bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Crystallinity on Properties of Autoclaved Aerated Concrete Matrix Materials
Authors: Pan Yunfeng , Jiang Yaqing , Liu Zongqi , Xiang Qiudi , Gao Chao 
Published: February 2023

Abstract
The properties of Autoclaved Aerated Concrete (AAC) are related to the crystallinity of hydration products of matrix materials. This study describes the effects of tobermorite and C-S-H gel contents in hydration products of AAC matrix materials on mechanical and drying shrinkage properties. In this study, the mass contents of tobermorite and C-S-H gel were semiquantitative calculated By XRD and nitrogen adsorption method respectively. According to the data obtained from the orthogonal design, the influences of the contents of tobermorite and C-S-H gel on the mechanical properties and drying shrinkage were analyzed, and the optimum mass ratio of tobermorite to C-S-H gel was determined. The factors affecting the crystallization of AAC matrix materials were investigated. The results manifest that the matrix material has higher compressive strength, higher flexural strength and smaller drying shrinkage when the tobermorite content is 0.18~0.23, and the C-S-H gel content is 0.440~0.500. The fineness of quartz sand is the primary factor affecting the performance of AAC matrix materials, followed by constant temperature time, calcium-silica ratio and cement-lime ratio. The research results provide a reference for predicting or designing the performance of AAC.
Prediction Model for Microstructure Evolution of 610L during Hot Rolling Process
Authors: Zhang Siyuan , Jiang Haitao , Xin Jiangping , Zhang Yefei , Yang Zhenyu , Tian Shiwei 
Published: February 2023

Abstract
The microstructure evolution of steels through the whole process method can guide steel production at a lower cost. In this paper, the stress-strain curves of 610L under different deformation conditions are studied using a Gleeble-3500 testing machine. This work combines dynamic recrystallization, static recrystallization, and sub-dynamic recrystallization models to predict the recrystallization fraction and grain size during the rolling process. Through linear fitting, the parameters m1
, Q, and A are 0.15, 9030.19, and 0.062, respectively. Comparing the experimental results with the fitted model, it is found that the grain size calculated by the model is close to the experiment, proving the model’s accuracy.
Compressive Strain Sensing Elastic Foam Based on Sericin Dispersed Carbon Nanotubes
Authors: Li Ming , Xiao Ming , Jiang Weidong , Ran Jianhua , Min Yuhuan , Yang Tong , Bi Shuguang , Xia Long 
Published: February 2023

Abstract
The flexible strain sensor can transform the micro or macro deformation into the visual electrical signals for monitoring the physiological and motor characteristics of human body. However, the current commercial strain sensors generally have some shortcomings such as large stiffness and small strain range. In this work, a flexible compressive strain sensor with the 3D conductive network was fabricated by using biomacromolecule sericin protein dispersed carbon nanotubes (SSCNTs) as the conductive material and melamine foam (MF) as the elastic matrix. The results showed that the sensitivity of MF/SSCNTs elastic foam was 1.36 in the strain range of 0-70% with the CNTs content of 10 wt% and the cyclic compressive sensing performance was stable for at least 1600 cycles. This kind of flexible compressive strain sensor is environmentally friendly, low cost, simple process, and provides a new method for the preparation of green flexible sensor.
Determination and Application of Similar Materials in a Subway Excavation and Support Model Test
Authors: Jian Xiuwen , Wang Zhongrong , Wang Yang 
Published: February 2023

Abstract
In order to study the mechanical response of strata during the construction of a subway, it is crucial to develop similar materials suitable for indoor model tests. Therefore, based on the similarity theory, combined with the uniaxial compressive test results of similar materials, the similar materials and their ratios of advanced small pipes, shotcrete and steel frames were determined. Then, they were applied to the model test of a subway excavation and support. The variation laws of surface displacement, stress distribution around the tunnel and internal force of the steel frame during tunnel excavation and support were obtained to verify the reliability of similar materials. The results show that the aluminum arch frame with width of 4.87 mm and thickness of 5.00 mm can be used to simulate the grid steel frame. Nine fine steel wires in a ring are taken to simulate the advanced small pipes, and gypsum with elastic modulus of about 1.12 GPa are prepared to simulate the initial shotcrete. They are proven to accurately simulate the physical characteristics of supporting materials in practical engineering, and the variation is similar to that obtained from the field test, which improves the authenticity of the model test results.
Numerical and Experimental Study on Axial Feed Skew Rolling of Small-Diameter GH4169 Alloy Bars
Authors: Zhang Huibo , Wang Baoyu , Feng Pengni , Wang Jiapeng , Liu Wei 
Published: February 2023

