论寿命学:2.梦想与现实

以人类最大寿命的相对有限性为基础 。

寿命学概述(二)

(二)百岁老年人群的崛起与保健 1 长命百岁是人类增寿的新纪元 20世纪人类寿命普遍增长的洪流中,出现了人类寿命史上前所未有的新局面--百岁老年人群的崛起,见附图.

论寿命学:1.成熟与成就

从寿命研究的历史轨迹和令人瞩目的成就着重论述了寿命学已经发展成熟 ,成为独立的学术体系并进一步从寿命进化的历程中探讨寿命形成的原因 ,指出氧的决定性作用 ,为提高生命质量 。

寿命学概述(三)

(三)限食:最有发展前景的延寿研究成就 1 用寿命学观点探讨限食延寿的科学价值 1935年,美国Cornel大学的McCay首次报告:与正常自由进食的大鼠比较,限制饮食的大鼠延缓衰老的速度并且存活的时间也延长了.从那时起到现在这一重要发现将近70年了.这期间,限制饮食延寿抗衰老的事实反反复复地被证实.当今,限食延寿是公认的最有效的抗衰老的范例.因此限食也是研究老化过程的最佳的模式,优于与之比较的任何候选的抗衰老方案.

寿命学概述(四)

(四)寿命评估 1 寿命学发展的瓶颈 寿命评估就是用特异的生物学指标测定生命质量,推算机体的生物学年龄,是衰老的生物学鉴定或衰老生物指标测定的延伸与发展.

寿命学概述(一)

(一)医学伟大变革的理论基础 1 延长寿命面临的困境与困惑 医学实践的最终目的是实现人类的健康与长寿;争取最大寿命并保障身心健康是一切医学活动的出发点和归宿.1997年8月4日去世的法国老妇人,J.Calment终年122岁又164天.这是经过严格检证的人类最高存活年限,与推算人类的最高寿限吻合.

寿命学的难题

寿命学研究的根本宗旨和归宿是揭示延长寿命的理论导向和途径,其核心问题是延长预期寿命使之日益接近最大寿命,甚至与最大寿命重合。但是,达到这一目标及其困难,甚至是不能实现的遐想。我们只能尽一切可能使两者更加接近,完全重合是在可望而不及的未来。

老年生命活动的基本类型及演变——兼论寿命学研究对象

文章论述了老年人生命活动的基本类型及其演变。经典的观念用衰老或老化表达成年之后或老年人的生活活动本质。这一概念有局限性,不能概括老年人生命活动的本质。作者认为老年生活有两种基本类型:一是增生型活动,二是退行型活动;两类活动的整合形成老年生命活动的表观现象。文章论述了此命题所属的一些学主观点。

用^(22)Na的正电子测量固体表面膜的寿命谱学技术

以薄金属膜为例,全面地阐述在等温和金属原子所占空间体积不变的条件下,用^(22)Na的正电子测量固体表面膜的寿命谱学法的原理和实用技术。

用正电子湮没寿命谱学法研究BBO单晶缺陷

低温相偏硼酸钡(BBO)单晶是一种新型的非线性光学晶体。本文用正电子湮没寿命谱学法首次研究了它的缺陷,分析了它的缺陷类型及其成因。为克服缺陷、生长高质量的晶体提供科学依据。

Cycle life prediction and match detection in retired electric vehicle batteries

The lifespan models of commercial 18650-type lithium ion batteries （nominal capacity of 1150 mA-h） were presented. The lifespan was extrapolated based on this model. The results indicate that the relationship of capacity retention and cycle number can be expressed by Gaussian function. The selecting function and optimal precision were verified through actual match detection and a range of alternating current impedance testing. The cycle life model with high precision （〉99%） is beneficial to shortening the orediction time and cutting the prediction cost.

巧用人体生物钟

生命寿命学的支持者说,我们应该使每天的活动遵循人体生物节律。例如,如果你要打针,最好选择在上午9点左右,因为此时人体的疼痛感最迟钝。当然,这不适用于牙齿,如果要治牙,应在下午3点前后。参加考试或打算进行至关重要的谈话,则应尽量选择在上午10点至11点之间。据说,在这段时间。

Study of the Bc—Meson Lifetime

We in terms of optical theorem estimate the lifetime of Bc meson with the parameters which are determined by fitting the data for the lifetimes and inclusive semileptonic decays of various B and D mesons. In the estimation, we find that the bound-state effects are important, and take them into account carefully in the framework which attributes the effects to the effective masses of the decay heavy quarks in the inclusive processes. We also find that to Bc lifetime the penguin contribution is enhanced due to possible interference between the penguin and the 'tree part' c1O1 + c2O2.

Electrochemical hydrogen storage performance of as-cast and as-spun RE-Mg-Ni-Co-Al-based alloys applied to Ni/MH battery

The La-Mg-Ni-Co-Al-based AB2-type La0.8-xCe0.2YxMgNi3.4Co0.4Al0.1(x=0,0.05,0.1,0.15,0.2)alloys were prepared via melt spinning.The analyses of the X-ray diffraction(XRD)and scanning electron microscopy(SEM)proved that the experimental alloys contain the main phase LaMgNi4 and the second phase LaNi5.Increasing Y content and spinning rate lead to grain refinement and obvious change of the phase abundance without changing phase composition.Y substitution for La and melt spinning make the life-span of the alloys improved remarkably,which is attributed to the improvement of anti-oxidation,anti-pulverization and anti-corrosion abilities.In addition,the discharge capacity visibly decreases with increasing the Y content,while it firstly increases and then decreases with increasing spinning rate.The electrochemical kinetics increases to the optimum performance and then reduces with increasing spinning rate.Moreover,all the alloys achieve to the highest discharge capacities just at the initial cycle without activation.

