农用稀土对糯玉米幼苗光合变化和生理指标的分析

为了探明农用稀土对糯玉米幼苗光合和生理指标,采用随机区组排列,研究了农用稀土对糯玉米幼苗叶绿素荧光参数、光合参数、根系活力、植株形态和生物量、MDA和抗氧化酶活性的影响.结果表明,施用农用稀土能显著提高荧光参数Fv/Fm,ETR,NPQ,Fv/F0,Yield,qP最大值分别比对照增加了4.8%,23.9%,45.3%,11.01%,14.8%,26.5%;糯玉米幼苗的光合参数、根系活力、植株形态、生物量、抗氧化酶活性等变化趋势是一致的,在低浓度时,随着农用稀土浓度提高,它们逐渐地提高;到一定浓度后,随着农用稀土浓度升高,它们反而降低;MDA的变化趋势与它们是相反的.     

农用稀土施用量、宽窄行配置对鲜食糯玉米产量构成因素及品质的影响

通过田间小区试验,研究了不同稀土施用量、不同宽窄行配置对鲜食糯玉米产量、产量构成要素和品质的影响。结果表明:农用稀土施用量为200 mg.kg-1时,宽窄行配置为70+50 cm时,吐丝进程最快;皮渣比率、可溶性糖含量、籽粒粗淀粉含量、植株全氮含量均比较小;蒸煮品质即风味、气味,糯性等表现最佳。小花总数、受精小花数、结粒数随着农用稀土施用量增加而减少,且宽窄行配置70+50 cm时,为最大。在农用稀土施用量为600 mg.kg-1时,宽窄行配置60+60 cm时,鲜穗产量为最高,达11883.9 kg.hm-2,在农用稀土施用量为800 mg.kg-1时,宽窄行配置70+50 cm时,鲜穗产量为最低,为9355.8 kg.hm-2。     

缺磷胁迫对脐橙光合色素和光合作用的影响

经缺磷处理后，脐橙叶片的无机磷（Pi)含量，光合色素含量，净光合速率（Pn)，光化学效率（Fv/Fm) ,最大荧光（Fm)下降，细胞间CO2浓度（Ci)和初始荧光（F0)升高，气孔导率（Gs)无明显变化。     

钕对甜瓜光合特性、产量和品质的影响

以甜瓜为材料,探讨了叶面喷施不同浓度硝酸钕(0,5,10,25,50,100 mg·L-1)对甜瓜光合特性、产量和品质的影响。结果表明,10和25 mg·L-1硝酸钕处理的表现最突出:这两个处理的甜瓜叶片净光合速率(Pn)、蒸腾速率(Tr)和气孔导度(Gs)均极显著或显著高于其他处理,胞间CO2浓度(Ci)均极显著低于其他处理;PSⅡ潜在活性(Fv/Fo)、PSⅡ最大光化学量子产量(Fv/Fm)、PSⅡ实际光化学量子产量(ΦPSⅡ)、相对光合电子传递速率(ETR)和光化学猝灭系数(qP)均极显著或显著高于其他处理,非光化学猝灭系数(qN)均极显著低于其他处理;且10 mg·L-1硝酸钕处理的果实产量最高、品质最佳。100 mg·L-1硝酸钕处理对甜瓜生长后期的光合作用产生抑制,降低了果实产量和品质。25 mg·L-1硝酸钕处理浓度较高,但对于甜瓜光合、产量和品质等指标的影响与10 mg·L-1硝酸钕处理并无显著差异,因此认为,10mg·L-1硝酸钕可以作为稀土钕在甜瓜生产上应用的适宜浓度。     

华北模拟实验块地大气、降水、地表径流和土壤中的稀土浓度分布及施用农用稀土的影响

通过模拟实验块地，初步研究了在一个土壤生态系统中稀土的浓度分布以及施用稀土微肥的影响。结果表明：降水、地表径流水溶液中的稀土浓度均为μｇ／Ｌ量级（０１～１２μｇ／Ｌ），降水中的稀土主要来源于附近地表土壤。大气中的稀土含量随粒径分布有所不同，粒径越小含量越低，且其来源主要是附近的土壤，水可溶性的硝酸稀土微肥在施用后很快转化为水不溶性形态，施加稀土前后实验组表层土壤中稀土含量基本相同。与对照组相比，施加的稀土微肥对地表径流水溶性和悬浮物稀土浓度未产生明显影响。     

生物活性稀土微肥对红地球葡萄产量与品质的影响

通过田间试验,研究了生物活性稀土微肥对红地球植株性状、光合作用、葡萄产量和产品品质的影响.结果表明,一定浓度的生物活性稀土微肥可以使红地球葡萄的叶片干物质积累增加,叶片生长发育得到加强,生长状况得到改善;提高叶绿素含量和光合速率;提高红地球葡萄的单粒重、果穗重,提高红地球葡萄的产量,增产效果达到显著水平;红地球葡萄果实含糖量与Vc含量也有显著提高,改善了果品质量.     