Abstract
This study relates to an innovative method for forming small-diameter GH4169 superalloy bars by Axial Feed Skew Rolling (AFSR). The finite element (FE) model was established to reveal the deformation characteristics and rolling force parameters of GH4169 superalloy bar in AFSR process. The distribution of stress field reveals that in the deformation area, the stress state in the center of the workpiece is radial compression, axial and tangential tension. In the deformation area, the core temperature of the workpiece rises due to plastic deformation, but after leaving the deformation area, the temperature of workpiece decreases significantly. Therefore, for small-diameter long bars, especially temperature-sensitive materials, auxiliary heating equipment is required when using AFSR technology. Furthermore, the roller with clamping sections was designed, and the rolling experiments were carried out on a double-rotating-arm skew mill. The rolled pieces obtained have no helical grooves on the surface, and the diameter deviations are less than 0.1 mm. The actual rolling process is stable and highly consistent with the FE simulation, which verifies the reliability of the FE model and the feasibility of forming superalloy bars by the AFSR method.
Construction of Conductive Network in Carbon-Nanotube-Based Nanocomposites for Electromagnetic Wave Absorption via Diameter and Composition Regulation
Authors: Fang Yuan , Wang Wenjian , Wang Shuai , Xue Weidong , Zhao Rui 
Published: February 2023

Abstract
Nitrogen-doped carbon nanotubes (NCNTs) and their composites are promising electromagnetic wave absorbers for their strong dielectric polarization and tunable conductivity. However, further investigation is needed to understand the relationship between diameter, composition, and absorption performance. Herein, using the Trojan catalyst strategy in which the catalyst emerged in-situ from a solid solution, the diameter of NCNTs and the composition of the absorber composite were regulated to achieve an effective absorption bandwidth of 4.4 GHz at 1.6 mm. This study showed that the diameter of NCNTs plays a critical role in the formation of conductive network, and an insulating phase can act as a modulator of impedance.
Influence of Solvothermal Reaction Temperature on Hydroxyapatite Nanowires
Authors: Wu Jinan , Nan Xiangkai , Qi Liang , Zhao Yanwei , Zhang Haijun , Qi Mei-li 
Published: February 2023

Abstract
Nowadays, nanomaterials have become the focus of many scientific researchers. As one of the mostly used biomaterials, the special structure and good performance of hydroxyapatite (HA) nanowires is a research hotspot. However, the synthesis of ultralong HA nanowires with highly efficiency and relatively low-cost is still a great challenge. In this work, HA nanowires are successfully synthesized through a simple solvothermal route, with calcium oleate and sodium hexametaphosphate as the calcium and phosphorus source, respectively. Influence of the solvothermal reaction temperature on the HA products are investigated. As the solvothermal temperature increases, the morphology of the HA crystals become nanowires and the length increases. This method is one-step and environmentally friendly without any pollution, since no organic solvent is allowed to be used in the whole experiment. The as-synthesized ultralong HA nanowires have enhanced mechanical properties and can be used in bone tissue engineering, drug delivery, adsorbents, and many other applications.
Study on TIG Process of AZ31 Magnesium Alloy
Authors: Liang Chunping , Li Ming , Peng Huining , Chen Yanyun , Li Guochao 
Published: February 2023

