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1

Fatigue life prediction for Ni-based superalloy GH4169 considering machined surface roughness and residual stress effects

Wu Z. R., Wang S. Q., Yang X., Pan L., Song Y. D.

Journal of Theoretical and Applied Mechanics

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2021

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Vol. 59 nr 2

215--226

EN

Establishing a fatigue life prediction model considering the machined surface state is of great significance to improve fatigue life prediction accuracy. Fatigue tests with different machined surface states of GH4169 alloy were conducted firstly. The influence of surface state parameters on the fatigue life was analyzed. Then, the machined surface stress concentration factor and residual stress were introduced into the fatigue crack initiation and propagation models. Finally, the fatigue life prediction model of GH4169 material considering the surface states was established. The prediction results based on the proposed model are almost within a factor of two scatter band of the test results.

2

Exploration and mining learning robot of autonomous marine resources based on adaptive neural network controller

Pan L.

Polish Maritime Research

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2018

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S 3

78--83

EN

To study the autonomous learning model of the learning robot for marine resource exploration, an adaptive neural network controller was applied. The motion characteristics of autonomous learning robots were identified. The mathematical model of the multilayer forward neural network and its improved learning algorithm were studied. The improved Elman regression neural network and the composite input dynamic regression neural network were further discussed. At the same time, the diagonal neural network was analysed from the structure and learning algorithms. The results showed that for the complex environment of the ocean, the structure of the composite input dynamic regression network was simple, and the convergence was fast. In summary, the identification method of underwater robot system based on neural network is effective.

3

Enhanced Non-linear Viscoelastic Properties of Polymer Bonded Explosives Based on Graphene and a Neutral Polymeric Bonding Agent

Lin C., He G., Liu J., Pan L., Liu S.

Central European Journal of Energetic Materials

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2017

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Vol. 14, no. 4

788--805

EN

During their long-term storage and transport, polymer bonded explosives (PBXs) will be subjected to complex thermal physical environments with combined thermal and mechanical loads. The creep behaviour results in a change of physical and mechanical properties, which consequently influences the explosive performance. In this work, graphene and a neutral polymeric bonding agent (NPBA) were selected to improve the non-linear creep properties of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)-based PBXs. The results were compared with the creep response of the corresponding PBXs without additives and with graphene alone. It was observed that graphene and an NPBA exhibited a positive effect, improving the creep resistance of TATB-based PBXs. The compressive and tensile strength of 0.5 wt.% graphene-filled PBXs were improved by 5.1% and 29.2%, respectively, compared to raw TATB-based PBXs without additives. The performance of the PBXs was further enhanced by the addition of 0.1 wt.% NPBA. For a given stress and temperature, the TATB-based PBXs with graphene and NPBA deformed significantly less than the PBXs filled with graphene alone.

4

Tissue P Systems with Protein on Cells

Song B., Pan L., Pérez-Jiménez M. J.

Fundamenta Informaticae

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2016

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Vol. 144, nr 1

77--107

EN

Tissue P systems are a class of distributed parallel computing devices inspired by biochemical interactions between cells in a tissue-like arrangement, where objects can be exchanged by means of communication channels. In this work, inspired by the biological facts that the movement of most objects through communication channels is controlled by proteins and proteins can move through lipid bilayers between cells (if these cells are fused), we present a new class of variant tissue P systems, called tissue P systems with protein on cells, where multisets of objects (maybe empty), together with proteins between cells are exchanged. The computational power of such P systems is studied. Specifically, an efficient (uniform) solution to the SAT problem by using such P systems with cell division is presented. We also prove that any Turing computable set of numbers can be generated by a tissue P system with protein on cells. Both of these two results are obtained by such P systems with communication rules of length at most 4 (the length of a communication rule is the total number of objects and proteins involved in that rule).

5

On the Universality of Colored One-Catalyst P Systems

Wu T., Zhang Z., Paun G., Pan L.

