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A novel gate-voltage-modulated strategy based on FET biosensors is developed to comprehensively improve the detection performance of telomerase.

SnSe2–SnO2@NC were investigated for lithium-ion batteries with a capacity of 1023.5 mA h g−1 at 0.2 A g−1 and a capacity of 632.7 mA h g−1 after 2800 cycles at 5 A g−1. DFT calculations revealed the high adsorption energy of SnSe2–SnO2.

Zinc ion hybrid capacitors (ZHCs) are expected to be candidates for large-scale energy storage products due to their high power density and large energy density. Due to their low cost and stability, carbon materials are generally the first choice for the cathode of ZHCs, but they face a challenge in the serious self-discharge behavior. Herein, zinc ion hybrid capacitors with high-performance are successfully assembled using a porous carbon cathode derived from low-cost p-doped waste biomass and a commercial zinc foil anode. The p-doped walnut shell ZHCs delivered a specific capacity of 158.9 mA h g

Through the uniaxial compression deformation test, this work focuses on analyzing the microstructure evolution of the alloy in the two stages of dynamic softening and strain hardening in the true stress-true strain curve during hot deformation, including grain size, local misorientation and The interaction of its relative mobility, and through the grain boundary orientation difference and grain orientation, explained the dynamic softening mechanism and strain hardening phenomenon, so as to find the microstructure-determining characteristic parameters of the dynamic recrystallization nucleation and core growth of the alloy and its evolution.

Brannerite-type NaVMoO6 with vanadium (V5+) and molybdenum (Mo6+) elements in the highest valence states is synthesized by a sol-gel method using Na2CO3, NH4VO3, MoO3 and citric acid reagents. The results of X-ray diffraction (XRD) with Rietveld refinement and X-ray photoelectron spectroscopy (XPS) show that the obtained NaVMoO6 sample is single-phase. Novel electrode material (NaVMoO6) with layered structure is first utilized as cathode material for lithium ion batteries (LIBs). The NaVMoO6 electrode delivers reversible specific capacity of 126.4 mA h g−1 at 5 mA g−1 after 50 cycles. The stable structure of NaVMoO6 is corroborated by ex-situ XRD, suggesting that this material is considered as a prospective cathode for LIBs. This studying enriches the possibilities of molybdenum-based materials as cathodes for LIBs.

Suitable intercalation cathodes and fundamental insights into the Zn-ion storage mechanism are the crucial factors for the booming development of aqueous zinc-ion batteries. Herein, a novel nickel vanadium oxide hydrate (Ni0.25V2O5·0.88H2O) is synthesized and investigated as a high-performance electrode material, which delivers a reversible capacity of 418 mA h g-1 with 155 mA h g-1 retained at 20 A g-1 and a high capacity of 293 mA h g-1 in long-term cycling at 10 A g-1 with 77% retention after 10,000 cycles. More importantly, multistep phase transition and chemical-state change during intercalation/deintercalation of hydrated Zn2+ are illustrated in detail via in situ/ex situ analytical techniques to unveil the Zn2+ storage mechanism of the hydrated and layered vanadium oxide bronze. Furthermore, morphological development from nanobelts to hierarchical structures during rapid ion insertion and extraction is demonstrated and a self-hierarchical process is correspondingly proposed. The unique evolutions of structure and morphology, together with consequent fast Zn2+ transport kinetics, are of significance to the outstanding zinc storage capacity, which would enlighten the mechanism exploration of the aqueous rechargeable batteries and push development of vanadium-based cathode materials.

Flexible three-dimensional interconnected carbon nanotubes on the carbon cloth (3D-CNTs/CC) were obtained through simple magnesium reduction reactions. According to the Nernst equation, the cell voltage based on these pure carbon electrodes without any additives could reach 1.5 V due to the higher di-hydrogen evolution over potential in neutral 3.5 M LiCl electrolytes. In order to improve the electrochemical performance of the electrodes, 3D-CNTs/CC electrodes covered with polyaniline barrier layer (3D-PANI/CNTs/CC) were prepared by in situ electropolymerization using interfacial engineering method. The assembled symmetric supercapacitors display a broadened voltage of 1.8 V, high areal capacitance of 380 mF cm−2, outstanding areal energy density of 85.5 μWh cm−2 and 84% of its initial capacitance after 20 000 charge-discharge cycles. This work demonstrated that the interface engineering strategy provides a promising way to improve the energy density of carbon-based aqueous supercapacitors by widening the voltage and boosting the capacitance simultaneously.

