JOURNAL OF ALLOYS AND COMPOUNDS
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2017
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IF 3.133
P. Wang,Y.R. Wang,J.X. Bi,H.T. Wu
The rock salt structured Li 2 Mg 1-x Zn x TiO 4 ceramics were prepared by the conventional solid-state method. X-ray diffraction, bond energy and Raman spectra were employed to investigate the crystal structure and polarization characteristics of the ceramics. With the x value increasing from 0 to 0.5, the dielectric constant of Li 2 Mg 1-x Zn x TiO 4 gradually increased from 15.36 to 18.42, which was attributed to the higher polarizability of zinc ions . The variation trend of the polarizability was also in accordance with that of Raman vibration modes. The quality factor of specimens initially increased and then significantly decreased with the increase in Zn 2+ substitution, which could be explained in the variation of packing fraction. In addition, the temperature coefficient of resonant frequency showed a tendency of decrease with the decreasing bond energy, implying that the substitution of Zn 2+ influenced the crystal stability of Li 2 MgTiO 4 . An appropriate amount of zinc substitution effectively improved the dielectric permittivity and decreased the dielectric losses of the matrix. The Li 2 Mg 0.9 Zn 0.1 TiO 4 ceramics sintered at 1350 °C possessed excellent microwave dielectric properties with ε r = 16.20, Q·ƒ = 145,200 GHz and τ f = −4.03 ppm/°C, which made these ceramics promising for future applications.
研究领域:
材料科学
·
物理学
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DOI
高影响因子
International Journal of Nanomedicine
·
2019
·
IF 4.471
Junhui Shi,Zhengyan Zhao,Zongjun Liu,Ruozheng Wu,You Wang
Background: The design of novel nanoparticles with higher therapeutic efficacy and lower side effects, is still difficult but encouraging in cancer therapy. Specifically, for upconversion nanoparticles (UCNP)-based drug release, a high intensity of NIR light (1.4~5.0 W/cm2) above the maximum permissible exposure (0.33 W/cm2 for 980 nm) is commonly used and severely limits its practical application.Methods: The highly emissive UCNP is first synthesized and then coated with mesoporous silica (MS) shell (UCMS). Next, the surface of UCMS is modified with the thioether (-S-BP) linker, leading to UCMS-S-BP nanoparticles. Finally, after the drug doxorubicin (Dox) is loaded into the pore channels of UCMS, the pore openings are blocked by the β-cyclodextrin (β-CD) gatekeeper through the association with the -S-BP linker (UCMS(Dox)-S-BP@β-CD).Results: Upon 980 nm NIR light irradiation with an ultralow intensity of 0.30 W/cm2, it is found that the loaded Dox can be released through the cleavage of thioether linkers triggering dissociation of β-CD gatekeepers. The in vitro results exhibited significantly therapeutic efficacy with 85.2% of HeLa cells killed in this study.Conclusions: An ultralow-intensity NIR light triggered on-demand drug release system has been developed by employing highly emissive UCNP and photocleavable linker with low bond dissociation energy to avoid the potential photodamage on healthy neighbor cells.
研究领域:
纳米医学
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肿瘤学
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光化学
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DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2025
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IF 6.4
Jie Tu,Siyuan Du,Hangren Li,Jing Xia,Longyuan Shi,Jianjun Tian,Linxing Zhang
Strain engineering has emerged as a powerful strategy for optimizing the material structure and enhancing performance across a wide range of applications. Herein, we report the deployment of substrate-imposed strain to govern the dissolution kinetics of an epitaxial sacrificial layer. The epitaxial LaCoO3 (LCO) has been employed as a sacrificial layer: a lattice-matched and environmentally benign perovskite for releasing freestanding oxide membranes. Intriguingly, the decomposition efficiency of LCO can be precisely controlled by the substrate strain, whether tensile or compressive, which can induce changes in chemical bonds and lattice distortion, thereby altering the reactivity of LCO with the decomposition solution. Under a tensile strain of 2.09% on SrTiO3 substrate, the decomposition efficiency of LCO was accelerated by 66.7% compared with that on LaAlO3 substrate with compressive strain. Synchrotron X-ray absorption spectroscopy, high-angle annular dark-field scanning transmission electron microscopy and semi-in situ optical absorption spectra reveal that tensile strain reduces La–O bond energy and enhances octahedral distortion, making the lattice more susceptible to collapse. Furthermore, freestanding PbZrO3 films were fabricated using the LCO sacrificial layer, showing a ferroelectric-to-antiferroelectric transition. These findings underscore the potential of strain engineering in controlling material properties and fabrication processes, offering new strategies for developing flexible electronic devices.
