木材运输船舶发展趋势

木材水运是各种木材运输类型中最为经济的一种方式。而船舶又是木材水运中重要的常用设备,约占木材水运机械设备的半数以上。目前,由于木材水运生产工艺的各个环节,因用途的不同对船舶均有各自的特殊要求,现有船舶的数量和种类远不能适应木材水运事业发展的需要。因此,从改进现有船舶的线型和功能入手,研制更多的适用于木材流送工艺的各种新型船舶,是当前木材水     

船舶靠泊过程中废气排放特征及控制措施

指出了船舶大气污染防治将是未来交通运输行业环境保护领域的重点,介绍了船舶废气污染控制技术发展现状,对船舶靠泊过程中的废气排放进行了分析,并对相应的污染控制措施及其实际应用现状进行总结。     

远程监测技术在港口气体污染物监测中的应用研究

对青岛前湾港进行实地考察,确定了港口监测设备布点位置,通过试验验证,论证了监测设备距船舶的距离、风向与船舶航行的测试夹角、湿度、环境温度等参数对港口船舶运行过程中烟气扩散测试结果的影响,同时,确定了影响船舶气态污染物监测的关键因素,为在我国港口搭建船舶排放监测系统提供一些参考。     

绿色制造工艺在船舶结构中的应用

指出了随着经济的发展,船舶制造业为了适应社会发展的需求,逐渐改善了自身浪费资源、污染严重等问题,尤其是船舶结构中的改变较大,运用了较多的绿色制造工艺。首先对船舶结构中绿色制造工艺设计思路进行了分析,然后对船舶结构中绿色制造工艺的有效应用进行了探讨,这些应用表明减轻了对海水和大气环境的污染程度。     

节能环保型360°全回转对转浆

节能环保型360°全回转对转桨是一种全新的船舶推进装置。该技术成果由3叶、4叶双螺旋桨组成，增加了对转桨理论图谱，是在前人研究基础上结合我国船舶现状的创新和发展，属原始型创新（发明专利）。经过对不同类型船舶的对比试验，大量数据证明：     

基于模糊灰色综合评价法的船舶溢油风险评价

指出了模糊综合评价法是广泛应用于油污溢油风险评估中的一种方法。模糊灰色综合评价法主要用来评估船舶溢油风险的不确定性,同时用来解决船舶溢油风险评估中“样本少、信息少”的特性。如果只采用模糊法进行风险评估会引起信息丢失的缺陷,而灰色理论评价法又不能实现重复利用面模糊评价的特点,结合上述两种方法的优缺点,适当建立一种模糊灰色综合评价法应用于船舶溢油风险的评估,可为长江沿岸港口主管机关加强船舶溢油风险监控提供有效的建议。     

节能环保型360° 全回转对转桨

节能环保型360°全回转对转桨是一种全新的船舶推进装置。该技术成果由3叶、4叶双螺旋桨组成,增加了对转桨理论图谱,是在前人研究基础上结合我国船舶现状的创新和发展,属原始型创新(发明专利)。     

SUSAN算子角点提取在船舶舷号定位中的应用

指出了船舶的舷号包含着船舶的基本身份信息以及船只在其所属部门和序列中的位置,通过对船舶舷号的检测,可以迅速识别出对方船只的身份信息.这对舰艇在海洋航行中区别和联络他国船舶以及在海事营救时搜寻并确认失事船只中有着重要的应用.提出了一种船舶舷号的检测方法,该法先将彩色船舶图像转化为HSI模型,然后利用SUSAN算子角点检测算法提取饱和度图像中的角点.当检测出角点以后,再进行多次搜索,实现对舷号的检测和定位.实验表明:这种方法拥有非常好的稳定性和有效性.     

基于无人机的船舶尾气监测系统设计

为快速且方便地在无电信运营商信号区域实现船舶气态污染物排放的快速遥测,根据船舶气态污染物排放特点,设计了基于电化学传感器的船舶气态污染物排放监测系统,且使用无人机搭载监测系统近距离监测了目标船舶气态污染物的排放,同时系统使用无线LoRa数据传递技术,解决了在无信号区域不能传递数据的问题,经试验测试:监测系统在气态污染物...     

