一种数字投影式顶焦度测量仪

提出一种数字投影式顶焦度测量的技术方案。根据此方案设计的焦度测量仪,通过精密机械传动,嵌入以单片微型计算机为核心的硬件控制系统和软件处理系统,对眼镜镜片球镜顶焦度、球柱镜顶焦度及轴位角等进行了测量。它通过光学投影的方式进行对焦,测量活动标尺的平动量和转动量来计算相应参数,并利用液晶 LCD 显示结果。采用一种动态基准存储技术,通过预先存储的动态基准来计算顶焦度,可以有效消除系统误差,提高测量精度。对产品样机的试验结果表明,顶焦度的测量精度达到±0.03D。     

Development of a resin curing model for UV nanoimprint

UV nanoimprint lithography uses UV light as an energy source. It is performed at room temperature and low pressure, and has its own merits as compared to thermal nanoimprint. In this paper, a measurement system was developed to measure the degree of resin curing in UV nanoimprint to improve our understanding of the resin solidification phenomenon. A curing model was then established based on the measurement results. The measurement system measured the degree of cure in real time and was composed of a Fourier transform infrared spectroscopy system, a UV light source, and an optical guide. Also, new UV-curable resins that had low viscosity values were developed for the UV nanoimprint process, and imprint tests using these resins were performed successfully. The curing model considered the UV irradiation time, power, and curing temperature, which are important parameters in the UV nanoimprint process. The degree of cure had an exponential relation to UV irradiation time, power, and temperature; thus, the curing model was expressed as an exponential function of the UV irradiation time, power, and temperature. The developed model was verified for various UV-curable resins.     

基于矩阵方法的共轴球面系统屈光特性研究

基于眼科屈光学理论,运用矩阵方法建立了单个球镜片及多个球镜片组合的复杂共轴球面系统的精确屈光特性模型,并与简化模型进行比较,分析镜片间距及放置顺序对组合后屈光特性的影响。基于该精确屈光特性模型,对影响球镜度的各项不确定度分量进行分析。组成镜片的前、后表面曲率半径是影响屈光特性的主要不确定度分量,其次是镜片材料折射率和镜片间距引入的不确定度分量,中心厚度引入的不确定度分量最小。     

Profiles of interval bounds around the coordinates of antistigmatic powers

A cylinder that supplements the best vision sphere power appropriately, may improve visual acuity, but this cylinder power can displace the circle of least confusion. A sphere of opposite sign and half the power of the cylinder lens moves the circle back. This added sphere combined with the cylinder is the power of a cross-cylinder lens which, when resolved into independent components called the orthogonal and the oblique antistigmatic components, contains unique, meaningful, calculation-friendly dioptric powers. We calibrate bounds around the antistigmatic coordinates with regular bounds estimated around pure cylinder refractions. The bounds that are then plotted are called profiles of power ranges. The purpose of this article is to determine whether profiles of bounds of the components of antistigmatic lenses, are well-behaved with good foundation with respect to all cylinder axes. Profiles convey the degree of confidence and are key indicators of the quality of the reported powers or calculation.     

Experimental determination of the fundamental-mode diameter in solid-state lasers

A method to determine directly the radius of the fundamental mode in a laser crystal has been developed. The radius is measured by comparison of the distribution of the spontaneous emission in the pumped region during laser operation with the fluorescence distribution without laser emission. Measuring the mode radius with various pump powers enables one to optimize the overlap between the pump and the cavity beam and to determine the dioptric power of the thermally induced lens.     

