载人航天技术及其发展

太空是人类继陆地、海洋、大气层之后的第四活动领域。第四活动领域具有高真空、微重力、强辐射、改变昼夜节律等特点,为人类的发展带来了巨大的潜力和开发前景。以发展载人航天器为重点的、由航天员参与的载人航天技术是以对太空进行探索以及利用太空环境进行科学研究、资源开发与应用的综合工程技术,它是新技术群中的一个重要领域,是高技术密集的尖端科学技术。 文章从载人航天技术的概念、内容和发展载人航天技术的意义三个方面对载人航天技术进行阐述,说明载人航天技术对人类社会发展的重要性。文章还对世界载人航天技术发展的概况与未来的发展做了介绍,最后提出了中国发展载人航天技术的设想。     

基于半导体和纳米金属的高效人工光合成材料体系构建与应用

通过人工光合成技术把二氧化碳转换成碳氢化合物燃料,是人类梦寐以求的一种太阳能化学转化和利用的理想技术,近年来受到科学界和工业界越来越广泛的关注。从以下3个技术途径综述了近年来基于半导体和纳米金属的宽光谱响应高效人工光合成材料体系的构建与应用:(1)从人工光合成热力学条件出发,基于半导体能带工程设计制备新型高效人工光合成材料;(2)利用纳米贵金属表面等离子共振效应,设计和制备基于纳米金属的宽广谱响应人工光合成体系,可以有效拓展其光吸收范围至近红外区;(3)利用Ⅷ过度族金属光热效应,设计与制备基于Ⅷ族金属纳米粒子的全光谱响应人工光合成体系,可以有效拓展光吸收范围至红外区,使人工光合成体系具有全光谱响应。特别关注在上述人工光合成材料体系中非极性CO_2分子活化、表/界面现象及光化学反应微观机制,为开发高效人工光合成材料体系提供理论和实验依据。     

计量科学技术为"神舟"载人飞船铺垫飞向蓝天之路

“神舟”五号载人飞船成功地飞向蓝天 ,准确入轨并顺利返回 ,实现了中华民族千年遨游太空的梦想。我们为之激动的欢庆和自豪。从此中国成为继美国、前苏联之后第三个拥有太空飞船的国家。这是我国实现航天现代化的辉煌成果。随着现代化建设的不断发展 ,人类的活动范围已经从陆地、从海洋扩展到太空。 2 0世纪 5 0年代 ,航天技术的出现开辟了人类探索太空的新时代。空间以其蕴藏着巨大的政治、经济、军事、科技价值 ,世界各国不断加大空间技术开发和应用 ,对空间资源进行竞争越来越激烈。计量科学技术在空间技术的研究、制造、发射、回收的各…     

国外动态

正韩国利用太阳光开发出二氧化碳转换技术韩国《亚洲经济》发布消息称,韩国高丽大学利用太阳光能源中的红色光开发出将二氧化碳转换成合成燃料的转换技术。该研究成果发表在化学领域国际学术杂志《Acs Catalysis》上。二氧化碳是全球变暖的主要原因,二氧化碳在结构上非常稳定,无法轻易转换成其它物质。目前技术主要利用电热能源来分解二氧化碳,但是无法广泛使用。即使通过使用人工光合作用,在二氧化碳转换过程中同样出现了催化效率低,转换反应不     

火星二氧化碳及水资源利用的研究进展

对于未来火星采样返回、载人火星探测任务而言,火星原位资源利用技术的研究具有必要性。在火星上提取并提前存储火星可用物资,可保障载人火星探测任务甚至火星殖民的需求。基于火星原位资源利用概念,对火星大气可利用的资源进行分析,分别从两大方面(二氧化碳资源和水资源利用)对国内外相关技术的发展情况进行分析,给出宇航员在火星活动和返回舱返回时,获取所需甲烷和氧气的方法。     

