Experimental Scheme Research Articles

Constraint of d = 8 Lorentz Invariance Violation with New Experimental Design

Short-range gravity experiments are more suitable for the testing of high-order Lorentz symmetry breaking effects. In our previous work, we proposed a new experimental design based on precision torsion balance technology to test the Lorentz violation force effect that varies inversely with the fourth power of distance (corresponding to mass dimension d = 6 term), and the corresponding experiment is currently underway. In this paper, we focus on analyzing the potential of this experimental scheme to test the Lorentz violation force that varies inversely with the sixth power of distance (corresponding to mass dimension d = 8 term). The results show that, compared with the current best limit, the new experimental scheme can improve the constraints on the Lorentz violation coefficients with d = 8 by at least one order of magnitude.

Lubrication, Friction and Wear Characteristics of Textured Surface Slipper Pairs in Axial Piston Pumps

The study investigates the impact of textured surface parameters and pump operating parameters on the friction performance of slipper pairs in axial piston pumps. The orthogonal experimental scheme was developed, and the influence of several factors was explored, such as rotational speed, area ratio, micro-pit shape, diameter, depth-to-diameter ratio and film thickness. Optimal dimension combinations of the micro-pit were identified by numerical simulation and standard pin–disk friction experiment. In the pin–disk friction pair test, the friction coefficient of the textured surface compared to the smooth surface showed a maximum average friction reduction rate of 26.974%. Under various pump pressures (4, 8, 12 MPa) and pump displacements (10, 20, 35 L/min), the friction reduction rates of the textured surface slipper pairs (texture diameter 500 µm, depth 250 µm, area ratio 20%) ranged from 0.78% to 18.13%. The study underscores the importance of surface texture in enhancing the operational efficiency and reliability of axial piston pumps, offering valuable insights for the design and maintenance of hydraulic pumps.

Model study on transmission loss of the split-stream rushing exhaust muffler for diesel engine

Numerical simulation was carried out on the transmission loss of the split-stream rushing exhaust muffler, and the accuracy of the simulation method was verified through experiments. Taking the transmission loss as the response value, the experiment was designed by using Box-Behnken module of Design Expert software. A mathematical regression model of transmission loss with experiment factors was established by using the Box-Behnken experimental design scheme, the experiment factors include the diameter of the interior pipe, the shape of the rushing hole, the center distance of the rushing hole, the cone angle of the interior pipe as well as the number of rushing holes, and the mathematical regression model's significance was tested. The response curvatures of second order interaction to the transmission loss by different variables were obtained and the interaction relationships among variables were analyzed. The results showed that the diameter of the interior pipe and the center distance of the rushing hole are the main factors that affect the transmission loss. The transmission loss increases with the increase of the diameter of the interior pipe. When the diameter of the interior pipe is between 70 mm and 80 mm, the transmission loss firstly increases and then decreases with the center distance of the rushing hole changes from Smin to Smax. When the diameter of the interior pipe is between 80 mm and 90 mm, the transmission loss decreases with the center distance of the rushing hole changes from Smin to Smax. The effect of the rushing hole shape on transmission loss is not significant. The transmission loss increases with the increase of the number of rushing holes, but the increase of transmission loss is not significant with the number of rushing holes changes from 4 to 6 groups. Taking the transmission loss as the optimization index, the better experimental condition was obtained. Compared to the not optimized muffler of the sample engine, the average transmission loss of the optimized muffler is increased by 48.70 % when the frequency is 0-1000 Hz, the average insertion loss of the optimized muffler is increased by 7.4 %. At inlet air velocity of 40 m/s, the pressure loss is reduced by 56.8 %.

Unconventional structural evolution of an oxide surface in water unveiled by in situ sum-frequency spectroscopy.

Oxide-water interfaces host a wide range of important reactions in nature and modern industrial applications; however, accurate knowledge about these interfaces is still lacking at the molecular level owing to difficulties in accessing buried oxide surfaces. Here we report an experimental scheme enabling in situ sum-frequency vibrational spectroscopy of oxide surfaces in liquid water. Application to the silica-water interface revealed the emergence of unexpected surface reaction pathways with water. With ab initio molecular dynamics and metadynamics simulations, we uncovered a surface reconstruction, triggered by deprotonation of surface hydroxylated groups, that led to unconventional five-coordinated silicon species. The results help demystify the multimodal chemistry of aqueous silica discovered decades ago, bringing in fresh information that modifies the current understanding. Our study will provide new opportunities for future in-depth physical and chemical characterizations of other oxide-water interfaces.

