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陆炳情 《防灾科技学院学报》2008,10(1):82-86
2006年起,广西壮族自治区地震局把做好政务信息工作摆上了重要议事日程,安排了专人负责,落实了措施,落实了专项经费,政务信息工作发生了质的飞跃.特别是信息管理员制度和激励机制从根本上改观了政务信息往日的面貌.本文介绍了广西壮族自治区地震局电子政务信息工作在事业发展中的定位、主要做法、成效和经验,意在抛砖引玉,加强学习和交流. 相似文献
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介绍了近年来生物絮凝剂的研究和应用现状,详细总结了几种生物絮凝剂的絮凝机理,并对生物絮凝剂的分类进行了阐述,列举了生物絮凝剂的应用情况,文中还提到了近年来的研究新进展,特别是提到了复合型生物絮凝剂的研制情况,最后文章对未来生物絮凝剂的发展趋势进行了叙述. 相似文献
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为了进一步提高HSE管理水平,切实加强采油队在施工中的风险管理,我们在采油队推行了HSE作业指导书,实施以来,增强了职工的HSE意识,规范了HSE管理,有效地防范了作业风险,取得了良好效果. 相似文献
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水是生命之源、文明之泉."凡有水井之处,即能歌柳词"讲的是凡是有水的地方都有酿育文明的源泉.但遗憾的是,现代社会经济发展了、文明进步了,水环境却退化了,一条条河流干涸了,一个个湖泊消失了,甚至到了有河皆干、有水皆污的地步. 相似文献
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可持续发展的生态公路建设研究 总被引:1,自引:0,他引:1
分析了生态公路产生的背景,探讨了生态公路的哲学思想,进而深入剖析了生态公路的内涵,提出了生态公路实现的措施,最后对中国生态公路建设实践进行了探讨。 相似文献
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通过合理的毛坯选择,典型零件的工艺方案对比,刀具的选用原则及切削参数研究试验,大大提高了铝合金原材料的利用率,降低了生产成本,缩短了加工周期并提高了铝合金机械加工零件的袁面质量。探索出了提高铝合金机械加工效率的方法。 相似文献
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运用水样叶绿素荧光仪(Water-PAM)研究了桉树叶水浸出液胁迫下湛江叉鞭金藻(Dicrateria zhanjiangensis)和纤细角毛藻(Chaetoceros gracilis)2种海洋微藻叶绿素荧光特性〔包括PS(光系统)Ⅱ的Fv/F0(潜在活性)、Fv/Fm(最大光能转化效率)、Yield(实际光能转化效率)、ETR(电子传递效率),其中Fm和F0分别为最大荧光和基础荧光〕的变化,同时监测微藻的生长情况,以研究桉树叶水浸出液对海洋微藻的影响,从而为探讨华南沿海大量种植桉树所造成潜在的海洋生态问题提供一些依据. 结果表明:①低浓度(以φ计,0.4、0.8、1.2mL/L)胁迫在96h内对湛江叉鞭金藻的上述4项荧光参数均无显著影响(P>0.05);高浓度(2.0mL/L)胁迫下,24h时湛江叉鞭金藻的4项荧光参数都处于最低值,48h时处于次低值. 表明高浓度在胁迫早期(48h内)对湛江叉鞭金藻4项荧光参数有抑制作用,而后期(72、96h)这4项荧光参数又恢复到正常水平,抑制作用解除. ②低浓度(0.4、0.8mL/L)胁迫下纤细角毛藻的4项荧光参数在24、48h内均得到促进,而高浓度(2.0mL/L)胁迫下Fv/Fm在24h时为最小值,表现抑制作用;另外3项荧光参数则未受显著影响. 在胁迫后期(72、96h),纤细角毛藻的4项荧光参数均随着胁迫浓度的增大而增加,表现为促进作用. ③就生长情况而言,随着胁迫浓度的增大,2种海洋微藻细胞密度的增长明显变缓. 表明桉树叶水浸出液对2种海洋微藻的生长以及叶绿素荧光特性都有影响,从而将会对整个海洋生态系统产生影响. 相似文献
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《Journal of Cleaner Production》2000,8(3):233-241
This paper reports experimental results on the effect of prebleaching lignin content and chlorine load on chlorinated organic (AOX) formation from Chilean pinewood and eucalyptus kraft pulp bleaching. Unbleached pulp with kappa number in the range 14–30 and 7–22, for pine and eucalyptus, respectively, were assayed. Bleaching sequences based on Cl2/ClO2, ClO2 and oxidative alkaline extraction, were studied here. Residual chlorinated organics were found in the range 0.8–7.0 (kg AOX/ton dry pulp) and 0.6–4.2 (kg AOX/ton dry pulp), for pine and eucalyptus, respectively. AOX in effluents were linearly correlated with the unbleached pulp lignin content and the ratio between Cl2 and ClO2 used in bleaching. It is concluded that around 8.6% and 7.9% of added chlorine is bounded to soluble organic compounds, for pine and eucalyptus, respectively. Investment requirements and reductions in operating costs associated with upgrading conventional pulp mills are presented here. In all cases, economic benefits off-set investment costs. 相似文献
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Impacts of land cover change on plant and bird species diversity in Hainan Island,China 总被引:2,自引:0,他引:2
1IntroductionLandcoverchangehasanincreasingimpactonforestecosystemsworldwide.Thedestructionofnativehabitatsisrecognizedasoneo... 相似文献
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不同土地利用方式对赤红壤理化性质的综合影响 总被引:2,自引:0,他引:2
