Search

Aiming at the problems of poor segmentation effect, low efficiency and poor robustness of the Ransac ground segmentation algorithm, this paper proposes a radar segmentation algorithm based on Ray-Ransac. This algorithm combines the structural characteristics of three-dimensional lidar and uses ray segmentation to generate the original seed point set. The random sampling of Ransac algorithm is limited to the original seed point set, which reduces the probability that Ransac algorithm extracts outliers and reduces the calculation. The Ransac algorithm is used to modify the ground model parameters so that the algorithm can adapt to the undulating roads. The standard deviation of the distance from the point to the plane model is used as the distance threshold, and the allowable error range of the actual point cloud data is considered to effectively eliminate the abnormal points and error points. The algorithm was tested on the simulation platform and the test vehicle. The experimental results show that the lidar point cloud ground segmentation algorithm proposed in this paper takes an average of 5.784 milliseconds per frame, which has fast speed and good precision. It can adapt to uneven road surface and has high robustness.

The reliable and lightweight deployable solar arrays require the capability of large deformation for packaging and the ability to actively deform for deployment. To satisfy such demands, the shape memory polymer solar cells (SMPSCs) are fabricated and demonstrated in this paper by using flexible and conductive silver nanowire/shape memory copolyamide (AgNW/SMPI) composite film as the transparent substrates. The AgNW/SMPI composite film has good optical transparency (~73% at the wavelength of 450 ~ 1100 nm), smooth surfaces (average RMS: ~3.32 nm), good shape memory performances (shape fixation ratio > 98%, shape recovery ratio > 98%), and can maintain excellent conductivity (~10Ω/□) after mechanical deformations with large strain. Owing to the shape memory effect of the substrate, SMPSCs can be deformed into arbitrary shape and actively recover to the original shape upon heating. The power conversion efficiency of SMPSC (2.94%) is lower than that of ITO-based solar cells with the same structure (3.44%), due to the relatively lower optical transparency of SMPI. However, SMPSCs can maintain good photovoltaic performances after 50 bending-recovery cycles or few shape recovery cycles, demonstrating better flexibility and durability than ITO-based solar cells. The SMPSCs have the potential to be used in deployable solar arrays, and the transparent conductive SMPI film electrodes have the potential to be used in areas of sensors, medical probes, and displays.

Based on our previous successful material-level verification of a shape-memory polymer composite (SMPC) on the SJ-17 geostationary satellite on a geostationary orbit since November 2016, a structur...

This study investigated contamination status of eight trace elements (As, Cd, Cr, Hg, Pb, Cu, Zn and Ni) in farmland soils and crops at 535 sites across the Xinjiang Uygur Autonomous Region, Northwest China. Land use types of the sampling sites included vegetable patch, grain field and orchard. Our experimental results indicated all farmland soils were considered as trace element contamination based on the Nemerow comprehensive pollution index (NCPI > 1). However, 91.97% of the crop samples were uncontaminated according to the Chinese Risk Control Standard. Soils from the vegetable patch showed higher pollution level comparison with that from grain field and orchard. Health risks for both non-carcinogenic and carcinogenic risks were calculated through crop ingestion exposure pathway. Grain samples showed highest health risks, followed by melon and fruit, and vegetables. The health risks of crops were mainly driven by Cr and Cd. Crop consumption may pose risks for children but not adults. The source of trace element contamination in the different farmland soils varied and may be attributed to the different agricultural activities. Plant type had a greater influence on the trace element accumulation in crops compared with soil trace element contents and physicochemical properties.

Pneumatic artificial muscles (PAMs) are an extensively investigated type of soft actuator. However, the PAM motions have been limited somewhat to uniaxial contraction and extension, restraining the development of PAMs. Given the current strong interest in soft robotics, PAMs have been gaining renewed attention due to their excellent compliance and ease of fabrication. Herein, under the inspiration of the elephant trunk, a family of bending and helical extensile PAMs (HE-PAMs)/helical contractile PAMs (HC-PAMs) was proposed and analyzed. Through both experiment and analysis, a model of generalized bending behavior of PAMs was built and developed to investigate the properties of axial, bending, and helical PAMs in the same theoretical framework. The topological equivalence and bifurcation were found in the analysis and utilized to explain the behaviors of these different PAMs. Meanwhile, a coupled constant curvature and torsion kinematics model was proposed to depict the motion of PAMs more accurately and conveniently. Moreover, a soft tandem manipulator consisting of bending and helical PAMs was proposed to demonstrate their attractive potential.

Shape memory polymers (SMPs) are a type of smart materials that can return to their original shape in response to external stimuli. Shape memory polymer composites (SMPCs) are created combining SMPs with other functional materials and can provide intelligent deformation with a variety of external stimuli. SMPs are not typically electrically conductive but can be combined with conductive materials to form a continuous internal network that can impart conductivity to the material. When electricity is applied, the current heats the material, resulting in electroactivation. Electroactive SMPCs afford advantages including remote activation, adjustable activation voltage, and insensitivity to environmental factors; they have great potential for application in aerospace, microelectronics, and biomedicine. They can also be used in 4D printing, a new intelligent material-forming technology whose printed products exhibit excellent shape memory performance. This paper reviews the current state of research into various types of electroactive SMPC, compares the relative performance of different types of conductive fillers and material structures, introduces the application of electroactive SMPCs to various fields, presents the advantages and disadvantages of SMPCs, and suggests directions for future development.