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高影响因子
Journal of Materials Chemistry C
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2025
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IF 5.1
Kui Liu,Yuran Yang,Gongwen Gan,Gaojie Zou,Jie Luo,Yida Lei,Cheng Liu,Huaiwu Zhang,Zongliang Zheng
The development of high-performance microwave dielectric ceramics requires precise control of both intrinsic and extrinsic factors governing dielectric response. This work systematically investigates aliovalent ion doping (Na+, Ca2+, Al3+, Ge4+, Nb5+) in LiMg0.5Ti0.5O2 ceramics to establish composition-structure-property relationships. First-principles calculations reveal enhanced electron density in [Li/Ti/MgO6] octahedra across all doped systems, indicating improved polarization characteristics. Experimental results demonstrate that Al3+ doping achieves optimal performance by completely suppressing secondary phases, enhancing densification at reduced sintering temperature (1225 °C), and strengthening bond energy. The Al3+-modified ceramic exhibits superior properties: Q×f = 124,535 GHz, εr = 15.99, and τf = +20.5 ppm/°C. Comparative analysis identifies the critical role of bond energy in controlling τf, while lattice vibration damping governs dielectric loss. This study not only identifies Al3+ as the optimal dopant for LiMg0.5Ti0.5O2 ceramics but also provides fundamental insights into designing thermally stable microwave materials through crystal chemistry engineering.
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高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
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2023
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IF 3.4
Shiyuan Sun,Biyue Cui,Fanyu Kong,Zitong Zhang,Youfu Qiao,Shuting Zhang,Xinran Zhang,Changhai Sun
A quantitative structure retention relationship (QSRR) method was developed to identify flavonoid isomers auxiliary using an ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method based on the linear relationships between the Ln( k' ) values of flavonoids and their hydrogen bonding energy ( X AH ) and dissolution energy ( E S ). Chromatographic separation was achieved with a Hypersil GOLD C18 (100 mm × 2.1 mm, 1.9 µm) column and Agilent SB-C18 (2.1 ×50 mm, 1.8 µm) column on a Dionex Ultimate 3000 RSLC chromatograph . Compounds were eluted isocratically using a mobile phase containing 0.1% formic acid/water solution and methanol at a ratio of 55:45 (v/v). Mass spectrometry was performed in the negative and positive ionization modes on a Thermo Fisher Q Exactive Orbitrap mass spectrometer equipped with an electrospray ionization interface. The established QSRR model was Ln ( k ′) = 5.6163 + 0.0469 E S − 0.0984 X AH, with a determination coefficient (R 2 ) of 0.9981, adjusted determination coefficient (adjR 2 ) of 0.9976, and corrected root mean square error of 0.0682. The determination coefficient of the leave-one-out (LOO) cross-validation (Q 2 LOO ) was 0.9976, and the cross-verification root mean square error was 0.0754. Simulated samples containing 7 flavonoids were used to validate the feasibility of the method. The classical method (UHPLC-MS/MS combined the CD software and the mzCloud, mzVault and Chemspider databases) was used to identify the seven flavonoids in the simulated samples. This classic identification strategy cannot provide accurate identification results, which provided multiple identification results for each compound in the simulated samples. On the basis of the results, the 7 flavonoids were accurately identified by the established QSRR model, and the reference standards were used to validate it. The relative error of retention time(RE(t R )) between the model calculation and experimental results was less than 10%. This method effectively complements and improves the classical methods, that UHPLC-MS/MS combined the CD software and the mass spectra databases were used to identify flavonoids identification.
