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Graphene is a two-dimensional material that can be folded into diverse and yet interesting nanostructures like macro-scale paper origami. Folding of graphene not only makes different morphological configurations but also modifies their mechanical and thermal properties. Inspired by paper origami, herein we studied systemically the effects of creases, where sp2 to sp3 bond transformation occurs, on the thermal properties of graphene origami using molecular dynamics (MD) simulations. Our MD simulation results show that tensile strain reduces (not increases) the interfacial thermal resistance owing to the presence of the crease. This unusual phenomenon is explained by the micro-heat flux migration and stress distribution. Our findings on the graphene origami enable the design of the next-generation thermal management devices and flexible electronics with tuneable properties.

Fermentation and chemical methods for industrial cytidine diphosphate choline (CDP-choline) catalytic production both suffer from several disadvantages such as relatively low efficiency and productivity. To overcome these problems, we applied the concept of synthetic biology to develop a new one-pot multi-enzyme system to produce CDP-choline from orotic acid. Enzymes from different sources were selected and optimized as building blocks of the system, and parameters such as oxygen supply were also optimized. This system shows a titer of 37.6 ± 1.1 mM and a reaction rate of 1.6 mM L-1 h-1, both increase 66 % from traditional processes. It also has an efficiency of energy of 25.4%, improves 2-folds. This new one-pot CDP-choline-producing system has a potential for industrial use, and the procedure to design one-pot multi-enzyme system can be applied to build other one-pot system producing energy-rich compounds.

MoO2 is a promising anode material for lithium-ion batteries, however, the lithiation of bulk MoO2 is usually limited to addition-type reaction at room temperature, and the conversion reaction is hindered because of the sluggish kinetics. Herein, a nanocomposite of MoO2 embedded in nitrogen-doped carbon (MoO2/NC) is synthesized through the in situ thermolysis of an organic molybdenum complex MoO2(acac)(phen) (acac = acetylacetone, phen = 1,10-Phenanthroline). Owing to the fact that [MoO2]2+ can be strongly chelated by phen, the molybdenum source in the MoO2(acac)(phen) precursor is highly dispersed, leading to the formation of ultra-small MoO2 nanoparticles in the nanocomposite, which can facilitate the conversion reaction. Moreover, the NC matrix can guarantee a high electrical conductivity and effectively accommodate the volume changes triggered by the conversion reaction. Consequently, the MoO2/NC nanocomposite exhibits outstanding electrochemical properties, including large reversible capacity of 950 mA h g−1 at 0.1 A g−1, high-rate capability of 605 mA h g−1 at 2 A g−1, and excellent cycling stability over 500 cycles as an anode material for lithium-ion batteries.

Metal oxide/graphene hybrids are promising anode materials for sodium-ion batteries (SIBs). However, avoiding the overgrowth of the metal oxide nanoparticles (NPs) with high content and eliminating the blocking effect of graphene towards ion diffusion are still hard to achieve, lowering the active material utilization. Herein, we prepare a Fe2O3/holey graphene (FHG) anode for SIBs with enhanced electrochemical performance. The introduced hole edges and functional groups in holey graphene help adsorb Fe3+ and anchor the formed NPs to avoid their aggregation through the formation of Fe–O–C bonds, effectively confining the growth of Fe2O3 NPs and enhance their electrochemical activity. Besides, the holes on graphene facilitate the ion-transport to enhance the utilization of Fe2O3 and decrease the ion-diffusion resistance. As a result, FHG shows the uniformly distributed NPs with around 30 nm with a high Fe2O3 content of ∼73 wt%, and thus, the improved reversible capacity (923 mAh g−1 at 0.1 A g−1) and rate capability (318 mAh g−1 at 2 A g−1), much better than the Fe2O3/graphene hybrid without holes. This work demonstrates an effective method to improve the utilization and reaction kinetics of metal oxide, which can be extended to prepare the other hybrid materials for different applications.

Aims The introduction of Robinia pseudoacacia (RP) has some effects on undergrowth herbaceous plants (UH), soil properties and their relationships, which may be related to the vegetation zone. However, few studies have tested effects of RP on UH and soil over a large-scale area of the Loess Plateau. Methods The study area consisted of three vegetation zones (the steppe, forest-steppe and forest zone). Two canopy plant types were selected: RP stands and adjacent native vegetation. We measured five leaf functional traits: leaf carbon content (LC), leaf nitrogen content (LN), leaf phosphorus content (LP), specific leaf area (SLA) and leaf tissue density (LTD). The functional diversity, species diversity and community-weighted mean (CWM) traits were calculated. Important Findings (i) CWM.LN, CWM.LP and CWM.SLA increased significantly, whereas CWM.LC and CWM.LTD decreased significantly in the three vegetation zones, compared with the native communities. (ii) Species diversity, functional diversity and community biomass decreased in the steppe zone, increased in the forest zone, and did not differ significantly in the forest-steppe zone. (iii) We found only soil organic carbon (P < 0.05) and soil total nitrogen (P < 0.05) in the forest zone decreased significantly compared with the native plots. (iv) The relationship between UH and soil properties was affected by RP and the vegetation zone. Overall, the effect of RP on UH and soil properties was associated with the vegetation zone. This result is of great significance to the planning of restoration and reconstruction of artificial forests in the Loess Plateau.

