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Underground disposal repositories are considered the most effective solution for the safe disposal of high-level radioactive waste (HLW), yet excavation-induced stress variations will influence the permeability properties and form nuclide migration pathways in the host rock, posing significant ecological resource pollution risks. This study focuses on the impact of stress on granite permeability of the Beishan HLW disposal repository. Through triaxial compression-seepage experiments, we measured permeability and acoustic emission (AE) characteristics. Analyzing the experimental process revealed that variations in rock volume and permeability are predominantly influenced by cracks. To account for the contribution of multi-scale cracks and pores to these variations, we treated fractured rock as a dual medium, consisting of the matrix (with inner micro-cracks/pores) and fractures, following distinct Hooke's laws under identical stress. Based on the relationship between axial stress and rock volume, we propose a dual-medium model describing the stress-induced permeability evolution of fractured granite. Model calibration demonstrates its ability to accurately depict stress-induced permeability variation and reflect the mutual transformation between micro-cracks/pores in matrices and fractures. We further implement the proposed constitutive equations in FLAC3D, successfully reproducing the permeability evolution of the tested sample during deformation. Additionally, we simulate the permeability distribution around the HLW disposal repository.

In addressing the challenge of lacking precise mathematical and mechanical models, as well as data labels in structural damage identification, this paper proposes an innovative approach that eliminates the need for such models and labels. Initially, raw acceleration responses serve as input data, which undergo data preprocessing to derive training samples and labels. Subsequently, these training samples and labels are fed into the bidirectional convolutional recurrent neural network constructed in this study for parameter optimization through training. Finally, synthesized acceleration signals are input into the trained network to obtain predictive signals, and a custom-defined damage index is employed to compute structural damage. The applicability of this methodology is validated through numerical simulations and experimental study. The research findings demonstrate that the proposed approach is an unsupervised, data-driven method capable of identifying dynamic structural damage without reliance on the presence of structural labels or precise computational models.

Deep learning (DL) has gained great success in recent years, leading to state-of-the-art performance in research community and industrial fields like computer vision and natural language processing. One of the reasons for this success is the huge amount parameters adopted in DL models. However, it is impractical to train a moderately large model with a large number of parameters on a typical single device. Thus, It is necessary to train DL models in clusters with distributed training algorithms. However, traditional distributed training algorithms are usually sub-optimal and highly customized, which owns the drawbacks to train large-scale DL models in varying computing clusters. To handle the above problem, researchers propose auto-parallelism, which is promising to train large-scale DL models efficiently and practically in various computing clusters. In this survey, we perform a broad and thorough investigation on challenges, basis, and strategy searching methods of auto-parallelism in DL training. First, we abstract basic parallelism schemes with their communication cost and memory consumption in DL training. Further, we analyze and compare a series of current auto-parallelism works and investigate strategies and searching methods which are commonly used in practice. At last, we discuss several trends in auto-parallelism which are promising in further research.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.cie.2007.12.018 Byline: Ying-Chin Ho, Teng-Sheng Su, Zhi-Bin Shi Keywords: Order batching; Order picking; Seed-order selection; Accompanying-order selection Abstract: Order batching is one of the methods used in warehouses to minimize the travel distance of pickers. In this paper, we focus on developing order-batching methods for an order-picking warehouse with two cross aisles and an I/O point at one of its corners. Each of these methods is made up of one seed-order selection rule and one accompanying-order selection rule. Eleven seed-order selection rules and 14 accompanying-order selection rules are studied here. These rules include those newly proposed by us and those by others. Rules proposed by others have been shown to perform well in minimizing the travel distance of pickers. They are included here for the comparison purpose. Unlike previous studies that only focus on developing aisle or location-based rules, this study also develops rules that are distance- or area-based. In addition, two different route-planning methods and two different aisle-picking-frequency distributions are considered in this paper. This study's objective is to investigate not only the performance of seed-order selection rules and accompanying-order selection rules, but also the mutual effects between route-planning methods, aisle-picking-frequency distributions, seed-order selection rules, and accompanying-order selection rules on their performance. The result of this study shows that some of the newly proposed rules outperform those from other studies. It also shows that seed-order selection rules and accompanying-order selection rules significantly affect each other's performance. Lastly, the performance rankings of seed-order selection rules and accompanying-order selection rules are affected by aisle-picking-frequency distributions, but not by route-planning methods. Author Affiliation: Institute of Industrial Management, National Central University, No. 3, Chung-Li, Taoyuan 32045, Taiwan Article History: Received 7 August 2006; Revised 12 August 2007; Accepted 19 December 2007

The vascularized cardiac patch strategy is promising for ischemic heart repair after myocardial infarction (MI), but current fabrication processes are quite complicated. Vascularized cardiac patches that can promote concurrent restoration of both the myocardium and vasculature at the injured site in a large animal model remain elusive. The safety and therapeutic benefits of a cardiac stromal cell patch integrated with engineered biomimetic microvessels (BMVs) were determined for treating MI. By leveraging a microfluidic method employing hydrodynamic focusing, we constructed the endothelialized microvessels and then encapsulated them together with therapeutic cardiosphere-derived stromal cells (CSCs) in a fibrin gel to generate a prevascularized cardiac stromal cell patch (BMV–CSC patch). We showed that BMV–CSC patch transplantation significantly promoted cardiac function, reduced scar size, increased viable myocardial tissue, promoted neovascularization, and suppressed inflammation in rat and porcine MI models, demonstrating enhanced therapeutic efficacy compared to conventional cardiac stromal cell patches. BMV–CSC patches did not increase renal and hepatic toxicity or exhibit immunogenicity. We noted a significant increase in endogenous progenitor cell recruitment to the peri-infarct region of the porcine hearts treated with BMV–CSC patch as compared to those that received control treatments. These findings establish the BMV–CSC patch as a novel engineered-tissue therapeutic for ischemic tissue repair.

