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The Qizimeishan National Nature Reserve is situated in the southwestern region of Hubei Province, adjacent to the northeastern edge of the Yunnan-Guizhou Plateau. A survey of spiders of this reserve was conducted recently, leading to the discovery of three new species of the genus Pseudopoda Jäger, 2000: P. arcuata Zhang, J. Liu & Hu, sp. nov. (♀), P. qizimeishanensis Zhang, J. Liu & Hu, sp. nov. (♂, ♀) and P. weimiani Zhang, J. Liu & Hu, sp. nov. (♂, ♀). Diagnoses, descriptions, photos, and a distribution map are provided.

The genus Xilithus Liu & Li, 2023 contains 22 species, three of which are known from Hubei Province, China: X. acerosus (Yao, Irfan & Peng, 2019), X. auritus (Fu, Zhang & Zhang, 2016) and X. xingdoushanensis (Yao, Irfan & Peng, 2019).One new Xilithus species from Hubei, China is described: X. qizimeishanensis Liu & Hu sp. nov. Morphological description, digital photos and distribution map are provided.

Polymer-derived ceramics (PDCs) can be used in wide applications due to their high hardness and stable chemical properties. However, these characteristics lead to the challenging controllable deformation of additively manufactured PDCs. Herein, ultraviolet (UV)-curable polymer precursors were developed and a pyrolysis strategy was proposed. Through the two-stage folding-assisted pyrolysis strategy, the printed precursor can deform with programmable shape to attain 4D printing. Regardless of very low precursor ceramic yield (13.5 wt%), leading to a huge pyrolysis shrinkage (59.91%), the SiOC ceramics with dense, crack-free complex programmable shapes were successfully obtained. The working mechanism of the two-stage pyrolysis was explained by characterising and analysing the chemical bond status. The effects of unpyrolyzed, first-pyrolysed and second-pyrolysed samples on the skeleton shrinkage, weight loss, and mechanical properties were also studied and compared. The proposed strategy provides a feasible way for the preparation of PDCs with complex programmable shapes that are dense and crack-free by photopolymerization 4D printing.

Laser powder bed fusion (LPBF) has emerged as a powerful tool to develop heat transfer devices with higher efficiency. Corrugated tubes are commonly used components to achieve enhanced heat transfer in these devices. However, there still lacks a comprehensive study on the thermal-hydraulic performance of LPBF-fabricated corrugated tubes. In this work, we investigated the heat transfer enhancement characteristics of sinusoidal corrugated tubes (SCTs) fabricated via LPBF. SCTs with different amplitude-to-diameter ratios (A/D ratio) and wavelength-to-diameter ratios (S/D ratio) were designed and fabricated. The geometrical morphologies and surface roughness of LPBF-fabricated SCTs were characterized. Numerical simulations were performed to investigate the effects of A/D ratio and S/D ratio on the flow patterns and flow dynamics. A test system was developed to measure the pressure loss and thermal performance. Performance Evaluation Criterion were calculated to characterize the heat transfer enhancement. A/D ratio was found to have more significant impacts on the friction factor and Nusselt numbers than S/D ratio. Correlation models were developed to predict friction factors and Nusselt numbers based on the least square method. Mean prediction errors of ±3.3 % and ±5.3 % and maximum prediction errors of ±11.6 % and ±18.1 % were achieved for Nusselt numbers and friction factor, respectively.

Work-related musculoskeletal disorders (WMSDs) represent a significant health challenge for workers in construction environments, often arising from prolonged exposure to ergonomic risks associated with manual labor, awkward postures, and repetitive motions. These conditions not only lead to diminished worker productivity but also incur substantial economic costs for employers and healthcare systems alike. Thus, there is an urgent need for effective tools to assess and mitigate these ergonomic risks. This study proposes a novel monocular 3D multi-person pose estimation method designed to enhance ergonomic risk assessments in construction environments. Leveraging advanced computer vision and deep learning techniques, this approach accurately captures and analyzes the spatial dynamics of workers’ postures, with a focus on detecting extreme knee flexion, a critical indicator of work-related musculoskeletal disorders (WMSDs). A pilot study conducted on an actual construction site demonstrated the method’s feasibility and effectiveness, achieving an accurate detection rate for extreme flexion incidents that closely aligned with supervisory observations and worker self-reports. The proposed monocular approach enables universal applicability and enhances ergonomic analysis through 3D pose estimation and group pose recognition for timely interventions. Future efforts will focus on improving robustness and integration with health monitoring to reduce WMSDs and promote worker health.

