CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Jinpeng Ma,Ke Zhu,Da Huo,Bingzhong Shen,Yang Liu,Xudong Qi,Enwei Sun,Rui Zhang
The performances of 1–3 piezocomposite materials under various poling conditions were compared and analysed. The dielectric , piezoelectric , and electromechanical properties of 1–3 piezocomposite materials were studied with variations in the electric field amplitude ( E p ), poling frequency ( f ), and number of cycles ( C ). It was found that the piezoelectric coefficient ( d 33 ), free dielectric constant ( ε 33 T / ε 0 ), and electromechanical coupling factor ( k t ) of 1–3 piezocomposite materials exhibit an increase of 21.4%, 13%, and 10.7%, respectively, under the optimum alternating current poling (ACP) condition ( f = 1.25 Hz, E p = 2 kV/mm, C = 16), compared with that of the samples poled using the direct current polarisation (DCP) method. The studies of the domain pattern indicate that the performance enhancement originates from the remarkable regularly striped domain structure and high domain wall density in ACP-poled samples. Our results suggest that the ACP method is effective in enhancing the performance of composite piezoelectric materials , which possess great benefits and potential for application in acoustic/medical transducers.
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LIQUID CRYSTALS
·
2010
·
IF 1.451
Yan Li,Xinbing Chen,Pei Chen,Zhongwei An,Juan Li
A new series of fused polyheterocyclic aromatic compounds, 7-alkoxybezopyrano[2,3-c]pyrazol-3-one (C-
n
BPP), were synthesised and characterised by infrared, 1H-nuclear magnetic resonance (NMR), 13C-NMR and two-dimensional 1H-13C cosy spectra. Their phase transition behaviour was investigated by differential scanning calorimetry and polarising optical microscopy. All of these compounds showed enantiotropic mesophases with temperature domains of 12–60°C and 22–69°C on heating and cooling processes for a carbon number of the alkoxy chain from 2 to 10. The effect of the length of the alkoxy chain on the mesomorphic properties was discussed. Comparison of C-
n
BPP and several kinds of coumarin derivatives indicated that the intermolecular hydrogen bonding acted as the driving force of the mesophase formation.
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CRYOGENICS
·
2022
·
IF 2.134
Yuwei Chen,Wang Liu,Jingcheng Feng,Ruixin Guo,Feidi Fan,Jun Shen,Guochun Zhang,Heng Tu
A series of lanthanide-rich oxyborates LiLn 6 O 5 (BO 3 ) 3 (LLnOB, Ln = Gd, Tb, Dy, and Ho) have been synthesized using high temperature solid state method. Their magnetic and magnetocaloric properties were investigated upon magnetic susceptibility ( χ ), magnetization ( M ), and isothermal magnetic entropy change ( −ΔS m ) measurements. The maximum − ΔS m, max of LiGd 6 O 5 (BO 3 ) 3 is 44.7 J kg −1 K −1 at 4 K and Δμ 0 H = 9 T, which is higher than the one of commercial Gd 3 Ga 5 O 12 (GGG, −ΔS m, max = 41.8 J kg −1 K −1 at 2 K for Δμ 0 H = 9 T). For LiHo 6 O 5 (BO 3 ) 3 , −ΔS m, max is 14.12 J kg −1 K −1 at 3 K and Δμ 0 H = 2 T, which is also larger than that of Ho 3 Ga 5 O 12 (HoGG, − ΔS m, max = 4.38 J kg −1 K −1 at 2 K for Δμ 0 H = 2 T) and Dy 3 Ga 5 O 12 (DGG, − ΔS m, max = 11.0 J kg −1 K −1 at 2 K for Δμ 0 H = 2 T). These results indicate that LiGd 6 O 5 (BO 3 ) 3 and LiHo 6 O 5 (BO 3 ) 3 may be competitive candidates for applications as magnetic refrigerants. Moreover, thermal stability, infrared spectrum (IR), and ultraviolet–visible-near-infrared diffuse reflectance spectrum (UV–Vis-NIR) were carried out to characterize the title compounds.