Transition metal dichalcogenides (TMDCs) have recently attracted a tremendous amount of attention owing to their superior optical and electrical properties as well as the interesting and various nanostructures that are created by different synthesis processes. However, the atomic thickness of TMDCs limits the light absorption and results in the weak performance of optoelectronic devices, such as photodetectors. Here, we demonstrate the approach to increase the surface area of TMDCs by a one-step synthesis process of TMDC nanowalls from WOxinto three-dimensional (3D) WS2nanowalls. By utilizing a rapid heating and rapid cooling process, the formation of 3D nanowalls with a height of approximately 150 nm standing perpendicularly on top of the substrate can be achieved. The combination of core–shell colloidal quantum dots (QDs) with three different emission wavelengths and 3D WS2nanowalls further improves the performance of WS2-based photodetector devices, including a photocurrent enhancement of 320–470% and shorter response time. The significant results of the core–shell QD–WS2hybrid devices can be contributed by the high nonradiative energy transfer efficiency between core–shell QDs and the nanostructured material, which is caused by the spectral overlap between the emission of core–shell QDs and the absorption of WS2. Besides, outstanding NO2gas-sensing performance of core–shell QDs/WS2devices can be achieved with an extremely low detection limit of 50 ppb and a fast response time of 26.8 s because of local p–n junctions generated by p-type 3D WS2nanowalls and n-type core–shell CdSe-ZnS QDs. Our work successfully reveals the energy transfer phenomenon in core–shell QD–WS2hybrid devices and shows great potential in commercial multifunctional sensing applications.

The rechargeable aluminum-ion battery (AIB) is a promising candidate for next-generation high-performance batteries, but its cathode materials require more development to improve their capacity and cycling life. We have demonstrated the growth of MoSe2three-dimensional helical nanorod arrays on a polyimide substrate by the deposition of Mo helical nanorod arrays followed by a low-temperature plasma-assisted selenization process to form novel cathodes for AIBs. The binder-free 3D MoSe2-based AIB shows a high specific capacity of 753 mAh g–1at a current density of 0.3 A g–1and can maintain a high specific capacity of 138 mAh g–1at a current density of 5 A g–1with 10 000 cycles. Ex situRaman, XPS, and TEM characterization results of the electrodes under different states confirm the reversible alloying conversion and intercalation hybrid mechanism during the discharge and charge cycles. All possible chemical reactions were proposed by the electrochemical curves and characterization. Further exploratory works on interdigital flexible AIBs and stretchable AIBs were demonstrated, exhibiting a steady output capacity under different bending and stretching states. This method provides a controllable strategy for selenide nanostructure-based AIBs for use in future applications of energy-storage devices in flexible and wearable electronics.

In this work, we demonstrated nano-scaled Laue diffractions by a focused polychromatic synchrotron radiation beam to discover what happens in MoS2when van der Waals epitaxy is locally invalid. A stronger exciton recombination with a local charge depletion in the density of 1 × 1013cm–2, extrapolated by Raman scattering and photoluminescence, occurs in grains, which exhibits a preferred orientation of 30° rotation with respect to the c-plane of a sapphire substrate. Else, the charge doping and trion recombination dominate instead. In addition to the breakthrough in extrapolating mesoscopic crystallographic characteristics, this work opens the feasibility to manipulate charge density by the selection of the substrate-induced disturbances without external treatment and doping. Practically, the 30° rotated orientation in bilayer MoS2films is promoted on inclined facets in the patterned sapphire substrate, which exhibits a periodic array of charge depletion of about 1.65 × 1013cm–2. The built-in manipulation of carrier concentrations could be a potential candidate to lateral and large-area electronics based on 2D materials.

Aluminum–sulfur batteries (ASBs) have attracted substantial interest due to their high theoretical specific energy density, low cost, and environmental friendliness, while the traditional sulfur cathode and ionic liquid have very fast capacity decay, limiting cycling performance because of the sluggishly electrochemical reaction and side reactions with the electrolyte. Herein, we demonstrate, for the first time, excellent rechargeable aluminum–selenium batteries (ASeBs) using a new deep eutectic solvent, thiourea-AlCl3, as an electrolyte and Se nanowires grown directly on a flexible carbon cloth substrate (Se NWs@CC) by a low-temperature selenization process as a cathode. Selenium (Se) is a chemical analogue of sulfur with higher electronic conductivity and lower ionization potential that can improve the battery kinetics on the sluggishly electrochemical reaction and the reduction of the polarization where the thiourea-AlCl3electrolyte can stabilize the side reaction during the reversible conversion reaction of Al–Se alloying processes during the charge–discharge process, yielding a high specific capacity of 260 mAh g–1at 50 mA g–1and a long cycling life of 100 times with a high Coulombic efficiency of nearly 93% at 100 mA g–1. The working mechanism based on the reversible conversion reaction of the Al–Se alloying processes, confirmed by the ex situ Raman, XRD, and XPS measurements, was proposed. This work provides new insights into the development of rechargeable aluminum–chalcogenide (S, Se, and Te) batteries.

