PHYSICS AND CHEMISTRY OF LIQUIDS
·
2019
·
IF 1.526
Mengsha Cai,Zhaoshan Liu,Haiyun Sun,Yongsheng Guo,Wenjun Fang
Densities (ρ) and viscosities (η) of a ternary system cyclopropanemethanol (1) + 2,2,4-trimethylpentane (2) + decalin (3) and three corresponding binary systems were measured at temperatures from 293.15 K to 323.15 K and atmospheric pressure. Densities were obtained by using a vibrating-tube densimeter. Viscosities were determined by an automatic microviscometer based on the rolling ball principle. The excess molar volumes (VmE) and viscosity deviations (Δη) of the ternary system were derived from the experimental data and then were fitted to Clibuka, Nagata–Tamura and Redlich–Kister equation, respectively. The binary subsystems were correlated by Redlich–Kister equation. The values of VmE and Δη were used to discuss the nature of mixing behaviours between mixture components.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
·
2017
·Vol. 83
·期 10
·
IF 3.807
Yaojie Gao,Gudan Xu,Pan Wu,Jin Liu,You-sheng Cai,Zixin Deng,Wenqing Chen
2′-Chloropentostatin (2′-Cl PTN, 2′-chloro-2′-deoxycoformycin) and 2′-amino-2′-deoxyadenosine (2′-amino dA) are two adenosine-derived nucleoside antibiotics coproduced by Actinomadura sp. strain ATCC 39365. 2′-Cl PTN is a potent adenosine deaminase (ADA) inhibitor featuring an intriguing 1,3-diazepine ring, as well as a chlorination at C-2′ of ribose, and 2′-amino dA is an adenosine analog showing bioactivity against RNA-type virus infection. However, the biosynthetic logic of them has remained poorly understood. Here, we report the identification of a single gene cluster (ada) essential for the biosynthesis of 2′-Cl PTN and 2′-amino dA. Further systematic genetic investigations suggest that 2′-Cl PTN and 2′-amino dA are biosynthesized by independent pathways. Moreover, we provide evidence that a predicted cation/H+ antiporter, AdaE, is involved in the chlorination step during 2′-Cl PTN biosynthesis. Notably, we demonstrate that 2′-amino dA biosynthesis is initiated by a Nudix hydrolase, AdaJ, catalyzing the hydrolysis of ATP. Finally, we reveal that the host ADA (designated ADA1), capable of converting adenosine/2′-amino dA to inosine/2′-amino dI, is not very sensitive to the powerful ADA inhibitor pentostatin. These findings provide a basis for the further rational pathway engineering of 2′-Cl PTN and 2′-amino dA production.IMPORTANCE 2′-Cl PTN/PTN and 2′-amino dA have captivated the great interests of scientists, owing to their unusual chemical structures and remarkable bioactivities. However, the precise logic for their biosynthesis has been elusive for decades. Actually, the identification and elucidation of their biosynthetic pathways not only enrich the biochemical repertoire of novel enzymatic reactions but may also lay solid foundations for the pathway engineering and combinatorial biosynthesis of this family of purine nucleoside antibiotics to generate novel hybrid analogs with improved features.
