RSC Advances
·
2018
·Vol. 8
·期 68
·38850-38859
·
IF 2.936
Yaozu Guo,Dong Zhao,Junhua You,Wenli Pei,Yingdong Qu,Xiaoyang Wang,Qingyu Meng
Nd2Fe14B nanoparticles were successfully prepared by using a low-energy chemical method. The microscopic characteristics and formation mechanisms of the phases were investigated at each stage during the preparation of Nd-Fe-B nanoparticles. The Nd-Fe-B intermediates, Nd-Fe-B oxides and reduced Nd-Fe-B nanoparticles were detected and analyzed by using TEM, STEM, XRD, SEM, VSM and Rietveld calculations. The results showed that the intermediate of Nd-Fe-B consisted of Fe3O4 and Nd and Fe elements surrounded by nitrile organic compounds. The Nd-Fe-B oxide was composed of NdFeO3 (48.619 wt%), NdBO3 (31.480 wt%) and α-Fe (19.901 wt%), which was formed by the reaction among Nd, Fe3O4 and B2O3. NdFeO3 and NdBO3 exhibited a perovskite-like lamellar structure, and the grain size was smaller than that of α-Fe. Nd-Fe-B particles were mainly composed of Nd2Fe14B and α-Fe phases. The small particles of NdFeO3 and NdBO3 and the interstitial position between oxide particles and α-Fe were more favorable for the formation of Nd2Fe14B particles. At the same time, the surface of α-Fe particles can also diffuse to form Nd2Fe14B nanoparticles. The coercivity of Nd-Fe-B particles was 5.79 kOe and the saturation magnetization was 63.135 emu g−1.
研究领域:
材料科学
·
纳米材料
·
磁性材料
·
无机非金属材料
·
固体化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 48
·期 22
·33455-33461
·
IF 5.532
Yuyu Liu,Wenye Deng,Xianghui Chen,Yan Xue,Xuelian Bai,Huimin Zhang,Aimin Chang,Yongxin Xie
A series of novel high temperature negative temperature coefficient (NTC) composite ceramics based on (1- x )CaMn 0.05 Zr 0.95 O 3 - x NiMn 2 O 4 ( x = 0, 0.1, 0.2, 0.3) were fabricated by using the solid-state method. The Rietveld refinement method and backscattered electron (BSE) image confirmed the absence of any other phase. The conduction mechanism of the composite ceramics was determined by analyzing the complex impedance and resistance-temperature characteristics, which could be related to the formation of a continuous Mn 3+ -O-Mn 4+ network. The effect of spinel content on the high temperature stability was analyzed using aging tests. The ρ 400°C , ρ 700°C and B 400/700 values of the NTC thermistors were determined to be 4.9 × 10 6 –1.2 × 10 4 , 1.4 × 10 5 –0.8 × 10 3 Ω cm and 12739-5712 K, respectively. This indicated that the electrical properties could be tuned by adjusting the weight ratio of CaMn 0.05 Zr 0.95 O 3 and NiMn 2 O 4 . The findings obtained in this study reveal that the composite NTC thermistor exhibits a good application potential at high temperatures and under harsh environments.
研究领域:
材料科学
·
无机非金属材料
·
电子功能材料
·
固态离子学
·
高温传感器技术
✓ 已验证
DOI
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
✓ 已验证
DOI
高影响因子
Journal of Global Antimicrobial Resistance
·
2016
·
IF 1.087
Dongmei Wu,Ruochen Lu,Yuquan Chen,Jie Qiu,Chaocheng Deng,Qiang Tan
This study aimed to determine whether selection by antibiotics, chlorhexidine (CHX) and Rhizoma coptidis extract (RCE) would lead to cross-resistance or decreased susceptibility in Staphylococcus aureus . The S. aureus reference strain ATCC 25923 as well as 14 clinical isolates were exposed to antibiotics, CHX and RCE at sublethal doses for up to 14 days. Changes in susceptibility were determined by analysis of minimum inhibitory concentrations (MICs). All isolates were cross-resistant to more than one other antibiotic following tetracycline exposure, and increased resistance (≥4-fold MIC increase) to RCE and CHX was observed in six and three isolates, respectively. Following selection by CHX, most of the treated strains showed no significant change in sensitivity to CHX. However, all strains developed cross-resistance to at least one antibiotic, and decreased susceptibility (≥4-fold MIC increase) to RCE appeared in seven strains. Following exposure to RCE, 11 isolates showed cross-resistance to at least one antibiotic. In addition, three RCE-exposed strains showed reduced susceptibility to CHX (4- or 8-fold MIC increase). The results obtained in this study imply that antibiotics, biocides and antimicrobial Chinese herbs might employ some of the same mechanisms of action against bacteria, triggering mutual cross-resistance to further foster the development of bacterial resistance.
