Dynamic water vapour sorption properties of wood treated with glutaraldehyde

The dynamic water vapour sorption properties of Scots pine (Pinus sylvestris L.) wood samples were studied to investigate the modifying effects of glutaraldehyde. Pine sapwood was treated with solutions of glutaraldehyde and a catalyst (magnesium chloride) to obtain weight per cent gains of 0.5, 8.6, 15.5, and 21.0%, respectively. The sorption behaviour of untreated and treated wood was measured using a Dynamic Vapour Sorption apparatus. The results showed considerable reduction in equilibrium moisture content of wood and the corresponding equilibrium time at each target relative humidity (RH) due to glutaraldehyde treatment. The moisture adsorption and desorption rates of modified and unmodified wood were generally faster in the low RH range (up to approximate 20%) than in the high range. Modification primarily reduced the adsorption and desorption rates over the high RH range of 20–95%. Glutaraldehyde modification resulted in a reduction in sorption hysteresis due to the loss of elasticity of cell walls.     

八种热带花卉林下复合种植模式探讨

对八种海南热带花卉复合种植模式的生态效益和经济效益进行了探索性试验。结果表明:热带花卉复合种植,能有效降低林内温度、增加林内湿度,对生态环境有显著改善;从经济收益方面考虑,火焰木+散尾葵、盆架子+鹤蕉、鸡蛋花+黄金榕模式的苗木的平均年生长量与纯林对照相比不仅没有减少,反而有所增加。因此,选用合适的品种进行复合种植,能有效提高土地利用率,在获得同等经济收益的情况下,还可改善生态环境。     

宝华玉兰在海南的引种栽培试验初报

通过宝华玉兰在海南的生长情况观测,研究了宝华玉兰对海南气候的适应情况;通过试验比较了嫁接宝华玉兰中的各个影响因素的作用,找到嫁接宝华玉兰的最佳条件.     

The influence of curing conditions on the chemical distribution in wood modified with thermosetting resins

Scots pine (Pinus sylvestris L.) sapwood was impregnated with aqueous solutions of phenol formaldehyde and methylated melamine formaldehyde resins and subsequently cured in an oven. One set of specimens was cured in plastic bags to avoid drying (wet curing) while another set of samples was heated and water was allowed to freely evaporate (dry curing). Macroscopic resin distribution was investigated using X-ray densitometry and infrared spectroscopy (FTIR-ATR). During dry curing, the resins migrated to the wood surface resulting in a gradient. Wet curing resulted in even distribution of the resins because it was immobilized due to condensation and precipitation in the wood. Neither densitometry nor FTIR-ATR was found to be generally applicable for investigating resin distribution in modified wood. Wet curing resulted in low cell wall bulking as compared to dry curing, probably because resin precipitated before drying. Storing impregnated wood prior to curing under non-drying conditions (“diffusion phase”) also reduced cell wall penetration and bulking.     

“5·12”汶川大地震后无林地土壤物理性质的变化

2008年5月12日,四川省汶川县发生Ms8．0、裂度1l级的灾难性特大地震,造成了严重的人员伤亡,同时也对森林生态系统造成了严重伤害。在主地震带上的四川省绵阳市,以无林地上未滑坡、滑坡和崩塌3种立地类型的土壤为研究对象,于2009和2010年分别研究了地震后各立地类型不同层次的土壤容重、毛管持水量、毛管孔隙度和非毛管孔隙度。结果如下：（1）大地震后无林地土壤物理性质受影响程度为崩塌〉滑坡〉未滑坡;（2）经过1a的自然恢复,各立地类型的土壤容重没有恢复;未滑坡样地和滑坡样地土壤表层（0～10cm）的毛管持水量、毛管孔隙度和非毛管孔隙度得到有效的恢复,土壤中层（10～20cm）和深层（20～40cm）的相应指标虽有相同的变化趋势,但变化并不显著;而崩塌样地由于土壤结构被严重破坏,恢复缓慢。     

Observation of the scale of patchy stomatal behavior in leaves of Quercus crispula using an Imaging-PAM chlorophyll fluorometer