Application of artificial neural networks for modeling of the treatment of wastewater contaminated with methyl tert-butyl ether (MTBE) by UV/H2O2 process

During the last two decades, methyl tert-butyl ether (MTBE) has been widely used as an additive to gasoline (up to 15%) both to increase the octane number and as a fuel oxygenate to improve air quality by reducing the level of carbon monoxide in vehicle exhausts. The present work mainly deals with photooxidative degradation of MTBE in the presence of H2O2 under UV light illumination (30W). We studied the influence of the basic operational parameters such as initial concentration of H2O2 and irradiation time on the photodegradation of MTBE. The oxidation rate of MTBE was low when the photolysis was carried out in the absence of H2O2 and it was negligible in the absence of UV light. The addition of proper amount of hydrogen peroxide improved the degradation, while the excess hydrogen peroxide could quench the formation of hydroxyl radicals (OH). The semi-log plot of MTBE concentration versus time was linear, suggesting a first order reaction. Therefore, the treatment efficiency was evaluated by figure-of-merit electrical energy per order (E(Eo)). Our results showed that MTBE could be treated easily and effectively with the UV/H2O2 process with E(Eo) value 80 kWh/m3/order. The proposed model based on artificial neural network (ANN) could predict the MTBE concentration during irradiation time in optimized conditions. A comparison between the predicted results of the designed ANN model and experimental data was also conducted.     

Study of the Photodegradation Process of Vitamin E Acetate by Optical Absorption, Fluorescence, and Thermal Lens Spectroscopy

The stability of vitamin E acetate exposed to ultraviolet (UV) light was studied using three spectroscopic methods. An ethanol solution of vitamin E acetate was treated with either UVC light (254?nm) or UVA light (366?nm) during a period of 10?min followed by a study of UV?CVis optical absorption, then by fluorescence spectroscopy excitation by UV radiation at either 290?nm or 368?nm and, finally the solution was studied by thermal lens spectroscopy. Immediately, the same solution of vitamin E acetate was subjected to the UV irradiation process until completion of six periods of irradiation and measurements. UVC light treatment induced the appearance of a broad absorption band in the range of 310?nm to 440?nm with maximum absorbance at 368?nm, which progressively grew as the time of the exposure to UVC light increases. In contrast, UVA light treatment did not affect the absorption spectra of vitamin E acetate. Fluorescence spectra of the vitamin E acetate (without UV light treatment) showed no fluorescence when excited with 368?nm while exciting with 290?nm, an intense and broad emission band (300?nm to 440?nm) with a maximum at 340?nm appeared. When vitamin E acetate was treated with UVC light, this emission band progressively decreased as the time of the UVC light irradiation grew. No signal from UV-untreated vitamin E acetate could be detected by the thermal lens method. Interestingly, as the time of the UVC light treatment increased, the thermal lens signal progressively grew. Additional experiments performed to monitor the time evolution of the process during continuous UVC treatment of the vitamin E acetate using thermal lens spectroscopy exhibited a progressive increase of the thermal lens signal reaching a plateau at about 8000 s. This study shows that the vitamin E acetate is stable when it is irradiated with UVA light, while the irradiation with UVC light induces the formation of photodegradation products. Interestingly, this photodegradation process using the study of the thermal lens effect could be followed closely even though poor absorption of the photodegraded product of the vitamin E acetate was observed at the laser wavelength used. As the thermal lens method allowed for accurate monitoring of the extent of photodegradation of the vitamin E acetate, this study opens the photodegradation process as a new application to be added to the recent applications of thermal lens spectroscopy in chemical analysis.     

Exploring the possibility of early cataract diagnostics based on tryptophan fluorescence

A novel route for early cataract diagnostics is investigated based on the excitation of tryptophan fluorescence (TF) at the red edge of its absorption band at 317 nm. This allows penetration through the cornea and aqueous humour to provide excitation of the ocular lens. The steepness of the red edge gives the potential of depth control of the lens excitation. Such wavelength selection targets the population of tryptophan residues, side chains of which are exposed to the polar aqueous environment. The TF emissions around 350 nm of a series of UV-irradiated as well as control lenses were observed. TF spectra of the UV cases were red-shifted and the intensity decreased with the radiation dose. In contrast, intensity of non-tryptophan emission with maximum at 435 nm exhibited an increase suggesting photochemical conversion of the tryptophan population to 435 nm emitting molecules. We demonstrate that the ratio of intensities at 435 nm to that around 350 nm can be used as a measure of early structural changes caused by UV irradiation in the lens by comparison with images from a conventional slit-lamp, which can only detect defects of optical wavelength size. Such diagnostics at a molecular level could aid research on cataract risk investigation and possible pharmacological research as well as assisting surgical lens replacement decisions.     

