Processes
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2022
·Vol. 10
·期 7
·1302
·
IF 3.352
Hailun Ren,Weihong Li
3-hydroxybutyraldehyde (3-HBA) is mainly employed to synthesize 1,3-BDO (1,3-butanediol), which is one of the most important components in cosmetics moisturizers. In this study, a series of composite oxide catalysts were prepared by bringing alkaline earth metal Ca and rare earth metal La to the composite oxide MgO/Al2O3, which were made through the co-precipitation method. These catalysts were applied in the synthesis of 3-HBA through acetaldehyde (AcH) condensation. The structure, texture, and acidic properties of these catalysts were characterized using various characterization methods, and the effects of catalyst composition, reaction temperature, reaction pressure, and residence time on the conversion of AcH were investigated as well. The results showed that the introduction of Ca and La weakened the acidic property and enhanced the basic property, which favored the AcH condensation to synthesize 3-HBA. At a temperature of 20 °C, pressure of 200 kPa, and residence time of 70 min, 0.5%La-2.3%Ca-2MgO/Al2O3exhibited a better catalytic activity, and the conversion of AcH reached 95.89%. The selectivity and yield of 3-HBA were 92.08% and 88.30%, respectively. The stability test indicated that the high AcH conversion could be maintained for 5 h.Keywords:composite oxides;acetaldehyde;condensation catalyst;3-hydroxybutyraldehyde
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高影响因子
ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
·
2019
·
IF 4.527
Peng Gu,Qi Li,Weizhen Zhang,Zheng Zheng,Xingzhang Luo
Eastern China is a typical region that suffers from harmful cyanobacterial blooms. Numerous studies have focused on bloom formation mechanisms; however, the detailed mechanisms remained unclear. Our study explored the influence of four metal ions (Ca, Cu, Pb and Cd) on Microcystis aeruginosa to determine their effects on bloom formation. We found that Ca concentrations higher than 100 mg L −1 contributed to cyanobacterial bloom formation. The presence of Ca triggered the anti-oxidation process and promoted the secretion of extracellular polysaccharides , thus inducing aggregation of algal cells and enhancing their buoyancy 2.1-fold more than the control ( p ＜0.05). The reverse regulation of dissolved CO 2 to bicarbonate by carbonic anhydrase formed a large amount of carbonate and decreased the growth rate by 38–56%. Cu (>0.1 mg L −1 ) presented significant toxicity to algal cells while Pb (>1 mg L −1 ) suppressed the algal growth rate due to the acidic condition. Cd (<0.1 mg L −1 ) exhibited no apparent toxicity to the algae. Furthermore, as the buoyancy increased, Cd was likely to facilitate the formation of cyanobacterial blooms, which needs further research. These findings can provide a theoretical basis for eutrophic lake management and contribute to the development of water quality and wastewater discharge standards.
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PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2025
·
IF 7.7
Liang Shi,Liangliang Lin,Lijiang Zhang,Lili Wu,Junjie Chi,Keqing Shi,Xing Dong
Tumor markers (TMs) are crucial indicators of preneoplastic and neoplastic diseases, which provide the basis for the accurate diagnosis of malignant tumors. We present a diagnostic platform utilizing magnetic photonic microspheres (mPCMs) for simultaneous detection of various sorts of TMs, specifically for reliable breast cancer identification. The multiplex detection capability of mPCMs stems from the color encoding function of the photonic crystal structure formed by self-assembled silica nanoparticles, while their magnetic responsiveness is achieved through ferric oxide nanoparticle doping. The ordered nanostructure offers a large specific surface area for biological detection, and the magnetically controlled movement enhances the capture efficiency of target biomarkers. Specifically, CA 15–3, miRNA-21, and exosomes are used as target biomarkers, reflecting different aspects of breast cancer biology. Our multivariate detection platform effectively identifies proteins, nucleic acids, and exosomes through specific binding and base complementary pairing. Thus, mPCMs provide a novel approach for the combined analysis of diverse biomarkers.
