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1.
于涛 《飞碟探索》2013,(12):30-31
我们对于生命起源的认识还相当肤浅,大病毒的发现进一步拉近了生命与非生命之间的距离。也为生命起源和进化的研究提供了重要的信息。  相似文献   

2.
在巴斯德与普歇就生命能否自发产生的问题争得热火朝天的同时,达尔文《物种起源》的发表引发了生物学上另一场更为重大的辩论。这场有关生物是否进化而来的大辩论也包含了有关自发发生说的辩论,达尔文的进化论被许多人认为替自发发生说提供了支持。进化论本身并不解决生命起源的问题,但是如果生命不是一直存在的,而是有个起点,那么,最初的生命要么是神创的,  相似文献   

3.
吴再丰 《飞碟探索》2013,(11):48-50
生命是怎样诞生和进化的呢?地球外的宇宙存在吗?对于这些问题,人类至今还不清楚。美国航空航天局主导开创了“宇宙生物学”学科,在一个广阔的范围内对生命起源与进化进行研究。  相似文献   

4.
天文学研究并不意味着一定要拥有一架太空望远镜。在研究过程中,天体生物学家借助的设备便不是太空望远镜,而是显微镜。天体生物学研究宇宙中生命的起源、进化、分布和未来。这一涉及多学科的研究领域将目光聚焦于寻找太阳系的适居环境和系外适居行星,寻找火星及太阳系其他天体生命起源前的化学迹象和生命存在证据,对地球生命的起源和早期进化进行实验室和实地研究,同时研究生命适应地球和太空环境的潜力。  相似文献   

5.
刘艳 《空间科学学报》2021,41(1):167-169
2020年中国空间科学学会成立40周年。回顾学会成立之初的种种不易,联想到了空间生命起源与进化专业委员会从成立到成长、发展的点点滴滴,总结过往,展望未来。学会的健康蓬勃发展,必将为专业委员会的发展提供良好的交流学习平台,我相信在学会的带领下,通过专业委员会委员们的共同努力,空间生命起源与进化专业委员会定会越办越好。  相似文献   

6.
人类起源、生命起源和宇宙起源,是人类一直关注的三大问题.达尔文学说认为,人是由猿进化来的;恩格斯说,劳动创造了人,考古科学似乎也证实了这一点、因此.多数人也就接受了这两位伟人的观点.但是,近代生物科学研究发现,人的生活习性更接近于海豚,这就促使我们开始了对人类起源的新探索.  相似文献   

7.
陈季  朱听 《空间科学学报》2021,41(1):141-144
生物分子的手性均一性是地球上生命的重要标志.生命对D型核糖和L型氨基酸的依赖究竟是生命起源的必然,还是早期地球上发生的一次偶然事件,目前尚无定论.地球上生命手性均一性的原因还未能被很好地解释,但一些实验证据已显示基于L型核糖和D型氨基酸的镜像生命被合成出来的可能性.本文简要总结了当前对镜像生物分子的研究进展和方向,并探讨了在实验室中运用新型镜像分子生物学工具构建镜像生命的可行性.   相似文献   

8.
给生命下定义是一件很麻烦的事,现在仍然没有一个统一的界定,大家都围绕着复制、生长、代谢、进化以及有无碳和水的概念讨论这个问题。  相似文献   

9.
《飞碟探索》2014,(12):6-6
据报道,欧空局的彗星登陆器“菲莱”在主电池耗尽之前,已经探测到了有机分子。含碳有机分子是地球生命的基础,这一发现有助于我们了解地球生命的起源。  相似文献   

10.
巨尤 《太空探索》2002,(1):40-41
我们寻找天外朋友,不可不了解生命的起源。地球上生命的起源,或许可以作为了解地外高级文明起源的借鉴。 20世纪20年代,科学家提出一种理论,认为在45亿年前,在地球的海洋中就产生了存在有机分子的“原始汤”,这些有机分子是闪电等能源对原始大气中的甲烷、氨和氢等的化学作用而形成的。  相似文献   

