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Blue phosphorene (blue-P), an allotrope of black phosphorene, is prone to oxidize under ambient conditions, which significantly hinders its incorporation in anode for Li/Na ion batteries (LIBs/NIBs). Combining blue-P and hexagonal boron nitride (h-BN) together to construct h-BN/blue-P heterostructure (BN/P) can break the limitation of the restricted properties of blue-P. By means of first-principles computations, we explored the potential of using BN/P as anode material for LIBs/NIBs. Our computations show that the adsorption energies of Li/Na in BN/P are stronger than those in blue-P. Interestingly, although Li has similar chemical properties to Na, their the most energetically favorable sites on BN/P are different. Li prefers to insert into the interlayer of BN/P while Na prefers to absorb on the blue-P surface of BN/P. Furthermore, BN/P can achieve high theoretical specific capacities 801 and 541 mAh/g and low diffusion barriers 0.08 and 0.07 eV for LIBs and NIBs, respectively. All these characteristic...

Objective Although angiogenesis plays an important role in coronary collateral circulation (CCC) formation and there are many determinants of coronary angiogenesis, they cannot fully explain the mechanism of CCC formation or as potent biomarker for CCC status. Therefore, there is of great clinical significance to identify the novel molecules associated with CCC. Previously, miR-503 exerts anti-angiogenesis effect via inhibition of VEGF-A and its expression is associated with many angiogenesis-related factors. Thus, we aimed to investigate the relationship of plasma miR-503 with CCC formation as well as its predictive power for CCC status in patients with coronary artery disease. Methods Among patients who underwent coronary angiography with coronary artery disease and a stenosis of ≥90% were included in our study. Collateral degree was graded according to Rentrop Cohen classification. The patients were divided to good CCC group (grade 2 or 3) and poor CCC group (grade 0 or 1) according to Rentrop grade. We investigated the plasma levels of miR-503 and VEGF-A by ELISA or q RT-PCR, respectively. In addition, we assayed the correlations of plasma miR-503 with VEGF-A or Rentrop grade using the spearman correlation test and its predictive power by receiver operating characteristic (ROC) and binary logistical regression analysis. Results Our data showed that plasma VEGF-A was significantly higher in good CCC group than that in poor group. Plasma miR-503 was lower in CAD patients with good CCC or poor CCC compared with control subjects and lowest in good CCC group. In addition, miR-503 negatively correlated with VEGF-A and Rentrop grade, respectively. Moreover, miR-503 displayed more potent predictive power for CCC status than VEGF-A, but its sensitivity and specificity for CCC status were only 72.4 or 60.9%, respectively. Conclusions Lower plasma miR-503 level was related to better CCC formation, accompanied by up-regulation of VEGF-A. In addition, miR-503 displayed potent predictive power for CCC status, but its sensitivity and specificity were not high enough, indicating that miR-503 might be as an additional prognosis biomarker for CCC.

In this work, dual-wavelength UV photodetectors were successfully constructed by growing ZnO and MgZnO layers on SiO2 substrates with ZnO/Au/MgZnO structure. The photodetectors exhibited high performance and the influence of different thickness of MgZnO layers was investigated. Moreover, simply by adjusting the applied voltage on the devices, the ratio of the two response peaks (caused by MgZnO and ZnO layers) changed therewith. The detecting properties may originate from the two layers having different increasing rates where the existence of Schottky junctions plays an important role. The photodetectors are meaningful for fabricating dual-wavelength optoelectronic devices for practical applications.

Here, we report that the co-loading of graphene quantum dots (GQDs) and PdS dual cocatalysts on ZnCdS surface achieves a high efficiency photocatalytic H2 evolution under visible light (≥420 nm). The GQDs/ZnCdS/PdS photocatalyst was prepared by a facile two steps: hydrothermal coupling of GQDs on ZnCdS surface followed by an in-situ chemical deposition of PdS. The resulted GQDs/ZnCdS/PdS exhibits a H2 evolution rate of 517 μmol h−1, which is 15, 7, and 1.7 times higher than that of pure ZnCdS, GQDs/ZnCdS, and ZnCdS/PdS, respectively, demonstrating the synergistic effects of GQDs and PdS dual cocatalysts. A high apparent quantum efficiency (AQE) up to 22.4% can be achieved over GQDs/ZnCdS/PdS at 420 nm. GQDs/ZnCdS/PdS also has a relatively good stability. Such a considerable enhancement of photocatalytic activity was attributable to the co-loading of the GQDs and PdS as respective reduction and oxidation cocatalysts, leading to an efficient charge separation and surface reactions.

Characterizing the structure of knowledge, the evolution of research topics, and the emergence of topics has always been an important part of information science (IS). Our previous scientometric review of IS provided a snapshot of this fast-growing field up to the end of 2008. This new study aims to identify emerging trends and new developments appearing in the subsequent 7574 articles published in 10 IS journals between 2009 and 2016, including 20,960 references. The results of a document co-citation analysis show great changes in the research topics in the IS domain. The positions of certain core topics found in the previous study, namely, information retrieval, webometrics, and citation behavior, have been replaced by scientometric indicators (H-index), citation analysis (citation performance and bibliometrics), scientific collaboration, and information behavior in the most recent period of 2009–2016. Dual-map overlays of journals show that the knowledge base of IS research has shifted considerably since 2010, with emerging topics including scientific evaluation indicators, altmetrics, science mapping and visualization, bibliometrics, citation analysis, and scientific collaboration.

