CEMENT & CONCRETE COMPOSITES
·
2020
·
IF 6.257
Woo Sung Yum,Jung-Il Suh,Dongho Jeon,Jae Eun Oh
This study investigated the effect of calcium formate (CF) on the strength development and microstructure of the CaO-activated ground granulated blast furnace slag (GGBFS) system. The main activator (i.e., CaO) was fixed at 4 wt%, and the GGBFS was replaced with CF at 0, 1, 3, and 5 wt%. The use of CF significantly increased the strength of the binder system by inducing (1) more dissolution of GGBFS, (2) greater C–S–H formation although when CF was used over a certain limit (i.e., 3 wt%), the formation of C–S–H began to be disturbed, and most importantly, (3) an increase in C2AH8 formation. In this study, although the greater formation of C2AH8 was the main cause of the strength enhancement, the C2AH8 phase also likely increased porosity and reduced strength as it was metastable; thus, strength increasing effect and reducing effect likely offset each other; thus, with increasing CF dosage, when the former was more dominant, the strength was enhanced (e.g., up to 3 wt%), but when the latter was larger, the strength enhancement decreased (e.g., at 5 wt%).
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2020
·
IF 4.419
Woo Sung Yum,Jung-Il Suh,Do Hoon Kim,Jae Eun Oh
Recently, the combined use of calcium oxide (CaO) and calcium formate (Ca(HCOO) 2 ) has been proposed as an alternative activator for ground granulated blast furnace slag (GGBFS) (referred to as CaO-Ca(HCOO) 2 -activated GGBFS system). However, this clinker-free binder system produces calcium aluminate hydrate (C 2 AH 8 ), generally leading to the degradation of cementitious binder systems by its conversion to other phases. Thus, in this study, attempts to remove C 2 AH 8 from this system without losing the strength are suggested by the use of two additives (i.e., calcium sulfate (CaSO 4 ) and calcium nitrate (Ca(NO 3 ) 2 ), respectively). Results revealed that the above-mentioned additives completely remove C 2 AH 8 in the initial curing stage via its conversion to ettringite or NO 3 - and NO 2 -AFm, respectively. In addition, the additives reduced the extent of the total shrinkage and the standard deviation of strength results of triplicate samples. However, CaSO 4 exerted a beneficial effect on the strength, while Ca(NO 3 ) 2 exerted a marginal or detrimental effect on the strength. Therefore, this study suggested a new mixture form of an activator, comprising CaO , Ca(HCOO) 2 , and CaSO 4 , to activate GGBFS for maintaining strength without the conversion issue of C 2 AH 8 .
研究领域:
建筑材料学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2021
·
IF 5.279
Hua Yang,Zhiting Xiong,Zhongrui Xu,Rongxiang Liu
Lanthanum (La), calcium (Ca), and cadmium (Cd) have similar physical and chemical properties because of their similar ionic radius. Although the interactions between La, Ca, and Cd have been frequently reported in plants, few studies have investigated the interactive effects of La and Ca on the growth and Cd accumulation in plants. Therefore, we investigated the interactive effects of La and Ca on the growth and Cd accumulation in wheat under Cd exposure by a hydroponic experiment. The results indicated that wheat growth was significantly affected by La–Cd and La–Ca interactions. The accumulation of Cd in wheat was significantly affected by La–Ca and La–Cd interactions and La–Ca–Cd interplay. Correlation analysis indicated that Ca deficiency stimulated La to promote wheat growth and mitigate Cd toxicity. Simultaneously, a low Ca supply stimulated La to decrease Cd accumulation in wheat and induce TaNramp5 expression. In addition, Cd accumulation in wheat was significantly affected by the W7–La interaction and W7–La–Ca interplay. All of the results suggested that La, Ca, and Cd probably share the same binding sites in calmodulin (TaCaM) and La could affect Cd accumulation in wheat by interacting with TaCaM and then downregulating the expression of TaNramp5.
研究领域:
植物生理学
·
环境毒理学
·
分子生物学
·
农学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2023
·
IF 6.4
Fang Sun,Xueyu Pang,Jianqiang Wei,Jing Zeng,Jiacheng Niu
Understanding the synthesis process of Portland cement's various mineral phases and the phase interactions during hydration is highly critical for the design and optimization of cement-based materials. In this work, by using an optimized solid-state reaction method, three pure clinker phases (alite, belite and ferrite) and two polyphase phases (alite-belite and alite-ferrite-belite) of Portland cement were synthesized. The optimized method is featured with high-quality product yield, short burning time without regrinding or reburning. The factors that influence synthesis results, such as crystallinity/purity of the synthesized pure phases, were discussed based on X-ray powder diffraction (XRD) tests along with Rietveld refinement analysis with an external standard. The hydration behavior of the synthesized phases in monophase, polyphase as well as mixture states was investigated via isothermal calorimetry along with thermogravimetry and XRD. The results indicate that alite and belite have relatively little interactions during hydration, while the hydration rate of ferrite can be strongly inhibited in the presence of alite both in mixture and polyphase states.
