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医院中子照射器I型堆 5

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A highly efficient methodology for the preparation of

Yongxin Zhang, Shucheng Wang, Yaodong Huang

《化学科学与工程前沿（英文）》 2021年第15卷第3期页码 679-686 doi: 10.1007/s11705-020-1979-9

摘要： A convenient and highly efficient method is described for the synthesis of -methoxycarbazole derivatives, including those with sterically demanding, benzannulated, or strongly electron-donating or -withdrawing substituents. Various -methoxycarbazole derivatives were directly prepared in good-to-moderate yields by the Pd (dba) CHCl /9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene-catalyzed reactions of the corresponding dibromobiphenyl compounds and methoxya-mine. Based on this methodology, the first total synthesis of 3,3′-[oxybis(methylene)]bis(9-methoxy-9 -carbazole), an antimicrobial dimeric carbazole alkaloid previously isolated from the stem bark of , was achieved in 18% yield over seven steps from 1,2-dibromobenzene.

关键词： N-methoxyl carbazole dimeric N-methoxyl carbazole alkaloid total synthesis double N-arylation of methoxyamine

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Inhibition of NO emission by adding antioxidant mixture in

A. PRABU,R. B. ANAND

《能源前沿（英文）》 2015年第9卷第2期页码 238-245 doi: 10.1007/s11708-015-0356-8

摘要： In this paper, the effect of adding an antioxidant mixture in biodiesel as fuel, in a single cylinder, direct injection compression ignition engine was experimentally investigated and the level of pollutants in the exhaust and performance characteristics of the engine were analyzed. Nine test fuels were prepared with three antioxidants, namely, Succinimide (C H NO ), , dimethyl- -phenylenediamine-dihydrochloride (C H Cl N ), and -phenyl- -phenylenediamine (C H NHC H NH ) added to neat biodiesel at 500 parts per million (ppm), 1000 ppm and 2000 ppm and the observed experimental results were compared with those of neat biodiesel and neat diesel as base fuels. The comparison showed that NO emission was reduced drastically for the test fuels with the antioxidant addition of 2000 ppm. The maximum reduction of 10% of NO emission was observed for the antioxidant mixture in neat biodiesel, with a slight increase in unburned HC, CO and smoke opacity. In addition, the obtained experimental results reveal that the addition of two antioxidants as mixture in neat biodiesel caused improved NO emission reduction for all test fuels.

关键词： NO emission antioxidants Succinimide N N-dimethyl-p-phenylenediamine-dihydrochloride N-phenyl-p-phenylenediamine

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Thermogravimetric kinetic analysis of

SUKARNI,SUDJITO,Nurkholis HAMIDI,Uun YANUHAR,I.N.G. WARDANA

《能源前沿（英文）》 2015年第9卷第2期页码 125-133 doi: 10.1007/s11708-015-0346-x

摘要： The thermal behavior of combustion in air atmosphere were investigated by performing experiments on STA PT1600 Thermal Analyzer at heating rates of 10°C/min, 40°C/min and 70°C/min and range of temperatures from room temperature to 1200°C. The kinetic parameters were evaluated by using Kissinger and Ozawa methods. The result showed that combustion occurred in five stages. Started with initial devolatilization, the main thermal decomposition and combustion process, transition stage, the combustion of char and the last stage was the slow burning reaction of residual char. In line with increasing heating rate, the mass loss rate increased as well, but it delayed the thermal decomposition processes toward higher temperatures. The average activation energy at the main thermal decomposition stage and the stage of char combustion were approximately 251 kJ/mol and 178 kJ/mol, respectively.

关键词： Nannochloropsis oculata combustion kinetic parameters air atmosphere thermogravimetric

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Ni>-Positive ion activated rapid addition and mitochondrial targeting ratiometric fluorescent probesfor in vivoi> cell H₂S imaging

Yan Shi, Fangjun Huo, Yongkang Yue, Caixia Yin

《化学科学与工程前沿（英文）》 2022年第16卷第1期页码 64-71 doi: 10.1007/s11705-021-2048-8

摘要： Heterocyclic compound quinoline and its derivatives exist in natural compounds and have a broad spectrum of biological activity. They play an important role in the design of new structural entities for medical applications. Similarly, indoles and their derivatives are found widely in nature. Amino acids, alkaloids and auxin are all derivatives of indoles, as are dyes, and their condensation with aldehydes makes it easy to construct reaction sites for nucleophilic addition agents. In this work, we combine these two groups organically to construct a rapid response site (within 30 s) for H S, and at the same time, a ratiometric fluorescence response is presented throughout the process of H S detection. As such, the lower detection limit can reach 55.7 nmol/L for H S. In addition, cell imaging shows that this probe can be used for the mitochondrial targeted detection of endogenous and exogenous H S. Finally, this probe application was verified by imaging H S in nude mice.