材料专家聚宁热议减排

资源、能源和环境问题已成为当代人类社会面临的重大挑战,11月28日,“第十二届全国青年材料科学技术研讨会”在南京举办,如何减少能源消耗,降低二氧化碳排放成为与会材料专家和青年学者的热议话题。     

中国航天发展 获益的是全球

从1999年11月20日第一艘飞船升空到2011年9月29日天宫一号发射,12年间,中国载人航天工程以坚实的步伐迈向建造空间站这一19年前启动载人航天工程时便确定的目标;从神舟载人飞船上天,嫦娥探月成功,北斗导航卫星投入使用……中国人向太空探索的步伐正一步步延伸。北京时间9月29日21时16分,"天宫"一号目标飞行器发射升空,标志着中国航天事业进入新的历史阶段。胡锦涛等国家领导人分别在北京航天飞行控制中心和酒泉卫星发射中心观看了发射实况。在这个时候,不禁让人想起去年"五四"青年节温总理和北大学生交流的场景——当时,一位同学写下总理一首诗的题目《仰望星空》赠送给总理,总理则写下"脚踏实地"四个大字。"天宫一号"是一个具有浓郁中国特色、寄托了华人无限憧憬的名字,她承载着中国人的航天梦想。可以说,"仰望星空"和"脚踏实地"是中国航天事业取得成功的关键要素,是中国航天精神这个"硬币"的两面。二者近乎完美地结合在一起,不可分割。尽管,载人航天投入大,回报周期长,但是"仰望星空"的价值毋庸置疑。宇航开发是综合性很强的学科,包括物理、材料、通信、机器人等关键领域的技术都会在这种综合性开发中得到考验和锻炼,这既是挑战,也是战略投资。不仅如此,一些看似与宇航没有直接关系的学科,如生命医学、拓扑学、系统学、运筹学等,也因大型航天项目运作的需要,而得到实际的应用、考验和发展,这一切不仅能作用于太空,更会带动整个国家科技水平的提高,并直接造福于人类和社会。无垠的太空是人类共同的财富,探索太空是人类的共同追求,而中国航天技术的进一步发展,获益的是全球。一项载人航天工程要想取得成功涉及方方面面,而我国的航天发射保持了极高的成功率。这说明,在这个综合性较强的科研系统工程内,如何通过严格精密的管理,确保各程序的安全,确保每一个元器件都不出现问题,一定有很多值得总结的地方。而在当下,很多领域产品质量问题层出不穷,安全事故多发,"中国制造"毁誉参半,所以,航天人的"脚踏实地",尤其值得某些监管部门和产品以及装备制造企业好好学习。     

《飞天》—梦想的实现——后期数字特技介绍

《飞天》是一部励志影片。讲述中国了第一代航天员张天聪为了飞天梦想,永不言败,坚持在载人航天一线奋斗20多年的故事,塑造了以张天聪为代表的航天员英雄群体,全面展示了宇航员的工作、生活情感、日常训练和太空升空,抢险等一系列不为人知的内容场景。让人们从不同侧面了解到中国载人航天工程伟大壮举的可歌可泣。为了展现人物的情绪转承以及故事的发展,再现恢宏的太空奇观,后期制作团队面对《飞天》高难度特效带来的技术挑战,在最大程度遵循科学理论依据的同时重新赋予了《飞天》美学上的壮丽,特别是片尾太空一场的描绘(见图1、图2),更是成为了是中国电影史上的补白作品。2011年是中国航天事业创建55周年,也是人类首次载人航天50周年,在庆祝建党90周年之际推出《飞天》这部影片,既是向党的生日献礼,也是为了纪念中国航天和人类历史上那些具有里程碑意义的重大事件。     