Leaf-stem diseases of soybean on varieties of diferent ripenity groups in the conditions of the Amur region

The Amur region is the main producer of soybeans in the Russian Federation, where one of the significant phytosanitary problems of soybean cultivation technologies is leaf and stem infections. The susceptibility of soybeans to diseases varies greatly depending on weather conditions, used agricultural technology and the resistance of cultivated varieties. Since the soybean varieties, cultivated in the region, have significant differences in early maturity, it remains relevant to monitor leaf and stem infections and identify the degree of their development depending on the length of the crop growing season and the year conditions. The purpose of the study was to assess the influence of soybean variety by maturity groups and year conditions on the incidence of leaf-stem infections. Research was carried out in 2022 and 2023 in the Tambov district of the Amur region on 32 soybean varieties of domestic and foreign selection, belonging to 3 ripeness groups: early ripening, mid-ripening and late ripening. A phytopathological examination of soybean crops revealed Septoria blight (Septoria glycines T. Hemmi. Syn.), Cercospora blight (Cercospora sojina Hara), Ascochyta blight (Ascochyta sojaecola Abramoff. Syn.), downy mildew (Peronospora manshurica (Naum.) Syd. Syn.), purple Cercospora blight (Cercospora kikuchii (Matsuet Tomoyasu) Yardn) and angular bacterial spot. According to the indicator of disease incidence on soybean varieties of three ripeness groups, it was revealed that the incidence of downy mildew significantly, at the level of 90 %, depended on the variety ripeness group: mid-, and especially late-ripening varieties, were affected by the disease in both years an order of magnitude more strongly than early-ripening varieties. No significant influence of soybean varieties maturity groups on other infections was detected after the use of the fungicide, while analysis of variance according to the two-factor experiment scheme showed a significant influence of year weather conditions on the diseases incidence: Cercospora blight – at the level of 75.7 %, Cercospora purple blight – 77.1 %, Ascochyta blight – 98.5%. Both the ripeness group of soybean varieties and the year conditions influenced the bacteriosis incidence: the disease was more pronounced on early-ripening varieties, which were more populated by mites, the vectors of the disease pathogen, and was noted only in 2023. Analysis of variance according to the two-factor experiment scheme did not reveal a significant influence of varieties and year conditions on the incidence of Septoria blight, which indicates significant adaptations of the pathogen to weather factors and the physiology of plants from different ripeness groups, as well as the stable effectiveness of fungicidal treatment of soybean crops against Septoria blight.

Improved experimental scheme for the generation of pair coherent state in traveling-wave optical fields

Abstract Pair coherent state (PCS) is a two-mode non-Gaussian state recently generated within spatially confined superconducting cavities. Under typical conditions, it is unsuitable for performing global quantum missions in open space. Several methods have been proposed to generate this state with the capability to propagate unrestrictedly. However, these methods employed an excessive amount of unnecessary physical resources or relied on coherent displacement within the low regime. This paper presents a novel experimental approach to generate this state, specifically designed for facilitating long-distance quantum information processing and communication tasks. The method involves the utilization of two weak cross-Kerr nonlinear media, two balanced beam splitters, and an on/off photodetector. Furthermore, the input comprises three CSs with high amplitudes. These physical resources are potentially accessible within existing technology. The analysis of success probability and fidelity demonstrates that the PCS can be successfully generated with a high coherent parameter amplitude, even in scenarios where the photodetector efficiency is low, provided that the coherent amplitudes are sufficiently high.

On the possibility of studying the effect of magnetic reconnection in a laboratory astrophysical experiment using X-ray emission L-spectra of multiply charged ions

The paper considers the application of X-ray spectroscopy with high spatial resolution for investigation of magnetic reconnection in laboratory astrophysical experiments carried out on laser facilities of nano- and pico-second duration at moderate laser intensity on the target 1018 W/cm2. A brief overview of commonly used experimental schemes is given. We present atomic kinetic calculations for the spectra from the L-shells of Ne- and F-like iron ions (Fe, Z = 26), which demonstrate the high sensitivity of the spectra to changes in plasma parameters. An analysis of the range of applicability of various diagnostic approaches to assessing the electron temperature and laser plasma density is carried out. It is shown that transition lines in Ne-like ions are a universal tool for measuring plasma parameters, both in the region of laser interaction with the target and in the reconnection zone.