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INORGANIC CHEMISTRY
·
2020
·
IF 4.825
Yun-Xiang Ma,Ya-Ping Gong,Chun-Li Hu,Fang Kong,Jiang-Gao Mao
The search of novel second-harmonic generation crystals in gallium selenite systems results in three new compounds of MGa2(SeO3)4 (M = Sr, Pb) and BiGa(SeO3)3. The isostructural MGa2(SeO3)4 (M = Sr, Pb) are centrosymmetric (P1̅, no. 2). The structures represent a complicated three-dimensional skeleton containing two different types of Ga4Se4 8-member polyhedral ring tunnels with the counter cations located at the broad ones. When the divalent counter cations were substituted by a trivalent lone pair cation of Bi(III), a novel noncentrosymmetric compound of BiGa(SeO3)3 was achieved. BiGa(SeO3)3 displays a 3D gallium selenite framework with 1D bismuth oxide chains filling in the 12-member polyhedral ring tunnels. Frequency doubling measurements showed that BiGa(SeO3)3 presented an apparent SHG signal comparable to the commercial KDP and can realize phase matching. The lone pair anionic groups of SeO32– made the major contribution according to the SHG density analyses. BiGa(SeO3)3 exhibits a wide transparent range and large optical bandgap (3.90 eV). The laser-induced damage threshold of BiGa(SeO3)3 was estimated to be 98.68 MW/cm2, about 44 × AGS.
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JOURNAL OF SOLID STATE CHEMISTRY
·
2023
·
IF 3.3
Yue-Ling Sun,Gang-Xiang Liu,Yi-Lei Lv,Liang Ma,Wen-Dong Yao,Ru-Ling Tang
Phosphate crystals are valuable materials according to their diverse structures and physical and chemistry properties. A zinc orthophosphate, (NH 4 ) 3 (H 3 O)Zn 4 (PO 4 ) 4 , has been obtained via hydrothermal route. It was crystallized in hexagonal space group P 6 3 , featuring a three-dimensional (3D) [Zn(PO 4 )] – anion network built by corner-sharing connected ZnO 4 and PO 4 tetrahedra. The NH 4 + and H 3 O + units are located in the six-member cavities of the framework as the balanced cations. (NH 4 ) 3 (H 3 O)Zn 4 (PO 4 ) 4 exhibits a moderate and phase matchable second harmonic generation effect (SHG) about 1.4 times of KH 2 PO 4 (KDP), which is the strongest in zinc orthophosphates. Besides structural features, optical properties measurements and theoretical analyses of (NH 4 ) 3 (H 3 O)Zn 4 (PO 4 ) 4 were performed.
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JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Weimin Dong,Yingjie Sun,Qian Yao,Lintao Liu,Qingbo Wang,Hang Wen,Jing Li,Xinguang Xu,Jiyang Wang,Robert I. Boughton
Single crystal Pr(BO 2 ) 3 with centimeter size was grown successfully by a flux method using 3Li 2 CO 3 -2H 3 BO 3 as a flux. The absorption spectrum , emission spectrum , and luminescence lifetime of the Pr(BO 2 ) 3 crystal were measured. The crystal has a relatively large absorption cross section and full widths at half maximum (FWHM), which is advantageous for energy absorption from a pumping source. The spectrum parameters were calculated based on Judd–Ofelt (J-O) theory, and the effective J-O parameters were determined to be: Ω 2 = 37.47 × 10 20 cm 2 , Ω 4 = 6.80 × 10 20 cm 2 , and Ω 6 = 1.05 × 10 20 cm 2 . Furthermore, the emission cross section for the 3 P 0 → 3 F 2 transition at 650 nm was calculated to be 13.6 × 10 −19 cm 2 . The fluorescence lifetime of the 3 P 0 level was obtained to be 4.5 ns. The Raman spectrum of the crystal was also analyzed in detail. Physical properties such as thermal and chemical stability, hardness, and cleavage properties were explored. The refractive index and electronic structure were calculated by the first-principles method.
