NEW JOURNAL OF CHEMISTRY
·
2023
·Vol. 47
·期 29
·13697-13702
·
IF 3.3
Qiuyuan Feng,Jianyi Zuo,Hong Du
A novel congruent melting compound Cs2Zn4V4O15 has been synthesized by conventional high-temperature solid-state reactions. The compound crystallizes in the monoclinic system, C2/c (No. 15) space group, with a = 15.724(4) Å, b = 5.3548(15) Å, c = 20.921(6) Å, β = 102.572(11)°, V = 1719.3(8) Å3, Z = 4. It is a cesium zinc vanadate with [VO4] units and [V2O7] dimers, which construct the final three-dimensional framework by binding to a one-dimensional zinc oxide chain. In addition, the optical properties and thermal stability of the compound have been studied, and the relationship between the structure and properties has been analyzed through first-principles calculations.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Natural Fibers
·
2023
·
IF 3.5
Xuan Yang,Yunbo Zheng,Xiaohui Liu,Yuanlin Ren,Xianwen Yang,Qiuyan Zhang
Creatinine O-phosphate (COP) containing phosphorus and nitrogen elements was used as eco-friendly flame-retardant for lyocell/cotton blended fabric (L/C fabric). The flame retardant fabrics are prepared by a simple and effective dip-dry-cure method. Fourier infrared spectroscopy (FTIR), scanning electron microscope (SEM), and X-ray photoelectron spectroscopy (XPS) analyses certified that COP has been successfully grafted onto the surface of the L/C fabric and distributed evenly. Compared with the control fabric, the thermogravimetric analysis (TG) results showed that the char residue rate of the flame-retardant fabric at 800°C increased by 229% (air atmosphere), indicating that it has excellent char-forming ability. Besides, cone calorimetry results showed that the PHRR and THR values of the treated L/C fabric were reduced by 88.83% and 76.65%, respectively. The volatile pyrolysis products of the treated L/C fabric were determined by thermogravimetric analysis coupled with Fourier transform infrared analysis (TG-IR). In general, these results indicated that the L/C fabric treated with COP had high flame retardancy, excellent washing resistance and thermal stability.
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
·
2023
·Vol. 365
·期 7
·1048-1057
·
IF 5.4
Xiao-Ling Tang,Ning Li,Yan-Lai Liu,Jing-Peng Li,Kai-Xuan Zhao,Zhi-Qiang Liu,Yu-Guo Zheng
L-Methionine is the unique sulfur-containing amino acid essential for humans and animals, which is widely used in pharmaceutical, food and feed industries. Its green and efficient production has attracted a great deal of attention. Fermentation-enzymatic coupling route is regarded to be promising for L-methionine biosynthesis, while O- succinyl-L-homoserine mercaptotransferase (MetZ) is the key biocatalyst. Exploring and engineering of MetZ with ideal catalytic properties is highly desired. Herein, the MetZ from Chromobacterium violaceum ( Cv MetZ) was screened and through in silico analyses, potential beneficial amino acid residues both at the access channel and around the oxygen anion holes were anchored for site-saturation mutagenesis. The positive mutants were obtained with improved activity for L-methionine biosynthesis using O -succinyl-L-homoserine (OSH) and methyl mercaptan as substrate. The best mutant was further applied for L-methionine production and supply of methyl mercaptan was optimized in a fed-batch approach. The conversion of 100 g/L OSH reached 92% with L-methionine yield of 62.6 g/L, which was well coupled with the OSH fermentation level.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Hui Liu,Hongyan Li,Bin Lu,Songnan Li,Jingxiang Zhao,Qinghai Cai
A composite catalyst was prepared by impregnation of ZSM-5 in mixture solution of Co(NO 3 ) 2 , ZrOCl 2 and phosphotungstic acid (PW) and characterized by XRD , FT-IR, UV–vis, XPS , SEM and TEM techniques to confirm its structure and composition . The pre-prepared composite is composed of Co 2 (PO 4 )Cl, ZrO 2 , P 2 O 5 and WO 3 crystalline nanoparticles uniformly dispersed on ZSM-5 zeolite . The prepared composite demonstrates effective catalytic function for solvent-free oxidation of toluene into benzaldehyde with H 2 O 2 oxidant, achieving 16.6% conversion and 90% selectivity . The effect of various components composed of the catalyst and reaction conditions on the catalytic function were explored. Moreover, the recovery and reusability of the catalyst were estimated, presenting good reusability.