N-changing population of Rydberg states by low-energy electron-Rydberg collisions.

Inelastic n-changing collisions play an important role in the evolution of Rydberg atoms into ultracold plasmas. However, for the initially intermediate n (n ∼ 40) Rydberg states, these collisions can hardly be observed due to the low electron temperature in ultracold plasmas. In this work, we designed an experimental scheme to facilitate collisions between free electrons at 1.5eV and intermediate n Rydberg atoms. Using the field ionization technique, we measured the state distributions resulting from the evolution of initially cold rubidium atoms in the 45P3/2 Rydberg state. The experimentally obtained probability of inelastic collisions excitation agrees well with the Monte Carlo simulation results. In addition, our experimental results indicate that the n-changing population induced by hot electrons is significant for lower nP Rydberg states. Our work plays a significant role in calculating the rates of electron-ion three-body recombination in ultracold plasmas.

Power data analysis and mining technology in smart grid

This study proposes a smart grid model named “GridOptiPredict”, which aims to achieve efficient analysis and processing of power system data through deep fusion of deep learning and graph neural network, so as to improve the intelligent level and overall efficiency of power grid operation. The model integrates three core functions of load forecasting, power grid state sensing and resource optimization into one, forming a closely connected and complementary framework. Through carefully designed experimental scheme, the practical value and effectiveness of “Grid OptiPredict” model are fully verified from three aspects: accuracy of load forecasting, sensitivity of power grid state sensing and efficiency of resource allocation strategy. Experimental results show that the model has significant advantages in prediction accuracy, model stability and robustness, resource optimization, security, information security, social and economic benefits and user experience.

Logical and Situational Analysis of the Possibilities of Innovative Development of the Agroindustrial Sector

The author has identified a low level of innovative development of the agroindustrial complex and the reasons for the delay in its growth in comparison with other industries and types of economic activity in Russia. The consequence is a noticeable trend of changes in the positive dynamics of economic efficiency indicators of agricultural production in the recent past. This trend indicates weakening Russia’s food security. The article considers one of the possible options for import substitution of innovative means of production used in the agroindustrial sector in the conditions of external economic isolation of the country. It implies the participation of the state in supporting the development and assimilation of knowledge embodied in the real economy as well as in the financing of national innovative solutions. The option under consideration has the following features: selection on a competitive basis and priority financing of means of production with a high technological potential, which are most in demand among agroindustrial enterprises; reimbursement of payment for information on the state of the markets for technology, means of production, resources, food, raw materials provided by IT specialists, as well as for making calculations to optimize the structure and volumes of production, product exports and technological training to enterprises. This kind of financial support is provided in addition to the current practice of state compensation for losses to low-profit agricultural businesses. An experimental scheme for making decisions on priority financing of innovations is examined. The creators of these innovations are economic entities with the highest indicators of production activities and a high probability of fulfilling an order for the output of innovative products. The list of indicators includes many quantitative and qualitative characteristics. This means that the problem is classified as one that can be solved by using algorithms of multiple criteria modeling.

