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Along with the demand for further miniaturization of high and pulsed power devices, it becomes more and more important to realize ultrahigh recoverable energy storage density (Wrec ) with high energy storage efficiency (η) and ultrahigh discharge energy storage density (Wd ) accompanied by high power density (Pd ) in dielectrics. To date, it remains, however, a big challenge to achieve high Wrec or Wd in glass ceramics compared to other dielectric energy storage materials. Herein, a strategy of defect formation modulation is applied to form "amorphous-disordered-ordered" microstructure in BaTiO3 -based glass ceramics so as to achieve a high Wrec of 12.04 J cm-3 with a high η of 81.1% and an ultrahigh Wd of 11.98 J cm-3 with a superb Pd of 973 MW cm-3 . This work demonstrates a feasible route to obtain glass ceramics with an outstanding energy storage performance and proves the enormous potential of glass ceramics in high and pulsed power applications.
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To realize efficient water splitting, a highly promising hydrogen evolution reaction (HER) electrocatalyst is needed for the generation of hydrogen. Herein, we demonstrate a novel acenaphthenediimine complex-bridged porphyrin porous organic polymer (NiTAPP-NiACQ) with enriched active metal sites and hierarchical pores. The as-prepared NiTAPP-NiACQ exhibits good long-term durability and remarkable HER performance in 1.0 M KOH with a low overpotential of 117 mV at 10 mA cm-2, which is comparable to many previously reported electrocatalytic HER systems. Furthermore, a simple water-alkali electrolyzer using NiTAPP-NiACQ as the cathode requires a small cell voltage of 1.59 V to deliver a current density of 10 mA cm-2 at room temperature, along with outstanding durability. NiTAPP-NiACQ features not only a metal ion as the catalytic active center in the porphyrin core but also metal ion coordination on the anthraquinone component to promote HER performance, enabling multiple metal ions as the electrocatalytic active sites for the HER reaction. The excellent HER activity of NiTAPP-NiACQ is ascribed to a combination of mechanisms. These findings highlight the viability of porphyrin-derived porous organic polymers in energy conversion processes.
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Nickel-rich layered cathode LiNi0.8Co0.1Mn0.1O2 (NCM811) is the most promising cathode material due to its high specific capacity and lower cost than lithium cobalt oxides. However, NCM811 suffers from structural instability and capacity degradation during charge-discharge cycles. Herein, we report a strategy to construct a conductive network by employing a holistic Ge coating, which interconnects Mg-doped NCM811 particles. Dopant Mg ions, serving as a "pillar" in the Li slab of NCM811, substantially enhance the structural reversibility. The Ge particles are not only coated on the electrode surface but also enter into the electrode pores to form a multidimensional conductive structure, which improves the conductivity of the electrode and slows down the interface side reaction, thus minimizing the irreversible loss of NCM811 upon long cycling. The modified NCM811 electrode delivers a high discharge capacity (â¼204 mAh g-1 at 0.1C), excellent rate performance (â¼155 mAh g-1 at 10C), and high capacity retention (83% after 200 cycles) even at 4.4 V. Additionally, a cylindrical full battery with graphite/modified NCM811 undergoes 1000 cycles with 86% capacity retention at 2C.
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Interaction of multi-active components can effectively maximize the overall catalytic ability of alcohol fuel cells. Herein, the self-assembled nitrogen doped carbon nanotubes (NCNTs) containing Co-MnO composite (Co-MnO/NCNTs) are successfully synthesized using dihydrodiamine as carbon and nitrogen source through one-step synthesis. In order to further improve the catalytic activity of Co-MnO/NCNTs for alcohol oxidation, small amounts of platinum quantum dots are uniformly loaded on Co-MnO/NCNTs formation of quaternary hybrid (named Pt/Co-MnO/NCNTs) during microwave reduction stage. Notably, the prepared Pt/Co-MnO/NCNTs hybrids possess the excellent methanol and ethanol oxidation mass current density of 1775.4 and 1112.8 mA mg-1 in alkaline condition, which are 3.6 and 2.25 times higher than that of Pt/C catalysts, respectively. The current density of ethanol catalytic oxidation is lower than that of methanol, which may be due to the partial oxidation of acetyl (the intermediate product of ethanol) on the Pt (1 1 1) crystal surface. More importantly, CO oxidation experiments reveal that strong electronic synergistic effect between MnO and Pt quantum dot can greatly improve the CO anti-poisoning ability. Another significant advantage of Pt/Co-MnO/NCNTs is that low platinum loading leads to low cost effective, which demonstrates that the modification non-noble metal catalysts with a few noble metals quantum dots is a promising choice to mass produce high performance catalyst with remarkably boosting electrocatalytic activity for alcohol oxidation.
