Understorey plant community and light availability in conifer plantations and natural hardwood forests in Taiwan

Questions: What are the effects of replacing mixed species natural forests with Cryptomeria japonica plantations on understorey plant functional and species diversity? What is the role of the understorey light environment in determining understorey diversity and community in the two types of forest? Location: Subtropical northeast Taiwan. Methods: We examined light environments using hemispherical photography, and diversity and composition of understorey plants of a 35‐yr C. japonica plantation and an adjacent natural hardwood forest. Results: Understorey plant species richness was similar in the two forests, but the communities were different; only 18 of the 91 recorded understorey plant species occurred in both forests. Relative abundance of plants among different functional groups differed between the two forests. Relative numbers of shade‐tolerant and shade‐intolerant seedling individuals were also different between the two forest types with only one shade‐intolerant seedling in the plantation compared to 23 seedlings belonging to two species in the natural forest. In the natural forest 11 species of tree seedling were found, while in the plantation only five were found, and the seedling density was only one third of that in the natural forest. Across plots in both forests, understorey plant richness and diversity were negatively correlated with direct sunlight but not indirect sunlight, possibly because direct light plays a more important role in understorey plant growth. Conclusions: We report lower species and functional diversity and higher light availability in a natural hardwood forest than an adjacent 30‐yr C. japonica plantation, possibly due to the increased dominance of shade‐intolerant species associated with higher light availability. To maintain plant diversity, management efforts must be made to prevent localized losses of shade‐adapted understorey plants

Зарубіжний досвід стимулювання розвитку малого та середнього бізнесу

У статті визначено основні сучасні центри ефективних технологій підтримки підприємництва, проведено аналіз особливостей державної політики розвитку малого та середнього бізнесу в США, визначено ефективні методи стимулювання розвитку малого та середнього бізнесу в умовах кризи.В статье определены основные современные центры эффективных технологий поддержки предпринимательства, проведен анализ особенностей государственной политики развития малого и среднего бизнеса в США, определены эффективные методы стимулирования развития малого и среднего бизнеса в условиях кризиса.In the article the main modern centers of effective technologies of supporting of business development are identified, the features of the state policy of small and medium businesses development in the U.S. are analyzed; most effective methods of stimulating of small and medium businesses development in conditions of crisis are identified

High performance Beowulf computer for lattice QCD

We describe the construction of a high performance parallel computer composed of PC components, as well as the performance test in lattice QCD.Comment: Lattice 2001 (Algorithms and Machines) 3 page

Bis (1Z,3Z)-1,3-bis(4-fluorophenyl)-N,N '-diphenylpropanediiminato magnesium(II)

In the title complex, [Mg(C27H19F2N2)(2)], the Mg-II atom, lying on a crystallographic twofold rotation axis, is tetrahedrally coordinated by four N atoms from two diiminate ligands

Effect of microstructures on the electron-phonon interaction in the disordered metals Pd60_{60}Ag40_{40}

Using the weak-localization method, we have measured the electron-phonon scattering times $\tau_{ep}$ in Pd$_{60}$Ag$_{40}$ thick films prepared by DC- and RF-sputtering deposition techniques. In both series of samples, we find an anomalous $1/\tau_{ep} \propto T^2\ell$ temperature and disorder dependence, where $\ell$ is the electron elastic mean free path. This anomalous behavior cannot be explained in terms of the current concepts for the electron-phonon interaction in impure conductors. Our result also reveals that the strength of the electron-phonon coupling is much stronger in the DC than RF sputtered films, suggesting that the electron-phonon interaction not only is sensitive to the total level of disorder but also is sensitive to the microscopic quality of the disorder.Comment: accepted for publication in Phys. Rev.

Bis{N- (1Z, 3Z)-1,3-bis(4-fluorophenyl)-3-(phenylimino)prop-1-enyl aniline(1-)}zinc( II)

In the title complex, [Zn(C27H19F2N2)(2)], a twofold rotation axis passes through the Zn atom, which is tetrahedrally coordinated by four N atoms from two diketiminate ligands. There are no intermolecular interactions of note in the crystal structure

Residual Strains of Filter Materials Reinforced with Grid Inclusions under Cyclic Loading

Reinforcement technology is widely used for filter dams in high-seismicity zones. The effect of reinforcement on deformation and safety is evaluated, and it is one of the primary objectives to be investigated in filter engineering. Residual strains of reinforced filter materials were experimentally studied using a triaxial apparatus. The effect of reinforcement mesh sizes, confining pressures, and cyclic loading modes on residual strains was analyzed. The results show that the reinforcement reduces residual strains of filter materials. Both residual shear and volume strains are determined. Based on the test results, one of the possible mechanisms of the reinforcement effect on residual strains is proposed..Технология армирования широко используется для упрочнения фильтрующих плотин в зонах высокой сейсмичности. Оценено влияние армирования на их деформирование и надежность, что является одной из основных проблем, рассматриваемых при разработке фильтровальных материалов. Выполнены экспериментальные исследования по оценке остаточных деформаций упрочненных фильтровальных материалов с использованием трехосного устройства. Проанализировано влияние размера ячеек армирующей сетки, ограничивающих давлений и режимов циклического нагружения на остаточные деформации. Результаты показывают, что армирование уменьшает остаточную деформацию фильтровальных материалов. Определены остаточные сдвиговые и объемные деформации. На основании результатов испытаний предложен один из возможных механизмов влияния упрочнения на остаточные деформации

Galerkin FEM for fractional order parabolic equations with initial data in H−s, 0<s≤1H^{-s},~0 < s \le 1

We investigate semi-discrete numerical schemes based on the standard Galerkin and lumped mass Galerkin finite element methods for an initial-boundary value problem for homogeneous fractional diffusion problems with non-smooth initial data. We assume that $\Omega\subset \mathbb{R}^d$, $d=1,2,3$ is a convex polygonal (polyhedral) domain. We theoretically justify optimal order error estimates in $L_2$- and $H^1$-norms for initial data in $H^{-s}(\Omega),~0\le s \le 1$. We confirm our theoretical findings with a number of numerical tests that include initial data $v$ being a Dirac $\delta$-function supported on a $(d-1)$-dimensional manifold.Comment: 13 pages, 3 figure