镧对金银花中重金属及药效成分含量的影响

以金银花为试材,研究了叶面喷施稀土镧对金银花中重金属及药效成分含量的影响。结果显示以过氧化物酶活性和叶绿素含量为指标,确定以30 mg·L-1的甘氨酸镧水溶液叶面喷施效果较好。30 mg·L-1的甘氨酸镧水溶液处理的金银花中,Cd,Cu和As含量与对照相比明显下降,同时药效成分绿原酸和木犀草苷的含量分别增加了9.14%和43.86%。与药典标准相比,重金属含量和药效成分含量都明显优于2010版药典标准。结果表明:适宜浓度稀土镧对金银花吸收重金属元素有抑制作用,并且能促进其药效成分的合成,进而提高金银花的品质。     

镧和铈对大豆开花期叶绿素含量的影响

以大豆东农42和47为试验材料,采用盆栽方式,使用乙醇分光光度计法研究在大豆开花期喷施不同浓度稀土元素La(Ⅲ)和Ce(Ⅲ)(RE1/60 mg·L-1,RE2/90 mg·L-1,RE3/120 mg·L-1和RE4/150 mg·L-1)对叶片叶绿素含量(Chl)的影响。结果表明:与对照组(CK)相比,La对两种大豆Chl含量呈现"低促高抑"的现象:在RE1浓度下,Chl含量高于CK值,并且达到最大值,随着浓度增大,促进作用降低,抑制作用明显,RE2～RE4浓度下Chl含量降低,并且低于CK值;Ce对两种大豆Chl含量呈现下降趋势,在RE1浓度下下降幅度最为明显,RE2～RE4浓度下叶绿素含量有所上升并低于CK值。     

添加稀土对镉污染土壤上青椒生长与镉吸收分布的影响

分别以青椒为供试蔬菜、以Cd为供试重金属,采用盆栽试验探索相同规格根际调控基质块中添加不同剂量的碳酸轻稀土对青椒生长、Cd吸收和在器官分配的影响,为今后复合根际修复技术的开展提供理论和实践依据。结果表明:当稀土剂量为40 mg·kg-1时,与不添加稀土的对照相比,极大地促进了青椒苗株高和干重的增加,它们分别提高了21.52%和11.11%。在土壤中含量为5.19 mg·kg-1的Cd胁迫下,保留基质块处理比冲掉块(裸栽)处理的植株地上部干重、生物量、果干重均显著增加,而对根系却没有明显的促进作用。不管基质块中添加不添加稀土,此浓度的Cd胁迫显著抑制了植株根系生长。但适当的稀土添加能够在基质块缓解Cd对青椒毒害的基础上使青椒的生理状况得到进一步改善,而对植株产果没有显著的促进作用。结果还表明:任何剂量的稀土添加对根系Cd含量没有显著降低作用。而当稀土剂量为10 mg·kg-1时,虽然显著促进了茎、叶中Cd的含量,但也显著降低了果实中Cd的含量。由于果实是食用器官,这些结果支撑了稀土添加到基质块作为根际调控方法具有应用价值的重要依据。本试验为以后系统开展复合根际重金属调控研究奠定了基础。     

土壤中稀土对有效氮形态分配和转化的影响

在土壤旱作和淹水培养两种方式下, 通过添加外源稀土研究了黄褐土中稀土对有效氮形态分配和转化的影响.结果表明, 在旱培条件下, 土壤中稀土含量的提高增加铵态氮和水解氮的含量, 减少硝态氮的含量, 两周内增加矿质态氮的含量, 八周以后则无显著影响; 有效氮的含量在稀土含量较低时升高, 高含量时则下降, 实验确定外源稀土对旱培土壤有效氮作用的无观察效应浓度(NOEC)为443.8 mg*kg-1. 在淹水培养条件下, 稀土含量较低时对土壤铵态氮和水解氮含量无显著影响, 含量较高时则降低铵态氮和水解氮含量, 外源稀土对淹水土壤铵态氮和水解氮含量影响的无观察效应浓度分别为 171.2, 256.9 mg*kg-1. 分析表明, 土壤中稀土含量的变化对氮素的影响在旱培条件下主要与稀土对土壤硝化过程作用有关, 淹水条件下与稀土对土壤氨化过程作用有关.     