关键词： heterocyclic compound hydrogen sulfide ratiometric mitochondrial targeted

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Accounting for the uncertainties in the estimation of average shear wave velocity using – correlations

《结构与土木工程前沿（英文）》 2021年第15卷第5期页码 1199-1208 doi: 10.1007/s11709-021-0749-1

摘要： Site-specific seismic hazard analysis is crucial for designing earthquake resistance structures, particularly in seismically active regions. Shear wave velocity ( V _S) is a key parameter in such analysis, although the economy and other factors restrict its direct field measurement in many cases. Various V _S–SPT– N correlations are routinely incorporated in seismic hazard analysis to estimate the value of V _S. However, many uncertainties question the reliability of these estimated V _S values. This paper comes up with a statistical approach to take care of such uncertainties involved in V _S calculations. The measured SPT– N values from all the critical boreholes were converted into statistical parameters and passed through various correlations to estimate V _S at different depths. The effect of different soil layers in the boreholes on the Vs estimation was also taken into account. Further, the average shear wave velocity of the top 30 m soil cover ( V _S30) is estimated after accounting for various epistemic and aleatoric uncertainties. The scattering nature of the V _S values estimated using different V _S– N correlations was reduced significantly with the application of the methodology. Study results further clearly demonstrated the potential of the approach to eliminate various uncertainties involved in the estimation of V _S30 using general and soil-specific correlations.

关键词： uncertainties V _S– N correlations V _S30 SPT data statistical methodology

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Hydroxyl radical intensified Cu

Wenyue Li, Min Chen, Zhaoxiang Zhong, Ming Zhou, Weihong Xing

《环境科学与工程前沿（英文）》 2020年第14卷第6期 doi: 10.1007/s11783-020-1281-6

摘要： Abstract • Cu2O NPs/H2O2 Fenton process was intensified by membrane dispersion. • DMAc removal was enhanced to 98% for initial DMAc of 14000 mg/L. • Analyzed time-resolved degradation pathway of DMAc under ·OH attack. High-concentration industrial wastewater containing N,N-dimethylacetamide (DMAc) from polymeric membrane manufacturer was degraded in Cu2O NPs/H2O2 Fenton process. In the membrane-assisted Fenton process DMAc removal rate was up to 98% with 120 min which was increased by 23% over the batch reactor. It was found that ·OH quench time was extended by 20 min and the maximum ·OH productivity was notably 88.7% higher at 40 min. The degradation reaction rate constant was enhanced by 2.2 times with membrane dispersion (k = 0.0349 min−1). DMAc initial concentration (C0) and H2O2 flux (Jp) had major influence on mass transfer and kinetics, meanwhile, membrane pore size (rp) and length (Lm) also affected the reaction rate. The intensified radical yield, fast mass transfer and nanoparticles high activity all contributed to improve pollutant degradation efficiency. Time-resolved DMAc degradation pathway was analyzed as hydroxylation, demethylation and oxidation leading to the final products of CO2, H2O and NO3− (rather than NH3 from biodegradation). Continuous process was operated in the dual-membrane configuration with in situ reaction and separation. After five cycling tests, DMAc removal was all above 95% for the initial [DMAc]0 = 14,000 mg/L in wastewater and stability of the catalyst and the membrane maintained well.

关键词： Ceramic membrane reactor N N-dimethylacetamide Fenton process Cu₂O Wastewater treatment

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grown TiN/N-TiO composite for enhanced photocatalytic H evolution activity

《能源前沿（英文）》 2021年第15卷第3期页码 721-731 doi: 10.1007/s11708-021-0766-8

摘要： Titanium nitride (TiN) decorated N-doped titania (N-TiO₂) composite (TiN/N-TiO₂) is fabricated via an in situ nitridation using a hydrothermally synthesized TiO₂ and melamine (MA) as raw materials. After the optimization of the reaction condition, the resultant TiN/N-TiO₂ composite delivers a hydrogen evolution activity of up to 703 μmol/h under the full spectrum irradiation of Xe-lamp, which is approximately 2.6 and 32.0 times more than that of TiO₂ and TiN alone, respectively. To explore the underlying photocatalytic mechanism, the crystal phase, morphology, light absorption, energy band structure, element composition, and electrochemical behavior of the composite material are characterized and analyzed. The results indicate that the superior activity is mainly caused by the in situ formation of plasmonic TiN and N-TiO₂ with intimate interface contact, which not only extends the spectral response range, but also accelerates the transfer and separation of the photoexcited hot charge carrier of TiN. The present study provides a fascinating approach to in situ forming nonmetallic plasmonic material/N-doped TiO₂ composite photocatalysts for high-efficiency water splitting.

