活性炭用作抗癌药缓释剂的研究与应用

以药用植物为原料，进行多道工艺精制成吸附抗癌药载体活性炭，其亚甲基蓝脱色力达到２８ｍＬ，平均粒度为０．７μｍ，孔半径〈２ｍｍ的占７２．９％，测定其对抗癌药顺铂，卡铂及丝裂霉素的吸附量，每克分别吸附６４ｍｇ，７９５ｍｇ及５９０ｍｇ；３０ｍｉｎ，６０ｍｉｎ及１２０ｍｉｎ对卡铂脱吸附率分别为５．６％，９．８％及１１．３％，活性炭吸附的抗癌药浓度及其周围游离的抗癌药浓度两者之间保持动态平衡，活性炭作为缓释     

活性炭处理环己酮废水研究

研究了活性炭对废水中环己酮的吸附规律,结果表明：在吸附温度为20℃时,动态吸附饱和时间为60min,对于环己酮浓度为2.0g/L的废水,活性炭最佳加入量为20g/L,吸附最佳pH值为5,活性炭对环己酮的吸附符合Langmuir等温模型。     

工况条件对活性炭吸附-脱附CS_2的影响

CS_2是一种典型的工业化学毒物,对人体和环境危害极大,目前常用去除方法为活性炭吸附。笔者采用动态吸附装置研究活性炭对CS_2吸附-脱附性能,考察温度、气体流速、CS_2浓度和气流湿度对活性炭吸附-脱附CS_2的影响。结果表明:活性炭对CS_2吸附量和残存量随着吸附温度的升高而降低。当流速小于625 mL/min,随着流速的增加,活性炭对CS_2吸附量增加,残存量降低;当流速大于625 mL/min,随着流速的增加,活性炭对CS_2的吸附量降低,残存量增加。活性炭对CS_2吸附量随着CS_2质量浓度增加而增加。但当CS_2质量浓度小于1 643 mg/m~3时,随着质量浓度的增加,残存量增加;当CS_2质量浓度大于1 643 mg/m~3,随着质量浓度的增加,残存量降低。随着湿度的增加,活性炭对CS_2吸附量降低,残存量增加。综合上述研究结果可以得出:吸附温度、气体流速、CS_2浓度和湿度等工况条件对活性炭CS_2吸附量和残存量均有较大影响,其中CS_2浓度对吸附的影响最大,而脱附残存量主要与吸附温度和CS_2浓度有关。为实现活性炭高效吸附和脱附,最佳工艺条件为:干燥状态下,吸附温度25℃,流速小于625 mL/min, CS_2质量浓度为1 643 mg/m~3。     

利用Frendlich吸附曲线分光光度法测定活性炭的亚甲兰脱色力

利用分光光度计测定活性炭对亚甲兰吸附平衡液的浓度．应用Ｆｒｅｎｄｌｉｃｈ吸附曲线可精确计算出活性炭亚甲兰脱色力．方法快速、正确。     

改性玉米芯活性炭对镉的吸附性能研究

利用农业固体废物玉米芯作原料制备了活性炭,通过吸附热力学和吸附动力学过程,探讨了改性玉米芯活性炭对Cd²⁺模拟废水的吸附性能研究,以及考察了溶液pH值、活性炭投加量和温度对活性炭吸附Cd²⁺的影响。研究结果表明:磷酸改性600℃下裂解的活性炭吸附能力最好;改性玉米芯活性炭对Cd²⁺的吸附等温线更符合Freundlich模型;改性玉米芯活性炭对Cd²⁺的吸附动力学过程用准二级动力学模型能更好地拟合;经过单因素影响试验的研究表明,溶液初始pH值为6、活性炭投加量为0.01g、吸附温度为40℃时,活性炭的吸附效果最好。     