三○四所发挥计量测试技术优势

前不久 ,中航一集团第三 O四研究所获得了由中国载人航天工程办公室颁发的奖状 ,表彰该所参与中国载人航天工程研制、建设、试验的协作配套工作 ,为我国首次载人航天飞行任务圆满完成做出了贡献。三 O四所发挥其大尺寸计量技术优势 ,不仅提供量值传递和溯源保障 ,同时利用现场测量技术 ,保证了“长三甲”和“神舟”五号几何联接数据准确可靠 ,有力地提高了整体飞行质量 ,为首次载人航天飞行发挥了长度计量技术支撑平台的作用。利用动态温度校准装置 ,三 O四所为“长三甲”和“神舟”五号发动机高温高速下工作的动态温度测量系统 ,提供动态…     

CHINA质量中国的动人凯歌

2003年10月15日和16日,"神舟五号"载人飞船成功发射和安全返回,揭开了中国载人航天史上崭新的一页,实现了中华民族遨游太空的千年飞天夙愿.中国已成为继前苏联、美国之后第三个进入"太空俱乐部"的成员.举国振奋,世界瞩目.     

Nanostructure Engineering of Sn-Based Catalysts for Efficient Electrochemical CO2 Reduction

Excessive anthropogenic CO₂ emission has caused a series of ecological and environmental issues, which threatens mankind's sustainable development. Mimicking the natural photosynthesis process (i.e., artificial photosynthesis) by electrochemically converting CO₂ into value-added products is a promising way to alleviate CO₂ emission and relieve the dependence on fossil fuels. Recently, Sn-based catalysts have attracted increasing research attentions due to the merits of low price, abundance, non-toxicity, and environmental benignancy. In this review, the paradigm of nanostructure engineering for efficient electrochemical CO₂ reduction (ECO₂R) on Sn-based catalysts is systematically summarized. First, the nanostructure engineering of size, composition, atomic structure, morphology, defect, surficial modification, catalyst/substrate interface, and single-atom structure, are systematically discussed. The influence of nanostructure engineering on the electronic structure and adsorption property of intermediates, as well as the performance of Sn-based catalysts for ECO₂R are highlighted. Second, the potential chemical state changes and the role of surface hydroxides on Sn-based catalysts during ECO₂R are introduced. Third, the challenges and opportunities of Sn-based catalysts for ECO₂R are proposed. It is expected that this review inspires the further development of highly efficient Sn-based catalysts, meanwhile offer protocols for the investigation of Sn-based catalysts.     

Clover leaf-shaped Al2O3 extrudate as a support for high-capacity and cost-effective CO2 sorbent

Amine-functionalized clover leaf-shaped Al₂O₃ extrudates (CA) were prepared for use as CO₂ sorbent. The as-synthesized materials were characterized by N₂ adsorption, XRD, SEM and elemental analysis followed by testing for CO₂ capture using simulated flue gas containing 15.1% CO₂. The results showed that a significant enhancement in CO₂ uptake was achieved with the introduction of amines into CA materials. A remarkably high volume-based capacity of 70.1 mg/mL of sorbent of this hybrid material suggests that it can be potentially used for CO₂ capture from flue gases and other stationary sources, especially those with low CO₂ concentration. The novel adsorbent reported here performed well during prolonged cyclic operations of adsorption-desorption of CO₂.     

Photocatalytic Conversion of CO2 into Renewable Hydrocarbon Fuels: State‐of‐the‐Art Accomplishment,Challenges, and Prospects

Photocatalytic reduction of CO₂ into hydrocarbon fuels, an artificial photosynthesis, is based on the simulation of natural photosynthesis in green plants, whereby O₂ and carbohydrates are produced from H₂O and CO₂ using sunlight as an energy source. It couples the reductive half‐reaction of CO₂ fixation with a matched oxidative half‐reaction such as water oxidation, to achieve a carbon neutral cycle, which is like killing two birds with one stone in terms of saving the environment and supplying future energy. The present review provides an overview and highlights recent state‐of‐the‐art accomplishments of overcoming the drawback of low photoconversion efficiency and selectivity through the design of highly active photocatalysts from the point of adsorption of reactants, charge separation and transport, light harvesting, and CO₂ activation. It specifically includes: i) band‐structure engineering, ii) nanostructuralization, iii) surface oxygen vacancy engineering, iv) macro‐/meso‐/microporous structuralization, v) exposed facet engineering, vi) co‐catalysts, vii) the development of a Z‐scheme system. The challenges and prospects for future development of this field are also present.     