Stone curtain walls are widely used in contemporary architectures; however, their regular inspection is always labor-intensive, time-consuming, and hazardous due to the complex and enclosed spatial structure of these high-rise building enclosures. To address this issue, this study proposes an automated and novel inspection method, which is composed of the following three steps: First, we utilize 3D laser scanning technology to capture colored point cloud data of the stone curtain wall system; subsequently, by extracting and processing the integration of color and depth information, the stone panels and end sealants are precisely segmented; finally, various defects, such as cracks, unevenness, and irregularities, are automatically identified through artificial intelligence algorithms in a timely manner. To validate the proposed method, an on-site experiment was carried out to demonstrate the effectiveness in detecting multiple defects concurrently on stone curtain walls. The experimental results showed that our proposed method could provide a non-contact and automated inspection alternative for all the stone curtain walls with a high accuracy of anomaly detection, facilitating rational maintenance plans and strategies to ensure the safety and performance of these modern building enclosures.

The saline, alkaline environment of arid soils is conducive to the diffusion of the metalloid arsenic (As). Desert plants in this area are of great ecological importance and practical value. However, there are few studies on the mechanism of arsenic action in desert plants. Therefore, in this study, Eremostachys moluccelloides Bunge was treated with different concentrations of As2O5 [As(V)] to analyze the physiological, biochemical, and transcriptomic changes of its roots and leaves and to explore the molecular mechanism of its response to As(Ⅴ) stress. The activities of catalase, superoxidase, peroxidase, and the contents of malondialdehyde and proline in roots and leaves first increased and then decreased under the As(Ⅴ) stress of different concentrations. The content of As was higher in roots than in leaves, and the As content was positively correlated with As(Ⅴ) stress concentration. In the differentially expressed gene analysis, the key enzymes of the oxidative stress response in roots and leaves were significantly enriched in the GO classification. In the KEGG pathway, genes related to the abscisic acid signal transduction pathway were co-enriched and up-regulated in roots and leaves. The related genes in the phenylpropanoid biosynthesis pathway were significantly enriched and down-regulated only in roots. In addition, the transcription factors NAC, HB-HD-ZIP, and NF-Y were up-regulated in roots and leaves. These results suggest that the higher the As(V) stress concentration, the more As is taken up by roots and leaves of E. molucelloides Bunge. In addition to causing greater oxidative damage, this may interfere with the production of secondary metabolites. Moreover, it may improve As(V) tolerance by regulating abscisic acid and transcription factors. The results will deepen our understanding of the molecular mechanism of As(Ⅴ) response in E. moluccelloides Bunge, lay the foundation for developing and applying desert plants, and provide new ideas for the phytoremediation of As pollution in arid areas.