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Yi-Gang Chen,Meiling Xing,Yao Guo,Zheshuai Lin,Xiujun Fan,Xian-Ming Zhang
Beryllium (Be) has high ionization energy (9.32 eV) with the greatest degree of covalency in the group IIA elements, and BeO4 tetrahedra (and BeO3 triangles) with covalent character are generally presented in beryllates. An unprecedented BeO6 trigonal prism with ultralong Be–O bonds as well as a BeO4 common tetrahedron is discovered in a new deep ultraviolet crystal Li13BeBe6B9O27 (LBeBBO) with a ∞2[Be6B9O33] double-layer framework. The BeO6 unit and its bond character are verified by an isostructural crystal Li13(Mg0.45Be0.55)Be6B9O27, while the orbital theory and charge density difference further clarify the ionic character of the BeO6 unit. Phonon dispersion confirms the structural stability of LBeBBO.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Haibin Wang,Shaodong Liu,Tingting Sun,Zhanao Lv,Zhen Zhan,Guochuan Yin,Zhuqi Chen
In catalytic double bond migration reaction, E -configuration olefins were normally generated as the dominant product because E -configuration was thermodynamically favored. However, Z-configuration products are sometimes desired in pharmaceutical chemistry owing to the structure-activity relationship. In this paper, we have demonstrated a new strategy that Lewis acid promoted an widely employed and convenient ruthenium(II) complex for the catalytic isomerization of O-allylethers, leading to thermodynamic-unfavored Z-product under mild conditions. The model substrate of allyl phenyl ether can be simply scaled up to 20 mmol to produce Z-product with TON of 2453 and TOF of 13,430 h −1 at 40–60 °C. The system of Ru(II)/Lewis Acid catalysts was suitable for various substituted O -allylethers and other types of substrates. Through mechanism study including kinetic study, ligand inhibition effect and molecular spectroscopy, the dissociation of PPh 3 ligand by the addition of Lewis acid, and the formation a five-membered Ru complex from anchimeric assistance were both recognized as essential steps to improve the reactivity and to control the stereoselectivity of catalytic double bond migration reaction through metal hydride addition-elimination mechanism. This new strategy may provide a new opportunity to produce thermodynamic-unfavored product in heterocyclic compounds for pharmaceutical chemistry.
✓ 已验证
产品关联
DOI
高影响因子
Environmental Science-Processes & Impacts
·
2019
·Vol. 21
·期 7
·1184-1192
·
IF 2.688
Yaqin Gao,Yan Lyu,Xiang Li
The present study was conducted to examine the potential mechanisms responsible for the distribution of polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (o-PAHs) in size fractionated particles and their environmental implications. Size-fractionated atmospheric particles were collected at urban Shanghai, China and analyzed for 5 PAHs and 6 o-PAHs. The concentrations of particle-bound ∑6o-PAHs (sum of 6 o-PAH congeners, 19.1 ± 4.5 ng m−3) were significantly higher than those of ∑5PAHs (sum of 5 PAHs, 9.5 ± 1.9 ng m−3). The size-fractionated distributions of airborne ∑5PAHs and ∑6o-PAHs displayed bimodal peaks at 0.7–1.1 and 9.0–10.0 μm. Emission sources and volatility were important factors influencing