Double Scanning Method Research Articles

Enhanced mechanical property through high-yield fabrication process with double laser scanning method in two-photon lithography

Two-photon lithography (TPL) is a representative fabrication process for micro 3D structures with a sub-micron fabrication resolution. As the TPL process is developed and commercialized, the TPL process requires higher process yield to be a considered reliable manufacturing technique for mass production. However, delamination is one of the main factors that reduce the yield of the TPL process. In this study, a double-step laser scanning method is proposed as a reliable high-yield TPS process to reduce the delamination effect. The method entails a simple process that polymerizes the initial interfacial layer between the structures and substrate twice. The additional laser scanning step induces a strong crosslinking in the polymer, and thereby preventing swelling and delamination. Furthermore, the effectiveness of the method is evaluated with large-scale microlens arrays. Although the process time is slightly increased, the process yield is significantly improved through the use of the double-step laser scanning method. Hence, the double-step laser scanning process can be employed as a reliable additive manufacturing process for various 3D microscale devices, and more importantly, it can be used to increase the manufacturing yield through the reduction of defects caused by surface delamination.

Controlling self-healing of optical field based on moiré dual-microlens arrays

Optical self-healing is a repairing phenomenon of a beam in the propagation, as it is perturbed by an opaque object. In this work, we demonstrate experimentally and theoretically that the moiré distributed dual-microlens array enables to generate optical fields with better healing ability to withstand defects than their counterparts of a single microlens array. By utilizing the double parameter scanning method, the self-healing degree of the optical field is significantly affected by both the interval distance and the relative angle of the dual-microlens arrays. The self-healing level is decreased significantly by lengthening the interval between the two microlens array with a small twist angle, while increasing the angle enhances the self-healing degree. Further study manifests the self-healing process with respect to the size and central location of the obstacle. The research results provide a simple and effective method to generate self-healing optical wave fields, which have potential applications including optical communication, assisted imaging technology, and even intense laser physics.

Generation of periodic nanobumps through a double-scan method with femtosecond lasers

Ultrafast laser surface structuring is a promising technique for precisely controlling the surface functions of materials. Nanoripples, the typical laser-induced periodic surface structures, are effective at regulating surface colors, but only in one view direction. To overcome this issue, effective methods for fabricating other types of structures are needed. In this study, we successfully form periodic nanobump structures using a simple double-scan approach, in which the same surface is subjected to two consecutive laser scans with different polarization directions. The formation behavior of these intriguing nanostructures is investigated in relation to laser parameters such as peak laser fluence, overlapping ratio, and polarization angle between two scans. The formation mechanism is hypothesized and confirmed. The obtained nanobumps exhibit exceptional optical performance compared to nanoripples by enhancing the visibility angle, hence expanding the possible applications of the ultrafast laser surface structuring technique.

Time-resolved photoconductivity distribution measurement by a synchronized double-scanning method.

The lifetime and the distribution of photoconductivity generated in laser-illuminated semiconductors are critical to photoconductivity-based applications. We propose a synchronized double-scanning method to measure time-resolved diffusion in the form of an afterglow embedded in the distribution map. The method combines spatial scanning of a coaxial resonator with synchronized laser scanning to map the dynamically excited conductivity on a semiconductor wafer. Thus, the photoconductivity afterglow effects can be mapped and retrieved by images of dynamic photoconductivity distribution. The photoconductivity lifetimes of silicon wafers with different thicknesses and by different lasers were measured and evaluated, which were also validated by the microwave photoconductivity decay (μ-PCD) method. In addition, the behavior of photoconductivity diffusion around a structural defect was exhibited. The method is nondestructive and can be applied in the photoconductivity property diagnostic.

Measurement-device-independent quantum key distribution protocol with phase post-selection

Measurement-device-independent quantum key distribution (MDI-QKD) protocol can remove all the loopholes of the detection devices and, thus, has attracted much attention. Based on the technique of single-photon interference, we propose a modified MDI-QKD protocol with phase post-selection. We prove the security of the announcement of the private phases in the X basis and show how to apply the phase post-selection method to the double-scanning four-intensity MDI-QKD protocol. The numerical results show that the phase post-selection method can significantly improve the key rates at all distances. In the double-scanning method, two parameters need to be scanned in the calculation of the final key rate, and the global parameter optimization is pretty time-consuming. We propose an accelerated method that can greatly reduce the running time of the global parameter optimization program. This makes the method practically useful in an unstable channel.

