Bioastrophysical aspects of low energy ion irradiation of frozen anthracene containing water

The origin of life on Earth remains a fascinating mystery in spite of many theories existing on this subject. However, it seems that simple prebiotic molecules could play an essential role in the formation of more complex organisms. In our experiment, we synthesized a class of these molecules (quinones) bombarding frozen anthracene containing water with low energy hydrogen ions. This experiment roughly simulated the astrophysical conditions which one can find in the solar system. Thus, we can hypothesize that prebiotic molecules could be created by interaction of the solar wind with interplanetary dust grains. The delivery of these molecules to early Earth may have contributed to the generation of life on our planet.     

Micromachining bulk glass by use of femtosecond laser pulses with nanojoule energy

Using tightly focused femtosecond laser pulses of just 5 nJ, we produce optical breakdown and structural change in bulk transparent materials and demonstrate micromachining of transparent materials by use of unamplified lasers. We present measurements of the threshold for structural change in Corning 0211 glass as well as a study of the morphology of the structures produced by single and multiple laser pulses. At a high repetition rate, multiple pulses produce a structural change dominated by cumulative heating of the material by successive laser pulses. Using this cumulative heating effect, we write single-mode optical waveguides inside bulk glass, using only a laser oscillator.     

Vortex revivals with trapped light

We predict that vortex dipoles nested in light beams trapped in graded-index media can undergo closed Berry trajectories, yielding periodic vortex annihilations and revivals along the light-propagation direction. The vortex revivals from vortex-free wave fronts are mediated by Freund stationary point bundles that carry the necessary Poincaré-Hopf indices. Vortex spiraling and spontaneous generation of circular-edge dislocations are also found to occur.     

Syntheses and Structures of Lanthanide Complexes with Isonicotinate

1 INTRODUCTION In recent years, chemists have paid their attention to the design and construction of extended metal- organic framework solids with potential applications, such as catalysts, nonlinear optical devices, ion ex- change, adsorption, sensors etc.[1, 2]. As one kind of polydentate ligands, isonicotinic acid has been exte- nsively employed to synthesize transition metal coo- rdination polymers[3, 4] with one-[5～8], two-[9～12] and three- dimensional[13～21] extended frameworks b…     

Synthesis and Crystal Structure of a Dinuclear Cobalt(II) Complex [Co2(1H-benzimidazole)4(1,4-bdoa)2]

1 INTRODUCTION In the last decades, metal carboxylate complexes have become a particularly important subject in mo- dern coordination chemistry owing to their fascina- ting structural diversity and potential applications as functional materials[1～3]. The generation of supramo- lecular architectures relies on the combination of se- veral factors, such as the coordination geometry of metals, bonding of the ligands and reaction condi- tions[4, 5]. In relation to the ligands, the judicious c…     

Synthesis and Crystal Structure of N-methyl- 9- （4-bromophenyl）-1,2,3,4,5,6,7,8,9,10- decahydroacridine- 1,8-dione under Microwave Irradiation

1 INTRODUCTION Since the discovery of pharmacological effectsof 1,4-dihydropyridine (1,4-DHPs) as calcium mo-dulators[1], a great deal of work has been directedtowards the synthesis of 1,4-DHPs acting as cal-cium antagonists[2]. The chemical modifications onthe DHP ring, such as the introduction of differentsubstituents on heteroatoms[3], have allowed theexpansion of researches on structure-activity rela-tionship to have new insight into the molecularinteractions at the receptor l…     

Synthesis and Crystal Structure of 3-（ 2- Hydroxybenzly ）-4-（ 4- Hydro xybenzylideneamino ）-（1H） - 1,2,4- Triazole-5-Thione and Its Antibacterial Activities

1 INTRODUCTION 2. 1 Physical measurements Azole derivatives, such as pyrazole, imidazole, All solvent and chemicals were commercial rea- triazole(including benzotriazole), tetrazole and indole, gents and used without further purification. Ele- have extensive biological activities. They have be- mental analyses were performed on a PE 1700 CHN come the central focus of studies for agricultural che- auto elemental analyzer. IR spectra were recorded on micals, medicines, plant growth regul…     

Assignment of cis-Epoxides and Crystal Structure of cis-4-Nitro-N-（7-oxabicyclo[4.1.0]hept-2-yl）benzamide

1 INTRODUCTION The success of strategies for total synthesis con-tinues to depend on high levels of stereoselectivityobserved in substrate-directed diastereoselective re-actions[1]. In this context, one of the most widelyused processes is diastereoselective epoxidation ofcyclic alkenes with allylic O- and N-directing group,which is very useful in building stereodefined syn-thetic blocks[2, 3] .However, in some circumstances,the assignment of resulting epoxides is not straight-forward[4～8…     

内燃机缸套-活塞环磨合过程中微凸体承载研究

为获得内燃机缸套-活塞环磨合磨损过程中微凸体的承载情况,利用粗糙峰的接触模型推导出磨合过程中微凸体承载方程,其中对弹性变形部分微凸体承载和塑性变形部分微凸体承载分别进行了研究,重点比较了内燃机缸套-活塞环磨合过程中假定接触微凸体全部为弹性变形与考虑接触微凸体产生弹?塑性变形时承载能力的不同.研究结果表明,在磨合磨损的中后期,即当h/σ大于0.5,ψ小于0.9时,两者差别不大,可以假定微凸体变形全部为弹性变形进行微凸体载荷的计算;而在磨合磨损初期,即当h/σ小于0.5,ψ大于0.9时,假定微凸体变形全部为弹性变形时的承载为考虑弹?塑性变形时的50%~85%左右.考虑到内燃机缸套-活塞环磨合过程中初期磨合的重要性,在计算缸套-活塞环磨合过程中微凸体承载时,应将塑性变形部分微凸体和弹性变形部分微凸体承载分别进行研究.也说明了本文所建立的微凸体承载方程更有益于缸套-活塞环磨合过程的摩擦学状态分析.     

Crystal and Molecular Structure of 4-Hydroxy-3-Methoxy-4-N-Methylstilbazonium Iodide C_(15) H_(16) NO_2 +·I~-CrystalandMolecularS

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