RESUMEN
A transition away from coal power always maintains a high level of complexity as there are several overlapping considerations such as technical feasibility, economic costs, and environmental and health impacts. Here, we explore the cost-effectiveness uncertainty brought by policy implementation disturbances of different coal power phaseout and new-built strategies (i.e., the disruption of phaseout priority) in China based on a developed unit-level uncertainty assessment framework. We reveal the opportunity and risk of coal transition decisions by employing preference analysis. We find that, the uncertainty of a policy implementation might lead to potential delays in yielding the initial positive annual net benefits. For example, a delay of six years might occur when implementing the prior phaseout practice. A certain level of risk remains in the implementation of the phaseout policy, as not all strategies can guarantee the cumulative positive net benefits from 2018-2060. Since the unit-level heterogeneities shape diverse orientation of the phaseout, the decision-making preferences would remarkably alter the selection of a coal power transition strategy. More strikingly, the cost-effectiveness uncertainty might lead to missed opportunities in identifying an optimal strategy. Our results highlight the importance of minimizing the policy implementation disturbance, which helps mitigate the risk of negative benefits and strengthen the practicality of phaseout decisions.
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Daily emission estimates are essential for tracking the dynamic changes in emission sources. In this work, we estimate daily emissions of coal-fired power plants in China during 2017-2020 by combining information from the unit-based China coal-fired Power plant Emissions Database (CPED) and real-time measurements from continuous emission monitoring systems (CEMS). We develop a step-by-step method to screen outliers and impute missing values for data from CEMS. Then, plant-level daily profiles of flue gas volume and emissions obtained from CEMS are coupled with annual emissions from CPED to derive daily emissions. Reasonable agreement is found between emission variations and available statistics (i.e., monthly power generation and daily coal consumption). Daily power emissions are in the range of 6267-12,994, 0.4-1.3, 6.5-12.0, and 2.5-6.8 Gg for CO2, PM2.5, NO x , and SO2, respectively, with high emissions in winter and summer caused by heating and cooling demand. Our estimates can capture sudden decreases (e.g., those associated with COVID-19 lockdowns and short-term emission controls) or increases (e.g., those related to a drought) in daily power emissions during typical socioeconomic events. We also find that weekly patterns from CEMS exhibit no obvious weekend effect compared to those in previous studies. The daily power emissions will help to improve chemical transport modeling and facilitate policy formulation.
RESUMEN
The development of multifarious stationary phases is still a growing demand so as to solve the tasks of ever evolving actual applications. Herein, with D-2-allylglycine hydrochloride (AG·HCl) as the hydrophilic monomer, diene ionic liquid 1-allyl-3-vinylimidazolium bromide (AVI·Br) and polyhedral oligomeric silsesquioxane methacryl substituted (POSS-MA) as the dual crosslinkers, the highly cross-linked imidazolium-bridged POSS-AVI-AG hybrid monolithic column was fabricated via the "one-pot" free radical copolymerization. The AG·HCl embedded POSS-AVI-AG column displays typical reversed-phase liquid chromatography/hydrophilic interaction liquid chromatography mixed-mode retention mechanisms. Both hydrophobic phenols, alkylbenzenes, aromatic amines and hydrophilic nucleosides/nucleic acid bases, amides and thioureas were successfully separated with high column efficiencies (up to 571,000 plates/m for amides), outperforming our previously reported AVI·Br modified POSS-AVI column. Moreover, the column was also explored for the separation of cytochrome c tryptic digests and egg white protein extraction. All these results demonstrate that the POSS-AVI-AG column has a good potential in separation of both small molecules and complex biological samples with multiple mechanisms.
Asunto(s)
Alilglicina/química , Imidazoles/química , Sustancias Macromoleculares/aislamiento & purificación , Compuestos de Organosilicio/química , Citocromos c/aislamiento & purificación , Nucleósidos/aislamiento & purificación , Péptidos/aislamiento & purificación , Polimerizacion , Proteínas/aislamiento & purificaciónRESUMEN
A novel compound containing active amine groups of polyphosphazene (PBFA) was successfully synthesized and applied as a reactive flame-retardant additive in epoxy (EP) resin. It was synthesized from N-aminoethylpiperazine and hexachlorocyclotriphosphazene using a simple method, and its structure was well-characterized. The results indicated that introducing PBFA into EP composites significantly improves the resistance to fire and suppresses smoke generation. An EP composite with 9.0 wt% PBFA can pass the vertical burning tests V-0 rating, the peak heat release rate and total heat release of the sample decreased by 46.7% and 29.3%, respectively. Moreover, it decreased the total smoke release by 48.0%. Thermogravimetric analysis showed that the presence of PBFA can accelerate EP decomposition at comparatively low temperatures and lead to the formation of a stable char layer, which protects the matrix from fire, therefore improving the amount of char residue at 800 °C. The degree of small molecule degradation characterized by gas chromatograph/mass spectrometer, which was lower than that of pure EP, demonstrating that PBFA reduces the risk of fire. The glass transition temperature of EP composites increased with the amount of PBFA increasing owing to the presence of active amine groups. Notably, its mechanical properties were not degraded.
