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1

Nitrogen Deposition Influences the Allelopathic Effect of an Invasive Plant on the Reproduction of a Native Plant : Solidago canadensis versus Pterocypsela laciniata

Wang C., Liu J., Xiao H., Zhou J., Du D.

Polish Journal of Ecology

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2017

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Vol. 65, nr 1

87--96

EN

This study aims to gain insights into the allelopathic effects (by using leaf extracts) of the notorious invasive Solidago canadensis L. on seed germination of the associated Pterocypsela laciniata (Houtt.) C. Shih under different nitrogen (N) forms added: inorganic (NO3- -N and NH4+ -N), organic (urea-N), and mixed N (a mixture of the three N forms at 1:1:1 ratio). Among the two used concentrations of S. canadensis leaf extracts the higher exhibited inhibitory allelopathic effects on seedling height and biomass, germination potential, germination index, and vigor index of P. laciniata. N demonstrated positive effects on seed germination of P. laciniata. The effects of mixed and organic N on the seedling biomass of P. laciniata were more pronounced than those of inorganic N and control treatment. The vigor index of P. laciniata under mixed N was significantly higher than those under single N form and control treatment. Thus, organic and mixed N showed higher ecological effects on seed germination of P. laciniata than inorganic and single N form. All N forms could alleviate the inhibitory allelopathic effects of S. canadensis on seed germination of P. laciniata. Overall, the inhibitory allelopathic impact of S. canadensis on seed germination of native species may be attenuated under increased and diverse N deposition, thus it could prevent its further invasion.

2

Structure and Improvement of Properties of Floss Silk via Scouring and Finishing Treatment

Lin H., Ma P., Ning W., Huang J., Jiang F., Hu Z., Xiao H.

Fibres & Textiles in Eastern Europe

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2013

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Vol. 21, no. 3 (99)

18--21

EN

In the present study, floss silk was treated by scouring and finishing, respectively. The micro structure was observed with scanning electron microscopy (SEM), the mechanical property tested by an Instron 5566 tensile tester, and the crystal structure was analysed with Fourier transform attenuated total reflection infrared spectroscopy (FTIR) and X-ray diffraction (XRD), respectively. The results show that the properties of floss silk treated with the refining method are better than with the alkali method.

PL

Badania dotyczyły obróbki wykańczalniczej jedwabiu naturalnego. Mikrostruktura jedwabiu była badana za pomocą skaningowej mikroroskopii elektronowej, a właściwości mechaniczne testowane były klasyczną zrywarką firmy Instron, podczas gdy strukturę krystaliczną analizowano za pomocą spektroskopii w podczerwieni (FTIR) oraz rozproszenia promieniowania rentgenowskiego. Wyniki pozwoliły wytypować najlepszą w danych warunkach metodę obróbki.

3

The Design of the Signal Generator Circuit for Single-Phase Industrial Frequency Power Based on XC2C64A

Xiao H., Lv K.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 5b

76-78

EN

The paper mainly introduces the new signal generator circuit of industrial frequency power based on XC2C64A, which focus all digital circuit in a CPLD chip, making simple structure and convenient debugging. And the general diagram, design idea, the benchmark waveform signal oscillating circuit, frequency synthesis circuit, phase synthesis circuit and D/A transformation circuit are given in the paper. The phase and frequency of the circuits are simulated.

PL

Zaprezentowano nową koncepcję genertatora sygnałów o częstotliwości przemysłowej wykorzystujący syntezę częstotliwości i fazy oraz przetwornik cyfrowo-analogowy. Układ bazuje na obwodzie XC2C64A.

4

A quantum chemical study on thermolysis initiation mechanisms and impact sensitivity of energetic materials

Xu X., Xiao H., Fan J., Chen Z.