南京市船舶制造业VOC_S成分谱特征分析

通过对南京市典型民用钢质船舶制造企业开展挥发性有机物采样监测,建立了该行业VOC_S源成分特征谱,结果表明:南京市民用钢质船舶制造业VOC_S排放源以苯系物及烷烃为主,分别占91.34%及8.14%。焊接及喷漆工序是造船企业主要的VOC_S排放源,两个工序最主要的污染物都是苯系物,占比分别为87%和94%。故建议将船舶制造行业优先纳入到VOC_S的重点管控行业。     

Canopy management possibilities for arboreal Leucaena in mixed sorghum and livestock small farm production systems in semi-arid India

A major problem for small farmers in the semi-arid tropics is the chronic shortage of fodder for draft animals. Leucaena leucocephala has improved productivity in many places in India and in various cropping systems, usually as either a pure crop or in a hedgerow alley-cropping configuration. Mixed cropping with arboreal forms is seldom seen. For off-season fodder production, hedgerows have the disadvantage of being open to unmanaged browsing when unfenced (as is usual). Arboreal forms are generally far less vulnerable. In this paper, the components of production of sorghum and arboreal Leucaena are measured under different intensities of canopy lopping. The most productive management system of those examined was pollarding of the Leucaena at the time of under-sowing with sorghum. In a year with less than 50% of average seasonal rainfall, this system gave a yield of 4.6 tonnes/ha/yr fresh wt fodder and 3.8 tonnes/ha/yr dry wt. of fuel harvests, while increasing the standing crop of wood by 1.8 t/ha/yr and retaining a yield of sorghum grain equivalent to 46% of pure sorghum cropping; the LER of this system was 1.35. Cash values of the alternative management systems were estimated, including the discounted Net Present Value of the standing crop of timber. Maximum value was attained with unlopped pure crop Leucaena followed by pollarded Leucaena with sorghum; pure crop sorghum achieved a lower value. These results demonstrate both the high productivity of Leucaena/sorghum based systems, and the stability of production even in poor rainfall conditions. Pollarding transferred the high future value of Leucaena timber to the present value of sorghum grain and fuelwood.     

天牛体内纤维素酶研究进展

文章综述近年来国内外有关天牛体内纤维素酶的研究进展,主要包括:天牛体内纤维素酶的来源、不同天牛种类纤维素酶的性质、纤维素酶抑制剂、纤维素酶同工酶、纤维素酶基因以及天牛体内纤维素酶活性变化与寄主的关系,并展望了未来的研究方向。     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Modeling spatial variability and pattern of rust and brown eye spot in coffee agroecosystem

The advent of Precision Agriculture has made possible the analysis of complex spatial patterns of plant disease epidemiology considering statements of integrated disease management. The objective of this work was to use geostatistics, statistics and geographical information systems to characterize the structure and magnitude of spatial dependency of rust (Hemileia vastatrix) and brown eye spot (Cercospora coffeicola) incidence and severity in coffee agroecosystem cultivated with Catuai Vermelho IAC-99 (Coffea arabica L.). Evaluations of incidence and severity of rust and brown eye spot were accomplished at 67 georeferenced points arranged in 6.6202 ha of coffee crop, in the years of 2005, 2006 and 2007. Exponential models of covariance enabled the characterization of the magnitude and structure of rust and brown eye spot spatial variability in the evaluated dates. Ordinary block kriging presented satisfactory performance to map rust and brown eye spot outbreaks based on kriging error coefficients. Kriged maps enabled the visualization of intensity of rust and brown eye spot in each evaluation date. Assessments of incidence and severity presented highly statistical correlation based on linear regression models, also confirmed by the spatial variability of kriging maps. Kriging maps of rust and brown eye spot enabled to observe that intensity of disease was dispersed in foci patterns along the coffee plantation, indicating that the current strategy of disease control based in total area may be replaced by site specific disease management, with less environmental impact and sustainability of coffee crop, according to statements of integrated disease management and precision agriculture.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Nutrient cycling and growth in forest ecosystems of south western Australia: Relevance to agricultural landscapes

Nutrient and hydrologic cycles in harvested native forests in southern Australia are largely balanced. For example, we have little or no evidence of any decline in nutrient capital or availability in harvested forests. Short-term and small-scale reductions in evapotranspiration due to loss of leaf area after harvesting are adequately balanced at the landscape scale by large areas of regenerating or older-age forest. In contrast, agricultural systems on similar soils are a) dependent on large inputs of fertilisers to maintain growth and b) frequently subject to increasing salinity and waterlogging or other forms of degradation. The large-scale replacement of long-lived communities of perennial and often deep- rooting native species with annual crops or other communities of shallow-rooting species might be better managed within the framework of knowledge developed from studies of native plant communities. However, application of such a mimic concept to systems of low natural productivity is limited when agricultural systems require continued high productivity. Nonetheless, the mimic concept may help in developing sustainable management of agriculture on marginal lands, and contribute to the nutritional resilience of agroecosystems. Relevant characteristics for mimic agroecosystems in south western Australia include: high species diversity, diversity of rooting attributes, utilisation of different forms of nutrients (especially of N and P) in space and time, and the promotion of practices which increase soil organic matter content. This revised version was published online in June 2006 with corrections to the Cover Date.     