Non-proportional hazards (NPH) have been observed in many immuno-oncology clinical trials. Weighted log-rank tests (WLRT) with suitable weights can be used to improve the power of detecting the difference between survival curves in the presence of NPH. However, it is not easy to choose a proper WLRT in practice. A versatile max-combo test was proposed to achieve the balance of robustness and efficiency, and has received increasing attention recently. Survival trials often warrant interim analyses due to their high cost and long durations. The integration and implementation of max-combo tests in interim analyses often require extensive simulation studies. In this report, we propose a simulation-free approach for group sequential designs with the max-combo test in survival trials. The simulation results support that the proposed method can successfully control the type I error rate and offer excellent accuracy and flexibility in estimating sample sizes, with light computation burden. Notably, our method displays strong robustness towards various model misspecifications and has been implemented in an R package.

Lithiated transition metal oxide cathode materials that combine oxygen-anion redox [O2–/(O2)n−] with cation redox offer substantial capacities and higher voltage than cathodes without oxygen redox,...

Electro-mechanical impedance (EMI) method utilizing smart materials is an effective way for liquid property identification. In this article, we report on a 1-3 piezoelectric composite sensor used for identifying liquid property based on EMI method. To understand the operation mechanism of the sensor immersed in liquid, a fluid-structure interaction model was established. An analytical solution to govern the electrical impedance of the 1-3 piezoelectric composite sensor coupled with a liquid was derived. Based on the model, the influence of the acoustic impedance of a liquid on electrical impedance of piezoelectric materials is clearly revealed. The experimental results show that the measured acoustic impedance of 3 liquids using the fluid-structure interaction model agrees well with the reference values. The maximum relative error in the experiments is merely 2.4%, much less than that obtained by equivalent circuit model, confirming the accuracy of the model we built. Moreover, the 1-3 piezoelectric composite sensor based on EMI method exhibits a higher resolution than frequency drift method. The method presented provides a simple, cost-effective, and convenient way in liquid property identification.

We present an all-polarization-maintaining (PM) compact passively mode-locked fiber laser using a PM wavelength division multiplexer (WDM)-isolator-tap (WIT) hybrid device with good stability. Compared with inserting the WDM, isolator, and tap into a traditional cavity, only a PM WIT device could simultaneously inject the pump light into the cavity, control the unidirectional operation of the ring cavity, and provide the lasing output from the cavity. With this simple structure, the system generated a soliton pulse of 1.085 ps at 17.77 MHz, with a 54 dB signal-to-noise ratio (SNR).

Heart valve replacement is an effective therapy for patients with moderate to severe valvular stenosis or regurgitation. Most bioprosthetic heart valves applied clinically are based on cross-linking with glutaraldehyde (GLUT), but they have some drawbacks like high cytotoxicity, severe calcification, and poor hemocompatibility. In this study, we focused on enhancing the properties of bioprosthetic heart valves by cross-linking with 3,4-dihydroxybenzaldehyde (DHBA). The experiment results revealed that compared with GLUT cross-linked porcine pericardium (PP), the relative amount of platelets absorbed on the surface of DHBA cross-linked PP decreased from 0.294 ± 0.034 to 0.176 ± 0.028, and the activated partial thromboplastin time (APTT) increased from 9.9 ± 0.1 to 15.2 ± 0.1 s, indicating improved hemocompatibility. Moreover, anticalcification performance and cytocompatibility were greatly enhanced by DHBA cross-linking. In conclusion, the properties of bioprosthetic valves could be effectively improved by processing valves with a DHBA-based cross-linking method.

The magnetic composites consisting of a porous graphitic carbon nitride (g-C3N4) and the core-shell Fe3O4@SiO2 were facilely prepared. Subsequently, the Pd nanoparticles (NPs) were stabilized on the composites by the in-situ reduction of PdCl2 with sodium borohydride. The mass ratio of Fe3O4@SiO2 to g-C3N4 was optimized in view of the catalytic activity of the corresponding Pd-based catalysts for ammonia borane (AB) hydrolysis. The results showed that the catalyst fabricated with a mass ratio of 1:1 (Fe3O4@SiO2: g-C3N4) displayed the highest catalytic activity. The Pd NPs were mainly distributed in the region of 5.4–9.8 nm in the optimal Pd/Fe3O4@SiO2-g-C3N4 catalyst, which had a specific surface area of 47.5 m2 g−1 and a total pore volume of 0.126 cm3 g−1. Catalyzed by the optimal catalyst, the turnover frequency was 33.7 mol H 2 · mol Pd − 1 · min − 1 , and the apparent activation energy was 31.4 kJ mol−1. Also, the recycling experiments indicated that the optimal catalyst still maintained a high catalytic activity even after eight runs. The superior catalytic performance is presumably due to the highly dispersed Pd NPs and the stably porous structure with large specific surface area. The excellent catalytic and magnetic properties endow Pd/Fe3O4@SiO2-g-C3N4 exciting potential in the hydrogenation generation from the hydrolysis of solid hydrogen storage materials.

Intense 1–5 μm infrared emission from near- to mid-infrared was obtained from Ho3+/Yb3+ codoped TeO2-ZnF2 oxyfluorotellurite glasses which were prepared by melt-quenching method under the 980 nm LD excitation, and the emission intensity can be enhanced with the increase of ZnF2 content. Judd-Ofelt analysis was used to evaluate the radiative transition parameters of the excited levels according to the absorption spectra. The stimulated emission cross section of 5I6→5I8 (1.2 μm), 5I7→5I8 (2.0 μm), 5I6→5I7 (2.85 μm) and 5I5→5I6 (4.0 μm) transitions were calculated to reach 0.639 × 10–20, 0.760 × 10–20, 0.985 × 10–20 and 0.484 × 10−20 cm2, respectively. The energy transfer coefficients (CDA) are enhanced with the increase of ZnF2 content and phonon contribution ratios of phonon assisted energy transfer process between Ho3+ and Yb3+ were figured out. Our results demonstrate that these TeO2-ZnF2 glasses, which possess good thermal stability and transparency, low phonon energy (about 600 cm−1), excellent near- and mid-infrared emission in the range of 1–5 μm wavelength, would be promising material for infrared optical fibers and infrared lasers.