the size distribution of particle-bound 5 PAHs and 6 o-PAHs. The dry deposition fluxes of particle-bound 6 o-PAHs estimated from the measured data (3087 ± 467 ng m−2 d−1) were approximately 2 times higher than those of PAHs (1531 ± 344 ng m−2 d−1), with a total deposition flux of 4618 ± 743 ng m−2 d−1. The relative contributions of particles to dry deposition were also size-dependent, e.g., coarse (aerodynamic diameters (Dp) > 2.1 μm) particles dominated the dry deposition fluxes of PAHs and o-PAHs. These results highlight the significance of providing a comprehensive understanding of particle size distribution of PAHs and o-PAHs and their implication for dry deposition in China.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INFLAMMOPHARMACOLOGY
·
2018
·Vol. 27
·期 5
·969-974
·
IF 3.304
Zhao Mingyi,Zhou Peng,Yu Jun,James Asenso,Xiao Feng,Wang Chun,Wei Wei
Paeoniflorin-6′-O-benzene sulfonate (code: CP-25) is a novel ester derivative of paeoniflorin (Pae). Compared to Pae, CP-25 has higher lipid solubility, bioavailability and better bioactivity. However, the tissue distribution and excretion of CP-25 still remain unknown. The LC–MS method was applied to investigate the tissue distribution and excretion of CP-25 in rats. As such, 50 mg/kg of CP-25 and Pae were administered to rats in multiple doses via an oral route. CP-25 and Pae were distributed widely and rapidly in all the tested tissues. Compared with Pae, the concentrations of CP-25 were almost increased evidently in most tissues. The highest CP-25 level was found in the liver (1476.33 ± 535.20 ng/g, male; 1970.38 ± 177.21 ng/g, female) at 3 h, and a high concentration of CP-25 was detected in male and female intestine, synovium, muscle, lung, and brain. Following a single oral dose of 50 mg/kg of CP-25 in rats, the total excretion of CP-25 was merely 21.8% (18.40, 3.19 and 0.22% for feces, bile and urine, respectively) in males; and was approximately 21.3% (14.04, 7.16 and 0.14% for feces, bile and urine, respectively) in females. The results indicated that the CP-25 concentration was higher in major tissues than Pae; CP-25 was primarily excreted through the feces; and there were gender-related differences in the tissue distribution and excretion.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Ruyi Zhong,Zisheng Zhang,Huqiang Yi,Lei Zeng,Chao Tang,Limin Huang,Meng Gu
Visible-light photocatalytic hydrogen evolution is a key step towards utilizing solar energy. Here we constructed covalently bonded oxidized graphitic C 3 N 4 /TiO 2 (O-g-C 3 N 4 /TiO 2 ) heterostructure with high surface area via an in-situ solvothermal synthetic strategy. The edge-anchoring of two-dimensional (2D) TiO 2 on 2D O-g-C 3 N 4 was evidenced by the HAADF-STEM EDS mapping, EELS and XPS analysis. Density functional theory computations suggest strong affinity between TiO 2 and O-g-C 3 N 4 2D structures through N O Ti covalent bonding, which drastically enhances the synergetic effect of the light absorption of O-g-C 3 N 4 and high surface area of TiO 2 . The as-formed heterojunction can remarkably boost the visible-light photocatalytic activity for H 2 evolution by 6.1 times compared to physical mixture of TiO 2 nanosheets (NS) and O-g-C 3 N 4 .
