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PurposeThe safety management of construction machines is of primary importance. Considering that traditional construction machine safety monitoring and evaluation methods cannot adapt to the complex construction environment, and the monitoring methods based on sensor equipment cost too much. This paper aims to introduce computer vision and deep learning technologies to propose the YOLOv5-FastPose (YFP) model to realize the pose estimation of construction machines by improving the AlphaPose human pose model.Design/methodology/approachThis model introduced the object detection module YOLOv5m to improve the recognition accuracy for detecting construction machines. Meanwhile, to better capture the pose characteristics, the FastPose network optimized feature extraction was introduced into the Single-Machine Pose Estimation Module (SMPE) of AlphaPose. This study used Alberta Construction Image Dataset (ACID) and Construction Equipment Poses Dataset (CEPD) to establish the dataset of object detection and pose estimation of construction machines through data augmentation technology and Labelme image annotation software for training and testing the YFP model.FindingsThe experimental results show that the improved model YFP achieves an average normalization error (NE) of 12.94 × 10–3, an average Percentage of Correct Keypoints (PCK) of 98.48% and an average Area Under the PCK Curve (AUC) of 37.50 × 10–3. Compared with existing methods, this model has higher accuracy in the pose estimation of the construction machine.Originality/valueThis study extends and optimizes the human pose estimation model AlphaPose to make it suitable for construction machines, improving the performance of pose estimation for construction machines.

Biomineralization of CaCO

Biomineralization of CaCO3 by microorganisms is a well-documented process considered applicable to concrete self-healing and metal bioremediation. Urea hydrolysis is the most widely explored and efficient pathway regarding concrete bioprotection. However, the potential of fungi has received relatively little attention compared to bacteria. In this work, we show that Fusarium cerealis, Phoma herbarum and Mucor hiemalis, isolated from concrete, could produce 828.6–941.3 mg L−1 ammonium‑nitrogen in liquid media through urea hydrolysis indicating significant urease activity, and could grow in moderate (pH 8.3) or even extremely alkaline (pH 10.6) conditions. After culture in media containing 50 mM CaCl2, at least 48.8% Ca2+ was removed from solution by the selected fungi as calcite. The accumulation of Ca by the biomass was around 83.64–114.21 mg g−1. In addition, all fungi could mediate strontium carbonate formation with F. cerealis processing the highest ability for Sr removal, with ~61% added Sr being removed from solution. Scanning electron microscopy showed carbonate biominerals were encrusted on hyphae or aggregated in fungal pellets. When equivalent concentrations of Ca2+ and Sr2+ were supplemented to the media, CaCO3 with incorporated Sr formed with F. cerealis and M. hiemalis, and Sr(Sr, Ca)(CO3)2 with P. herbarum. Our results demonstrate the potential of fungi in providing carbonate coatings for concrete surfaces and simultaneous immobilization of Sr. We anticipate our work will promote further practical field research on porous cementitious materials protection by fungi and immobilization of potentially toxic metals from metal-laden ingredients, such as fly ash and granulated ground blast furnace slag.

The purpose of this work was to assess the effect of different packaging methods on the shelf life and bacterial communities of roast duck meat. Samples were packaged under the following five conditions: overwrapped packaging (OWP), 100% N2 (100% N2-MAP), 30% CO2/70% N2 (30% CO2-MAP), 50% CO2/50% N2 (50% CO2-MAP), and 0.4% CO/30% CO2/69.6% N2 (CO-MAP). Physicochemical and microbiological parameters were monitored during 14 days of chilled storage (0–4 °C). Results showed that MAP samples obtained higher and more stable redness, better sensory scores, and lower lipid oxidation, compared with OWP, in which CO-MAP samples had the lowest TBARS values (0.13–0.22 MDA/kg) during storage. Moreover, 30% CO2-MAP, 50% CO2-MAP, and CO-MAP effectively retarded the onset of bacterial spoilage and extended shelf life by 7 days compared with 100% N2-MAP and OWP treatments. Additionally, bacterial succession was significantly affected by the gas composition used in the packages, especially the dominant biota at the end of storage, which played an important role in the spoilage of roast duck meat under specific packaging. On day 14, Pseudoalteromonas spp., Lactobacillus spp., and Pseudomonas spp. became the most predominate genera in OWP, 100% N2-MAP, and 50% CO2-MAP, respectively. Notably, Vibrio spp. was dominant in both 30% CO2-MAP and CO-MAP, indicating 0.4% CO did not exert a further inhibitory effect on this genus. Additionally, the growth inhibition of Pseudoalteromonas spp., Lactobacillus spp., and Leuconostoc spp. by high CO2 concentration might be the reason for MAP (CO2/N2) samples having lower levels of TVC. Globally, these results indicate that 30% CO2-MAP, 50% CO2-MAP, and CO-MAP are promising packaging methods to improve roast duck meat quality and achieve shelf life extension.

