CARBOHYDRATE POLYMERS
·
2020
·
IF 7.182
Renliang Lyu,Ting Xia,Cheng Liang,Cheng Zhang,Zeqin Li,Lichun Wang,Yi Wang,Ming Wu,Xiaogang Luo,Jiayu Ma,Cunwen Wang,Caili Xu
Three kinds of novel environmentally benign and high-efficiency crude oil demulsifiers were prepared using methoxy polyethylene glycol (MPEG) to modify alkylated carboxymethyl chitosan (ACMC). Structures of the demulsifiers were confirmed using FT-IR and 1 H NMR, and the relationship between surface tension and concentration was tested. Demulsification performance was investigated using the bottle test method with oil-in-water (O/W) emulsions that were prepared in lab conditions. The demulsification efficiency was as high as 79.1 %–84.9 %, and the possible mechanism of the demulsification process is discussed. Results show that MPEG-grafted ACMC (MPEG-ACMC) has a promising application as a demulsifier for dealing with emulsified O/W crude oil.
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PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2019
·
IF 7.65
Bo Sheng,Xin Zhou,Zhun Shi,Zhaohui Wang,Yaoguang Guo,Xiaoyi Lou,Jianshe Liu
The interaction of reductive metal ions and peroxymonosulfate (PMS) is necessary for the generation of sulfate radials (SO 4 − ), however, this process is greatly restrained by the sluggish reduction of high-valent metal ions. Here we report that commercially available reductive metal (Mo or W) powders are capable of unlocking this kinetic constraint. The reduction of Fe(III) to Fe(II), decomposition of PMS, and degradation/mineralization of 4-chlorophenol (4-CP) are all accelerated in the Mo/Fe 2+ /PMS process at a very low Fe 2+ /PMS ratio (Fe 2+ /PMS = 1/10). In such an accelerated system, common adverse effects of natural water constituents such as chloride and humic acid are largely mitigated. According to the fluorescence measurement and scavenging tests, sulfate and hydroxyl radicals dominate in Mo/Fe 2+ /PMS process. The addition of Mo or W is further confirmed to favor Cu 2+ /PMS process, but this is not the case for other metal ions (Mn 2+ , Ni 2+ , Ce 3+ and Co 2+ ). Reductive zero-valence and four-valence active sites (Mo 0 and Mo 4+ ; W 0 and W 4+ ) play key roles in overall redox reaction. Overall, our present work provides an alternative route for expediting redox cycling of transition metals in advanced oxidation processes, without useless consumption of PMS and increase of total organic carbon.
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高影响因子
POWDER TECHNOLOGY
·
2019
·
IF 3.413
Zhi-Bo Li,Guo-Hua Zhang,Kuo-Chih Chou
The ultrafine composite powders of two different compositions (90W-7Ni-3Fe and 93W-4.9Ni-2.1Fe, wt%) were synthesized by a two-stage reduction process consisting of carbothermic pre-reduction and the following deep reduction by hydrogen, and then the densification behaviors of them were investigated. The prepared W-Ni-Fe composite powders by the new proposed two-stage method had the particle size ranged from 200 nm to 400 nm. The sintered compacts of these two kinds of W-Ni-Fe powders achieved nearly full densification at a sintering temperature of 1400 °C within 3 h. The maximum hardness of the alloys obtained at 1300 °C were 411 HV and 358 HV, and the bending strength of >1500 MPa was achieved at 1400 °C for the compositions of 90W-7Ni-3Fe and 93W-4.9Ni-2.1Fe, respectively. Meanwhile, the bending fracture mechanism was also investigated, which was different for the samples sintered at different temperatures.
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高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 11
·115507
·
IF 1.449
Qiong Wu,Tiankuo Yao,Minqi Sheng,Jialun Shi,Fan Lv
The high-performance catalytic electrodes are always required in industrial water electrolysis for enhancing the efficiency of energy conversion. In this paper, we utilized a simple electroless deposition method to deposit Co-W-P on carbon cloth (CC), to construct a bifunctional Co-W-P/CC self-supported electrode for electrochemical water splitting in 1.0 M KOH. The Co-W-P on CC is amorphous and displays nodular structure. The molar ratio of Co2+/WO42− in the synthesis process makes remarkable influence on the catalytic activity of Co-W-P/CC. For optimized Co-W-P/CC-3 (Co2+/WO42− molar ratio about 6:1), an overpotential of 150 mV at −10 mA·cm−2 is required with a Tafel slope of 137.3 mV·dec−1 toward hydrogen evolution reaction (HER), and an overpotential of 350 mV at 10 mA·cm−2 is required with a Tafel slope of 113.2 mV·dec−1 toward oxygen evolution reaction (OER). Furthermore, when functioned as a bifunctional electrode for overall water splitting, the electrolyzer of Co-W-P/CC (−)//Co-W-P/CC (+) shows the cell voltage of 1.74 V at 10 mA·cm−2, as well as superior stability with negligible increase of cell voltage (0.05 V) over 20 h. The work provides an efficient and inexpensive electrode material, which can be used to replace the noble metal-based catalysts for electrochemical water splitting.
