JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2022
·
IF 10.319
Liang Xu,Lei Su,Hongjie Wang,Hongfei Gao,Pengfei Guo,Min Niu,Kang Peng,Lei Zhuang,Zhiwei Dai
Materials with ultralow thermal conductivity and good thermal stability are of great interest in numerous applications such as energy storage and conversion devices, and thermal insulation components. In this work, a family of high-entropy Sm 2 B 2 O 7 (B=Ti, Zr, Sn, Hf, Y, Yb, Nb, and Ta) oxides with highly disordered cations on the B-site has been synthesized by introducing large atomic-size mismatch, mass and charge disorder. Through tuning the composition, the high-entropy Sm 2 B 2 O 7 oxides can be engineered from pyrochlore to fluorite structure, accompanied with an order-disorder transition. The pyrochlore Sm 2 (Nb 0.2 Sn 0.2 Ti 0.2 Y 0.2 Zr 0.2 ) 2 O 7 and fluorite Sm 2 (Nb 0.2 Ta 0.2 Y 0.2 Yb 0.2 Zr 0.2 ) 2 O 7 exhibit low thermal conductivities of 1.35 W·m −1 ·K −1 and 1.23 W·m −1 ·K −1 , respectively, indicating their good thermal insulation. In addition, the high-entropy fluorite Sm 2 (Nb 0.2 Ta 0.2 Y 0.2 Yb 0.2 Zr 0.2 ) 2 O 7 also shows average thermal expansion coefficient of 10.2 × 10 −6 °C −1 and high-temperature stability even after thermal exposure at 1600 °C in air for 30 h. These results indicate that the high-entropy Sm 2 B 2 O 7 (B=Ti, Zr, Sn, Hf, Y, Yb, Nb, and Ta) can be promising candidates for thermal barrier coatings and thermally insulators.
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Huihui Liu,Yiping Wang,Jun Chen,Kai Xia,Ying Yang
High-power piezoelectric ceramics require both a high piezoelectric coefficient and a large vibration output. Yet, simultaneous optimization remains challenging because of the intrinsic coupling between polarization activity and mechanical loss. Here, Mn/Nb ratio engineering was applied to 0.9 Pb(Zr 0.5 Ti 0.5 )O 3 -0.1 Pb(Mn 1/3 Nb 2/3 )O 3 -0.01Co 3 O 4 -0.001Fe 2 O 3 (PZT-PMN) ceramics to regulate phase structure and electromechanical properties. An optimized R3m/Cm/P4mm multiphase coexistence was achieved through composition tuning, together with regulated grain growth and polarization behavior. At a Mn/Nb ratio of 0.4, the ceramic exhibits a superior piezoelectric coefficient ( d 33 = 420 pC/N), electromechanical coupling factor ( k p = 0.62), and mechanical quality factor ( Q m = 1608), along with stable d 33 variation <5% from 25 to 275 °C and a maximum vibration velocity of 0.57 m/s, exceeding that of commercial PZT4 under identical conditions. The enhanced performance is associated with the coupled regulation of defect chemistry, phase coexistence, and domain-wall dynamics. A composition-driven strategy for balancing piezoelectric activity and high-power output in PZT-based ceramics is identified.
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高影响因子
MICROCHEMICAL JOURNAL
·
2014
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IF 3.583
Shengling Sun,Jie Li
A method has been developed for the determination of zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), molybdenum (Mo), tungsten (W), and tin (Sn) in seawater by quadrupole inductively coupled plasma-mass spectrometry (Q-ICP-MS). The method is based on separation of the seven elements by extraction chromatography using N-benzoyl-N-phenylhydroxylamine (BPHA) supported on a microporous acrylic ester polymeric resin. The optimized procedure indicates that the BPHA resin has high selective adsorption for Zr, Nb, Mo, Sn, Hf, Ta, and W (known as fluoride soluble elements), whereas other interference and matrix elements are minimally adsorbed. The optimized eluent mixture with their molarity gives satisfactory recoveries for all analytes. The recovery can be achieved 99% for Zr, 97% for Nb, 97% for Mo, 99% for Sn, 99% for Hf, 95% for Ta, and 98% for W, respectively, by eluting with 6 mL of 6 mol L − 1 HF/1 mol L − 1 HCl. Furthermore, the technique for separation and enrichment of these elements provides a low total method blank. The detection limits for this method are 0.5 ppt for Zr, 0.2 ppt for Nb, 1.7 ppt for Mo, 1.0 ppt for Sn, 0.1 ppt for Hf, 0.1 ppt for Ta, and 0.3 ppt for W, respectively. The validity of the method is evaluated by replicate analyses of seawater reference materials; the precision of the results is better than 3% (RSD, n = 4), and the results are in good agreement with certified values. The established procedure has proved to be both practical and effective for seawater sample analyses.