Improving tumor oxygenation and concentrating X-ray radiation energy inside the tumor have received considerable attention in cancer radiotherapy. Herein, core-shell tantalum oxide@manganese dioxide (TaOx@MnO

Concrete can face serious deterioration issues due to different physical, chemical, or biochemical factors. Structural integrity and durability are significantly impaired by cracks which provide channels for water or gases to penetrate concrete matrices, ultimately attacking the steel reinforcements. In this research, we show that a urease-positive fungus, Neurospora crassa, can deposit calcium carbonate on mortar through microbiologically-induced calcium carbonate precipitation (MICP) forming a dense biomineralized mycelial network resulting in a protective coating on Portland cement, fly ash, and ground granulated blast furnace slag based mortar. Rietveld refinement of X-ray diffraction data showed that greater amounts of calcium carbonate were precipitated with increasing mortar porosity. Water repellence was enhanced after fungal colonization and carbonate biodeposition on the surface, and water absorption coefficients improved 17% at least after development of the boioprotective coating. Overall, this work demonstrates that fungal biomineralization could act as biocement to protect porous mineral-based materials from water infiltration, thus improving their durability.

Ni-rich layered oxides are regarded as next-generation cathode materials for lithium-ion batteries with high energy density. However, these materials suffer capacity degradation and power fade at high cutoff voltages. Herein, a robust La, Zr nanocomposite oxide coating layer is successfully deposited on the LiNi0.6Co0.2Mn0.2O2 surface using a wet-chemical method. The surface modified LiNi0.6Co0.2Mn0.2O2 exhibits improved rate capability and superior cycling performance even at a high cutoff voltage of 4.5 V. Ex situ analyses uncover the capacity fading mechanisms of LiNi0.6Co0.2Mn0.2O2 and the effects of the coating layer by a combination of X-ray diffraction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The results show that particle cracking, structural transformation, and interfacial side reactions are responsible for the inferior performance of pristine LiNi0.6Co0.2Mn0.2O2. Nevertheless, the coating layer not only retains structural integrity and suppresses irreversible surface phase transformation, but also alleviates accumulation of highly resistive species on the cathode surface. This investigation highlights the advantages of combining multiple techniques in investigating the effects of surface modification and could be extended to explore other coating materials.

LiNixCoyMnzO2 cathode materials play a vital role in next-generation lithium-ion batteries because of their high energy density, but they suffer capacity decay at elevated temperatures. Improving the cycling stability of LiNixCoyMnzO2 requires a basic comprehension of its capacity fade mechanisms. Here, we investigate the electrochemical performance of LiNi0.6Co0.2Mn0.2O2 at 55 °C under various cutoff voltages and examine the corresponding degradation mechanisms. The discharge capacity of LiNi0.6Co0.2Mn0.2O2 increases from 176.0 mAh g−1 to 218.1 mAh g−1 at 1 C as the cutoff voltage increases from 4.3 V to 4.7 V, whereas the capacity retention decreases from 96.3% to 78.9% after 50 cycles, respectively. Ex situ analyses via high-resolution transmission electron microscopy illuminate structural transformations of cathode materials after electrochemical cycling. This accounts for the increase in charge transfer resistance and capacity loss. In addition, X-ray photoelectron spectroscopy analyses highlight the correlations between the electrochemical performance and interfacial compositions of the cathode/electrolyte interface. These data provide another explanation for the capacity degradation. Our results underscore the value of improving the surface structural stability of cathode materials and reducing the charge transfer resistance of the electrode/electrolyte interface.

