Super Light Research Articles

Super broadband light source: a promising master oscillator source for high brightness and high-power fiber amplifiers.

Stimulated Raman scattering (SRS) and transverse mode instability (TMI) effects are crucial limitation factors for further power scaling of high-power fiber amplifiers with near-diffraction-limited beam quality. It is an important research direction to carry out laser system optimization from the perspective of seed construction. In this work, we experimentally investigated the impact of utilizing different seed lasers on the SRS and TMI characteristics in high power ytterbium-doped fiber amplifiers. Both the phase modulated single frequency fiber laser (PMSFL), fiber oscillator laser (FOL), and superfluorescent fiber source (SFS) as a typical type of temporally stable broadband light source (SBLS) are employed as seed lasers. The experimental results indicated that the SRS intensity in the fiber amplifier is influenced by the properties of the seed laser source. Notably, the SRS threshold of the SBLS could be comparable to that of a low-noise PMSFL source. There is a significant increase in TMI threshold when employing SBLS as a seed laser in high-power fiber amplifiers, which is 3.86times that of the injected seed laser with a 3dB narrow linewidth of 0.74nm. Considering the combined threshold characteristics of SRS and TMI, it can be found that SBLS is a promising master oscillator source for high brightness and high-power fiber amplifiers. Our work could provide a good reference for the selection of a master oscillator source, and we believe that it is an important direction to go beyond the power limitation of high-power fiber lasers by constructing a light source with broader spectral linewidth and temporal stability.

P911 Development and Characterization of SPY002, a Novel Extended Half-life Monoclonal Antibody Drug Candidate Targeting TL1A for the Treatment of IBD

Abstract Background Tumor necrosis factor (TNF)-like ligand 1A (TL1A) mediates a broad spectrum of pro-inflammatory and fibrotic effects and is implicated in the pathogenesis of several immunologic disorders. Blockade of the interaction of TL1A with its cognate receptor, DR3, has been shown to ameliorate disease activity patients with Crohn’s disease (CD) and ulcerative colitis (UC). SPY002 is a novel, extended half-life fully human IgG1 monoclonal antibody (mAb) that binds soluble TL1A with high affinity and specificity, and potently inhibits TL1A-mediated signaling. Methods SPY002 was evaluated in multiple in vitro and ex vivo assays compared to other clinical anti-TL1A mAbs (PRA023/MK-7240, RVT-3101, and TEV-48574). Binding affinity to soluble TL1A was determined by surface plasmon resonance (SPR) and binding to membrane-bound TL1A was confirmed by flow cytometry (FACS). Competitive blockade of TL1A binding to cell-surface DR3 was determined by FACS, and competition against the decoy receptor, DcR3, was evaluated by ELISA. The binding epitope of SPY002 was determined using cryogenic electron microscopy. TF-1 cell apoptosis and a primary human whole blood-based assay measuring IFNg secretion were used to assess functional blockade of exogenously added TL1A. Half-life extension was measured via pharmacokinetic analysis in both Tg276 transgenic mice (hemizygous for human FcRn) and cynomolgus monkeys given a single bolus of SPY002 by intravenous and/or subcutaneous administration. Results SPY002 binds specifically to monomeric and trimeric TL1A and not to related TNF super family proteins TNF, FasL, TRAIL, or LIGHT. SPY002 demonstrates sub-nanomolar affinity for soluble TL1A and binds to TL1A over-expressed on the surface of human embryonic kidney (HEK) cells. SPY002 potently inhibits both TL1A-induced apoptosis of TF-1 cells and TL1A-induced secretion of IFNg in human whole blood, with IC50 values comparable to those of RVT-3101 and TEV-48574, and a substantially lower IC50 than that of PRA023/MK-7240. The half-life of SPY002 is significantly extended in Tg276 mice compared to RVT-3101. In cynomolgus monkeys, the half-life of SPY002 is at least 18 days, compared to an observed half-life of 9-12 days for RVT-3101 and PRA023/MK-7240. Conclusion SPY002 exhibits high selectivity and affinity for TL1A, demonstrates effective blockade of the TL1A interaction with DR3, and potently inhibits downstream cellular signaling. With an extended half-life in NHP, SPY002 demonstrates therapeutic potential for effective and safe treatment of CD and UC with the advantage of infrequent SC dosing. Further preclinical and clinical studies are warranted to demonstrate this potential.

