bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-assembly Hybridization of CL-20 and Hydrazone-based Polymeric Carbon Nitrides for High Performance Explosive
Authors: Wei Xiangshuai , Huang Wei , Lv Qianyang , Zeng Tianyou , Liu Yuji , Tang Yongxing
Published: June 2023

A strategy for desensitization of the highly sensitive explosive CL-20 with polymeric carbon nitrides is described. The hybrid energetic material (MHGP-CL-20) was synthesized via a self-assembly approach, where CL-20 molecules are immobilized on the hydrazone-based polymeric carbon nitrides. The good detonation performances (detonation velocity 9608 m·s−1, detonation pressure 42.8 GPa) show that MHGP-CL-20 retains the excellent performance of CL-20 to the greatest extent. More importantly, its sensitivities were effectively reduced with the impact sensitivity (IS) 10 J and the friction sensitivity (FS) 160 N, which is much lower compared with rawε-CL-20 (IS: 4 J; FS: 94 N). In addition, its specific impulse was improved to 276.6 s, higher than that ofε-CL-20 (272.4 s). By preparing solid composite propellants, the burning rate of the propellant grain PMC20 based on MHGP-CL-20 is higher than PC20 based onε-CL-20. The addition of hybrid energetic complex could keep the stability of combustion and improve the burning rate of solid propellant. The combination of PCNs material and CL-20 sustains the excellent performance of CL-20 and reduces the sensitivity effectively. The preparation of hybrid energetic material MHGP-CL-20 finds a new balance in the contradictory system of high energy and low sensitivity.
Study on TaN Thin Film Transducer Fabricated on the AlN Surface
Authors: Ren Xiao-Ming , Ding Yue-Wei , Wang Zhuo , Zhang Pei-Jia
Published: June 2023

In order to develop a new type of transducer for insensitive explosive devices, the problems in the film forming process of AlN ceramic surface were studied and the solutions were given. By comparison of ignition experiments, the surface roughness and average ignition current of the TaN film energy commutator prepared on the surface of polished AlN ceramics were smaller and higher. It met the technical requirements of insensitive explosive devices, which provided a new way for insensitive explosives.
Small opening cascade synchronous scanning underwater laser fuze using an adaptive backscatter filtering method
Authors: Xu Guangbo
Published: June 2023

To alleviate the problem of the low spatial utilization rate of underwater single-beam rotating scanning laser fuzes, a multi-beam rotating scanning fuze structure is proposed in this paper. It was used as a platform to study the interference mechanism of underwater pulsed laser backscatter, and Monte Carlo simulations were performed for typical detection situations of the underwater laser fuze. It was found that the interference echoes resulting from backscatter could even drown the actual target echoes and cause severe interference to the target identification of the fuze. To this end, this paper proposes an adaptive filtering algorithm called “VSS-DLMS” suitable for the fuze FPGA platform and simulated using echo data obtained by a real detection environment. The simulation results demonstrate that the algorithm can effectively suppress the backscattered signal of the pulsed laser in seawater and improve the signal-to-noise ratio of fuze detection.
A far-field super-resolution imaging method based on phase constructive
Authors: Guan Haitao , Hu Yan
Published: June 2023

Super-resolution imaging under passive illumination is always a crucial issue to be addressed. Because the wavefront of an incoherent light field is not easily detected, it is hard to achieve super-resolution imaging by synthetic aperture under passive illumination. In this work, we proposed a super-resolution method based on phase constructive. We use a quadrature phase-shifting algorithm to retrieve the wavefront from a series of correlation patterns and reconstruct the super-resolution image with a wavefront synthesis algorithm. A simulation result verifies the effectiveness of our proposed method with a USAF-1951 target as the object.
Small target location algorithm based on optimized template matching
Authors: Zhang Jiayu
Published: June 2023

At present, few published template matching algorithms can achieve the performance of commercial software. This paper studies and optimizes the existing geometric feature template matching algorithm, and combines it with the improved Fourier Merlin transform registration algorithm, and finally obtains a fast small target location algorithm. The matching time of the algorithm is 1-4ms, its positioning accuracy is sub-pixel level, the angle accuracy is less than 1 °, and it has good robustness to illumination. The experimental data show that the algorithm meets the requirements of real-time and accurate industrial automation production.
Numerical Simulation on Shaped Charge Jet Penetrating Single / Composite Structure of Target Plate
Authors: Niu Y Q , Jia X , Yu Y Q , Huang Z X , Xiao Q Q , Zu X D , Ma B
Published: June 2023

In order to study the ability of the target plate in the fortification to resist the penetration of the front-stage shaped jet of the tandem warhead, four common target materials of ceramic, reinforced concrete, steel fiber reinforced concrete and high-strength steel were selected as the target plate, and the finite difference software LS-DYNA was used. Software to carry out numerical simulation research on metal jet penetration into single/composite target plate. The research results show that when the structure of the shaped charge is the same, the jet penetration resistance of the four target materials is high-strength steel, ceramics, steel fiber reinforced concrete, and reinforced concrete in descending order; the C40 national military standard reinforced concrete target is used as a reference. The jet penetration depth of the composite target is reduced by 28%; due to the consumption of jet energy by multiple pit opening and high-strength interlayer materials, the jet penetration resistance of the composite target with the same thickness is better than that of a single.
Fast Prediction for Dynamic Response of Cellular Material under Dynamic Crushing
Authors: Liu Ting , Chen Changhai , Cheng Yuansheng
Published: June 2023