Fluorescence biosensors that enable highly sensitive detection of glutathione (GSH) are in great demand for various biological investigations and early disease diagnoses. Here, we report a turn-on fluorescence nanoplatform based on fluorescent semiconducting polymer nanoparticle@MnO2 nanosheets (P-dot@MnO2) nanocomposites for rapid homogeneous determination of GSH. The near-infrared (NIR) fluorescent P-dots were prepared by doping NIR dyes into polymer matrix and then encompassed by MnO2, which resulted in a remarkable fluorescence quenching. Owing to the selective decomposition of MnO2 by GSH, the fluorescence recovery was achieved in the presence of GSH. On the basis of the target-induced turn-on fluorescence response, the developed nanoplatform can readily detect GSH with a high sensitivity up to 0.26 μM, as well as a superior specificity. Furthermore, it was successfully applied in monitoring the intracellular GSH in living cells, revealing its great potential in biomedical applications.

Graphene origami (G-ori) can possess unique mechanical properties and achieve some distinctive functionalization by engineering their configurations. However, it remains a tremendous challenge to modulate its formation and properties at the micro- and nano-scales. Herein, we systemically present the formation of G-ori activated by creased marks via molecular dynamics (MD) simulations. The pre-existing creased mark in graphene is created in a controlled way by transforming sp2 to sp3 bonds at the crease. Our results show that the presence of interlayer sp3 bonds at the crease can direct crack growth and hence pave a new way to tailor graphene sheets into specified pieces. The crease also guides the folding process of graphene into various geometric configurations. Sophisticated G-ori can be constructed by designing rational crease distribution on the graphene surface. Checking against the folding process of paper origami shows that the crease-induced targeted folding can be achieved at both nano- and macro-scales in exactly the same way. Our findings provide a simple and feasible method to construct graphene-based nano-devices by designing rational morphological configurations of G-ori.

The Madden–Julian oscillation (MJO) is the dominant mode of tropical intraseasonal variability. Many studies have found that the MJO, which acts as a tropical heating source, can excite Rossby waves that propagate into the midlatitude and modulate midlatitude circulation. The extratropical mean flow can modulate the MJO extratropical response. Rossby waves can grow or decay in different extratropical background flows, and the propagation of the Rossby waves also varies as the background flow acts as a waveguide. In this study, how extratropical mean flow modulates the MJO extratropical response is explored by using a nonlinear baroclinic primitive equation model. MJO-associated heating, as an external forcing of the model, is imposed into scenarios with different extratropical background flows. Different background flow modulates the generation and advection of the vorticity anomalies induced by the MJO, which determines the initial location and strength of the Rossby waves. The midlatitude waveguides can be different as the background flow changes. As the propagation of Rossby waves follows the waveguides, the background flow determines whether the Rossby waves are trapped in the Pacific Ocean region or can propagate to the north and to the east into North America. The experiments also show that the anomalies associated with the Rossby waves can extract energy from the midlatitude jet over the jet exit region and the southern flank of the jet. This further modulates the strength, location, and duration of the MJO extratropical response.

It is a crucial and urgent task to develop high performance catalysts for the hydrolysis of ammonia borane (NH3¬BH3, AB), which is thought to be an effective strategy for the hydrogen generation at...

This paper presents an experimental study to investigate the effects of compressive stress during the CO2 attack on wellbore cement under carbon capture and storage (CCS) conditions. Oil well cement samples were designed to be exposed to humid supercritical CO2 gas and CO2-saturated brine and simultaneously subjected to external compressive stresses with load levels of 0, 25%, 50%, and 75% of the ultimate compressive strength. Morphology changes were determined using phenolphthalein dye testing and scanning electron microscopy. Mineral changes were detected by X-ray diffraction. Relative compressive strength and gas permeability of exposed cement were analyzed. It is shown that the 25% stress level has little effect on degradation of cement while the applied compression load up to 50% increased the compactness of cement and finally slowed down the degradation rate. In contrast, a much higher compressive stress level up to 75% facilitated the generation and propagation of micro-cracks. The stress induced micro-crack finally caused a surge in CO2-rich fluids and then significantly accelerated the degradation rate of oil well cement. Findings from this study expanded the understanding of the integrity of oil well cement for CCS wells.

TP321 stainless steel is widely used in hydrogenation refining pipes owing to its excellent performance of creep stress resistance and high-temperature resistance. In this study, thermal simulation tests were carried out on the welding heat-affected zone (HAZ) of TP321 stainless steel at temperatures of 1300 °C, 1100 °C, and 850°C using a Gleeble 3800 testing machine. Slow strain tensile tests were conducted under the condition of electrolytic hydrogen charging (EHC) and the metallographic microstructure of cracks as well as the morphology of fractures were analyzed in detail. The result shows that hydrogen can change the fracture mode of tensile specimen and the cracks initiated from and near the specimen surface after EHC. Hydrogen significantly decreases the plastic deformation capability of HAZ in TP321 stainless steel. The reduction of area after the fracture decreases by 58%, 41%, and 45% for HAZ at 1300 °C, 1100 °C, and 850 °C, respectively. The existence of δ ferrite was considered to be the main reason for the aggravation of hydrogen-induced plasticity loss.