Prediction of low-cycle crack initiation life of powder superalloy FGH96 with inclusions based on damage mechanics

The effects of inclusions in powder superalloy FGH96 on low-cycle fatigue life were studied, and a low-cycle crack initiation life prediction model based on the theory of damage mechanics was proposed. The damage characterization parameter was proposed after the construction of damage evolution equations. Fatigue tests of the powder superalloy specimens with and without inclusion were conducted at 530 and 600 ℃, and the model verification was carried out for specimens with elliptical, semi-elliptical, polygon and strip-shaped surface/subsurface inclusion. The stress analysis was performed by finite element simulation and the predicted life was calculated. The results showed a satisfying agreement between predicted and experimental life.

Influences on Generation of White Etching Crack Networks in Rolling Bearings

In rare cases rolling bearings fail by WEC （white etching crack） damage before reaching their calculated rating life, if so called additional loads are applied on the bearing in addition to the normal Hertzian stress （PHz）. A number of additional loads have been identified by means of tests with rolling bearings. These can be small direct currents as a result of electrostatic charge or large alternating currents from inverter-fed drives that unintentionally flow through the bearing. WEC damages can also be initiated by a pure mechanical additional load which is dependent on factors including the bearing kinematics but also on the dynamics of the drive train. The current state of knowledge on this subject is presented and taken as the basis for developing a hypothesis on the WEC damage mechanism. If load situations critical for WEC cannot be avoided, the risk of WEC can be considerably reduced by the selection of suitable materials and coatings as well as, in some cases, of suitable lubricants.

Systemic therapy of non-colorectal gastrointestinal malignancies in the elderly

In the coming years life expectancy is expected to increase and with this the percentage of the population above age 65 will grow. Patients above 65 make up more than two thirds of those currently diagnosed with gastrointestinal malignancies. Available evidence based medicine does not focus on the average patient, above the age 70, encountered in every day practice. Most guidelines and clinical trials are not designed to take into account the special considerations needed when treating the elderly such as functional status, comorbidities, polypharmacy, life expectancy, and social support. The majority of available data is based on retrospective reviews or subset analyses of larger studies where the elderly represent a fraction of the studied population. This review focuses on the toxicities and tolerability of current standard therapies for noncolorectal gastrointestinal malignancies, including gastroesophageal, pancreatic, bile duct and hepatocellular cancers in the elderly. With careful patient selection and geriatric assessment the elderly can safely benefit from standard therapies offered to younger patients.

Corrosion Processes in the Concrete of the Dams

During the whole operation life of Bratsk and Ust-Ilimsk hydroelectric plants, chemical analysis of water filtering through the pressure front of the concrete dams was under systematic monitoring by sampling in places of concemrated outcome in the inspection galleries of a dam. Long-term cumulative observations made up a basis for study of the indicated dams concrete corrosion caused by the Angara water in the process of its filtration through the cracks formed in the period of the dam erection, through construction joims and other defects. Mathematical-statistical analysis allowed the classification the processes of corrosion from the point of view of their time dynamics and divided them correspondingly into stationary （stable） and non-stationary. On the basis of a calculation of the cement stone componem removal along with the ideas of the process dynamics the pressure from filtration developmem forecast has been made and their danger level has been estimated. The developed conception is of rather a general character and can be used when analyzing the state of concrete dams of the Angara cascade and other similar cases.

Energy of Long-Lifetime Configurations in Zero-Temperature Dynamics

Using Monte Carlo method with zero-temperature dynamics, we investigate energy evolution of Ising spin configuration on a square lattice. The energies of some configurations exhibit long duration before those configurations reach the final state -- ground state or frozen stripe state. For ground-state dynamical realization, the duration occurs when the energy per spin is 4/L, where L is the lattice size. For stripe-state dynamical realization, the energy is slightly higher than 2/L when the duration appears in the last evolution stage. In addition, it is found that the average energy per spin in final state is approximately 2/3L.

Deep-water Riser Fatigue Monitoring Systems Based on Acoustic Telemetry

Marine risers play a key role in the deep and ultra-deep water oil and gas production. The vortex-induced vibration （VIV） of marine risers constitutes an important problem in deep water oil exploration and production. VIV will result in high rates of structural failure of marine riser due to fatigue damage accumulation and diminishes the riser fatigue life. In-service monitoring or full scale testing is essential to improve our understanding of V1V response and enhance our ability to predict fatigue damage. One ma- rine riser fatigue acoustic telemetry scheme is proposed and an engineering prototype machine has been developed to monitor deep and ultra-deep water risers＇ fatigue and failure that can diminish the riser fatigue life and lead to economic losses and eco-catastrophe. Many breakthroughs and innovation have been achieved in the process of developing an engineering prototype machine. Sea trials were done on the 6th generation deep-water drilling platform HYSY-981 in the South China Sea. The inclination monitoring results show that the marine riser fatigue acoustic telemetry scheme is feasible and reliable and the engineering prototype machine meets the design criterion and can match the requirements of deep and ultra-deep water riser fatigue monitoring. The rich experience and field data gained in the sea trial which provide much technical support for optimization in the engineering prototype machine in the future.