JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 31
·1-12
·
IF 2.8
Ma Juncheng,Xiong Zhe,Xiong Ying,Zhang Xing,Tang Bin
The purpose of this study was to synthesize a low-firing ceramic, namely Li 2 O–B 2 O 3 –SiO 2 (LBS) glass-doped 0.35Na 0.5 Nd 0.5 TiO 3 –0.65Li 0.5 Nd 0.5 TiO 3 (NLNT), with desired properties including a high dielectric constant ( ɛ r ), high quality factor ( Q × f ), and near-zero temperature coefficient of resonant frequency ( τ f ). The NLNT ceramic was synthesized using the solid-state reaction method, and XRD analysis confirmed the presence of a single perovskite phase in all NLNT + x wt% LBS ( x = 0, 2, 3, 4, 5) ceramic samples. The LBS glass demonstrated excellent wetting behavior on the NLNT ceramic, ensuring effective densification at low sintering temperatures. The grain size, bulk density, densification temperature, and microwave dielectric properties were influenced by the doping level of LBS glass. Ultimately, NLNT + 4 wt% LBS glass sample, sintered at 950 °C, exhibited favorable microwave dielectric properties: ɛ r = 110.9, Q × f = 2,065 GHz, and τ f = + 4.6 ppm/°C.
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高影响因子
Science China-Chemistry
·
2022
·Vol. 66
·期 2
·548-561
·
IF 10.138
Zhao Ying-Han,Li Wenhao,Shen Tao,Zhao Yan,Liu Yunqi,Wang Yang
The development of readily accessible high-mobility n-type semiconducting polymers is in great demand for realizing high-performance p-n junction-based organic electronics. In this study, we demonstrate that with the combination of dual-acceptor strategy and C-H direct arylation polymerization (DArP), unipolar n-type semiconducting polymers can be conveniently synthesized. By tuning the monomer concentration, three dual-acceptor polymers, namely, poly(naphthalene diimide- alt -dithiophenyl pyrrolopyrrole-dione) (PNDI-DPP), poly(naphthalene diimide- alt -dithiophenyl isoindigo) (PNDI-IID), and poly (naphthalene diimide- alt -dithiophenyl bezothiadiazole) (PNDI-BT) can be obtained via C-H activation with decent number average molecular weight of ∼10 to 30 kg mol −1 and relatively narrow polydispersity index of ∼2. In addition, these polymers are defect-free in nature as evidenced by the nuclear magnetic resonance. Moreover, we attribute the different molar masses of the three copolymers under the same DArP condition to the different α-C-H acidity, which may stem from different electron-withdrawing capability of the hydrogenated acceptor units. Furthermore, the influence of the hydrogenated acceptor monomers on the optical, electrochemical and charge transporting properties is comprehensively studied. Among the three dual-acceptor polymers, PNDI-BT demonstrates the highest electron mobilities of up to 0.6 cm 2 V −1 s −1 in unipolar n-type organic transistors because of its relatively planar backbone, larger overlaps of the lowest unoccupied molecular orbital and strong H-aggregation. Note that the transistor performance of PNDI-BT synthesized via C-H activation in this study is at least comparable to the one made by conventional C(sp 2 )-C(sp 2 ) Stille or Suzuki cross-coupling polymerization. This study demonstrates the presented protocol can be a useful platform for sustainable and convenient synthesis of high-performance n-type semiconducting polymers.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2021
·Vol. 28
·期 45
·64307-64321
·
IF 4.223
Yang Hang,Cai Jiaxi,Sun Jianfa,Zhou Zejun,Zhang Yi,Xia Shibin
In this study, demulsification separation-Fenton oxidation technology was employed as a combined technology to treat total petroleum hydrocarbons (TPH) in oil-based drill cuttings (OBDC). Batch experiments were carried out to optimize the technology parameter. Under the optimal condition, 70% and 51% TPH removal rate was obtained for demulsification technology and Fenton oxidation technology, respectively. Eighty-five percent of TPH removal rate was obtained using combination technology of demulsification separation and Fenton oxidation. Multiple characterizations were used to analyze the physical and chemical properties of treated OBDC. The result of XRD pattern indicated the combination technology had no obvious effect for structure phase of OBDC. The results of FTIR, GC-MS, TG-DTG and SEM were used to characterize the treated OBDC. This paper provides an efficient and feasible combined technology for OBDC treatment, which expands a new strategy for the removal of TPH from solid waste
