Comparative Alpha Tracks Counting Using an Optical Microscope and a Spark Counter

In the metrology of radon, an environmental lung carcinogen, the integrated measurements necessary for epidemiological studies are made very often using the tracks detector LR 115 type 2. For dosimetric analysis, the etched tracks from radon alpha particles on this detector are usually counted by means of an optical microscope or a spark counter. An optimal reading of the track densities which must be converted into radon concentrations, can’t be done without a good mastery of the mode of operation and use of these devices. Furthermore, investigations to know as to whether or not each of those can be used to determine radon concentration are necessary. These are the objectives of the present work in which LR 115 samples exposed to radon for at least 3 months, were chemically developed under standard conditions and read. The track densities obtained with the microscope are very much higher than those of the counter for each sample. These results are consistent with those published by other authors. However, each of these devices can be used interchangeably for alpha tracks counting, as both provide radon concentrations with a very good linear correlation coefficient of 0.95 taking into account their respective calibration factors for the reading of this detector. In addition, the saturation phenomenon for the spark counter reading of LR 115 detector occurs beyond 11,000 tr/cm2, a density never reached during our environmental radon measurements.

A novel phase-sensitive scanning near-field optical microscope

Phase is one of the most important parameters of electromagnetic waves. It is the phase distribution that determines the propagation, reflection, refraction, focusing, divergence, and coupling features of light, and further affects the intensity distribution. In recent years, the designs of surface plasmon polariton （SPP） devices have mostly been based on the phase modulation and manipulation. Here we demonstrate a phase sensitive multi-parameter heterodyne scanning near-field opti- cal microscope （SNOM） with an aperture probe in the visible range, with which the near field optical phase and amplitude distributions can be simultaneously obtained. A novel architecture combining a spatial optical path and a fiber optical path is employed for stability and flexibility. Two kinds of typical nano-photonic devices are tested with the system. With the phase-sensitive SNOM, the phase and amplitude distributions of any nano-optical field and localized field generated with any SPP nano-structures and irregular phase modulation surfaces can be investigated. The phase distribution and the interference pattern will help us to gain a better understanding of how light interacts with SPP structures and how SPP waves generate, localize, convert, and propagate on an SPP surface. This will be a significant guidance on SPP nano-structure design and optimization.

Position-resolved Surface Characterization and Nanofabrication Using an Optical Microscope Combined with a Nanopipette/Quartz Tuning Fork Atomic Force Microscope

In this work, we introduce position-resolved surface characterization and nanofabrication using an optical microscope(OM) combined with a nanopipette-based quartz tuning fork atomic force microscope(nanopipette/QTF-AFM) system. This system is used to accurately determine substrate position and nanoscale phenomena under ambient conditions. Solutions consisting of 5 nm Au nanoparticles, nanowires, and polydimethylsiloxane(PDMS) are deposited onto the substrate through the nano/microaperture of a pulled pipette. Nano/microscale patterning is performed using a nanopipette/QTF-AFM, while position is resolved by monitoring the substrate with a custom OM. With this tool, one can perform surface characterization(force spectroscopy/microscopy) using the quartz tuning fork(QTF) sensor. Nanofabrication is achieved by accurately positioning target materials on the surface, and on-demand delivery and patterning of various solutions for molecular architecture.

Microstructure Investigation on Refractories Under Optical Microscopes

Optical microscopes with polishing equipment possess high performance/cost ratio for refractories industry. Here, the preparation of polishing sections of refractory materials and products and their observation under microscopes were introduced in detail. The observation of microstructures helps to improve and optimize production process. Optical microscopes can observe （1） homogenous or inhomogeneous composition distribution to improve mixing intensity; （2） coarse grains contact or not and contacted grain edges broken or intact to adjust the pressing parameters to avoid overpressure ; （ 3 ） the filling degree of components to optimize the particle size distribution; （4） the sintering necks and bridges and matrix shrinkage status to adjust sintering intensity or sintering atmosphere; （5） the crack edge in round or sharp to know when the cracks formed （ before or after entering sintering zone） and take countermeasures ; （6） used refractories to find the wear mechanism.

