ASTROPHYSICAL JOURNAL
·
2007
·Vol. 662
·期 2
·1059
·
IF 6.119
Bruce J. Hrivnak,T. R. Geballe,Sun Kwok
Medium-resolution spectra have been obtained of seven carbon-rich proto-planetary nebulae (PPNs) and one young planetary nebula from 3.2 to 3.8 μm, an interval containing the prominent hydrocarbon C–H stretches at 3.3 and 3.4 μm due to aromatic and aliphatic structures, respectively. The 3.3 μm feature is newly identified in IRAS 23304+6147, 22223+4327, and 06530-0213 and is confirmed in Z02229+6208. Three of the PPNs emit in the 3.4 μm feature, two of these being new identifications, IRAS 20000+3239 and 01005+7910, with two others showing possible detections. The 3.3 and 3.4 μm emission features in IRAS 22272+5435 are seen in the nebula offset from the star but not at the position of the central star, consistent with the 2003 results of Goto et al. A similar distribution is seen for the 3.3 μm feature in IRAS 22223+4327. All of the PPNs except IRAS 22272+5435 show Class A 3 μm emission features. These observations, when combined with those of the approximately equal number of other carbon-rich PPNs previously observed, demonstrate that there are large differences in the 3 μm emission bands, even for PPNs with central stars of similar spectral type, and thus that the behavior of the bands does not depend solely on spectral type. We also investigated other possible correlations to help explain these differences. These differences do not depend on the C/O value, since the Class B sources fall within the C/O range found for Class A. All of these 3.3 μm sources also show C2 absorption and 21 μm emission features, except IRAS 01005+7910, which is the hottest source at B0.
研究领域:
天文学
·
星云研究
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DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2025
·
IF 6.2
Qi Zhang,Minghui Li,Zhuofan Zuo,Tianhang Zhan,Xiaoyan Li,Wei Zhang
Cotton, as one of the world’s most crucial economic crops, suffers from a markedly shortened service life of its fabrics due to microbial degradation. In this study, N-isopropylacrylamide (NIPAM) containing amide bonds was grafted onto cotton fibers via atom transfer radical polymerization (ATRP) to develop a heat-resistant and wash-durable N-halamine functionalized cotton fabric (PN@CF-Cl). The resulting material exhibited rapid and potent antibacterial activity, killing over 85 % of bacteria within 1 min of contact and achieving > 99.9 % inactivation of Staphylococcus aureus and Escherichia coli within 10 min. After 50 washing cycles at 75 °C, the antibacterial activity retention remained above 97 %. Following storage for 30 days, rechlorination restored the active chlorine content to its initial level. Even after 10 consecutive chlorination–reduction cycles, the active chlorine recovery reached 98.9 %. In addition, the fabric demonstrated high hydrophobicity, air permeability, and moisture vapor transmission. Molecular dynamics (MD) simulations further validated the dynamic interconversion between N–Cl and N–H in the material, elucidating the underlying mechanism for its regenerative performance. Functionalized cotton fabrics based on the N–Cl/N–H dynamic cycling mechanism can extend product lifespan and hold significant promise for applications in medical protective equipment and smart home textiles.
研究领域:
材料科学
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纺织工程
·
抗菌技术
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高分子化学
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分子动力学模拟
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xinru Wang,Yannan Zhou,Jiaoyu Peng,Wenhu Li,Xin Liu
Octadecylamine hydrochloride (ODA H) as an efficient flotation collector is extensively employed in KCl manufacturing. However, the residual of ODA-H not only directly influences KCl application fields, but also poses environmental risks owing to its low biodegradability. Meanwhile, the removal cost is comparatively high because of KCl solubility. In this study, a simple yet effective strategy was proposed to achieve efficient in-situ desorption of ODA-H from the solid KCl surface. The desorption behavior and underlying mechanism were systematically investigated, focusing on charge state conversion, interfacial wettability change, and ODA-H aggregation. The results demonstrated that OH − significantly enhanced the removal efficiency of ODA H, with a removal rate of 86 % achieved when the pH of the saturated KCl solution was raised to 14. In-situ Raman spectroscopy and Molecular Dynamics simulation elucidated the mechanism of OH − , which could accelerate ODA-H desorption kinetics by disrupting the electrostatic interaction between ODA-H and KCl surface, thereby altering its aggregation behavior. Furthermore, the disruption mechanism of interfacial hydrogen-bonding networks during the OH − -promoted desorption process was confirmed. The synergistic effects resulting from these enhancements facilitated the highly efficient desorption of ODA-H from the solid KCl surface. Importantly, industrial-grade KCl was refined with the ODA-H desorption efficiency of 73.95 %. This study will provide a new idea and mechanism explanation for the removal of pollutants on the soluble solid surface in high-salt solution.