研究领域:
材料科学
·
水泥化学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-9
·
IF 12.121
Wang Jifei,Luo Shiqiang,Lin Yun,Chen Yifu,Deng Yehao,Li Zhimin,Meng Ke,Chen Gang,Huang Tiantian,Xiao Si,Huang Han,Zhou Conghua,Ding Liming,He Jun,Huang Jinsong,Yuan Yongbo
The manipulation of crystal orientation from the thermodynamic equilibrium states is desired in layered hybrid perovskite films to direct charge transport and enhance the perovskite devices performance. Here we report a templated growth mechanism of layered perovskites from 3D-like perovskites which can be a general design rule to align layered perovskites along the out-of-plane direction in films made by both spin-coating and scalable blading process. The method involves suppressing the nucleation of both layered and 3D perovskites inside the perovskite solution using additional ammonium halide salts, which forces the film formation starts from solution surface. The fast drying of solvent at liquid surface leaves 3D-like perovskites which surprisingly templates the growth of layered perovskites, enabled by the periodic corner-sharing octahedra networks on the surface of 3D-like perovskites. This discovery provides deep insights into the nucleation behavior of octahedra-array-based perovskite materials, representing a general strategy to manipulate the orientation of layered perovskites.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Zhan-Kuo Guo,Han-Qing Chen,Hui-Lin Jiang,Bao-Xia Dong,Yun-Lei Teng
Storing and hydrogenating CO2 to CH4 is an efficient solution to alleviate the greenhouse effect and energy shortage. This work demonstrated that the CaO-captured CO2 could be selectively converted to CH4 by Ni- and hydrogen-assisted calcium looping (CaL) processes in a batch reactor. The Ni/CaO composite was first synthesized in one step at room temperature by calcium-induced hydrogenation of Ni-mixed calcium carbonate without the use of any solvent and CO2 emission. The CO2 capture properties over the Ni/CaO composite and the methanation properties of the Ni/CaCO3 composite produced after CO2 capture were then studied in a batch reactor. It was proved that the CO2 capture properties of CaO can be improved, the CaO recovering temperature can be significantly lowered, and valuable CH4 can be selectively produced by Ni- and hydrogen-assisted calcium looping processes at moderate/high temperature. The 68.58% methane yield and 100% methane selectivity were achieved under relatively mild conditions. After five Ni- and hydrogen-assisted CaL processes, the methane yield still reaches 45%. This study offers a novel energy-saving CaL process, which can be utilized for facile and selective conversion of the CaO-captured CO2 to CH4.
研究领域:
化学工程
·
环境科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2011
·
IF 2.138
Chao Zou,Kui Cheng,Wenjian Weng,Chenlu Song,Piyi Du,Ge Shen,Gaorong Han
α-tricalcium phosphate (α-TCP), biphasic α/β-tricalcium phosphate (α/β-TCP) with different two phase ratio and β-tricalcium phosphate (β-TCP) powders were prepared by calcining an amorphous calcium phosphate (ACP) precursor at a temperature ranging from 800 to 900 °C. The microstructural characterization revealed that the particles in the monophasic and the biphasic TCP powders had about 1 μm in size, and agglomerated by 500 nm ones. In comparison with monophasic TCP powders, the dissolution–reprecipitation behaviors of the biphasic TCP powders in an acetate buffer solution with pH 5 were studied. The biphasic TCPs demonstrated a different behavior from the monophasic TCPs, including changes in morphology and crystalline phase. The unique behavior can be tailored by controlling the α-TCP content in the biphasic TCP powders.
研究领域:
材料科学
·
生物医学工程
·
化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Environmental Research and Public Health
·
2021
·Vol. 18
·期 22
·12051
·
IF 3.39
Yifei Duan,Hua Shi,Yongmei Jiang
In order to understand current blood lead levels (BLLs), we investigated the BLLs of children in Sichuan Province from 2011 to 2020. We then monitored the treatment effects of calcium in children with high BLLs to assess their treatment status. Finally, we explored the effects of lead on Ca2+through in-situ experiments. Whole blood samples were used for BLL tests. The BLLs of 76,362 children aged 0–7 years were measured using atomic absorption spectrometry. The median BLL was 35 μg/L (interquartile range: 28–47). The BLLs were significantly higher in boys than in girls (p< 0.001). The BLLs generally decreased annually and increased with age. The overall prevalence of BLLs ≥ 100 μg/L was 1.20%. The children with high BLLs received subsequent check-ups, and the median time required for effective treatment was 18 months. We observed that lead exposure led to a gradual and persistent loss of Ca2+levels in neurons of mice brain slices, and the effect did not subside immediately even after the lead was removed. China has made rapid progress in pediatric healthcare, but the treatment status remains unsatisfactory. Because lead causes an irreversible loss of Ca2+, there is an urgent need to develop new standardized treatments to reduce the treatment duration.Keywords:blood lead levels;treatment status;calcium supplement;Ca2+imaging
研究领域:
公共卫生
·
神经生物学
·
儿科医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Sustainable Cement-Based Materials
·
2025
·
IF 4.2
Yimu Wang,Jinqing Jia,Dingming Zhang
The effect of low concentration (not exceeding 2%) calcium formate (CF) on the hydration process of tricalcium aluminate (C3A, Ca3Al2O6, the fastest hydrating component in cement)-gypsum systems was investigated in this study using methods such as isothermal calorimetry, XRD, TGA-DSC and SEM. Results demonstrate that a higher dosage of CF corresponds to a more pronounced enhancement in C3A hydration. Furthermore, CF inhibits the initial formation of hydrogarnet (C3AH6, Ca3Al2(OH)12) and promotes the formation of ettringite (AFt) in C3A-gypsum system at 2 h hydration. However, after 1 d hydration, CF facilitates the conversion of excess C3A to C3AH6, which delays the transformation of AFt to AFm. SEM observations reveal that the CF-induced reduction in the size of AFt crystals, formed during C3A hydration, facilitates their more effective filling of interstitial voids within the hydration products, thereby contributing to the formation of a more resilient interlocking structure.