研究领域:
生物医学工程
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肿瘤学
·
纳米技术
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生物传感器
·
分子诊断学
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DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2024
·
IF 8.1
Zhibin Lu,Liang Wang,Xiaohui Qiu,Zheqin Chen,Yongmin Xie,Yan Liu,Ruixiang Wang
Direct carbon solid oxide fuel cells (DC-SOFCs) offer the potential for clean and efficient conversion of chemical energy in carbon fuels into electricity. However, the reverse Boudouard gasification of carbon requires a high operating temperature (≥800 °C), which hinders the development of DC-SOFCs. We present a completely sealed DC-SOFC with in situ steam-carbon gasification. The cells have a symmetrical cell structure (Ag–Ce 0.8 Gd 0.2 O 1.9 /La 0.9 Sr 0.1 Ga 0.8 Mg 0.2 O 3−δ /Ag–Ce 0.8 Gd 0.2 O 1.9 ) and are loaded with K-loaded activated carbon fuel. Ca(OH) 2 and Li 4 SiO 4 are loaded into the anode chamber as the steam feedstock and CO 2 sorbent, respectively. Completely sealed DC-SOFCs with Ca(OH) 2 –C of 0 %, 5 %, 10 %, 15 %, and 20 % have been tested at 700 °C. Compared with a cell with a conventional structure and a completely sealed cell without Ca(OH) 2 loading, the electrochemical performances of all the completely sealed cells with Ca(OH) 2 loading are significantly enhanced. The cell with Ca(OH) 2 to C of 15 % obtained the highest maximum power density of 75 mW cm −2 , which is approximately two-fold that of the conventional DC-SOFC. The mechanism for improving the performance of the cell is the introduction of steam. This study offers a new method to develop high-performance DC-SOFCs and reduce their operating temperatures.
研究领域:
能源科学
·
材料科学
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高影响因子
BIOSENSORS & BIOELECTRONICS
·
2019
·
IF 9.518
Shuang Yin,Zhanfang Ma
Sensitivity amplification strategies in electrochemical immunoassays are mainly limited by redox signal leaking, degradation of catalytic activity caused by layers of decoration and the large hindrance effect caused by immunoprobes. Herein, we developed an innovative sensitivity amplification strategy based on the self-sacrificial label-assisted electroactivity conversion of a sensing interface, utilizing Fe 3+ -loaded polydopamine (Fe 3+ -PDA) nanoparticles as the self-sacrificial labels, which can be decomposed under acidic conditions and release Fe 3+ . When the assembled sensing interface was immersed in a prussian blue (PB) precursor solution (a mixed solution of 0.1 M KCl, 0.1M HCl and 1 mM K 3 Fe(CN) 6 ), the as-formed sandwich-type structure was destroyed due to the decomposition of Fe 3+ -PDA caused by HCl in PB precursor solution, resulting in the reduce of interface resistance. The released Fe 3+ reacted with the PB precursor solution and triggered the growth of electroactive PB nanoparticles (PB NPs) on the sensing interface. Assisted by self-sacrificial Fe 3+ -PDA, the sensing interface was converted from electrochemically inactive to electroactive with a strong redox signal, high catalytic activity, and decreased interface resistance. The PB NPs can catalyse H 2 O 2 to amplify the redox signal, thus improving sensitivity. The redox signal and catalysts were generated in the final assembly step, which can avoid signal leaking and decreases of catalytic activity caused by layers of decoration. The decomposition of Fe 3+ -PDA can eliminate the large hindrance effect of the immunoprobe. Ultrasensitive quantification of carbohydrate antigen 125 (CA 125) was realized with a detection range from 0.00001 to 1000 U mL −1 and detection limit of 0.25 × 10 −6 U mL −1 .
研究领域:
生物医学工程
·
分析化学
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PubMed
高影响因子
Fuels
·
2025
·Vol. 6
·期 4
·89
·
IF 2.8
Zhibing Shen,Ruiyuan Tang,Shengrong Liang,Juntao Zhang,Leyuan Li,Shangli Zhang
The conversion of polycyclic aromatic hydrocarbons (PAHs) to monocyclic aromatic hydrocarbons holds significant importance in the petrochemical and coal chemical industries, as it enables the production of high-value-added chemicals. In this study, we investigated the methane-assisted hydroconversion of PAHs to monocyclic aromatic hydrocarbons with methyl side chains over Zn-based catalysts from Hβ zeolites treated with citric acid (CA) at different concentrations. The CA-modified Hβ catalysts were characterized using X-ray diffraction (XRD), N2adsorption–desorption, pyridine–Fourier transform infrared spectroscopy (Py-FTIR), and ammonia temperature-programmed desorption (NH3-TPD). The results show that low CA concentrations facilitate the removal of amorphous aluminum from the zeolite framework, thereby increasing the specific surface area, pore volume, and pore diameter of the Zn/Hβ catalyst, as well as improving its Lewis/Brønsted (L/B) acid ratio. In contrast, excessive CA treatment causes the undesirable removal of framework aluminum and leads to structural collapse in the mesoporous regions formed at the interfaces between certain crystal aggregates. This, in turn, has a negative impact on the catalyst’s specific surface area, pore volume, pore size distribution, total acidity, and L/B ratio. Experimental data further indicate that the optimal Zn/Hβ catalyst, prepared using Hβ treated with 0.08 M CA, achieves a naphthalene conversion rate of up to 99% and a benzene–toluene–xylene (BTX) selectivity of 60% in the liquid product over a 10 h reaction period. These findings confirm that CA treatment not only enhances the catalytic activity of Zn/Hβ but also significantly improves its operational stability. This work provides new insights into the rational design of catalysts for the efficient conversion of PAHs to monocyclic aromatic hydrocarbons and the utilization of methane resources.
