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Converting the γ phase into the α phase completely is necessary in the presintering stage of industrial alumina (Al2O3), which requires high temperature and energy consumption. To reduce the presintering temperature, γ-Al2O3 was activated by oxalic acid. XRD, 27Al-MAS-NMR and TG-DSC were used to characterize the γ - alumina before and after activation, and the phase transformation was studied. The formation temperature of α-Al2O3 decreased to 1029 °C for oxalic acid activated γ-Al2O3, and the α-fraction was 100% for activated γ-Al2O3 at 1300 °C. After oxalic acid activation, the diffraction peak intensity of γ-Al2O3 decreased significantly; the results of 27Al-MAS-NMR suggested that octahedral [AlO6] in γ-Al2O3 was easier than tetrahedral [AlO4] to be attacked by oxalic acid, and the formation of pentavalent [AlO5] with higher reaction activity, which was in favour of the lowering formation temperature of α-Al2O3. The dissolution concentration of Al increased after oxalic acid activation, and the dissolution process was controlled by surface reactions. Oxalic acid mainly attacked the octahedral aluminium in γ-Al2O3 and extracted Al as three complexes of [Al(C2O4)]+, [Al(C2O4)2]- and [Al(C2O4)3]3-. Oxalic acid activated γ - Al2O3 with a lower phase transformation temperature has broad application prospects in the alumina industry.

The development of high–efficiency and low–cost bifunctional oxygen electrocatalysts is critical to enlarge application of zinc–air batteries (ZABs). However, it still remains challenges due to their uncontrollable factor at atomic level during the catalysts preparation, which requires the precise regulation of active sites and structure engineering to accelerate the reaction kinetics for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, a novel Co–doped mixed lanthanum oxide and hydroxide heterostructure (termed as Co–LaMOH|OV@NC) was synthesized by pyrolysis of La–MOF–NH2 with spontaneous cobalt doping. Synergistic coupling of its hollow structure, doping effect and abundant oxygen vacancies creates more active sites and leads to higher electroconductivity, which contribute to the better performance. As employed as a bifunctional oxygen electrocatalyst, the resulting 3Co–LaMOH|OV@NC exhibits superior electrocatalytic activity for both ORR and OER. In assembled ZAB, it also demonstrates an excellent power density of 110.5 mW cm−2, high specific capacity of 810 mAh gZn−1, and good stability over 100 h than those of Pt/C + RuO2. Density functional theory (DFT) calculation reveals that the heterointerfaces coupled with oxygen vacancies lead to an enhanced charge state and electronic structure, which may optimize the conductivity, charge transfer, and the reaction process of catalysts. This study provides a new strategy for designing highly efficient bifunctional oxygen electrocatalysts based on rare earth oxide and hydroxides heterointerface.

Machine learning is widely used in our daily lives. Large amounts of data have been continuously produced and transmitted to the cloud for model training and data processing, which raises a problem: how to preserve the security of the data. Recently, a secure machine learning system named SecureML has been proposed to solve this issue using two-party computation. However, due to the excessive computation expenses of two-party computation, the secure machine learning is about 2× slower than the original machine learning methods. Previous work on secure machine learning mostly focused on novel protocols or improving accuracy, while the performance metric has been ignored. In this article, we propose a GPU-based framework ParSecureML to improve the performance of secure machine learning algorithms based on two-party computation. The main challenges of developing ParSecureML lie in the complex computation patterns, frequent intra-node data transmission between CPU and GPU, and complicated inter-node data dependence. To handle these challenges, we propose a series of novel solutions, including profiling-guided adaptive GPU utilization, fine-grained double pipeline for intra-node CPU-GPU cooperation, and compressed transmission for inter-node communication. Moreover, we integrate architecture specific optimizations, such as Tensor Cores, into ParSecureML. As far as we know, this is the first GPU-based secure machine learning framework. Compared to the state-of-the-art framework, ParSecureML achieves an average of 33.8× speedup. ParSecureML can also be applied to inferences, which achieves 31.7× speedup on average.

Utilizing heterogeneous accelerators, especially GPUs, to accelerate machine learning tasks has shown to be a great success in recent years. GPUs bring huge performance improvements to machine learning and greatly promote the widespread adoption of machine learning. However, the discrete CPU-GPU architecture design with high PCIe transmission overhead decreases the GPU computing benefits in machine learning training tasks. To overcome such limitations, hardware vendors release CPU-GPU integrated architectures with shared unified memory. In this article, we design a benchmark suite for machine learning training on CPU-GPU integrated architectures, called iMLBench, covering a wide range of machine learning applications and kernels. We mainly explore two features on integrated architectures: 1) zero-copy, which means that the PCIe overhead has been eliminated for machine learning tasks and 2) co-running, which means that the CPU and the GPU co-run together to process a single machine learning task. Our experimental results on iMLBench show that the integrated architecture brings an average 7.1× performance improvement over the original implementations. Specifically, the zero-copy design brings 4.65× performance improvement, and co-running brings 1.78× improvement. Moreover, integrated architectures exhibit promising results from both performance-per-dollar and energy perspectives, achieving 6.50× performance-price ratio while 4.06× energy efficiency over discrete GPUs. The benchmark is open-sourced at https://github.com/ChenyangZhang-cs/iMLBench .

Summary Conjugated coordination polymers (CCPs) with extended π-d conjugation can effectively facilitate the delocalization of charges, form a continuous electron transfer pathway, and enhance the stability, which enable their potential applications in various devices. However, the CCPs are so unique that the accurate chemical states or structures of most CCPs, such as the valence of metal ions, the single/double bond characters of ligands, and the presence/absence of counter ions and radicals, still have disputations in the literature. Herein, we focus on disclosing the fundamental understanding of the chemical states and structures of CCPs based on our previous works and other literatures. The synthetic control for a desired/ideal structure with high crystallinity and the variation of chemical states during the charge storage further deepen the understanding of the chemical states of CCPs. On this basis, the challenges and opportunities for further development of CCPs are also prospected.

In this work, multi-layer stacked two-dimensional (2D) covalent organic framework of TpPa-1 was synthesized as nanocontainer to fabricate self-healing epoxy coating. The corrosion inhibitor of benzotriazole (BTA) was loaded into porous TpPa-1 (Tp: 1,3,5-Triformylphrogroglucinol, Pa-1: 1,4-phenylenediamine), and the load capacity was further improved by electrostatic adsorption. Then, 0.5 wt.% BTA/TpPa-1 and 0.5 wt.% TpPa-1 were added to the epoxy coating, respectively. The electrochemical Impedance Spectroscopy (EIS) test shown that after 60 days of immersion, the impedance of the BTA/TpPa-1/EP in low-frequency region was 6.45 × 108 Ω cm2, while the impedance corresponding to the TpPa-1/EP coating was 9.04 × 107 Ω cm2. In addition, in the localized electrochemical impedance spectroscopy (LEIS) test, as the immersion time was extended, the impedance of TpPa-1/EP coating at the defect continued to decrease, while the impedance at the defect of the BTA/TpPa-1/EP coating shown an upward trend, showing self-healing performance. This was due to the pH change when the metal at the defect is corroded, which caused the BTA to be released from the nanocontainer and adhered to the metal surface to form a protective film. The improvement of the anti-corrosion performance of BTA/TpPa-1/EP coating mainly comes from two aspects: (1) The good dispersion of TpPa-1 in EP coating improves the physical shielding effect of the coating; (2) The controlled release of BTA can Realize the continuous formation of the bare metal surface protective layer.