关键词： photocatalytic H₂ evolution TiN/N-TiO₂ composite plasmonic effect in-situ nitridation

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Association between heavy metals and antibiotic-resistant human pathogens in environmental reservoirs: A review

Nguyen, Cody N. Hugie, Molly L. Kile, Tala Navab-Daneshmand

《环境科学与工程前沿（英文）》 2019年第13卷第3期 doi: 10.1007/s11783-019-1129-0

摘要：

Heavy metals can act as co-selecting agents and promote antibiotic resistance.

Most frequent resistances to heavy metals are observed for zinc and cadmium.

P. aeruginosa and E. coli are commonly resistant to heavy metals and antibiotics.

Heavy metals proliferate antibiotic resistance through co- and cross-resistance.

Heavy metal and antibiotic resistances are common near anthropogenic activities.

关键词： Zinc Cadmium Copper Lead E. coli P. aeruginosa

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Kinematical synthesis of an inversion of the double linked fourbar for morphing wing applications

AVILéS, I. FERNáNDEZ, M. ABASOLO

《机械工程前沿（英文）》 2013年第8卷第1期页码 17-32 doi: 10.1007/s11465-013-0364-5

摘要：

This paper presents the kinematical features of an inversion of the double linked fourbar for morphing wing purposes. The structure of the mechanism is obtained using structural synthesis concepts, from an initial conceptual schematic. Then, kinematic characteristics as instant center of rotation, lock positions, dead point positions and uncertainty positions are derived for this mechanism in order to face the last step, the dimensional synthesis; in this sense, two kinds of dimensional synthesis are arranged to guide the wing along two positions, and to fulfill with the second one some aerodynamic and minimum actuation energy related issues.

关键词： morphing wing structural synthesis dimensional synthesis geometrical kinematics

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Separation of

Wei Hou, Qingjun Zhang, Aiwu Zeng

《化学科学与工程前沿（英文）》 2021年第15卷第5期页码 1169-1184 doi: 10.1007/s11705-020-2018-6

摘要： In this study, vapor recompression and heat integration assisted distillation arrangements with either the low or high pressure in the reflux drum are proposed to reduce and/or eliminate the application of the costly refrigerant for the separation of -heptane and isobutanol mixture. The high-pressure arrangement with vapor recompression and heat integration is the most attractive among these four intensified configurations since it can reduce total annual cost by 18.10%, CO emissions by 75.01% based on natural gas (78.78% based on heavy oil fuel), and second-law efficiency by 61.20% compared to a conventional refrigerated distillation system. Furthermore, exergy destruction in each component is calculated for the heat integration configurations and is shown in pie diagrams. The results demonstrate that the high-pressure configuration presents unique advantages in terms of thermodynamic efficiency compared to the low-pressure case. In addition, dynamic control investigation is performed for the economically efficient arrangement and good product compositions are well controlled through a dual-point temperature control strategy with almost negligible product offsets and quick process responses when addressing 20% step changes in production rate and feed composition. Note that there are no composition measurement loops in our developed control schemes.

关键词： n-heptane/isobutanol vapor recompression heat integration low and/or high-pressure options

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Development of a simplified ni>-heptane/methane model for high-pressure direct-injection natural

Jingrui LI, Haifeng LIU, Xinlei LIU, Ying YE, Hu WANG, Xinyan WANG, Hua ZHAO, Mingfa YAO

《能源前沿（英文）》 2021年第15卷第2期页码 405-420 doi: 10.1007/s11708-021-0718-3

摘要： High-pressure direct-injection (HPDI) of natu-ral gas is one of the most promising solutions for future ship engines, in which the combustion process is mainly controlled by the chemical kinetics. However, the employment of detailed chemical models for the multi-dimensional combustion simulation is significantly expensive due to the large scale of the marine engine. In the present paper, a reduced -heptane/methane model consisting of 35-step reactions was constructed using multiple reduction approaches. Then this model was further reduced to include only 27 reactions by utilizing the HyChem (Hybrid Chemistry) method. An overall good agreement with the experimentally measured ignition delay data of both -heptane and methane for these two reduced models was achieved and reasonable predictions for the measured laminar flame speeds were obtained for the 35-step model. But the 27-step model cannot predict the laminar flame speed very well. In addition, these two reduced models were both able to reproduce the experimentally measured in-cylinder pressure and heat release rate profiles for a HPDI natural gas marine engine, the highest error of predicted combustion phase being 6.5%. However, the engine-out CO emission was over-predicted and the highest error of predicted NO emission was less than 12.9%. The predicted distributions of temperature and equivalence ratio by the 35-step and 27-step models are similar to those of the 334-step model. However, the predicted distributions of OH and CH O are significantly different from those of the 334-step model. In short, the reduced chemical kinetic models developed provide a high-efficient and dependable method to simulate the characteristics of combustion and emissions in HPDI natural gas marine engines.