研究领域:
材料科学
·
水泥化学
·
无机非金属材料
·
建筑材料
·
水化动力学
✓ 已验证
产品关联
DOI
高影响因子
TRIBOLOGY INTERNATIONAL
·
2024
·
IF 6.1
Longqi Sun,Qin Zhao,Gaiqing Zhao,Huaigang Su,Bingbing Lai,Feng Guo,Xiaobo Wang
Calcium sulfonate complex grease exhibits different lubrication mechanisms due to its different combination of calcium carbonate soap and complex agents. In an effort to explore the synergistic lubricating effect of complex agents and find breakthroughs in the performance of calcium sulfonate grease, calcium phosphate modified calcium sulfonate grease was prepared and tested compared with borates. At high loads of 600 N, the introduction of P-containing complex improved load bearing capacity of calcium sulfonate grease. The advantage it exhibited in terms of lubrication was attributed to the synergistic effect of calcium carbonate and calcium phosphate in thickener under harsh condition. The synergistic films about 30 nm depth composed of iron oxide, calcium oxide and iron phosphate played a decisive role in lubrication.
研究领域:
材料科学
·
润滑工程
✓ 已验证
产品关联
DOI
高影响因子
e-Journal of Surface Science and Nanotechnology
·
2012
·
IF 0
L. Z. Pei,Y. Q. Pei,Y. K. Xie,Z. Y. Cai
Calcium sulfate and calcium vanadate nanostructures have been synthesized by a hydrothermal route using calcium sulfate and sodium vanadate as the raw materials. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectrum. XRD and SEM observation show that the products are composed of calcium sulfate nanosheets with orhorhombic CaSO4 phase and calcium vanadate nanorods with tetragonal CaV4O9 phase. The size and morphology of the products can be adjusted by controlling the hydrothermal conditions and raw materials. The size of calcium sulfate nanosheets and calcium vanadate nanorods increases obviously with increasing the hydrothermal temperature and reaction time. The formation process of the calcium sulfate and calcium vanadate nanostructures is also discussed. [DOI: 10.1380/ejssnt.2012.585]
研究领域:
无机化学
·
材料科学
·
纳米技术
·
固体化学
·
功能材料
✓ 已验证
DOI
POLYMER COMPOSITES
·
2016
·
IF 2.004
Peng Wang,Pengzheng Liu,Fan Xu,Xiaoxia Fan,Huipin Yuan,Hong Li,Yonggang Yan
Ternary biocomposites of dicalcium phosphate (DCP), calcium sulfate (CS), and poly(amino acid) copolymer (PAA) could be used as a promising degradable biomimic bone substitute. Using an in vitro degradation model, we evaluated the influence of polymerization conditions, initial amino acids, and (DCP + CS)/PAA ratio on the degradation of the resulting materials. PAA degradation was affected by both the polymerization conditions and the initial amino acids, and the degradation of the DCP/CS/PAA composites was affected by the (DCP + CS)/PAA ratio. Using a certain initial amino acids (75% ε-aminohexanoic acid, 19% γ-aminobutanoic acid, 4% l -proline, and 2% l -lysine) and polymerization conditions (i.e., 210°C for 2.5 h) as the polymeric phase, (DCP + CS)/PAA biocomposites were prepared with 70%, 60%, and 40% PAA. All of the biocomposites were degradable, which resulted in the release of ions/amino acids and a slight pH fluctuation of 6.76 to 7.20. In addition, these biocomposites were biocompatible based on the proliferation of L929 but varied with the degradation rates. These results suggest the potential to control the degradation rates of (DCP + CS)/PAA biocomposites for bone regeneration. POLYM. COMPOS., 39:E122–E131, 2018. © 2016 Society of Plastics Engineers
研究领域:
生物材料学
·
组织工程学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）