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1.
焦性没食子酸制备新工艺的研究   总被引:5,自引:1,他引:5  
以工业没食子酸为原料,采用常压溶剂法制备出焦性没食子酸,并经IR、UV、HPLC、TLC以及熔点测定等进行了鉴定,其质量达到试剂级焦性没食子酸标准。每生产1吨焦性没食子酸消耗没食子酸1.54吨(按绝干计)。这种制备新工艺在国内尚未见报道,它具有产品得率高、质量好、反应条件缓和、成本低等优点。  相似文献   

2.
将不同的苏云金杆菌菌株Bt1.Bt2、Bt3及白僵菌菌株5SO3、LS、GD,配制成不同浓度的悬浮液,饲喂感染3龄云南松毛虫幼虫。实验结果表明:生物活性较强的菌株有Bt2及5SO3,其感染浓度与死亡率值回归方程式为Y(Bt2)=-3.8162+1.1665x;Y(5SO3)=-2.3274+1.0062x。致死中浓度LO_(50)为3.614×10 ̄7细菌/ml和1.917×10 ̄7孢子/ml;致死中时间LT_(50)分别为2.641天和7.619天。  相似文献   

3.
塔拉粉直接碱水解制备没食子酸的工艺研究及应用   总被引:9,自引:3,他引:6  
利用南美洲产的塔拉(Caesalpinia spinosa)豆荚粉进行直接碱水解制取没食子酸并应用于工业生产。研究选择了最佳工艺条件。没食子酸产率近塔拉粉投料量计达33%以上。  相似文献   

4.
经致病力测定,比较出8株球孢白僵菌菌株对松褐天牛幼虫毒力的差异,并结合菌株的发芽率,优选出僵死率达96%的B1、B2菌株作为林间应用菌种。由皖东微生物制剂厂生产出高孢粉。采用纱布袋撒菌粉和侵入孔注射菌液两种方法秋季野外布菌,翌年松褐天牛羽化期过后,劈样调查,结果显示:撒菌粉的僵死率为18.3%(B1)、13.4%(B2),占死亡百分比为41.3%(B1)、32.7%(B2);注射菌液的僵死率为10.5%(B1)、10.7%(B2),占死亡百分比为29.4%(B1)、25.4%(B2),都比对照高,但持效不明显  相似文献   

5.
海南岛清澜港红树林垂直结构与演变动态规律*   总被引:3,自引:1,他引:3       下载免费PDF全文
清澜港的红树林在保护较好的条件下具有乔灌两层,乔木层高4~8m,灌木层高0.4~1.2m。上层立木地上部分生物量垂直分布随树体部位增高而减少,0~2m占50%,2~4m占40.3%,4m以上占9.7%。乔木群落被破坏后,面积锐减,27a减少1611hm2,且形成仅有单层结构的灌丛,其生物量和生产力很低,分别为9.6~14.3t/hm2和1.1~2.0t/(hm2·a)。本项研究测定了木榄林的生物量和净生产量分别为91.5t/hm2和4.7t/(hm2·a),预测以后第6年的生物量和年净生产量将是350.7t/hm2和13.5t/(hm2·a),为红树林造林和经营提供了理论依据。  相似文献   

6.
塔拉及其繁殖栽培技术塔拉(CaesalpiniaspinosaKuntze)又名刺云实,原产南美洲秘鲁、厄瓜多尔、哥伦比亚等国。塔拉的豆壳富含塔拉单宁,破碎后得塔拉粉,可替代五倍子用于生产没食子酸、抗菌素增效剂(TMP)等百余种化工、医药产品。其种子...  相似文献   

7.
蜡蚧轮枝菌用湿地松粉蚧连续复壮2~3次后,用其防治湿地松粉蚧,杀虫效果可提高12.3%以上,筛选出轮枝菌复合剂的最优配方为轮枝菌0.3亿/ml加机油乳剂1:28.6(机油乳剂:水)及适量增效剂、悬浮剂及轮枝菌0.25亿/ml加机油乳剂1:80及增效剂。悬浮剂,它们室内杀虫效果分别为92.8%和83.5%。林间采用轮枝菌151亿/hm2加机油乳剂0.75kg/hm2和轮枝菌15万亿/hm2加机油乳剂3.75kg/hm2,喷洒量为10kg/hm2,越冬代粉蚧(成虫)的死亡率分别为48.5%和71.2%,第一代粉蚧(若虫、成虫)的死亡率分别为99.3%和92.7%。越冬后期喷菌,第一代的虫口密度比未喷菌区下降52.7%;采用液、固双相发酵工艺生产的轮枝菌含孢量达55亿/g,比前人用高梁、小米作培养基密封培养的产孢量(4.1亿/g)提高了12.4倍,成本为3.38元/kg,此工艺流程可以推广应用。  相似文献   

8.
通过时来舟林场三块立地条件大体属优良、中等、不良的样地进行生物量调查,探讨不同立地条件下杉木林的生长差异。调查结果表明:20年生杉木人工林优良林分现存生物量为154.2t/hm2(干重),而不良地只有62.6t/hm2;其中优良地的干干重为128.9t/hm2,不良地只有其37%,为48.1t/hm2;优良地的枝、叶干重分别为13.0t/hm2、12.3t/hm2,不良地为7.4t/hm2、7.1t/hm2,分别是优良地的57%与58%;干的年生长量优良地为,19.63m3/hm2,不良地只有5.64m3/hm2,是优良地的29%。优良地与不良地林分生物量的显著差异说明适地适树造林对南方低山丘陵区具有非常重要的意义。同时也指出坡位是划分立地条件的重要因子。  相似文献   

9.
用粉锈灵(15% WP)、苯来特(50% WP)药土田间撒施防治香荚兰镰刀菌根腐病,原药用量为3.7g/m 2 ,施药3 个月后的平均防效分别为49.74% 和28.51% ,施药6个月后的平均防效分别为54.32% 和28.91% 。在当年新植苗较多、生长较差的园地,粉锈灵处理出现了强烈的抑制幼株生长的药害反应  相似文献   

10.
1植物名称:四季海棠(Begoniafibrous)。2材料类别:刚展平的嫩叶。3培养条件培养基:(单位:mg/L)(1)MS+BA3+2.4-D1,(2)MS+BA2+NAA0.2,(3)MS+BA1+NAA0.5,(4)MS+BA1+NAA0.1,(5)MS+BA1+2.4-D0.05,(6)MS+BA2+2.4-D0.05,(7)MS+BA0.4+NAA0.1,(8)1/2MS+NAA0.5,(9)1/2MS+BA0.01。其中蔗糖浓度除培养(8)为2%,其余均为3%,琼脂为0.8%~1.0%,pH值为5.7~5.8,培养温度为20±4…  相似文献   

11.

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.  相似文献   

12.

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.  相似文献   

13.

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.

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.  相似文献   

15.
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。  相似文献   

16.

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.  相似文献   

17.
18.

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.  相似文献   

19.
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   

20.
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.  相似文献   

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