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1.
金属—陶瓷界面结构的研究   总被引:2,自引:0,他引:2  
金属-陶瓷界面结构的研究是一个对基础科学理论和应用技术都十分有意义的研究课题。本文从实验和理论两方面概述了近年金属-陶瓷界面结构的研究结果,指出了其中存在的问题。从微观层次-陶瓷界面结构的实验方法在不断的探索和发展,相应的理论研究有处于初始阶段。  相似文献   

2.
利用电子动量谱仪对甲烷分子价电子测量了电子动量谱和束缚能谱。实验中的入射电子能量为1000eV加电子束缚。实验结果与Hartree-Fock理论及组态相互作用理论进行比较表明,两者相当一致。  相似文献   

3.
测定了一系列氧化物的电子结合能,显示了铋系超导体与二元氧化物衬底材料的化学反应性可以用固态酸碱反应理论来描述,其反应性大小除了可以用衬底氧化物的酸碱参数估计以外,还可以用衬底氧化物氧离子的内层电子结合能估计.  相似文献   

4.
金属-陶瓷界面结构的研究   总被引:2,自引:0,他引:2  
金属-陶瓷界面结构的研究是一个对基础科学理论和应用技术都十分有意义的研究课题。本文从实验和理论两方面概述了近年金属-陶瓷界面结构的研究结果,指出了其中存在的问题。从微观层次研究金属-陶瓷界面结构的实验方法在不断的探索和发展,相应的理论研究仍处于初始阶段。  相似文献   

5.
黄金饰品中金含量的X—荧光能谱分析   总被引:5,自引:1,他引:4  
应用X-荧光能谱分析和新的定量分析软件测定了26个黄金标样,研究了饰品形状的影响,不同方法,不同实验室测试结果的比对,表明在所选的工作条件下样品形状无明显影响。方法可靠、快速、简便,非破坏性,适于常规、批量分析。  相似文献   

6.
DNA中编码序列的分形特征研究   总被引:1,自引:0,他引:1  
随着基因组数据库的日益增大,如何从这庞大的数据库中提取有用的信息已成为全世界科学家迫在眉睫的难题。本文运用网格维数分别刻画了60个人类基因序列编码区的分形特征。研究结果表明:在同一个基因中,外显子的维数一般要大于整个蛋白质编码序列的维数,并通过对比随机序列的网格维数,证实了这一结论。结合分形理论及功率谱研究可以得出,具有较少外显子的基因,外显子中包含有较多的遗传信息,而对于较多外显子的基因则相反,遗传信息可能储存于内含子中。这些结论对内含子功能以及DNA序列的复杂性的研究具有一定的理论意义和实用价值。  相似文献   

7.
获得瞬变种的紫外光电子能谱(UPS)是国际UPS界一直追逐的目标,但终因瞬变种的超短寿命,仅为少数实验所实现。本文评述了这方面新进展,同时着重介绍了笔者首先开拓的UPS技术用于化学反应动力学研究的成果以及首先获得某些原子种的UPS谱,并展望了这一领域的发展前景。  相似文献   

8.
用U(2)代数模型,对H2O分子OH键的高激发振动能谱进行了理论计算,并与其它模型的计算相比较,结果表明,代数模型能以较小的标准偏差描述这一分子OH键的振动能谱.  相似文献   

9.
苯氰基衍生物气相HeI紫外光电子能谱研究   总被引:2,自引:0,他引:2  
气相Hel(21.22eV)紫外光电子能谱(UPS)能从孤立分子的分子轨道特性上,给出研究分子的轨道能量、电子结构以及成键特性的大量信息.UPS谱的特性揭示了被电离分子轨道的成键性质,而量子化学计算能正确地指认UPS谱带的归属,从而化合物的UPS研究从分子轨道的属性上提供了研究体系的实验和理论基础.苯基腈(C6H5CN)的UPS已有过研究[1-3],但作为系列分子的间-二氰基苯(1)、对-二氰基苯(2)、1;2,4,5-四氰基苯(3)的HeI光电子能谱未见报道.这一系列分子的特点是-CN取代的数目和位置不同,通过这些分子UPS的研究找…  相似文献   