Fundamenta Informaticae

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2016

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Vol. 144, nr 2

205--212

EN

A control strategy on the computations in a one-catalyst P system is provided: the rules are assumed “colored” and in each step only rules of the same “color” are used. Such control leads to Turing universality for one-catalyst P systems with one membrane. Turing universality is also reached for purely catalytic P systems with two catalysts, and for purely catalytic P systems with only one catalyst and cooperating rules working in the so-called terminal mode.

6

On String Languages Generated by Sequential Numerical P Systems

Zhang Z., Wu T., Pan L.

Fundamenta Informaticae

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2016

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Vol. 145, nr 4

485--509

EN

Numerical P systems are a class of P systems inspired both from the structure of living cells and from economics. In this work, we further investigate the generative capacity of numerical P systems as language generators. The families of languages generated by non-enzymatic, by enzymatic, and by purely enzymatic (all programs are enzymatic) numerical P systems working in the sequential mode are compared with the language families in the Chomsky hierarchy. Especially, a characterization of recursively enumerable languages is obtained by using purely enzymatic numerical P systems working in the sequential mode.

7

Extending Simulation of Asynchronous Spiking Neural P Systems in P–Lingua

Macías-Ramos L. F., Pérez-Jiménez M. J., Song T., Pan L.

Fundamenta Informaticae

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2015

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Vol. 136, nr 3

253--267

EN

Spiking neural P systems (SN P systems for short) are a class of neural-like computing models in the framework of membrane computing. Inspired by the neurophysiological structure of the brain, SN P systems have been extended in various ways. P–Lingua is a standard language for the definition of P systems, where pLinguaCore library provides particular implementations of parsers and simulators for the models specified in P–Lingua. A support for simulating SN P systems in P–Lingua was introduced recently and soon expanded to cover further features of these systems. In this paper, we present an extension of P–Lingua related to asynchronous SN P systems, in order to incorporate simulation capabilities for limited asynchronous SN P systems and asynchronous SN P systems with local synchronization.

8

A P–Lingua Based Simulator for P Systems with Symport/Antiport Rules

Macías-Ramos L. F., Valencia-Cabrera L., Song B., Song T., Pan L., Pérez-Jiménez M. J.

Fundamenta Informaticae

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2015

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Vol. 139, nr 2

211--227

EN

Inspired by mitosis process and membrane fission processes, cell-like P systems with symport/antiport rules and membrane division rules or membrane separation rules have been introduced, respectively. These computation systems have two key features: the ability to have infinite copies of some objects (within an active environment) and to generate an exponential workspace in polynomial time. In this work, we extend the P-Lingua framework for simulating that kind of P systems taking into account these two features. Consequently, a new simulator has been developed and included in pLinguaCore library. The functioning of the simulator has been checked by simulating efficient solutions to SAT problem using a family of cell-like P systems with symport/antiport rules and membrane division rules or membrane separation rules. The corresponding MeCoSim based application is also provided.

9

Effect of dispersion order on the spectral degree of polarization of stochastic electromagnetic pulsed beams

Wang H., Ding C., Zhang Y., Zhao Z., Pan L.

Optica Applicata

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2014

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Vol. 44, nr 1

147--158

EN

The analytical expression for the cross-spectral density function of stochastic electromagnetic Bessel–Gauss pulsed beams through a dispersive aperture lens is derived and used to study the changes in the spectral degree of polarization in an optical focus system. The changes in the spectral degree of polarization at the focal plane and on the z-axis are performed in the case of dispersion-free, dispersion of the first, second, and higher orders, respectively. It is shown that the dispersion affects the peak value of the spectral degree of polarization, and the higher order dispersion leads to a more obvious effect on the peak value of the spectral degree of polarization at the focal plane. On the z-axis, the spectral degree of polarization in the dispersion-free case is different form that in the dispersion case, however, the dispersion of different orders almost has the same effect on the spectral degree of polarization. The results obtained in this paper may be crucial for high precision laser detection.

10

Weighted Spiking Neural P Systems with Rules on Synapses

Zhang X., Zeng X., Pan L.

