over 2004... Neon flying squid, Ommastrephes bartramii, is a squid species of the North Pacific Ocean, which plays an important economical role in the international fishery. Logbook data for Chinese squid-jigging fishery over 2004–2011 were used to evaluate the relationship between the fishing grounds of the squid and the convergent frontal areas, which were defined by the contour lines of specific sea surface temperature(SST) and chlorophyll-a(Chl-a) concentration. Our results indicate that the SST in the range of 15 to 19℃ and the Chl-a concentration in the range of 0.1 to 0.4 mg m^(-3) are the favorable conditions for the aggregation of the squid. Additionally, we deduced that the SST at 17.5℃ and the Chl-a concentration at 0.25 mg m^(-3) are the optimal environmental conditions for the aggregation of O. bartramii. In August, the annual CPUE is positively correlated with the proportion of the fishing grounds with favorable SST and Chl-a concentration, as well as the combination of the two variables, implying that the abundance of the squid annually is largely depending on the presence of the favorable environmental conditions for fishery in August. Minor spatial difference between mean latitudinal location of the 17.5℃ SST and 0.25 mg m^(-3) Chl-a fronts can increase the CPUEs of O. bartramii. Furthermore, the monthly latitudinal gravity centers of the CPUE closely followed the mean latitudinal position of the contour lines of the 17.5℃ SST and the 0.25 mg m^(-3) Chl-a concentration. Our findings suggest the convergent oceanographic features(fronts) play significant roles in regulating the distribution and abundance of the western stock of the winter-spring cohort of O. bartramii, which can help people to improve their ability to discover the O. bartramii fishing grounds with higher productivity. 展开更多
关键词 NEON FLYING SQUID sea surface temperature CHLOROPHYLL-A oceanic FRONTS fishing ground the Northwest Pacific OCEAN
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面向仿射目标识别的几何与仿生融合特征提取方法 被引量:1
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作者 余伶俐 易倩 +1 位作者 金鸣岳 周开军 《电子学报》 EI CAS CSCD 北大核心 2023年第6期1607-1618,共12页
针对由于拍摄视角不同,目标图像在水平或垂直方向发生拉长或压缩等仿射变换,进而无法正确识别的问题,本文设计了一种几何与仿生融合的特征提取方法 .首先,对传统的角点和直线检测进行改进,提出自适应Harris角点检测方法和去冗余的直线... 针对由于拍摄视角不同,目标图像在水平或垂直方向发生拉长或压缩等仿射变换,进而无法正确识别的问题,本文设计了一种几何与仿生融合的特征提取方法 .首先,对传统的角点和直线检测进行改进,提出自适应Harris角点检测方法和去冗余的直线检测方法,并将角点数、直线数和面积比向量作为几何特征.然后,采用生物启发变换算法提取图像的仿生启发特征,该算法包括两个阶段,每个阶段均需执行方向边缘检测和局部空间频率检测.接着,将输入图像的两种特征向量分别与标准数据库中的特征向量进行Pearson相关距离计算,获得匹配得分.最后,在考虑不同数据库两种特征区分性强弱的基础上自适应确定权值,最高融合分数所对应的标签即为该图像的识别结果.实验结果表明,该方法能较好地提取图像的仿射不变特征,并且该方法在Alphanumeric,MPEG-7,GTSRB和MNIST数据库的识别准确率分别为92.2%,96%,90%和87.3%. 展开更多