In this study, a dynamic enhancement stress model for cellular materials was derived from kinematics perspective, which directly reflected the influence of inertia effect on dynamic stress. Based on the proposed dynamic enhancement stress model, a densification strain calibration (DSC) analytical model with wider applicability for cellular materials was established, in which stress-dependent densification strain was employed. FE simulations for linear hardening and power hardening material under dynamic impact were conducted to validate DSC model. Comparing with idealized model (rigid, perfectly-plastic, locking model), dynamic plateau stress obtained by using of DSC model matched better with numerical results. Moreover, experimental results in published literature were employed to further confirm the reliability of DSC model in predicting projectile deceleration and final crushing depth. Finally, DSC model was used to predict dynamic response of gradient PVC foam, and the relative errors of final crushing depth to numerical results was within 8%.
Experimental Study on the Effect of Disturbed Tube on the Propagation Mechanism of Methane-Oxygen Detonation
Authors: Zhao Huan-juan , Liu Jing , Lin Min , Niu Shu-zhen , Yang Lian-zhi , Gao Na
Published: June 2023

The detonation experiments of unstable mixture CH4 + 2O2 were carried out in smooth and disturbed tube under different initial pressures(P
0) to study the effects of inner tube disturbance(d) on the propagation velocity of detonation wave and the characteristics of cellular structure. The results show that these are mainly affected by the initial pressure and boundary conditions (confined wall). With the increase of P
0, the change trend of cell size remains unchanged whether there is disturbance or not. However, when P
0 rises to 15kPa, it can not offset the detonation failure caused by the d = 60mm tube. While, the turbulence effect caused by d = 20mm tube maintains the wave propagation through the flow fluctuation of leading shock wave and the interaction of boundary layer. When P
0 increases to 14kPa, the shear wave intensity of the detonation wave increases. The high initiation energy leads to the instability of the detonation wave front. A relatively fine secondary cellular structure is observed near the main cellular structure. So after inserting the inner tube disturbance, the decrease of cell size is due to the generation of secondary cellular structure, and the size of main cellular structure actually becomes larger.
Research Status and Development Trend of Tandem Armor-Breaking Warheads
Authors: Peng-fei Kou , Lei Cao , Zheng-feng Liang
Published: June 2023

In order to cope with the continuous progress of tank protection technology, it is imperative to optimize and improve the ability of existing armor-breaking warheads. This paper mainly introduces the development history of explosive reactive armor, shaped charge jet formation theory, shaped charge jet penetration theory, armor-breaking warhead technology, series armor-breaking warhead technology and research status of armor-breaking/killing compound warhead technology. Finally, the development trend of armor-breaking warhead in the future is described, in order to provide some enlightenment for the design and improvement of armor-breaking warhead in the future.
Study on the characteristics of initial shock waves generated by cylindrical charge for underwater explosion
Authors: Ma T , Wang J X , Liu L T , Li H , Gu Y C , Zhang Y F
Published: June 2023

In order to provide a theoretical basis for studying the shock wave propagation and evolution generated by cylindrical charge of near-field underwater explosion, the characteristics of initial shock waves generated by cylindrical charge are studied. First, a new theoretical model for initial shock waves is proposed by the polar curve method. Based on the theoretical model and the simulated results, the influences of incident angle, length-to-diameter ratio and type of charge on the initial shock waves are analysed. Then the experiments of underwater explosion load tests are carried out to verify the theoretical and simulation results. Finally some instructive conclusions are drawn: i) The two-dimensional theoretical model can calculate the initial underwater shock wave pressure and its direction of cylindrical charge through detonation velocity, detonation pressure, explosive density and incident angle, which is provides a theoretical basic for studying the shock wave propagation and evolution studies. By comparing the theoretical results with the numerical results verified by experiments, the maximum error is not more than 9.93%. ii) Increasing the incident angle α
0 will reduce the initial shock wave pressure of cylindrical charge and make its direction deflect towards the material interface. When the incident angle α
0 is in the range of 0 - 10°, increasing the incident angle makes the initial shock wave pressure decrease rapidly as a power function. With the increasing of the incident angle, the attenuation rate of the initial shock wave firstly decreases and then increases when the incident angle α
0 is in the range of 10 - 72°. This phenomenon explains the reason that the axial and radial initial shock wave pressures are much higher than those in other directions after the central initiation of cylindrical charge. iii) According to the geometric relationship, the length-to-diameter ratio of the charge will limit the range of the incident angle. The length-to-diameter ratio will affect the initial shock wave pressure at the same initiation time. The pressure decreases with the increase of the length-to-diameter ratio when the initial shock wave is formed on the cylindrical surface of the charge.
Analysis the Influence of Projectile Penetration Velocity and Length - Diameter Ratio on Fuze Overload Signal Adhesion
Authors: Zhang Hongrui , Niu Shaohua
Published: June 2023