In this paper, we report a highly active and robust three-dimensional (3D) Cu foam@MoSx electrode for electrocatalytic hydrogen evolution reaction (HER) prepared by a simple and controllable electrochemical deposition method. Highly conductive Cu foam scaffold with exposed 3D frameworks can not only ensure an intimate interface for facilitate a fast electron transfer but also render the deposited amorphous MoSx with abundant exposed active sites and large contact area for electrolyte diffusion. As a result, the optimized Cu foam@MoSx electrode exhibits high activity for electrocatalytic H2 evolution in 0.5 M H2SO4, the required overpotentials to reach current densities of 10 and 100 mA cm−2 are 200 and 250 mV, respectively. Moreover, the Cu foam@MoSx electrode shows no obvious deactivation after 2000 potential cycling and also retains its outstanding electrocatalytic activity after 10 h bulk electrolysis for H2 evolution due to the robust adhesion of MoSx. This work provides a new strategy to the development of highly active HER electrocatalyst by integrating high-surface-area and conductive substrate and the favorable surface structures of active components.

Efficient photocatalysts induced by visible light (e.g. BiOI) have attracted wide attention for energy storage and environmental pollutant rehabilitation. In this work, N-doped bamboo tube-like carbon (NTC) was derived directly from the carbonization of bio-waste (withered typha grass) under an ammonia atmosphere. During fabrication, the BiOI/NTC material was used as a self-sacrificing template and I- ions were gradually replaced by OH- ions from NH3·H2O solution. Then Bi7O9I3/NTC was formed with micro-/nanohierarchical structures, which could exactly be explained by the in situ ion exchange-recrystallization mechanism. Thereinto, the well-defined hierarchical lantern-like Bi7O9I3 composed of interconnecting ultrathin nanosheets firmly embedded the "bamboo tubes" of NTC, which endow sufficient interface and high specific surface area (40 m2 g-1). The multiple synergistic effects of the lantern-like structure with ultrathin nanosheets, low iodine content and well-contacted interface endow the synthesized Bi7O9I3/NTC with outstanding visible-light catalytic activity. The results show that the obtained Bi7O9I3/NTC degraded 93.5% of methyl orange and 97.6% of rhodamine B within 2 hours, showing superior performance as compared to the pure BiOI. Therefore, our work demonstrates a controllable approach that can provide guidelines for designing optimized bismuth oxyiodide-based photocatalyst materials and has the potential for application in environmental remediation.

CoAl-layered double hydroxide nanosheets (CoAl-NSs) could serve as an active matrix to effectively anchor amorphous MoSx nanoparticles with high dispersion and the formation of an additional active “CoMoS” phase. The resulting CoAl-NSs/MoSx catalyst showed 13 times higher H2 evolution activity than free MoSx nanoparticles from an erythrosin B–triethanolamine (ErB–TEOA) system under visible light.

In this study, a facile one-step route was used to synthesize a novel magnetic mesoporous greigite (Fe3S4)-CTAB composite, which was utilized to remove hexavalent chromium (Cr(VI)). The optimized Fe3S4-CTAB0.75 composite with a CTAB dosage of 0.75 g possessed the maximum specific surface, showing the highest Cr(VI) adsorption capacity of 330.03 mg g−1. The mechanism analysis revealed that Fe(II) and S(−II) were critical for the reduction of Cr(VI). CTAB can promote the removal of Cr(VI) by Fe3S4-CTAB composites, possibly due to increased S(−II) concentration, better dispersion of nanoparticles, and greater zeta potential. Besides, there is mild effect of Fe0 on Cr(VI) removal, which is confirmed by the disappearance of the Fe0 peak from the XPS analysis. The pseudo-second-order kinetic model could explain the Cr(VI) removal processes well. The adsorption of Cr(VI) at different initial concentrations was more consistent with a Langmuir isotherm. The existence of H+ was beneficial for Cr(VI) removal by Fe3S4-CTAB0.75. Our work confirmed that the obtained Fe3S4-CTAB0.75 composites exhibit considerable potential for Cr(VI) removal from aqueous solution.

Two new all-metal molecules Be6Li8 and Be6Li14 have been designed theoretically. They possess Oh symmetric geometries and centrosymmetric electric structures. The number of their valence electrons satisfying Hirsch's rule and the highly negative nucleus independent chemical shifts at their centers reveal that they are spherical aromatic, which leads to their good chemical stabilities. When an external electric field is applied to Be6Li8 and Be6Li14, the centrosymmetry of their electric structures is broken, which brings high first hyperpolarizability (β0) contrasts. We find that β0 of Be6Li14 is larger than that of Be6Li8 under an electric field. The reason for this is that the electron density is altered more easily in Be6Li14 than in Be6Li8, which is clearly shown in the evolutions of their HOMOs with increasing electric field strength. The calculated electron spectra show that Be6Li8 and Be6Li14 have infrared transparent wavebands from 2.5 to 8.0 μm. Thus, our calculated results demonstrate that they can act as electric-field-induced infrared nonlinear optical switches.

Thiomolybdate [Mo3S13]2− nanoclusters, as a molecular mimic of MoS2 edge sites, showed high efficiency in catalyzing photochemical H2 evolution from a molecular system of Ru(bpy)3Cl2–ascorbic acid (H2A) under visible light irradiation (≥420 nm), providing a turnover number of 1570 and an initial turnover frequency of 335 h−1 for H2 evolution based on the [Mo3S13]2− catalyst.