✓ 已验证
产品关联
DOI
高影响因子
3 Biotech
·
2018
·Vol. 8
·期 7
·1-9
·
IF 1.497
Huang Jian-Feng,Zhang Bo,Shen Zhen-Yang,Liu Zhi-Qiang,Zheng Yu-Guo
O -succinyl- l -homoserine (OSH) is a promising platform chemical for the production of C4 chemicals with huge market potential which can be produced by fermentation from glucose. To construct a strain capable of producing OSH with high yield, the metJ (encodes transcriptional repressor) and metI (encodes a subunit of dl -methionine transporter) were deleted in Escherichia coli W3110 to obtain a strain E. coli ∆JI. Then, overexpression of metL (encodes bifunctional aspartate kinase/homoserine dehydrogenase II) and inactivation of metB (encodes cystathionine γ-synthase) were implemented in one step, and the OSH titer of the resulting strain E. coli ∆JIB * Trc metL was dramatically increased to 7.30 g/L. The feedback regulation was further relieved by progressively overexpressing metA fbr (encodes homoserine O -succinyltransferase), yjeH (encodes l -methionine exporter), and thrA fbr (encodes bifunctional aspartate kinase/homoserine dehydrogenase I) to increase the metabolic flux from aspartate to OSH. The 100% rationally designed strain E. coli ∆JIB * Trc metL /pTrc- metA fbr -Trc- thrA fbr - yjeH produced 9.31 g/L OSH from 20 g/L glucose (0.466 g/g glucose) in batch fermentation, which represents the highest OSH yield from glucose reported to date. The culture profiles of the newly constructed strains were recorded to investigate their productive properties. The effects of l -methionine addition on the fermentation process of the optimal strain were also studied. Our results demonstrate that tuning the expression level of metL , inactivation of metB , and attenuation of feedback resistance of the crucial enzymes in the biosynthetic pathway are the key factors that impact the OSH production in E. coli .
✓ 已验证
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2017
·Vol. 47
·期 1
·180-189
·
IF 4.029
Dandan Yang,Jie Dong,Baiquan Wang
A series of new pincer-type tridentate o-aryloxide-N-heterocyclic carbene nickel complexes Ni1–Ni3 were synthesized, and the molecular structure of Ni3 was confirmed by X-ray crystallography. In comparison with the above tridentate complexes, the bidentate bis(aryloxide-NHC) nickel complex Ni4 was also synthesized. On activation with either Et2AlCl or Me2AlCl, all nickel complexes showed low activity toward norbornene (NB) homopolymerization. Surprisingly, Ni1–Ni3 catalysts exhibited moderate to high activity toward the homopolymerization (up to 3.21 × 106 g PNB (mol of Ni)−1 h−1) and copolymerization of norbornene with 1-octene (up to 1.39 × 105 g polymer (mol of Ni)−1 h−1) with B(C6F5)3 as the cocatalyst even at 100 °C, showing that tridentate nickel catalysts have high thermal stability. Notably, the tridentate Ni1–Ni3 complexes showed better activities than the corresponding bidentate bis(aryloxide-NHC) nickel complex Ni4. The obtained poly(NB-co-1-octene)s were confirmed to be vinyl-addition copolymers, which exhibited high 1-octene insertion ratio (9%–17%), good thermal stability (Td > 400 °C), high molecular weight (up to 105), and narrow molecular weight distribution (PDI ≤ 1.91).
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chemical Engineering and Processing-Process Intensification
·
2017
·
IF 2.234
Xiaoming Luo,Juhang Cao,Haipeng Yan,Haiyang Gong,Haoran Yin,Limin He
The separation characteristics of W/O emulsion were investigated under ultrasonic standing wave field in this paper. The effects of the irradiation time, acoustic intensity, frequency, oil viscosity, and oil-water interfacial tension on the separation characteristics of emulsion were studied in details. It was proved that there existed an optimal irradiation time, acoustic intensity and oil-water interfacial tension to achieve the maximum separation efficiency in ultrasonic treatment process. Excessive long irradiation time had little effect on improving the dehydration rate of emulsion but rather increased unnecessary processing time. Excessive high acoustic intensity caused the occurrence of acoustic cavitation phenomenon. The acoustic cavitation would cause the aggregated droplets to be dispersed by oscillating bubbles or even emulsified again by high speed micro jets. The acoustic cavitation threshold is effectively and accurately obtained by a spectral analysis method. The micro acoustic streaming which resulted from the attenuation of acoustic energy occurred with the increase of frequency. It sheared the aggregated droplets, destroyed the stable droplets banding and reduced the separation efficiency of emulsion. The excess surfactant adsorbed on the oil-water interface resulted in the increase of the interfacial film strength, which hindered the coalescence process of droplets and reduced the separation efficiency.
✓ 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）