IONICS
·
2019
·Vol. 26
·期 5
·2129-2137
·
IF 2.289
Zhai Huanhuan,Du Xinyang,Wang Fei,Wang Dudan,Li Yupeng,Chen Kanghua
As a prospective cathode material, the main shortages of Li 2 MnO 3 are its low practical capacity and poor cycling stability. Here, an electrochemically stable and low-cost nickel nitrate surface treatment of Li 1.96 Mg 0.02 MnO 3 cathode material is prepared by solid-state reaction. The advantage of this material lies in Mg 2+ ions playing a key role in improving the discharge capacities by larger amount of Li + extracted and inserted through Li vacancies. Meanwhile, nickel containing layered oxide coating layer serves as the protector to suppress the dissolution of manganese as well as stabilizing the layer structure. As a result, this cathode delivered a superior discharge capacity of 177.4 mAh g −1 after 40 cycles at 0.1C, which was approximately 57.8% higher than that of pristine Li 2 MnO 3 . After comparison, it presented an optimal rate performance at different C rate. Therefore, surface treatment will bring Li 1.96 Mg 0.02 MnO 3 a bright future at the race of cathode development for lithium ion batteries.
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DOI
高影响因子
Science China-Physics Mechanics & Astronomy
·
2024
·Vol. 68
·期 2
·226811
·
IF 6.4
Liu Xueying,Liu Shiying,Xiao Yulong,Xu Chang,Wu Jiaxin,Li Kaihui,Li Si-Yu,Pan Anlian
Twisted transition metal dichalcogenides (TMDs) homo-bilayers host unique quantum properties, which can be tuned by interlayer twist angle θ . However, the systematic evolution of their typical electronic properties with respect to the twist angle θ , which is crucial for identifying the “special angle” analogous to the “magic angle” of twisted bilayer graphene in correlation physics studies, remains incompletely understood. Here, via scanning tunneling microscopy (STM) and spectroscopy (STS), we investigate the variation of the moiré potential, flat band, and layer polarization characteristics across a wide range of twist angle θ in twisted bilayer MoS 2 (TB-MoS 2 ). The moiré potential of the valence band exhibits a non-monotonic variation with θ , peaking at a maximum value up to 204 meV at θ ∼1.7°. Concurrently, at the same θ , the bandwidth of the flat band at the Γ V point of the valence band attains its minimum, precisely signifying the “special angle” θ c ∼1.7° in TB-MoS 2 . Interestingly, layer polarization in the moiré superlattice is spatially visualized through the distribution of local density of states (LDOS) at the energies of both Γ V and K V points of the valence band, where the polarization degree at the Γ V point demonstrates a close dependency on θ . Our findings deepen understanding of twist-angle effect in TMDs, advancing both fundamental physics and practical application.
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高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
·
2013
·Vol. 116
·期 1
·241-248
·
IF 1.982
Xin Mingliang,Ma Yujie,Lin Weihong,Xu Kai,Chen Mingcai
Myricetin (MY) was firstly synthesized from dihydromyricetin (DMY), and its antioxidant activity was analyzed. FTIR, NMR, and TG measurements confirmed that the DMY turned to MY. Scanning electron microscope observation showed that the 2,3-single bond offered great flexibility on the stage of crystallization to form imperfect crystalline regions; hence, DMY tends to form larger columnar crystals than MY. It has been found that the antioxidative efficiency of DMY was superior to MY, based on the measurement of radical scavenging activity by DPPH and the oxidation induction time of PP-antioxidant samples. The 2,3-double bond in MY structure, known as one of the characteristic determinants, was not an important requirement for antioxidant capacity or even negative correlation observed. Such a deduction was further supported by UV–Vis absorption spectra change when the pH was raised to pH 9. It was concluded that the ortho-trihydroxyl group in the B ring provides an antioxidant defense, and the 2,3-single band of C ring provides the structural stability.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 12
·11499-11507
·
IF 2.195
Tao Yue,Wang Bo,Qiao Hui,Huang Zongyu,Qi Xiang
In this report, WS 2 -reduced graphene oxide (WS 2 -rGO) hybrid was successfully synthesized through a hydrothermal reduction process in which WS 2 nanosheets (WS 2 NSs) were prepared by a lithium-ion intercalation and exfoliation technique. The photodetection properties of as-synthesized samples have been systematically investigated using a photoelectrochemical (PEC) system, which presents a reproducible photoresponse of WS 2 -rGO under zero bias, indicating that such hybrid is a promising photoanode for self-powered photodetectors. At a bias of 0.8 V, the photocurrent density of WS 2 -rGO hybrid was 4.32 μA/cm 2 , which is approximately 800% of that of the bare WS 2 photodetector. Meanwhile, the photoresponsivity of as-prepared WS 2 -rGO hybrid increases linearly with the irradiation intensity, up to 9.3 μA/W at power density of 30 mW/cm 2 . In addition, the stability test exhibits no conspicuous degradation after 100 cycles. The enhanced performance of the WS 2 -rGO hybrid benefits from the high carrier mobility of rGO and the efficient separation of photogenerated carriers at the WS 2 -rGO interface. This research demonstrates that the WS 2 -rGO hybrid has a good prospect in PEC-type photodetectors.