The overload signal of fuze is prone to be adhesion while projectile penetrating multi-layer target with high speed. This problem would cause failure of judgment the layers. The ahhesion phenomenon is related to many factors, such as the penetration speed, parameters of the projectile, the characteris of target and so on. In this paper, the influence of penetration speed and projectile length-diameter ratio on the overlaod signal adhesion is analyzed by numerical simulation. Firstly, the reliability of the material model and its material parameters are verified by simulating the penetration experiments of reduced-scale projectiles. Then three projectile models with different length-diameter ratios are established to compare and analyze the adhesion of overload signals penetrating the five-layer concrete target. The analysis shows that the signal is easy to be adhesion with the increasing of penetrating speed and the length-diameter ratio. However, with the increase of the penetrating speed of the projectile, the influence of its length-diameter ratio on the adhesion gradually decreases.
Experimental study on damage aftereffect of several types of metallic energetic fragments
Authors: Liu G T , Liu K , Zhang J J , Liu Y T , Liang D , Chen M , Wu B H
Published: June 2023

Metallic energetic fragments are the most widely used and technologically mature damage fragments at present. In this study, four types of typical tungsten/zirconium (W/Zr) energetic fragments are examined by static explosion test, and the penetration, hole enlargement, and ignition performance and characteristics of different fragment materials are investigated. The results show that all the four W/Zr energetic fragments have good anti-detonation and penetration capabilities, which can effectively penetrate 6 mm thick Q235 steel plate, aluminum spacer plate and fuel tank behind the target at impact velocity of 1050 m/s. 1#, 2# and 4# energetic fragments exhibit significant behind-target hole enlargement effect, and the enlarged area of holes in the aftereffect aluminum plate behind the steel plate with a spacing of 10 cm is 6~8 times the cross-sectional area of the original fragment, and the enlarged hole area of the fuel tank (outlet) behind the aluminum plate is 12~14 times the cross-sectional area of the original fragment. 3# fragments has weaker behind-target hole enlargement effect. Low-density 2# and 4# fragments can ignite the aviation kerosene tank behind the target, and 4# fragments show the best ignition effect. There is an internal consistency between hole enlargement capability on the aftereffect target of energetic fragments and the behind-target ignition capability. Without sacrificing the anti-detonation and penetration performance, low-density energetic fragments can be preferentially selected to ensure the behind-target damage effect.
Damage aftereffect of energetic materials in armor piercing incendiary projectiles on diesel fuel tanks
Authors: Liu K , Liu G T , Luo P G , Chen Z H , Liu Y T , Chen Z M , Huang K D
Published: June 2023

In order to investigate the damage aftereffect of energetic materials on diesel fuel tanks, this study compares the damage effects of three energetic materials, namely CuO/Al thermite, PTFE/Al+CuO/Al composite, and Zr powder, on diesel fuel tanks. The hole area on fuel tanks and the length and duration of diesel deflagration-formed fireballs are characterized, and the damage process and mechanism of armor piercing incendiary (API) projectiles are explored. According to the results, the CuO/Al thermite releases energy rapidly during projectile penetration into the target and exhibits the highest damage power. The hole produced by the thermite projectiles has an area twice as large as that produced by the composite projectiles, and the maximum fireball induced by the thermite persists twice as long as that induced by the composite. The rapid energy release of the CuO/Al thermite is primarily attributed to the vaporization of copper atoms into free copper at high temperatures, which further increases the pressure in fuel tanks. CuO/Al-filled API projectiles at a velocity of 950 m/s can produce violent deflagration and petaling damage to diesel fuel tanks.
Research on mass distribution characteristics of the behind armor debris of the EFP penetrating target
Authors: Li Rui , Huang Zhengxiang , Yu Wanqian , Zu Xudong , Xiao Qiangqiang , Jia Xin
Published: June 2023

Based on the AUTODYN, a numerical simulation model for EFP warhead penetrating finite thickness target was established, and the mass distribution characteristic of the armor debris behind target was analyzed. The result shows that the whole mass of behind armor debris(BAD) of the EFP with 1790m/s and target with 0° inclination angle increased and the quantity of BAD firstly increased and then decreased as target thickness ranging from 10mm to 70mm. For the experiments with employing the EFP with 1790m/s and 40mm target thickness, the BAD mass initially rose and then to drop off, as well as the quantity of BAD increased over inclination angle increasing from 0° to 60°.According to the results with 0° inclination angle and 40mm target thickness, the quantity of BAD also increased and the mass generally decreased as EFP velocity increasing from 1.2km/s to 2.6km/s. Verifications were conducted by using EFP penetrating into the 40mm thickness target with varying inclination angles. The simulation results correlate with the experimental results reasonably well.
Numerical Simulations of Plasmas Generated by Air Explosion
Authors: Chu Z X , Li J Q , Lei Xiao , Gan Y D , Zhang Y L , Liang H Z
Published: June 2023