Defect engineering have profound influence on the energy storage properties of electrode hybrids by adjusting their intrinsic electronic characteristics. For iron carbide based materials, however, the effect of defect (especially cation vacancies) toward their electrochemical performance are still unclear. Herein, the feasible and scalable synthesis of Fe

We successfully designed and prepared hierarchical Ni

Nanostructured tin dioxide (SnO2) has emerged as a promising anode material for lithium‐ion batteries (LIBs) due to its high theoretical capacity (1494 mA h g−1) and excellent stability. Unfortunately, the rapid capacity fading and poor electrical conductivity of bulk SnO2 material restrict its practical application. Here, SnO2 nanospheres/reduced graphene oxide nanosheets (SRG) are fabricated through in‐situ growth of carbon‐coated SnO2 using template‐based approach. The nanosheet structure with the external layer of about several nanometers thickness can not only accommodate the volume change of Sn lattice during cycling but also enhance the electrical conductivity effectively. Benefited from such design, the SRG composites could deliver an initial discharge capacity of 1212.3 mA h g−1 at 0.1 A g−1, outstanding cycling performance of 1335.6 mA h g−1 after 500 cycles at 1 A g−1, and superior rate capability of 502.1 mA h g−1 at 5 A g−1 after 10 cycles. Finally, it is believed that this method could provide a versatile and effective process to prepare other metal‐oxide/reduced graphene oxide (rGO) 2D nanocomposites.

Here, 2, 3-dicyano-5, 6-dichloro-1, 4-benzoquinone (DDQ) composites have been tested as the anodes in sodium-ion batteries. When mixed with the amount of 60% carbon black in the electrode composites, it is not at all prone to dissolving in the traditional electrolytes, but enhances the electronic conductivity and manifests good electrochemical performances instead. Additionally, the ex-situ scanning electron microscope (SEM) images interpret the excellent cycling performance during charging/discharging.

Cornlike ordered N-doped carbon coated hollow Fe3O4 (OH-Fe3O4@NC) composites are prepared through a facile strategy. The unique structure is composed of hundreds of N-doped carbon coated hollow Fe3O4 nanospheres. Successive carbon shell and hollow structure address the irreversibility issue of Fe3O4-based electrodes. Owing to the unique cornlike ordered structure, the as-prepared OH-Fe3O4@NC composites exhibit appealing electrochemical performance as anode materials for lithium-ion batteries (LIBs). It delivers a high reversible capacity of 1316 mA h g−1 at 0.1 A g−1 after 50 cycles and a remarkable rate performance (725, 551 and 361 mA h g−1 at 1, 4, and 10 A g−1, respectively). Our results demonstrate that the OH-Fe3O4@NC composites are the promising anode materials with high capacity for next generation LIBs.

Organic electrode materials with superiorities of low price, structural diversity, abundant resources and renewability have been regarded as the promising candidates for rechargeable batteries. However, the poor electronic conductivity and strong solubility in aprotic electrolytes limit the applications for energy storage systems. Here, the ortho-di-sodium salts of tetrahydroxyquinone (o-Na2C6H2O6) was successfully designed via a facile salinization process. Benefitted from the salt formation, the o-Na2C6H2O6 electrode exhibits a potential electrochemical performance, when applied to lithium-ion batteries and potassium-ion batteries for the first time. For Li-ion batteries, it delivers a good reversible capacity of 141 mA h g−1 over 100 cycles at 25 mA g−1, outstanding rate performance of 55.0 mA h g−1 at 5 A g−1 rate and the long cyclability with a capacity decay of 0.0075% per cycle at 5 A g−1 exceeding 2000 cycles. On the other hand, the o-Na2C6H2O6 also exhibits a high reversible capacity of 168.1 mA h g−1 under the current density of 25 mA g−1, good rate performance (26.7 mA h g−1 at 5 A g−1 rate) in the K-ion cells. This finding might offer an effective insight to develop other organic salt materials for lithium-ion and potassium-ion batteries.