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高影响因子
GRAEFES ARCHIVE FOR CLINICAL AND EXPERIMENTAL OPHTHALMOLOGY
·
2018
·Vol. 256
·期 3
·559-566
·
IF 2.249
Calvo-Sanz Jorge A.,Portero-Benito Alejandro,Arias-Puente Alfonso
Purpose To compare and evaluate the agreement between the measurements obtained with a swept-source optical coherence tomography (OCT)-based biometer, the IOLMaster® 700 (IOLM), and those obtained by an optical biometer based on optical low-coherence interferometry (OLCI), the Aladdin (ALD); To evaluate the ability to perform biometric measurements in those eyes with transparency alterations. Methods Fifty-five eyes of 55 subjects were included in this study. Axial length (AL), corneal power (K, in diopters) and its astigmatism, anterior chamber depth (ACD), central corneal thickness (CCT), and lens thickness (LT) measures were obtained within both biometers, Zeiss IOLMaster 700 and Topcon Aladdin. Results were analyzed and compared using the Student’s paired samples t -test, Bland–Altman analysis and intraclass correlation coefficient (ICC). Results Mean age was 73.12 ± 2.63 (62–89 years). The IOLM mean AL, K, and LT values did not show a statistically significant difference from ALD values and showed excellent agreement and correlation (ICC = 1.000, 0.970, 0.952). IOLM measured a lower mean ACD (−0.036 mm) and higher CCT measurements (9.296 μm). Those results were statistically different ( p < 0.001 in both cases) but showed an excellent correlation coefficients (ICC = 0.994, 0.938). IOLM was able to obtain measures from all the eyes examined, while ALD did not measure in two cases with dense nuclear cataract. ALD showed spherical K measures in 7.27% of cases. Conclusion Overall a quite good agreement between IOLM and ALD was found. ALD showed spherical keratometry measures in 7.27% of cases. IOLMaster 700 was more effective in obtaining AL measurements in eyes with dense cataracts.
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高影响因子
FOLIA MICROBIOLOGICA
·
2015
·Vol. 61
·期 3
·249-253
·
IF 1
Hu Ruixue,Du Na,Chen Nan,Lin Li,Zhai Yanhua,Gu Zemao
The mechanisms of resistance to levofloxacin for Aeromonas hydrophila isolated from diseased fish and selected in vitro were examined in this study. Levofloxacin-resistant mutants were obtained by selection of A. hydrophila in vitro. The quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes were sequenced in Lev R strains and reverse mutation strains. All Lev R strains carried a point mutation at codon 83 (Ser → Ile), and one strain (25 %) harbored a mutation at position 92 (Leu → Met) in the GyrA-QRDR. After being transferred in a levofloxacin-free medium, one strain of the mutants was successfully reversed and the reversion was related with mutations o f GyrA-QRDR at positions 81 (Gly → Asp) and 83 (Ile → Ser). No amino acid alteration was found in the ParC-QRDR. In addition, the minimum inhibitory concentration (MIC) of levofloxacin for the mutants was lower in the presence of reserpine, and all mutants were also resistant to some of the other quinolones. It was found that the mechanism of levofloxacin resistance of A. hydrophila selected in vitro was related to gyrA of type II topoisomerase, and an efflux mechanism was involved in the resistance as well.