The explosion process of explosives is very complex, often accompanied by phenomena such as luminescence, heat, and electromagnetic radiation. Many studies have shown that the electromagnetic radiation of explosive explosions is related to plasma generated by explosion. In this paper, through the thermal equilibrium ionization model, the plasma model of explosive explosion is established, the calculation formula of plasma state parameters is obtained, and the plasma dynamics program is written. The numerical simulation analysis of the air explosion conditions is carried out by using the plasma dynamics program, and the relationship between the electron density and conductivity of the air explosion plasma and the mass of explosive and distance are summarized.
Orthogonal Structure Design of the Linear Shaped Charge Based on Steady-State Velocity Model
Authors: Li Yishu , Zhai Zhe , Fan Xuefei , Han Hongwei , Zhao Yan , Cao Hequan
Published: June 2023

The velocity of the linear jet beams/slugs are one of the key factors affecting the penetration performance of the linear shaped charge (LSC). In order to obtain the velocity of the linear jet beams/slugs, we build the steady-state velocity model of the LSC first. Subsequent the LSC structures are designed by the orthogonal method based on the key factors of the LSC velocity model including the liner material, thickness, vertex angle, charge shape, explosive density, etc. The shape and velocity of the linear jet beams after the charge explosion are obtained by numerical simulation. Furthermore, X-ray tests are carried out to verify the simulation results. The average error of theoretical value, simulation and experimental result is less than 6%. The velocity model of the linear jet beams/slugs can guide the structural design of the LSC and play an important role in improving the penetration performance.
JUSMAR-MANS: a platform software for compressible multimedium flow large-scale numerical simulation on JASMIN framework
Authors: Yu Y Q , Liu N , Zhang P , Zhang A Q
Published: June 2023

A new platform software named JUSMAR-MANS based on JASMIN was developed for the massively parallel numerical simulation on compressible multimedia multiphase flow under complex conditions. Different from the traditional “chimney” program research and development (r&d) pattern, the MANS who adopted the “platform” r&d pattern provides a way by which the users can rapidly and conveniently customize personalized high-credibility program of multimedium without considering in numerical discrete and parallel computing. MANS has the following advantages: 1) Decoupling of disciplines: In architecture design, physical modeling, numerical discreting, parallel computing are separated from each other and concept shielding so that the high barriers of program r&d caused by interdisciplinary are broken down. 2) Expandability: enables to easily extend new physical models and numerical schemes based on single point/element interfaces. 3) Rapid customization: enable to quickly assemble personalized program based on various models and algorithms libraries integrated by MANS. Based on MANS, it only takes serial code within a few days to obtain a well-posed large - scale multimedium simulation, which greatly reduce the complexity of software r&d for compressible multimedium flow.
Research on Potential Equilibrium of Dynamic Combustion Performance in Electrothermal-Chemical Launching
Authors: Zong Sijia , Yang Chunxia
Published: June 2023

The interior ballistic potential equilibrium theory is used to analyse the parameters at the potential equilibrium points of pressure curves of 30mm conventional launching experiment and electrothermal-chemical (ETC) launching experiments. Analysis shows that: compared to the conventional launching experiment, (1) the time for ETC launching experiment to arrive the potential equilibrium point is apparently shortened; (2) the relative burnt percentages of the propellants at the potential equilibrium points are smaller in ETC launching tests. And the curves of gas generation brisance in the three ETC launching experiments are consistent. Then based on the measured pressure curves, the actual gas generation functions in chamber for conventional launching experiment and ETC launching experiments are fitted respectively. Using the average actual gas generation functions to replace the shape functions which are derived from the hypothesis of Geometric Combustion Law, the interior similarity equations of ETC Gun are established with the potential equilibrium point as the reference state. The calculated pressure curve obtained by solving the interior ballistic similarity equations of electrothermal chemical gun is in good agreement with the experimental pressure curve. Therefore, it is expected that the interior similarity equations of ETC Gun could predict the experimental pressure curve.
Experimental study on Hugoniot parameters of U71Mn steel under high pressure
Authors: Zhang Q D , Yan H D , Xie Z Z , Yu Y F
Published: June 2023

The Hugoniot parameters of U71Mn steel under high pressure were studied by hypervelocity impact test of U71Mn steel with two-stage light gas gun. The plate impact test of U71Mn steel sample was carried out by means of symmetrical impact. The minimum impact speed was 1.843km/s and the maximum impact speed was 5.018km/s. The Hugoniot relation and Hugoniot parameter C and λ, then the accuracy of Hugoniot parameters of U71Mn steel under high pressure is verified according to Hugoniot equation of state (the relationship curve between impact pressure and density). The research results can provide reference for the application of U71Mn steel in the field of hypervelocity impact.
High-power Microwave Damage Assessment Method for UAV
Authors: Yang Chong-Xiang , Cui Dong-Hua , Chen Zhi-Hua , Xiao Yu-Jie , Zheng Chun
Published: June 2023

To evaluate the damage assessment of high-power microwaves on complex electronic systems, a damage assessment method combining top-down system analysis and bottom-up comprehensive evaluation is proposed. A UAV damage tree model was constructed, and the FAHP-CRITIC method was used to assign weights to system components. The pulse energy transfer and coupling process are analyzed, and a neural network system is introduced to predict the damage degree of the parts considering the influencing factors of the damage degree of the parts. Based on the obtained component weights and damage degree, the system damage degree is calculated by the constructed nonlinear discontinuity function which satisfies the serial structure of the electronic system. Then, the mapping of system damage degree to ruin level is realized through the affiliation function. Finally, simulation calculations are carried out for the UAV to verify the feasibility and effectiveness of the proposed method.
Investigation on structural failure of filament reinforced barrel containment
Authors: Xiao Hongcheng , Ruxiang Li , Li Wei , Wang Junhao , Li Yingjie
Published: June 2023