研究领域:
分析化学
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海洋化学
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环境地球化学
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痕量元素检测
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质谱分析
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DOI
高影响因子
Inorganic Chemistry Frontiers
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2022
·Vol. 9
·期 17
·4442-4451
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IF 7.779
Pengcheng Zhang,Hao Li,Xiaoqing Chen,Shucheng Liu,Quanzhang Wen,Canbing Li,Hanning Xiao
In this work, we prepare novel Ba7Zr2Nb4O21 and Ba8Zr3Nb4O24 ceramics with a smaller tolerance factor (for the AnBn−1O3n type hexagonal perovskite in BaO–ZrO2–Nb2O5 system) using a solid-phase reaction method, which shows good microwave dielectric properties of εr ∼ 33.5, Q × f ∼ 56 500 GHz and τf ∼ −17 ppm °C−1 (Ba7Zr2Nb4O21) and εr ∼ 32, Q × f ∼ 63 000 GHz and τf ∼ −27 ppm °C−1 (Ba8Zr3Nb4O24). Rietveld refinement of XRD and TEM shows that Ba7Zr2Nb4O21 and Ba8Zr3Nb4O24 with the BaO3 layer stacking sequence of (cccccchh) and (ccch)2 are eight-layer shifted and twinned hexagonal perovskite, respectively. As the sintering temperature increases, the εr and Q × f values of Ba7Zr2Nb4O21 and Ba8Zr3Nb4O24 exhibit a strong correlation with relative density. The relationship between the structure and properties is discussed in BaO–Zr/Sn/TiO2–Nb2O5 systems. The porosity excluded εr is mainly influenced by ion polarization, while the cell volume is also an essential factor affecting the permittivity. The variation of Q × f is related to the packing fraction in BaO–Zr/SnO2–Nb2O5 systems. The variation of τf is mainly regulated by the tolerance factor. This study shows that there is an opportunity to improve the microwave dielectric properties by adjusting the size of the B-site cation.
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高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2026
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IF 4.6
Xiuyuan Yin,Xinxing Li,Hu Sun,Ning Ding,Lei Ren,Hongqi Shi,Hongxia Wang,Jing Liang,Changsheng Liu
During the rapid solidification of laser melting deposition, poor melt pool fluidity in Nb Si based alloys results in insufficient pore wetting and filling, significantly degrading the mechanical properties. To address this issue, controlled addition of rare earth Yttrium (Y) was utilized to improve melt fluidity, thereby enhancing the density of the deposited layer and optimizing mechanical properties. Results show that an appropriate Y (0.15 at.%) addition increased sample density from 99.83 % to 99.97 %. Y addition did not alter the primary phase constituents of the alloy, which remained Nbss, α-Nb 5 Si 3 , and γ-Nb 5 Si 3 phases, but it affected the phase fractions. With the increase of Y content, the total silicide content increased in the alloys, alongside the precipitation of more nanoscale Y 2 O 3 and γ-Nb 5 Si 3 phases. The alloy with 0.15 at.% Y addition achieved maximum fracture toughness of 15.13 MPa·m 1/2 due to microstructure refinement and compactness improvement. For compressive strength, a continuous enhancement was observed up to 2358.9 MPa in alloys with 1.0 at.% Y addition, which was attributed to increased silicide content, the enhanced solid solubility of Y in the Nbss phase, and the increased content of nanoscale Y 2 O 3 and γ-Nb 5 Si 3 precipitates.
