的吸附特性研究

以富含单宁的杨梅树皮为原料,通过甲醛交联剂原位固化杨梅单宁(SIBT)制备吸附材料,研究了该吸附材料对Nd3 +的吸附特性.实验表明:当Nd3 +溶液的初始质量浓度为 432 mg/L、反应温度为 303 K 时,该吸附材料对Nd3 +的平衡吸附量可达到 342.14 mg/g, 其吸附等温线符合Freundlich方程.平衡吸附量受pH值和温度的影响: pH值在3.0 ～ 5.5范围内,吸附量随pH值升高而增加,pH值>5.5时,吸附量开始逐渐下降;温度为283 ～ 313 K 时,Nd3 +的吸附量变化不大,温度超过 313 K 时,吸附量开始下降;与温度因素的影响相比较,pH值对平衡吸附量影响较大.研究还表明,这种吸附剂对Nd3 +的吸附动力学可用拟二级速率方程来描述,由拟二级速率方程计算所得到的平衡吸附量与实测值的偏差在 4 % 以内,具有很好的一致性.     

原位固化杨梅单宁对Nd~(3+)的吸附特性研究

以富含单宁的杨梅树皮为原料,通过甲醛交联剂原位固化杨梅单宁(SIBT)制备吸附材料,研究了该吸附材料对Nd3+的吸附特性。实验表明:当Nd3+溶液的初始质量浓度为432 mg/L、反应温度为303 K时,该吸附材料对Nd3+的平衡吸附量可达到342.14 mg/g,其吸附等温线符合Freundlich方程。平衡吸附量受pH值和温度的影响:pH值在3.0~5.5范围内,吸附量随pH值升高而增加,pH值5.5时,吸附量开始逐渐下降;温度为283~313 K时,Nd3+的吸附量变化不大,温度超过313 K时,吸附量开始下降;与温度因素的影响相比较,pH值对平衡吸附量影响较大。研究还表明,这种吸附剂对Nd3+的吸附动力学可用拟二级速率方程来描述,由拟二级速率方程计算所得到的平衡吸附量与实测值的偏差在4%以内,具有很好的一致性。     

胶原纤维固化杨梅单宁对Mo(Ⅵ)的吸附

研究了胶原纤维固化杨梅单宁(IBT)这一新型吸附材料对Mo6 的吸附特性.实验表明,温度对吸附容量影响不大,而pH值对吸附容量有显著影响,Mo6 的吸附容量随pH值降低而增加,表明其吸附机理是吸附剂与聚钼阴离子之间的静电结合.当Mo6 的初始质量浓度为100.0mg/L、吸附剂用量0.100 g、温度为303 K、pH值2.0时,IBT对Mo6 的吸附量为82.4 mg/g.Freundlich方程可以很好地描述IBT对Mo6 的吸附等温线.动力学研究表明,初始吸附速率很快,吸附达到平衡的时间约为600 min,其吸附动力学可很好地用拟二级速率方程描述,计算所得的平衡吸附量与实测值误差很小.解吸实验表明,0.02 mol/L EDTA溶液能使吸附剂再生,并能循环使用.选择性吸附研究表明,在酸性(pH值2.0)条件下,IBT对Mo6 的吸附率大于95%,而对Ni2 和Cu2 的吸附率低于5%,可用于Mo6 -Ni2 和Mo6 -Cu2 二元混合溶液中Mo6 的分离和提取.     

CTMAB改性凹凸棒土对磺胺嘧啶的吸附研究

以江苏盱眙和甘肃白银两地出产的凹凸棒土(ATP)为基底物质,用十六烷基三甲基溴化铵(CTMAB)对两种凹凸棒土进行改性,分别制备了10倍阳离子交换容量的CTMAB-江苏凹土和5倍阳离子交换容量的CTMAB-白银凹土两种改性吸附剂。通过批量平衡吸附实验研究了两种吸附剂对磺胺嘧啶(SD)的吸附效果,由动力学实验可知CTMAB-江苏凹土对SD有更好的吸附效果,吸附过程符合拟二级动力学模型。CTMAB-江苏凹土对SD的吸附过程可用Langmuir模型拟合,最大吸附容量为12.440 mg/g。SD浓度越高,越有利于CTMAB-江苏凹土对SD的吸附。pH值为弱酸性和中性时有利于CTMAB-江苏凹土对SD的吸附。腐殖酸浓度大于10 mg/L时会严重影响CTMAB-江苏凹土对SD的吸附。     

