Ferromagnetic MnSb Films Consisting of Nanorods and Nanoleaves

Ferromagnetic MnSb films were synthesized on Si wafers by physical vapor deposition. X-ray diffraction revealed that the films primarily consisted of MnSb alloy. Nanorods and nanoleaves were observed in the MnSb films by field-emission scanning electron microscopy. These nanorods had an average diameter of 20nm and a length of up to hundreds of nanometers. The nanoleaves had a width and thickness of about 100 and 20nm, respectively. Magnetic hysteresis loops were measured by an alternative gradient magnetometer, and the loops showed strong geometrical anisotropy.

Distribution of Sediment Chloroplastic Pigments in the Southern Yellow Sea,China

The distribution of sediment chloroplastic pigments (Chl-a, i.e. chlorophylla and Pha-a, i.e. phaeophorbide a) in the Southern Yellow Sea of China was studied. Samples werecollected from four cruises in January and June 2003, and January and June 2004. The results showthat the vertical distribution of Chl-a and Pha-a in the sediment layers 0-2cm, 2-5cm and 5-8cm,follows a stable ratio, 5:3:2. The average ratio of Pha-a to Chl-a in sediment is 2.83. Spearman2-tailed rank correlation analysis shows that Chl-a and Pha-a contents in each sediment layer have ahighly significant correlation. The average contents of Chl-a and Pha-a in the sediment of the0-8cm layer in the investigated area are 0.31-0.47 μg g^(-1) and 1.28-1.40 μg g^(-1) sediment (dryweight), respectively. The average Chl-a and Pha-a contents in sediment are higher in summer thanin winter. ANOVA analysis shows that there is a highly significant variation among the Chl-acontents (P = 0.002 【 0.01) of the four cruies, but this is not true for the case of Pha-a content(P = 0.766 】0.05). The average Chl-a and Pha-a contents in the 2 sediment layers (0-2cm and 2-5cm)have significant or highly significant correlations with organic matter (OM), median diameter(Md_φ), silt plus clay percentage in the January 2003 cruise. In the June 2003 cruise, the averageChl-a content in the 3 sediment layers (0-2cm, 2-5cm, and 5-8cm) has a significant correlation withmeiofauna biomass, and Pha-a content has highly significant correlations with water depth, bottomwater temperature, OM and Md_φ. The contents of Chl-a and Pha-a are lower than those in estuariesand intertidal areas, but close to those in the same area studied previously.

Contribution of Atmospheric Nitrogen Compounds to N Deposition in a Broadleaf Forest of Southern China

A one-year study in a typical red soil region of southern China was conducted to determine atmospheric nitrogen (N) fluxes of typical N compounds (NH3, NH4-N, NO3-N, and NO2) and contribution of three sources (gas, rainwater, and particles) to N deposition. From July 2003 to June 2004, the total atmospheric N deposition was 70.7 kg N ha-1, with dry deposition accounting for 75% of the total deposition. Dry NH3 deposition accounted for 73% of the dry deposition and 55% of the total deposition. Moreover, NO2 contributed 11% of the dry deposition and 8% of the total deposition. Reduced N compounds (NH4+ and NH3) were the predominate contributors, accounting for 66% of the total deposition. Therefore, atmospheric N deposition should be considered when soil acidification and critical loads of atmospheric deposition on soils are estimated.

Study on the production effect and prevention index of the forthputting of sonsau cocuus sinensis chen on the Pinus tabulaeformis

The growth of Pinus tabulaeformis is influenced by the sonsau cocuus sinensis chen. When the insect density is more than 300-350 head/hundred beam conifer, sonsau cocuus sinensis chen occurred significantly influence the Pinus tabulaeformis＇ s growth. when the insect density reached 250-300 head/100 beam coniferous, sonsau cocuus sinensis chen significantly influence the accumulation of Pinus tabulaeformis volume. To determine the sonsau cocuus sinensis chen 2nd instar nymph theory control index was 220.5 / hundred beam needles has a guiding significance to the production practice.