Improving wear resistance of acrylic resin denture teeth by using zirconia complete crowns fabricated with a CAD-CAM double-scanning method: A clinical report

Acrylic resin denture teeth can wear and chip when opposed by zirconia prostheses. This clinical report describes the use of zirconia complete crowns to prevent these problems. The predictability of treatment was improved by using the computer-aided design and computer-aided manufacturing (CAD-CAM) double-scanning method.

Practical Long‐Distance Measurement‐Device‐Independent Quantum Key Distribution By Four‐Intensity Protocol

AbstractQuantum key distribution (QKD) can provide unconditionally secure private communication between two remote parties. The measurement‐device‐independent (MDI) QKD can remove all security loopholes in measurement devices. However, the large value of the observed error rate in X basis has severely limited its key rate. The four‐intensity protocol with fully optimized post data processing can improve the key rate and distance of MDI‐QKD effectively. In this paper, the four‐intensity MDI‐QKD protocol is reviewed. In the four‐intensity protocol, each of Alice and Bob uses one intensity in Z basis and three intensities in X basis (normally including one vacuum). This improves the number of effective bits in Z basis. The joint mathematical treatment for statistical fluctuation and the parameter scan pointing directly to the final key rate are applied to reduce the effect of statistical fluctuation. The double scanning method further improves the key rate and the secure distance of the four‐intensity protocol. These have greatly improved the performance of the protocol with finite‐key effects. So far, many MDI‐QKD experiments are based on the four‐intensity protocol. The successful results of these experiments have clearly shown the superiority of the four‐intensity protocol in practical long‐distance MDI‐QKD.

Experimental measurement-device-independent quantum key distribution with the double-scanning method.

The measurement-device-independent quantum key distribution (MDI-QKD) can be immune to all detector side-channel attacks. Moreover, it can be easily implemented combining with the matured decoy-state methods under current technology. It, thus, seems a very promising candidate in practical implementation of quantum communications. However, it suffers from a severe finite-data-size effect in most existing MDI-QKD protocols, resulting in relatively low key rates. Recently, Jiang et al. [Phys. Rev. A103, 012402 (2021).PLRAAN1050-294710.1103/PhysRevA.103.012402] proposed a double-scanning method to drastically increase the key rate of MDI-QKD. Based on Jiang et al.'s theoretical work, here we for the first time, to the best of our knowledge, implement the double-scanning method into MDI-QKD and carry out corresponding experimental demonstration. With a moderate number of pulses of 1010, we can achieve 150 km secure transmission distance, which is impossible with all former methods. Therefore, our present work paves the way toward practical implementation of MDI-QKD.

Research on Thermal Decomposition Kinetics and Thermal Safety for a New Epoxiconazole Crystal.

To clarify the thermal safety inherent in a new epoxiconazole crystal, differential scanning calorimetry (DSC) and adiabatic accelerating rate calorimetry (ARC) were used for testing and research. The Friedman method and model method were used to analyze thermal decomposition kinetics based on the DSC data, and the N-order and autocatalytic decomposition reaction kinetic models were established. The double scan method was utilized to verify the autocatalytic effect during the decomposition process. The Friedman method, N-order, and autocatalytic model methods were used to study the substance’s thermal decomposition characteristics. ARC data are utilized to verify the aforementioned prediction results and the kinetic parameters that were obtained based on ARC data from N-order and autocatalytic model methods that concur with the simulation results. This paper applies the N-order and autocatalytic model to the kinetic model to further predict thermal safety parameter time to maximum rate under adiabatic conditions.

Higher key rate of measurement-device-independent quantum key distribution through joint data processing

We propose a method named as double-scanning method, to improve the key rate of measurement-device-independent quantum key distribution (MDI-QKD) drastically. In the method, two parameters are scanned simultaneously to tightly estimate the counts of single-photon pairs and the phase-flip error rate jointly. Numerical results show that the method in this work can improve the key rate by $35\%-280\%$ in a typical experimental set-up. Besides, we study the optimization of MDI-QKD protocol with all parameters including the source parameters and failure probability parameters, over symmetric channel or asymmetric channel. Compared with the optimized results with only the source parameters, the all-parameter-optimization method could improve the key rate by about $10\%$.