Central European Journal of Energetic Materials

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2005

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Vol. 2, nr 4

5-21

EN

Thermolysis initiation mechanisms of polynitro compounds, tetrazole derivatives and their metallic salts, and cage high energy density compounds have been investigated using quantum chemical approaches. Our calculations showed that the trigger bonds whose breaking initiate a decomposition or an explosion were C-NO2 or N-NO2 bonds for nitro derivatives of benzene and aminobenzenes, CL-20 and polynitroadamantanes. Explosion of nitro derivatives of phenol and toluene were most likely triggered by the isomerization reactions involving the H-shift. Due to larger strain energy, the trigger bond was found to be the C-C bond in the framework of polynitrocubanes. Regarding tetrazoles and their metallic salts, opening of the tetrazole ring, i.e., scission of the N-N bond, followed by formation of N2 molecules, initiate explosive reactions. We found for energetic materials having similar molecular structures and following similar thermal decomposition mechanisms, the bond orders of the trigger bond and the activation energy to break the bond were directly related to the impact sensitivity. We thus proposed two criteria used to evaluate the relative ordering of impact sensitivity for energetic materials with similar structures: the smaller the bond order, the more sensitive an energetic material, which was called the principle of the smallest bond order (PSBO). And the higher the activation energy, the less sensitive a material was. We demonstrated that in most cases the PSBO was equivalent to the activation energy criterion. The former was more convenient and easier to obtain while the latter could be applied more universally.

5

Crystal Structure, Infrared Spectra and Density Functional Theory Study on 2,3-Diketo-benzopiperazine Dimer

Zhao P., Jian F. F., Xiao H., Sun P.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 10

1935-1944

EN

2,3-Diketo-benzopiperazine, which exists as dimeric form in its crystal structure has been synthesized. The calculated results on the dimer at B3LYP/6-31G* level show that the average strength of the double hydrogen bonds is of medium-grade. Natural bond orbital analyses have been performed. The predicted harmonic vibration frequencies support the experimental values. The thermodynamic properties of the dimer at different temperatures have been calculated and the change of Gibbs free energy for the aggregation from the monomer to the dimerDelta GT = -30.86 kJ/mol at 298.15 K, which implies the spontaneous process of the dimer formation.

6

Irreducible representations for constitutive equations of anisotropic solids III: crystal and quasicrystal classes D[2m+1h] and D[2md]

Xiao H., Bruhns O., Meyers A.

Archives of Mechanics

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2000

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Vol. 52, nr 3

347-395

EN

A simple, unified procedure is applied to derive irreducible nonpolynomial representations for scalar-, vector-, skewsymmetric and symmetric second order tensor-valued anisotropic constitutive equations involving any finite number of vector variables and second order tensor variables. In this part, our concern is for the crystal classes and quasicrystal classes D[2m+1h] and D[2md] for all integers m>=1.

7

Irreducible representations for constitutive equations of anisotropic solids II: crystal and quasicrystal classes D[2m+1d], D[2m+1] and C[2m+1v]

Xiao H., Bruhns O., Meyers A.

Archives of Mechanics

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2000

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Vol. 52, nr 1

55-88

EN

A simple, unified procedure is applied to derive irreducible nonpolynomial representations for scalar-, vector-, skewsymmetric and symmetric second order tensor-valued anisotropic constitutive equations involving any finite number of vector variables and second order tensor variables. In this part, our concern is for all crystal classes and quasicrystal classes D[2m+1d], D[2m+1] and C[2m+1v] for all integers m >= l.

8

Hencky's elasticity model with the logarithmic strain measure : a study on Poynting effect and stress response in torsion of tubes and rods

Bruhns O., Xiao H., Meyers A.

Archives of Mechanics

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2000

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Vol. 52, nr 4-5

489-509

EN

Hencky's elasticity model is a finite strain elastic constitutive equation derived by replacing the infinitesimal strain measure in the classical strain-energy function of infinitesimal isotropic elasticity with Hencky's logarithmic strain measure. ANAND [1, 2] has demonstrated that, with only the two classical Lame elastic constants measurable at infinitesimal strains, predictions of the just-mentioned simple model for a wide class of materials for moderately large deformations may be in better agreement with experimental data than other known finite elasticity models. The deformation modes considered in Anand's work are simple tension and compression, simple shear, and simple torsion and combined extension-torsion of solid cylinders, etc. Here, we indicate some remarkable properties of this Hencky model and, mainly, we investigate the large deformation responses of this model in torsion of cylindrical tubes and rods with free ends. It is noticeable that, with only the material properties measurable at infinitesimal strains, the Hencky model can predict the just-mentioned second order effects, in particular the Poynting effect, and its predictions are in good accord with experiments reported in the literature.

9

Irreducible representations for constitutive equations of anisotropic solids I: crystal and quasicrystal classes D[2mh], D[2m] and G[2mv]

Xiao H., Bruhns O., Meyers A.