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Nanopillar crystalline indium tin oxide (ITO) thin films were deposited on soda-lime glass substrates by radio frequency (RF) magnetron sputtering under the power levels of 100 W, 150 W, 200 W and 250 W. The preparation process of thin films is divided into two steps, firstly, sputtering a very thin and granular crystalline film at the bottom, and then sputtering a nanopillar crystalline film above the bottom film. The structure, morphology, optical and electrical properties of the nanopillar crystalline ITO thin films were investigated. From X-ray diffraction (XRD) analysis, the nanopillar crystalline thin films shows (400) preferred orientation. Due to the effect of the bottom granular grains, the crystallinity of the nanopillar crystals on the upper layer was greatly improved. The nanopillar crystalline ITO thin films exhibited excellent electrical properties, enhanced visible light transmittance and a highly infrared reflectivity in the mid-infrared region. It is noted that the thin film deposited at 200 W showed the best combination of optical and electrical performance, with resistivity of 1.44 × 10-4 Ω cm, average transmittance of 88.49% (with a film thickness of 1031 nm) and IR reflectivity reaching 89.18%.
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A facile preparation method of a Si-based anode with excellent cycling property is urgently required in the process of preparing lithium-ion batteries (LIBs). Here, lithium titanate (LTO) matrix-supported nanocrystalline Si film is prepared by radio frequency (RF) magnetron cosputtering utilizing LTO and silicon (Si) targets as the sputtering source. LTO-supported nanocrystalline Si film electrodes revealed a repeatable specific capacity of 1200 mA h g-1 at 150 mA g-1 with a maintenance of more than 75% even after 800 cycles. The remarkable electrochemical properties of the LTO-Si composite films could be attributed to the LTO matrix, preventing the electrolyte from directly making contact with the nanocrystalline Si materials, alleviating the stress of the periodic volume change and further providing efficient and rapid pathways for lithium-ion transport. The results suggest that Si-based LTO composite films are prospective anodes for LIBs, with high capacities and long cycling stabilities.
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ZnMn2O4 microtubules (ZMO-MTs) with a mesoporous structure are fabricated by a novel yet effective biomorphic approach employing cotton fiber as a biotemplate. The fabricated ZMO-MT has approximately an inner diameter of 8.5 µm and wall thickness of 1.5 µm. Further, the sample of ZMO-MT displays a large specific surface area of 48.5 m2 g-1. When evaluated as a negative material for Li-ion batteries, ZMO-MT demonstrates an improved cyclic performance with discharge capacities of 750.4 and 535.2 mA h g-1 after 300 cycles, under current densities of 200 and 500 mA g-1, respectively. Meanwhile, ZMO-MT exhibits superior rate performances with high reversible discharge capacities of 614.7 and 465.2 mA h g-1 under high rates of 1000 and 2000 mA g-1, respectively. In sodium ion batteries applications, ZMO-MT delivers excellent high discharge capacities of 102 and 71.4 mA h g-1 after 300 cycles under 100 and 200 mA g-1, respectively. An excellent rate capability of 58.2 mA h g-1 under the current density of 2000 mA g-1 can also be achieved. The promising cycling performance and rate capability could be benefited from the unique one-dimensional mesoporous microtubular architecture of ZMO-MT, which offers a large electrolyte/electrode accessible contact area and short diffusion distance for both of ions and electrons, buffering the volume variation originated from the repeated ion intercalation/deintercalation processes.
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A novel meosoporous tubular Co3O4 has been fabricated by a simple and cost-effective biomorphic synthesis route, which consists of infiltration of cotton fiber with cobalt nitrate solution and postcalcination at 673 K for 1 h. Its electrochemical performance as a supercapacitor electrode material is investigated by means of cyclic voltammetry and chronopotentiometry tests. Compared with bulk Co3O4 prepared without using cotton template, biomorphic Co3O4 displays 2.8 fold enhancement of pseudocapacitive performance because of the unique tubular morphology, relative high specific surface area (3 and 0.8 m(2)/g for biomorphic Co3O4 and bulk Co3O4, respectively), and mesoporous nature.
Asunto(s)
Biotecnología/métodos , Ingeniería Química/métodos , Cobalto/química , Óxidos/química , Materiales Biomiméticos , Biomimética , Fibra de AlgodónRESUMEN
OBJECTIVE: To investigate the interventional effect of comprehensive behaviour psychotherapy on the ejaculatory latency of premature ejaculation (PE) patients, sexual satisfaction of sexual partners, as well as its influence on the results of clinical treatment. METHODS: Ninety PE patients were randomly divided into a psychological intervention group (n = 45) and a control group (n = 45). Both groups were given medicine therapy, and the former also received comprehensive behaviour psychotherapy for 6 weeks. All the patients were assessed with the Chinese index of sexual function for PE and ejaculatory latency in the vagina, and the clinical efficacy was compared between the two groups. RESULTS: Before treatment, the ejaculatory latency in the vagina was (0.69 +/- 0.25) min and (0.71 +/- 0.19) min respectively in the intervention and the control groups, as compared with (5.87 +/- 0.59) min and (4.76 +/- 0.54) min before treatment, with significant difference (P < 0.01). In the intervention group, the scores in the control of ejaculatory reflex, the sexual satisfaction of the patients and their sexual partners and anxiety or depress in sexual activity in CIPE were higher than in the control group, with significant difference between the two groups (t = 2.12, 2.31, 2.01, 2.24, P < 0.05). The difference in the SAS score after therapy was of significance (P < 0.01). A month after treatment, the effectivity rates of the two groups were 82.9% and 30% respectively, and the difference was significant (P < .01). CONCLUSION: Comprehensive behaviour psychotherapy obviously adds to the clinical efficacy of drugs in the treatment of PE.