scholarly journals Base-triggered self-amplifying degradable polyurethanes with the ability to translate local stimulation to continuous long-range degradation

2020 ◽  
Vol 11 (12) ◽  
pp. 3326-3331 ◽  
Author(s):  
Yanhua Xu ◽  
Samya Sen ◽  
Qiong Wu ◽  
Xujia Zhong ◽  
Randy H. Ewoldt ◽  
...  
Keyword(s):  
Long Range ◽  
Mild Conditions ◽  
New Type ◽  
Local Stimulation

A new type of base-triggered self-amplifying degradable polyurethane is reported that degrades under mild conditions, with the release of increasing amounts of amine product leading to self-amplified degradation.

scholarly journals Evaluation of Lipases from Wild Microbial Strains as Biocatalysts in Biodiesel Production

Separations ◽  
2018 ◽  
Vol 5 (4) ◽  
pp. 53 ◽  
Author(s):  
Carlos Luna ◽  
Diego Luna ◽  
Felipa Bautista ◽  
Juan Calero ◽  
Antonio Romero ◽  
...  
Keyword(s):  
Biodiesel Production ◽  
Purification Process ◽  
Bacterial Strains ◽  
Production Methods ◽  
Mild Conditions ◽  
New Type ◽  
Microbial Strains ◽  
The Stability ◽  
Microbial Strain ◽  
Biodiesel Industry

In this study, the evaluation of the catalytic behavior of several wild bacterial strains in the 1,3-selective ethanolysis of triglycerides with ethanol to produce a new type of biodiesel (Ecodiesel) that integrates glycerol as monoacylglycerols was carried out. The Ecodiesel production not only avoids the elimination of glycerol, which is largely generated as a by-product in the biodiesel industry, but also results in an increase in the biofuel yield. The wild microbial strain samples were obtained from several lipophilic organisms. In addition to evaluate the enzymatic extracts, the minimum grade of purification of the strains, necessary to obtain similar results to those attained with commercial lipases was studied. This purification treatment included a dialysis followed by a lyophilization process. Such extracts were directly used as biocatalysts in the transesterification reaction of sunflower oil with ethanol, attaining much better results (yield close to 100%) than those obtained with strains which were not submitted to the purification process (yields lower than 10%). Furthermore, the results here obtained are similar to those obtained with commercial lipases but were achieved under mild conditions and lower reaction time (2 h). In addition, the stability of the enzymatic extracts was corroborated by subsequent reactions, showing no loss of activity. Thus, this study brings to light that enzymatic extracts obtained by a very simple purification process can be economically competitive with the conventional biodiesel production methods.

Quasicrystal-related mosaics with periodic lattices interlaid with aperiodic tiles

2020 ◽  
Vol 76 (2) ◽  
pp. 137-144
Author(s):  
Zhanbing He ◽  
Yihan Shen ◽  
Haikun Ma ◽  
Junliang Sun ◽  
Xiuliang Ma ◽  
...  
Keyword(s):  
Solid State ◽  
Long Range ◽  
Orientational Order ◽  
Translational Symmetry ◽  
Repeated Unit ◽  
Unit Cells ◽  
Potential Applications ◽  
New Type ◽  
Structural Blocks

Quasicrystals, which have long-range orientational order without translational symmetry, are incompatible with the theory of conventional crystals, which are characterized by periodic lattices and uniformly repeated unit cells. Reported here is a novel quasicrystal-related solid state observed in two Al–Cr–Fe–Si alloys, which can be described as a mosaic of aperiodically distributed unit tiles in translationally periodic structural blocks. This new type of material possesses the opposing features of both conventional crystals and quasicrystals, which might trigger wide interest in theory, experiments and the potential applications of this type of material.

A Solution Method for Engineering Equilibrium Mathematics Modeling under Mild Conditions

2011 ◽  
Vol 225-226 ◽  
pp. 1279-1283
Author(s):  
Guo Cheng Li
Keyword(s):  
Solution Method ◽  
Mild Conditions ◽  
Alternating Direction ◽  
New Type

In this paper, a solution for engineering equilibrium mathematics modeling (EEMM) is considered. To obtain a solution of EEMM, we present a new type alternating direction solution method, and then its convergence is also shown under mild conditions. The results obtained in this paper can be taken as an extension of the existing method for EEMM.

scholarly journals Synthesis of a New Type of Trans-Decalin Vitamin D Analogue through a Dyotropic Ring Expansion

2021 ◽  
Vol 2021 ◽  
pp. 1-5
Author(s):  
Hugo Santalla ◽  
Uxía Gómez-Bouzó ◽  
Irene Sánchez-Sanz ◽  
Yagamare Fall
Keyword(s):  
Vitamin D ◽  
Research Group ◽  
Ring Expansion ◽  
Ring System ◽  
Side Chain ◽  
Sulphur Atom ◽  
Mild Conditions ◽  
New Type ◽  
Vitamin D Analogue

A new vitamin D analogue with a trans-fused decalin as the CD-ring system and containing a sulphur atom in the side chain has been synthesized in our research group. The obtention of this analogue is based on a recently discovered transformation of hydrindane cores into decalins through a dyotropic ring expansion in very mild conditions.

scholarly journals Design, synthesis and application of a new type of bifunctional Le-Phos in highly enantioselective γ-addition reactions of N-centered nucleophiles to allenoates

2019 ◽  
Vol 10 (45) ◽  
pp. 10510-10515 ◽  
Author(s):  
Haile Qiu ◽  
Xiaofeng Chen ◽  
Junliang Zhang
Keyword(s):  
Addition Reactions ◽  
Design Synthesis ◽  
Mild Conditions ◽  
New Type

A novel class of bifunctional cyclic phosphine catalysts (Le-Phos) is reported, which showed good performances in enantioselective γ-addition reactions of N-centered nucleophiles and allenoates under mild conditions.