Application of a microscopic optical potential of chiral effective field theory in (p, d) transfer reactions

The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave approximation.The target nuclei included both stable and unstable nuclei,and the incident energies reached 200 MeV.The results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 potential.Overall,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive targets.On average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 MeV.However,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.

Oversample Reconstruction Based on a Strong Inter-Diagonal Matrix for an Optical Microscanning Thermal Microscope Imaging System

Based on a strong inter-diagonal matrix and Taylor series expansions,an oversample reconstruction method was proposed to calibrate the optical micro-scanning error. The technique can obtain regular 2 ×2 microscanning undersampling images from the real irregular undersampling images,and can then obtain a high spatial oversample resolution image. Simulations and experiments show that the proposed technique can reduce optical micro-scanning error and improve the system＇s spatial resolution. The algorithm is simple,fast and has low computational complexity. It can also be applied to other electro-optical imaging systems to improve their spatial resolution and has a widespread application prospect.

IN-SITU DISTANCE RESOLVED OPTICALLY TRANSPARENT THIN-LAYER MICROSCOPIC FTIR SPECTROELECTROCEMISTRY.ESTIMATION OF THE ELECTROCHEMICAL CONCENTRATION-DISTANCE PROFILE

An in-situ optically transparent thin-layer microscopic FTIR spectroelectro- chemical cell was constructed.Using this cell,we characterize a concentration-distance profile in the electrochemical diffusion thin-layer by in-situ adjusting the focal point at different distances to the electrode surface.

Compact in situ microscope for photoelectron spectroscopy via two-mirror reflection

Photoelectron spectroscopy is a powerful tool in characterizing the electronic structure of materials.To investigate the specific region of interest with high probing efficiency,in this work we propose a compact in situ microscope to assist photoelectron spectroscopy.The configuration of long objective distance of 200 mm with two-mirror reflection has been introduced.Large magnification of 5×to 100×,lateral resolution of 4.08μm,and longitudinal resolution of 4.49μm have been achieved.Meanwhile,the testing result shows larger focal depth of this in situ optical microscope.Similar configurations could also be applied to other electronic microscopes to improve their probing capability.

Analysis of Near-Field Diffraction Pattern of a Metallic Probe Tip with the Boundary Diffraction Wave Method

The boundary diffraction wave theory is introduced to analyse a near-field diffraction （NFD） pattern of a metallic probe tip of apertureless scanning near-field microscopy. This method is simple and can give a clear physical picture. The polarization effect of the incident light and the different shapes of the metallic probe tip are simulated. The results show that the NFD pattern of the metallic probe tip is directly related to those factors.

Deterministic loading of an individual atom:Towards scalable implementation of multi-qubit

We report the realization of a deterministic single-atom preparation by the method of all-optical feedback. Using a fast-real-time feedback, the light-induced atom desorption effect and blue detuned light-induced atom collision process can increase a success probability of single-atom preparation up to more than 99%. We investigate the dynamics of loading single atom trapped in a trap with a size of hundreds of micrometers into a pair of microscopic tweezers. The detailed experimental results show that the feedback loading is spatially insensitive, which implies that it is possible to use the feedback protocol to simultaneously implement the loading of large number of qubits arrays.

Elastic scattering and total reaction cross sections of^(6)Li examined via a microscopic continuum discretized coupled-channels model

We present a systematic study of 6Li elastic scattering and total reaction cross sections at incident energies around the Coulomb barrier within the continuum discretized coupled-channels(CDCC)framework,where 6Li is treated in anα+d two-body model.Collisions with 27Al,64Zn,138Ba,and 208Pa are analyzed.The microscopic optical potentials(MOP)based on Skyrme nucleon-nucleon interaction forαand d are adopted in CDCC calculations and satisfactory agreement with the experimental data is obtained without any adjustment on MOPs.For comparison,αand d global phenomenological optical potentials(GOP)are also used in CDCC analysis and a reduction of no less than 50%on the surface imaginary part of deuteron GOP is required for describing the data.In all cases,the 6Li breakup effect is significant and provides repulsive correction to the folding model potential.The reduction on the surface imaginary part of GOP of deuteron reveals a strong suppression of the reaction probability of deuteron as a component of 6Li when compared with that of a free deuteron.Further investigation is performed by considering the d breakup process equivalently within the dynamic polarization potential approach,and the results show that d behaves in a manner similar to a tightly bound nucleus in 6Li induced reactions.

