FOOD CONTROL
·
2014
·
IF 2.819
Chunmei Jiang,Junling Shi,Xianqing Chen,Yanlin Liu
Fungal profiles and ochratoxin A (OTA) accumulation during wine making were investigated using five different wine grape cultivars, Cabernet Sauvignon, Pinot Noir, Merlot, Syrah and Petit Verdot and the intrinsic influences caused by sulfur dioxide, ethanol and combine effect of ethanol and reducing sugar were analyzed using Cabernet Sauvignon and inoculation of Aspergillus carbonarius . Aspergillus spp. and Penicillium spp. were found as the major fungi in all winemaking processes and were highly correlated with OTA accumulation in wine. Most fungi died and OTA production decreased after 48 h of alcoholic fermentation , being consistent with the period when ethanol accumulation increased. The addition of SO 2 significantly inhibited the growth and OTA production of A. carbonarius with complete inhibition at 500 mg/L. When the ethanol concentration in the must increased to the range of 2–4%, growth and OTA production of A. carbonarius were significantly inhibited. Reducing sugar concentration had no significant effect on the growth and OTA production of A. carbonarius within the levels changing during the winemaking. Therefore, the increase of ethanol concentration played an important role in causing the decrease of fungal contamination and OTA accumulation during winemaking.
研究领域:
食品微生物学
·
真菌毒素学
·
酿酒科学
·
食品安全
·
应用微生物学
·
分子毒理学
✓ 已验证
DOI
高影响因子
Geoscience Frontiers
·
2020
·Vol. 12
·期 2
·957-963
·
IF 4.202
Ruijing Fu,Yaping Chen,Lingrui Wang,Zhiwei Ma,Pengfei Lv,Ying Song,Songrui Yang,Guanjun Xiao,Bo Zou
SiO 2 is the major mineral substance in the upper mantle of the earth. Therefore, studies of the silica-coated materials under high-pressure are essential to explore the physical and chemical properties of the upper mantle. The silica-confined CsPbBr 3 nanocrystals (NCs) have recently attracted much attention because of the improved photoluminescence (PL) quantum yield, owing to the protection of silica shell. However, it remains considerable interest to further explore the relationship between optical properties and the structure of CsPbBr 3 @SiO 2 NCs. We systemically studied the structural and optical properties of the CsPbBr 3 @SiO 2 NCs under high pressure by using diamond anvil cell (DAC). The discontinuous changes of PL and absorption spectra occurred at ∼1.40 GPa. Synchrotron X-ray diffraction (XRD) studies of CsPbBr 3 @SiO 2 NCs under high pressure indicated an isostructural phase transformation at about 1.36 GPa, owing to the pressure-induced tilting of the Pb-Br octahedra. The isothermal bulk moduli for two phases are estimated about 60.0 GPa and 19.2 GPa by fitting the equation of state. Besides, the transition pressure point of CsPbBr 3 @SiO 2 NCs is slightly higher than that of pristine CsPbBr 3 NCs, which attributed to the buffer effect of coating silica shell. The results indicate that silica shell is able to enhance the stabilization without changing the relationship between optical properties and structure of CsPbBr 3 NCs. Our results were fascinated to model the rock metasomatism in the upper mantle and provided a new ‘lithoprobe’ for detecting the upper mantle.
研究领域:
材料科学
·
高压物理
·
纳米材料
·
光学性质
·
地球物理学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 16
·24799-24804
·
IF 3.83
Pengfei Pan,Xu Wang,Yaqi Ji,Wumei Dong,Lei Zhang,Ling Wang,Ming Zhang
A simple, efficient and low-cost method to synthesize zirconia nanopowders dispersed with graphene by wet ball milling was reported in this paper. The raw material for ball milling is cheap graphite powder rather than expensive graphene. Graphite powders were exfoliated into graphene nanosheets (GNSs) in the process of ball milling, as a result of strong shear forces and moderate impact forces between graphite powders, milling balls, and ZrO 2 nanoparticles . The mixed powders were milled for 3, 10, 20, 30, 40, and 50 h, respectively. Moreover, the morphology, composition and structure of the mixed powders milled were characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, Raman spectroscopy , Fourier transform infrared spectroscopy , and field emission transmission electron microscopy . Results showed that the graphite powders were exfoliated effectively, and the GNSs were dispersed uniformly in the zirconia simultaneously. The presence of zirconia nanoparticles significantly improved the efficiency of ball milling exfoliation.