RESUMEN
A novel periodic imidazolium-bridged hybrid monolithic column was developed. With diene imidazolium ionic liquid 1-allyl-3-vinylimidazolium bromide as both cross-linker and organic functionalized reagent, a new periodic imidazolium-bridged hybrid monolithic column was facilely prepared in capillary with homogeneously distributed cationic imidazolium by a one-step free-radical polymerization with polyhedral oligomeric silsesquioxane methacryl substituted. The successful preparation of the new column was verified by Fourier transform infrared spectroscopy, scanning electron microscopy, elemental analysis, and surface area analysis. Most interestingly, the bonded amount of 1-allyl-3-vinylimidazolium bromide of the new column is three times higher than that of the conventional imidazolium-embedded hybrid monolithic column and the specific surface area of the column reached 478 m2 /g. The new column exhibited high stability, excellent separation efficiency, and enhanced separation selectivity. The column efficiency reached 151 000 plates/m for alkylbenzenes. Furthermore, the new column was successfully used for separation of highly polar nucleosides and nucleic acid bases with pure water as mobile phase and even bovine serum albumin tryptic digest. All these results demonstrate the periodic imidazolium-bridged hybrid monolithic column is a good separation media and can be used for chromatographic separation of small molecules and complex biological samples with high efficiency.
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Cromatografía Liquida , Imidazoles/química , Nucleósidos/aislamiento & purificación , Compuestos de Vinilo/química , Radicales Libres , Microscopía Electrónica de Rastreo , Polimerizacion , Albúmina Sérica Bovina/químicaRESUMEN
A novel imidazolium-embedded N,N-dimethylaminopropyl-functionalized silica-based stationary phase (Sil-ImCl) was prepared and further used for hydrophilic interaction/reversed-phase mixed-mode chromatography. The Sil-ImCl stationary phase was respectively characterized by Fourier transform infrared spectrometry, thermogravimetric analysis, and element analysis. A variety of hydrophilic or hydrophobic compounds were used to evaluate the retention mechanisms of the developed stationary phase, and the effects of buffer salt concentration and pH of mobile phase on the retention of these compounds were also investigated. The developed stationary phase was successfully applied for separation of nucleosides and nucleic acid bases, water-soluble vitamins, phenols, and positional isomers. Moreover, simultaneous separation of polar and nonpolar compounds was also achieved with high resolution, outperforming the commercially available C8 column and amino column. Furthermore, the Sil-ImCl stationary phase has been successfully applied for separation of secondary metabolites of Hansfordia sinuosae. All these results demonstrate that the Sil-ImCl stationary phase might be promising for separation of complex polar and nonpolar compounds with high efficiency, especially in biological industry.
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Cromatografía de Fase Inversa/instrumentación , Dióxido de Silicio/química , Cromatografía de Fase Inversa/métodos , Interacciones Hidrofóbicas e Hidrofílicas , Isomerismo , Ácidos Nucleicos/química , Ácidos Nucleicos/aislamiento & purificación , Nucleósidos/química , Nucleósidos/aislamiento & purificaciónRESUMEN
A new imidazolium embedded C8 based stationary phase (SIL-MPS-VOL) was facilely prepared by two steps and characterized by Fourier transform infrared spectrometry and thermogravimetric analysis. Due to the introduction of quaternary imidazolium group to the traditional C8 stationary phase, the developed SIL-MPS-VOL column demonstrated both reversed-phase liquid chromatography (RPLC) and hydrophilic interaction liquid chromatography (HILIC) retention mechanisms. A series of hydrophobic and hydrophilic test samples, including benzene homologues, anilines, positional isomers, nucleosides and nucleotides, were used to evaluate the developed SIL-MPS-VOL stationary phase. A rapid separation time, high separation efficiency and planar selectivity were achieved, compared with the commercially available C8 column. Moreover, the developed stationary phase was further used to detect and separate of melamine in powdered infant formula and high polar component of secondary metabolites of Trichoderma, and improved separation efficiency was achieved, indicating the potential merits of the developed SIL-MPS-VOL stationary phase for simultaneous separation of complex hydrophobic and hydrophilic samples with high selectivity.
