bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast non-singular terminal sliding mode control of the cubesat attitude for on-orbit assembly process
Authors: Yan Mingzheng , Song Xiaodong , Shi Jixin , Zhao Bo , Zhang Haosen 
Published: August 2024

Abstract
The construction of space assemblies using on-orbit assembly technology is beneficial for supporting various complex space missions, and has broad application prospects and high practical significance. This paper designs a novel terminal sliding mode attitude controller to address the time-varying mass parameters and suppress internal and external disturbances during the on-orbit assembly process of CubeSat. Specifically, the CubeSat attitude dynamics model with a telescopic mechanism is established based on the vector mechanics method. Subsequently, given the expressions for fast, non-singular terminal sliding surfaces and adaptive power-reaching laws, the controller’s stability is demonstrated. Then, the variation pattern of the model parameters is determined through dynamic simulations, and finally, extensive simulations verify the attitude control effect of the two CubeSats in the on-orbit assembly process. The simulation results demonstrate that the proposed method is robust to time-varying and jumping CubeSat mass parameters and presents a significant suppression effect on random interference caused by the shaking of the telescopic mechanism and the impact torque at the moment of the docking lock. The proposed method has faster attitude convergence and smoother control torque than traditional sliding mode control methods.
MGCNet: Low-cost MEMS gyro correction network
Authors: Yin Yunsheng , Xu Linhai 
Published: August 2024

Abstract
MEMS gyro is widely used in the field of autonomous system navigation, but due to the large measurement error of low-cost MEMS gyro, the orientation estimation of gyro carriers cannot be met by simple calibration only. In this paper, we propose a learning method to correct the measurement error of MEMS gyro in IMU. Our method utilizes dilated convolution to increase the receptive field, designs a lightweight attention module to extract the gyro random error, and uses channel transformation to extract deterministic errors. We also design a multi-timescale loss function, enabling the network to notice the cumulative orientation errors at different timescales. We tested our method on public datasets EUROC and TUM-VI and compared it with the Visual-Inertial Odometry (VIO) methods as well as other gyro correction methods. The experimental results show that the proposed method can have comparable or even higher accuracy of orientation estimation than the visual inertial combination method, and the gyro orientation estimation error using MGCNet correction is reduced by 15-20% compared to other advanced gyro processing methods.
Design approach of contingency point return trajectory for manned lunar missions based on homotopy continuation
Authors: Lu Lin , Li Haiyang , Dong Tianshan , Zhu Binyu 
Published: August 2024

Abstract
In terms of the requirement of contingency return during the circumlunar flight phase in manned lunar missions, this article presents a contingency point return trajectory design approach. In consideration of the point return constraint, an initial value estimate model is proposed. A nonlinear programming problem is constructed and solved by adopting an improved differential evolution algorithm with good global search ability. On the basis of the initial value estimate, homotopy continuation is used to gradually approximate and obtain the high-fidelity solution. The simulation results indicate that the design approach can effectively calculate a contingency point return trajectory with good convergence.
Optimal design of uniform magnetic field coils within irregular magnetic shielding based on coupled SNOPT-finite element method analysis
Authors: Jie Shaofeng , Liu Zhanchao , Zhang Shuai , Wang Jingsong , Wu Zekun , Zhao Kangnan 
Published: August 2024

Abstract
The highly uniform magnetic field coil is one of the most important components of miniaturized atomic inertial sensors. However, the development of the magnetic field model of coils in magnetic shielding with irregular shapes is difficult in practice. In this study, an optimization method for the design of coil structure parameters based on hybrid modelling with the finite element method and the SNOPT algorithm was proposed. The finite element method was used to characterize the geometric structure of the magnetic shield accurately and incorporate the characteristic B-H parameters of the material into the optimization model to improve the design accuracy. The three-dimensional model was reduced to two dimensions, and the parameters of the coil structure were optimized by an intelligent algorithm, which improved the solution efficiency. The effectiveness of the proposed approach was demonstrated by optimizing the design of a solenoid coil inside the cylindrical magnetic shielding with holes and stovepipes, which reduced the design error caused by the magnetic leakage flux.
Modal classification and identification of hypersonic inlet
Authors: Yang Kongqiang , Fan Xiaoqiang , Xiong Bing , Tang Xiao , Mou Wanhui 
Published: August 2024

