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Hydroponic experiments conducted to examine the chromiun uptake by C. communis in the presence of different Cr concentrations (Cr6+ 100 and 200 mg/L, respectively) and free histidine supplementation (0.5 and 1.0 mol/L) showed that shoot and root growth of C. communis decreased greatly with increasing Cr concentrations in the medium; and that the species was a typical excluder since it accumulated high concentrations of Cr in roots but comparatively low concentrations in shoots. Chromium in shoots and roots of Cr24 -supplied plants ranged from 329-1880 and 3788-4240 mg/kg DW, respectively, while those of Cr24 -histidine-supplied plants ranged from 478 to 629 mg/kg and 4157-4303 mg/kg DW, respectively. With Cr present in the hydroponic solution, C. communis accumulated more Cr in its tissues. Increasing histidine application to the solution significantly increased chromium accumulation in the plant tissues but could not alter the accumulation pattern of plants although it induced a higher concentration of Cr in its shoots and roots. These features suggested that C. communis may serve as an alternative species in a constructed wetland for phytoextraction treatment of Cr-containing wastewater and for phytostabilization of Cr mining spoils. 相似文献
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Hydroponic experiments conducted to examine the chromiun uptake by C. communis in the presence of different Cr concentrations (Cr6+ 100 and 200 mg/L, respectively) and free histidine supplementation (0.5 and 1.0 mol/L) showed that shoot and root growth of C. communis decreased greatly with increasing Cr concentrations in the medium; and that the species was a typical excluder since it accumulated high concentrations of Cr in roots but comparatively low concentrations in shoots. Chromium in shoots and roots of Cr42?-supplied plants ranged from 329–1880 and 3788–4240 mg/kg DW, respectively, while those of Cr42?-histidine-supplied plants ranged from 478 to 629 mg/kg and 4157–4303 mg/kg DW, respectively. With Cr present in the hydroponic solution, C. communis accumulated more Cr in its tissues. Increasing histidine application to the solution significantly increased chromium accumulation in the plant tissues but could not alter the accumulation pattern of plants although it induced a higher concentration of Cr in its shoots and roots. These features suggested that C. communis may serve as an alternative species in a constructed wetland for phytoextraction treatment of Cr-containing wastewater and for phytostabilization of Cr mining spoils. 相似文献
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Zhao YP Wang XY Wang ZC Lu Y Fu CX Chen SY 《Journal of Zhejiang University. Science. B》2006,7(9):708-712
Objective： To identify compounds that may be responsible for catnip response of Actinidia macrosperma, and compare chemical compositions in the wild and in vitro regenerated plants. Methods： GC-MS and relative retention indices with n-alkanes as reference points were used for compound identification, and component relative percentage was calculated based on GC peak areas without using correction factors. Results： There are 28 compounds （92.72%） and 15 compounds （93.88%） identified in the essential oils from the wild and regenerated plants, respectively. Dihydronepetalactone, iridomyrmecin, and dihydroactinidiolide, which are believed to be attractive to felines, are present in both wild and regenerated plants. Actinine was not detected, and beta-pheylethyl alcohol was only present in wild plant, in addition, short-chain enol derivatives, messengers in chemical communication, are commonly present in wild plant of A. macrosperma, but absent in regenerated one. Conclusion： Dihydronepetalactone, iridomyrmecin, and dihydroactinidiolide are responsible for the catnip response ofA. macrosperma. 相似文献
