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1.
Heliyon ; 10(3): e25421, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38322844

RESUMEN

This study was conducted for four organic fractions (carbohydrates, proteins, cellulose, lipids) at an inoculum concentration of 30 % and a total solid (TS) of 8 % to investigate the effect of the main components of food waste on the performance of the two-stage anaerobic digestion. The results showed that the gas phase products were closely related to the composition of the substrate, with the carbohydrate and lipid groups showing the best hydrogen (154.91 ± 2.39mL/gVS) and methane (381.83 ± 12.691mL/gVS) production performance, respectively. However, the increased protein content predisposes the system to inhibition of gas production, which is mutually supported by changes in the activity of dehydrogenase and coenzyme F420. Butyric acid (53.19 %) dominated the liquid phase products in both stages, indicating that all four organic fractions were butyric acid-based fermentation and that the final soluble chemical oxygen demand degradation reached 72.97 %-82.86 %. The carbohydrate and cellulose groups achieved the best energy recovery performance, with conversion rates exceeding 65 %. The above results can provide a useful reference for the resource utilization of food waste.

2.
Water Sci Technol ; 86(5): 1181-1192, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-36358054

RESUMEN

To explore the effect of low temperature on the anaerobic digestion of pig manure, the anaerobic digestion experiment was carried out under the conditions of inoculum concentration of 30% and TS of 8%. Five low-temperature gradients of 4, 8, 12, 16 and 20 °C were set to study the activities of gas production, pH, solluted chemical oxygen demand (SCOD), volatile fatty acids (VFAs), coenzymes F420 and archaea community composition in the digestion process. The results were demonstrated: as the temperature decreased, the more unstable the gas production became, the less gas production produced, and the later the gas peak occurred. There were no significant peaks at either 4 °C or 8 °C, and the SCOD was unstable over time. From 12 °C, the SCOD increased over time, and the higher the temperature, the faster the growth trend. The pH was always greater than 7.6. 8, 12, 16, 20 °C had different degrees of VFAs accumulation at the late digestion stage. The higher the temperature, the greater the amount of volatile acid accumulation. When the VFAs of each reactor reached the maximum, the proportion of acetic acid also reached the highest. The digestion system of the five treatment groups was dominated by hydrogen-nutrient methanogenic pathway. The results could provide a further reference for the mechanism of anaerobic digestion of pig manure at low temperatures.


Asunto(s)
Archaea , Estiércol , Porcinos , Animales , Archaea/metabolismo , Anaerobiosis , Temperatura , Ácidos Grasos Volátiles/metabolismo , Reactores Biológicos , Metano/metabolismo
3.
Org Lett ; 14(10): 2618-21, 2012 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-22548500

RESUMEN

An efficient metal-free ortho C-H borylation has been developed via sequential borylation of substituted 2-phenoxypyridines with BBr3 following esterification with pinacol. The corresponding aryl boronates were obtained in good yields. The synthesized aryl boronates can be easily transformed into various useful products. Therefore, the present method makes functionalizations of aryl C-H bonds easy.


Asunto(s)
Compuestos de Boro/síntesis química , Paladio/química , Piridinas/química , Compuestos de Boro/química , Catálisis , Técnicas Químicas Combinatorias , Estructura Molecular
4.
Nanoscale ; 4(8): 2713-9, 2012 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-22460235

RESUMEN

We report the synthesis of a series of AAg(m)I(n) single-crystals within 24 h, at room temperature, utilizing AgI nanoparticles (NPs) as the precursor. The AgI NPs impart high reactivity under mild conditions and favor the growth kinetics. 0D, 1D and 2D iodoargentate crystals can be obtained. This work represents the first application of NPs in the field of organo-metal-halide crystals and will inspire the design of other AM(m)X(n) crystals.

5.
Langmuir ; 28(11): 5023-30, 2012 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-22429120

RESUMEN

A bolaamphiphile (5,5-B2NBr8) bearing a functional bipyridine moiety as the mesogenic core is reported for the first time. 5,5-B2NBr8 was found to self-assemble into uniform fibrous structure in aqueous solution, when the concentration was higher than cmc. Analogues of 5,5-B2NBr8 with structural differences in chain length, headgroup, mesogenic core, and substituted position were synthesized, elucidating that small variances of the molecular structure could lead to dramatic changes of the resulting assemblies. For example, compound 4,4-B2NBr8 showed only spherical colloidal aggregates rather than fibers as 5,5-B2NBr8 did, while the only difference between them was the position at which the alkyl chains were attached onto bipyridine. A probable model for the fibrous structure of 5,5-B2NBr8 was proposed. Moreover, exploiting the coordination capacity of bipyridine, assembly and disassembly of 5,5-B2NBr8 could be reversibly controlled through the addition of EDTA and Cu(II), respectively.