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Nanoscale
·
2019
·Vol. 11
·期 13
·6182-6191
·
IF 6.97
Jinjin Ma,Qianting Yao,John A. McLeod,Lo-Yueh Chang,Chih-Wen Pao,Jiatang Chen,Tsun-Kong Sham,Lijia Liu
Inorganic lead halide perovskite CsPbX3 (X = Cl, Br, or I) nanocrystals are promising candidate materials for light-emitting devices and optoelectronics. Mn-Doped CsPbX3 is of particular interest, as the Mn-doping introduces an additional emission band, making this material a promising white-light emitter. In this study, Mn-doped CsPb(Br/Cl)3 nanocrystals are prepared at room-temperature and ambient pressure. The chemical environment of Mn, and the luminescence of these nanocrystals are analyzed in detail using X-ray diffraction (XRD), extended X-ray absorption fine structure (EXAFS), X-ray absorption near-edge structure (XANES) and X-ray excited optical luminescence (XEOL). Although the introduction of Mn does not alter the long-range order of the CsPbX3 crystal, it leads to a local lattice contraction with the bond length of Mn–X much shorter than Pb–X. We also find excitation energy-dependence in both the intensity and wavelength of the perovskite excitonic emission band, while only in intensity of the Mn emission band. Detailed fitting of the XEOL reveals that the perovskite emission band is dual-channel, and it is the excitation energy-dependent intensity variation of these two channels that drives the observed red-shift of the combined emission band. Our findings also confirm that the Mn emission band is driven by exciton-Mn energy transfer and clarify the Mn chemical environment and the luminescence mechanism in Mn-doped CsPb(Br/Cl)3 nanocrystals.
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MOLECULES
·
2024
·Vol. 29
·期 17
·3990
·
IF 4.2
Shuang Tian,Yinxu Zhao,Siqi Deng,Liman Hou,Juan Song,Ming Wang,Ming Bu
In the following study, a series of new lupeol-3-carbamate derivatives were synthesized, and the structures of all the newly derived compounds were characterized. The new compounds were screened to determine their anti-proliferative activity against human lung cancer cell line A549, human liver cancer cell line HepG2, and human breast cancer cell line MCF-7. Most of the compounds were found to show better anti-proliferative activity in vitro than lupeol. Among them, obvious anti-proliferation activity (IC50= 5.39~9.43 μM) was exhibited by compound3iagainst all three tumor cell lines. In addition, a salt reaction was performed on compound3k(IC50= 13.98 μM) and it was observed that the anti-proliferative activity and water solubility of compound3k·CH3I(IC50= 3.13 μM), were significantly enhanced subsequent to the salt formation process. The preliminary mechanistic studies demonstrated that apoptosis in HepG2 cells was induced by compound3k·CH3Ithrough the inhibition of the PI3K/AKT/mTOR pathway. In conclusion, a series of new lupeol-3-carbamate derivatives were synthesized via the structural modification of the C-3 site of lupeol, thus laying a theoretical foundation for the design of this new anticancer drug.
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DOI
PubMed
高影响因子
Ocular Surface
·
2024
·
IF 5.9
Xiaozhao Zhang,Guangjin Chen,Yan He,Qingming Tang,Ying Yin,Ying Jie
Secretory glands, responsible for tears and saliva production, play essential roles in maintaining ocular and oral well-being. Disruptions in gland secretion can arise from various factors, including rhythm disturbances associated with sleep disorders. However, the underlying mechanisms governing these disruptions remain largely unexplored. We demonstrate that BMAL1, a core component of the circadian system, plays a critical role in regulating secretory gland secretion. Loss of BMAL1 induces vacuolation and atrophy phenotypes in acinar cells, subsequently leading to cell apoptosis and gland hypofunction, but does not cause Sjogren's syndrome, which is characterized by localized inflammatory cell infiltration. Mechanically, BMAL1 directly modulates the transcription of ITPR2 and ITPR3, thereby altering the secretion of Lactoferrin and Lysozyme. Restoration of ITPR2 and ITPR3 expression in Bmal1 -deficient rats effectively alleviated the symptoms of lacrimal and parotid glands secretory dysfunction and significantly reduced dry mouth and dry eye conditions in rhythm-disordered rats. These findings highlight the essential role of BMAL1 in regulating salivary and lacrimal gland secretion and suggest a novel therapeutic approach for treating dry mouth and dry eyes associated with rhythm disorders.