研究领域:
材料科学
·
纳米技术
·
无机非金属材料
·
复合材料
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2019
·
IF 6.395
Duchao Zhang,Hongbin Ling,Tianzu Yang,Weifeng Liu,Lin Chen
Electric arc furnace (EAF) dust is a hazardous waste material containing valuable elements, such as zinc (Zn) and iron (Fe), as well as other environmentally harmful elements. In the conventional process, the existence of zinc ferrite (ZnFe 2 O 4 ) in EAF dust results in a low recovery ratio of zinc and can induce high energy consumption or difficulties utilizing iron resources. In this article, a hydrothermal reduction method in a NaOH system is proposed to recover Zn selectively from EAF dust. First, when pure ZnFe 2 O 4 was used as the input material to test the feasibility of the new method, 70% Zn leaching efficiencies and the isolation of Fe in the residue through the formation of ferroferric oxide (Fe 3 O 4 ) were achieved at the optimal conditions of 260 °C, 6 M [NaOH], 10 g/L [C 6 H 12 O 6 ] n and 50 mL/g of L/S. Second, a leaching process of EAF dust was proposed using the following two procedures: (i) first leaching under normal pressure to dissolve zinc oxide (ZnO); and (ii) second leaching of the first leach residue under hydrothermal reduction conditions to dissolve ZnFe 2 O 4 . The leach liquor from the second step was recycled to the first step. Under optimum conditions, the leaching efficiencies of Zn during the first and second leaching were 66.4% and 69.3%, respectively. The total Zn leaching efficiency was calculated to be 89.7%, producing Zn-impregnated leach solution and a leach residue rich in Fe (up to 39.4 wt%) that are suitable as resources for a steel-making plant. However, this process also has its shortcomings owning to larger liquid-solid ratio in the leaching process. Overall, the study technically provides an alternative approach to improve the recycling of zinc and iron and effectively reduce environmental risks from EAF dust.
研究领域:
环境工程
·
冶金工程
·
资源循环利用
·
清洁生产技术
·
工业废物处理
✓ 已验证
DOI
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2018
·
IF 2.826
Linchao Li,Huili Hu,Xiangguo Teng,Yuanchun Yu,Yongming Zhu,Xiaoqiang Su
The aim of this work is to prepare a hydrophobic cathode equipped with quite a few cracks for gas transfer, which can prepare H 2 O 2 in the course of electro-Fenton process. Scanning electron microscopy (SEM) and optical digital microscope are used to characterize the morphology of electrode, and an electrochemical workstation (CHI660e) is used to carry out all electrochemical studies with a conventional three-electrode system. The results demonstrate that the porous electrode is conducive to gas transmission with these cracks which can avoid the formation of bubbles. Additionally, the reaction is almost not affected by the content of dissolved oxygen and the gas flow with this structure. Under the conditions of 300 mA/cm 2 (current density), the H 2 O 2 concentration is up to 14.4 mmol/L after 30 min electrolysis with current efficiency beyond 90%. Furthermore, the cathode is successfully applied to electro-Fenton process which reduced catalyst loading. The results indicate that total degradation of MO is observed at the first 10 min, and 81% of TOC can be removed when the dosage of catalyst is 0.4 mmol/L within 60 min.
研究领域:
环境化学
·
电化学工程
·
水处理技术
·
反应器设计
·
污染物降解
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2018
·Vol. 29
·期 16
·13925-13930
·
IF 2.324
Li Tianjing,Shi Qingle
In this paper, explain a new relationships between Bi 3+ content, the phase crystal, microstructure and conductivity for Sm and Bi co-doped Ce 0.8− x Sm 0.2 Bi x O 1.9−1/2 x ( x = 0, 0.05, 0.1, 0.15, 0.2) electrolytes prepared by co-precipitation method. The XRD patterns showed that this compounds exhibit a fluorite-type cubic structure after the samples calcined at 700 °C for 4 h and the cell volumes of increased when the Bi content increased. In addition, for the samples sintered at 1400 °C for 4 h, the Bi doping improves the relative density, the grain size and the average thermal expansion coefficient (TEC). More in details, the relative density and TEC increase with the Bi content. Form the AC impedance spectroscopy measurements, the conductivity of the sintered samples is found to improve with the increasing of Bi content (for x ≤ 0.15), which is ascribed to the increasing of the number of oxygen ion vacancies and the increase in the unit cell volume. However, the conductivity decreases when the Bi content is further increased (0.15 < x ≤ 0.2), which is ascribed the reduction of the number of free oxygen vacancies. The highest conductivity at 800 °C is 5.6 × 10 −2 S/cm and the activation energy is 0.83 eV for Ce 0.65 Sm 0.2 Bi 0.15 O 1.825 , indicating that this would be a promising electrolyte for the intermediate temperature-solid oxide fuel cell applications.