研究领域:
分析化学
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药物化学
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植物化学
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
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2022
·Vol. 46
·期 27
·12934-12940
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IF 3.925
Hansen Yang,Zhimiao Wang,Hualiang An,Qiusheng Yang,Wei Xue,Fang Li,Yanji Wang
Theobromine is an important pharmaceutical intermediate and food additive. We have developed a green method for theobromine synthesis, namely catalyst-free methylation of 3-methylxanthine with dimethyl carbonate (DMC). The effects of various solvents on the reaction were investigated; H2O was found to be the most appropriate solvent. The bond energies of C–O in DMC and N–H in 3-methylxanthine were calculated at the M06-2x/6-311G(d,p) level, and the role of the solvent was examined theoretically. The use of H2O as the solvent and the effects of DMC hydrolysis on the reaction were investigated. The results show that DMC hydrolysis was, to some extent, beneficial to theobromine synthesis. The reaction conditions were optimized. When the molar ratio of DMC to 3-methylxanthine was 11 : 1 and the 3-methylxanthine dosage was 0.1 g per mL-H2O, reaction at 160 °C for 9 h gave a 3-methylxanthine conversion of 89.9% with 98.2% theobromine selectivity.
研究领域:
药物化学
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绿色化学
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有机合成
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2022
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IF 9.221
Liupeng Zhao,Xueqin Gong,Wei Tao,Tianshuang Wang,Xiaomin Liu,Fangmeng Liu,Xu Yan,Chenguang Wang,Peng Sun,Geyu Lu
A challenge for low-valence cation doping in SnO 2 materials is that the sharply elevated baseline resistance is detrimental to sensor stability and the subsequent signal acquisition. In contrast, Homovalent doping has little effect on resistance but the effective homovalent dopant is few. Herein, we find the non-metallic element Se is prone to form cationic Se Sn defects in SnO 2 , which can improve the sensitivity of the SnO 2 -based sensors with a moderate rise in baseline resistance. The homovalent Se doping make the species and ratio of adsorbed oxygen on Se-doped SnO 2 surface basically unchanged after doping. Further experiments and theoretical calculations confirm the sensitization mechanism of Se-doped SnO 2 can be attributed to the higher activity of adsorbed oxygen on its surface. Therefore, the sensor based on Se-doped SnO 2 can have sufficient sensing-reactions and charge transfer at a temperature close to the maximum value of the baseline resistance, which makes the sensor better to sensitize the target gases requiring high temperature for sensing-reactions. This noble metal-like activation behavior of Se dopant is derived from the easier breaking of Se-O bond compared to Sn-O bond during CO oxidation which provides a new basis for the selection of dopants from the perspective of bond energy.
研究领域:
材料科学
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传感器技术
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化学工程
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DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 56
·32325-32332
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IF 2.936
Yuhan Zhu,Yu Pan,Wenjun Wang,Haibing Xu,Liqun Zhou,Xiaoguang Liu,Ling Li
The local crystal sites occupied by Eu3+ in Ca5(BO3)3F:1% Eu3+ phosphor were investigated experimentally and theoretically. Ca5(BO3)3F:1% Eu3+ was synthesized by high-temperature solid-state method in air. The crystal structure and optical properties of the phosphor were studied by X-ray powder diffraction and photoluminescence, respectively. Two different O2− → Eu3+ CT broad bands with the peaks at 266 and 283 nm in Ca5(BO3)3F:1% Eu3+ were detected, indicating the Eu3+ sites occupied Ca2 and Ca1, respectively. The different sharp f–f emission spectra under the excitation of 283 and 266 nm proved that there are two different local lattice environments around Eu3+ existing in Ca5(BO3)3F:1% Eu3+. Environmental factor he, the standard deviation of environmental factor (EFSD) and the bond energy were used to illustrate and explain the site occupancy mechanism of Eu3+ into the host lattice. By comparing the intensity ratios of 5D0 → 7F2 transition to the 5D0 → 7F1 transition, I(5D0/7F2)/I(5D0/7F1) of Eu3+ at Ca2 (7.381) was found to be 2.5 times stronger than that of Eu3+ at Ca1 site (2.933). was calculated to analyze the I(5D0/7F2)/I(5D0/7F1) value. On the basis of the bond valence model, a bond-energy method was used to study the occupancy of the Eu ion, which indicated that the preferential sites of Eu ion occupancy in the Ca5(BO3)3F are the Ca2 and Ca1 sites. All three theoretical calculation results are consistent with each other.