Noble-metal-free, durable and high-efficiency electrocatalysts for oxygen reduction and evolution reaction (ORR/OER) are vital for rechargeable Zn-air batteries (ZABs). Herein, a flexible and free-standing carbon fiber membrane immobilized with atomically dispersed Fe-N4 /C catalysts (Fe/SNCFs-NH3 ) is synthesized and used as air cathode for ZABs. The intertwined carbon fibers with hierarchical nanopores facilitate the gas transportation, electrolyte infiltration and electron transfer. The larger specific surface area after NH3 activation exposes a high concentration of Fe-N4 /C sites that embedded in the carbon matrix. Modulation of local atomic configurations by sulfur doping in Fe/SNCFs-NH3 catalyst leads to excellent ORR and enhanced OER activities. As-synthesized Fe/SNCFs-NH3 catalyst demonstrates a positive half-wave potential of 0.89 V and a small Tafel slope of 70.82 mV dec-1 , outperforming the commercial Pt/C (0.86 V/94.74 mV dec-1 ) and most reported M-Nx /C (M = Fe, Co, Ni) catalysts. Experimental characterizations and theoretical calculations uncover the crucial role of S doping in regulating ORR and OER activity. The liquid-state ZABs with Fe/SNCFs-NH3 catalyst as air cathode deliver a large peak power density of 255.84 mW cm-2 and a long-term cycle durability over 1000 h. Solid-state ZAB shows stable cycling at various flat/bent/flat states, demonstrating great prospects in portable and wearable device applications. This article is protected by copyright. All rights reserved.

The flexible contract is an important mechanism for owners to govern contractors in construction projects. Given the limited explanatory power of the justice mechanism and the important role of relational factors, this study explored the role of ongoing trust and justice perception in the relationship between contractual flexibility and the contractor’s cooperative behavior and aimed to further reveal the potential influence paths through an empirical analysis. We found the following: (1) apart from justice perception, ongoing trust is another crucial mediation factor in the relationship. (2) Together with the former, ongoing trust plays significantly multiple mediation effects and constitutes the main indirect influence paths, among which the parallel one is strongest and the chain one comes third. (3) Moreover, both factors are more likely to be impacted by contract executing flexibility, compared with contract content flexibility. These findings enrich relational mechanism research and provide some guidance for the owner to build contractual flexibility to govern contractors’ behavior.

This study investigates the photocatalytic degradation of nitrogen oxides over graphitic carbon nitride (g-C3N4) based photocatalysts. The synthesis procedure of g-C3N4 consists of two-step: in the first step, the synthesis of g-C3N4 is carried out through a microwave heating method, whereas in the second step the as-synthesized product is annealed. The characterization was carried out by XRD (X-ray Diffraction), FESEM (Field Emission Scanning Electron Microscopy), TEM (Transmission Electron Microscopy), BET (Brunauer-Emmet-Teller), and XPS (X-ray Photoelectron Spectroscopy). Photocatalytic activities for the degradation of NOx (Nitrogen Oxides) are compared with commercial TiO2 and g-C3N4, to investigate the structural and physio-chemical features of prepared samples and their correlation with the catalytic activity. The results show that g-C3N4 nanosheets have better activity and stability as compared to TiO2. The deposition effect of 1 wt% Pt to the g-C3N4 nanosheets is also observed which puts a negative effect on the degradation results.

Based on the interesting Janus-type all-cis1,2,3,4,5,6-hexafluorocyclohexane (1) molecule, a novel type of excess electron compounds MF-1-MH (MF = Li, Na and K, MH = Zn, Cd and Hg) were designed theoretically. The geometric structures, electronic structures and nonlinear optical properties of MF-1-MH compounds were studied by density functional theory. Our results show that in Li-1-MH, the obvious charge transfer between Li and MH can be observed while in Na/K-1-MH, the charge transfer between Na/K and MH is negligible. Particularly, the MF-1-MH exhibit remarkable nonlinear optical (NLO) response and the first hyperpolarizability of the K-1-Zn almost achieve 1.0 × 106 au. We hope this work will further enrich the family of excess electron compounds, so that more experimental interests and efforts can be attracted to propose and synthesize new excellent NLO materials.

The development of green and clean synthetic techniques to overcome energy requirements have motivated the researchers for the utilization of sustainable biomass. Driven by this desire we choose rice as starting materials source. After the explosion effect, the precursor is converted into puffed rice with a honeycomb-like structures composed of thin sheets. These honeycomb-like macrostructures, effectively prevent the cross-linking tendency towards the adjacent nanosheets during activation process. Furthermore, tuneable micro/mesoporous structures with ultrahigh specific surface areas (SBET) are successfully designed by KOH activation. The highest SBET of 3326 m2 g−1 with optimized proportion of small-mesopores is achieved at 850 °C. The rice-derived porous N-doped carbon nanosheets (NCS-850) are used as the active electrode materials for supercapacitors. It exhibites high specific capacitance specifically of 218 F g−1 at 80 A g−1 in 6 M KOH and a high-energy density of 104 Wh kg−1 (53 Wh L−1) in the ionic liquid electrolytes. These are the highest values among the reported biomass-derived carbon materials for the best of our knowledge. The present work demonstrates that the combination of “puffing effect” and common chemical activation can turn natural products such as rice into functional products with prospective applications in high-performance energy storage devices.