Effects of Nitrogen Deposition on Tundra Vegetation Undergoing Invasion by Deyeuxia angustifolia in Changbai Mountains

In recent years, herbaceous species such as Deyeuxia angustifolia （Kom.） Y. L. Chang has invaded alpine tundra regions of the western slope of the Changbai Mountains. Because atmospheric nitrogen deposition is predicted to increase under a warming climate and D. angustifolia is sensitive to nitrogen addition, field experiments were conducted from 2010 to 2013 to determine the effect of increased nitrogen deposition on the mechanisms of D. angustifolia invasion. The goal of this study is to evaluate the impact of increased nitrogen deposition on the changes in alpine tundra vegetation （consisting mostly of Rhododendron chrysanthum Pall. and Vaccinium uliginosum Linn.）. The results showed that： 1） simulated nitrogen deposition affected overall characteristics and structure of R. chrysanthum and E uliginosum communities and had a positive impact on the growth of tundra vegetation invaded by 1）. angustifolia; 2） R. chrysanthum was more resistant to invasion by D. angustifolia than V.. uliginosum; 3） simulated nitrogen deposition could improve the growth and enhance the competitiveness of D. angustifolia, which was gradually replacing R. chrysanthum and V. uliginosum and might become the dominant species in the system in future, transforming alpine tundra into alpine meadow in the Chanebai Mountains.

Experimental study by online measurement of the precipitation of nickel hydroxide: Effects of operating conditions

The objective of this work is using the online measurement method to study the process of precipitation of nickel hydroxide in a single-feed semi-batch stirred reactor with an internal diameter ofD = 240mm. The effects of impeller speed, impeller type, impeller diameter and feed location on the mean particle size d43 and particle size distribution （PSD） were investigated, d43 and PSD were measured online using a Malvern Insitec Liquid Pro- cess Sizer every 20 s. It was found that d43 varied between 13 kwh and 26 lain under different operating conditions, and it decreased with increasing impeller diameter. When feeding at the off-bottom distance of D/2 under lower impeller speeds, d43 was significantly smaller than that at D/3. PSDs were slightly influenced by operating conditions.

Nematode Community Structure and Diversity Pattern in Sandy Beaches of Qingdao,China

We investigated the diversity and structure of free-living marine nematode communities at three sandy beaches representing typical intertidal environments of a temperate zone in Qingdao,Shandong Province,China.Average nematode abundance ranged from 1006 to 2170 ind.10 cm-2,and a total of 34 nematode genera were recorded,of which only 8 were common in all the studied beaches.Pielou's evenness and Shannon-Wiener diversity index were the lowest at the second beach where nematode abundance was the highest.The highest species diversity index coincided with the lowest nematode abundance at Shilaoren beach.Sediment median grain size,sorting coefficient,and chlorophyll-a content were essential for differentiation in nematode abundance and species diversity,whereas taxonomic diversity of nematode was homogeneous across the three beaches.In 0–20 cm sediment profile,nematode abundance declined abruptly with depth,whereas nematode diversity changed gently with obvious difference in 16–20 cm layer.Sediment granulometry and chlorophyll-a content were the two foremost factors which influenced the vertical distribution pattern of nematode generic diversity.Non-selective deposit feeders constituted the most dominant trophic group,followed by epistratum feeders.Bathylaimus(family:Tripyloididae) dominated at the second and Yangkou beach,while Theristus(family:Xyalidae) prevailed at Shilaoren beach.Omnivores and predators became important at Shilaoren beach because of the high proportion of Enoplolaimus.Even though,nematode community of the studied beaches did not differ significantly from each other.