Davidia involucrata Baill. 1871 (D. involucrata), as a tertiary relict plant unique to China, is a national Class I protected plant with high economic value. Oil extracted from its seeds and peels can be used for both consumption and industrial purposes. It has become a popular income-earning export tree in China because of its graceful posture and beautiful white bracts. Climate change affects the distribution of the species’ potential habitat areas. Thus, studying its natural distribution pattern and future potential habitat distribution changes has great significance for the sustainable resource utilization and biodiversity conservation of D. involucrata. Here, we employed the MaxEnt model and ArcGIS software to predict the current and future (the 2050s and 2070s) potential habitats of D. involucrata via 130 species distribution records and 37 environmental variables. Meanwhile, we used the jackknife method to assess the importance of environmental factors. Our results showed the following: (1) When the RM = 4 and FC = LQHPT, the MaxEnt model exhibited the lowest complexity and overfitting degree while achieving high model prediction accuracy. The area under the curve (AUC) value of the simulated training was 0.958, indicating an excellent forecast. (2) Under the current climate scenario, D. involucrata was mainly concentrated in eastern Sichuan, western Hubei, northern Guizhou, and northwestern Hunan, with an area of 98.02 × 104 km2. (3) The precipitation in the warmest quarter (Bio18, 30%), mean temperature in the driest quarter (Bio9, 24.4%), annual mean radiation (Bio20, 14.6%), and elevation (ele, 12.7%) were the main environmental factors affecting its habitat distribution; the t contribution was 82.1%. (4) Under different future climate scenarios, the potential habitat area of D. involucrata decreased overall. Compared with the current climate scenario, the areas of potential habitats gradually decreased in both the 2050s and 2070s under the ssp126 and ssp585 climate scenarios but decreased in the 2050s and then increased in the 2070s under the ssp370 climate scenario. Therefore, it is of great significance to track and monitor the existing population or community on the basis of the possible changes in its distribution area. Moreover, the artificial breeding of its seedlings should be considered in the future to improve the quality of its germplasm resources. In summary, our findings can provide a scientific understanding of D. involucrata distribution in China and are conducive to conservation and utilization.

The study’s objective is to analyze the mechanical properties of steel pipe piles as a part of a trestle bridge subjected to five years of natural marine corrosion degradation. Sixteen tensile specimens are extracted from the steel pipe piles in the splash, tidal, and immersion zones. The experimental tensile test results are used to establish regression equations defining the elastic modulus, yield strength, strain hardening index, and strength coefficient for the true stress–strain curves of the three regions. A non-linear time-dependent mathematical model is exploited to identify the corrosion degradation, using the data from one single corrosion degradation measurement campaign. The analysis indicates that the splash zone is experiencing the most severe corrosion degradation, and there are progressive losses in the mechanical properties of each zone as the corrosion degradation progresses. The established relationships of the mechanical properties, as a function of the ratio of corroded plate thickness to the as-built one, can be used as a fast-engineering approach to identify the mechanical properties of severely corroded piles. The corrosion degradation allowance is also defined using the first-order reliability method, accounting for existing uncertainties covered by the partial safety factors. By examining the impact of marine corrosion on the mechanical properties of marine structures and developing predictive models to assess the corrosion’s effect on material strength and corrosion allowance, the study aims to improve offshore structures’ safety, design, and maintenance.

A precipitation hardening high-entropy alloy (HEA) (FeCoNi)86Al7Ti7 was fabricated by selective laser melting (SLM) and ageing treated under different temperatures and time conditions. Yield strength of the aged HEA increases substantially from 710 to 934 and then to 1203 MPa. Theoretical analyses reveal that the coherent L12 precipitate contributes most of the improved strength for the aged HEAs, whereas recovery during ageing causes the decrease of dislocation density thus exerts a softening effect. In addition, it is found that ductility decreases with increasing volume fraction of the incoherent L21 precipitates. Based on a void growth model, the trend is qualitatively explained. Moreover, a new fracture mode, intercellular fracture, is proposed to account for the strong dependence of fracture dimple size on the dislocation cells, also directly validated by delicate microstructural examination. The findings provide an effective strengthening method and propose a unique fracture mechanism for the additively manufactured HEA.

A rising quantity of coal gasification slag (CGS) is produced annually. Land reclamation is a valuable method for efficiently utilizing coal gasification slag on a large scale. The ecological influence of CGS during land reclamation has not been widely investigated. This article covers the entire CGS use cycle for land reclamation, which includes generation, storage, and disposal. The environmental risk of using CGS for land reclamation was assessed by combining four environmental risk assessment methods. The results show no environmental risk for coal gasification coarse slag (CGCS) and coal gasification fine slag (CGFS) at the generation and storage stages. However, a concern remains regarding manganese leaching from CGCS during the storage stage. In the disposal phase, no environmental risk is present when up to 15% of CGCS and CGFS are applied to land reclamation projects. However, the environmental risk of disposing of 100% of CGS in a landfill cannot be disregarded. Conversely, the full-cycle use of CGS for land reclamation carries no environmental risk.

