菊花组织培养中的光质效应研究

光质在菊花培养过程中具显著的生物学效应。试验表明,绿色光可促进菊花试管苗的生长,绿色、红色、蓝色光能部分解除60Co γ射线照射试管苗后所产生的抑制生长作用,红色光有利于花瓣愈伤组织的形成。菊花在组织培养过程中的光质效应,尚与品种有关,表明品种间存在光质敏感性的差异。

水稻蓝膜育秧光质效应的研究

本研究采用蓝色聚乙烯薄膜在自然光温条件下育秧,分析了蓝膜光质处理的光温变化规律,生物效应及其对产量的影响。研究结果表明,蓝膜育秧在短波(波长410～530nm)、弱光(1～3Lux)下透光率高;保温性能好,膜内温度平稳;胚乳利用率和叶绿素含量高,氮、磷、钾吸收量增加,干物质累积加快,超重期提前,秧苗素质好,栽后分蘖速度快,供试的转蓝光膜,蓝色膜分别比透明膜平均增产8.9％和7.7％。

露薇花离体培养及光质效应分析

为了开展露薇花无菌播种试验,研究不同外植体类型、植物激素种类与浓度对愈伤组织诱导及增殖分化影响,并探讨露薇花不同花色品种在不同光质条件下对植株株高的作用。光源采用LED灯管的8种不同光质配比,分别是100%蓝光(B)、100%红光(R)、20%蓝光+80%红光(B:R=2:8)、80%蓝光+20%红光(B:R=8:2)、30%蓝光+70%红光(B:R=3:7)、70%蓝光+30%红光(B:R=7:3)、50%蓝光+50%红光(B:R=5:5)、PGF (植物组培用荧光灯),用以筛选愈伤增殖分化、诱导胚性愈伤组织的最适光质条件。试验结果表明:愈伤组织诱导最适外植体为叶片,最适培养基为MS+6-BA 1.0 mg/L+2,4-D 0.2 mg/L+NAA 0.1 mg/L,继代愈伤组织增殖分化最适光质条件为20%蓝光+80%红光(B:R=2:8);最适培养基为MS+6-BA 2.5 mg/L+NAA 0.1 mg/L,诱导胚性愈伤最适光质条件为20%蓝光+80%红光(B:R=2:8)。5个花色品种在100%红光下株高生长效应值最大,并且随着蓝光比例的增加,株高增长趋势変缓,在100%蓝光时株高生长效应值最小。带边双色对光质敏感性最高。通过本次试验,为露薇花快繁过程中进行合理补光提供理论基础。

不同光质对华黄芪愈伤组织诱导、增殖及器官分化的效应

华黄芪叶片在离体培养过程中，不同光质对愈伤组织诱导、增殖及根、芽分化有不同的效应．（１）叶片在黄光、蓝光、红光、绿光、白光及黑暗条件下均能诱导产生愈伤组织，黄光、蓝光、红光对愈伤组织的诱导有促进作用．（２）在愈伤组织增殖过程中，蓝光有明显的促进作用，而黄光则表现出比较明显的抑制作用．（３）黄光、蓝光对根、芽的分化具有较明显的促进作用，而绿光则对根、芽的分化表现出抑制作用．

Optical Study on Concentration-Driven Rayleigh-Bénard-Marangoni Convection

By utilizing optical Schlieren method, the Rayleigh Bénard Marangoni convection in mass transfer process was observed. A recorder and a camera separately recorded dynamic and static convective flow patterns during experiments . Different organic solvents were selected to investigate the RBM effects induced by different driving mechanisms including density gradient, surface tension gradient and their combination. Thermal effects produced by solvents evaporation and solute absorption/desorption are thought as an important factor in the creation of RBM convection during the mass transfer process. Qualitative analysis of experimental results is presented on the basis of photos and videotapes that were taken as direct visual evidences. Experimental results show that the thermal effect accompanying the mass transfer can be a cause at the onset of RBM convection and can′t be neglected simply in study of RBM effect driven by mass transfer.

