Characteristics of optical multi-peak solitons induced by higher-order effects in an erbium-doped fiber system

We study multi-peak solitons \textit{on a plane-wave background} in an erbium-doped fiber system with some higher-order effects, which is governed by a coupled Hirota and Maxwel-Bloch (H-MB) model. The important characteristics of multi-peak solitons induced by the higher-order effects, such as the velocity changes, localization or periodicity attenuation, and state transitions, are revealed in detail. In particular, our results demonstrate explicitly that a multi-peak soliton can be converted to an anti-dark soliton when the periodicity vanishes; on the other hand, a multi-peak soliton is transformed to a periodic wave when the localization vanishes. Numerical simulations are performed to confirm the propagation stability of multi-peak solitons riding on a plane-wave background. Finally, we compare and discuss the similarity and difference of multi-peak solitons in special degenerate cases of the H-MB system with general existence conditions.Comment: 7 pages, 4 figure

Small polaron with generic open boundary conditions revisit: exact solution via the off-diagonal Bethe ansatz

The small polaron, an one-dimensional lattice model of interacting spinless fermions, with generic non-diagonal boundary terms is studied by the off-diagonal Bethe ansatz method. The presence of the Grassmann valued non-diagonal boundary fields gives rise to a typical $U(1)$-symmetry-broken fermionic model. The exact spectra of the Hamiltonian and the associated Bethe ansatz equations are derived by constructing an inhomogeneous $T-Q$ relation.Comment: 12 pages, no figure, published versio

Numerical Simulation of Aerodynamic Noise of Soundproof Enclosure of Air Compressor Unit

During the operation of the air compressor unit, the suction and exhaust process of the air compressor and the operation of other equipment will cause air flow pulsation, which is often accompanied by the generation of air compressor noise. Numerical simulation method, as an important means to study the flow field characteristics and noise characteristics of air compressors, has been widely used in recent years. This article takes the noise enclosure of a certain air compressor unit as the research object, and use numerical simulation method to study the air intake part of the enclosure. The influence of inlet louver and suction deflector on the aerodynamic performance of air compressor noise enclosure was analyzed, and the influence of different inlet louver structures and different suction deflector structures on noise was compared. This paper uses the broadband noise model to predict the distribution of air flow pulsation noise. In order to quantitatively study the noise, the FW-H model based on Lighthill\u27s acoustic analogy method was used for the aerodynamic noise simulation, and the frequency response of the aerodynamic noise of air compressor was obtained

Determinant representations for scalar products of the XXZ Gaudin model with general boundary terms

We obtain the determinant representations of the scalar products for the XXZ Gaudin model with generic non-diagonal boundary terms.Comment: Latex file, 17 page

SC-TVP Green Practice Initiative in China’s Logistics Market Based on Case Analysis

In the era of circular economy, the concept of sustainable development has attracted more and more attention. With the development of cross-border e-commerce, the demand for logistics services has continued to surge, and the pressure on them to provide sustainable services has risen sharply. In 2020, China officially put forward the “double carbon” strategic goal, and green logistics has become the new direction of industry development, in line with the concept of sustainable development. However, the actual impact of green logistics practice on China’s sustainable logistics services is unknown. This paper aims to study the current situation and results of green logistics practice through data analysis and case analysis, including green design, green transportation, green management and other indicators. Based on the case analysis in this paper, the SC-TVP model is constructed to provide an effective green logistics practice framework, with a view to improving the management level of green logistics, promoting the development of enterprises, and providing some reference for the logistics development in the post-epidemic era

Analysis of functional gene polymorphism in Glycyrrhiza uralensis

Glycyrrhiza uralensis is widely used in Chinese herbal compound prescriptions. Itcontains various natural active components, among them glycyrrhizic acid is believed tobe the main effective constituent. The biosynthetic pathway of glycyrrhizic acid iscontrolled and regulated by many different enzymes. In our studies two functional genescoding 3-hydroxy-3-methylglutary CoA reductase (HMGR) and squalene synthase (SQS)were selected as target genes. Several kinds of polymorphism were discovered in thecDNA sequences and amino acid sequences of the two genes, and which inflected thelevel of glycyrrhizic acid in G. uralensis

Responses of Three Successive Generations of Beet Armyworm, Spodoptera exigua, Fed Exclusively on Different Levels of Gossypol in Cotton Leaves

The beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), is an important pest of numerous crops, and it causes economic damage in China. Use of secondary metabolic compounds in plants is an important method used to control this insect as a part of integrated pest management. In this study the growth, development, and food utilization of three successive generations of S. exigua fed on three cotton gossypol cultivars were examined. Significantly longer larval life-spans were observed in S. exigua fed on high gossypol cultivar M9101 compared with those fed on two low gossypol cultivars, ZMS13 and HZ401. The pupal weight of the first generation was significantly lower than that of the latter two generations fed on ZMS13 group. Significantly lower fecundity was observed in the second and third generations of S. exigua fed on M9101 compared with S. exigua fed on ZMS13 and HZ401. The efficiency of conversion was significantly higher in the first and third generations fed on HZ401 compared with those fed on ZMS13 and M9101. A significantly lower relative growth rate was observed in the three successive generations fed on M9101 compared with those fed on ZMS13 and HZ401. Cotton cultivars significantly affected the growth, development, and food utilization indices of S. exigua, except for frass and approximate digestibility. Development of S. exigua was significantly affected by relative consumption rate and efficiency of conversion of ingested food, but not by relative growth rate or approximate digestibility, suggesting that diet-utilization efficiency was different based on food quality and generation. Measuring the development and food utilization of S. exigua at the individual and population levels over more than one generation provided more meaningful predictions of long-term population dynamics