6.
Chemistry ; 17(24): 6765-71, 2011 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-21538622

RESUMEN

An efficient copper-catalyzed method has been developed for the synthesis of poly-N-heterocycles containing amino acid residues. The protocol uses readily available 2-halobenzamides containing amino acids and their methyl esters, substituted phenylacetonitriles, and malononitrile as the starting materials and the reactions were performed well under mild conditions. The method should provide a novel and useful strategy for synthesis of N-heterocyclic compounds.


Asunto(s)
Aminoácidos/química , Cobre/química , Compuestos Heterocíclicos/química , Compuestos Heterocíclicos/síntesis química , Hidantoínas/síntesis química , Hidrocarburos Halogenados/química , Quinolonas/síntesis química , Catálisis , Hidantoínas/química , Estructura Molecular , Quinolonas/química
8.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 1): i1, 2009 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-21579905

RESUMEN

Lanthanum zinc penta-borate, LaZnB(5)O(10), was synthesized by flux-supported solid-state reaction. It is a member of the LnMB(5)O(10) (Ln = rare earth ion and M = divalent metal ion) structure type. The crystal shows a three-dimensional structure constructed from two-dimensional {[B(5)O(10)](5-)}(n) layers with the lanthanum (coordination number nine) and zinc (coordination number six) ions filling in the inter-layers.

9.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 7): o1547, 2009 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-21582833

RESUMEN

THE TITLE COMPOUND [SYSTEMATIC NAME: 11-oxo-2,3-(oxy-dinitrilo)olean-12-en-29-oic acid], C(30)H(42)N(2)O(4), contains a linear array of five six-membered rings and a five-membered heterocyclic ring. The C ring, containing an α,ß-unsaturated ketone, has a slightly distorted half-chair conformation, as does the A ring, with N-C-C angles 125.3 (5), 111.2 (4), 124.9 (5) and 109.2 (5)°, while the other three six-membered rings adopt chair conformations. The enanti-omer has been assigned by reference to unchanging chiral centres in the synthetic procedure. An intramolecular C-H⋯O interaction is present. In the crystal structure, inter-molecular O-H⋯O hydrogen bonds link the mol-ecules.

10.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 8): o1872, 2009 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-21583566

RESUMEN

The title compound, C(37)H(50)N(2)O(3), is a benzyl ester derivative of oleanolic acid, a penta-cyclic triterpene, with a five-membered oxadiazole ring fused to the ring A. The triterpene A and C rings adopt slightly distorted half-chair conformations, whereas the remaining three six-membered rings are in chair forms.

11.
Inorg Chem ; 47(3): 769-71, 2008 Feb 04.
Artículo en Inglés | MEDLINE | ID: mdl-18177036

RESUMEN

By using 1,3-cyclohexane-bis(methylamine) (CHBMA) as the template, a novel zinc phosphatophosphite (TJPU-3) with extra-large 20-ring channels was synthesized. Cobalt doping produced a bimetallic phosphite (TJPU-6) with 12-ring apertures. While the templates sit in the cis configuration in TJPU-3, they are in the trans configuration in TJPU-6. This result has the potential for separation and recognition of CHBMA isomers.

12.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 4): o745, 2008 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-21202135

RESUMEN

The title compound, C(7)H(6)N(4)O(4), plays an important role in the synthesis of biologically active compounds. The planar hydrazone group is oriented at a dihedral angle of 8.27 (3)° with respect to the benzene ring. In the crystal structure, inter-molecular N-H⋯O and N-H⋯N hydrogen bonds link the mol-ecules.

13.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 7): o1317, 2008 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-21202943

RESUMEN

In the crystal structure of the title compound, C(11)H(14)ClNO(3), inter-molecular hydrogen bonds link mol-ecules in the ab plane, forming layers that stack along the c axis.