Surface coordination chemistry is important in areas such as adsorption, separation, and catalysts. In this work, surface coordination interactions of benzohydroxamic acid (BHA) with the lead ion [Pb(II)] adsorbed on the cassiterite surface have been investigated by first-principles calculations due to its great significance in froth flotation. Cluster calculations show that BHA possesses the weakest chelation with Pb(II) due to the electron withdrawal ability of the benzyl ring in comparison with other hydroxamic acids. Pb(II) thermodynamically prefers to react with the cassiterite surface rather than BHA. On the other hand, the partial density of states and the atomic overlap populations have consistently verified that the adsorption of BHA results in a better symmetry in electron densities than the hydrated Pb(II). The electron density maps and the electronic localization functions have further visualized the rearrangement of the 6s2 lone pair around the lead atom. It can be concluded that the surface coordination mechanisms of Pb(II) on oxide minerals can be attributed to the coordination ability of BHA and the unique electronic structure of Pb(II), which accounts for the reported better flotation performance of the pre-assemble strategy than the pre-activating approach. This work sheds some new light on the unique coordination activation mechanism of metal ions on oxide mineral surfaces. It should be instructive to design and screen new environment-friendly flotation reagents and flotation flowsheets.

This work proposes a strategy to synthesize N-doped defective carbon (NDC), followed by trapping the FePc precursor. After pyrolysis, the optimized Fe–N–NDC-1-900 exhibits robust anchoring ability to immobilize atomic Fe species with abundant Fe–N4 sites, demonstrating excellent electrocatalytic activity in both the oxygen reduction reaction (ORR, E1/2 = 0.89 V, Eonset = 1.06 V) and oxygen evolution reaction (OER, E10 = 1.58 V). It also shows outstanding stability and delivers faster kinetics in oxygen electrocatalysis. Furthermore, the bifunctional Fe–N–NDC-1-900 is fabricated for a Zn–air battery, which demonstrates a high open-circuit voltage of 1.479 V, power density of 266 mW cm−2, specific capacity of 786 mA h gZn−1, and excellent reversibility with long-term cycling. DFT suggests that the high ORR activity is mainly ascribed to its high electronegativity and small energy barriers, produced by the adjacent pore defects and optimal charge redistribution.

Introducing a metal sulfide-based co-catalyst is an effective strategy to substantially enhance the Fenton reaction. Manipulation of the co-catalyst's structure is expected to further boost the co-catalytic capability. Herein, we demonstrate that the intrinsic high-defect surface of a natural molybdenite material contributes to the enhancement of catalytic performance of the Fenton reaction. The defective surface not only exposes more Mo(IV) active sites for rapid Fe3+/Fe2+ conversion but also promotes cooperation with H2O2 molecules for reactivation. This synergistic effect brings about enhanced reaction kinetics and boosts the decomposition of H2O2, which causes the molybdenite co-catalytic system to display an efficient removal rate for various organic pollutants. This work unveils the defects’ contribution for catalyzing the Fenton reaction and sheds light on the potential large-scale water treatment use cases for abundant high-defect molybdenite materials.

In the study of RGB-D SLAM (Simultaneous Localization and Mapping), two types of primary visual features, point and line features, have been widely utilized to calculate the camera pose. As an RGB-D camera can capture RGB and depth information simultaneously, most RGB-D SLAM methods only utilize the 2D information within the point and line features. To obtain a higher accuracy camera pose and utilize the 2D and 3D information within points and lines better, a novel geometric constraint model of points and lines (PL-GM) using an RGB-D camera is proposed in this paper. Our contributions are threefold. Firstly, the 3D points and lines generated by an RGB-D camera combining with 2D point and line features are utilized to establish the PL-GM, which is different from most models of point-line SLAM (PL-SLAM). Secondly, in addition to the 2D re-projection error of point and line features, the constraint errors of 3D points and lines are constructed and minimized likewise, and then a unified optimization model based on PL-GM is extended to the bundle adjustment model (BA). Finally, extensive experiments have been performed on two public benchmark RGB-D datasets and a real scenario sequence. These experimental results demonstrate that our method achieves a comparable or better performance than the state-of-the-art SLAM methods based on point and line features, and point features.

This paper presents details of the recently reactivated landslide in Wushan Town, Chongqing, China. The landslide was reactivated on July 17, 2019, by slope cutting, and thereafter, entered a state of imminent sliding. The landslide involved 4 million m3 of rock and soil masses, thereby threatening National Road G348 and the safety of 588 residents in 136 households in Xiping Village and over 1000 residents in the Jinke Community. Field investigations, drilling, and in situ monitoring were performed to determine the landslide deformation characteristics and reactivation mechanism. The results show that the regional abundant rainfall, formation lithology, and tectonic effects were responsible for the formation of the ancient Baiyangwan landslide. Moreover, the building load on the rear and middle parts increased the sliding force. Open excavation at the toe decreased the anti-sliding force and directly promoted landslide reactivation. In particular, the groundwater table rise caused by gully filling in recent years also played a key role in the reactivation of the ancient landslide.

Intrusive granite dykes and their weathered layers can have great effects on seepage into slopes and on their stability. However, few studies of this topic have been reported. Using the Zhonglincun landslide as an example, we investigate the impact of a dyke and its weathered layer on the formation mechanism of a rainfall-induced residual soil slope failure. The sliding mass of Zhonglincun landslide is mainly composed of residual soils of both tuff and an intrusive granite dyke. We used laboratory soil column tests to obtain rainfall infiltration characteristics of the two residual soils. The SEEP/W mode of Geo-studio software was then used to replicate the above soil column tests to back-analyze unsaturated hydraulic parameters of the two soils, which were later used to simulate seepage fields and stress-strain fields of the slope under Typhoon Tailim. The results indicate that the movement of rainwater in the residual soil of the granite dyke is much faster than that of the residual soil of the tuff. Rainwater infiltrates rapidly into the granite soil, and then flows laterally into the tuff residual soil, raising the groundwater table in the slope, especially near the contact between the two residual soils. This leads to a rapid increase in pore-water pressure and initiates the serious deformation of the landslide. The granite dyke and its residual soil have played a key role in the formation of Zhonglincun landslide.