Shape memory polymers are smart materials that produce shape changes under external stimulus conditions. Four-dimensional (4D) printing is a comprehensive technology originate from deformable materials and three-dimensional (3D) printing technology. At present, 4D printed shape memory polymers and shape-changing structures have been applied in various fields, especially in the field of biomedical science. 4D printing technology has made a breakthrough of personalized customization in the traditional medical field, providing a new direction for the further development of the biomedical field. In this review, the recent research and development of shape memory polymer, 3D printing technology, 4D printed shape memory polymers and shape-changing structures in biomedical area are present. The examples and applications of 4D printed shape memory polymers and their structures in the area of biomedical are also introduced. Based on 4D printing, stimulated by different conditions, 3D printed objects can be fabricated into various biomedical applications such as cell scaffolds, vascular stents, bone scaffolds, tracheal stents and cardiac stents by different 3D printing techniques. Finally, the application prospects, existing technical restriction and future development directions of 4D printed shape memory polymers and their structures in the biomedical field are summarized.

The co-combustion characteristics of coal, two types of carbonaceous wastes (HDPE and scrap tire) and their blends were investigated in this study via a non-isothermal thermogravimetric met...

3D printing of conductive polymer nanocomposites, which combines the electrical conductivity of nanofillers with customer-designed geometries, is promising for various sensors. However, the single shape of sensors restricts their environmental adaptability if the detecting environment changes. Herein, 3D and 4D printing of poly (D,L-lactide-co-trimethylene carbonate) (PLMC)/CNT nanocomposites with electro-responsive shape-changing capability was achieved by direct ink writing (DIW). The rheological and solvent evaporation capabilities of PLMC/CNT ink were modulated to make it printable. Electrical, mechanical, thermal and shape memory properties were investigated and various structures from micro to macro were constructed. The printed structure showed excellent shape-changing behavior under 25 V within 16 s. Then UV photoinitiators were introduced to trigger hydrogen abstraction reaction to make PLMC chains form cross-linking networks. The modified composite ink was printed into shape-changing liquid sensors. The influence of three solvents and layer thickness on liquid sensitivity was compared. The shape-changing capability helped the sensor maintain a high precision for liquid detection. The sensor in its original, deformed and recovered shape showed similar changing trend of resistance and exhibited excellent repeatability. We envision wide environmental adaptability of using the shape-changing sensor for detecting leakage of various solvents in varying environment.

Shape memory polymers have been studied as the matrix of lightweight self-deployable space structures for decades. The epoxy-based shape memory polymer, which is a potential material for aerospace application, has been tested about their resistance abilities to the ultraviolet radiation and vacuum thermal cycling by using ground-based simulation facilities. The wavelength of ultraviolet radiation is 250–400 nm with not less than five times the solar constant, and the irradiation times are 80, 160, and 240 h, respectively. The vacuum level, temperature range, and cycling times of vacuum thermal cycling are 10−5 Pa; −100°C to +100°C; and 0 cycle and 15, 30, and 45 cycles, respectively. The shape memory polymer specimens are compared for mass loss ratio, chemical compositions, surface morphology, and mechanical properties before and after the ultraviolet radiation and thermal cycling. The experimental results indicate that the glass transition temperature (Tg), mass loss ratio, modulus, and yield and break strength increase after experiencing 240h ultraviolet radiation or 45 thermal cycles, which shows great potential of epoxy-based shape memory polymer in aerospace structures and device applications.

Unclear established standard of bran-fried Atractylodis Rhizoma (BFAR), a commonly used drug in Traditional Chinese Medicine (TCM), compromised its clinical efficacy. In this study, we explored the correlation between color and near-infrared spectroscopy (NIR) feature with content of atractylodin, then established a rapid recognition model for the optimal degree of processing for BFAR preparation. The results of the Pearson analysis indicated that the color values were significantly and positively correlated with atractylodin content. The back propagation artificial neural network algorithm and cluster analysis revealed the color of different BFAR could be accurately divided into three categories; subsequently, the color range for the optimal degrees of stir-frying was established as follows: R[red value (105.79-127.25)], G[green value(75.84-89.64)], B[blue value(33.33-42.73)], L[Lightness (81.26-95.09)].Using NIR, principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and cluster analysis, three types of BFAR were accurately identified. The prediction model of atractylodin content was established using partial least squares regression analysis. The R2 of the validation set was 0.9717 and the root mean square error was 0.026. In the color judgment model, the processing degree of 8 batches of BFAR from the market is inferior. According to the NIR judgment model, the processing degree of all samples from the market is inferior. In conclusion, the best fire degree of BFAR can be identified quickly and accurately based on our established model. It is a potential method for quality evaluation of Chinese Materia Medica processing.

In this study, we provide large-sample evidence on how corporate in-house human capital investments in accounting affect earnings management. We construct a dataset of more than 411,000 individual-years of corporate accountants between 2009 and 2015 and measure firms’ accounting human capital using the proportion of their accountants with Big N work experience or a CPA designation. We find that firms with higher accounting human capital have a lower probability of accounting irregularities, lower discretionary accruals, better internal control quality, and fewer unintentional accounting errors. The results hold when we control for potential endogeneity by using the staggered adoption of the CPA mobility law and the number of top accounting undergraduate programs near the firm as instrumental variables for accounting human capital. We further find that firms with higher accounting human capital exhibit stronger market reactions to earnings news and pay lower audit fees, confirming that external stakeholders perceive these firms as having better financial reporting quality.

