Wyniki wyszukiwania - BazTech

1

Significance of Stump-Sprouting for the Population Size Structure and Spatial Distribution Patterns of Endangered Species, Magnolia cylindrical

Li J., Wu Y., Wu T., Cao L., Chen J., Qiu Z., Zhang Y., Xu G., Zhang J., Liu P.

Polish Journal of Ecology

|

2017

|

Vol. 65, nr 2

247--257

EN

Magnolia cylindrica Wils. is one of the third most-protected wild plants in China. To describe the size structure and dynamics of its population, field data were obtained from eight newly established sites, using a contiguous grid quadrate method in Jiulong Mountain of East China. The population size structure and spatial distribution pattern were discussed based on a theoretical distribution model and assembling intensity index. The population size structure showed a declining trend because of the lack of seedlings. The number of stump-sprouting, size class III (sapling trees) individuals was large enough to make up for the shortage of small seedlings and the complete regeneration of populations through sprouting. The distributions of M. cylindrica, both seedling populations (Group A) and overall populations (Group B), were mostly clumped. The spatial pattern intensities of the populations at different stages (mainly small trees, middle trees, and big trees) were higher for Group A than those for Group B. The two groups have the same tendency in that the pattern intensity declined from small trees to the larger ones. Group A and Group B differed in spatial pattern: small and middle trees were randomly distributed in seedling populations, but aggregated in overall populations. The populations of M. cylindrica (both group A and B) were characterized by the pattern scale between 16 to 32 m2, measured by Greig-Smith and Kershaw methods. These results suggest that sprouting should be seriously considered in population rehabilitation and forest tending management and the area of forest tending management should be close to the maximum intensity.

2

Spiking Neural P Systems with Rules on Synapses Working in Sum Spikes Consumption Strategy

Su Y., Wu T., Xu F., Păun A.

Fundamenta Informaticae

|

2017

|

Vol. 156, nr 2

187--208

EN

Spiking neural P systems with rules on synapses (RSSN P systems, for short) are a class of distributed and parallel computation models inspired by the way in which neurons process and communicate information with each other by means of spikes, where neurons only contain spikes and the evolution rules are on synapses. RSSN P systems have been proved to be Turing universal, using the strategy that restricts all the applied rules to consume the same number of spikes from the given neuron, termed as equal spikes consumption strategy. In this work, in order to avoid imposing the equal spikes consumption restriction on the application of rules, a new strategy for rule application, termed as sum spikes consumption strategy, is considered in RSSN P systems, where a maximal set of enabled rules from synapses starting from the same neuron is nondeterministically chosen to be applied, in the sense that no further synapse can use any of its rules, and the sum of these numbers of spikes that all the applied rules consume is removed from the neuron. In this way, the proposed strategy avoids checking whether all the applied rules consume the same number of spikes from the given neuron. The computation power of RSSN P systems working in the proposed strategy is investigated, and it is proved that such systems characterize the semilinear sets of natural numbers, i.e., such systems are not universal. Furthermore, RSSN P systems with weighted synapses working in the proposed strategy are proved to be Turing universal. These results show that the weight on synapses is a powerful ingredient of RSSN P systems in terms of the computation power, which makes RSSN P systems working in sum spikes consumption strategy become universal from non-universality.

3

A Note on Spiking Neural P Systems with Homogenous Neurons and Synapses

Yu Y., Wu T., Xu J., Wang Y., He J.

Fundamenta Informaticae

|

2017

|

Vol. 150, nr 2

231--240

EN

Spiking neural (SN, for short) P systems are a class of computation models inspired from the way in which neurons communicate by exchanging spikes. SN P systems with homogenous neurons and synapses are a new variant of SN P systems, where the spiking and forgetting rules are placed on synapses instead of in neurons and each synapse has the same set of spiking and forgetting rules. Recent studies illustrated that this variant of SN P systems is Turing universal as both number generating and accepting devices. In this note, we prove that SN P systems with homogenous neurons and synapses without the feature of delay are also Turing universal. This result gives a positive answer to an open problem formulated in [K. Jiang, et al. Neurocomputing 171(2016) 1548-1555] “whether SN P systems with homogenous neurons and synapses are Turing universal when the feature of delay is not used”.

