Important Application Value Research Articles

Node fault diagnosis algorithm for wireless sensor networks based on BN and WSN

Wireless sensor networks, as an emerging information exchange technology, have been widely applied in many fields. However, nodes tend to become damaged in harsh and complex environmental conditions. In order to effectively diagnose node faults, a Bayesian model-based node fault diagnosis model was proposed. Firstly, a comprehensive analysis was conducted into the operative principles of wireless sensor systems, whereby fault-related features were then extrapolated. A Bayesian diagnostic model was constructed using the maximum likelihood method with sufficient sample features, and a joint tree model was introduced for node diagnosis. Due to the insufficient accuracy of Bayesian models in processing small sample data, a constrained maximum entropy method was proposed as the prediction module of the model. The use of small sample data to obtain the initial model parameters leads to improved performance and accuracy of the model. During parameter learning tests, the limited maximum entropy model outperformed the other two learning models on a smaller dataset of 35 with a distance value of 2.65. In node fault diagnosis, the diagnostic time of the three models was compared, and the average diagnostic time of the proposed diagnostic model was 41.2 seconds. In the node diagnosis accuracy test, the proposed model has the highest node fault diagnosis accuracy, with an average diagnosis accuracy of 0.946, which is superior to the other two models. In summary, the node fault diagnosis model based on Bayesian model proposed in this study has important research significance and practical application value in wireless sensor networks. By improving the reliability and maintenance efficiency of the network, this model provides strong support for the development and application of wireless sensor networks.

Electric-field strengthening uranium extraction from seawater assisted by nanofiltration membranes with sieving-adsorption properties

Electric-field driven uranium extraction from seawater has been proved to greatly enhance the performances of various adsorbents via gathering uranyl ions at the surfaces, but high-concentration interfering cations would also be enriched which generates shielding effects to reduce adsorption capacity. To address this issue, we have fabricated nanofiltration membranes with sieving-adsorption properties by choosing polyamidoxime (PAO) as substrates and polyamide as skin layers. On the one hand, the polyamide skin layers fabricated by interfacial polymerization could effectively separate uranyl ions from other metal ions according to the size-sieving effect since the size of uranyl ions is much larger than most interfering cations. The results demonstrated that the nanofiltration membranes could nearly 100 % reject uranyl ions while the rejections of other metal ions below 30 %. On the other hand, the rejected uranyl ions would be enriched at the surfaces of PAO substrates and followed by adsorption. The increased uranium concentrations are beneficial for both adsorption capacity as well as adsorption rate. Therefore, the adsorption capacity increased by 30 % compared with the pristine PAO adsorbents. This work not only provides a new strategy for the design of high-performance adsorbents, but also could promote the engineering process of uranium extraction from seawater which has an important scientific significance and application value.

A fatigue life prediction model of flexible spoke non-pneumatic tires

To solve the complex problems of fatigue life of non-pneumatic tires, this paper constructs a fatigue life prediction fitting model for flexible spoke non-pneumatic tire based on fatigue failure evaluation indicators. The fatigue life prediction of flexible spoke non-pneumatic tire was carried out based on the J-integral method, and the effectiveness of the prediction method was verified by fatigue durability tests. The relationship between Mises stress σr, maximum principal strain εL, strain energy density W, strain energy density gradient GSED and fatigue life was obtained by numerical analysis methods. A fatigue life prediction fitting model for each evaluation indicator was established based on power function relationships, and a comparative analysis of the fitting accuracy and prediction accuracy of different fitting models was performed. The results show that the fatigue life prediction models based on Mises stress σr, maximum principal strain εL, strain energy density W, strain energy density gradient GSED all had high fitting accuracy and prediction accuracy, with the Mises stress-based fatigue life prediction model having the highest fitting accuracy and prediction accuracy. The development of the content of this paper has important theoretical significance and application value for the development of tire safety technology.

Microstructure Optimization for Design of Porous Tantalum Scaffolds Based on Mechanical Properties and Permeability.