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高影响因子
CELLULOSE
·
2018
·Vol. 26
·期 2
·1157-1167
·
IF 3.809
Tang Lirong,Hong Biyun,Li Tao,Huang Biao
Bilayer films were fabricated based on natural-based and biocompatible polymers such as esterified cellulose nanocrystals (ECNCs) and shellac, aiming for use in buccal drug delivery. Baicalin was used as the model drug. The swelling properties, drug loading and mechanical properties of films were evaluated and further characterized for mucoadhesion and in vitro drug release properties. The film (F2) containing ECNCs 45%, shellac 25% and polyethylene glycol 30% shows the best properties for the development of the film formulation. The swelling capacity of films was in the range of 36.5 ± 4.1–279.2 ± 14.1%. In vitro drug release shows that anomalous transport behavior indicates that transport includes drug diffusion and polymer relaxation. For film F2, the tensile strength and adhesion strength reaches to the maximum value of 21.57 ± 0.83 MPa and 0.073 ± 0.004 N, respectively. The interfacial interactions between drug and film components were confirmed by FTIR and XRD.
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高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2022
·Vol. 194
·期 7
·2919-2930
·
IF 3.094
Gu Yuanjie,Guo Jianming,Zhou Xin,Xu Yong
Xylo-oligosaccharides have great value in food, feed fields. Previous studies have shown that organic acids catalyze the hydrolysis of xylan-rich sources for the production of xylo-oligosaccharides. In this study, gluconic acid of aldonic acid generated xylo-oligosaccharides via hydrolysis of xylan from corncob. In order to maximize efficiency of xylo-oligosaccharides production, the optimum conditions was ascertained by Box-Behnken design-based response surface methodology. The developed process resulted in a maximum xylo-oligosaccharides yield of 57.73% using 4.6% gluconic acid at 167 °C for 28 min, which was similar to the predicted value and fitted models of xylo-oligosaccharides production. The results showed that the reaction temperature was crucial to xylo-oligosaccharides production, and by-product yields (xylose and furfural) could be effectively controlled by both reaction temperature and time. In addition, 44.87 g/L XOS was achieved by decreasing the solid-liquid ratio. Overall, the described process may be a preferred option for future high concentration xylo-oligosaccharides production.
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高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 7
·2131-2140
·
IF 3.186
Zhu Kehui,An Yunlei,Yu Fei,Liu Li,Zhong Liangshu
The structure-performance evolution of Co/N-AC catalyst during ethylene oligomerization was investigated in detail. It was found that the catalytic activity sharply decreased in the first 30 h with the ethylene conversion decreasing from 64 to 4%. Butene selectivity increased gradually in the first 10 h then remained about 74%, while the selectivity for hexene and octene exhibited an opposite trend. The ratio of α-olefin to isomers for butene increased greatly with time on stream and most of the generated butene was 1-butene. Based on the structure characterization at different reaction stages, CoO x was suggested to be major active phase and the coverage of long-chain hydrocarbons as well as the loss of surface CoO x active sites due to size growth of Co 3 O 4 nanoparticles were the main reasons for catalytic deactivation. Graphic Abstract The structure-performance evolution of Co/N-AC catalyst during ethylene oligomerization was investigated and the coverage of long-chain hydrocarbons as well as the loss of surface CoO x active sites due to size growth of Co 3 O 4 nanoparticles were the main reasons for catalytic deactivation
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高影响因子
CELLULOSE
·
