Nd：MgO：LiNbO＿3晶体的荧光光谱及其双晶体腔内互倍频实验

采用激光感生荧光技术测量了Ｎｄ：ＭｇＯ：ＬｉＮｂＯ＿３晶体的偏振荧光光谱。简要地说明了Ｎｄ：ＭｇＯ：ＬｉＮｂＯ＿３双晶体腔内互倍频的基本原理，并在实验中用染料激光作泵浦源实现了其双晶体腔内互倍频运转；得到５４３ｎｍ单横模倍频绿光单端输出约６ｍＷ，腔前泵浦阈值约３８ｍＷ，总转换效率约为１．３％。

A tetragonal tungsten bronze-type photocatalyst:Ferro-paraelectric phase transition and photocatalysis

Although ferroelectrics have potential applications in photocatalysis due to their highly efficient charge separation, their mechanism of charge separation is still unknown. A ferroelectric Sr0.7Ba0.3Nb2O6 （SBN‐70） semiconductor with a low ferro‐paraelectric phase transition （65℃） was studied. The photocatalytic activity for H2 production by ferroelectric and paraelectric SBN‐70 was examined. The spontaneous polarization in the ferroelectric phase strongly affected the photocata‐lytic performance and parallel ferroelectric domains significantly promoted photogenerated charge separation to result in better photocatalytic H2 production. This knowledge provides an important basis for the fabrication of ferroelectric photocatalysts with improved charge separation ability.

Kinetics of Coil-to-Globule Transition of DansyI-Labeled Poly（N-isopropyl- acrylamide） Chains in Aqueous Solution

The coil-to-globule transition of thermally sensitive linear poly（N-isopropylacrylamide） （PNIPAM） labeled with dansyl group is induced by 1.54 μm laser pulses （widths10 ns）. The dansyl group is used to follow the transition kinetics because its fluorescence intensity is very sensitive to its micro-environment. As the molar ratio of NIPAM monomer to dansyl group increases from 110 to 300, the effect of covalently attached dansyl fluorophores on the transition decreases. In agreement with our previous study in which we used 8-anilino- l-naphthalensulfonic acid ammonium salt free in water as a fluorescent probe, the current study reveals that the transition has two distinct stages with two characteristic times, namely, Tfast≈0.1 ms, which can be attributed to the nucleation and formation of some ＂pearls＂ （locally contracting segments） on the chain, and tslow≈0.5 ms, which is related to the merging and coarsening of the ＂pearls＂.Tfast is independent of the PNIPAM chain length over a wide range （Mw=2.8× 10^6-4.2 × 10^7 g/mol）. On the other hand, Tslow only slightly increases with the chain length.

Binding interactions of pefloxacin mesylate with bovine lactoferrin and human serum albumin

The binding of pefloxacin mesylate （PFLX） to bovine lactoferrin （BLf） and human serum albumin （HSA） in dilute aqueous solution was studied using fluorescence spectra and absorbance spectra. The binding constant K and the binding sites n were obtained by fluorescence quenching method. The binding distance r and energy-transfer efficiency E between pefloxacin mesylate and bovine lactoferrin as well as human serum albumin were also obtained according to the mechanism of Forster-type dipole-dipole nonradiative energy-transfer. The effects of pefloxacin mesylate on the conformations of bovine lactoferrin and human serum albumin were also analyzed using synchronous fluorescence spectroscopy.

Thermochromism of 1,4-Bis[2-(4-pyridyl)ethenyl]-benzene Derivatives

Three kinds of thermochromic materials(DC8,DC12,DC16)were synthesized by linking the rigid 1,4-bis[2-(4-pyridyl)ethenyl]-benzene(bpeb)with different lengths of alkyl chains.They exhibit remarkable fluorescent color changes under the irradiation of 365 nm light with elevating temperature,which is supposed to be caused by the transition between the crystal state and the amorphous state.Interestingly,the DC16 solid also has a photochromic character.It should be noticed that the phase transition temperatures of three materials measured by differential scanning calorimetry are higher than those of the fluorescence color changes during the heating process.Thus,the allochroic effect is attributed to the synergistic effect of both heating and photo-inducement(365 nm).Ethanol can turn the heated powder into the initial crystal again which indicates that their thermochromic behavior is reversible and makes the fluorescence recover.

New Insights into Folding Kinetics of α,ω Dye-Functionalized Poly(N-isopropylacrylamide)

Two narrowly-distributed poly(N-isopropylacrylamide)(PNIPAM) samples were prepared via atom transfer radical polymerization (ATRP) with a novel dansyl functionalized initiator. The other end of the PNIPAM was functionalized by dabcyl group via click reaction. From the static fluorescence measurements, the fluorescence intensity of dansyl group and energy transfer efficiency between dansyl and dabcyl groups increased when the temperature increased from 36 °C to 45 °C, indicating that the microenvironment surrounding dansyl became hydrophobic and the distance between dansyl and dabcyl decreased. The kinetics of the conformational change of the dye-labeled PNIPAM was studied by a home-made laser-induced temperature jump device with fluorescent measurement. Our results revealed that the characteristic transition time was 3.8 and 5.8 ms for PNIPAM with degrees of polymerization of 85 and 142, respectively, indicating that the characteristic transition time was related to the chain length. Besides, characteristic transition time for the change of the energy transfer efficiency was 2.9 ms for PNIPAM with the degree of polymerization of 85, suggesting that the energy transfer efficiency change was faster than the fluorescence intensity change of dansyl group.