Lithium-rich layered oxides are widely considered as the most promising candidate for high energy density cathode in lithium-ion batteries (LIBs) due to their extraordinary capacity. However, cycle instability, poor rate capability and voltage decay impede their practical applications, which are caused by oxygen release and phase transformation during cycling. In this work, an ultrathin spinel Li4Ti5O12 (LTO) coating acting alike a “lithium ion pump” is built on the surface of lithium-rich layered oxides Li1.2Ni0.2Mn0.6O2 (LLNMO) through solvothermal method. It is identified that spinel LTO and layered LLNMO phases display heteroepitaxial structure resulting in reduction of oxygen loss, phase transformation, capacity decline and voltage fading. The cathode with heteroepitaxial structure demonstrates an acceptable initial coulombic efficiency up to 87.7% (only 79.8% for LLNMO), highly competitive cycling stability (97.9% capacity retention at 0.1C after 100 cycles), minimal voltage decay of 1.22 mV cycle−1 and excellent rate capability (171.5 mAh g−1 at 10C). The supreme electrochemical performances suggest that epitaxial spinel LTO coating can effectively stabilize oxygen framework and the layered structure on the surface of lithium-rich layered oxides for modification of high-capacity cathode in next generation LIBs.

A novel Ag-Bi2WO6-TiO2 (ABT) ternary photocatalyst was synthetized using a surface deposition and solvothermal method and its composite starch films with different amounts of ABT loading were prepared via a casting method. The morphology and microstructure of the ABT/starch composite films were characterized and their photocatalytic activity during the degradation of ethylene were evaluated. The results showed that the ABT photocatalyst exhibits excellent photocatalytic activity for the removal of ethylene under visible light with the maximum mineralization rate of 96% and CO2 production of 0.81 × 10-4. Compared with that of pure TiO2, Bi2WO6 and Bi2WO6-TiO2 composite, the reaction rate constant (k’) of ABT was improved by 188.13, 150.51, and 64.62%, respectively. When the surface loading of ABT was 2%, the photocatalytic performance of the ABT/starch film under visible-light reached its maximum with k’ increasing by 61.8% compared with the starch film without ABT loading on the surface. The improvement in the photocatalytic activity was attributed to the synergistic effect of nano-Ag, TiO2 and Bi2WO6. Ag nanoparticles are anchored on the Bi2WO6-TiO2 heterojunction, which increases the number of reactive active sites, broadens the absorption of visible light and produces more active species ·O2– and ·OH, thus enhancing the photocatalytic performance. The cooperative synergy over as-prepared ABT formed by multiple electron transfer channels composed of localized surface plasmon resonance (LSPR) enhancement, Z-sheme charge transfer and electronic sink effect results in effective charge separation and inhibits the recombination of photogenerated carriers, thus exhibiting exceptional photocatalytic activity.

We theoretically designed a novel two-dimensional (2D) donor-acceptor heterostructure, hydrogenated borophene (HB)/blue phosphorene (BP), with a very short interlayer distance (2.38 A). The molecular dynamics simulations indicate that the HB/BP heterostructure exhibits the high dynamic stability. Besides, we also explored the possibility of using HB/BP heterostructure as a potential anode for Li/Na-ion batteries (LIBs/NIBs) by performing density functional theory. Our results indicate that the HB/BP heterostructure has large adsorption energies (2.61 eV for Li and 2.17 eV for Na), low diffusion barriers (0.11 eV for Li and 0.10 eV for Na) and high storage capacities (1520 mAh/g for Li and 719 mAh/g for Na). Moreover, when the storage capacity reaches the maximum, the interlayer distances of the HB/BP heterostructure can shrink to about 2.27 A, which can buffer the anode volume change during charging/discharging of the battery. These excellent characteristics show that HB/BP heterostructure can be a new choice as anode material for LIBs/NIBs.

Low-crystalline or amorphous molybdenum sulfides (MoS x ), bearing abundant unsaturated active sites, have been identified as efficient catalysts for electrocatalytic and photocatalytic H 2 evolution reactions, however, their intrinsic activity is still low and need to be further improved for large-scale applications. In this paper, we report that low-crystalline MoS x doped with Co (Co-MoS x ) as efficient cocatalysts could be loaded on CdS nanoparticles through a facile and controllable photochemical reduction method and showed high performances in catalyzing H 2 evolution under visible light irradiation (≥420 nm). The photochemical loading of Co-MoS x was accomplished by using an in-situ formed molecular complex precursor and photogenerated electrons on CdS as reductants under mild conditions. The optimized CdS/Co-MoS x (Co:Mo = 1:4, 2 mol% loading) photocatalyst exhibited a catalytic H 2 evolution rate of 535 μmol h −1 , which is 1.8 times higher than that of CdS/MoS x , and an apparent quantum efficiency (AQE) of 23.5% was achieved over CdS/Co-MoS x photocatalyst at 420 nm. Co-MoS x catalyst also shows a long-term stability without noticeable activity degradation. Notably, Co-MoS x cocatalyst was found more efficient than that of noble metals in catalyzing photocatalytic H 2 evolution on CdS. The formation of CoMoS phase, the enhanced electrocatalytic activity as well as reduced electron transfer resistance due to the doping effects of Co ions, account for the enhanced catalytic activity of this Co-MoS x cocatalyst.

This paper demonstrates surface plasmons (SPs) enhanced MgZnO ultraviolet (UV) photodetectors grown by a radio frequency (RF) magnetron sputtering technique, and the magnesium concentration is 30%. Predominantly, well-defined Au NPs with different sizes were produced embedded in MgZnO thin films. Notably, at 30 V applied bias, the proper combination MgZnO/Au NPs (40 s), responsivity as high as 341.08 A/W is achieved after optimizing the process. Impressively, the excellent comprehensive performance of MgZnO/Au NPs UV photodetectors should have great applied potential, a physical mechanism is given to explain the above results.