11.
The moon has longstanding questions such as lunar environments, origin, formation and evolution, magnetization of crustal rocks, internal structure and possible life. The recent lunar missions, e.g., SELenological and ENgineering Explorer “KAGUYA” (SELENE), Chang’E-1, Chandrayaan-1, and Lunar Reconnaissance Orbiter/Lunar CRater Observation and Sensing Satellite (LRO/LCROSS), have provided new opportunities to explore and understand these issues. In this paper, we reviewed and presented the results and findings in the fields of lunar gravity, magnetic field, atmosphere, surface geomorphology and compositional variations, volcano, craters, internal structure, water and life science from new lunar exploration missions. In addition, the new objectives and scientific questions on lunar explorations in near future are presented and discussed.  相似文献   

12.
装备平行仿真是系统建模与仿真领域的新兴仿真技术,已经成为研究热点。在装备维修保障领域中,分析了装备剩余寿命(RUL)预测存在的突出问题,即模型参数固定、不具备自适应演化能力,成为阻碍实现装备剩余寿命自适应预测的首要因素。结合装备平行仿真理论,在建模分析的基础上提出了面向装备剩余寿命预测的平行仿真框架,该框架以Wiener状态空间模型为基础仿真模型,在动态注入的装备退化观测数据驱动下,利用期望最大化(EM)算法在线更新模型参数,并利用卡尔曼滤波(KF)算法实现仿真输出数据与观测数据的同化(DA),从而实现仿真模型动态演化,使得仿真输出不断逼近装备真实退化状态,为准确预测剩余寿命提供高逼真度仿真模型和数据输出。以某轴承性能退化数据为数据驱动源,对该框架进行了验证,仿真结果表明平行仿真方法能准确仿真装备性能退化过程,在提高预测精度的基础上实现了装备剩余寿命的自适应预测,有力证明了平行仿真方法的可行性和有效性。   相似文献   

13.
小行星的有机物记录了太阳系早期有机物的形成发展历史,为地球早期生命前体出现的研究提供了重要依据,对于研究生命起源和演化具有重要意义.本文综合分析了小行星表面可能存在的有机物成分、种类及其赋存状态,利用红外光谱开展地面模拟实验,探讨有机物的红外光谱特征及其影响因素.结果表明,不同类型有机物的红外光谱特征与其类型、结构、温...  相似文献   

14.
Searching for extraterrestrial life attracts more and more attention. However this searching hardly can be effective without sufficiently universal concept of life origin, which incidentally tackles a problem of origin of life on the Earth. A concept of initial stages of life origin is stated in the paper. The concept eliminates key difficulties in the problem of life origin, and allows experimental verification of it. According to the concept the predecessor of living beings has to be sufficiently simple to provide non-zero probability of self-assembling during short (in geological or cosmic scale) time. In addition the predecessor has to be capable of autocatalysis, and further complication (evolution). A possible scenario of initial stage of life origin, which can be realized both on other planets, and inside experimental facility is considered. In the scope of the scenario a theoretical model of multivariate oligomeric autocatalyst is presented. Results of computer simulation of two versions of oligomeric autocatalytic reactions are presented. It is shown that the contribution of monomer activation reaction is essential, and in some cases autocatalysis in polymerizing reaction can be achieved without catalyzing proper monomer binding reaction.  相似文献   

15.
An over-all organizational framework for the origin of life is outlined and attemps for realization are given. Evolution can be described as a process resulting in an increase of “knowledge” where knowledge is the number of carriers of genetic information discarded, on the average, until the evolutionary state under consideration is reached. A model for the evolution of a translation device, a crucial event in the origin of life, is described in detail. Aggregates of short polynucleotide strands in a hairpin conformation play a major role in this model. Experimental evidence for the selectivity of aggregation supports the idea of aggregates as error filters. Chromatographic separation as selection process during chemical evolution supports the model of the early translation device leading to the origin of the genetic code.  相似文献   