A dual measurement method of strain and temperature

With the rapid development of China's foreign trade, the coastal and inland waterway transport has been increased rapidly. The potential market for marine engines is more and more obvious. The measurement of the engine temperature and strain becomes very important. The fluorescence fiber sensors are broadly used to measure temperature, concentration, and pH value, etc. The fluorescence sensing systems are based on different principles, namely fluorescence intensity, fluorescence intensity ratio, and fluorescence lifetime. The fluorescence lifetime is an effective parameter for sensing purpose, because it is independent of the intensity of the pumping source and does not need expensive narrow-band filters. An experiment system has been established, in which some samples were produced to measure the fluorescence lifetime and temperature characteristics and the relationship of the strain and temperature versus the fluorescence lifetime was achieved at the same time. The experiment result was fitted and analyzed. The test results show that the fluorescence lifetime decreases with the increasing of temperature. The change of fluorescence lifetime with the strain is inconspicuous comparing to that with the temperature.

Chlorophyll-a Fluorescence in Ecology： Theoretical Considerations and Examples around Marine Macroalgae

Over the last decades, the usage of PAM （pulse amplitude modulated） fluorometers for assessment of chlorophyll-a fluorescence variations became widely applied on marine macroalgae physiology and ecophysiology researches. Due to the increased use of these methods, a large number of studies, mainly relating to macroalgae ecology and physiology were worldwide reported. In this context, it was also created a mismatch of concepts about fluorescence of the chlorophyll-a and its application. Under this background, this study compile and summarize the state of the art knowledge regarding to the chlorophyll fluorescence, contextualizing the use of the PAM method with the main factors regulating photosynthesis （light, temperature, salinity nitrogen and phosphorus） in marine macroalgae. Moreover, this study also references the most used terms and shows some examples found in literature about the applicability of fluorescence parameters. The herein findings and the discussed examples, helps to emphasize the importance of fluorescence usage, that highlights the understanding of photosynthetic responses in macroalgal physiology and ecology.

Phase transition and photoluminescence properties of Eu^3＋-doped ZnMoO4 red phosphors

Eu3＋-doped ZnMoO4 with different doping concentrations were synthesized by a hydrothermal method. The effects of Eu3＋ doping on the phase structure and photoluminescence （PL） properties of ZnMoO4 were investigated. The result showed that the introduction of Eu3~ could lead to phase transition of ZnMoO4. With the increase of Eu3-- doping amount, [3-ZnMoO4 was transformed to ct phase gradually, which led to different photoluminescence performances. The optimized doping concentration of Eu3＋ was 6 mol% for the highest emission intensity at 615 nm. Its CIE chromaticity coordinates were （0.667, 0.331）, which were very close to the values of standard chromaticity （0.67, 0.33） for National Television Standards Committee （NTSC） system. Therefore, Eu3＋-doped ZnMoO4 is considered to be a promising red-emitting phosphor for white LED applications.

A turn-on fluorescent probe for Au^(3+) based on rodamine derivative and its bioimaging application

A new fluorescent probe RY was synthesized for the detection of Au3+ions based on a rhodamine B derivative.The fluorescent probe showed good selectivity and sensitivity to Au3+ions.Obvious color and fluorescence changes could be observed with the naked eye while the fluorescent probe reacted with the Au3+ions.The detection limit of the probe was determined to be 36 ppb by the fluorescence titration.The excellent linear relationship suggests that the probe is potentially useful for quantitative detection of Au3+in vitro.We also demonstrated its bioimaging application in both living cells and mice.This was the first time that a fluorescent probe was successfully applied to imaging Au3+in living animals.

Investigation of nitroxoline-human serum albumin interactions by spectroscopic methods

Nitroxoline is a wide spectrum antibacterial and is one of the most important urinary antiseptics.The interaction between nitroxoline and human serum albumin(HSA)has been investigated systematically by fluorescence spectroscopy,synchronous fluorescence,three-dimensional fluorescence,CD spectroscopy and UV-Vis absorption spectroscopy.The results indicated that the quenching of HSA by nitroxoline was static.The corresponding thermodynamic parameters △H,△S and △G calculated according to van’t Hoff equation revealed that the intermolecular forces acting between nitroxoline and HSA were mainly hydrogen bonding and van der Waals forces.The conformational changes in the interaction were studied by synchronous fluorescence,CD spectroscopy and three-dimensional fluorescence spectra which showed changes in the microenvironment and conformation of HSA.