Hierarchical Theory of Quantum Adiabatic Evolution

Quantum adiabatic evolution is a dynamical evolution of a quantum system under slow external driving. According to the quantum adiabatic theorem, no transitions occur between non-degenerate instantaneous eigen-energy levels in such a dynamical evolution. However, this is true only when the driving rate is infinitesimally small. For a small nonzero driving rate, there are generally small transition probabilities between the energy levels. We develop a classical mechanics framework to address the small deviations from the quantum adiabatic theorem order by order. A hierarchy of Hamiltonians are constructed iteratively with the zeroth-order Hamiltonian being determined by the original system Hamiltonian. The $k$th-order deviations are governed by a $k$th-order Hamiltonian, which depends on the time derivatives of the adiabatic parameters up to the $k$th-order. Two simple examples, the Landau-Zener model and a spin-1/2 particle in a rotating magnetic field, are used to illustrate our hierarchical theory. Our analysis also exposes a deep, previously unknown connection between classical adiabatic theory and quantum adiabatic theory.Comment: 10 pages, 6 figures, 29 reference

A similarity-based cooperative co-evolutionary algorithm for dynamic interval multi-objective optimization problems

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Dynamic interval multi-objective optimization problems (DI-MOPs) are very common in real-world applications. However, there are few evolutionary algorithms that are suitable for tackling DI-MOPs up to date. A framework of dynamic interval multi-objective cooperative co-evolutionary optimization based on the interval similarity is presented in this paper to handle DI-MOPs. In the framework, a strategy for decomposing decision variables is first proposed, through which all the decision variables are divided into two groups according to the interval similarity between each decision variable and interval parameters. Following that, two sub-populations are utilized to cooperatively optimize decision variables in the two groups. Furthermore, two response strategies, rgb0.00,0.00,0.00i.e., a strategy based on the change intensity and a random mutation strategy, are employed to rapidly track the changing Pareto front of the optimization problem. The proposed algorithm is applied to eight benchmark optimization instances rgb0.00,0.00,0.00as well as a multi-period portfolio selection problem and compared with five state-of-the-art evolutionary algorithms. The experimental results reveal that the proposed algorithm is very competitive on most optimization instances

Nonlocal theory solution of two collinear cracks in the functionally graded materials

AbstractIn this paper, the interaction of two collinear cracks in functionally graded materials subjected to a uniform anti-plane shear loading is investigated by means of nonlocal theory. The traditional concepts of the nonlocal theory are extended to solve the fracture problem of functionally graded materials. To make the analysis tractable, it is assumed that the shear modulus varies exponentially with the coordinate vertical to the crack. By use of the Fourier transform, the problem can be solved with the help of a pair of triple integral equations, in which the unknown variable is the displacement on the crack surfaces. To solve the triple integral equations, the displacement on the crack surfaces is expanded in a series of Jacobi polynomials. Unlike the classical elasticity solutions, it is found that no stress singularity is present near the crack tips. The nonlocal elastic solutions yield a finite hoop stress at the crack tip, thus allowing us to use the maximum stress as a fracture criterion in functionally graded materials. The magnitude of the finite stress field depends on the crack length, the distance between two cracks, the parameter describing the functionally graded materials and the lattice parameter of the materials

Review of Melatonin in Horticultural Crops

Melatonin is an indoleamine, abundant in animals and plants, which has the functions of regulating circadian rhythm, improving immunity and anti-aging in animals, and is a good health care product beneficial to human health. Recent studies have shown that melatonin has physiological functions including regulating plant growth, promoting seed germination, controlling root development and delaying leaf senescence. The antioxidant properties of melatonin give it the ability to strengthen plants’ resistance to stress. The comprehensive researches in recent years, involving five aspects of "the biosynthetic pathway of melatonin in plants, the melatonin in horticultural crops and its influencing factors, the roles of melatonin in the growth and development of horticultural crops, in the response to stress of horticultural crops, the signal transduction network of melatonin in regulating plant growth and the development and stress resistance," are reviewed in the present paper. The application of melatonin in horticulture production is also discussed, which can provide a theoretical reference for the application of melatonin in horticultural production

Sensitive frequency-dependence of the carrier-envelope phase effect on bound-bound transition: an interference perspective