Übergangsmetallkomplexe mit Schwefelliganden, C*. Unerwartet einfache Bildung von Diazen-Komplexen und ein neuer Typ von Diastereomerie: [µ-N2H2{Fe(PPr3)('S4')}2] und analoge Komplexe mit [FeS]-Zentren. ( 'S4'2-= 1,2-Bis(2-mercaptophenylthio)ethan(2-)) / Transition Metal Complexes with Sulfur Ligands, C*. Unexpectedly Facile Formation of Diazene Complexes and a New Type of Diastereomerism: [µ-N2H2{Fe(PPr3)('S4')}2] and Analogous Complexes with [FeS]-Centers. ('S4'2- = 1,2-Bis(2-mercaptophenylthio)ethane(2-))

1994 ◽  
Vol 49 (1) ◽  
pp. 76-88 ◽  
Author(s):  
Dieter Sellmann ◽  
Helge Friedrich ◽  
Falk Knoch ◽  
Matthias Moll
Keyword(s):  
Transition Metal Complexes ◽  
Hydrogen Bridge ◽  
Nmr Studies ◽  
Tertiary Butyl ◽  
X Ray ◽  
Mild Conditions ◽  
New Type ◽  
Second Wave ◽  
Dinitrogen Complex ◽  
Fold Excess

Abstract Single pot reactions of FeCl2∙4H2O with the tetradentate thioether-thiol 'S4-H2' = 1,2-bis(2-mercaptophenylthio)ethane, phosphines such as PEt3, PPr3 or PBu3, and a ca. 40-fold excess of N2H4∙H2O yield, in the presence of air, diazene complexes of the general formula [µ-N2H2{Fe(PR3)('S4')}2]. In contrast to previous syntheses of diazene complexes, the yields can excel 80%, and the syntheses can be carried out on a 10 g scale. [µ-N2H2{Fe(PPr3)('S4')}2], 1 and [µ-N2H2{Fe(PEt3)('buS4')}2], 2 were characterized by X-ray structure analysis. 2 contains 'buS4'2−= 1,2-bis(3,5-ditertiarybutyl-2-mercaptophenylthio)-ethane(2-), which is the tertiary-butyl derivative of 'S4'2−. 1 and 2 contain trans-HN=NH which bridges enantiomeric [Fe(PPr3)('S4')] or [Fe(PEt3)('buS4')] fragments. HN=NH is stabilized by 4c - 6 e− - π bonds, strong tricentric N − H∙∙∙(S)2 bridges, and steric shielding. NMR studies show that centrosymmetric 1 isomerizes in solution at temperatures around 0 °C in order to give a diastereomerie diazene complex which is also centrosymmetric. The diastereomerism is traced back to bridging the chiral [Fe(PPr3)('S4')] fragments by trans-HN=NH in a different way. The two different bridging modes are verified by X-ray structure analyses of analogous ruthenium complexes. Because this new type of diastereomerism is basically caused by a different position only of the N − H∙∙∙(S)2 bridges, it is termed hydrogen bridge diastereomerism. A mechanism for the isomerization is suggested. 1 exhibits three anodic waves in the cyclovoltammogram. The second wave indicates formation of the dication [1]2+, which is a redox isomer of the diprotonated (and as yet hypothetical) dinitrogen complex [µ-N2{Fe(PPr3)('S4')}2]. The significance of [1]2+ and of its Lewis basic thiolate donors with respect to electrochemical reduction of molecular dinitrogen under mild conditions is discussed.

scholarly journals Zigzag Solitons and Spontaneous Symmetry Breaking in Discrete Rabi Lattices with Long-Range Hopping

Symmetry ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 277
Author(s):  
Haitao Xu ◽  
Zhelang Pan ◽  
Zhihuan Luo ◽  
Yan Liu ◽  
Suiyan Tan ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Long Range ◽  
Input Power ◽  
Discrete Soliton ◽  
Coupled Effect ◽  
Total Input ◽  
New Type ◽  
Discrete Solitons ◽  
Symmetric Soliton

A new type of discrete soliton, which we call zigzag solitons, is founded in two-component discrete Rabi lattices with long-range hopping. The spontaneous symmetry breaking (SSB) of zigzag solitons is also studied. Through numerical simulation, we found that by enhancing the intensity of the long-range linearly-coupled effect or increasing the total input power, the SSB process from the symmetric soliton to the asymmetric soliton will switch from the supercritical to subcritical type. These results can help us better understand both the discrete solitons and the Rabi coupled effect.

A new type of smectic A phase with long range modulation in the layers

1981 ◽  
Vol 42 (1) ◽  
pp. 107-111 ◽  
Author(s):  
G. Sigaud ◽  
F. Hardouin ◽  
M. F. Achard ◽  
A.M. Levelut
Keyword(s):  
Long Range ◽  
Smectic A ◽  
Smectic A Phase ◽  
New Type
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