Human dermal fibroblasts (HDFs), the main cell population of the dermis, gradually lose their ability to produce collagen and renew intercellular matrix with aging. One clinical application for the autologous trans-dermis injection of HDFs that has been approved by the Food and Drug Administration aims to refine facial contours and slow down skin aging. However, the autologous HDFs used vary in quality according to the state of patients and due to many passages they undergo during expansion. In this study, factors and exosomes derived from three-dimensional spheroids (3D HDF-XOs) and the monolayer culture of HDFs (2D HDF-XOs) were collected and compared. 3D HDF-XOs expressed a significantly higher level of tissue inhibitor of metalloproteinases-1 (TIMP-1) and differentially expressed miRNA cargos compared with 2D HDF-XOs. Next, the efficacy of 3D HDF-XOs in inducing collagen synthesis and antiaging was demonstrated in vitroand in a nude mouse photoaging model. A needle-free injector was used to administer exosome treatments. 3D HDF-XOs caused increased procollagen type I expression and a significant decrease in MMP-1 expression, mainly through the downregulation of tumor necrosis factor-alpha (TNF-α) and the upregulation of transforming growth factor beta (TGF-β). In addition, the 3D-HDF-XOs group showed a higher level of dermal collagen deposition than bone marrow mesenchymal stem cell-derived exosomes. These results indicate that exosomes from 3D cultured HDF spheroids have anti-skin-aging properties and the potential to prevent and treat cutaneous aging.

Stem cell therapies have shown promise in treating acute and chronic ischemic heart disease. However, current therapies are limited by the low retention and poor integration of injected cells in the injured tissue. Taking advantage of the natural infarct-homing ability of platelets, we engineered CD34 antibody-linked platelets (P-CD34) to capture circulating CD34-positive endogenous stem cells and direct them to the injured heart. In vitro, P-CD34 could bind to damaged aortas and capture endogenous stem cells in whole blood. In a mouse model of acute myocardial infarction, P-CD34 accumulated in the injured heart after intravenous administration, leading to a concentration of endogenous CD34 stem cells in the injured heart for effective heart repair. This represents a new technology for endogenous stem cell therapy.

Stem cell therapy is one of the promising strategies for the treatment of ischemic heart disease. However, the clinical application of stem cells transplantation is limited by low cell engraftment in the infarcted myocardium. Taking advantage of pretargeting and bioorthogonal chemistry, we engineered a pretargeting and bioorthogonal chemistry (PTBC) system to capture endogenous circulating stem cells and target them to the injured heart for effective repair. Two bioorthogonal antibodies were i.v. administrated with a pretargeting interval (48 h). Through bioorthogonal click reaction, the two antibodies are linked in vivo, engaging endogenous stem cells with circulating platelets. As a result, the platelets redirect the stem cells to the injured heart. In vitroand in vivostudies demonstrated that bioorthogonal click reaction was able to induce the conjugation of platelets and endothelial progenitor cells (EPCs) and enhance the binding of EPCs to collagen and injured blood vessels. More importantly, in a mouse model of acute myocardial infarction, the in vivoresults of cardiac function, heart morphometry, and immunohistochemistry assessment all confirmed effective heart repair by the PTBC system.

In addition to reconciling the cost and energy density of the battery pack, the “LiFePO4- LiCoxNiyMn1-x-yO2” (LFP - NMC) hybrid battery pack can also effectively reduce the risk of thermal spread, so it has been initially applied in the industry. However, the electrochemical properties of the two batteries are very different, so realizing the state estimation of the single cell is the key to the effective management of the hybrid battery pack. Therefore, a novel state estimation method for hybrid battery packs is proposed in this paper. First, the easy-to-estimate NMC as the “ruler” to estimate the SOC of the LFP based on the principle of the same amount of electricity in the series cells. Second, through the design of a “difference state observer (DSO)” with fuzzy logic, continuous feedback correction of electricity is realized. Results from the experiments have verified that when the LFP is connected to a 200 Ω resistor to simulate the self-discharge difference along with sensor errors, the algorithm can control the SOC estimation error of the LFP to about 1 %, which has excellent estimation accuracy. In addition, the algorithm has good robustness. In the scenario with current and voltage sensor errors, the SOC estimation error of LFP is within 2 %. Finally, the capacity and SOC of the hybrid battery pack are solved by using the “Electric quantity - Capacity Scatter Diagram” (ECSD), and the estimation errors are within 1.5 Ah and 1 %, respectively.

Selenium (Se) is one of the potential candidates as photodetector because of its outstanding properties such as high photoconductivity (∼8 × 104S cm–1), piezoelectricity, thermoelectricity, and nonlinear optical responses. Solution phase synthesis becomes an efficient way to produce Se, but a contamination issue that could deteriorate the electric characteristic of Se should be taken into account. In this work, a facile, controllable approach of synthesizing Se nanowires (NWs)/films via a plasma-assisted growth process was demonstrated at the low substrate temperature of 100 °C. The detailed formation mechanisms of nanowires arrays to thin films at different plasma powers were investigated. Moreover, indium (In) layer was used to enhance the adhesive strength with 50% improvement on a SiO2/Si substrate by mechanical interlocking and surface alloying between Se and In layers, indicating great tolerance for mechanical stress for future wearable devices applications. Furthermore, the direct growth of Se NWs/films on a poly(ethylene terephthalate) substrate was demonstrated, exhibiting a visible to broad infrared detection ranges from 405 to 1555 nm with a high on/off ratio of ∼700 as well as the fast response time less than 25 ms. In addition, the devices exhibited fascinating stability in the atmosphere over one month.

Cardiac stem cell (CSC) therapy has shown preclinical and clinical evidence for ischemic heart repair but is limited by low cellular engraftment and survival after transplantation. Previous versions of the cardiac patch strategy improve stem cell engraftment and encourage repair of cardiac tissue. However, cardiac patches that can enhance cardiomyogenesis and angiogenesis at the injured site remain elusive. Therapies that target cardiomyocyte proliferation and new blood vessel formation hold great potential for the protection against acute myocardial infarction (MI). Here, we report a new strategy for creating a vascularized cardiac patch in a facile and modular fashion by leveraging microfluidic hydrodynamic focusing to construct the biomimetic microvessels (BMVs) that include human umbilical vein endothelial cells (HUVECs) lining the luminal surface and then encapsulating the BMVs in a fibrin gel spiked with human CSCs. We show that the endothelialized BMVs mimicked the natural architecture and function of capillaries and that the resultant vascularized cardiac patch (BMV–CSC patch) exhibited equivalent release of paracrine factors compared to those of coculture of genuine human CSCs and HUVECs after 7 days of in vitro culture. In a rat model of acute MI, the BMV–CSC patch therapy induced profound mitotic activities of cardiomyocytes in the peri-infarct region 4 weeks post-treatment. A significant increase in myocardial capillary density was noted in the infarcted hearts that received BMV–CSC patch treatment compared to the infarcted hearts treated with conventional CSC patches. The striking therapeutic benefits and the fast and facile fabrication of the BMV–CSC patch make it promising for practical applications. Our findings suggest that the BMV–CSC patch strategy may open up new possibilities for the treatment of ischemic heart injury.