Solvent effects on infrared spectra of 2-methyl-4,5-dimethoxy-3-oxo-2H-pyridizine： Part 1. Single solvent systems

Infrared spectroscopy studies of 2 methyl 4,5 dimethoxy 3 oxo 2H pyridizine (MDOP) in 12 pure organic solvents were undertaken to investigate the solvent solute interactions. The frequencies of the carbonyl (C=O) of MDOP were correlated with solvent properties such as solvent acceptor number (AN) and the linear solvation energy relationships (LSER). These frequencies showed a good correlation with the solvent acceptor number (AN) and the LSER.

Fundamental aspects in CO_(2) electroreduction reaction and solutions from in situ vibrational spectroscopies

Using renewable energy to drive carbon dioxide reduction reaction(CO_(2)RR)electrochemically into chemicals with high energy density is an efficient way to achieve carbon neutrality,where the effective utilization of CO_(2) and the storage of renewable energy are realized.The reactivity and selectivity of CO_(2)RR depend on the structure and composition of the catalyst,applied potential,electrolyte,and pH of the solution.Besides,multiple electron and proton transfer steps are involved in CO_(2)RR,making the reaction pathways even more complicated.In pursuit of molecular-level insights into the CO_(2)RR processes,in situ vibrational methods including infrared,Raman and sum frequency generation spectroscopies have been deployed to monitor the dynamic evolution of catalyst structure,to identify reactive intermediates as well as to investigate the effect of local reaction environment on CO_(2)RR performance.This review summarizes key findings from recent electrochemical vibrational spectrosopic studies of CO_(2)RR in addressing the following issues:the CO_(2)RR mechanisms of different pathways,the role of surface-bound CO species,the compositional and structural effects of catalysts and electrolytes on CO_(2)RR activity and selectivity.Our perspectives on developing high sensitivity wide-frequency infrared spectroscopy,coupling different spectroelectrochemical methods and implementing operando vibrational spectroscopies to tackle the CO_(2)RR process in pilot reactors are offered at the end.

Hydrogen Bonding Effects on the Photophysical Properties of 2,3-dihydro-3-keto- 1H-pyrido[3,2,1-kl] phenothiazine

Time-dependent density functional theory （TDDFT） and femtosecond transient absorption spectroscopy were used to investigate the photophysical properties of 2,3-dihydro-3-keto-lH- pyrido[3,2,1-kl]phenothiazine （PTZ4） and 3-keto-lH-pyrido[3,2,1-kl]phenothiazine （PTZ5）. The calculated results obtained from TDDFT suggest that the red-shifts of the absorption spectra of these two fluorophores in methanol are due to the formation of hydrogen-bonded complexes at the ground state. Four conformers of PTZ4 were obtained by TDDFT. The two fluorescence peaks of PTZ4 in tetrahydrofuran （THF） came from the ICT states of the four conformers. The fluorescence of PTZ4 in THF showed a dependence on the excitation wavelength because of butterfly bending. The excited state dynamics of PTZ4 in THF and methanol were obtained by transient absorption spectroscopy. The lifetime of the excited PTZ4 in methanol was 53.8 ps, and its relaxation from the LE state to the ICT state was completed within several picoseconds. The short lifetime of excited PTZ4 in methanol was due to the formation of out-of-plane model hydrogen bonds between PTZ4 and methanol at the excited state.

Properties of Linear Entropy in k-Photon Jaynes-Cummings Model with Stark Shift and Kerr-Like Medium

The time evolution of the linear entropy of an taking into consideration Stark shift and Kerr-like medium. atom in k-photon daynes-Cummings model is investigated The effect of both the Stark shift and Kerr-like medium on the linear entropy is analyzed using a numerical technique for the field initially in coherent state and in even coherent state. The results show that the presence of the Kerr-like medium and Stark shift has an important effect on the properties of the entropy and entanglement. It is also shown that the setting of the initial state plays a significant role in the evolution of the linear entropy and entanglement.

A New Method of Profiling Remote-Sensing Reflectance of Coastal Waters

The profiling method is the first method to select in measuring the remote-sensing reflectance. In the light of the characteristics of China’s coastal waters, we develop a new method to compensate the environment’s effects with the downwelling (λ)rsi r radiance’s profile and to estimate the underwater remote-sensing reflectance r. (λ)rsT he result indicates that the relative deviation of repetitious r in one station is around 10 %.