We investigate numerically with Hylleraas coordinates the frequency dependence of the carrier-envelope phase (CEP) effect on bound-bound transitions of helium induced by an ultrashort laser pulse of few cycles. We find that the CEP effect is very sensitive to the carrier frequency of the laser pulse, occurring regularly even at far-off resonance frequencies. By analyzing a two-level model, we find that the CEP effect can be attributed to the quantum interference between neighboring multi-photon transition pathways, which is made possible by the broadened spectrum of the ultrashort laser pulse. A general picture is developed along this line to understand the sensitivity of the CEP effect to laser's carrier frequency. Multi-level influence on the CEP effect is also discussed

Troika: Multi-Path Cross-Modal Traction for Compositional Zero-Shot Learning

Recent compositional zero-shot learning (CZSL) methods adapt pre-trained vision-language models (VLMs) by constructing trainable prompts only for composed state-object pairs. Relying on learning the joint representation of seen compositions, these methods ignore the explicit modeling of the state and object, thus limiting the exploitation of pre-trained knowledge and generalization to unseen compositions. With a particular focus on the universality of the solution, in this work, we propose a novel paradigm for CZSL models that establishes three identification branches (i.e., Multi-Path) to jointly model the state, object, and composition. The presented Troika is our implementation that aligns the branch-specific prompt representations with decomposed visual features. To calibrate the bias between semantically similar multi-modal representations, we further devise a Cross-Modal Traction module into Troika that shifts the prompt representation towards the current visual content. We conduct extensive experiments on three popular benchmarks, where our method significantly outperforms existing methods in both closed-world and open-world settings.Comment: 14 page

Efficient callus induction and indirect plant regeneration from various tissues of Jatropha curcas

The Jatropha curcas is considered as an important energy plant due to the fact that its seed contains high oil content. Nowadays focus is being placed on J. curcas callus induction and plant regeneration. In this study, explants epicotyl, hypocotyl, petiole and cotyledon of 8-day-old seedlings of J. curcas were utilized for callus induction on media supplied with 1 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D), naphthyl acetic acid (NAA) or indolebutyric acid (IBA) and 0.1 mg/L kinetin (Kin), and the results demonstrated that the combination of 1 mg/L NAA and 0.1 mg/L Kin was the best medium for callus induction and growth. In addition, induced calli were transferred to regeneration medium containing different combination of auxins and cytokinins, and the data showed that the medium containing 1 mg/L thidiazuron (TDZ) and 1 mg/L Kin combined with 0.1 mg/L IBA was propitious to plant regeneration compared with other combinations.Keywords: Callus induction, indolebutyric acid, Jatropha curcas, kinetin, naphthyl acetic acid, plant regeneration, thidiazuro

Molecular cloning and expression of a novel trehalose synthase gene from Enterobacter hormaechei

<p>Abstract</p> <p>Background</p> <p>Trehalose synthase (TreS) which converts maltose to trehalose is considered to be a potential biocatalyst for trehalose production. This enzymatic process has the advantage of simple reaction and employs an inexpensive substrate. Therefore, new TreS producing bacteria with suitable enzyme properties are expected to be isolated from extreme environment.</p> <p>Results</p> <p>Six TreS producing strains were isolated from a specimen obtained from soil of the Tibetan Plateau using degenerate PCR. A novel <it>treS </it>gene from <it>Enterobacter hormaechei </it>was amplified using thermal asymmetric interlaced PCR. The gene contained a 1626 bp open reading frame encoding 541 amino acids. The gene was expressed in <it>Escherichia coli</it>, and the recombinant TreS was purified and characterized. The purified TreS had a molecular mass of 65 kDa and an activity of 18.5 U/mg. The optimum temperature and pH for the converting reaction were 37°C and 6, respectively. Hg²⁺, Zn²⁺, Cu²⁺and SDS inhibited the enzyme activity at different levels whereas Mn²⁺showed an enhancing effect by 10%.</p> <p>Conclusion</p> <p>In this study, several TreS producing strains were screened from a source of soil bacteria. The characterization of the recombinant TreS of <it>Enterobacter hormaechei </it>suggested its potential application. Consequently, a strategy for isolation of TreS producing strains and cloning of novel <it>treS </it>genes from natural sources was demonstrated.</p