2022
·Vol. 29
·期 8
·4439-4453
·
IF 6.123
Li Yinan,Li Huixin,Huang Jin,Huang Liulian,Chen Lihui,Ni Yonghao,Zheng Qinghong
A highly transparent ZnO/cellulose composite membrane with UV sensing and shielding abilities was prepared via a facile blending method. ZnO nanoparticles (ZnO NPs) without additional surface modification are uniformly dispersed in the regenerated cellulose (RGC) matrix through the N-methyl-morpholine-N-oxide (NMMO) dissolution of cellulose. Agglomeration of the ZnO NPs is effectively minimized, thanks to the strong hydrogen bonds between ZnO NP and cellulose. The optimized ZnO/RGC membrane exhibits not only high a shielding ratio of 97.67 ± 0.11% for UV lights (< 360 nm) but also high transparency of 87.12±1.55% in the visible light region, which is comparable to traditional plastic products. Benefiting from the high photoelectric performance of ZnO NPs, a UV sensor and a UV blocker were integrated into the same device. The as-fabricated ZnO/RGC membrane, with sensitive UV detecting and effective blocking, as well as the rich availability of cellulose as raw material and its biodegradable nature, is an ideal candidate for high-performance UV detection and protection applications. Graphical abstract
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 4
·3590-3597
·
IF 2.22
Ye Fengjiao,Dai Haiyang,Wang Manman,Chen Jing,Li Tao,Chen Zhenping
GdMnO 3 (GMO) ceramics were prepared by solid-state reaction method, the structure, defects, dielectric, and magnetic properties of GMO ceramics sintered at different temperatures have been studied. Characterization by XRD indicates that impurity phase-free GMO can be synthesized at 1350 °C. SEM measurements show that the grain size of GMO increases and the microstructure becomes denser with increasing sintering temperature. Positron annihilation results reveal that the vacancies concentration decreases when sintering temperature increases from 1300 to 1350 °C, and then increases when sintering temperature increases from 1350 to 1400 °C. Dielectric measurements indicate that the GMO ceramic sintered at 1350 °C presents higher dielectric constant and smaller dielectric loss. Magnetic properties measurements show that the magnetic properties of GMO can be modulated by sintering temperature. The relation between structure and properties implies that the cation vacancy defect has remarkable effects on the dielectric and magnetic properties of GMO.
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高影响因子
PHARMACEUTICAL RESEARCH
·
2022
·Vol. 39
·期 9
·2305-2314
·
IF 4.58
Guo Minshan,Sun Xiaojie,Zhang Shaozheng,Cai Ting
Purpose Gabapentin (GBP) is an anticonvulsant drug with poor chemical stability that is particularly sensitive to heat and mechanical stress, which can lead to intramolecular lactamization. The purpose of this study was to enhance the chemical stability of GBP by cocrystallization with organic acids. Method Two novel multicomponent crystals, GBP-2,6-pyridinedicarboxylic acid salt (GBP-2,6PDA salt) and GBP-2,5-pyridinedicarboxylic acid cocrystal (GBP-2,5PDA cocrystal) were synthesized and characterized by various solid-state analytical techniques. The degradation behavior of GBP, GBP-2,6PDA salt and GBP-2,5PDA cocrystals were evaluated under thermal and mechanical stresses. Result Under thermal and mechanical stresses, GBP-2,5PDA cocrystals were found to undergo severer degradation than GBP-2,6PDA salt and neat GBP. GBP-2,6PDA salt exhibited superior chemical stability compared to the others. Furthermore, the crystal structure revealed that the order of atomic distance between the carboxyl group (C7) and amino group (N12) of GBP is as follows: GBP-2,5PDA cocrystal < GBP < GBP-2,6PDA salt, which is consistent with the chemical stability of GBP in different solid forms. Therefore, we believe that the distance between C7 and N12, the reaction active sites leading to dehydrative condensation of GBP, is a key factor determining the chemical stability of GBP in the solid state. Conclusions These results provide a potential method to improve the chemical stability of GBP during the manufacturing process and storage.