Abstract Three-dimensional (3D) grid porous electrodes introduce vertically aligned pores as a convenient path for the transport of lithium-ions (Li-ions), thereby reducing the total transport distance of Li-ions and improving the reaction kinetics. Although there have been other studies focusing on 3D electrodes fabricated by 3D printing, there still exists a gap between electrode design and their electrochemical performance. In this study, we try to bridge this gap through a comprehensive investigation on the effects of various electrode parameters including the electrode porosity, active material particle diameter, electrode electronic conductivity, electrode thickness, line width, and pore size on the electrochemical performance. Both numerical simulations and experimental investigations are conducted to systematically examine these effects. 3D grid porous Li4Ti5O12 (LTO) thick electrodes are fabricated by low temperature direct writing technology and the electrodes with the thickness of 1085 µm and areal mass loading of 39.44 mg·cm−2 are obtained. The electrodes display impressive electrochemical performance with the areal capacity of 5.88 mAh·cm−2@1.0 C, areal energy density of 28.95 J·cm−2@1.0 C, and areal power density of 8.04 mW·cm−2@1.0 C. This study can provide design guidelines for obtaining 3D grid porous electrodes with superior electrochemical performance.

Graphite has been the major anode material of choice for lithium-ion batteries (LIBs) for over 30 years. This study reports three-dimensional (3D) printing of comb-like 3D natural graphite (NG) electrodes for high-performance interdigitated 3D LIBs. Printable NG inks were developed and 3D NG electrodes with the thickness of 347.3 μm, 581.7 μm and 786.7 μm (corresponding areal mass loading: 16.3 mg cm−2, 24.4 mg cm−2 and 32.9 mg cm−2) were fabricated via a low temperature direct write 3D printing technology. The 3D-printed electrodes had tri-modally hierarchical porous microstructures with a high porosity of 54.84%. In addition, these thick electrodes showed excellent electrochemical performance with an impressive areal capacity of 13.68 mAh cm−2 @ 0.1C for electrodes with the thickness of 786.7 μm. With this type of 3D electrodes, the capacity fade over the increase of discharge rates was greatly reduced in comparison with tape casted electrodes with the same electrode thickness. This study demonstrates the potential of 3D-printed NG electrodes for high-performance LIBs.

Strength and ductility were simultaneously enhanced in the additively manufactured CoCrFeMnNi high-entropy alloy by laser powder bed fusion (LBPF) under reactive N2 atmosphere. It was found that nitrogen atoms picked up during additive manufacturing line-up to form ordered nitrogen complexes (ONCs) in the octahedral interstitial position of the HEA matrix. Dislocation multiplication is then facilitated by the formation of ONCs during LPBF, leading to a higher dislocation density with smaller dislocation cells. Dislocation strengthening, combined with interstitial strengthening, endows the additively manufactured HEA with the yielding strength of 690 MPa, 15% higher than that of the counterparts fabricated under inert atmosphere. More interestingly, the ONCs stimulate dislocation nucleation and engender more heterogeneous microstructure, giving rise to an outstanding ductility of 15.3%, with an increment of 34%. As a result, the strength–ductility trade-off was successfully reversed by the nitrogen doping during LPBF under reactive atmosphere.

Lightweight and high-strength polymer-derived SiOC ceramics with varied lattice structures have been successfully produced using different polysiloxanes as preceramic polymers (PCPs) via photopolymerisation-based digital-light-processing 3D printing and pyrolysis. Photocurable precursor resins were prepared by simple mixing of polysiloxanes with photosensitive acrylate monomers, achieving good flowability and preserving desirable stability under different heating and oscillation conditions. Complex micron-sized structures were manufactured with high precision via the optimisation of polymer formula and printing parameters. The printed PCPs pyrolysed at 600–1000°C preserved fine features with uniform shrinkage. The skeletons were almost fully dense, with smooth and flawless surfaces at macro/micro scale. Porosities and mechanical properties, including apparent compressive strength, elastic modulus, and indentation hardness, were characterised. XRD, FT-IR, Raman spectroscopy, and XPS were used to explore the chemical variations in elements and atomic bonds. High specific compressive strength to density ratios was obtained for the SiOC lattices compared with other porous ceramics.

