光纤光隔离器研制的进展

本文介绍了光隔离器国内外研制的现状与发展，扼要说明光隔离器的原理，结构，分类与器件小型化等问题。最后提出了该器件今后发展方面的几个问题。     

一种新的植物N2O释放光调节模式

植物释放N2O可能是大气N2O的重要来源。植物N2O释放与体内的NO3-还原过程有关,并且受光照强度的调节。较低光强有利于植物产生N2O。作者根据自己的研究结果和他人的工作,提出一个新的N2O释放与光合作用光反应和CO2同化作用关系以及呼吸作用关系的模式。在非光合作用器官,NO3-还原所需要的还原力和碳架来自呼吸作用,而在光合器官则主要来自光合作用。在光合器官中,N2O产生于NO3-还原和NO2-还原过程。硝酸还原对光合作用的CO2同化既有依赖关系,又有竞争关系。当光照较弱时,光合作用提供的还原力不足,对NO2-还原的抑制大于NO3-还原,因此有利于NO2的产生。     

Evidence that Crystal Facet Orientation Dictates Oxygen Evolution Intermediates on Rutile Manganese Oxide

Elucidating the mechanism that differentiates the oxygen‐evolving center of photosystem II with its inorganic counterpart is crucial to develop efficient catalysts for the oxygen evolution reaction (OER). Previous studies have suggested that the larger overpotential for MnO₂ catalysts under neutral conditions may result from the instability of the Mn³⁺ intermediate to charge disproportionation. Here, by monitoring the surface intermediates of electrochemical OER on rutile MnO₂ with different facet orientations, a correlation between the stability of the intermediate species and crystal facets is confirmed explicitly for the first time. The coverage of the Mn³⁺ intermediate is found to be 11‐fold higher on the metastable (101) surfaces compared to (110) surfaces, leading to the superior OER activity of (101) surfaces. The difference in OER activity may result from the difference in surface electronic states of Mn³⁺, where interlayer charge comproportionation of Mn²⁺ and Mn⁴⁺ to generate two Mn³⁺ species is favored on (101) facets. Considering the fact that the OER enzyme accommodates Mn³⁺ stably during the Kok cycle, the enhanced OER activity of the rutile MnO₂ catalyst with a metastable surface highlights the importance of mimicking not only the crystal structure but also the electronic structure of the targeted natural enzyme.     

Porphyrin/SiO2/Cp*Rh(bpy)Cl Hybrid Nanoparticles Mimicking Chloroplast with Enhanced Electronic Energy Transfer for Biocatalyzed Artificial Photosynthesis

A biocatalyzed artificial photosynthesis system (APS) based on porphyrin/SiO₂/Cp*Rh(bpy)Cl hybrid nanoparticles (TCPP/SiO₂/Rh HNPs) to mimic chloroplasts in green plant is reported. The TCPP/SiO₂/Rh HNPs are fabricated via sol–gel reaction of silica precursors functionalized with photosensitizer (porphyrin, TCPP) and electron mediator (Cp*Rh(bpy)Cl, M); while the integration of enzyme and coenzyme nicotinamide adenine dinucleotide (NAD)(H), on the outer surface of the HNPs is achieved through electrostatic‐interaction‐driven assembling under the entanglement of a negatively charged polyelectrolyte. The chloroplast‐mimicking, highly integrated APS exhibits remarkably superior performance over a free system such that the regeneration of NADH is improved from 11% to 75%, and the synthesis of formic acid from CO₂ increased from 15 to 100 µmol. Based on the detailed investigations into the photochemical and electrochemical properties, it is speculated that the covalent linking of the photosensitizer and electron mediator via silicon hydride bonds, and the formed SiO₂ network through sol–gel reaction, may form intramolecular and intermolecular electron transfer chains to direct more efficient electron transfer from TCPP to M. Such intramolecular and intermolecular electrons and energy transfer, cooperated with the integrated biocatalytic process, lead to the significantly enhanced overall reaction efficiency. Moreover, the integrated APS also allows facile recycling of expensive M, enzymes, and cofactors.     

东白城子站畅流期停测侵蚀CO_2和游离CO_2的探讨

根据东白城子河段近十几年试验监测资料,采用几种化学计量关系,分析论证了该河段的侵蚀CO_2和游离CO_2的含量周期性变化规律,为合理利用这一规律提供科学依据,并为该河段的水质监测评价工作节省了人力、物力、财力。     

ZnO薄膜的Ag改性及其光催化性能

利用光合成方法将Ag负载在阴极电沉积得到的ZnO上,成功制备出了Ag／ZnO薄膜．并用XRD、SEM和UV—Vis漫反射光谱对其进行了表征．以甲基橙为目标有机物,测试了其光催化活性．实验结果表明,Ag负载使ZnO的吸收带边明显蓝移;Ag／ZnO薄膜的光催化性能与Ag的负载量有关,在适量负载量下呈现出比纯ZnO更高的催化活性．文中对吸收带边蓝移和ZnO薄膜光催化活性提高的原因也进行了讨论．     

wPMLG-5 Spectroscopy of Self-Aggregated BChl e in Natural Chlorosomes of Chlorobaculum Limnaeum

¹H magic angle spinning (MAS) nuclear magnetic resonance (NMR), employing rapid spinning and the wPMLG-5 pulse sequence, was used to explore the possibility for performing ¹H solid state NMR of a light-harvesting organelle, the chlorosome antenna of Chlorobaculum limnaeum. This natural antenna system is built from bacteriochlorophyll e (BChl e) molecules that are self-assembled to form a supramolecular scaffold for in vivo harvesting of light. We present preliminary data on this chlorosome species and address the feasibility of performing wPMLG spectroscopy, in terms of high power irradiation on a fragile biological sample. In parallel, enhancing the ¹H shift dispersion from the magnetic field can help to resolve signals from protons that resonate downfield. Different line narrowing mechanisms operating in parallel provide access to resolving selected ¹H signals collected from the moderately sized and chemically diverse BChl e molecular motif in the chlorosome scaffold. These discoveries will be helpful for future studies of structural and functional characteristics of self-assembled natural and artificial light-harvesting molecules.     

江西省永修县土地生产潜力初探

对永修县土地生产潜力的估算方法进行了阐述，并估算了永修县土地的光合生产潜力、光温生产潜力、气候生产潜力、土地生产潜力及社会生产潜力。和现实生产力进行了比较和分析，提出了一些提高土地生产力的主要途径。