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1.
以环氧氯丙烷(ECH)和脱氢枞胺(DHA)为基本原料,首先通过Eschweiler-Clarke反应使DHA转化为N,N-二甲基脱氢枞胺(DMDHA),再用DMDHA和盐酸作用生成的盐酸盐与ECH。经季铵化反应合成3-氯-2-羟丙基二甲基脱氢枞基氯化铵(CHPDMDHA),并表征其结构,测定产物中CHPDMDHA含量,研究其表面活性。结果表明,CHPDMDHA相对于纯化后DHA的收率约在60%,离子色谱(IC)分析结果显示经乙酸乙酯/乙醇(体积比2.0∶1.0)构成的混合溶剂重结晶后的产物中CHPDMDHA质量分数为98.32%,表面张力测定显示25℃时产物的临界胶束浓度(cmc)为1.60×10-5mol/L,达到cmc时水溶液的表面张力(γcmc)为30.38mN/m,能够达到的最低表面张力值(γmin)为27.4 mN/m。  相似文献   

2.
以脱氢枞酸为原料,经酰胺化、还原、季铵化反应制备了N,N,N',N'-四甲基-N-去氢枞基-N'-十二烷基-二溴化-1,3-丙二铵(V3)、N,N,N',N'-四甲基-N-去氢枞基-N'-十二烷基-二溴化-1,4-丁二铵(V4)、N,N,N',N'-四甲基-N-去氢枞基-N'-十二烷基-二溴化-1,5-戊二铵(V5)及N,N,N',N'-四甲基-N-去氢枞基-N'-十二烷基-二溴化-1,6-己二铵(V6)等4种松香基季铵盐型杂双子表面活性剂。通过FT-IR及1H NMR表征了产物的结构,并对该系列表面活性剂的表面张力(γcmc)和临界胶束浓度(Ccmc)、Krafft点、乳化性能、泡沫性能等表面活性以及抑菌性能进行了研究。研究结果表明,该系列表面活性剂具有良好的表面性能及抑菌性能;Ccmc分别为3.32×10-5、2.86×10-5、2.54×10-5、2.28×10-5mol/L;γcmc值分别为24.7、26.5、28.9、32.3 m N/m;Krafft点分别为12、17、20、23℃;松节油/水乳化体系中分出10 m L水的时间分别为42、45、53、48 h;初始起泡高度分别为137、128、131、135 mm,5 min后泡沫高度分别为125、121、127、131 mm;对大肠杆菌的最小抑菌浓度为4、2、2和2 mg/L,抑菌性均优越于市售抑菌剂新洁尔灭(64 mg/L)。  相似文献   

3.
以壳聚糖(相对分子质量为1 000、1 500、3 000)和脱氢枞胺为原料,合成了一类新型壳聚糖衍生物——脱氢枞胺-壳聚糖阳离子表面活性剂(a、b、c),通过FT-IR、1H NMR对产物结构进行了分析和表征,并对产物的表面活性、乳化性能及抑菌性能进行了研究。研究结果表明,25℃下产物a、b、c的临界胶束浓度(CMC)为3.98×10-4,2.51×10-3,5.01×10-3mol/L,CMC对应的表面张力(γcmc)分别为38.6,36.8,36.6 mN/m;乳化时间分别为44、71、148 s;采用最低抑菌浓度法对目标产物的抑菌性能进行了测试,初步的结果显示化合物都有一定的抑菌活性,特别是化合物a、b、c对产气肠杆菌的抑菌效果优于市售杀菌剂新洁尔灭和氨苄青霉素钠,对其最低抑菌浓度分别为2、2和4 mg/L。产物的抑菌性能随取代度的增大而增强,随壳聚糖分子质量的增大而有所降低。  相似文献   