During the launching process of a composite railgun, some working conditions may lead to the structure failure of its filament reinforced barrel. For instance, the instantaneous electric power impact caused by the unexpected large pulse current and surge from the pulse-forming network, which inspires the electrodynamic response beyond the safety limit of the barrel. More importantly, the alternating load after a long-term working causes damage accumulation and failure in the composite structure. For the railgun, considering that the radial deformation of the barrel has special effect on the contact state of the rail and armature in bore, it is necessary to focus on whether the radial stiffness of the barrel is affected even if the strength of the barrel does not decrease significantly by hidden injuries in the fiber wraps. In this study, based on the common used method of progressive failure theory, the radial stiffness attenuation process of the barrel is analyzed. The fiber fracture and composite delamination failure modes are found to be the main factors for radial stiffness attenuation of railgun barrel containment as persistent deformation will generate after these damage propagation. In addition, the loss of prestress in the fiber containment is evaluated based on structural analysis for the barrel in service and in manufacturing time. The research has found that optimized preloading seems important for improving the strength performance of the barrel.
Research on Evaluation Technology of Key Parameter Error Scheme for Medium and Long Range Suppression Artillery
Authors: Xiao-ke Gao , Ying-chao Wu
Published: June 2023

Aiming at the evaluation of the key parameter error scheme of medium and long-range suppression artillery, the evaluation index system is established, and the analytic hierarchy process of different evaluation index systems is constructed. In view of the complexity of the evaluation of the key parameter error scheme of the medium and long-range suppression artillery, a comprehensive evaluation scheme is constructed from three aspects: first, the evaluation method of the key parameter error method of the medium and long-range suppression artillery is determined, then the evaluation index system of the key parameter error scheme of the medium and long-range suppression artillery is designed, and finally the comprehensive evaluation model of the key parameter error is constructed. This paper studies the design principles of the evaluation index system of the key parameter error scheme of the medium and long-range suppression artillery, establishes a comprehensive evaluation index system, and comprehensively evaluates the key parameter error scheme based on AHP and ANP methods. Through the comprehensive evaluation of a group of error schemes, the effectiveness of the method is verified.
Research on key technology of complex components based on 3D printing
Authors: Liu D , Liu J B , Ren Y Q , Zhang Y T
Published: June 2023

3D printing technology as the advanced technology has developed rapidly in recent years. In order to study the problem of design and manufacture of gun complex components, applications of the muzzle brake with a high efficiency and low impact are of a special interest. This paper studied a number of key technologies of the complex components based on 3D printing, focusing on the discussion of the 3D model design, mold direction design, support structure design, 3D model layered slice and 3D printing process. The research for the improvement of the success rate of complex workpiece based on 3D printing has a good reference value, and expand the application of this technology in military field further.
Non-linear effective field theory simulators in two-fluid interfaces
Authors: Barroso Vitor S. , Bunney Cameron R. D. , Weinfurtner Silke
Published: June 2023

Analogue gravity offers an approach for testing the universality and robustness of quantum field theories in curved spacetimes and validating them using down-to-earth, laboratory-based experiments. Fluid interfaces are a promising framework for creating these gravity simulators and have successfully replicated phenomena such as Hawking radiation and black hole superradiance. Recent work has shown that hydrodynamical instabilities on the interface between two fluids can capture features of the post-inflationary thermalisation of the Early Universe. In this study, we extend fluid dynamics methods to develop an effective field theory for the interface between two fluids, demonstrating the equivalence between the governing equations and a relativistic scalar field in an analogue spacetime. We also show that the interfacial height field serves as the analogue relativistic field even in a nonlinear, interacting field theory. We propose that these mathematical equivalences can be extrapolated to probe regimes where calculations are challenging or impractical. Our work provides a new framework for simulating far-from-equilibrium cosmological and gravitational scenarios in the laboratory.
Hadamard and boundary conditions for the Big Bang quantum vacuum
Authors: Beltrán-Palau Pau , Nadal-Gisbert Sergi , Navarro-Salas José , Pla Silvia
Published: June 2023

General relativity predicts final-type singularities inside black holes, as well as a cosmological initial-type singularity. Cosmic censorship protects external observers from black hole singularities, while Penrose’s Weyl curvature hypothesis protects the smoothness of the initial (Big Bang) singularity. We discuss a simple realization of the Weyl curvature hypothesis by assuming a very early radiation-dominated universe and analytically extending the expansion factor to negative values of conformal time. We impose time-reversal conditions at the Big Bang to characterize a natural set of preferred vacuum states for quantized matter fields. We implement the prescription of States of Low Energy constructed around the Big Bang obtaining Hadamard states. We also explore the physical implications of these vacua for cosmological dark matter production.
Flow cytometry as an analytical method of drug-induced apoptosis in 3D bioprinted melanoma cells
Authors: de Villiers Maryke , Du Plessis Lissinda H
Published: June 2023