Acute liver failure is a critical condition characterized by global hepatocyte death and often time needs a liver transplantation. Such treatment is largely limited by donor organ shortage. Stem cell therapy offers a promising option to patients with acute liver failure. Yet, therapeutic efficacy and feasibility are hindered by delivery route and storage instability of live cell products. We fabricated a nanoparticle that carries the beneficial regenerative factors from mesenchymal stem cells and further coated it with the membranes of red blood cells to increase blood stability. Unlike uncoated nanoparticles, these particles promote liver cell proliferation in vitroand have lower internalization by macrophage cells. After intravenous delivery, these artificial stem cell analogs are able to remain in the liver and mitigate carbon tetrachloride-induced liver failure in a mouse model, as gauged by histology and liver function test. Our technology provides an innovative and off-the-shelf strategy to treat liver failure.

Direct reduction of metal oxides into a few transition metal dichalcogenide (TMDCs) monolayers has been recently explored as an alternative method for large area and uniform deposition. However, not many studies have addressed the characteristics and requirement of the metal oxides into TMDCs by the selenization/sulfurization processes, yielding a wide range of outstanding properties to poor electrical characteristics with nonuniform films. The large difference implies that the process is yet not fully understood. In particular, the selenization/sulfurization at low temperature leads to poor crystallinity films with poor electrical performance, hindering its practical development. A common approach to improve the quality of the selenized/sulfurized films is by further increasing the process temperature, thus requiring additional transfer in order to explore the electrical properties. Here, we show that by finely tuning the quality of the predeposited oxide the selenization/sulfurization temperature can be largely decreased, avoiding major substrate damage and allowing direct device fabrication. The direct relationship between the role of selecting different metal oxides prepared by e-beam evaporation and reactive sputtering and their oxygen deficiency/vacancy leading to quality influence of TMDCs was investigated in detail. Because of its outstanding physical properties, the formation of tungsten diselenide (WSe2) from the reduction of tungsten oxide (WOx) was chosen as a model for proof of concept. By optimizing the process parameters and the selection of metal oxides, layered WSe2films with controlled atomic thickness can be demonstrated. Interestingly, the domain size and electrical properties of the layered WSe2films are highly affected by the quality of the metal oxides, for which the layered WSe2film with small domains exhibits a metallic behavior and the layered WSe2films with larger domains provides clear semiconducting behavior. Finally, an 8′′ wafer scale-layered WSe2film was demonstrated, giving a step forward in the development of 2D TMDC electronics in the industry.

Integration of strain engineering of two-dimensional (2D) materials in order to enhance device performance is still a challenge. Here, we successfully demonstrated the thermally strained band gap engineering of transition-metal dichalcogenide bilayers by different thermal expansion coefficients between 2D materials and patterned sapphire structures, where MoS2bilayers were chosen as the demonstrated materials. In particular, a blue shift in the band gap of the MoS2bilayers can be tunable, displaying an extraordinary capability to drive electrons toward the electrode under the smaller driven bias, and the results were confirmed by simulation. A model to explain the thermal strain in the MoS2bilayers during the synthesis was proposed, which enables us to precisely predict the band gap-shifted behaviors on patterned sapphire structures with different angles. Furthermore, photodetectors with enhancement of 286% and 897% based on the strained MoS2on cone- and pyramid-patterned sapphire substrates were demonstrated, respectively.

ABSTRACTBackground: This paper describes the synthesis of thiolated chitosan-based hydrogels with varying degrees of crosslinking that has been utilized to modulate release kinetics of two clinically relevant FDA-approved anti-VEGF protein drugs, ranibizumab and aflibercept. These hydrogels have been fabricated into disc shaped structures for potential use as patches on ocular surface.Methods: Protein conformational changes and aggregation after loading and release was evaluated by circular dichroism (CD), steady-state tryptophan fluorescence spectroscopy, electrophoresis and size-exclusion chromatography (SEC). Finally, the capacity of both released proteins to bind to VEGF was tested by ELISA and surface plasmon resonance (SPR) technology.Results: The study demonstrates the versatility of thiolated chitosan-based hydrogels for delivering proteins. The effect of various parameters of the hydrogel on protein release kinetics and mechanism of protein release was studied using the Korsmeyer-Peppas release model. Furthermore, we have studied the stability of released proteins in detail while comparing it with non-entrapped proteins under physiological conditions to understand the effect of formulation conditions on protein stability.Conclusions: The disc-shaped thiolated chitosan-based hydrogels provide a potentially useful platform to deliver ranibizumab and aflibercept for the treatments of ocular diseases such as wet AMD, DME and corneal neovascularization

Recent advances in the use of organic-inorganic hybrid perovskites have been investigated in a variety of applications, such as solar cells, photodetectors, light-emitting devices, and lasers, because of their outstanding semiconductor properties. Furthermore, the perovskite structure can host extrinsic elements, making it a promising candidate for battery applications. Previous studies have shown that organic-inorganic hybrid perovskites can be suitable anode materials for both lithium- and sodium-ion batteries. However, multivalent rechargeable batteries with perovskite materials have not yet been realized. Herein, we studied the electrochemical performance of three-dimensional (CH3NH3PbI3(MAPbI3) and long-chain alkylammonium (C4H9NH3)2(CH3NH3)3Pb4I13((iBA)2(MA)3Pb4I13) thin films as electrode materials for rechargeable Al-ion batteries. Our results showed that (iBA)2(MA)3Pb4I13presented a specific capacity of 257 mAh g–1at a current density of 0.1Ag−1and delivered 108 mAh g–1after 250 cycles at a current density of 0.3Ag−1with a retention of as high as 91%, demonstrating a crucial role of isobutyl amine (C4H9NH3) due to the unique hydrogen-bonding interaction of isobutyl amine that hinders the shuttle effect of polyiodide. The results open a new direction for the use of organic–inorganic hybrid perovskites for new secondary aluminum ion batteries.