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赵荣乐 《上海大学学报(英文版)》2000,4(2):171-174
1 Ｉｎｔｒｏｄｕｃｔｉｏｎ Ｓｑｕａｓｈｍｏｓａｉｃｖｉｒｕｓ (ＳｑＭＶ)ｉｓｏｎｅｏｆｔｈｅｍｏｓｔｉｍ ｐｏｒｔａｎｔｃｕｃｕｒｂｉｔｖｉｒｕｓｅｓ[1～ 3] ,ａｎｄｉｔｃａｕｓｅｓｇｒｅａｔｌｏｓｓｅｓｉｎｍｕｓｋｍｅｌｏｎｐｒｏｄｕｃｔｉｏｎ[4 ] .Ｏｎｅｏｆｔｈｅｍａｉｎｗａｙｓｔｏｃｏｎｔｒｏｌｐｌａｎｔｖｉｒｕｓｄｉｓｅａｓｅｓｉｓｔｈｅｉｎｄｕｃｅｍｅｎｔｏｆｒｅｓｉｓ ｔａｎｃｅｔｏｖｉｒｕｓｅｓ[5] ｂｙｓｏｍｅｂｉｏｌｏｇｉｃａｌａｎｄｎｏｎ ｂｉｏｌｏｇｉｃａｌｆａｃｔｏｒｓ[6～ 9… 相似文献
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Lignocellulosic biomass, being treated only with ammonia, treated with ammonia and then autoclaved, and treated with white-rot fungi after being mechanically chipped, were carried out to access the effects of lignocellulose degradation by white-rot fungi cultured on rapeseed straw. Fourier transform infrared spectroscopic analysis was used to show that the white-rot fungus Bjerkandera sp. strain increase the susceptibility of straw to enzymatic saccharification by modifying the lignin component, revealing the effect of these pretreatments on enzymatic saccharification. Reducing sugar production from straws pretreated by ammonia/mechanical chipping/fungi degradation was 29.80? higher than the samples treated with ammonia/autoclaving, indicating an effective degradation of phenolic compounds. After ammonia pretreatment 41? of the straw was converted to RS(reducing sugars) (glucose 50?). After 5 weeks pretreatment with the white-rot fungus, 54.8? of rapeseed straw was further converted to RS, 74? of which was glucose; while only 12? of the control straw was converted (glucose 42?). The white-rot fungus Bjerkandera sp. strain degraded rapeseed straw preferentially at the early stage (before 20 d), and the degradation selectivity was 0.181 1 (cellulose), 0.364 1 (hemicellulose), and 0.454 8 (lignin), suggesting that removal of the phenolic barriers enhanced reducing sugar yield, and the efficiency of fungal pretreatment was comparable with that after alkali treatment, resulting a higher proportion of glucose in the hydrolysates. 相似文献
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INDRODUCTIONMeso-poroussilicafilmswithanexcellentheat-insulatingpropertyandtherelativelylowdielectricvalueplayparticularlyimportantroleinelectronicandmagneticdevices(Moonetal.,1997),etc.;thosewithporesizesof5nmto50nmarealsoofinterestforapplicationsinphotonics,optoelec-tronics,lightweightstructuralmaterialthermalin-sulation,opticalcoating(Moonetal.,1997;HusingandSchulert,1998;Davis,2002).Theirspecialnetworkstructureisusedinsounddetector(HusingandSchubert,1998);theirexcellentinsulatingpro… 相似文献
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Two experiments with rat subjects examined whether a saccharin taste could potentiate the conditioning of an aversion to a salty taste when the two stimuli were presented together prior to lithium-induced illness. In Experiment 1, a 0.1% (w/v) saccharin solution potentiated conditioning of a very dilute (0.03%) NaCl solution, but had no demonstrable effect on two stronger NaCl solutions (0.6% and 1.2%). In Experiment 2, the 0.1% saccharin solution again potentiated the 0.03% NaCl target, but weaker and stronger saccharin concentrations (0.033% and 0.3%) did not. The ability of a taste to potentiate a secondtaste is not consistent with theories that assume that potentiation is unique to compounds composed of tastes and other, functionally different, nontaste cues. Potentiation may occur when the target stimulus is weakly conditionable on its own and when the particular combination of target and potentiator facilitates perceptual integration of the compound. 相似文献