研究领域:
材料科学
·
无机非金属材料
·
固态离子学
·
能源材料
·
燃料电池
✓ 已验证
DOI
高影响因子
RENEWABLE ENERGY
·
2019
·
IF 5.439
Zhao Li,Baorang Li,Xiaoze Du,Hongwei Wu
It is recognized that the thermal performances of the molten salt based nanocomposite can be significantly enhanced. However, there were rare investigations regarding its stability under practical operating thermal environments . In this study, both of the specific heat capacity and thermal diffusivity of the molten salt based nanocomposite were experimentally evaluated under various operating conditions, including that of exposure to constant high temperature and low-high temperature circulation. The typical solar salt based nanofluid was prepared via the modified two-step method. The selected nanoparticle was SiO 2 with an average diameter of 30 nm. Experimental results indicated that both the heat treatments could significantly decrease the thermophysical properties , which would result in poor thermal stability. In comparison with the samples exposing to constant high temperature, the thermal cycled samples showed a more stable thermal property. Further investigations on the SiO 2 particle morphology transition in the process of the heat treatments revealed that the impact of both temperature field and natural convection on particle agglomeration should be responsible for the decrease in thermophysical properties of nanofluid.
研究领域:
材料科学
·
热物理学
·
能源工程
·
纳米科技
·
化学工程
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Hui He,Xueting Lin,Shujun Li,Zeng Wu,Jingheng Gao,Junliang Wu,William Wen,Daiqi Ye,Mingli Fu
Surface species and oxygen vacancies were studied in MnO x (0.4)-CeO 2 toward repeated soot oxidation. MnO x (0.4)-CeO 2 catalysts prepared by the citric acid complex method were repeatedly used in a 10% O 2 /Ar gas flow and showed favorable activity and satisfactory durability toward soot oxidation. X-ray diffraction (XRD), N 2 adsorption/desorption, Electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS) and in situ visible/UV Raman characterization methods were utilized to investigate the structural features of fresh and reused catalysts. The irreversible conversion of high valence manganese species as well as the reduction of Frenkel-type oxygen vacancies and lattice oxygen could be clearly observed in the reused samples, which were associated with the slight deactivation. Spectators and participators were two existing forms of Frenkel-type oxygen vacancies. It was noteworthy that the participators almost fully regenerated after each reaction cycle, which ensured the ability to activate O latt in repeated soot oxidation process. Therefore, the catalysts maintained favorable activity and satisfactory durability, which was mainly because the relatively stable level of participators.
研究领域:
催化化学
·
环境催化
·
材料化学
·
表面科学
·
能源化学
✓ 已验证
DOI
高影响因子
WATER AIR AND SOIL POLLUTION
·
2019
·Vol. 230
·期 2
·41
·
IF 1.774
Wang Wanfeng,Liang Fang,Guo Yanling,Wu Ruijie,Pan Feng,Jin Caixia,Wang Jun
Since nitrosamine disinfection by products is highly carcinogenic, they have attracted considerable attention due to their increased presence in ambient waterways and potable water supplies. For the present study, the potential formation of nitrosamines from corresponding precursor secondary amines during ozonation was investigated. The results revealed that five nitrosamines were observed during the ozonation of their corresponding secondary amines. The molar yields initially increased and then decreased with longer contact times and higher ozone doses. These phenomena indicated that ozone not only promoted nitrosamine formation but also degraded the formed nitrosamines. High pH had a positive influence on nitrosamine formation at room temperature. Further, coexisting substances including nitrate, nitrite, humic acid, and tert-butanol inhibited the generation of nitrosamines due to hydroxyl radical (·OH) competition and scavengers, whereas in the presence of hydroxylamine, nitrosamine formation increased considerably without ozone due to its capacity for independent formation between secondary amines and hydroxylamine. Further, the generation of nitrosamines from secondary amines was primarily attributed to O 3 and ·OH oxidation, which was produced through the decomposition of ozone. The transformation pathways were mainly comprised of the indirect routes between the O 3 /·OH intermediates. The findings of this study were helpful toward expanding the knowledge of nitrosamine formation during the corresponding precursor secondary amine ozonation process.
