银杏酚酸类物质防治农业害虫的研究

银杏酚酸类物质即银杏酸、银杏酚和白果酚是从银杏(Ginkgo biloba L.)外种皮中分离得到的杀虫活性成分。利用银杏外种皮粗提物配制的生物农药，具有广谱防治农业害虫的作用。     

银杏外种皮中银杏酚酸类物质防治农业害虫试验初报

从银杏外种皮中分离到的银杏酚酸类物质具有杀虫活性，利用银杏外种皮粗提物配制的生物农药，对多种蚜虫及蓟马、菜青虫等农业害虫具有防治作用。     

核壳型松香基高分子键合硅胶液相色谱固定相高效分离紫杉醇

将富马海松酸三(β-丙烯酰氧基乙基)酯(FATE)通过自由基聚合反应键合到烷基化硅胶(TPM-SiO₂)表面，制备了核壳型松香基高分子键合硅胶(RP@SiO₂)固定相，对RP@SiO₂固定相进行了一系列表征和评价，探讨了RP@SiO₂柱对紫杉醇(PTX)及其类似物的分离性能和分离机理，并将其用于红豆杉树皮粗提物中PTX的分离纯化。结果表明：FATE成功键合在硅胶表面，核壳型结构材料成功制备，RP@SiO₂的平均粒径约为5μm; RP@SiO₂柱是类似于C18柱的典型反相色谱柱，表现出优异的色谱性能、良好的重现性和典型的反相色谱行为；采用RP@SiO₂柱分离紫杉醇类似物，连续洗脱样品的分离度均超过6.6。计量置换保留理论(SDT-R)和van’t Hoff热力学分析结果表明：疏水相互作用决定了分析物的保留，在RP@SiO₂柱上分离紫杉醇类似物是一个焓驱动的放热过程，SDT-R可用于解释其保留机理。采用RP@SiO<...     

高速逆流色谱分离制备胡椒中的胡椒碱

利用高速逆流色谱从胡椒粗提物中分离制备其主要成分胡椒碱,两相溶剂系统为石油醚-乙酸乙酯-甲醇-水(体积比1:0.8:0:0.8),上相为固定相,下相为流动相.从300 g的粗提物中经过一次分离得到纯度为99.1％的胡椒碱65.2 mg,其化学结构由EI-MS、1H NMR和13CNMR鉴定.     

臭蒿抗菌成分的分离和鉴定

采用硅胶柱层析法对臭蒿粗提物进行分离纯化,利用孢子萌发法对抗菌流分进行活性评价,采用高效液相色谱-质谱联用技术(HPLC-MS)分析抗菌流分的物质组成。结果显示:臭蒿粗提物分离纯化得到13种流分(Fr.1~Fr.13),其中流分Fr.5抗菌活性最好,对流分Fr.5进一步硅胶柱层析分离得到4种流分(Fr.5.1~Fr.5.4)。臭蒿粗提物对烟草链格孢菌孢子的EC50为5.04 g/L,流分Fr.5.2的EC50为0.57 g/L。LC-MS分析出流分Fr.5.2主要由去氧双羟基蒿甲醚(17.00%)、去氧双氢青蒿素(43.65%)、去氧青蒿素(16.15%)组成。以双氢青蒿素为标准品,测得流分Fr.5.2中双氢青蒿素的质量分数为40.95%,双氢青蒿素对烟草链格孢菌孢子的EC50为2.70 g/L,表明流分Fr.5.2中主要抗菌物质为青蒿素衍生物。     

银杏叶色素类化合物的提取分离及结构鉴定

以银杏鲜叶(样品1)、银杏干叶(样品2)和银杏陈叶(样品3)为原料，制备了3个样品的乙醇提取物，采用HPLC-DAD-MS法分析3个样品中银杏叶色素类化合物的组成；通过液液萃取、硅胶柱层析和HPLC制备色谱等技术手段对样品2和样品3的银杏叶色素类化合物进行了分离纯化和结构鉴定。从3个样品中初步推测出24种银杏叶色素类化合物，其中叶绿素类化合物17种，类胡萝卜素类化合物7种。从样品2和样品3的乙醇提取物浸膏中分离纯化出10种银杏叶色素单体化合物，通过质谱、紫外光谱、红外光谱和核磁共振氢谱数据分析，并结合文献对照鉴定化合物分别为：β-胡萝卜素(A)、脱镁叶绿素a(B)、脱镁叶绿素b(C)、叶黄素(D)、植基紫红素18a(E)、焦脱镁叶绿素a(F)、 13²-羟基脱镁叶绿素a(G)、 13²-羟基脱镁叶绿素a′(H)、 13²-羟基脱镁叶绿素b(I)、 13²-羟基脱镁叶绿素b′(J),其中E、F、G、H、I、J为首次从银杏叶中分离得到。     