Lanthanide-doped near-infrared Ⅱ luminescent nanoprobes for bioapplications

Luminescent biosensing in the second nearinfrared(NIR-II) region is featured with superior spatial resolution and high penetration depth by virtue of the suppressed scattering of long-wavelength photons. Hitherto, the reported NIR-II nanoprobes are mostly based on carbon nanotubes, organic fluorophores or semiconducting quantum dots. As an alternative, trivalent lanthanide ions(Ln3+) doped nanoparticles have been emerging as a novel class of promising nanoprobes. In this review, we highlight the recent progress in the design of highly efficient Ln3+-doped NIR-II nanoparticles towards their emerging bioapplications, with an emphasis on autofluorescence-free bioimaging, sensitive bioassay, and accurate temperature sensing. Moreover, some efforts and challenges towards this rapidly expanding field are envisioned.

Rare earth doping effect on the optical properties of several fluorescence materials

Based on the optical properties of rare earth fluorescence materials, a set of fluorescence optical fiber systems was designed. The system selects the emitting LED, which is economical and practical as a light source. The experiment of the emission and excitation optical spectrum, decay curve of fluorescence and residuals for several sensitive materials confirms the match of Y2O2S:Eu using the light source and the feasibility of the system. The rare earth material Y2O2S:Eu is selected as the material candidate for being the most sensitive.

Interaction between water molecules and 3C-SiC nanocrystal surface

The influence of water permeates almost all areas including biochemistry,chemistry,physics and is particularly evident in phenomena occurring at the interfaces of solid surface such as SiC nanocrystals,which are promising nanomaterials and exhibit unique surface chemical properties.In this paper,the quantum confinement effect and stability of 3C-SiC nanocrystals in aqueous solution as well as photoluminescence properties in water suspensions with different pH values are reviewed based on design and analysis of surface structures.On this basis,the significant progress of 3C-SiC nanocrystals in efficiently splitting water into usable hydrogen is summarized and the relative mechanisms are described.In addition,the water-soluble 3C-SiC quantum dots as robust and nontoxic biological probes and labels also are introduced as well as future prospects given.

Recent progress in the fields of tuning the band gap of quantum dots

Band gap, which can be tuned by changing the size of quantum dots (QDs) based on the quantum confinement effect, plays a fundamental role in electrical and optical properties of QDs. However, the tuning of the band gap by changing the size results in a series of intrinsic problems, such as the instability of the extremely small QDs, negative combination with biomolecules because of the large size of QDs, etc. Recently, several new methods have been developed to further study and improve the tuning of the band gap. In this paper, we summarized the recent progress in the fields of tuning the band gap of QDs, including alloyed QDs, core-shell QDs and doped QDs. The review has also prospected the development trend of tuning the band gap as well as their applications.

Advances in organic micro/nanocrystals with tunable physicochemical properties

Organic micro/nanocrystals based on small organic molecules have drawn extensive attention due to their potential application in organic field-effect transistors,electrochemical sensors,solar cells,etc.Herein,the recent advances for organic micro/nanocrystals from the perspective of molecule aggregation mode,morphology modulation,and optical property modulation are reviewed.The stacking mode and the intermolecular interaction depend on the molecular structure,which eventually determines the morphology of organic micro/nanocrystals.The morphologies of the organic micro/nanocrystals make the aggregates exhibit photon confinement or light-guiding properties as organic miniaturized optoelectronic devices.In this review,we conclude with a summary and put forward our perspective on the current challenges and the future development of morphology and optical tunable direction for the organic micro/nanocrystals.

Study of doping effect,phase separation and heterojunction in CMR manganites

Mixed-valence manganites have attracted considerable research focus in recent years not only because of the potential application of colossal magnetoresistance(CMR) in magnetic devices,but also because of many intriguing physical properties observed in these materials.Doping elements at A-site can alter the filling of 3d Mn band and the tolerance factor.Therefore the hole-and electron-doped CMR manganites exhibit a rich phase diagram.In addition,more theoretical and experimental results suggest that phase separation is a critical factor for the understanding of CMR phenomena.Recently,there is an increasing interest in the fabrication and investigation on manganite-based heterojunction,which demonstrated excellent rectifying property,large MR,and photovoltaic effect.