The impact of reservoirs on downstream river channel change has been a scientific issue in fluvial geomorphology during the last few decades. However, it is still a difficult issue as to how to express quantitatively the channel adjustment in the Inner Mongolian reach of the Yellow River induced by the joint operation of upstream reservoirs. Based on the shape parameters of channel cross-sections at four gauging stations in this river reach over a flooding season in two periods, 1978–1982 and 2008–2012, the present work investigated the channel changes in terms of shape parameter change rate under the same controlling water level in each flooding season at the channel cross-sections. Results showed that most of the change rates of the parameters evidently increased over a flooding season in both periods. However, the change rate of each parameter at the cross-sections decreased evidently in the latter period, compared with the former period. At the same time, the distribution pattern of the change rate of the shape parameters along the cross-sections thus changed from a convex curve in the former period to an S-shaped curve in the latter period. The obvious decrease of the change rates is related to the joint operation of the Liujiaxia and Longyangxia reservoirs. The reservoirs stored a large volume of water and decreased the peak discharge and maximum velocity in the flooding season; as a result, the erosion ability of the flood decreased accordingly. With the joint operation of the large reservoirs, the Inner Mongolian channel shrunk markedly. Therefore, the channel will present the possibility of an extreme flood in the future. Consequently, it is reasonable to adjust the function of the reservoirs in future. The total water and sediment discharges and the peak discharge in flooding seasons should be effectively controlled. Continuous shrinkage of the channel can thus be avoided and it can be ready for a potential extreme flood.

Two-dimensional layered materials such as graphene, transition metal dichalcogenides, and black phosphorus have demonstrated outstanding properties due to electron confinement as the thickness is reduced to atomic scale. Among the phosphorus allotropes, black phosphorus, and violet phosphorus possess layer structure with the potential to be scaled down to atomically thin film. For the first time, the plasma-assisted synthesis of atomically layered violet phosphorus has been achieved. Material characterization supports the formation of violet phosphorus/InN over InP substrate where the layer structure of violet phosphorus is clearly observed. The identification of the crystal structure and lattice constant ratifies the formation of violet phosphorus indeed. The critical concept of this synthesis method is the selective reaction induced by different variations of Gibbs free energy (ΔG) of reactions. Besides, the Hall mobility of the violet phosphorus on the InP substrate greatly increases over the theoretical values of InP bulk material without much reduction in the carrier concentration, suggesting that the mobility enhancement results from the violet phosphorus layers. Furthermore, this study demonstrates a low-cost technique with high compatibility to synthesize the high-mobility atomically layered violet phosphorus and open the space for the study of the fundamental properties of this intriguing material as a new member of the fast growing family of 2D crystals.

A dual-enzyme-loaded multifunctional hybrid nanogel probe (SPIO@GCS/acryl/biotin-CAT/SOD-gel, or SGC) has been developed for dual-modality pathological responsive ultrasound (US) imaging and enhanced T2-weighted magnetic resonance (MR) imaging. This probe is composed of functionalized superparamagnetic iron oxide particles, a dual enzyme species (catalase and superoxide dismutase), and a polysaccharide cationic polymer glycol chitosan gel. The dual-modality US/MR imaging capabilities of the hybrid nanogel for responsive US imaging and enhanced T2-weighted MR imaging have been evaluated both in vitroand in vivo. These results show that the hybrid nanogel SGC can exhibit efficient dual-enzyme biocatalysis with pathological species for responsive US imaging. SGC also demonstrates increased accumulation in acidic environments for enhanced T2-weighted MR imaging. Further research on these nanogel systems may lead to the development of more efficient US/MR contrast agents.

Recently, a few attempts to synthesize monolayers of transition metal dichalcogenides (TMDs) using the chemical vapor deposition (CVD) process had been demonstrated. However, the development of alternative processes to synthesize TMDs is an important step because of the time-consuming, required transfer and low thermal efficiency of the CVD process. Here, we demonstrate a method to achieve few-layers WSe2on an insulator vialaser irradiation assisted selenization (LIAS) process directly, for which the amorphous WO3film undergoes a reduction process in the presence of selenium gaseous vapors to form WSe2, utilizing laser annealing as a heating source. Detailed growth parameters such as laser power and laser irradiation time were investigated. In addition, microstructures, optical and electrical properties were investigated. Furthermore, a patternable WSe2concept was demonstrated by patterning the WO3film followed by the laser irradiation. By combining the patternable process, the transfer-free WSe2back gate field effect transistor (FET) devices are realized on 300 nm-thick SiO2/P+Si substrate with extracted field effect mobility of ∼0.2 cm2V–1s–1. Similarly, the reduction process by the laser irradiation can be also applied for the synthesis of other TMDs such as MoSe2from other metal oxides such as MO3film, suggesting that the process can be further extended to other TMDs. The method ensures one-step process to fabricate patternable TMDs, highlighting the uniqueness of the laser irradiation for the synthesis of different TMDs.