研究领域:
微生物学
·
分子生物学
·
药理学
·
水产病害防治
·
抗菌药物耐药性
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高影响因子
IONICS
·
2019
·Vol. 26
·期 2
·649-660
·
IF 2.289
Yan Honglin,Ru Qiang,Gao Ping,Cheng Shikun,Ling Francis Chi-Chung
In the past few years, silane coupling agents are often used to modify the surface of silicon materials; however, researches in preparation of SiO X -based materials pyrolyzed from silane coupling agents are seldom reported. Hence, in order to prepare amorphous SiO X @C anodes for Li-ion storage, we adopted three kinds of silane coupling agents as organic silicon sources. The results show that silane coupling agents with vinyl group is the optimum organic silicon source. Owing to the strong chemical bonds of Si–O–C, amorphous SiO X particles are uniformly embedded in carbon matrix, forming monodisperse microbeads architecture with good buffer abilities. Therefore, the V-SiO X @C anodes derived from silane coupling agents with vinyl groups show good electrochemical performance, retaining a reversible discharge capacity of 940 mAh g −1 at a current density of 100 mA g −1 after 200 cycles, and it still depicts a good long-term cycling durability, maintaining 739 mAh g −1 at a current density of 400 mA g −1 after 400 cycles.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
功能材料
·
锂离子电池
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 28
·期 16
·11563-11568
·
IF 2.019
Sun Xinjie,Tong Hua,Yuan Xiao,Liu Cui,Yuan Shuanglong,Chen Guorong,Yang Yunxia
Thermal boron diffusion, which forms highly doped and shallow p-emitters on phosphor-doped silicon wafers, is one of the primary processes in commercial-scale production of n-type cells. Here, we report on the use of nontoxic and nonvolatile borosiloxane sols as the spin-on boron source. In comparison to the tribromide (BBr 3 ) boron diffusion that is applied in the production of most commercial n-type cells, borosiloxane boron diffusion may have potential advantages in terms of cost, safety, operability, etc. The borosiloxane sols studied here were formed from a cross-linking reaction between boron acid and a mixture of two types of silicon alkoxides, methyltriethoxysilane (MTEOS) and dimethyldiethoxysilane (DMDEOS). The MTEOS/DMDEOS ratio was found to be the key factor determining the synthetic period, net structure, thermal transformation property, and coating behavior of the borosiloxane sols. In combination with the spin-coating method, the performance of borosiloxane boron diffusion into phosphor-doped silicon wafers (1–3 Ω·cm) was systematically investigated by varying the borosiloxane composition (boron/silicon or MTEOS/DMDEOS ratio) and the diffusion process parameters (temperature, ambience, and period of individual sub-steps), and by relating them to the resulting sheet resistance and boron doping profile. The results show that under the diffusion conditions in conventional cell production lines, the formed p-emitters can have variable sheet resistance in the range of 35–582 Ω/□ and boron doping depth of 100–300 nm.