研究领域:
材料科学
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固体化学
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光学
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晶体学
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
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2018
·Vol. 102
·期 7
·4092-4102
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IF 2.956
Yunhui Zhang,Haitao Wu
La 2 (Zr 1− x Ti x ) 3 (MoO 4 ) 9 (0 ≤ x ≤ 0.1) ceramics were prepared by the traditional solid-state reaction method. XRD analysis showed that La 2 (Zr 1− x Ti x ) 3 (MoO 4 ) 9 (0 ≤ x ≤ 0.1) ceramics belonged to a trigonal system. Based on the chemical bond theory, the consequences of bond energy, bond ionicity, lattice energy, and thermal expansion coefficient of ceramics on microwave dielectric properties were discussed. As Ti 4+ addition was increased, the reduction in dielectric constant was ascribed to the fact that the polarizability of Ti 4+ is smaller than Zr 4+ , and the downward trend was related to the bond ionicity. Besides, the tendency of Q·f value depended on the packing fraction and the lattice energy. The improvement in τ f value, the increase in bond energy, and the decrease in the coefficient of thermal expansion were all correlated. The far-infrared spectra implied that the absorptions of structural phonon oscillation were the main reason for the maximum polarization contribution. La 2 (Zr 0.92 Ti 0.08 ) 3 (MoO 4 ) 9 ceramics sintered at 750°C for 4 hours exhibited the best dielectric properties ( ε r = 10.33, Q·f = 80 658 GHz, and τ f = 3.48 ppm/°C).
研究领域:
材料科学
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陶瓷工程
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电气工程
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DOI
高影响因子
CHEMISTRY OF MATERIALS
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2020
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IF 9.567
Chenghao Bi,Xuejiao Sun,Xin Huang,Shixun Wang,Jifeng Yuan,Jun Xi Wang,Tönu Pullerits,Jianjun Tian
All inorganic halide perovskites in the form of colloidal quantum dots (QDs) have come into people’s view as one of the potential materials for the high-efficiency solar cells; nevertheless, the high surface trap density and poor stability of QDs restrict the performance improvement and application. Here, we obtain colloidal inorganic perovskite CsPb1–xZnxI3 QDs by the hot-injection synthesis process with the addition of ZnCl2. Synchrotron-based X-ray absorption fine structures demonstrate that the guest Zn2+ ions are doped into the CsPbI3 structure to improve the local ordering of the lattice of the perovskite, reducing the octahedral distortions. The increase of the Goldschmidt tolerance factor and the Pb–I bond energy also enhance the stability of the perovskite structure. Furthermore, the Cl– ions from ZnCl2 occupy the iodide vacancies of the perovskite to decrease the nonradiative recombination. The synergistic effect of doping and defect passivation makes for stable colloidal CsPb0.97Zn0.03I3 QDs with ultralow density of trap states. The champion solar cell based on the QDs shows a power conversion efficiency of 14.8% and a largely improved stability under ambient conditions.
研究领域:
材料科学
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纳米技术
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太阳能
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化学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
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IF 3.83
Liang Shi,Rui Peng,Huaiwu Zhang,Cheng Liu,Gongwen Gan,Xiaolei Shi,Xueying Wang
CaTi 1-x (Mg 1/2 W 1/2 ) x O 3 (x = 0, 0.02, 0.04, 0.06, 0.08) dielectric ceramics were synthesized via the traditional solid-state reaction method. Crystal structure and microwave dielectric properties of CaTi 1-x (Mg 1/2 W 1/2 ) x O 3 system were systematically investigated based on chemistry bond theory (P–V-L theory) for the first time. The pure perovskite phase was obtained for all doped samples, as confirmed through the XRD and Rietveld refinement results. The lattice characteristics were closely related to the microwave dielectric properties. The bond ionicity, lattice energy, and bond energy affected the dielectric constant, quality factor, and temperature stability of the ceramic material. Through the use of (Mg 1/2 W 1/2 ) 4+ doped on B-site, the CaTi 1-x (Mg 1/2 W 1/2 ) x O 3 system can maintain a high dielectric constant (ε r > 100) while effectively reducing the τ f value from 800 ppm/ ° C to less than 300 ppm/ ° C and improving the Q × f value to 9650 GHz (at 3.76 GHz).
研究领域:
材料科学
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陶瓷工程
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微波工程
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固体化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）