研究领域:
催化化学
·
石油化工
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煤化工
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材料科学
·
多相催化
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高影响因子
ENERGY & FUELS
·
2017
·
IF 3.091
Linlin Yi,Huan Liu,Geng Lu,Qiang Zhang,Jiaxing Wang,Hongyun Hu,Hong Yao
Considerable amounts of NOx are generated from the thermal utilization of solid wastes. To control NOx emission, we investigated the influence of mixed Fe/Ca additives on the generation of NOx precursors (HCN and NH3) during pyrolysis at 873, 1073, and 1273 K. Protein, proline, and phenylalanine were selected as model compounds to represent the primary nitrogen forms in typical solid wastes, such as biomass and sludge. According to the results, the iron effect is a remarkable property that enables the obvious reduction of NH3. This was most likely because NH3 was consumed by iron compounds to generate FeNx. Iron compounds facilitated thermal cracking of heterocyclic N with the release of HCN. Ca(OH)2 promoted the conversion of HCN to NH3 and fixed HCN to form CaCxNy simultaneously. These intermediates (FeNx and CaCxNy) play important roles in the reduction of NOx precursors. A lower emission of NOx precursors was observed with mixed Fe/Ca additives than with either Fe or Ca individually. This is because the generation of Ca2Fe2O5 enhanced the tranformation of intermediates to N2. The transformation of intermediates to N2 was enhanced at elevated temperatures, which allows for the lowest emission of precursors (NH3 and HCN) at 1273 K, with a higher ratio of Ca2Fe2O5 in char.
研究领域:
环境科学
·
化学工程
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高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2023
·
IF 3.3
Yingguang Li,Mingwei Fu,Peng Qiao,Shulian Liu,Degang Deng,Shiqing Xu,Hongping Ma
In this study, a non-activated ion-doped full-spectrum emission phosphor for white light-emitting diode (WLED) lighting is proposed using oxygen defect engineering. The YMZn 3 AlO 7 (M = Ca, Sr, Ba) phosphors with "114″ structure were prepared via a high-temperature solid-state reaction. Under excitation with 373 nm ultraviolet (UV) light, YSrZn 3 AlO 7 in YMZn 3 AlO 7 (M = Ca, Sr, Ba) exhibited the highest emission intensity and formed a wide yellow emission band centred at 563 nm. The full width at half maximum of the YSrZn 3 AlO 7 phosphor was 172.6 nm. A theoretical model based on the designed oxygen vacancies was proposed to determine the self-activated luminescence mechanism. Density functional theory calculations revealed that oxygen vacancies lead to the generation of new energy levels. Electron paramagnetic resonance experiments further confirmed that the luminescence originated from oxygen vacancies. Eventually, a warm WLED device ((x, y) = (0.4057, 0.4359)) with a correlated color temperature of 3814 K and a relative color rendering index of 83 was successfully prepared using the YSrZn 3 AlO 7 phosphor and a 365 nm UV LED chip. These results suggest that YSrZn 3 AlO 7 is a promising WLED phosphor and provide new insights into the application of self-activated phosphors in WLED.
研究领域:
材料科学
·
光电技术
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照明技术
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高影响因子
International Journal of Minerals Metallurgy and Materials
·
2020
·Vol. 27
·期 5
·687-692
·
IF 1.713
Chen Zhang-lin,Liu Kai,Yuan Xuan-yi,Chen Ke-xin
Nitrogen-rich Eu 2+ -doped Ca-α-SiAlON phosphors (Ca m /2− x Si 12− m−n Al m+n O n N 16− n : x Eu) were synthesized by a freeze-drying assisted combustion synthesis (CS) route. Fast-synthesized products with high purity and uniform particle morphology were confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The analysis of lattice parameters by comparison with empirical equations showed that the as-prepared phosphors had low oxygen content. A series of samples were prepared according to the stoichiometry of Ca m /2−0.08 Si 12− m Al m N 16 :0.08Eu for further research. The influences of m value on the luminescence properties were investigated in detail. As m increased, a redshift phenomenon was observed in both the excitation and emission spectra. First-principle electronic structure calculations showed that the 3d energy level of Ca played an important role in the occurrence of the redshift phenomenon.