Popcorn-derived porous carbon flakes have been successfully fabricated from the biomass of maize. Utilizing the “puffing effect”, the nubby maize grain turned into materials with an interconnected honeycomb-like porous structure composed of carbon flakes. The following chemical activation method enabled the as-prepared products to possess optimized porous structures for electrochemical energy-storage devices, such as multilayer flake-like structures, ultrahigh specific surface area (SBET: 3301 m2 g–1), and a high content of micropores (microporous surface area of 95%, especially the optimized sub-nanopores with the size of 0.69 nm) that can increase the specific capacitance. The as-obtained sample displayed excellent specific capacitance of 286 F g–1 at 90 A g–1 for supercapacitors. Moreover, the unique porous structure demonstrated an ideal way to improve the volumetric energy density performance. A high energy density of 103 Wh kg–1 or 53 Wh L–1 has been obtained in the case of ionic liquid electrolyte,...

Amorphous molybdenum sulfide catalysts (MoSx) can efficiently catalyze the H2 evolution reaction (HER); however, their catalytic activities are still limited that need to be improved. Herein, transition metal-promoted MoSx H2 evolution catalysts were facilely fabricated through an in-situ photochemical reduction with inexpensive organic dye as photosensitizers. Under visible light (λ ≥ 420 nm), the promotional effect of transition metals on the H2 evolution over MoSx follows the order of Co > Fe ≈ Ni > unpromoted > Cu > Zn in Erythrosin B-triethanolamine (ErB-TEOA) system. The most active Co-promoted MoSx (Co-MoSx) catalyst is amorphous and composed of inter-connected nanoparticles with diameters of 30–50 nm. The Co-MoSx catalyst contains both CoMoS phase and Co oxides/hydroxides. At the optimal reaction conditions, the Co-MoSx catalyst with Co:Mo ratio of 4:6 exhibits enhanced H2 evolution activity by 2 times as compared to unpromoted MoSx and turnover numbers (TONs) of 30 and 60 based on ErB and catalyst used, respectively. The Co-MoSx catalyst also shows a long-term stability without noticeable activity degradation. The formation pathways of Co-MoSx catalyst and the photocatalytic mechanism for enhanced H2 evolution performance were studied and a two-step reaction mechanism involved an oxidative quenching pathway of dye was proposed. This study demonstrates that in-situ concurrent photochemical fabrication with transition metal modification of amorphous MoSx catalyst is an effective strategy for development of MoSx-based HER catalysts with enhanced performances.

The coupling of semiconductor photocatalysts with graphene quantum dots (GQDs) has been proven to be an effective strategy to enhance the photocatalytic and photoelectrical conversion performances of the resulted composites; however, the preparation of semiconductor/GQDs composites usually involves several time-inefficient and tedious post-treatment steps. Herein, we present a facile one-step hydrothermal route for the preparation of GQDs coupled TiO2 (TiO2/GQDs) photocatalysts using 1,3,6-trinitropyrene (TNP) as the sole precursor of GQDs. During the hydrothermal process, TNP molecules undergo an intramolecular fusion to form GQDs, which simultaneously decorate on the surface of TiO2 nanoparticles, leading to a strong surface interaction between the two components. The effective coupling of GQDs on TiO2 can effectively extend the light absorption of the TiO2 to visible region and enhance the charge separation efficiency of TiO2/GQDs composites as a result of GQDs acting as a photosensitizer and an excellent electron acceptor. These key advances make the TiO2/GQDs photocatalyst highly active towards the H2 evolution reaction, resulting in 7 and 3 times higher H2 evolution rate and photocurrent response at optimal GQDs content than TiO2 alone, respectively. This study provides a new methodology for the development of high-performance GQDs modified semiconductor photocatalysts for energy conversion applications.

In this study, we investigated the evolution process and historical roots of citation analysis study by reference publication year spectroscopy (RPYS), which is an advanced research method recently introduced in the field of Scientometrics. Through analyzing the publication year and citation frequency of cited references in a knowledge domain, RPYS can identify the citation peak of such cited references. We collected 2543 articles including 56,392 references regarding citation analysis in SCI-E and SSCI databases between 1970 and July 2016 as our data source. Based on the RPYS method by the CRExplorer program, the results showed that the peak citation publication years by chronological order occurred in 1955, 1963, 1973, 1979, 1981, 1990, 2005 and 2008 in the field of citation analysis study. According to the overall distribution of peak citation publication years, the RPYS for citation analysis was divided into five time periods for the convenience of comparison in this paper: that is, before 1900, 1901–1950, 1951–1970, 1971–2000, and 2001–2016. Pre 1950, especially during the 1900s–1950s, before the citation analysis method was introduced, there were three rather high peak citation publication years, Lotka’s law and Bradford’s law laid the knowledge foundation for citation analysis. 1950s–1970s was the forming period of citation analysis, among the three citation peaks in this period, Garfield (Science 122(3159):1127–1128, 1955), Price (Von Der Studierstube Zur 7(3–6):443–458, 1963, Science 149:510–515, 1965), and Kessler (1963) established an important knowledge base for the formation of citation analysis study. 1971–2000 was a developing period of citation analysis. Document Co-citation Analysis and Author Co-citation Analysis methods laid the foundation of the development of citation analysis study. Since 2000, citation analysis study has been expanding rapidly. By the number of published papers and number of cited references with highly cited frequency, Garfield E., White H.D., Small H., MacRoberts M.H., Price D.D. have played an important role in promoting the evolution of citation analysis study.