Nanoscale coordination polymers (NCPs) are promising nanomedicine platforms featured with biodegradability and versatile functionalities. However, multi-step post-synthesis surface modification is usually required to functionalize as-made NCPs before their biomedical applications. Moreover, efforts are still required to design therapeutic NCPs responsive to the unique tumor microenvironment to achieve more specific and effective therapy. Herein, we uncover a simple yet general strategy to synthesize a series of polyethylene glycol (PEG) modified NCPs via a one-step method by adding poly-histidine-PEG co-polymer into the mixture of metal ions and organic ligands during NCPs formation. With NCPs consisting Ca2+/dicarboxylic cisplatin (IV) prodrug as the example, we show that such Ca/Pt(IV)@pHis-PEG NCPs are highly sensitive to pH changes. With slightly negative charges and compact structure under pH 7.4 during blood circulation, those NCPs exhibit efficient passive accumulation in the tumor, in which the reduced pH (c.a. 6.5) would trigger charge conversion and size expansion to enhance their tumor retention and cell internationalization. After cellular uptake, NCPs within cell endo-/lysosomes with further reduced pH would then lead to decomposition of those NCPs and thus drug release. Chemotherapy with Ca/Pt(IV)@pHis-PEG NCPs in our animal tumor model demonstrates great efficacy under low drug doses, and is found to be particularly effective towards solid tumors with reduced pH.

Ni-rich cathode materials attract ongoing interest due to their high specific capacity (∼200 mAh g−1). However, these materials suffer rapid capacity fading when charged to a high voltage and cycled at elevated temperature. In this study, we propose a facile method to reconstruct the surface structure of LiNi0.6Co0.2Mn0.2O2 via Nb modification, which integrates the merits of partial Nb5+ doping in the pristine structure and surface Li3NbO4 coating. The obtained results from Rietveld refinement and high resolution transmission electron microscopy confirm that Nb5+ is partially doped into Li+ sites within the surface lattice. Further ex-situ powder X-ray diffraction and kinetic analysis using electrochemical impedance spectroscopy reveal that Nb modification stabilizes the layered structure and facilitates the charge transfer process. Owing to the robust surface structure, 1 mol% Nb modified LiNi0.6Co0.2Mn0.2O2 delivers a discharge capacity of 160.9 mAh g−1 with 91% capacity retention after 100 cycles at 3.0–4.5 V, whereas the discharge capacity of the pristine sample drops to 139.6 mAh g−1, corresponding to 78% of its initial value. The presence of Nb5+ in the Li layer exhibits positive effects on stability of layered structure, and the surface Li3NbO4 coating layer increases interfacial stability, which results in superior electrochemical performance.

Improving tumor oxygenation and concentrating X-ray radiation energy inside the tumor have received considerable attention in cancer radiotherapy. Herein, core–shell tantalum oxide@manganese dioxide (TaOx@MnO2) nanostructures are prepared as an efficient radiosensitizer for enhancing radiotherapy (RT). In these nanostructures, the TaOx core serves as a RT sensitizer that efficiently concentrates X-ray radiation energy inside the tumor, while the MnO2 shell may trigger the decomposition of endogenous H2O2 in the tumor microenvironment (TME) to generate oxygen and overcome hypoxia-associated radiation resistance. In vitro and in vivo experiments demonstrated that the synthesized TaOx@MnO2-PEG nanostructures could accomplish an excellent synergistic radiotherapy sensitization effect. Furthermore, TaOx@MnO2-PEG nanoparticles could also serve as promising agents for MR/CT dual-modal imaging. In brief, our study highlights a new type of multifunctional radiosensitizer agent to enhance radiotherapy treatment by means of simultaneously concentrating radiation energy inside tumors and overcoming tumor hypoxia, promising for applications in tumor radiotherapy.