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高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Yanping Song,Bin Yao,Yongfeng Li,Zhanhui Ding,Huanhuan Sun,Zhenzhong Zhang,Ligong Zhang,Haifeng Zhao
Cu2ZnSn(S,Se)4 (CZTSSe) thin-film solar cells have been encountering a bottleneck period since the champion power conversion efficiency (PCE) of 12.7% was achieved by Kim et al. in 2014. One of the critical factors that impede its further development is the relatively low open-circuit voltage (VOC) caused by serious interface carrier recombination. In this regard, back surface field (BSF) employment is a feasible strategy to address the VOC issue of CZTSSe solar cells to some extent. Here, we demonstrated a self-organized BSF introduced by prompting interfacial MoSe2 layer transition from inherent n-type to desirable p-type with Nb doping (p-MoSe2:Nb). The BSF application can significantly reduce the carrier recombination at the back electrode interface (BEI) and lower down the back contact barrier height. The PCE of the corresponding cell was improved from 4.72 to 7.15% because of the enhancement of VOC and fill factor, primarily stemming from the doubling aspects of increased shunt resistance (RSh), decreased series resistance (RS), and alleviative recombination velocity of the BEI induced by the BSF. Our results suggest that introducing a BSF fulfilled with p-MoSe2:Nb is a facile and promising route to improve the performance of CZTSSe thin-film solar cells.
研究领域:
光伏技术
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薄膜太阳能电池
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半导体材料
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材料科学
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可再生能源
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DOI
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 46
·12566-12574
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IF 5.976
Xiaohui Li,Lei Zhou,Miroslav D. Dramićanin,Qiang Tang,Xiping Jing,Jianxin Shi,Yiqin Xu,Mingmei Wu
Broad emission with a full and continuous color spectrum realized by crystal engineering is extensively desired to simulate natural sunlight and improve the white color quality. Herein, new insight into the modulation of B site order–disorder and intrinsic oxygen defects for complex perovskite (A3B′B2′′O9) Sr3−xScxZnNb2O9 (0 ≤ x ≤ 0.1) phosphors is demonstrated for broad-band emission via crystal engineering. We elucidate that the spectrum of Sr3ZnNb2O9 synthesized at an optimal temperature exhibits two emission bands under near-ultraviolet excitation (λex = 374 nm) which is readily available from near ultraviolet chips. The two broad emission bands can be ascribed to charge transfer from the empty 4d (t2g)-orbitals of Nb5+ ions to the filled 2p-orbitals of O2− ions and the intrinsic oxygen defects. Further, as a proposed strategy to optimize the luminescence property of Sr3ZnNb2O9 (SZN), we realized A-site nonequivalent doping to induce B-site disordering and cancel the luminescence quenching which results from B site ordering. The A-site nonequivalent doping efficiently offsets intrinsic oxygen defects, as validated by systematic analyses of experiments and DFT calculations. Consequently, the novel phosphor Sr3−xScxZnNb2O9 (x = 0.1) shows a high color rendering index (Ra = 82.2) and negligible color shift. In addition, its emission intensity is enhanced by ∼70 times as compared to the pristine Sr3ZnNb2O9.
研究领域:
材料科学
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发光材料
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固态化学
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荧光粉
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光学材料
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DOI
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-15
·
IF 17.694
Hou Yun Nan,Cai Yang,Li Wan Hua,He Wei Ming,Zhao Zhi Ying,Zhu Wen Jie,Wang Qiang,Mai Xinyi,Liu Jun,Lee Hon Cheung,Stjepanovic Goran,Zhang Hongmin,Zhao Yong Juan
Sterile alpha (SAM) and Toll/interleukin-1 receptor (TIR) motif containing 1 (SARM1) is an autoinhibitory NAD-consuming enzyme that is activated by the accumulation of nicotinamide mononucleotide (NMN) during axonal injury. Its activation mechanism is not fully understood. Here, we generate a nanobody, Nb-C6, that specifically recognizes NMN-activated SARM1. Nb-C6 stains only the activated SARM1 in cells stimulated with CZ-48, a permeant mimetic of NMN, and partially activates SARM1 in vitro and in cells. Cryo-EM of NMN/SARM1/Nb-C6 complex shows an octameric structure with ARM domains bending significantly inward and swinging out together with TIR domains. Nb-C6 binds to SAM domain of the activated SARM1 and stabilized its ARM domain. Mass spectrometry analyses indicate that the activated SARM1 in solution is highly dynamic and that the neighboring TIRs form transient dimers via the surface close to one BB loop. We show that Nb-C6 is a valuable tool for studies of SARM1 activation.