16.
An approach to searching for extraterrestrial life on the base of "autotroph" concept of the origin of life is presented in the paper. According to this concept the origin of life took place in three stages. The first stage was developed inside the global geochemical cycle in which the turnover of different chemical transformations was implemented by solar radiation and/or heat energy of bowels of the Earth. At the second stage, after the autocatalytic systems have emerged these systems evolved as a result of "natural selection" by autocatalysis parameters up to emergence of special inheritance systems that drastically improved the autocatalysis parameters. The best in terms of autocatalysis parameters were the autocatalysis systems based on phase-separated particles where complex structures can form not only on the basis of covalent interactions. Such autocatalysis systems can emerge only in liquid in a certain range of temperatures and pressures. At this stage the geochemical cycle complicated involving new substances. At the third stage the evolution involved improvement of inheritance systems resulting in formation of the modern type of genetic apparatus. This concept formed the basis to consider approaches to experimental modeling of major aspects of the origin of life and to outlining some general features of life that can extend the sensitive horizon of searching for extraterrestrial life.  相似文献   

17.
近年来,越来越多的观测结果均显示月球上存在水.本文通过运用Monte-Carlo方法及基于能量守恒的有心力场中粒子轨道算法对水分子在近月表的输运过程进行建模,得到了水分子在近月表分布随时间演化的图像.模拟结果显示,分布在高纬地区的水分子较同经度的中低纬地区要多,这与目前探测得到的结论是一致的.同时,对最终进入永久阴影区的水分子的百分比进行了统计,在光解离常数为6.4×104s的情况下,有大约4.12%的水分子会被永久阴影区存储下来,这个比例与前人估算结果相吻合.   相似文献   

18.
Life support system designs for long-duration space missions have a multitude of requirements drivers, such as mission objectives, political considerations, cost, crew wellness, inherent mission attributes, as well as many other influences. Evaluation of requirements satisfaction can be difficult, particularly at an early stage of mission design. Because launch cost is a critical factor and relatively easy to quantify, it is a point of focus in early mission design. The method used to determine launch cost influences the accuracy of the estimate. This paper discusses the appropriateness of dynamic mission simulation in estimating the launch cost of a life support system. This paper also provides an abbreviated example of a dynamic simulation life support model and possible ways in which such a model might be utilized for design improvement.  相似文献   

19.
木星冰卫星(尤其是"木卫2")在整个太阳系中有非常独特的探测价值,也是当前国际深空探测最前沿、最受关注的领域之一。在对国外相关探测技术归纳总结的同时,结合木星冰卫星冰下海洋探测的若干科学问题,次表层模型、温度廓线及探测深度、电离层的影响等方面,提供了几种木星冰卫星冰下液态水海洋探测的新思路,并给出了一些初步的系统框架设计和次表层介电特性仿真分析等结果。通过对新方法、新模式的探索,有望对我国自主木星冰卫星的次表层液态海洋探测起到良好的借鉴作用。  相似文献   

20.
During the entire evolution of life on Earth, the development of all organisms took place under constant gravity conditions, against which they achieved specific countermeasures for compensation and adaptation. On this background, it is still an open question to which extent altered gravity such as hypergravity (centrifuge) or microgravity (spaceflight) affects the normal individual development, either on the systemic level of the whole organism or on the level of individual organs or even single cells. The present review provides information on these questions, comprising gravistimulated effects on invertebrates and vertebrates (with the exception of mammals, since respective biomedically oriented reviews abound), focusing on developing fish as model systems, with special emphasis on the effect of altered gravity on the developing brain and vestibular system, comprising investigations on behaviour and plastic reactivities of the brain and inner ear. Clues and insights into the possible basic causes of space motion sickness-phenomena (SMS; a kinetosis) are provided as well as perspectives in regard to future work to be done including studies on the ISS concerning the analysis of gravistimulated effects on developmental issues (imprinting phase for graviperception?).  相似文献   

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