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Wuwei heavy ion therapy center is the first Chinese heavy ion accelerator facility developed for cancer therapy, in which four terminals are distributed and the height of the vertical terminal is u...

Heterostructures have broad potential application in energy conversion material and optoelectronic device since of novel interface effect and enhanced electron transport dynamics at heterointerfaces. Herein, we report a heterostructured SnS/SnO2/spherical graphene composite, in which ultrafine SnS/SnO2 nanoparticles with heterostructures are sandwiched between multi-layers of graphene sheets, exhibiting a hollow spherical architecture as a whole. Detailed electrochemical studies indicate that the molar ratio of SnS to SnO2 has great influence on the charge transport efficiency. Theoretical calculation reveals that SnS and SnO2 exhibit different work functions and the Fermi level shift is affected by the SnS/SnO2 molar ratio, thus the hybrid with the ratio close to 1.0 owns the most adsorbed lithium ions, which leads to the highest specific charge-transfer kinetics and lowest ion-diffusion resistance than other samples. Electrochemical tests show that the composite with appropriate composition delivers the best lithium storage rate performance (620 and 312.7 mAh g−1 at 1 C and 10 C). A much stable and high reversible specific capacity of 850 mAh g−1 is obtained after 200 cycles at 0.1 C. The appropriate molar ratio of nano-heterostructures and the novel sandwich hollow spherical composite structure are attributed to the excellent electrochemical performances.

Efficient electrocatalysts for hydrogen evolution reaction (HER) are critical to reduce energy losses in alkaline water electrolysis. Herein, CoNiSe2 heteronanorods decorated with layered-double-hydroxides (LDHs) nanosheets are designed, in which the selenide-LDHs interfaces can boost H2O chemisorption to produce reactive H intermediate, resulting in fast HER kinetics. Such promotion in HER is further interpreted by theoretical calculation and in-situ Raman investigation. By contrast, it’s negligible for anodic oxygen evolution. Assembled as an electrolyzer for overall water splitting, the heteronanorods afford a quite low cell voltage of 1.44 V at a geometric current density of 10 mA cm−2 and remarkable stability for more than 48 h in 1.0 M KOH, performing among the best of non-precious electrocatalysts. Identifying efficient electrocatalysis on engineered heterointerfaces, this work is anticipated to open up new opportunities for catalyst design in energy chemistry.

The reunion of Sn is always a troublesome issue when it’s used as the energy storage materials, on the one hand it comes from the preparation process due to its low melting point, and on the other hand it comes from the Li-Sn alloying process because of its natural tendency of migration. The Sn/SnO2/spherical graphene composite prepared by one-step low temperature hydrothermal reduction method can effectively solve this problem. In the composite, Sn/SnO2 tiny nanoparticles with average diameter of 5 nm distribute evenly between multilayers of graphene sheets presenting a hollow spherical structure. The introduction of SnO2 can effectively restrain the agglomeration of Sn nanoparticles during alloying process since an amorphous Li2O matrix is formed to separate the adjacent active particles. The sandwich graphene hollow sphere skeleton effectively buffers the volume expansion of Sn/SnO2 and further restricts their migration and agglomeration. Due to the above advantages, the nano-Li2O generating from the decomposition of SnO2 can contact closely with excessive nano-Sn in restricted area, promoting facile conversed conversion reaction. Therefore, the composite exhibits high reversible capacity and excellent cycle performance. A stable and high specific capacity of 843.8 mAh g−1 is obtained after 100 cycles at 0.1 C.

Based on non-equilibrium Green's function combined with density functional theory (NEGF-DFT), we investigate the spin dependent transport in the ferromagnetic 6,6,12/γ-graphyne zigzag nanoribbon (GYZNR) heterojunction under different magnetic configurations. It is found that, at low bias ([−0.05, 0.1] V), the junction presents metallic transport with negligible spin polarization in parallel configuration (PC) while it behaves as an insulator in anti-parallel configuration (APC), which results in giant magnetoresistance. Interestingly, when we increase the bias voltage beyond [−0.05, 0.1] V, dual spin filtering characterized by electron transport of different spin channels under different polarity of bias is observed in APC but not in PC. All these findings are understood from the symmetry matching of wave functions in two nanoribbons at equilibrium or finite bias. Furthermore, dual spin filtering can also be achieved in PC by applying a gate voltage on the central interface region, which arises from the shift of different single spin channel of the central gate region into the bias window at a different polarity of the gate voltage. Thus, our work demonstrates the great potential of the 6,6,12/γ-GYZNR heterojunction as a multi-functional device and its great perspectives in carbon-based nanoelectronics and spintronics.

The discharge caused by metals triggered by microwave radiation is a key issue, whereas little attention was paid to the pyrolysis of waste tires by using the interaction between microwave and meta...