A modified Stober method is applied to synthesize the magnetic core-shell Fe3O4@SiO2 particles, followed by compositing a series of porous glucose-derived carbon with ZnCl2 as etchant. Then, ultrafine Pd nanoparticles (NPs) are successfully anchored to the resulting Fe3O4@SiO2-PC composites with an in-situ reduction strategy. The particle sizes of Pd NPs are mainly centered in the range of 2.3–4.3 nm in the as-prepared Pd/Fe3O4@SiO2-PC catalysts, owning a hierarchical porous structure with high specific surface area (SBET = 626.0 m2 g−1) and large pore volume (Vp = 0.61 cm3 g−1). Their catalytic behavior for the hydrogen generation from ammonia borane (AB) hydrolysis is investigated in details. The corresponding apparent activation energy is as low as 28.4 kJ mol−1 and the reaction orders with AB and Pd concentrations are near zero and 1.10 under the present conditions, respectively. In addition, the magnetic catalysts, which could be easily separated out by a magnet, are still highly active even after nine runs, revealing their excellent reusability.

A series of bola-type dipeptides based on an Ala–Phe building block was synthesized by altering the chirality of Ala and Phe. They were able to self-assemble into right- or left-handed helical nanofibers in a mixture of methanol and water. Both the handedness of the nanofibers and that of the molecular stacking were controlled by the chirality of the phenylalanine residue. 1H NMR, circular dichroism and FT-IR characterizations indicated that the formation of the nanofibers was driven by the hydrophobic association of the hydrocarbon chains, π–π stackings of the phenyl rings and hydrogen bonds. X-ray diffraction patterns showed that the diastereoisomers packed into different structures. These bola-type Ala–Phe dipeptides can be potentially used for 3D printing.

We investigate temperature-dependent carrier transfer and efficiency droop on AlGaN-based deep ultraviolet light-emitting diodes. The Shockley-Read-Hall (SRH) recombination and carrier leakage are highly associated with the poor thermal stability. The existence of Auger recombination and carrier leakage is identified by the m-power method. A modified ABC model with an additional term f ( n ) related to carrier leakage is employed to analyze the evolution of multiple recombination mechanisms. The SRH process strongly suppresses both Auger recombination and carrier leakage at low currents. At high currents, the latter two processes are responsible for the efficiency droop and exhibit an anti-correlation upon temperature.

Selenicereus undatus (Haw.) D.R.Hunt is a member of the family Cactaceae. The chloroplast genome of S. undatus was sequenced, assembled, and annotated in the present study. The chloroplast genome was 133,326 bp in length, consisting of a typical quadripartite circle: a large single-copy region of 68,256 bp, two inverted repeat regions of 21,677 bp, and a small single copy region of 21,716 bp. A total of 120 predicted genes were identified, and a maximum likelihood was constructed, placing S. undatus as the sister taxon of Lophocereus schottii and Carnegiea gigantea, other members of the family Cactaceae.

The Chong’an Mustache Toad, Leptobrachium liui (Pope, 1947) is a Chinese endemic species, inhabiting the mountain streams with rich vegetation in southeastern China. The first complete mitochondria...

Nephelium lappaceum is a popular tropical fruit belonging to the Sapindaceae family. The plant originated in Malaysia and Indonesia and is commonly called rambutan. Because of its refreshing flavor...

The fabrication of small-scale electronics usually involves the integration of different functional materials. The electronic states at the nanoscale interface plays an important role in the device performance and the exotic interface physics. Photoemission spectroscopy is a powerful technique to probe electronic structures of valence band. However, this is a surface-sensitive technique that is usually considered not suitable for the probing of buried interface states, due to the limitation of electron-mean-free path. This article reviews several approaches that have been used to extend the surface-sensitive techniques to investigate the buried interface states, which include hard X-ray photoemission spectroscopy, resonant soft X-ray angle-resolved photoemission spectroscopy and thickness-dependent photoemission spectroscopy. Especially, a quantitative modeling method is introduced to extract the buried interface states based on the film thickness-dependent photoemission spectra obtained from an integrated experimental system equipped with in-situ growth and photoemission techniques. This quantitative modeling method shall be helpful to further understand the interfacial electronic states between functional materials and determine the interface layers.

Hevea benthamiana is a SALB-resistant wild species of H. brasiliensis, the only source of mass production of high quality natural rubber. This study sequenced and analyzed the chloroplast genome of...

In survival analysis, Cox model is widely used for most clinical trial data. Alternatives include the additive hazard model, the accelerated failure time (AFT) model and a more general transformation model. All these models assume that the effects for all covariates are on the same scale. However, it is possible that for different covariates, the effects are on different scales. In this paper, we propose a shape-invariant hazard regression model that allows us to estimate the multiplicative treatment effect with adjustment of covariates that have non-multiplicative effects. We propose moment-based inference procedures for the regression parameters. We also discuss the risk prediction and the goodness of fit test for our proposed model. Numerical studies show good finite sample performance of our proposed estimator. We applied our method to the HIVNET 012 study, a milestone trial of single-dose nevirapine in prevention of mother-to-child transmission of HIV. From the HIVNET 012 data analysis, single-dose nevirapine treatment is shown to improve 18-month infant survival significantly with appropriate adjustment of the maternal CD4 counts and the virus load.