Nanoscale coordination polymers (NCPs), with inherent biodegradability, chemical diversities, and porous structures, are a promising class of nanomaterials in the nanomedicine field. Herein, a unique type of redox-sensitive NCPs is constructed with manganese ions (Mn2+) and dithiodiglycolic acid as the disulfide (SS)-containing organic bridging ligand. The obtained Mn-SS NCPs with a mesoporous structure could be efficiently loaded with doxorubicin (DOX), a chemotherapeutics. The yielded Mn-SS/DOX nanoparticles are coated with a layer of polydopamine (PDA) and then modified by poly(ethylene glycol) (PEG). In such a Mn-SS/DOX@PDA-PEG NCP structure, the disulfide linkage (SS) within dithiodiglycolic acid can be cleaved in the presence of glutathione (GSH), leading to efficient redox-responsive dissociation of NCPs and the subsequent drug release. Meanwhile, Mn2+ in Mn-SS/DOX@PDA-PEG NCPs would offer a strong T1 contrast in magnetic resonance (MR) imaging, Upon intravenous injection, these Mn-SS/DOX@PDA-PEG N...

A high-capacity Si anode is always accompanied by very large volume expansion and structural collapse during the lithium-ion insertion/extraction process. To stabilize the structure of the Si anode, magnesium vapor thermal reduction has been used to synthesize porous Si and SiO2 (pSS) particles, followed by in situ growth of carbon nanotubes (CNTs) in pSS pores through a chemical vapor deposition (CVD) process. Field-emission scanning electron microscopy and high-resolution transmission electron microscopy have shown that the final product (pSS/CNTs) possesses adequate void space intertwined by uniformly distributed CNTs and inactive silica in particle form. pSS/CNTs with such an elaborate structural design deliver improved electrochemical performance, with better coulombic efficiency (70% at the first cycle), cycling capability (1200 mAh g–1 at 0.5 A g–1 after 200 cycles), and rate capability (1984, 1654, 1385, 1072, and 800 mAh g–1 at current densities of 0.1, 0.2, 0.5, 1, and 2 A g–1, respectively), co...

In this study, Zn–Fe–O@C hollow microspheres are prepared by chemical vapor deposition (CVD) method with ZnFe2O4 hollow microspheres as precursors which are synthesized via a facile solvothermal method. ZnFe2O4 hollow microspheres and Zn–Fe–O@C hollow microspheres are characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. The physical analysis shows a fraction of Fe(III) reduced to Fe(II) and the hollow microspheres maintained during the CVD process. Zn–Fe–O@C hollow microspheres can deliver a reversible specific capacity of 1035.6 mA h g−1 after 50 cycles at a current density of 100 mA g−1, and maintain a stable capacity as high as 1000 mA h g−1 at 500 mA g−1 after 200 cycles. Compared with ZnFe2O4 hollow microspheres, Zn–Fe–O@C hollow microspheres present excellent rate performance. The better electrochemical performances of the Zn–Fe–O@C hollow microspheres should be ascribed to the carbon coating, which can elevate electrical conductivity and improve the structural stability of the active materials.

The detection of tomato fruit physiological diseases can increase tomato yields and facilitate tomato fruit quality control. In this paper, a convolutional neural network called YOLOv2 was applied on the detection of healthy tomato fruits and tomato fruits with common physiological diseases. YOLOv2 is a target detection algorithm based on regression model, which has fast detection speed and good accuracy. In order to improve the network detection performance, the following improvements were made: First, image datasets were extended by data augmentation methods to decrease the chance of overfitting, and the augmented datasets containing 1000 tomato fruit images were obtained. Second, a grayscale processing module and a foreground extraction module were constructed to investigate the importance of image data type. Third, k-means clustering algorithm was applied in order to reduce model training time as well as improve detection effects. The mAP (mean Average Precision) of YOLOv2 tomato fruit detection network was 97.24%. Experimental results showed that the proposed method was effective on the detection of healthy tomato fruits and tomato fruits with common physiological diseases.

