Exceptional cycles in a triangulated category T with Serre duality, introduced by N. Broomhead, D. Pauksztello, and D. Ploog, have a notable impact on the global structure of T. In this paper we show ...that if T is homotopy-like, then any exceptional 1-cycle is indecomposable and at the mouth (i.e., the middle term of the Auslander-Reiten triangle ending at it is indecomposable); and any object in an exceptional n-cycle with n≥3 is at the mouth. Let A be an indecomposable gentle k-algebra with A≠k. The Hom spaces between string complexes at the mouth are explicitly determined. The main result classifies “almost all” the exceptional n-cycles in Kb(A-proj), using characteristic components and their AG-invariants, except those exceptional 1-cycles which are band complexes. Namely, the mouth of a characteristic component C of Kb(A-proj) forms a unique exceptional cycle in C, up to an equivalent relation ≈; if the quiver of A is not of type A3, this gives all the exceptional n-cycle in Kb(A-proj) with n≥2, up to ≈; and a string complex is an exceptional 1-cycle if and only if it is at the mouth of a characteristic component with AG-invariant (1,m). However, a band complex at the mouth is possibly not an exceptional 1-cycle.
•Analysis for Hybrid-HVDC transmission line fault evolution process.•Adaptive criterion for judging when the fault evolves into the AC feed-in stage.•Equivalent characteristic impedance-based ...Hybrid-HVDC line fault location principle.•Extraction algorithm for the characteristic component at the AC feed-in stage.•Comparison of the proposed fault location principle with the existing methods.
Aiming at the transmission line fault in Hybrid-HVDC system, this paper divides the fault evolution process into different stages according to the difference of transition resistance at the fault point and the conduction state change of power electronic devices, emphatically analyzes the conversion conditions between different stages, and proposes an adaptive criterion for judging the moment when the fault evolves into AC feed-in stage. Based on the characteristic component of electrical quantities at AC feed-in stage, this paper defines the equivalent characteristic impedance at any point of transmission line, derives the functional relationship between the fault distance and the equivalent characteristic impedance at inverter side DC bus, and locates the fault point according to this relationship. In order to extract the characteristic component of electrical quantities, a characteristic component extraction algorithm is studied, it can effectively eliminate the influence of constant DC component and decaying aperiodic component. This paper builds the Hybrid-HVDC system simulation model and carries out simulation experiments on PSCAD/EMTDC, and compares the proposed fault location principle with the existing methods. The simulation results verify the effectiveness of the adaptive criterion for judging the AC feed-in stage starting moment and the proposed fault location principle.
•Two voltage symbolic functions are defined to determine the fault segment.•Fault location equation is established based on the characteristic component.•Two-population Differential Evolution ...algorithm can accurately solve the equation.•ACD-IGLFD adaptively extracts the characteristic component and its appearing moment.
Because the traditional fault location method cannot be applied to overhead and cable hybrid transmission line in the VSC-HVDC system, this paper proposes a novel fault location method, which primarily uses the principle of first determining the fault segment and then locating the fault point in the fault segment. Two voltage symbolic functions are defined, and the fault segment is determined according to the different numerical combinations of the two voltage symbolic functions. Through combining adaptive characteristic scale decomposition with improved general local frequency decomposition to adaptively extract the fault characteristic component, the intra-segment location equation is established based on the characteristic component to locate the fault point. The simulation results verify that the proposed method can accurately locate the fault point for the overhead and cable hybrid transmission line in the VSC-HVDC system.
Erigeron breviscapus injection is widely used in clinical treatment of ischemic stroke and coronary heart disease. More than 80 chemical components have been identified from Erigeron breviscapus ...herb. However, chemical components of Erigeron breviscapus injection remain unclear. In this study, a rapid qualitative method of ultra-performance liquid chromatography-linear ion trap/electrostatic field Orbitrap combined high resolution mass spectrometry (UHPLC-LTQ-Orbitrap MS) coupled with molecular network was established for identification of Erigeron breviscapus injection. UPLC BEH C18 column (2.1 mm×50 mm×1.7 μm) was employed and the gradient elution was carried out with the mobile phase of acetonitrile-0.1% formic acid aqueous solution. According to the similarity of MS/MS fragmentation patterns, GNPS molecular network was established based on LTQ-Orbitrap MS data, which was collected in positive and negative ion modes, respectively. Molecules with similar structure were screened and clustered with Cytoscape 3.6.1 software. Components in Erigeron breviscapus injection were further identified based on information of retention time, molecular weight, and MSn multistage fragmentations. The result of GNPS molecular network displayed two major component communities of caffeinyl ester derivatives and flavonoids. Component community of caffeinyl ester derivatives was established based on seed nodes of chlorogenic acid, isochlorogenic acid, and erigoster B. Component community of flavonoids was established based on seed nodes of scutellarein and scutellarin. Eighty-four components, including mono-caffeoyl esters, di-caffeoyl esters, tri-caffeoyl esters and flavonoids, were identified in the major component communities of Erigeron breviscapus injection, of which 49 were identified in Erigeron breviscapus injection production for the first time. This study provides reference for quality control and pharmacodynamics research of Erigeron breviscapus injection.