In this article, we present an optimization method for threshold logic networks (TLNs) based on observability don’t-care-based node merging. To reduce gate count in a TLN, it iteratively merges two gates that are functionally equivalent or whose differences are never observed at the primary outputs. Furthermore, it is able to identify redundant wires and replace wires for removing more gates. Basically, the proposed method is primarily adapted from an ATPG-based node-merging approach which works for conventional Boolean logic networks. To extend the approach for TLNs, we develop a method for computing mandatory assignments of a stuck-at fault test on a threshold gate and a method for conducting logic implication in a TLN. Additionally, to achieve a better optimization quality, we integrate the proposed method with other optimization methods. The experimental results show that the overall optimization method can save an average of approximately 4.7% threshold gates for a set of TLNs which are generated by using the latest TLN synthesis method. The experimental results also demonstrate the efficiency of the optimization method.

Because of the rapid development in the utilization hydrogen energy, various hydrogen storage techniques have attracted much attention. Among them, the hydrolysis of ammonia borane (NH3BH3, AB) over high-efficient and low-cost catalysts is one of the most interesting pathways. In this work, the magnetic collagen powder-graphene oxide hybrids (CGP-GO-Fe3O4) are synthesized by a facile self-assembly method combined with co-precipitation synthesis routes. Then, the hybrids are employed to immobilize palladium nanoparticles with an in-situ reduction strategy. The as-prepared Pd/CGP-GO-Fe3O4 catalysts exhibit good catalytic activity and excellent recyclability for H2 generation from AB. Under the present reaction conditions, the activation energy and turnover frequency for the hydrolysis of AB are 36.5 kJ mol−1 and 27.4 m o l H 2 · m o l P d − 1 · m i n − 1 , respectively. In addition, the hydrolysis reaction is found to be of 0.93 and 0.40 orders with respect to the palladium and AB concentrations, respectively. The results demonstrate that Pd/CGP-GO-Fe3O4 could be efficiently applied in the utilization of hydrogen energy.

Glucose-derived porous activated carbon materials (AGC-600-4 and AGC-180-x) are prepared using ZnCl2 as the etching agent via impregnation treatment and hydrothermal method followed by the calcination process. The analytic results indicate that the obtained materials exhibit higher specific surface area and superior double-layer capacitive behavior than the corresponding pristine carbon (GC-600 and GC-180) when used as electrode materials for supercapacitors. Moreover, compared with the AGC-600-4 nanosheets, the optimal AGC-180-4 microspheres have a high specific surface area of 1713 m2 g−1 and a maximum specific capacitance of 235.9 F g−1 at a current density of 1.0 A g−1 in the three-electrode system. Meanwhile, AGC-180-4 also exhibits better capacitive properties than AGC-600-4 in the two-electrode system, showing an excellent cyclic stability with a high energy density of 24.63 Wh kg−1 at the power density of 949.5 W kg−1. It is thus demonstrated that AGC-180-4 could be ideal electrode materials for supercapacitor due to its unique etched spherical structure and excellent electrochemical properties.

Sodium/potassium-ion batteries (SIBs/PIBs) arouse intensive interest on account of the natural abundance of sodium/potassium resources, the competitive cost and appropriate redox potential. Nevertheless, the huge challenge for SIBs/PIBs lies in the scarcity of an anode material with high capacity and stable structure, which are capable of accommodating large-size ions during cycling. Furthermore, using sustainable natural biomass to fabricate electrodes for energy storage applications is a hot topic. Herein, an ultra-small few-layer nanostructured MoSe2 embedded on N, P co-doped bio-carbon is reported, which is synthesized by using chlorella as the adsorbent and precursor. As a consequence, the MoSe2 /NP-C-2 composite represents exceedingly impressive electrochemical performance for both sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs). It displays a promising reversible capacity (523 mAh g-1 at 100 mA g-1 after 100 cycles) and impressive long-term cycling performance (192 mAh g-1 at 5 A g-1 even after 1000 cycles) in SIBs, which are some of the best properties of MoSe2 -based anode materials for SIBs to date. To further probe the great potential applications, full SIBs pairing the MoSe2 /NP-C-2 composite anode with a Na3 V2 (PO4 )3 cathode also exhibits a satisfactory capacity of 215 mAh g-1 at 500 mA g-1 after 100 cycles. Moreover, it also delivers a decent reversible capacity of 131 mAh g-1 at 1 A g-1 even after 250 cycles for PIBs.

The hybrids consisting of chitosan (CS) and reduced graphene oxide (rGO) were assembled with an in-situ reduction strategy. Then, the resulting CS-rGO was used to encapsulate palladium nanoparticles (Pd NPs) via reducing PdCl2 with NaBH4. The mass ratios of CS to GO were optimized to increase the catalytic activity of the resultant Pd NPs/CS-rGO catalysts for the hydrolysis of ammonia borane (AB). The analytic results revealed that the Pd NPs (1.1–2.3 nm in diameter) were evenly encapsulated in the CS-rGO hybrids. Under the present conditions, the optimized Pd NPs/CS-rGO offered a high turnover frequency (TOF) value of 42.5 m o l H 2 m o l P d − 1 m i n − 1 . The activation energy of the AB hydrolysis was 39.02 kJ mol−1 and the corresponding orders of Pd and AB concentrations were 0.90 and 0.33, respectively. In addition, the Pd NPs/CS-rGO catalysts retain a stable hydrogen generation activity after four runs.