In the present study, a novel bioglass (BG)-incorporated α-triphosphate calcium (α-TCP)/gypsum composite cement with poly (γ-glutamic acid) (PGA) aqueous solution as a reactive liquid phase was dev...

Understanding of the structure-function relationships of natural protein channels remains a challenging task because of their unattainable physiological functions in terms of selectivity. To achieve this, a synthetic system of chemically modified channels has been constructed based on helical polymer scaffolds. Here, we report a type of positively charged channels in which multiple quaternary ammonium groups are covalently modified on the lumen surface of helical polymer while the helical conformation is intact. Compared to unmodified channels, the existence of multiple charged groups in the cavity not only makes the lumen size narrower but also essentially changes the channel properties without obstructing channel structure. Our study indicates that positively charged channels preferentially transport anions with size-dependent selectivity, whereas alkali metal ions are almost completely suppressed by electrostatic repulsion. As a consequence, a specific artificial channel with high Cl

Radiotherapy (RT) in practical use often suffers from off-target side effects and ineffectiveness against hypoxic tumor microenvironment (TME) as well as remote metastases. With regard to these problems, herein, we provide semiconductor heterojunction structured WO2.9-WSe2-PEG nanoparticles to realize a synergistic RT/photothermal therapy (PTT)/checkpoint blockade immunotherapy (CBT) for enhanced antitumor and antimetastatic effect. Based on the heterojunction structured nanoparticle with high Z element, the nanosystem could realize non-oxygen-dependent reactive oxygen species generation by catalyzing highly expressed H2O2 in TME upon X-ray irradiation, which could further induce immunogenic cell death. Meanwhile, this nanosystem could also induce hyperthermia upon near-infrared irradiation to enhance RT outcome. With the addition of anti-PD-L1 antibody-based CBT, our results give potent evidence that local RT/PTT upon mild temperature and low radiation dose could efficiently ablate local tumors and inhibit tumor metastasis as well as prevent tumor rechallenge. Our study provides not only one kind of radiosensitizer based on semiconductor nanoparticles but also a versatile nanoplatform for simultaneous triple-combined therapy (RT/PTT/CBT) for treating both local and metastasis tumors.

While quantitative precipitation estimation (QPE) using weather radar is widely adopted in operation, precipitation data sets are often highly imbalanced. In particular, extreme precipitation usually lacks representation, which may introduce the bottleneck for radar QPE with machine learning models. Discovering the intrinsic characteristic of extreme precipitation with few samples is challenging. In this letter, we focus on the radar reflectivity data and aim to generate synthetic radar image sequences with respect to extreme precipitation. Considering the relatively long interval between continuous radar images due to radar volume scan, traditional methods in video generation are not suitable. In this letter, we propose Two-stage Generative Adversarial Networks (TsGANs) to address the above-mentioned problem. In general, our TsGAN constructs adversarial process between generators and discriminators: the generator produces samples similar to real data, while the discriminator determines whether or not a sample is eligible. In Stage I, we generate an image sequence containing content and motion features. In Stage II, we design an enhanced net structure to enrich the adversarial processes and further improve the motion features. Experimental testing is performed within the radar coverage in Shenzhen, China, on rainfall events in 2014–2016. Results show that our TsGAN is superior to previous works.

Electroencephalogram (EEG) signal processing has emerged as a critical problem for biometric applications due to its real-time requirement. While compressive sensing is an efficient method for signal compression, its application in EEG signal processing is limited due to its noise unawareness during transmission and time-consuming reconstruction procedure. In this paper, we propose a noise-aware sparse Bayesian learning approach with block structure (NA-BSBL) to achieve higher efficiency on data compression, reconstruction and classification. By applying novel structure for parameter and introducing the Mahalanobis Distance, our approach achieves an almost 20% reconstruction performance lift and 10% accuracy lift under noise condition. For further application of reconstructed EEG signal, we extract both the spatial and frequency domain features for classification. Experimental results show that the proposed approach can achieve 94% classification accuracy with 16% speed up compared with the conventional approach.

Butyrylcholinesterase (BChE) activity is an important index for a variety of diseases. In this work, a "turn-on" assay is proposed based on controlling the inner filter effect (IFE) of MnO2 nanosheets (NSs) on sulfur nanodots (S-dots). The fluorescence of S-dots is effectively quenched by the MnO2 NSs, due to the wide overlap of the emission spectrum of S-dots and absorption spectrum of MnO2 NSs, together with the superior light absorption capability of MnO2 NSs. BChE can catalyze acetylthiocholine and produce thiocholine, which effectively decomposes the MnO2 NSs into Mn2+, resulting in the disappearance of the IFE and recovery of fluorescence of S-dots. Two-stage linear relationships between the ratio of fluorescence intensity and concentration of BChE are observed from 0.05 to 10 and from 10 to 500 U L-1. A limit of detection of 0.035 U L-1 is achieved, which is the best performance so far. The as-proposed assay is robust enough for practical detection in human serum, and it can avoid interference from its sister enzyme (acetylcholinesterase) and glutathione at the micromolar level. The presented results provide a clue for the functionalization of S-dots, and offer a powerful tool as an analytic technique for nanomedicine and environmental science.

The effectiveness and mechanism of dimethyldithiocarbamate (DDTC) for recovering low-grade cobalt and nickel from the lixivium of a manganese-rich slag have been investigated via a computational and experimental study. First principles calculations using a solvation model showed that DDTC can efficiently bind Fe(III), Co(II), Ni(II), and Cu(II) via the carbon disulfide functional group, indicating that Fe(III) and Cu(II) should be removed before addition of DDTC. Experimentally, 80.2% Co and 78.0% Ni were extracted from the slag containing low-grade 0.09% Co and 0.073% Ni under optimal conditions. Then, 99.92% of iron was removed from the lixivium via hydroxide precipitation. Finally, after the treatment with DDTC, excellent recoveries of 97.98% and 98.08% were obtained for Co and Ni, respectively. Further, high-resolution X-ray photoelectron spectroscopy results showed that the added DDTC can collect not only the free metal ions but also the nano-sized sulfide mineral particles. Thus, DDTC shows potential for the recycling of low-grade Co and Ni resources from solution.