旨在为我国甘肃陇南产区初榨橄榄油（VOO）的快速鉴别以及工业生产过程中的风味品质评价提供数据支撑和理论依据，采用HS-GC-IMS技术对甘肃陇南主栽品种莱星(LX)、佛奥(FO)、科拉蒂(KLD)、皮削利(PXL)、鄂植8号(EZ8)以及LX与KLD的混合品种(HH)6种VOO中的风味特征成分进行定性和差异分析。结果表明：6种VOO中共检测出39种风味特征物质，定性出22种，其中醛类(9种)、酮类(5种)化合物为主要的风味特征成分，此外还包括酯类(3种)、醇类(3种)、萜烯类(1种)和呋喃类(1种)等物质；6种VOO中含有的风味特征物质均存在不同程度的差异，其中，LX、KLD和HH中的风味特征物质较为相似，其2-甲基丁醛、3-甲基丁醛、(E)-2-戊烯醛、辛醛和2-正戊基呋喃含量较高，FO中的正戊醇、正己醛和3-戊酮含量较高，PXL中的（Z）-3-己烯乙酸酯、α-松油烯、2-己酮的含量较高，EZ8中的乙酸乙酯含量最高，HH中的2-丁酮、丙酮、(E)-2-庚烯醛的含量较高。综上，采用HS-GC-IMS可以有效检测VOO中的风味特征物质，定性出的风味特征物质可作为区分6种VOO的依据之一。 Aiming to provide data support and theoretical basis for the rapid identification of virgin olive oil (VOO) in Longnan, Gansu province and the evaluation of flavor quality in the industrial production process, HS-GC-IMS technology was used to qualitatively and differentially analyze the flavor characteristic component of six kinds of VOO extracted from main cultivars in Longnan (Gansu) Leccino (LX), Frantoio (FO), Coratina (KLD), Picholine (PXL), Ezhi-8 (EZ8) and mixed with LX and KLD varieties (HH). The results showed that a total of 39 volatile flavor components were detected in six kinds of VOO, and 22 compounds were identifined, among which aldehydes (9 kinds) and ketones (5 kinds) were the main flavor characteristic components,also including esters (3 kinds), alcohols (3 kinds), terpenes (1 kind), and furans (1 kind).The flavor characteristic components of six kinds of VOO were different in different degrees, among which the flavor characteristic components in LX, KLD and HH were similar, and the contents of 2-methylbutanal, 3-methylbutanal, (E)-2-pentenal, octanal and 2-pentylfuran were higher. The contents of n-pentanol, hexanal and 3-pentanone in FO were higher. The contents of (Z)-3-hexenyl acetate, α-terpinene and 2-hexanone in PXL were higher. Ethyl acetate was the main flavor characteristic component in EZ8.The main flavor characteristics components in HH included 2-butanone, acetone and (E)-2-heptenal. In conclusion, HS-GC-IMS can effectively detect the flavor characteristic component in VOO, and the flavor characteristic components identified can be used as one of the bases for distinguishing the six kinds of VOO.
Few studies have comprehensively screened for ionic small molecules with high water-solubility in the traditional Japanese mandarin orange Citrus unshiu Marc. Here, we performed metabolomic analysis ...with capillary electrophoresis-mass spectrometry (CE-MS) to comprehensively identify and accumulate gross quantitative data for water-soluble components in the different varieties of ‘Aoshima’ and ‘Okitsu/Miyagawa Wase’, according to grade and processing method. In this analysis, we focused on 151 components and showed the characteristic components related to each different variety and processing method, e.g., Met, Gly, and Asp in var. Wase; ornithine, putrescine, synephrine, and Gln in var. Aoshima; and pyroglutamate, GABA (γ-aminobutyric acid), and malonate in the juice of var. Aoshima. Furthermore, we conducted processing tests and identified components that were affected by squeezing or heating. These data represent basic data for further investigation of the metabolism of C. unshiu Marc. or chemical changes in their components due to external factors such as processing.
High-frequency transient current component is used to select fault line in indirectly grounding power system, but the frequency range is usually chosen by experience method. In the view of this ...situation, this paper analytically analyses the frequency characteristics, proposes a method to estimate the frequency range, provides the feature components between fault line and non-fault line and lays the theoretical foundations for high-frequency component selecting. On the basis of frequency analysis, this paper extracts high-frequency components in the selected frequency range by using the existing filtering tool, calculates the relative entropy coefficient matrix combined with the relative entropy theory and then identifies the fault line. Simulation results show that the proposed route selection method has wide applicability and accuracy.
The effects of innovative infrared-steam blanching (ISB) on the peroxidase (POD) inactivation, POD inactivation kinetics, characteristic component (phenolics, carotenoids and flavonoids) content, ...colour and regeneration of POD activity during storage of
Chrysanthemum indicum
L. flowers were comparatively studied following steam blanching (SB) and infrared blanching (IB). ISB and SB allowed a stable surface temperature of the flowers at approximately 100 °C, and IB caused the temperature rose up to a high value of 129.2 °C. POD was inactivated to 5.7% of its residual activity after ISB for 90 s, 5.8% after SB for 180 s and 5.3% after IB for 270 s. In all processes, the POD inactivation kinetics followed a first-order model (
R
2
varied from 0.932 to 0.957) and ISB achieved lower
T
1/2
,
E
a
and
D
values and a higher
k
value than SB and IB. The sample blanched with ISB maintained more characteristic components and colour retention than those blanched with SB and IB. Moreover, ISB allowed the brightest colour and prevented the regeneration of POD activity in dried
C. indicum
flowers during storage. Therefore, ISB for 90 s at 100 °C is recommended as a more suitable method for blanching
C. indicum
flowers. The findings in the current work provide a new blanching method for natural plant products.
To solve this problem that harmonic grounding system fault line zero sequence admittance levy does not highlight, this paper proposes a new resonant grounding line selection method based on EMD. In ...this method, each line zero sequence admittance is decomposed with EMD, characteristic component is extracted, and the fault line is selected by comparing the characteristic component symbols of the fault line and non-fault lines. Extensive simulations show that this method is not impacted by the ground fault resistance and the initial angle, and can accurately select the fault line.
PDF