10.
用XPS研究我国一些煤中有机硫的存在形态   总被引:4,自引:2,他引:4  
本文用电子能谱(xps)方法研究了我国九个不同牌号煤中有机硫的存在形态,并得到这些煤中各种不同形态硫的结合能数据。根据Lindberg等人所做模型化合物结果,给出了这些煤中硫元素结构能的化学归属。各种煤中硫的存在形态是不同的,有硫醇、硫醚、双硫醚、硫杂环、硫桥和取代基上的硫等。这一研究结果为今后研究煤的分子结构及脱硫方法提供了重要的科学依据。  相似文献   

11.
In this article the world's potential energy reserves are summarized on the basis of available estimates, and the future energy consumption is estimated with the aid of a working hypothesis relating to the growth of the world's population (P) and the energy consumption per capita (γ). According to this estimate, the energy requirements in 30 years will be about seven times and in 80 years about fifty times as high as they are today, and all the concentrated energy sources will be exhausted in about 120 to 160 years. – The energy requirements in the steady state (Pγ = const.) could be of the order of 1013 MWh per year and could be met out of magmatic rocks (U,Th) and sea water (U,D). High priority should be given to research and development work on the construction, reliability, and safety of breeder and fusion reactors, the chemical treatment and final disposal of radioactive waste, the extraction of uranium, thorium, and deuterium from the “primitive” raw materials, the relevant problems relating to protection of the environment, and the worldwide control of the excess birthrate.  相似文献   

12.
In this opinion piece, we highlight and discuss beyond state-of-the-art transition metal oxide materials for the oxygen evolution reaction and oxygen reduction reaction, which are essential for the renewable energy conversion and storage of H2 to electricity. We pinpoint some of the synthetic routes taken and discuss essential measurements required in the highlighted works, which others should undertake to achieve highly active and stable oxygen evolution reaction and oxygen reduction reaction catalysts in both acidic and alkaline media.  相似文献   

13.
In this paper, we review the generalized Forster-Dexter theory to treat photoinduced electronic energy transfer for a system in dense media and for an isolated system (i.e., a system in the collision-free condition). Instead of expressing the rate of energy transfer in terms of spectral overlap, the expression of the energy-transfer rate constant is obtained by evaluating a Fourier integral involved in the energy transfer rate constant using the saddle-point method. In this way, the energy-gap dependence, and the effect of temperature and the isotope effect on the energy transfer can be easily studied. The effect of bridge groups connecting between donor and acceptor chromophores on the intramolecular energy transfer is also studied.  相似文献   

14.
随着能源问题的日益突显,开发新型多功能材料以满足能源存储与转换应用的需求变得尤为重要.在众多功能材料中,复杂中空结构材料由于其独特的结构和物理化学特性而备受关注.本文综合评述了复杂中空结构材料的普适性构筑方法(硬模板法、软模板法、自模板法、次序模板法和选择性刻蚀法)及在能源方面的应用(锂/钠/钾离子电池、锂硫电池、超级电容器、电催化、光催化及染料敏化电池等).最后,对复杂空心结构研究领域存在的问题及未来的发展方向进行了展望.  相似文献   

15.
通过电催化实现可再生能源的存储与转化对于改善能源结构、保护生态环境、实现碳达峰和碳中和的国家战略具有重大意义。而开发低成本、高效的电催化剂成为全世界科学家共同面对的挑战。微生物在自然界中广泛存在,具有结构、组成和代谢丰富的特点,可以成为电催化剂的模板以及碳、磷、硫等非金属元素以及金属元素的来源,而且具有无毒、生产可重复性好、易于规模化等优点,已成为电催化剂制备的新趋势。对此,本文综述了微生物“智能”引导制备电催化剂的发展及在电催化析氢(HER)、电催化析氧(OER)、氧还原反应(ORR)、二氧化碳还原(CO2RR)、锂电池(LBs)等领域的应用现状。希望有助于推动微生物代谢与催化剂微纳结构关系以及与催化反应的构效关系的深入理解,最后针对这类材料的问题挑战及其未来发展方向进行了探讨与展望。  相似文献   