通过比较不同土地利用方式下赤红壤pH值、粘粒、容重、孔隙度、有机碳、氮磷钾全量及其速效养分含量的差异,并运用主成分分析方法分析各变量的相互关系、土壤综合理化特征及其关键改良因子。研究结果表明:新垦旱地容重最高,粘粒含量和孔隙度最低;有机碳、全量氮磷钾养分和速效氮磷养分含量均处于较低水平(P<0.05)。果园土容重显著低于其他土地利用方式土壤,且全氮、碱解氮和速效磷钾水平均处于较高水平(P<0.05)。桉树林的全钾和速效钾含量显著高于灌木林,而粘粒含量和速效磷含量相对较低(P<0.05)。主成分分析结果显示:新垦旱地、果园和桉树林、灌木林土壤理化综合质量差异显著(P<0.05),其中新垦旱地当前质量相对较差。有机碳、全氮和速效氮养分缺乏是当前新垦旱地土壤理化质量较差的主要原因。较少的速效磷钾养分含量是当前桉树林地、灌木林土壤质量的限制因素。主成分分析不仅能够区分不同土地利用方式下赤红壤理化质量差异,而且也是探查改良土壤质量因子的有效方法。 相似文献
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--Hainan
Island, located at the southern end of China, hasless than 0.4% of land area but contains
13% of plant and animalspecies in China. During the last four decades many primary
forestshave been converted to shrub land, grassland, and tree planation(e.g., eucalyptus
forest). As a result, area of primary tropicalforest has been reduced from 25.8% in the
1950s to 4% in the 1990s.To assess impacts of land conversion on plant and bird
speciesdiversity, a series of samples in primary forest and four types ofconverted lands
were took. The land conversion had tremendouslyreduced both plant and bird species
diversity. Specifically, plantspecies richness per site was 83.7 in primary forest, 28.3
in shrubland, 12.5 in grassland, 14.4 in eucalyptus forest, and 21.4 inAcacia forest. Bird
species richness showed a similar trend 22.0in primary forest, 14.5 in shrub land, 2.5 in
grassland, 4.9 ineucalyptus forest, and 9.0 in Acacia forest. The Shannon speciesdiversity
indices for plants in the five types of land cover were3.69, 1.99, 0.97, 1.47 and 2.07,
respectively. Similarly, the Shannon indices for bird species diversity were the highest
in primary forest, and lowest in grassland, and intermediate in shrubland and eucalyptus
forest. 相似文献
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通过对桉树速生林基地的生态调查及监测,分析得出以前我国桉树速生林普遍存在地力衰退的问题,导致土壤肥力下降及目前桉树人工林地力衰退已经得到根本性的逆转的主要原因。速生林基地种植的桉树林林下植被与林缘、林外植被没有显著不同,特别是与桉树林地块相近的稀疏马尾松林林下植被以及荒坡植被相比,无论从植被覆盖度、植物种类、高度等看都呈现出增高、增多的趋势,而广东雨量丰富,桉树能同绝大部分林下植物共生。 相似文献
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Patrick RoussetArmando Caldeira-Pires Alexander SablowskiThiago Rodrigues 《Journal of Cleaner Production》2011,19(14):1647-1653
This paper sets out to describe the environmental impact assessment for wood charcoal briquettes produced from eucalyptus wood in Brazil, with specific reference to those impacts associated with Global Warming Potential. To achieve that objective, the work was undertaken in accordance with ISO 14040 "Environmental management - Life cycle assessment - Principles and framework" which describes essential LCA characteristics and good practices. Charcoal briquettes are produced from two basic raw materials, charcoal fines and starch. The fines result from the production of charcoal from sustainably managed eucalyptus plantations. Starch is extracted from babaçu pulp in the Amazon region. Multi-output processes were allocated based on income from the different by-products. The results showed that more than 90% of incoming CO2 was due to biomass production for charcoal, and the remainder to starch biomass production. Based on Brazilian data, as well as information provided by the GaBi4.3 database, it turned out that supplying the energy content of 1 kg of briquettes resulted in the sequestration of 3.9690 kg of CO2, i.e. around 4 kg of CO2 per kg of briquettes produced. CO2 emissions throughout the briquette production process are totally compensated for by the environmental quality of the raw materials used. 相似文献
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《Agriculture, ecosystems & environment》2005,105(1-2):77-86