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A homogeneous crack-free nano- or meso-porous silica films on silicon was fabricated by colloidal silica sol derived by hydrolyzing tetraethyl orthosilicate (TEOS) catalyzing with (C4H9)4N OH- in water medium. The solution with ratio of H2O/TEOS≥15, R4N and glycerol as templates, combining with the hydrolyzed intermediate, controlled the silica aggregating; the templated silica film with heterostructure was developed into homogeneous nano-porous then meso-porous silica films after being annealed from 750 ℃ to 850 ℃; the formation mechanism of the porous silica films was discussed; morphologies of the silica films were characterized. The refractive indexes of the porous silica films were 1.256-1.458, the thermal conductivity < 0.7 W/m/K. The fabricating procedure and the sequence had not been reported before. 相似文献
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An animal’s appetitive behavior is not a fixed response to current stimulation but can be affected by the anticipation of future events. For example, rats regularly given access to a moderately valued solution followed by a higher value solution (e.g., 4 % sucrose → 32 % sucrose) consume less of the initial solution than in control conditions where the initial solution is not followed by a higher value solution (e.g., 4 % sucrose → 4 % sucrose). Previous analyses have suggested that this negative anticipatory contrast effect does not depend on the “expectation” of a valuable stimulus producing a functional devaluation of a currently available stimulus of lesser value. In a within-subjects anticipatory contrast procedure, this study revealed that both consumption and the mean size of licking clusters were smaller for a 4 % sucrose solution on days when it preceded 32 % sucrose than on days when 4 % preceded 4 %. Since lick cluster size typically bears a positive monotonic relationship with the concentration of palatable solutions, this reduction is indicative of a decrease in the palatability/hedonic value of the solution subject to contrast. As such, we provide direct evidence that negative anticipatory contrast does produce a functional devaluation of the solution, thus challenging prevailing theoretical assumptions. 相似文献
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菘蓝易感病品种窄叶植株的患病叶片与正常叶片相比过氧化物酶同工酶谱带加强,并且产生2条新的Rf=0.11和Rf=0.51过氧化物酶同工酶谱带,抗病植株与易感病植株的正常叶片中同工酶酶谱基本一致,但后者的酶带强度高于前者。过氧化物酶活性测定结果表明:菘蓝叶片中过氧化物酶活性与霜霉病有一定关系。叶片感病后,POD活性增强。同时本文还探讨了过氧化物酶同工酶与菘蓝品种鉴定之间的关系。 相似文献
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利用演化算法的自适应、自组织、自学习的特性设计了遗传程序与遗传算法相嵌套的混合演化建模算法 ,以遗传程序设计优化模型结构 ,以遗传算法优化模型参数 ,为山东省工业固废产量随年迹变化关系自动建立微分方程演化模型 .结果表明演化模型不仅其拟合精度明显高于常规的GM(1,1)模型 ,而且其预测的趋势比后者更具合理性 相似文献
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耿森林 《渭南师范学院学报》2014,(11):16-20
研究了一维情况下,光激励液体辐射光声波的特性．通过解声压波动方程,得到光激励流体辐射产生的光声波的时间函数,研究了空间热函数与时间6函数乘积所描绘的热沉积产生的超声波情况．结果表明：热的空间沉积形式直接描绘光声波的时间图像,对于脉冲宽度比声波通过声源的时间长的激光来说,光声波形也是与激光脉冲时间图形相称的,同时,也导出了具有任意空间函数辐射源的多级辐射表达式． 相似文献
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采用浸渍法在二氧化硅多孔材料中负载壳聚糖制备壳聚糖/SiO2复合材料,通过X射线衍射、扫描电子显微镜、傅立叶变换红外光谱等方法对所制备材料的组成与结构进行了表征,采用热重-差示扫描量热法研究了复合材料的热稳定性,采用电流中断法测定所制备材料的电导率来衡量其质子传导性能,并考察了壳聚糖溶液浓度对壳聚糖/SiO2复合材料导电性能的影响。结果表明,壳聚糖/SiO2复合材料具有较高的热稳定性,复合材料的电导率随着壳聚糖乙酸溶液浓度的增加而增加,当壳聚糖乙酸溶液质量百分比浓度为2.5%时,电导率可达1.82 S/cm。 相似文献
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KOTA K LANGRISH T.A.G 《浙江大学学报(A卷英文版)》2007,8(2):301-312
INTRODUCTION Abbott (1990) reported that wall deposition inspray dryers may pose a potential fire risk and com-promise hygiene requirements, and reduce productquality and yield. Spray dryer hazards include igni-tion of explosible dust clouds, dust deposits, bulkpowder deposits and flammable vapour. Kieviet(1997) noted that wall deposition affected the resi-dence time distribution of particles, and particularlythat an important factor in determining residencetimes with high wall deposition… 相似文献
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罗曦芸 《实验室研究与探索》2000,19(4):50-52
分别测定了用加填充物法脱水加固饱水古木时加固液渗透量受木材含水率的影响以及浸渍温度、添加溶剂对处理周期的影响。结果表明：高含水率古木由于内部木纤维素几乎全部降解,在相同浓度加固液中,加固剂的尖一增加,在实际自理中采用高浓度加固液更有利于器物定型,温度升高和添加溶剂,有利于降你加固液的黏度和表面张力,提高渗透速度,缩短处理时间。 相似文献