Porous tantalum (Ta) implants have important clinical application prospects due to their appropriate elastic modulus, and their excellent bone growth and bone conduction ability. However, porous Ta microstructure designs generally mimic titanium (Ti) implants commonly used in the clinic, and there is a lack of research on the influence of the microstructure on the mechanical properties and penetration characteristics, which will greatly affect bone integration performance. This study explored the effects of different microstructure parameters, including the fillet radius of the middle plane and top planes, on the mechanics and permeability properties of porous Ta diamond cells through simulation, and put forward an optimization design with a 0.5 mm midplane fillet radius and 0.3 mm top-plane fillet radius in order to significantly decrease the stress concentration effect and improve permeability. On this basis, the porous Ta structures were prepared by Laser Powder Bed Fusion (LPBF) technology and evaluated before and after microstructural optimization. The elastic modulus and the yield strength were increased by 2.31% and 10.39%, respectively. At the same time, the permeability of the optimized structure was also increased by 8.25%. The optimized microstructure design of porous Ta has important medical application value.

Analysis of the Impact of Digital Currency on Traditional Banking and Financial Stability

Digital currency, as a representative product of blockchain technology, such as Bitcoin and Ethereum, has begun to have a far-reaching impact on traditional banking business, but also brought new challenges to financial stability. This article studies the financial risk assessment and pre-alarm model based on support vector machine (SVM) algorithm, aiming at accurately assessing the risks in digital currency market and providing timely pre-alarm. Through comparative experiments, it is found that the algorithm has obvious advantages in dealing with high-dimensional and nonlinear problems, and can accurately classify and warn financial risks. The accuracy of the model is as high as 96.88%, and the average absolute error is reduced by 40.22%, which proves the effectiveness and superiority of the model. Generally speaking, the financial risk assessment and pre-alarm model studied in this article provides a scientific and effective method for digital currency market risk management, which has important application value. Regulators need to invest more resources and energy to monitor and analyze the dynamic changes in the digital currency market and reduce financial risks.

All-dielectric metasurface with multiple Fano resonances supporting high-performance refractive index sensing

All-dielectric metasurface has important application value in many fields, especially in refractive index sensing. In this paper, an all-dielectric metasurface composed of a silicon triangular-hole nanodisk array is designed and studied numerically. Through introducing asymmetry in the proposed metasurface and transforming the bound states in the continuum (BIC) into the quasi-BIC, three sharp Fano resonances with almost 100% modulation depth can be achieved, and the highest quality factor (Q-factor) can reach 49,915. Further, the three Fano resonances can be regulated and controlled by adjusting the structural parameters. Moreover, the sensing performance of the structure is researched by changing the ambient refractive index. The maximum sensitivity obtained is 248 nm/RIU, and the best figure of merit is 3815RIU−1. The proposed structure provides a scheme for the design of optical devices, especially refractive index sensors.

Chromatin regulator Eaf3p regulates nitrogen metabolism in Saccharomyces cerevisiae as a trans-acting factor.

In this study, the mechanism of chromatin regulator Eaf3p regulating nitrogen metabolism in S. cerevisiae was investigated. It provides theoretical support for epigenetic modifications of cells to alter the level of histone modifications, coordinate the expression of multiple genes, and make it more conducive to the co-metabolism of multiple nitrogen sources. Moreover, it provides new ideas for industrial brewing yeast strains to achieve nitrogen source metabolism balance, reduce the accumulation of harmful nitrogen metabolites, and improve fermentation efficiency. This study provides a reference for changing the performance of microbial strains and improving the quality of traditional fermentation products and provides a theoretical basis for studying epigenetic modification and nitrogen metabolism regulation. It has an important theoretical explanation and practical application value. In addition, this study also provides useful clues for the study.