Inspired by the accommodation mechanism of the human eye, several soft tunable lenses have been fabricated and demonstrated the capability of controllable focus tuning. This paper presents a computational model of a dielectric elastomer-based soft tunable lens with a compact structure that is composed of a lens frame, two soft films, and the optically transparent fluid enclosed inside. The two soft films, respectively, serve as the active film and passive film. The active film is a dielectric elastomer film and can be coated with the annular electrode or circular electrode. The deformation of the lenses with both electrode configurations can all be formulated by a boundary value problem with different boundary conditions and be solved as the initial value problem using the shooting method. Two common failure modes of loss of tension and electrical breakdown are considered in the calculation of the lens. The computational results can well fit the experimental data. The focus tuning performances as well as the distributions of stretches, stresses, and electric field in the active films of the lenses with two different electrode configurations are compared. The influences of several parameters on the performances of the lenses are discussed, such that the tunable lens can be designed to have maximum focal length change or to be optimized based on different application requirements.

Smart, deformable, and transparent electrodes are a significant part of flexible optoelectronic devices. In this work, a novel approach to making highly transparent, smooth, and conductive shape memory polyimide hybrids has been proposed. Colorless shape memory polyimide (CSMPI) with high optical transparency and high heat resistance is served as the substrate for flexible electronic devices for the first time. A hybrid (Au/Ag) metal grid electrode embedded in CSMPI (BMG/CSMPI) is first fabricated via self-cracking template and solution-coating, the advantages of which include ultrasmooth surface, superior mechanical flexibility and durability, strong surface adhesion, and excellent chemical stability due to the unique embedded hybrid structure. The resulting white polymer light emitting diodes (WPLEDs) based on BMG/CSMPI with shape memory effect are active and deformable, and are converted from 2D device into 3D devices depending on its variable stiffness characteristics. The deformed 3D devices could actively recover to the original shape upon heating. Furthermore, ultrathin and flexible 3D optoelectronic devices fabricated using shape memory polymers can promote the development of advanced optoelectronic applications in the future.

Climate change has a distinct impact on agriculture in China, particularly in the northeast, a key agriculture area sensitive to extreme hydroclimate events. Using monthly climate and agriculture data, the influence of drought on maize and soybean yields&mdash, two of the main crops in the region&mdash, in northeast China since 1961 to 2017 were investigated. The results showed that the temperature in the growing season increased by 1.0 &deg, C from the period 1998&ndash, 2017 to the period 1961&ndash, 1980, while the annual precipitation decreased slightly. However, precipitation trends varied throughout the growing season (May&ndash, September), increasing slightly in May and June, but decreasing in July, August and September, associated with the weakening of the East Asian summer monsoon. Consequently, the annual and growing season drought frequency increased by 15%, and 25%, respectively, in the period 1998&ndash, 2017 relative to the period 1961&ndash, 1980. The highest drought frequency (55%) was observed in September. At the same time, the drought intensity during the growing season increased by 7.8%. The increasing frequency and intensity of drought had negative influences on the two crops. During moderate drought years in the period 1961&ndash, 2017, 3.2% and 10.4% of the provincial maize and soybean yields were lost, respectively. However, during more severe drought years, losses doubled for soybean (21.8%), but increased more than four-fold for maize (14.0%). Moreover, in comparison to the period 1961&ndash, 1980, a higher proportion of the yields were lost in the period 1998&ndash, 2017, particularly for maize, which increased by 15% (increase for soybean was 2.4%). This change largely depends on increasing droughts in August and September, when both crops are in their filling stages. The impact of drought on maize and soybean production was different during different growth stages, where a strong relationship was noted between drought and yield loss of soybean in its filling stage. Given the sensitivity of maize and soybean yields in northeast China to drought, and the observed production trends, climate change will likely have significant negative impacts on productivity in the future.

An expert workshop focusing on per- and poly-fluoroalkyl substances (PFAS) was held in Adelaide, South Australia, Australia in September 2019 following the 8th International Contaminated Site Remediation Conference — CleanUp 2019. The workshop was organised by the Cooperative Research Centre for Contamination and Remediation of the Environment (CRC CARE) and was chaired by Professor Ravi Naidu, CEO and Managing Director of CRC CARE and Director of the Global Centre for Environmental Remediation at the University of Newcastle, NSW. The purpose of the workshop, which was attended by more than 50 experts in the field of contaminated land assessment and management, was to discuss the current state of play and research needs relating to PFAS contaminated sites. This paper provides a summary of the discussions and conclusions and lists actions and needs that the expert group identified as critical for pursuing successful PFAS management and remedy approaches. This paper is intended to capture the shared information, comments, and current thinking related to PFAS challenges and research needs as identified by the group of expert participants; the write up is not intended to be a complete dissertation on the science and work that has been carried out. With a fast-evolving subject and increased government and public attention on PFAS presence in the environment, the group was convened with the objective of providing value in contributing to solutions to the PFAS challenges that are faced both in Australia and internationally. The text contained herein provides references to observations and methods that the experts drew on in their discussions and in support of their commentary; documentation of the original references was not provided, and the reader should consult the scientific literature if further information and confirmation of observations is required. Following a brief on the background to PFAS challenges, the paper focusses on research gaps identified by experts with focus on Australian soils and groundwater including climatic patterns, an overview of PFAS research in Australia with emphasis on: • Regulatory • Analytical considerations • Ecological and Human Health Risks • Fate and Transport • Remediation and Risk Management.

4D printing adds time as the fourth dimension to 3D printing, which has been actively explored in the biomedical field to develop patient-specific implants due to the ease of manufacturing complex architectures and the capability of dynamic transformations. However, the 4D printing filament used for fused deposition modeling (FDM) is quite limited. Here, 4D printing shape memory polybutylene succinate/polylactic acid (PBS/PLA) composite filament is prepared. The mechanical properties, surface morphology, and shape memory performances of the printed specimens are investigated. Besides, graphene oxide functionalized PBS/PLA shows attractive photothermal properties under near-infrared (NIR) irradiation, and a dynamic, remote, and accurate controlled 4D transformation of a porous scaffold is exhibited. As the first demonstration of 4D printing filament of PBS/PLA for FDM, this work shows its promising application prospects in tissue engineering, photothermal therapy, etc. Additionally, NIR-triggered 4D transformation solves the problem that the conventional thermal-trigger transformation process is difficult to control.