The structural information (including the lattice parameters, atomic sites and coordinates (x, y, z)) of Na2VMn2(PO4)3/C has been presented for the first time. It has a monoclinic lattice with the space group of C2/c and cell parameters of a = 12.0494 A, b = 12.6198 A, c = 6.5170 A, β = 114.7°. The valence states of elements and the vibrational modes of Na2VMn2(PO4)3/C are performed by X-ray photoelectron spectroscopy, Raman and FTIR. Furthermore, at 5 mA g−1, Na2VMn2(PO4)3/C as cathode for SIBs shows a reversible discharge capacity of 80.4 mAh g−1. At 20 mA g−1, Na2VMn2(PO4)3/C shows an initial charge capacity of 46.1 mAh g−1 with the capacity retentions of 63.7% after 100 cycles. The poor cycle stability may be attributed to its low intrinsic Na+ diffusion coefficient (DNa+) and Jahn-Teller effect during the sodiation/desodiation process.

With the rapid development of the Internet, the popularization of the mobile technology and the information technology, the smart phones, as a new learning tool based on the network technology, have been widely used in more and more courses. The advent of the new generation learning mode of “Internet+smart phones” has changed students’ learning location and learning space, and students’ learning is more casual, intelligent and personalized. How to maximize the positive role of the smart phones in their learning and how to develop their strengths and avoid their weaknesses is a problem that teachers engaged in the front-line teaching should ponder. In the computer intelligence classrooms, how to effectively solve the problems existing in the process of the teacher-student interaction and put forward the targeted and reasonable countermeasures is of vital importance.

Defect engineering have profound influence on the energy storage properties of electrode hybrids by adjusting their intrinsic electronic characteristics. For iron carbide based materials, however, the effect of defect (especially cation vacancies) toward their electrochemical performance are still unclear. Herein, the feasible and scalable synthesis of Fe x C@NC with 3D honeycomb-like carbon architecture and abundant Fe vacancies via template etching is reported. Such structure enable outstanding lithium-ion storage properties owing to hierarchical pores, improved intrinsic electrochemical activity, as well as the introduction of more active sites. As a result, the Fe x C@NC-2 presents a high reversible specific capacity of 1079 mAh g−1 after 1000 cycles. Moreover, an excellent cycling stability can be achieved via maintaining a high-capacity retention (689 mAh g−1, 98.4%) over 1000 cycles at 5 A g−1. This study provides a feasible strategy for developing high-performance hybrids with hierarchical pore and rich defects structures.

A (MoS2/carbon fiber (CF))@MoS2@C hybrid has been prepared by an efficient method combining the electrospinning, hydrothermal and annealing techniques. Coupled with graphite as cathode, the hybrid enables the full cell (i.e., dual ion batteries) to deliver a high initial discharge capacity of 112.3 mAh g−1 at 0.2 A g−1 and maintain a high reversible capacity of 90.5 mAh g−1 at 0.5 A g−1 after 500 cycles. These remarkable sodium storage properties of (MoS2/CF)@MoS2@C are mainly attributed to its three-dimensional framework with its highly conductive, cross-linked structure, which effectively increases the conductivity of the hybrid and the mass loading of MoS2. Moreover, the MoS2 nanoplates embedded inside CF, as well as being sandwiched between the CF/MoS2 and a thin carbon layer, also can effectively buffer the pulverization and aggregation of the electrode, and thus maintain the structural integrity of (MoS2/CF)@MoS2@C during the charge-discharge process.

Transition metal borates, attracting researchers to investigate whether they can exhibit Li cycling similar to the metal oxides, were criticized for their poor electrochemical reversibility. Herein, citric acid assisted sol-gel technique had been used to synthesize high-performance VBO3 anode for Li-ion batteries. High-purity and well-crystallized VBO3 particles covered with amorphous carbon layer (VBO3/carbon) were applied as electrodes for both rechargeable Li and Na batteries. In the Li system, the VBO3/carbon composite delivered a high reversible capacity of 859.5 mA h g−1 in the first cycle, and showed an outstanding rate ability of ∼720 mA h g−1 even at a current density of 200 mA g−1, which suggests both V and B in VBO3 had participated in the electrochemical redox reaction during the Li intercalation and extraction. However, the Na storage of VBO3/carbon after conversion reaction exhibited typical capacitance behavior but poor electrochemical reversibility.

