JOURNAL OF LOSS PREVENTION IN THE PROCESS INDUSTRIES
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2024
·
IF 3.6
Dongyan Yang,Lei Ni,Luping Gu,Qiang Chen,Juncheng Jiang,Jimi Su
Thermal runaway accounts for a high proportion of chemical safety accidents and poses a serious threat to the operational safety of personnel. Phase change materials (PCMs) have a high enthalpy of melting, if the latent heat energy of their phase change can be stored and used to absorb the heat released during thermal runaway, this phenomenon can provide a new approach for the control of reaction thermal runaway. In this work, microencapsulated phase change materials (microPCMs) were prepared by the suspension polymerization method using n -octadecane as the core material and polystyrene (PS) as the shell material. The prepared microPCMs had regular spherical morphologies with smooth surfaces, and the average particle size was 7.54 μm, the thermal conductivity was 0.05964 W/m∙K. The melting enthalpy of the microPCMs was 142.2 J/g, and the encapsulation percentage of the PCMs was 62.15%. The synthesis of the n -butylmagnesium bromide Grignard reagent occurred via a strong exothermic reaction, which was very likely to lead to overpressure venting once control was lost. The prepared microPCMs were applied as inhibitors in this reaction to investigate the temperature control effect under different operating conditions. The results showed that the amount of microPCMs added, and the timing of the addition affected the control effect. The addition of microPCMs could effectively reduce the reaction temperature and slow the rate of temperature increase. Even in the event of an emergency situation, such as a control failure, time could be gained for other emergency measures, effectively reducing the probability of thermal runaway accidents.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2020
·
IF 2.888
Taotao Zhan,Yuqi Su,Ying Zhang,Xiangyang Liu,Maogang He
The mutual diffusion coefficients of ethanol + n-heptane and diethyl carbonate (DEC) + n-heptane binary solutions were measured over the mass fraction from 0.05 to 0.95 at the pressure of 0.101 MPa, and at temperatures T = 288.15 K, 298.15 K, 308.15 K and 318.15 K. The expanded relative uncertainty ( k = 2) of the Mach-Zehnder digital holographic interferometry employed in the measurements was estimated to be less than 2.4% with the confidence level of 0.95. A semi-empirical correlation was used to fit the mutual diffusion coefficients as a function of concentration and temperature, which represents the experimental values with the absolute average relative deviations being 0.94% for ethanol + n-heptane and 0.90% for DEC + n-heptane. The temperature and concentration dependences of the mutual diffusion coefficients were investigated. The strongest non-ideal thermodynamic behaviors appear when the mass fraction of ethanol is within the limits of 0.45 to 0.65 or that of DEC is within the limits of 0.45 to 0.65. Besides, the mutual diffusion coefficients of ethanol + n-heptane and DEC + n-heptane binary solutions are found to be extremely sensitive to the solute concentration over the mass fraction of ethanol and DEC from 0.00 to 0.05, respectively.
研究领域:
物理化学
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热力学
✓ 已验证
DOI
高影响因子
POLYMER TESTING
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2017
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IF 2.464
Chandra Sekhar Biswas,Qiao Wang,Bing Du,Florian J. Stadler
Random copolymer gels of N -isopropylacrylamide (NIPAM) and N -ethylacrylamide (NEAM) were synthesized in using different monomer compositions in 1:1 methanol-water mixtures and in pure water. The samples were characterized by cononsolvency study in methanol-water mixtures at various temperatures by swelling ratio measurements. It is observed that with the variation of the temperature and monomer compositions in the synthesis reaction mixture, the cononsolvency properties varied significantly. But the variation in the solvents compositions by keeping monomer compositions fixed does not affect the cononsolvency much. All results can be explained on the basis of the differences in thermoresponsive character or difference in the hydrophilicity of PNIPAM and PNEAM in water, preferential adsorption of the solvents by polymer networks , solvent-solvent interactions, heterogeneity of the polymer networks synthesized at different solvent compositions and at different temperatures, difference in their morphological properties, etc.
研究领域:
高分子化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
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2018
·
IF 0.668
Can Jin,Feng Wang,Bin Sun,Xiaohui Zhuang
A novel method for the preparation of N-chloroaldimines from commonly available aromatic aldehydes has been developed. The reaction proceeded effectively by two steps: aldehydes were initially transformed into imines and then chloro-substitution with NaClO2 gave the N-chloroaldimines. This simple protocol allows for the preparation of a variety of aromatic N-chloroaldimines in moderate to excellent yields without the isolation of the imine intermediate. We also found that 3-nitrobenzaldehyde and 4-cyanobenzaldehyde were converted into the related benzonitrile directly under the standard conditions.