Dissociation of 6,7Li nuclei in nuclear photographic emulsion

Diffraction dissociation process of 6Li at incident momentum 4.5 AGeV/c and 7Li at incident momentum 3 AGeV/c, provided by the JINR Synchrophastron, were studied using the photographic emulsion technique. The two stable isotopes of 6Li and 7Li were treated as two weakly-bound systems composed of (4He+d) and (4He+t) cluster configurations, respectively. Along the track double scanning method was carried out in order to search for 6,7Li interactions in emulsion( Em). For 6Li-Em and 7Li-Em about 1050 and 1015 events were recorded with mean free path 14.5±0.5 cm and 15.1±0.6 cm respectively. The measured angular distributions of the outgoing fragments were compared with that calculated theoretically and good agreement between the experimental and theoretical values is obtained. This agreement supported the presence of 6,7Li nuclei in a cluster mode at high energy reactions.

Using Pseudoorthogonal Signals to Reduce Noise Level in Ultrasound Testing of Highly Absorptive Materials

To increase the signal-to-noise ratio when testing materials with a high level of absorption, it has been proposed to use complex signals, formed on the basis of code sets employed in Code Division Multiple Access (CDMA) technology, as probing signals. The code sequences in the code sets have a low level of cross-correlation function and a delta-like autocorrelation function. Echo signals are recorded by the double-scanning method, in which the elements of an antenna array sequentially emit unique probing signals phase-shift keyed according to the Kasami code, with the echo signals being recorded in each radiation cycle concurrently by all the elements in the antenna array. Since the shape of the “side lobes” of the compressed echo signals is different for each shot, reconstructing the image of reflectors using digital focusing of the antenna (DFA) reduces the level of the “side lobes”. As a result, when different code sequences of length 15 are used for each antenna-array element, this level may prove to be lower than when one sequence of length 63 is used for all the elements. Provided that a unique code set is used in each position, reconstructing the DFA image when scanning with an antenna array should further reduce the noise level and the level of the “side lobes”. The effectiveness of the proposed approach was demonstrated in a model experiment on reconstructing the image of side-drilled holes in a Plexiglas™ SO-1 calibration block, when using Kasami codes of lengths 15 and 63.

Effect of anisotropy in the build direction and laser-scanning conditions on characterization of short-glass-fiber-reinforced PBT for laser sintering

Copolymer poly(butylene terephthalate) with 30- wt% short glass fiber (SGF) added was used to evaluate the dependence of the properties of specimens manufactured by selective laser sintering (SLS) and the influence of laser-irradiation conditions on build direction. The degree of orientation of SGFs in SLS is ranked in descending order of roller-movement direction, vertical direction in the powder-bed plane, and direction of lamination-layer thickness. Moreover, the influence of fiber orientation on mechanical properties, thermal properties, and shrinkage ratio was found to be remarkable. In the case of the double-scan method, in comparison to the single-scan case, while thermal degradation was suppressed, porosity was reduced, and mechanical properties were improved. In addition, degree of crystallinity of the SLS specimens increased, and heat-deflection temperature increased slightly. Furthermore, in regard to roller-movement direction and lamination-layer thickness direction, the trends of shrinkage ratio differ in the cases of the single- and double-scan scanning methods.

In Silico Identification of Rescue Sites by Double Force Scanning

Motivation. Deleterious amino acid changes in proteins can be compensated by second-site rescue mutations. These compensatory mechanisms can be mimicked by small molecules. Therefore, the location of rescue mutations can be used to identify protein regions that can be targeted by drugs to reactivate a damaged mutant. Methods. Here we present the first general computational method to detect rescue sites. By mimicking the effect of mutations through the application of forces, the Double Force Scanning (DFS) method identifies the second-site residues that make the protein structure most resilient to the effect of pathogenic mutations. The method is based on an elastic network model. All the possible residue pairs in the protein are scanned and a rescue effect is detected when the simultaneous application of forces at the two sites affects the protein structure less than a force at a single site. Results. We tested DFS predictions against two datasets containing experimentally validated and putative evolutionary-related rescue sites. A remarkably good agreement was found between predictions and experimental data. Indeed, almost half of the rescue sites in p53 was correctly predicted by DFS, with 65% of remaining sites in contact with DFS predictions. Similar results were found for other proteins in the evolutionary dataset. Finally, we showed how the prediction of rescue sites can be used to identify potential pockets for the binding of reactivating drugs. The source code for DFS is available at https://fornililab.github.io/dfs.