Large scale synthesis of ZnO nanoparticles via homogeneous precipitation

In order to synthesize ZnO nanoparticles economically, industrial-grade zinc sulfate and urea were utilized to synthesize ZnO precursors in a stirred-tank reactor or a Teflon-lined autoclave at 100-180 ℃ under complete sealing condition. The ZnO precursors were calcined at 450 ℃ for 3 h to, synthesize ZnO nanoparticles. The composition of the precursors and the formation mechanism of ZnO were studied by thermogravimetric analysis and Fourier transform infrared spectroscopy. The results of X-ray diffraction, transmission electron microscopy and scanning electron microscopy of the ZnO powders demonstrate that high-purity zincite ZnO nanoparticles are synthesized. Orthogonal experiments were performed to find out the optimal conditions for the maximum yield and the minimum size. The ettect of temperature on the size ofZnO nanoparticles was investigated. The results show that a higher temperature is propitious to obtain smaller nanoparticles.

Effects of an artificial oyster shell reef on macrobenthic communities in Rongcheng Bay, East China

An artifi cial oyster shell reef was deployed in Rongcheng Bay, East China. However, the effects of this reef on the surrounding macrobenthic communities were unknown. We compared sedimentary factors, macrobenthic biomass, abundance, and community composition and ecological indicators between the reef and non-reef areas over a one year period. The mean values for chlorophyll a(Chl a), total organic matter(TOM), total organic carbon(TOC), and total nitrogen(TN) content in surface sediments in the reef area were slightly higher than those in the non-reef area. The Chl a levels differed signifi cantly between the two areas, but the TOM, TOC, and TN were not signifi cantly different. The abundance of crustaceans was signifi cantly different between the two areas, but the abundance and biomass of polychaetes, echinoderms, mollusk did not differ signifi cantly. The permutational multivariate analysis of variance(PERMANOVA) revealed that the macrobenthic community differed signifi cantly through time and analysis of similarity multivariate analyses(ANOSIM) revealed that the macrobenthic community differed signifi cantly in some months. The ecological indicators revealed that the environmental quality of the reef area was slightly better than that of the non-reef area. Overall, our results suggest that the artifi cial oyster shell reef may change the macrobenthic community and the quality of the environment. Despite the lack of an effect in the short term, long-term monitoring is still needed to evaluate the effects of artifi cial oyster shell reefs on macrobenthic communities.

Fluorescence Properties of Submerged Macrophytes in Nanjishan Wetland,Southern Poyang Lake

We used a FluorCam portable chlorophyll fluorescence imaging system to measure QY-max （the maximum light quantum yield, Fv/Fm, the largest light quantum efficiency of PS Ⅱ） of submerged plants in wetlands of Baisha Lake and Changhu Lake, Jiangxi Nanjishan Wetland National Nature Reserve, in winter 2013. Specifically, we measuredΦPS Ⅱ （PS Ⅱ actual quantum efficiency）, qP （photochemical quenching） and corresponding fluorescence images. Using the visual method and sampling sites method to obtain coverage, richness and abundance of submerged plants, and determined nutrient levels in water. The results show that the QY-max ofHydrilla verticillata andVallisneria natans in Baisha Lake ranged from 0.48 to 0.68 and 0.52 to 0.71, respectively; theΦPS Ⅱ of these two species ranged from 0.32 to 0.58 and 0.20 to 0.46, respectively. The two plants had similar photosynthetic efifciency. The QY-max ofNymphoides peltatum andV. natans in Changhu Lake ranged from 0.66 to 0.77 and 0.19 to 0.68, respectively; theΦPS Ⅱ of these two species ranged from 0.26 to 0.48 and 0.22 to 0.43, respectively. The observed higher photosynthetic efifciency of N peltatum suggests it is more likely to become the dominant species. In Baisha Lake, the frequency of occurrence of plants was：H. verticilata, 90%;V. natans, 93.3%;Najas minor26.7%, andPotamogeton francheti10%. In Changhu Lake, the frequency of N. pel-tatum was 86.7%,V. natans was 16.7%, andN. minor was 56.7%. The overal frequency of submerged plants living in Baisha Lake was much higher than that of submerged plants living in Changhu Lake, with different species dominating the two lakes. According to comprehensive analysis and comparison of trophic levels, biodiversity and photosynthetic fluorescence characteristics in the two lakes, eutrophication of Baisha Lake was higher than for Changhu Lake; andH. verticillata andV. natans were the dominant species, with similar photosynthetic activity. Conversely, in Changhu Lake,N. peltatum andV. natans were the dominant species, but the photosynthetic activity of N. peltatum was higher thanV. natans. Differences in eutrophication levels in different water bodies in the Nanjishan Wetland and differing ecological niches of submerged plant species are characteristic of this system.