Synthetic aperture radar (SAR), a sensor with all weather and day and night working capacity, has been considered one of the most powerful tools for sea surface oil spill detection. However, lookalikes frequently appear in SAR images, limiting the operational use of SAR to detect oil spilled at sea. 20 scenes of Envisat ASAR images, which were acquired during the oil spill accident in the Gulf of Mexico in 2010, are utilized, with the objective to study how to better differentiate oil spills from lookalikes. 145 and 134 samples for oil spill and lookalike, respectively, are extracted, and their object-based geometric, physical and textural features are analyzed, in order to find the most effective features for oil spill classification. Based on the results of feature analysis, fuzzy logic (FL) is employed to construct a classifier for oil spill detection. One advantage of the proposed method is that it can produce the crisp probability of a dark segment being oil spill. The experiment shows that our method can derive promising result.

Wear behavior of AZ51 magnesium alloy was studied using a pin-on-disc type wear apparatus at 20-360 N and 0.785 m/s. Wear mechanisms were determined using scanning electron microscope (SEM), including abrasion, oxidation, delamination, thermal softening and surface melting. Microstructural evolution, plastic deformation and microhardness in the subsurfaces were examined with optical microscope and hardness tester before and after mild to severe wear transition. The subsurface microstructure experienced deformation, dynamic recrystallization (DRX) and surface melting successively with increasing load. These changes in subsurface microstructure result in strain hardening and thermally-activated softening in the near-surface layers. The thermal softening originating from DRX and surface melting in subsurface is responsible for the mild to severe wear transition.

Here, we provide an effective method to fabricate magnetic ZnO clay nanocomposite hydrogel via the photopolymerization. The inorganic components endow the hydrogel with high mechanical strength, while the organic copolymers exhibit good adsorption capacity and separation selectivity to La (III) ions. An optimized hydrogel has the maximum compressive stress of 316.60 ± 15.83 kPa, which still exhibits 138.98 ± 7.32 kPa compressive strength after swelling. The maximum adsorption capacity of La ion is 58.8 mg/g. The adsorption matches the pseudo-second-order kinetics model. La (III) ions can be effectively separated from the mixtures of La/Ni, La/Co, La/Cu, and La/Nd in a broad pH range (2.0 to 8.0). After six adsorption–desorption cycles, the hydrogel can maintain its adsorption capacity. This work not only provides a new approach to the synthesis of tough hydrogels under irradiation, but also opens up enormous opportunities to make full use of magnetic nanocomposite hydrogels in environmental fields.

Water pollution caused by heavy metals is still a serious problem, consequently; Developing an efficient adsorbent for easy recovery and separation is an essential issue. In this work, Chitosan-ZIF-8 (CS-ZIF-8) composite beads were prepared by in situ synthesis of a zeolitic imidazolium-based MOF (ZIF-8) on low-cost chitosan (CS) to adsorb Cu(Ⅱ) and Pb(Ⅱ) from water, which were characterized by FT-IR, PXRD and TGA, etc. The optimal adsorption conditions were obtained through a series of the condition optimization. The adsorption of Cu(Ⅱ) and Pb(Ⅱ) by CS-ZIF-8-1:2was in accordance with both the Langmuir adsorption mode and the pseudo-secondary kinetic model, and the theoretical maximum adsorption amounts were 165.7 mg/g and 131.4 mg/g, respectively. The adsorption thermodynamics demonstrated that the adsorption process of CS-ZIF-8-1:2on Cu(Ⅱ) and Pb(Ⅱ) was spontaneous and endothermic. The cycling test confirmed the good cycling stability of the adsorbent. In summary, this strategy provides a new idea for designing efficient and easily recyclable Chitosan-MOFs composites for the removal of heavy metals from water.

Tunable multilevel storage of complementary resistive switching (CRS) on single-step formation of ZnO/ZnWOxbilayer structure via interfacial engineering was demonstrated for the first time. In addition, the performance of the ZnO/ZnWOx-based CRS device with the voltage- and current-sweep modes was demonstrated and investigated in detail. The resistance switching behaviors of the ZnO/ZnWOxbilayer ReRAM with adjustable RESET-stop voltages was explained using an electrochemical redox reaction model whose electron-hopping activation energies of 28, 40, and 133 meV can be obtained from Arrhenius equation at RESET-stop voltages of 1.0, 1.3, and 1.5 V, respectively. In the case of the voltage-sweep operation on the ZnO-based CRS device, the maximum array numbers (N) of 9, 15, and 31 at RESET-stop voltages of 1.4, 1.5, and 1.6 V were estimated, while the maximum array numbers increase into 47, 63, and 105 at RESET-stop voltages of 2.0, 2.2, and 2.4 V, operated by the current-sweep mode, respectively. In addition, the endurance tests show a very stable multilevel operation at each RESET-stop voltage under the current-sweep mode.

For the functional requirements of motion control in the new wave / tide testing and verifying system, the free port communication protocol between the PC and the master controller is developed, and the control software programmed in Matlab is prepared, so the handling and data acquisition to wave / tide simulate apparatus (hereinafter referred to as simulate apparatus) is realized. The results of testing on prototype show that the control software based on free port communication protocol is reliable, stable and functioning well, meeting the needs of testing, experimentation and data analysis in the development.

To make up the shortage of the existing calibration equipments of the wave measurement instruments, the WTTVS is designed, and the design of the wave height standard device as a subsystem of the WTTVS is introduced in this paper. The subsystem consists of two invar leveling staffs, a laser range finder and an incremental encode, in which the invar leveling staffs and the laser range finder are used to calibrate the encode. At the same time, the uncertainty of the subsystem is evaluated. As the result, the uncertainty is 3.48mm (confidence probability is 99%), which proves the feasibility of the design.