关键词 自适应Harris角点检测 去冗余的直线检测 几何特征 仿生启发特征 仿射目标识别
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汽车CFRP结构件涂层去除机理研究
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作者 易茜 赵洋洋 唐家慧 《表面技术》 EI CAS CSCD 北大核心 2023年第12期369-378,418,共11页
目的实现汽车碳纤维增强树脂基复合材料(CFRP)结构件表面有机涂层的高效无损去除。方法选择可回收密胺类塑料制备磨料,提出了用气射流携带并高速喷射加工的新方法。通过单因素控制试验和数值模拟相结合的方法,在0.3 MPa射流压力下用500... 目的实现汽车碳纤维增强树脂基复合材料(CFRP)结构件表面有机涂层的高效无损去除。方法选择可回收密胺类塑料制备磨料,提出了用气射流携带并高速喷射加工的新方法。通过单因素控制试验和数值模拟相结合的方法,在0.3 MPa射流压力下用500μm的磨料对涂装聚氨酯涂层的CFRP试样进行冲蚀,借助SEM和超景深三维显微镜观察冲蚀形貌。为了阐明涂层的去除机理,建立了基于能量守恒定律的微切削和重复变形模型,分析了塑性磨料的颗粒速度和撞击工件的接触应力,定量分析了磨料在0.3 MPa射流压力下的涂层去除量。研究了磨料形状、旋转和回弹对冲蚀机理的影响。结果当冲蚀角为30°时,涂层的材料去除量最大,去除率为5.8×10^(4)g/s,表现为延性冲蚀行为。此时的冲蚀机理为微耕犁和微切削,随着冲蚀角的增大,材料去除量降低。当冲蚀角为90°时,去除率为1.2×10^(4)g/s,冲蚀机理为重复塑性变形去除。尖角磨料以集中应力冲击涂层,磨损后的磨料(可循环15次)以分布应力冲击涂层。与正向旋转相比,磨料自身的反向旋转对涂层的去除量更大,大粒径磨料的回弹导致了不完整的切削路径,而小粒径磨料的回弹使涂层产生了撕裂。结论为了实现基材不损伤,推荐使用大角度冲蚀,这样可以在保留底漆的同时实现基材不损伤。 展开更多
关键词 回收利用 密胺树脂 塑料磨料 CFRP 有机涂层
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磨料颗粒速度对汽车CFRP表面涂层去除率的影响
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作者 易茜 张莹 张红新 《塑料工业》 CAS CSCD 北大核心 2023年第11期123-128,共6页
针对汽车碳纤维增强树脂基复合材料(CFRP)表面损伤涂层的无损基材去除,收集牌号为2124的酚醛类树脂塑料制备磨料,提出塑性磨料气-固两相射流加工方法。通过单因素控制试验和数值模拟相结合的方法,在不同气体压力下用30~40目的塑性磨料... 针对汽车碳纤维增强树脂基复合材料(CFRP)表面损伤涂层的无损基材去除,收集牌号为2124的酚醛类树脂塑料制备磨料,提出塑性磨料气-固两相射流加工方法。通过单因素控制试验和数值模拟相结合的方法,在不同气体压力下用30~40目的塑性磨料对涂装有机涂层的CFRP试样板进行冲蚀试验,研究了颗粒速度随气体压力的变化规律。借助扫描电子显微镜(SEM)和超景深三维显微镜观察涂层冲蚀表面的三维形貌,阐明了涂层去除机理,研究了冲蚀角度和磨料形状对冲蚀机理的影响,定量分析了塑性磨料在不同气体压力下的涂层去除量。结果表明,随着气体压力的增加,涂层去除率增加。涂层在较低的颗粒速度下主要以微耕犁导致塑性变形的方式去除,在较高的颗粒速度下主要以微切削的方式去除。本研究可为塑性磨料气射流去除汽车CFRP表面涂层技术提供理论参考。 展开更多
关键词 气射流加工 酚醛树脂 塑料磨料 碳纤维增强树脂基复合材料 有机涂层
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基层医院运用Seminar联合CBL模式对新入职护士培训的应用效果研究
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作者 雷志英 邹琴 +2 位作者 李丽 易倩 蔡倩 《中国社区医师》 2023年第3期166-168,共3页
目的:探讨基层医院应用讨论会教学法(Seminar)联合以案例为基础(CBL)模式在新入职护士培训中的效果及对其评判性思维能力培养的影响。方法:选取2019年7月-2020年7月新进入什邡市人民医院工作的40名临床护士为研究对象,随机分为对照组与... 目的:探讨基层医院应用讨论会教学法(Seminar)联合以案例为基础(CBL)模式在新入职护士培训中的效果及对其评判性思维能力培养的影响。方法:选取2019年7月-2020年7月新进入什邡市人民医院工作的40名临床护士为研究对象,随机分为对照组与试验组,各20例。对照组采用以问题为基础教学模式培训,试验组采用Seminar联合CBL模式完成培训计划,培训时间均为1年。对比两组培训前后理论知识及操作技能评分、评判性思维能力及满意度。结果:培训前,两组理论知识及操作技能考核评分比较,差异无统计学意义(P>0.05);培训1年后,试验组理论知识及操作技能考核评分均高于对照组,差异有统计学意义(P<0.05)。培训前,两组寻求真相、开放思想、分析能力、系统化能力、自信心、求知欲、认知成熟度评分比较,差异无统计学意义(P>0.05);培训1年后,试验组各项评分均优于对照组,差异有统计学意义(P<0.05)。患者对试验组总满意度高于对照组,差异有统计学意义(P<0.05)。结论:Seminar联合CBL模式有助于提高新入职护士理论、操作技术水平及评判性思维能力,调动其主动学习能力,激发其创新思维和意识,提高其临床实践能力等。 展开更多
关键词 SEMINAR模式 CBL模式 基层医院 新入职护士培训
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