SnS is widely studied as anode materials since of its superior structural stability and physicochemical property comparing with other Sn-based composites. Nevertheless, the inconvenience of phase morphology control and excessive consumption of sulfur sources during synthesis hinder the scalable application of SnS nanocomposites. Herein, we report a facile in-situ sulfuration strategy to synthesize sandwiched spherical SnS/sulfur-doped graphene (SnS/S-SG) composite. An ultra-low sulfur content with approximately stoichiometric ratio of Sn:S can effectively promote the sulfuration reaction of SnO2 to SnS and simultaneous sulfur-doping of graphene. The as-prepared SnS/S-SG composite shows a three-dimensional interconnected spherical structure as a whole, in which SnS nanoparticles are sandwiched between the multilayers of graphene sheets forming a hollow sphere. The sandwiched sphere structure and high S doping amount can improve the binding force between SnS and graphene, as well as the structural stability and electrical conductivity of the composite. Thus, a high reversibility of conversion reaction, promising specific capacity (772 mAh g−1 after 100 cycles at 0.1 C) and excellent rate performance (705 and 411 mAh g−1 at 1 C and 10 C, respectively) are exhibited in the SnS/S-SG electrode, which are much higher than that of the SnS/spherical graphene synthesized by traditional post-sulfuration method.

Lithium sulfide as a promising cathode material not only have a high theoretical specific capacity, but also can be paired with Li-free anode material to avoid potential safety issues. However, how to prepare high electrochemical performance material is still challenge. Herein, we present a facile way to obtain high crystal quality Li 2 S nanomaterials with average particle size of about 55 nm and coated with Li 3 PS 4 to form the nano-scaled core-shell Li 2 S@Li 3 PS 4 composite. Then nano-Li 2 S@Li 3 PS 4 /graphene aerogel is prepared by a simple liquid infiltration-evaporation coating process and used directly as a composite cathode without metal substrate for lithium-sulfur batteries. Electrochemical tests demonstrate that the composite delivers a high discharge capacity of 934.4 mAh g −1 in the initial cycle and retains 485.5 mAh g −1 after 100 cycles at 0.1 C rate. In addition, the composite exhibits much lower potential barrier (∼2.40 V) and overpotential compared with previous reports, indicating that Li 2 S needs only a little energy to be activated. The excellent electrochemical performances could be attributed to the tiny particle size of Li 2 S and the superionic conducting Li 3 PS 4 coating layer, which can shorten Li-ion and electron diffusion paths, improve the ionic conductivity, as well as retarding polysulfides dissolution into the electrolyte to some extent.

Exploring noble-metal-free electrocatalysts with high efficiency for both the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) holds promise for advancing the production of H2 fuel through water splitting. Herein, one-pot synthesis was introduced for MoS2–Ni3S2 heteronanorods supported by Ni foam (MoS2–Ni3S2 HNRs/NF), in which the Ni3S2 nanorods were hierarchically integrated with MoS2 nanosheets. The hierarchical MoS2–Ni3S2 heteronanorods allow not only the good exposure of highly active heterointerfaces but also the facilitated charge transport along Ni3S2 nanorods anchored on conducting nickel foam, accomplishing the promoted kinetics and activity for HER, OER, and overall water splitting. The optimal MoS2–Ni3S2 HNRs/NF presents low overpotentials (η10) of 98 and 249 mV to reach a current density of 10 mA cm–2 in 1.0 M KOH for HER and OER, respectively. Assembled as an electrolyzer for overall water splitting, such heteronanorods show a quite low cell voltage of 1.50 V at 10 mA...

Three-dimensional (3D) interconnected spherical graphene framework-decorated SnS nanoparticles (3D SnS@SG) is synthesized by self-assembly of graphene oxide nanosheets and positively charged polystyrene/SnO2 nanospheres, followed by a controllable in situ sulfidation reaction during calcination. The SnS nanoparticles with diameters of ∼10–30 nm are anchored to the surface of the spherical graphene wall tightly and uniformly. Benefiting from the 3D interconnected spherical graphene framework and subtle SnS nanoparticles, the generated Li2S could keep in close contact with Sn to make possible the in situ conversion reaction SnS + 2Li+ + 2e– ↔ Sn + Li2S. As a result, the 3D SnS@SG as the anode material for lithium ion batteries shows a high initial Coulombic efficiency of 75.3%. Apart from the irreversible capacity loss of 3D spherical graphene, the initial Coulombic efficiency of SnS in the 3D SnS@SG composite is as high as 99.7%, demonstrating the almost complete reversibility of Li2S in this system. Furth...

