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Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency 被引量:1
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作者 李静 逄少军 +2 位作者 刘峰 单体锋 高素芹 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2013年第4期774-781,共8页
During sexual reproduction of seaweeds, spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes. The chemotactic ability of the sperm ensures fertilization succes... During sexual reproduction of seaweeds, spermatozoid (sperm) discharge is triggered by chemical messengers (pheromones) released by the female gametes. The chemotactic ability of the sperm ensures fertilization success. Using unialgal male and female gametophyte material under designated standard gametogenesis testing (SGT) conditions, the potential life-span of the sperm of two seaweeds, Saccharina japonica and Undaria pinnatifida, was assessed by their ability to fertilize eggs. Results show that within 20-30 min after being discharged, sperm of both species could complete fertilization without an apparent decline in fertilization rate. Although fertilization rate 60-120 min after sperm discharge dropped significantly in both species, some sperm were viable enough to fertilize the eggs. In S.japonica, at 12°C, some sperm were able to fertilize eggs up to 12 h after discharge. In both species, egg discharge rates (EDR) in the male and female mixed positive controls were significantly higher than those of all the sperm-testing groups. Doubling the seeded male gametophytes of S. japonica in the SGT tests significantly increased the EDR, further confirming the effect of the presence of the male on the female in terms of facilitating egg discharge from oogonia. 展开更多
关键词 GAMETOGENESIS life-span of sperm Saccharinajaponica seaweeds Undaria pinnatifida
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Life-span of classical solutions for one-dimensional hydromagnetic flow
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作者 刘法贵 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第4期511-520,共10页
The paper concerns Cauchy,problem for one-dimensional hydromagnetic dynamics with dissipative terms. When the dissipation coefficient is equal to zero it is shown that the smooth solutions develop shocks in the finite... The paper concerns Cauchy,problem for one-dimensional hydromagnetic dynamics with dissipative terms. When the dissipation coefficient is equal to zero it is shown that the smooth solutions develop shocks in the finite time if the initial amounts of entropy and magnetic field are smaller than those of sound waves; when it is larger than zero, and the initial amounts of entropyI this dissipation coefficient and the magnetic field in each period are smaller than those of sound Waves, then the smooth solutions blow up in the finite time. Moreover, the life-span of the smooth solution is given. 展开更多
关键词 hydromagnetic flow Cauchy' problem classical solution life-span
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LIFE-SPAN OF CLASSICAL SOLUTIONS TO HYPERBOLIC GEOMETRY FLOW EQUATION IN SEVERAL SPACE DIMENSIONS
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作者 孔德兴 刘琦 宋长明 《Acta Mathematica Scientia》 SCIE CSCD 2017年第3期679-694,共16页
In this article, we investigate the lower bound of life-span of classical solutions of the hyperbolic geometry flow equations in several space dimensions with "small" initial data. We first present some estimates on... In this article, we investigate the lower bound of life-span of classical solutions of the hyperbolic geometry flow equations in several space dimensions with "small" initial data. We first present some estimates on solutions of linear wave equations in several space variables. Then, we derive a lower bound of the life-span of the classical solutions to the equations with "small" initial data. 展开更多