4.
在25%NaOH溶液催化下,通过3-氯-2-羟丙基二甲基脱氢枞基氯化铵(CHPDMDHA)与N,O-羧甲基壳低聚糖(N,O-CMC)缩合,得到3-氯-2-羟丙基二甲基脱氢枞基氯化铵接枝N,O-羧甲基壳低聚糖(CHPDMDHA-g-N,O-CMC);采用FT-IR和1H NMR表征了产物结构,元素分析法确定了产物接枝度(DQ);根据CHPDMDHA-g-N,O-CMC水溶液表面张力随浓度的变化,确定了其临界胶束浓度(CCMC)及对应的表面张力(γCMC);根据振荡乳化法得到的苯/水体系乳状液稳定时间研究了产物的乳化能力。结果表明:对于接枝度分别为18.7%、21.5%和23.1%的CHPDMDHA-g-N,O-CMC,其CCMC值分别为4.82×10~(-4)、1.33×10~(-4)和7.50×10~(-5)mol/L,γCMC分别为35.1、33.7和32.7 m N/m;接枝度为23.1%的CHPDMDHA-g-N,O-CMC,其1.0 g/L的水溶液与等体积的苯构成的乳液的稳定时间为195 s,大于同等条件下蔗糖酯和单甘酯为乳化剂时形成的乳液。  相似文献   

5.
以脱氢枞酸、3-二甲氨基丙胺为原料通过酰胺化反应制备了N-(3-二甲氨基)丙基-脱氢枞酸酰胺(DHADA),然后再和3-溴丙醇丙烯酸酯经过季铵化反应合成了水溶性松香可聚合单体(3-丙烯酰氧基)丙基(3-脱氢枞酰胺)丙基二甲基溴化铵(DHA-DA-Br)。使用核磁共振(NMR)、红外光谱(FT-IR)、质谱(MS)等对其进行结构表征,利用差示扫描量热仪(DSC)对其聚合行为进行研究,采用表面张力仪对其表面张力(γ_(CMC))、临界胶束浓度(CMC)进行测定。结果表明:试验成功合成了水溶性松香可聚合松香基单体DHA-DA-Br;DHA-DA-Br单体可发生自聚反应(DSC最大放热峰为131℃),在引发剂偶氮二异丁腈作用下,反应温度明显降低(DSC最大放热峰为112℃);DHA-DA-Br水溶液在25℃时CMC为0.003 2 mol/L,此时单体水溶液的γ_(CMC)值为35 mN/m。DHADA-Br在制备或改性水溶性聚合物领域具有较好应用前景。  相似文献   

6.
以脱氢枞酸、丙烯海松酸、马来海松酸为原料分别与2,3-环氧丙基三甲基氯化铵反应,得到单、双、三季铵盐Ⅰ、Ⅱ及Ⅲ3种松香酯羟丙基季铵盐表面活性剂。采用IR,1H NMR,13C NMR对产物结构进行了表征,并对产物的临界胶束浓度(Ccmc)、表面张力(γcmc)、乳化性能、泡沫性能及抑菌性能进行了研究。结果表明,3种松香酯羟丙基季铵盐表面活性剂的Ccmc值分别为3.58×10-4、2.53×10-4和3.25×10-4mol/L,对应的γcmc分别为38.9、28.9、33.5 m N/m;乳化时间分别为31、33、38 min;表面活性剂Ⅰ的起泡性较好,起泡高度达到115 mm、5 min后泡沫高度为85 mm;随着季铵盐数量的增加,亲水亲油平衡值(HLB)增大,表面活性剂的亲水性增强;季铵盐Ⅰ对金黄色葡萄球菌具有良好的抑制活性,最小抑菌浓度为4 mg/L,抑菌效果优于市售的新洁尔灭,与氨苄青霉素钠相当。  相似文献   

7.
以四甲基乙二胺及三乙烯二胺为连接基制备了两种松香基季铵盐Gemini表面活性剂Ⅰ与Ⅱ,经表面活性分析:Ⅰ与Ⅱ的CMC值分别为1.42×10-4、9.7×10-4 mol/L,γCMC为36.69、43.41 mN/m;乳化时间为16、10 min;降低表面张力的效率(pc20)计算值为4.2、3.2;HLB计算值皆约为14.45;Ⅰ与阴离子相溶性好,Ⅱ与阴离子相溶性较差.由实验分析结果探讨了连接基性质对松香基季铵盐Gemini表面活性剂的影响,结果表明:以柔性链为连接基的松香基季铵盐Gemini表面活性剂Ⅰ的活性优于以刚性链为连接基的松香基季铵盐Gemini表面活性剂Ⅱ.  相似文献   

