光学空间频率合成器及其在无分散三维形状计测中的应用(英文)

传统的白光干涉法、光学频谱扫描干涉法、低相干度断层扫描法以及其他三维形状计测法均采用宽带光学频谱光源实现绝对高度的测量,因此当测量对象存在不均匀的折射率分布或者光学吸收特性时,以上方法将不能给出准确的测量结果。针对传统绝对干涉法的这些制约,本研究通过干涉现象中时空参数的类比,提出了宽带空间频谱单色光源的概念,并通过改变光源的空间频谱构造验证了无分散三维绝对形状测定方法的可行性。     

Convenient Preparation of Self-Assembled Monolayers Derived from Calix[4]resorcinarene Derivatives Exhibiting Resistance to Desorption

Crown conformers of O-carboxymethylated calix[4]resorcinarenes (CRA-CMs) bearing four perfluorooctyl- and octylazobenzene residues at the lower rim of the cyclic skeleton were synthesized to investigate the resistance to desorption of CRA-CMs forming self-assembled monolayers on aminosilylated silica substrates and the surface energy photocontrol based on E- to-Z photoisomerization of the azobenzene moiety. In comparison with CRA-CM monolayers on silica substrates, the desorption of CRA-CMs on the aminated substrate was remarkably suppressed even when CRA-CM monolayers were sonicated in polar solvents and even in water. The high desorption-resistance was attributable to multi-point adsorption of CRA-CMs through COOH/NH₂ interactions. UV-Vis spectral studies revealed that CRA-CM substituted with p-octylazobenzene exhibited high E- to-Z photoisomerizability up to 92% in self-assembled monolayers, while less photoisomerizability was observed for CRA-CM bearing p-perfluorooctylazobenzenes due to the steric hindrance of the larger perfluoroalkyl chains. Photoinduced changes of contact angles for water up to 8.3° were observed for a CRA-CM monolayer.     

E' centers in amorphous SiO(2) revisited: a new look at an old problem.

We present theoretical evidence that the paramagnetic E' defect centers in amorphous silicon dioxide (a-SiO(2)) do not have the same microscopic structures as those well-defined in the corresponding crystalline counterparts such as alpha-quartz. We then present alternative models of some paramagnetic defects that account for the underlying experimental features of the E'-center variants in a-SiO(2). We suggest that our new model should take the place of the conventional defect model of a-SiO(2).     

Needle-type ultra micro silver/silver chloride reference electrode for use in micro-electrochemistry.

A needle-type ultra micro silver/silver chloride reference electrode having a micro capillary with outer and inner diameters of 1.0 microm and 0.5 +/- 0.2 microm, respectively, was constructed. This micro reference electrode can be stuck into a living cell, and is applicable to use in very small environments, such as an electrochemical cell of an electrochemical scanning tunneling microscope or the detection portion of a micro-TAS. Excellent stability and repeatability of the micro reference electrode potential could be obtained by filling the micro capillary with agar gel containing 3.33 mol/L potassium chloride as a salt bridge, by covering the bare part of the silver wire on which silver chloride was deposited, and by electromagnetic shielding of the measurement cell and wire lead from the electromagnetic waves. The electrode showed stable potential for 7 days after its fabrication using 3.3 mol/L potassium chloride aqueous solution containing silver chloride as an internal electrolyte solution. The electrode exhibited constant electrode potential and excellent stability in test solutions of pH 5-9. The electrode potential of a commercial pH glass electrode measured against the micro reference electrode in standard pH buffer solutions was in good accordance with the Nernst equation.     

A simple determination of mizoribine in human plasma by liquid chromatography with UV detection

A simple liquid chromatography (LC) method was developed for determination of the therapeutic level of mizoribine in human plasma. After precipitation of plasma proteins with 6% perchloric acid, mizoribine was determined by LC with spectophotometric detection. The peak height for mizoribine was linearly related to its concentrations, which ranged from 0.09 to 3.13 microg/mL. Therefore, the limit of quantitation was considered to be 0.09 microg/mL. The accuracy was 104.96-107.37%. The intra- and interday relative standard deviation values were in the range of 1.10-3.25%. The detection limit was 0.025 microg/mL, defined as a signal-to-noise ratio of 3. The plasma concentrations of mizoribine were not related to the dosage. Because mizoribine was mainly excreted in the urine, the plasma concentrations of mizoribine might be affected by a change in renal function. Therefore, the mizoribine concentration in blood should be monitored and the dosage adjusted, depending on the condition of renal function. It was suggested that the present method may be applied well in the therapeutic drug monitoring for mizoribine.     

New entry of coupling reaction of phenacylamine derivatives with silylstannane

The new coupling reaction of phenacylamines with silylstannane and lithium diisopropylamide (LDA) is reported. The treatment of a phenacylamine iodide 1 with (trimethylsilyl)tributylstannane (Me3SiSnBu3) and cesium fluoride (CsF) gave a dimerization product 2 having no iodine atom. Reaction of 1 with LDA afforded a dimerization product 3 with an iodine atom. The products 2 and 3 were separated to the meso and racemic isomers, respectively.     

A crossed molecular beam study of the chemiluminescent reaction Xe(3P2,0) + BrCN → Xe(1S0) + Br + CN(B2Σ+)

The chemiluminescent interaction of Xe(³P_2,0) and BrCN has been studied under crosscd-beam conditions at collision energies ranging up to 70 kj mol^?1. The CN(B → X) fluorescence spectrum, the excitation function for its production and the fluorescence polarisation - or rather its absence - have been determined. The results can be explained by a two-stage harpooning mechanism involving an inert-gas cyanide (Xe⁺CN^?)¹ intermediate but not by a “sensitisation” mechanism proceeding through electronic energy transfer.     

Reorientational motion of acetone in solutions

Dipolar correlation functions of acetone in various solvents are obtained by Fourier transform of infrared spectra. The analysis of the shapes of correlation functions shows that the reorientational process is diffusional in the time scale longer than about 0.3 × 10^?12 sec. In nonpolar solvents the ratios of correlation times τ_A : τ_B : τ_C do not vary in different solvents, and the reorientation around b axis is more restricted than around the other axis. The length of correlation time is dependent on the density of solvent rather than the viscosity. These observations are unexpected if only the electrostatic interaction is considered. In polar solvents correlation times are longer than in nonpolar solvents and the tendency is especially remarkable in τ_B. An electrostatic interaction between polar molecules seems to be responsible for these observations. The solvent effect on the frequency shifts of carbonyl stretching vibration is consistent with the result of correlation times.