三维地震勘探低速带静校正系统的研制

本文在研究目前三维地震勘探中常用的低速带静校正算法的基础上，根据几年来低速带静校正处理情况，研制出一种计算三维地震勘探低速带的静校正系统，简述了这种处理系统的原理，并对吉林油田某三维地震工区的低速带资料进行了处理。结果表明，该系统计算速度快、精度高、实用性强，对改善地震剖面质量和提高信噪比是有效的。     

Mechanization techniques for poplar development in Turkey

Annual commercial poplar wood production in Turkey is about 3.6 million cubic meters, half of which comes from hybrid poplar I-214. The poplar plantation areas of Turkey are 70% of the poplar plantation areas of the Near and Middle Eastern countries, and nearly 5% of the world. In this study, unit times of standard operations were investigated in poplar nurseries and plantations in which new mechanical technology was applied and compared with traditional methods. Analyses of unit times were made on 11 treatments for poplar nurseries and nine treatments for poplar plantations; some new methods are also recommended. Mechanization methods based on new technologies give promising results in poplar nurseries and plantations.     

A methodology for assessing gamebird use of short rotation coppice

Gamebirds provide a considerable incentive to plant and manage new woodlands. The supplementary income thus generated can improve their overall value. Other studies suggest that Short Rotation Coppice (SRC) crops may provide an attractive habitat for some gamebird species and could increase the value of the crop. To investigate this, the use by pheasants and partridge of different types of SRC at one site was assessed.

A method using sand quadrats to record gamebird footprints and hence relative use was developed. Pheasant footprints were recorded more frequently in the quadrats alongside the willow coppice, whereas partridge footprints occurred more frequently alongside the poplar coppice. Footprint analysis offers a reliable method of investigating how gamebirds use different types of SRC within small areas. The results are considered in terms of the placement of short rotation coppice plantations in the landscape to improve their ecological design.     

A Degeneration Gradient of Poplar Trees Contributes to the Taxonomic,Functional, and Resistome Diversity of Bacterial Communities in Rhizosphere Soils

Bacterial communities associated with roots influence the health and nutrition of the host plant. However, the microbiome discrepancy are not well understood under different healthy conditions. Here, we tested the hypothesis that rhizosphere soil microbial diversity and function varies along a degeneration gradient of poplar, with a focus on plant growth promoting bacteria (PGPB) and antibiotic resistance genes. Comprehensive metagenomic analysis including taxonomic investigation, functional detection, and ARG (antibiotics resistance genes) annotation revealed that available potassium (AK) was correlated with microbial diversity and function. We proposed several microbes, Bradyrhizobium, Sphingomonas, Mesorhizobium, Nocardioides, Variovorax, Gemmatimonadetes, Rhizobacter, Pedosphaera, Candidatus Solibacter, Acidobacterium, and Phenylobacterium, as candidates to reflect the soil fertility and the plant health. The highest abundance of multidrug resistance genes and the four mainly microbial resistance mechanisms (antibiotic efflux, antibiotic target protection, antibiotic target alteration, and antibiotic target replacement) in healthy poplar rhizosphere, corroborated the relationship between soil fertility and microbial activity. This result suggested that healthy rhizosphere soil harbored microbes with a higher capacity and had more complex microbial interaction network to promote plant growing and reduce intracellular levels of antibiotics. Our findings suggested a correlation between the plant degeneration gradient and bacterial communities, and provided insight into the role of high-turnover microbial communities as well as potential PGPB as real-time indicators of forestry soil quality, and demonstrated the inner interaction contributed by the bacterial communities.     

杨树叶片的微观结构及拉伸特性

观察了杨树(Ponulus hopeiensis)叶片的微观结构,测定了叶片叶脉和叶肉的拉伸性能,分析了叶片拉伸特性与微观结构之间的关系。结果表明:杨树叶片的叶脉是由表皮组织、薄壁组织、维管束及其周围的机械组织构成的多孔、蜂窝状的复合结构;叶肉主要是由栅栏组织和海绵组织组成的分层结构。杨树叶片主脉和附带叶肉的主脉具有不同的拉伸性能,附带的叶肉越宽,最大拉力越大;叶片具有一定的强度,其承载能力主要取决于叶脉中表皮组织、维管束及机械组织的发达程度。本研究可为工程仿生的抗疲劳设计提供有益参考。     

Effect of nitrogen–phosphorus fire retardant blended with Mg(OH)2/Al(OH)3 and nano‐SiO2 on fire‐retardant behavior and hygroscopicity of poplar