Modeling and optimization strategies for dye-doped super twisted nematic liquid crystal light valves

This study provides a comprehensive investigation of dye-doped super twisted nematic liquid crystal (DDSTNLC) with the aim of uncovering its potential applications. Using design of experiments (DoE) techniques, we elucidated the relationships between physical variables and constructed a transmission model. We then used Monte Carlo simulations to demonstrate the potential applications of DDSTNLC in various optical performances, including high light transmittance and contrast ratio. The investigation combining the modeling and DoE paves the way for advancing progress in the development of DDSTNLC-based light valves.

Robust Embedded Autonomous Driving Positioning System Fusing LiDAR and Inertial Sensors

Autonomous driving emphasizes precise multi-sensor fusion positioning on limit resource embedded systems. LiDAR-centered sensor fusion system serves as a mainstream navigation system due to its insensitivity to illumination and viewpoint change. However, these types of systems suffer from handling large-scale sequential LiDAR data using limited resources on board, leading LiDAR-centralized sensor fusion unpractical. As a result, hand-crafted features such as plane and edge are leveraged in majority mainstream positioning methods to alleviate this unsatisfaction, triggering a new cornerstone in LiDAR Inertial sensor fusion. However, such super light weight feature extraction, although it achieves real-time constraint in LiDAR-centered sensor fusion, encounters severe vulnerability under high speed rotational or translational perturbation. In this paper, we propose a sparse tensor based LiDAR Inertial fusion method for autonomous driving embedded system. Leveraging the power of sparse tensor, the global geometrical feature is fetched so that the point cloud sparsity defect is alleviated. Inertial sensor is deployed to conquer the time-consuming step caused by the coarse level point-wise inlier matching. We construct our experiments on both representative dataset benchmarks and realistic scenes. The evaluation results show the robustness and accuracy of our proposed solution compared to classical methods.

Corrosion and adhesion properties of MAO-coated LA91 magnesium alloy

Magnesium–lithium alloy is used in different areas of industry and is known as a super light metallic engineering material. However, the use of these alloys is limited due to their surface properties under extreme loads and aggressive environments. Surface treatments can be applied to these alloys to increase their usage areas and improve their weak surface properties. In this study, the micro-arc oxidation method was applied to improve the surface properties of LA91 alloy. The corrosion and adhesion behaviour of the coated samples were investigated. The lowest corrosion current density in the coatings was obtained under Experiment 3. Experiment 3 has the highest Lc2 value due to the coating thickness and the denser and smaller diameter pores of the functional intermediate layer.

Using different strategies to improve properties of the biodegradable Mg–4Li–4Zn alloy

Recently, novel super light Mg–Li based alloys have attracted wide attention for potential use as biodegradable implants. However, like most of the biodegradable Mg alloys, Mg–Li alloys suffer from high degradation rate and poor mechanical properties, but the degradation is much faster and thus critical in these alloys. Different strategies have been introduced and used to address these weaknesses, including alloying, heat treatment and severe plastic deformation. However, efficiency of these methods have not been yet evaluated and compared with each other. In this investigation, the effects of alloying (0.5 and 1.0 wt% Ca addition), homogenization heat treatment and multidirectional forging process on the microstructure, biodegradation behavior, and mechanical properties of the as-cast Mg–4Li–4Zn base alloy are evaluated and compared. The obtained results indicate that Ca addition is beneficial to improving both mechanical strength and corrosion resistance of the as-cast base alloy. In addition to microstructural refinement, the addition of Ca resulted in formation of Ca- and Zn-rich precipitates, with a network-like structure, which was found to be beneficial to inhibiting the corrosion progress. Although homogenization treatment led to a slight decrease in mechanical strength, it considerably improved the corrosion resistance, through partial dissolution of precipitates and more uniformity of the as-cast microstructure. Finally, it was found that the multi-directionally forged alloy demonstrated improved mechanical and corrosion properties in comparison with the as-cast alloy, which stemmed mainly from the more uniform distribution of fine secondary phases, as well as the reduced average grain size.