Effects of submerged sheet pile vanes on mobile river beds

Submerged vanes are low-height flow-training structures emerging from the riverbed with a suitable angle of attack to the incoming flow. These structures redirect the stream flow and modify erosion and depositional rates in the bottom and in the banks of a river as a result of the secondary currents generated by their installation. For this reason they have many applica- tions in river hydraulics for controlling river bed morphology. An experimental investigation is carried out to compare the effi- ciency of sheet-piling vanes versus thin plane ones in controlling sediment redistribution in the channel bed. In particular, exper- imental tests were carried out within a straight water channel, in conditions of bed load motion. The morphology of the river bed both in the area close to the structure and in the far field was examined at different angles of attack of the vane to the incoming flow and at different values of the submergence parameter, which is the ratio between the height of the water above the structure and the water level. The experimental results show that both the shape of the vanes as well as the angle of attack affect their per- formance in terms of the effects on the bed morphology, especially for greater submergence parameters. Specifically, plane and sheet-piling vanes produce comparable remodelings of the channel bed in the downstream region, but when the attack angle is increased, the thin plane vane causes deeper scour holes close to the structure. This last effect is probably due to the increased erosive capacity of the horseshoe vortex associated with the plane vane, while the uneven surface of the sheet-piling vane miti- gates the erosive strength of that vortex.

Leaf hydraulic traits of larch and ash trees in response to long-term nitrogen addition in northeastern China

Aims Atmospheric nitrogen(N)deposition influences tree hydraulic architecture and thus the growth and survival;but the responses of leaf hydraulic traits remain uncertain,and may vary with species or plant functional types.Methods We used the 16-year N addition experiment(10 g N m−2 year−1)on Fraxinus mandshurica(ash,broadleaf angiosperm)and Larix gmelinii(larch,conifer gymnosperm)plantations in northeastern China and examined the effect of N addition on their leaf hydraulics.We measured the leaf pressure–volume traits by the bench drying method and quantified the maximum leaf hydraulic conductance(K_(leaf_max))and resistance to embolism(P50leaf)by the timed rehydration method.Important Findings Larch had higher K_(leaf_max)and stronger drought tolerance(i.e.,lower relative water content at turgor loss point(RWC_(tlp))and modulus of elasticity(ε),and more negative P50leaf)than ash.N addition increased the leaf osmotic potential at turgor loss(πtlp)and full turgor(π0),and leaf capacitance(Cleaf_mass)for ash but not for larch,indicating that ash is more sensitive to N addition.N addition consistently increased K_(leaf_max)and P50leaf values for both species.πtlp andπ0 were positively while Cleaf_mass was negatively correlated with leaf density(LD)for ash.K_(leaf_max)was positively but P50leaf was negatively related with LD for larch.There were negative relationships between K_(leaf_max)and P50leaf for both species.Overall,our findings suggest that long-term N addition decreases the leaf drought tolerance for these two important tree species,which improve the understanding of the tree hydraulic performance under N deposition.

Interface effects on the electroluminescence spectra in amorphous-Si/silicon oxynitride multilayer structures

We report room-temperature electroluminescence (EL) from as-deposited amorphous-Si/silicon oxynitride multilayer structure prepared by plasma enhanced chemical vapor deposition. We prepared 8-period a-Si/SiOxNy multilayer with thickness of 4 nm both for the Si and SiOxNy sublayers. The EL spectral profile exhibits some obviously modulated features upon the barrier material. By adjusting the nitride/oxygen ratio in the barrier layer, the EL peak position can be tuned from 750 nm to 695 nm. From the result of the Raman and Fourier transform infrared results, the EL is attributed to the radiative recombination of electrons and holes in luminescent centers related to the interface. The different interface characteristics induce the shift of EL peak position.