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高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Run Zheng,Baolong Wang,Kai Shi,Di Sha,Xiangling Ji
The emulsion separation of oily wastewater is always a challenge topic in both fundamental research and practical application. In this paper, polyvinyl alcohol formaldehyde composite sponges (PVF/PVF) with hierarchical pore structure were established by physical absorption/chemical crosslinking and hydrophobic modification via introducing hydrophobic long alkyl chain. As a result, pore size was adjusted from 74.8 µm of pristine PVF to less than 20 µm of hydrophobic PVF, the water contact angle was 120° for final as-prepared sponges, i.e. size sieving and surface wettability could meet the need of emulsion separation. As-prepared sponges could separate W/O (water-in-oil) emulsion efficiently only under the action of gravity, with a maximum flux of 2.9 × 10 5 L m -2 h −1 bar −1 and separation efficiency nearly 100 %. More importantly, the as-prepared sponges displayed excellent reusability, which could be recovered by simply washing. These composite sponges, which were obtained by a simple method and low cost, could be easily scaled up in practical production process, providing an outstanding candidate material for efficient W/O emulsion separation.
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FOOD HYDROCOLLOIDS
·
2017
·
IF 4.747
Ping Shao,Huiling Ma,Jieyu Zhu,Qiang Qiu
The aim of this research was to investigate the effect of ionic strength (Na + 0.1–0.5 mol/L, Ca 2+ 0.01–0.05 mol/L) on the physicochemical stability of o/w emulsions stabilized by Ulva fasciata polysaccharide . Droplet diameter, Polydispersity Index (PDI), zeta-potential value, microscopic morphology and rheological properties were achieved to investigate the possible stability mechanisms. The results showed that different metal ions had significant effects on the stability of o/w emulsions. When compared the effect of Ca 2+ with that of Na + , it was found that Na + concentration did not have a significant effect on emulsions stability. The results indicated that zeta-potential decreased sharply with increasing calcium ionic strength (CaCl 2 :0.01 mol/L - 0.05 mol/L) and the minimum zeta-potential value was −27.5 mV, while zeta-potential changed slightly when NaCl (0.1 mol/L - 0.5 mol/L) were added. As for z-average size and PDI, they changed significantly with higher valence metallic ions. With increasing NaCl and CaCl 2 concentration, the retention rate of R-(+)-Limonene was reduced and emulsions exhibited non-Newtonian behavior. Another interesting result was that the addition of Ca 2+ at low concentration (0.01 mol/L - 0.02 mol/L) managed to improve the stability of emulsions .
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Huali Hao,Wei Mo,Yonghu Lv,Shulong Ye,Ruinan Gu,Peng Yu
The influence of trace elements on the powder metallurgy of Cu was investigated. It was found that 1 wt. % of Ti can effectively increase the green density of the compacts and facilitate the subsequent sintering process, thus resulting in increased sintered density. Although 1 wt. % of W added into the Cu leads to similar increasing of green density, W significantly retarded the sintering process and has a negative effect on the sintered density. Moreover, intermetallic Cu 4 Ti were formed, which not only creates a short-circuit diffusion path for Cu but also forms liquid phases during sintering. However, it was hardly dissolved between W and Cu.