Regeneration of corneal stroma has been a challenge due to its sophisticated structure and the easy transformation of the keratocyte. Here, the authors use a hydrogel reinforced with orthogonally aligned fibres and serum free medium to maintain keratocyte phenotype for the in vivo stromal regeneration.

In this study, a triple-band microstrip antenna with compact size and simple structure is proposed for WLAN and 5G applications. The radiating element consists of a circular patch, a Y-shaped patch, and a monopole impedance converter. In order to obtain the desired operating bands, the monopole impedance converter is inserted between the circular patch and Y-shaped patch. The proposed antenna can work in the frequency range of 2.38∼2.53 GHz, 3.29∼4.11 GHz, and 4.72∼5.01 GHz, with the corresponding peak gains of 4.09 dBi (2.4 GHz), 2.95 dBi (3.5 GHz), and 4.01 dBi (4.9 GHz), respectively. The measures’ results are in approximate agreement with the simulated values, which shows that the proposed compact antenna can offer omnidirectional radiation, appropriate gains, and sufficient bandwidths.

Thick electrodes with higher energy density are highly desirable for lithium-ion batteries (LIBs). However, the sluggish transport of Li-ions in thick electrodes is a critical challenge. In this study, a novel synchronously interdigitated/winded battery configuration enabled by 3D printing is proposed. The cathode, separator, and anode are synchronously interdigitated in the core and synchronously winded in the outer-rings to form an integrated full battery. With this novel battery configuration, Li-ions can transport between neighboring cathode and anode, thereby significantly reduce the transport distance of Li-ions, and improve the electrochemical reaction kinetics. To evaluate the electrochemical performance of this battery configuration, this study investigates the effects of various parameters including the electronic conductivity, electrode porosity, electrode line width, separator thickness, and number of winded outer-rings on the electrochemical performance through numerical simulations. Results showed that electronic conductivity is the most crucial factor in determining the electrochemical performance. In combination with multi-material 3D printing, the battery configuration proposed in this study may be utilized to build LIBs with higher energy density.

This paper aims to investigate the impact of recycled coarse aggregate (RCA) on the time-dependent behavior of composite steel–recycled aggregate concrete (RAC) beams. The FE models of the composite beams were established, and a parametric study was conducted to obtain the primary factors. Furthermore, the design method for predicting the long-term deflection was proposed by including the shrinkage deflection component. The results showed that the RCA replacement ratio significantly influenced the long-term deflection of composite beams; the long-term deflection of composite beams with 100% RCA increased by 3.5–17.2% compared with those without RCA. Moreover, using uniform shrinkage and creep models led to a 4.5–10.3% overestimation of the long-term deflection of the composite beams with the composite slabs due to nonuniform shrinkage and creep distributions. Finally, the proposed design procedures could accurately predict the long-term deflection of the composite steel–RAC beams, and the difference between the calculated and FE results ranged from 0.961 to 0.986.

This study investigated the effects of hot isostatic pressing (HIP) on the microstructures and mechanical properties of Ti6Al4V fabricated by electron beam melting (EBM). The differences of surface morphologies, internal defects, relative density, microstructures, textures, mechanical properties and tensile fracture between the as-built and HIPed samples were observed using various characterization methods including optical metallography microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and electron backscattered diffraction (EBSD) and tensile tests. It was found that the main effects of HIP on microstructures include—the increase of average grain size from 7.96 ± 1.21 μm to 11.34 ± 1.89 μm, the increase of α lamellar thickness from 0.71 ± 0.15 μm to 2.49 ± 1.29 μm and the increase of β phase ratio from 4.7% to 10.5% in terms of area fraction on the transversal section. The combinatorial effects including densification, increase of grain size, α lamellar thickness, β phase ratio, reduction of dislocation density and transformation of dislocation patterns contributed to the improvement of elongation and ductility of EBM-fabricated Ti6Al4V. Meanwhile, these effects also resulted in a slight reduction of the yield strength and UTS mainly due to the coarsening effect of HIP.