Shift Pruning-Based SCL Decoding for Polar Codes

In the context of the high-speed development of 5G communications, high-performance decoding schemes for polar codes are a hot spot in channel coding research. Shift pruning successive cancellation list (SP-SCL) decoding aims to recover the correct path by shift pruning in the extra SCL decoding. However, the current SP-SCL decoding is inflexible in determining the shift positions. In this paper, a flexible shift pruning SCL (FSP-SCL) decoding is proposed. Firstly, the reasons for movement and the eliminated states of the correct path are analyzed in detail using the path metric range (PMR), and on this basis, the validity of the method adopted in this paper for determining the shift priority of the information bits is verified. Secondly, the FSP-SCL decoding proposes two methods for determining the shift positions. One is the log-likelihood ratio (LLR) threshold method, which compares the LLR values of the eliminated paths on the shift bit with the corresponding LLR threshold to determine the shift positions. The other is the path distance method. It combines the minimum distance between the eliminated paths and the received vector with the path metrics to determine the shift positions. Both methods are more flexible and practical, as they can calculate the corresponding shift positions online based on a specific shift bit, avoiding the high complexity caused by the simulation method. Finally, this paper designs various experimental schemes to verify the decoding performance of the FSP-SCL. The experimental results show that in terms of error-correction performance, the LLR threshold-based FSP-SCL (FSPL (LLR threshold)) decoding, the path distance-based FSP-SCL (FSPL (path distance)) decoding and the existing SP-SCL decoding are roughly equal overall. In terms of decoding complexity, FSPL (LLR threshold) decoding is slightly better than FSPL (path distance) decoding, and the decoding complexity of both is lower than that of SP-SCL decoding, with the difference being more pronounced in the medium to high SNR regions.

Experimental evaluation of municipal solid waste air-gasification in a pilot-scale reciprocating moving-grate furnace

The increasing volume of municipal solid waste (MSW) worldwide presents significant environmental challenges, necessitating the development of efficient waste-to-energy (WtE) solutions. Among various thermochemical methods, gasification offers a promising approach for converting MSW into syngas, which can be utilized for energy generation. This study investigates the gasification characteristics of MSW in a pilot-scale reciprocating moving-grate furnace, focusing on the effect of key operating parameters such as equivalence ratio (ER), gasification temperature, and gasifying agent-staged ratio on gasification characteristics.Seven experimental schemes were tested with varying lower heating values (LHV) of MSW (ranging from 6.98 to 15.1 MJ/kg) and throughputs (ranging from 0.77 to 1.67 tons per day) to assess the adaptability and stability of the moving-grate system under different conditions. The results indicate that an ER between 0.6 and 0.7, a gasification temperature of 760 °C, and a gasifying agent-staged ratio of 7:3 are optimal for achieving a maximum energy conversion efficiency of 71.6 %. It was observed that the LHV of syngas decreases when the gasification temperature exceeds 850 °C due to increased oxidation of light hydrocarbons. Moreover, the study highlights the influence of grate moving speed on residence time and reaction completeness, which are critical for optimizing syngas yield and quality.The findings demonstrate that while the maximum energy conversion efficiency of the moving-grate system is lower than other reactor types, its lower capital and operating costs, due to the lack of dedicated feedstock pretreatment, make it a viable option for small-scale and pilot-scale applications. This study provides valuable insights into optimizing MSW gasification processes and underscores the potential of the moving-grate furnace for adaptable and cost-effective WtE applications. The novelty of this work lies in the comprehensive evaluation of the moving-grate gasification process under varied operating conditions, providing a foundation for future research on improving efficiency and reducing environmental impact in large-scale MSW management.

Discontinuous hyperpolarization schemes in liquid-state overhauser dynamic nuclear polarization experiments

Liquid-state Overhauser Dynamic Nuclear Polarization (ODNP) is an emerging technique, aimed at shortening NMR experiment times. It achieves this by increasing the otherwise poor nuclear polarization at room temperature, by polarization transfer from excited electron spins. The present work explores two ideas, aimed at achieving the optimal signal-to-noise per time unit for a given system, and quantitation of spectra showing a large disparity in ODNP enhancements at high magnetic fields (≥ 9.4 T). Both of these ideas are predicated on, perhaps counterintuitively, not allowing full dynamic nuclear polarization to build up, either by rapid rf pulsing, or gating of the microwave irradiation.

The effects of fiber load and frictional work on fatigue behavior of water hydraulic artificial muscles in underwater environment