Preparation of carbon-based active nanofluids with temperature and salt resistance for enhanced oil recovery

The abundant hydrophilic surface groups endow carbon-based nanoparticles (CDs) with intrinsic great dispersibility, however, the strong hydrophilicity limits the oil–water interface activity, restraining the performance in enhanced oil recovery. Developing CDs with simultaneously ultra-small sizes, high temperature and salt tolerance, as well as superior interfacial activity is of great significance. In this work, CDs with the size of 3.3 nm and excellent temperature and salt resistance were prepared by hydrothermal reaction, using citric acid (CA) and ethylenediamine (EDA) as precursors. Carboxyl ether carboxylate-6Na (APEC-6Na) was selected as the compound agent to construct carbon-based active nanofluids (CANs) with excellent oil–water and oil-solid interfacial activities. CANs can reduce the oil–water interfacial tension to 8.9 × 10-4 mN m−1, withstand a temperature up to 90°C and a salinity up to 6.3 × 104 mg·L-1. Even at the highest tolerant salinity, the underwater oil contact angle of 155° can be achieved, demonstrating excellent wettability control capability, which could be attributed to the synergistic effect of the compound CANs system. The increase of the contact angle of underwater oil droplets facilitates the coalescence of oil film on the lipophilic surface to form oil droplets. The electrostatic repulsion generated by the adsorption of CDs and APEC-6Na at the oil–water interface and rock surface makes the coalesced oil droplets more easily detached from the rock surface, and the oil film reduction rate exceeds 97.7 % within 24 h. The excellent oil–water and oil-solid interface properties and the structural separation pressure endows CANs with remarkable performance in core displacement experiments. Compared with simulated formation water, CANs can improve the recovery rate by 26.3 %, exhibiting important application value for improving the recovery rate of ultra-low permeability reservoirs.

Extraction of Elemental Information of Slope Steps in Open Pit Mine Based on UAV

The information of step width, height and angle of open-pit slope is of great value for open-pit mining. However, the existing methods of obtaining step element information are inefficient, and are greatly affected by staff and environmental factors, this reduces the production efficiency and acceptance accuracy of the mine. Therefore, this paper proposes a method to extract step element information based on UAV tilt photogrammetry technology. The method firstly acquires the dense point cloud data of the slope steps of the open pit based on the UAV inclined photogrammetry, preprocesses the point cloud data by using the bilateral filtering algorithm, then extracts the edge feature points of the point cloud based on the normal and curvature estimation method, and fits the step lines using the moving least squares method, and builds a step model based on the step lines, so that the profile lines at any position of the steps can be extracted on the model and obtains the step element information. The experiments show that the feature extraction method can extract the step element information efficiently and accurately, which has important application value for the production and safety of open pit mine.

Highly Efficient STEs NIR‐II Broadband Emission in a Perovskite System and its Spectroscopy Applications

AbstractEfficient NIR emitting materials have important application value in phosphor‐converted light‐emitting diodes (pc‐LEDs), due to their high sensitivity of tissue composition responsiveness, and penetration depth (spatial resolution). In this work, a perovskite structure material CaSnO3 that can emit strong broad NIR light at the range of 850–1300 nm peaking at 1010 nm second biological window with a super large Stokes shift of 24463 cm−1 and a sensitive broad UV light response (λmax = 291 nm) by traditional high‐temperature solid‐state reaction that does not require additional doping ions is innovatively developed. Spectroscopic and theoretical calculations reveal that the NIR emission originates from self‐trapped excitons (STEs) enhanced by Jahn–Teller effect when Sn4+ is spontaneously reduced to Sn2+ and occupies the position of Ca2+ 8‐coordinate lattice. A prototype NIR‐II emitting LED device is successfully fabricated combining this perovskite CaSnO3 phosphor with UV 285 nm chip to evaluate its application value. This work provides a novel NIR‐II luminescent material, which is different from other doping types of systems, and STEs luminescence in perovskite has been achieved in the NIR‐II region for the first time, providing a new approach and choice for the development of NIR luminescent materials.