研究领域:
微生物学
·
感染病学
·
药理学
·
分子生物学
·
抗菌药物耐药性
·
天然药物学
✓ 已验证
DOI
高影响因子
Theranostics
·
2019
·
IF 8.063
Weipan Peng,Qian Zhao,Minghui Chen,Jiafang Piao,Weichen Gao,Xiaoqun Gong,Jin Chang
The accurate and quantitative detection of microRNAs (miRNAs) as next-generation, reliable biomarkers will provide vital information for cancer research and treatment. However, their unique, intrinsic features pose quite a challenge for miRNA profiling, especially for multiplexed detection. Thus, there is a strong and an ever-growing need to develop an accurate, simple, sensitive and specific miRNA sensing method. Methods: In this study, a simple and novel sensor is presented that uses a flow cytometry (FCM) method based on the double key “unlocked mechanism” and a fluorescence enrichment signal amplification strategy. The “unlocked mechanism” was cleverly designed via using hairpin DNA probes (HDs) labeled by fluorescent particles (FS) as the lock to block part of them, which can specifically hybridize with the probe on polystyrene microparticles (PS). The target miRNA and duplex-specific nuclease (DSN) forming the double key can specifically open the HDs and cleave a single-stranded DNA (ssDNA) into DNA/RNA dimers circularly in order to unlock the special part of the HDs to be specially enriched further on the PS. Results: The designed sensor with a hairpin structure and DSN special performance was found to have a high specificity. The circularly unlocking fluorescent probes and fluorescent signal enrichment can be beneficial for achieving a high sensitivity with a detection limit of 3.39 fM for miRNA-21. Meanwhile, the performance of multiplexing was estimated by simultaneous detection of miR-21 and miR-141, and the method also allowed for miR-21 detection in breast cancer blood samples. Conclusion: The designed sensor based on an “unlocked mechanism” and a signal enrichment strategy resulted in a one-pot, highly specific and sensitive detection of multiplex miRNAs. The whole detection without the need for a complex purification process is based on a FCM and is expected to have a great value in cancer diagnosis and biomedical research.
研究领域:
生物标志物检测
·
癌症研究
·
生物医学工程
·
分子生物学
✓ 已验证
DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2012
·Vol. 24
·期 24
·3201-3204
·
IF 13.877
Shaohua Liu,Haiping Jia,Lu Han,Jiulin Wang,Pengfei Gao,Dongdong Xu,Jun Yang,Shunai Che
Graphical Hierarchical porous TiO 2 –B with thin nanosheets is successfully synthesized. TiO 2 –B polymorph ensures fast insertion of Li-ion due to its pseudocapacitive mechanism. The thin nanosheet walls with porous structure allow exposure to electrolytes for facile ionic transport and interfacial reaction. The joint advantages endow this material with high reversible capacity, excellent cycling performance, and superior rate capability.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
无机非金属材料
·
电极材料
·
锂离子电池
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
·
IF 3.133
Lei Meng,Bin Yao,Yongfeng Li,Zhanhui Ding,Zhenyu Xiao,Kaisi Liu,Gang Wang
The back contact adhesion is the important factor of the microstructural performance which can determine the optoelectronic properties of the kesterite-based solar cells. Here, we present a rational and effective strategy to significantly enhance the back contact adhesion of Cu 2 (Zn,Cd)Sn(S,Se) 4 (CZCTSSe) absorber layers by insetting the appropriate thickness carbon-doping CZCTS thin films . We chose the oleylamine as the carbon-doping reagent which can generate a small amount of carbon in the annealing process . The suitable thickness carbon-doping CZCTS films can significantly change the crystal growth mechanism of CZCTSSe absorber layers, and eliminate the holes in the back contact. The efficiency of CZCTSSe solar cells fabricated by insetting the appropriate thickness carbon-doping CZCTS films is above 7%, and shows the excellent repeatability and long-term air stability compared with the control devices.