Water Hydraulic Artificial Muscles (WHAMs) exhibit characteristics of high pressure and substantial load capacity. In previous work, the fatigue life of WHAMs under elastic load has been investigated, and experimental results have indicated that the fatigue life is related to both fiber load and frictional work. To individually investigate the impact of fiber load and frictional work on the fatigue life of WHAMs, an experimental scheme was designed to test the fatigue life under different levels of fiber load and frictional work. Meanwhile, the working pressure and contraction range were determined for various working conditions, in order to assess their effects on the fatigue life of WHAMs. The W-test confirms that the fatigue life of WHAMs under each working condition follows a normal distribution. Based on the experimental results, the influence of fiber load and frictional work on fatigue life was analyzed. And the experimental results indicate that the impact of fiber load on the fatigue life of WHAMs is approximately three times greater than that of frictional work. Furthermore, substituting aramid 1414 fiber with aramid 3 fiber in the fiber sleeve led to a substantial increase in fatigue life, elevating the average fatigue life to more than 4 times. Based on the power-law model, a fatigue model of WHAM is established with fiber load and frictional work as factors. The relative error between the fatigue model and experimental results in previously published work demonstrates that the new fatigue model can accurately predict the fatigue life of WHAMs.

Numerical study on surface treatment of vibration-impact composite electric spark based on ABAQUS

Abstract Through numerical simulation, this study explores the effect of vibration-impact composite electric spark (VIES) surface treatment technology on the temperature and thermal stress fields of 2024-T3 aluminum alloy surfaces. The depth of the molten pool and residual stress are evaluated using orthogonal experiments to score different experimental schemes, resulting in three experimental parameters categorized as good, medium, and poor. The study then examines the temperature and thermal stress fields for these three sets of parameters during the strengthening process. The results indicate that, considering the temperature field, the distance between the heat source and the work piece directly affects the heating efficiency and temperature distribution. An appropriate distance and sufficient dwell time are essential for creating the ideal molten pool thickness. Analysis of the stress field results shows that in the early stage of strengthening, the inertia force of the small spheres is dominant, while in the later stage, the stress field created by the electric current becomes decisively dominant. This indicates that the electric current is the core of the three influencing factors in the orthogonal experiment.

Counter-rotating synchronization theory and experiment of tri-rotor actuated with dual-frequency considering adaptive global sliding mode control strategy

In petroleum drilling engineering, self-synchronous vibration screen with single-frequency actuation is difficult to implement the scheduled synchronous behavior caused by its invariance and instability of dynamic characteristics, which usually leads to reduction of the production efficiency. Hence, to solve the problem mentioned above, a dual-frequency counter-rotating synchronization control method among three exciters is presented by combining adjacent cross-coupling control (ACCC) structure with global sliding mode control (GSMC) theory. Firstly, motion differential equation of the vibration system in each direction is derived according to mathematical model of the tri-rotor vibration machine. Secondly, considering exponential reaching law and adaptive control algorithm, the adjacent cross-coupling controller and the vector controller of each induction motor are investigated to achieve the stable zero phase difference synchronization between double-frequency rotors. Subsequently, Runge-Kutta method is introduced to establish the electromechanical coupling control model and prove validity of the control theory. Meanwhile, it is also discussed that the rotors cannot obtain an ideal self-synchronization state since velocity of high-frequency motor is not strictly equal to twice that of low-frequency motor. Finally, based on the experimental test scheme, an experimental prototype related to controlled multi-rotor synchronization vibration system is designed independently, which further verifies the validity of theory and computer simulation. Research shows that the desirable synchronous state of the vibration system can be accurately controlled via the designed control strategy, and the control system can implement diversity of the dynamical characteristics, due to the existence of strong robustness.

Correction to the quantum relation of photons in the Doppler effect based on a special Lorentz violation model

The possibility of the breaking of Lorentz symmetry has been discussed in many models of quantum gravity. In this paper we follow the Lorentz violation model in Ref. [14] (i.e., our previous work) to discuss the Doppler frequency shift of photons and the Compton scattering process between photons and electrons, pointing out that following the idea in Ref. [14] we have to modify the usual quantum relation of photons in the Doppler effect. But due to the current limited information and knowledge, we could not yet determine the specific expression for the correction coefficient in the modified quantum relation of photons. However, the phenomenon called spontaneous radiation in a cyclotron maser give us an opportunity to see what the expression for this correction coefficient might look like. Therefor, under some necessary constraints, we construct a very concise expression for this correction coefficient through the discussion of different cases. And then we use this expression to analyze the wavelength of radiation in the cyclotron maser, which tends to a limited value at v → c, rather than to 0 as predicted by the Lorentz model. And the inverse Compton scattering phenomenon is also discussed and we find that there is a limit to the maximum energy that can be obtained by photons in the collision between extremely relativistic particles and low-energy photons, which conclusion is also very different from that obtained from the Lorentz model, in which the energy that can be obtained by the photon tends to be infinite as the velocity of particle is close to c. This paper still follows the purpose in Ref. [14] that the energy and momentum of particles (i.e., any particles, including photons) cannot be infinite, otherwise it will make some physical scenarios invalid. When the parameter Q characterizing the degree of deviation from the Lorentz model is equal to 0, all the results and conclusions in this paper will return to the case as in the Lorentz model, so this paper also provides us with a possible experimental scheme to determine the value of Q in Ref. [14], although it still requires extremely high experimental energy.

