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  • Author: H. Zhang x
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Semi-Analytical Solution of Optimization on Moon-Pool Shaped WEC

Abstract

In order to effectively extract and maximize the energy from ocean waves, a new kind of oscillating-body WEC (wave energy converter) with moon pool has been put forward. The main emphasis in this paper is placed on inserting the damping into the equation of heaving motion applied for a complex wave energy converter and expressions for velocity potential added mass, damping coefficients associated with exciting forces were derived by using eigenfunction expansion matching method. By using surface-wave hydrodynamics, the exact theoretical conditions were solved to allow the maximum energy to be absorbed from regular waves. To optimize the ability of the wave energy conversion, oscillating system models under different radius-ratios are calculated and comparatively analyzed. Numerical calculations indicated that the capture width reaches the maximum in the vicinity of the natural frequency and the new kind of oscillating-body WEC has a positive ability of wave energy conversion.

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Anatomical and Physiological Effects of Phytohormones on Adventitious Roots Development in Larix kaempferi × L. olgensis

Abstract

Adventitious root development is crucial for cutting propagation in hybrid larch. In the present study, semilignified cuttings of Larix kaempferi × L. olgensis clones were used to study the morphological and anatomical changes during the different development stages and compare the changes in contents of endogenous phytohormone in two clones with evidently different rooting capacity (25-5 and 23-12), and the effects of exogenous Indole-3-Butyric Acid (IBA) on phytohormone content of a very low native rooting capacity clone (8-9) during the development of adventitious roots. The results showed that the development of adventitious root in semi-lignified cuttings involves three key stages: root cell dedifferentiation and division (14-18 DAC); meristem formation and development (25-35 DAC); root formation and elongation (50-55 DAC). The endogenous phytohormones play a key role during adventitious root development. For 25-5 and 23-12, the level of endogenous phytohormones, especially the ABA content, has an important effect on rooting capacity. For the effects of IBA on 8-9, except lower ABA content, the temporary peak of IAA on the 1 DAC was important for initiating the rooting process. The ratio of (IAA + GA3 + ZR)/ABA can be used as an indicator of rooting capacity. The anatomical and physiological data described here for semi-lignified cuttings of L. kaempferi × L. olgensis clones improves our knowledge of adventitious roots development. Our study will also benefit future research on examining the molecular mechanisms of the adventitious roots development in hybrid larch.

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Neogene seismites and seismic volcanic rocks in the Linqu area, Shandong Province, E China

Abstract

The Yishu Fault Zone runs through the centre of Shandong Province (E China); it is a deep-seated large fault system that still is active. Two volcanic faulted basins (the Shanwang and Linqu Basins) in the Linqu area, west of the fault zone, are exposed to rifting, which process is accompanied by a series of tectonic and volcanic earthquakes with a magnitude of 5-8. Lacustrine sediments in the basins were affected by these earthquakes so that seismites with a variety of soft-sediment deformation structures originated. The seismites form part of the Shanwang Formation of the Linqu Group. Semi-consolidated fluvial conglomerates became deformed in a brittle way; these seismites are present at the base of the Yaoshan Formation. Intense earthquakes triggered by volcanic activity left their traces in the form of seismic volcanic rocks associated with liquefied-sand veins in the basalt/sand intercalations at the base of the Yaoshan Formation. These palaeo-earthquake records are dated around 14-10 Ma; they are responses to the intense tectonic extension and the basin rifting in this area and even the activity of the Yishu Fault Zone in the Himalayan tectonic cycle.

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Genetic parameters and prediction of breeding values in Castanopsis hystrix A.DC. for growth and form traits

Abstract

Castanopsis hystrix A.DC. is one of the most important and multipurpose tree species native to China. 157 open-pollinated families collected from 11 provenances in Guangdong, Guangxi, and Fujian province were used to estimate genetic parameters for height (H), diameter at breast height (DBH), ground diameter (GD), and crown width (CW) for each province and combined three provinces at ages from 3 to 9 years. The variance component was small and non-significant among provenances but was highly significant among families within provenances for H, DBH, GD, and CW. Heritability estimates were significant except for a few traits from Fujian’s provenances. Heritability ranged from 0.20 to 0.57 for H, 0.19 to 0.38 for DBH, 0.21 to 0.55 for GD, and 0.09 to 0.39 for CW. Heritability estimates for H and DBH decreased with increased age for each province and combined three provinces. Significantly high genetic correlations were observed for ageage and trait-trait correlations, indicating that genetic performance at one trait was well correlated with another trait. In total, 22 families and 60 individuals were selected for backward and forward selection based on breeding values.

Open access
Triploid Induction in Populus alba x P. glandulosa by Chromosome Doubling of Female Gametes

Abstract

Efficient methods for obtaining unreduced female gametes are needed for triploid induction in Populus alba x P. glandulosa. A cytological study of MMCs and PMCs meiosis and staminate floral elongation revealed that there was a close association between MMCs meiotic stage and male bud phenology during development under the same environment conditions. Female buds of Populus alba x P. glandulosa were treated with 0.5% colchicine solution at the selected meiotic stages based on male bud phenology. The treated buds were pollinated with pollen of P. tomentosa. A high rate of unreduced female gametes occurred in late leptotene and pachytene stages of MMC, as evidenced by a relatively higher percentage of triploids in the progeny, when compared to progeny from colchincine application at other meiotic stages. The present results demonstrated that male bud phenology can be used to guide colchicine applications to female buds and cause a more efficient production of triploids.