Abstract
In this paper, manual argon tungsten arc welding is used to weld AZ31 magnesium alloy plate with thickness of 2.5mm on both sides. The welding current parameters are changed. The best welding current is explored by analyzing the performance of welding joint; The corrosion resistance of welded joint was studied in the same medium. The results show that the microstructure of base metal zone is α- Mg solid solution, and the microstructure of the weld seam is mg solid solution α- Mg solid solution and β- Mg17Al12 intermetallic compound. When the welding current increases from 80A to 120A, the welding heat input increases gradually, and the grain size of HAZ increases gradually. The results of microhardness test show that the microhardness of weld zone is the largest, that of base metal is moderate, and that of heat affected zone is the lowest. The corrosion resistance of AZ31 magnesium alloy welded joint shows that the corrosion resistance of the weld zone is better than that of the base metal zone.
Modelling EPS Beads Distribution in 2D and 3D and Its Compressive Strength
Authors: Li Qiang , Xie Dongbai , Jiang Weiguo 
Published: February 2023

Abstract
The paper aims to build a distribution model for the EPS beads distribution in 2 and 3 dimensions. An EPS distribution model is built firstly, in which the calculated 2D distribution with volume fraction of 10%,20%,30% and the radius of 1.35mm and 3.5 mm are compared with the real experimental image of EPS distribution, and the calculated results match the real EPS bead distribution well. Secondly, the 3D distribution model is presented, and then the 3D model is incorporated into the finite element model to calculate the stress distribution. Finally, the failure of EPS concrete is predicted under different volume fraction and the radius of EPS bead according to the calculated stress distribution. From the simulated results of 3D stress distribution, it can be found that under the same volume fraction condition, reducing the radius of EPS bead can improve the compressive strength of EPS concrete.
Effect of Particle Size and Concentration of Nanocellulose on Thermal Properties of Nanocellulose Aerogel
Authors: Yang Xue , Wang Ziyang 
Published: February 2023

Abstract
Traditional building thermal insulation materials are mostly from petrochemical materials or high energy consumption processing process, which seriously restricts the sustainable development of the economy. Therefore, it is urgent to develop high-performance green insulation materials with high efficiency, energy saving, light weight and environmental protection. In this paper, nanocellulose aerogels made from cellulose nanocrystal (CNC) and cellulose nanofibril (CNF) with different concentrations were prepared by freeze-drying process. The effect of the concentration of nanocellulose on the thermal properties of aerogel was fully studied by infrared thermal imager, thermogravimetric analyser, and thermal conductivity meter. The study found that the overall thermal insulation performance of CNF aerogel was better than that of CNC aerogel. The concentration had a significant effect on the thermal insulation performance and thermal conductivity of the two aerogels. Among all the prepared nanocellulose aerogels, CNF aerogel with a concentration of 1% showed the best thermal insulation performance, which had a temperature difference of 24.1°C and a thermal conductivity of 0.030 W/mK.
Optimization of Trunk Phase Difference for Seeking Maximum Bidirectional Green Wave Bandwidth
Authors: Zhang Jie , Zhang Junyou , Zhu Qinglin , Luo Yuqiu , Lv Fengfei , Gao Han 
Published: February 2023

Abstract
This paper first analysis the shortcomings of the existing traditional numerical solution algorithm to solve the two-way green wave bandwidth problem, then improves the traditional numerical solution algorithm, constructs the objective function, proposes a trunk phase difference optimization method to seek the maximum two-way green wave bandwidth, constructs the model and solves it using Lingo optimization software, which can overcome the disadvantages of artificially fixed speed and common signal period and the lack of connection between green wave speed and common signal period. It can overcome the disadvantages of artificially fixed speed and common signal period and the lack of connection between green wave speed and common signal period, and optimize the signal period, phase difference, green signal ratio and green wave speed simultaneously. Meanwhile, the simulation analysis by VISSIM software verifies that the method can significantly reduce the stopping delay and improve the intersection capacity.
Structural Design and Analysis of an Airborne Equipment
Authors: Zheng Xiaodong , Su Zhiqiang , Wang Cangcang 
Published: February 2023

Abstract
The airborne electronic equipment has high requirements in high temperature resistance, vibration resistance, humidity and heat resistance and salt spray resistance, and the technical indexes of heat dissipation, vibration resistance and three-proof performance are determined through reliability analysis and the working characteristics of the components themselves. This paper introduces the design process of an airborne electronic equipment structure scheme. Under the conditions of meeting the structural size requirements and three-proof performance, the mainframe and antenna structure scheme is designed by analyzing the heat generation and vibration resistance requirements of components, and the temperature and mechanical simulation is verified by using ANSYS software. The design scheme meets the requirements of environmental adaptability.
Control Performance of Tuned Liquid Dampers for Construction Platform and Super Tall-Rise Building
Authors: Sun Haoding , Cao Qing , He Haoxiang , Zhou Daxing 
Published: February 2023

