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1.
丹妮 《绿色中国(A版)》2008,(20)
走进建材城,各式各样的龙头让人眼花缭乱,款式有手按的、提拉的、旋转的、脚踏的、混水的、自动感应的很多种,适用地点还各不相同,价格也参差不齐,要想从中选购一款合适自己的产品还真不容易,所以请看以下选购龙头的小指南,希望能给你一些帮助。 相似文献
2.
吴春泉 《绿色中国(A版)》2008,(13)
没有哪次巨大的灾难,不是以巨大的进步为补偿的。汶川大地震发生以后的一个月里,我耳闻目睹了今生以来最悲壮的一幕幕,总想起伟人恩格斯的一句名言:没有哪次巨大的灾难,不是以巨大的进步为补偿的。汶川大地震是一场空前的大灾难,但更是一次深刻的教育。本来一些抽象的、难以理解难以领悟的东西,在短暂的时间里,在特定的境况下,一下子都化为了具体的、非常清晰也非常深刻的理解。 相似文献
3.
赵一曼 《绿色中国(A版)》2008,(22)
白皙美丽的肌肤是所有女性梦寐已求的,只有保养好内层肌肤,表面的肌肤才能健康美丽。健康的内层肌肤对美化表面肌肤至关重要。随着冬季的来临,由于温度和湿度的变化,皮肤新陈代谢的速度减慢,使皮肤保留水份的能力降低,因此皮肤变得很干。而新陈代谢减慢,又会导致受伤的皮肤细 相似文献
4.
初雪 《绿色中国(A版)》2008,(22)
一、遗失的手套段小苏:初春的午后,我将满满两抽屉的手套整理出来,洗净,晾晒,那一排排粉红、浅蓝、鹅黄、草绿、雪白的手套吸引了对面楼里那个扎着好多辫子的小女孩,她趴在阳台上,用兴奋的语调问我:姐姐,你的那些漂亮手套为什么只有一只呢,它们的另一半呢?它们的另一半被我落在了夏宇的口袋里。以前,每次让他把手套还给我的时候, 相似文献
5.
近年来,绿色建筑成为国内乃至国际建筑界、房地产界的一个热点话题,绿色建筑的发展也越来越受到关注,许多国家都开展了绿色建筑的研究和实践,取得了很多的研究成果.尤其在去年经历了一场与"非典"的斗争之后,人类更加深刻地认识到绿色建筑在生活中的重要性,由此也引发了一场关于绿色建筑的革命,将绿色建筑向更深入、更科学的方向推进. 相似文献
6.
企业生产成本管理浅析 总被引:1,自引:0,他引:1
在我国经济飞速发展的今天,任何一个企业要想在竞争的浪潮中立于不败之地,获取高额的利润,对生产成本进行合理的控制,是非常重要的.而我国部分企业,特别是国有企业在长期的计划经济体制的运作下,形成了许多弊端,要改掉这些弊病,成为国有企业改革中的成功者,通过对生产成本的有效控制来提高自身的竞争力,是一个可以立竿见影的有效方法,而在企业中对生产成本的控制则是任何一个会计人员都必需具备的能力. 相似文献
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9.
《绿色中国(A版)》2010,(9):56-61
总政歌舞团著名青年歌唱演员、国家一级演员蔡国庆获奖感言:这样的时刻在我心中是充满真情和温暖的,因为我始终坚信绿色的中国才是一个更加和谐美丽的中国。我愿意作军中的一棵小白杨,我希望用我的爱心和歌声守护祖国每一片绿色的森林和我们心中绿色的家园。 相似文献
10.
丹妮 《绿色中国(A版)》2008,(22)
在滇、桂、黔三省(区)结合部,有一片美丽而神秘的地方——罗平。去那里旅游不仅可以欣赏气势雄伟的瀑布群落、幽深险峻的峡谷、挺拔秀丽的峰丛、独特的地貌奇观、苍莽的林海、溢彩流金的油菜花海、蜿蜒曲折的河流、玲珑剔透的滩跌、碧绿如玉的湖泊构成的一道道靓丽的自然风景,还能看到丰富的文物古迹、感受古朴浓郁的布依风情、品尝许多美味佳肴,难怪明代大旅行家、地理学家徐霞客游览后写下罗平著名迤东的赞叹。 相似文献
11.
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. 相似文献
12.
Srisuda Thippayarugs Banyong Toomsan Patma Vityakon Viriya Limpinuntana Aran Patanothai Georg Cadisch 《Agroforestry Systems》2008,72(2):137-148
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. 相似文献
13.
《Scandinavian Journal of Forest Research》2012,27(1):53-61
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. 相似文献
14.
Marcelo de Carvalho Alves Fábio Moreira da Silva Edson Ampélio Pozza Marcelo Silva de Oliveira 《Journal of pest science》2009,82(2):137-148
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. 相似文献
15.
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. 相似文献
16.
Native woody species regeneration in exotic tree plantations at Munessa-Shashemene Forest,southern Ethiopia 总被引:2,自引:0,他引:2
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. 相似文献
17.
《Scandinavian Journal of Forest Research》2012,27(4):377-384
The objective of this study was to predict the amount and the distribution of compression wood (CW) within a Norway spruce [ Picea abies (L.) Karst.] plank based on green plank curvature. The findings indicated a possibility of predicting the longitudinal distribution of CW from the green plank curvature. Areas free from CW showed a typical concave shape in relation to the centre of the log, while CW was present when a convex shape was shown. The larger the magnitude of convex curvature, the higher the concentrations of CW that could be found, and a larger fraction of dried planks was rejected due to excessive warp. This study also determined what information can be used to eliminate areas of high concentrations of CW by cutting and how cutting affects the grading results with respect to warp. Over 50% of the plank length showing a high concentration of CW (>30% of the cross-cut volume) was successfully cut off. Cutting strategies based on predicted CW concentrations resulted in a 10-40% increase in accepted plank length. 相似文献
18.
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。 相似文献
19.
杨树天牛灾害可持续控制策略与技术 总被引:14,自引:2,他引:14
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 相似文献
20.
Andrzej Borkowski 《Journal of Forest Research》2007,12(5):358-364
Methods of spatial distribution of fallen shoots, pruned by pine shoot beetles, and estimation of efficiency of methods based
on collection of fallen shoots and used in forecasting of the occurrence of these insects, are presented in this paper. The
fallen shoots were distributed in clusters. The distribution was statistically different from random. Relative errors in estimation
of shoot-fall density were the smallest in study transects. Early and late autumn and the following spring, after the snow
melt, are the optimum seasons for collecting fallen shoots. 相似文献