Fast Non-Local Attention network for light super-resolution

Although convolutional neural network-based methods have achieved significant performance improvement for Single Image Super-Resolution (SISR), their vast computational cost hinders real-world environment application. Thus, the interest in light networks for SISR is rising. Since existing SISR light models mainly focus on extracting fine local features using convolution operation, they have a limitation in that networks hardly capture global information. To capture the long-range dependency, Non-Local (NL) attention and Transformers have been explored in the SISR task. However, they are still suffering from a balancing problem between performance and computational cost. In this paper, we propose Fast Non-Local attention NETwork (FNLNET) for a super light SISR, which can capture the global representation. To acquire global information, we propose The Fast Non-Local Attention (FNLA) module that has low computational complexity while capturing global representation that reflects long-distance relationships between patches. Then, FNLA requires only 16 times lower computational cost than conventional NL networks while improving performance. In addition, we propose a powerful module called Global Self-Intension Mining (GSIM) that fuses the multi-information resources such as local, and global representation. Our FNLNET shows outstanding performance with fewer parameters and computational costs in the experiments on the benchmark datasets against state-of-the-art light SISR models.

Suppression of stimulated Raman scattering by angularly incoherent light, towards a laser system of incoherence in all dimensions of time, space, and angle

Laser–plasma instability (LPI) is one of the main obstacles to achieving predictable and reproducible fusion at high gain through laser-driven inertial confinement fusion (ICF). In this paper, for the first time, we show analytically and confirm with three-dimensional particle-in-cell simulations that angular incoherence provides suppression of the instability growth rate that is additional to and much stronger than that provided by the well-known temporal and spatial incoherence usually used in ICF studies. For the model used in our calculations, the maximum field ratio between the stimulated Raman scattering and the driving pulses drops from 0.2 for a Laguerre–Gaussian pulse with a single nonzero topological charge to 0.05 for a super light spring with an angular momentum spread and random relative phases. In particular, angular incoherence does not introduce extra undesirable hot electrons. This provides a novel method for suppressing LPI by using light with an angular momentum spread and paves the way towards a low-LPI laser system for inertial fusion energy with a super light spring of incoherence in all dimensions of time, space, and angle, and may open the door to the use of longer-wavelength lasers for inertial fusion energy.

Ultracompact Vernier-effect-improved sensor by a single microfiber-knot resonator.

Fiber-optic sensors are an indispensable element of modern sensing technologies by virtue of their low cost, excellent electromagnetic immunity, and remote sensing capability. Optical Vernier effect is widely used to enhance sensitivity of fiber-optic sensors but requires bulky and complex cascaded interferometers. Here we propose and experimentally demonstrate an ultracompact (∼2 mm by ∼2 mm) Vernier-effect-improved sensor by only using a single microfiber-knot resonator. With the Vernier effect achieved by controlling the optical beating with the spectral ripple of a super light emitting diode (SLED), we show ∼20x sensitivity enhancement for quantitative temperature monitoring. Our sensor creates a new practical method to realize Vernier effect in fiber-optic sensors and beyond.