研究领域:
有机化学
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合成化学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 23
·7208-7218
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IF 6.177
Wenjing Song,Yujie Wan,Yuefeng Li,Xin Luo,Weiping Fang,Quanxing Zheng,Pengfei Ma,Jianping Zhang,Weikun Lai
Low cost and high efficiency catalysts for the reductive amination of carbonyl compounds are critical to the utilization of renewable biomass. In this paper, a highly efficient N-doped porous carbon supported Ni catalyst was prepared by a template-assisted pyrolysis and impregnation method. In the presence of NH3 and H2, the as-prepared catalyst could effectively catalyze the reductive amination of various carbonyl compounds into corresponding primary amines with high yield and excellent stability. Comprehensive characterization demonstrated that the reductive amination of furfural towards furfuryl amine was linked to the formation of Ni–Nx sites and the electronic interaction of N and Ni species on the N-doped carbon surface, which promoted the reductive amination of CO bonds and significantly reduced the activation energy in reductive ammonolysis of trimers and Schiff base intermediates. This work provided a new insight into rational design of reductive amination catalysts for primary amine production.
研究领域:
催化化学
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可再生资源利用
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DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
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2024
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IF 2.4
Chen Mao,Chen Buxin,Jiang Yang,Zheng Kui,Hu Meilong,Qiu Shuxing
Ti(C,N) is commonly observed in vanadium titanomagnetite blast furnaces and greatly affects the stable and smooth operation of the smelting processes. To get fundamental insight into Ti(C, N) formation, systematic experiments were conducted to investigate the effects of the composition of slags, temperatures, reaction time and reaction atmosphere on the formation of Ti(C,N) from TiO 2 -containing slags. The results show that TiN and TiC contents increase with TiO 2 content increases. When TiO 2 is larger than 30 wt pct, TiN contents increase dramatically. Control of basicity, MgO and Al 2 O 3 concentrations in the slag could help to reduce Ti(C,N) contents in slags. TiN and Ti(C,N) contents increase dramatically with the extension of time. TiN is more easily formed at high temperatures, and TiN contents increase with the increase of temperature. With the increase of N 2 contents, TiC contents are relatively stable, and TiN and Ti(C,N) contents increase almost linearly. H 2 would greatly promote the formation of TiC. This paper can provide a theoretical basis for minimizing the formation of Ti(C,N) in different blast furnace conditions.
研究领域:
冶金学
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材料科学
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产品关联
DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2025
·
IF 3.8
Xie Baogang,Zhan Dujuan,Wu Le,Wang Lele,Lei Yongrong,Liu Meng,Liu Xiaodan,Li Suping
Congenital heart disease (CHD) poses significant clinical challenges due to limitations in early prenatal diagnosis. This study aimed to identify serum metabolic biomarkers for CHD using a combined metabolomics approach. Serum samples from 55 pregnant women carrying fetuses with confirmed CHD (CHDP group) and 49 healthy controls (ZCP group) were analyzed via non-targeted 1 HNMR metabolomics, revealing distinct metabolic profiles. Six choline pathway metabolites were further quantified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Among these, N,N-dimethylglycine (DMG) exhibited the most significant reduction in the CHDP group (1.07 ± 0.03 vs. 1.55 ± 0.04 µg/mL, p < 0.001), with an area under the ROC curve (AUROC) of 0.883 in the discovery cohort. Validation in an independent cohort (58 CHDP vs. 62 ZCP) confirmed DMG’s diagnostic potential (AUROC = 0.818). While betaine-homocysteine methyltransferase 2 (BHMT2) activity showed no intergroup differences, DMG’s consistent performance highlights its utility as a non-invasive biomarker. This study underscores the clinical value of metabonomics in prenatal CHD screening and establishes DMG as a promising diagnostic marker, potentially improving early detection and perinatal management. Graphical abstract
研究领域:
代谢组学
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儿科心脏病学
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产前诊断
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生物医学研究
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysts
·
2022
·Vol. 12
·期 10
·1278
·
IF 4.501
Ying Wang,Huilin Xie,Kunming Liu,Jinhui Li,Jin-Biao Liu
Herein, we report a copper-catalyzed C-O cross-coupling of N-methoxy amides and arylboronic acids for the synthesis of aryl-N-methoxy arylimides. The fully selective O-arylation of the N-methoxy amides is found to be greatly prompted by the inexpensive and commercially available CuI. The reaction conditions tolerate a variety of functional groups and promote different reactivities depending on the electronic and steric properties of the distorted substrates.Keywords:copper catalyzed;N-methoxy amides;selective C-O cross-coupling;aryl-N-methoxy arylimides
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
POLYMER BULLETIN
·
2019
·Vol. 77
·期 2
·963-974
·
IF 1.858
Yang Xu,Sun Zhaojie,Gao Jingru,Yang Chunhui,Tang Dongyan
Temperature-responsive films of poly( N -isopropylacrylamide) (PNIPAM) were facilely fabricated by one-step plasma-initiated polymerization and then functionalized by self-polymerization of dopamine on the surface. High retention of the monomer structure and temperature-responsive properties in PNIPAM films were confirmed. After plasma-initiated polymerization, PNIPAM films formed protrusions and ridges surfaces. Moreover, cross-linker of N , N ′-methylenebisacrylamide with different dosage was introduced into the systems to effectively modulate the roughness of PNIPAM films and to supply better adhesive surface. Furthermore, in cell culture, satisfactory survival rate of the attached Hela cells was obtained on PNIPAM films, and the cell viability was improved further on PNIPAM/PDA films. The results indicated that such films might be applicable in medical treatment and tissue engineering, due to their adjusted adhesion ability and less toxicity to cells.