Numerical Study of Nonlinear Effects on the Performance of the Self-Protected Energy Concentrator

Wave concentrators have important application value in ocean engineering. Moreover, the performance of a concentrator on structural protection is important in the context of the complex ocean environment. A series of numerical simulations of the self-protected energy concentrator (SPEC) is performed under nonlinear wave conditions. The SPEC includes eight truncated cylinders arranged in a concentric circle. The performance of SPEC and the distribution of fluid field are studied by establishing a computational fluid dynamics (CFDs) model. It can be concluded that increasing wave steepness can weaken the self-protection performance and concentration effects due to its strong nonlinearity. The wave directions have little effect on the performance of SPEC. In addition, the change based on the target wave number can result in poor performance of SPEC.

Whole genome sequencing provides evidence for Bacillus velezensis SH-1471 as a beneficial rhizosphere bacterium in plants

Bacillus is widely used in agriculture due to its diverse biological activities. We isolated a Bacillus velezensis SH-1471 from the rhizosphere soil of healthy tobacco, which has broad-spectrum antagonistic activity against a variety of plant pathogenic fungi such as Fusarium oxysporum, and can be colonized in the rhizosphere of a variety of plants. This study will further explore its mechanism by combining biological and molecular biology methods. SH-1471 contains a ring chromosome of 4,181,346 bp with a mean G + C content of 46.18%. We identified 14 homologous genes related to biosynthesis of resistant secondary metabolite, and three clusters encoded potential new antibacterial substances. It also contains a large number of genes from colonizing bacteria and genes related to plant bacterial interactions. It also contains genes related to environmental stress, as well as genes related to drug resistance. We also found that there are many metabolites in the strain that can inhibit the growth of pathogens. In addition, our indoor pot test found that SH-1471 has a good control effect on tomato wilt, and could significantly improve plant height, stem circumference, root length, root weight, and fresh weight and dry weight of the aboveground part of tomato seedlings. Therefore, SH-1471 is a potential biological control strain with important application value. The results of this study will help to further study the mechanism of SH-1471 in biological control of plant diseases and promote its application.

Construct electron transport path through NH2-MIL-125 modified Fe-doped W18O49 nanowires to enhance photocatalytic nitrogen fixation performance

Ammonia has important application value in agriculture and industry as a raw material for producing nitrogen fertilizers and organic chemicals. The Haber-Bosch method is generally utilized to synthesize ammonia through N2 and H2 as raw materials in industry, but the process generates serious energy consumption and pollution. In the paper, a heterojunction catalyst is constructed that adopts NH2-MIL-125 and Fe-doped W18O49 (Fe-W18O49) for photocatalytic nitrogen fixation. Fe-W18O49 is a nanowire containing oxygen vacancies (OVs). OVs can provide active sites for the adsorption and activation of nitrogen gas. The 3D plate-like morphology of NH2-MIL-125 can observably reduce the occurrence of nanowires aggregation. This phenomenon can be attributed to NH2-MIL-125 playing a supporting role in the fixation of nanowires. New mesoporous are formed between NH2-MIL-125 and Fe-W18O49 in the constructed compound catalyst, which can realize efficient mass transfer between the inside and outside of the catalyst. EPR characterization discovers that Fe-W18O49/NH2-MIL-125 cannot produce •O2˗ and •OH radicals. The type II heterojunction forms between Fe-W18O49 and NH2-MIL-125. The heterojunction improves the carrier migration path, and the photocurrent intensity is significantly increased. Under simulated sunlight, Fe-W18O49/NH2-MIL-125–2 emerges the best catalytic performance with an ammonia formation rate of 128.2 µmol g−1 h−1. The yield of ammonia is boosted in comparing with NH2-MIL-125 (13 times) and Fe-W18O49 (1.7 times). After several cycles, Fe-W18O49/NH2-MIL-125 remain maintains good stability during the catalytic process. This paper provides a possibility for constructing low-cost heterojunction catalysts in the territory of photocatalytic nitrogen fixation.