✓ 已验证
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2026
·Vol. 40
·期 33
·18043-18052
·
IF 6
Pang Bo,Pu Baian,Peng Hao,Xue Kang,Shi Chengxiang,Gao Ruijie,Ai Minhua,Huang Zhen-Feng,Zhang Xiangwen,Zou Ji-Jun,Pan Lun
Conventional
high-energy-density hydrocarbon fuels face an intrinsic
trade-off between increasing ring number and decreasing net heat of
combustion. To address this limitation, we propose a synthetic strategy
based on tandem [4 + 2]/[2 + 1] cycloaddition. Norbornadiene and methyl
dicyclopentadiene were employed as feedstocks to develop a coupled
synthetic approach that combines Diels–Alder [4 + 2] cycloaddition
for constructing a polycyclic framework with Simmons–Smith
[2 + 1] cyclopropanation for energy enhancement. By optimizing the
reaction parameters, the Diels–Alder and Simmons–Smith
reactions achieved optimal conversions of 77.89% and 90.96%, respectively,
with selectivities of 43.54% and 85.82%. The resulting fuel fraction
exhibits a high density of 1.060 g cm –3 , a volumetric
net heat of combustion of 44.85 MJ L –1 , and a freezing
point below −60 ° C. This study demonstrates an effective
strategy for simultaneously achieving high density, high volumetric
energy content, and excellent low-temperature performance, providing
useful guidance for the molecular design and synthesis of next-generation
high-energy-density fuels.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 36
·
IF 1.866
Yangzhi Xie,He Huang
On the basis of 2-hydroxyl-2-methyl-1-phenylpropanone (HMPP) and poly(ethylene glycol) (PEG), we prepared amphiphilic macrophotoinitiators (HMPP–PEG–HMPP) by first reacting HMPP with isophorone diisocyanate and subsequently reacting it with PEGs with different chain lengths. Fourier transform infrared spectroscopy, high-performance liquid chromatography, and 1 H-NMR were used to confirm the structure of the amphiphilic macrophotoinitiators. Ultraviolet (UV) absorption spectra showed that the amphiphilic macrophotoinitiators had maximum absorption wavelengths that were similar to those of the low-molecular-weight photoinitiator HMPP. The photolysis rate of the amphiphilic macrophotoinitiators was slightly lower than that of HMPP, but the migration rate of the amphiphilic macrophotoinitiators from a UV-cured matrix was much lower compared to that of HMPP. Because of their amphiphilic nature, these macrophotoinitiators may play roles as both photoinitiators and emulsifiers, and they have been applied to the solution polymerization of water-soluble monomer acrylamide in water and the emulsion polymerization of methyl methacrylate. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43910.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2022
·
IF 3.119
Tiantian Ping,Qinghai Long,Shufeng Shen
Solubility of N2O and CO2 in pure 2-butoxyethanol (2-BE) was determined in a stirred equilibrium cell at temperatures ranging from 283.2 to 333.2 K and correlated as an exponential function of temperature. Ratios of solubility of CO2 to N2O in several reported solvents were found to be strongly dependent on the order of solvent dielectric constants. Solubility of N2O in 2-(butylamino)ethanol (BAE) and the binary blends of 2-BE and BAE was measured over the temperature range from 283.2 to 333.2 K and with BAE concentration from 6.5 to 65.4 mass%. N2O solubility data were well represented by correlation models with AARDs within 0.8%. Physical solubility of CO2 in a nonaqueous 2-BE/BAE system can be estimated using the N2O analogy method.
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2021
·Vol. 223
·期 3
·2100340
·
IF 2.527
Jianxiong Zhang,Junjin Duan,Dong Chen,Yuhong Ma,Wantai Yang
A direct photolysis reversible addition-fragmentation chain transfer (RAFT) polymerization of (meth)acrylates is developed with 2-cyano-2-propyldodecyl trithiocarbonate (TTP), which plays the dual role as photoinitiator and chain transfer agent. The polymerizations can be efficiently activated by blue light while maintaining a linear increase in M n versus conversion. With poly(methyl methacrylate)-TTP (PMMA-TTP, M n = 6700 g mol –1 , Ð = 1.29) as precursor, a higher molecular weight PMMA ( M n = 14 600 g mol –1 , Ð = 1.67) by chain extension, and a series of block copolymers, including poly(methyl methacryalte)- b -poly(glycidyl methacrylate), poly(methyl methacrylate)- b -poly(tert-butyl methacrylate), and poly(methyl methacrylate)- b -poly(benzyl meacrylate)(PMMA- b -PBnMA), are prepared. The M n,NMR = 14 900 g mol –1 of PMMA- b -PBnMA measured by NMR is very close to M n,GPC = 14 200 g mol –1 determined by gel permeation chromatography. Furthermore, the polymerization of acrylates exhibits higher controllability in regarding to dispersity ( Ð < 1.20) compared to those of polymethacrylates ( Ð = 1.10–1.80). With poly(methyl acrylate) (PMA-TTP, M n = 11 900 g mol –1 , Ð = 1.09) as macro-RAFT agent, a higher molecular weight PMA ( M n = 23 500 g mol –1 , Ð = 1.28) by chain extension, and PMA- b -PBnA ( M n = 26 500 g mol –1 , Ð = 1.19) are also prepared. A positive synergic effect is demonstrated by enhanced apparent polymerization rates at elevated temperature. For example, the apparent polymerization rates of MA increases from 0.0860 to 0.115 h –1 with temperature rising from 32 to 50 °C.