研究领域:
材料科学
·
光伏技术
·
半导体物理
·
表面与界面工程
·
无机功能材料
✓ 已验证
DOI
高影响因子
EcoMat
·
2021
·Vol. 3
·期 5
·e12134
·
IF 0
Weixia Lan,Jialu Gu,Shiwei Wu,Yan Peng,Min Zhao,Yingjie Liao,Tao Xu,Bin Wei,Liming Ding,Furong Zhu
Improved efficiency and stability of the organic solar cells (OSCs) are the critical considerations for practical applications. The interface between the interlayer and bulk heterojunction has recently been shown as one of the weak links associated with the degradation in the nonfullerene acceptor (NFA)-based OSCs. It shows that the removal of the interfacial chemical reactions between the 2-(3-oxo-2,3-dihydroinden-1-ylidene)malononitrile (INCN) moieties in NFA and poly(3,4-ethylenedioxythiophene)-polystyrene sulfonate (PEDOT:PSS) hole extraction layer (HEL) is desired for enhancing the device stability. In this work, we show that the use of a bilayer MoO 3 /antimonene HEL favors the operational stability in OSCs through maintaining a high built-in potential and suppression of an undesired interfacial reaction between INCN moieties in NFA and the PEDOT structures in PEDOT:PSS. A power conversion efficiency of 16.68% is also obtained for the OSCs with a bilayer MoO 3 /antimonene HEL, prepared using a blend system of PM6:Y6, demonstrating its suitability for high-performance OSCs.
研究领域:
材料科学
·
光伏技术
·
纳米材料
·
表面化学
·
器件物理
✓ 已验证
DOI
Small
·
2017
·Vol. 13
·期 25
·1700364
·
IF 8.643
Xuhai Liu,Dejian Yu,Fei Cao,Xiaoming Li,Jianping Ji,Jun Chen,Xiufeng Song,Haibo Zeng
All-inorganic photodetectors based on scattered CsPbBr 3 nanoplatelets with lateral dimension as large as 10 µm are fabricated, and the CsPbBr 3 nanoplatelets are solution processed governed by a newly developed ion-exchange soldering mechanism. Under illumination of a 442 nm laser, the photoresponsivity of photodetectors based on these scattered CsPbBr 3 nanoplatelets is as high as 34 A W −1 , which is the largest value reported from all-inorganic perovskite photodetectors with an external driven voltage as small as 1.5 V. Moreover, the rise and fall times are 0.6 and 0.9 ms, respectively, which are comparable to most of the state-of-the-art all-inorganic perovskite-based photodetectors. All the material synthesis and device characterization are conducted at room temperature in ambient air. This work demonstrates that the solution-processed large CsPbBr 3 nanoplatelets are attractive candidates to be applied in low-voltage, low-cost, ultra highly integrated optoelectronic devices.
