橡胶木胶合板阻燃技术研究 Ⅳ.橡胶木胶合板的燃烧性质及热性质

通过对橡胶木胶合板与水曲柳胶合板、杨木胶合板、椴木胶合板的点着性、燃烧释热性、火焰传播性、发烟性以及热重曲线的对比,了解橡胶木胶合板的燃烧性质和热性质,并进一步探讨ＷＦＲ作为橡胶木胶合板阻燃剂的处理效果。     

我国杨树人工林材性与加工利用研究现状及发展趋势

本文概述了杨树人工林发展概况,全面分析了杨树人工林木材性质与加工利用研究现状和存在问题,指出将杨树人工林材性与加工利用结合起来进行研究是合理、高效利用杨树人工林木材的必由之路。     

Influence of single passes with high wheel load on a structured, unploughed sandy loam soil

In a field experiment, a sandy loam was subjected to single passes with a sugar beet harvester at two different soil water potentials. Different hopper fillings resulted in ground contact pressures of 130 kPa (partial load) and 160 kPa (full load) underneath the tyre. Bulk density, macroporosity (equivalent pore radius >100 μm), penetrometer resistance, air permeability and pre-consolidation pressure were measured within and next to the wheel tracks at depths of 0.12–0.17, 0.32–0.37 and 0.52–0.57 m. Furthermore, the soil structure at two horizons (Ahp 7–24 cm, B(C) 24–38 cm) was visually assessed and classified.

The moist plot responded to a wheel load of 11.23 mg (160 kPa) with an increase in bulk density and pre-consolidation pressure as well as with a decrease in air permeability and macroporosity at a depth of 0.12–0.17 m. With a wheel load of 7.47 mg (130 kPa) on the moist plot and with both wheel load levels on the dry plot, only slight changes of the soil structure were detected. At a depth of 0.32–0.37 and 0.52–0.57 m, the measurements did not indicate any compaction. An ANOVA indicates that the factor “soil water potential” and the factor “wheel load” significantly influence the bulk density at a depth of 0.12–0.17 m. No interactions occurred between these two factors. The wheel traffic on the test plot had no effect on the yield of winter wheat planted after the experimental treatment.

Bulk density, macroporosity and pre-consolidation pressure proved to be sensitive to detect compaction because they varied only slightly and are easy to measure. In contrast, the standard deviation of air permeability is large. The soil structure determined visually in the field confirms the values measured in the laboratory. The results of the penetrometer resistance measurements were not explainable.     

Relationship of percolation stability of soil aggregates to land use, selected properties, structural indices and simulated rainfall erosion

Simple tests of structural stability are needed for evaluating the ease with which soils slake and erode when in contact with water. In a laboratory study, we related the percolation stability (PS) of 22 Nigerian soils to land use, soil properties, structural stability indices and simulated rainfall erosion. All measurements were carried out with the 1–2 mm diameter air-dry aggregates. Land use influenced PS more than the type of soil. Forest soils, bush fallows, mulched, minimally tilled plots and pasture lands had rapid PS (>250 ml/10 min) values, whereas mulched conventionally tilled plots, bare fallows and continuously cultivated plots from where residues were removed by burning had relatively slow to moderate PS values (34–241 ml/10 min). The single most important soil property that correlated positively with PS is organic matter (OM) (r = 0.55^*) followed by total Fe + Al (r = 0.52^*). The significant inverse relationship (r = −0.49^*) between log (PS) and log (pH/OM) indicates a decrease in PS of these acidic, low-OM soils with increasing pH levels. The percent water-stable aggregate (WSA) >0.20 mm diameter, aggregated clay index (AC) and clay dispersion ratio (CDR) correlated weakly with PS. Conversely, the sealing index (SI) (i.e. the ratio of saturated hydraulic conductivity of an uncrusted to that of a crusted soil) had a strong, inverse relationship with PS (r = −0.97^***). These relationships indicate that PS measures the slakability (and not dispersibility) of soils. The relationship between PS and erosion (E) was an exponential decay form, E = 102 e^−0.0043PS (r² = 0.98) and showed that high interrill erosion rates would be expected on soils with PS < 250 ml/10 min. The PS which is simple to measure, is, therefore, a good indicator of structural stability for assessing the potential of these soils to erode.     