Study of OPD based on PC60BM+P3HT bulk heterojunction

Junction organic photodetectors (OPD) based on the principle of photovoltaic generation have been widely studied. Firstly, this paper introduces the bulk heterojunction OPDs using ZnO for electron transport layer, PC60BM+P3HT for active layer structure, and MoO3 for hole transport layer to improve the photoelectric conversion efficiency. Secondly, the OPD device was prepared by specific experimental scheme, and the advantages of using the polymer-organic small molecular heterojunction were pointed out. Finally, the performance of the device was analyzed, including external quantum efficiency (EQE), responsiveness, specific detectivity, dark current and so on in different bands. Finally, the shortcomings of the device are pointed out, and the improvement scheme and possible improvement direction are put forward to improve the photoelectric conversion efficiency and fabricate high performance organic photodetectors.

A locally resonant metamaterial and its application in vibration isolation: Experimental and numerical investigations

AbstractVibration isolation metamaterial barrier has been extensively studied in mitigating the damage induced by vibration, while a deeper understanding of the vibration isolation characteristics based on laboratory experiments is still lacking. In this work, a locally resonant metamaterial barrier is proposed, and a large‐scale laboratory experiment was first designed to investigate the isolation mechanism of the proposed metamaterial barrier. The metamaterial vibration isolation barrier is assembled by arraying 5 × 5 resonators. To better explain the observations in experiments and unveil the underlying isolation mechanism, COMSOL Multiphysics was also employed to simulate the laboratory experiment. Subsequently, the vibration isolation effect is quantitatively analyzed by analyzing the acceleration amplitude reduction spectrum (ARS) of the ground surface. The vibration isolation mechanism is discussed by monitoring the acceleration field around the metamaterial barrier. The results indicate that two significant locally resonant attenuation domains are observed, which are induced by the first‐order and second‐order vertical resonance frequencies of the metamaterial. Another experimental scheme that simultaneously monitored the acceleration of the mass block and the bottom of resonators was implemented to investigate vibration in the resonator. The vibration energy distribution on the mass block and the bottom of the resonator is found to depend significantly on the vibration frequency. When the frequency is lower than a certain frequency, the locally resonant is dominant. Otherwise, the geometric scattering is dominant. The vibration isolation mechanism of the locally resonance metamaterial was investigated by laboratory experiments and provided an effective solving path for isolating the low‐frequency vibration.

Phytoplankton cell-states: multiparameter fluorescence lifetime flow-based monitoring reveals cellular heterogeneity.

Phytoplankton are a major source of primary productivity. Their photosynthetic fluorescence are unique measures of their type, physiological state, and response to environmental conditions. Changes in phytoplankton photophysiology are commonly monitored by bulk fluorescence spectroscopy, where gradual changes are reported in response to different perturbations, such as light intensity changes. What is the meaning of such trends in bulk parameters if their values report ensemble averages of multiple unsynchronized cells? To answer this, we developed an experimental scheme that enables tracking fluorescence intensities, brightnesses, and their ratios, as well as mean photon nanotimes equivalent to mean fluorescence lifetimes, one cell at a time. We monitored three different phytoplankton species during diurnal cycles and in response to an abrupt increase in light intensity. Our results show that we can define specific subpopulations of cells by their fluorescence parameters for each of the phytoplankton species, and in response to varying light conditions. Importantly, we identify the cells undergo well-defined transitions between these subpopulations. The approach shown in this work will be useful in the exact characterization of phytoplankton cell states and parameter signatures in response to different changes these cells experience in marine environments, which will be applicable for monitoring marine-related environmental effects.