Adenylyl cyclases (ACs), which are responsible for catalyzing the conversion of adenosine triphosphate (ATP) into the second messenger cyclic adenosine monophosphate (cAMP), play a critical role in cell signal transduction. In this study, a combined approach involving docking-based virtual screening, with the combination of homology modeling followed by an in-vitro, and cell-based biological assay have been performed for discovering a class of novel potent and selective isoform adenylyl cyclase type 8 (AC8) agonist. The computer-aided virtual screening was used to identify fourteen virtual cluster compounds as potential hits which were further subjected to rigorous bioassays. A novel hit compound VHC-7 (ethyl 3-(2,4-dichlorobenzyl)-2-oxoindoline-3-carboxylate) was identified as a highly potent selective AC8 agonist with EC50 value of 0.1052 ± 0.038 µM. Remarkably, the molecule herein reported can be explored further to discover greater number of hit compounds with better pharmacokinetic properties as well as to serve as a promising novel hit agonist of AC8 for the treatment of various central nervous system disorders and its associated diseases.

Ultrathin, undersized MoS2/graphene composites are fabricated by a facile acetic acid assisted hydrothermal route and post-annealing. The structure and morphology characterization reveals that the MoS2 nanosheets with ∼5 layers and 130–160 nm in size are decorated on the surface of graphene nanosheets homogeneously and tightly. The effects of acetic acid and N-methyl-pyrrolidone solvent on the microstructures and electrochemical performances of the MoS2/graphene composites are investigated. It is found that the acetic acid could maintain a constant pH and promote hydrolysis of thiourea, and thus many more MoS2 crystals nucleus were formed, while the N-methyl-pyrrolidone could inhibit the aggregation of the as-prepared MoS2 sheets, and therefore few-layered MoS2 sheets with a small size are obtained. Electrochemical tests confirmed that the lithium storage performance of ultrathin, undersized MoS2/graphene is greatly improved compared to that without addition of acetic acid or N-methyl-pyrrolidone solvent. A high reversible capacity of 1229 mA h g−1 is achieved in the initial cycle and is maintained at 942.6 mA h g−1 after 50 cycles at a current density of 100 mA g−1. Even at a current density of 1000 mA g−1, the reversible capacity could be maintained as high as 747 mA h g−1.

Adenylate cyclases (ACs), play a critical role in the conversion of adenosine triphosphate (ATP) into the second messenger cyclic adenosine monophosphate (cAMP). Studies have indicated that adenylyl cyclase type 2 (AC2) is potential drug target for many diseases, however, up to now, there is no AC2-selective agonist reported. In this research, docking-based virtual screening with the combination of cell-based biological assays have been performed for discovering novel potent and selective AC2 agonists. Virtual screening disclosed a novel hit compound 8 as an AC2 agonist with EC50 value of 8.10 μM on recombinant human hAC2 + HEK293 cells. The SAR (structure activity relationship) based on the derivatives of compound 8 was further explored on recombinant AC2 cells and compound 73 was found to be the most active agonist with the EC50 of 90 nM, which is 160-fold more potent than the reported agonist Forskolin and could selectively activate AC2 to inhibit the expression of Interleukin-6. The discovery of a new class of AC2-selective agonists would provide a novel chemical probe to study the physiological function of AC2.

Rational design of composite with other electroactive materials can effectively improve the supercapacitive performances through the modulation of electronic structure and conductivity of the hybrid material. In this work, core-shell structured Ni3S2@VO2 nanorods on the nickel foam are prepared through a one-pot hydrothermal method. The addition of VO2 effectively reduces the charge transfer resistance and thus enhances the electrochemical conductivity. The nickel foam provides a platform for the in situ dispersive growth of Ni3S2@VO2 as well as a “superhighway” for the transformation of electrons. The Ni3S2@VO2 shows a high areal specific capacity of 1.09 C cm−2 at 1 mA cm−2. After a slight decrease in the initial 200 cycles, the discharge capacity remains almost constant at about 1.00 C cm−2 during the following cycles. At a high current of 50 mA cm−2, the areal specific capacitance is 0.09 C cm−2. A symmetric supercapacitor is assembled using Ni3S2@VO2 as both the anode and cathode. The specific capacity of it is 0.864 C cm−2 at a current of 1 mA cm−2. Good cycling stability and rate capability are also obtained. All these features promise it a high performance supercapacitor electrode.

The Heavy Ion Medical Machine (HIMM) is China’s first heavy ion accelerator specifically for cancer treatment. To minimize the uncontrollable beam orbit and beam loss, the HIMM accelerator magnets require the condition of stringent field uniformity. The best way to examine whether the actual field is consistent with the design or not is to perform an accurate and reliable measurement on the magnetic field, which requires the accurate alignment of the magnetic field measurement system as the prerequisite. This research adopts the alignment of a Hall probe mapping system, long coil integral system and harmonic coils system. Firstly, the preliminary test launched at the HIMM is described. Then, a new alignment method is developed to improve the positioning accuracy and performance of magnetic field measurement system. The experimental results show that the alignment accuracy (maximum deviations) of all components of each magnetic field measurement system is higher than 0.1 mm, which satisfies the requirements for the positioning accuracy of high-precision magnetic field measurement system.