Web 2.0 enables a two-way interaction between servers and clients. GPS receivers become available to more citizens and are commonly found in vehicles and smart phones, enabling individuals to record and share their trajectory data on the Internet and edit them online. OpenStreetMap (OSM) makes it possible for citizens to contribute to the acquisition of geographic information. This paper studies the use of OSM data to find newly mapped or built roads that do not exist in a reference road map and create its updated version. For this purpose, we propose a progressive buffering method for determining an optimal buffer radius to detect the new roads in the OSM data. In the next step, the detected new roads are merged into the reference road maps geometrically, topologically, and semantically. Experiments with OSM data and reference road maps over an area of 8494 km2 in the city of Wuhan, China and five of its 5 km × 5 km areas are conducted to demonstrate the feasibility and effectiveness of the method. It is shown that the OSM data can add 11.96% or a total of 2008.6 km of new roads to the reference road maps with an average precision of 96.49% and an average recall of 97.63%.

Extrusion container is the most important tooling for steel hot extrusion process. Conventional design using large castings and forgings is very difficult to execute due to high cost and risk. Steel wire wound containers have many advantages over conventional designs. However, conventional wire wound containers are developed for use at room temperature which are not applicable to steel hot extrusion process. In this article, the impacts of preheating on the design of steel wire wound containers are discussed in detail. A finite element model was established to examine the preheating temperature distribution, and a 1:10 scaled extrusion container was manufactured to verify the effectiveness of the finite element model. Based on the finite element model–computed temperature field, thermal stress analysis was performed. The thermal impacts on the stress of extrusion container and steel wire were obtained. Results showed that insufficient stability of internal cylinder and greatly enhanced steel wire stress may lead to the failure of extrusion container. To solve the problems, an improved design was put forward by increasing the stability factor of internal cylinder, reducing the prestress factor and lowering the allowable stress of steel wire. Results showed that the improved design can meet the requirements and counteract the thermal impacts.

In this work, a novel strategy was developed to fabricate prevascularized cell-layer blood vessels in thick tissues and small-diameter blood vessel substitutes using three-dimensional (3D) bioprinting technology. These thick vascularized tissues were comprised of cells, a decellularized extracellular matrix (dECM), and a vasculature of multilevel sizes and multibranch architectures. Pluronic F127 (PF 127) was used as a sacrificial material for the formation of the vasculature through a multi-nozzle 3D bioprinting system. After printing, Pluronic F127 was removed to obtain multilevel hollow channels for the attachment of human umbilical vein endothelial cells (HUVECs). To reconstruct functional small-diameter blood vessel substitutes, a supporting scaffold (SE1700) with a double-layer circular structure was first bioprinted. Human aortic vascular smooth muscle cells (HA-VSMCs), HUVECs, and human dermal fibroblasts–neonatal (HDF-n) were separately used to form the media, intima, and adventitia through perfusion into the corresponding location of the supporting scaffold. In particular, the dECM was used as the matrix of the small-diameter blood vessel substitutes. After culture in vitro for 48 h, fluorescent images revealed that cells maintained their viability and that the samples maintained structural integrity. In addition, we analyzed the mechanical properties of the printed scaffold and found that its elastic modulus approximated that of the natural aorta. These findings demonstrate the feasibility of fabricating different kinds of vessels to imitate the structure and function of the human vascular system using 3D bioprinting technology.

3D printing has attracted a lot of attention in recent years. Over the past three decades, various 3D printing technologies have been developed including photopolymerization-based, materials extrusion-based, sheet lamination-based, binder jetting-based, power bed fusion-based and direct energy deposition-based processes. 3D printing offers unparalleled flexibility and simplicity in the fabrication of highly complex 3D objects. Tactile sensors that emulate human tactile perceptions are used to translate mechanical signals such as force, pressure, strain, shear, torsion, bend, vibration, etc. into electrical signals and play a crucial role toward the realization of wearable electronics and electronic skin. To date, many types of 3D printing technologies have been applied in the manufacturing of various types of tactile sensors including piezoresistive, capacitive and piezoelectric sensors. This review attempts to summarize the current state-of-the-art 3D printing technologies and their applications in tactile sensors for wearable electronics and electronic skin. The applications are categorized into five aspects: 3D-printed molds for microstructuring substrate, electrodes and sensing element; 3D-printed flexible sensor substrate and sensor body for tactile sensors; 3D-printed sensing element; 3D-printed flexible and stretchable electrodes for tactile sensors; and fully 3D-printed tactile sensors. Latest advances in the fabrication of tactile sensors by 3D printing are reviewed and the advantages and limitations of various 3D printing technologies and printable materials are discussed. Finally, future development of 3D-printed tactile sensors is discussed.