研究领域:
环境化学
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表面科学
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胶体与界面科学
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化学工程
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可持续化学
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产品关联
DOI
高影响因子
ChemSusChem
·
2015
·Vol. 8
·期 12
·2066-2072
·
IF 7.657
Yehong Wang,Jian Zhang,Jing Liu,Chaofeng Zhang,Zhixin Zhang,Jie Xu,Shutao Xu,Fangjun Wang,Feng Wang
Graphical CO 2 -mediated reactions: CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides are described. The N -formylation of amines to formamides is achieved by activating amines, not DMF, via a C N and N H bond metathesis reaction. Using this method, primary, secondary, aromatic, and heterocyclic amines as well as diamines can be obtained with good to excellent formamide yields. Herein, we report CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides. More than 20 amines, including primary, secondary, aromatic, and heterocyclic amines, diamines, and amino acids, are converted to the corresponding formamides with good-to-excellent conversions and selectivities under mild conditions. This strategy employs CO 2 as a mediator to activate the amine under metal-free conditions. The experimental data and in situ NMR and attenuated total reflectance IR spectroscopy measurements support the formation of the N -carbamic acid as an intermediate through the weak acid–base interaction between CO 2 and the amine. The metathesis reaction is driven by the formation of a stable carbamate, and a reaction mechanism is proposed.
研究领域:
有机化学
·
绿色化学
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DOI
PubMed
高影响因子
CEMENT AND CONCRETE RESEARCH
·
2025
·
IF 13.1
Xin Liu,Dining Li,Hui Xie,Jiachen Yao,Xuyan Shen,Haochuan Wang,Zhengyao Qu,Zuhua Zhang,Pan Feng
Alkali-free aluminum sulfate (AS)-based accelerators have become a widely adopted and indispensable admixture for shotcrete applications. However, their effects on the formation kinetics and properties of calcium silicate hydrate (C-S-H) – the primary hydrate in shotcrete – remain insufficiently understood. To bridge this knowledge gap, a combination of isothermal calorimetry, QXRD, and TGA was employed to uncover the temporal evolution of C-S-H. In addition, the chemical compositions and silicate chain structure were comprehensively examined using BSE-EDS, 27 Al NMR, coupled with 29 Si NMR techniques. Our results demonstrate that AS addition accelerated C 3 S hydration, promoting the C-S-H nucleation and growth rate. This acceleration effect can be ascribed to (1) the accelerated dissolution of silicate phases at early stages, and (2) the formation of divergent C-S-H needles, providing more nucleation sites while mitigating impingement between adjacent C-(A)-S-H needles. Multiple characterizations confirmed the enhanced incorporation of aluminum into C-S-H, predominately at the bridging site. Notably, increasing AS content decreased the Si/Ca of the C-(A)-S-H and concurrently enhanced the aluminum incorporation. This compositional shift led to the formation of longer aluminosilicate chains and concomitant improvements in the hardness and elastic modulus of C-(A)-S-H. These findings offer valuable insights into AS-induced alterations in C-(A)-S-H within accelerated cement pastes, facilitating the deeper understanding of the role of C-(A)-S-H in strength development and long-term durability of shotcrete.
研究领域:
材料科学
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水泥化学
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建筑材料
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水化机理
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无机非金属材料
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纳米矿物表征
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固态核磁共振
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热分析
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产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2019
·
IF 7.149
Huiling Liu,Jinglong Han,Jili Yuan,Chengbin Liu,Dong Wang,Tian Liu,Meijun Liu,Jinming Luo,Aijie Wang,John C. Crittenden
Efficient elimination of antibacterial activity of halogenated antibiotics by dehalogenation pretreatment is desired for a biochemical treatment process. In this study, crystalline cobalt phosphide nanosheet arrays on a Ti plate (C-CoP/Ti) are fabricated by a simple electrodeposition and phosphorization process. The crystalline structure greatly promotes atomic hydrogen (H*) generation. Moreover, the nanosheet arrays can provide abundant active sites and accelerate electron transfer and mass transport. As a result, the dehalogenation rate of florfenicol (FLO, an emerging organic pollutant) on C-CoP/Ti is 11.1, 2.97, and 13.6 times higher than that on amorphous CoP/Ti, Pd/Ti, and bare Ti, respectively. The C-CoP/Ti electrode achieves 97.4% dehalogenation of FLO (20 mg L–1) within 30 min at −1.2 V (vs Ag/AgCl). Nearly 100% of Cl and 20% of F are broken away within 120 min, showing the highest electrocatalytic defluorination efficiency reported so far. Both experimental results and theoretical calculations reveal that the dehalogenation of FLO on C-CoP/Ti is synergistically accomplished via direct reduction of electron transfer and indirect reduction of H*. This study develops a highly efficient non-noble metal electrode material for dehalogenation of halogenated organic compounds.