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高影响因子
RARE METALS
·
2025
·
IF 11
Cheng-Feng Yi,Jing-Wen Li,Jia-Rui Li,Bing-Chuan Xue,Xing Lin,Zhi-Gang Liu
en Ni 3 S 2 has emerged as a promising catalyst for the electrochemical oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), driven by its distinctive physicochemical properties. However, its practical catalytic efficiency is severely hindered by abundant electrochemically inactive surface sites and poor electronic conductivity. To overcome these challenges, an N,W-cooperative modulation of Ni 3 S 2 catalyst (N,W-Ni 3 S 2 ), featuring an engineered crystalline-amorphous heterostructure, is designed, utilizing 5,10,15,20-tetraphenylporphine (TPP) as the N source. This innovative architecture integrates W-doped crystalline Ni 3 S 2 and N-doped amorphous carbon, which synergistically enhances charge transport and induces interfacial charge polarization, substantially boosting catalytic activity. The optimized N,W-Ni 3 S 2 demonstrates unprecedented electrocatalytic performance for the oxidation of HMF to FDCA, achieving 100% HMF conversion, 97% FDCA yield, and 97% Faradaic efficiency, with over 95% retention in both FDCA yield and Faradaic efficiency across 10 consecutive cycles. Theoretical calculations and experimental results unveil that N incorporation exerts a more profound influence than W in reshaping the electronic landscape of Ni 3 S 2 , triggering an asymmetric electron redistribution at the heterogeneous interface. This unique electronic perturbation depletes the electron density around Ni active sites, creating an electron-deficient state that dramatically promotes the in situ generation of NiOOH as the true active species. Furthermore, the tailored electronic environment significantly lowers the energy barrier for the rate-determining step in the oxidation pathway, thereby enabling near-quantitative FDCA production with high efficiency. 摘要 zh Ni 3 S 2 凭借其独特的物理化学性质,已成为一种极具前景的催化剂,可用于将生物质衍生的5-羟甲基糠醛(HMF)电化学氧化为2,5-呋喃二甲酸(FDCA)。然而,其实际催化效率因大量电化学惰性表面位点和较差的电子导电性而受到严重阻碍。为解决这些问题,本研究设计了一种具有工程化晶态-非晶态异质结构的Ni 3 S 2 催化剂的氮、钨协同调控体系(N,W-Ni 3 S 2 ),并以5,10,15,20-四苯基卟啉(TPP)作为氮源。这种创新结构整合了钨掺杂的晶态Ni 3 S 2 与氮掺杂的非晶碳,二者协同增强电荷传输并诱导界面电荷极化,显著提升了催化活性。优化后的N,W-Ni 3 S 2 在HMF氧化生成FDCA的反应中表现出优异的电催化性能:HMF转化率达100%,FDCA产率达97%,法拉第效率达97%; 在10次连续循环中,FDCA产率和法拉第效率均保持在95%以上。理论计算与实验结果表明,在重构Ni 3 S 2 的电子结构方面,氮掺杂比钨掺杂的影响更为显著,可在异质界面处引发不对称的电子重新分布。这种独特的电子扰动会降低Ni活性位点周围的电子密度,形成缺电子状态,从而显著促进真正活性物种NiOOH的原位生成。此外,这种定制化的电子环境大幅降低了氧化路径中决速步的能垒,进而实现了高效且接近定量的FDCA生成。
研究领域:
电催化
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可再生能源
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生物质转化
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材料化学
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可持续化学
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高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2022
·Vol. 106
·期 7
·2619-2636
·
IF 5.56
Chen Yunni,Xu Chenglong,Yang Huilin,Liu Zhenying,Zhang Zhibin,Yan Riming,Zhu Du
Abstract Perylenequinones (PQ) are natural polyketides used as anti-microbial, -cancers, and -viral photodynamic therapy agents. Herein, the effects of L-arginine (Arg) on PQ biosynthesis of Shiraia sp. Slf14(w) and the underlying molecular mechanism were investigated. The total content of PQ reached 817.64 ± 72.53 mg/L under optimal conditions of Arg addition, indicating a 30.52-fold improvement over controls. Comparative transcriptome analysis demonstrated that Arg supplement promoted PQ precursors biosynthesis of Slf14(w) by upregulating the expression of critical genes associated with the glycolysis pathway, and acetyl-CoA and malonyl-CoA synthesis. By downregulating the expression of genes related to the glyoxylate cycle pathway and succinate dehydrogenase, more acetyl-CoA flow into the formation of PQ. Arg supplement upregulated the putative biosynthetic gene clusters for PQ and activated the transporter proteins (MFS and ABC) for exudation of PQ. Further studies showed that Arg increased the gene transcription levels of nitric oxide synthase (NOS) and nitrate reductase (NR), and activated NOS and NR, thus promoting the formation of nitric oxide (NO). A supplement of NO donor sodium nitroprusside (SNP) also confirmed that NO triggered promoted biosynthesis and efflux of PQ. PQ production stimulated by Arg or/and SNP can be significantly inhibited upon the addition of NO scavenger carboxy-PTIO, NOS inhibitor N ω -nitro-L-arginine, or soluble guanylate cyclase inhibitor NS-2028. These results showed that Arg-derived NO, as a signaling molecule, is involved in the biosynthesis and regulation of PQ in Slf14(W) through the NO-cGMP-PKG signaling pathway. Our results provide a valuable strategy for large-scale PQ production and contribute to further understanding of NO signaling in the fungal metabolite biosynthesis. Key points • PQ production of Shiraia sp. Slf14(w) was significantly improved by L-arginine addition. • Arginine-derived NO was firstly reported to be involved in the biosynthesis and regulation of PQ. • The NO-cGMP-PKG signaling pathway was proposed for the first time to participate in PQ biosynthesis.