A series of bola-type Ala-Ala dipeptides with different alkylene bridges (n = 10-15) were synthesized. In methanol, the molecules with even-numbered carbon bridges self-assembled into twisted nanoribbons, while those with odd-numbered carbon bridges self-assembled into straight belts. The morphology displays a pronounced odd-even dependence upon the number of carbons (n) in the connecting alkylene bridge. The circular dichroism spectra of the self-assemblies showed that molecules with even- and odd-numbered carbon bridges stacked in different structures. FT-IR spectra indicated that the dipeptides with even-numbered carbon bridges formed hydrogen bonds between the amide group and carboxyl ester group, while those with odd-numbered carbon bridges formed hydrogen bonds only between the amide groups. X-ray diffraction patterns revealed that molecules with odd- and even-numbered carbon bridges stacked in monoclinic and triclinic structures, respectively.

Karst Rocky Desertification (KRD) has become the most serious ecological disaster in Southwest China. We used the data of Thematic Mapper (TM) images from 1990, 1995, 2000, 2004, and 2011 and the 2...

The correlation between electronic properties and epitaxial strain in a cation-deficient system has rarely been investigated. Cation-deficient SrVO3 films are taken as a model system to investigate the strain-dependent electrical and electronic properties. Using element- and charge-sensitive soft X-ray absorption, V L-edge absorption measurements have been performed for Sr1–y VO3 films of different thicknesses capped with 4 u.c. (unit cell) SrTiO3 layers, showing the coexistence of V4+ and V5+ in thick films. A different correlation between V valence state and epitaxial strain is observed for Sr1–y VO3 ultrathin films, i.e. a variation in V valence state is only observed for tensile-strained films. Sr1–y VO3 thin films are metallic and exhibit a thickness-driven metal–insulator transition at different critical thicknesses for tensile and compressive strains. The asymmetric response of electrical conductivity to strain observed in cation-deficient Sr1–y VO3 films will be beneficial for functional oxide electronic devices.

The structures, energetics, and infrared spectra of the cationic monomethylamine clusters (MMA)n+ were studied using quantum chemical calculations. The results reveal the preference of the formation of proton-transferred CH3NH3+-NH2CH2 ion-radical contact pair structure via the intermolecular proton transfer from the CH3 group to the nitrogen atom, which feature is different from the cationic dimethylamine and trimethylamine clusters reported recently. The CH3NH3+-CH2NH2 and CH3NH3+-NHCH3 ion-radical structures and the charge-shared (hemibonded) N N type (MMA)2+ ion core structure are predicted to be less energetically favorable. Simulated infrared spectra suggest that vibrational frequencies of the NH2 antisymmetric stretch of CH2NH2 radical would afford a sensitive probe for fundamental understanding of ion-radical networks generated from the radiation-induced chemical processes in the (MMA)n+ complexes.

In this paper, we give a definition of Diophantine points of type $\gamma$ for $\gamma\geq0$ in a homogeneous space $G/\Gamma$, and compute the Hausdorff dimension of the subset of points which are not Diophantine of type $\gamma$ when $G$ is a semisimple Lie group of real rank one. We also deduce a Jarn\'ik-Besicovitch Theorem on Diophantine approximation in Heisenberg groups., Comment: Acknowledgements updated. To appear in Monatsh. Math

Fluorosilicone polyether polyurethane (FSPU) was successfully prepared from polytetramethylene glycol, hydroxyl fluorosilicone oil, toluene diisocyanate and chain extender 2,4-diamino-3,5-dimethylthiotoluene. The obtained material was characterized by Fourier transform infrared spectroscopy, dynamic mechanical analysis and scanning electron microscopy. And the water resistance, mechanical and acoustic performance of the materials were tested by video optical contact angle measuring instrument, electronic universal testing machine and sound field, respectively. The results showed that the glass transition temperature of FSPU was lowered and the cold resistance was improved with the addition of hydroxyl fluorosilicone oil. When the amount of hydroxyl fluorosilicone oil was 40 wt%, the water contact angle of FSPU increased to 113.6°, and the water absorption reached a minimum of 0.7%. Compared with polyurethane, the hydrophobic performance of FSPU was significantly improved. The insertion loss of FSPU-40 at 1000 kHz was only 220.60 dB/m, which was 68.7% lower than that of polyurethane. Above all, FSPU has excellent water resistance, cold resistance and acoustic performance, and is an ideal material for underwater acoustically transparent encapsulant.

A series of new doramectin derivatives containing carbamate, ester and sulfonate were synthesized, and their structures were characterized by 1H and 13C nuclear magnetic resonance (NMR) and high-resolution mass spectrum (HRMS). Their insecticidal activities against oriental armyworm, diamondback moth, and corn borer were evaluated and compared with the parent doramectin and commercial avermectins, metolcarb, fenpropathrin. Among all compounds, three compounds (3a, 3g and 3h) showed excellent insecticidal effect. In particular, compound 3g containing cyclopropyl carbamate against oriental armyworm, diamondback moth, and corn borer, exhibited the most promising insecticidal activity with the final mortality rate of 66.67%, 36.67%, 40.00% at the concentration of 12.5 mg/L, respectively. The LC50 values of 3g were 5.8859, 22.3214, and 22.0205 mg/L, showing 6.74, 2.23, 2.21-fold higher potency than parent doramectin (LC50 values of 39.6907, 49.7736, and 48.6129 mg/L) and 6.83, 1.93, 3.36-fold higher potency than commercial avermectins (LC50 values of 40.2489, 42.9922, and 73.9508 mg/L). Additionally, molecular docking simulations revealed that 3g displayed stronger hydrogen-bonding action in binding with the GABA receptor than parent doramectin, which were crucial for keeping high insecticidal activity. The present work demonstrated that these compounds containing alkyl carbamate group could be considered as potential candidates for the development of novel pesticides in the future.