Analysis of the scattering of chiral layered particle by dual beams

The present study investigates the interaction between a chiral multilayer dielectric sphere and dual laser beams. Using the generalized Lorenz-Mie theory (GLMT), we extend the theory of single laser beam expansion to dual laser beam expansion. Analytical solutions of the scattering on chiral layered particles by dual laser beams are derived based on the boundary continuum condition. To validate the efficiency of our theory and methodologies proposed in this paper, we conduct a comparative analysis between our findings and the simulation results reported in existing literature. The numerical outcomes presented on the scattering pattern of far region and near-surface fields are analyzed in detail with the impact of various parameters, such as the incident angle, polarization angle, waist width, beam center position, inner and outer chiral parameters. The investigations are of significant importance for the analytical understanding of the optical scattering properties of multilayered biological cells with complex shapes and possess important application values in micro-manipulation of multilayered biological structures.

Effects of nanosilica on the properties of brine-base drilling fluid

In the process of drilling oil and gas wells, the shrinkage and falling of wellbore walls are often caused by the expansion of mud shale water. To date, conventional additives have been unable to plug the pore throats of shale rock with nanoscale pores and thus cannot effectively solve the problem of wellbore instability encountered in shale formation drilling. In view of this situation, the idea of using nanosilica to plug the nanopore throat of mud shale is proposed to reduce its permeability and to slow water intrusion. The influences of nanosilica on the properties of brine-base drilling fluid drilling fluid are evaluated by measuring the viscosity, filtration loss and swelling of the drilling fluid. The results of laboratory experiments show that the improvement in drilling fluid properties can only be achieved on the basis of salt resistance; that is, a salt-resistant soil slurry should be used. A concentration of 1–5% nanosilica can improve the viscosity of the drilling fluid by increasing the internal friction between particles. However, nanosilica materials are sensitive to salt concentration. Nanosilica particles can be deposited on the surface of a filter cake to block the pores of the filter paper, and the filtration loss reduction rate can reach 40.2%. Blocking the pores of the clay plays a role in preventing the clay from absorbing water and expanding. The optimal addition amount of silica is 3%, and its salt resistance can reach 16%. Considering the experimental results of filtration loss, swelling amount and cost performance, 3%NP + 4%NaCl + SWM-B is selected as the optimal formula. The results of this study can be applied to effectively improve the phenomenon of wellbore instability during drilling in shale formations, and it has important application value.

Preparation of ZnO Nanosheet Array and Research on ZnO/PANI/ZnO Ultraviolet Photodetector.

High-performance ultraviolet photodetectors have important scientific research significance and practical application value, which has been the focus of researchers. In this work, we have constructed a highly photosensitive UV photodetector with a unique "sandwich" structure, which was mainly composed of two layers of ZnO nanosheet arrays and one layer of polyaniline (PANI). The results showed that the UV current of ZnO/PANI devices was 100 times higher than that of pure ZnO devices under the same UV irradiation time. At a 365 nm wavelength, the device had excellent photocurrent responsiveness and photoconductivity. This high performance was attributed to the large specific surface area of ZnO nanosheets and the p-n junction formed between P-type PANI nano-porous film and N-type ZnO nanosheets. This provides a solid theoretical basis for the application of ZnO nanosheets in ultraviolet detection, and possesses significance for the development of ultraviolet photodetectors.

Important application value of injectable hydrogels loaded with omeprazole Schiff base complex in the treatment of pancreatitis

Abstract In this study, a novel Ho(iii) coordination complex with the chemical composition of [Ho6(acac)4L4(CH3O)6]·xCH3OH (1) has been prepared via using a polydentate Schiff base ligand N′-(2,3-dihydroxybenzylidene) picolinohydrazide (H2L) and a β-diketone (Hacac = acetylacetone) co-ligand, and then successfully loaded with drug omeprazole. Hyaluronic acid, a natural polysaccharide with good biocompatibility, was used as raw material to prepare drug carriers that can be injected into hydrogels based on chemical synthesis method. The internal microstructure of the hydrogel was observed by scanning electron microscope, which showed a good three-dimensional connected porous structure. After the synthesis of the hydrogel, the value of their application in the treatment of pancreatitis was evaluated and the related mechanisms were explored at the same time.