研究领域:
微生物学
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生物化学
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药理学
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分子生物学
·
真菌代谢
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PubMed
高影响因子
Applied Food Research
·
2026
·
IF 6.2
Lihui Yang,Xian’e Ren,Yuting Wu,Feng Yang,Kunming Zhang,Yongchun Huang,Xiaolong Miao
To enhance the bioaccessibility of vitamin D3 in fortified food systems, hydrodynamic cavitation, ultrasonic cavitation, and an ascorbic acid/hydrogen peroxide system were employed to generate free radicals that mediated the formation of gallic acid-soy protein isolate (GA-SPI) conjugates. The resulting conjugates were used to stabilize emulsions. The emulsion properties and their effects on vitamin D3 delivery were investigated. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) confirmed that covalent conjugation between GA and SPI was promoted by free radical generation in all three treatments. Compared with emulsions prepared with soy protein isolate alone, significant improvements were observed for emulsions stabilized by GA-SPI conjugates, including smaller particle size, higher absolute zeta potential, higher storage modulus, and improved storage stability and antioxidant capacity. These improvements were attributed to GA incorporation and the processing methods. More importantly, when used to encapsulate vitamin D3, bioaccessibility ranged from 53.36 ± 0.57% to 80.06 ± 0.12% for GA-SPI stabilized emulsions prepared by these methods, compared with the untreated group. These findings confirm that emulsion delivery performance can be improved by the three free radical-mediated treatments through promotion of polyphenol-protein conjugation.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Nan Liu,Zhi Dong,Zongqing Ma,Liming Yu,Chong Li,Chenxi Liu,Qianying Guo,Yongchang Liu
The bimodal distribution of tungsten grain size, which is also called bimodal structure, is a universal phenomenon in synthesizing tungsten based nanopowders by wet chemical method , and could significantly deteriorate further sintering characteristics of the powders. In this paper, W-Y 2 O 3 composite nanopowders with small grain size and no bimodal structure were synthesized by an improved wet chemical method. It was found that reaction conditions, especially the hydrogen ion concentration(ρ(H + )) could significantly influence the microstructure and morphology of the prepared composite nanopowders and has an optimum value of approximately 0.16 mol L −1 . W-Y 2 O 3 composite nanopowders synthesized under this optimum value got not only the minimum average grain size, which is about 17 nm, but also the best grain size uniformity with no bimodal structure. The microstructure of co-deposited precursors and prepared powders was analyzed in detail to figure out the specific influence mechanism of ρ(H + ), and it was indicated that ρ(H + ) could influence the microstructure and the Y 2 O 3 content of the reduced powders through affecting the fraction of precursor that has little yttrium content, which may lead to the bimodal distribution of tungsten grain size of the prepared powders. Furthermore, the formation mechanism of bimodal structure was systematically analyzed and a feasible method was proposed to eliminate the bimodal structure. It is suggested that the bimodal distribution of tungsten grain size is attributed to the distribution of Y 2 O 3 during hydrogen reduction process and can be well avoided by controlling ρ(H + ).
研究领域:
材料科学
·
纳米材料
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粉末冶金
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无机非金属材料
·
功能材料
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 20
·1-10
·
IF 2.8
Ji Changjian,Zhang Hailong,Wang Wenjing,Yuan Huimin,Zhao Gang
In order to acquire a red light-emitting component for an efficient w -LEDs device, we synthesized a series of Eu 3+ -doped Sr 2 GaTaO 6 (SGT) phosphors using a traditional high-temperature solid-phase technique. The results of UV diffuse reflectance proved that the SGT host possesses a broad optical energy bandgap ( E gap ) of 4.47 eV (calculated value). The relevant characteristic spectra were also tested. By monitoring the emission at 612 nm, the excitation peak at 466 nm matches the blue light region (460–470 nm) of the popular blue LED chips on the market. The photoluminescence (PL) spectra of SGT: Eu 3+ phosphors at room temperature consisting of four obvious PL bands ( 5 D 0 → 7 F 1 , 5 D 0 → 7 F 2 , 5 D 0 → 7 F 3 , and 5 D 0 → 7 F 4 ) in the visible range. And the PL properties are necessarily analyzed by fluorescence decay curves. And it exhibits a decent photoluminescence quantum yield (39.88%). Moreover, the color purity and the ∆E of the SGT: 0.2Eu 3+ sample are 96.5% and 0.29 eV, respectively, demonstrating that the ∆E of SGT: Eu 3+ phosphor is superior to other reported Eu 3+ -doped materials for w -LEDs applications. The results manifest that the Eu 3+ doped SGT phosphors can be outstanding candidates for w -LEDs applications with high color purity and activation energy.
研究领域:
材料科学
·
光电
·
固体化学
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高影响因子
危险品化学品经营许可证（带存储）