16.
The latest applications of plasma in energy storage and conversion are summarized here, including using it as the preparation and modification technology of the various electrocatalysts and the usage of it as the synthesis technology directly. Also, the challenges and outlook of plasma technology in energy storage and conversion were summarized, and the solutions and prospected its development in the future were present.  相似文献   

17.
有机太阳能电池具有成本低廉、质量轻、柔性可折叠以及可以大面积印刷等优点,受到广泛关注。但与无机太阳能电池相比,其能量损失较高。在有机光伏分子中引入氟原子是一种有效提高器件性能的分子设计策略。本文从氟原子特点出发,总结了氟化给体、π桥和受体单元对分子能级调控和形貌优化的作用,阐明了氟原子降低能量损失的内在原因;并通过代表性分子设计实例,简要阐述了氟化策略在高效聚合物给体材料、高效可溶性小分子给体材料以及高效非富勒烯受体材料中的应用;最后,对氟化策略的应用进行了总结,并展望了未来的研究方向。  相似文献   

18.
随着小型化、可穿戴等特征的智能电子以及物联网传感设备的发展,新型纤维状柔性化、小型化电化学储能器件已成为重要的研究方向。同时,对纤维材料和柔性储能器件的性能提出了更高的要求,如可任意弯折、可拉伸、可折叠、高储能密度等。石墨烯纤维具有独特的结构、优异的导电性、良好机械性能和电化学性质,已证明了是一种极具前景、高性能的新型纤维状柔性储能材料。目前,研究者已开发了多种石墨烯基纤维微观结构的调控策略来进一步改进其性能。本文首先系统总结了石墨烯基纤维的制备方法和其性能提升的策略,然后详细讨论其在柔性化纤维状超级电容器、金属离子电池、热电发电机、太阳能电池和相变材料等储能领域中的最新应用进展。最后,对石墨烯基纤维在能源存储和转换领域中存在的挑战和机会进行了展望。  相似文献   

19.
Since the initial MXenes were discovered in 2011, several MXene compositions constructed using combinations of various transition metals have been developed. MXenes are ideal candidates for different applications in energy conversion and storage, because of their unique and interesting characteristics, which included good electrical conductivity, hydrophilicity, and simplicity of large-scale synthesis. Herein, we study the current developments in two-dimensional (2D) MXene nanosheets for energy storage and conversion technologies. First, we discuss the introduction to energy storage and conversion devices. Later, we emphasized on 2D MXenes and some specific properties of MXenes. Subsequently, research advances in MXene-based electrode materials for energy storage such as supercapacitors and rechargeable batteries is summarized. We provide the relevant energy storage processes, common challenges, and potential approaches to an acceptable solution for 2D MXene-based energy storage. In addition, recent advances for MXenes used in energy conversion devices like solar cells, fuel cells and catalysis is also summarized. Finally, the future prospective of growing MXene-based energy conversion and storage are highlighted.  相似文献   

20.
As a close relative of ferroelectricity,antiferroelectricity has received a recent resurgence of interest driven by technological aspirations in energy-efficient applications,such as energy storage capacitors,solid-state cooling devices,explosive energy conversion,and displacement transducers.Though prolonged efforts in this area have led to certain progress and the discovery of more than 100 antiferroelectric materials over the last 70 years,some scientific and technological issues remain unresolved.Herein,we provide perspectives on the development of antiferroelectrics for energy storage and conversion applications,as well as a comprehensive understanding of the structural origin of antiferroelectricity and field-induced phase transitions,followed by design strategies for new lead-free antiferroelectrics.We also envision unprecedented challenges in the development of promising antiferroelectric materials that bridge materials design and real applications.Future research in these directions will open up new possibilities in resolving the mystery of antiferroelectricity,provide opportunities for comprehending structure-property correlation and developing antiferroelectric/ferroelectric theories,and suggest an approach to the manipulation of phase transitions for real-world applications.  相似文献   

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