A novel strategy was used for preparation of flame retardant based on biomass debris to improve the flame retardant property of silicone rubber (SR). [(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)methyl]butanedioic acid (DDP) was used to modify diatomite by esterification method, and DDP@diatomite was obtained. The structure and morphology of this novel additive was identified using Fourier transform infrared spectroscopy (FTIR), Brunner-Emmet-Teller (BET) measurements, and X-ray photoelectron spectroscopy (XPS) together with scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDXS) techniques. Thermogravimetric (TG) analysis was performed to evaluate the thermal degradation behaviors of diatomite and DDP@diatomite. This novel additive was applied into silicone rubber (SR) composites. Combustion parameters, including heat release rate (HRR), total heat release (THR), smoke production rate (SPR), carbon monoxide (CO), peak smoke production rate (PSPR), peak carbon monoxide (PCO) and vertical burning time, were characterized by cone calorimeter and vertical burning tests. Results indicated that this flame retardant can reduce fire risk and toxicity effectively. TG and X-ray diffraction (XRD) patterns of SR and its composites were also investigated. The inexpensive property of modified diatomite could also expand its fire safe applications.

Large volume changes (∼300%) during cycling and low electronic conductivity of silicon (Si) always lead to the failure of the Si anode for lithium-ion batteries. In this paper, we report a facile method to fabricate Si/Ti3SiC2 composites by one-step sand-milling process. Ti3SiC2 is used as a mechanical strengthening and high conductive matrix for Si-based anode for the first time. X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) are conducted to characterize the structure and morphology of the Si/Ti3SiC2 composites. Capacity and cycling performance are studied by galvanostatic method. Nanoindentation test is performed to measure the elastic modulus and hardness of the electrodes. Electrochemical impedance spectroscopy (EIS) and four-probe electronic conductivity measurement are used to assess the effect of Ti3SiC2 on the electronic conductivity of Si anode. Electrochemical investigations show that both cycling stability and rate performance of Si/Ti3SiC2 anodes are significantly improved comparing with those of the pure Si anode. SEM, nanoindentation and four-probe electronic conductivity measurement results reveal that the Ti3SiC2 can not only significantly enhance the electronic conductivity of the Si/Ti3SiC2 anodes but also maintain the integrity of the electrode during cycling by markedly increasing the elastic modulus and hardness of the electrodes.

Since the excessive dosage of Pb2+ ions could facilitate the gangue mineral quartz activation and cause serious environmental problems, this work has an attempt to examine the performance of cupferron as a new alternative collector in selective separation of cassiterite from quartz with low dose of Pb2+ ions. Microflotation results show the improved selectivity of cupferron towards cassiterite as compared to quartz. Accordingly, its selective adsorption mechanism has been investigated by zeta potential measurements, X-ray photoelectron spectroscopy (XPS) analysis and first-principle density functional theory (DFT) calculations. The results of zeta potential measurements demonstrate the stronger adsorption of cupferron on cassiterite surface than quartz whether Pb2+ ion was added or not. The XPS analysis and first-principle DFT calculations consistently show that Sn4+ ions on the hydrated cassiterite surface exhibit much stronger reactivity towards cupferron adsorption than Si atoms on the hydrated quartz surface, resulting in a remarkable difference between the collecting ability of cupferron towards cassiterite and quartz. This work should shed new light on the discovery of cleaner flotation reagents for cassiterite beneficiation.

Daytime passive radiative cooling can achieve a cooling surface by reflecting the sunlight and radiating the heat to the outer space without consuming any energy. Aluminum phosphate (AlPO4) is a novel inorganic daytime passive radiative cooling material which has high solar reflectivity and high mid-infrared emissivity. The influence of heat treatment temperatures on crystallization behavior and optical properties are investigated by X-ray diffraction and spectrographs. The results demonstrate that increased heat treatment temperature will result in increased reflectivity but decreased mid-infrared emissivity. The effect of polyhedral structural differences between tridymite-type AlPO4 and cristobalite-type AlPO4 on mid-infrared and selective emissivity are discussed and analyzed. Furthermore, the tridymite-type AlPO4 fabricated at 700 °C possesses high solar reflectivity of 97% and selective emission with an emissivity of 0.90 across 8–13 µm. When made into coating, the optimum cooling effect could reach a temperature drop of ~4.2 °C lower than the ambient temperature and ~4.8 °C compared with commercial heat insulation coating under direct sunlight. This proves that AlPO4 is a promising energy-saving material for daytime passive radiative cooling application. Thus, it can greatly lower the indoor temperature and improve comfortability of people's living in buildings.

Despite the development of nanomaterials with high-Z elements for radiosensitizers, most of them suffer from their oxygen-dependent behavior in hypoxic tumor, nonideal selectivity to tumor, or inevasible damages to normal tissue, greatly limiting their further applications. Herein, we develop a Schottky-type heterostructure of Au–Bi2S3 with promising ability of reactive free radicals generation under X-ray irradiation for selectively enhancing radiotherapeutic efficacy by catalyzing intracellular H2O2 in tumor. On the one hand, like many other nanomaterials with rich high-Z elements, Au–Bi2S3 can deposit higher radiation dose within tumors in the form of high energy electrons. On the other hand, Au–Bi2S3 can remarkably improve the utilization of a large number of X-ray-induced low energy electrons during radiotherapy for nonoxygen dependent free radicals generation even in hypoxic condition. This feature of Schottky-type heterostructures Au–Bi2S3 attributes to the generated Schottky barrier between metal ...

The excellent energy storage performance of covalent sulfur-carbon material has gradually attracted great interest. However, in the electrochemical sodium storage process, the bond evolution mechanism remains an elusive topic. Herein, we develop a one-step annealing strategy to achieve a high covalent sulfur-carbon bridged hybrid (HCSC) utilizing phenylphosphinic acid as the carbon-source/catalyst and sodium sulfate as the sulfur-precursor/salt template, in which the sulfur mainly exists in the forms of C–S–C and C–S–S–C. Notably, most of the bridge bonds are electrochemically cleaved when the cycling voltage is lower than 0.6 V versus Na/Na+, leading to the appearance of two visible redox peaks in the following cyclic voltammogram (CV) tests. The in-situ and ex-situ characterizations demonstrate that S2− is formed in the reduction process and the carbon skeleton is concomitantly and irreversibly isomerized. Thus, the cleaved sulfur and isomerized carbon could jointly contribute to the sodium storage in 0.01–3.0 V. In a Na-S battery system, the activated HCSC in cut off voltage window of 0.6–2.8 V achieves a high reversible capacity (770 mA h g−1 at 300 mA g−1). This insight reveals the charge storage mechanism of sulfur-carbon bridged hybrid and provides an improved enlightenment on the interfacial chemistry of electrode materials.

Polycrystalline Bi4(Ti3-xFex/2Cox/2)O12 (0 ≤ x ≤ 0.4) ceramics are prepared by solid state reaction method. The low temperature ferromagnetism is successfully induced by Fe/Co co-doping. Particularly, the x = 0.3 ceramics possess the largest remnant magnetization (2Mr) of about 0.272 emu/g at 100 K. Furthermore, all the doped ceramics undergo a ferromagnetic to paramagnetic transition, and show typical spin glass behavior, which is confirmed by the isothermal remnant magnetization and Memory Effect. The magnetic mechanisms probably originate from the coexistence and competition between ferromagnetic double exchange interactions and antiferromagnetic superexchange interactions, which lead to the appearance of the spin glass behavior in the doped ceramics and the strongest ferromagnetism in the x = 0.3 ceramics. The present work provides basic data and theoretical reference for the exploitation of the new multifunctional materials.