Liquid-liquid solvent extraction of rare earths from chloride medium with sec-nonylphenoxy acetic acid and its mixtures with neutral organophosphorus extractants

In the present study, sec-nonylphenoxy acetic acid (CA100) and its mixtures with four neutral organophosphorus extractants, tri-butyl-phosphate (TBP), 2-ethylhexyl phosphonic acid di-2-ethyl ester (DEHEHP), Cyanex923, and Cyanex925 have been applied to the extraction of rare earths. Results show that all the four mixing systems do not have evident synergistic effects on the extraction of rare earths. The different extraction effects have been considered to the separation of rare earths. The four mixtures may be applied to the separation of yttrium from some certain lanthanoids at proper mole fractions of CA100.     

Effect of aggregation state, temperature and phospholipids on photobleaching of photosynthetic pigments in spinach Photosystem II core complexes

Photosystem II (PSII) complex activity is known to decrease under strong white light illumination, and this photoinhibition phenomenon is connected to the photobleaching of the PSII photosynthetic pigments. In this work the pigment photobleaching has been studied on PSII core complexes, by observing the effects of different factors such as the aggregation state (PSII monomers and dimers were used), temperature (20 degrees C and 10 degrees C temperatures were tested) and the presence of the exogenous phospholipids (cardiolipin and phosphatidylglycerol). In particular, PSII resistance against white light stress was studied by means of UV/VIS Absorption and Fluorescence Emission measurements. It was found that PSII dimers resulted more resistant against photobleaching and that lower temperature reduces the pigment photodestruction. Moreover, the presence of phosphatidylglycerol or cardiolipin enhanced the PSII resistance to the photobleaching phenomenon, mainly at lower temperatures.     

Assessment of waxy and non-waxy corn and wheat cultivars as starch substrates for ethanol fermentation

The amylose/amylopectin ratio in cereal substrates is one of the parameters affecting starch hydrolysis and fermentation process. Waxy (less than 1 mass % of amylose) starch seems to be suitable for improving the fuel ethanol production. The main aim of this paper was to characterize the fermentation performance of corn and wheat waxy and non-waxy cultivars in terms of simultaneous saccharification and fermentation (SSF) as well as of the separated hydrolysis and fermentation (SHF) type. Two corn (waxy and non-waxy) and two wheat (waxy and non-waxy) cultivars were used for the comparison applying separate enzymatic hydrolysis and fermentation. In the SHF process, the glucose content was higher after saccharification in the waxy corn and wheat compared to that in non-waxy corn and wheat. In the SSF of waxy varieties, the glucose content after the pre-saccharification was also higher than in the non-waxy ones. Although the starch content did not vary significantly, differences in the glucose content after saccharification were observed. The ethanol yield obtained after the distillation of mash varied from 229.2–262.3 L per ton for the SHF fermentation, while it was in the range of 311.5–347.9 L per ton for the SSF process.     

稀土-蛋氨酸配合物的热力学

在25 ℃和μ=0.15 mol·L~(-1)[NaCl]条件下, 用pH电位法测定了L-蛋氨酸的质子化常数、15个稀土元素与该配体生成配合物的稳定常数。表明稀土与L-蛋氨酸可生成1:1配合物。讨论了“四分组效应”及钇的位置。用量热滴定法直接测定了稀土与L-蛋氨酸生成1:1配合物的△H_(101)值, 计算了△S_(101)和△G_(101)值。     

Relationship between the structural and functional changes of the photosynthetic apparatus during chloroplast-chromoplast transition in flower bud of Lilium longiflorum