A three-dimensional hybrid consisting of nitrogen-doped graphene aerogel and the fusiform CuO nanoparticles is facilely assembled by using a gas-liquid interfacial reaction followed by freeze-drying. The results show that the CuO particles are dispersed evenly into the three-dimensional architecture of graphene aerogel to form a hierarchal porous structure. When used as anode materials for lithium-ion batteries, the resultant CuO@N-GA hybrid possesses a large first discharge specific capacity of 1442.2 mAh g−1 at 100 mA g−1 with a coulombic efficiency of 58.1%. Moreover, the hybrid exhibits superior cycle stability and excellent rate performance. Its discharge specific capacity maintains as high as 725.3 mAh g−1 at 100 mA g−1 after 100 cycles and 502.4 mAh g−1 at 1000 mA g−1. The enhanced electrochemical performance of CuO@N-GA is mainly originated from its unique interconnected porous structure, the incorporation of nitrogen, and the well dispersed CuO nanoparticles.

Carbon anchored titanium carbonitride for supercapacitor electrode material was prepared by a direct semi-solid-sate carbonitridation method. The prepared sample is highly conductive and mesoporous (250 m2 g−1), enabling fast electron transfer and ion transport. As a result, a high capacitance of 360 F g−1 at 0.5 A g−1, and an impressive capacitance retention ratio 100Ag-1/1 A g−1 of 53%, as well as long cyclic capability (>10,000 cycles) can be obtained in 1 M H2SO4. The thick electrode also presents a high area capacitance up to 1.77 F cm−2. A flexible H2SO4/PVA symmetric supercapacitor was fabricated to demonstrate its practicality. Remarkably, the supercapacitor presents high-rate performance (up to 25 kW kg−1) and long cyclic performance (>10,000 cycles), illustrating its potential application in flexible integrated energy storage devices. This work provides a novel insight into designing and preparing carbonitride based materials for high performance supercapacitor.

Novel biologic markers have been used to predict clinical outcomes of many diseases. One specific feature of biomarkers is that they often are measured with variations due to factors such as sample preparation and specific laboratory process. Statistical methods have been proposed to characterize the effects of underlying error-free quantity in association with an outcome, yet the impact of measurement errors in terms of prediction has not been well studied. We focus in this manuscript on using biomarkers for predicting an individual’s future risk for survival outcome. In the setting where replicates of error-prone biomarkers are available in a ‘training’ population and risk projection is applied to individuals in a ‘prediction’ population, we propose two-step measurement-error-corrected estimators of absolute risks. We conducted numerical studies to evaluate the predictive performance of the proposed and routine approaches under various assumptions about the measurement error distributions to pinpoint situations when correction of measurement errors might be necessary. We studied the asymptotic properties of the proposed estimators. We applied the estimators to a liver cancer biomarker study to predict risk of liver cancer incidence using age and a novel biomarker, $$\alpha $$ -Fetoprotein.

Objective To assess the efficacy and safety of the combination therapy of Chinese herbal medicines , tripterygium glycosides, plus valsartan for the treatment of diabetic nephropathy (DN). Methods A comprehensive research of 12 electronic databases was performed. Data of the included studies were extracted and analyzed independently by two authors, and were synthesized using Review Manager (version 5.2) and Stata (version 12.0). Results A total of 12 randomized controlled trials (RCTs) involving 829 patients were included. Pooled results showed that the combination therapy significantly increased total efficacy of DN patients [RR = 1.35, 95% CI (1.22, 1.50), P 0.05), blood urea nitrogen [MD = 0.25, 95% CI (−0.23, 0.74), P > 0.05], and endogenous creatinine clearance rate [MD = −0.43, 95% CI (−3.48, 2.62), P > 0.05]. However, tripterygium glycosides plus valsartan seemed to exert higher adverse reaction rate than valsartan monotherapy [MD = 3.41, 95% CI (1.34, 8.66), P Conclusion Combination therapy of tripterygium glycosides plus valsartan may be effective for the treatment of DN. However, the safety of the combination therapy need to be further confirmed.

The low-cost and environmentally friendly solid acid catalysts for the efficient synthesis of ethyl levulinate fuel additives were prepared from pine needles through the partial carbonization, followed by a hydrothermal H2SO4 sulfonation procedure. The resultant sulfonated carbon catalysts possessed an amorphous carbon structure and high contents of the sulfate groups. Other than that, they had good thermal stability and the total acid density was as high as 2.28 mmol g−1. In this work, noticeably, the parameters of both synthetic and catalytic reactions were optimized to enhance the conversion of levulinic acid (LA). The results showed that the LA conversion was as high as 96.1% over the catalysts carbonizated at 700 °C for 90 min and sulfonated at 160 °C for 15 h under the optimized conditions (5:1 ethanol/LA molar ratio, 5 wt% catalyst dosage, 80 °C reaction temperature, 8 h reaction time). Meanwhile, the recyclability experiments confirmed that the resultant catalysts exhibited satisfactory reusability and the corresponding conversion of LA was maintained as 63.0% in the fourth run. Remarkably, the reused catalysts can be easily activated again and the corresponding LA conversion could reach up to 90.1%. The results demonstrated that the catalysts had great potential in the synthesis of biofuels, which could be efficient and could have excellent recyclability.