关键词 Hyperbolic geometry flow classical solution life-span
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Convenient design of anti-wetting nano-Al/WO_(3)metastable intermolecular composites(MICs)with an enhanced exothermic life-span
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作者 Xiaogang Guo Taotao Liang +5 位作者 Junfeng Guo Huisheng Huang Shuying Kong Jianwei Shi Binfang Yuan Qi Sun 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第2期84-92,共9页
For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)M... For solving the dilemma of the short exothermic life-span of WO_(3)based metastable interstitial composites(MICs)with extensive application prospect,this paper has firstly designed the promising antiwetting Al/WO_(3)MICs via electrophoresis assembly of nano-Al and WO_(3)particles fabricated by hydrothermal synthesis method,followed by the subsequent fluorination treatment.A combination of X ray diffraction(XRD),field emission scanning electron microscope(FESEM),energy dispersive X-ray spectroscopy(EDX),and Fourier transform infrared spectroscopy(FT-IR)techniques were utilized in order to characterize the crystal structure,microstructure,and elemental composition distribution of target films after different natural exposure tests.The product with uniform distribution and high purity possesses a high contact angle of~170°and a minute sliding angle of~1°,and displays the outstanding anti-wetting property using droplets with different surface tensions.It also shows great moisture stability in high relative-humidity circumstances after one year of the natural exposure experiment.Notably,the heat output of a fresh sample can reach up to 2.3 kJ/g and retain 96%after the whole exposure test,showing outstanding thermo-stability for at least one year.This work further proposed the mechanism of antiwetting Al/WO_(3)MICs considering the variation tendency of their DSC curve,providing a valuable theoretical reference for designing other self-protected MICs with a long exothermic life-span applied in wide fields of national defense,military industry,etc. 展开更多
关键词 Electrophoresis assembly Al/WO_(3)MICs Fluorination treatment Anti-wetting property Exothermic life-span
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Investigating the Life-Span of Cork Products through a Longitudinal ApproachmOverview of Two Years Results
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作者 Ana Carina Pereira Helena Pereira 《Journal of Environmental Science and Engineering(B)》 2013年第7期436-441,共6页
Products with long life-spans are generally acknowledged to have a significant contribution towards sustainability. This paper provides an overview and discussion of the two years results of a longitudinal study perfo... Products with long life-spans are generally acknowledged to have a significant contribution towards sustainability. This paper provides an overview and discussion of the two years results of a longitudinal study performed with users and several cork products. The research aimed to tackle the process of life-span, and the results include: (1) the identification and interrelation of the aspects influencing the life-span of the products; (2) the evolution of life-span over time; and (3) new knowledge and guidelines arising about the material. Overall, most cork products are still being used, have a very good life-span, and most issues arising are material related. 展开更多
关键词 Product life-span USERS longitudinal study cork products and materials.
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Increased life-span of Drosophila melanogaster by Flavonoids from Scutellariabaicalensis Georgi induced by hydrogen peroxide