The relationship between the structural and functional changes of the photosynthetic apparatus in the flower bud of Lilium longiflorum during chloroplast-chromoplast transition was examined. Compared with green petals, there was a five-fold increase of the carotenoid content in yellow petals, whereas the chlorophyll content decreased five-fold. Absorption and emission fluorescence spectra of chromoplasts indicated that newly synthesized carotenoids were not associated with photosystem II (PSII) photochemistry. The maximum quantum yield in the remaining PSII reaction centers remained constant during the chromoplast formation, whereas the photosynthetic electron transport beyond PSII became inhibited, as indicated by a marked decrease of the O2 evolution capacity, of the photochemical quenching of chlorophyll-alpha fluorescence and of the operational quantum yield of photosynthetic electron transport. Deconvoluted fluorescence emission spectra indicated a more rapid degradation of photosystem I (PSI) complexes than of PSII during chromoplast formation. Compared with green petals, the spillover between PSII and PSI decreased by approximately 40% in yellow petals. Our results indicate that during chloroplast-chromoplast transition in the flower bud of L. longiflorum, PSII integrity was preserved longer than the rest of the photosynthetic apparatus.     

稀土金属在离子液体中催化甲苯的选择性硝化反应

摘 要 将稀土金属盐负载在己内酰胺类离子液体上组成稀土金属盐和离子液体的复合物作为催化剂和溶剂,用于催化甲苯与等摩尔67%硝酸的硝化反应,利用核磁共振对离子液体的结构进行了表征。考察了不同的反应温度、反应时间及催化剂的种类和用量等因素对甲苯硝化反应的产率和对位选择性的影响。得出反应的最佳反应条件为：反应温度55℃,反应时间24h,苯磺酸镱（Yb）和苯磺酸离子液体（CPBSO）用量分别占甲苯的摩尔分数为5%和10%。产物硝基甲苯中邻、对位异构体质量比o/p=1.1,较硝硫混酸硝化(o/p=1.6)显著降低,产率达46.5 %。离子液体重复使用4次均表现出较好的催化活性及对位选择性。     

Differential effects of plasma membrane electric excitation on H+ fluxes and photosynthesis in characean cells

Cells of characean algae exposed to illumination arrange plasma-membrane H(+) fluxes and photosynthesis in coordinated spatial patterns (bands). This study reveals that H(+) transport and photosynthesis patterns in these excitable cells are affected not only by light conditions but also by electric excitation of the plasma membrane. It is shown that generation of action potential (AP) temporally eliminates alkaline bands, suppresses O(2) evolution, and differentially affects primary reactions of photosystem II (PSII) in different cell regions. The quantum yield of PSII electron transport decreased after AP in the alkaline but not in acidic cell regions. The effects of electric excitation on fluorescence and the PSII electron flow were most pronounced at light-limiting conditions. Evidence was obtained that the shift in chlorophyll fluorescence after AP is due to the increase in DeltapH at thylakoid membranes. It is concluded that the AP-triggered pathways affecting ion transport and photosynthetic energy conversion are linked but not identical.     

稀土在烤烟植株中的分布及其对烟叶化学成份影响的研究

作为一种生理活性物质,稀土施用在烟草上平均增产11％,上中等烟比例提高7．53％左右,稀土应用于烤烟大部分限于田间试验,缺深入的机理研究^[2-4]。本试验用低浓度混合硝酸稀土喷施烤烟叶面,研究了稀土在烤烟植株中的含量,分布及土壤中可溶态稀土的变化情况及稀土对烟叶化学成份的影响,旨在为烤烟施用稀土提供科学依据。     

多壁碳纳米管对稀土元素的吸附性能

研究了改性多壁碳纳米管(MWCNTs)对稀土元素的吸附。 采用硝酸、次氯酸钠、过氧化氢、高锰酸钾4种方法对MWCNTs进行改性,考察了改性MWCNTs对稀土元素的吸附能力。 采用紫外-可见分光光度法测定稀土元素的浓度,比较了未处理和不同方法处理的MWCNTs对稀土元素的吸附能力。实验结果表明,NaClO改性的MWCNTs对稀土元素的吸附能力最强。以稀土元素钐(Sm)、钆(Gd)、镱(Yb)为代表,研究了NaClO改性MWCNTs对稀土元素的吸附性能。 考察了溶液pH值、离子强度、吸附剂用量、温度等因素对吸附性能的影响。当溶液pH值在2~7范围内,NaClO改性的MWCNTs对Sm、Gd、Yb的吸附随pH值增大而增强。 当离子强度和MWCNTs的用量增大时,对稀土元素的吸附能力降低。3种元素在NaClO改性的MWCNTs上的吸附均为放热过程,其反应焓变ΔH分别为：-6.44、-5.63和8.31 kJ/mol。吸附等温线符合Langmuir和Freundlich等温吸附方程。