关键词： high-pressure direct-injection natural gas chemical kinetics combustion modelling marine engine

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FeNi doped porous carbon as an efficient catalyst for oxygen evolution reaction

Jun-Wei Zhang, Hang Zhang, Tie-Zhen Ren, Zhong-Yong Yuan, Teresa J. Bandosz

《化学科学与工程前沿（英文）》 2021年第15卷第2期页码 279-287 doi: 10.1007/s11705-020-1965-2

摘要： Polymer-derived porous carbon was used as a support of iron and nickel species with an objective to obtain an efficient oxygen reduction reaction (OER) catalyst. The surface features were extensively characterized using X-ray diffraction, X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy. On FeNi-modified carbon the overpotential for OER was very low (280 mV) and comparable to that on noble metal catalyst IrO . The electrochemical properties have been investigated to reveal the difference between the binary alloy- and single metal-doped carbons. This work demonstrates a significant step for the development of low-cost, environmentally-friendly and highly-efficient OER catalysts.

关键词： OER polystyrene salt porous carbon FeNi alloy p/n junction

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Floret-like Fe–N nanoparticle-embedded porous carbon superstructures from a Fe-covalent triazine polymer

《化学科学与工程前沿（英文）》 2023年第17卷第5期页码 525-535 doi: 10.1007/s11705-022-2232-5

摘要： Fe–N_x nanoparticles-embedded porous carbons with a desirable superstructure have attracted immense attention as promising catalysts for electrochemical oxygen reduction reaction. Herein, we employed Fe-coordinated covalent triazine polymer for the fabrication of Fe–N_x nanoparticle-embedded porous carbon nanoflorets (Fe/N@CNFs) employing a hypersaline-confinement-conversion strategy. Presence of tailored N types within the covalent triazine polymer interwork in high proportions contributes to the generation of Fe/N coordination and subsequent Fe–N_x nanoparticles. Owing to the utilization of NaCl crystals, the resultant Fe/N@CNF-800 which was generated by pyrolysis at 800 °C showed nanoflower structure and large specific surface area, which remarkably suppressed the agglomeration of high catalytic active sites. As expect, the Fe/N@CNF-800 exhibited unexpected oxygen reduction reaction catalytic performance with an ultrahigh half-wave potential (0.89 V vs. reversible hydrogen electrode), a dominant 4e^– transfer approach and great cycle stability (> 92% after 100000 s). As a demonstration, the Fe/N-PCNF-800-assembled zinc–air battery delivered a high open circuit voltage of 1.51 V, a maximum peak power density of 164 mW·cm^–2, as well as eminent rate performance, surpassing those of commercial Pt/C. This contribution offers a valuable avenue to exploit efficient metal nanoparticles-based carbon catalysts towards energy-related electrocatalytic reactions and beyond.

关键词： Fe–N_x nanoparticles hypersaline-confinement conversion floret-like carbon covalent triazine polymers oxygen reduction reaction

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Fabrication of a superhydrophilic/underwater superoleophobic stainless steel mesh for oil/water separation with ultrahigh flux

《化学科学与工程前沿（英文）》 2023年第17卷第1期页码 46-55 doi: 10.1007/s11705-022-2170-2

摘要： Because of the increasing amount of oily wastewater produced each day, it is important to develop superhydrophilic/underwater superoleophobic oil/water separation membranes with ultrahigh flux and high separation efficiency. In this paper, a superhydrophilic/underwater superoleophobic N-isopropylacrylamide-coated stainless steel mesh was prepared through a simple and convenient graft polymerization approach. The obtained mesh was able to separate oil/water mixtures only by gravity. In addition, the mesh showed high-efficiency separation ability (99.2%) and ultrahigh flux (235239 L∙m^–2∙h^–1). Importantly, due to the complex cross-linked bilayer structure, the prepared mesh exhibited good recycling performance and chemical stability in highly saline, alkaline and acidic environments.

关键词： oil/water separation N-isopropylacrylamide stainless steel mesh ultrahigh flux