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作者 Dan-Dan Duan Li Gao +3 位作者 Xue-Ling Zhang Jian-Qin Zhang Xue-Mei Qin Guan-Hua Du 《TMR Integrative Medicine》 2017年第3期79-85,共7页
Objective: To explore the effects and mechanisms of flavonoids from Scutellaria baicalensis Georgi in hydrogenperoxide (H2O2) induced Drosophila melanogaster model. Method: H2O2 induced Drosophila melanogaster agi... Objective: To explore the effects and mechanisms of flavonoids from Scutellaria baicalensis Georgi in hydrogenperoxide (H2O2) induced Drosophila melanogaster model. Method: H2O2 induced Drosophila melanogaster agingmodel was used to study the effects of flavonoids from Scutellaria baicalensis Georgi. Secondly, the effects ofbaicalein and wogonin on mRNA expressions were examined. Results: Our results found that baicalein andwogonin could extend the life-spans of H2O2 induced Drosophila melanogaster aging model via increased mRNAexpressions of superoxide dismutase catalase and rosy. Conclusion: Baicalein and wogonin could extend life-spansof H2O2 induced Drosophila melanogaster aging model through increasing mRNA expressions of superoxidedismutase, catalase and rosy. 展开更多
关键词 BAICALEIN WOGONIN life-span Hydrogen peroxide Drosophila melanogaste
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Life-Spans and Blow-Up Rates for aρ-Laplacian Parabolic Equation with General Source
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作者 LONG Qunfei 《Journal of Partial Differential Equations》 CSCD 2024年第2期187-197,共11页
This article investigates the blow-up results for the initial boundary value problem to the quasi-linear parabolic equation with p-Laplacian■where p≥2 and the function f(u)satisfies■for some positive constantsα,β... This article investigates the blow-up results for the initial boundary value problem to the quasi-linear parabolic equation with p-Laplacian■where p≥2 and the function f(u)satisfies■for some positive constantsα,β,γwith 0<■,which has been studied under the initial condition Jp(u0)<0.This paper generalizes the above results on the following aspects:a new blow-up condition is given,which holds for all p>2;a new blow-up condition is given,which holds for p=2;some new lifespans and upper blow-up rates are given under certain conditions. 展开更多
关键词 P-LAPLACIAN parabolic equation blow-ups life-spans blow-up rates
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不同居住方式与老年人寿命的关系研究
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作者 温勇 俞周强 宗占红 《中国社会医学杂志》 2025年第1期35-38,共4页
目的探讨我国60岁及以上老年人的寿命情况,分析不同居住方式与老年人寿命间的关系。方法基于CLHLS2014-2018年跟踪数据,利用多元回归与倾向性得分匹配模型,探讨不同居住方式对老年人寿命的影响。结果共纳入2100个样本,其中与家人合住的... 目的探讨我国60岁及以上老年人的寿命情况,分析不同居住方式与老年人寿命间的关系。方法基于CLHLS2014-2018年跟踪数据,利用多元回归与倾向性得分匹配模型,探讨不同居住方式对老年人寿命的影响。结果共纳入2100个样本,其中与家人合住的老年人为1749人(83.29%),独居的老年人为351人(16.71%)。多元回归模型结果显示,相较于独居老年人,与家庭成员合住对老年人寿命有显著的积极影响(β=3.779,95%CI=2.850~4.708,P<0.001),且个人特征、家庭经济特征、健康因素均会影响老年人的寿命;居住方式对老年人寿命的影响因城乡、文化及婚姻状况的不同而存在差异。结论应发挥家庭养老功能;鼓励老年人加强自身健康管理,增强老年人的健康意识;对于弱势老年群体应予以重点关注;培养良好家风,传承“孝”文化,多方协同,共同促进健康老龄化。 展开更多
关键词 居住方式 老年人 寿命 倾向性得分匹配法 异质性
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设计前期的建筑全生命期碳排放与降碳量预测方法 被引量:1
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作者 罗智星 云朵 仓玉洁 《西安建筑科技大学学报(自然科学版)》 北大核心 2025年第1期1-9,F0003,共10页
设计前期作为建筑概念设计和方案设计的前置环节,其相关决策直接影响建筑全生命期碳排放水平.然而,设计信息和清单数据的匮乏,致使该阶段碳排放量化和设计优化面临着诸多困难.对此,本研究依据已有成果、案例统计和标准限额,构建了建筑... 设计前期作为建筑概念设计和方案设计的前置环节,其相关决策直接影响建筑全生命期碳排放水平.然而,设计信息和清单数据的匮乏,致使该阶段碳排放量化和设计优化面临着诸多困难.对此,本研究依据已有成果、案例统计和标准限额,构建了建筑设计前期全生命期碳排放预测模型,形成基于建筑高度和结构形式的隐含碳排放估算公式,以及不同能效等级及能源消耗模式下的运行碳排放量化指标.同时,整合涵盖“六化”设计策略等在内的各项降碳措施量化评估体系,从而为后续设计指明改进优化方向.本研究构建的建筑设计前期碳排放和降碳量预测方法能够有效指导建筑师在项目的设计前期阶段快速评估其碳排放总水平,明确降碳重点要素,最终实现建筑全生命期碳优化的源头把控. 展开更多
关键词 建筑碳排放 全生命期 设计前期 预测模型 建筑降碳