Patchy stomatal closure occurs in plants with heterobaric leaves, in which vertical extensions of bundle sheath cells delimit the mesophyll and restrict the diffusion of CO(2). The scale of patchy stomatal behavior was investigated in this study. The distribution of PSII quantum yield (Φ(II)) obtained from chlorophyll fluorescence images was used to evaluate the scale of stomatal patchiness and its relationship with leaf photosynthesis in the sun leaves of 2-year-old saplings of Quercus crispula Blume. Fluorescent patches were observed only during the day with low stomatal conductance. Comparison of numerical simulation of leaf gas exchange and chlorophyll fluorescence images showed that heterogeneous distribution of electron transport rate through PSII (J) was observed following stomatal closure with a bimodal manner under both natural and saturated photosynthetic photon flux densities. Thus, fluorescence patterns can be interpreted in terms of patchy stomatal closure. The mapping of J from chlorophyll fluorescence images showed that the scale of stomatal patchiness was approximately 2.5-fold larger than that of anatomical patches (lamina areas bounded by bundle sheath extensions within lamina). Our results suggest the spatial scale of stomatal patches in Q. crispula leaves.     

试论福州北峰生态旅游发展战略

福州北峰具有明显的区位优势和丰富的生态旅游资源,但旅游业的发展还是“各自为战”,形不成规模。在深入分析北峰生态旅游现状和存在问题的基础上,提出一些见解,旨在对新世纪北峰生态旅游业的良性发展有所启示。     

高温气相色谱法定性检测粒状口香糖和巧克力豆中的巴西棕榈蜡

建立了一种操作简单、快速定性检测粒状口香糖和巧克力豆中的巴西棕榈蜡高温气相色谱分析法,标样溶液直接用三甲基硅烷(BSTFA)衍生,样品经超声加热充分提取后用BSTFA衍生,用氢火焰离子检测器(FID)直接检测,在检测的3种口香糖样品和2种巧克力豆样品中,均检测出巴西棕榈蜡相关成分,并对样品中的巴西棕榈蜡含量进行了粗略估算。     

旱地小麦窄行条播渗灌栽培技术研究

1997－1999年对渗灌与播种方式在旱地小麦产量形成中的作用进行了研究。结果表明，在两个栽培因素中，渗灌有极显著的增产作用，两年平均渗灌量为32.0mm，产量达6686．7kg/hm^2，较对照增产19．4％，播种方式间产量存在一定差异，其中，窄行条播与露地穴播增产幅度较大，二者产量分别为6477．9kg/hm^2和6405．4kg/hm^2，分别较诉露地条播增产15．9％与14．6％，窄行条播与渗灌措施间存在明显的协同效应，窄行条播加渗灌产量达7112．0kg/hm^2，较露地条播（不灌）增产33．9％，大于两单项技术与对照相比所表现的增产效应之和。窄行条播、渗灌以及二者的协同作用所表现的增产效应形成了旱地小麦渗灌窄行条播栽培技术体系的基础。     

A new DNA marker for sex identification in purple asparagus

Garden asparagus (Asparagus officinalis L.) is an economically-important perennial crop. This plant is dioecious, as there are both male and female individuals; male individuals are preferred over females for agricultural production. To reduce the time required for garden asparagus breeding, various male-specific DNA markers are utilized. Male-specific DNA markers, such as Asp1-T7sp and MSSTS710, are currently available for sex identification in many asparagus cultivars. In the current study, we found that these markers are not suitable for sex identification in the purple asparagus cultivar ‘Pacific Purple’, as male-specific amplification of this marker was detected in some male individuals of this cultivar but not in other males. The Asp1-T7sp marker is suitable for use in sex identification in various Asparagus species related to A. officinalis, indicating that the region around this marker is conserved among these species. Thus, we isolated a DNA fragment around this marker by inverse PCR and produced a new DNA marker, MspHd, based on this sequence. However, like Asp1-T7sp and MSSTS710, MspHd was not suitable for sex identification in the cultivar ‘Pacific Purple’. Since all ‘Pacific Purple’ males have morphologically similar male flowers with functional stamens, we produced a new male-specific marker based on the sex determination gene, MSE1/AspMYB35/AspTDF1, which is responsible for stamen development. This marker, named AspMSD, is suitable for sex identification in ‘Pacific Purple’. In addition, this marker can be utilized for sex identification in various asparagus cultivars and some related Asparagus species.