Spermatozoid life-span of two brown seaweeds, Saccharina japonica and Undaria pinnatifida, as measured by fertilization efficiency

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.

Life-span of classical solutions for one-dimensional hydromagnetic flow

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.

LIFE-SPAN OF CLASSICAL SOLUTIONS TO HYPERBOLIC GEOMETRY FLOW EQUATION IN SEVERAL SPACE DIMENSIONS

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.

Convenient design of anti-wetting nano-Al/WO_(3)metastable intermolecular composites(MICs)with an enhanced exothermic life-span

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.

Investigating the Life-Span of Cork Products through a Longitudinal ApproachmOverview of Two Years Results

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.

Increased life-span of Drosophila melanogaster by Flavonoids from Scutellariabaicalensis Georgi induced by hydrogen peroxide

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.

Life-Spans and Blow-Up Rates for aρ-Laplacian Parabolic Equation with General Source

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.

LIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATALIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATA

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.

Life-Span of Classical Solutions to a Semilinear Wave Equation with Time-Deppendent Damping

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.

LIFE-SPAN OF CLASSICAL SOLUTIONS OF INITIAL-BOUNDARY VALUE PROBLEM FOR FIRST ORDER QUASILINEAR HYPERBOLIC SYSTEMS

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.

LIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATALIFE-SPAN OF CLASSICAL SOLUTIONSTO QUASILINEAR HYPERBOLIC SYSTEMSWITH SLOW DECAY INITIAL DATA

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.

The adaptive characteristics of memory: A perspective from the life-span development of associative memory illusion

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.

基于CLD模型的风电叶片延寿区间估计

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。

基于自适应非线性维纳过程的剩余寿命预测

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。

不同雌雄成虫密度及性比对红彩瑞猎蝽繁殖力和寿命的影响

在室内条件[温度(28±1)℃,相对湿度70%±7%,光照周期16 h(L)∶8 h(D)]下,测定不同雌雄成虫密度(雌∶雄=1∶1、2∶2、3∶3和4∶4)和不同性比(头/盒)(雌∶雄=1∶0、1∶2、1∶3、1∶4、2∶1、3∶1、3∶2和4∶1)对捕食性天敌红彩瑞猎蝽(Rhynocoris fuscipes Fabricius)产卵前期、产卵期、产卵量、孵化率、寿命和子代雌雄性比的影响。结果表明,红彩瑞猎蝽成虫繁殖存在孤雌生殖现象,可产下有效卵。不同雌雄成虫密度和雌雄性比对红彩瑞猎蝽产卵前期和卵孵化率的影响不明显,对产卵期、产卵量、子代雌雄性比和雌雄成虫寿命有显著影响,总产卵量随着配比中雌成虫密度的增加而增加,但是每雌产卵量和孵出若虫数量逐渐减少;雌成虫、雄成虫平均寿命均随着雌雄成虫密度的增加而减小。其中雌雄性比为2∶1的处理平均产卵期最长(39.5 d),平均每雌产卵量最高(136.40粒),每雌孵出若虫数最多(130.30头)。在交配过程中,红彩瑞猎蝽成虫密度过大会出现种内互残现象,基于研究结果中各项繁殖力和寿命参数结果,雌雄性比2∶1是人工饲养红彩瑞猎蝽成虫繁殖的较佳密度和性比。

氧化锌避雷器故障状态指示器试验方法研究

氧化锌阀片在冲击电流的作用下,短时间内有大量的电流流过,阀片吸收冲击能量后的升温过程可近似看作绝热温升,因而冲击老化的机理主要是热老化。冲击老化会给阀片造成较大的损坏,多次冲击对阀片老化造成累积效应。资料中显示阀片在4/10μs波形、100 kA冲击电流作用后,其在直流1 mA电压下的功率损耗可增加20%。试验发现,用于线路避雷器标称放电电流为10 kA的ZnO阀片在经过18次20 kA、8/20s电流的冲击后,阀片功率损耗为初始功率损耗的2倍,根据功率损耗密度分析法,可认为此时阀片已接近其寿命终点。对于带间隙线路避雷器,在正常运行时不承受工频电压,不存在泄漏电流,可以记录避雷器遭受冲击大电流的次数,用于反映避雷器的寿命检测,达到设定值会有告警指示。

地中海贫血合并自身或同种异体抗体的研究进展

地中海贫血是一种严重的进行性贫血,需要规范化输血和祛铁才能达到预期寿命。输血最重要的并发症之一是同种异体免疫和自身免疫,增加了配血的难度,也降低了输血的效果。本文综述了地中海贫血合并自身免疫性溶血性贫血(AIHA)的发生率、诊断及临床特点、输血及药物治疗现状,并对红细胞寿命(RBCS)检测的方法及在地中海贫血合并AIHA中的应用可行性进行了分析。

超大跨桥梁用长寿命缆索材料和技术的需求、发展与创新

自20世纪90年代以来,中国在跨江跨海大桥、跨峡谷桥梁建设方面持续取得重大突破,桥梁跨径不断提升,斜拉桥跨径突破1200 m,悬索桥跨径突破2300 m,目前正从“桥梁大国”向“桥梁强国”转型发展,其中缆索材料技术进步发挥了重要作用。本文分析了桥梁技术发展尤其是跨径提升和长寿命对桥梁缆索材料的要求,明确了缆索材料与技术的发展需求。综述了国内外桥梁缆索用盘条、钢丝及锚固体系,缆索系统的损伤失效机理、性能评估与保障、标准体系、制造与架设技术等最近进展。从高性能钢丝和锚固体系研发、严酷环境下缆索损伤与失效机理、性能评估与长效保障技术、缆索系统制造和架设技术等方面对桥梁缆索材料和技术提出了创新方向和技术路线,进行创新性研究,为超大跨索承桥梁用缆索的研发和应用提供参考。

基于层次分析法的医疗机器人可靠性分配研究

医疗机器人在手术、康复、诊断、护理等多个医疗领域发挥着重要作用,对其寿命进行可靠性分配是至关重要的一个环节,但目前对医疗机器人的可靠性研究还暂未有有效的方法。采用层次分析分配法来解决某型医疗机器人各分系统的可靠性分配的问题。首先,对比了众多可靠性分配方法,发现层次分析法在解决复杂系统可靠性分配中具有独特的优势;其次,建立了层次分析法的分配模型;最后,将医疗机器人的寿命不少于8000 h的条件带入模型中求解每个零部件的可靠性分配结果。

一种新型家用电器寿命试验机的设计与应用

本研究旨在开发一种新型的家用电器寿命试验机,以解决现有试验方法的局限性和不足。通过模拟家用电器在实际使用中的环境和操作条件,该试验机能够更真实、更快速地评估家用电器的性能和寿命。本研究详细介绍了新型试验机的设计原理、结构组成和技术特点,并通过实验验证了其有效性和可靠性。结果表明,该试验机能够准确模拟家用电器的实际使用情况,为制造商提供可靠的产品性能评估数据。本研究对于提升家用电器质量、满足市场需求、推动行业发展和节约资源具有重要意义。