研究领域:
环境科学
·
材料科学
·
化学
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DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Jingxian Wang,Xueyang Liu,Yixuan Lin,Junjie Wang,Hanwen Zhang,Luoxin Wang,Hua Wang,Siwei Xiong
The integration of ceramic fillers with high thermal conductivity into polymer fiber insulating paper enhances both thermal conductivity and dielectric strength. Nonetheless, elevated filler loadings augment the filler-matrix interface, thereby intensifying phonon scattering. Additionally, filler agglomeration, driven by van der Waals forces, impedes the formation of a continuous thermal network and introduces defects that facilitate electrical treeing. This research draws inspiration from “brick-and-mortar” architectures, employing high-surface-area thermotropic liquid crystal polyarylate (PAR) nanofibers as the continuous mortar and surface-modified hexagonal boron nitride (TMS@h-BN) nanoplates as the bricks. A scalable papermaking process is employed to fabricate high-thermal-conductivity insulating paper with a high filler content. The three-dimensional network structure of PAR nanofibers spatially confines the h-BN nanoplates, effectively preventing their agglomeration. Furthermore, π-π conjugation between the aromatic structures of PAR and the benzene rings of h-BN enhances interfacial bonding by facilitating the diffusion and entanglement of PAR molecular chains during thermal pressing. This results in a dense interfacial structure that provides an efficient pathway for phonon transport, thereby enhancing thermal conductivity and minimizing electrical distortion. At a filler loading of 70 wt%, the TMS@h-BN/PAR nanocomposite paper exhibits superior mechanical performance and flexibility, achieving an in-plane thermal conductivity of 14.19 W·m −1 ·K −1 and a breakdown field strength of 111.17 kV/mm, which represent significant improvements over commercial insulating paper. Additionally, it demonstrates exceptional thermal stability and flame retardancy, with minimal dimensional changes following heat treatment.
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产品关联
DOI
高影响因子
FUEL
·
2026
·
IF 7.8
Bingshuo Li,Xinhang Lv,Tianhua Yang,Haijun Zhang,Xingping Kai,Rundong Li
Catalytic hydrodeoxygenation (HDO) is a promising strategy for upgrading phenolic bio-oil into cycloalkanes. Conventional catalysts often rely on strongly acidic supports, which tend to suffer from rapid deactivation. In this study, 4-ethylphenol was selected as a model compound derived from lignin bio-oil to investigate the effects of active sites on an inert support during the hydrogenation and deoxygenation of the phenolic group. Acid-site–support decoupling catalysts, denoted as Ni-HSiW/h-BN, were successfully prepared and were applied in the HDO of 4-ethylphenol to produce ethylcyclohexane. Using 0.5 g of 4-ethylphenol as the substrate and n-dodecane (30 mL) as solvent, the optimal reaction conditions were identified as a temperature of 300 °C, a reaction time of 3 h and the use of 15% Ni-HSiW 0.25 /h-BN catalyst. Under these conditions, complete conversion of 4-ethylphenol was achieved with 100% selectivity toward ethylcyclohexane. When the temperature was lowered to 180 °C and the reaction time reduced to 1 h using 15% Ni/h-BN, the main product shifted to ethylcyclohexanol with a selectivity of 94.4%. A reaction mechanism was proposed, indicating that the combination of Ni and HSiW synergistically enhances HDO efficiency.
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产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Muhammad Yousaf,Yuzheng Lu,Majid Niaz Akhtar,Ali Sarosh Khawaja,Khalid Mujasam Batoo,Sajjad Hussain,Asma Noor,Muhammad Akbar,Hu Enyi,M.A.K Yousaf Shah,Naveed Mushtaq,Bin Zhu
Lattice defects in rare earth (RE) doped single-phase semiconductor materials play a key role in structural modifications and physicochemical characteristics, resulting to enhance the ionic conductivity. In this work, we synthesized lanthanum doped samarium oxide with different mole ratios and applied it as a ceramics membrane fuel cell device to enable high peak power density (PPD) at low operational temperatures (520–400 °C). The samples are capable of triple charge H + /O 2− /e − conduction and enhance the catalytic function of the cell in terms of HOR and ORR kinetics by producing lattice defects. The fabricated Sm 1.5 La 1.5 Fe 5 O 12 (2-SLFO) fuel cell device exhibits a high OCV of 1.13 V with a maximum PPD of 864.26 mW/cm 2 at 520 °C. Durability measurement verifies that 2-SLFO-based fuel cell device can be worked for 60 h under fuel cell conditions (H 2 /air) at 520 °C. The first principle calculations using density functional theory (DFT) demonstrate that the higher oxygen vacancy concentration in the 2-SLFO sample may cause to the higher charge-transfer kinetics, subsequent in the enhancement of ions transportation of the fabricated fuel cell device.