A novel 3D interconnected NH4Fe0.6V2.4O7.4@C nanocomposite was in situ synthesized through a facile hydrothermal reaction at low temperature (98 °C), and its electrochemical performance as a cathode for sodium-ion batteries (SIBs) was investigated for the first time. Under the intercalation of Fe3+ and carbon-coating, as-prepared samples turned to 3D interconnected structures, which were composed of NH4Fe0.6V2.4O7.4 nanoparticles and carbon chains. The 3D interconnected NH4Fe0.6V2.4O7.4@0.5 wt%C nanocomposite exhibits a high discharge specific capacity of 306 mA h g-1 at a current density of 20 mA g-1 and a high-rate capacity of 130 mA h g-1 at 0.4 A g-1. The results of EIS and ex situ SEM indicated that the 3D interconnected NH4Fe0.6V2.4O7.4@0.5 wt%C nanocomposite possesses good electrical conductivity and structural stability. The ex situ XRD results suggest that NH4Fe0.6V2.4O7.4@0.5 wt%C undergoes a reversible insertion/de-insertion mechanism during a charge/discharge process. Our work demonstrates that the 3D interconnected NH4Fe0.6V2.4O7.4@C nanocomposite material could be considered as a potential cathode for sodium ion batteries.

We successfully designed and prepared hierarchical Ni3S2 nanorod@nanosheet arrays on three-dimensional Ni foam via facile hydrothermal sulfuration. We conducted a series of time- and temperature-dependent experiments to determine the Ostwald ripening process of hierarchical Ni3S2 nanorod@nanosheet arrays. The rationally hierarchical architecture creates an excellent supercapacitor electrode for Ni3S2 nanorod@nanosheet arrays. The areal capacitance of this array reaches 5.5 F cm−2 at 2 mA cm−2, which is much higher than that of Ni3S2 nanosheet arrays (1.5 F cm−2). The corresponding asymmetric supercapacitor exhibits a wide potential window of 1.6 V and energy density up to 1.0 Wh cm−2 when the proposed array is utilized as the positive electrode with activated carbon as the negative electrode. This electrochemical performance enhancement is attributable to the hierarchical structure and synergistic cooperation of macroporous Ni foam and well-aligned Ni3S2 nanorod@nanosheet arrays. Our results represent a promising approach to the preparation of hierarchical nanorod@nanosheet arrays as high-performing electrochemical capacitors.

With the rapid development of the online game industry, more and more enterprises have begun to attract more consumers to use their services and product. In Guizhou, the online game market could be one of the critical developments in the entertainment sector for the number of young consumers. This research focused on investigating how online marketing empowers consumers to market the products, study the various tools and techniques for influencing consumer purchasing decision and brand perception and suggest policies to game developers for game enhancement in the online game industry.

Although the NASICON-type of Na3V2(PO4)3 is regarded as a potential cathode candidate for advanced sodium-ion batteries (SIBs), it has an undesirable rate performance and low cyclability, which are a result of its poor electronic conductivity. Here, we utilized conductive polyaniline (PANI) grown in situ to obtain the hard carbon-coated porous Na3V2(PO4)3@C composite (NVP@C@HC) with a typically simple and effective sol–gel process. Based on the restriction of double carbon layers, the NVP size decreases distinctly, which can curtail the sodium-ion diffusion distance and enhance the electronic conductivity. As expected, the product displays good discharge capacity (111.6 mA h g–1 at 1 C), outstanding rate capacity (60.4 mA h g–1 at 50 C), and remarkable cycling stability (63.3 mA h g–1 with a retention of 83.3% at 40 C over 3000 cycles). Also, it performs a long-term cycling capacity of 58.5 mA h g–1 exceeding 15 000 cycles at 20 C (with a capacity loss of 0.24% per cycle).

Lithium ion batteries (LIBs) with organic electrode materials have drawn considerable attentions with advantages of their flexibility, low cost, and green sustainability, but been limited by high solubility in aprotic electrolytes, leading to capacity decay and short cycling life. Herein, we focus on the co-effect of structural modification and the increase of conductive carbon in electrode composites to accommodate soluble quinonic materials and achieve a long cycling life. Here, 2,3-dichloro-5-hydroxy-6-cyano-1,4-benzoquinone (DHCQ) is synthesized through a simple chemical hydrolysis of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The increase of conductive additive not only enhances the electronic conductivity but also suppresses the dissolution of DHCQ. Benefiting from reasonable molecular design and appropriate control of conductive carbon, the as-prepared material demonstrates a high reversible capacity (921 mA h g−1 at 50 mA g−1), good rate capability (207 mA h g−1 at 5 A g−1) and long-term cycling stability (remaining retention of around 78% after 400 cycles at 500 mA g−1).