Three-dimensional (3D) cell culture systems have gained increasing interest in drug discovery and tissue engineering due to its inherent advantages in providing more physiologically relevant information and more predictive data for in vivo tests. Along with the development of more physiologically relevant 3D cell culture models, researchers bear the responsibility to validate new cell assay techniques capable of measuring and evaluating constructs that are physically larger and more complex compared to two-dimensional cell cultures. It is important to note that assays based on monolayer cultures may be insufficient for the use in 3D cell cultures models. In this study we firstly fabricated a 3D bioprinted hydrogel melanoma scaffold. This was used to validate a flow cytometry-based analytical method as a tool for 3D bioprinted structures to assess drug-induced apoptosis. The results indicated high robustness, reproducibility and sensitivity of the flow cytometric method established on the 3D cell-laden A375 melanoma hydrogel scaffolds. Over and above this, it was possible to determine the effect of etoposide on A375 melanoma cells using Annexin V and propidium iodide apoptosis assay.
Contrasting responses of the ocean’s oxygen minimum zones to artificial re-oxygenation
Authors: Beghoura Houda , Gorgues Thomas , Fransner Filippa , Auger Pierre-Amaël , Memery Laurent
Published: June 2023

Studies assessing potential measures to counteract the marine deoxygenation attributed to anthropogenic activities have been conducted in a few coastal environments and at regional scale, but not yet on a global scale. One way toward global scale artificial oxygenation would be to use oxygen produced as a by-product from hydrogen-production through electrolysis. The low-carbon footprint renewable production of hydrogen from offshore wind energy offers such a possibility. Here, we assessed the potential of this artificial oxygenation method on a global scale using a coupled physical-biogeochemical numerical model. The anthropogenic oxygen source scenario assumes worldwide adoption of hydrogen, considering demographic changes and the feasibility of offshore wind turbine deployment. Following this scenario, artificial oxygenation had a negligible effect on the overall oxygen inventory (an increase of 0.07%) but showed a reduction in the overall volume of Oxygen Minimum Zones (OMZs) between 1.1% and 2.4%. Despite the decrease in the mean OMZ volume globally, OMZs display distinct and contrasting regional patterns notably due to the oxygen impacts on the nitrogen cycle. Artificial oxygenation can inhibit denitrification resulting in a net gain of nitrate that promotes locally and remotely increased biological productivity and consequent respiration. Increased respiration could ultimately lead to an oxygen loss at and beyond injection sites as in the Tropical Pacific and Indian Ocean and particularly expand the Bay of Bengal OMZ. In contrast, the tropical OMZ shrinkage in the Atlantic Ocean is attributed to oxygen enrichment induced by advective transport into the OMZ, while the absence of denitrification in this area precludes any biochemical feedback effect on oxygen levels. These results suggest that the impacts of artificial oxygenation on oxygen concentrations and ecosystems are highly non-linear. It can produce unexpected regional responses that can occur beyond the injection sites which make them difficult to forecast.
Convergence of melt electrowriting and extrusion-based bioprinting for vascular patterning of a myocardial construct
Authors: Ainsworth Madison Jade , Chirico Nino , de Ruijter Mylène , Hrynevich Andrei , Dokter Inge , Sluijter Joost P G , Malda Jos , van Mil Alain , Castilho Miguel
Published: June 2023

To progress cardiac tissue engineering strategies closer to the clinic, thicker constructs are required to meet the functional need following a cardiac event. Consequently, pre-vascularization of these constructs needs to be investigated to ensure survival and optimal performance of implantable engineered heart tissue. The aim of this research is to investigate the potential of combining extrusion-based bioprinting (EBB) and melt electrowriting for the fabrication of a myocardial construct with a precisely patterned pre-vascular pathway. Gelatin methacryloyl (GelMA) was investigated as a base hydrogel for the respective myocardial and vascular bioinks with collagen, Matrigel and fibrinogen as interpenetrating polymers to support myocardial functionality. Subsequently, extrusion-based printability and viability were investigated to determine the optimal processing parameters for printing into melt electrowritten meshes. Finally, an anatomically inspired vascular pathway was implemented in a dual EBB set-up into melt electrowritten meshes, creating a patterned pre-vascularized myocardial construct. It was determined that a blend of 5% GelMA and 0.8 mg·ml−1 collagen with a low crosslinked density was optimal for myocardial cellular arrangement and alignment within the constructs. For the vascular fraction, the optimized formulation consisted of 5% GelMA, 0.8 mg·ml−1 collagen and 1 mg·ml−1 fibrinogen with a higher crosslinked density, which led to enhanced vascular cell connectivity. Printability assessment confirmed that the optimized bioinks could effectively fill the microfiber mesh while supporting cell viability (∼70%). Finally, the two bioinks were applied using a dual EBB system for the fabrication of a pre-vascular pathway with the shape of a left anterior descending artery within a myocardial construct, whereby the distinct cell populations could be visualized in their respective patterns up to D14. This research investigated the first step towards developing a thick engineered cardiac tissue construct in which a pre-vascularization pathway is fabricated within a myocardial construct.
Schottky barrier heights and electronic transport in Ga2O3 Schottky diodes
Authors: Kim Min-Yeong , Byun Dong-Wook , Lee Geon-Hee , Pookpanratana Sujitra , Li Qiliang , Koo Sang-Mo
Published: June 2023