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酸雨对纤维增强轻骨料混凝土疲劳行为的影响
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作者 李静 郭红军 +1 位作者 王婧 年立辉 《合成纤维》 2025年第9期62-67,共6页
为研究酸雨对纤维增强轻骨料混凝土疲劳行为的影响,采用室内模拟酸雨腐蚀过程的方法,研究了棱柱体纤维增强轻骨料混凝土试件疲劳裂缝的扩展过程,分析了混凝土试件跨中挠度与荷载作用次数的关系,探讨了纤维质量分数与疲劳寿命的关系。研... 为研究酸雨对纤维增强轻骨料混凝土疲劳行为的影响,采用室内模拟酸雨腐蚀过程的方法,研究了棱柱体纤维增强轻骨料混凝土试件疲劳裂缝的扩展过程,分析了混凝土试件跨中挠度与荷载作用次数的关系,探讨了纤维质量分数与疲劳寿命的关系。研究结果表明:在作用次数小于200万次时,酸雨腐蚀30、60 d的混凝土表面最大裂缝宽度与未腐蚀时差异较小,在作用次数大于40万次时,酸雨腐蚀的影响显著放大,腐蚀60 d的最大裂缝宽度较腐蚀30 d、未腐蚀时的分别增大80.0%、418.85%;未腐蚀、腐蚀30、60 d条件下,轻骨料混凝土最大挠度均随作用次数的增加呈上升趋势,随着腐蚀时间的延长,作用次数为0次的初始挠度逐渐增大,未腐蚀时最大挠度为21.90 mm,腐蚀30 d时为22.99 mm,腐蚀60 d时为25.09 mm;所有应力水平下,随着钢纤维质量分数的增加,混凝土的疲劳寿命呈先增加后减小的趋势,应力水平为0.6、钢纤维质量分数为1.5%时疲劳寿命最高,较质量分数为1.0%时增大56.58%,而当钢纤维质量分数为2.0%时则略有下降。 展开更多
关键词 酸雨腐蚀 纤维增强轻骨料混凝土 裂缝扩展 跨中挠度 疲劳寿命
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LIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATALIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATA 被引量:14
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作者 KONG DEXING (Department of Applied Mathematics, Shanghai Jiaotong University, Shanghai 200030, China.) 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2000年第4期413-440,共28页
The author considers the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with "slow" decay initial data. By con... The author considers the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with "slow" decay initial data. By constructing an example, first it is illustrated that the classical solution to this kind of Cauchy problem may blow up in a finite time, even if the system is weakly linearly degenerate. Then some lower bounds of the life-span of classical solutions are given in the case that the system is weakly linearly degenerate. These estimates imply that, when the system is weakly linearly degenerate, the classical solution exists almost globally in time. Finally, it is proved that Theorems 1.1-1.3 in [2] are still valid for this kind of initial data. 展开更多
关键词 Quasilinear strictly hyperbolic system Weak linear degeneracy Cauchy problem Classical solution life-span
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风电叶片用涂料的现状及研究进展
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作者 彭亚 李诚亮 +4 位作者 黄明富 陈煌 付国良 陈文津 甄波 《涂层与防护》 2025年第10期33-37,48,共6页
风力发电作为一种清洁能源在全球范围内得到了广泛应用。风电机组叶片是将风能转化为机械能的关键部件,受到恶劣环境的侵蚀和机械疲劳的作用,涂层材料可以抵抗恶劣环境下的风沙侵蚀、盐雾、紫外线照射和温度变化等,其耐久性和保护能力... 风力发电作为一种清洁能源在全球范围内得到了广泛应用。风电机组叶片是将风能转化为机械能的关键部件,受到恶劣环境的侵蚀和机械疲劳的作用,涂层材料可以抵抗恶劣环境下的风沙侵蚀、盐雾、紫外线照射和温度变化等,其耐久性和保护能力是决定叶片使用寿命的关键因素。本研究围绕风电叶片用涂料的性能要求、分类及其特性、寿命评估方法、发展方向等展开综述,旨在为风电叶片涂层材料的研发提供参考。 展开更多
关键词 风电叶片 涂料 寿命 发展方向
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Life-Span of Classical Solutions to a Semilinear Wave Equation with Time-Deppendent Damping
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作者 GUO Fei LIANG Jinling XIAO Changwang 《Journal of Partial Differential Equations》 CSCD 2023年第3期235-261,共27页
This paper is concerned with the Cauchy problem for a semilinear wave equation with a time-dependent damping.In case that the space dimension n=1 and the nonlinear power is bigger than 2,the life-span T(ε)and global ... This paper is concerned with the Cauchy problem for a semilinear wave equation with a time-dependent damping.In case that the space dimension n=1 and the nonlinear power is bigger than 2,the life-span T(ε)and global existence of the classical solution to the problem has been investigated in a unified way.More precisely,with respect to different values of an index K,which depends on the time-dependent damping and the nonlinear term,the life-span T(ε)can be estimated below byε-p/1-k,e^(ε)-p or+∞,where e is the scale of the compact support of the initial data. 展开更多
关键词 Semilinear wave equation time-dependent damping life-span global iteration method.