In this study, propyl gallate (propyl 3,4,5-trihydroxybenzoate; PG) was introduced as a collector for scheelite. The adsorption mechanism on the scheelite surface was investigated by computational and experimental methods, including first principle calculations and Fourier transform infrared (FTIR) spectroscopy. Flotation experiments were conducted to investigate the flotation performance of PG on scheelite. Ethyl p-hydroxybenzoate (EPHB) and ethyl 3,4-dihydroxybenzoate (EDHB), acting separately as collectors for scheelite, were also investigated for comparison. Our results consistently demonstrated that PG chemisorbed onto the scheelite surface by forming a five-member ring through its ortho oxygens. As speculation, the chelating ability of PG was greater than that of EDHB, and EPHB cannot coordinate to Ca(II), which was in excellent agreement with FTIR results. The flotation results showed that PG exhibited an excellent collecting ability for scheelite, followed by the weaker collecting ability of EDHB. EPHB had nearly no ability to collect scheelite, thus confirming the first principle calculation and FTIR analysis. In addition, PG has a stronger ability to collect scheelite than BHA without activation by any metallic ions. Overall, PG is a promising scheelite collector for application and the activate polyphenolic hydroxyl groups offer a new insight for the development of flotation collectors.

Lead complexes of benzohydroxamic acid (Pb-BHA complexes) have been successfully applied to the industrial separation of scheelite from calcite and fluorite minerals. However, the separation of scheelite from calcite using Pb-BHA complexes in the absence of fluorite is difficult. In flotation tests, both sodium fluoride and fluorite particles have been shown to depress calcite but not scheelite. Therefore, fluoride ions from the dissolved fluorite particles play an important role in the flotation separation of scheelite from calcite. In the current study, the results of zeta potential analysis confirmed that fluoride ions are strongly adsorbed on calcite surfaces and that the point of zero charge for calcite shifts to that of fluorite. X-ray photoelectron spectroscopy and atomic force microscopy analyses clearly indicated that the fluoride ions are adsorbed on the calcite surface to form a fluorite film. Thus, this type of surface transformation shows promise as a strategy for the flotation separation of semi-soluble minerals.

Traditional radiotherapy can induce injury to the normal tissue around the tumor, so the development of novel radiosensitizer with high selectivity and controllability that can lead to more effective and reliable radiotherapy is highly desirable. Herein, a new smart radiosensitizer based on Cu2(OH)PO4 nanocrystals that can simultaneously respond to endogenous stimulus (H2O2) and exogenous stimulus (X-ray) is reported. First, Cu2(OH)PO4 nanocrystals can generate CuI sites under X-ray irradiation through X-ray-induced photoelectron transfer process. Then, X-ray-triggered CuI sites serve as a catalyst for efficiently decomposing overexpressed H2O2 in the tumor microenvironment into highly toxic hydroxyl radical through the Fenton-like reaction, finally inducing apoptosis and necrosis of cancer cells. Meanwhile, this nonspontaneous Fenton-like reaction is greatly limited within normal tissues because of its oxygen-rich condition and insufficient H2O2 relative to tumor tissues. Thus, this strategy can ensure that the process of radiosentization can only be executed within hypoxic tumors but not in normal cells, resulting in the minimum damages to surrounding healthy tissues. As a result, the X-ray-triggered Fenton-like reaction via introducing nontoxic Cu2(OH)PO4 nanocrystals under the dual stimuli provides a more controllable and reliable activation approach to simultaneously enhance the radiotherapeutic efficacy and reduce side effects.

The development of a new multifunctional nanomedicine capable of enhancing radiosensitization by photo-induced hyperthermia for the inhibition of cancer growth and metastasis is highly required for efficient treatment of cancer cells. Compared to the first near-infrared (NIR) window, the second NIR window light could provide a maximum penetration depth as well as minimizing autofluorescence due to its low scattering and energy absorption. Here, we report a new versatile theranostic agent based on ternary Cu3BiSe3 nanoparticles (NPs) modified by poly(vinylpyrollidone) (PVP-Cu3BiSe3). Benefiting from their preferable X-ray attenuation ability and strong NIR absorbance in the second NIR biological window, PVP-Cu3BiSe3 NPs can not only deposit more radiation doses to destroy the cancer cells, but also conduct the optical energy into hyperthermia for thermal eradication of tumor tissues and the improvement of the tumor oxygenation to overcome the hypoxia-associated radio-resistance of tumors. According to both in vitro and in vivo results, exposure to an X-ray plus 1064 nm laser completely kills cancer cells and even inhibits tumor metastasis, displaying no warning signs of a relapse. On the other hand, PVP-Cu3BiSe3 NPs can be used as a multi-model imaging agent for X-ray computer tomography (CT) and photoacoustic tomography (PAT) imaging. These demonstrate the potential of PVP-Cu3BiSe3 NPs in multimodal imaging-guided synergetic radiophotothermal therapy of deep-seated tumors and effective inhibition of their metastasis.

Drug-induced liver injury is one of the main causes of drug non-approval and drug withdrawal by the Food and Drug Administration (FDA). Acetaminophen (APAP) is a widely used non-steroidal anti-inflammatory drug for treating fever and headache. APAP is considered safe at therapeutic doses; however, there have been reports of acute liver injury following the administration of APAP. To explore APAP hepatotoxicity and its mechanisms, we designed and synthesized a new click chemistry probe, APAP-P1, in our current study. We introduced the PEG-azide probe linker into the acetyl group of acetaminophen. First, we evaluated the probe toxicity in HepaRG cells and found that it still retained hepatotoxicity. We also found that this probe APAP-P1 can be metabolized by HepaRG cells. This demonstrated that the APAP-P1 probe still kept its metabolism characteristics. Using this probe, we pulled down its potential targets in vivo and in vitro. APAP can directly target TrxR1; thus, we tested for this interaction by Western blotting of pull-down proteins. The results showed that APAP-P1 can pull down TrxR1 in vivo and in vitro.

