共查询到20条相似文献，搜索用时 546 毫秒
1.
β-环糊精对室内空气中苯系物净化作用的研究 总被引：1，自引：0，他引：1
将苯、甲苯、二甲苯蒸气分别通入β-环糊精填充柱，尾气用正庚烷吸收得苯系物正庚烷溶液。用紫外分光光度计测定β-环糊精吸收前后的苯系物正庚烷溶液的吸光度，从而确定β-环糊精对苯系物包合吸收作用的强弱。研究结果表明每克β-环糊精对苯、甲苯、二甲苯的饱和吸收量分别为0．54ml、0．63ml和0．62ml，β-环糊精对室内空气中苯系物的净化效果良好。 相似文献
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β—环糊精与香精包合物的制备及紫外光谱和差热分析 总被引：2，自引：0，他引：2
制备了β－环糊精与薄荷、玫瑰等７种香精的包合物,在紫外区有吸收峰的香精,其紫外光谱与包合物水溶液的紫外光谱的峰形一致,保持香精浓度不变,β－环糊精的加入对最大吸收的波长和吸光度的影响很小,香精包合物的差热分析表明,除玫瑰和菠萝香精包合物外,其他５种香精的包合物在温度低于２３０℃的条件下是稳定的。 相似文献
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β-环糊精具有内亲脂的空腔和外亲水的表面,可广泛应用于分离、药物包结及分子催化等方面。然而,由于β-环糊精母体的溶解度较低,使其应用受到一定的限制。为了克服β-环糊精溶解度小的缺点,我们对其进行改性研究,利用β-环糊精合成其衍生物-甲基化β-环糊精,使其具有更优良的性质,提高其应用效果。 相似文献
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香茅油β-环糊精包合工艺条件的探讨 总被引：1，自引：0，他引：1
研究了香茅油β-环糊精包合物的制备方法，通过红外光谱法对包合物进行理化鉴别，发现包合物的红外光谱与混合物的谱图具有较显著的差异，考察了溶媒、温度等因素对包埋率的影响．采用β-环糊精作为新型的辅料，在开发药物新剂型等方面有广泛的研究，而包合作为新的技术在日用香料领域进行探索，也是一项有意义的工作。 相似文献
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目的:从温度、pH、空气、白炽光照和紫外光照五个方面,研究环境变化对微胶囊贮存稳定性的影响。创新点:首次证实乳清蛋白与半乳糖美拉德反应产物(WPI-半乳糖MRPs)有助于提高β-胡萝卜素微胶囊的贮存稳定性。方法:利用扫描电镜观察β-胡萝卜素微胶囊形态特征;用激光粒度分析微胶囊颗粒的大小;以微胶囊的保留率为检测指标,研究温度、pH、空气、白炽光照及其紫外光照对微胶囊贮存稳定性的影响。结论:以WPI-半乳糖MRPs为壁材的β-胡萝卜素微胶囊表面光滑完整,没有裂缝和孔隙,有少量典型的凹陷;以WPI-半乳糖MRPs为壁材的微胶囊粒径比以WPI-半乳糖混合物为壁材的微胶囊粒径小;从温度、pH、空气、白炽光照及紫外光照五个方面进行研究发现,以WPI-半乳糖MRPs为壁材的β-胡萝卜素微胶囊贮存稳定性显著优于以WPI半乳糖的混合物为壁材的β-胡萝卜素微胶囊贮存稳定性;WPI-半乳糖MRPs有助于提高β-胡萝卜素微胶囊的稳定性。 相似文献
6.