Abstract
To meet the engineering demand for vibration control of a super-tall integral jacking platform moulding system, a tuned liquid damper (TLD) is used for the tuned control device of the construction steel platform. An experimental method for isolating the substructure is proposed, and the effectiveness of the TLD for vibration damping control of the steel platform is verified by shaking table tests. The test results show that the dynamic response of the construction steel platform and the main body of the structure under earthquake can be suppressed simultaneously by controlling the mass ratio of TLD to the construction platform within 5%, and the displacement damping effect is good.
A Health Assessment Technique Based on WPD and Multiple Linear Regression Analysis
Authors: Lv Saige , Hu Xiong 
Published: February 2023

Abstract
A health assessment technique based on WPD and multiple linear regression analysis is studied in this paper. Firstly, the Temperature-Vibration function model is established by analyzing the mechanism of vibration and temperature of the gearbox. Secondly, the vibration and temperature signals and ambient temperature of the quayside crane lifting gearbox were decomposed by wavelet packet, and the total energy after wavelet packet reconstruction was calculated respectively. Thirdly, multiple linear regression analysis is carried out to obtain the multiple linear regression model of the lifting gearbox based on the established function model. Finally, the absolute error between the total energy of the wavelet packet of the actual and the calculated temperature is calculated to judge the health status of the gearbox during 2009-2015 according to the model. The results show that the judged health state of the quayside crane lifting gearbox is consistent with the actual situation, indicating that the technique can be effectively applied to the health assessment of the gearbox.
Health Status Characterization and RUL Prediction Method of Escalator Bearing Based on VMD-GRU
Authors: Zhang Yi , Guan Peng 
Published: February 2023

Abstract
In order to solve the problem of life index extraction and prediction of rolling bearings in the case of small samples, a bearing health index extraction and prediction method based on variational mode decomposition (VMD) and Gate Recurrent Unit (GRU) network is proposed. First, in view of the scarcity of bearing fault life data of field equipment, the sample data is expanded, and the one-dimensional data is decomposed into multi-dimensional data by VMD decomposition; Then, the multi-dimensional features are extracted and normalized in time domain; Finally, the normalized features are used as the input and the bearing life percentage are used as the output to train the GRU network, which is used to extract the bearing health index and predict the remaining useful life. The test-bed data verification shows that the bearing health index based on VMD-GRU method has better trend, monotonicity, robustness and the predicted residual life is more accurate. The analysis results based on escalator motor bearing fault cases show that: in the case of small samples, the health index performance of GRU network is better based on the features used VMD decomposition and feature extraction.
Study on the External Skeletal Power System Transmission Institution
Authors: Bao Jinfeng , Li Xiang 
Published: February 2023

Abstract
The power exoskeleton system can effectively extend the working hours of firefighters and improve the efficiency of work in the fire field. When firefighters are facing danger, the auxiliary device that comes with the system will greatly ensure the safety of the lives and reduce the casualties of personnel. Research projects first understand the hazards, causes, and solutions of forest fires. Secondly, the analysis of human skeletal structure and sports, and provide theoretical basis for the structural design of the power exoskeleton system. The pre -plan is designed according to the principles of simplicity, non -imitation, and quasi -imitation simulation design, and optimized the pre -planning plan in combination with sports and dynamics. Based on the limited element analysis, the structure, transmission principle, and transmission method of the power exoskeleton system were combined with the analysis of the power exoskeleton system. Finally, according to the use environment for power exoskeleton with auxiliary tools, build power exoskeleton sample machines to verify theoretical models and control planning. This topic conducts a variety of research on the exoscoligoral power system, the theoretical research, theoretical research, the simulation experiments, the manufacturing process, and the prototype production, which provides theoretical reference and technical support for the research of the exoskeleton dynamic system.
Indigenous peoples and the COVID-19 pandemic: a systematic scoping review
Authors: Pickering Kerrie , Galappaththi Eranga K , Ford James D , Singh Chandni , Zavaleta-Cortijo Carol , Hyams Keith , Miranda J Jaime , Arotoma-Rojas Ingrid , Togarepi Cecil , Kaur Harpreet , Arvind Jasmitha , Scanlon Halena , Namanya Didacus B , Anza-Ramirez Cecilia 
Published: February 2023