Photocatalytic decolorization of azo-dye with zinc oxide powder in an external UV light irradiation slurry photoreactor

Photocatalytic decolorization of azo-dye Orange II in water has been examined in an external UV light irradiation slurry photoreactor using zinc oxide (ZnO) as a semiconductor photocatalyst. The effects of process parameters such as light intensity, initial dye concentration, photocatalyst loading and initial solution pH on the decolorization rate of Orange II have been systematically investigated. A two-stage photocatalytic decolorization of Orange II, the first stage of fast decolorization rate and the subsequent second stage of rather slow decolorization rate, was found. The efficiency of decolorization of Orange II increased as initial Orange II concentration decreased and UV light intensity increased. There was the optimal ZnO concentration being around 1000 mg L(-1). The optimal pH was around 7.7, which was at the natural pH of the dye solution. The effect of aeration rate on the decolorization of Orange II has been also investigated and the enhancement of decolorization of Orange II with increasing aeration rate was found. By using a model for the light intensity profile in the external UV light irradiation slurry photoreactor, the simulation model for the decolorization of Orange II with ZnO photocatalyst has been developed. The proposed model in which the slow decolorization in the second stage as well as the initial fast decolorization is also taken into account could simulate the experimental results for UV light irradiation satisfactorily. The proposed simulation model in which the change of light intensity with time due to the decolorization of Orange II and the light scatter due to solid photocatalysts are considered will be very useful for practical engineering design of the slurry photoreactor of wastewater including textile dyes.     

Nanoarchitectonics of SnSe with the impacts of ultrasonic powers and ultraviolet radiations on physical and optoelectronic properties

In this study, SnSe nanostructures prepared by the precipitation method were exposed to the irradiation of ultrasound waves at different powers and ultraviolet (UV) rays. The results of structural analyses revealed the formation of SnSe nanostructure phases and the presence of Sn and Se, respectively. The structural properties, including stress and strain, were calculated for all main peaks obtained from the XRD analysis conformed to the orthorhombic phase. The FESEM images demonstrated that they were narrow-size nanorods alongside agglomeration particles dispersed in all samples. PL results illustrated changes in the ultrasonic power, UV, and simultaneous irradiation of these waves led to the shift of emission bands and intensities. The absorption spectra were measured in the range of 200–1100 nm, indicating that they were shifted into higher wavelengths. Additionally, energy band gap (E_g) changes showed that their E_g was in the range of ～ 1.30 eV. I-V characteristics results demonstrated that increase of ultrasonic power, UV, and ultrasound irradiation resulted in the enhancement of responsivity and sensitivity. Furthermore, they had detectivity in the range of 12–122 × 10⁷ (Jones). Moreover, the irradiation of ultrasound and UV rays had a considerable impact on mobility and carrier concentration.     

Optical quality of intraocular lenses after several years in the human eye

The optical quality of explanted intraocular lenses (IOLs) was analysed to verify if their quality is maintained after having been in the human eye for several years. Twenty-five explanted IOLs were studied, 10 because of intraocular luxation and 15 from corneal donors. The dioptric power and modulation transfer function (MTF) were determined to discover the image quality of the IOLs. The spectral transmission was also established to ascertain whether the filter against ultraviolet (UV) radiation was still effective. The results show that the MTF of implanted IOLs is maintained and therefore so is the image quality they provide. Only decay in the MTF of some of the explanted IOLs was observed because of intraocular luxation. The transmission of the UV filters incorporated in the different IOLs hardly varied; thus they maintained their effectiveness.     