✓ 已验证
产品关联
DOI
高影响因子
POLYHEDRON
·
2020
·
IF 2.343
Jian-Han Zhang,Zhi-Zhong Su,Ju-Xiang Luo,Yi Zhao,Hong-Gang Wang,Shao-Ming Ying
A mixed amines thiogermanate, namely (NH 4 ) 2 [NH 2 (CH 3 ) 2 ] 2 Ge 2 S 6 has been successfully synthesized by solvothermal reaction. Single crystal X-ray diffraction indicates the compound crystallizes in monoclinic space group P 2 1 / c with the lattice parameters: a = 6.9647(14) Å, b = 15.719(3) Å, c = 7.2042(14) Å, β = 92.76(3)°. The structure features a zero-dimensional [Ge 2 S 6 ] 4− anions which are separated by NH 4 + and [NH 2 (CH 3 ) 2 ] + . Hydrogen bond interactions play a crucial role in its structure formation. X-ray powder diffraction and TG-DSC measurements were performed to study its phase purity and thermal stability. UV–Vis diffuse reflectance spectroscopy coupled with Urbach fitting indicates an indirect optical transition semiconductor with a bandgap value of 3.50 eV. The result of first-principles electronic structure calculation supported the experimental indirect optical transition but the value was under estimated as 3.061 eV. Density of states and population analysis were also calculated to reveal the origin of the bandgap and bond interaction for its structure formation.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Xiaoqin Shi,Shufeng Shen
Nonaqueous secondary alkanolamine-based systems, replacing conventional water with 2-alkoxyethanols as cosolvents, have recently attracted much attention for an energy-efficient CO 2 capture process. In this work, physical solubility of N 2 O and CO 2 in 2-(methylamino)ethanol (MAE), 2-methoxyethanol (2-ME) and their blends was measured and correlated at temperatures ranging from (283.2 to 333.2) K. Vapor-liquid equilibrium (VLE) data for the CO 2 + MAE + 2-ME system at 7.8, 19.4 and 39.1 mass% MAE were also measured in a stirred equilibrium cell at temperatures of (313.2–393.2) K and CO 2 partial pressures up to 270 kPa. VLE data were represented by a modified Kent-Eisenberg model with an AARD of 12.6%. The apparent equilibrium constants considering the liquid nonideality were well correlated as a function of temperature, concentration of carbamate product and CO 2 loading.