An IoT-Based Intelligent Selection of Multidomain Feature for Smart Healthcare Using Reinforcement Learning in Schizophrenia

Currently, the health industry by the Internet of Things (IoT) is developing rapidly, and Electroencephalogram (EEG) signal has become a bridge for human-machine communication. EEG signal feature selection is a key link in brain nerves research and has important practical application value. Therefore, we propose an IoT-based Intelligent Selection of Multi-domain Feature for multimodal transformer EEG signal using reinforcement learning in Schizophrenia. First of all, the features of the multimodal EEG signal sequence by the IoT were extracted from time domain, frequency domain, and spatial domain; Second, the average pooling layer was added to improve the design of the transformer model for deep feature extraction of EEG signal; finally, reinforcement learning was introduced to run operation with the extracted features as input and the improved transformer model as agent. At the same time, entropy and Pearson correlation coefficient calculation were introduced to select feature subsets, and feature intelligent selection of EEG signal in multiple domains was completed through interaction between the agent and the environment. Experiments were performed on DEAP, EEG Motor Movement/Imagery Data set, BCI2008 competition data set and data set of a hospital. The results show that the feature extraction and feature visualization effect of the proposed algorithm is good, and the feature selection precision is as high as about 90%, and the average time is only about 13 seconds. These findings indicate the feasibility of the proposed feature intelligent selection algorithm in the study of EEG signal in schizophrenia, which provides a good basis for further study on the integration of IoT with the healthy industry.

Process parameter analysis of ultrasonic vibration-assisted polishing of SiCp/Al ceramics based on optimized Hilbert trajectories

As an important ceramic matrix composite material, SiCp/Al ceramics have found extensive applications across several domains. However, the intricate nature of their material properties has resulted in a scarcity of scholarly investigations pertaining to the topic of ultrasonic vibration-assisted polishing (UVAP) of SiCp/Al ceramics. To solve this problem, a theoretical derivation of the material removal model (MRM) for UVAP SiCp/Al ceramics is presented in this paper. The selection of UVAP feeding speed is analyzed and discussed. The process parameters of UVAP of SiCp/Al ceramics are optimized based on the improved Hilbert's trajectory characteristics. According to the experimental results, high-quality machined surfaces can be obtained and the “fish scale” phenomenon can be avoided when the feeding speed is 0.015 m/s. Compared with the traditional trajectory, the improved Hilbert trajectory is easier to achieve uniform surface polishing. The introduction of ultrasonic amplitude (UA) can increase the material removal rate (MRR) by more than 21.6 % compared with the conventional polishing method. The maximum removal depth (MRD) increased by more than 27.76 % and the surface roughness (SR) is reduced by more than 76.45 %. The research results have an important application value for realizing efficient and high-quality polishing of SiCp/Al ceramics.

Study on the Diffraction-like and Interference-like Mechanisms of Particle Flow

This paper demonstrates that the light and dark fringe in Young's double-slit experiment is not actually the diffraction and interference pattern of light wave. We investigate the scattering phenomenon after the particle flow passes through the gaps and find that the scattering type and scattering degrees of freedom of the particle flow depend on the physical parameters of the particles and the gaps. When the particle flow undergoes uniform scattering, a uniform "yes" and "no" interspersed discrete distribution pattern will form on the receiving screen. Based on the diffraction-like and interference-like mechanism of particle flow, this paper explains the electron diffraction and interference experiment, as well as the Young's double-slit interference experiment and the diffraction of light through circular holes and plates. This article provides an in-depth discussion on Einstein's concept of wave particle duality and de Broglie's matter wave hypothesis, as well as an analysis of Feynman's experimental idea of electron double slit interference. Our research shows that the matter wave hypothesis is not valid, which has shaken the foundation of modern quantum mechanics and has significant scientific significance. In addition, this study has important application value for the development of technology for detecting and analyzing particles or gaps.