In this work, geoactive fungi including Aspergillus niger, Beauveria caledonica and Paecilomyces javanicus, were used to investigate their biocorrosion and deteriorative effects on copper metal to gain an understanding of the roles that fungi may play in biodeterioration of such a material in the built environment. It was clearly demonstrated that the test fungi possessed a high tolerance to copper metal. New biominerals resulted from fungal interactions with copper metal mainly arising from organic acid excretion. Copper oxalate was formed by oxalate excretion from the fungi and different patterns of bioweathering and biomineralization were generated on the copper surfaces. In addition, copper could be dissolved by certain fungi, result in significant biodeterortive effects such as etching and pitting. These results provide compelling evidence for deteriortion of copper metal by fungi and that organic acids, particularly oxalate, play an important role in this process. Such properties of metal biocorrosion and deterioration indicate the potential significance of fungi in biodeterioration of metal substrates and the importance of considering methods of protection and preservation in the built environment.

Disease is one of the key problems that can cause serious yield lost. The effective detection of healthy and diseased tomatoes is of great significance for the development of tomato intelligent farm machinery technologies. This paper analyzed the application of YOLOv2 model on the detection of healthy and diseased tomatoes. Firstly we collected and processed the images available for study. And then the object fruits in the images were manually labeled with unified standards. Using the experimental data set, we finally obtained a YOLOv2 tomato detection network with great performance. When the threshold is 0.25, the precision rate of the network reaches up to 0.96 and the mAP reaches up to 0.91. The results indicate that YOLOv2 can be effectively applied to the detection of healthy and diseased tomatoes. This application also provides an idea for the detection of other fruits and vegetables.

Nickel removal from wastewater by a zero valent iron sulfate-reducing bacteria (ZVI-SRB) filter and a sulfate-reducing bacteria (SRB) filter were investigated in this study on the basis of the assumption that integrating SRB with the ZVI system should enhance the removal efficiency of heavy metals from solution. The variation in oxidation–reduction potential (ORP) and pH in the effluent indicated that ZVI provided favorable anaerobic conditions for SRB growth. Measurement of sulfate concentrations confirmed that ZVI promoted sulfate-reducing activity of SRB. When the nickel concentration of influent was 150 mg/l with a HRT of 19h, the nickel-removal efficiency was > 98% for the ZVI-SRB filter and 94.3–96.5% for the SRB filter; with a hydraulic retention time (HRT) of 12h, the nickel-removal efficiency was 95.3–97.0% for the ZVI-SRB filter and 84.3–88.2% for the SRB filter, with a HRT of 6h, the nickel-removal efficiency was 94.2–96.5% for the ZVI-filter and 78.2–81.4% for the SRB filter. This resu...

A high-capacity Si anode is always accompanied by very large volume expansion and structural collapse during the lithium-ion insertion/extraction process. To stabilize the structure of the Si anode, magnesium vapor thermal reduction has been used to synthesize porous Si and SiO

Both nanoscale metal organic frameworks (NMOFs) with ordered crystalline structure and nanoscale coordination polymers (NCPs) which instead show non-crystalline structure are formed by coordination interactions between inorganic metal ions or clusters with organic bridging ligands. NMOFs and NCPs have shown great potential in the field of biomedicine in recent years, owning to their unique advantages including inherent biodegradability, the mesoporous structure to enable loading of various therapeutic or imaging molecules, as well as diverse compositions in both metal ions and organic ligands to render them multiple functionalities in a single system. In this review article, the synthesis and modification strategies of NMOFs/NCPs, together with their applications in drug delivery, biomedical imaging and various types of cancer therapies will be summarized. In addition to reviewing the latest advances in this rapid growing direction, the future prospects of applying NMOFs/NCPs for cancer theranostics will also be addressed.