An activated carbon (AC)-supported nanocomposite was prepared by precipitating β-FeOOH onto KOH activated soybean meal-derived biochar (SYBK). The as-prepared β-FeOOH/SYBK composites were characterized by N2-Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM), X-ray diffractions (XRD) and X-ray photoelectron spectroscopy (XPS). XRD results confirmed that β-FeOOH was impregnated by AC. The chromate (Cr(VI)) removal capacity was investigated in a batch experiment with different conditions. The ratios of β-FeOOH and AC were compared for Cr(VI) removal and a loading quantity of 20 wt% β-FeOOH was considered as the most efficient amount. This was possibly ascribed to it having the highest surface area (670.65 m2 g−1) of the β-FeOOH/SYBK nanocomposites. It was found that 20β-FeOOH/SYBK could remove as much as 96% Cr(VI) at pH 1–2 with 2 mmol L−1 EDTA and 2.0 g L−1 nanocomposites. The maximal Cr(VI) removal by 20β-FeOOH/SYBK was 37.04 g kg−1, as estimated by a Langmuir isotherm model. The removal mechanisms were examined by studying the speciation of Cr on sorbents as well as in aqueous solution. The XPS analysis of spent sorbents and chemical speciation of Cr in aqueous solutions revealed that partial Cr(VI) was reduced to Cr(III) on sorbents and in aqueous solution. This suggests that Cr(VI) can be removed by simultaneous sorption and reduction by the as-prepared nanocomposites.

In this work, cobalt micro-particles containing various nanoscale subunits were hydro- thermally synthesized and controlled by the content of sodium tartrate in reaction solution. Both the static and dynamic magnetization properties of cobalt particles changes accordingly. As the content of sodium tartrate varies from 0 g, 0.552 g to 4.416 g, subunits of the cobalt particles shrinks from dendrites, coralloids to small bumps, saturation magnetization changes from 122.5 emu/g, 86.5 emu/g, to 95.79 emu/g, and the coercive force reduces from 195 Oe, 148 Oe, to 62 Oe. Consequently, ferromagnetic resonance bandwidth of the cobalt particles decreases due to the diminishing surface scatterers (subunits), whereas low frequency loss tangential increases following the growth of spherical particle core. The proposed cobalt particles with nanoscale subunits shows potential for electromagnetic wave absorption and shielding application.

We report on metal-semiconductor-metal ultraviolet photodetectors based on a ZnO film/Pt nanoparticles/ZnO film composite structure. The responsivity of the sandwich photodetector is 45 times greater for the back-illuminated than the front-illuminated. Surprisingly, the responsivity of a ZnO photodetector without the Pt nanoparticles has rather feeble enhancement under the same conditions (illumination from back and front). The responsivity of the sandwich photodetector can be enhanced from 14 to 45 times by adjusting the embedded depth of the Pt nanoparticles. Combining this result with the optical absorption spectra of ZnO films with and without Pt nanoparticles, we can reasonable to deduce the underlying mechanism and attribute it to the coupling of the localized surface plasmon from Pt nanoparticles with ZnO films. These results demonstrate a method to control the responsivity enhancement by adjusting the embedded depth of the Pt nanoparticles in the sandwich photodetector.

The purpose of this study is to develop an active, low cost, non-precious, stable, and high-performance catalyst for oxygen reduction reaction (ORR). In this regard, Mn2O3-decorated nitrogen-doped carbon nanosheets (Mn2O3/NC) are fabricated by a two-step strategy involving a hydrothermal method and a solid-state method. In the resultant structures, very fine Mn2O3 nanoparticles with an average size of about 5 nm are strongly attached to nitrogen-doped carbon nanosheets. The role of the Mn2O3 nanoparticles is to provide active sites for ORR, while the presence of the nitrogen-doped carbon not only enhances the conductivity of the overall structure but is also helpful for overall stability. The Mn2O3/NC shows good onset potential (0.80 V@−1 mA/cm2), methanol crossover effect, and stability (90%).

Sodium (Na)-ion batteries (NIBs) and potassium (K)-ion batteries (KIBs) have grabbed great attention because they are cheaper, more abundant in earth, and safer alternatives of lithium-ion batteries. However, the lack of anode materials for NIBs/KIBs with good performance has been the main obstacle. In this paper, we studied monolayer MnC by carrying out calculations on the basis of first principle study to see if it can be a potential anode material for NIBs and KIBs. Calculation results show that monolayer MnC processes good negative adsorption energies of - 2.83 eV for Na and - 2.16 eV for K. Moreover, MnC has comparable theoretical capacities for Na and K of 475 mAh/g and 253 mAh/g, respectively. Our calculation results manifest that the MnC can be a promising anode material for NIBs. MnC monolayer absorbed with two layers of Na atoms.

Background: Current WHO guidelines (2018) recommend screening for cryptococcal antigen (CrAg) in HIV+ persons with CD4

Background Current WHO guidelines (2018) recommend screening for cryptococcal antigen (CrAg) in HIV-infected persons with CD4+ T cell counts Method We conducted a meta-analysis using data extracted from randomized controlled studies (RCTs) and cohort studies found in a search of Pubmed, Web of Science, the Cochrane Library and the EMBASE/MEDLINE database. Results The pooled prevalence of CrAg positivity in HIV-infected persons with CD4+ T cell countsp Conclusions In our meta-analysis the incidence of CM was significantly reduced by pre-emptive antifungal therapy in CrAg+ HIV-infected persons with CD4

In a study of sexually-active HIV-negative men who have sex with men (MSM) in China, we compared behavioral indication for pre-exposure prophylaxis (PrEP) based on risk criteria to self-perception of PrEP candidacy (SPC) and explored factors associated with SPC. Of 708 MSM surveyed, 323 (45.6%) were behaviorally-indicated for PrEP, among whom 42.1% self-perceived as appropriate PrEP candidates. In a multivariable model we found no association between sexual behavior nor HIV risk perception and SPC but found that higher perceived benefits of PrEP, increased frequency of HIV testing, and low condom use self-efficacy were positively-associated with SPC. In a sub-analysis restricted to MSM behaviorally-indicated for PrEP, relationship-factors were also significant. Our findings suggest that PrEP implementers should look beyond risk criteria to consider shared decision-making tools that support individuals to assess whether they are appropriate PrEP candidates based on their existing HIV prevention strategies, sexual health goals, and relationship dynamics.