Life sciences issues affecting space exploration

The U.S. space program is undertaking a serious examination of new initiatives in human space exploration involving permanent colonies on the Moon and an outpost on Mars. Life scientists have major responsibilities to the crew, to assure their health, productivity, and safety throughout the mission and the postflight rehabilitation period; to the mission, to provide a productive working environment; and to the scientific community, to advance knowledge and understanding of human adaptation to the space environment. Critical areas essential to the support of human exploration include protection from the radiation hazards of the space environment, reduced gravity countermeasures, artificial gravity, medical care, life support systems, and behavior, performance, and human factors in an extraterrestrial environment. Developing solutions to these concerns is at the heart of the NASA Life Sciences ground-based and flight research programs. Facilities analogous to planetary outposts are being considered in Antarctica and other remote settings. Closed ecological life support systems will be tested on Earth and Space Station. For short-duration simulations and tests, the Space Shuttle and Spacelab will be used. Space Station Freedom will provide the essential scientific and technological research in areas that require long exposures to reduced gravity conditions. In preparation for Mars missions, research on the Moon will be vital. As the challenges of sustaining humans on space are resolved, advances in fundamental science, medicine and technology will follow.     

Loaded Cu-Er metal iso-atoms on graphdiyne for artificial photosynthesis

Herein we report a bimetal atomic catalyst that features atomically dispersed Cu and Er atoms anchored on all crystalline graphdiyne (CuEr-GDY) for efficient artificial photosynthesis converting CO₂ into sustainable fuel at the gas–solid interfaces with water as reducing medium instead of organic reagent. The CuEr-GDY can promote the efficient separation of photogenerated electron-hole pairs to drive water oxidation and CO₂ activation/reduction, together with Cu/Er promoted CO₂/H₂O adsorption and CO desorption. This result indicates that bimetallic atoms on the high-crystalline GDY surface have high activity. This heteroatomic catalyst of CuEr-GDY demonstrates high catalytic activity with the reaction selectivity up to 97.6%, and the competitive hydrogen evolution reaction is almost completely suppressed. The CO₂ conversion achieves the CO yield of 181.04 μmol g⁻¹ h⁻¹ under ambient conditions.     

Ultrathin and Small‐Size Graphene Oxide as an Electron Mediator for Perovskite‐Based Z‐Scheme System to Significantly Enhance Photocatalytic CO2 Reduction

The judicious design of efficient electron mediators to accelerate the interfacial charge transfer in a Z‐scheme system is one of the viable strategies to improve the performance of photocatalysts for artificial photosynthesis. Herein, ultrathin and small‐size graphene oxide (USGO) nanosheets are constructed and employed as the electron mediator to elaborately exploit an efficient CsPbBr₃‐based all‐solid‐state Z‐scheme system in combination with α‐Fe₂O₃ for visible‐light‐driven CO₂ reduction with water as the electron source. CsPbBr₃ and α‐Fe₂O₃ can be closely anchored on USGO nanosheets, owing to the existence of interfacial strong chemical bonding behaviors, which can significantly accelerate the photogenerated carrier transfer between CsPbBr₃ and α‐Fe₂O₃. The resultant improved charge separation efficiency endows the Z‐scheme system exhibiting a record‐high electron consumption rate of 147.6 µmol g^?1 h^?1 for photocatalytic CO₂‐to‐CO conversion concomitant with stoichiometric O₂ from water oxidation, which is over 19 and 12 times higher than that of pristine CsPbBr₃ nanocrystals and the mixture of CsPbBr₃ and α‐Fe₂O₃, respectively. This work provides a novel and effective strategy for improving the catalytic activity of halide‐perovskite‐based photocatalysts, promoting their practical applications in the field of artificial photosynthesis.     