The Schottky contact, formed at the interface between a metal and a semiconductor, is instrumental in defining the electrical properties of Schottky barrier diodes (SBDs). The characteristics of the Schottky contact are contingent on the properties of interacting metal and semiconductor properties. Herein, we studied the carrier-transport mechanisms and electrical characteristics at room and elevated temperatures. These SBDs employ pre-treated Ga2O3 thin films and either Ni or Au Schottky contacts. The SBDs pre-treated (pre-T) via annealing at 900 °C under an N2 atmosphere for the Ni contact showed highest on/off ratio at room temperature. They also demonstrated ideality factors and Schottky barrier heights (SBHs) that remained relatively stable between 298 K and 523 K. To ascertain the SBH, ideality factors (n) derived from the thermionic emission (TE) and thermionic field emission (TFE) models were used, and results were subsequently compared. Moreover, SBDs employing Ni as the anode material exhibited lower SBHs than those employing Au. The pre-T Ni SBD was best described by the TFE model, wherein the SBH and ideality factor varied by 0.14 eV and 0.13, respectively, between 298 K and 523 K. Conversely, for pre-T Au, untreated Ni, and untreated Au SBDs, neither TE and TFE provided a satisfactory fit due to the ideality factor is greater than 2 at room temperature and the variation of SBH and n with temperature. These suggests that the transport mechanism should be described by other physical mechanisms. Without pre-treatment, both the Ni and Au SBDs exhibited more significant variation in the SBH and n with temperature. SBHs values were determined using measurement of current, capacitance and x-ray photoelectron spectroscopy, and were found to depend on the interface quality, indicating inhomogeneous SBH. Our results suggest that the use of annealing pre-treatments and anode metals with low work functions holds considerable potential for reducing Schottky barrier heights in Schottky diodes, thereby enhancing their electrical performance.
Proposal for practical Rydberg quantum gates using a native two-photon excitation
Authors: Li Rui , Qian Jing , Zhang Weiping
Published: June 2023

Rydberg quantum gate serving as an indispensable computing unit for neutral-atom quantum computation, has attracted intense research efforts for the last decade. However, the state-of-the-art experiments have not reached the high gate fidelity as predicted by most theories due to the unexpected large loss remaining in Rydberg and intermediate states. In this paper, we report our findings in constructing a native two-qubit controlled-NOT gate based on pulse optimization. We focus on the method of commonly-used two-photon Rydberg excitation with smooth Gaussian-shaped pulses which is straightforward for experimental demonstration. By utilizing optimized pulse shapes the scheme reveals a remarkable reduction in the decays from Rydberg and intermediate states, as well as a high-tolerance to the residual thermal motion of atoms. We extract a conservative lower bound for the gate fidelity>0.9921after taking into account the experimental imperfections. Our results not only reduce the gap between experimental and theoretical prediction because of the optimal control, but also facilitate the connectivity of distant atomic qubits in a larger atom array by reducing the requirement of strong blockade, which is promising for developing multiqubit quantum computation in large-scale atomic arrays.
Ink engineering for slot-die coated perovskite solar cells and minimodules
Authors: Li Bowei , Zhang Wei
Published: June 2023

The power conversion efficiencies of perovskite solar cells (PSCs) have approached 26% for single-junction and 33% for multi-junction cells. Thus, various scalable depositions are studied to improve the manufacturability of PSCs for market entry. Of all types, slot-die coating is a promising technique thanks to its excellent compatibility with versatile systems. However, the complicated ink chemistry and film formation are major obstacles to scaling up devices. In this review, we systematically discuss ink engineering in the fabrication of slot-die-coated PSCs and perovskite minimodules, covering all functional layers that are processed using solution-based means. We then summarize a range of strategies to improve ink compatibility with slot-die coating, focusing on how to optimize the ink formulation to achieve high-quality films. Finally, we highlight the existing challenges and potential avenues for further development of slot-die-coated devices.
Enhanced variable universe fuzzy PID control of the active suspension based on expansion factor parameters adaption and genetic algorithm
Authors: Ji Guanggang , Zhang Lidong , Shan Mingyang , Zhang Jiwei
Published: June 2023

The optimal value of the expansion factor and quantization factor parameters is the key to determine the performance of the variable domain fuzzy proportion-integral-derivative (PID) controller. In view of the problem that the relevant parameters are fixed, difficult to determine and cannot be adjusted adaptively in the traditional variable domain fuzzy PID control, a kind of enhanced variable domain fuzzy PID control (EVUFP) is proposed to improve the ride comfort of vehicles. First, based on the traditional variable domain fuzzy PID control, an adaptive expansion factor controller is constructed to determine and adjust adaptively the parameters of the expansion factor in real time. Then the genetic algorithm is used to optimize the quantization factor and scale factor parameters to seek the optimal value of relevant parameters. And the obtained optimal parameters are substituted into the Simulink model to realize the design of the EVUFP controller. The simulation experiment results under different working conditions show that the proposed EVUFP control strategy can reduce the root mean square (RMS) values of the body acceleration, suspension dynamic deflection and tire dynamic load by more than 54%, 50% and 23%, respectively, improve the ride comfort of vehicles, and provide a new idea for the development of active suspensions.
A Fourier-Legendre spectral method for approximating the minimizers of 𝜎_{2,𝑝}-energy
Authors: Taghavi M. , Shahrokhi-Dehkordi M.
Published: June 2023