磷酸活化法制备棉秆活性炭的研究

通过研究活化工艺条件对棉秆活性炭吸附性能的影响，探讨了磷酸活化棉秆原料制备活性炭的可行性。结果表明：磷酸活化棉秆原料能制备出糖液脱色用活性炭的优级品，其碘吸附值、亚甲基蓝以及焦糖脱色力分别达N920mg／g、200mL/g和130％。其最佳活化工艺务件为：磷酸浓度50％，浸渍比2．5：1，浸溃时间60min，活化温度500％，活化时间60min。其中浸渍比对棉秆活性炭的脱色能力影响最大。     

多元酚焦炭化料制取活性炭的研究

研究用多元酚焦炭化料制取活性炭的方法,并探索合适的工艺条件。研究表明,破碎至不同粒度的多元酚焦炭化料通过水蒸气活化制取活性炭较适宜的工艺条件是：活化温度800～850℃;活化时间分别为：颗粒炭1h、定型颗粒炭2．5-3h,制得的活性炭的吸附指标超过国家标准GB／T13803．2-1999木质净水用活性炭的指标。碘吸附值在1000mg／g以上,亚甲基蓝吸附值在12mL／0．1mg以上研究结果还表明,磷酸法不适宜用于多元酚焦炭化料制造活性炭。     

饮用水净化用炭基滤芯成型工艺优化

为获得优良竹活性炭基饮用水净化用滤芯,笔者以毛竹活性炭为基材,椰壳活性炭为对比材料,添加高密度聚乙烯,采用活性炭挤出机(CTO)进行基础成型,采用响应曲面法,选取密度、抗压性、渗水率及碘吸附值作为响应值,对施胶量、含水率和粒径3个因素进行优化,确定最佳成型工艺,并对其饮用水净化效果进行了评价。结果表明:毛竹活性炭滤芯的密度随含水率和施胶量的增加而降低,随粒炭粉径的变小呈现先减小后增大的趋势;随含水率和施胶量的增加抗压性降低,随着炭粉粒径的变小抗压性增加;含水率和炭粉粒径对滤芯的碘吸附值影响不明显,随施胶量的增加滤芯的碘吸附值降低;随粒径目数、含水率和施胶量的增加滤芯的渗水率呈降低趋势; SEM和EPR分析表明,滤芯的净水主要为物理吸附,化学吸附微弱;有机物吸附模拟试验表明,滤芯对水质甲醛去除效果良好,可有效吸附水中有机污染物;随竹活性炭滤芯投加量的增加,饮用水CODMn的去除率增加,当投加量大于400 mg时吸附饱和;竹活性炭和椰壳活性炭滤芯对CODMn的吸附均符合Freundlich模型。     

梭梭材活性炭的制备工艺研究

研究了以梭梭材为原料,用氯化锌溶液和磷酸溶液作为活化剂来制备活性炭。探讨了活化温度、活化时间、液固比以及活化液浓度对制备梭梭材活性炭的影响以及梭梭材活性炭对碘吸附值的影响,确定了以氯化锌溶液和磷酸溶液作为活化剂生产活性炭的最佳工艺条件,对开辟梭梭材综合利用和活性炭原料来源具有重要意义。结果表明,氯化锌活化法制备活性炭,最佳工艺为液固比2.5:1,活化液浓度50%,活化温度450℃,活化时间90min,吸附值为1 068.86mg/g;磷酸法为液固比1.5:1,活化液浓度85%,活化温度500℃,活化时间120min,吸附值为885.38mg/g。     

磷酸法竹活性炭除铬性能的研究

以磷酸法制备的不定型竹活性炭为原料,分析其脱除六价铬的过程,探讨吸附时间、温度、浓度和p H值对竹活性炭除铬性能的影响。结果表明,随着吸附时间和温度的增大,竹活性炭对K2Cr2O7溶液的吸附量不断上升;溶液起始浓度的提高,有利于活性炭对六价铬的吸附量和吸附速率的增大,且吸附速率与起始浓度成线性关系,速率方程为r=0.07835c-0.805。     

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.