Pd nanoparticle catalysts supported by multiwall carbon nanotubes (Pd/MWNTs) prepared using a complexation–reduction method are used in this study for the electrochemical determination of hydrazine. The physico-chemical properties of the Pd/MWNT catalyst were characterized by X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) and scanning electron microscopy physico-chemical (SEM). These structural analyses reveal that the Pd/MWNTs-modified glassy carbon electrode possesses a three-dimensional network structure in which the Pd nanoparticles, with an average size of 5 nm, are uniformly distributed on the surface of the MWNTs. After Nafion solution was coated on the surface of the Pd/MWNT layer, the resulting Pd/MWNT–Nafion modified electrode retained the three-dimensional network structure. Electrochemical measurements show that the oxidation peak current of hydrazine decreases with increasing pH. Under optimum conditions, the Pd/MWNT–Nafion-based hydrazine sensor exhibits a broad linear calibration range (2.5–700 μM) and a low detection limit of 1.0 μM for hydrazine.

The highly dispersed and ultrafine carbon supported Pd nanoparticles (Pd/C) catalyst was synthesized by NaBH4 reduction method in the presence of ethylenediamine-tetramethylene phosphonic acid (EDTMP) ligand. The formation of the ultrafine Pd nanoparticles can be attributed to the avoidance of Pd(OH)2 precipitation and the decrease in the reduction potential of PdII species in EDTMP–PdII complex during the preparation of Pd/C catalyst. Electrochemical measurements indicated the resulting Pd/C catalyst possessed a significant electrocatalytic performance for hydrazine oxidation under the strong acidic conditions, indicating that the Pd/C catalyst has potential application in fabrication of acidic direct hydrazine fuel cell.

With the rapid development, Microblog as an important interactive media, has become a kind of transmission carrier of the false information. Therefore, the research significance of Micro-blog information credibility becomes more and more important today. In this paper, different representative factors are selected from three facets--text contents, information dissemination and information source--which influence the information credibility of Micro-blog. We choose Netica software to build Bayesian network model and use the rumors grabbed from Sina Weibo as experimental data in order to get the relationship between conditions and phenomena from the changes of probability distribution in Bayesian network. On the basis of this, we find the influences of the representative factors on the subjective credibility of objective unreliable information.

A simple and novel ultra-wideband (UWB) printed planar monopole antenna with dual band-notched characteristics is proposed in this paper. The two notches are realized by employing two different types of U-shaped SIR defected ground structure (DGS) on the ground plane. The antenna presented has a wide band covering the frequency band from 2.8GHz to 10.6GHz. The two notched bands are located at 3∼4GHz (WiMAX) band and 5∼6GHz band (WLAN) respectively. A good agreement was achieved between the simulated and the measured results.

A novel printed UWB monopole antenna with dual notched band characteristics fed by microstrip transmission line is proposed in this article. The gradual changing structure produces a wide band of 2.2–12GHz. By employing a split ring slot on the radiation element, adding two coupled SIRs adjacent to the microstrip line, the two notched bands of 3.2–3.7GHz and 5–6GHz can be adopted, covering the bands of WLAN and WIMAX. The proposed antenna is simulated, manufactured and measured, and the measured results confirm that the proposed antenna is suitable for UWB applications.

Nanostructured polyurethane (PU) synthesized by an emulsion polymerization with narrow size distribution was employed for the first time directly as a novel matrix for enzyme immobilization to develop sensitively amperometric biosensors. When Microperoxidase-11 (MP-11) was selected as a model protein, the resulting hydrogen peroxide (H(2)O(2)) biosensor exhibited improved sensitivity of 29.6μAmM(-1)cm(-2) with quite good response time of (1.3±0.4)s and remarkable limit of detection as low as 10pM (S/N 3) over existing protocols. A linear calibration curve for hydrogen peroxide was obtained up to 1.3μM under the optimized conditions with a relative low calculated Michaelis-Menten constant (K(M)(app)) (1.87±0.05)μM, which indicated the enhanced enzymatic affinity of MP-11 to H(2)O(2) via PU. The possible interferents had negligible effect on the response current and time of the prepared biosensor. Results suggest that the PU nanoparticles (PU-NPs) with good biocompatibility and sufficient interfacial adhesion hold promise as an attractive support material for construction of ultrasensitive amperometric biosensor.