土耳其桔子化学成分及抑菌活性的研究

对土耳其掊子的抑菌活性成分进行研究。采用硅胶柱色谱、Sephadex LH-20凝胶柱色谱、制备薄层色谱、HPLC,对土耳其掊子中的化学成分进行分离,通过理化性质和光谱数据鉴定其结构,采用抑菌试验对土耳其槽子不同提取部位和单体化合物进行抑菌活性筛选。分离得到7个化合物,分别鉴定为：没食子酸（Ⅰ）、间-二没食子酸（Ⅱ）、对-二没食子酸（Ⅲ）、没食子酸甲酯（Ⅳ）、没食子酸乙酯（Ⅴ）、1,2,3,6-四-O-没食子酰基-β-D-葡萄糖（Ⅵ）和1,2,3,4,6-五-O-没食子酰基-β-D-葡萄糖（Ⅶ）。土耳其桔子乙酸乙酯部位含主要抑菌活性成分,其中化合物Ⅲ和Ⅴ均为首次从该桔子中分离得到。     

楸树叶中抗氧化活性成分的分离和鉴定

前期研究发现,楸树叶粗提物的乙酸乙酯萃取相具有较强的抗氧化活性。为了进一步明确其抗氧化活性成分,以硅胶柱色谱结合清除 DPPH自由基法,寻找抗氧化能力较强的组分,并利用半制备液相色谱对该组分进行分离、纯化,以清除 DPPH自由基、还原力和清除 ABTS自由基能力作为考察指标,根据理化性质及光谱数据鉴定化合物。结果从楸树叶粗提物的乙酸乙酯萃取相中分离得到了2个化合物,分别为木犀草素(1)和芹菜素(2)。化合物1的抗氧化活性强于BHT和化合物2;化合物1清除DPPH自由基、还原力及清除ABTS自由基的IC50值分别为23.89,29.77和43.47μg mL -1;化合物1的抗氧化活性强于化合物2,主要因其在黄酮类化合物母核的 B环上具有邻二酚羟基结构。木犀草素和芹菜素2个化合物首次从楸树叶中分离得到。     

异海松酸光固化产物中7-羰基-8,15-异海松酸的分离与结构鉴定

利用HPLC-UV研究了异海松酸(iPA) UV光固化反应产物,从中检测到了一种具有较强紫外吸收的非聚合物成分.通过硅胶柱色谱和制备型HPLC分离得到了该物质,经气相色谱分析检验,其纯度为82.6％.通过UV-vis、FT-IR、MS、1H NMR及13C NMR等光谱分析研究,该物质的化学结构被鉴定为7-羰基-8,15-异海松酸(7-O-8,15-iPA),这是异海松酸的一种氧化衍生物,与文献报道结构一致.还探讨了异海松酸发生氧化反应生成7-羰基-8,15-异海松酸的反应机理.     

漆酚酯键合SiO2色谱柱分离纯化天麻素及其热力学研究

利用天麻素(GAS)的结构类似物苯基-β-D-吡喃葡萄糖苷(PGL)和4-甲氧基苯基-β-D-吡喃葡萄糖苷(MGL)作为竞争分子,考察漆酚酯键合SiO₂色谱柱对天麻素的分离性能,并对其分离过程进行热力学分析。研究发现：漆酚酯键合SiO₂色谱柱分离天麻素的最佳色谱条件为以乙腈-0.05%磷酸水溶液(体积比3∶97)为流动相,流速0.4 mL/min,柱温25℃,检测波长220 nm,进样量20 mL。在该色谱条件下,漆酚酯键合SiO₂色谱柱对PGL-GAS的分离度达到7.8,对MGL-GAS的分离度达到14.0。热力学研究发现：分离过程中PGL-GAS和MGL-GAS的ΔH、ΔΔH和ΔΔG均小于0,ΔΔS均大于0,表明漆酚酯键合SiO₂色谱柱对天麻素及其结构类似物的分离过程是一个自发的放热过程,分离既受熵驱动又受焓驱动;随着柱温的升高,分析物的保留因子与分离度均有所下降。天麻粗提物经漆酚酯键合SiO₂色谱柱纯化后,杂质明显降低,天麻素的纯度由粗提物中的17.06%提升至93.45...     

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.