Shape memory polymers (SMPs) as a class of smart materials, can remember various shapes and return to their original shapes upon external stimuli. 4D printing that is the combination of 3D printing and SMPs has been used for fabrication of various SMPs in many areas of science and technology. At present, 4D printing technology plays an important role and shows promising applications in biomedical field. 4D printing breaks through the technical bottleneck of customization in traditional medical field and provides a new opportunity for the further development of biomedical field. In this article, we review the research progress of SMPs, 3D printing technology and 4D printed SMPs used in biomedical science. Moreover, we introduce some typical biomedical applications of 4D printing of SMPs. Furthermore, we summary the application prospects, existing problems and future development direction of 4D printed SMPs in biomedical field.

Recently, shape memory polymers (SMPs) with high optical transmittance have been paid great attentions to endow the flexible optoelectronics with shape memory functions. Herein, a low colored and transparent shape memory copolyimide (SMcoPI) is obtained by suppressing the charge transfer complex interactions. The optical transmittance of the synthesized SMcoPI film could reach at ∼86% at the wavelength of 450 nm, far higher than the nearly zero optical transmittance of yellow and brown Kapton H. The better optical transparency could be attributed to the loose molecular chain arrangements induced by the meta-substituted groups and flexible ether linkages. The glass transition temperature (Tg) range of the synthesized SMcoPI films is from 179 °C to 220 °C, which is higher than that of reported optically transparent SMPs. The effective decomposition temperature at the weight loss of 5 wt% is 517 °C, showing excellent thermal stability. The SMcoPI also demonstrated good shape memory behaviors with high shape recovery ratio (Rr, >96%) and shape fixity ratio (Rf, >97%). In addition, the SMcoPI could maintain high optical transmittance, good thermostability and excellent shape memory behaviors after the ground-stimulated space thermal cycling test for 250 h. The synthesized SMcoPI has application potentials in high temperature areas or optoelectronic devices.

Hepatocellular carcinoma (HCC) is a deadly malignancy with limited treatment options. Recently, it was found that Dasatinib treatment led to synthetic lethality in c‐Myc high‐expressing human cancer cells due to inhibition of p‐Lyn. Overexpression of c‐Myc is frequently seen in human HCC. We investigated the sensitivity to Dasatinib in vitro using HCC cell lines and in vivo using c‐Myc mouse HCC model. We found that HCC cell line responsiveness to Dasatinib varied significantly. However, there was no correlation between c‐Myc expression and IC 50 to Dasatinib. In c‐Myc‐induced HCC in mice, tumors continued to grow despite Dasatinib treatment, although the eventual tumor burden was lower in Dasatinib treatment cohort. Molecular analyses revealed that Dasatinib was effective in inhibiting p‐Src, but not p‐Lyn, in HCC. Importantly, we found that in HCC cell lines as well as c‐Myc mouse HCC, Dasatinib treatment induced up regulation of activated/phosphorylated (p)‐focal adhesion kinase(FAK). Concomitant treatment of HCC cell lines with Dasatinib and FAK inhibitor prevented Dasatinib‐induced FAK activation, leading to stronger growth restraint. Altogether, our results suggest that Dasatinib may have limited efficacy as single agent for HCC treatment. Combined treatment with Dasatinib with FAK inhibitor might represent a novel therapeutic approach against HCC.

Shape memory polymers (SMPs) are a class of active, deformable materials that can switch between a temporary shape, which can be freely designed, and their original shape. With their large deformation, low density, various stimulation methods, good biocompatibility and other advantages, SMPs have become widely accepted as smart materials. However, SMPs have many limitations and weaknesses that are exposed in engineering applications. For this reason, the significance of SMP composites (SMPCs) has been analyzed in terms of four aspects: reinforcement, innovation and improvement of driving methods, the creation of specific deformations and the creation of multifunctional materials. We then introduce the constitutive theory of SMPs and the post-buckling analysis of SMPCs. Afterward, we introduce the extensive applications of SMPCs in the fields of aerospace, biomedical equipment, self-finishing, deformable mandrels and the 4D printing of active origami structures, demonstrating their ability to undergo active driving and deformation, their adaptiveness, their ease of transport and their rapid production capacity, which fully demonstrate the unique advantages of SMPs in solving application problems. Finally, the advantages and disadvantages of SMPCs in applications are summarized, and the prospects for new SMPCs and new SMPC structures are described.

This work describes the out-of-plane bending performance, shape memory effect and variable stiffness of a zero Poisson’s ratio honeycomb structure made from the tessellation of re-entrant hexagons and thin plates. The re-entrant hexagons are fabricated with ABS plastics and the thin plates are made from thermosetting styrene-based shape memory polymers (SMPs). The hexagons and the SMP plates are bonded within the groove joints in the thickness direction of the re-entrant cell units. The re-entrant hexagons generate out-of-plane flatwise compressive stiffness and in-plane compliance, while the SMPs thin plates support out-of-plane flexibility, the shape memory effect and a variable bending stiffness. Because the ABS plastics possesses a significantly higher glass transition temperature than the SMPs, the ZPR honeycomb structure features a higher out-of-plane flexibility when the environmental temperature rises from room temperature to the glass transition temperature of the SMPs. On the contrary, the flatwise compressive stiffness of the ZPR honeycomb remains unchanged. Three-point bending tests have also been performed to determine the out-of-plane bending performance of the ZPR structures at varying temperatures.