主要研究了β-环糊精(-βCD)与罗丹明B的荧光光谱性质,探讨了β-环糊精浓度、乙醇对β-环糊精与罗丹明B包合物的荧光的影响。研究结果表明,随着环糊精浓度的增大,体系的荧光强度逐渐降低,计算表明环糊精与罗丹明B形成1∶1的包合物,其包合常数K=5.29×103,当向体系中加入少量乙醇时,环糊精与罗丹明B形成的包合物的包合比未发生改变,但其包结常数减小为K=1.72×102,由此我们认为乙醇的存在对包合物的稳定性有一定的影响。 相似文献
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基于微波法合成β-环糊精-聚乳酸共聚物．在微波辐射下丙交酯（D,L-LA）单体开环聚合形成聚乳酸（PLA）,然后与β-环糊精（β—CD）发生接枝共聚而成,并通过红外光谱、x-射线衍射、核磁共振技术对所合成聚合物的结构与性能进行了研究． 相似文献
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Phil Reed 《Learning & behavior》2000,28(2):136-146
In four experiments, the effect of sequential exposure to a series of five novel flavors on the subsequent neophobic response
of water-deprived rats to those flavors when they were presented simultaneously was examined. After a list-test interval of
30 min and a list-interstimulus interval of 10 sec, the rats generally consumed more of the first and last flavors presented
in the initial sequence. This finding was taken to reflect the existence of primacy and recency effects. Experiment 1 provided
evidence that successive contamination can occur between flavors in the initial list, making subsequent recognition of later
flavors in the list more difficult. However, this effect was overcome by presentation of water between each flavor during
the list exposure. Experiments 2 and 4 showed that primacy was not a necessary result of successive contamination in this
procedure, by demonstrating that increasing the interstimulus interval between list items decreased the size of the primacy
effect. This result suggests that rats’ memory for serially presented items may be controlled by mechanisms different from
those typically implicated in the human verbal memory literature. In Experiment 3, the question of whether the testing procedure
adopted here could have introduced sources of artifactually produced serialposition effects was explored, but no such influence
was found. 相似文献
12.
In four experiments, rats’ preferences for flavors consumed under high deprivation versus low deprivation were measured. In Experiment 1, rats preferred flavors received in unsweetened food under high deprivation to flavors received in unsweetened food under low deprivation. This preference did not vary with amount of food used to deliver the flavors (1-g vs. 16-g wet mash). Sweetening the food (0.10% saccharin) eliminated this preference when 16 g of mash was received, but not when 1 g of mash was received (Experiments 2 and 3). Sweetening the mash even more (0.15% saccharin) eliminated the preference when 1 g of mash was received, as well as when 20 g of mash was received. We suggested that the reinforcing value of sweetness is reduced by increasing deprivation level. 相似文献
13.
Two experiments allowed rats to drink freely two neutral flavors (almond and vanilla) in simultaneous compound with two hedonically valued flavors (quinine and saccharin). The neutral flavor previously paired with saccharin was subsequently preferred. The neutral flavor that had been paired with quinine was subsequently avoided. Experiment 3 found similar results when the animals were hand-fed a preset amount of the solution. Preference shifts were not obtained when differential amounts of the neutral flavors were consumed in isolation. The data indicate that flavor-flavor associations can shift taste preferences. 相似文献
14.
Animals were presented with (1) one solution which differed from that of the test solution, (2) a series of distinctly flavored solutions whose flavors differed from that of the test solution, or (3) with a flavored solution whose flavor was the same as that of the test solution. When animals received the solution whose flavor was the same as that of the test solution prior to a test for neophobia and prior to a conditioning trial, neophobia was reduced and aversions were weakened. However, when animals received a solution or a series of solutions whose flavors differed from that of the test solution, neophobia was reduced but conditioned aversions were unaffected. Presentations of solutions that differed from the test solution following aversion formation left the association between the taste of the test solution and the effects of the aversion-inducing treatment intact. In a final experiment it was discovered that neophobia was reduced as much when animals drank solutions whose flavors changed every third day as when they drank the same solution throughout testing. 相似文献
15.
Dwyer DM 《Learning & behavior》2008,36(2):149-158
The microstructure of licking responses was analyzed to investigate the interaction between unconditioned responses to maltodextrin and the responses to flavor cues previously associated with maltodextrin. Experiment 1 demonstrated that although the consumption of maltodextrin peaked at intermediate concentrations, the mean lick cluster size showed a positive, monotonic increase with concentration. In Experiment 2, a (conditioned stimulus) CS+ flavor was paired with 16% maltodextrin, whereas a CS- flavor was paired with 2% maltodextrin. During test, consumption of the CS+ was higher than that of the CS- when the flavors were combined with 2% maltodextrin, but not when combined with 16% maltodextrin. In contrast, cluster size was larger with the CS+ than with the CS-, regardless of the concentration of maltodextrin present on test. Previous analyses of licking microstructure indicate that cluster size reflects the palatability of the ingested solution. Thus, the present results indicate that flavor conditioning can change the palatability of the cue flavors. Adding the CS+ flavor to maltodextrin produced results analogous to increasing the concentration of maltodextrin (in terms of both consumption and licking microstructure measures), which is consistent with the idea that after conditioning, responses to the CS+ flavor and to the unconditioned stimulus are mediated via the same representation. 相似文献
16.