Study on Key Technologies of Drilling and Completion of 8000 Meter Ultra Deep Wells in Platform Basin

In order to solve the problems faced by 8000m class drilling and completion in tarim Basin, such as high temperature, high pressure, complicated formation, low bearing capacity of Permian tuff and development of fractures and pores in basalt segment, etc. Combined with the actual construction situation, has formed the basin area of 8000 m class drilling and well completion key technology optimization results, including optimization of casing program design and matching high crowded outside casing strength, super light corrosion resistance of titanium alloy pipe, under different working condition of the high strength developeded. These technologies, new anti-gas channeling resistance to high temperature high density cement slurry system in sectors such as advanced and practical technology. The successful application of the technology system in the 8000m class drilling in the Platform basin area has greatly boosted the exploration and development process of deep oil and gas resources, and helped improve the competitiveness of the drilling and completion market in China.

Chlorella vulgaris cultivation under super high light intensity: An application of the flashing light effect

Chlorella vulgaris was grown under super high illumination (7000 μmolPhotonPAR/m2/s). Continuous and flashing light patterns were applied to investigate potential gain originating from the flashing light effect (square pattern, duty cycle of 0.5). Three control configurations were tested, all under continuous light: 200 μmolPhotonPAR/m2/s (conventional cultivation conditions), 4000 μmolPhotonPAR/m2/s (about the same average amount of energy), and 7000 μmolPhotonPAR/m2/s (maximum incident light intensity, cells did not grow). The experiments were conducted in ultra-thin flat-panel photobioreactors to ensure isoactinic growth conditions. After acclimation, the monitored outcomes were: growth rate, macronutrient composition (proteins, carbohydrates, lipids), pigment content, and transient fluorescence (OJIP assays). The results showed that Chlorella vulgaris can grow at a similar rate under 200 μmolPhotonPAR/m2/s of continuous light and under 7000 μmolPhotonPAR/m2/s of flashing light for frequencies between 0.1 and 100 Hz. Acclimation mechanisms did not alter cell macronutrient composition, yet, chlorophyll contents decreased while carotenoids increased (allegedly linked to an increased expression of the VAZ cycle). OJIP tests also revealed potential up-regulation of the water-water cycle (featuring PTOX enzyme), which would allow faster repletion of the PQ pool, delaying photosynthetic apparatus saturation. Above 100 Hz (1000 Hz in this study), cells exhibited the same growth rate as under the equivalent amount of continuous light. It suggests that light alternation is too fast for the cells to perceive it. On the contrary, too low frequencies (0.01 Hz) showed lower performances than under the same average intensity. In this condition, during the light phase, cells are exposed to harmful conditions (continuous 7000 μmolPhotonPAR/m2/s), and the too-long dark phase only allows the cells some rest but does not bring any benefits. In terms of applicability, these results pave the way for the use of super high light (either artificial or by sunlight concentration) to overcome the energy limitation burdening photoautotrophic microalgae cultivation.

Polarization stabilization of the mean wavelength of erbium-doped super fluorescent fiber optic sources

We investigate the influence of polarization on the stability of a single-pass fiber super fluorescent light source (SFS) operating under the forward or reverse setup. The measurement of amplified spontaneous emission (ASE) spectra obtained using different values for the power and state of polarization (SOP) of the optical pump (980 nm) is the basis of the analysis. The mean wavelength was the stability evaluation criterion used for comparing the forward and backward SFS emission. The results indicate that both super fluorescent sources become insensitive to the polarization state when the pump power reaches a saturated absorption condition. The influence of the SFS spectral range is also analyzed, defining four spectral bands; Ctot band (1520–1570 nm), C band (1530–1560 nm), C+ band (1520–1540 nm), and C− band (1540–1560 nm). We show that the stability of the SFS improves by discriminating one of the two peaks of the ASE emission spectrum, reaching the performance required for inertial grade sensors.