4

Small Universal Spiking Neural P Systems with Homogenous Neurons and Synapses

Wu T., Wang Y., Jiang S., Shi X.

Fundamenta Informaticae

|

2016

|

Vol. 149, nr 4

451--470

EN

Spiking neural (SN, for short) P systems are a class of distributed parallel computing models inspired by the way in which neurons communicate with each other by means of electrical impulses. Recently, a new variant of SN P systems, called SN P systems with homogenous neurons and synapses (HRSSN P systems for short) was proposed, where the spiking and forgetting rules are placed on synapses instead of in neurons and each synapse has the same set of spiking and forgetting rules. This variant of SN P systems has already been proved to be Turing universal as both number generating and accepting devices. In this work, we consider the problem of looking for small universal HRSSN P systems. Specifically, a universal HRRSN P system with standard rules and weight at most 5 having 70 neurons is constructed as a device of computing functions; as a number generator, we find a universal system with standard rules and weight at most 5 having 71 neurons.

5

On the Universality of Colored One-Catalyst P Systems

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

Fundamenta Informaticae

|

2016

|

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

|

2016

|

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

Effects of the Horizontal offset of the Ring Spinning Triangle on Yarn

Liu X., Su X., Wu T

Fibres & Textiles in Eastern Europe

|

2013

|

Vol. 21, no. 1 (97)

35--40

EN

The spinning triangle is a critical region in the spinning process of yarn. Its geometry influences the distribution of fibre tension in the spinning triangle and, thus, affects the properties of spun yarns. Therefore, taking appropriate measures to influence the spinning triangle geometry and thus improve the quality of yarn has attracted great interesting in recent years. During the geometry parameters, the horizontal offset of the twisting point to the symmetric axis of the nip line of the spinning triangle d has attracted more and more attention and is considered as one of the most critical factors influencing the quality of yarn. Therefore, in this paper, the effects of the horizontal offset d of the ring spinning triangle on yarn qualities is investigated. Firstly a theoretical model of the fibre tension distributions in the spinning triangle is given. Relationships between the fibre tension and horizontal offset of the spinning triangle are analysed theoretically. Secondly, as an application of the model proposed, the spinning triangles of a modified ring spinning system with a pair of offset devices which can change the horizontal offset ‘d’ continuously are studied. The distributions of fibre tension in the spinning triangle are simulated numerically, with the horizontal offset varying continuously. Furthermore the properties of spun yarns produced by the modified system are evaluated and analysed by using the simulation results.

PL

Trójkąt przędący jest istotnym parametrem w procesie przędzenia. Jego geometria wpływa na rozkład naprężeń włókien w trójkącie przędącym, co oddziałuje na właściwości przędzy. Dlatego w ostatnich latach dużym zainteresowaniem cieszą się badania nad wpływem geometrii trójkąta przędącego w celu uzyskania możliwie najwyższej jakości. Konfiguracja geometryczna, w tym poziome przesunięcie trójkąta przędącego odgrywają coraz większą rolę w analizach procesu przędzenia obrączkowego. Autorzy przedstawili teoretyczny model rozkładów naprężeń włókien w trójkącie przędącym i przeanalizowali teoretyczne zależności pomiędzy naprężeniem włókien a ustawieniem trójkąta przędącego. Przeprowadzono symulację numeryczną i na jej podstawie wyciągnięto wnioski dotyczące jakości produkowanej przędzy.

8

Laser diode array (LDA) end-pumped multi-watt Yb:YAG 1030 nm laser

Cao H., Peng H., Zhang M., Chen Y., Zhang B., Chen B., Zhang J., Wu T., Zhao X., Tan H.