研究领域:
材料科学
·
电化学
·
能源材料
·
固态离子学
·
燃料电池技术
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Chia-Tse Lee,Haoyuan Zheng,Chen Jin,Hang Che,Li Wang,Yuyuan Zhao,Shixuan He,Xinhua Wang,Yifeng Yu,Mi Yan
Metal nitrogen hydride (Li-Mg-N-H) is regarded as an ideal hydrogen storage material for automotive applications due to its advantages of high hydrogen storage capacity (5.6 wt%), low operating temperature, and good cycling performance, but the comprehensive hydrogen storage performance of this material still could be improved. For this reason, this paper constructed a Li-Na-Mg-N-H composite system by synthesizing NaMgH 3 to replace MgH 2 in the Li-Mg-N-H system. The improvement of the hydrogen absorption and desorption properties of the composite system after the replacement of MgH 2 by NaMgH 3 was investigated. Various properties and test results showed that the composite system after the replacement of MgH 2 by NaMgH 3 showed better hydrogen absorption and desorption properties. The initial/peak hydrogen release temperatures of Li-Na-Mg-N-H decreased from 135 ˚C/245 ˚C to 105 ˚C/145 ˚C, and the apparent activation energy of hydrogen release was reduced from 114.90 to 104.05 kJ/mol which means the kinetics of hydrogen absorption and desorption was greatly improved. The mechanism study shows that NaMgH 3 will react with LiNH 2 and forms the intermediate product Li 3 Na(NH 2 ) 4 during the hydrogen release process, which changes the hydrogen desorption pathway of the composite system and thus the hydrogen absorption and desorption kinetics were improved.
研究领域:
材料科学
·
氢气储存
·
能源材料
·
固态化学
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DOI
高影响因子
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Mengfei Zhu,Yuepeng Pang,Fuqiang Lu,Xinxin Shi,Junhe Yang,Shiyou Zheng
Li–B–H complexes facilely prepared via partial dehydrogenation of LiBH4 are presented in this study as solid electrolytes for Li batteries. An exceptionally high Li-ion conductivity is found for the Li–B–H complex with 7.5 wt % H2 desorption under 3 bar H2 pressure, which reaches 2.7 × 10–4 S cm–1 at 35 °C, more than 4 orders higher than that of LiBH4. In-depth characterizations show that LiH and [Li2B12H11+1/n]n are in situ formed in the LiBH4 matrix and the interface layer between [Li2B12H11+1/n]n and LiBH4 is believed to be responsible for the high Li-ion conductivity. Moreover, this Li–B–H complex also exhibits excellent electrochemical stability, which enables the stable cycling of all-solid-state batteries at room temperature.
研究领域:
材料科学
·
储能
·
固态化学
·
电化学
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DOI
高影响因子
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
·
2015
·Vol. 2016
·期 2
·325-330
·
IF 3.065
Wannian Zhao,Lei Xu,Yingcai Ding,Ben Niu,Ping Xie,Zhaogang Bian,Denghong Zhang,Aihua Zhou
Coumarin derivatives are highly valuable compounds in drug discovery. Herein, we have developed two new coupling reactions that involve coumarins and either aldehydes or di- tert -butyl peroxide (DTBP) in the presence of inexpensive copper or iron catalysts. Both of these reactions proceed through a C(sp 2 )–H functionalization process to regioselectivity generate keto- or methyl-substituted coumarin derivatives in moderate to good yields These coupling reactions will enrich current coumarin chemistry. Graphical Two coupling reactions that regioselectively yield either keto- or methyl-substituted coumarin derivatives by proceeding through a C(sp 2 )–H functionalization process were successfully developed. The coupling of coumarins with either aldehydes or di- tert -butyl peroxide (DTBP) generated the corresponding products in moderate to good yields.
研究领域:
有机化学
·
药物化学
·
合成方法学
·
催化
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DOI
高影响因子
危险品化学品经营许可证（带存储）