研究领域:
材料科学
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生物材料
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细胞生物学
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组织工程
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2014
·
IF 5.825
Jing Li,Laizhong Chen,Wenxiao Wu,Wei Zhang,Zhao Ma,Yanna Cheng,Lupei Du,Minyong Li
To find an approach that can image the hydrolysis activity of aminopeptidase N (APN) both in vitro and in vivo, three bioluminescent probes have been well designed and synthesized herein. All of them can be recognized and hydrolyzed by APN to produce bioluminescence emission in the presence of firefly luciferase. To the best of our knowledge, they are the first bioluminescent probes for imaging APN in deep tissues and living animals.
研究领域:
生物化学
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分子影像学
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医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF BIOACTIVE AND COMPATIBLE POLYMERS
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2013
·
IF 2.207
Feng Xu,Ting-Ting Yan,Yan-Ling Luo
Novel amphiphilic block copolymers consisting of hydrophobic poly(D,L-lactide) segments and hydrophilic poly(N-isopropylacrylamide-co-N, N-dimethylacrylamide) blocks were designed and synthesized through a simple free radical copolymerization route based on a bifunctional initiator, followed by the ring-opening polymerization of D,L-lactide. The copolymers self-assembled into thermosensitive spherical-nanosized core–shell micelles in aqueous solution in the presence or the absence of the model drug prednisone. The chemical and physical characterizations of drug-loaded and unloaded micelles revealed a lower critical solution temperature of 40°C–47°C, and a critical micelle concentration less than 7.20 mg L−1, a transmission electron microscope mean particle size from 50 to 75 nm, and a narrow dynamic light scattering diameter below 180 nm. The prepared blank and drug-loaded micellar nanoparticles were thermodynamically stabile and employed in targeted drug delivery by responding to the higher temperature of the local microenvironment. Based on prednisone release kinetic studies, structural changes of the self-assembled micelles as well as temperature- or environment-induced diffusion controlled drug release and improved bioavailability. The copolymer micelles exhibited good biocompatibility as established by the MTT cytotoxicity assay. Therefore, an effective target therapy against lesion tissues is feasible using these polymeric micelles.
研究领域:
材料科学
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生物医学工程
·
药学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2018
·
IF 4.513
Shuai Zhang,Long Zhao,Xiaoqing Yue,Bin Li,Jianbin Zhang
Density ( ρ ), viscosity ( η ) and surface tension ( γ ) are always significant physicochemical properties for liquid mixtures. In this work, the ρ , η and γ data for the liquid mixture of tetraethylene glycol (T 4 EG) + N , N -dimethylformamide (DMF) were systemically measured from 293.15 to 318.15 K with a step of 5 K and p = 0.1 MPa. From these physicochemical properties, viscosity deviation ( ∆η ), excess molar volume ( V m E ), and surface tension deviation (∆ γ ) were calculated. Meanwhile, V m E , ∆η and ∆ γ of activation functions were fitted with Redlich-Kister (R-K) equation to evaluate the coefficients and standard deviations. The η values of the liquid mixtures were fitted with Grunberg and Nissan equation and three-body McAllister expression. UV–vis and FTIR spectra were measured to discuss the intermolecular interaction of T 4 EG with DMF, which indicated that there was hydrogen bonds interaction between hydroxyl hydrogen atoms in T 4 EG and oxygen atoms in DMF.
研究领域:
物理化学
·
分子相互作用
✓ 已验证
产品关联
DOI
高影响因子