Fundamenta Informaticae

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2014

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Vol. 134, nr 1/2

201--218

EN

Spiking neural P systems (SN P systems, for short) with rules on synapses are a new variant of SN P systems, where the spiking and forgetting rules are placed on synapses instead of in neurons. Recent studies illustrated that this variant of SN P systems is universal working in the way that the synapses starting from the same neuron work in parallel (i.e., all synapses starting from the same neuron should apply their rules if they have rules to be applied). In this work, we consider SN P systems with rules on synapses working in another way: the synapses starting from the same neuron are restricted to work in a sequential way (i.e., at each step at most one synapse starting from the same neuron applies its rule). It is proved that the computational power of SN P systems with rules on synapses working in this way is reduced; specifically, they can only generate finite sets of numbers. Such SN P systems with rules on synapses are proved to be universal, if synapses are allowed to have weight at most 2 (if a rule which can generate n spikes is applied on a synapse with weight k, then the neuron linking to this synapse will receive totally nk spikes). Two small universal SN P systems with rules on synapses for computing functions are also constructed: a universal system with 26 neurons when using extended rules and each synapse having weight at most 2, and a universal system with 26 neurons when using standard rules and each synapse having weight at most 12. These results illustrate that the weight is an important feature for the computational power of SN P systems.

11

Limited Asynchronous Spiking Neural P Systems

Pan L., Wang J., Hoogeboom H.J.

Fundamenta Informaticae

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2011

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Vol. 110, nr 1-4

271-293

EN

In a biological system, if a long enough time interval is given, an enabled chemical reaction will finish its reaction in the given time interval. With this motivation, it is natural to impose a bound on the time intervalwhen an enabled spiking rule in a spiking neural P system (SN P system, for short) remains unused. In this work, a new working mode of SN P systems is defined, which is called limited asynchronous mode. In an SN P system working in limited asynchronous mode, if a rule is enabled at some step, this rule is not obligatorily used. From this step on, if the unused rule may be used later, it should be used in the given time interval. If further spikes make the rule non-applicable, then the computation continues in the new circumstances. The computation result of a computation in an SN P system working in limited asynchronous mode is defined as the total number of spikes sent into the environment by the system. It is proved that limited asynchronous SN P systems with standard spiking rules are universal. If the number of spikes present in each neuron of a limited asynchronous SN P system with standard spiking rules is bounded during a computation, then the power of a limited asynchronous SN P system with standard spiking rules falls drastically, and we get a characterization of semilinear sets of numbers.

12

A Tissue P Systems Based Uniform Solution to Tripartite Matching Problem

Niu Y., Pan L., Pérez-Jiménez M.J., Font M. R.

Fundamenta Informaticae

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2011

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Vol. 109, nr 2

179-188

EN

A tissue P system with cell division is a computing model which has two basic features: intercellular communication and the ability of cell division. The ability of cell division allows us to obtain an exponential amount of cells in linear time and to design cellular solutions to computationally hard problems in polynomial time. In this work we present an efficient solution to the tripartite matching problem by a family of such devices. This solution leads to an interesting open problem whether tissue P systems with cell division and communication rules of length 2 can solve NPcomplete problems. An answer to this open problem will provide a borderline between efficiency and non-efficiency in terms of the lengths of communication rules.

13

Homogeneous Spiking Neural P Systems

Zeng X., Zhang X., Pan L.

Fundamenta Informaticae

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2009

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Vol. 97, nr 1/2

275-294

EN

Spiking neural P systems are a class of distributed parallel computing models inspired from the way the neurons communicate with each other by means of electrical impulses (called "spikes"). In this paper, we consider a restricted variant of spiking neural P systems, called homogeneous spiking neural P systems, where each neuron has the same set of rules. The universality of homogeneous spiking neural P systems is investigated. One of universality results is that it is sufficient for homogeneous spiking neural P system to have only one neuron that behaves nondeterministically in order to achieve Turing completeness.

14

Smaller Universal Spiking Neural P Systems

Zhang X., Zeng X., Pan L.

