Although research into big data technologies is advancing quickly, it has not yet been used for the “party building + political thinking” paradigm of grassroots mass organizations. The structure, ...purpose, and method of clustering analysis in data mining technology, as well as the various data types involved in clustering analysis technology, are studied in this paper after first analyzing the development status of data mining technology and the issues in the process of data mining. Secondly, we investigate the advantages of big data mining for “Party formation + Civic Affairs” at the local level, including four points, the management of grassroots party members, the education of party members, the ideological dynamics of party members and cadres, and the development of the relationship between party groups and teachers and students. Moreover, the “task assessment quantification table” from the “party building + thinking and politics” model was utilized as the data source, and cluster analysis was carried out using the k-mean technique. The percentages of the three categories of grades in the cluster assessment, which were 30%, 62%, and 8%, were found to be compatible with the percentages of the three categories of scores, which were 21%, 68%, and 11%. This study brings some reference significance to both party building and thinking and the government work of college counselors; this contributes to raising the bar for political thinking, party organization, and governance.
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•Protective performance of ACH and full-covered helmet under blast wave were quantitatively analysis by the degree of cranial injury.•ACH does not provide blast protection and may ...even slightly aggravate cranial injury.•Fully-covered helmet can reduce the brain acceleration, strain, displacement, pressure, von-Mises stress and energy absorption.•The lighter fully-covered helmet can effectively reduce head injury by 35%, especially by reducing acceleration, strain and pressure.
Blast traumatic brain injury (BTBI) is the major type of injury, existing helmets are mainly designed to resist bullets and fragments, so it is necessary to study the explosion- proof performance of helmets. In this study, the validated finite element models including head, Advanced Combat Helmet (ACH), fully-covered helmet based on the prototype of Iron Man helmet were used to establish the blast wave-helmet-head fluid–solid coupling model, dynamic responses such as blast wave flow field pressure, skull stress, brain tissue pressure, displacement and energy absorption were obtained through simulations.
Quantitatively analyzed the protective performance of helmets show that wearing ACH can’t reduce the severity of brain injury, but rather increased about 5% compared to without wearing helmet. Wearing fully-covered helmet with same thickness as ACH can reduces the degree of brain injury by about 5%. Fully-covered helmet with same weight as ACH provides better protection, which can reduce the degree of brain injury to 65% than without wearing helmet. Research show that optimizing the shape and thickness of helmet can greatly reduce the brain injury, lighter fully-covered helmet can provide better protection for the brain under blast wave environment. The results can provide reference for new design of helmets.
•The modeling considers the anisotropy of battery heat transfer along the positive, negative, and radial electrodes.•A micro thermal resistance method is proposed to calculate the equivalent thermal ...resistance for heat transfer.•The modeling considers the impact of temperature on heat transfer characteristics.•The results derived align closely with the empirical evidence presented by Du et al., confirming the integrity of the model.•The proposed model exhibits a lower RMSE(0.329) than that of ECM, EKF, NNEKF, and NNUKF(1.08, 0.95, 0.58, and 0.61).
In the current study, the CN-CD30V10A battery tester, K-type temperature sensor, and RS485 are utilized to perform charging and discharging tests on the Panasonic 21,700 lithium-ion battery at various rates. The voltage and temperature changes are measured in real-time, with the data transmitted to the computer via RS485. Then a micro-thermal resistance method is proposed to calculate the equivalent thermal resistance of the cell core along the axial positive and negative poles, as well as along the radial outer circumference surface under anisotropic conditions. Based on the experimental results and the equivalent thermal resistance, an electrothermal coupling model is established for battery internal temperature estimation, taking into account anisotropy and temperature effects on heat transfer. Through the integration of the model and externally measured temperature, the internal temperature is accurately estimated. Moreover, the proposed model (Root-Mean-Square Error, RMSE=0.329) exhibits a significant improvement in accuracy compared to equivalent circuit model (RMSE=1.08), extended Kalman filter (RMSE=0.95), network extended Kalman filter (RMSE=0.58), and neural network unscented Kalman filter (RMSE=0.61). Specifically, the model achieves an approximately 76 % to 228 % reduction in RMSE compared to these methods.