14.
Acta Crystallogr C ; 63(Pt 12): m560-2, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18057594

RESUMEN

In the title complex, [Ag(NO3)(C6H7N3O)]n or [Ag(NO3)(pyaoxH2)] (pyaoxH2 is N-hydroxypyridine-2-carboxamidine), the Ag+ ion is bridged by the pyaoxH2 ligands and nitrate anions, giving rise to a two-dimensional molecular structure. Each pyaoxH2 ligand coordinates to two Ag+ ions using its pyridyl and carboxamidine N atoms, and the OH and the NH2 groups are uncoordinated. Each nitrate anion uses two O atoms to coordinate to two Ag+ ions. The Ag...Ag separation via the pyaoxH2 bridge is 2.869 (1) A, markedly shorter than that of 6.452 (1) A via the nitrate bridge. The two-dimensional structure is fishscale-like, and can be described as pyaoxH2-bridged Ag2 nodes that are further linked by nitrate anions. Hydrogen bonding between the amidine groups and the nitrate O atoms connects adjacent layers into a three-dimensional network.

15.
Acta Crystallogr Sect E Struct Rep Online ; 64(Pt 1): o63, 2007 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-21200940

RESUMEN

The title compound, C(22)H(22)N(2)O(10), was prepared by the glycosidation method through nitrite displacement on substituted nitro-phthalonitrile. The mol-ecule contains a benzene ring, two nitrile groups and an acetyl-protected d-glucose fragment which adopts a chair conformation. The absolute configuration was determined by the use of d-glucose as starting material. All substituents of the protected sugar are in equatorial positions, with the exclusive presence of the α-anomer. The crystal packing is stabilized by C-H⋯O and C-H⋯N hydrogen-bonding inter-actions.

16.
Artículo en Inglés | MEDLINE | ID: mdl-16843705

RESUMEN

A novel photochromic diarylethene, 1,2-bis{2-ethyl-5-[2-(1,3-dioxolane)]-3-thienyl}perfluorocyclopentene (BEDTP), was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. Its photochromic and fluorescent properties were also investigated. The results showed that this compound exhibited reversible photochromism, changing from colorless to magenta after irradiation with UV light both in solution and in the crystalline phase. In hexane solution, the open-ring isomer of BEDTP exhibited relatively strong fluorescence at 400 nm when excited at 282 nm. The fluorescence intensity decreased along with the photochromism upon irradiation with 254 nm light and its closed-ring isomer showed almost no fluorescence.


Asunto(s)
Ciclopentanos/química , Ciclopentanos/síntesis química , Modelos Moleculares , Cristalización , Cristalografía por Rayos X , Fluorescencia , Isomerismo , Estructura Molecular , Fotoquímica , Estereoisomerismo , Rayos Ultravioleta
17.
Inorg Chem ; 44(25): 9405-15, 2005 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-16323927

RESUMEN

A general synthesis route to a family of single-crystal chromate nanorods/nanobelts has been established. The effects of pH and surfactant on phase and morphology of these microcrystalline materials have been investigated. The physical properties of the as-synthesized chromate nanocrystals such as dielectric, electrochemical, UV-vis absorbance, and photoluminescent properties have also been studied. The present general synthesis of various low-dimensional chromate nanomaterials provides useful information on the possible synthesis of other microcrystalline transition metal oxysalts.

19.
Acta Crystallogr C ; 61(Pt 10): o599-601, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16210768

RESUMEN

The title compound, C27H18F6S2, a novel photochromic hybrid diarylethene derivative containing 2- and 3-thienyl substituents, is one of the most promising photochromic candidates with shorter wavelength for optical storage and other optoelectronic devices. In the crystal structure, the molecule adopts a photoactive antiparallel conformation. The distance between the two reactive C atoms, i.e. the ring C atoms to which the methyl groups are attached, is 3.430 (4) A. The dihedral angles between the thienyl and adjacent phenyl rings are 26.8 (2) and 33.98 (9) degrees.

20.
Acta Crystallogr C ; 61(Pt 9): o568-70, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16143783

RESUMEN

The title compound, C23H22F6O4S2, a photochromic dithienylethene, is a promising material for optical storage and other optoelectrical devices. The molecule adopts a photoactive antiparallel conformation in the crystalline state. The distance between the two reactive C atoms which are involved in potential ring closure is 3.829 (4) A. The dihedral angles between the central cyclopentene ring and the adjacent thiophene rings are 55.38 (7) and 54.81 (9) degrees. The colourless crystals turn magenta when exposed to UV radiation and the process is reversible.

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