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Técnicas de Química Analítica/métodos , Cromatografía Liquida , Cromatografía de Fase Inversa , Compuestos de Anilina/análisis , Análisis de los Alimentos , Interacciones Hidrofóbicas e Hidrofílicas , Nucleósidos/químicaRESUMEN
Ten novel palladium(II) complexes with dipyrido[3,2-d:2',3'-f]quinoxaline (Dpq)/dipyrido[3,2-a:2',3'-c](6,7,8,9-tetrahydro)phenazine (Dpqc) and 4-toluensulfonyl-L-amino acid dianion, [Pd(Dpq)(TsvalNO)]·H2O (1a), [Pd(Dpq)(TsileNO)]·H2O (1b), [Pd(Dpq)(TsserNO)] (1c), [Pd(Dpq)(TsthrNO)]·1.5H2O (1d), [Pd(Dpq)(TsleuNO)]·0.5H2O (1e), [Pd(Dpq)(TspheNO)] (1f), [Pd(Dpqc)(TsvalNO)] (2a), [Pd(Dpqc)(TsileNO)] (2b), [Pd(Dpqc)(TsserNO)]·H2O (2c) and [Pd(Dpqc)(TsthrNO)]·0.5H2O (2d) have been synthesized and characterized by elemental analysis, IR, UV, (1)H NMR and mass spectrometry techniques. Crystal structure of the complex 1f has been determined by X-ray diffraction. The cytotoxicity was tested by MTT assay. The results indicated that the complexes 1a and 2a showed better cytotoxicity than cisplatin against MCF-7. The complex 1e had higher cytotoxicity than cisplatin against K562. Both the N donating ligands and the amino acid have important effects on the cytotoxicity.
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Aminoácidos/química , Ensayos de Selección de Medicamentos Antitumorales , Paladio/química , Fenazinas/síntesis química , Fenazinas/farmacología , Quinoxalinas/síntesis química , Quinoxalinas/farmacología , Tolueno/química , Línea Celular Tumoral , Humanos , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Fenazinas/química , Quinoxalinas/química , Espectrometría de Masa por Ionización de ElectrosprayRESUMEN
Chemical derivatization is a very promising technique for improving analysis of peptides by mass spectrometry (MS). Thereinto, development of novel tags compatible with MS and/or MS/MS has always been the focus point of study. In this review, the recent reported tags for derivatization of thiol groups of cysteine, carboxyl groups, and amino groups on peptides as well as peptides with post-translational modifications (PTMs) are summarized. Moreover, the tags used for derivatization of glycans or oligosaccharides released from glycoproteins are also reviewed.
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Glicoproteínas/análisis , Péptidos/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Cisteína/química , Cisteína/metabolismo , Glicoproteínas/química , Glicoproteínas/metabolismo , Estructura Molecular , Oligosacáridos/química , Oligosacáridos/metabolismo , Péptidos/química , Péptidos/metabolismo , Polisacáridos/química , Polisacáridos/metabolismo , Procesamiento Proteico-Postraduccional , Reproducibilidad de los ResultadosRESUMEN
A simple and rapid micellar electrokinetic chromatography method was developed for simultaneous determination of indole-3-acetic acid, indole-3-butyric acid, gibberellic acid, abscisic acid and naphthylacetic acid in mungbean sprouts for monitoring plant growth and development. The effects of several parameters related to the separation and determination were investigated in detail. The analysis was carried out using 10 mM borax, 10 mM sodium dihydrogen phosphate, 90 mM sodium dodecyl sulfate and 5% acetonitrile as running buffer (pH 9.0). Under optimum conditions, the method demonstrated good performance concerning linearity (r, 0.9954-0.9991), precision (0.77-4.97%), the method limit of detection (LOD) and the method limit of quantitation (LOQ) (LOD, 0.011-0.177 mg/kg; LOQ, 0.035-0.590 mg/kg) and accuracy (83.62-102.56%). The results confirmed that the method is rapid, convenient and of low cost for the determination of the phytohormones.