研究领域:
材料科学
·
光学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·Vol. 42
·期 33
·21167-21176
·
IF 3.582
Weizi Cai,Jiang Liu,Fangyong Yu,Qian Zhou,Yapeng Zhang,Xiaoqiang Wang,Meilin Liu,Meng Ni
Ca-loaded activated carbon is developed as fuel for direct carbon solid oxide fuel cells (DC-SOFCs), operating without any carrier gas and liquid medium. Ca is loaded on activated carbon through impregnation technique in the form of CaO, which exhibits excellent catalytic activity and significantly promotes the output performance of DC-SOFCs. DC-SOFCs fueled by activated carbon with different Ca loading content (0, 1, 3, 5 and 7 wt. %) are tested and the performances are compared with the DC-SOFC running on the conventional Fe-loaded activated carbon. It is found that the performance of the DC-SOFC with 5 wt. % (373 mW cm −2 ) and 7 wt. % (378 mW cm −2 ) Ca-loaded activated carbon is significantly higher than that of the cells operated on 5 wt. % Fe-loaded activated carbon, 1 wt. % and 3 wt. % Ca-loaded activated carbon. The discharging time and fuel utilization of the DC-SOFC with 5 wt. % Ca-loaded activated carbon are also the optimal ones among all the cells. The microstructure, element distribution and carbon conversion rate of the Ca-loaded carbon, the impedance spectra of the corresponding DC-SOFCs are measured. The reasons for the reduced fuel utilization of 7 wt. % Ca-loaded carbon fuel are analyzed and the advantage of Ca-loaded carbon for DC-SOFCs is demonstrated in detail.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Shunhang Wei,Guan Zhang,Xiaoxiang Xu
Despite a strong visible light absorbance as far as 660 nm, BaTaO 2 N generally exhibits a poor photocatalytic activity for water splitting under ordinary conditions. High levels of defects as well as photocatalytic self-decomposition are likely the major causes for this incommensuration. In this work, we have modified BaTaO 2 N by introducing Ca to the structure, i.e. BaCa x/3 Ta 1-x/3 O 2+y N 1-y (0 ≤ x, y ≤ 1). A number of important properties such as band gap, defects levels and nitrogen content can be tuned by varying the amounts of Ca in the structure. In particular, defects such as Ta 4+ species can be effectively suppressed by Ca incorporation. More importantly, photocatalytic activity for water oxidation has been significantly enhanced and stability against photocatalytic self-decomposition has also been largely improved in Ca modified BaTaO 2 N. An apparent quantum efficiency as high as ∼ 2.1% at 420 ± 20 nm has been achieved and stands as the highest AQE for BaTaO 2 N reported to date. Photoelectrochemical (PEC) analysis reveals a much higher photocurrent in Ca modified BaTaO 2 N and identifies the role of cocatalyst CoO z in reducing charge transfer resistance for water oxidation reactions. Open-circuit voltage decay (OCVD) measurements further confirm the improved charge separation conditions in Ca modified BaTaO 2 N and functions of cocatalyst CoO z in collecting and storing photo-generated holes. The optimal loading point for cocatalyst CoO z corresponds to the one that gives the highest capacity for hole storage.
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高影响因子
POLYMER
·
2022
·
IF 4.432
Hui Wang,Chongrui Zhang,Lusha Jiang,Shan Tong,Yu-Chao Li,Hefu Pu,Qiang Zhao
Calcium bentonites (CaB), rich in European and Asian countries, are potential barrier materials for landfill leachate containment. However, CaB has to be converted into sodium bentonite (NaB) by Na-activation so as to facilitate intercalation modification. In this study, salt-resistant poly(acrylic acid-N, N-diethyl acrylamide) [P(AA-DEA)] was designed to intercalate and graft CaB by in situ polymerization without prior Na-activation. By this design, acrylic acid monomers were first adsorbed into interlayers of Ca-montmorillonite (Ca-MT) through the electrostatic complexation with Ca 2+ , dislodging Ca 2+ from montmorillonite surfaces. Then, ammonium ions of N, N-diethyl acrylamide were adsorbed into Ca-MT interlayers. Swelling index of the obtained CaB/P(AA-DEA) nanocomposite in aggressive coal combustion product (CCP) leachate is 15.8 mL/2g, which is as high as 3.4 times that of CaB. CaB/P(AA-DEA)-based geosynthetic clay liners (GCLs) exhibit very low hydraulic conductivity (1.6✕10 −12 m/s) to CCP leachate, which is as low as 3.3% that of the U.S. standard requirement and ∼4 orders of magnitude lower than that of CaB-based GCL. Polymer elution of CaB/P(AA-DEA)-8% in CCP leachate is as low as 1.9% that of the dry mixed samples.
研究领域:
环境工程
·
材料科学
·
土木工程
·
高分子化学
·
地质屏障材料
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高影响因子
危险品化学品经营许可证（带存储）