Shape memory polymers (SMPs) are a kind of smart material that can present active shape-changing behavior under external stimulus. Shape-changing structures based on SMPs have shown great potential to be applied in the areas ranging from aerospace to biomedicine. However, the design flexibility of such smart structures is restricted by conventional processing technique. 4D printing as the additive manufacturing technique for smart materials provides the new opportunities for the further development of SMPs. In this paper, we first reviewed the research progress about 4D printing of SMPs. Then, the investigation about the application of SMPs-based 4D structures was summarized. At last, we discussed the existing problems and further development of 4D printing of SMPs.

This paper details a novel morphing composite propeller (MCP) to improve the performance for marine vehicles (MVs). A MCP is designed with an active rotatable flap (ARF) to change the blade’s local camber with flap rotation. A piezo-stack actuator has been connected with one transmission mechanism housed in the propeller blade to push the ARF to obtain various configuration of the MCP. A commercial Finite Element (FE) software ANSYS Fluent was employed to analyse and simulate the hydrodynamics around the propeller with the ARF ranging from −5° to +5° and the advance speeds ranging from 1.08 to 2.52 m/s. Finally, the FE results has been used to predict improved performances of the MCP and found the morphing composite propeller configuration has improved the efficiency by 1.1% while improving the structural durability.

Objective To investigate the activity and safety of carfilzomib-containing combinations as frontline therapy for multiple myeloma. Methods We searched published carfilzomib reports for newly diagnosed multiple myeloma. Results Thirteen trials were identified, covering 704 subjects. Pooled analysis showed that carfilzomib combinations as frontline therapy for multiple myeloma attained an impressive at least complete response (≥CR) rate of 21%, at least very good partial response (≥VGPR) rate of 68%, overall response rate (ORR) of 94%. The ≥CR rates of 18% pre-SCT were increased to 43% of post-ASCT, and 64% of postconsolidation (P

This work presents a novel negative Poisson's ratio honeycomb design composed by two parts (a re-entrant hexagonal component and a thin plate part) that provide separate contributions to the in-plane and out-of-plane mechanical properties. The re-entrant hexagons provide the in-plane negative Poisson's ratio, the in-plane compliance and the out-of-plane compressive strength, while the thin plate part connecting the re-entrant hexagonal section bears the large out-of-plane flexibility. This paper focuses on the in-plane mechanical properties of the auxetic cellular structure. Theoretical models related to the in-plane uniaxial tensile modulus, the shear modulus, and the Poisson's ratios have been built and validated using the finite element techniques. The in-plane behavior of the honeycomb has also been investigated against the geometrical parameters of the unit cell using a parametrical analysis. The theoretical and numerical models illustrate good agreement and show the potential of its application in morphing structures. We also provide a benchmark of the auxetic configuration proposed in this work against negative Poisson's ratio topologies from open literature.

According to the theories of traditional Chinese medicine, spleen deficiency often leads to diarrhea, and deep-fried Atractylodis Rhizoma (DAR) is commonly used for the treatment. However, the association between spleen deficiency and diarrhea remains unclear. The present study aimed to investigate the therapeutic effect of DAR for the treatment of diarrhea caused by spleen deficiency and analyze the related mechanisms. It was found that a high dose group of an ethanolic extract of deep-fried Atractylodis Rhizoma (EEDAR-H) significantly inhibited weight loss, diarrhea, and pathological changes in colon tissue induced by rhubarb. EEDAR-H was found to significantly reduce the level of intestinal inflammatory cytokines and increase the expression of gastrointestinal motility hormones. In addition, EEDAR-H significantly increased the expression of aquaporin 3 (AQP3) and aquaporin 8 (AQP8) and restored abnormal water metabolism, Shen-Ling-Bai-Zhu-San (SLBZS) induced the same effect as EEDAR-H. Additional tests on the mechanism found that EEDAR-H and SLBZS promoted the integrity of the intestinal barrier. Both significantly increased the expression of the tight junction protein ZO-1 and Occludin, inhibited the phosphorylation of p38MAPK and MLC, and significantly reduced the expression levels of PAR-2. Analysis of the gut microbiota indicated that overall changes in its structure were reversed after treatment with EEDAR-H or SLBZS, in addition to significant modulation of the abundance of different phyla. At the genus level, EEDAR-H or SLBZS significantly reduced the levels of potential pathogens and increased those of beneficial bacteria.

The Tibetan plateau is one of the most sensitive areas in China and has been significantly affected by global warming. From 1961 to 2017, the annual air temperature increased by 0.32 &deg, C/decade over the Tibetan Plateau, which is the highest in the whole of China. Furthermore, this is a trend that is projected to continue by 0.30 &deg, C/decade from 2018 to 2050 due to global warming using the Regional Climate Model version 4 (RegCM4). The increased temperature trend in recent decades has been highest in winter, which has been positive for the safe dormancy of winter wheat. In order to investigate agricultural adaptation to climate change in the Tibetan plateau, we used the World Food Studies (WOFOST) cropping systems model and weather data from the regional climate model RegCM4, to simulate winter wheat production in Guide county between 2018 and 2050. The simulated winter wheat potential yields amounted to 6698.3 kg/ha from 2018 to 2050, which showed the wheat yields would increase by 81%, if winter wheat was planted instead of spring wheat in the Tibetan Plateau with the correct amount of irrigation water. These results indicate that there are not only risks to crop yields from climate change, but also potential benefits. Global warming introduced the possibility to plant winter wheat instead of spring wheat over the Tibetan Plateau. These findings are very important for farmers and government agencies dealing with agricultural adaptation in a warmer climate.