Comparison between global phenomenological and microscopic optical potentials for proton as projectile below 100 MeV

For 112 target nuclei （52 elements） with proton as projectile, we calculate the reaction cross sections and elastic scattering angular distributions, as well as the X^2 values for 16 kinds of proton optical model potentials： two sets of phenomenological global optical potentials and the microscopic optical potentials proposed by Shen et al for 14 sets of Skyrme force parameters： GSI-6, SBJS, SKM, SGI-Ⅱ, SKa-b, SCOI-Ⅱ. We find that for obtaining the proton microscopic optical potential based on the nuclear matter approach with Skyrme force, SGI, SKa and SKb are the three sets of optimal Skyrme force parameters.

Effects of CaO on Precipitation Morphology of Metallic Iron in Reduction of Iron Oxides Under CO Atmosphere

Growth process of iron whiskers and mechanism of CaO influence on precipitation morphology of metallic iron at the gas-solid interfaces was studied. Analytical reagents of Fe（NO3）3 and Ca（NO3）2 aqueous solution were used to prepare sheet film sample of Fe2 O3-CAO by thermal decomposition at high temperature. In-situ observation was con-ducted using a stereo optical microscope and a hot-stage. And reduction kinetics of samples was studied by thermo gravimetrie （TG） method. Some samples after reduction were analyzed by using the scanning electron microscope （SEM）, energy dispersive spectrometer （EDS） and fourier transform infrared （FT-IR） spectrometer. Results indi-cate that during the reduction of iron oxides with CO, metallic iron is mostly precipitated as whisker and the precipi- tation behavior mainly depends on reduction rate. Doping CaO can significantly increase the reduction rate and effec-tively change the precipitation morphology of metallic iron after the reduction. When CaO doping concentration is less than 4% （mass percent）, CaO can promote whisker formation of reduced iron; as it reaches 6% （mass per- cent）, CaO inhibits iron whiskers growth; as it is more than 8% （mass percent）, no whiskers could be observed. Therefore, controlling the quantity of Ca^2＋ is effective to control the formation and growth of iron whiskers during gaseous reduction and thus eliminating ore grain sticking caused by intertexture of iron whiskers.

A Comparative Study of Human and Animal Hairs:Microscopic Hair Comparison and Cytochrome c Oxidase I Species Identification

Human and animal hairs have been used in forensic investigations for over a century.Hair is stable under adverse natural conditions;hence,it is often recovered at the crime scene,and it is necessary to determine whether the hair is of human or animal origin.Morphological and genetic characteristics are useful to differentiate human hair from animal hair.In the present study,we analyzed the distinguishing characteristics of hair of various species.In addition,we explore species identification by cytochrome c oxidase I mitochondrial gene analysis.We confirm that both the microscopic and molecular analyses of hairs are useful in forensic investigations.

Elastic scattering of ~6He from ^(12)C at 38.3 MeV/nucleon

The microscopic optical potential of nucleus-nucleus interaction is presented via a folding method with the isospin dependent complex nucleon-nuclear potential,which is first calculated in the framework of the Dirac-Bruecker-Hartree-Fock approach. The elastic scattering data of ^6He at 229.8 MeV on 12C target are analyzed within the standard optical model. To take account of the breakup effect of 6He in the reaction an enhancing factor 3 on the imaginary potential is introduced. The calculated ^6He＋^12C elastic scattering differential cross section is in good agreement with the experimental data. Comparisons with results in the double-folded model based on the M3Y nucleon-nucleon effective interaction and the few the body Glaubermodel calculations are discussed. Our parameter free model should be of value in the description of nucleusnucleus scattering,especially unstable nucleus-nucleus systems.