The aim of the study was to screen any possible synergistic effects related to the combination of nitrogen–phosphorus fire retardant and Mg(OH)₂/Al(OH)_3. This combination is used to improve fire performance, especially smoke suppression of poplar through ultrasonic wave impregnation after microwave treatment. In this study, nano‐SiO₂ was used to impregnate poplar treated with nitrogen–phosphorus fire retardant and form a hydrophobic layer on wood cells in order to improve hygroscopicity and reduce water uptake. Cone tests and thermal analysis showed that poplar treated with blended fire retardant had improved behavior. Results show that a 20% and 25% nitrogen–phosphorus fire‐retardant solution (blended by adding 10% Mg(OH)₂/Al(OH)₃ based on the dry weight of nitrogen–phosphorus fire retardant) was more effective for smoke suppression. The heat release rate, total heat release, and total smoke production of a 25% nitrogen–phosphorus fire‐retardant solution blended by adding 10% Mg(OH)₂/Al(OH)₃ showed significant reduction. The char residual yield showed a marked increase to 35.5%. Fourier transform infrared analysis suggested a –CH₂–Si–CH₂– and Si–O–C stretching vibration in nano‐SiO₂ treated poplar, which greatly decreased the hygroscopicity of fire‐retardant‐treated poplar. Copyright © 2014 John Wiley & Sons, Ltd.     

Trade‐Offs in Seed Dispersal Strategies Across Riparian Trees: The How Matters as Much as the When

Riparian Salicaceae are prolific producers of short‐lived seeds that require very restrictive hydro‐geomorphic conditions for establishment. It is generally assumed that if floods are able to create nursery sites timed with seed dispersal, recruitment will occur. Other spatial and temporal seed dispersal patterns besides the dispersal period have historically received little attention. However, seed dispersal patterns can be highly variable between regions, species and over the years. In this paper, we report the seed dispersal patterns of three dominant riparian Salicaceae trees in Europe: Populus alba, P. nigra and Salix alba to suggest possible trade‐offs between seed dispersal patterns, germinability, longevity and establishment. Seed rain of the three species was monitored in 33 glue‐coated traps for three months yearly from 2006 to 2008 in an 8‐km stretch of the Middle Ebro River (N Spain), which has a pluvio‐nival regime. P. alba dispersed seeds earlier during a shorter time period and with a fewer number of seed release pulses compared with P. nigra, and especially with S. alba. With overlapping seed dispersal periods, the two latter species occupy similar landform units but rarely compete with P. alba, usually at higher elevations, as shown in a previous study in the same study area. The three species had very high germinability immediately after release (>90%), but longevity in S. alba was eight times shorter than that of its two Populus counterparts. We suggest that S. alba has compensated its lower seed quality with a more spaced seed release in several pulses of similar magnitude. With similar seed dispersal patterns and germinability but a higher longevity, P. nigra had a much higher density of individuals than S. alba in the recruitment zones of the study area. We hope that our results may inform river managers about how to optimize river flows to promote sexual regeneration of these species. Copyright © 2015 John Wiley & Sons, Ltd.     

Electrochemical conversion of switchgrass and poplar in molten carbonate direct carbon fuel cell

One way of sustaining fuel cell technology is using renewable and sustainable energy means provided by biomass. This article explores switchgrass and poplar in a molten carbonate electrolyte direct carbon fuel cell. It investigates their electrochemical conversions and provides results of power density, current density, open circuit voltage (OCV) and other parameters. The biomasses were pyrolysed at 800°C to produce carbon fuels. Biomass carbon fuels were mixed with molten carbonate and subjected to different operating conditions (600–800°C) in the fuel cell. The electrochemical performances of the poplar fuel were better than those experienced with switchgrass fuel. At 800°C the OCV of poplar fuel (1.08?V) has higher output than switchgrass (0.87?V). The peak power density recorded for poplar fuel was 23.91?mW/cm² while switchgrass fuel was lower at 21.60?mW/cm². Poplar fuel (81.53?mA/cm²) gave a maximum current density with switchgrass fuel lower at 74.00?mA/cm².     

Adhesive properties of water-washed cottonseed meal on four types of wood

The interest in natural product-based wood adhesives has been steadily increasing due to the environmental and sustainable concerns of petroleum-based adhesives. In this work, we reported our research on the utilization of water-washed cottonseed meal (WCM) as wood adhesives. The adhesive strength and water resistance of WCM adhesive preparations on poplar, Douglas fir, walnut, and white oak wood veneers were tested with press temperatures of 80, 100, and 130 °C. Our data indicated that raising the hot press temperature from 80 to 100–130 °C greatly increased the bonding strength and water resistance of the WCM adhesives. The general trend of the adhesive strength of WCM on the four wood species was Douglas fir > poplar ≈ white oak > walnut. The rough surface of Douglas fir with tipping features could enhance the mechanical interlocking between the wood fibers and adhesive slurry, contributing to the high adhesive strength. The dimensional swelling of the bonded wood pairs due to water soaking was in the order: thickness > width (i.e. perpendicular to the wood grain) > length (i.e. parallel to the wood grain). The greatest dimensional changes were observed in Douglas fir specimens. However, the highest decrease in adhesive strength by water soaking was with poplar wood specimens. These observations suggested that the wood dimensional changes were not dominant factors on water weakening the bonding strength of these wood pairs.