研究领域:
材料科学
·
半导体物理
·
光伏技术
·
表面工程
·
纳米材料
·
化学气相沉积
·
微电子学
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DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 10
·6241-6258
·
IF 3.917
Garba Zaharaddeen N.,Zhou Weiming,Lawan Ibrahim,Zhang Mingxi,Yuan Zhanhui
In this work, we incorporated Cu 2+ on to microcrystalline cellulose (MCC) powder by a simple synthesis method to produce a composite material (Cu-MCC) with its suitability in prometryn (Pr) adsorption tested from synthetic wastewater. Various characterization techniques were applied in studying the prepared Cu-MCC with response surface methodology applied in order to study the influence of adsorbent dosage, solution pH and shaking speed, which suggested a quadratic model for the response (Pr percentage removal). The optimum adsorption conditions obtained were adsorbent dosage of 0.40 g, solution pH of 11 and shaking speed of 215 rpm with the model adequacy and significance validated by ANOVA. Langmuir and pseudo-second order were the most appropriate models in describing the generated equilibrium and kinetic data, giving rise to a monolayer adsorption capacity value of 97.80 mg/g at room temperature. The desorption of Pr on Cu-MCC was also probed depicting the adsorption capacity to be about 66.7% of its initial value after six sequential adsorption–desorption cycles. Overall, the prepared Cu-MCC was revealed to have great potential for being a good adsorbent in the removal of water contaminants such as Pr, based on the obtained results. Graphic abstract
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APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2023
·Vol. 129
·期 10
·682
·
IF 2.7
Yin Chunmei,Li Qinghua,Lu Zhiyi,Shi Yaochen,Lin Wei
A highly sensitive pressure-sensitive sensor based on MXene was developed using the electrostatic self-assembly method, with carbide sponges as the elastic substrate and a rational design. Specifically, CTAB was used to treat the carbide triamine sponge and conduct the electrostatic self-assembly with MXene to achieve a tightly combined conductive filler and substrate. The resulting pressure sensor showed excellent performance, with a high sensitivity of 15.05 kPa −1 under a range of 0–20 kPa, a response time of 0.1 s, and high durability under 2000 loading–unloading cycles. The minimum detection limit of the sensor was as low as 0.3 Pa, demonstrating excellent monitoring performance. Additionally, finite-element simulation analysis showed that MXene@CTAB@CMF had even better sensing performance at the same stress level. Moreover, the pressure sensor exhibited good sensing performance for various physiological signals and daily work monitoring of the human body, indicating its potential application value.
研究领域:
生物医学工程
·
纳米医学
·
柔性电子学
·
传感技术
·
材料科学
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高影响因子
IONICS
·
2020
·Vol. 26
·期 9
·4257-4265
·
IF 2.394
Jiang Huize,Han Yu,Wang Hui,Zhu Yuhao,Guo Qingpeng,Jiang Haolong,Zheng Chunman,Xie Kai
The poor interface between the active materials, solid electrolytes, and conductive additives in composite cathode materials is the key factor restricting the performance of the all-solid-state lithium-sulfur battery. Here, the composite cathode material was prepared through the method of one-step ball milling. The sulfide electrolyte Li 3 PS 4 (LPS) was formed on the surface of the active material Li 2 S while the conductive additives were incorporated, and the conductive ions and electronic network were constructed simultaneously. After adding an appropriate amount of carbon nanotubes (cnt), the composite cathode exhibited high specific capacity of 1145.2 mAh g −1 after 30 times of cycling at a current density of 0.2 mA cm −2 , and the battery with ultrahigh areal Li 2 S loading also displays high capacity of 962.6 mA g −1 . The composite cathode with high Li 2 S content (56.3%) was prepared, with excellent performance exhibited: the capacity is 741 mAh g −1 after 30 times of cycling at a current density of 0.2 mA cm −2 .
Without additional sulfide electrolyte, the composite cathode materials were prepared by one-step ball milling with lithium sulfide, phosphorus pentasulfide, acetylene black, and carbon nanotubes as raw materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
固态离子学
·
纳米复合材料
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 24
·1707
·
IF 2.8
Van Ngo Hoanh,Nguyen Hung Tran,Le Hieu Trung,Le Thanh Huu,Vu Thien Tri,Pham Kien Trung,Phung Thinh Xuan
A study area in supercapacitor research is the design and manufacturing of composite electrode materials that combine the advantages of various materials. The rGO/CoFe 2 O 4 composite material is produced by growing cobalt ferrite particles on the surface of rGO using a simple and highly efficient thermal reduction technique. The results show that the electrochemical properties of rGO are significantly improved by the incorporation of cobalt ferrite. rGO sheets are used as supporting frameworks for the CoFe 2 O 4 nanoparticles, while the CoFe 2 O 4 particles provide more active sites for redox reactions. The prepared rGO/CoFe 2 O 4 show excellent electrochemical properties, with a high specific capacitance of 283 F/g at a current density of 0.1 A/g and a specific capacitance retention of 90.5% after 1000 cycles. The attractive performances exhibited by rGO/CoFe 2 O 4 composites make them potential electrode materials for supercapacitors in future.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
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高影响因子
危险品化学品经营许可证（带存储）