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LIFE-SPAN OF CLASSICAL SOLUTIONS OF INITIAL-BOUNDARY VALUE PROBLEM FOR FIRST ORDER QUASILINEAR HYPERBOLIC SYSTEMS
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作者 Lu Hong 《Journal of Partial Differential Equations》 2007年第2期131-154,共24页
In this paper, we consider the mixed initial-boundary value problem for quasilinear hyperbolic systems with nonlinear boundary conditions in a half-unbounded domain {(t, x)|t ≥ 0, x ≥ 0}. Under the assumption tha... In this paper, we consider the mixed initial-boundary value problem for quasilinear hyperbolic systems with nonlinear boundary conditions in a half-unbounded domain {(t, x)|t ≥ 0, x ≥ 0}. Under the assumption that the positive eigenvalues are not all weakly linearly degenerate,we obtain the blow-up phenomenon of the first order derivatives of C^1 solution with small and decaying initial data.We also give precise estimate of the life-span of C^1 solution. 展开更多
关键词 Quasilinear hyperbolic system mixed initial-boundary value problem life-span weak linear degeneracy.
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某型液压挖掘机履带链轨开裂问题的分析及优化
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作者 陈义才 曾超 +1 位作者 张玲利 谭伟芬 《内燃机与配件》 2025年第5期33-35,共3页
液压挖掘机履带链轨开裂是挖掘机底盘件常见故障之一,但是随着挖掘机作业工况越来越复杂(如矿山工况、石方、岩石等)及整机的机重及驱动力不断提升,对于链轨的损伤也越来越大,链轨的寿命也呈现直线下滑的状态,通过分析链轨造型及过渡设... 液压挖掘机履带链轨开裂是挖掘机底盘件常见故障之一,但是随着挖掘机作业工况越来越复杂(如矿山工况、石方、岩石等)及整机的机重及驱动力不断提升,对于链轨的损伤也越来越大,链轨的寿命也呈现直线下滑的状态,通过分析链轨造型及过渡设计上存在不足及缺陷,因此通过采用大圆弧及圆弧平滑过渡,降低链轨应力集中,提升链轨寿命。 展开更多
关键词 液压挖掘机 链轨 应力集中 开裂 寿命
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LIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATALIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATA
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《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2000年第4期413-440,共页
The author considers the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with "slow" decay initial data. By con... The author considers the life-span of classical solutions to Cauchy problem for general first order quasilinear strictly hyperbolic systems in two independent variables with "slow" decay initial data. By constructing an example, first it is illustrated that the classical solution to this kind of Cauchy problem may blow up in a finite time, even if the system is weakly linearly degenerate. Then some lower bounds of the life-span of classical solutions are given in the case that the system is weakly linearly degenerate. These estimates imply that, when the system is weakly linearly degenerate, the classical solution exists almost globally in time. Finally, it is proved that Theorems 1.1-1.3 in [2] are still valid for this kind of initial data. 展开更多
关键词 QUASILINEAR STRICTLY hyperbolic system Weak linear DEGENERACY Cauchy problem Classical solution life-span
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The adaptive characteristics of memory: A perspective from the life-span development of associative memory illusion
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作者 WANG Mi GENG HaiYan 《Chinese Science Bulletin》 SCIE EI CAS 2010年第16期1581-1589,共9页