Lead(II)-benzohydroxamic acid (lead-BHA) is a metal-organic complex system used as a highly selective collector in the flotation separation of oxide minerals. In the current study, the surface microstructures and adsorption mechanism of lead-BHA on mineral surfaces were comprehensively investigated using diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), Raman spectroscopy, atomic force microscopy (AFM) and first-principles calculations. The characteristic Raman peak indicated that lead-BHA adsorbs on mica surfaces. The AFM topography of a mica surface (0 0 1) treated with lead-BHA at a ratio of 1:1 showed many local adsorption layers, but no obvious adsorption layer was observed for the same surface treated with lead-BHA at a ratio of 1:2, which suggests that Pb(BHA)+ might be the effective species for mineral flotation. First-principles density functional theory (DFT) calculations indicated that the lowest unoccupied molecular orbital (LUMO) of Pb(BHA)+ was mainly localized on the lead atom, while the LUMO of Pb(BHA)2 was distributed over the whole molecule, implying that Pb(BHA)+ exhibits better affinity to the mica surface than Pb(BHA)2, and further suggesting that Pb(BHA)+ might be an effective specie. The further first-principle calculation, from the molecular level on mica surface, showed that the Pb(BHA)+ could produce a higher adsorption energy than Pb(BHA)2, revealing that the Pb(BHA)+ should be an effective specie that can efficiently adsorb onto the mica surface. This work may shed new light on the effective species of metal-organic complex collectors on oxide mineral surfaces in flotation separation.

Honeycomb materials have low density, high specific strength and stiffness, impact resistance, and good sound insulation effect, and therefore are widely used in aerospace, automobile, and ship field applications. In this paper, we study the in-plane impact response of a second-order hierarchical honeycomb (SHH) material. Its main structure is a hexagonal honeycomb, and the substructure is composed of an augmented double arrow honeycomb (ADAH) negative Poisson’s ratio unit. Through a finite element simulation, the failure stress of an hierarchical honeycomb in two directions of quasi-static crushing and dynamic crushing was analyzed, the failure stress of the hierarchical honeycomb under different densities, different speeds, and different substructures was discussed, and the theoretical failure stress was verified. The numerical analysis results show that a second-order hierarchical honeycomb (SHH) has better collapse stress than a first-order regular hexagonal honeycomb (FHH) and an augmented double arrow honeycomb (ADAH).

RGB-D SLAM (Simultaneous Localization and Mapping) generally performs smoothly in a static environment. However, in dynamic scenes, dynamic features often cause wrong data associations, which degrade accuracy and robustness. To address this problem, in this paper, a new RGB-D dynamic SLAM method, PLD-SLAM, which is based on point and line features for dynamic scenes, is proposed. First, to avoid under-over segmentation caused by deep learning, PLD-SLAM combines deep learning for semantic information segmentation with the K-Means clustering algorithm considering depth information to detect the underlying dynamic features. Next, two consistency check strategies are utilized to check and filter out the dynamic features more reasonably. Then, to obtain a better practical performance, point and line features are utilized to calculate camera pose in the dynamic SLAM, which is also different from most published dynamic SLAM algorithms based merely on point features. The optimization model with point and line features is constructed and utilized to calculate the camera pose with higher accuracy. Third, enough experiments on the public TUM RGB-D dataset and the real-world scenes are conducted to verify the location accuracy and performance of PLD-SLAM. We compare our experimental results with several state-of-the-art dynamic SLAM methods in terms of average localization errors and the visual difference between the estimation trajectories and the ground-truth trajectories. Through the comprehensive comparisons with these dynamic SLAM schemes, it can be fully demonstrated that PLD-SLAM can achieve comparable or better performances in dynamic scenes. Moreover, the feasibility of camera pose estimation based on both point features and line features has been proven by the corresponding experiments from a comparison with our proposed PLD-SLAM only based on point features.

The strategy of enhancing the surface activity by preadsorption of metal ions (surface activation) is an effective way to promote the adsorption of surfactant on surfaces, which is very important in surface process engineering. However, the adsorption mechanism of surfactant (collector) on the surface preadsorbed by metal ions in the explicit solution phase is still poorly understood. Herein, the effects of hydration on the adsorption of benzohydroxamic acid (BHA) onto the oxide mineral surface before and after lead-ion activation are investigated by first-principles calculations, owing to its importance in the field of flotation. The results show that the direct adsorption of BHA on the hydrated surface is not thermodynamically allowed in the absence of metal ions. However, the adsorption of BHA onto the lead-ion-activated surface possesses a very low barrier and a very negative reaction energy difference, indicating that the adsorption of BHA on hydrated Pb2+ at cassiterite surface is very favorable in both thermodynamics and kinetics. In addition, the adsorption of BHA results in the dehydration of hydrated Pb2+. More interestingly, the surface hydroxyl groups could participate in and may promote the coordination adsorption through proton transfer. This work sheds some new lights on understanding the roles of interfacial water and the mechanisms of metal-ion surface activation.

The torque mode is more suitable for the direct drive 6 degree of freedom (6-DOF) parallel mechanism than the speed mode that both dynamic coupling and current coupling among motors are easily solved, but its key parameters and dynamic characteristics have never been studied, which are important and are the goals of this paper. First the hydraulic system of the direct drive 6-DOF parallel mechanism is simplified. Then the transfer function of the direct drive hydraulic system with the torque mode is deduced together with that of the speed mode. Finally, comparative experiments are conducted. Results show that the dynamic characteristics of the system with the torque mode which are generally worse than those with the speed mode, are mainly determined by the parameters of the motor-pump second-order element of the transfer function composed of two under-damped second-order elements, proportion differentiation (PD) control strategy and dynamic pressure feedback (DPF) control strategy are useful for the system with the torque mode, but practical and effective methods are still needed.

Sulfuration flotation is the most widely used technology in malachite beneficiation. However, the inhomogeneity of malachite surfaces usually results in a non-uniform sulfuration surface. The motivation of this work is attempt to adopt different functional combination collectors to enhance the sulfuration flotation of malachite. Accordingly, the flotation behaviors and adsorption mechanisms of benzohydroxamic acid (BHA) and sodium butyl-xanthate (SBX) on the surface of malachite were systematically investigated using flotation tests, zeta-potential measurements, Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, and first-principle calculations. The test results of vulcanization flotation showed that the combined collectors of SBX with BHA possessed a higher recovery than only using SBH by 20%, indicating that there may be a synergistic effect between BHA and SBX. The IR and Raman spectroscopy demonstrated that both BHA and SBX could chemically adsorb onto the malachite surface. The density functional theory (DFT) calculation results further indicated that the combined adsorption energy of BHA and SBX was much lower than that of only BHA or SBX, which confirmed the synergistic effects of BHA and SBX on the malachite surface. This work may shed new light on the design and development of more efficient combined flotation reagents.

Work in the construction site is considered to be one of the occupations with the highest safety risk factor. Therefore, safety plays an important role in construction site. One of the most fundamental safety rules in construction site is to wear a hardhat. To strengthen the safety of the construction site, most of the current methods use multi-stage method for hardhat-wearing detection. These methods have limitations in terms of adaptability and generalizability. In this paper, we propose a one-stage object detection method based on convolutional neural network. We present a multi-scale strategy that selects the high-resolution feature maps of DarkNet-53 to effectively identify small-scale hardhats. In addition, we propose an improved weighted bi-directional feature pyramid network (BiFPN), which could fuse more semantic features from more scales. The proposed method can not only detect hardhat-wearing, but also identify the color of the hardhat. Experimental results show that the proposed method achieves a mAP of 87.04%, which outperforms several state-of-the-art methods on a public dataset.