8.
以脱氢枞酸、脱氢枞胺马来酸、丙烯海松酸、马来海松酸为原料,分别与胆碱反应合成了4种松香基胆碱季铵盐表面活性剂(Ⅰ1~Ⅳ1),同时分别与四甲基氢氧化铵反应合成了4种不含羟基松香基四甲基氢氧化铵季铵盐表面活性剂(Ⅰ2~Ⅳ2)。采用IR、1H NMR及13C NMR表征了产物的结构,并对其临界胶束浓度(CMC)、表面张力(γCMC)、乳化性能、泡沫性能、亲水亲油平衡值(HLB)等表面活性及抑菌性能进行了研究。结果表明,Ⅰ1、Ⅱ1、Ⅲ1和Ⅳ1的CMC值为6.9、2.0、3.8和8.0 mmol/L,对应γCMC为37.9、35.1、40.0和42.4 m N/m;Ⅰ2、Ⅱ2、Ⅲ2和Ⅳ2的CMC值为9.4、5.2、6.2和10.0 mmol/L,对应γCMC为39.7、39.0、43.1和45.1 m N/m。通过比较可知,带有羟基的季铵盐表面活性剂的CMC值和γCMC均小于相应不含羟基的季铵盐表面活性剂,说明羟基的存在能够提高表面活性剂的表面活性。8种松香基季铵盐表面活性剂的HLB值均大于18,具有较好的亲水性。表面活性剂Ⅱ1起泡性较好,起泡高度达到202 mm,5 min后对应的泡沫高度为165 mm。季铵盐Ⅲ1、Ⅲ2、Ⅳ1和Ⅳ2对表皮葡萄球菌具有良好的抑制效果,最小抑菌浓度为2 mg/L,优于市售的新洁尔灭和氨苄青霉素钠。羟基的存在对松香基季铵盐的抑菌性能无明显影响。  相似文献   

9.
利用纯度99%的脱氢枞胺原料经烷基化和氧化两步反应合成了一种含松香基三元菲环结构的N,N-二甲基脱氢枞基氧化叔胺。采用红外光谱(FT-IR)、核磁(1H NMR)对其结构进行表征,并通过L16(45)正交试验,对双氧水氧化法合成氧化叔胺的工艺条件进行了优化研究,制备反应的最佳工艺条件:双氧水与叔胺的物质的量比为1.5∶1,反应时间12 h,催化剂用量1.5%,反应温度80℃。在优化的工艺条件下重复试验,氧化叔胺的产率为80%,GC含量均大于70%。产物的临界胶束浓度(CMC)为0.2 g/L,表面张力为22.75 mN/m,并且经此氧化叔胺改性得到的新型沸石吸附剂对一定浓度的腐殖酸、刚果红等环境污染物具有较佳的吸附效果,当初始质量浓度达到40 mg/L左右时吸附基本达到平衡,去除率分别为51.1%和91.0%。  相似文献   

10.
以左旋海松酸(0.3 mmol)为原料、三乙胺(TEA)为碱、1-(3-二甲胺基丙基)-3-乙基碳二亚胺盐酸盐(EDCI)为脱水剂、1H-苯并三唑-1-基氧三吡咯烷基六氟磷酸盐/4-二甲氨基吡啶(n(PyBOP)∶n(DMAP)=0.03 mmol∶0.01 mmol)为催化剂、乙腈(MeCN)为溶剂,简单、高效地合成了脱氢枞基伯胺衍生物:脱氢枞酰胺甲酸(1),脱氢枞酰胺乙酸(2),脱氢枞酰胺丙酸(3),脱氢枞酰胺丁酸(4),并对其结构进行了表征,其中化合物3产率可达78%。经伯胺酰胺化后的化合物3对人胃癌MKN-45细胞株具有较高的增殖抑制活性,IC50值为31.26μmol/L。  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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