Abstract
Based on previous research, as flight parameters change, the inlet will undergo four operating modes, among which the non-starting mode significantly degrades the quality of the inhaled airflow, thereby affecting engine performance. To identify the operating modes, this paper proposes an analysis method based on the ISOMAP dimensionality reduction model. First, preprocess the wall pressure data, and ISOMAP is used to extract features and reduce dimensionality. Then, the corresponding relationship between characteristic points and modes is established manually, and the pressure distribution is labeled and compared with the known sequence. The result shows that the established dimensionality reduction model can effectively identify the inlet operating modes, reveal four types of flow field characteristics, and provide a new method for rapid identification of inlet operating modes.
Dynamic simulation analysis and experimental verification of a typical aircraft structure
Authors: Fu Yue , Li Kun , Ren Jiannan , Zhao Cheng 
Published: August 2024

Abstract
Finite element software was adopted to conduct the vibration modal analysis and frequency analysis of a typical aircraft structure, and modal verification tests were conducted on the typical aircraft structure. Based on the indicator functions, the effectiveness of experimental results was evaluated and the pure modal results as evaluation criteria for simulation analysis results were selected. Among the eight results, the simulation analysis results of six modes are in good agreement with the experimental results, while the two modes of the simulation analysis results are consistent with the experimental results.
Optimization method based on approximate gradient analysis and its application in aerodynamic design
Authors: Liu Miao , Qian Ruizhan , Wei Jianlong , Lei Wutao 
Published: August 2024

Abstract
An efficient optimization method based on approximate gradient analysis was proposed to reduce the substantial computational burden in expensive optimization problems, in which the objective functions are evaluated with high-fidelity analyses in one-dimensional linear search, while the gradients are evaluated with an approximation model during the optimization process. Taking advantage of the similarity of CFD models with different fidelities, we employ a less time-consuming low-fidelity model as its main section, and use the gradient information of the high-fidelity model at the initial point as an amendment. The proposed procedure was applied to the aerodynamic optimization of a well-designed supercritical wing, resulting in obvious drag reduction, but the CPU time is only 28.5% as its SQP counterpart. The investigation indicates the proposed method is suitable for aerodynamic improvement of an existing baseline configuration to meet specified engineering requirements.
Equivalent simulation test method of engine plume thermal environment in aerobic environment
Authors: Pan Shangjie , An Wanqing , Liu Zhe , Xia Chaoran , Meng Ran , Jin Chenwei 
Published: August 2024

Abstract
The deep space probe is generally composed of the lander and the lander. During the take-off and landing of the extraterrestrial body, the engine jet flows through the top surface of the lander or the surface of the extraterrestrial body to reflect on the bottom surface of the lander, which will produce strong aerodynamic and thermal effects in a small space, thus affecting the stability and surface thermal protection of the lander. The plume heat effect refers to the impact of the flyover engine gas flow movement or heat radiation on the lander surface on the flyover bottom, tank, lander top surface, buffer mechanism, and key equipment. This paper calculates from the probe plume thermal environment equivalent simulation method, and heat flow simulation loading system design until the test verifies that the affected product surface temperature rises. It can provide necessary technical support for the selection of thermal control protection materials (conventional thermal control, flexible thermal protection materials, high-temperature thermal protection materials).
Numerical study on the interaction between turbulent grazing flow excitation and Helmholtz cavity
Authors: Li Xingda , Yu Zhefeng , Dang Huixue 
Published: August 2024