LiFePO4 (LFP) is a promising cathode material for lithium-ion batteries. In this study, low temperature direct writing (LTDW)-based 3D printing was used to fabricate three-dimensional (3D) LFP electrodes for the first time. LFP inks were deposited into a low temperature chamber and solidified to maintain the shape and mechanical integrity of the printed features. The printed LFP electrodes were then freeze-dried to remove the solvents so that highly-porous architectures in the electrodes were obtained. LFP inks capable of freezing at low temperature was developed by adding 1,4 dioxane as a freezing agent. The rheological behavior of the prepared LFP inks was measured and appropriate compositions and ratios were selected. A LTDW machine was developed to print the electrodes. The printing parameters were optimized and the printing accuracy was characterized. Results showed that LTDW can effectively maintain the shape and mechanical integrity during the printing process. The microstructure, pore size and distribution of the printed LFP electrodes was characterized. In comparison with conventional room temperature direct ink writing process, improved pore volume and porosity can be obtained using the LTDW process. The electrochemical performance of LTDW-fabricated LFP electrodes and conventional roller-coated electrodes were conducted and compared. Results showed that the porous structure that existed in the printed electrodes can greatly improve the rate performance of LFP electrodes.

The nitrogen-containing austenitic stainless steel 316LN has been chosen as the material for nuclear main-pipe, which is one of the key parts in 3rd generation nuclear power plants. In this research, a constitutive model of nitrogen-containing austenitic stainless steel is developed. The true stress-true strain curves obtained from isothermal hot compression tests over a wide range of temperatures (900-1250°C) and strain rates (10(-3)-10 s(-1)), were employed to study the dynamic deformational behavior of and recrystallization in 316LN steels. The constitutive model is developed through multiple linear regressions performed on the experimental data and based on an Arrhenius-type equation and Zener-Hollomon theory. The influence of strain was incorporated in the developed constitutive equation by considering the effect of strain on the various material constants. The reliability and accuracy of the model is verified through the comparison of predicted flow stress curves and experimental curves. Possible reasons for deviation are also discussed based on the characteristics of modeling process.

A dual-band metasurface antenna is designed consisting of three-layer metal patches and two-layer dielectric substrates. To facilitate the modal analysis of the metasurface, Characteristic Mode Analysis (CMA) is used to analyze the metasurface antenna with 4 × 4 rectangular patches, and the performance of the antenna is optimized based on the Modal Significance (MS) curves. In order to excite the current of different characteristic modes at certain frequencies, symmetric resonant arms and cross-shaped impedance matching converters are used in the feeding structure. The measured results are consistent with the simulated values, and the designed antenna can yield gains of 7.67 dBi at 3.5 GHz and 7.28 dBi at 4.9 GHz, which provides the potential applications in 5G and other wireless communications. [ABSTRACT FROM AUTHOR]

LiFePO4 (LFP) is a promising cathode material for lithium-ion batteries. In this study, low temperature direct writing (LTDW)-based 3D printing was used to fabricate three-dimensional (3D) LFP electrodes for the first time. LFP inks were deposited into a low temperature chamber and solidified to maintain the shape and mechanical integrity of the printed features. The printed LFP electrodes were then freeze-dried to remove the solvents so that highly-porous architectures in the electrodes were obtained. LFP inks capable of freezing at low temperature was developed by adding 1,4 dioxane as a freezing agent. The rheological behavior of the prepared LFP inks was measured and appropriate compositions and ratios were selected. A LTDW machine was developed to print the electrodes. The printing parameters were optimized and the printing accuracy was characterized. Results showed that LTDW can effectively maintain the shape and mechanical integrity during the printing process. The microstructure, pore size and distribution of the printed LFP electrodes was characterized. In comparison with conventional room temperature direct ink writing process, improved pore volume and porosity can be obtained using the LTDW process. The electrochemical performance of LTDW-fabricated LFP electrodes and conventional roller-coated electrodes were conducted and compared. Results showed that the porous structure that existed in the printed electrodes can greatly improve the rate performance of LFP electrodes. [ABSTRACT FROM AUTHOR]