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高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2020
·Vol. 21
·期 1
·215-234
·
IF 2.763
Wei Liang,Ding Qian,Guo Huaming,Xiu Wei,Guo Zhengcai
Purpose Heavy metal/metalloid pollution in sewage-irrigated soils (SIS) is one of the major environmental issues in China. Mobility of heavy metals/metalloids in the contaminated soils and their potential threats to groundwater are needed to be understood. This study investigated impacts of organic matter, solution pH, and water level on forms and migration of heavy metals/metalloids (As, Cr, Cu, Pb, and Cd) in the contaminated soils from a typical sewage-irrigated area in the North China Plain (NCP). Materials and methods Based on extensive field measurements, two sewage-irrigated sites and a non-sewage-irrigated site were selected in the study area. Soil samples were collected every 10 cm in a profile (no more than 1 m) from each site. The release and mobility of heavy metals/metalloids in the SIS were investigated using column experiments with two leaching stages (stage I: low water level; stage II: high water level). Deionized water, synthesized acid rain, and poultry manure extractant were used as influents for different columns to stimulate leaching of rainfall, acid rain, and compost leachate, respectively. Soil samples before and after leaching were subjected to sequential extraction for 7 target phases, evaluating the impacts of three leaching conditions on forms of heavy metals/metalloids in soils at different depths. Results and discussion Results revealed that more As and Cu were mobilized in the column with a compost leachate as the influent than the columns with organic matter-free influents, resulting from reductive dissolution, complexation, and desorption. Cr and Pb concentrations were higher in effluents from the column with low pH influent (acid rain) than those from near-neutral pH influents (rainfall and compost leachate). Proton-promoted desorption and dissolution of very amorphous Fe oxides was the major cause for mobilized Cr and Pb in porewater. Moreover, decrease in dissolved oxygen (DO) was observed with the increase in water level in the column, triggering microbial respiration of Fe/Mn oxide reductions in the presence of bioactive dissolved organic matter, which elevated concentrations of porewater heavy metals/metalloids. Conclusions This study suggested that sewage irrigation significantly increased heavy metal/metalloid contents associated with labile and bioavailable fractions in the SIS, and both the compost leachate and low pH solution should enhance the mobility of heavy metals/metalloids in the SIS and potentially contaminate groundwater.
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高影响因子
BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
·
2020
·Vol. 106
·期 1
·126-133
·
IF 1.657
Zhang Liyang,Xiao Jian,Ji Junfeng,Liu Yuanyuan
Adsorption of arsenate, a common soil contaminant, on natural occurring iron oxides controls arsenate adsorption on soils, especially on iron rich soils. However, soils contain multiple iron minerals and their contributions for arsenate adsorption on the bulk soil are unclear. In this study, Wenzel’s sequential extraction procedure (SEP) was used to characterize different fractions of iron oxides in the paddy soils from Guangxi, China. Soils treated with different extractants in the SEP (i.e. soils contained different iron fractions) were used to study arsenate adsorption on different iron fractions in the soil. Langmuir model was used to assess arsenate adsorption capacities of those iron fractions. The results showed that though amorphous iron made up only 16% of the total iron in the soil, it accounted for 82% of the soil adsorption capacity. Besides, arsenate adsorption capacity on the soils could be estimated by linear addition of arsenate adsorption capacity on the amorphous iron oxides fraction and that on the other iron oxides fraction. This study implied a possibility to use iron fractions characterized by Wenzel’s SEP to evaluate arsenate adsorption on the bulk soils.
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PubMed
高影响因子
Chemistry of Heterocyclic Compounds
·
2017
·Vol. 53
·期 1
·42-45
·
IF 0.865
Yu Xueying,Wang Kangnan,Cao Duxia,Wu Qianqian,Guan Ruifang,Xu Yongxiao,Sun Yatong,Liu Zhiqiang
A benzothiazolium salt containing carbazole group has been synthesized in a good yield via simple condensation reaction. Its photophysical properties and affinity for cyanide anion (tetrabutylammonium cyanide) have been investigated. The compound exhibited quick and well visible UV/Vis absorption and fluorescence responses to cyanide anion in MeCN, as the yellow color faded and the orange fluorescence disappeared. The in situ analysis by 1H NMR indicated that the cyanide anion was added to the C=N bond in the benzothiazolyl group.
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高影响因子
危险品化学品经营许可证（带存储）