Fundamenta Informaticae

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2008

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Vol. 87, nr 1

117-136

EN

The problem of finding small universal spiking neural P systems was recently investigated by Andrei P˘aun and Gheorghe P˘aun, for spiking neural P systems used as devices computing functions and as devices generating sets of numbers. For the first case, a universal spiking neural P system was produced by using 84 neurons for standard rules and using 49 neurons for extended rules. For spiking neural P systems used as generators of sets of numbers, a universal system with standard rules having 76 neurons, and one with extended rules having 50 neurons were obtained. In this paper, we continue the study of small universal spiking neural P systems and we improve in the number of neurons as follows. The small universal spiking neural P systems use 67 neurons for standard rules and 41 neurons for extended rules in the case of computing functions, and 63 neurons for standard rules and 41 neurons for extended rules in the case of generating sets of numbers.

15

Synthesis, Structure and Third-Order Nonlinear Optical Properties of a Iodoargentate(I) Cluster Polymer of [(Et4N)(Ag2I3)]n

Zhang X., Li Y., Li K., Song W., Wang C., Pan L.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 7

1313-1320

EN

Apolynuclear silver(I) cluster polymer [(Et4N)(Ag2I3)]n 1 with iodo-bridging ligands has been prepared by low-temperature solid-state reaction. Single crystal X-ray analyses reveal that compound 1 possesses a new type of one-dimensional (1-D) structure. The cluster anion of the title compound can be described as polymeric chain with [Ag2I2] plane. This cluster polymer shows nice third-order nonlinear optical (NLO) absorption and refraction with absorption coefficient alfa 2 = 9.1×10-11 mźw-1 and refractive index n2 = -3.4×10-17 m2źw-1 in a 2.6×10-4 molźdm-3 DMF solution.

16

A Hexanuclear Iodoargentate(I) Cluster of the Coplanar Dicubane-like Type: Structure and Nonlinear Optical (NLO) Properties of {[(t-Bu)4N]2[Ag6I8]}n

Li Y., Zhang Z., Li K., Song W., Huang F., Li S., Li X., Xu J., Pan L.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 9

1533-1539

EN

A polynuclear silver(I) complex {[(t-Bu)4N]2[Ag6I8]} n 1 with iodo-bridging ligands has been prepared, the centrosymmetric cluster anion can be described as two [Ag4I4] distorted cubane units sharing one [Ag2I2] plane. This cluster polymer shows strong third-order nonlinear optical (NLO) absorption and refraction with absorption coefficient alfa 2 = 8.9 × 10-10 m_w-1 and refractive index n2 = -6.6 × 10-17 m2. w-1.

17

Synthesis, Structure and Non-Linear Optical Properties of a Copper(II) Ethyl Bisulfate Two-Dimensional Supramolecular Compound {Cu(Him)4(Cu(Him)4(CH3CH2OSO3H)2]

Li Y., Lu J., Cui X., Xu J., Sun Y., Pan L., Bie H., Zhang X.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 6

779-787

EN

A novel copper(II) ethyl bisulfate complex [Cu(Him)4(Eb)2] 1 (Him = imidazole, Eb = ethyl bisulfate) has been prepared and characterized by means of elemental analysis, IR and ESR. The structure was determined by single crystal X-ray diffraction analysis, which suggests that compound 1 exhibits a two-dimensional supramolecular structure through hydrogen bonds. Compound 1 displays strong third-order non-linear optical (NLO) absorption and refraction with absorption coefficient _2 1.10_10-11 m_w-1 and refractive index n2 5.60_10-16m2_w-1. The third-order non-linear optical susceptibility _(3) of compound 1 is 3.07_10-10 esu.

18

Solving a PSPACE-Complete Problem by Recognizing P Systems with Restricted Active Membranes

Alhazov A., Martin-Vide C., Pan L.

Fundamenta Informaticae

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2003

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Vol. 58, nr 2

67--77

EN

P systems are parallel molecular computing models based on processing multisets of objects in cell-like membrane structures. Recently, Petr Sosík has shown that a semi-uniform family of P systems with active membranes and 2-division is able to solve the PSPACE-complete problem QBF-SAT in linear time; he has also conjectured that the membrane dissolving rules of the (d) type may be omitted, but probably not the (f) type rules for non-elementary membrane division. In this paper, we partially confirm the conjecture proving that dissolving rules are not necessary. Moreover, the construction is now uniform. It still remains open whether or not non-elementary membrane division is needed.