Metal‐Complex/Semiconductor Hybrid Photocatalysts and Photoelectrodes for CO2 Reduction Driven by Visible Light

CO₂ reduction to carbon feedstocks using heterogeneous photocatalysts is an attractive means of addressing both climate change and the depletion of fossil fuels. Of particular importance is the development of a photosystem capable of functioning in response to visible light, which accounts for the majority of the solar spectrum, representing a kind of artificial photosynthesis. Hybrid systems comprising a metal complex and a semiconductor are promising because of the excellent electrochemical (and/or photocatalytic) activity of metal complexes during CO₂ reduction and the ability of semiconductors to efficiently oxidize water to molecular O₂. Here, the development of hybrid photocatalysts and photoelectrodes for CO₂ reduction in combination with water oxidation is described.     

Fundamental Understanding of Nonaqueous and Hybrid Na–CO2 Batteries: Challenges and Perspectives

Alkali metal–CO₂ batteries, which combine CO₂ recycling with energy conversion and storage, are a promising way to address the energy crisis and global warming. Unfortunately, the limited cycle life, poor reversibility, and low energy efficiency of these batteries have hindered their commercialization. Li–CO₂ battery systems have been intensively researched in these aspects over the past few years, however, the exploration of Na–CO₂ batteries is still in its infancy. To improve the development of Na–CO₂ batteries, one must have a full picture of the chemistry and electrochemistry controlling the operation of Na–CO₂ batteries and a full understanding of the correlation between cell configurations and functionality therein. Here, recent advances in CO₂ chemical and electrochemical mechanisms on nonaqueous Na–CO₂ batteries and hybrid Na–CO₂ batteries (including O₂-involved Na–O₂/CO₂ batteries) are reviewed in-depth and comprehensively. Following this, the primary issues and challenges in various battery components are identified, and the design strategies for the interfacial structure of Na anodes, electrolyte properties, and cathode materials are explored, along with the correlations between cell configurations, functional materials, and comprehensive performances are established. Finally, the prospects and directions for rationally constructing Na–CO₂ battery materials are foreseen.     

Surface potentials of magnetron sputtered transparent conducting oxides

Work functions, ionization potentials (electron affinities) and Fermi level positions measured in-situ by photoelectron spectroscopy at surfaces of transparent conducting oxides are presented. Thin films of ZnO, ZnO:Al, SnO₂, SnO₂:Sb, In₂O₃, In₂O₃:Sn, and In₂O₃:(Zn,Sn) are prepared by magnetron sputtering. The Fermi level position is strongly affected by the oxygen content in the sputter gas. The ionization potential and work function of ZnO are strongly affected by surface orientation. In contrast, SnO₂-based and In₂O₃-based materials show pronounced changes of ionization potential and work function induced by surface oxidation and reduction. Unlike SnO₂, the oxidation of the In₂O₃-based TCO surfaces does not occur during deposition but can be induced by post-deposition treatments.     

Recent progress in electrochemical reduction of carbon monoxide toward multi-carbon products

The increasing CO₂ emissions and accompanying climate challenges have boosted the exploration of candidate pathways for storing and utilizing renewable carbon resources. Electrochemical CO₂ reduction (ECO₂R) has been proven as a promising technology for artificial carbon fixation. Nevertheless, the unsatisfactory multi-carbon (C₂₊) product selectivity hinders its widespread use. Recently, the indirect route via electrochemical CO reduction (ECOR) to C₂₊ products has become a potential alternative through the combination with ECO₂R. In this review, we briefly summarize the most recent and instructive research in the ECOR development process from advanced ECOR catalysts and reaction mechanisms. Furthermore, the challenges and outlooks based on current understanding in this field are expounded. These insights and perspectives offer meaningful guidance for grasping ECOR and designing relevant catalysts with enhanced C₂₊ product selectivity.