In this study, the model compound esculetin that has functional groups typical for natural organic matter (NOM) was used to ascertain the nature of the characteristic bands in the differential UV-visible absorbance spectra (DAS) associated with the formation of metal-NOM complexes. The binding of ten different metal ions (Cu(II), Ni(II), Co(II), Fe(III), Cr(III), Al(III), Zn(II), Ca(II), Mg(II) and Pb(II)) with esculetin generate four bands in the DAS. These bands are similar to those present in the DAS of metal-NOM complexes. The UV-visible absorbance spectra of the metal-esculetin systems were calculated using time-dependent density functional theory (TD-DFT). The TD-DFT results demonstrate that the prominent features of the DAS of esculetin are primarily associated with the electron transitions between the molecular orbitals near the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) in the metal-esculetin complex. Charge decomposition analysis (CDA) results demonstrated that these electron transitions originate from the esculetin fragment to the Zn(II) fragment in the complex. Covalent indexes [(χm)2rc] of the metal ions were found to be correlated with the metal-specific features of the DAS of metal-esculetin systems. The strength of the linear correlations between the quantitative parameters of the electron density of the bond critical points (BCP) is indicative of the strength of the metal-esculetin interactions.

Reactive oxygen species (ROS) play an essential role in physiological and pathological processes. Studies on the regulation of ROS for disease treatments have caused wide concern, mainly involving the topics in ROS‐regulating therapy such as antioxidant therapy triggered by ROS scavengers and ROS‐induced toxic therapy mediated by ROS‐elevation agents. Benefiting from the remarkable advances of nanotechnology, a large number of nanomaterials with the ROS‐regulating ability are developed to seek new and effective ROS‐related nanotherapeutic modalities or nanomedicines. Although considerable achievements have been made in ROS‐based nanomedicines for disease treatments, some fundamental but key questions such as the rational design principle for ROS‐related nanomaterials are held in low regard. Here, the design principle can serve as the initial framework for scientists and technicians to design and optimize the ROS‐regulating nanomedicines, thereby minimizing the gap of nanomedicines for biomedical application during the design stage. Herein, an overview of the current progress of ROS‐associated nanomedicines in disease treatments is summarized. And then, by particularly addressing these known strategies in ROS‐associated therapy, several fundamental and key principles for the design of ROS‐associated nanomedicines are presented. Finally, future perspectives are also discussed in depth for the development of ROS‐associated nanomedicines., Reactive Oxygen Species (ROS)‐regulating nanomedicines for disease treatments mainly include ROS‐upregulating nanomedicines and ROS‐downregulating nanomedicines. Here, ROS‐upregulating nanomedicines can exert the toxic effect by employing nanoplatforms to enhance ROS generation in pathological sites for ROS‐induced toxic therapy, and ROS‐downregulating nanomedicines can scavenge excess ROS to maintain normal physiological process and avoid oxidative stress injuries for antioxidant therapy.

A single-machine infinite system (SMIS) simulation model with AVR, thyristor high gain exciter and PSS is established by using the mathematical mode and Simulink. Firstly, the dynamic performance simulation of the system is carried out under different disturbance conditions. Then analyze the dynamic performance of the system with different types of power system stabilizer ( PSS ) . The experimental results show that the system with PSS can effectively suppress the low-frequency oscillation and maintain the dynamic stability of the system. And the two-input PSS provides better robustness to the system than a single-input PSS.

Concentrations of several toxic disinfection by-products (DBP), notably haloacetonitriles (e.g., trichloroacetonitrile, TCAN) and haloketones (e.g., di- and trichloropropanone, DCPN and TCPN, respectively) are affected by chlorination conditions and the inherent instability of these DBPs. In this study, effects of temperature, chlorine dose and reaction time on the formation of TCAN, DCPN and TCPN were interpreted using the approach of differential absorbance spectroscopy. Experimental data obtained for a wide range of water quality conditions demonstrate that in some cases the concentrations of some of the unstable DBPs increased rather than decreased at low temperatures and realistically long contact times. Despite the presence of pronounced changes of the kinetics of generation and degradation of these DBPs at varying temperatures and chlorine doses, their concentrations were strongly correlated with the concurrent changes of spectroscopic properties of DOM quantified via differential absorbance measurements at 272 nm (ΔA272). The maximum values of TCAN, DCPN and TCPN concentrations observed for the chlorination of eight different surface waters occur at the relative decreases of absorbance at 272 nm (defined as RΔA272) values of ca. 0.32 (±0.03), 0.24 (±0.05), and 0.42 (±0.03), respectively. The activation energies of degradation reactions of unstable DBPs were examined and the results indicate that TCAN and TCPN are caused by their hydrolysis with OH− while the degradation of DCPN is mainly caused by halogenation reaction with HOCl. These results in this study may be important for controlling the formation of unstable DBPs and further optimization of drinking water treatment.

Residual dissolved aluminum (Al) in drinking water is becoming a serious concern due to its high potential risks to human health. However, the mechanism by which residual dissolved Al forms is yet to be elucidated in detail. In this study, the effects of pre-oxidation by ozonation and chlorination on the properties of dissolved organic matter (DOM) and residual Al concentrations remaining in solution after coagulation were explored in a pilot-scale test. Changes in the DOM properties caused by the water treatment process were characterized by ultraviolet-visible absorbance spectroscopy. Theprotonation-active sites, carboxylic- and phenolic-type groupsof DOM were quantified by spectral parameter DlnA400 (differential log-transformed spectra at wavelength 400 nm) in combination with the revised non-ideal competitive adsorption model. The results show that ozonation and chlorination significantly affect the properties of DOM and the amount of residual dissolved Al in coagulated drinking water. This effect was associated with the changes in the carboxylic- and phenolic-type groups in DOM. Results of the study show that residual dissolved Al in coagulated water can be controlled by affecting theAl binding sites in DOM by pre-oxidation before coagulation. The nature of pre-oxidation agent and its dosage should be selected depending on the quality of the raw water to be treated. Ozonation was concluded to be preferable pre-oxidation agent for the water in examined this study.