In silico identification of rescue sites by double force scanning.

MotivationA deleterious amino acid change in a protein can be compensated by a second-site rescue mutation. These compensatory mechanisms can be mimicked by drugs. In particular, the location of rescue mutations can be used to identify protein regions that can be targeted by small molecules to reactivate a damaged mutant.ResultsWe present the first general computational method to detect rescue sites. By mimicking the effect of mutations through the application of forces, the double force scanning (DFS) method identifies the second-site residues that make the protein structure most resilient to the effect of pathogenic mutations. We tested DFS predictions against two datasets containing experimentally validated and putative evolutionary-related rescue sites. A remarkably good agreement was found between predictions and experimental data. Indeed, almost half of the rescue sites in p53 was correctly predicted by DFS, with 65% of remaining sites in contact with DFS predictions. Similar results were found for other proteins in the evolutionary dataset.Availability and implementationThe DFS code is available under GPL at https://fornililab.github.io/dfs/ Supplementary information Supplementary data are available at Bioinformatics online.

Implant supported prosthesis with high performance polymers using a double scanning method

Implant supported prosthesis with high performance polymers using a double scanning method

Efficient arithmetic on ARM‐NEON and its application for high‐speed RSA implementation

AbstractAdvanced modern processors support single instruction, multiple data instructions (e.g., Intel‐AVX and ARM‐NEON) and a massive body of research on vector‐parallel implementations of modular arithmetic, which are crucial components for modern public‐key cryptography ranging from Rivest, Shamir, and Adleman (RSA), ElGamal, Digital Signature Algorithm (DSA), and elliptic curve cryptography, have been conducted. In this paper, we introduce a novel double operand scanning method to speed up multi‐precision squaring with non‐redundant representations on single instruction, multiple data architecture where the part of the operands are doubled to compute the squaring operation without read‐after‐write dependencies between source and destination variables. Afterwards, Karatsuba algorithm is applied to both multiplication and squaring operations. For modular multiplication, separated Montgomery algorithm is chosen. Finally, the Rivest, Shamir, and Adleman (RSA) implementations outperform the best‐known results on the ARM‐NEON platforms. Copyright © 2017 John Wiley & Sons, Ltd.

Complete-mouth rehabilitation using a 3D printing technique and the CAD/CAM double scanning method: A clinical report

According to evolving computer-aided design/computer-aided manufacturing (CAD/CAM) technology, ceramic materials such as zirconia can be used to create fixed dental prostheses for partial removable dental prostheses. Since 3D printing technology was introduced a few years ago, dental applications of this technique have gradually increased. This clinical report presents a complete-mouth rehabilitation using 3D printing and the CAD/CAM double-scanning method.

The analysis and application of simplified two-parameter moveout equation for C-waves in VTI anisotropy media

Several parameters are needed to describe the converted-wave (C-wave) moveout in processing multi-component seismic data, because of asymmetric raypaths and anisotropy. As the number of parameters increases, the converted wave data processing and analysis becomes more complex. This paper develops a new moveout equation with two parameters for C-waves in vertical transverse isotropy (VTI) media. The two parameters are the C-wave stacking velocity (VC2) and the squared velocity ratio (γvti) between the horizontal P-wave velocity and C-wave stacking velocity. The new equation has fewer parameters, but retains the same applicability as previous ones. The applicability of the new equation and the accuracy of the parameter estimation are checked using model and real data. The form of the new equation is the same as that for layered isotropic media. The new equation can simplify the procedure for C-wave processing and parameter estimation in VTI media, and can be applied to real C-wave processing and interpretation. Accurate VC2 and γvti can be deduced from C-wave data alone using the double-scanning method, and the velocity ratio model is suitable for event matching between P- and C-wave data.

Three-dimensional measurement of a tightly focused laser beam

The spatial structure of a tightly focused light field is measured with a double knife-edge scanning method. The measurement method is based on the use of a high-quality double knife-edge fabricated from a right-angled silicon fragment mounted on a photodetector. The reconstruction of the three-dimensional structures of tightly focused spots is carried out with both uniform and partially obstructed linearly polarized incident light beams. The optical field distribution is found to deviate substantially from the input beam profile in the tightly focused region, which is in good agreement with the results of numerical simulations.