Three-dimensional (3D) printing with conductive polymer nanocomposites provides an attractive strategy for the "on-demand" fabrication of electrical devices. This paper demonstrates a family of highly conductive multimaterial composites that can be directly printed into ready-to-use multifunctional electrical devices using a flexible solvent-cast 3D printing technique. The new material design leverages the high aspect ratio and low contact resistance of the hybrid silver-coated carbon nanofibers (Ag@CNFs) with the excellent 3D printability of the thermoplastic polymer. The achieved nanocomposites are capable of printing in open air under ambient conditions, meanwhile presenting a low percolation threshold (i.e., 2.1 × 105 S/m) without any post-treatments. We further find that this hybrid Ag@CNF-based nanocomposite shows a quick and low-voltage-triggered electrical-responsive shape memory behavior, making it a great candidate for printing electroactive devices. Multiple different as-printed Ag@CNF-based highly conductive nanocomposite structures used as high-performance electrical devices (e.g., ambient-printable conductive components, microstructured fiber sensors, flexible and lightweight scaffolds for electromagnetic interference shielding, and low-voltage-triggered smart grippers) are successfully demonstrated herein. This simple additive manufacturing approach combined with the synergic effects of the multimaterial nanocomposite paves new ways for further development of advanced and smart electrical devices in areas of soft robotics, sensors, wearable electronics, etc.

Colorless shape memory polyimide (CSMPI) has potential applications in broad fields, especially in advanced optoelectronics due to the excellent optical transparency, shape memory effect and high temperature resistance. In this work, CSMPI prepared by high flexible dianhydrides and fluorine-containing diamines has excellent optical transparency, shape memory properties and high temperature resistance. High flexible dianhydrides that makes the molecule chains more easily twisted and tangled to form physical crosslinking points is favorable for possessing great shape memory property. The fluorine-containing diamines effectively destroyed the highly conjugated molecular structure and inhibited the formation of CTC, ensuring the CSMPI with excellent optical transparency. The effects of monomer ratio and imidization temperature on the molecular structure and properties were discussed. The CSMPI film possesses a higher glass transition temperature (Tg) of 234 °C, compared to the reported transparent shape memory polymers (SMPs). Most importantly, the transmittance of CSMPI film is 87~90% at 450~800nm, meeting the requirements of heat resistance and transmittance of the substrate. Both shape recovery and shape fixity are over 97%. Flexible and colorless CSMPI films has potential applications in broad fields, especially in advanced optoelectronics, such as flexible substrates for OLED and OPV devices, etc.

Guided wave (GW) plays an important role in nondestructive testing and structural health monitoring. In the general Lamb wave inspection, difference between the baselines and the measured signals are used for structural damage evaluation. However, the baselines are unavoidably influenced by operational and environmental conditions leads to an increased error during inspection. To deal with this issue, this paper presents a base-line free method based on the mode conversion and reciprocity principle of Lamb wave. Once the defect is asymmetrical with respect to the transducer pair (two identical piezoelectric transducers used as actuator and receiver respectively), the elastic wave path length of the converted mode will be different, resulting in failing of the reciprocity principle. By processing the signals received by the transducer pair and extracting the time parameters of the wave packets in mode conversion signals, the defect can be localized. Results from the signals generated by numerical simulation are presented to verify the feasibility of the method, and the effectiveness of the proposed baseline-free method is demonstrated with experimental results.

Exposure to per- and polyfluoroalkyl substances (PFASs) is a major concern due to their widespread occurrence and adverse health outcomes. The possible binding of PFASs to peroxisome proliferator-activated receptors (PPARs) and nuclear receptors raises concerns that PFASs may impact cholesterol levels in human. In this study, the U.S. National Health and Nutrition Examination Survey (NHANES) data were employed to address the temporal trend for PFAS concentrations in biomonitoring and associations between cholesterol levels and PFAS exposure. Compared to the PFAS levels in 2003–2004, the median perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), perfluorohexane sulfonic acid (PFHxS) and perfluorononanoic acid (PFNA) levels in human serum in 2013–2014 decreased from 3.7 to 1.8 ng/mL, 19.2–4.7 ng/mL, 1.7 ng/mL to 1.3 ng/mL and 0.8 ng/mL to 0.6 ng/mL, respectively. Also, an estimate of 1.5 ± 0.7 mg/dL (95% confidence interval: 0.2 − 2.8) and 0.4 ± 0.2 mg/dL (95% confidence interval: 0.1 – 0.6) total cholesterol increases for unit PFOA and PFOS increase (ng/mL), respectively. By using hybrid approach, RfDs were estimated to be 2.0 ng PFOS/kg per day and 0.8 ng PFOA/kg per day. However, it should be cautious when using proposed RfDs based on data obtained from cross-sectional datasets, especially evidence based on data originating from experimental or animal studies is still controversial.

Here, a co-extrusion-based 3D printing technology was applied to integrally manufacture continuous fiber reinforced composite trapezoidal corrugated sandwich structures (CFRCTCSs) with shape memory capability. The theoretical models were developed to analyze the bending performance and failure behavior of the 3D printed CFRCTCSs with various geometric configurations and verified by three-point bending tests. Good agreement between the predictions and the experimental measurements was achieved. Considering four dominant failure modes including face yielding, face buckling, core shear failure and indentation collapse, the failure maps based on the analysis models were constructed to highlight the failure mechanism of CFRCTCSs and provide a practical guide for the design of lightweight sandwich structures. Shape recovery tests were performed to confirm the shape memory capability of the 3D printed CFRCTCSs. Finally, the comparison of the bending properties with several competing structures indicates that the 3D printed CFRCTCSs possess the potential to provide new opportunities for lightweight systems and multifunctional applications.