Abstract
Past influenza pandemics including the Spanish flu and H1N1 have disproportionately affected Indigenous Peoples. We conducted a systematic scoping review to provide an overview of the state of understanding of the experience of Indigenous peoples during the first 18 months of the COVID-19 pandemic, in doing so we capture the state of knowledge available to governments and decision makers for addressing the needs of Indigenous peoples in these early months of the pandemic. We addressed three questions: (a) How is COVID-19 impacting the health and livelihoods of Indigenous peoples, (b) What system level challenges are Indigenous peoples experiencing, (c) How are Indigenous peoples responding? We searched Web of Science, Scopus, and PubMed databases and UN organization websites for publications about Indigenous peoples and COVID-19. Results were analyzed using descriptive statistics and content analysis. A total of 153 publications were included: 140 peer-reviewed articles and 13 from UN organizations. Editorial/commentaries were the most (43%) frequent type of publication. Analysis identified Indigenous peoples from 19 different countries, although 56% of publications were centered upon those in Brazil, United States, and Canada. The majority (90%) of articles focused upon the general adult population, few (<2%) used a gender lens. A small number of articles documented COVID-19 testing (0.04%), incidence (18%), or mortality (16%). Five themes of system level challenges affecting exposure and livelihoods evolved: ecological, poverty, communication, education and health care services. Responses were formal and informal strategies from governments, Indigenous organizations and communities. A lack of ethnically disaggregated health data and a gender lens are constraining our knowledge, which is clustered around a limited number of Indigenous peoples in mostly high-income countries. Many Indigenous peoples have autonomously implemented their own coping strategies while government responses have been largely reactive and inadequate. To ‘build back better’ we must address these knowledge gaps.
Investigating atmospheric nitrate sources and formation pathways between heating and non-heating seasons in urban North China
Authors: Yan Xiao , Hu Beibei , Li Yilan , Shi Guitao 
Published: February 2023

Abstract
In urban North China, nitrate (

NO

3
−

) is a primary contributor to haze formation. So far, the production processes and source apportionments of atmospheric

NO

3
−

during the heating season (i.e. the wintertime) have not yet been well understood. This study determined δ15N–

NO

3
−

, δ18O–

NO

3
−

, and Δ17O–

NO

3
−

of aerosol samples to compare the potential sources and formation pathways of atmospheric

NO

3
−

during heating (November to March) and non-heating (April to May) seasons. Combining stable isotope composition with the MixSIAR model based on Δ17O–

NO

3
−

showed that NO3 + DMS/HC (dimethyl sulfate/hydrocarbon) pathway was the dominant process of atmospheric nitrate formation during the heating season (mean = 52.88 ± 16.11%). During the non-heating season, the contributions of NO3 + DMS/HC (mean = 37.89 ± 13.57%) and N2O5 + H2O (mean = 35.24 ± 3.75%) pathways were comparable. We found that Δ17O–

NO

3
−

was negatively correlated with wind speed and positively correlated with relative humidity during the heating season, possibly associated with the sources and production of atmospheric

NO

3
−

. In specific, in a dust storm event, the very low Δ17O–

NO

3
−

is likely associated with particles from land surface. Under the premise of considering 15N fractionation, the constraint-based on δ15N–

NO

3
−

illustrated that coal combustion was the major source of NO
x
emission during the heating season, and the relative contribution of coal combustion decreased rapidly from the heating season (mean = 42.56 ± 15.50%) to the non-heating season (mean = 21.86 ± 4.91%). Conversely, the proportion of NOx emitted by soil microbes rose significantly from the heating (mean = 9.67 ± 5.99%) to non-heating season (mean = 24.02 ± 11.65%). This study revealed differences in the sources and formation processes of atmospheric

NO

3
−

during the heating and non-heating seasons, which are of significance to atmospheric nitrogen oxide/nitrate pollution mitigation.