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•A cranial model with human anatomy and mechanical properties was constructed.•Comparative analysis of the impact of the type and density of lining materials on the head protection ...performance.•Two key indicators for evaluating brain injury, acceleration and intracranial pressure characteristic parameters are analyzed.
With the upgrading of protective equipment, the penetration ability of bullets into protective equipment is reduced, and the problem of non-penetrating brain injury caused by bullet impact becomes prominent, but related experiment is still rare. Therefore, this study establishes a human head surrogate model with anatomical structure, and then an experimental study on the dynamic response of cranial model protected by bulletproof plate impacted by 5.56 mm rifle bullet was conducted. The influence of bulletproof plate and padding material (type and density) on the head protection performance is analyzed. The results show that the acceleration of the front of the skull is reduced by 600 times with the protection of pad. At the density of 30 kg/m3, the protective effect of EVA (Ethylene-Vinyl Acetate copolymer) foam is better than that of EPP (Expanded polypropylene), the peak acceleration at the front of the skull is reduced by 36%. As the density of EVA foam increases, the acceleration of skull and the peak intracranial pressure increase, which can be judged that the brain injury would be aggravated according to the existing injury criteria. The study has important guiding significance for the design of protective equipment and the mechanism of cranial injury.
Abstract
Protective equipment in war plays a vital role in the safety of soldiers, the threat to soldiers from brain damage caused by deformation at the back of the helmet cannot be ignored, so ...research on reduce blunt post-cranial injury has great significance and value. This study first conducted gunshot experiments, used rifle bullets impact bulletproof plate and different density liner foam to record the incident process and internal response of craniocerebral model. After verifying the accuracy of finite element model through experimental data, optimization model is established based on response surface method to optimize the structure of gradient foam, analyze the cranial strain and energy absorption to select the best density and thickness distribution of each foam layer. Optimization results show that liner foam which designed to have lower density and thicker thickness for impact and brace layers, higher density and thinner thickness for middle layer can significantly improve the energy absorption efficiency. Compared to the 40.65 J of energy absorption before optimization, the optimized gradient foam can absorb 109.3 J of energy, with a 169% increase in the absorption ratio. The skull strain in the craniocerebral model was reduced from 1.260 × 10
–2
to 1.034 × 10
–2
, with a reduction of about 22%. This study provides references for the design and development of protective equipment and plays an important role in ensuring the safety of soldiers in the battlefield environment.
In the micro-tube gas-assisted extrusion process, flow theories ignoring cross-scale viscoelastic variations fail to effectively characterize the rheological state of the melt. To investigate the ...impact of cross-scale viscoelastic variation on the quality of the micro-tube gas-assisted extrusion, a 3D multiphase flow extrusion model incorporating a double gas-assisted layer was developed. Subsequently, we modified the DCPP constitutive equations based on the cross-scale factor model. Both the traditional and gas-assisted extrusions were simulated under macroscale and cross-scale models using the Ansys Polyflow. Finally, using the established gas-assisted extrusion platform, extrusion experiments were conducted. The results indicate that, owing to the reduced melt viscosity under the cross-scale model, the deformation behavior of the melt is more pronounced than in the macroscale model. The cross-scale model's numerical results more closely match the experimental outcomes under the same parameters, thereby confirming the feasibility of the theoretical analysis and numerical simulation. Moreover, the predictive capability of the cross-scale model for the micro-tube gas-assisted extrusion is further validated through numerical and experimental analyses with varying parameters. It is demonstrated that the cross-scale viscoelastic variation is a critical factor that cannot be overlooked in the gas-assisted extrusion.