Abstract
In response to the problem of abnormal noise in typical aircraft structures with gaps and cavities, an experiment on a Helmholtz cavity excited by turbulent grazing flow was designed. The computational fluid dynamics software FLUENT was used to simulate the flow-induced noise of the Helmholtz cavity based on the Large Eddy Simulation (LES) method. By comparing with experimental data, the numerical simulation was validated. Meanwhile, under the given orifice size, the Helmholtz resonance effect of the cavity was studied at different velocities. It is found that the fluid oscillation frequency of the cavity orifice increases with the velocity under the given orifice size. When the fluid oscillation frequency at the cavity opening approaches the Helmholtz resonance frequency of the cavity, Helmholtz resonance occurs, leading to a significant increase in sound pressure level. Moreover, within a certain velocity range, the lock-in phenomenon occurs, and the lock-in frequency increases with the increase of inflow velocity, resulting in a frequency shift phenomenon. As the velocity increases, the lock-in phenomenon will break. This study suggests that Helmholtz coupling resonance and sound caused by the oscillatory flow with a close frequency to the cavity are one of the main causes of abnormal noise during aircraft flight.
Dynamic SLAM diagnosis method for uncontrolled fault of aircraft electronic anti slip braking system
Authors: Ma Haiguo , Ma Wenqian 
Published: August 2024

Abstract
In order to accurately diagnose the out-of-control fault of an aircraft’s electronic anti-skid braking system, a dynamic SLAM diagnosis method for the out-of-control fault of an aircraft electronic anti-skid braking system is proposed. Using an optical module, image acquisition module, power module, main control module, etc., the dynamic drawing image of aircraft taxiing is acquired. By establishing a dynamic map of aircraft taxiing, the dynamic semantic mapping results are obtained. The out-of-control fault diagnosis model of the depth residual network is constructed, and the aircraft taxiing semantic data is used as input data to output the out-of-control fault diagnosis results. The experimental results show that with the increase of Gaussian white noise intensity, the deviation factor of out-of-control fault diagnosis in the design method increases less, and the sample label misjudges less in the noise-free environment.
Synthetic reliability assessment for non-electric stimulus transfer system
Authors: Ma Xiaodong , Sun Liang , Gu Changchao , Gao Fei , Hong Dongpao 
Published: August 2024

Abstract
The Non-electric stimulus transfer system (NSTS) is a sensitivity product known for its high reliability. To enhance the accuracy of reliability assessment for NSTS, this study investigates the relationship between NSTS and initiating devices, and proposes a synthetic reliability assessment method. By considering the working principle and failure logic of typical NSTS, function-shared units are introduced to enhance the reliability model of NSTS. Subsequently, the reliability of NSTS is approximated by using the normal distribution, incorporating the reliability evaluation of initiating devices and the test data of NSTS to derive an approximated confidence interval. The analysis of a practical case demonstrates that this synthetic reliability assessment method is well-suited for engineering applications.
Study on aerodynamic noise of condensing fan of new energy vehicle air conditioner
Authors: Tong Guang , Li Sijie , Yang Haijun 
Published: August 2024

Abstract
With the growth of low-carbon environmental awareness, more and more new energy vehicles appear in the market. This paper focuses on the issue of noise caused by the condensing fan in new energy vehicles. The noise is generated due to the airflow in the blade gap. Starting from the fan structure, the paper proposes a serrated structure on the surface of the fan blade to improve the fluid vortex gas flow at the tip of the blade. The orthogonal test method sets the number of serrations, length, and cutting depth as three-level factors, and the noise at the monitoring point of the condensing fan is used as the evaluation index of aerodynamic performance. The results show that the noise of the condensing fan is significantly improved.
Wear and corrosion-resistant Al2FeCrMnTix laser cladding coatings - From powder production by high temperature remelting spheroidization to coating built-up by Laser Powder Bed Fusion
Authors: Liu Jie , Guo Yongqiang , Du Kang , Wang Wei , Fan Chenjie , Zhang Wenqi , He Jiayu , Guo Hongmin , Gu Zhen 
Published: August 2024