Trade-Offs in Forest Utilization from a Sustainability Perspective

Abstract

A sustainable use of forests may be conceived of differently by different scientific disciplines. An underlying definition of sustainability is therefore central to the understanding of any analysis on the subject. This paper approaches the idea of sustainability from an economic perspective. The interpretation of sustainability in terms of concepts such as efficiency, equity and welfare are initially described. Empirical research aiming at obtaining basic elements of economic sustainability analyses is subsequently outlined. Finally, the implications for applied welfare and sustainability analysis at different economic and geographical levels of aggregation are discussed     

闽南山地木荷林套种南方红豆杉的试验

为了解南方红豆杉在闽南山地生长所需的环境条件,开展了木荷林下套种南方红豆杉的试验研究,结果表明,在较高郁闭度的木荷林中套种南方红豆杉,随木荷林郁闭度的增大,南方红豆杉的树高、地径和生物量降低,叶绿素含量减少,养分含量下降。郁闭度为0.5的木荷林套种南方红豆杉,其生产力最高,叶绿素含量和养分含量均最大。     

Native woody species regeneration in exotic tree plantations at Munessa-Shashemene Forest,southern Ethiopia

Regeneration of native woody species was studied in the plantations and the adjacent natural forest at Munessa-Shashemene Forest Project Area, Ethiopia. The aim of the study was to test the hypothesis that tree plantations foster regeneration of native woody species. A total of 60 plots, having 10 × 10 m area each, were studied in monoculture plantations of 4 exotic species (Cupressus lusitanica, Eucalyptus globulus, E. saligna, Pinus patula) and an adjacent natural forest. Ages of the plantations ranged between 9 and 28 years. Soil seed bank analysis was also undertaken from soil samples collected in each of the 60 plots to examine the similarity between the soil seed flora and aboveground vegetation. A total of 56 naturally regenerated woody species were recorded beneath all plantation stands with densities ranging between 2300 and 18650 individuals / ha in different stands. There was a significant difference among plantation stands with regard to understorey density (standard deviation: 4836 ± 1341). Vegetation diversity was assessed through analyses of floristic composition, species richness and abundance. Generally, seedling populations were the most abundant components of the regeneration in most of the plantation stands, forming 68 % of the total regeneration count in all stands. A total of 77 plant species represented by 44 herbs, 13 woody species, 8 grasses and 12 unidentified species were recorded in the soil seed bank from all stands. Similarity between the soil seed bank and aboveground flora was very low implying that the role of soil seed banks is negligible rather dispersal plays an important role in the process of regeneration. These results support the concept that forest plantations can foster the regeneration of native woody species, thereby increasing biological diversity, provided that there are seed sources in the vicinity of the plantations.     

杨树天牛灾害可持续控制策略与技术

人工营建的森林生态系统组分过于单一 ,配置不当是三北地区森林生物灾害严重的根本原因。主要控制策略包括御灾控灾阵地前移 ,控制目标从种群密度控制转为灾害控制 ,对灾害调控从“点状调控”上升为“网状调控” ,提高对“潜在”生物灾害的预警能力。提出生物多样性与生态系统稳定性原理、风险分散理论和抗性相对论作为多树种合理配置抗御人工林生物灾害的 3大理论基础。以多树种合理配置控制杨树天牛灾害为实例 ,从结构和功能的关系 ,将现有防护林划分为 3类 :即一代林网、二代林网和加强型二代林网 ,分析了树种配置结构和抗天牛灾害的功能。进一步将加强型二代林网配置树种类群划分为非寄主树种、目标树种 (或抗性树种 )和诱饵树 ,并对各自的功能进行了定位 ,提出了较为合理的抗御天牛灾害的多树种配置模式以及简便有效的诱饵树管理技术。最后 ,以防护林 (特别是农田防护林 )的经营和管理由静态转变为动态为前提 ,探讨了诱饵树管理的一些新思路