Background Birdsong is an important form of communication that plays an important role in territorial defense and mate attraction by conveying valuable information. While body-size and song frequency are often negatively correlated among species, this relationship is only found in a few songbirds. Previous studies on the Dusky Warbler (Phylloscopus fuscatus) found that there was a positive correlation between tarsus length and peak frequency. And heavier male Dusky Warblers possess better territories and obtain more opportunities for mating; body condition may be related to reproduction of birds, so females may choose heavier mates or better body condition based on the singing characteristics of males. Methods We recorded spontaneous song and measured morphology of 33 male Dusky Warblers in Saihanba Forest Farm area between July 5 and August 10, 2015. We chose body weight as an indicator of body size and defined body condition as residuals from a linear regression between body weight and tarsus length. Frist, we used Pearson correlation to analyze whether date and time of day were correlated with weight, and then we used linear regression to analyze whether sound features could indicate the body weight and body condition. We call body weight and body condition the male condition. Results We found no effect of date and time of day on weight, and we showed a correlation between the male condition and song features in the small songbird, Dusky Warbler. Maximum trill quality and maximum peak frequency of songs were negatively related to male condition; the mean number of syllables of songs and maximum high frequency of songs were positively correlated with body weight and body condition. Conclusions In the small songbird, Dusky Warbler, four song parameters, including maximum trill quality, mean number of syllables of songs, maximum peak frequency of songs, maximum high frequency of songs, significantly predicted male condition change of which the most important song characteristic for male condition was maximum trill quality. This study suggested that the extreme song features were more constrained by male condition than mean sound characteristics.

With the aid of ab initio calculations at the MP2 level of theory, a novel type of alkaline-earthides, namely Li(NH3)4M (M = Be, Mg, Ca), has been theoretically designed and investigated. These compounds possess a similar geometric structure, in which the alkali-metal cation Li+ lies near the center of the cagelike (NH3)4 complexant and the alkaline-earth anion M− is located outside. All the proposed alkaline-earthides exhibit extremely large static first hyperpolarizability (β0) up to 8.01 × 106 au, indicating that they can be considered as novel NLO molecules with high performance. The calculated results reveal that the alkaline-earth atom is more suitable to serve as excess electron acceptor in excess electron compounds for increasing the β0 value. We hope that our study can attract more research interest in alkaline-earthides and further experimental research.

BiOI is a visible photocatalyst towards organic pollutant. In this work, biomass waste (withered typha grass) was used to fabricate nitrogen-doped hierarchical carbon (NHC) by an one-step carbonization route. Then NHC provided a good carrier to load the BiOI semiconductor materials by a green simple co-precipitation method, after adding NaOH solution, the irregular microspheres BiOI/NHC was gradually etched by OH

With the aid of ab initio calculations at the MP2 level of theory, a novel type of alkaline-earthides, namely Li(NH

Additional file 1: Table S1. Descriptive statistics of sound parameters in Dusky Warblers.

Table S1. Characteristics of the diagnostic performance of SWE imaging in included studies. Table S2. Quality assessment with QUADAS-2. Figure S1. Univariate meta-regression and subgroup analyses for sensitivity and specificity of SWE imaging. Figure S2. Deeksâ funnel plot asymmetry test for publication bias. (DOCX 1237 kb)

Background: Advanced/metastatic renal cell carcinoma (RCC) is a heterogeneous group of conditions with different risk stratification. The optimum systemic therapies for advanced/metastatic RCC of favorable-, intermediate-, and poor-risk have not been established. We aimed to compare and rank the effects associated with systemic therapies in the first-line setting. Methods: We searched Pubmed, Cochrane databases, Web of Science, and ClinicalTrials.gov for randomized controlled trials (RCTs) published up to October 2018, of systemic therapies for advanced/metastatic RCC. Analysis was done on a Bayesian framework. Findings: 13 unique RCTs including 7 248 patients were identified. For favorable-risk patients, temsirolimus plus bevacizumab, and nivolumab plus ipilimumab were associated with significantly worse progression-free survival (PFS) than sunitinib (HR 1.96, 95% CI 1.04-3.63; and HR 1.56, 95% CI 1.32-1.84, respectively). For intermediate-risk patients, nivolumab plus ipilimumab and cabozantinib were associated with significantly higher improvement in PFS than sunitinib (HR 0.66, 95% CI 0.54-0.81; HR 0.64, 95% CI 0.43-0.96, respectively). For poor-risk, nivolumab plus ipilimumab provided obvious PFS advantage over sunitinib (HR 0.57; 95% CI 0.4-0.70). For PFS, there was a 41.7% likelihood that sunitinib was the preferred treatment for favorable-risk patients. There was a 38.3% likelihood that cabozantinib was the preferred option for intermediate-risk patients. There was a 67.7% chance that nivolumab plus ipilimumab was the best therapy for poor-risk patients. There were no significant differences in the rate of drug-related adverse events. Interpretation: Sunitinib, cabozantinib, and nivolumab plus ipilimumab might be the optimum treatments for advanced/metastatic RCC of favorable-, intermediate-, and poor-risk, respectively. Funding Statement: The authors declare: "No Funding." Declaration of Interests: The authors state: "None declared." Ethics Approval Statement: All studies were selected compling with the search strategy on the basis of Preferred Reporting Items for Systematic Reviews and Meta-analyses criteria. (PRISMA)