Abstract
High entropy alloys (HEAs) have unique mechanical and electrochemical properties in various of fields. Laser powder bed fusion (LPBF) is a prominent additive manufacturing process. It uses thermal energy to bind powder materials together to build plastic or metal parts. The technology has a remarkable effect on improving the corrosion resistance and wear resistance of the agitating blade coatings. However, the traditional gas atomization method (GA) often produce alloy powder (containing refractory element, such as Nb, W) with uneven composition, affecting the quality and performance of specimens. That is why innovative or opposite classical production powder methods are in demand for LPBF. It is worth noting the mechanical alloying - high temperature remelting spheroidization dual process (DP) method could overcome the limitation of high temperature alloying of HEA containing refractory elements and realizes solid alloying of insoluble elements. In this paper, high entropy alloy Al2FeCrMnTix (x=0.25,0.5,0.75,1) is designed by means of composition control. The experimental results show that Al2FeCrMnTix is a single phase solid solution BCC structure. With the increase of Ti content, the corrosion resistance of Al2FeCrMnTix HEA coatings were enhanced at a certain range in simulated saturated brine solution. When Ti=0.75, the self-corrosion voltage is -0.179V and the self-corrosion current is 5.764×10−6 mA·cm−2. All coatings offer better corrosion resistance than 316L stainless steel substrates. Particularly, the Al2FeCrMnTix HEA coating can greatly improve the microhardness and wear resistance of the material surface. The average microhardness value of HEA coating reaches up to the maximum (726 HV0.2) when Ti=1, which is about 3.6 times that of the base matrix (316L). These findings have clear implications for coatings used to protect surfaces. Overall, It is clear that Ti0.75 represents lower volume wear rates and smoother wear surfaces, demonstrating better corrosion and wear resistance compared to other coatings.
Impact of Impurity Ions in Secondary Circuit Water on Cracking Behaviour of PWR Steam Generator 690TT Tube
Authors: Song Lijun , Tian Zhaohui , Xu Xinhe , Cui Tongming , Lu Zhanpeng , Qiao Hang 
Published: August 2024

Abstract
The impact of impurity ions on stress corrosion cracking (SCC) sensitivity of steam generator heat-exchange tube material Alloy 690TT in secondary circuit water (SCW) was studied at 285 °C. The pH of the test solution was adjusted using ammonia to be about 9.7. The dissolved oxygen concentration is less than 1 μg/kg, and the ammonia concentration is 50 to 100 μg/L. A slow strain rate test (SSRT) was employed to evaluate the SCC sensitivity in SCW with various types and concentrations of impurity ions. After the SSRT test, the fracture surfaces of the specimen were observed and analyzed using scanning electron microscope (SEM). In SCW environments containing 3 g/L Cl− or 5 g/L SO4
2−, local intergranular cracks were found at the fracture surface edges of the specimens, indicating a certain sensitivity to SCC. When the concentration of SO4
2− was reduced to 5 mg/L, the intergranular crack characteristics of the Alloy 690TT became less apparent, suggesting a high resistance to SCC under low SO42− concentrations.
Study on atmospheric corrosion characteristics and coating protection of urban water supply pipeline
Authors: Li Tao , Zhu Zhiping , Zhou ShangMing , Yang Huo 
Published: August 2024

Abstract
Most of the water supply pipes in the city have corrosion problems during long-term use. To comprehensively understand the corrosion law of water supply pipelines and put forward scientific and effective countermeasures, firstly, the two commonly used materials of ductile iron and Q235 water supply pipelines were subjected to outdoor exposure experiments for one year, and the corrosion kinetic process was analyzed using XRD, EDS, and electrochemical testing, and the atmospheric corrosion mechanism was analyzed; based on this, four kinds of heavy duty anti-corrosion coatings of polyurethane, fluorocarbon, cold galvanizing, and chlorinated rubber were used to coat the specimens of water supply pipelines. On this basis, four kinds of heavy-duty anti-corrosion coatings, polyurethane, fluorocarbon, cold galvanizing, chlorinated rubber, anti-corrosion coating of water supply pipe specimens, examined the four types of coatings of acid, alkali, salt resistance, electrochemical methods to assess their corrosion resistance characteristics, a comprehensive assessment of their application potential, the results show that chlorinated rubber heavy-duty anti-corrosion coating is more suitable for ductile iron pipes, fluorocarbon heavy-duty anti-corrosion coating is more ideal for Q235 pipeline. This study provides data reference for the coating method of corrosion protection for water supply pipelines.
Analysis of corrosion failure causes of hongjing line crude oil pipeline
Authors: Peng Yunchao , Chen Huang , Wen Mengnan , Yan Tong , Fu Yu , Sun Shuangqing , Hu Songqing 
Published: August 2024