A new alluaudite-type Na2VFe2(PO4)3 with carbon composite has been prepared for the first time via a simple sol-gel method using citric acid as an assistant agent and carbon source. The crystal structure and morphology of Na2VFe2(PO4)3/C composite are well characterized by X-ray diffraction, scan electron microscope, and energy-dispersive X-ray analysis. The experimental results show that a three-dimensional [VFe2(PO3)3]2− framework in this alluaudite structure provides two types of tunnels to enable the sodium-ion transporting which contributes to the electrochemical performance. When evaluated as a cathode for sodium-ion batteries, Na2VFe2(PO4)3/C composite delivers the first specific charge capacity of 66.7 mAh g−1 and discharge capacity of 65.8 mAh g−1 at 5 mA g−1 current density. After 100 cycles, the charge capacity (~52.2 mAh g−1at 5 mA g−1) shows a good capacity retention (~78%) compared to the first cycle. Cyclic voltammetric profiles confirm the activated multi-electron reactions including the Fe2+/Fe3+, V2+/V3+, and V3+/V4+ redox couples. Furthermore, the diffusion coefficient of sodium-ion (D Na +) in this structure is also calculated based on the result of electrochemical impedance spectroscopy.

Over-exploration of rare earth elements causes soil desertification and environmental degradation. However, the restoration of rare earth mine tailings requires the recovery of both vegetation and soil microbiota. Accordingly, the present study aimed to compare the efficacy of restoring mine tailings using organic compost and native plants (Miscanthus sinensis, Pinus massoniana, Bambusa textilis, or a mixture of all three). After three years, the mixed plantation harbored tenfold greater plant richness than that in the barren land. Among these, M. sinensis played a dominant role across all restored areas. The microbial communities of the soils were assessed using high-throughput 16S rDNA gene sequencing. A total of 34,870 16S rDNA gene sequences were obtained and classified into 15 bacterial phyla and 36 genera. The dominant genus across all the restored soils was Burkholderia, and the bacterial diversity of restored soils was greater than that of soils from either unrestored or natural (unexploited) areas, with the M. sinensis plantation yielding the greatest diversity. The effects of phytoremediation were mainly driven by changes in nutrient and metal contents. These results indicate that M. sinensis significantly improves phytoremediation and that mixed planting is ideal for restoring the soils of abandoned rare earth mines.

Here, we employ an effective one-step hydrothermal method to synthesize layered Ni3Ge2O5(OH)4 nanocomposite by introducing carbon matrix (Ketjen black, KB) in situ. The obtained Ni3Ge2O5(OH)4 nanosheets are uniformly attached to the KB matrix. The layered Ni3Ge2O5(OH)4/KB nanocomposite inherits the mesoporous feature of the KB and the specific surface area is 314 m2 g−1, which is significantly higher than that of bare Ni3Ge2O5(OH)4. As a result, layered Ni3Ge2O5(OH)4/KB nanocomposite exhibits a highly reversible specific capacity of nearly 580 mA h g−1 at 50 mA g−1 and an outstanding rate capability of around 245 mA h g−1 at 1000 mA g−1, which is obviously superior to that of the bare Ni3Ge2O5(OH)4 nanosheets. The remarkable sodium storage performances of layered Ni3Ge2O5(OH)4/KB nanocomposite should be assigned to the KB, which acts as a conductive matrix and uniformly adheres to the Ni3Ge2O5(OH)4 nanosheets, further increasing the specific surface area, improving electronic conductivity, and accommodating volume change during cycling.

Zinc ion batteries (ZIBs), the classic aqueous batteries with high safety, are regarded as a promising energy storage system. The study on optimizing engineering of ZIBs is still quite rare. Herein, we take a representative ammonium vanadium bronze (NH4V4O10) for example to perform the optimizing engineering through selecting electrolytes and adjusting the proportion of conductive carbon in the electrode. As expected, the electrochemical performance of NH4V4O10 electrode after the optimizing engineering is significantly boosted. NH4V4O10-541 electrode (NH4V4O10 sample, acetylene black and poly(vinylidene fluoride) in a weight ratio of 50:40:10) can deliver a high reversible capacity of 430.0 mA h g−1 at 0.1 A g−1, a good rate capability (277.1 mA h g−1 at 10 A g−1), and an excellent cycling stability (a specific capacity of 244.8 mA h g−1 with 72.2% capacity retention after 3000 cycles at 10 A g−1), superior to the most of cathode materials for ZIBs. The optimizing engineering presented here should provide useful information to improve the electrochemical performance for ZIBs.