Optica Applicata

|

2010

|

Vol. 40, nr 3

653--656

EN

A LDA (laser diode array) end-pumped Yb:YAG 1030 nm laser is reported. Using a plano-concave resonator, with input pump power of 11.79 W, 2.55 W TEM00 continuous wave laser at 1030 nm was obtained. The effective focal length of the thermal lens is also calculated.

9

Theoretical analysis of plastic zone of a circle crack under gigacycle fatigue regime

Wu T., Mo T., Chen W., Bayraktar E.

Archives of Computational Materials Science and Surface Engineering

|

2009

|

Vol. 1, nr 4

245-251

EN

Purpose: Different kinds of alloys used in industry for structures and engine components are subjected to very high cycle fatigue (gigacycle regime) damage under the service conditions. In this study, fatigue damage evolution of some metallic-industrial alloys was investigated on very high cycle fatigue regime and calculation of the stress intensity factor (SIF) using finite element method (FEM) was realized under the ultrasonic vibration conditions. A formula of SIF vs. Cracks size and position of the crack has been developed. In fact, calculation of the SIF under ultrasonic vibrating fatigue has to be a function of amplitude instead of nominal stress as frequently used in traditional fatigue from Woehler. Design/methodology/approach: The specimens are tested at ultrasonic fatigue frequency of 20 kHz with a stress ratio of R=-1 (tension-compression) under load control. In order to control the displacement amplitude at the end of the amplifier was calibrated by optical sensor before each fatigue test. Failure mechanisms have been studied by means of the scanning electron microscope (SEM). The fracture origin and/or inclusions were identified by use of energy disperse analysis. Findings: An analytical approach was validated to calculate the stress intensity factor, KI, for the specimen specially designed for Gigacycle fatigue test. Practical implications: This heat source will be useful to position and size the small crack inside the specimen according to surface temperature variation with further heat transfer analysis. The relation between energy power and stress intensity factor helps to determine crack size and position from the temperature field on the specimen surface. Originality/value: Based on the SIF calculation and from classical fracture mechanics, dissipated energy of the plastic zone of the crack is derived and considered as heat source when the crack initiates.

10

Preparation, Characterization of MCM-49 and Catalytic Performance of Pd/MCM-49 Catalysts in One-step Synthesis of MIBK from Acetone

Yang P., Wang Z., Yu J., Xu M., Liu Q., Jing S., Wu T.

Polish Journal of Chemistry

|

2005

|

Vol. 79 / nr 1

121-127

EN

Highly crystalline and pure MCM-49 was hydrothermally synthesized by a dynamic method, and it was used as supports to prepare Pd/MCM-49 catalysts by ion-exchange method. The physicochemical properties of the samples were characterized by XRD, TEM, TG-DTG and ICP. MCM-49 synthesized was markedly different from those in previous reports, showing much smaller crystals. One-step synthesis of methyl isobutyl ketone from acetone was investigated over Pd/MCM-49. These catalysts showed a high reactivity and selectivity to MIBK, reaching a conversion of 35.6% and a selectivity of 85% to MIBK. Stable MIBK yields were obtained during 60 h of time on stream.

11

Estimation of Consecutive and Parallel Reactions During Dehydrogenation with Carbon Dioxide over Co-MCM-41

Li Y., Guo X., Zhou G., He X., Bi Y., Li W., Cheng T., Wu T., Zhen K.

Polish Journal of Chemistry

|

2005

|

Vol. 79 / nr 8

1357-1364

EN

The main reactions between C2H6 and CO2 and their thermodynamics were studied, which indicated that there exist very complicated reactions between them. CO2 can enhance the equilibrium conversion of C2H4 formationvia dehydrogenation of C2H6 and react with the surface deposited carbon, resulting in stabilization of the activity and the prolongation of lifetime of the catalyst. Thus, the exploration of catalyst with desired C2H4 selectivity from oxidative dehydrogenation of ethane (ODE) is most important. In this study, the possible reactions of ODE with CO2 on Co-MCM-41 catalyst are discussed.