Heterojunction of cadmium sulfide (CdS) nanospheres and reduced graphene oxide (RGO) is performed by using an ice crystal template method combined with a freeze drying-calcination process. The resultant CdS-RGO with hierarchal porous structure possesses strong light absorption visible region and has higher specific surface area than the pristine CdS. Eventually, it exhibits much better adsorptivity and higher visible light-derived photocatalytic activity than the pristine CdS and RGO for eliminating organic pollutants in wastewater. The corresponding total removal efficiencies for rhodamine B (RhB) dyes and acid chrome blue K (AcbK) dyes are 97.2% and 65.7% under the present conditions, respectively. Remarkably, the heterojunction demonstrates excellent light corrosion resistance and superior reusability. The relative removal efficiency only loss 1.8% in the 4th run in comparison of that of the 1st run over the resultant CdS-RGO heterojunction. The results confirm the resultant heterojunction with high efficiency to be applied in elimination of organic pollutants in wastewater.

The sulfonated carbon derived from loofah sponge are prepared and used as catalysts to synthesize ethyl levulinate. Various synthetic and reaction parameters on the catalytic efficiency are comparatively investigated. The acidic density of the resultant catalysts with a satisfactory reusability is as high as 1.59 mmol g−1. The conversion of levulinic acid can reach 91% under the optimized conditions. The results show that the catalysts have great potential to be an environmentally friendly alternative solid acid for the synthesis of ethyl levulinate fuel additive.

Background and objectiveThis project links population data to the Wisconsin Violent Death Reporting System (WVDRS) to determine the extent to which firearm possession criteria are being followed as well as the potential impact of the adoption of proposed possession criteria.Design and study populationCriminal justice data for WVDRS homicide suspects and victims and suicide decedents 2008–2011 and a sample of matched control group of driver’s license holders (to characterise the state population) will be abstracted.MethodsIndividual legal possession statuses (prohibited/not prohibited) under each current and expanded criterion will be determined. Proportions of interest will be calculated from two-way contingency tables, and tests between groups with categorical variables (eg, criterion is met or not) will be performed with Fisher’s exact or binomial proportion tests. Tests between groups with continuous variables (eg, number of misdemeanours) will be performed by zero inflated negative binomial regression. Area under the receiver operating characteristic curve will be used to quantify the prediction accuracy of specific univariate or multivariate logistic model for prediction. Inverse probability weighting will be used for analyses that extend from matched controls to the general state population of license holders.DiscussionLinked data sets and partnerships are challenging, but necessary for comprehensive public health research. Results of this study will contribute knowledge on the proportion of prohibited suspects and suicide decedents that used firearms in violent deaths and, if applying expanded criteria would have increased prohibited persons. This study will also investigate risk and protective factors for being a victim of homicide.

Biocatalysis has become the main approach to produce cytidine diphosphate choline (CDP-choline), which has been applied for treatment of acute craniocerebral injury and consciousness after brain surgery. However, salt accumulates with the production and inhibits enzyme activity, and eventually reduces yield and product accumulation rate. Our work provided a possible solution to this problem by applying a computational designed halophilic choline kinase. The halotolerant CKI (choline kinase) was designed following a unique strategy considering the most variable residue positions on the protein surface among target enzymes from different sources. The basic and neutral surface residues were replaced with acidic ones. This approach was enlightened by features of natural halophilic enzymes. Mutants in the work represented higher catalytic activities and IC50 (inhibit activity by 50%) at high salt concentrations (over 1200 mM). Furthermore, when the mutant was used in fed-batch production, the CDP-choline accumulation rate doubled comparing with process using wild-type CKI at acetate concentration of over 700 mM. The maximum titer was 151 ± 3.2 mM, the productivity was 5.8 ± 0.1 mM·L−1 h−1, and molar yield to CMP and utilization efficiency of energy were 85.3 and 63.5%. The idea of computational design in our work can also be applied to modify other enzymes in industry, and sheds light on alleviating effect of salt accumulation during industrial manufacturing process.

A series of 1,2-N-substituted o-carboranes were obtained. The C-C bond lengths of secondary-amino o-carboranes 3 were compared. The relationship between C-C distances and the electron effects of the benzyl groups was discussed. DFT calculations with and without dispersion energy correction show that significant attractive dispersion forces were present, which arise from the skeletons of the o-carborane cages.

Excessive ultraviolet (UV) radiation is known to cause several skin diseases, and hence smart electronics with the capacity to measure and control UV radiation have attracted substantial attention. In this work, a dual-functional smart window that can detect outdoor UV intensity in real time and then respond by automatically adjusting its color to control UV transmission has been developed for the first time by integrating a TiO2 based photodetector with a viologen hydrogel based electrochromic device. Excellent photodetector properties, including high transparency of 90% at 585 nm, great photoresponsivity of 67.15 mA W−1 and an outstanding photo-dark current ratio of 1.48 × 104 have been demonstrated. Meanwhile, the viologen hydrogel based electrochromic device possesses a significant color change with modulation of transmittance up to 60% in the visible range and can efficiently block almost 94% radiation in the UV-A range. This work demonstrates the ability of real time monitoring and regulating the UV radiation via integration of TiO2 films with electrochromic hydrogels, which may guide the development of next generation multifunctional smart windows.