研究领域:
分子生物学
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神经科学
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结构生物学
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细胞生物学
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DOI
PubMed
高影响因子
Small
·
2024
·
IF 13
Qin Zhang,Weikai Chen,Guangfeng Li,Zhixin Ma,Mengru Zhu,Qianmin Gao,Ke Xu,Xinru Liu,Wenyi Lu,Wencai Zhang,Yan Wu,Zhongmin Shi,Jiacan Su
In view of the increased levels of reactive oxygen species (ROS) that disturb the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), the repair of diabetic bone defects remains a great challenge. Herein, a factor-free hydrogel is reported with ROS scavenging and responsive degradation properties for enhanced diabetic bone healing. These hydrogels contain ROS-cleavable thioketal (TK) linkers and ultraviolet (UV)-responsive norbornene (NB) groups conjugated with 8-arm PEG macromers, which are formed via UV crosslinking-mediated gelation. Upon reacting with high levels of ROS in the bone defect microenvironment, ROS-cleavable TK linkers are destroyed, allowing the responsive degradation of hydrogels, which promotes the migration of BMSCs. Moreover, ROS levels are reduced through hydrogel-mediated ROS scavenging to reverse BMSC differentiation from adipogenic to osteogenic phenotype. As such, a favorable microenvironment is created after simultaneous ROS scavenging and hydrogel degradation, leading to the effective repair of bone defects in diabetic mouse models, even without the addition of growth factors. Thus, this study presents a responsive hydrogel platform that regulates ROS scavenging and stromal degradation in bone engineering.
研究领域:
生物医学工程
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组织工程
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材料科学
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糖尿病研究
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干细胞生物学
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产品关联
DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2025
·
IF 26.8
Yongbo Fan,Wanbo Qu,Ke Xu,Xiyang Wang,Jie Dai,Yao Su,Yuxin Jia,Lin Lei,Shuwen Zhu,Luwei Peng,Yuxuan Yang,Saiwei Luan,Yang Zhang,Lei Zhang,Shuhui Yu,Molly Meng-Jung Li,Weijia Wang,Huiqing Fan,Haijun Wu,Houbing Huang,Haitao Huang
Toxic lead-based dielectrics dominate high-performance capacitors, creating urgent environmental and supply-chain challenges. Multi-polar order engineering is deployed to create an industrially scalable lead-free perovskite achieving simultaneous record efficiency (η ≈ 95%) and energy density (12 J cm −3 ). Phase-field simulations are also used to guide micro-to-nano domain design to construct switchable polar nano region that delay polarization saturation. Crucially, sub-angstrom electronic state optimization – previously unexplored in energy storage dielectrics – is revealed as pivotal: synchrotron XAS quantifies Nb-O dipole ionicity enhancement via electronic polarization, while atomic-resolution electron microscopy statistically confirms bond-length homogenization and distortion reduction that structurally anchor this effect. This hierarchical atomic-to-electronic control reshapes the electrical microstructure, enabling unified charge dynamics (validated by DRT analysis) that deliver ultrafast field response (<32 ns discharge) and exceptional thermal resilience (< ±4% current fluctuation, 25–150 °C). Fabricated from commodity precursors, the material eliminates the reliance on rare-earth precursors that are common in PLZT production, significantly lowering costs while mitigating environmental impacts. Overall, this work establishes a sustainable pathway for grid-scale power electronics.
研究领域:
材料科学
·
能量存储
·
介电材料
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可持续电子学
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纳米材料
·
电子结构工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）