Plasma has shown excellent potential prospects in sterilization applications nowadays. In this paper, we firstly design a novel sterilizer based on bipolar corona discharge of needle-dielectric-needle configuration. With the help of the dielectric plate, the new sterilizer can effectively avoid spark or arc discharge and eventually converge into a neutral ionic wind. The electrical and optical characteristics of bipolar corona discharge were studied in detail, and the ionic wind velocity with different electrode spacings was measured. The results revealed that the average current had a quadratic relationship with the overvoltage following Townsend relation, and the ionic wind velocity was positively correlated with the overvoltage. Furthermore, we simply estimated the sterilization effect of bipolar corona discharge. It was found that the sterilization efficiency increases with the increase of exposure time, and decreases with the rise of distance from the grounded electrode to the petri dish. In particular, the bipolar corona has a satisfactory sterilization efficiency which can reach 100% at 6 minutes.

Luminescence nanothermometry is promising for noninvasive probing of temperature in biological microenvironment at nanometric spatial resolution. Yet, wavelength- and temperature-dependent absorption and scattering of tissues distort measured spectral profile, rendering conventional luminescence nanothermometers (ratiometric, intensity, band shape, or spectral shift) problematic for in vivo temperature determination. Here, a class of lanthanide-based nanothermometers, which are able to provide precise and reliable temperature readouts at varied tissue depths through NIR-II luminescence lifetime, are described. To achieve this, an inert core/active shell/inert shell structure of tiny nanoparticles (size, 13.5nm) is devised, in which thermosensitive lanthanide pairs (ytterbium and neodymium) are spatially confined in the thin middle shell (sodium yttrium fluoride, 1nm), ensuring being homogenously close to the surrounding environment while protected by the outmost calcium fluoride shell (CaF2, ≈2.5nm) that shields out bioactive milieu interferences. This ternary structure enables the nanothermometers to consistently resolve temperature changes at depths of up to 4mm in biological tissues, having a high relative temperature sensitivity of 1.4–1.1% °C−1in the physiological temperature range of 10–64°C. These lifetime-based thermosensitive nanoprobes allow for in vivo diagnosis of murine inflammation, mapping out the precise temperature distribution profile of nanoprobes-interrogated area.

In this study, salicylhydroxamic acid (SHA), which exhibits superior flotation performance to conventional collector benzohydroxamic acid (BHA), was first introduced in ilmenite flotation. The addition of lead(II) can significantly increase the recovery of ilmenite using SHA as collector. Thus, the adsorption mechanism of SHA on lead(II)-activated ilmenite surface was systematically studied using micro-flotation tests, adsorption analysis, zeta potential measurements, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Micro-flotation results revealed that SHA had stronger collecting ability than BHA, and ilmenite floatability could be activated by lead ions with either SHA or BHA as collector. Ilmenite showed good floatability at pH 6–8 (over 90% recovery) in the presence of Pb2+ and SHA. In such conditions, the main lead species of Pb(OH)+ and Pb2+ acted as active sites and caused positive surface potential shifts, thereby increasing the adsorbed amounts of negatively charged SHA on the surface of the mineral. FTIR and XPS analyses suggested that the lead species was chemically adsorbed on the surface of ilmenite to form active sites chelated by SHA. Moreover, the free lead ions in solution might form the Pb–SHA complexes to adsorb on the mineral surface, thereby increasing the floatability of ilmenite.

The microcapsule containing phase change materials(microPCMs) with high efficiency of photothermal conversion was prepared by in-situ polymerization via ultrasonic dispersion which used capric acid(CA) as core material and nano silicon carbide(nano-SiC) modified melamine-urea-formaldehyde(MUF) resin as wall material. The nano-SiC has good cross-linking with MUF shell. When the nano-SiC was added in microPCMs, it behaves superior thermal conductivity and thermal storage properties. When the content of nano-SiC arrives 6 wt%, the performance of the microPCMs whose encapsulation efficiency is 65.7% is the best, and thermal conductivity increase by 59.2%. Due to the proper amount of nano-SiC added into the MUF shell, it can effectively fill the tiny holes on the MUF shell. Therefore, the microPCMs with appropriate nano-SiC have better leakage prevention. It is worth noting that MicroPCMs-6% and MicroPCMs-8% show excellent photothermal conversion property, and the photothermal conversion rate is 74.4% and 71.1% respectively in the photothermal conversion experiment. Because nano-SiC can effectively capture and absorb photons under light irradiation and convert light into heat through internal molecular vibration, the microPCMs with appropriate nano-SiC behaves well in photothermal conversion. In other words, microPCMs have potential in solar energy utilization and thermal energy storage.

This study compared chlorination-induced changes of the properties of natural organic matter (NOM) represented by standard humic substances and NOM present in pristine and anthropogenically-affect reservoirs, rivers, groundwater and seawater. The chlorination-induced changes of NOM properties were quantified using the differential absorbance spectra (DAS) which were processed via numeric deconvolution. Six Gaussian bands were found to comprise the DAS of all examined waters. These bands (denoted as A0, A1, A2, A3, A4 and A5, respectively) have maxima located at ca. 200, 240, 276, 316, 385 and 547 nm. The bands A1-A4 were observed in the DAS of representative model chlorinated compounds. Quantum chemical (QC) calculations were carried out to examine the intrinsic nature of these bands and electronic transitions associated with them. QC data demonstrate that bands A1 and A2 are present in almost all aromatic organic species, A3 is likely to be associated with acetophenone- and/or styrene-like groups. A4 can be attributed to the engagement of m-hydroxyaromatic and flavone-type groups typical for the polyphenolic moiety in NOM and known to be the key precursors of disinfection by-product (DBP) formation. Thus, the intensity of band A4 is predicted to be an especially strong predictor of DBP formation.

Aiming at inertial and viscous parameter identification for the Stewart manipulator regardless of the influence of Coulomb friction, a simple and effective dynamical parameter identification method based on wavelet transform and joint velocity analysis is proposed in this paper. Compared with previously known identification methods, the advantages of the new approach are that (1) the excitation trajectory is easy to design, and (2) it can not only identify the inertial matrix, but also the viscous matrix accurately regardless of the influence of Coulomb friction. Comparison is made among the identification method proposed in this paper, another identification method proposed previously, and the true value calculated with a formula. The errors from results of different identification methods demonstrate that the method proposed in this paper shows great adaptability and accuracy.

Accurate segmentation ofs organs-at-risk (OARs) in computed tomography (CT) is the key to planning treatment in radiation therapy (RT). Manually delineating OARs over hundreds of images of a typical CT scan can be time-consuming and error-prone. Deep convolutional neural networks with specific structures like U-Net have been proven effective for medical image segmentation. In this work, we propose an end-to-end deep neural network for multiorgan segmentation with higher accuracy and lower complexity. Compared with several state-of-the-art methods, the proposed accuracy-complexity adjustment module (ACAM) can increase segmentation accuracy and reduce the model complexity and memory usage simultaneously. An attention-based multiscale aggregation module (MAM) is also proposed for further improvement. Experiment results on chest CT datasets show that the proposed network achieves competitive Dice similarity coefficient results with fewer float-point operations (FLOPs) for multiple organs, which outperforms several state-of-the-art methods.