In this paper a new type of semi-active vibration absorber has been developed. The vibration absorber consists of mass block, cantilever beam, magnet lock system, vibration and distance sensors, controller and servo motor. The mass block is fixed on the tip of cantilever beam, and the control process is driven by a servo motor and a transmit gears. Portion of cantilever was cut in form of gear tracks, which can be driven by servo motor through transmit gear to regulate the length of the cantilever beam, and the natural frequency of absorber will also be regulated. After the mass locates in right position (i.e. the natural frequency of absorber is in assigned condition), the magnetic lock will clamp the cantilever beam. The design has the benefit of simplified control system, and extra unknown vibration modes will be averted. A fabrication prototype of the proposed semi-active vibration absorber is constructed and tested to demonstrate the application and modeling of the new cantilever beam damper. By performing the experimental work, the semi-active vibration control system is designed not only for reduce vibration level in resonant condition, but also considered for vibration attenuation in non-resonant conditions.

We report a facile solution polymerized approach to prepare nanocomposite hydrogels. The electrostatic assembly of positive TiO2nanoparticles with negative clay nanosheets obtained TiO2–clay composite particles, which was disassembled by the solution polymerization of N,N-dimethylacrylamide and homogeneously interacted with poly(N,N-dimethylacrylamide) chain to form nanocomposite hydrogels. The final nanocomposite hydrogels are mechanical tough and transparent, which has the maximum 598.21 KPa compressive strength. The immobilized TiO2not only acted as the photo-initiator for radical polymerization but also endowed the nanocomposite gel films good UV protective performance. This strategy can be very useful for preparing nanocomposite hydrogels with different functions.

The oxidation behavior of Fe-Cr-Ni-Mo-Ti maraging steel was investigated within an intermediate temperature range of 450-600°C. Analysis of oxidation kinetics demonstrated excellent oxidation resistance after exposure in air for 100 h; the oxide layer formed was protective and can resist further oxidation. Surface morphology evolution and oxidized surface hardness were characterized by scanning electron microscope and nanoindentation test. The surface oxidation film was rather smooth with Cr enriched at 450°C, appeared a needle-like structure at 500°C together with a few nodule protrusions enriched in O but absent in Fe and Cr; and then transformed to a smooth and compact oxide surface with some protrusion emerged on the original grain boundaries of austenite at 550°C; finally a Fe2O3 phase particle structure appeared at 600°C. The oxidation layer formed on substrate of Fe-Cr-Ni-Co-MoTi was harder than the substrate when oxidation temperature was lower than 550°C.

Zinc ion batteries have been extensively studied with an aqueous electrolyte system. However, the batteries suffer from a limited potential window, gas evolution, cathode dissolution, and dendrite formation on the anode. Considering these limitations, we developed an alternative electrolyte system based on deep eutectic solvents (DESs) because of their low cost, high stability, biodegradability, and non-flammability, making them optimal candidates for sustainable batteries. The DES electrolyte enables reversible Zn plating/stripping and effectively suppresses zinc dendrite formation. Furthermore, in-depth characterizations reveal that the energy storage mechanism can be attributed to [ZnCl]+ion intercalation and the intermediate complex ion plays a pivotal role in electrochemical reactions, which deliver a high reversible capacity of 310 mAh g–1at 0.1 A g–1and long-term stability (167 mAh g–1at a current density of 0.3 A g–1after 300 cycles, Coulombic efficiency: ∼98%). Overall, this work represents our new finding in rechargeable batteries with the DES electrolyte.

•Proposing the edge-cloud collaborative computing architecture combining BMS and cloud.•Realizing the 2σ range prediction of SOH and PDF prediction of RUL with RVM and PSO.•The number of samples required for model learning is reduced to 30% through horizontal parameter transfer.•A regression model of capacity and MVF based on historical data is established with BCT and LS.

Due to the ecological and health hazards of volatile organic compounds (VOCs), the removal of industrial VOCs has become an important issue of increasing concern. In this work, we synthesized easy-processing ZIF-8/agarose composite porous carbon aerogels and investigated their toluene adsorption performance. Results indicated that carbon aerogels had large specific surface area, uniform microporous structure and high nitrogen content. The toluene adsorption capacity of carbon aerogel was 511.2 mg/g under RH50%, which was higher than that of commercial adsorbents and other MOFs with the same specific surface area. The adsorption mechanism of carbon aerogels was further studied via DFT method and was determined as pore-filling effect, π-π interaction and electron donor/acceptor interaction. In addition, carbon aerogels also showed high efficiency and recyclability which kept 70% adsorption capacity at ambient humidity and successfully regenerated after three cycles without obvious loss of adsorption capacity. Therefore, the high adsorption capacity and recyclability facilitate the synthesized aerogels become a promising adsorbent in VOCs adsorption field.

Alluvial rivers commonly are subject to the integrated effects of hydrodynamic and eco‐geomorphologic controls and there has been a lack of suitable methods to measure the effects. By taking the alluvial reach of the Yellow River over the Yinchuan Plain as a suitable example, this study evaluates the degree of hydrodynamic control in the channel‐form adjustment of different channel patterns in light of the advances in equilibrium theory governing alluvial channel flow. In response to the significant variations in flow regime and channel forms, the non‐dimensional number Hthat measures the equilibrium state of alluvial channel flow varies in the ranges of 0.23–0.65, 0.047–0.17 and 0.0012–0.0024 respectively in the anabranching, meandering and braided reaches during 1993–2015. The significant differences among the H‐ranges are mainly because the individual anabranches have neither very narrow nor very deep cross‐sections, while the single‐thread channels in the meandering and braided reaches take moderately and significantly wider and shallower cross‐sections, respectively. These results demonstrate that the Hnumber is a good discriminator of river channel patterns, and the relatively small variability of Hwithin each channel pattern implies that the channels in the study reach are resilient to significant change in flow regime but yet hydrodynamic control is only partial. While the Hnumber is capable of embodying the outcome of the complex integrated effects of multiple localized eco‐geomorphic controls with flow dynamics, more studies are required to define its specific varying ranges for different river channel patterns and differing eco‐geomorphic controls. A new framework is provided for measuring the integrated effects of hydrodynamic and eco‐geomorphic controls on river channel adjustmentA non‐dimensional number reflecting the equilibrium state of alluvial channel flow is used to determine if hydrodynamic control is maximalValues of the non‐dimensional number can be used to discriminate different channel patterns A new framework is provided for measuring the integrated effects of hydrodynamic and eco‐geomorphic controls on river channel adjustment A non‐dimensional number reflecting the equilibrium state of alluvial channel flow is used to determine if hydrodynamic control is maximal Values of the non‐dimensional number can be used to discriminate different channel patterns