Abstract
Pipeline corrosion occurred somewhere in the Hongjing Line crude oil transmission pipeline. In order to investigate the cause of pitting perforation, the corrosion perforation of pipeline was analyzed by optical microscope, scanning electron microscope, fluorescence quantitative PCR and X-ray diffraction analysis, combined with the corrosion simulation experiment of weightloss method. Results On the surface, the pipeline material (L360) met the requirements of API5L standard, and the corrosion form was perforation caused by pitting on the inner wall. The main corrosion products are Fe2O3, FeCO3 and FeS. It is found that the concentration of Cl− in the sedimentary water is as high as 30363.8 ppm, which indicates that the main reason for the corrosion of the crude oil pipeline is the pitting corrosion caused by Cl−.
Research progress and risk analysis on internal corrosion of carbon dioxide pipeline steel with the influence of impurities
Authors: Zhang J 
Published: August 2024

Abstract
Under the increasing demand for safe operation and maintenance of supercritical CO2 pipeline transportation projects, this paper summarizes the synergistic mechanism of process parameters such as pressure and temperature on pipeline corrosion in current CO2 transportation pipelines. The critical phenomenon of water content affecting corrosion and the current research status of the intensification of CO2 corrosion by impurities such as O2, SO2, NO2, and H2S on typical pipeline steel corrosion behavior are summarized, aiming to provide theoretical guidance for the risk analysis of pipeline steel corrosion in CCUS engineering in China. Finally, based on practical engineering requirements, it is suggested that in future research, more attention should be paid to the impact of supercritical CO2 flow characteristics on pipeline corrosion risk.
Importance of nano-carriers, surfactant system, and their loading mechanism to improve the absorption and bio-availability of drugs: a review
Authors: Abdul Azeez Nazeer , Venkateshwaran Krishnaswami , Kandasamy Ruckmani , Saravanan Muthupandian , Sudarshana Deepa Vijaykumar 
Published: August 2024

Abstract
Improving the apparent solubility of poorly soluble therapeutic molecules with poor absorption into the circulatory system is a significant research question in drug discovery. This enhancement is achieved by delivering drugs through nano-carriers that provide apparent solubility with its surfactant. The effectiveness of a nano-carrier is relied majorly on its loading efficiency which is determined by the extent of interaction between the drug and the surfactants of the carriers. The loading effectiveness can be reckoned with a better understanding of the drug-surfactant conjugation mechanism. Hence this review comprehends the different nano-carriers, their appropriate surfactant systems, and the loading mechanism of drugs with surfactants through different bonds. Further, the current status and prospects of the nano-carriers are briefly summarized at last to expound on the significance of these nano-carriers in drug delivery.
Sensitivity optimization of monolithic integrated refractive index sensor based on grating LED
Authors: Gao Xumin , Yu Xuehui , Wu Dongmei , Xie Mingyuan , Shi Zheng 
Published: August 2024

Abstract
In this study, we present a potential ultra-thin refractive index sensor model that utilizes a monolithically integrated gallium nitride-based light-emitting diode platform. This light-emitting diode not only emits light but also detects changes in refractive index. The sensitivity of this sensor is defined as the response of light extraction efficiency to unit changes in refractive index. We have incorporated a one-dimensional grating on the surface of the light-emitting diode to investigate the effects of the grating’s modulation on the light field and the sensor’s sensitivity.Through strategic optimization of the grating structure, we have significantly enhanced the sensitivity of the sensor. Our results indicate that, compared to a conventional flat light-emitting diode, the optimized grating structure increases the light extraction efficiency by approximately 2 to 3 times. Furthermore, the sensitivity of the sensor has achieved a maximal enhancement of up to 41-fold.The device offers a compact design and demonstrates high levels of light extraction efficiency and sensitivity, making it highly suitable for monolithic integration in optical sensing applications. This advancement provides a substantial contribution to the field of optical sensing, indicating promising potential for future research and application.