The reconstructive process in memory may cause distortions or errors.Associative memory illusion is one of the most common types of false memories.It acts as a reflection of the adaptive characteristic of memory by su... The reconstructive process in memory may cause distortions or errors.Associative memory illusion is one of the most common types of false memories.It acts as a reflection of the adaptive characteristic of memory by suggesting its ability to adaptively use semantic gist information even with limited cognitive resources.Meanwhile, the adaptive characteristic of memory is also manifested by inhibiting false memories with certain strategies (e.g., encoding item-specific information) to ensure memory accuracy according to the demands of specific situations.This article looks into the life-span developmental features of the adaptive characteristic of memory by summarizing the age features of two types of abilities: employing gist representation and inhibiting associative memory illusion.In the future, further efforts in this field are proposed to explore the specific adaptive nature of memory from the perspective of evolution. 展开更多
关键词 联想记忆 错觉 适应特点 寿命 语义信息 自适应 重建过程 资源有限
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具非局部源的伪抛物型方程的Cauchy问题
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作者 杨春晓 樊婕妤 吉飞宇 《纯粹数学与应用数学》 2024年第4期648-663,共16页
本文研究了具有非局部源的伪抛物型方程u_(t)=∆u+k∆ut+∥w(x)u∥_(Lq)^(p-1)(Rn)ur+1(x,t)的Cauchy问题,其中权函数w(x)∼|x|-s(当|x|足够大).在w(x)∈Lq和w(x)/∈L^(q)两种情况下考虑这一问题的第二临界指标,即鉴别整体解与非整体解的... 本文研究了具有非局部源的伪抛物型方程u_(t)=∆u+k∆ut+∥w(x)u∥_(Lq)^(p-1)(Rn)ur+1(x,t)的Cauchy问题,其中权函数w(x)∼|x|-s(当|x|足够大).在w(x)∈Lq和w(x)/∈L^(q)两种情况下考虑这一问题的第二临界指标,即鉴别整体解与非整体解的初值的临界衰减阶.结果表明,三阶粘性项k∆ut和权函数w(x)的存在有益于解的整体存在或可延迟解的爆破时间. 展开更多
关键词 伪抛物型方程 非局部源 临界衰减阶 第二临界指标 生命跨度
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基于CLD模型的风电叶片延寿区间估计 被引量:1
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作者 曾世龙 马强 +2 位作者 白学宗 马辉东 安宗文 《太阳能学报》 EI CAS CSCD 北大核心 2024年第3期41-45,共5页
为确定在役风电叶片到达设计寿命后能否延寿继续使用,提出一种基于恒幅寿命图模型的延寿区间计算方法。首先,分析叶片在运行工况下的载荷状况,采用应力-寿命(S-N)曲线分析弯矩作用下的疲劳寿命,进而定义弯矩-寿命(M-N)曲线。根据M-N曲线... 为确定在役风电叶片到达设计寿命后能否延寿继续使用,提出一种基于恒幅寿命图模型的延寿区间计算方法。首先,分析叶片在运行工况下的载荷状况,采用应力-寿命(S-N)曲线分析弯矩作用下的疲劳寿命,进而定义弯矩-寿命(M-N)曲线。根据M-N曲线和CLD模型的映射关系建立延寿估计的CLD模型。基于延寿估计的CLD模型计算待退役叶片已累积的疲劳损伤,并从疲劳损伤估计可持续延寿的时间。最后,以某型叶片为例应用该方法进行延寿区间估计。 展开更多
关键词 风电叶片 疲劳损伤 延寿 CLD 区间
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基于自适应非线性维纳过程的剩余寿命预测 被引量:1
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作者 丁传彪 赵鑫 +2 位作者 朱海振 赵惠 张廷亮 《火力与指挥控制》 CSCD 北大核心 2024年第8期105-113,119,共10页
作为预测与健康管理的核心技术,准确的剩余寿命预测对于提高系统的安全性与可靠性具有重要意义。在实际工程应用中,同类产品的不同个体之间通常存在差异,其退化路径并不相同。这就导致通过同类产品历史数据所学习到的模型或参数并不能... 作为预测与健康管理的核心技术,准确的剩余寿命预测对于提高系统的安全性与可靠性具有重要意义。在实际工程应用中,同类产品的不同个体之间通常存在差异,其退化路径并不相同。这就导致通过同类产品历史数据所学习到的模型或参数并不能准确拟合新设备的退化过程。为解决这一问题,基于非线性维纳退化模型提出了一种自适应寿命预测方法。建立同时考虑个体不确定性与测量不确定性的自适应非线性维纳退化模型,并通过卡尔曼滤波、期望最大算法与Rauch-Tung-Striebel平滑减弱维纳过程的马尔科夫性,实现参数的在线更新。通过时间-空间变换推导出对应剩余寿命分布概率密度函数的解析表达式。仿真退化数据与C-MAPSS退化数据集被用于实验验证,实验结果表示,所提出的自适应非线性维纳退化模型能够在线更新模型参数,提高预测精度。 展开更多
关键词 自适应 维纳过程 非线性 剩余寿命 卡尔曼滤波 期望最大算法
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