Three experiments examined the habituation of rats’ neophobia to novel flavors, and the disruption of that habituation by presentation of a distractor flavor either immediately before or immediately after the target flavor. Habituation of neophobia to lemon solution was more seriously disrupted by presentation of saline as a distractor than by presentation of coffee as a distractor, and this was true whether the distractor was presented before or after the target on each habituation trial. Two further experiments established that the relative ineffectiveness of coffee as a distractor could not be attributed to its lack of salience, and was probably related to its greater similarity to the target lemon flavor. These results do not fully accord with those reported by Robertson and Garrud (1983), but are readily explained in terms of generalization of habituation between distractor and target flavors. 相似文献
17.
In two experiments, participants inspected and drank a series of drinks, half of which contained sugar and half unpalatable
Tween20 (tween). Each sugar and tween drink had a particular flavor and color. Following this training, the flavors of the
sugar drinks were assigned higher hedonic evaluations than were those of the tween drinks, even though the participants did
not reliably report which flavors had been present in the sugar and tween drinks during training. Moreover, the evaluative
conditioning of the flavors was unaffected by whether or not the colors alone had been pretrained to predict the presence
of sugar or tween in the drinks. In accord with Baeyens, Eelen, van den Bergh, and Crombez (1990), we conclude that flavor-evaluative
conditioning is not mediated by contingency learning. 相似文献
18.
Rats tend to prefer flavors previously consumed under low deprivation to flavors previously consumed under high deprivation (Capaldi & Myers, 1982). We attempted to distinguish among possible associative explanations by determining whether this conditioning phenomenon was based upon conditioned preferences, conditioned aversions, or both. We compared preference for flavors presented exclusively under either high or low deprivation with preference for a neutral flavor. In Experiments 1A and 1B the neutral flavor was one that had been randomly paired with both high and low deprivation, whereas in Experiments 2 and 3 the neutral flavors had not been associated with either high or low deprivation. Our results strongly suggest that this conditioning phenomenon is based upon an actual increase in preference for the flavor consumed under low deprivation rather than on any form of aversion conditioning. 相似文献
19.
Elizabeth D. Capaldi David E. Myers David H. Campbell Joan Denise Sheffer 《Learning & behavior》1983,11(1):107-115
In five experiments, rats’ preference for a flavor was greater if the flavor had previously been consumed under low rather than high deprivation. This preference was conditioned in as few as three flavor-deprivation pairings (Experiment 1), and persisted through 28 test days, half under each deprivation level (Experiment 2). Rats never preferred the flavor associated with high deprivation even when calories were increased by giving 40 ml of 8% sucrose or when caloric density was increased to the equivalent of 20% sucrose. The preference for the low-deprivation flavor was greater when saccharin solutions were used rather than sucrose solutions, but the preference did emerge when sucrose solutions were used as testing proceeded and when a lower concentration of sucrose was used. We suggest that these preferences may be a result of flavor-taste associations rather than associations between flavors and postingestive consequences, and that the taste of the solutions under low deprivation is preferred to the taste under high deprivation. 相似文献
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When a caloric substance is followed by a flavored substance, preference for the flavor that followed the calories can increase because of a flavor-nutrient association. We showed here that this effect is opposed by a fullness effect: consuming the caloric substance itselfreduces-consuniption of the flavor that follows. Because consumption of this flavor was less than consumption of a flavor that was given alone, there was a reduced preference for the flavor that followed the calories—an effect opposing flavor-nutrient learning. The preference for the flavor that was given alone and consumed in greater amounts seems to be due to exposure per se and is not a result of contrast. When the amount of the flavor given alone was directly controlled so that it was one half the amount of the flavor that followed the calories, preference for the flavor following the calories was no higher than when consumption of the two flavors was equal. Thus, exposure can interfere with flavor-nutrient learning, but does not enhance it. 相似文献