Study on biotribological properties of UHMWPE grafted with MPDSAH

In order to prolong the service life of artificial joints, a zwitterion monomer of MPDSAH ((3-(methacryloylamino)propyl)dimethyl (3-sulfopropyl)ammonium hydroxide) was grafted onto ultra-high molecular weight polyethylene (UHMWPE) powders to construct a brush-like structure by UV irradiation, and then the grafted UHMWPE powders were hot pressed as the bulk materials. The wettability of bulk materials surface with different monomer concentrations was analyzed. The tribological properties of modified UHMWPE bulk materials were investigated under distilled water and saline by sliding against stainless steel ball. The measurement of Fourier-transform infrared (FT-IR) spectroscopy indicates that MPDSAH is successfully grafted onto the surface of UHMWPE powders by UV irradiation. The contact angles of modified UHMWPE are decreased and the surface wettability is effectively improved. The friction coefficient of the modified sample is lower than that of untreated UHMWPE in aqueous lubricants during a long-term friction. With the increase of monomer concentration, the wear rate of grafted UHMWPE decreases gradually in distilled water. The grafting hydrophilic macromolecule polymer is helpful to form a lubricating film of water, which leads to the improvement of the lubricity of UHMWPE.     

Experimental investigation of new concentration measurements using nonlinear dynamics through laser-induced thermal lens oscillation

The laser-induced thermal lens oscillation that is generated in an organic solution by Ar-ion laser irradiation was studied as a nonlinear dynamic system. The different dynamic states depend on three control parameters: laser beam power (P), depth (d) from a surface to a laser beam position, and solvent concentration. The transitions of dynamic states including several complicated states, for example, periodic, double periodic, were investigated by varying the parameters (P, d) for 27%, 30%, and 33% of tri-n-butyl phosphate solution diluted with n-dodecane. It was found that these transitions were strongly dependent on the concentration of the TBP solution. Based on this result, we also propose an application to solvent concentration measurement with a difference of 3%.     

A new mathematical model for irradiance field prediction of upper-room ultraviolet germicidal systems

There has been an increasing interest in the use of upper-room ultraviolet germicidal irradiation (UVGI) system because of its proven disinfection effect for airborne microorganisms. To better design and explore further potential applications of UVGI systems, it is of critical importance to predict the spatial UV intensity in enclosures. In this paper, we developed a new mathematical model to predict spatial radiation intensity for upper-room ultraviolet germicidal irradiation systems. The detail geometries of the lamp and the reflector were removed and replaced by introducing a fictitious irradiation surface near louver slots. The view factor approach was applied to evaluate the UV irradiance in a three-dimensional space with different louver configurations. With this approach no detail meshing of the fixture is required and this leads to significant simplification of the entire systems from modeling perspectives. To validate the model, experiments were performed in a full-scale environmental controlled chamber in which one UVGI fixture was mounted on a sidewall. The UV irradiance was measured by a radiometer. The results predicted by the present model agree very well with the experimental measurements. Factors affect the accuracy of the model was also discussed.     

紫外辐照改性聚砜超滤膜

用紫外辐照的方法改性聚砚超滤膜，紫外辐照后膜性能的变化与辐照时间，改性剂种类，改性剂浓度等有关。聚砚超滤膜经紫外辐照改性后，通量增加，膜的亲水性增强，并讨论了此外辐照改性超滤膜的机理。     

Characterization and Photocatalytic Efficiency of TiO2 /Ti Beads Fabricated by Simple Heat-Treatment

The goal of the present study was to investigate the photocatalytic efficiency of titanium dioxide (TiO 2) formed on titanium (Ti) bead substrate (referred herein as TiO 2 /Ti beads) by heat treatment when exposing to ultraviolet (UV) light irradiation.Escherichia coli was used as the model test organism.The results show 4-log and 7-log decrease in bacterial concentration after a test time of 15 and 120 min,respectively,using TiO 2 /Ti beads irradiated with UV light in a tin-foil covered beaker.This article presents the potential of TiO 2 on Ti bead substrate formed by simple heat-treatment together with UV light for bacterial inactivation.     