Two submerged anaerobic membrane bioreactors (AnMBRs) with and without powdered activated carbon (PAC) were studied to revisit the effect of PAC on membrane fouling performance by long-term operation ...when treating synthetic sewage. The results showed that PAC remained efficient for membrane fouling control after long-term operation (over 140 d), and it reduced the fouling rate at a hydraulic retention time of 8 h from 3.12 to 0.89 kPa/d. PAC mainly mitigated the membrane fouling by restraining the formation of a cake layer while generating a gel layer on the membrane surface, which was attributed to the PAC-induced microbial community change in mixed liquor and the membrane surface. Microbial community analysis indicated the genera Pseudomonas (26.5%) and Methanothrix (79.21%) were the predominant bacteria and archaea, respectively, in the gel layer, and this result is completely different from the presence of a high abundance of Levilinea (7.1%), Aminivibrio (4.9%) and Methanothrix (90.04%) in the cake layer on the membrane surface without PAC. The significant difference in the predominant microbes in the membrane surface layer was attributed to the reduced enrichment of Levilinea and Methanothrix with PAC addition.
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•Long-term effects of PAC on fouling in anaerobic membrane bioreactors revisited.•PAC prevented the formation of microbial aggregates in mixed liquor.•PAC mitigated cake layer formation, giving a gel layer on membrane surface.•PAC reduced enrichment of filamentous microbes in surface layer.
In the process of double-layer gas-assiste extrusion of a plastic micro-tube, the tugging effect caused by the pressure difference of the gas cushion layer inside the die has a great influence on the ...external dimensions of the micro-tube. Therefore, this study establishes a two-phase extrusion model based on compressible gas and incompressible melt. Ansys Polyflow finite element software was used to numerically simulate the extrusion process of the melt to analyze the effect of the gas cushion layer pressure difference on the micro-tube deformation. The research shows that the shrinkage rate of the micro-tube increases with increasing pressure of the outer cushion layer, and the degree of tube wall migration increases, too. In the process of extrusion, the first normal stress difference at the entrance of the gas cushion layer shows a significant effect on the melt velocity field distribution and the extruded micro-tube cross-sectional deformation.
In this paper, aiming at a large infrastructure structural health monitoring network, a quaternion wavelet transform (QWT) image denoising algorithm is proposed to process original data, and a depth ...feedforward neural network (FNN) is introduced to extract physical information from the denoised data. A Brillouin optical time domain analysis (BOTDA)-distributed sensor system is established, and a QWT denoising algorithm and a temperature extraction scheme using FNN are demonstrated. The results indicate that when the frequency interval is less than 4 MHz, the temperature error is kept within ±0.11 °C, but is ±0.15 °C at 6 MHz. It takes less than 17 s to extract the temperature distribution from the FNN. Moreover, input vectors for the Brillouin gain spectrum with a frequency interval of no more than 6 MHZ are unified into 200 input elements by linear interpolation. We hope that with the progress in technology and algorithm optimization, the FNN information extraction and QWT denoising technology will play an important role in distributed optical fiber sensor networks for real-time monitoring of large-scale infrastructure.
Two-dimensional models of die-melt and die-gas-melt were created using Polyflow software. The radial and axial directions flow rate, shear rate, pressure, and first normal stress of the specimen were ...numerically simulated under conventional extrusion and gas-assisted extrusion while taking into consideration the heat transfer on the free surface of the specimen. The crystallinity was determined by combining the simulation data with the crystallization kinetics equation. The computation results are then examined using Origin software. The findings demonstrate that the use of gas-assisted extrusion technology can cause the
to decrease or even turn negative by reducing the friction between the melting edge and the die wall. Additionally, it makes
, pressure, shear rate, temperature, first normal stress, and crystallinity increasingly steady and aids in reducing or avoiding the Barus effect. The crystallization phenomena can be measured by using the crystallization kinetics equation. The study of extruded parts at the microscopic level will benefit from this application.
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