Optimization design of variable density lattice structure for additive manufacturing

Lattice material is a kind of super light and high strength porous material with high performance. At present, it is mainly composed of lattice structure with equal density components. In practice, each part of the lattice structure bears different loads, so the performance of the lattice structure with equal density can not be brought into full play. In view of the above problems, topology optimization was used to the process of lattice structure design to the optimal design of variable density lattice structure. According to the actual load, the optimal variable density lattice structure is designed to achieve the optimal performance. In the process of optimization, the most important design parameters are grid structure, grid filling ratio and mass constraint percentage. Taking aviation rocker arm as an example, orthogonal experiment is used to get the optimal optimization parameters, which makes the lightweight effect of rocker arm better. The numerical results show that by simulating nine groups of orthogonal experiments and integrating the factors of stress, strain and weight reduction, a lattice structure is finally selected. Compared with the original model, the strain is reduced by 14%, the stress is reduced by 68% and the weight is reduced by 23%. The rocker arm is processed and manufactured by adding material manufacturing technology, which solves the weight reduction optimization problem of aviation parts rocker arm.

Ultralong polypyrrole nanotubes aerogels with excellent elasticity for efficient solar steam generation

BackgroundSolar interface evaporation is considered to be a sustainable and environmentally friendly technology for obtaining fresh water from seawater. However, the preparation of photothermal conversion materials with excellent evaporation performance, good mechanical properties, and simple method for the solar interface evaporation still faces challenge. MethodsHerein, we report the fabrication of ultralong polypyrrole nanotubes aerogel-based solar steam generator through one-pot oxidative self-polymerization of pyrrole monomer using methyl orange as template and ferric chloride as oxidant. Significant findingsThe as-prepared aerogel shows excellent elasticity, which can be compressed by 30% and recover to its original shape within a few seconds. In combination with abundant porosity (92.3%), low thermal conductivity (0.077 W m−1 K−1), super hydrophilic wettability and high light absorption (94%), the as-prepared aerogel shows a high solar-to-vapor efficiency above 74.5% even in high concentration saline (20%). This work provides new opportunities for effective design of conductive polymer-based photothermal monolithic materials with tunable porosity, adjustable morphology, required mechanical properties and high evaporation performance.

A new low-density hydrogel-based matrix with hollow microsphere structure for weight reduction of microwave absorbing composites

A new low-density hydrogel-based composites matrix, super light clay (SLC), with a low density of 0.24 g/cm3, was prepared by mixing the hydrogel and hollow glass microspheres. The swelling-adsorption effect of hydrogel was used to adsorb carbonyl iron powder (CIP) on the surface of hollow microspheres. Benefitting from the existence of microporous structure and surface adsorption, the electromagnetic absorption performance of the obtained SLC/CIP composite microwave absorbing materials (MAMs) were greatly boosted. The results show that the composite filled with 11 vol% of the CIP had a minimum reflection loss (RL) of −45.3 dB and an effective absorption bandwidth (EAB, with a RL of less than −10 dB) of 4.81 GHz. In addition, the swelling-adsorption mechanism of the hydrogel-based SLC matrix and the high-frequency electromagnetic wave attenuation mechanisms have been also discussed. The environmentally friendly low-density matrix is of great significance for weight reduction of MAMs.

Flexible NiP2@hollow N-doped nanocapsules/carbon nanofiber as a freestanding electrode for glucose sensing

The development of flexible and binder free electrocatalytic materials based on low cost metal dichalcogenide and low weight carbon nanofibers (CNF) has been materialized as an effective strategy for the fabrication of advanced super light portable, wearable, and stretchable sensor devices. In this work, the NiP2/hollow N-doped nanocapsules decorated nitrogen-doped carbon nanofiber (NiP2/CNCNF), have been designed for the first time. The NiP2/CNCNF was used directly as a flexible and freestanding electrode toward electrocatalytic and nonoenzymatic glucose sensing. The NiP2/CNCNF displayed high conductivity, flexibility with low weight, excellent electrochemical activity, steadiness and enhanced electron transfer rate.