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ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Changwei Luo,Guoqiang Zhao,Mengyang Zhang,Bin Wu,Qingsong Hua
NASICON-type Li1.3Al0.3Ti1.7(PO4)3 (LATP) is a widely used solid electrolyte in solid-state lithium batteries, owing to its excellent chemical stability against moisture and high total ionic conductivity. However, traditionally, densification of LATP has been achieved through a high-temperature sintering process (approximately 1000 °C) owing to its poor sinterability. Herein, we report a facile synthesis route to obtain highly sinterable LATP solid electrolyte using tetrabutyl titanate (C16H36O4Ti) as the titanium source and incorporating the traditional solid-state reaction method. The synthetic LATP powder mixed with a low ratio of LiTiPO5 exhibited a hybrid crystalline–amorphous phase structure, which facilitated grain fusion, promoted structural homogeneity, and facilitated structural densification under low-temperature sintering. The sintered LATP pellet, which exhibited an interconnected structure and indistinct grain boundaries, achieved a relative density of >90% and an ionic conductivity of 0.667 mS/cm at a sintering temperature of only 750 °C. Additionally, we systematically studied and demonstrated the synthesis reaction mechanism, sintering behavior, and ionic diffusion kinetics of LATP electrolytes. Our study paves the way for synthesizing highly sinterable LATP solid electrolytes using a simple, additive-free, and cost-effective method.
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高影响因子
Journal of Nanomaterials
·
2019
·Vol. 2019
·期 1
·1251598
·
IF 2.233
He-Ping Shi,Da-Wei Lin,Rui-feng Wu
Carboxyl end-functionalized poly(3-hexylthiophene) (P3HT-COOH) was grafted chemically with CdSe nanocrystals (NCs) by a phosphine-free method. The particle quality of P3HT-COOH/CdSe nanocomposites was better than that of P3HT/CdSe nanocomposites, which were synthesized using the same method. Nanocrystals with controllable particle size exhibited a wurtzite crystalline structure and showed excellent nanocrystal dispersion in the P3HT-COOH matrix. Photoluminescence (PL) characterization performed on nanocomposites suggested the efficient charge transfer at the P3HT-COOH/CdSe interface. This approach based on the phosphine-free method is not only environmentally friendly but also highly efficient.
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JOURNAL OF CHROMATOGRAPHY A
·
2022
·
IF 4.601
You-Ping Zhang,Ling-Xiao Xiong,Ying Wang,Kuan Li,Bang-Jin Wang,Sheng-Ming Xie,Jun-Hui Zhang,Li-Ming Yuan
Polyimine macrocycles are a new class of organic macrocycles with cyclic structures, well-defined molecular cavities, and multiple cooperative binding sites, which have recently aroused considerable research interest in molecular recognition and separation. Herein, we report the bonding of a [3+3] chiral polyimine macrocycle (H 3 L, C 78 H 78 N 6 O 3 ) on thiol-functionalized silica gel using thiol-ene click chemistry to prepare a chiral stationary phase (CSP) for high performance liquid chromatography (HPLC). The fabricated column exhibited excellent chiral separation capability under both normal-phase and reversed-phase conditions. Fourteen and 10 racemates were well resolved on the column in normal-phase mode (using n -hexane/isopropanol as the mobile phase) and reversed-phase mode (using methanol/water as the mobile phase), respectively, including alcohols, esters, ethers, ketones, aldehydes, epoxides and organic acids. Moreover, the column also shows good selectivity toward positional isomers. Six positional isomers (dinitrobenzene, chloroaniline, bromoaniline, iodoaniline, nitrobrobenzene and nitrochlorobenzene) were well separated on the column. In addition, the effects of the injection mass and mobile phase composition on the separation were investigated. The column shows good reproducibility and stability after multiple injections with the relative standard deviation (RSD) ( n = 5) of the retention time and resolution being < 0.96 % and 0.65 %, respectively. This study indicates that this type of chiral polyimine macrocycles is a promising chiral selector for HPLC enantioseparation and will push forward the applications of more novel chiral macrocycles for chiral chromatographic separation.
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