Archives of Mechanics

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1999

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Vol. 51, nr 5

559-603

EN

A simple, unified procedure is applied to derive irreducible nonpolynomial representations for scalar-, vector-, skewsymmetric and symmetric second order tensor-valued anisotropic constitutive equations involving any finite number of vector variables and second order tensor variables. In the paper consisting of three parts, we consider all kinds of material symmetry groups as subgroups of the cylindrical group D[infinity]h. This paper, together with a previous work, covers all kinds of material symmetric groups of solids, except for the five cubic crystal classes and the two icosahedral quasicrystal classes. In this part, our concern is with all crystal classes and quasicrystal classes D[2mh], D[2m] and G[2mv] for all integers m [is greater than or equal to] 2.

10

On symmetric tensor-valued isotropic functions of a symmetric tensor and a skewsymmetric tensor and related transversely isotropic functions

Xiao H., Bruhns O., Meyers A.

Archives of Mechanics

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1998

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Vol. 50, nr 4

731-741

EN

A new generating set consisting of seven polynomial tensor generators is presented for symmetric second order tensor-valued isotropic functions of a symmetric second order tensor and a skewsymmetric second order tensor. It is smaller than the existing corresponding generating set consisting of eight tensor generators and shown to be minimal in all possible generating sets consisting of homogeneous polynomial tensor generators. This result indicates that the well-known results for isotropic functions may be sharpened. In addition, from the presented results a minimal generating set consisting of six tensor generators is derived for the symmetric second order tensor-valued transversely isotropic functions of a symmetric second order tensor relative to the transverse isotropy group C [...] consisting of all rotations about a fixed axis.

11

On anisotropic funcions of vectors and second order tensors - all subgroups of the transverse isotropy group C[infinity h]

Xiao H.

Archives of Mechanics

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1998

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Vol. 50, nr 2

281-319

EN

A unified procedure for constructing both the generating sets and the functional bases is suggested, which reduces the representation problem for anisotropic functions of any finite number of vector and second order tensor variables under any subgroup [...], to that for the same types of anisotropic functions of not more than twovector and/or second order tensor variables. By using this procedure and new results for isotropic extension of anisotropic functions, simple irreducible generating sets and functional bases in unified forms are presented to determine general reduced forms of scalar-, vector-, and second order tensor-valued anisotropic functions of any finite number of vectors and second order tensors, under all kinds of subgroups of the transvere isotropy group C[infinity h]. The results given are derived in the sense of nonpolynomial representation.

12

Objective corotational rates and unified work-conjugacy relation between Eulerian and Lagrangean strain and stress measures

Xiao H., Bruhns O., Meyers A.

Archives of Mechanics

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1998

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Vol. 50, nr 6

1015-1045

EN

By virtue of objective corotational rates and related corotating frames, a unified work-conjugacy relation between Eulerian and Lagrangean strain and stress measures is established, which is a natural extension of Hill's work-conjugacy relation between Lagrangean strain and stress measures. It turns out that the latter is the particular case of the former one when a corotating frame with the well-known spin ------ is concerned, where R is the rotation tensor defined by the polar decomposition of the deformation gradient. The work-conjugate stress measure of an arbitrary Hill's strain measure (either Eulerian or Lagrangean) with regard to any kind of objective corotational rate is determined in the seanse of the introduced unified work-conjugacy relation. The result is presented both in the principal component form and explicit basis-free form valid for all cases of the principal stretches. In particular, the intrinsic, unique relationship between Hencky's logarithmic strain measures --------------- and the fundamental mechanical quantities, i.e. the Eulerian and Lagrangean stretching tensors D and ------- and Eulerian and Lagrangean Kirchhoff stress measures -- and --------- are disclosed. It is shown that there are objective corotational rates of --------- that are identical with the Eulerian and Lagrangean stretching tensors D and ------- respectively, and further that only --------- enjoy the just-stated favourable properties. As a result, the two pairs of strain and stress measures, (-------) and (----------), form a work-conjugate Eulerian strain-stress pair and a work-conjugate Lagrangean strain-stress pair, respectively, in the sense of the introduced work conjugacy relation. Finally, application of the unified work-conjugacy notion in formulating the rate - type constitutive relations is indicated.