Effects of sewage sludge-derived biochar and its precursor on the accumulation of metals (Cd, Cu, Pb and Zn) in soil and their uptake by plants in a 1-year field experiment involving corn-radish rotation were comparatively studied. The human health risks were assessed, and the safe application period of biochar were estimated. The application of biochar, compares to sewage sludge, significantly enhanced the radish yield (p 0.05; not corn yield) and significantly reduced the accumulation of metals in both plants (p 0.05), especially the annual application at ≤15 t ha

Pneumatic artificial muscles (PAMs) are compliant fluidic actuators, usually consisting of a tubular bladder, a braided sleeve and end fittings. PAMs have been studied extensively by researchers; however, most previous researches are focused on the axial PAMs. Herein, a pair of nonlinear models were developed based on the principle of virtual work and the force balance analysis. And the two models are applicable to both bending extensile PAMs (BE-PAMs) and bending contractile PAMs (BC-PAMs). In this study, a cyclic bending moment loading experimental method were proposed and conducted with BE-PAMs and BC-PAMs to characterize their deformation and actuation performance and draw their overall relationships of actuation moment to bending curvature and inner pressure. With the experimental results, the validation analysis was carried out to demonstrate the validity of the two models. The energy model can get higher accuracy, while the force balance model could provide more details of the interior and interaction stress conditions. The combination of both can promote the comprehension of non-axial bending PAMs. Moreover, two three-finger soft grippers and a humanoid hand based on BE-PAMs and BC-PAMs were built and tested to investigate their performance on gripping objects. The BE-PAM gripper showed more accommodative gripping performance, whereas, the BC-PAM gripper owned higher gripping force. The humanoid hand combining the merits of both showed excellent flexibility, adaptability and decent load capability in gripping object with various sizes, shapes and materials.

A traditional aircraft is optimized for only one or two flight conditions, not for the entire flight envelope. In contrast, the wings of a bird can be reshaped to provide optimal performance at all flight conditions. Any change in an aircraft’s configuration, in particular the wings, affects the aerodynamic performance, and optimal configurations can be obtained for each flight condition. Morphing technologies offer aerodynamic benefits for an aircraft over a wide range of flight conditions. The advantages of a morphing aircraft are based on an assumption that the additional weight of the morphing components is acceptable. Traditional mechanical and hydraulic systems are not considered good choices for morphing aircraft. “Smart” materials and structures have the advantages of high energy density, ease of control, variable stiffness, and the ability to tolerate large amounts of strain. These characteristics offer researchers and designers new possibilities for designing morphing aircraft. In this article, recent developments in the application of smart materials and structures to morphing aircraft are reviewed. Specifically, four categories of applications are discussed: actuators, sensors, controllers, and structures.

In the study of mine GIS index optimization of mining decision support system, in order to reduce the overlap between the index nodes, in this paper we propose the intensity of polygon to ensure the index nodes have good geometry. In this paper, we also put forward artificial fish swarm clustering based on Voronoi diagram (AFSCV) and apply the AFSCV to mine GIS index splitting algorithm. In the end, we give the optimization rules of AFSCV. In order to verify the effectiveness of our algorithm we compare our method with traditional methods, the experimental results show that our method can improve the query performance of mine GIS database and greatly reduce the overlap which generates from reinsert after the index node split.

Lead (Pb) poisoning in children is a major public health catastrophe worldwide. This report summarises both exposure pathways and blood Pb levels in children below 7 years of age and adults (above 18 years) from the Adudu community living near a lead-zinc mine in Nasawara, Nigeria. The average and median blood Pb levels in children and adults were 2.1 and 1.3 μg/dL, 3.1 and 1.8 μg/dL, respectively. However, Pb in 14% of adults' blood exceeded 5 μg/dL, which is the recommended threshold blood Pb concentration in adults as established by the Centers for Disease Control and Prevention (CDC). Furthermore 68% of adults' blood exceeded blood Pb action level of 2 μg/dL. For children, 11.4% and 31% of the blood samples exceeded 5 μg/dL and 2 μg/dL, respectively, while no safe blood Pb level in children has been recommended. In Nasawara, a significant difference (p

Blending waste biomass for co-pyrolysis is generally regarded as a promising method for reduced-volume, value-added, and hazard-free treatment of sewage sludge. Hence, a comparison was made of the co-pyrolysis of sewage sludge with rice husk and with bamboo sawdust (1:1, w/w) at 400 and 700 °C and the properties and behaviors of selected metals in the corresponding biochars. Biochar produced by co-pyrolysis with both biomass wastes had larger (5 × 5 rectangle) aromatic clusters than did the sewage sludge biochar (4 × 4 rectangle) using the rectangle-like model on the basis of biochar molar H/C ratio, indicating increased aromaticity of the co-pyrolyzed biochars. Moreover, the molar O/C ratio of the sewage sludge-bamboo biochar was much lower than that of the sewage sludge-husk biochar, especially after pyrolysis at 700 °C (0.02 vs 0.27), suggesting greater recalcitrance to ageing. Co-pyrolysis of sewage sludge with husk invariably resulted in a higher percentage of metals studied in the residual fraction than co-pyrolysis with sawdust at the same temperature, leading to a lower risk index (14.2) because of the maximum metal encapsulation in the sewage sludge-husk biochar at 700 °C. Overall, co-pyrolysis of sewage sludge with husk provided higher metal immobilization but apparently lower biochar stability than co-pyrolysis with sawdust. These results provide an alternatively practical strategy for the safe disposal of sewage sludge and biomass wastes.