研究领域:
材料科学
·
光电子学
·
纳米科技
·
半导体器件
·
凝聚态物理
✓ 已验证
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2022
·
IF 6.76
Zihan Zhou,Yunwen Wu,Huiqin Ling,Jie Guo,Su Wang,Ming Li
3D NAND flash memory with vertically stacked cells has been developed to break through the limits of technology nodes. However, during the selective etching process, it is difficult to ensure the byproducts diffuse away from the trenches in the multistacked layers. Once saturated, the byproduct causes abnormal redeposition on the SiO 2 layers. This problem has restricted the development of high-density 3D NAND memory. To solve this problem, the composition and formation mechanism of the redeposited layer must be clarified. In this study, a ternary-wafer system comprising a Si 3 N 4 /SiO 2 /Si 3 N 4 stack was fabricated to study the redeposition mechanism, and the morphology, elastic properties , and chemical composition of the redeposited layer were clarified. The redeposited layer consists of spherical particles with elastic surfaces (average Young’s modulus of 24.17 GPa). The particles were confirmed to comprise colloidal silica gel covered by silanols . By considering the chemistry of silica , the redeposition mechanism was proposed as follows: colloidal silica gel is formed by the aggregation of silicic acids from Si 3 N 4 etching, which adsorb onto the SiO 2 layer through oxide bridges and hydrogen bonding . Our work will contribute to the development of high-density 3D NAND memory.
研究领域:
微电子学
·
半导体工艺
·
材料科学
·
表面化学
·
纳米材料
·
固态物理
·
集成电路制造
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2017
·
IF 6.216
Shiyuan Chen,Junheng Zhang,Jiliang Zhou,Daohong Zhang,Aiqing Zhang
A novel hyperbranched polymeric ionic liquid (HBP-AMIM + PF6 − ) was explored via a thiol-ene click reaction using thiol-ended hyperbranched polyesters (THBP) and 1-allyl-3-imethylimidazolium hexafluorophosphate (AMIMPF6). The effects of HBP-AMIM + PF6 − on the curing behavior, mechanical properties and thermal stability of benzoxazine/epoxy thermosets were investigated. The gelation time and differential scanning calorimetry of non-isothermal analysis indicated that the addition of HBP-AMIM + PF6 − significantly decreased the curing temperature of benzoxazine/epoxy thermosets. Simultaneously, the addition of HBP-AMIM + PF6 − also improved the strength, toghness and thermal properties of benzoxazine-epoxy thermosets. The addition of 3 wt% HBP-AMIM + PF6 − -2 could significantly improve the mechanical and thermal performance of thermosets compared with that of cured neat benzoxazine/epoxy resin. The tensile strength, tensile toughness, flexural strength and flexural modulus, impact strength of the thermosets were improved by about 76.6%, 279.3%, 57.8%, 22.3% and 80.4%, respectively, compared with those of cured neat resin. The toughening mechanisms was attributed to the “in situ” reinforcing and toughening mechanism.
研究领域:
高分子材料
·
材料科学
·
热固性树脂
·
复合材料
·
高分子化学
·
功能材料
✓ 已验证
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Jiajun Ma,Zongwei Guo,Shengtao Dai,Yannong Liu,Huiru Hu,Peikun Li,Lin Jin,Yuhui Ao
Inducing highly oriented 2D nanosheets to create a mussel-inspired interface phase on the carbon fiber (CF) surface to enhance its composites’ strength and toughness has become a great challenge. In this study, a novel coating was synthesized to induce the graphene oxide (GO) oriented distributed on the CF surface while constructing a biomimetic "Brick-and-Mortar" structural interface phase, which simultaneously promoted the strength and toughness of CF composites . Acting as a sizing agent, di-pyrene terminated PEG (py-PEG-py) facilitates abundant π-π* stacking interactions, and enables flexible chain segment motion during interface fracture of composites, as well as effectively improving the toughness of composites. Eventually, the formation of a superior mechanism on the CF surface results in remarkable properties for composites, including an interfacial shear strength (IFSS) of 99.3 MPa, interlaminar shear strength of 93.2 MPa, and flexural strength of 1430 MPa. The tensile strength and toughness increased to 1777 MPa and 45.0 MJm −3 , respectively. Simultaneously, the continuous thermal conduction pathway produced by the oriented attachment of GO on the CF surface increased in-plane thermal conductivity . The reinforcing mechanisms of the unique mussel-inspired coating were systematically investigated. This work opens up an effective and scalability avenue for obtaining high-performance CF composites.
研究领域:
材料科学
·
复合材料工程
·
界面化学
·
高分子化学
·
纳米材料学
·
仿生材料
·
力学性能
·
热传导
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）