Background Shear wave elastography (SWE) imaging have been proposed for characterization of focal liver lesions. We conducted a meta-analysis to evaluate the accuracy and clinical utility of SWE imaging for differentiation of malignant and benign hepatic lesions. Methods PubMed, Embase, Web of Science, and the Cochrane Library were systematically reviewed to search for studies published between January 1, 1990, and November 30, 2018. The studies published in English relating to the evaluation the diagnostic accuracy of SWE imaging for distinguishing malignant and benign liver lesions were retrieved and examined for pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratios, using bivariate random-effects models. The hierarchical summary receiver operating characteristic (HSROC) curve was estimated to assess the SWE imaging accuracy. The clinical utility of SWE imaging for differentiation of malignant liver lesions was evaluated by Fagan plot. Results A total of 15 studies, involving 1894 liver lesions in 1728 patients, were eligible for the meta-analysis. The pooled sensitivity and specificity for identification of malignant liver lesions were 0.82 (95% CI: 0.77–0.86) and 0.82 (95% CI: 0.76–0.87), respectively. The AUC was 0.89 (95% CI: 0.86–0.91). When the pre-test probability was 50%, after SWE imaging measurement over the cut-off value (positive result), the corresponding post-test probability for the presence of malignant liver lesions was 82%; the post-test probability was 18% after negative measurement. Conclusions SWE imaging showed high sensitivity and specificity in differentiating malignant and benign liver lesions and may be promising for noninvasive evaluation of liver lesions. Trial registration The review was registered in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42018104510.

Ideal anchoring materials can inhibit the shuttle effect which is one of the major challenging issues in lithium-sulfur (Li-S) batteries. Here, we employ first-principle calculations to systematically investigate the potential application of FeS monolayer as anchoring material for Li-S batteries. Our calculations show that the adsorption energies of Li2Sn (n = 1, 2, 4, 6 and 8) and S8 over FeS monolayer are moderately strong, about in the range 1.00 – 3.26 eV. Further analysis of the adsorption energy reveals that the van der Waals physical adsorptions mainly contribute to anchoring S8 and Li2Sn (n = 8, 6, 4 and 2) while the chemical interaction mainly contribute to anchoring Li2S. Moreover, the ultra-small energy barrier for Li2S diffusion over FeS monolayer will make Li2S transfer ultrafast, thereby restraining the agglomeration of Li2S and improving reaction rates. Our results demonstrate that the FeS monolayer may act as an excellent anchoring material for high-efficiency Li-S batteries.

Two-dimensional (2D) graphene-like hexagonal borophene sheet (HBS) is a kinetically unstable configuration since the electrons of π-valence orbitals of HBS are less than those of graphene. Inspired by the planar hexacoordinate wheel-type Fe©B6H6, we theoretically designed a novel 2D material FeB6 where the HBS can be stabilized by Fe atoms located at the center of partial boron rings. Moreover, we also investigated the possibility of using FeB6 monolayer as a potential anode for Li-ion batteries (LIBs) and Na-ion batteries (NIBs). Our calculations showed that FeB6 monolayer had strong adsorption energies (2.89 eV for Li and 2.39 eV for Na), low diffusion barriers (0.24 eV for Li and 0.10 eV for Na) and high theoretical specific capacities (991 mAh/g for Li and 622 mAh/g for Na), which indicates that FeB6 monolayer can be a potential anode material for LIBs/NIBs.

A novel 2D bonding heterostructure consisting of hexagonal borophene monolayer bonding with two blue phosphorene layers was designed theoretically, which possesses high stability, good conductivity and high in-plane stiffness. Subsequently, the heterostructure as an anchor material for lithium-sulfur (Li-S) batteries was investigated systematically by using density functional theory. Our results indicate that lithium polysulfides on the heterostructure have appropriate adsorption energies (0.60–2.68 eV) and moderate diffusion barriers (0.09–0.31 eV), which can suppress the “shuttle effect” and inhibit the agglomeration of lithium polysulfides. Therefore, the novel heterostructure can hold great promise as an anchoring material for Li-S batteries.

It remains a challenge to improve the photocatalytic activity of bismuth oxychloride (BiOCl) under visible light irradiation. In this work, BiOCl was changed by doping iron ions with a simple chemical precipitation method. During fabrication, under acidic conditions (pH = 3), bismuth nitrate and ferric chloride were mixed together and then annealed at 400 ℃, 450 ℃, 500 ℃ and 550 ℃, respectively. Finally, Bi0.7Fe0.3OCl with uniform doping of Fe (III) was obtained. The properties of Bi0.7Fe0.3OCl samples were characterized by XRD, SEM, TEM, XPS, and UV–vis. Bi0.7Fe0.3OCl nanomaterials synthesized at different temperatures were compared for their photocatalytic performance through investigating the degradation of a dye (Rhodamine B) under visible light. The experimental results showed that doping with Fe (III) can improve the visible light catalytic efficiency of BiOCl. Bi0.7Fe0.3OCl-450 had the best RhB removal rate, reaching 74 % within 3 h, which was about 4.8 times higher than pure BiOCl. This work may provide a promising method for preparing metal-doped BiOCl materials with efficient photocatalytic performance by generating large quantities of electron-holes during the photoreaction process.

In the above article [1] , the title is incorrect. The correct title is “End-to-End Learning Deep CRF Models for Multi-Object Tracking.”