Morphological transition of gold nanostructures induced by continuous ultraviolet irradiation

Gold nanoparticles were synthesized through a continuous UV irradiation method using citric acid as a reducer and protective agent. After a period of continuous UV irradiation, the nanoparticles transformed into two-dimensional (2D) nanonetworks, porous nanoplates and compact nanoplates with hexagonal, triangular or truncated triangular pores through a self-assembly process which was dependent on the citric acid concentration. Selected area electron diffraction (SAED) patterns indicated that both the nanonetworks and the porous nanoplates were single crystalline. The influence of citric acid concentration and irradiation time on the morphological transition of Au nanostructures was investigated. The process of morphological transition was presumably discussed.     

Nanosecond laser-induced photochemical oxidation method for protein surface mapping with mass spectrometry

We have developed an ultrafast pulse method for protein surface footprinting by laser-induced protein surface oxidations. This method makes use of a pulse UV laser that produces, in nanoseconds, a high concentration of hydroxyl (OH) free radicals by photodissociation of a hydrogen peroxide (H2O2) solution. The OH radicals oxidize amino acid residues located on the protein surface to produce stable covalent modifications. The oxidized protein is then analyzed by mass spectrometry to map the oxidized amino acid residues. Ubiquitin and apomyoglobin were used as model proteins in this study. Our results show that a single laser pulse can produce extensive protein surface oxidations. We found that monooxidized ubiquitins were more susceptible to further oxidations by subsequent laser irradiation, as compared to nonoxidized ones. This is due to the conformational changes of proteins by oxidation that increases the solvent-accessible surface area. Therefore, it is crucial to perform this experiment with a single pulse of laser so as to avoid oxidation of proteins after conformation of the protein changes. Subsequently, to obtain a high frequency and coverage of the oxidation sites while keeping the number of laser shots to one, we further optimized the laser power and concentration of hydrogen peroxide as well as the concentration of protein. This ultrafast OH radical generation method allows for rapid and accurate detection of surface residues, enabling mapping of the solvent-accessible regions of a protein in its native state.     

Designing artificial cells to harness the biological ion concentration gradient

Cell membranes contain numerous nanoscale conductors in the form of ion channels and ion pumps that work together to form ion concentration gradients across the membrane to trigger the release of an action potential. It seems natural to ask if artificial cells can be built to use ion transport as effectively as natural cells. Here we report a mathematical calculation of the conversion of ion concentration gradients into action potentials across different nanoscale conductors in a model electrogenic cell (electrocyte) of an electric eel. Using the parameters extracted from the numerical model, we designed an artificial cell based on an optimized selection of conductors. The resulting cell is similar to the electrocyte but has higher power output density and greater energy conversion efficiency. We suggest methods for producing these artificial cells that could potentially be used to power medical implants and other tiny devices.     

Phenanthrene and pyrene oxidation in contaminated soils using Fenton's reagent

Fenton's reagent has shown its applicability to oxidizing these biorefractory organic contaminants. The purpose of this contribution was to investigate the influence of operating parameters on the process efficiency for soil highly contaminated by PAHs. Five variables were selected: pH, reaction time, UV irradiation, hydrogen peroxide concentration and Fe (II) amendment. Their effects on the oxidation of (i) phenanthrene and on (ii) phenanthrene and pyrene present in freshly contaminated soil samples were studied through batch reactor experiments following factorial designs. For phenanthrene oxidation run with a soil contaminated at 700 mg kg(-1), one set of variables enabled us to reach a residual concentration lower than 40 mg kg(-1) (Dutch legislation threshold). The most important factor was the reaction time, followed at a certain distance by UV irradiation, Fe (II), H(2)O(2) concentration and pH, this last variable being the least significant. The possibility of operating without pH adjustment is of importance in the treatment at the field scale. This shows the feasibility of photo-Fenton-like oxidation for the treatment of soil highly contaminated with PAH and the relative importance of the process variables.