RESUMEN
Pd(II), Cu(II) and Zn(II) complexes (1-3) based on 4'-(4-(2-(piperidin-1-yl)ethoxy)phenyl)-2,2':6',2â³-terpyridine were synthesized and characterized by UV, IR, NMR, EPR, HRMS, elemental analyses, and molar conductivity measurements. The cytotoxicity of these complexes against HL-60, BGC-823, KB, Bel-7402, A549, Hela, K562 and MCF-7 cell lines in vitro was measured by MTT method. The DNA binding property of the complexes was evaluated by UV, fluorescence, CD spectroscopies and thermal denaturation. The cytotoxicity of complexes 1 and 3 against all the tested cell lines is better than that of cisplatin. Complexes 1 and 2 exhibit 7- and 4-folds higher cytotoxicity than cisplatin against Bel-7402 cell line. Complex 3 displays the highest cytotoxicity against all the cell lines tested, and shows 7-, 14-, 8-, 11- and 8-folds higher cytotoxicity than cisplatin against Bel-7402, A549, Hela, K562 and MCF-7 cell lines. The complexes bind to DNA via intercalation mode and complex 3 stabilizes the G-quadruplex. The results reveal that all the complexes display high cytotoxicity against all the tested cancer cell lines, and complex 3 is selective for G-quadruplex over duplex DNA.
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Antineoplásicos/farmacología , Cobre/química , ADN de Neoplasias/efectos de los fármacos , Compuestos Organometálicos/farmacología , Paladio/química , Piperidinas/química , Piridinas/química , Zinc/química , Antineoplásicos/síntesis química , Antineoplásicos/química , Sitios de Unión/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , ADN de Neoplasias/química , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Células HL-60 , Células HeLa , Humanos , Células K562 , Células KB , Células MCF-7 , Estructura Molecular , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/química , Relación Estructura-ActividadRESUMEN
A series of phenanthrene imidazole with polyglycol side chain (2a-2c and 3a-3c) were synthesized and characterized by IR, NMR and MS. The cytotoxicity of 2a-2c and 3a-3c against cancer cell lines (HL-60, BGC-823, Bel-7402 and KB) in vitro were measured using MTT method. The DNA binding properties of 3a-3c were investigated by UV, fluorescence, CD spectroscopies and thermal denaturation. The results indicate that 2a exhibits higher cytotoxicity than cisplatin against BGC-823 and Bel-7402 cell lines, 3b and 3c exhibit higher cytotoxicity than 2b and 2c against BGC-823, Bel-7402 and KB cell lines. The cytotoxic effect of 2a-2c decrease with the increase of side chains length, the cytotoxic effect of 3a-3c increased with the increasing length of side chains against BGC-823, Bel-7402 and KB cell lines. Compounds 3a-3c intercalated DNA with a vertical orientation in the intercalation pocket. The binding constants of 3a-3c with Ct-DNA are 1.68×10(6), 1.51×10(6) and 0.709×10(6)M(-1), respectively. The binding affinity of 3a-3c with Ct-DNA trended to decrease with the increasing length of polyglycol side chains.
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Antineoplásicos/química , Antineoplásicos/farmacología , ADN/metabolismo , Imidazoles/química , Imidazoles/farmacología , Fenantrenos/química , Fenantrenos/farmacología , Línea Celular Tumoral , Glicoles/química , Glicoles/farmacología , Humanos , Sustancias Intercalantes/química , Sustancias Intercalantes/farmacología , Neoplasias/tratamiento farmacológicoRESUMEN
A simple and rapid ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) coupled with liquid chromatography-ultraviolet detection (LC-UV) was developed for the determination of four fluoroquinolones (ofloxacin, norfloxacin, enrofloxacin, and lomefloxacin) in pharmaceutical wastewater samples. Various parameters affecting the extraction efficiency including type and volume of extraction and dispersive solvents, sample pH, and extraction time were investigated. Good linear relationships were obtained for all analytes in a range of 0.01-2.0 µg/ml with LODs ranged from 0.14 to 0.81 µg/l. Average recoveries at three spiking levels were over the range of 82.7-110.9% with RSD less than 5.2% (n=3). Under the optimized conditions the enrichment factors for the four fluoroquinolones were ranged from 32 to 134 folds. The presented method was applied for the determination of four fluoroquinolones in pharmaceutical wastewater samples.