This paper proposes a Fourier-Legendre spectral method to find the minimizers of a variational problem, called

σ

2
,
p

\sigma _{2,p}

-energy, in polar coordinates. Let

X

⊂

R

n

{\mathbb {X}}\subset \mathbb {R}^n

be a bounded Lipschitz domain and consider the energy functional

(
1.1
)

(1.1)

whose integrand is defined by
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="bold upper W left-parenthesis nabla u left-parenthesis x right-parenthesis right-parenthesis colon-equal left-parenthesis sigma 2 left-parenthesis u right-parenthesis right-parenthesis Superscript StartFraction p Over 2 EndFraction Baseline plus normal upper Phi left-parenthesis det nabla u right-parenthesis">

W

(
∇
u
(
x
)
)
≔
(

σ
2

(
u
)

)

p
2

+
Φ
(
det
∇
u
)

{\mathbf {W}}(\nabla u(x))≔(\sigma _2(u))^{\frac {p}{2}}+\Phi (\det \nabla u)

over an appropriate space of admissible maps,

A

p

(

X

)

\mathcal {A}_p({\mathbb {X}})

. Using Fourier and Legendre interpolation errors, we obtain an error estimate for the energy functional and prove a convergence theorem for the proposed method. Furthermore, we apply the gradient descent method to solve a nonlinear algebraic system which is obtained by discretizing the Euler-Lagrange equations. The numerical experiments are performed to demonstrate the accuracy and effectiveness of our method.
Utility of TRPS1 immunohistochemistry in confirming breast carcinoma: Emphasis on staining in triple-negative breast cancers and gynecologic tumors
Authors: Rammal Rayan , Goel Kanika , Elishaev Esther , Soong T Rinda , Jones Mirka W , Zhao Chengquan , Clark Beth Z , Carter Gloria J , Yu Jing , Fine Jeffrey L , Villatoro Tatiana M , Skvarca Lauren , Harinath Lakshmi , Bhargava Rohit
Published: June 2023

Objectives

Our aim was to explore the performance of TRPS1 as an immunohistochemical diagnostic marker; find the optimal conditions for its use in breast carcinomas, especially triple-negative breast cancers (TNBCs); and compare its results in carcinomas of a select few organ sites, with an emphasis on gynecologic tumors.

Methods

Tissue microarrays from breast carcinomas (n = 197), endometrial adenocarcinomas (n = 69), ovarian tumors (n = 250), vulvar squamous cell carcinomas (n = 97), pancreatic ductal adenocarcinomas (n = 20), and gastric adenocarcinomas (n = 12) were stained with TRPS1 using 2 different conditions (protocol 1: high pH; protocol 2: low pH). Breast carcinomas consisted of hormone receptor (HR)–positive/ERBB2 (formerly HER2 or HER2/neu)–negative (n = 53) samples, HR-positive/ERBB2-positive (n = 6) samples, and TNBCs (n = 138).

Results

Comparing TRPS1 results in breast carcinomas vs tumors from other organ sites, the sensitivity of TRPS1 was 91% and 87%, respectively, while the specificity was 66% and 74% for protocol 1 and 2, respectively. For TNBCs vs gynecologic tumors, the sensitivity of TRPS1 was 89% and 85%, respectively, while the specificity was 65% and 73%, respectively.

Conclusions

TRPS1 stains approximately 90% of breast carcinomas but also up to 71% of endometrial carcinomas, albeit with a weaker median expression. Our data show that although TRPS1 is a highly sensitive marker for TNBCs, it is not as highly specific as previously reported.
Safety evaluation and maximum use level for transient ingestion in humans of allitol
Authors: Miyoshi Miku , Yoshihara Akihide , Mochizuki Susumu , Kato Shiro , Yoshida Hiromi , Matsuo Tatsuhiro , Kishimoto Yuka , Inazu Tadao , Kimura Isao , Izumori Ken , Akimitsu Kazuya
Published: June 2023

Allitol is a hexitol produced by reducing the rare sugar D-allulose with a metal catalyst under hydrogen gas. To confirm the safe level of allitol, we conducted a series of safety assessments. From the results of Ames mutagenicity assay using Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537, Escherichia coli strain WP2uvrA, and an in vitro chromosomal aberration test on cultured Chinese hamster cells, allitol did not show any significant genotoxic effect. No significant effects on general condition, urinalysis, hematology, physiology, histopathology, or at necropsy were observed at a dose of 1500 mg/kg body weight of allitol in the acute and 90-day subchronic oral-toxicity assessments for rats. A further study performed on healthy adult humans showed that the acute use level of allitol for diarrhea was 0.2 g/kg body weight for both men and women. The results of current safety assessment studies suggest that allitol is safe for human consumption.