研究领域:
环境科学
·
水处理化学
·
污染物转化
·
消毒副产物
·
氧化过程
✓ 已验证
DOI
高影响因子
Biomed Research International
·
2020
·Vol. 2020
·期 1
·5084057
·
IF 2.276
Li Yang,Yiwei Fang,Ronghua Liu,Junwei He
Dendropanax dentiger root is a traditional medicinal plant in China and used to treat inflammatory diseases for centuries, but its phytochemical profiling and biological functions are still unknown. Thus, a rapid, efficient, and precise method based on ultra high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) was applied to rapidly analyse the phytochemical profiling of D. dentiger with anti-inflammatory and antioxidant activities in vitro . As a result, a total of 78 chemical compositions, including 15 phenylpropanoids, 15 alkaloids, 14 flavonoids, 14 fatty acids, 7 phenols, 4 steroids, 4 cyclic peptides, 3 terpenoids, and 2 others, were identified or tentatively characterized in the roots of D . dentiger . Moreover, alkaloid and cyclic peptide were reported from D . dentiger for the first time. In addition, the ethanol crude extract of D. dentiger roots exhibited remarkable anti-inflammatory activity against cyclooxygenase- (COX-) 2 inhibitory and antioxidant activities in vitro . This study is the first to explore the phytochemical analysis and COX-2 inhibitory activity of D. dentiger . This study can provide important phytochemical profiles and biological functions for the application of D. dentiger roots as a new source of natural COX-2 inhibitors and antioxidants in pharmaceutical industry.
研究领域:
天然药物化学
·
药用植物学
·
炎症生物学
·
自由基生物学
·
药物代谢
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·Vol. 45
·期 10
·13150-13157
·
IF 3.45
Yan Wang,Xiaoning Meng,Mengxia Yao,Guang Sun,Zhanying Zhang
In this paper, pristine ZnO and Pd modified ZnO nanosheets have been successfully prepared via a facile hydrothermal route and the subsequent calcination process. The composition, morphology and nanostructure of the as-obtained materials were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The methane (CH 4 ) sensing properties of Pd/ZnO were compared with those of pure ZnO , and the materials showed the noticeable sensing capability when the loading amount of Pd was 1 at%. Moreover, the optimal working temperature of ZnO was reduced from 240 °C to 200 °C after loading Pd. The synthesized 1% Pd/ZnO nanocomposites not only showed the maximum response value 19.20 toward 5000 ppm CH 4 at 200 °C, but also exhibited the excellent selectivity and good repeatability. The improvement of CH 4 sensing performance by Pd nanoparticles could be attributed to the synergy effect with the spill-over effect and the nano-Schottky barriers.
研究领域:
材料科学
·
纳米科技
·
传感器技术
·
表面化学
·
半导体材料
✓ 已验证
DOI
高影响因子
Nano Energy
·
2016
·
IF 11.553
Zhaoqiang Li,Caixia Li,Xiaoli Ge,Jingyun Ma,Zhiwei Zhang,Qun Li,Chengxiang Wang,Longwei Yin
Reduced graphene oxide (RGO) wrapped metal-organic frameworks (MOFs) derived cobalt doped porous carbon polyhedrons synthesized via a carbonization process, are for the first time used for sulfur immobilizers (RGO/C–Co-S) as cathodes for high performance lithium-sulfur (Li–S) batteries. The RGO/C–Co–S cathode exhibits greatly improved electrochemical performance, showing excellent specific capacity of 949 mAh g −1 at 300th cycle at a current density 0.3 A g −1 , displaying enhanced rate capability with specific capacity of 772, 704 and 606 mAh g −1 at current density of 0.5, 1 and 2 A g −1 , respectively. The synergetic effect of MOFs-derived porous carbon, homogeneously distributed Co nanoparticles and RGO nanosheets simultaneously contributes to the confinement of sulfur species. The presence of abundant mesopores and micropores is conducive to immobilize large amounts of S species. The homogenously inlaid ultrafine Co nanoparticles can further immobilize sulfur by chemical interactions between Co and S/polysulfides. The RGO nanosheets tightly wrapped on carbon hosts act as barrier layers to prevent polysulfides from diffusing out of the matrix, further suppressing shuttle effect. The porous structure and the RGO can effectively alleviate the volume changes resulted from charge–discharge process. This design strategy can be inspiring for MOF-derived materials in energy storage applications .
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
电池技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）