Open access
Heavy subgraph pairs for traceability of block-chains

Abstract

A graph is called traceable if it contains a Hamilton path, i.e., a path containing all its vertices. Let G be a graph on n vertices. We say that an induced subgraph of G is o−1-heavy if it contains two nonadjacent vertices which satisfy an Ore-type degree condition for traceability, i.e., with degree sum at least n−1 in G. A block-chain is a graph whose block graph is a path, i.e., it is either a P1, P2, or a 2-connected graph, or a graph with at least one cut vertex and exactly two end-blocks. Obviously, every traceable graph is a block-chain, but the reverse does not hold. In this paper we characterize all the pairs of connected o−1-heavy graphs that guarantee traceability of block-chains. Our main result is a common extension of earlier work on degree sum conditions, forbidden subgraph conditions and heavy subgraph conditions for traceability

Open access
Design Method of Winch Driven by Contactless Magnetic Coupling under Deepwater

Abstract

Through the combination subject of scientific research, the design method of the winch driven by contactless magnetic coupling is researched for the core purpose of the turning shaft sealing in a deepwater environment. This method has six design phases, including domestic and foreign information query and retrieval, graphic analyses of relevant structures, innovative design of 2D assembly sketches, a theoretical computation of structure parameters, the 3D modeling and motion simulation and engineering drawing. This method is of generality, which can provide examples for the postgraduate students and engineering personnel in self-renovation design of scientific research.

Open access
Serological survey for sparganum infection in people of central China

Abstract

During 2006–2008, twenty cases with sparganosis caused by eating live tadpoles emerged in Henan province, central China. To determine seroprevalence of anti-sparganum antibodies and obtain information about habits of eating live tadpoles and risks for sparganum infection, a serological survey was carried out in one village of Henan. Antisparganum IgG in 298 serum samples were assayed by ELISA using excretory and secretory (ES) antigens of Spirometra mansoni spargana. The results showed 56.71 % (169/298) of inhabitants had the history of eating live tadpoles. The overall seroprevalence was 5.7 % (17/298). The seroprevalence of the inhabitants who had the habit of eating tadpoles (9.47 %) was obviously higher than those who did not (0.78 %) (P < 0.01). Eating live tadpoles had become the most common risk behavior for sparganum infection. Hence, the comprehensive public health education should be carried out in endemic areas, and the habit of eating live tadpoles must be discouraged.

Open access
Genetic Variation and Structure of native and introduced Casuarina equisetifolia (L. Johnson) Provenances

Abstract

Casuarina equisetifolia is an important tree species in tropical/subtropical zones of Asia, the Pacific and Africa. In this study, 220 individuals from seven native provenances and eleven introduced provenances of C. equisetifolia were analyzed to assess the genetic variation and structure using amplified fragment length polymorphism (AFLP) markers. A total of 465 bands were obtained by eight primer pairs, among which 153 were polymorphic. The mean NEI’s gene diversity H = 0.2113 calculated for 18 provenances and the total gene diversity HT = 0.4065 calculated for native provenances suggested abundant variation within provenances and species. High genetic divergence coefficient (GST = 0.4737) and low gene flow (Nm = 0.5555) detected among native provenances suggesting high differentiation of C. equisetifolia. An AMOVA analysis for native provenances revealed a high proportion (46.07%) of the total genetic variation distributed among provenances. The UPGMA clustering (r = 0.8028) and the Mantel test (r = 0.0716) for native provenances showed there was no correlation among genetic relationships and geographical distribution. The genetic information provided important implications for the future conservation and breeding programs of C. equisetifolia.

Open access
Morphological and molecular characterization of Xiphinema species from Shenzhen, China

Summary

During a nematode biodiversity survey from 2012 to 2014 in Shenzhen, China, ten nematode populations (SZX1301–SZX1310) of Xiphinema were recovered from rhizosphere of different plants, namely Acacia mangium (SZX1306), A. confuse (SZX1309), Blechnum orientale (SZX1301, SZX1302, SZX1307, SZX1308), Litchi chinensis (SZX1304, SZX1310) in Tianxinshan and Gleichenia linearis (SZX1303, SZX1305) in Yangmeikeng environmental monitoring sites. Morphological and molecular profiles of these populations were determined. Three species of Xiphinema, i.e., X. hunaniense Wang & Wu, 1992, X. brasiliense Lordello, 1951 and X. americanum Cobb, 1913 sensu lato were identified using morphological characters and molecular data of partial 18S and 28S D2–D3 rDNA expansion segments. Four populations (SZX1301–SZX1304) were X. hunaniense, one population (SZX1305) X. brasiliense, and five populations (SZX1306–SZX1310) X. americanum s.l.. Phylogenetic analysis based on sequences of the 28S rDNA D2–D3 expansion segment revealed these three species are all distinct species and supported a close relationship with their corresponding species. This is the first report of X. hunaniense, X. brasiliense and X. americanum s.l. in their hosts except for L. chinensis.

Open access