Since wind turbines operate in a complex environment for long term, the fatigue behavior of the blades can be influenced by wind, illumination, moisture, temperature, and so forth. For wind turbine blade manufacturers, the determination of their fatigue limit before delivery is necessary and fatigue acceleration experiments usually require a lot of labor and experimental costs. As a machine learning paradigm, deep learning focuses on the inherent hierarchical models of data and has achieved notable success in computer vision, speech recognition, natural language processing, etc. Aimed at reducing the time and the costs during fatigue tests, this paper studies a training-based method for wind turbine blade stiffness prediction using time series stiffness data under fatigue tests. Based on deep learning methods including convolutional neural network, long-short term memory network and the hybrid network, the residual stiffness of the blade with fatigue life under fatigue tests is obtained by combining the fatigue historical data. The obtained results show that the developed models can learn features directly from raw stiffness data and complete the residual stiffness prediction in succession. White Gaussian noise with different signal-to-noise ratios is also added to all stiffness data to demonstrate the models’ feasibility of stiffness prediction.

In this paper, a comprehensive method is proposed to synergistically optimize the configuration and operation strategy of combined cooling, heating and power (CCHP) systems, considering configuration and strategy interact with each other. The mathematical model is established based on the energy flow and the energy balance relationship of CCHP system and traditional separate (SP) system with multi-objective evaluation criterion. The optimization based on an industrial park in Shanxi is carried out to find the optimal configuration and corresponding strategy. The results show that the optimized CCHP system outperforms the SP system in cost saving, energy consumption saving and CO2 emission reduction with the saving ratio of 17.37%, 33.72% and 55.76% respectively throughout the year. An analysis of the factors that affect the performance of CCHP systems is adopted in terms of: (1) price of electricity and gas; (2) the ratio of thermal load to waste heat; and (3) load rate of gas turbine. This paper may provide some new ideas for the optimization and performance improvement of CCHP systems.

4D printing has attracted academic interest in the recent years because it endows static printed structures with dynamic properties with the change of time. The shapes, functionalities, or properties of the 4D printed objects could alter under various stimuli such as heat, light, electric, and magnetic field. Briefly, 4D printing is the development of 3D printing with the fourth dimension of time. Among the fabrication techniques that have been employed for 4D printing, the direct ink writing technique shows superiority due to its open source for various types of materials. Herein, the state‐of‐the‐art achievements about the topic of 4D printing through direct ink writing are summarized. The types of materials, printing strategies, actuated methods, and their potential applications are discussed in detail. To date, most efforts have been devoted to shape‐shifting materials, including shape memory polymers, hydrogels, and liquid crystal elastomers, showing great prospects in areas ranging from the biomedical field to robotics. Finally, the current challenges and outlook toward 4D printing based on direct ink writing are also pointed out to leave open a significant space for future innovation., 4D printing has attracted wide attention due to its potential to extend the design space beyond complex geometries with the change of time. Recent achievements in 4D printing based on the direct ink writing technique are reviewed in detail, including types of materials, their functionalities, and applications. Current challenges, future developing trends, and directions are also presented.

A tip-loaded deployable truss (TLD truss) with gusseted base and auxiliary support frame has been developed to carry a heavy tip load. This paper presents details in a sequence of material characterization, structure description, finite element analysis, and mechanical experiments. It uses carbon fabric reinforced cyanate-based shape memory polymer composite as the driving source to unfold the packaged truss. The glass transition temperature of the shape memory polymer composite is 195 °C. The recovery moment of the composite increases first and then decreases with the increase of the recovery ratio. Three different structural forms have been compared by modal analysis and swept sine simulations; results show that the TLD truss with a tip load of 1.3 kg has the highest stiffness. Thus it was selected and manufactured to carry out a series of experiments, including swept sine vibration, acceleration and shock testings of the packaged TLD truss, and modal testing of the deployed TLD truss. No damage was observed, indicating the TLD truss has a relatively high stiffness and could withstand the required mechanical environment.

4D printing provides more design freedom for the static structures by adding time dimension in 3D printing. In recent years, some types of active origami structures fabricated by 4D printing have been developed, but most of these structures were thin sheets, which may lead to poor mechanical properties of the structures. In this work, honeycomb sandwich structures were designed to improve the stiffness and recovery force of origami structures. The in-plane tension, in-/out-plane three-point bending, recovery force and shape memory performances of the sandwich structures were investigated. The shape fixity and shape recovery ratio of the active sandwich structures were 98% and 99%, indicating excellent shape memory performance. The application of the sandwich structures in thermally activated self-deployment origami structures was verified. These developed origami structures have the advantages of large area change ratio and fast response speed, demonstrating the great application prospects in the space deployable structures such as antennas.

Proper fatigue life prediction is very essential for the safety of structural design, operation, and maintenance. This paper presents a modified composite fatigue damage model considering stiffness evolution aimed at simulating the three periods of damage development. The proposed model containing two parameters avoids the trouble and complexity of multiparameter. Meanwhile, the stiffness degradation model and the life prediction model of two-stage loading have a good agreement and high fitting accuracy with experiment data considering different types of composites. For better assessment, four existing models are also compared, demonstrated that the values predicted by the modified model are much closer to the experimental data upon most occasions. Moreover, this model is applied to the fatigue test of a full-size wind turbine blade to show its availability and future prospect on real-time monitoring in service.