秦岭火地塘林区森林根际微生物及其土壤生化特性研究

对秦岭林区几种主要林型根际土壤微生物的测定分析表明,根际微生物数量表现为油松－华山松混交林〉落叶松林〉锐齿栎－油松混交林,且以细菌数量为主。同一林型微生物状况为根际〉非根际,干基根区〉干基非根区,且不同林分差异显著,微生物的数量分布与土壤酶活性,有机质含量,土壤养分状况等强弱呈正相在关系。     

一株鹅源高致病力禽流感病毒分离株血凝素基因的分析

禽流感病毒（AIV）的表面结构蛋白血凝素（HA）在决定病毒致病力、受体结合特性、宿主范围等方面起着关键作用。本研究初步鉴定为高致病力毒株的AIV鹅体分离株A/Goose/Guangdong/1/96（H5N1）的HA基因进行了克隆并测序。结果表明,这一在无胰酶条件下可在单层鸡胚成纤维细胞培养物上形成蚀斑的毒株在其HA裂解位点附近有连续6个碱性氨基酸的插入物,从而揭示了其高致病力的分子基础。进一步的序列比较发现这一毒株与1997年香港流感病毒A/Hongkong/156/97（HK/97）的HA基因核苷酸和氨基酸同源率分别高达98.0%和98.2%,且其6个糖基化位点、2个受体结合位点及裂解位点碱性氨基酸插入物的序列均完全一致,提示该毒株与HK/97具有相似的生物学特性。     

左旋肉碱——类维生素的营养素

ｌ肉碱是动物体内与脂肪酸代谢 有关的化合物,它的主要功能是作为载体将长链脂肪酸从线粒体膜外运送到膜内促进脂肪酸的氧化⒚本文对 ｌ肉碱的研究历史、化学性质、食物中的含量、生物合成、生理功能、缺乏症及其危害性、营养状况、营养作用及其临床应用和生产方法进 行了阐述⒚     

Effects of infestation on the nutrient content and physiocochemical properties of two cowpea ( Vigna unguiculata) varieties

Two cowpea varieties (Ife-brown and Kano-white varieties) were used for the study. The effects of insect infestation on the chemical composition and physicochemical properties of these cowpea seeds were studied. The proximate composition, mineral content, total starch, total soluble sugars, bulk density, fat and water absorption capacities, viscosity, gelation capacity and emulsion properties of infested cowpea varieties were compared with those of uninfested cowpeas. Effects of infestation on nitrogen solubulity and on the protein fractions were also determined. lnfestation depleted the protein, starch and soluble sugar contents of cowpeas. Oil and water absorption capacities were increased while emulsification, foam and viscosity properties were reduced. The nitrogen solubility pattern was altered. Uninfested Kano-white cowpeas (UKW) possessed better foam properties than uninfested Ife-brown cowpeas (UFB). On the other hand, UFB had better emulsification properties than UKW.     

百喜草对丘陵红壤改土保肥的研究

通过对丘陵红壤种植百喜草,并结合某些乡土草种、引进草种的试验比较,探讨了百喜草的种植对土壤的理化因子（土壤容重、孔隙度、土壤中各营养元素、ｐＨ）的影响。结果表明：在丘陵红壤上种植百喜草具有百喜草具有明显改良红壤理化因子的作用,弥补了红壤理化因子的许多不足。     

FRW阻燃处理木材的颜色和涂饰性能

ＦＲＷ阻燃木材与未处理木材的颜色与涂饰性能的对比研究。旨在评价ＦＲＷ阻燃处理对木材这两方面性能的影响。试验测定了红松和紫椴两种木材经ＦＲＷ处理前后及其涂饰前后的色度指数。并用Ｌ＾＊ａ＾＊ｂ＾＊色空间评价其变化。结果表明,ＦＲＷ处理对木材本身的颜色基本无影响。