Improving the light absorption efficiency in thin-film plasmonic tandem solar cell

Recently, thin-film solar cells have received much attention due to low production cost. However, such cells suffer from low efficiency due to which they cannot be used for practical applications. To cater this problem, we have numerically investigated thin-film tandem solar cells comprising of double active layers made of amorphous silicon (a-Si) and crystalline silicon (c-Si) of different energy bandgaps. The tandem cell is found to absorb large amount of solar photons compared to a single a-Si and c-Si solar cells. To further improve the absorption efficiency, we efficiently utilized the surface plasmon resonance (SPR) effect of plasmonic nanoparticles, which are deposited in the form of a square lattice in the top a-Si active layer. The absorption characteristics of the cell are enhanced and tuned by optimizing the material and size of the nanoparticles. Moreover, periodic disorders are incorporated, which allow mixing of plasmonic modes having different angular momenta, resulting in a super broadband light absorption from 300 to 1100 nm and yielding a short circuit current density of 33.917 mA/cm2 in the active layers. The proposed plasmonic tandem cell can be advantageous for most of the photovoltaic applications.

Evaluation of Load Factor to Be Applied in Buckling Design of Cylindrical Lattice Shells Under Asymmetric Snow Load

The load factor is one of the keys in anti-buckling design for safety together for construction cost, and studies have been becoming demanded in a recent situation that super large and super light spatial structures have been constructed. This paper investigates the relationship between reliability index β and snow load factor γs for anti-buckling design of a simply supported cylindrical lattice shell roof under simultaneous action of both dead load and asymmetric snow load. The cylindrical lattice shell analyzed is composed of an equilateral triangle grid of which members are of steel circular hollow sections. Members are connected rigidly to nodes at their both ends. The snow distribution as a main target is assumed in a way that the snow depth on the half of the arch-like roof is half of the amount on the other half roof. The snow fall depth is here assumed 50cm evaluated as 100-year return period, and its probability is assumed as Gumbel distribution with 100-year reference period. The probability distribution of buckling strength Pcr including geometrical and material nonlinearities is approximately evaluated based on a first-order perturbation. The reliability is calculated based on AFOSM, and the relationship in a form of β to γs is finally expressed for design use.

Long-term activity of Comet C/2007 N3 (Lulin) as monitored by the SLT at the Lulin Observatory

Abstract The green comet C/2007 N3 (Lulin) is a new Oort cloud comet that has a retrograde orbit (inclination of $178^{\circ }$). It reached its perihelion on 2009 January 10, and its closest distance to Earth was 0.411 astronomical units (au) on February 24. Soon after its discovery on 2007 July 11, the coma activity of Comet Lulin was monitored closely by an Super Light Telescope 41 cm telescope until 2009 April. After long-term monitoring of Comet Lulin, the dust production rate [A(θ)fρ] was estimated. An unexpected increase in the ${A(0)f\rho}$ near the perigee appears to indicate an opposition effect. By investigating the surface brightness profiles, dust-to-gas ratios, and magnitudes, we ruled out the influences of gas and ion contamination and the outburst phenomenon. We discovered the anti-tail in late December 2008 but were unsure of the composition. We found that this abnormal tail lasted for a considerable time because of the effect of the orbital geometry. We also found that the jet activity coincided with the peak ${A(\theta)f\rho}$ values, and this clue helped us realize what was happening in the dust coma of Comet Lulin.

Standardization of a process for development of onion paste

A technology for onion paste was prepared form two onion varieties of Bhima Super and Agrifound Light Red. Effect of chemical preservatives was also studied on quality characteristics of onion paste. Onion paste was prepared by using various concentrations of salt (0.5 to 1.5%), palm oil (5 to 15%), citric acid (0.1 to 0.3%) and sodium meta bi sulfate (0.1 and 0.3%). Results showed that onion paste treated with concentration of 0.3% citric acid and 0.3% sodium meta bi sulphite were found as a best preservatives for Bhima super variety of onion.