The sugarcane (Sacharum officinarum) monocropping has had a great socio-economic and environmental impact in Brazil, and agroforestry (AFs) has been considered as an alternative to its sustainable production. However, there is a lack of field experiments results under such conditions. Therefore, yield measurement across transect in the tree–crop interface in on-farm conditions, as well as the use of simulation models, may allow the evaluation of biophysical interactions between trees and crops and system productivity. In this work, plant growth and yield in a sugarcane–eucalyptus (Eucalyptus grandis) on-farm interface were evaluated. The experimental site had a Chromic Ferralsol soil and it is located in a sub-tropical region of Brazil. Availability of solar radiation for the crop along the transect was estimated and its effect on sugarcane dry matter production was evaluated. Using such relations, two sugarcane–eucalyptus AFs cycles were simulated to estimate system productivity. The field results showed that the trees presented a higher growth in the AFs, while the crop growth and yield were inversely proportional to their distance from the trees. The eucalyptus wood volume increased from 0.15 to 0.29 m3 per tree from monocropping to AFs. The sugarcane dry matter decreased from 35.1 to 8.70 t ha−1 from the furthest to the closest position from tree along the transect. Simulations suggested that light was the main cause of the crop yield reduction, but the importance of competition for water and nutrients increased inversely according to tree distance. However, both simulated AFs provided land equivalent ratio (LER) similar to one (1). Field measurements and simulations indicate that agroforestry systems are a sound alternative for sugarcane cultivation in the studied region. Combination of on-farm studies and simulation models provided conditions to understand tree–crop interactions and to extrapolate field results so that the performance of a new system could be estimated. 相似文献
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《Agriculture, ecosystems & environment》1988,24(4):453-458
Vigna unguiculata (beans), Zea mays (maize) and Sorghum bicolor (sorghum) were grown with and without fertiliser in a savanna grassland (control) and under the effects of decomposing parts of eucalyptus in an old eucalyptus plantation with a well-lit floor (treatment).Morphological characters of the beans, compared between the two sites, showed that leaf dry-matter production, expressed as specific leaf area (SLA), did not differ between plants in the two sites (fertilised and unfertilised). Although the organic-matter content and water-holding capacity of the plantation soil were significantly higher than those of the control plants. beans, grain yield ha−1, shoot height, number of leaves and fruits were higher in the control plants. However, when beans were fertilised, shoot height did not differ between sites, but the other measured morphological characters and grain yield were significantly improved in both sites, although these characters still remained higher in the control. In maize and sorghum, grain yield ha−1 did not vary significantly in the two sites (fertilised or unfertilised). These findings suggest that beans can be incompatible with eucalypts, while maize and sorghum may be compatible with eucalypts for agrosilvicultural practices, and that fertilisation can offset, to an extent, the depressive effects of eucalypts on crops. 相似文献