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2019
·Vol. 32
·期 3
·306-312
·
IF 0.791
Yu Ye-peng,Li Zhao-hui,Lin Xuan,Chen Jun,Zhang Hang,Li Yan-bo,Wang Huang-huang,Sun Rui-rui,Meng Qing-hui,Shan Xiao-bin,Liu Fu-yi,Sheng Liu-si
The photoionization and dissociation of 2-methyl-2-propen-1-ol (MPO) have been investigated by using molecular beam experimental apparatus with tunable vacuum ultraviolet synchrotron radiation in the photon energy region of 8.0–15.5 eV. The photoionization efficiency (PIE) curves for molecule ion and fragment ions: C 4 H 8 O + , C 4 H 7 O + , C 3 H 5 O + , C 4 H 7 + , C 4 H 6 + , C 4 H 5 + , C 2 H 4 O + , C 2 H 3 O + , C 3 H 6 + , C 3 H 5 + , C 3 H 3 + , CH 3 O + , CHO + have been measured, and the ionization energy (IE) and the appearance energies (AEs) of the fragment ions have been obtained. The stable species and the first order saddle points have been calculated on the CCSD(T)/cc-pvTZ//B3LYP/6-31+G(d,p) level. With com-bination of theoretical and experimental results, the dissociative photoionization pathways of 2-methyl-2-propen-1-ol are proposed. Hydrogen migrations within the molecule are the dominant processes in most of the fragmentation pathways of MPO.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2015
·
IF 2.912
Rong Wang,Xiaoyan Zhi,Jie Li,Hui Xu
To discover novel natural-product-based pesticidal agents, we prepared a series of oxime sulfonate derivatives of 2′(2′,6′)-(Di)chloropicropodophyllotoxins by structural modification of podophyllotoxin. Their structures were well-characterized by proton nuclear magnetic resonance (1H NMR), high-resolution mass spectrometry (HRMS), optical rotation, and melting point. Moreover, the key steric structure of compound 5f was unambiguously determined by single-crystal X-ray diffraction. Additionally, their insecticidal activity was evaluated at 1 mg/mL against the pre-third-instar larvae of oriental armyworm (Mythimna separata Walker), a typical lepidopteran pest. Among all derivatives, compounds 4c, 5c, and 5d exhibited more promising insecticidal activity, with the final mortality rates greater than 60%, when compared to their precursor podophyllotoxin and the positive control, toosendanin. It demonstrated that introduction of the chlorine atom at the C-2′ or C-2′,6′ position on the E ring of picropodophyllotoxin or oxime sulfonate derivatives of picropodophyllotoxin was important for the insecticidal activity and introduction of a halogen (e.g., fluorine, chlorine, or bromine) atom-substituted phenylsulfonyl group on the oxime fragment of 2′(2′,6′)-(di)chloropicropodophyllones could lead to more promising compounds.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2015
·
IF 2.999
Qingnan Wu,Ming Wen,Shipei Chen,Qingsheng Wu
Ni(OH) 2 /CNTs/Ni(OH) 2 lamellar-crossing-nanostructure with a single lamellar spacing of ∼5 nm was effectively constructed through two-phase-interface reaction process followed by the CNTs crossed among the lamellar-nanostructured Ni(OH) 2 . The resultant nanocomposite can offer large active surface areas and short diffusion paths for electrons and ions, and is investigated as a potential pseudocapacitor electrode material for electrochemical energy storage applications. Electrochemical data demonstrate that the as-prepared nanocomposite exhibits a high specific capacitance of ∼1600 F g −1 at the scan rate of 1 mV s −1 in 6 M KOH solution at normal pressure and temperature, which is great higher than Ni(OH) 2 (∼1200 F g −1 ). Furthermore, Ni(OH) 2 /CNTs/Ni(OH) 2 nanocomposite shows a higher energy density (∼125 Wh kg −1 , 2 A g −1 ) and has a slightly decrease of 5% in specific capacitance after 1000 continuous charge/discharge cycles.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Chang Shen,Xiong Tong,Jing Qi,Xian Xie,Ruiqi Xie
This study evaluates the effectiveness of mono-2-ethylhexyl-2-ethylhexyl phosphonate (PC-88A) as a novel collector for the flotation separation of cassiterite from quartz. PC-88A exhibited stronger collecting power than benzohydroxamic acid (BHA) across a wide pH range. At pH 8.0±0.2 and a PC-88A concentration of 10.0×10 - 5 mol/L, high-quality concentrates were obtained, yielding 74.61% SnO 2 grade with 95.36% recovery. Contact angle measurements indicated that PC-88A adsorption significantly enhanced the hydrophobicity of cassiterite. AFM revealed a higher adsorption density of PC-88A on cassiterite than on quartz. Zeta potential results suggested chemisorption between negatively charged PC-88A anions and cassiterite surfaces. XPS and FTIR confirmed that P=O and P-OH groups of PC-88A chemically adsorbed onto Sn sites on cassiterite, forming P-O-Sn bonds. DFT simulations identified the two oxygen atoms in the PO(OH) group as the primary reactive centers, showing high chemical activity. The selective adsorption of PC-88A is therefore attributed to chemical bonding between its PO(OH) group and Sn active sites on the cassiterite surface.
✓ 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）