The current codes and specifications use the equivalent beam-column method to predict the in-plane stability capacity of concretefilled steel tubular (CFST) arches. Using this method, the effects of the rise-span ratio and the nonuniform moment on the stability capacity of CFST parabolic arches are not considered. This may induce a difference between calculation results and actual structural stability capacity. To study the effects of the rise-span ratio and the nonuniform moment, six fixed CFST parabolic arches, with rise-span ratios of 1/4.5, 1/6, and 1/9, were tested and analyzed in this study. The failure patterns and mechanisms were studied. The confining effect of the steel tube to the concrete at failure was investigated. The influence of the rise-span ratio and loading conditions on the in-plane stability of fixed CFST arches was also considered. A nonlinear elastic-plastic finite-element (FE) model was used to predict the buckling behavior of the fixed CFST parabolic arches. Based on the test and the FE results, a design equation is proposed for the design of in-plane stability of fixed CFST parabolic arches under combined bending and compression. [ABSTRACT FROM AUTHOR]

Concrete-filled steel tubular (CFST) arch bridges have the advantages of high compressive strength, light self-weight, and convenience in construction, and thus have been widely used in recent years. The current codes or specifications use the equivalent beam-column method to predict the in-plane strength of CFST arches. In this method, the CFST arches are considered under central or eccentric axial compression and are treated similarly to CFST columns. However, different from the CFST columns, the in-plane strength of CFST arches is affected by not only the slenderness ratio but also the rise-span ratio. Especially for the arches with small rise-span ratios, the prebuckling deformation becomes quite nonlinear, leading to a remarkable decrease in in-plane strength. Therefore, it is doubtful if the current method for in-plane strength design of CFST arches can provide correct predictions. In this paper, the elastic buckling and elastic-plastic buckling behaviors of fixed CFST parabolic arches that are subjected to uniform axial compression are investigated. The effect of the rise-span ratio on both the elastic buckling load and the in-plane strength are studied. A new method for the prediction of the in-plane strength of fixed CFST parabolic arches that are subjected to uniform axial compression is developed by considering both the slenderness ratio and the rise-span ratio. [ABSTRACT FROM AUTHOR]

BiHoTiO and (BiHo)TiVO (BHTV) ( x = 0.3, 1.2, 3.0 and 6.0%) thin films were prepared on Pt/Ti/SiO/Si substrates by sol-gel method. The effect of V content on their microstructure and ferroelectric properties were investigated. All the BHTV samples consisted of the single phase of Bi-layered Aurivillius phase. The B-site substitution with high-valent cation of V, in BiHoTiO films, enhanced the remanent polarizations (2P) and reduced the coercive field (2E). The BHTV film with x = 0.3% exhibited the better electrical properties with 2P 45.5 μC/cm, 2E 257 kV/cm, good insulting behavior, as well as the fatigue-free characteristic. [ABSTRACT FROM AUTHOR]

A novel ceramic packaging technology by using selective induction heating is presented. Some aspects of this packaging process, including local temperature distribution, hermetical, tensile strength, and fracture analysis, were tested and evaluated. For high-frequency (f = 350 kHz) induction heating, the temperature of cover edges near solder- loop reached up to 3200 C in several seconds, hermetic seal of the ceramic package can be promised because of solder reflowing, while the temperature of the ceramic bottom was only about 100°C, so thermal-sensitive devices and integrated circuits inside the ceramic package can be protected from high-temperature damage. Temperature variation and distribution were evaluated by an infrared imager and it agreed well with simulation results. Finally, tensile strength from 4.0 MPa to 13.0 MPa was achieved and the fracture interfaces were examined and analyzed depending on the induction heating time and packaging pressure. [ABSTRACT FROM AUTHOR]