红色基GP染料废水的脱色研究

指出了凹凸棒土作为载体,因其独特的三维空间型、较强的选择吸附性,被广泛用于吸附领域中。利用十八烷基三甲基氯化铵改性的凹凸棒土作为吸附剂,对废水进行了脱色研究。主要考察了吸附剂的加料量、吸附时间、十八烷基三甲基氯化铵的负载量等因素对染料废水脱色率的影响。实验结果表明:在吸附时间为1h、吸附剂的加入量为0.9g、十八烷基三甲基氯化铵的负载量为0.3 mmol/g时,脱色率达到91%。     

杨梅单宁膜吸附材料的制备及其对铜、锌离子的吸附特性研究

以杨梅单宁、魔芋葡苷聚糖和大米淀粉为原料,通过交联反应制备杨梅单宁膜吸附材料,分析其红外光谱(FT-IR),并系统地研究了其对Cu2+和Zn2+的吸附特性。结果表明:杨梅单宁膜吸附材料在pH值5.0时对Cu2+和Zn2+的吸附容量最高;当初始质量浓度为200mg/L,pH值5.0,反应温度为25℃,吸附剂用量为0.1 g时Cu2+和Zn2+的平衡吸附容量分别为12.79和6.13 mg/g;吸附容量随着温度的升高而增大,但影响不大;Freundlich方程可以很好地拟合吸附等温线;吸附动力学均可用拟二级速率方程进行拟合。在铜、锌混合溶液中,杨梅单宁膜材料可以优先去除铜离子。     

Lindetype F（K）沸石对Cd2＋的吸附性能研究

利用粉煤灰合成了Linde type F（K）沸石吸附重金属Cd2＋,考察了吸附剂量、初始pH值、反应温度以及反应时间对C d2＋吸附效果的影响,同时进行了吸附动力学数据模拟。结果表明：吸附剂量、初始p H值、反应温度以及反应时间均对C d2＋的去除率影响显著。随着吸附剂投加量的不断增大,C d2＋去除效果不断提高,饱和吸附量逐渐减小。初始pH值为7时沸石吸附Cd2＋的去除率为100％。反应温度越高,沸石吸附Cd2＋达到平衡的时间越短。Linde type F（K）沸石对Cd2＋的吸附行为符合准二级反应动力学方程。     

竹炭对水溶液中苯酚的吸附作用

以高温下炭化的竹炭为原料,探讨了接触时间、起始浓度、温度等因素对竹炭吸附苯酚的影响。结果表明,随着温度的升高,竹炭对苯酚的吸附量呈现下降的趋势;随着苯酚起始浓度的增加,竹炭对苯酚的吸附量呈现不断上升的趋势,而吸附率呈现下降趋势;通过准一级和准二级速率方程对其吸附过程的动力学进行拟合,得知竹炭对苯酚的吸附符合准二级速率方程。     

桂花树干生物炭对水中亚甲基蓝的吸附性能研究

通过桂花树干制备生物炭，利用硝酸和高锰酸钾对桂花树干生物炭进行修饰(活化)处理，研究了其对水溶液中染料亚甲基蓝(MB)的吸附能力。研究了温度、pH值、吸附时间和初始浓度对生物炭染料吸附性能的影响。生物炭及改性生物炭准二级动力学拟合的判决系数均为0.999。准二级动力学模型模拟的平衡吸附量更符合实际值。采用扫描电镜(SEM)和紫外分析方法(UV-vis)对生物炭吸附剂改性前后进行了测试，研究表明：改性桂花树干生物炭可以作为合成染料的高效吸附剂。     

硅藻土对重金属离子Mn2+的吸附研究

以硅藻土为吸附剂,采用静态吸附试验考查了吸附剂浓度、离子初始浓度、吸附质溶液温度、吸附质溶液初始pH值、时间等因素对硅藻土吸附模拟废水中Mn2+的影响.研究表明,硅藻土对Mn2+的最大吸附量可达到4.0486 mg·g-1,效果较好,可被用于去除重金属锰.适当增加吸附剂用量、离子初始浓度、控制吸附温度(＜50)、pH值(＜6)、延长吸附时间都能提高硅藻土对Mn2+的吸附效果.Langmuir吸附等温式相比Freundlich吸附等温式能更好的描述硅藻土对Mn2+的吸附过程.硅藻土吸附M2+的吸附动力学则符合二级动力学方程.     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

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.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

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.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.