A series of polyurethaneurea (PUU) aqueous dispersions were prepared via a prepolymer process from polyester polyol, α,ω‐dihydroxypoly[(3,3,3‐trifluoropropyl) methylsiloxane] (PTFPMS), dimethylolpropionic acid, isophorone diisocyanate, and ethylenediamine. These anionic‐type aqueous dispersions were stable at the ambient temperature for more than 6 months, with particle sizes ranging from 69 to 127 nm. For these aqueous dispersions, the surface tension decreased with increasing PTFPMS content, but the particle size increased with a maximum value. The film prepared from the PUU aqueous dispersion consisting of 5 wt % PTFPMS (APU‐FS‐5) exhibited excellent waterproof performance. Furthermore, the tensile strength of the APU‐FS‐5 film increased nearly 3 times compared with that of the PUU film without PTFPMS, whereas the elongation at break only decreased a little; this indicated that the water‐resistant and mechanical properties could be enhanced markedly and simultaneously for the PUU films containing both silicon and fluorine groups. The experimental results showed a high degree of hydrogen bonding for urea groups and an increased microphase‐separation degree between the hard and soft segments in the PTFPMS‐modified system, which resulted in the excellent mechanical properties of these films. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3365–3373, 2006

In this work, we, for the first time, observed the remarkable thermoelectric properties of a few high-quality PtSe2layered films fabricated by a post selenization of Pt thin films. An excellent power factor of ≳200 μW/mK2with a Seebeck coefficient of >100 μV/K in the PtSe2layered film of 10 layers can be experimentally demonstrated over a wide temperature range, which is much better than those of most of the two-dimensional materials reported in the literature. Optical absorption spectra and DFT (density functional theory) calculations indicate a semiconductor–metal transition at a critical thickness once the thickness increases from 7.7 (15 layers) to 14.3 nm (30 Layers). The results are consistent with the experimental results of the dramatic reduction in the power factor, the magnitude of the Seebeck coefficient, and the resistivity when the thickness increases from 7.7 (15 layers) to 14.3 nm (30 Layers). Nevertheless, the semiconductor–metal transition would occur when the thickness increases from 1.5 nm (3 layers) to 2 nm (4 layers). To figure out this unusual performance, a detailed material examination has been conducted. After the transmission electron microscopy examination, ∼7% biaxial compressive strain built in the polycrystalline PtSe2thin film can be observed. The strain, as revealed by our DFT calculations, plays an important role in opening the electronic energy gap and hence significantly improves the thermoelectric performance. Boltzmann transport calculation results suggested that both the strain and the hole concentration in the p-type specimens are well optimized. We further propose that an even better power factor can be achieved with n-type-doped PtSe2.

Cu(In, Ga)Se2(CIGS) solar cells have reached efficiencies over 23%. However, the scarcity of In and Se makes reducing the thickness of CIGS thin-film absorber desirable for mass production with low-cost and time-saving processes. Meanwhile, CIGS solar cells based on different architectures and strategies have drawn much attention for significant performance over conventional technologies, but rational design guidelines for optical and electrical performance optimization are yet to be completed. In this work, the reduced thickness of the CIGS thin film with the optical and electrical loss-passivated molybdenum Voronoi nanocavity arrays (VNCAs) electrodes were demonstrated. A structural-model under conformally coating criteria was investigated and optimized by a finite-difference time-domain method. The reduced parasitic absorption and rear surface recombination by Al2O3passivation layers on VNCAs substrates give rise to enhanced VOCand JSCup to 9.5 and 8.5%, respectively. These results confirm that the novel VNCAs electrodes can provide a cost-effective way for ultrathin CIGS solar cells with high efficiency.

Acellular patches embedded with encapsulated cell-secreted factors improve cardiac repair after acute myocardial infarction in rodents and pigs.

Stem cell therapies have made strides toward the efficacious treatment of injured endometrium and the prevention of intrauterine adhesions, or Asherman's syndrome (AS). Despite this progress, they are limited by their risk of tumor formation, low engraftment rates, as well as storage and transportation logistics. While attempts have been made to curb these issues, there remains a need for simple and effective solutions. A growing body of evidence supports the theory that delivering media, conditioned with mesenchymal stem cells, might be a promising alternative to live cell therapy. Mesenchymal stem cell‐secretome (MSC‐Sec) has a superior safety profile and can be stored without losing its regenerative properties. It is versatile enough to be added to a number of delivery vehicles that improve engraftment and control the release of the therapeutic. Thus, it holds great potential for the treatment of AS. Here, a new strategy for loading crosslinked hyaluronic acid gel (HA gel) with MSC‐Sec is reported. The HA gel/MSC‐Sec treatment paradigm creates a sustained release system that repairs endometrial injury in rats and promotes viable pregnancy. Mesenchymal stem cell‐secretome‐loaded, crosslinked hyaluronic acid geldemonstrates therapeutic efficiency for Asherman's syndrome in a rat model. This strategy can bypass the risks associated with stem cell therapies, but also construct an intrauterine sustained release system to repair endometrial injury and improve pregnancy rate.